JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Novel plasma biomarker surrogating cerebral amyloid deposition.
Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci.
PUBLISHED: 11-14-2014
Show Abstract
Hide Abstract
Alzheimer's disease (AD) is the most common and devastating dementia. Simple and practical biomarkers for AD are urgently required for accurate diagnosis and to facilitate the development of disease-modifying interventions. The subjects for the study were selected on the basis of PiB amyloid imaging by PET. Forty PiB-positive (PiB+) individuals, including cognitively healthy controls (HC), and mild cognitive impairment and AD individuals, and 22 PiB-negative (PiB-) HC participated. Employing our novel highly sensitive immunoprecipitation-mass spectrometry, we measured plasma amyloid ?-proteins (A?s; A?1-40 and A?1-42) and A?-approximate peptides (A?APs), which were cleaved from amyloid precursor protein (APP). Among the A?APs, APP669-711 appeared to be a good reference for deciphering pathological change of A?1-42. We evaluated the performance of the ratio of APP669-711 to A?1-42 (APP669-711/A?1-42) as a biomarker. APP669-711/A?1-42 significantly increased in the PiB+ groups. The sensitivity and specificity to discriminate PiB+ individuals from PiB- individuals were 0.925 and 0.955, respectively. Our plasma biomarker precisely surrogates cerebral amyloid deposition.
Related JoVE Video
Depletion of p62 reduces nuclear inclusions and paradoxically ameliorates disease phenotypes in Huntington's model mice.
Hum. Mol. Genet.
PUBLISHED: 10-09-2014
Show Abstract
Hide Abstract
Huntington's disease (HD) is a dominantly inherited genetic disease caused by mutant huntingtin (htt) protein with expanded polyglutamine (polyQ) tracts. A neuropathological hallmark of HD is the presence of neuronal inclusions of mutant htt. p62 is an important regulatory protein in selective autophagy, a process by which aggregated proteins are degraded, and it is associated with several neurodegenerative disorders including HD. Here, we investigated the effect of p62 depletion in three HD model mice: R6/2, HD190QG and HD120QG mice. We found that loss of p62 in these models led to longer life spans and reduced nuclear inclusions, although cytoplasmic inclusions increased with polyQ length. In mouse embryonic fibroblasts (MEFs) with or without p62, mutant htt with a nuclear localization signal (NLS) showed no difference in nuclear inclusion between the two MEF types. In the case of mutant htt without NLS, however, p62 depletion increased cytoplasmic inclusions. Furthermore, to examine the effect of impaired autophagy in HD model mice, we crossed R6/2 mice with Atg5 conditional knockout mice. These mice also showed decreased nuclear inclusions and increased cytoplasmic inclusions, similar to HD mice lacking p62. These data suggest that the genetic ablation of p62 in HD model mice enhances cytoplasmic inclusion formation by interrupting autophagic clearance of polyQ inclusions. This reduces polyQ nuclear influx and paradoxically ameliorates disease phenotypes by decreasing toxic nuclear inclusions.
Related JoVE Video
Regional white matter lesions predict falls in patients with amnestic mild cognitive impairment and Alzheimer's disease.
J Am Med Dir Assoc
PUBLISHED: 10-01-2014
Show Abstract
Hide Abstract
Preventive strategy for falls in demented elderly is a clinical challenge. From early-stage of Alzheimer's disease (AD), patients show impaired balance and gait. The purpose of this study is to determine whether regional white matter lesions (WMLs) can predict balance/gait disturbance and falls in elderly with amnestic mild cognitive impairment (aMCI) or AD.
Related JoVE Video
Live cell imaging of primary rat neonatal cardiomyocytes following adenoviral and lentiviral transduction using confocal spinning disk microscopy.
J Vis Exp
PUBLISHED: 07-08-2014
Show Abstract
Hide Abstract
Primary rat neonatal cardiomyocytes are useful in basic in vitro cardiovascular research because they can be easily isolated in large numbers in a single procedure. Due to advances in microscope technology it is relatively easy to capture live cell images for the purpose of investigating cellular events in real time with minimal concern regarding phototoxicity to the cells. This protocol describes how to take live cell timelapse images of primary rat neonatal cardiomyocytes using a confocal spinning disk microscope following lentiviral and adenoviral transduction to modulate properties of the cell. The application of two different types of viruses makes it easier to achieve an appropriate transduction rate and expression levels for two different genes. Well focused live cell images can be obtained using the microscope's autofocus system, which maintains stable focus for long time periods. Applying this method, the functions of exogenously engineered proteins expressed in cultured primary cells can be analyzed. Additionally, this system can be used to examine the functions of genes through the use of siRNAs as well as of chemical modulators.
Related JoVE Video
Three-dimensional X-ray micro-computed tomography analysis of polymerization shrinkage vectors in flowable composite.
Dent Mater J
PUBLISHED: 07-02-2014
Show Abstract
Hide Abstract
The polymerization shrinkage of flowable resin composites was evaluated using air bubbles as traceable markers. Three different surface treatments i.e. an adhesive silane coupling agent, a separating silane coupling agent, and a combination of both, were applied to standard cavities. Before and after polymerization, X-ray micro-computed tomography images were recorded. Their superimposition and comparison allowed position changes of the markers to be visualized as vectors. The movement of the markers in the resin composite was, therefore, quantitatively evaluated from the tomographic images. Adhesion was found to significantly influence shrinkage patterns. The method used here could be employed to visualize shrinkage vectors and shrinkage volume.
Related JoVE Video
[Preventive strategy for cognitive decline in elderly with diabetes mellitus].
Nippon Rinsho
PUBLISHED: 05-07-2014
Show Abstract
Hide Abstract
Diabetes increases the risk of cognitive decline including vascular dementia and Alzheimer's disease. Preventive strategy for cognitive impairment is thus needed in elderly with diabetes. To avoid brain injury in diabetic elderly patients, management of hypoglycemia, hyperglycemia, fluctuation of blood glucose, insulin resistance, and cerebral vessel disease is crucial. Recent clinical trials show hyperglycemia should be controlled with HbA1c of 7.2-7.4% for prevention of newly onset of dementia in the elderly. In contrast, little is known for target glucose levels in diabetic elderly combined with demented disease. Careful insight of hypoglycemia seems more important in the elderly. Now, a variety of pharmacological agents for treatment of diabetes is available and it seems clear that a comprehensive approach will be required in order to achieve healthy brain function.
Related JoVE Video
Two-dimensional microchemical observation of mast cell biogenic amine release as monitored by a 128 × 128 array-type charge-coupled device ion image sensor.
Anal. Chem.
PUBLISHED: 04-23-2014
Show Abstract
Hide Abstract
Available array-type, chemical-sensing image sensors generally only provide on/off responses to the sensed chemical and produce qualitative information. Therefore, there is a need for an array sensor design that can detect chemical concentration changes to produce quantitative, event-sensitive information. In this study, a 128 × 128 array-type image sensor was modified and applied to imaging of biogenic amines released from stimulated rat mast cells, providing recordable responses of the time course of their release and diffusion. The imaging tool was manufactured by an integrated circuit process, including complementary metal oxide semiconductor and charge-coupled device technology. It was fitted with an amine-sensitive membrane prepared from plasticized poly(vinyl chloride) including a hydrophobic anion, which allowed the sensor to detect amines, such as histamine and serotonin, in Tyrode's solution. As mast cells were larger in diameter than the pixel hollows, some pixels monitored amines released from single cells. The image from the array responses yielded sequential snapshots at a practical frame speed that followed amine concentration changes over time, after mast cell amine release was synchronized by chemical stimulation. This sensor was shown to be sensitive to amine release at very low stimulus concentrations and was able to detect localized spots of high amine release. The entire time course of the amine release was recorded, including maximum concentration at 4-6 s and signal disappearance at 30 s after stimulation. With further development, this sensor will increase opportunities to study a variety of biological systems, including neuronal chemical processes.
Related JoVE Video
Differential subtypes of diabetic older adults diagnosed with Alzheimer's disease.
Geriatr Gerontol Int
PUBLISHED: 03-22-2014
Show Abstract
Hide Abstract
The clinical management of diabetic elderly patients with Alzheimer's disease (AD) is hindered by several difficulties. The present study aimed to clarify the clinical characteristics and pathophysiological properties of AD in diabetic older adults.
Related JoVE Video
Effect of cerumen impaction on hearing and cognitive functions in Japanese older adults with cognitive impairment.
