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Find video protocols related to scientific articles indexed in Pubmed.
A novel pyrido-thieno-pyrimidine derivative activates p53 through induction of phosphorylation and acetylation in colorectal cancer cells.
Int. J. Oncol.
PUBLISHED: 08-19-2014
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The tumor suppressor p53 plays a key role in regulation of the cell cycle, apoptosis and senescence in response to various stresses. We screened a library of 7920 chemical compounds for the p53 activator and identified N-[2-(dimethylamino)ethyl]-2,3-dimethyl-4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine-9-carboxamide (PTP), which significantly increased p53-mediated reporter activity in colorectal cancer cells. PTP was found to induce p53 protein and activated transcription of downstream genes, such as p21 and PUMA, in HCT116 cells, leading to growth delay, G1-phase cell cycle arrest, cell senescence and cell death. Proximity ligation assay revealed that PTP weakened the interaction between p53 and murine double minute 2 (MDM2) in situ, thereby inhibiting MDM2-mediated p53 degradation. Although DNA damage has been known to promote phosphorylation of p53 and MDM2, thereby preventing their interaction and stabilizing p53, PTP did not cause DNA damage or activate any DNA damage response signaling. Instead, phosphorylation of p53 was mediated by Erk1/2 MAP kinase. In addition, PTP induced acetylation of p53 at Lys382 in a p300-dependent manner, but sirtuin (SIRT)1 and histone deacetylase (HDAC)1, a well-known p53-regulating deacetylase, were not involved. In the present study, the novel anticancer agent PTP was shown to cause the accumulation of p53 by inducing multiple post-translational modifications, as well as cell cycle arrest, senescence and cell death.
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Does Decreased Meniscal Thickness Affect Surgical Outcomes After Medial Meniscectomy?
Am J Sports Med
PUBLISHED: 08-12-2014
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There have been no clinical studies regarding the effect of decreased meniscal thickness on outcomes after meniscectomy.
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Down-regulation of MAPK/NF-?B signaling underlies anti-inflammatory response induced by transduced PEP-1-Prx2 proteins in LPS-induced Raw 264.7 and TPA-induced mouse ear edema model.
Int. Immunopharmacol.
PUBLISHED: 07-26-2014
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Excessive reactive oxygen species (ROS) production plays a crucial role in causing various diseases, including inflammatory disorders. The activation of mitogen-activated protein kinase (MAPK) and nuclear factor-kappaB (NF-?B) signaling is implicated in stimulating inflammatory response and cytokines. Peroxiredoxin 2 (Prx2) is a 2-cysteine (Cys) peroxiredoxin capable of removing endogenous hydrogen peroxide (H2O2). PEP-1 peptide, a protein transduction domain, consists of three domains which are used to transduce exogenous therapeutic proteins into cells. The correlation between effectively transduced PEP-1-Prx2 and ROS-mediated inflammatory response is not clear. In the present study, we investigated the protective effects of cell permeable PEP-1-Prx2 on oxidative stress-induced inflammatory activity in Raw 264.7 cells and in a mouse ear edema model after exposure to lipopolysaccharides (LPS) or 12-O-tetradecanoylphorbol-13-actate (TPA). Transduced PEP-1-Prx2 suppressed intracellular ROS accumulation and inhibited the activity of MAPKs and NF-?B signaling that led to the suppression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and cytokines in LPS-induced Raw 264.7 cells and TPA-induced mouse ear edema model. Given these results, we propose that PEP-1-Prx2 has therapeutic potential in the prevention of inflammatory disorders.
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Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells.
Biochem. Biophys. Res. Commun.
PUBLISHED: 06-17-2014
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Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by which ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced activation of the UPR signaling pathway on radiosensitivity in intestinal epithelial cells remain to be determined. In this study, we investigated the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhanced IR-induced caspase 3 activation and DNA fragmentation in intestinal epithelial cells. Knockdown of Xbp1 or Atf6 with small interfering RNA inhibited IR-induced caspase 3 activation. Treatment with chemical chaperones prevented ER stress and subsequent apoptosis in IR-exposed intestinal epithelial cells. Our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Furthermore, inhibiting ER stress may be an effective strategy to prevent IR-induced intestinal injury.
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Negative transcriptional regulation of mitochondrial transcription factor A (TFAM) by nuclear TFAM.
Biochem. Biophys. Res. Commun.
PUBLISHED: 05-09-2014
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The nuclear DNA-encoded mitochondrial transcription factor A (TFAM) is synthesized in cytoplasm and transported into mitochondria. TFAM enhances both transcription and replication of mitochondrial DNA. It is unclear, however, whether TFAM plays a role in regulating nuclear gene expression. Here, we demonstrated that TFAM was localized to the nucleus and mitochondria by immunostaining, subcellular fractionation, and TFAM-green fluorescent protein hybrid protein studies. In HT22 hippocampal neuronal cells, human TFAM (hTFAM) overexpression suppressed human Tfam promoter-mediated luciferase activity in a dose-dependent manner. The mitochondria targeting sequence-deficient hTFAM also repressed Tfam promoter activity to the same degree as hTFAM. It indicated that nuclear hTFAM suppressed Tfam expression without modulating mitochondrial activity. The repression required for nuclear respiratory factor-1 (NRF-1), but hTFAM did not bind to the NRF-1 binding site of its promoter. TFAM was co-immunoprecipitated with NRF-1. Taken together, we suggest that nuclear TFAM down-regulate its own gene expression as a NRF-1 repressor, showing that TFAM may play different roles depending on its subcellular localizations.
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?,?-Dimethylacrylshikonin sensitizes human colon cancer cells to ionizing radiation through the upregulation of reactive oxygen species.
Oncol Lett
PUBLISHED: 03-11-2014
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Shikonin, a naphthoquinone derivative, has been shown to possess antitumor activity. In the present study, the effects of shikonin and its analog, ?,?-dimethylacrylshikonin, were investigated as radiosensitizers on the human colon cancer cell line, HCT-116. Shikonin and, to a greater extent, its analog-induced apoptosis of HCT-116 cells further synergistically potentiated the induction of apoptosis when combined with ionizing radiation (IR) treatment. Shikonins also stimulated an increase in reactive oxygen species (ROS) production and IR-induced DNA damage. Pre-treatment with the ROS scavenger, N-acetylcysteine, suppressed the enhancement of IR-induced DNA damage and apoptosis stimulated by shikonins, indicating that shikonins exert their radiosensitizing effects through ROS upregulation. The radiosensitizing effect of shikonins was also examined in vivo using the xenograft mouse model. Consistent with the in vitro results, injection of ?,?-dimethylacrylshikonin combined with IR treatment significantly suppressed tumor growth of the HCT-116 xenograft. Taken together, the results show that ?,?-dimethylacrylshikonin is a promising agent for developing an improved strategy for radiotherapy against tumors.
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Neuroprotective effect of PEP-1-peroxiredoxin2 on CA1 regions in the hippocampus against ischemic insult.
Biochim. Biophys. Acta
PUBLISHED: 03-01-2014
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Oxidative stress is a leading cause of various diseases, including ischemia and inflammation. Peroxiredoxin2 (PRX2) is one of six mammalian isoenzymes (PRX1-6) that can reduce hydrogen peroxide (H2O2) and organic hydroperoxides to water and alcohols.
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The inhibitory effect of anthocyanins on Akt on invasion and epithelial-mesenchymal transition is not associated with the anti-EGFR effect of the anthocyanins.
Int. J. Oncol.
PUBLISHED: 02-13-2014
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Evidence suggests that anthocyanins inhibit EGFR and Akt activity. However, it is still unknown whether the inhibitory effect of anthocyanins on Akt is associated with the anti-EGFR effect. The effect of anthocyanins on epithelial-mesenchymal transition (EMT) has not been extensively studied. Therefore, we investigated the effects of anthocyanins from fruits of Vitis coignetiae Pulliat (AIMs) on EGF-induced EMT and the underlying molecular mechanisms. AIMs suppressed the invasion of A549 cells in a dose-dependent manner. AIMs inhibited the phosphorylation of Akt and EGFR, but the inhibitory effect on Akt was not derived from EGFR. EGF re-induced Akt phosphorylation at Thr308 in the AIM-treated cells, but not Akt phosphorylation at Ser473. AIMs also inhibited EMT of cancer cells. AIMs inhibited glycogen synthase kinase-3? phosphorylation and ?-catenin expression that are invovled in EMT. We confirmed these findings with transforming growth factor (TGF)-?. In conclusion, these data suggest that the inhibitory effect of AIMs on Akt activity is independent of EGFR, and that AIMs suppressed invasion and migration at least in part by suppressing EMT by inhibiting Akt activity as well as EGFR. This study provides evidence that AIMs may have anticancer effects on human cancer cells.
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Safety and efficacy of ulthera in the rejuvenation of aging lower eyelids: a pivotal clinical trial.
