Prolongation of Corneal Xenotransplant Survival by T-cell Vaccination-induced T-regulatory Cells

Xenotransplantation. May-Jun, 2008  |  Pubmed ID: 18611224

Corneal xenotransplantation is an alternative approach for overcoming shortage of allograft in clinics. However, the mechanism of acute corneal xenograft rejection and the method of prolonging xenograft survival have not been well defined.

Cellular Calcium Deficiency Plays a Role in Neuronal Death Caused by Proteasome Inhibitors

Journal of Neurochemistry. Jun, 2009  |  Pubmed ID: 19476541

Cytosolic Ca(2+) concentration ([Ca(2+)](i)) is reduced in cultured neurons undergoing neuronal death caused by inhibitors of the ubiquitin proteasome system. Activation of calcium entry via voltage-gated Ca(2+) channels restores cytosolic Ca(2+) levels and reduces this neuronal death (Snider et al. 2002). We now show that this reduction in [Ca(2+)](i) is transient and occurs early in the cell death process, before activation of caspase 3. Agents that increase Ca(2+) influx such as activation of voltage-gated Ca(2+) channels or stimulation of Ca(2+) entry via the plasma membrane Na-Ca exchanger attenuate neuronal death only if applied early in the cell death process. Cultures treated with proteasome inhibitors had reduced current density for voltage-gated Ca(2+) channels and a less robust increase in [Ca(2+)](i) after depolarization. Levels of endoplasmic reticulum Ca(2+) were reduced and capacitative Ca(2+) entry was impaired early in the cell death process. Mitochondrial Ca(2+) was slightly increased. Preventing the transfer of Ca(2+) from mitochondria to cytosol increased neuronal vulnerability to this death while blockade of mitochondrial Ca(2+) uptake via the uniporter had no effect. Programmed cell death induced by proteasome inhibition may be caused in part by an early reduction in cytosolic and endoplasmic reticulum Ca(2+,) possibly mediated by dysfunction of voltage-gated Ca(2+) channels. These findings may have implications for the treatment of disorders associated with protein misfolding in which proteasome impairment and programmed cell death may occur.

MicroRNA-145, a Novel Smooth Muscle Cell Phenotypic Marker and Modulator, Controls Vascular Neointimal Lesion Formation

Circulation Research. Jul, 2009  |  Pubmed ID: 19542014

Phenotypic modulation of vascular smooth muscle cells (VSMCs) plays a critical role in the pathogenesis of a variety of proliferative vascular diseases. Recently, we have found that microRNA (miRNA) miR-145 is the most abundant miRNA in normal vascular walls and in freshly isolated VSMCs; however, the role of miR-145 in VSMC phenotypic modulation and vascular diseases is currently unknown. Here we find that miR-145 is selectively expressed in VSMCs of the vascular wall and its expression is significantly downregulated in the vascular walls with neointimal lesion formation and in cultured dedifferentiated VSMCs. More importantly, both in cultured rat VSMCs in vitro and in balloon-injured rat carotid arteries in vivo, we demonstrate that the noncoding RNA miR-145 is a novel phenotypic marker and a novel phenotypic modulator of VSMCs. VSMC differentiation marker genes such as SM alpha-actin, calponin, and SM-MHC are upregulated by premiR-145 or adenovirus expressing miR-145 (Ad-miR-145) but are downregulated by the miR-145 inhibitor 2'OMe-miR-145. We have further identified that miR-145-mediated phenotypic modulation of VSMCs is through its target gene KLF5 and its downstream signaling molecule, myocardin. Finally, restoration of miR-145 in balloon-injured arteries via Ad-miR-145 inhibits neointimal growth. We conclude that miR-145 is a novel VSMC phenotypic marker and modulator that is able of controlling vascular neointimal lesion formation. These novel findings may have extensive implications for the diagnosis and therapy of a variety of proliferative vascular diseases.

Proteome Analysis of a Single Zebrafish Embryo Using Three Different Digestion Strategies Coupled with Liquid Chromatography-tandem Mass Spectrometry

Analytical Biochemistry. Nov, 2009  |  Pubmed ID: 19643073

Zebrafish is a powerful model to analyze vertebrate embryogenesis and organ development. Although a number of genes have been identified to specify embryonic development processes, only a few large-scale proteomic analyses have been reported in regard to these events to date. Here the total proteins of a single embryo were analyzed by urea-, sodium deoxycholate (SDC)-, and performic acid (PA)-assisted trypsin digestion strategies coupled to capillary liquid chromatography-tandem mass spectrometry (CapLC-MS/MS) identification. In total, 509 and 210 proteins were detected from the embryos at 72 and 120 hours postfertilization (hpf), respectively, with a false identification rate of less than 1%. Approximately 95% of those proteins could be observed by combining the urea- and SDC-assisted digestion strategies, suggesting that these two methods are more effective than the PA-assisted method. Compared with 0.5% SDC, 1% SDC was more effective to identify proteins in zebrafish embryos. In addition, removal of the predominant yolk proteins could significantly improve protein identification efficiency. Our study represents the first overview of the protein expression profile of a single zebrafish embryo at 72 or 120 hpf. More important, this single individual proteome methodology could be applied to multiple development stages of wide-type or mutant embryos, providing a simple and powerful way to further our understanding of embryonic development.