Geriatr Gerontol Int
PUBLISHED: 03-22-2014
Show Abstract
Hide Abstract
To assess the effect of cerumen impaction and its removal on hearing ability and cognitive function in elderly patients with memory disorders in Japan.
Related JoVE Video
Cell-to-cell propagation of intracellular signals fluorescently visualized with acridine orange in the gastric glands of guinea pigs.
Biochem. Biophys. Res. Commun.
PUBLISHED: 03-14-2014
Show Abstract
Hide Abstract
Secretion from the gastric gland involves the activation of various types of cells in a coordinated manner. In order to elucidate the mechanisms underlying the coordination of secretion, we studied live fluorescence images of guinea pig gastric glands stained with acridine orange (AO). On 2 ?M AO staining, individual cells were characterized by metachromatic colors and various intensities of fluorescence. When the gland was stimulated with 100 ?M of histamine, green fluorescence was transiently increased in parietal cells and intermediate cells and propagated along the gland for a long distance over many cells. Local stimulation in a couple of cells with histamine in the presence of suramin also induced propagation. However, the fluorescence response was suppressed by the addition of H-89, a protein kinase A inhibitor. These findings suggest that a cAMP-dependent signal propagates intercellularly through a variety of cells to induce coordinated secretion in the entire gastric gland.
Related JoVE Video
Mg(2+)- and ATP-dependent inhibition of transient receptor potential melastatin 7 by oxidative stress.
Free Radic. Biol. Med.
PUBLISHED: 02-06-2014
Show Abstract
Hide Abstract
Transient receptor potential melastatin 7 (TRPM7) is a Ca(2+)- and Mg(2+)-permeable nonselective cation channel that contains a unique carboxyl-terminal serine/threonine protein kinase domain. It has been reported that reactive oxygen species associated with hypoxia or ischemia activate TRPM7 current and then induce Ca(2+) overload resulting in neuronal cell death in the brain. In this study, we aimed to investigate the molecular mechanisms of TRPM7 regulation by hydrogen peroxide (H2O2) using murine TRPM7 expressed in HEK293 cells. Using the whole-cell patch-clamp technique, it was revealed that the TRPM7 current was inhibited, not activated, by the application of H2O2 to the extracellular solution. This inhibition was not reversed after washout or treatment with dithiothreitol, suggesting irreversible oxidation of TRPM7 or its regulatory factors by H2O2 under whole-cell recording. Application of an electrophile, N-methylmaleimide (NMM), which covalently modifies cysteine residues in proteins, also inhibited TRPM7 current irreversibly. The effects of H2O2 and NMM were dependent on free [Mg(2+)]i; the inhibition was stronger when cells were perfused with higher free [Mg(2+)]i solutions via pipette. In addition, TRPM7 current was not inhibited by H2O2 when millimolar ATP was included in the intracellular solution, even in the presence of substantial free [Mg(2+)]i, which is sufficient for TRPM7 inhibition by H2O2 in the absence of ATP. Moreover, a kinase-deficient mutant of TRPM7 (K1645R) was similarly inhibited by H2O2 just like the wild-type TRPM7 in a [Mg(2+)]i- and [ATP]i-dependent manner, indicating no involvement of the kinase activity of TRPM7. Thus, these data suggest that oxidative stress inhibits TRPM7 current under pathological conditions that accompany intracellular ATP depletion and free [Mg(2+)]i elevation.
Related JoVE Video
Association of grip strength and related indices with independence of activities of daily living in older adults, investigated by a newly-developed grip strength measuring device.
Geriatr Gerontol Int
PUBLISHED: 01-10-2014
Show Abstract
Hide Abstract
To investigate the association of grip strength and activities of daily living independence in older adults, using a newly-developed grip strength measuring device.
Related JoVE Video
Developing an interdisciplinary program of educational support for early-stage dementia patients and their family members: an investigation based on learning needs and attitude changes.
Geriatr Gerontol Int
PUBLISHED: 01-10-2014
Show Abstract
Hide Abstract
The National Center for Geriatrics and Gerontology has begun to provide educational support for family caregivers through interdisciplinary programs focusing on patients in the early stage of dementia. These interdisciplinary programs have established two domains for the purpose of "educational support": cure domains (medical care, medication) and care domains (nursing care, welfare). In the present study, we examined the learning needs and post-learning attitude changes of patients and their families who participated in these programs in order to assess the effectiveness of an interdisciplinary program of educational support in each of these domains.
Related JoVE Video
Left ventricular diastolic dysfunction is associated with cerebral white matter lesions (leukoaraiosis) in elderly patients without ischemic heart disease and stroke.
Geriatr Gerontol Int
PUBLISHED: 01-09-2014
Show Abstract
Hide Abstract
Cerebral white matter lesions (WML) are known to increase with age, as is left ventricular (LV) diastolic dysfunction with normal contraction. Although aging is a common risk factor, the link between these diseases is not fully understood. The aim was to clarify this relationship, using the ratio between early diastolic mitral inflow and early diastolic mitral annular tissue velocity (E/E'). E/E' measured by tissue Doppler echocardiography offers an indicator of the severity of LV diastolic dysfunction, reflecting both diastolic LV stiffness and diastolic LV filling pressure.
Related JoVE Video
Factors associated with increased caregivers' burden in several cognitive stages of Alzheimer's disease.
Geriatr Gerontol Int
PUBLISHED: 01-08-2014
Show Abstract
Hide Abstract
To investigate factors associated with caregiver burden (CB) in persons caring for older adults with various cognitive stages of Alzheimer's disease (AD).
Related JoVE Video
Assembly of the cochlear gap junction macromolecular complex requires connexin 26.
J. Clin. Invest.
PUBLISHED: 01-02-2014
Show Abstract
Hide Abstract
Hereditary deafness affects approximately 1 in 2,000 children. Mutations in the gene encoding the cochlear gap junction protein connexin 26 (CX26) cause prelingual, nonsyndromic deafness and are responsible for as many as 50% of hereditary deafness cases in certain populations. Connexin-associated deafness is thought to be the result of defective development of auditory sensory epithelium due to connexion dysfunction. Surprisingly, CX26 deficiency is not compensated for by the closely related connexin CX30, which is abundantly expressed in the same cochlear cells. Here, using two mouse models of CX26-associated deafness, we demonstrate that disruption of the CX26-dependent gap junction plaque (GJP) is the earliest observable change during embryonic development of mice with connexin-associated deafness. Loss of CX26 resulted in a drastic reduction in the GJP area and protein level and was associated with excessive endocytosis with increased expression of caveolin 1 and caveolin 2. Furthermore, expression of deafness-associated CX26 and CX30 in cell culture resulted in visible disruption of GJPs and loss of function. Our results demonstrate that deafness-associated mutations in CX26 induce the macromolecular degradation of large gap junction complexes accompanied by an increase in caveolar structures.
Related JoVE Video
Effects of candesartan on electrical remodeling in the hearts of inherited dilated cardiomyopathy model mice.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Inherited dilated cardiomyopathy (DCM) is characterized by dilatation and dysfunction of the ventricles, and often results in sudden death or heart failure (HF). Although angiotensin receptor blockers (ARBs) have been used for the treatment of HF, little is known about the effects on postulated electrical remodeling that occurs in inherited DCM. The aim of this study was to examine the effects of candesartan, one of the ARBs, on cardiac function and electrical remodeling in the hearts of inherited DCM model mice (TNNT2 ?K210). DCM mice were treated with candesartan in drinking water for 2 months from 1 month of age. Control, non-treated DCM mice showed an enlargement of the heart with prolongation of QRS and QT intervals, and died at t1/2 of 70 days. Candesartan dramatically extended the lifespan of DCM mice, suppressed cardiac dilatation, and improved the functional parameters of the myocardium. It also greatly suppressed prolongation of QRS and QT intervals and action potential duration (APD) in the left ventricular myocardium and occurrence of ventricular arrhythmia. Expression analysis revealed that down-regulation of Kv4.2 (Ito channel protein), KChIP2 (auxiliary subunit of Kv4.2), and Kv1.5 (IKur channel protein) in DCM was partially reversed by candesartan administration. Interestingly, non-treated DCM heart had both normal-sized myocytes with moderately decreased Ito and IKur and enlarged cells with greatly reduced K+ currents (Ito, IKur IK1 and Iss). Treatment with candesartan completely abrogated the emergence of the enlarged cells but did not reverse the Ito, and IKur in normal-sized cells in DCM hearts. Our results indicate that candesartan treatment suppresses structural remodeling to prevent severe electrical remodeling in inherited DCM.
