👤 Chih-Chang Hsieh

To demonstrate the loci that relate to high-density lipoprotein cholesterol (HDL-C) levels and genetic sex heterogeneity, we enrolled 41,526 participants aged between 30 and 70 years old from the Taiwan Biobank in a genome-wide association study. We applied the Manhattan plot to display the p-values estimated for the relationships between loci and low HDL-C. A total of 160 variants were significantly associated with low HDL-C. The genotype TT of rs1364422 located in the KLF14 gene has 1.30 (95% CI=1.20 - 1.42) times the risk for low-HDL compared to genotype CC in females (log(-p) =8.98). Moreover, the genes APOC1, APOE, PVRL2, and TOMM40 were associated significantly with low-HDL-C in males only. Excluding the variants with high linkage disequilibrium, we revealed the rs429358 located in APOE as the major genetic variant for lowering HDL-C, in which genotype CT has 1.24 (95% CI= 1.16 - 1.32) times the risk. In addition, we also examine 12 genes related to HDL-C in both sexes, including LPL, ABCA1, APOA5, BUD13, ZPR1, ALDH1A2, LIPC, CETP, HERPUD1, LIPG, ANGPTL8, and DOCK6. In conclusion, low-HDL-C is a genetic and sex-specific phenotype, and we discovered that the APOE and KLF14 are specific to low-HDL-C for men and women, respectively. Show less

Next-generation phenotyping (NGP) is an application of advanced methods of computer vision on medical imaging data such as portrait photos of individuals with rare disorders. NGP on portraits results in gestalt scores that can be used for the selection of appropriate genetic tests, and for the interpretation of the molecular data. Here, we report on an exceptional case of a young girl that was presented at the age of 8 and 15 and enrolled in NGP diagnostics on the latter occasion. The girl had clinical features associated with Koolen-de Vries syndrome (KdVS) and a suggestive facial gestalt. However, chromosomal microarray (CMA), Sanger sequencing, multiplex ligation-dependent probe analysis (MLPA), and trio exome sequencing remained inconclusive. Based on the highly indicative gestalt score for KdVS, the decision was made to perform genome sequencing to also evaluate noncoding variants. This analysis revealed a 4.7 kb de novo deletion partially affecting intron 6 and exon 7 of the KANSL1 gene. This is the smallest reported structural variant to date for this phenotype. The case illustrates how NGP can be integrated into the iterative diagnostic process of test selection and interpretation of sequencing results. Show less

Norcantharidin (NCTD) is a demethylated derivative of cantharidin demonstrated to have anti-proliferative, anti-inflammatory, and anti-fibrosis properties. The purpose of the current study is to investigate the underlying mechanisms and signaling pathways affected by NCTD in human ARPE-19 cells. Cell growth and rate of proliferation were assayed by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, colony formation assay, and cell cycle distribution/quantification. Cell motility was detected with in vitro migration assay. The level of epithelial-mesenchymal transition (EMT)-related proteins and mRNA (Snail, Slug, E-cadherin) were detected using Western blotting, real-time quantitative polymerase chain reaction, and immunofluorescence assay. Overexpression of Snail plasmid was determined by transfection assay. We found that NCTD reduced epidermal growth factor (EGF)-induced ARPE-19 cell viability and proliferation through increasing the p21 and p27 expression and decreasing the cyclin D1 expression. NCTD also inhibited EGF-mediated EMT and cell motility through increased protein and mRNA levels of E-cadherin and decreased Snail in EGF-induced ARPE-19 cells. Overexpression of Snail significantly decreased ARPE-19 cell motility and increased E-cadherin expression in NCTD-treated cells. Additionally, when NCTD was combined with a PI3K inhibitor (LY294002) significantly decreased the p-AKT and Snail expression, and increased the E-cadherin expression of EGF treatment in ARPE-19 cells. The current findings revealed that NCTD suppresses the EGF-induced proliferation, motility, and EMT of ARPE-19 cells through inactivation of the AKT-mediated Snail/E-cadherin pathway. NCTD may be a potential preventive agent for proliferative vitreoretinopathy. Show less