Complete Resequencing of 40 Genomes Reveals Domestication Events and Genes in Silkworm (Bombyx)

Science (New York, N.Y.). Oct, 2009  |  Pubmed ID: 19713493

A single-base pair resolution silkworm genetic variation map was constructed from 40 domesticated and wild silkworms, each sequenced to approximately threefold coverage, representing 99.88% of the genome. We identified ~16 million single-nucleotide polymorphisms, many indels, and structural variations. We find that the domesticated silkworms are clearly genetically differentiated from the wild ones, but they have maintained large levels of genetic variability, suggesting a short domestication event involving a large number of individuals. We also identified signals of selection at 354 candidate genes that may have been important during domestication, some of which have enriched expression in the silk gland, midgut, and testis. These data add to our understanding of the domestication processes and may have applications in devising pest control strategies and advancing the use of silkworms as efficient bioreactors.

Association of the Actin-binding Protein Transgelin with Lymph Node Metastasis in Human Colorectal Cancer

Neoplasia (New York, N.Y.). Sep, 2009  |  Pubmed ID: 19724680

Metastatic dissemination of primary tumors is responsible for 90% of colorectal cancer (CRC) deaths. The presence of positive lymph nodes, which separates stage I/II from stage III CRC, is a particularly key factor in patient management. Here, we describe results of a quantitative proteomic survey to identify molecular correlates of node status. Laser capture microdissection and two-dimensional difference gel electrophoresis were used to establish expression profiles for 980 discrete protein features in 24 human CRC specimens. Protein abundances were determined with a median technical coefficient of variation of 10%, which provided an ability to detect small differences between cancer subtypes. Transgelin, a 23-kDa actin-binding protein, emerged as a top-ranked candidate biomarker of node status. The area under the receiver operating characteristic curve for transgelin in predicting node status was 0.868 (P = .002). Significantly increased frequency of moderate- and high-level transgelin expression in node-positive CRC was also seen using semiquantitative immunohistochemistry to analyze 94 independent CRC specimens on tissue microarrays (P = .036). Follow-up studies in CRC cell lines demonstrated roles for transgelin in promoting invasion, survival, and resistance to anoikis. Transgelin localizes to the nucleus of CRC cells, and its sequence and properties suggest that it may participate in regulation of the transcriptional program associated with the epithelial-to-mesenchymal transition.

Association Study of Genetic Variants in Eight Genes/loci with Type 2 Diabetes in a Han Chinese Population

BMC Medical Genetics. 2010  |  Pubmed ID: 20550665

At least twenty genes/loci were shown to be associated with type 2diabetes in European original populations. Five of these genes were shown to be associated with type 2 diabetes (T2D) in Chinese populations. The purpose of this study was to replicate the association of genetic vairants in the eight diabetes-related genes/loci with type 2 diabetes in a Han Chinese cohort from western part of China. Nineteen single nucleotide polymorphisms (SNPs) from the eight genes/loci including TCF7L2, HHEX, CDKAL1, SLC30A8, PPARG, IGF2BP2, KCNJ11, and CDKN2A/CDKN2B were genotyped in 1,529 cases and 1,439 controls in a Han Chinese population using the ABI SNaPshot method. The meta-analysis of the association between rs7903146 in TCF7L2 gene and T2D in the Han Chinese was performed.

A Role for the Ubiquitin-proteasome System in Activity-dependent Presynaptic Silencing

The Journal of Neuroscience : the Official Journal of the Society for Neuroscience. Feb, 2010  |  Pubmed ID: 20130189

Chronic changes in electrical excitability profoundly affect synaptic transmission throughout the lifetime of a neuron. We have previously explored persistent presynaptic silencing, a form of synaptic depression at glutamate synapses produced by ongoing neuronal activity and by strong depolarization. Here we investigate the involvement of the ubiquitin-proteasome system (UPS) in the modulation of presynaptic function. We found that proteasome inhibition prevented the induction of persistent presynaptic silencing. Specifically, application of the proteasome inhibitor MG-132 (carbobenzoxy-L-leucyl-L-leucyl-L-leucinal) prevented decreases in the size of the readily releasable pool of vesicles and in the percentage of active synapses. Presynaptic silencing was accompanied by decreases in levels of the priming proteins Munc13-1 and Rim1. Importantly, overexpression of Rim1alpha prevented the induction of persistent presynaptic silencing. Furthermore, strong depolarization itself increased proteasome enzymatic activity measured in cell lysates. These results suggest that modulation of the UPS by electrical activity contributes to persistent presynaptic silencing by promoting the degradation of key presynaptic proteins.