Related JoVE Video
Inter-cellular exchange of cellular components via VE-cadherin-dependent trans-endocytosis.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Cell-cell communications typically involve receptor-mediated signaling initiated by soluble or cell-bound ligands. Here, we report a unique mode of endocytosis: proteins originating from cell-cell junctions and cytosolic cellular components from the neighboring cell are internalized, leading to direct exchange of cellular components between two adjacent endothelial cells. VE-cadherins form transcellular bridges between two endothelial cells that are the basis of adherence junctions. At such adherens junction sites, we observed the movement of the entire VE-cadherin molecule from one endothelial cell into the other with junctional and cytoplasmic components. This phenomenon, here termed trans-endocytosis, requires the establishment of a VE-cadherin homodimer in trans with internalization proceeding in a Rac1-, and actomyosin-dependent manner. Importantly, the trans-endocytosis is not dependent on any known endocytic pathway including clathrin-dependent endocytosis, macropinocytosis or phagocytosis. This novel form of cell-cell communications, leading to a direct exchange of cellular components, was observed in 2D and 3D-cultured endothelial cells as well as in the developing zebrafish vasculature.
Related JoVE Video
Evaluation of silicon nitride as a substrate for culture of PC12 cells: an interfacial model for functional studies in neurons.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Silicon nitride is a biocompatible material that is currently used as an interfacial surface between cells and large-scale integration devices incorporating ion-sensitive field-effect transistor technology. Here, we investigated whether a poly-L-lysine coated silicon nitride surface is suitable for the culture of PC12 cells, which are widely used as a model for neural differentiation, and we characterized their interaction based on cell behavior when seeded on the tested material. The coated surface was first examined in terms of wettability and topography using contact angle measurements and atomic force microscopy and then, conditioned silicon nitride surface was used as the substrate for the study of PC12 cell culture properties. We found that coating silicon nitride with poly-L-lysine increased surface hydrophilicity and that exposing this coated surface to an extracellular aqueous environment gradually decreased its roughness. When PC12 cells were cultured on a coated silicon nitride surface, adhesion and spreading were facilitated, and the cells showed enhanced morphological differentiation compared to those cultured on a plastic culture dish. A bromodeoxyuridine assay demonstrated that, on the coated silicon nitride surface, higher proportions of cells left the cell cycle, remained in a quiescent state and had longer survival times. Therefore, our study of the interaction of the silicon nitride surface with PC12 cells provides important information for the production of devices that need to have optimal cell culture-supporting properties in order to be used in the study of neuronal functions.
Related JoVE Video
Functional cooperation of metabotropic adenosine and glutamate receptors regulates postsynaptic plasticity in the cerebellum.
J. Neurosci.
PUBLISHED: 11-22-2013
Show Abstract
Hide Abstract
G-protein-coupled receptors (GPCRs) may form heteromeric complexes and cooperatively mediate cellular responses. Although heteromeric GPCR complexes are suggested to occur in many neurons, their contribution to neuronal function remains unclear. We address this question using two GPCRs expressed in cerebellar Purkinje cells: adenosine A1 receptor (A1R), which regulates neurotransmitter release and neuronal excitability in central neurons, and type-1 metabotropic glutamate receptor (mGluR1), which mediates cerebellar long-term depression, a form of synaptic plasticity crucial for cerebellar motor learning. We examined interaction between these GPCRs by immunocytochemical, biochemical, and Förster resonance energy transfer analyses in cultured mouse Purkinje cells and heterologous expression cells. These analyses revealed that the GPCRs closely colocalized and formed heteromeric complexes on the cell surfaces. Furthermore, our electrophysiological analysis showed that CSF levels (40-400 nm) of adenosine or synthetic A1R agonists with comparable potencies blocked mGluR1-mediated long-term depression of the postsynaptic glutamate-responsiveness (glu-LTD) of cultured Purkinje cells. A similar dose of the A1R agonist decreased the ligand affinity of mGluR1 and did not affect depolarization-induced Ca(2+) influx, which is an essential factor in inducing glu-LTD. The A1R agonist did not affect glu-LTD mimicked by direct activation of protein kinase C. These results suggest that A1R blocked glu-LTD by decreasing the ligand sensitivity of mGluR1, but not the coupling efficacy from mGluR1 to the intracellular signaling cascades. These findings provide a new insight into neuronal GPCR signaling and demonstrate a novel regulatory mechanism of synaptic plasticity.
Related JoVE Video
Axillary reverse mapping using fluorescence imaging is useful for identifying the risk group of postoperative lymphedema in breast cancer patients undergoing sentinel node biopsies.
J Surg Oncol
PUBLISHED: 09-22-2013
Show Abstract
Hide Abstract
Axillary reverse mapping (ARM) is a novel technique for preserving the upper extremity lymphatic pathways during axillary lymph node surgery. However, there is no evidence of the usefulness of ARM for patients undergoing sentinel lymph node biopsy (SNB).
Related JoVE Video
[Risks for impaired daily life function in the elderly with type 2 diabetes in Japan].
Nihon Ronen Igakkai Zasshi
PUBLISHED: 08-09-2013
Show Abstract
Hide Abstract
The purpose of the present investigation was to explore the process towards functional disability and predicting factors in Japanese diabetic elderly.
Related JoVE Video
Large-scale cell production of stem cells for clinical application using the automated cell processing machine.
BMC Biotechnol.
PUBLISHED: 05-07-2013
Show Abstract
Hide Abstract
Cell-based regeneration therapies have great potential for application in new areas in clinical medicine, although some obstacles still remain to be overcome for a wide range of clinical applications. One major impediment is the difficulty in large-scale production of cells of interest with reproducibility. Current protocols of cell therapy require a time-consuming and laborious manual process. To solve this problem, we focused on the robotics of an automated and high-throughput cell culture system. Automated robotic cultivation of stem or progenitor cells in clinical trials has not been reported till date. The system AutoCulture(R) used in this study can automatically replace the culture medium, centrifuge cells, split cells, and take photographs for morphological assessment. We examined the feasibility of this system in a clinical setting.
Related JoVE Video
Cardiomyocyte FGF signaling is required for Cx43 phosphorylation and cardiac gap junction maintenance.
Exp. Cell Res.
PUBLISHED: 04-16-2013
Show Abstract
Hide Abstract
Cardiac remodeling resulting from impairment of myocardial integrity leads to heart failure, through still incompletely understood mechanisms. The fibroblast growth factor (FGF) system has been implicated in tissue maintenance, but its role in the adult heart is not well defined. We hypothesized that the FGF system plays a role in the maintenance of cardiac homeostasis, and the impairment of cardiomyocyte FGF signaling leads to pathological cardiac remodeling. We showed that FGF signaling is required for connexin 43 (Cx43) localization at cell-cell contacts in isolated cardiomyocytes and COS7 cells. Lack of FGF signaling led to decreased Cx43 phosphorylation at serines 325/328/330 (S325/328/330), sites known to be important for assembly of gap junctions. Cx43 instability induced by FGF inhibition was restored by the Cx43 S325/328/330 phospho-mimetic mutant, suggesting FGF-dependent phosphorylation of these sites. Consistent with these in vitro findings, cardiomyocyte-specific inhibition of FGF signaling in adult mice demonstrated mislocalization of Cx43 at intercalated discs, whereas localization of N-cadherin and desmoplakin was not affected. This led to premature death resulting from impaired cardiac remodeling. We conclude that cardiomyocyte FGF signaling is essential for cardiomyocyte homeostasis through phosphorylation of Cx43 at S325/328/330 residues which are important for the maintenance of gap junction.
Related JoVE Video
Sperm-associated antigen 4, a novel hypoxia-inducible factor 1 target, regulates cytokinesis, and its expression correlates with the prognosis of renal cell carcinoma.
Am. J. Pathol.