Aesthetic Plast Surg
PUBLISHED: 02-04-2014
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The changes in the periorbital region are among the most prominent features of the aging process in the lower eyelids. Intense focused ultrasound (IFUS), known as the Ulthera System, was designed to correct this process. The current study assessed the safety and efficacy of the Ulthera System.
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Preperimetric normal tension glaucoma study: long-term clinical course and effect of therapeutic lowering of intraocular pressure.
Acta Ophthalmol
PUBLISHED: 01-23-2014
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The purpose of this study was to investigate the long-term clinical course of normotensive preperimetric glaucoma (PPG).
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Face reconstruction using lateral intercostal artery perforator-based adipofascial free flap.
Arch Plast Surg
PUBLISHED: 01-13-2014
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The aim of this study was to determine the efficacy of lateral intercostal artery perforator-based adipofascial free flaps for facial reconstruction in patients with facial soft tissue deficiency.
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PEP-1-PON1 protein regulates inflammatory response in raw 264.7 macrophages and ameliorates inflammation in a TPA-induced animal model.
PLoS ONE
PUBLISHED: 01-01-2014
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Paraoxonase 1 (PON1) is an antioxidant enzyme which plays a central role in various diseases. However, the mechanism and function of PON1 protein in inflammation are poorly understood. Since PON1 protein alone cannot be delivered into cells, we generated a cell permeable PEP-1-PON1 protein using protein transduction domains, and examined whether it can protect against cell death in lipopolysaccharide (LPS) or hydrogen peroxide (H2O2)-treated Raw 264.7 cells as well as mice with 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced skin inflammation. We demonstrated that PEP-1-PON1 protein transduced into Raw 264.7 cells and markedly protected against LPS or H2O2-induced cell death by inhibiting cellular reactive oxygen species (ROS) levels, the inflammatory mediator's expression, activation of mitogen-activated protein kinases (MAPKs) and cellular apoptosis. Furthermore, topically applied PEP-1-PON1 protein ameliorates TPA-treated mice skin inflammation via a reduction of inflammatory response. Our results indicate that PEP-1-PON1 protein plays a key role in inflammation and oxidative stress in vitro and in vivo. Therefore, we suggest that PEP-1-PON1 protein may provide a potential protein therapy against oxidative stress and inflammation.
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Low and high linear energy transfer radiation sensitization of HCC cells by metformin.
J. Radiat. Res.
PUBLISHED: 12-28-2013
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The purpose of this study was to investigate the efficacy of metformin as a radiosensitizer for use in combination therapy for human hepatocellular carcinoma (HCC). Three human HCC cell lines (Huh7, HepG2, Hep3B) and a normal human hepatocyte cell line were treated with metformin alone or with radiation followed by metformin. In vitro tests were evaluated by clonogenic survival assay, FACS analysis, western blotting, immunofluorescence and comet assay. Metformin significantly enhanced radiation efficacy under high and low Linear Energy Transfer (LET) radiation conditions in vitro. In combination with radiation, metformin abrogated G2/M arrest and increased the cell population in the sub-G1 phase and the ROS level, ultimately increasing HCC cellular apoptosis. Metformin inhibits the repair of DNA damage caused by radiation. The radiosensitizing effects of metformin are much higher in neutron (high LET)-irradiated cell lines than in ? (low LET)-irradiated cell lines. Metformin only had a moderate effect in normal hepatocytes. Metformin enhances the radiosensitivity of HCC, suggesting it may have clinical utility in combination cancer treatment with high-LET radiation.
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Versatility of retroauricular mastoid donor site: a convenient valuable warehouse of various free graft tissues in cosmetic and reconstructive surgery.
J Craniofac Surg
PUBLISHED: 09-17-2013
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Soft-tissue deficiency is a critical issue in facial cosmetic and reconstructive surgery. Harvesting autografts from other anatomical sites has been a common practice in overcoming soft-tissue insufficiency for many years. However, donor-site complications and visible scars are of important concerns. Therefore, we would like to introduce an alternative donor site of free-tissue grafts and its inherent advantages: the retroauricular mastoid area located along the mastoid hair line. From August 1991 to June 2011, we performed facial reconstructive surgeries for cosmetic correction of disfigurements from both congenital and complications of previous cosmetic procedures on a total of 213 patients. These patients had undergone either 1 or more facial cosmetic surgeries in the past. In this study, our primary goal focused on revising facial asymmetries or defects from previous surgical scars, tissue contraction, undercorrection, or underdevelopment. For autograft harvesting, we incised an elliptical shape along the retroauricular hairline. We then harvested sufficient amount of skin, dermal fat, fascia, or a piece of the mastoid bone if needed. After harvesting, we closed the incisional area and covered it with a compressive dressing. In evaluation of our results, we compared the preoperative photographs with postoperative and constructed a survey on patient satisfaction. Overall, the patients in this study were greatly satisfied with their surgical results. No major complications were reported. As a result of our long-term study, we believe that the retroauricular mastoid area has been shown to be an indispensable donor site for a variety of autograft tissues in terms of safety, convenience, and versatility of its unique structural composition consisting of skin, dermal fat, fascia, and bone.
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A psychological analysis of the Korean mothers of cleft lip and palate patients: screening for psychological counseling and neuropsychiatric treatment.
J Craniofac Surg
PUBLISHED: 09-17-2013
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The purpose of this study is to examine the psychological states and the stress levels of the Korean mothers who have cleft lip and palate child patients. The authors explored whether psychological assessments of the mothers with child patients could play a role in screening for psychiatric counseling. Thirty-six mothers of child patients admitted to receive cleft lip and palate surgery at Seoul National University Childrens Hospital were recruited as subjects of this study. The 3 questionnaires included in the study were the Beck Depression Inventory, Beck Anxiety Inventory, and Parenting Stress Inventory. We compared these results with those of general population according to the domestic studies. The statistical significances of these results were analyzed using Mann-Whitney method. The average score from the Beck Depression Inventory was 8.89 with standard deviation of 6.08. The average score from the Beck Anxiety Inventory was 9.69 with standard deviation of 6.89. In the Parenting Stress Inventory, the average score was 55.06 and standard deviation was 16.45. However, there were no statistically significant differences between mothers whose children have underwent surgery versus no surgery and mothers whose children had visible versus invisible anomalies. The reliable psychological analysis of depression, anxiety, and stress levels of the mothers of child patients allowed the authors to assess the psychological states of the mothers of child patients. Such assessment can play a vital role in the screening of candidates who need psychiatric treatment or consultation.
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A case of squamous metaplasia of the stomach.
Clin Endosc
PUBLISHED: 07-31-2013
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Intestinal metaplasia of the stomach is a common metaplastic lesion associated with chronic gastritis and mucosal atrophy. However, squamous metaplasia is a comparatively rare condition. On endoscopy, squamous metaplasia is usually observed as a whitish mucosal lesion in the lesser curvature of the cardiac region of the stomach. When Lugols iodine solution is applied, the lesion stains brown in the same way as normal esophageal mucosa. We report a case of 79-year-old man with a whitish flat lesion in the lesser curvature of the cardiac region on surveillance endoscopy after endoscopic treatment of gastric adenoma. The endoscopic biopsy showed stratified squamous epithelial mucosa.
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The results and complications of cranial bone reconstruction in patients with craniosynostosis.
J Craniofac Surg
PUBLISHED: 07-16-2013
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The aim of this study was to report the treatment results and complications of cranial bone reconstruction in patients with craniosynostosis at the Seoul National University Childrens Hospital over the 14-year period from 1996 to 2009. A retrospective study was undertaken on 96 cases of 94 consecutive patients diagnosed with craniosynostosis, operated on between 1996 and 2009. The authors collected the data regarding age at surgery, operative time, duration of hospitalization, and follow-up period. Surgical results including the amount of blood loss, signs related to increased intracranial pressure, aesthetic results, cranial index, and complications were evaluated. The authors compared these results with those of the past 10-year period from 1986 to 1995 at the same hospital. There were 81 patients with single synostosis and 13 patients with multiple synostoses. The age of patients ranged from 3 months to 130 months (mean, 27.9 months). The mean operative time was 7.54 ± 1.77 hours. The duration of hospital stay ranged from 5 to 70 days with a mean period of 8.97 days. The intraoperative loss of hemoglobin ranged from 0 to 9.2 g/dL (mean, 2.35 g/dL). The symptoms of increased intracranial pressure were improved after cranioplasty. With regard to aesthetic results, 94 patients were classified into category I and 2 into category IV. The cranial index decreased from 88.0% ± 1.2% to 86.9% ± 1.1% on average. There were 34 minor complications in 28 operations (29.2%). There were statistically significant differences in age at surgery, operative time, duration of hospital stay, and reoperation rate between the recent 14-year study and the past 10-year study. We observed good surgical results and low complications of cranial bone reconstruction in patients with craniosynostosis. The results of the recent 14-year operations were better than those of the past 10-year operations.
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p53 restoration can overcome cisplatin resistance through inhibition of Akt as well as induction of Bax.
Int. J. Oncol.