A Facile Strategy for Constructing Boron-rich Polymer Nanoparticles Via a Boronic Acid-related Reaction

Macromolecular Rapid Communications. Mar, 2011  |  Pubmed ID: 21433212

We present here a facile strategy for constructing Dextran-poly(3-acrylamidophenylboronic acid) (Dextran-PAPBA) nanoparticles (NPs) through a radical polymerization of the monomer 3-acrylamidophenylboronic acid (APBA) bound by dextran via a boronic acid-diol reaction in aqueous solution. The synthesized Dextran-PAPBA NPs are stable in a wide pH range. Their size and composition are tunable by varying the feeding molar ratio of the glucopyranoside unit in dextran to APBA. Additionally, the NPs have good biocompatibility and cell membrane penetrability, as demonstrated by in vitro experiments. Doxorubicin was encapsulated in the NPs and exhibited a sustained and strongly pH-dependent release profile that would greatly favor the in vivo drug delivery performance of the NPs. The facility of this strategy together with the tunable boron content and outstanding drug release and cellular membrane crossing performance of the produced NPs should greatly boost their applications in boron neutron capture therapy (BNCT) and chemotherapy for cancer treatment.

Genetic Variants at 13q12.12 Are Associated with High Myopia in the Han Chinese Population

American Journal of Human Genetics. Jun, 2011  |  Pubmed ID: 21640322

High myopia, which is extremely prevalent in the Chinese population, is one of the leading causes of blindness in the world. Genetic factors play a critical role in the development of the condition. To identify the genetic variants associated with high myopia in the Han Chinese, we conducted a genome-wide association study (GWAS) of 493,947 SNPs in 1088 individuals (419 cases and 669 controls) from a Han Chinese cohort and followed up on signals that were associated with p < 1.0 × 10(-4) in three independent cohorts (combined, 2803 cases and 5642 controls). We identified a significant association between high myopia and a variant at 13q12.12 (rs9318086, combined p = 1.91 × 10(-16), heterozygous odds ratio = 1.32, and homozygous odds ratio = 1.64). Furthermore, five additional SNPs (rs9510902, rs3794338, rs1886970, rs7325450, and rs7331047) in the same linkage disequilibrium (LD) block with rs9318086 also proved to be significantly associated with high myopia in the Han Chinese population; p values ranged from 5.46 × 10(-11) to 6.16 × 10(-16). This associated locus contains three genes-MIPEP, C1QTNF9B-AS1, and C1QTNF9B. MIPEP and C1QTNF9B were found to be expressed in the retina and retinal pigment epithelium (RPE) and are more likely than C1QTNF9B-AS1 to be associated with high myopia given the evidence of retinal signaling that controls eye growth. Our results suggest that the variants at 13q12.12 are associated with high myopia.

Exome Sequencing Identifies ZNF644 Mutations in High Myopia

PLoS Genetics. Jun, 2011  |  Pubmed ID: 21695231

Myopia is the most common ocular disorder worldwide, and high myopia in particular is one of the leading causes of blindness. Genetic factors play a critical role in the development of myopia, especially high myopia. Recently, the exome sequencing approach has been successfully used for the disease gene identification of Mendelian disorders. Here we show a successful application of exome sequencing to identify a gene for an autosomal dominant disorder, and we have identified a gene potentially responsible for high myopia in a monogenic form. We captured exomes of two affected individuals from a Han Chinese family with high myopia and performed sequencing analysis by a second-generation sequencer with a mean coverage of 30× and sufficient depth to call variants at ∼97% of each targeted exome. The shared genetic variants of these two affected individuals in the family being studied were filtered against the 1000 Genomes Project and the dbSNP131 database. A mutation A672G in zinc finger protein 644 isoform 1 (ZNF644) was identified as being related to the phenotype of this family. After we performed sequencing analysis of the exons in the ZNF644 gene in 300 sporadic cases of high myopia, we identified an additional five mutations (I587V, R680G, C699Y, 3'UTR+12 C>G, and 3'UTR+592 G>A) in 11 different patients. All these mutations were absent in 600 normal controls. The ZNF644 gene was expressed in human retinal and retinal pigment epithelium (RPE). Given that ZNF644 is predicted to be a transcription factor that may regulate genes involved in eye development, mutation may cause the axial elongation of eyeball found in high myopia patients. Our results suggest that ZNF644 might be a causal gene for high myopia in a monogenic form.