Compared with the precise targeting of drug-resistant mutant cancer cells, strategies for eliminating non-genetic adaptation-mediated resistance are limited. The pros and cons of the existence of inflammasomes in cancer have been reported. Nevertheless, the dynamic response of inflammasomes to therapies should be addressed. Tumor-derived exosomes were purified by differential ultracentrifugation and validated by nanoparticle tracking analysis and transmission electron microscopy. A proximity ligation assay and interleukin-1β (IL-1β) level were used for detecting activation of NLRP3 inflammasomes. RNA sequencing was used to analyze the exosomal RNAs. We demonstrated that in cancer cells undergoing Snail-induced epithelial-mesenchymal transition (EMT), tumor cells suppress NLRP3 inflammasome activities of tumor-associated macrophages (TAMs) in response to chemotherapy through the delivery of exosomal miR-21. Mechanistically, miR-21 represses This finding reveals the mechanism of EMT-mediated resistance beyond cancer stemness through modulation of post-treatment inflammasome activity. It also highlights the dynamic remodeling of the TME throughout metastatic evolution. Show less

Oral cancer is one of the most common cancers worldwide, especially in South Central Asia. It has been suggested that cancer stem cells (CSC) play crucial roles in tumor relapse and metastasis, and approaches to target CSC may lead to promising results. Here, aldehyde dehydrogenase 1 (ALDH1) and CD44 were utilized to isolate CSCs of oral cancer. Butylidenephthalide, a bioactive phthalide compound from Show less

Basal macroautophagy/autophagy has recently been found in anucleate platelets. Platelet autophagy is involved in platelet activation and thrombus formation. However, the mechanism underlying autophagy in anucleate platelets require further clarification. Our data revealed that LC3-II formation and SQSTM1/p62 degradation were noted in H Show less

Malignant cancer may contain highly heterogeneous populations of cells, including stem-like cells which were resistant to chemotherapy agents, radiation, mechanical stress, and immune surveillance. The characterization of these specific subpopulations might be critical to develop novel strategy to remove malignant tumors. We selected and enriched small population of human melanoma A2058 cells by repetitive selection cycles (selection, restoration, and amplification). These subpopulation of melanoma cells persisted the characteristics of slower cell proliferation, enhanced drug-resistance, elevated percentage of side population as analyzed by Hoechst33342 exclusion, Show less

The FTO (fat mass- and obesity-associated) gene variant is an established obesity-susceptibility locus. FTO protein is a nucleic acid demethylase and FTO genetic variants form long-range functional connections with IRX3, which regulates fat mass and metabolism in humans. From our previous results, we found FTO regulates the metabolism of triglyceride in adipocytes through demethylating Angptl4 (angiopoietin-like protein 4) mRNA in mice. We hypothesized that the FTO genetic variants regulate ANGPTL4 abundances in human adipose tissues and affect the outcome after bariatric surgery. We recruited 188 obesity subjects with body mass indices (BMI)>35kg/m Adipose ANGPTL4 abundances were affected by the presence of FTO obesity risk haplotype and correlated with excess weight loss percentage after bariatric surgery. These data signify the critical role of FTO variants and adipose ANGPTL4 in fatty acid metabolism and bariatric outcomes in humans. Show less

Recently, the spectrum of background mutation in the genes implicated in sudden arrhythmic death syndrome (SADS), has been elucidated in the Caucasian populations. However, this information is largely unknown in the Asian populations. We assessed the background rare variants (minor allele frequency < 0.01) of major SADS genes in whole genome sequence data of 1514 healthy Taiwanese subjects from the Taiwan Biobank. We found up to 45% of healthy subjects have a rare variant in at least one of the major SADS genes. Around 3.44% of healthy subjects had multiple mutations in one or multiple genes. The background mutation rates in long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, and arrhythmogenic right ventricular cardiomyopathy genes were similar, but those in Brugada syndrome (BrS) (SCN5A) and hypertrophic cardiomyopathy (HCM) genes (MYBPC3, MYH7, and TNNT2) were higher, compared to those reported in the Caucasian populations. Furthermore, the rate of incidental pathogenic variant was highest in MYBPC3 gene. Finally, the number of variant was proportional to the exon length of the gene (R2 = 0.486, P = 0.0056) but not related to its functional or evolutionary importance (degree of evolutionary conservation) (R2 = 0.0008, P = 0.9218), suggesting that the mutation was random. The ratio of variant number over exon nucleotide length was highest in MYBPC3, MYH7, and TNNT2 genes. Unique features of background SADS gene mutation in the Asian populations include higher prevalence of incidental variant in HCM, BrS, and long QT 3 (SCN5A) genes. HCM genes have the highest variant number per exon length. Show less