PUBLISHED: 06-19-2013
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Cisplatin (CDDP) is a chemotherapeutic agent that is widely used to treat many cancers. However, initial resistance to CDDP is a serious problem in treating cancers. In this study, in order to develop an approach to overcome resistance to CDDP, we investigated the difference in apoptotic processes between CDDP-sensitive cells and CDDP-resistant cells. By screening with CDDP sensitivity tests, we chose SNU-16 cells which are relatively resistant to CDDP, and SNU-1 cells which are sensitive to CDDP. We compared the difference between the two cell lines focusing on apoptosis. CDDP-induced reactive oxygen species (ROS) generation significantly induced loss of mitochondrial membrane potential (MMP, ??m) in SNU-1 cells, but not in SNU-16 cells. In addition, the ratio of Bax to Bcl-2 was increased by CDDP treatment in SNU-1 cells, but not in SNU-16 cells. To augment the loss of MMP, ??m in SNU-16, we inhibited Akt activity of SNU-16 cells to suppress their anti-apoptotic activity. The inhibition of Akt activity led to suppression of the anti-apoptotic protein XIAP. Akt inhibition slightly enhanced CDDP-induced apoptosis in SNU-16 cells. In addition, we enhanced pro-apoptotic activity by transfecting the cells with the wild-type p53 gene. The induction of wild-type p53 can enhance CDDP-induced apoptosis not only by inducing Bax protein but also by suppressing anti-apoptotic proteins through inhibition of Akt. In conclusion, this study suggests that the primary contributor to resistance to CDDP in SNU-16 cells may well be a failure of induction of apoptosis due to a lack of induction of pro-apoptotic proteins rather than suppression of anti-apoptotic proteins, and that restoration of p53 function can overcome the resistance to CDDP not only by augmenting the pro-apoptotic drive through p53-mediated transcriptional activation but also by inhibiting the anti-apoptotic drive through inhibition of Akt activity.
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Tat-DJ-1 Protects Neurons from Ischemic Damage in the Ventral Horn of Rabbit Spinal Cord Via Increasing Antioxidant Levels.
Neurochem. Res.
PUBLISHED: 06-17-2013
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The DJ-1 gene is highly conserved in diverse species and DJ-1 is known as an anti-oxidative stress factor. In this study, we investigated the neuroprotective effects of DJ-1 against ischemic damage in the rabbit spinal cord. Tat-DJ-1 fusion proteins were constructed to facilitate the penetration of DJ-1 protein into the neurons. Tat-1-DJ-1 fusion protein was administered to the rabbit 30 min after ischemia/reperfusion, and transient spinal cord ischemia was induced by occlusion of the aorta at the subrenal region for 15 min. The administration of Tat-DJ-1 significantly improved the Tarlov score compared to that in the Tat (vehicle)-treated group at 24, 48 and 72 h after ischemia/reperfusion. At 72 h after ischemia/reperfusion, the number of cresyl violet-positive neurons was significantly increased in the Tat-DJ-1-treated group compared to that in the vehicle-treated group. Lipid peroxidation as judged from the malondialdehyde levels was significantly decreased in the Tat-DJ-1-treated group compared to that in the vehicle-treated group. In contrast, superoxide dismutase and catalase levels were significantly increased in the Tat-DJ-1-treated group compared to that in the vehicle-treated group. This result suggests that DJ-1 protects neurons from ischemic damage in the ventral horn of the spinal cord via its antioxidant effects.
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Levofloxacin, Metronidazole, and Lansoprazole Triple Therapy Compared to Quadruple Therapy as a Second-Line Treatment of Helicobacter pylori Infection in Korea.
Gut Liver
PUBLISHED: 06-11-2013
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Several rescue therapies have been recommended to eradicate Helicobacter pylori infection in patients with a failure of first-line eradication therapy, but they still fail in more than 20% of cases. The aim of this study was to evaluate the efficacy and safety of levofloxacin, metronidazole, and lansoprazole (LML) triple therapy relative to quadruple therapy as a second-line treatment.
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Sorafenib acts synergistically in combination with radiotherapy without causing intestinal damage in colorectal cancer.
Tumori
PUBLISHED: 06-11-2013
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Colorectal cancer is one of the commonest cancers. Chemoradiotherapy gives better results than radiotherapy or chemotherapy in colorectal cancer. To enhance radiosensitivity of tumor cells for chemoradiotherapy, targeted therapy drugs that act as radiosensitizers can be used. In the present study, we provide a scientific rationale for the clinical application of sorafenib as a radiosensitizer in colorectal cancer, without causing significant adverse effects on normal intestinal tissue.
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Repeated administration of PEP-1-Cu,Zn-superoxide dismutase and PEP-1-peroxiredoxin-2 to senescent mice induced by D-galactose improves the hippocampal functions.
Neurochem. Res.
PUBLISHED: 04-29-2013
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Oxidative stress initiates age-related reduction in hippocampal neurogenesis and the use of antioxidants has been proposed as an effective strategy to prevent or attenuate the reduction of neurogenesis in the hippocampus. In the present study, we investigated the effects of Cu,Zn-superoxide dismutase (SOD1) and/or peroxiredoxin-2 (PRX2) on cell proliferation and neuroblast differentiation in the dentate gyrus in a model of D-galactose-induced aging model. For this study, we constructed an expression vector, PEP-1, fused PEP-1 with SOD1 or PRX2, and generated PEP-1-SOD1 and PEP-1-PRX2 fusion protein. The aging model was induced by subcutaneous injection of D-galactose (100 mg/kg) to 6-week-old male mice for 10 weeks. PEP-1, PEP-1-SOD1 and/or PEP-1-PRX2 fusion protein was intraperitoneally administered to these mice at 13-week-old once a day for 3 weeks and sacrificed at 30 min after the last administrations. The administration of PEP-1-SOD1 and/or PEP-1-PRX2 significantly improved D-galactose-induced deficits on the escape latency, swimming speeds, platform crossings, spatial preference for the target quadrant in Morris water maze test. In addition, the administration of PEP-1-SOD1 and/or PEP-1-PRX2 ameliorated D-galactose-induced reductions of cell proliferation and neuroblast differentiation in the dentate gyrus and significantly reduced D-galactose-induced lipid peroxidation in the hippocampus. These effects were more prominent in the PEP-1-SOD1-treated group with PEP-1-PRX2. These results suggest that a SOD1 and/or PRX2 supplement to aged mice could improve the memory deficits, cell proliferation and neuroblast differentiation in the dentate gyrus of D-galactose induced aged mice by reducing lipid peroxidation.
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mTOR inhibitors radiosensitize PTEN-deficient non-small-cell lung cancer cells harboring an EGFR activating mutation by inducing autophagy.
J. Cell. Biochem.
PUBLISHED: 04-18-2013
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Clinical resistance to gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), in patients with lung cancer has been linked to acquisition of the T790M resistance mutation in activated EGFR or amplification of MET. Phosphatase and tensin homolog (PTEN) loss has been recently reported as a gefitinib resistance mechanism in lung cancer. The aim of this study was to evaluate the efficacy of radiotherapy in non-small-cell lung cancer (NSCLC) with acquired gefitinib resistance caused by PTEN deficiency to suggest radiotherapy as an alternative to EGFR TKIs. PTEN deficient-mediated gefitinib resistance was generated in HCC827 cells, an EGFR TKI sensitive NSCLC cell line, by PTEN knockdown with a lentiviral vector expressing short hairpin RNA-targeting PTEN. The impact of PTEN knockdown on sensitivity to radiation in the presence or absence of PTEN downstream signaling inhibitors was investigated. PTEN knockdown conferred acquired resistance not only to gefitinib but also to radiation on HCC827 cells. mTOR inhibitors alone failed to reduce HCC827 cell viability, regardless of PTEN expression, but ameliorated PTEN knockdown-induced radioresistance. PTEN knockdown-mediated radioresistance was accompanied by repression of radiation-induced cytotoxic autophagy, and treatment with mTOR inhibitors released the repression of cytotoxic autophagy to overcome PTEN knockdown-induced radioresistance in HCC827 cells. These results suggest that inhibiting mTOR signaling could be an effective strategy to radiosensitize NSCLC harboring the EGFR activating mutation that acquires resistance to both TKIs and radiotherapy due to PTEN loss or inactivation mutations.
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Anthocyanins from Vitis coignetiae Pulliat Inhibit Cancer Invasion and Epithelial-Mesenchymal Transition, but These Effects Can Be Attenuated by Tumor Necrosis Factor in Human Uterine Cervical Cancer HeLa Cells.