[Analysis of Risk Factors of Prolonged Intensive Care Unit Stay of Critically Ill Obstetric Patients: a 5-year Retrospective Review in 3 Hospitals in Beijing]

Zhongguo Wei Zhong Bing Ji Jiu Yi Xue = Chinese Critical Care Medicine = Zhongguo Weizhongbing Jijiuyixue. Aug, 2011  |  Pubmed ID: 21878165

To identify the risk factors of prolonged intensive care unit (ICU) stay of critically ill obstetric patients.

MBD 4--a Potential Substrate for Protein Kinase X

Acta Biochimica Et Biophysica Sinica. Nov, 2011  |  Pubmed ID: 21971312

ABCB6 Mutations Cause Ocular Coloboma

American Journal of Human Genetics. Jan, 2012  |  Pubmed ID: 22226084

Ocular coloboma is a developmental defect of the eye and is due to abnormal or incomplete closure of the optic fissure. This disorder displays genetic and clinical heterogeneity. Using a positional cloning approach, we identified a mutation in the ATP-binding cassette (ABC) transporter ABCB6 in a Chinese family affected by autosomal-dominant coloboma. The Leu811Val mutation was identified in seven affected members of the family and was absent in six unaffected members from three generations. A LOD score of 3.2 at θ = 0 was calculated for the mutation identified in this family. Sequence analysis was performed on the ABCB6 exons from 116 sporadic cases of microphthalmia with coloboma (MAC), isolated coloboma, and aniridia, and an additional mutation (A57T) was identified in three patients with MAC. These two mutations were not present in the ethnically matched control populations. Immunostaining of transiently transfected, Myc-tagged ABCB6 in retinal pigment epithelial (RPE) cells showed that it localized to the endoplasmic reticulum and Golgi apparatus of RPE cells. RT-PCR of ABCB6 mRNA in human cell lines and tissue indicated that ABCB6 is expressed in the retinae and RPE cells. Using zebrafish, we show that abcb6 is expressed in the eye and CNS. Morpholino knockdown of abcb6 in zebrafish produces a phenotype characteristic of coloboma and replicates the clinical phenotype observed in our index cases. The knockdown phenotype can be corrected with coinjection of the wild-type, but not mutant, ABCB6 mRNA, suggesting that the phenotypes observed in zebrafish are due to insufficient abcb6 function. Our results demonstrate that ABCB6 mutations cause ocular coloboma.

Urinary Titanium and Vanadium and Breast Cancer: A Case-Control Study

Nutrition and Cancer. Feb, 2012  |  Pubmed ID: 22332886

Titanium and vanadium are essential trace elements. This study examined the associations of urinary titanium and vanadium with breast cancer risk in a hospital-based case-control study comprising 240 women with incident breast cancer, and 246 cancer-free and age-matched controls who attended health screening assessments in 2 affiliated hospitals of Sun Yat-sen University in Guangzhou between October 2009 and July 2010. Survey data and urine specimens were collected before treatment for the patients and after interview for the controls. The urinary concentrations of titanium and vanadium were measured by inductively coupled plasma mass spectrometry. Women in the second and the highest tertile of vanadium showed 64% and 40% decreased risk of breast cancer, respectively, when compared with those in the lowest tertile after adjustment for established risk factors of breast cancer (ORs [95%CI]: 0.36 [0.21-0.60] and 0.60 [0.37-0.97], respectively). In contrast, urinary titanium was not significantly related to a decreased risk of breast cancer. These results have potentially significant implications on nutritional chemoprevention of breast cancer and the development of new anticancer drugs. Further replications of the study are recommended, and the biological mechanisms warrant clarification.

Fluorescent Micelles Based on Star Amphiphilic Copolymer with a Porphyrin Core for Bioimaging and Drug Delivery

Macromolecular Bioscience. Jan, 2012  |  Pubmed ID: 22052617

Star-shaped poly(ε-caprolactone)-b-poly(ethylene oxide) amphiphilic copolymer with a tetrakis-(4-aminophenyl)-terminated porphyrin core was synthesized. Paclitaxel (PTX)-loaded polymeric micelles were prepared by the self-assembly of the star copolymer and in situ encapsulation of PTX. The fluorescent characteristic of the porphyrin moiety allowed the cellular uptake and biodistribution of the PTX-loaded micelles to be monitored by fluorescent imaging. The PTX-loaded micelles can be readily internalized by cancer cells and have a slightly higher cytotoxicity than clinic PTX injection Taxol. In vivo real-time fluorescent imaging revealed that the micelles could accumulate at tumor site via the blood circulation in tumor-bearing mice. In vivo antitumor efficacy examinations indicated that the PTX-loaded micelles had significantly superior efficacy in impeding tumor growth than Taxol and low toxicity to the living mice.