Anticancer therapies reportedly promote pro-survival autophagy in cancer cells that confers drug resistance, rationalizing the concept to combine autophagy inhibitors to increase their therapeutic potential. We previously identified that MPT0L145 is a PIK3C3/FGFR inhibitor that not only increases autophagosome formation due to fibroblast growth factor receptor (FGFR) inhibition but also perturbs autophagic flux via PIK3C3 inhibition in bladder cancer cells harboring FGFR activation. In this study, we hypothesized that combined-use of MPT0L145 with agents that induce pro-survival autophagy may provide synthetic lethality in cancer cells without FGFR activation. The results showed that MPT0L145 synergistically sensitizes anticancer effects of gefitinib and gemcitabine in non-small cell lung cancer A549 cells and pancreatic cancer PANC-1 cells, respectively. Mechanistically, drug combination increased incomplete autophagy due to impaired PIK3C3 function by MPT0L145 as evidenced by p62 accumulation and no additional apoptotic cell death was observed. Meanwhile, drug combination perturbed survival pathways and increased vacuolization and ROS production in cancer cells. In conclusion, the data suggest that halting pro-survival autophagy by targeting PIK3C3 with MPT0L145 significantly sensitizes cancer cells to targeted or chemotherapeutic agents, fostering rational combination strategies for cancer therapy in the future. Show less

Urothelial carcinoma (UC) carcinogenesis has been hypothesized to occur through epigenetic repression of tumor-suppressor genes (TSGs). By quantitative real-time polymerase chain reaction array, we found that one potential TSG, angiopoietin-like 4 (ANGPTL4), was expressed at very low levels in all bladder cancer cell lines we examined. Previous studies had demonstrated that ANGPTL4 is highly expressed in some cancers, but downregulated, by DNA methylation, in others. Consequently, owing to these seemingly conflicting functions in distinct cancers, the precise role of ANGPTL4 in the etiology of UC remains unclear. In this study, using methylation-specific PCR and bisulfite pyrosequencing, we show that ANGPTL4 is transcriptionally repressed by DNA methylation in UC cell lines and primary tumor samples, as compared with adjacent noncancerous bladder epithelium. Functional studies further demonstrated that ectopic expression of ANGPTL4 potently suppressed UC cell proliferation, monolayer colony formation in vitro, and invasion, migration, and xenograft formation in vivo. Surprisingly, circulating ANGPTL4 was significantly higher in plasma samples from UC patients than normal control, suggesting it might be secreted from other cell types. Interestingly, our data also indicated that exogenous cANGPTL4 could promote cell proliferation and cell migration via activation of signaling through the Erk/focal adhesion kinase axis. We further confirmed that mouse xenograft tumor growth could be promoted by administration of exogenous cANGPTL4. Finally, immunohistochemistry demonstrated that ANGPTL4 was downregulated in tumor cells but overexpressed in tumor adjacent stromal tissues of muscle-invasive UC tissue samples. In conclusion, our data support dual roles for ANGPTL4 in UC progression, either as a tumor suppressor or oncogene, in response to microenvironmental context. Show less