Evid Based Complement Alternat Med
PUBLISHED: 03-29-2013
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Recently we have demonstrated that anthocyanins from fruits of Vitis coignetiae Pulliat (AIMs) have anticancer effects. Here, we investigate the effects of AIMs on cell proliferation and invasion as well as epithelial-mesenchymal transition (EMT) which have been linked to cancer metastasis in human uterine cervical cancer HeLa cells. AIMs inhibited the invasion of HeLa cells in a dose-dependent manner. AIMs inhibited MMP-9 expression in a dose-dependent manner. AIMs inhibited the motility of HeLa cells in a wound healing test. AIMs still suppressed NF- ? B activation induced by TNF. AIMs also inhibited EMT in HeLa cells. AIMs suppressed vimentin, N-cadherin, and ?-catenin expression and induced E-cadherin. AIMs also suppressed expression of ?-catenin and Snail, which was regulated by GSK-3. These effects of AIMs were also limited in the HeLa cells treated with TNF. In conclusion, this study indicates that AIMs have anticancer effects by suppressing NF- ? B-regulated genes and EMT, which relates to suppression of I ? B ? phosphorylation and GSK-3 activity, respectively. However, the effects of AIMs were attenuated in the TNF-high condition.
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Novel cell-based assay reveals associations of circulating serum AhR-ligands with metabolic syndrome and mitochondrial dysfunction.
Biofactors
PUBLISHED: 01-30-2013
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Serum concentrations of environmental pollutants have been positively correlated with diabetes and metabolic syndrome in epidemiologic studies. In turn, abnormal mitochondrial function has been associated with the diseases. The relationships between these variables, however, have not been studied. We developed novel cell-based aryl hydrocarbon receptor (AhR) agonist bioassay system without solvent extraction process and analyzed whether low-dose circulating AhR ligands in human serum are associated with parameters of metabolic syndrome and mitochondrial function. Serum AhR ligand activities were measured as serum 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent (sTCDDeq) in pM using 10 ?L human sera from 97 Korean participants (47 with glucose intolerance and 50 matched controls, average age of 46.6 ± 9.9 years, 53 male and 45 female). sTCDDeq were higher in participants with glucose intolerance than normal controls and were positively associated (P < 0.01) with obesity, blood pressure, serum triglyceride, and fasting glucose, but not with HDL-cholesterol. Body mass index was in a positive linear relationship with serum AhR ligands in healthy participants. When myoblast cells were incubated with human sera, ATP generating power of mitochondria became impaired in an AhR ligand concentration-dependent manner. Our results support that circulating AhR ligands may directly reduce mitochondrial function in tissues, leading to weight gain, glucose intolerance, and metabolic syndrome. Our rapid cell-based assay using minute volume of human serum may provide one of the best monitoring systems for circulating AhR ligands, good clinical biomarkers for the progress of disease and therapeutic efficacy.
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Bilateral osteochondritis dissecans of the femoral condyles in both knees: a report of two sibling cases.
Knee Surg Relat Res
PUBLISHED: 01-24-2013
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Osteochondritis dissecans (OCD) of both femoral condyles is very rare, with no previously reported cases of bilateral OCD of both knees in two siblings. We report on a brother and sister with both femoral condyle OCD with a description of surgical technique and clinical results. Fixation using headless compressive screws, osteochondral autologous transplantation and autologous chondrocyte implantation were all successful.
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Overnight fasting regulates inhibitory tone to cholinergic neurons of the dorsomedial nucleus of the hypothalamus.
PLoS ONE
PUBLISHED: 01-01-2013
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The dorsomedial nucleus of the hypothalamus (DMH) contributes to the regulation of overall energy homeostasis by modulating energy intake as well as energy expenditure. Despite the importance of the DMH in the control of energy balance, DMH-specific genetic markers or neuronal subtypes are poorly defined. Here we demonstrate the presence of cholinergic neurons in the DMH using genetically modified mice that express enhanced green florescent protein (eGFP) selectively in choline acetyltransferase (Chat)-neurons. Overnight food deprivation increases the activity of DMH cholinergic neurons, as shown by induction of fos protein and a significant shift in the baseline resting membrane potential. DMH cholinergic neurons receive both glutamatergic and GABAergic synaptic input, but the activation of these neurons by an overnight fast is due entirely to decreased inhibitory tone. The decreased inhibition is associated with decreased frequency and amplitude of GABAergic synaptic currents in the cholinergic DMH neurons, while glutamatergic synaptic transmission is not altered. As neither the frequency nor amplitude of miniature GABAergic or glutamatergic postsynaptic currents is affected by overnight food deprivation, the fasting-induced decrease in inhibitory tone to cholinergic neurons is dependent on superthreshold activity of GABAergic inputs. This study reveals that cholinergic neurons in the DMH readily sense the availability of nutrients and respond to overnight fasting via decreased GABAergic inhibitory tone. As such, altered synaptic as well as neuronal activity of DMH cholinergic neurons may play a critical role in the regulation of overall energy homeostasis.
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Imipramine enhances neuroprotective effect of PEP-1-Catalase against ischemic neuronal damage.
BMB Rep
PUBLISHED: 10-27-2011
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The protein transduction domains have been reported to have potential to deliver the exogenous molecules, including proteins, to living cells. However, poor transduction of proteins limits therapeutic application. In this study, we examined whether imipramine could stimulate the transduction efficiency of PEP-1 fused proteins into astrocytes. PEP-1-catalase (PEP-1- CAT) was transduced into astrocytes in a time- and dose-dependent manner, reducing cellular toxicity induced by H(2)O(2). Additionally, the group of PEP-1-CAT (+) imipramine showed enhancement of transduction efficiency and therefore increased cellular viability than that of PEP-1-CAT alone. In the gerbil ischemia models, PEP-1-CAT displayed significant neuroprotection in the CA1 region of the hippocampus. Interestingly, PEP-1-CAT (+) imipramine prevented neuronal cell death and lipid peroxidation more markedly than PEP-1-CAT alone. Therefore, our results suggest that imipramine can be used as a drug to enhance the transduction of PEP-1 fusion proteins to cells or animals and their efficacies against various disorders.
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Anti-inflammatory effect of transduced PEP-1-cyclophilin A in Raw264.7 cells and 12-O-tetradecanoylphorbol-13-acetate-induced mice.
Life Sci.
PUBLISHED: 09-21-2011
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Cyclophilin A (CypA) is an immunophilin that acts as a receptor for the immunosuppressant drug cyclosporine A (CsA). CypA has emerged as a potential drug target for several inflammatory diseases, although the details of its mechanism are unclear. We examined the protective effects of CypA on inflammation in Raw 264.7 cells and animal models.
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Compensatory growth factor and cytokine response in tears after subconjunctival bevacizumab injection.
Cornea
PUBLISHED: 07-22-2011
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Recent studies support the use of bevacizumab to treat ocular neovascularization (NV). In this study, we aimed to investigate changes in growth factors and cytokines in human tears after a subconjunctival bevacizumab injection and to evaluate the clinical effects and safety of the drug in ocular surface NV.
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Anti-inflammatory effect of transduced PEP-1-heme oxygenase-1 in Raw 264.7 cells and a mouse edema model.
Biochem. Biophys. Res. Commun.
PUBLISHED: 06-04-2011
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Heme oxygenase-1 (HO-1), which catalyzes the degradation of free heme to biliverdin, carbon monoxide (CO), and free iron (Fe(2+)), is up-regulated by several cellular stress and cell injuries, including inflammation, ischemia and hypoxia. In this study, we examined whether fusion of HO-1 with PEP-1, a protein transduction domain that is able to deliver exogenous molecules to living cells or tissues, would facilitate HO-1 delivery to target cells and tissues, and thereby effectively exert a therapeutically useful response against inflammation. Western blot analysis demonstrated that PEP-1-HO-1 fusion proteins were transduced into Raw 264.7 cells in time- and dose-dependent manners, and were stably maintained in the cells for about 60h. In addition, fluorescence analysis revealed that only PEP-1-HO-1 fusion proteins were significantly transduced into the cytoplasm of cells, while HO-1 proteins failed to be transduced. In lipopolysaccharide (LPS)-stimulated Raw 264.7 cells and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse edema model, transduced PEP-1-HO-1 fusion proteins effectively inhibited the overexpression of pro-inflammatory mediators and cytokines. Also, histological analysis demonstrated that PEP-1-HO-1 remarkably suppressed ear edema. The results suggest that the PEP-1-HO-1 fusion protein can be used as a therapeutic molecule against reactive oxygen species-related inflammatory diseases.
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Transduced PEP-1-FK506BP ameliorates atopic dermatitis in NC/Nga mice.
J. Invest. Dermatol.
PUBLISHED: 03-24-2011
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Immunophilin, FK506-binding protein 12 (FK506BP), is a receptor protein for the immunosuppressive drug FK506 by the FK506BP/FK506 complex. However, the precise function of FK506BP in inflammatory diseases remains unclear. Therefore, we examined the protective effects of FK506BP on atopic dermatitis (AD) in tumor necrosis factor-? (TNF-?)/interferon-? (IFN-?)-induced HaCaT cells and 2,4-dinitrofluorobenzene-induced AD-like dermatitis in Nishiki-nezumi Cinnamon/Nagoya (NC/Nga) mice using a cell-permeable PEP-1-FK506BP. Transduced PEP-1-FK506BP significantly inhibited the expression of cytokines, as well as the activation of NF-?B and mitogen-activated protein kinase (MAPK) in TNF-?/IFN-?-induced HaCaT cells. Furthermore, topical application of PEP-1-FK506BP to NC/Nga mice markedly inhibited AD-like dermatitis as determined by a histological examination and assessment of serum IgE levels, as well as cytokines and chemokines. These results indicate that PEP-1-FK506BP inhibits NF-?B and MAPK activation in cells and AD-like skin lesions by reducing the expression levels of cytokines and chemokines, thus suggesting that PEP-1-FK506BP may be a potential therapeutic agent for AD.