PUBLISHED: 02-05-2013
Show Abstract
Hide Abstract
Hypoxia plays a crucial role in many pathophysiological conditions, including cancer biology, and hypoxia-inducible factor (HIF) regulates transcriptional responses under hypoxia. To elucidate the cellular responses to hypoxia, we performed chromatin immunoprecipitation with deep sequencing in combination with microarray analysis and identified HIF-1 targets. We focused on one of the novel targets, sperm-associated antigen 4 (SPAG4), whose function was unknown. SPAG4, an HIF-1-specific target, is up-regulated in various cultured cells under hypoxia. Examination of SPAG4 expression using a tissue microarray consisting of 190 human renal cell carcinoma (RCC) samples revealed that SPAG4 is an independent prognostic factor of cancer-specific mortality. Live-cell imaging revealed localization of SPAG4 at the intercellular bridge in telophase. We also studied cells in which SPAG4 was knocked down. Hypoxia enhances tetraploidy, which disturbs cell proliferation, and knockdown of SPAG4 increased tetraploid formation and decreased cell proliferation under both normoxic and hypoxic conditions. Studies using deletion mutants of SPAG4 also suggested the involvement of SPAG4 in cytokinesis. Microarray analysis confirmed dysregulation of cytokinesis-related genes by knockdown of SPAG4. In conclusion, SPAG4 is an independent prognostic factor in RCC and plays a crucial role in cytokinesis to defend against hypoxia-induced tetraploid formation. This defensive mechanism may promote survival of cancer cells under hypoxic conditions, thus leading to poor prognosis.
Related JoVE Video
Treatment of salivary gland hypofunction by transplantation with dental pulp cells.
Arch. Oral Biol.
PUBLISHED: 01-12-2013
Show Abstract
Hide Abstract
This study aimed to establish a mouse model in which dental pulp cells (DPCs) could be used as a cell source for the treatment of salivary gland hypofunction.
Related JoVE Video
Inositol 1,4,5-trisphosphate receptor regulates replication, differentiation, infectivity and virulence of the parasitic protist Trypanosoma cruzi.
Mol. Microbiol.
PUBLISHED: 01-09-2013
Show Abstract
Hide Abstract
In animals, inositol 1,4,5-trisphosphate receptors (IP3 Rs) are ion channels that play a pivotal role in many biological processes by mediating Ca(2+) release from the endoplasmic reticulum. Here, we report the identification and characterization of a novel IP3 R in the parasitic protist, Trypanosoma cruzi, the pathogen responsible for Chagas disease. DT40 cells lacking endogenous IP3 R genes expressing T.?cruzi IP3 R (TcIP3 R) exhibited IP3 -mediated Ca(2+) release from the ER, and demonstrated receptor binding to IP3 . TcIP3 R was expressed throughout the parasite life cycle but the expression level was much lower in bloodstream trypomastigotes than in intracellular amastigotes or epimastigotes. Disruption of two of the three TcIP3 R gene loci led to the death of the parasite, suggesting that IP3 R is essential for T.?cruzi. Parasites expressing reduced or increased levels of TcIP3 R displayed defects in growth, transformation and infectivity, indicating that TcIP3 R is an important regulator of the parasites life cycle. Furthermore, mice infected with T.?cruzi expressing reduced levels of TcIP3 R exhibited a reduction of disease symptoms, indicating that TcIP3 R is an important virulence factor. Combined with the fact that the primary structure of TcIP3 R has low similarity to that of mammalian IP3 Rs, TcIP3 R is a promising drug target for Chagas disease.
Related JoVE Video
Usefulness of running wheel for detection of congestive heart failure in dilated cardiomyopathy mouse model.
PLoS ONE
PUBLISHED: 01-02-2013
Show Abstract
Hide Abstract
Inherited dilated cardiomyopathy (DCM) is a progressive disease that often results in death from congestive heart failure (CHF) or sudden cardiac death (SCD). Mouse models with human DCM mutation are useful to investigate the developmental mechanisms of CHF and SCD, but knowledge of the severity of CHF in live mice is necessary. We aimed to diagnose CHF in live DCM model mice by measuring voluntary exercise using a running wheel and to determine causes of death in these mice.
Related JoVE Video
Predictive factors for hospitalized and institutionalized care-giving of the aged patients with diabetes mellitus in Japan.
Kobe J Med Sci
PUBLISHED: 09-23-2011
Show Abstract
Hide Abstract
To identify predictive factors for hospitalized and institutionalized care-giving among a group of aged patients with diabetes mellitus in Japan, retrospective chart review was performed in 288 diabetic subjects aged 65 years or older. Independent variables, based on the chart review, were age, sex, diagnosis, diabetic control and complications. Comprehensive geriatric assessment was performed to obtain information on the functional capacity and demographic variables, including physical and mental function, and socioeconomic status. 131 diabetic patients were considered as frail elderly and characterized for their higher age, longer duration of diabetes, higher frequency of insulin use, lower cognitive function, and lower QOL, in comparison with those of non-frail patients. All non-frail diabetic patients were independently treated at their homes, while 38 subjects out of 131 frail diabetic patients were hospitalized or institutionalized. Apparent clinical features of hospitalized/institutionalized patients were higher age, higher serum creatinine, and higher prevalence of stroke episodes, advanced cognitive decline and absence of key caregiver in the family members, in comparison with those of in-home frail diabetic patients. The predicted probabilities from the multivariate logistic regression analysis in predicting hospitalized and institutionalized care-giving were as follows: Log p/(1 - p) = -19.801x1 - 54.269x2 + 721.405; where x1 = cognitive function (score), x2 = social support (score). Receiver operating characteristic curve analysis revealed a satisfactory discrimination for hospitalized and institutionalized care-giving in frail diabetic elderly with 92.9% of sensitivity and 91.4% of specificity, when the cutoff point of the model was set at 0.992. We concluded that cognitive decline and low social support are the predictive for hospital and institutional care-giving, and that demographic and mental information as well as diagnostic data should be analyzed to predict the hospitalization/institutionalization among frail diabetic elderly.
Related JoVE Video
Role of amino-terminal half of the S4-S5 linker in type 1 ryanodine receptor (RyR1) channel gating.
J. Biol. Chem.
PUBLISHED: 08-23-2011
Show Abstract
Hide Abstract
The type 1 ryanodine receptor (RyR1) is a Ca(2+) release channel found in the sarcoplasmic reticulum of skeletal muscle and plays a pivotal role in excitation-contraction coupling. The RyR1 channel is activated by a conformational change of the dihydropyridine receptor upon depolarization of the transverse tubule, or by Ca(2+) itself, i.e. Ca(2+)-induced Ca(2+) release (CICR). The molecular events transmitting such signals to the ion gate of the channel are unknown. The S4-S5 linker, a cytosolic loop connecting the S4 and S5 transmembrane segments in six-transmembrane type channels, forms an ?-helical structure and mediates signal transmission in a wide variety of channels. To address the role of the S4-S5 linker in RyR1 channel gating, we performed alanine substitution scan of N-terminal half of the putative S4-S5 linker (Thr(4825)-Ser(4829)) that exhibits high helix probability. The mutant RyR1 was expressed in HEK cells, and CICR activity was investigated by caffeine-induced Ca(2+) release, single-channel current recordings, and [(3)H]ryanodine binding. Four mutants (T4825A, I4826A, S4828A, and S4829A) had reduced CICR activity without changing Ca(2+) sensitivity, whereas the L4827A mutant formed a constitutive active channel. T4825I, a disease-associated mutation for malignant hyperthermia, exhibited enhanced CICR activity. An ?-helical wheel representation of the N-terminal S4-S5 linker provides a rational explanation to the observed activities of the mutants. These results suggest that N-terminal half of the S4-S5 linker may form an ?-helical structure and play an important role in RyR1 channel gating.
Related JoVE Video
Fucoidan suppresses endocytosis in cultured HeLa cells.
Chin J Integr Med
PUBLISHED: 08-18-2011
Show Abstract
Hide Abstract
OBJECTIVE: To evaluate the effects of fucoidan on endocytosis in cultured HeLa cells: in vitro using live cell imaging. METHODS: A confocal scanning system and an incubation imaging system were used to: observe the effects of fucoidan on the initial (6 h) stages of endocytosis using the fl uorescent probe FM1-43 and inorganic fl uorescent quantum dot (Q-dots). RESULTS: According to the time-lapse images, fucoidan inhibited the: formation of endocytic vesicles in HeLa cells, in which the FM1-43 dye was entrapped. Fucoidan also had an inhibitory effect on the uptake of the Q-dots by the cell membranes of HeLa cells. CONCLUSION: It was concluded: that fucoidan suppresses Ca(2+)-dependent endocytosis in HeLa cells, which may be caused by its inhibitory -effects on agonist-induced Ca(2+) responses.
Related JoVE Video
Lidocaine attenuates the development of diabetic-induced tactile allodynia by inhibiting microglial activation.
Anesth. Analg.
PUBLISHED: 07-25-2011
Show Abstract
Hide Abstract
Lidocaine is used clinically for tactile allodynia associated with diabetes-induced neuropathy. Although the analgesic effect of lidocaine through suppression of microglial activation has been implicated in the development of injury-induced neuropathic pain, its mechanism of action in diabetes-induced tactile allodynia has not yet been completely elucidated.