Upon environmental changes, proliferating cells delay cell cycle to prevent further damage accumulation. Yeast Cip1 is a Cdk1 and Cln2-associated protein. However, the function and regulation of Cip1 are still poorly understood. Here we report that Cip1 expression is co-regulated by the cell-cycle-mediated factor Mcm1 and the stress-mediated factors Msn2/4. Overexpression of Cip1 arrests cell cycle through inhibition of Cdk1-G1 cyclin complexes at G1 stage and the stress-activated protein kinase-dependent Cip1 T65, T69, and T73 phosphorylation may strengthen the Cip1and Cdk1-G1 cyclin interaction. Cip1 accumulation mainly targets Cdk1-Cln3 complex to prevent Whi5 phosphorylation and inhibit early G1 progression. Under osmotic stress, Cip1 expression triggers transient G1 delay which plays a functionally redundant role with another hyperosmolar activated CKI, Sic1. These findings indicate that Cip1 functions similarly to mammalian p21 as a stress-induced CDK inhibitor to decelerate cell cycle through G1 cyclins to cope with environmental stresses.A G1 cell cycle regulatory kinase Cip1 has been identified in budding yeast but how this is regulated is unclear. Here the authors identify cell cycle (Mcm1) and stress-mediated (Msn 2/4) transcription factors as regulating Cip1, causing stress induced CDK inhibition and delay in cell cycle progression. Show less

Autophagy is essential for maintaining cellular homeostasis and survival under various stress conditions. Autophagy-related gene 9 (Atg9) encodes a multipass transmembrane protein thought to act as a membrane carrier for forming autophagosomes. However, the molecular regulation and physiological importance of Atg9 in animal development remain largely unclear. Here, we generated Show less

Metabolic syndrome has closely linked to the development of human hepatocellular carcinoma (HCC). By using the hepatitis B virus (HBV) X (HBx) transgenic mouse model, we studied the dynamic evolution of serum and liver profiles of lipids and global cDNA expression at different stages of HBx tumorigenesis. We observed that the lipid (triglycerides, cholesterol, and fatty acids) profiles revealed a biphasic response pattern during the progression of HBx tumorigenesis: a small peak at early phase and a large peak or terminal switch at the tumor phase. By analyzing cDNA microarray data, the early peak correlated to the oxidative stress and pro-inflammatory response, which then resolved at the middle phase and were followed by the terminal metabolic switch in the tumor tissues. Five lipid metabolism-related genes, the arachidonate 5-lipoxygenase, lipoprotein lipase, fatty acid binding protein 4, 1-acylglycerol-3-phosphate O-acyltransferase 9, and apolipoprotein A-IV were identified to be significantly activated in HBx transgenic HCCs and further validated in human HBV-related HCCs. Inhibition of these lipid genes could reverse the effect of HBx on lipid biosynthesis and suppress HBx-induced cell proliferation in vitro. Our results support the concept that metabolic syndrome plays an important role in HBV tumorigenesis. The dysregulation of lipid metabolic genes may predict the disease progression to HCC in chronic hepatitis B patients. Show less

Recent molecular and pathological studies suggest that endometriosis may serve as a precursor of ovarian cancer (endometriosis-associated ovarian cancer, EAOC), especially of the endometrioid and clear cell subtypes. Accordingly, this study had two cardinal aims: first, to obtain mutation profiles of EAOC from Taiwanese patients; and second, to determine whether somatic mutations present in EAOC can be detected in preneoplastic lesions. Formalin-fixed paraffin-embedded (FFPE) tissues were obtained from ten endometriosis patients with malignant transformation. Macrodissection was performed to separate four different types of cells from FFPE sections in six patients. The four types of samples included normal endometrium, ectopic endometriotic lesion, atypical endometriosis, and carcinoma. Ultra-deep (>1000×) targeted sequencing was performed on 409 cancer-related genes to identify pathogenic mutations associated with EAOC. The most frequently mutated genes were PIK3CA (6/10) and ARID1A (5/10). Other recurrently mutated genes included ETS1, MLH1, PRKDC (3/10 each), and AMER1, ARID2, BCL11A, CREBBP, ERBB2, EXT1, FANCD2, MSH6, NF1, NOTCH1, NUMA1, PDE4DIP, PPP2R1A, RNF213, and SYNE1 (2/10 each). Importantly, in five of the six patients, identical somatic mutations were detected in atypical endometriosis and tumor lesions. In two patients, genetic alterations were also detected in ectopic endometriotic lesions, indicating the presence of genetic alterations in preneoplastic lesion. Genetic analysis in preneoplastic lesions may help to identify high-risk patients at early stage of malignant transformation and also shed new light on fundamental aspects of the molecular pathogenesis of EAOC. Molecular characterization of endometriosis-associated ovarian cancer genes by targeted NGS. Candidate genes predictive of malignant transformation were identified. Chromatin remodeling, PI3K-AKT-mTOR, Notch signaling, and Wnt/β-catenin pathway may promote cell malignant transformation. Show less