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Shot-gun proteomic analysis of mitochondrial D-loop DNA binding proteins: identification of mitochondrial histones.
Mol Biosyst
PUBLISHED: 02-28-2011
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Transcription and replication of mitochondrial DNA (mtDNA) are regulated by nuclear DNA-encoded proteins that are targeted into mitochondria. A decrease in mtDNA copy number results in mitochondrial dysfunction, which may lead to insulin resistance and metabolic syndromes. We analyzed mitochondrial proteins that physically bind to human mitochondrial D-loop DNA using a shot-gun proteomics approach following protein enrichment by D-loop DNA-linked affinity chromatography. A total of 152 D-loop DNA binding proteins were identified by peptide sequencing using ultra high pressure capillary reverse-phase liquid chromatography/tandem mass spectrometry. Bioinformatic analysis showed that 68 were mitochondrial proteins, 96 were DNA/RNA/protein binding proteins and 114 proteins might form a complex via protein-protein interactions. Histone family members of H1, H2A, H2B, H3, and H4, were detected in abundance among them. In particular, histones H2A and H2B were present in the mitochondrial membrane as integral membrane proteins and not bound directly to mtDNA inside the organelle. Histones H1.2, H3 and H4 were associated with the outer mitochondrial membrane. Silencing of H2AX expression inhibited mitochondrial protein transport. Our data suggests that many mitochondrial proteins may reside in multiple subcellular compartments like H2AX and exert multiple functions.
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A study of eccentric viewing training for low vision rehabilitation.
Korean J Ophthalmol
PUBLISHED: 02-22-2011
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The definition of eccentric viewing (EV) is using non-foveal preferred retinal loci (PRL) for viewing. The purpose of the present study was to investigate the clinical effect of EV training for low vision rehabilitation in patients with central scotomas.
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Network clustering revealed the systemic alterations of mitochondrial protein expression.
PLoS Comput. Biol.
PUBLISHED: 01-03-2011
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The mitochondrial protein repertoire varies depending on the cellular state. Protein component modifications caused by mitochondrial DNA (mtDNA) depletion are related to a wide range of human diseases; however, little is known about how nuclear-encoded mitochondrial proteins (mt proteome) changes under such dysfunctional states. In this study, we investigated the systemic alterations of mtDNA-depleted (?(0)) mitochondria by using network analysis of gene expression data. By modularizing the quantified proteomics data into protein functional networks, systemic properties of mitochondrial dysfunction were analyzed. We discovered that up-regulated and down-regulated proteins were organized into two predominant subnetworks that exhibited distinct biological processes. The down-regulated network modules are involved in typical mitochondrial functions, while up-regulated proteins are responsible for mtDNA repair and regulation of mt protein expression and transport. Furthermore, comparisons of proteome and transcriptome data revealed that ?(0) cells attempted to compensate for mtDNA depletion by modulating the coordinated expression/transport of mt proteins. Our results demonstrate that mt protein composition changed to remodel the functional organization of mitochondrial protein networks in response to dysfunctional cellular states. Human mt protein functional networks provide a framework for understanding how cells respond to mitochondrial dysfunctions.
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Combination effect of cetuximab with radiation in colorectal cancer cells.
Tumori
PUBLISHED: 12-28-2010
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Colorectal cancer (CRC) is one of the commonest malignant disorders and frequently associated with high expression of epidermal growth factor receptor (EGFR), resulting in advanced disease and a poor prognosis. In this study, we investigated the radiosensitizing effects of the selective EGFR inhibitor cetuximab in human CRC cell lines.
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Transduced PEP-1-FK506BP inhibits the inflammatory response in the Raw 264.7 cell and mouse models.
Immunobiology
PUBLISHED: 09-05-2010
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FK506 binding protein 12 (FK506BP) is an immunophilin that acts as a receptor for the immunosuppressant drug FK506. Although the precise action of FK506BP remains unclear, it has emerged as a potential drug target for several inflammatory diseases. This study investigated the protective effects of FK506BP on inflammation in vitro and in vivo using protein transduction. A cell-permeable expression vector PEP-1-FK506BP was constructed. Lipopolysaccharide (LPS)- or 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated Raw 264.7 cells and ICR mice were treated with PEP-1-FK506BP. The expression of inflammatory response enzymes and cytokines was analyzed by Western blot, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, and electrophoretic mobility shift assay. PEP-1-FK506BP efficiently transduced into Raw 264.7 cells and markedly inhibited the expression levels of cyclooxygenase-2 as well as pro-inflammatory cytokines. Furthermore, transduced PEP-1-FK506BP significantly reduced activation of nuclear factor-kappa B (NF-?B) and phosphorylation of p38 mitogen-activated protein kinase (MAPK) in the cells, whereas PEP-1-FK506BP reduced phosphorylation of p38 and extracellular signal-regulated kinase (ERK) in the animal models. These results indicate that PEP-1-FK506BP inhibits inflammatory response cytokines and enzymes by blocking NF-?B and MAPK including the phosphorylation of p38 and/or ERK MAPK in vitro and in vivo, suggesting that PEP-1-FK506BP may be a therapeutic agent against inflammatory skin diseases.
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Enhancement of HIV-1 Tat fusion protein transduction efficiency by bog blueberry anthocyanins.
BMB Rep
PUBLISHED: 08-28-2010
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Though protein transduction domains (PTDs) are well known for the delivery of exogenous therapeutic proteins into living cells, the overall low efficiency of transduction is a serious obstacle. We investigated the effect of bog blueberry anthocyanins (BBA) on protein transduction efficiency and found that BBA enhanced the transduction efficiencies of Tat-SOD fusion protein into HeLa cells and mice skin. The enzymatic activities in the cells and skin tissue in the presence of BBA were markedly increased compared to controls. Further, BBA did not demonstrate any cell toxicity at various concentrations. Although the mechanism is not fully understood, we suggest that BBA might alter the conformation of the membrane, which would indicate that BBA can be used as a protein transduction enhancer for the efficient delivery of therapeutic proteins for a variety of disorders.
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Characterization of mitochondria isolated from normal and ischemic hearts in rats utilizing atomic force microscopy.
Micron
PUBLISHED: 06-19-2010
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Mitochondria play critical roles in both the life and the death of cardiac myocytes. Various factors, such as the loss of ATP synthesis and increase of ATP hydrolysis, impairment in ionic homeostasis, formation of reactive oxygen species (ROS), and release of proapoptotic proteins are related to the generation of irreversible damage. It has been proposed that the release of cytochrome c is caused by a swelling of the mitochondrial matrix triggered by the apoptotic stimuli. However, there is a controversy about whether or not the mitochondria, indeed, swell during apoptosis. The major advantages of atomic force microscopy (AFM) over conventional optical and electron microscopes for bio-imaging include the fact that no special coating and vacuum are required and imaging can be done in all environments--air, vacuum or aqueous conditions. In addition, AFM force-distance curve measurements have become a fundamental tool in the fields of surface chemistry, biochemistry, and material science. In this study, we used AFM to observe the morphological and property changes in heart mitochondria that were isolated from a rat myocardial infarction model. From the shape parameters of the mitochondria in the AFM topographic image, it seemed that myocardial infarction caused the mitochondrial swelling. Also, the results of force-distance measurements showed that the adhesion force of heart mitochondria was significantly decreased by myocardial in infarction. Therefore, we suggested that myocardial infarction might be the cause of mitochondrial swelling and the changes in outer membrane of heart mitochondria.
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Protective effects of transduced PEP-1-Frataxin protein on oxidative stress-induced neuronal cell death.
J. Neurol. Sci.
PUBLISHED: 06-10-2010
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Reactive oxygen species (ROS) actively contribute to the development of a number of human diseases including ischemia. In response to oxidative stress, frataxin has a significant ability to improve cell survival though its biological function is unclear in relation to ischemia. To explore frataxins role in protecting against ischemic cell death, we constructed PEP-1-Frataxin cell-permeable fusion protein. In a dose- and time-dependent manner PEP-1-Frataxin rapidly transduced into astrocyte cells and protected them against oxidative stress-induced cell death. Further, using an animal model, immunohistochemical analysis revealed that PEP-1-Frataxin prevented neuronal cell death in the CA1 region of the hippocampus induced by transient forebrain ischemia. These results demonstrate that transduced PEP-1-Frataxin protects against cell death in vitro and in vivo, suggesting that transduction of PEP-1-Frataxin could be useful as a therapeutic agent for various human diseases related to oxidative stress.