Related JoVE Video
Laminin ?1 is essential for mouse cerebellar development.
Matrix Biol.
PUBLISHED: 06-19-2011
Show Abstract
Hide Abstract
Laminin ?1 (Lama1), which is a subunit of laminin-1 (laminin-111), a heterotrimeric ECM protein, is essential for embryonic development and promotes neurite outgrowth in culture. Because the deletion of Lama1 causes lethality at early embryonic stages in mice, the in vivo role of Lama1 in neural development and functions has not yet been possible to determine. In this study, we generated conditional Lama1 knockout (Lama1(CKO)) mice in the epiblast lineage using Sox2-Cre mice. These Lama1(CKO) mice survived, but displayed behavioral disorders and impaired formation of the cerebellum. Deficiency of Lama1 in the pial basement membrane of the meninges resulted in defects in the conformation of the meninges. During cerebellar development, Lama1 deficiency also caused a decrease in the proliferation and migration of granule cell precursors, disorganization of Bergmann glial fibers and endfeet, and a transient reduction in the activity of Akt. A marked reduction in numbers of dendritic processes in Purkinje cells was observed in Lama1(CKO) mice. Together, these results indicate that Lama1 is required for cerebellar development and functions.
Related JoVE Video
Practical method to derive nonlinear response functions of cameras for scientific imaging.
Appl Opt
PUBLISHED: 06-02-2011
Show Abstract
Hide Abstract
We developed a practical method to derive response functions that convert the amount of incident light to the counts of analog-to-digital conversion (A/D) of cameras for scientific imaging. In this method, we need a mechanism to accurately control the amount of incident light into cameras just within a limited dynamic range and at a limited number of steps. A variable brightness light source, which supplies the incident light into cameras, is also necessary, but we do not need to know its accurate brightness. Thus, this method enables us to derive the nonlinear response functions accurately with such a simple setup.
Related JoVE Video
Nitric oxide-induced calcium release via ryanodine receptors regulates neuronal function.
EMBO J.
PUBLISHED: 05-25-2011
Show Abstract
Hide Abstract
Mobilization of intracellular Ca(2+) stores regulates a multitude of cellular functions, but the role of intracellular Ca(2+) release via the ryanodine receptor (RyR) in the brain remains incompletely understood. We found that nitric oxide (NO) directly activates RyRs, which induce Ca(2+) release from intracellular stores of central neurons, and thereby promote prolonged Ca(2+) signalling in the brain. Reversible S-nitrosylation of type 1 RyR (RyR1) triggers this Ca(2+) release. NO-induced Ca(2+) release (NICR) is evoked by type 1 NO synthase-dependent NO production during neural firing, and is essential for cerebellar synaptic plasticity. NO production has also been implicated in pathological conditions including ischaemic brain injury, and our results suggest that NICR is involved in NO-induced neuronal cell death. These findings suggest that NICR via RyR1 plays a regulatory role in the physiological and pathophysiological functions of the brain.
Related JoVE Video
Effects of insulin and amyloid ?(1-42) oligomers on glucose incorporation and mitochondrial function in cultured rat hippocampal neurons.
Geriatr Gerontol Int
PUBLISHED: 05-18-2011
Show Abstract
Hide Abstract
The molecular basis for impaired glucose metabolism in patients with Alzheimers disease (AD) has not been fully clarified. We tested whether insulin and amyloid (A)?(1-42) oligomers would regulate glucose metabolism and energy homeostasis directly in cultured rat hippocampal neurons and evaluated possible interactions between insulin signaling and A?(1-42) oligomers.
Related JoVE Video
Usefulness of 18F-fluorodeoxyglucose positron emission tomography for diagnosis of asymptomatic giant cell arteritis in a patient with Alzheimers disease.
Geriatr Gerontol Int
PUBLISHED: 05-18-2011
Show Abstract
Hide Abstract
It is often difficult to diagnose disease in elderly patients, in particular those with dementia, who do not present with typical symptoms. This report describes our experience of an elderly patient (an 83-year-old woman) who presented with a chief complaint of memory loss, showed a marked inflammatory response, and was diagnosed with large-vessel giant cell arteritis (GCA) on the basis of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) findings. She had no symptoms typical of GCA including jaw claudication, visual field defect and heavy headed feeling. Corticosteroid therapy resulted in a trend toward improvement in the inflammatory response and then she first recognized that she might have experienced slight dull headache before treatment of GCA. This was probably because this patient had large-vessel GCA, which produces a few symptoms in the head and neck, and because she had Alzheimers disease and could not accurately describe her symptoms. Our experience suggests the usefulness of FDG-PET for the diagnosis of GCA, particularly in elderly patients without typical symptoms.
Related JoVE Video
The macrophage-mediated effects of the peroxisome proliferator-activated receptor-gamma agonist rosiglitazone attenuate tactile allodynia in the early phase of neuropathic pain development.
Anesth. Analg.
PUBLISHED: 04-13-2011
Show Abstract
Hide Abstract
Neuroinflammation triggered by macrophage infiltration into sites of peripheral nerve injury may result in neuropathic pain. Peroxisome proliferator-activated receptor (PPAR)? signaling regulates the properties of macrophages. However, the macrophage-mediated effects of PPAR? signaling on neuropathic pain triggered by peripheral inflammation have not been investigated.
Related JoVE Video
Hydrolyzed eggshell membrane immobilized on phosphorylcholine polymer supplies extracellular matrix environment for human dermal fibroblasts.
Cell Tissue Res.
PUBLISHED: 04-05-2011
Show Abstract
Hide Abstract
We have found that a water-soluble alkaline-digested form of eggshell membrane (ASESM) can provide an extracellular matrix (ECM) environment for human dermal fibroblast cells (HDF) in vitro. Avian eggshell membrane (ESM) has a fibrous-meshwork structure and has long been utilized as a Chinese medicine for recovery from burn injuries and wounds in Asian countries. Therefore, ESM is expected to provide an excellent natural material for biomedical use. However, such applications have been hampered by the insolubility of ESM proteins. We have used a recently developed artificial cell membrane biointerface, 2-methacryloyloxyethyl phosphorylcholine polymer (PMBN) to immobilize ASESM proteins. The surface shows a fibrous structure under the atomic force microscope, and adhesion of HDF to ASESM is ASESM-dose-dependent. Quantitative mRNA analysis has revealed that the expression of type III collagen, matrix metalloproteinase-2, and decorin mRNAs is more than two-fold higher when HDF come into contact with a lower dose ASESM proteins immobilized on PMBN surface. A particle-exclusion assay with fixed erythrocytes has visualized secreted water-binding molecules around the cells. Thus, HDF seems to possess an ECM environment on the newly designed PMBN-ASESM surface, and future applications of the ASESM-PMBN system for biomedical use should be of great interest.
Related JoVE Video
Causes of decreased activity of daily life in elderly patients who need daily living care.
Geriatr Gerontol Int
PUBLISHED: 01-28-2011
Show Abstract
Hide Abstract
The causes of decreased activity of daily life (ADL) in elderly patients include cerebrovascular diseases, bone fracture by falls, and dementia. The present study was conducted among elderly patients with decreased ADL who were hospitalized in nursing wards in order to investigate the causes of becoming early bedridden and to determine precautionary measures against decreased ADL.
Related JoVE Video
Basic helix-loop-helix transcription factor DEC1 negatively regulates cyclin D1.
J. Pathol.
PUBLISHED: 01-12-2011
Show Abstract
Hide Abstract
DEC1 (also known as Stra13/Bhlhb2/Sharp2) and DEC2 (also known as Bhlhb3/Sharp1) are two paralogous basic helix-loop-helix (bHLH) transcriptional regulators which exhibit a robust circadian gene expression pattern in the suprachiasmatic nucleus (SCN) and in peripheral organs. DEC1 has been suggested to play key roles in mammalian cell differentiation, the cell cycle and circadian regulation, hypoxia response, and carcinogenesis. Here we show that DEC1 overexpression exhibits delayed wound healing and reduces cell proliferation, migration, and invasion. DEC1 strongly repressed the promoter activity of cyclin D1. We further identify a possible DEC-response element in the cyclin D1 promoter region, and confirmed the direct binding of DEC1 to that element. Forced expression of DEC1 efficiently repressed the cyclin D1 promoter and expression. Our clinical data provide the first evidence that there is a strong inverse correlation between DEC1 and cyclin D1 expression in oral cancer, and DEC1 expression significantly correlated with clinicopathological parameters. We suggest that radiation-induced DEC1 overexpression and Akt phosphorylation in cancer cells are mediated via PI-3K signalling. Overexpression of DEC1 activates the PI-3K/Akt signalling pathway through reactive oxygen species (ROS).