Cellular mechanisms that mediate steatohepatitis, an increasingly prevalent condition in the Western world for which no therapies are available, are poorly understood. Despite the fact that its synthetic agonists induce fatty liver, the liver X receptor (LXR) transcription factor remains a target of interest because of its anti-atherogenic, cholesterol removal, and anti-inflammatory activities. Here we show that tetratricopeptide repeat domain protein 39B (Ttc39b, C9orf52) (T39), a high-density lipoprotein gene discovered in human genome-wide association studies, promotes the ubiquitination and degradation of LXR. Chow-fed mice lacking T39 (T39(-/-)) display increased high-density lipoprotein cholesterol levels associated with increased enterocyte ATP-binding cassette transporter A1 (Abca1) expression and increased LXR protein without change in LXR messenger RNA. When challenged with a high fat/high cholesterol/bile salt diet, T39(-/-) mice or mice with hepatocyte-specific T39 deficiency show increased hepatic LXR protein and target gene expression, and unexpectedly protection from steatohepatitis and death. Mice fed a Western-type diet and lacking low-density lipoprotein receptor (Ldlr(-/-)T39(-/-)) show decreased fatty liver, increased high-density lipoprotein, decreased low-density lipoprotein, and reduced atherosclerosis. In addition to increasing hepatic Abcg5/8 expression and limiting dietary cholesterol absorption, T39 deficiency inhibits hepatic sterol regulatory element-binding protein 1 (SREBP-1, ADD1) processing. This is explained by an increase in microsomal phospholipids containing polyunsaturated fatty acids, linked to an LXRα-dependent increase in expression of enzymes mediating phosphatidylcholine biosynthesis and incorporation of polyunsaturated fatty acids into phospholipids. The preservation of endogenous LXR protein activates a beneficial profile of gene expression that promotes cholesterol removal and inhibits lipogenesis. T39 inhibition could be an effective strategy for reducing both steatohepatitis and atherosclerosis. Show less

Hepatocyte-like cells, differentiated from different stem cell sources, are considered to have a range of possible therapeutic applications, including drug discovery, metabolic disease modelling, and cell transplantation. However, little is known about how stem cells differentiate into mature and functional hepatocytes. Using transcriptomic screening, a transcription factor, liver X receptor α (NR1H3), was identified as increased during HepaRG cell hepatogenesis; this protein was also upregulated during embryonic stem cell and induced pluripotent stem cell differentiation. Overexpressing NR1H3 in human HepaRG cells promoted hepatic maturation; the hepatocyte-like cells exhibited various functions associated with mature hepatocytes, including cytochrome P450 (CYP) enzyme activity, secretion of urea and albumin, upregulation of hepatic-specific transcripts and an increase in glycogen storage. Importantly, the NR1H3-derived hepatocyte-like cells were able to rescue lethal fulminant hepatic failure using a non-obese diabetic/severe combined immunodeficient mouse model. In this study, we found that NR1H3 accelerates hepatic differentiation through an HNF4α-dependent reciprocal network. This contributes to hepatogenesis and is therapeutically beneficial to liver disease. Show less

Identification of genetic variants that influence bipolar I disorder (BPD-I) through genome-wide association (GWA) studies is limited in Asian populations. The current study aimed to identify novel common variants for BPD-I in an ethnically homogeneous Taiwanese sample using a multi-stage GWA study design. At the discovery stage, 200 BPD-I patients and 200 controls that combined to form 16 pools were genotyped with 1 million markers. Utilizing a newly developed rank-based method, top-ranked markers were selected. After validation with individual genotyping, a fine-mapping association study was conducted to identify associated loci using 240 patients and 240 controls. At the last stage, independent samples were collected (351 cases and 341 controls) for replication. Among the top-ranked markers from the discovery stage, eight genes and 15 individual SNPs were evaluated in the fine-mapping stage. At this stage, rs7619173, which is not in a gene coding region, showed the most significant association (P = 2 ∗ 10(-5)) with BPD-I. Four genes had empirical P-values<0.05, including KCNH7 (P = 0.0047), MYST4 (P = 0.0047), NRXN3 (P = 0.0095), and SEMA3D (P = 0.037). For markers genotyped in replication samples, rs7619173 exhibited a significant association (P(combined) = 2 ∗ 10(-4)) after multiple testing correction, while markers rs11001178 (MYST4) and rs2217887 (NRXN3) showed weak associations (P(combined) = 0.02) with BPD-I. A multi-stage GWA design has the potential to uncover the underlying pathogenesis of a complex trait. Findings in the present study highlight three loci that warrant further investigation for bipolar. Show less