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The statistically optimized production of poly(gamma-glutamic acid) by batch fermentation of a newly isolated Bacillus subtilis RKY3.
Bioresour. Technol.
PUBLISHED: 01-14-2010
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For the production of poly(gamma-glutamic acid), a newly isolated Bacillus sp. RKY3 was phylogenetically identified as Bacillus subtilis based on its 16S rRNA gene sequence. The culture medium for the production of poly(gamma-glutamic acid) by B. subtilis RKY3 was optimized statistically. The parameters significantly affecting poly(gamma-glutamic acid) production were found to be glycerol, glutamic acid, yeast extract, and K(2)HPO(4). A further advanced statistical approach, central composite design, found the optimum levels of the screened variables as follows (gl(-1)): glycerol 17.6, glutamic acid 59.6; yeast extract 2.7; K(2)HPO(4) 2.3. The predicted response as poly(gamma-glutamic acid) production under the statistically optimized conditions was 48.5 g l(-1), which was only 0.4% different from the maximum poly(gamma-glutamic acid) concentration (48.7 g l(-1)) observed at the validation experiment using 7-l lab-scale fermentor containing 3 l of working volume.
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Transduced Tat-SAG fusion protein protects against oxidative stress and brain ischemic insult.
Free Radic. Biol. Med.
PUBLISHED: 01-09-2010
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Reactive oxygen species (ROS) have been implicated in the pathogenesis of ischemic brain injury. Sensitive to apoptosis gene (SAG) is a RING-finger protein that exhibits antioxidant activity against a variety of redox reagents. However, the protective effect of SAG in brain ischemic injury is unclear. Here, we investigated the protective effects of a Tat-SAG fusion protein against cell death and ischemic insult. When Tat-SAG fusion protein was added to the culture medium of astrocytes, it rapidly entered the cells and protected them against oxidative stress-induced cell death. Immunohistochemical analysis revealed that, when Tat-SAG fusion protein was intraperitoneally injected into gerbils, wild-type Tat-SAG prevented neuronal cell death in the CA1 region of the hippocampus in response to transient forebrain ischemia. In addition, wild-type Tat-SAG fusion protein decreased lipid peroxidation in the brain compared with mutant Tat-SAG- or vehicle-treated animals. Our results demonstrate that Tat-SAG fusion protein is a tool for the treatment of ischemic insult and it can be used in protein therapy for various disorders related to ROS, including stroke.
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Hsp90-functionalized polypyrrole nanotube FET sensor for anti-cancer agent detection.
Biosens Bioelectron
PUBLISHED: 08-13-2009
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A rapid and efficient strategy to detect novel heat shock protein 90 (Hsp90) inhibitors as anti-cancer agents was developed with field-effect transistor (FET) sensor based on carboxylated polypyrrole nanotubes (CPNTs). First of all, the CPNTs were successfully fabricated by using cylindrical micelle templates in a water-in-oil emulsion system, and the functional carboxyl groups were effectively incorporated into the polymer backbone during the polymerization by using pyrrole-3-carboxylic acid (P3CA) as a co-monomer. A liquid-ion gated FET-type sensor was readily constructed on the basis of CPNTs as the conductive channel. The CPNTs were covalently immobilized onto the microelectrode substrate to maintain stable electrical contact between the CPNTs and the microelectrodes in the liquid phase. Subsequently, Hsp90 was attached to the CPNTs surface through condensation reactions between the terminal amino groups in Hsp90 amino acid residues and the carboxyl groups on the CPNTs. The Hsp90-conjugated CPNT FET sensor provided a convenient and sensitive method to observe the affinity between Hsp90 to Hsp90 inhibitors in real-time. This result suggests that the FET sensor will open up the potential application for new anti-cancer drug discovery (Hsp90 inhibitors) after a judicious optimization.
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Arthroscopic repair of the posterior horn of the medial meniscus with opening wedge high tibial osteotomy: surgical technique.
J Knee Surg
PUBLISHED: 07-29-2009
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Simultaneous repair of a radial tear at the tibial attachment site of the posterior horn of the medial meniscus under special circumstances requiring tibial valgus osteotomy is technically difficult. First, most patients who need an osteotomy have a narrowed medial tibiofemoral joint space. In such a situation, the pull-out suture technique is more difficult to perform than in a normal joint space. Second, pulling out suture strands that penetrate the posterior horn of the medial meniscus to the anterior tibial cortex increases the risk of transection during osteotomy. We performed a meniscus repair combined with an opening wedge tibial valgus osteotomy without complications and present our technique as a new method for use in selective cases necessitating both meniscus repair of a complete radial tear and opening wedge tibial osteotomy.
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Inhibition of LPS-induced nitric oxide production by transduced Tat-arginine deiminase fusion protein in Raw 264.7 cells.
BMB Rep
PUBLISHED: 05-28-2009
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Arginine deiminase (ADI), an arginine-degrading enzyme, has anti-proliferative and anti-tumor activities and is capable of inhibiting the production of nitric oxide (NO). Modulation of nitric oxide (NO) production is considered a promising approach for the treatment of various diseases including cancer, inflammation and neuronal disorders. In this study, an ADI gene was fused with an HIV-1 Tat peptide in a bacterial expression vector to produce an genetic in-frame Tat-ADI fusion protein. When added exogenously to the culture media, the expressed and purified Tat-ADI fusion proteins were efficiently transduced into macrophage Raw 264.7 cells in a time- and dose-dependent manner. Furthermore, transduced Tat-ADI fusion proteins markedly increased cell viability in cells treated with lipopolysaccharide (LPS). This increase in viability was mediated by an inhibition of NO production. These results suggest that this Tat-ADI fusion protein can be used in protein therapies of NO-related disorders such as cancer, inflammation and neuronal diseases.
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Transduced human PEP-1-catalase fusion protein attenuates ischemic neuronal damage.
Free Radic. Biol. Med.
PUBLISHED: 05-11-2009
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Antioxidant enzymes are considered to have beneficial effects against various diseases mediated by reactive oxygen species (ROS). Ischemia is characterized by both oxidative stress and changes in the antioxidant defense system. Catalase (CAT) and superoxide dismutase (SOD) are major antioxidant enzymes by which cells counteract the deleterious effects of ROS. To investigate the protective effects of CAT, we constructed PEP-1-CAT cell-permeative expression vectors. When PEP-1-CAT fusion proteins were added to the culture medium of neuronal cells, they rapidly entered the cells and protected them against oxidative stress-induced neuronal cell death. Immunohistochemical analysis revealed that PEP-1-CAT prevented neuronal cell death in the hippocampus induced by transient forebrain ischemia. Moreover, we showed that the protective effect of PEP-1-CAT was observed in neuronal cells treated with PEP-1-SOD. Therefore, we suggest that transduced PEP-1-CAT and PEP-1-SOD fusion proteins could be useful as therapeutic agents for various human diseases related to oxidative stress, including stroke.
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Mitochondrial dysfunction enhances the migration of vascular smooth muscles cells via suppression of Akt phosphorylation.
Biochim. Biophys. Acta
PUBLISHED: 04-09-2009
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Atherosclerosis is one of the major complications of diabetes, which may result from insulin resistance via mitochondrial dysfunction. Although a strong association between insulin resistance and cardiovascular disease has been suggested, it is not clear yet whether stress-inducing factors damage mitochondria and insulin signaling pathway in cardiovascular tissues.
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Transduced HSP27 protein protects neuronal cell death by enhancing FALS-associated SOD1 mutant activity.
BMB Rep
PUBLISHED: 04-02-2009
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Familial Amyotrophic lateral sclerosis (FALS) is a progressive neurodegenetative disorder induced by mutations of the SOD1 gene. Heat shock protein 27 (HSP27) is well-defined as a stress-inducible protein, however the its role in ALS protection has not yet been established. To investigate the role HSP27 may have in SOD1 mutant-mediated apoptosis, human SOD1 or HSP27 genes were fused with a PEP-1 peptide in a bacterial expression vector to produce a genetic in-frame fusion protein, which was then transduced into cells. We found the purified PEP-1-HSP27 fusion proteins can be transduced efficiently into neuronal cells and protect against cell death by enhancing mutant SOD1 activity. Moreover, transduced PEP-1-HSP27 efficiently prevents protein aggregation produced by oxidative stress. These results suggest that transduced HSP27 fusion protein may be explored as a potential therapeutic agent for FALS patients.
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Sterol-independent repression of low density lipoprotein receptor promoter by peroxisome proliferator activated receptor gamma coactivator-1alpha (PGC-1alpha).
Exp. Mol. Med.