Related JoVE Video
Decrease in the density of t-tubular L-type Ca2+ channel currents in failing ventricular myocytes.
Am. J. Physiol. Heart Circ. Physiol.
PUBLISHED: 12-30-2010
Show Abstract
Hide Abstract
In some forms of cardiac hypertrophy and failure, the gain of Ca(2+)-induced Ca(2+) release [CICR; i.e., the amount of Ca(2+) released from the sarcoplasmic reticulum normalized to Ca(2+) influx through L-type Ca(2+) channels (LTCCs)] decreases despite the normal whole cell LTCC current density, ryanodine receptor number, and sarcoplasmic reticulum Ca(2+) content. This decrease in CICR gain has been proposed to arise from a change in dyad architecture or derangement of the t-tubular (TT) structure. However, the activity of surface sarcolemmal LTCCs has been reported to increase despite the unaltered whole cell LTCC current density in failing human ventricular myocytes, indicating that the "decreased CICR gain" may reflect a decrease in the TT LTCC current density in heart failure. Thus, we analyzed LTCC currents of failing ventricular myocytes of mice chronically treated with isoproterenol (Iso). Although Iso-treated mice exhibited intact t-tubules and normal LTCC subunit expression, acute occlusion of t-tubules of isolated ventricular myocytes with osmotic shock (detubulation) revealed that the TT LTCC current density was halved in Iso-treated versus control myocytes. Pharmacological analysis indicated that kinases other than PKA or Ca(2+)/calmodulin-dependent protein kinase II insufficiently activated, whereas protein phosphatase 1/2A excessively suppressed, TT LTCCs in Iso-treated versus control myocytes. These results indicate that excessive ?-adrenergic stimulation causes the decrease in TT LTCC current density by altering the regulation of TT LTCCs by protein kinases and phosphatases in heart failure. This phenomenon might underlie the decreased CICR gain in heart failure.
Related JoVE Video
Tissue stiffness induced by prolonged immobilization of the rat knee joint and relevance of AGEs (pentosidine).
Connect. Tissue Res.
PUBLISHED: 07-06-2010
Show Abstract
Hide Abstract
Joints, connective tissues consisting of extracellular matrix (ECM) with few blood vessels, transfer tension to the skeleton in response to environmental demand. Therefore, joint immobilization decreases active and passive mechanical stress, resulting in increased joint stiffness and tissue degeneration; however, the cause of joint stiffness is obscure. Using a rat knee immobilization model, we examined the relationship between range of motion (ROM) and cell numbers and ECM cross-links by accumulation of advanced glycation end products, pentosidine, in the posterior joint capsule of immobilized joints during 16 weeks of immobilization. The left knee joint was immobilized by internal fixation and compared with the non-immobilized right leg. As early as 2 weeks of immobilization, joint ROM and torque significantly decreased and in parallel, disordered alignment of collagen fiber bundles significantly increased, compared with non-immobilized joints. Those changes continued until 16 weeks of immobilization. Significant increases in pentosidine-positive areas after 8 weeks and significantly decreased cell numbers after 16 weeks of immobilization were also observed compared to the contralateral side. A significant negative correlation between tissue stiffness measured by restriction of ROM and accumulation of pentosidine was observed. This study is the first to show that immobilization of knee joints induces articular contracture associated with sequential changes of ECM alignment, influencing ROM and later pentosidine accumulation and decreased cell numbers during the 16-week immobilization period. Pentosidine appears to be an indicator toward a chronic tissue stiffness leading to decreased cell number rather than a cause of ROM restriction induced by joint immobilization.
Related JoVE Video
Intravital oxygen radical imaging in normal and ischemic rat cortex.
Neurosurgery
PUBLISHED: 06-19-2010
Show Abstract
Hide Abstract
We examined reactive oxygen species (ROS) generation on cerebral ischemia/reperfusion by intravital fluorescence imaging.
Related JoVE Video
Amyloid-? neurotoxicity restricts glucose window for neuronal survival in rat hippocampal slice cultures.
Exp. Gerontol.
PUBLISHED: 05-20-2010
Show Abstract
Hide Abstract
Diabetes may increase the risk of Alzheimers disease (AD). However, a preventive strategy to combat cognitive decline in diabetic elderly with preexisting AD has remained unknown. The aim of this study was to determine the effects of metabolic perturbation on amyloid-? (A?) neurotoxicity and the optimal glucose range for improved neuronal survival, which is referred to as the "glucose window". Organotypic hippocampal slice cultures were incubated in either normoglycemic or hyperglycemic medium for 48 h, and subsequently treated in experimental media containing 0-30 mM glucose, with and without A?(25-35). Neuronal survival was evaluated by the propidium iodide method. A? neurotoxicity was exacerbated during hypoglycemia/hyperglycemia (?2 mM/?30 mM) without A? and ?3 mM/?20 mM with A?. ROS elevated in the respective glucose ranges and supplementation of ROS scavengers effectively improved neuronal survival. Interestingly, a sharp and sudden drop in glucose levels from preceding hyperglycemia further increased A? neurotoxicity. Supplementation of pyruvate protected exacerbated A? neurotoxicity. These results indicate that increased oxidative stress during severe hypoglycemia, hyperglycemia and fluctuation of blood glucose enhances neuronal cell death, resulting in the extremely limited glucose window, and therefore suggest that careful management of glucose avoiding hypoglycemia is needed to prevent brain degeneration in diabetic patients with AD.
Related JoVE Video
Association of higher carbohydrate intake with depressive mood in elderly diabetic women.
Nutr Neurosci
PUBLISHED: 11-21-2009
Show Abstract
Hide Abstract
The rates of co-morbid depression with elderly diabetes are reportedly high. Although the intake of several nutrients has been suggested to be associated with depressive symptoms, the chronic effects of carbohydrate intake on mood remain unclear. In the current study, the association of the carbohydrate energy/total energy (C/E ratio) and other factors with depressive mood in the diabetic elderly were investigated.
Related JoVE Video
Protective effect of lecithinized SOD on reactive oxygen species-induced xerostomia.
Radiat. Res.
PUBLISHED: 08-28-2009
Show Abstract
Hide Abstract
Reactive oxygen species (ROS) are believed to be involved in radiation-induced xerostomia, and the application of antioxidants may be a promising method for treating patients suffering from salivary gland dysfunction. In this study, we examined the ability of the antioxidant superoxide dismutase (SOD) to restore radiation-induced salivary gland dysfunction using a mouse model of radiation-induced salivary gland hypofunction and ultraviolet B (UVB)-irradiated human salivary gland cells. We administered lecithinized SOD (PC-SOD) prior to and after irradiation and measured the amount of saliva secreted. To confirm ROS generation, flow cytometry was performed using an oxidant-sensitive fluorescent dye, dihydroethidium, and CM-H(2)DCFDA. While no significant decrease in saliva secretion was observed after irradiation in the mice that were treated with PC-SOD, a significant reduction in saliva secretion was noted in the irradiated mice that were not treated with PC-SOD. Furthermore, flow cytometry clearly revealed that PC-SOD eliminated superoxide (O(2)(-)) induced by UVB radiation. These results suggested that PC-SOD may protect against exocrine gland dysfunction induced by radiation, presumably by rapidly converting O(2)(-) to hydrogen peroxide. We believe that our results may advance the potential application of antioxidants for the prevention of ROS-induced xerostomia.
Related JoVE Video
Dilation of perforating arteries in rat brain in response to systemic hypotension is more sensitive and pronounced than that of pial arterioles: simultaneous visualization of perforating and cortical vessels by in-vivo microangiography.
Microvasc. Res.