The fatty acid desaturase (FADS) gene family at 11q12-13.1 includes FADS1 and FADS2, both known to mediate biosynthesis of omega-3 and omega-6 long-chain polyunsaturated fatty acids (LCPUFA). FADS3 is a putative desaturase due to its sequence similarity with FADS1 and FADS2, but its function is unknown. We have previously described 7 FADS3 alternative transcripts (AT) and 1 FADS2 AT conserved across multiple species. This study examined the effect of dietary LCPUFA levels on liver FADS gene expression in vivo and in vitro, evaluated by qRT-PCR. Fourteen baboon neonates were randomized to three diet groups for their first 12 weeks of life, C: Control, no LCPUFA, L: 0.33% docosahexaenoic acid (DHA)/0.67% arachidonic acid (ARA) (w/w); and L3: 1.00% DHA/0.67% ARA (w/w). Liver FADS1 and both FADS2 transcripts were downregulated by at least 50% in the L3 group compared to controls. In contrast, FADS3 AT were upregulated (L3 > C), with four transcripts significantly upregulated by 40% or more. However, there was no evidence for a shift in liver fatty acids to coincide with increased FADS3 expression. Significant upregulation of FADS3 AT was also observed in human liver-derived HepG2 cells after DHA or ARA treatment. The PPARγ antagonist GW9662 prevented FADS3 upregulation, while downregulation of FADS1 and FADS2 was unaffected. Thus, FADS3 AT were directly upregulated by LCPUFA by a PPARγ-dependent mechanism unrelated to regulation of other desaturases. This opposing pattern and mechanism of regulation suggests a dissimilar function for FADS3 AT compared to other FADS gene products. Show less

Obesity is associated with an increased risk of development of numerous diseases including type 2 diabetes, hypertension, hyperlipidemia, and cardiovascular disease. In this study, we investigated the effects of lucidone in vitro on gene expression during adipogenesis in 3T3-L1 cells and in vivo on high-fat diet induced obesity in C57BL/6 mice. Lucidone at 40 μmol/L suppressed adipogenesis in 3T3-L1 cells by reducing transcription levels of adipogenic genes, including PPARγ, C/EBPα, LXR-α, LPL, aP2, GLUT4 and adiponectin. Five-week-old male C57BL/6 mice fed a high fat diet (60% energy from fat) supplemented with lucidone at a dosage of 1250 mg/kg of diet for 12 weeks had reduced body and liver weight, reduced epididymal and perirenal adipose tissue, decreased food efficiency (percentage of weight gain divided by food intake), and lowered plasma cholesterol, triglyceride, glucose, and insulin levels. Dissection of adipose tissue from lucidone-treated mice showed a reduction in the average fat-cell size and percentage of large adipocytes. These results provide evidence that dietary intake of lucidone alleviates high fat diet-induced obesity in C57BL/6 mice and reveals the potential of lucidone as a nutraceutical to prevent obesity and consequent metabolic disorders. Show less