PUBLISHED: 03-27-2009
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Peroxisome proliferator activated receptor (PPAR) gamma coactivator-1alpha (PGC-1alpha) may be implicated in cholesterol metabolism since PGC-1alpha co-activates estrogen receptor alpha (ERalpha) transactivity and estrogen/ERalpha induces the transcription of LDL receptor (LDLR). Here, we show that overexpression of PGC-1alpha in HepG2 cells represses the gene expression of LDLR and does not affect the ERalpha-induced LDLR expression. PGC-1alpha suppressed the LDLR promoter-luciferase (pLR1563- luc) activity regardless of cholesterol or functional sterol-regulatory element-1. Serial deletions of the LDLR promoter revealed that the inhibition by PGC-1alpha required the LDLR promoter regions between -650 bp and -974 bp. Phosphorylation of PGC-1alpha may not affect the suppression of LDLR expression because treatment of SB202190, a p38 MAP kinase inhibitor, did not reverse the LDLR down-regulation by PGC-1alpha. This may be the first report showing the repressive function of PGC-1alpha on gene expression. PGC-1alpha might be a novel modulator of LDLR gene expression in a sterol-independent manner, and implicated in atherogenesis.
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Arthroscopic removal of proud metallic suture anchors after Bankart repair.
Arch Orthop Trauma Surg
PUBLISHED: 03-07-2009
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This study presents an arthroscopic removal technique for proud metallic suture anchor after Bankart repair and analyzes the cause of anchor failures.
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Effects of low dose quercetin: cancer cell-specific inhibition of cell cycle progression.
J. Cell. Biochem.
PUBLISHED: 02-14-2009
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Quercetin is a flavonoid present in many vegetables, fruits, and beverages. Due to its anti-oxidant, anti-tumor, and anti-inflammatory activity, quercetin has been studied extensively as a chemoprevention agent in several cancer models. Since most of these studies used higher doses of quercetin than clinically achievable, we focused on the effectiveness of physiologically relevant doses of quercetin. A low dose of quercetin exerted cancer cell-specific inhibition of proliferation and this inhibition resulted from cell cycle arrest at the G(1) phase. Quercetin induced p21 CDK inhibitor with a concomitant decrease of phosphorylation of pRb, which inhibits the G(1)/S cell cycle progression by trapping E2F1. A low dose of quercetin induced mild DNA damage and Chk2 activation, which is the main regulator of p21 expression by quercetin. In addition, quercetin down-regulated the cyclin B1 and CDK1, essential components of G(2)/M cell cycle progression. Inhibition of the recruitment of key transcription factor NF-Y to cyclin B1 gene promoter by quercetin led to transcriptional inhibition. This study proved that the chemo-preventive efficacy of a physiologically relevant dose of quercetin can be achievable through the inhibition of cell cycle progression.
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Analysis of a novel class 1 integron containing metallo-beta-lactamase gene VIM-2 in Pseudomonas aeruginosa.
J. Microbiol.
PUBLISHED: 02-13-2009
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Carbapenems such as imipenem are stable to most beta-lactamases. Recently, increased numbers of carbapenemase producing Gram-negative bacterial strains have been isolated because of the increased use of cabapenems. In this respect, control of these infectious carbapenemase producing Gram-negative bacteria and understanding their resistance mechanism are becoming more important. These carbapenem-hydrolyzing beta-lactamase genes have been reported to exist mostly as gene cassettes in an integron. This implies that antibiotic resistance genes may be transferred to other bacteria via the integron. In the present study, we identified and analyzed an integron containing VIM-2 type metallo-beta-lactamase gene in a carbapenemase producing Pseudomonas aeruginosa. In addition, the possibility of resistance spread by integron located in a plasmid was tested. Among glucose non-fermenting Gram-negative bacilli with reduced imipenem susceptibility (MIC > or = 8 microg/ml) isolated from Korean patients, P. aeruginosa 1082 showed resistance to most beta-lactams, cephalosporin, and aminoglycoside. We found that P. aeruginosa 1082 was inhibited by EDTA in EDTA double disk synergy test which means that this strain produces metallo-beta-lactamase. Class 1 integron containing bla (VIM-2) (carbapenem resistance gene), qacF (quaternary ammonium compound resistance gene), aacA4 (aminoglycoside resistance gene), catB3 (chloramphenicol resistance gene), bla (oxa-30) (extended-spectrum beta-lactam resistance gene), and aadAl (aminoglycoside resistance gene) gene cassettes was detected in P. aeruginosa 1082. The size of the integron was 5,246 bp and the structure and arrangement of the integron was a novel one in comparison with other integrons found in other P. aeruginosa. The integron could be transferred to Escherichia coli JM109 from P. aeruginosa 1082 possibly via self-transferable plasmid DNA. The integron and a bla (VIM-2) gene were detected in the plasmid DNA of the transconjugants whose imipenem resistance was slightly increased as a result of accepting the integron from the donor strain.
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Identification of new Hsp90 inhibitors by structure-based virtual screening.
Bioorg. Med. Chem. Lett.
PUBLISHED: 02-10-2009
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Structure-based virtual screening identified pyrimidine-2,4,6-trione and 4H-1,2,4-triazole-3-thiol as novel scaffolds of Hsp90 ATPase inhibitors. Their binding modes in the ATP-binding pocket of Hsp90 were analyzed using AutoDoc program combined with molecular dynamics (MD) simulations.
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High-mobility group box 2 (HMGB2) modulates radioresponse and is downregulated by p53 in colorectal cancer cell.
Cancer Biol. Ther.
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Overexpression of high-mobility group box 2 (HMGB2) is recently reported in several malignant cancers and was correlated with poor response to preoperative chemoradiotherapy of colorectal cancer patients. To enhance the chemoradiotherapy efficacy, the biological function of HMGB2 was investigated with respect to radiation response. HMGB2 gene knockdown cells were constructed by infecting shRNA expressing lentivirus and clonogenic assay was performed to count the radiosensitivity. HMGB2 knockdown sensitized HCT-116 and HT-29 colorectal cancer cells to ionizing radiation. This could be due to an increased DNA damage and an inefficient DNA damage repair in HMGB2 knockdown cells. In addition, an exposure to radiation downregulated HMGB2 expression in colorectal cancer cells with an intact TP53 gene. HMGB2 gene expression of TP53-mutant cell was not affected by irradiation. p53-mediated downregulation of HMGB2 was confirmed by direct activation of p53 using Nutlin-3 or by inducing p53 expression using Tet-On system. Luciferase reporter assay showed that HMGB2 promoter activity was inversely correlated with the amount p53 cotransfected. Our study revealed that HMGB2 is necessary to protect colorectal cancer cells from DNA damage and efficient DNA repair and p53-mediated downregulation is a critical mechanism of modulating HMGB2 expression.
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Dynamic nucleotide-dependent interactions of cysteine- and histidine-rich domain (CHORD)-containing Hsp90 cochaperones Chp-1 and melusin with cochaperones PP5 and Sgt1.
J. Biol. Chem.
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Mammals have two cysteine- and histidine-rich domain (CHORD)-containing Hsp90 cochaperones, Chp-1 and melusin, which are homologs of plant Rar1. It has been shown previously that Rar1 CHORD directly interacts with ADP bound to the nucleotide pocket of Hsp90. Here, we report that ADP and ATP can bind to Hsp90 cochaperones Chp-1 and PP5, inducing their conformational changes. Furthermore, we demonstrate that Chp-1 and melusin can interact with cochaperones PP5 and Sgt1 and with each other in an ATP-dependent manner. Based on the known structure of the Rar1-Hsp90 complex, His-186 has been identified as an important residue of Chp-1 for ADP/ATP binding. His-186 is necessary for the nucleotide-dependent interaction of Chp-1 not only with Hsp90 but also with Sgt1. In addition, Ca(2+), which is known to bind to melusin, enhances the interactions of melusin with Hsp90 and Sgt1. Furthermore, melusin acquires the ADP preference for Hsp90 binding in the presence of Ca(2+). Our newly discovered nucleotide-dependent interactions between cochaperones might provide additional complexity to the dynamics of the Hsp90 chaperone system, also suggesting potential Hsp90-independent roles for these cochaperones.
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In situ-prepared composite materials of PEDOT: PSS buffer layer-metal nanoparticles and their application to organic solar cells.
Nanoscale Res Lett
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We report an enhancement in the efficiency of organic solar cells via the incorporation of gold (Au) or silver (Ag) nanoparticles (NPs) in the hole-transporting buffer layer of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), which was formed on an indium tin oxide (ITO) surface by the spin-coating of PEDOT:PSS-Au or Ag NPs composite solution. The composite solution was synthesized by a simple in situ preparation method which involved the reduction of chloroauric acid (HAuCl4) or silver nitrate (AgNO3) with sodium borohydride (NaBH4) solution in the presence of aqueous PEDOT:PSS media. The NPs were well dispersed in the PEDOT:PSS media and showed a characteristic absorption peak due to the surface plasmon resonance effect. Organic solar cells with the structure of ITO/PEDOT:PSS-Au, Ag NPs/poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM)/LiF/Al exhibited an 8% improvement in their power conversion efficiency mainly due to the enlarged surface roughness of the PEDOT:PSS, which lead to an improvement in the charge collection and ultimately improvements in the short-circuit current density and fill factor.