PUBLISHED: 07-14-2009
Show Abstract
Hide Abstract
Autoregulatory responses of perforating arteries play a key role in the maintenance of microcirculation of the deep brain regions. The aim of this study was to test our hypothesis that autoregulatory vasodilatation of perforating arteries is more effective than that of cortical arteries. We performed cerebral microangiography in adult Wistar rats using monochromatic synchrotron radiation at SPring-8 and for the first time radiographically visualized perforating arteries and cortical arteries simultaneously in a single view. In response to hypotension induced by arterial bleeding, both arteries showed significant vasodilatation. Steady-state responses of increments in caliber to stepwise hypotension revealed that perforating arteries exhibited significant vasodilatation at blood pressure below 80-99 mm Hg. Cortical arteries, on the other hand, showed a gradual and smaller vasodilatation beginning at 60-79 mm Hg. For the lowest blood pressure range at 40-59 mm Hg, the smallest arteries with a diameter of 20-40 microm showed maximal dilation in both groups, but perforating arteries showed significantly larger dilatation (185.0% of baseline diameter) than cortical arteries (152.7%; P=0.003). Our results indicate that vasodilatation of perforating arteries is more sensitive and pronounced in response to systemic hypotension than that of pial arteries, which explains how cerebral microcirculation is maintained efficiently in the deep brain regions.
Related JoVE Video
The temporomandibular joint in a rheumatoid arthritis patient after orthodontic treatment.
Angle Orthod
PUBLISHED: 06-23-2009
Show Abstract
Hide Abstract
A 32-year-old Japanese female patient consulted the authors dental clinic with a 4.5-year history of rheumatoid arthritis (RA). She complained of pain during mouth opening and difficulty in eating due to masticatory dysfunction caused by an anterior open bite. Imaging showed severe erosion and flattening of both condyles. RA stabilized after pharmacological therapy and became inactive during the orthodontic therapy aimed at reconstructing an optimal occlusion capable of promoting functional repositioning of the mandible. At present, 4 years and 2 months postretention, the reconstructed occlusion remains stable, and both condyles continue to be remodeled. The distance from reference position to intercuspal position has gradually decreased throughout the 4-year posttreatment and postretention periods. Orthodontic therapy that comprehensively reconstructs occlusion and enhances the functioning of the mandible can induce remodeling of eroded condyles, even those with a history of rheumatoid arthritis.
Related JoVE Video
Hypothalamic orexin stimulates feeding-associated glucose utilization in skeletal muscle via sympathetic nervous system.
Cell Metab.
PUBLISHED: 05-12-2009
Show Abstract
Hide Abstract
Hypothalamic neurons containing orexin (hypocretin) are activated during motivated behaviors and active waking. We show that injection of orexin-A into the ventromedial hypothalamus (VMH) of mice or rats increased glucose uptake and promoted insulin-induced glucose uptake and glycogen synthesis in skeletal muscle, but not in white adipose tissue, by activating the sympathetic nervous system. These effects of orexin were blunted in mice lacking beta-adrenergic receptors but were restored by forced expression of the beta(2)-adrenergic receptor in both myocytes and nonmyocyte cells of skeletal muscle. Orexin neurons are activated by conditioned sweet tasting and directly excite VMH neurons, thereby increasing muscle glucose metabolism and its insulin sensitivity. Orexin and its receptor in VMH thus play a key role in the regulation of muscle glucose metabolism associated with highly motivated behavior by activating muscle sympathetic nerves and beta(2)-adrenergic signaling.
Related JoVE Video
Quantitative evaluation of bone resorption activity of osteoclast-like cells by measuring calcium phosphate resorbing area using incubator-facilitated and video-enhanced microscopy.
Microsc. Res. Tech.
PUBLISHED: 05-06-2009
Show Abstract
Hide Abstract
Quantitative evaluation of the ability of bone resorption activity in live osteoclast-like cells (OCLs) has not yet been reported on. In this study, we observed the sequential morphological change of OCLs and measured the resorbing calcium phosphate (CP) area made by OCLs alone and with the addition of elcatonin utilizing incubator facilitated video-enhanced microscopy. OCLs, which were obtained from a coculture of ddy-mouse osteoblastic cells and bone marrow cells, were cultured on CP-coated quartz cover slips. The CP-free area increased constantly in the OCLs alone, whereas it did not increase after the addition of elcatonin. This study showed that analysis of the resorbed areas under the OCL body using this method enables the sequential quantitative evaluation of the bone resorption activity and the effect of several therapeutic agents on bone resorption in vitro.
Related JoVE Video
Pattern of rise in subplasma membrane Ca2+ concentration determines type of fusing insulin granules in pancreatic beta cells.
Biochem. Biophys. Res. Commun.
PUBLISHED: 04-24-2009
Show Abstract
Hide Abstract
We simultaneously analyzed insulin granule fusion with insulin fused to green fluorescent protein and the subplasma membrane Ca2+ concentration ([Ca2+](PM)) with the Ca2+ indicator Fura Red in rat beta cells by dual-color total internal reflection fluorescence microscopy. We found that rapid and marked elevation in [Ca2+](PM) caused insulin granule fusion mostly from previously docked granules during the high KCl-evoked release and high glucose-evoked first phase release. In contrast, the slow and sustained elevation in [Ca2+](PM) induced fusion from newcomers translocated from the internal pool during the low KCl-evoked release and glucose-evoked second phase release. These data suggest that the pattern of the [Ca2+](PM) rise directly determines the types of fusing granules.
Related JoVE Video
Mutant SOD1 impairs axonal transport of choline acetyltransferase and acetylcholine release by sequestering KAP3.
Hum. Mol. Genet.
PUBLISHED: 04-07-2009
Show Abstract
Hide Abstract
Mutations in the superoxide dismutase 1 (sod1) gene cause familial amyotrophic lateral sclerosis (FALS), likely due to the toxic properties of misfolded mutant SOD1 protein. Here we demonstrated that, starting from the pre-onset stage of FALS, misfolded SOD1 species associates specifically with kinesin-associated protein 3 (KAP3) in the ventral white matter of SOD1(G93A)-transgenic mouse spinal cord. KAP3 is a kinesin-2 subunit responsible for binding to cargos including choline acetyltransferase (ChAT). Motor axons in SOD1(G93A)-Tg mice also showed a reduction in ChAT transport from the pre-onset stage. By employing a novel FALS modeling system using NG108-15 cells, we showed that microtubule-dependent release of acetylcholine was significantly impaired by misfolded SOD1 species. Furthermore, such impairment was able to be normalized by KAP3 overexpression. KAP3 was incorporated into SOD1 aggregates in human FALS cases as well. These results suggest that KAP3 sequestration by misfolded SOD1 species and the resultant inhibition of ChAT transport play a role in the dysfunction of ALS.
Related JoVE Video
Age-associated increase in abdominal obesity and insulin resistance, and usefulness of AHA/NHLBI definition of metabolic syndrome for predicting cardiovascular disease in Japanese elderly with type 2 diabetes mellitus.
Gerontology
PUBLISHED: 03-31-2009
Show Abstract
Hide Abstract
Management of metabolic syndrome (MetS) seems to constitute an efficient strategy to attain successful ageing. Although the clinical entity of MetS in patients with diabetes mellitus has been discussed, there is very little information on MetS-type cardiometabolic risk factor clustering in diabetic elderly.
Related JoVE Video
Significant roles of microtubules in mature striated muscle deduced from the correlation between tubulin and its molecular chaperone alphaB-crystallin in rat muscles.
J Physiol Sci
PUBLISHED: 03-24-2009
Show Abstract
Hide Abstract
To elucidate the significance of cytoskeletal microtubule networks in striated muscles, we analyzed correlation between the content of tubulin (building block of microtubules) and alphaB-crystallin (a molecular chaperone for tubulin) in a variety of striated muscles expressing different myosin heavy-chain (MHC) isoforms. The content of both tubulin and alphaB-crystallin was larger in MHC-I dominant soleus muscle and in MHC-alpha dominant cardiac (atrium and ventricle) muscles; intermediate in MHC-IId dominant masseter, tongue, and diaphragm muscles; and smaller in MHC-IIb dominant plantaris, gastrocnemius, psoas, extensor digitorum longus, and tibialis anterior muscles. Since the muscles of slow-type MHC (MHC-I/alpha) show the most economical features in their function and metabolism, which suit for continuous activity required to sustain posture and blood pumping, the present results afforded additional support to our hypothesis that microtubule networks transduce mechanical environmental demands to morphological and biochemical responses that eventually evolve adaptive transformation in the function and metabolism of the mature muscles. The comparison of tubulin/alphaB-crystalline ratios across the muscles of varied MHC isoforms further suggested that mechanical stress fluctuating at the rhythmic frequency of walking and breathing efficiently activates the hypothesized dynamic function of microtubules.
Related JoVE Video
Label-free characterization of living human induced pluripotent stem cells by subcellular topographic imaging technique using full-field quantitative phase microscopy coupled with interference reflection microscopy.