Proteome analysis is frequently applied in identifying the proteins or biomarkers in knee synovial fluids (SF) that are associated with osteoarthritis and other arthritic disorders. The 2-dimensional gel electrophoresis (2-DE) is the technique of choice in these studies. Disease biomarkers usually appear in low concentrations and may be masked by high abundant proteins. Therefore, the main aim of this study was to find the most suitable sample preparation method that can optimize the expression of proteins on 2-DE gels that can be used to develop a reference proteome picture for non-osteoarthritic knee synovial fluid samples. Proteome pictures obtained from osteoarthritic knee synovial fluids can then be compared with the reference proteome pictures obtained in this study to assist us in identifying the disease biomarkers more correctly. The proteomic tool of 2-DE with immobilized pH gradients was applied in this study. A total of 12 2-DE gel images were constructed from SF samples that were free of osteoarthritis. In these samples, 3 were not treated with any sample preparation methods, 3 were treated with acetone, 3 were treated with 2-DE Clean-Up Kit, and 3 were treated with the combination of acetone and 2-D Clean-Up Kit prior to 2-DE analysis. Gel images were analyzed using the PDQuest Basic 8.0.1 Analytical software. Protein spots that were of interest were excised from the gels and sent for identification by mass spectrometry. Total SF total protein concentration was calculated to be 21.98 ± 0.86 mg/mL. The untreated SF samples were detected to have 456 ± 33 protein spots on 2-DE gel images. Acetone treated SF samples were detected to have 320 ± 28 protein spots, 2-D Clean-Up Kit treated SF samples were detected to have 413 ± 31 protein spots, and the combined treatment method of acetone and 2-D Clean-Up Kit was detected to have 278 ± 26 protein spots 2-DE gel images. SF samples treated with 2-D Clean-Up Kit revealed clearer presentation of the isoforms and increased intensities of the less abundant proteins of haptoglobin, apolipoprotein A-IV, prostaglandin-D synthase, alpha-1B-glycoprotein, and alpha-2-HS-glycoprotein on 2-DE gel images as compared with untreated SF samples and SF samples treated with acetone. The acetone precipitation method and the combined treatment effect of acetone and 2-DE Clean-Up Kit are not preferred in preparing SF samples for 2-DE analysis as both protein intensities and numbers decrease significantly. On the other hand, 2-D Clean-Up Kit treated SF samples revealed clearer isoforms and higher intensities for the less abundant proteins of haptoglobin, apolipoprotein A-IV, prostaglandin-D synthase, alpha-1B-glycoprotein, and alpha-2-HS-glycoprotein on 2-DE gels. As a result, it is recommended that SF samples should be treated with protein clean up products such as 2-D Clean-Up Kit first before conducting proteomic research in searching for the relevant biomarkers associated with knee osteoarthritis. Show less

Huntington's disease (HD) is a progressive neurodegenerative disease caused by an unstable CAG trinucleotide repeat expansion. The need for biomarkers of onset and progression in HD is imperative, since currently reliable outcome measures are lacking. We used two-dimensional electrophoresis and mass spectrometry to analyze the proteome profiles in cerebrospinal fluid (CSF) of 6 pairs of HD patients and controls. Prothrombin, apolipoprotein A-IV (Apo A-IV) and haptoglobin were elevated in CSF of the HD patients in comparison with the controls. We used western blot as a semi-quantified measurement for prothrombin and Apo A-IV, as well as enzyme linked immunosorbent assay (ELISA) for measurement of haptoglobin, in 9 HD patients and 9 controls. The albumin quotient (Qalb), a marker of blood-brain barrier (BBB) function, was not different between the HD patients and the controls. The ratios of CSF prothrombin/albumin (prothrombin/Alb) and Apo A-IV/albumin (Apo A-IV/Alb), and haptoglobin level were significantly elevated in HD. The ratio of CSF prothrombin/Alb significantly correlated with the disease severity assessed by Unified Huntington's Disease Rating Scale (UHDRS). The results implicate that increased CSF prothrombin, Apo A-IV, and haptoglobin may be involved in pathogenesis of HD and may serve as potential biomarkers for HD. Show less

Liver is unique in its capability to regenerate after an injury. Liver regeneration after a 2/3 partial hepatectomy served as a classical model and is adopted frequently to study the mechanism of liver regeneration. In the present study, semiquantitative analysis of protein expression in mouse liver regeneration following partial hepatectomy was performed using an iTRAQ technique. Proteins from pre-PHx control livers and livers regenerating for 24, 48 and 72 h were extracted and inspected using 4-plex isotope labeling, followed by liquid chromatography fractionation, mass spectrometry and statistical differential analysis. A total of 827 proteins were identified in this study. There were 270 proteins for which quantitative information was available at all the time points in both biologically duplicate experiments. Among the 270 proteins, Car3, Mif, Adh1, Lactb2, Fabp5, Es31, Acaa1b and LOC100044783 were consistently down-regulated, and Mat1a, Dnpep, Pabpc1, Apoa4, Oat, Hpx, Hp and Mt1 were up-regulated by a factor of at least 1.5 from that of the controls at one time point or more. The regulation of each differential protein was also demonstrated by monitoring its time-dependent expression changes during the regenerating process. We believe this is the first report to profile the protein changes in liver regeneration utilizing the iTRAQ proteomic technique. Show less