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Protective effects of transduced Tat-DJ-1 protein against oxidative stress and ischemic brain injury.
Exp. Mol. Med.
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Reactive oxygen species (ROS) contribute to the development of a number of neuronal diseases including ischemia. DJ-1, also known to PARK7, plays an important role in transcriptional regulation, acting as molecular chaperone and antioxidant. In the present study, we investigated whether DJ-1 protein shows a protective effect against oxidative stress-induced neuronal cell death in vitro and in ischemic animal models in vivo. To explore DJ-1 proteins potential role in protecting against ischemic cell death, we constructed cell permeable Tat-DJ-1 fusion proteins. Tat-DJ-1 protein efficiently transduced into neuronal cells in a doseand time-dependent manner. Transduced Tat-DJ-1 protein increased cell survival against hydrogen peroxide (H2O2) toxicity and also reduced intracellular ROS. In addition, Tat-DJ-1 protein inhibited DNA fragmentation induced by H2O2. Furthermore, in animal models, immunohistochemical analysis revealed that Tat-DJ-1 protein prevented neuronal cell death induced by transient forebrain ischemia in the CA1 region of the hippocampus. These results demonstrate that transduced Tat-DJ-1 protein protects against cell death in vitro and in vivo, suggesting that the transduction of Tat-DJ-1 may be useful as a therapeutic agent for ischemic injuries related to oxidative stress.
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Polysplenia syndrome with congenital agenesis of dorsal pancreas presenting as acute pancreatitis and the role of endoscopic ultrasonography in its diagnosis.
Korean J Gastroenterol
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A 49-year-old female was admitted to our hospital for acute pancreatitis. The abdomen CT scan incidentally showed midline liver with hepatomegaly, centrally located gallbladder, pancreas truncation, right sided small bowel, left sided large bowel, interruption of the inferior vena cava with azygos continuation, preduodenal portal vein, and multiple spleens in the left upper quadrant. In MRCP, the head of pancreas was enlarged and short main pancreatic duct without accessory duct was showed. EUS revealed enlarged ventral pancreas with a main pancreatic duct of normal caliber, absence of the accessory pancreatic duct and the dorsal pancreas. She was diagnosed as polysplenia syndrome with agenesis of dorsal pancreas. It is a rare congenital anomaly frequently associated with various visceral anomalies including multiple spleens, impaired visceral lateralization, congenital heart diseases, gastrointestinal abnormalities and azygos continuation of the inferior vena cava. We report a case of polysplenia syndrome with agenesis of dorsal pancreas presenting acute pancreatitis.
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Quantitative and qualitative analysis of heart mitochondria for evaluating the degree of myocardial injury utilizing atomic force microscopy.
Micron
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Mitochondrial dysfunction plays a central role in mediating both the necrotic and apoptotic components of reperfusion injury. Because mitochondrial swelling is one of the most important indicators of the beginning of mitochondrial permeability transition, quantification of morphological changes in mitochondria would be useful in evaluating the degree of IR injury, as well as the protective effects of various therapies. In this study, we characterized the morphological changes in heart mitochondria caused by the duration and severity of ischemia utilizing particle shape analysis on atomic force microscopy (AFM) topographic images. We also simultaneously investigated the nano-mechanical changes in rat heart mitochondria by injury using force-distance curve measurements. Rats were randomly divided into 3 groups: control group (n=3), myocardial ischemia without reperfusion (PI group, n=3), and myocardial ischemia with reperfusion (IR group, n=4). Normal mitochondria appeared ellipsoidal with a mean area of 3551±1559 nm(2) and mean perimeter of 217.54±52.09 nm (n=60). The mean area and perimeter of mitochondria in the IR groups increased to 28,181±21,248 nm(2) and 595.74±234.29 nm (n=40, p<0.0001 vs. control group, respectively), maintaining oval in shape. But, in the PI group, all parameters showed significant differences compared to parameters of the control group (n=35, p<0.0001). In particular, the mean axial ratio and roundness were significantly different from those in the IR group. Mitochondria in the PI group looked more spherical than those of control and IR groups. Adhesion force is the force before the last event on the retraction half of force-distance curve measurements, corresponding to the point where the tip and the surface loose contact. The adhesion forces of heart mitochondria in the IR and PI groups significantly decreased to 19.56±1.08 nN (n=30, p<0.0001) and 18.65±3.18 nN (n=30, p<0.0001), compared to normal mitochondria which had an adhesion force of 27.64±0.88 nN (n=30). Adhesion force is governed by the attractive portion of the interacting forces between the surface atoms of the contacts. From the morphological and nano-mechanical changes in heart mitochondria, we suggested that the outer membranes of mitochondria were broken by myocardial ischemic injury before they became swollen, and the swelling might be correlated with the ischemic injury. We inferred that the breakage of membranes leads to uptake of water and matrix swelling. As a result, shape measurement parameters for the quantitative analysis of mitochondrial swelling could be very effective for evaluating the myocardial injury.
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Tat-Frataxin protects dopaminergic neuronal cells against MPTP-induced toxicity in a mouse model of Parkinsons disease.
Biochimie
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Parkinsons disease (PD) is caused by various factors such as reactive oxygen species (ROS), dysfunction of mitochondria, and aggregation of misfolded proteins, thereby leading to loss of dopaminergic (DA) neurons in the substantia nigra (SN) of the brain. Frataxin (FXN) is associated with iron homeostasis and biogenesis of iron-sulfur clusters in the electron transport chain complex. In this study, we investigated the potential of Tat-FXN to cross the blood-brain barrier (BBB) and protect DA neurons against oxidative stress in a mouse model of PD. Tat-FXN was effectively transduced into SH-SY5Y cells and blocked production of ROS and cleavage of DNA, significantly improving cell survival against 1-methyl-4-phenylpyridinium induced toxicity. In addition, Tat-FXN efficiently penetrated the BBB and exhibited a clear neuroprotective effect on tyrosine hydroxylase-specific DA neurons in the SN in a mice model of 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine-induced PD. Therefore, these results suggest that Tat-FXN may provide neuroprotective therapy for ROS related diseases including PD.
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PEP-1-metallothionein-III protein ameliorates the oxidative stress-induced neuronal cell death and brain ischemic insults.
Biochim. Biophys. Acta
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Oxidative stress is considered to be involved in a number of human diseases including ischemia. Metallothioneins (MT)-III can protect neuronal cells from the cytotoxicity of reactive oxygen species (ROS). However, MT-III proteins biological function is unclear in ischemia. Thus, we examined the protective effects of MT-III proteins on oxidative stress-induced neuronal cell death and brain ischemic insult.
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Transduced Tat-DJ-1 protein protects against oxidative stress-induced SH-SY5Y cell death and Parkinson disease in a mouse model.
Mol. Cells
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Parkinsons disease (PD) is a well known neurodegenerative disorder characterized by selective loss of dopaminergic neurons in the substantia nigra pars compact (SN). Although the exact mechanism remains unclear, oxidative stress plays a critical role in the pathogenesis of PD. DJ-1 is a multifunctional protein, a potent antioxidant and chaperone, the loss of function of which is linked to the autosomal recessive early onset of PD. Therefore, we investigated the protective effects of DJ-1 protein against SH-SY5Y cells and in a PD mouse model using a cell permeable Tat-DJ-1 protein. Tat-DJ-1 protein rapidly transduced into the cells and showed a protective effect on 6-hydroxydopamine (6-OHDA)-induced neuronal cell death by reducing the reactive oxygen species (ROS). In addition, we found that Tat-DJ-1 protein protects against dopaminergic neuronal cell death in 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP)-induced PD mouse models. These results suggest that Tat-DJ-1 protein provides a potential therapeutic strategy for against ROS related human diseases including PD.
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PEP-1-heat shock protein 27 protects from neuronal damage in cells and in a Parkinsons disease mouse model.
FEBS J.
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Heat shock proteins (HSPs) are a highly conserved family of proteins that are induced in response to various environmental stressors including reactive oxygen species. HSP27 is a chaperone protein with the ability to increase cell survival in response to oxidative stress. Parkinsons disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons. Although the mechanism of PD remains unclear, oxidative stress is known to be important in its pathogenesis. This study investigated the protective effects of PEP-1-HSP27 on neuronal damage induced by 1-methyl-4-phenyl pyridinium (MPP(+) ) in SH-SY5Y cells and in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model. PEP-1-HSP27 rapidly entered the cells and protected them against MPP(+) -induced toxicity by inhibiting the reactive oxygen species levels and DNA fragmentation. Furthermore, transduced PEP-1-HSP27 prevented dopaminergic neuronal cell death in the substantia nigra of MPTP-induced PD mouse models. These results demonstrate that PEP-1-HSP27 provides a potential strategy for therapeutic delivery against various diseases and is a potential tool for the treatment of PD.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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