Biomed Opt Express
Show Abstract
Hide Abstract
There is a need for a noninvasive technique to monitor living pluripotent stem cell condition without any labeling. We present an optical imaging technique that is able to capture information about optical path difference through the cell and cell adhesion properties simultaneously using a combination of quantitative phase microscopy (QPM) and interference reflection microscopy (IRM) techniques. As a novel application of QPM and IRM, this multimodal imaging technique demonstrated its ability to distinguish the undifferentiated status of human induced pluripotent stem (hiPS) cells quantitatively based on the variation of optical path difference between the nucleus and cytoplasm as well as hiPS cell-specific cell adhesion properties.
Related JoVE Video
Role of fibroblast growth factor signaling in vascular formation and maintenance: orchestrating signaling networks as an integrated system.
Wiley Interdiscip Rev Syst Biol Med
Show Abstract
Hide Abstract
The vascular system has begun to be perceived as a dynamic organ actively controlling a wide variety of physiological processes. The structural and functional integrity of blood vessels, regulated by signaling activities finely modulating cell-cell and cell-matrix interactions, is crucial for vessel physiology, as well as basic functionality of the tissue. Throughout the process of new vessel formation, while blood vessels are actively reorganized and remodeled with migration and proliferation of vascular cells, maintenance of vascular barrier function is essentially important. These conflicting properties, i.e., dynamic cellular mobilization and maintenance of barrier integrity, are simultaneously achieved through the interaction of highly organized signaling networks governing coordinated cell-cell interplay. Recent evidence suggests that the fibroblast growth factor (FGF) system plays a regulatory role in several physiological conditions in the vascular system. In this article, we will attempt to summarize current knowledge in order to understand the mechanism of this coordination and evaluate the pivotal role of FGF signaling in integrating a diverse range of signaling events in vascular growth and maintenance.
Related JoVE Video
Transplantation of side population cells restores the function of damaged exocrine glands through clusterin.
Stem Cells
Show Abstract
Hide Abstract
Stem cell-based therapy has been proposed as a promising strategy for regenerating tissues lost through incurable diseases. Side population (SP) cells have been identified as putative stem cells in various organs. To examine therapeutic potential of SP cells in hypofunction of exocrine glands, SP cells isolated from mouse exocrine glands, namely, lacrimal and salivary glands, were transplanted into mice with irradiation-induced hypofunction of the respective glands. The secretions from both glands in the recipient mice were restored within 2 months of transplantation, although the transplanted cells were only sparsely distributed and produced no outgrowths. Consistent with this, most SP cells were shown to be CD31-positive endothelial-like cells. In addition, we clarified that endothelial cell-derived clusterin, a secretory protein, was an essential factor for SP cell-mediated recovery of the hypofunctioning glands because SP cells isolated from salivary glands of clusterin-deficient mice had no therapeutic potential, whereas lentiviral transduction of clusterin restored the hypofunction. In vitro and in vivo studies showed that clusterin had an ability to directly inhibit oxidative stress and oxidative stress-induced cell damage. Thus, endothelial cell-derived clusterin possibly inhibit oxidative stress-induced hypofunction of these glands.
Related JoVE Video
Factors associated with progression of diabetic nephropathy in Japanese elderly patients with type 2 diabetes: sub-analysis of the Japanese Elderly Diabetes Intervention Trial.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
Diabetic nephropathy is a serious complication in patients with type 2 diabetes. The aim of this study was to explore the factors associated with the progression of this complication in elderly patients with type 2 diabetes.
Related JoVE Video
Risk factors for a 6-year decline in physical disability and functional limitations among elderly people with type 2 diabetes in the Japanese Elderly Diabetes Intervention Trial.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
Type 2 diabetes increases the risk of disability. The purpose of this study was to clarify the explanatory factors for disability in Japanese diabetic elderly.
Related JoVE Video
Risk factors associated with cognitive decline in the elderly with type 2 diabetes: pooled logistic analysis of a 6-year observation in the Japanese Elderly Diabetes Intervention Trial.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
Considerable attention has been paid to the association between type 2 diabetes mellitus (T2DM) and cognitive dysfunction in the elderly. T2DM is often comorbid with several other metabolic disturbances, including hypertension and dyslipidemia. These comorbid diseases might be associated with cognitive impairment. Many clinical indices should be included as variables for the association with cognitive decline. In the current study, we tried to identify the associated factors with cognitive decline during a 6-year period in elderly T2DM considering the changes in the clinical indices during the follow-up period.
Related JoVE Video
Risk factors associated with cognitive decline in the elderly with type 2 diabetes: baseline data analysis of the Japanese Elderly Diabetes Intervention Trial.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
Recent evidence has shown that type 2 diabetes mellitus (T2DM) in the elderly is a risk factor for cognitive dysfunction or dementia. However, the precise mechanisms have not yet been elucidated. In the current study, we attempted to elucidate the association of clinical indices and diabetic complications at baseline with cognitive declines after 6-year follow up in type 2 diabetic elderly.
Related JoVE Video
Effective prevention of cardiovascular disease and diabetes-related events with atorvastatin in Japanese elderly patients with type 2 diabetes mellitus: adjusting for treatment changes using a marginal structural proportional hazards model and a rank-pres
Geriatr Gerontol Int
Show Abstract
Hide Abstract
To assess the preventive effect of atorvastatin on cardiovascular disease and on diabetes-related events in elderly type 2 diabetic patients enrolled in the Japanese Elderly Diabetes Intervention Trial (J-EDIT).
Related JoVE Video
Lower physical activity is a strong predictor of cardiovascular events in elderly patients with type 2 diabetes mellitus beyond traditional risk factors: the Japanese Elderly Diabetes Intervention Trial.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
It is well known that a decline in physical activity is associated with lifestyle-related diseases including cardiovascular (CV) events. However, little is known about the association between physical activity and CV events in elderly patients, because recent accumulating reports have mainly dealt with middle-aged populations. In this study, we investigated the correlation between physical activity and CV events in Japanese elderly patients with type 2 diabetes mellitus (T2DM).
Related JoVE Video
Lower physical activity, but not excessive calorie intake, is associated with metabolic syndrome in elderly with type 2 diabetes mellitus: the Japanese Elderly Diabetes Intervention Trial.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
A decline in physical activity has been shown to be associated with metabolic syndrome (MetS), leading to cardiovascular events. However, this is difficult to manage well in the elderly with multiple atherosclerotic risk factors. In this study, we investigated the correlation between physical activity and clinical parameters in the presence and absence of MetS in Japanese elderly subjects with type 2 diabetes mellitus (T2DM). In addition, we determined which factor, calorie intake or physical activity, mainly contributes to the prevalence of MetS.
Related JoVE Video
Dietary pattern and mortality in Japanese elderly patients with type 2 diabetes mellitus: does a vegetable- and fish-rich diet improve mortality? An explanatory study.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
To assess the effect of dietary patterns on all deaths and diabetes-related deaths in the Japanese Elderly Diabetes Intervention Trial (J-EDIT).
Related JoVE Video
Effects of total and green vegetable intakes on glycated hemoglobin A1c and triglycerides in elderly patients with type 2 diabetes mellitus: the Japanese Elderly Intervention Trial.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
Many reports have shown that vegetable intake is effective in inhibiting the onset and progression of diabetes mellitus, although the amount of vegetable intake required to be effective remains as unclear. The present study therefore aimed to clarify the relationship between the amount of vegetable intake and glycated hemoglobin A1c (HbA1c) and other metabolic parameters using male Japanese type 2 diabetic patients aged 65 years or older as subjects.
Related JoVE Video
Optimal energy distribution of carbohydrate intake for Japanese elderly patients with type 2 diabetes: the Japanese Elderly Intervention Trial.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
In diet therapy for diabetes, optimal energy intake and the energy distribution of macronutrients (protein : fat : carbohydrate [PFC] energy ratio) are important. We aimed to clarify the correlation between the PFC energy ratio and metabolic parameters including glycated hemoglobin A1c (HbA1c) and triglycerides in Japanese elderly patients with type 2 diabetes mellitus aged 65 years or older.
Related JoVE Video
Relations of nutritional intake to age, sex and body mass index in Japanese elderly patients with type 2 diabetes: the Japanese Elderly Diabetes Intervention Trial.
Geriatr Gerontol Int
Show Abstract
Hide Abstract
To determine the status of nutritional intake in elderly Japanese patients with type 2 diabetes aged 65 years or older, and to clarify relations of nutritional intake to age, sex and body mass index (BMI).
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.