We investigated the relationship between hypertriglyceridemia and the single-nucleotide polymorphisms (SNPs) on APOA5 in human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy (HAART) in Taiwan. Receipt of protease inhibitor-based HAART, high baseline triglyceride levels, and carriage of APOA5 SNP3 or c.553G>T variants or APOA5 SNP1T/SNP2G/SNP3C/c.553T haplotype were statistically significantly associated with development of extreme hypertriglyceridemia (triglyceride level, >500 mg/dL). Show less

Canonical Wnt/beta-catenin signaling has central roles in development and diseases, and is initiated by the action of the frizzled (Fz) receptor, its coreceptor LDL receptor-related protein 6 (Lrp6), and the cytoplasmic dishevelled (Dvl) protein. The functional relationships among Fz, Lrp6 and Dvl have long been enigmatic. We demonstrated previously that Wnt-induced Lrp6 phosphorylation via glycogen synthase kinase 3 (Gsk3) initiates Wnt/beta-catenin signaling. Here we show that both Fz and Dvl functions are critical for Wnt-induced Lrp6 phosphorylation through Fz-Lrp6 interaction. We also show that axin, a key scaffolding protein in the Wnt pathway, is required for Lrp6 phosphorylation via its ability to recruit Gsk3, and inhibition of Gsk3 at the plasma membrane blocks Wnt/beta-catenin signaling. Our results suggest a model that upon Wnt-induced Fz-Lrp6 complex formation, Fz recruitment of Dvl in turn recruits the axin-Gsk3 complex, thereby promoting Lrp6 phosphorylation to initiate beta-catenin signaling. We discuss the dual roles of the axin-Gsk3 complex and signal amplification by Lrp6-axin interaction during Wnt/beta-catenin signaling. Show less

Guillain-Barré Syndrome (GBS) is a rare autoimmune inflammatory polyneuropathy with a high risk of respiratory failure and unclear pathogenesis. Currently, there are no valid biomarkers for diagnosis of GBS. We used 2-DE and MS to analyze the protein profiles of five pairs of cerebrospinal fluid (CSF) samples of the GBS patients and the patient controls. Three proteins (orosomucoid, haptoglobin and apolipoprotein A-IV) were up-regulated, and two proteins (prostaglandin D2 synthase and transthyretin) were down-regulated in the CSF of the GBS patients. The CSF haptoglobin level, quantified by enzyme-linked immunosorbent assay, was significantly higher in the GBS patients (12.44 ± 2.70 μg/mL) compared to the chronic inflammatory demyelinating polyradiculoneuropathy (2.82 ± 0.83 μg/mL), viral meningitis (3.57 ± 0.97 μg/mL) and control patients (1.44 ± 0.35 μg/mL, p<0.05). This study indicated that protein profile analysis using a combination of 2-DE and MS provides an effective strategy for elucidating the pathogenesis and identifying potential CSF biomarkers for GBS. The raised intrathecal synthesis of haptoglobin specifically only in GBS patients, but not in patients with other neurological diseases examined, provides evidence of central nervous system involvement in GBS, and may be used as a potential diagnostic marker for GBS. Show less

We have cloned a cardiovascular-restricted basic helix-loop-helix factor that interacts with arylhydrocarbon receptor nuclear translocator (ARNT) in a yeast two-hybrid screen. Cardiovascular helix-loop-helix factor 1 (CHF1) is distantly related to the hairy family of transcriptional repressors. We analyzed its expression pattern during mouse embryo development. At day 8.5, the expression of CHF1 is first detected in the primitive ventricle of the primordial heart tube and persists throughout gestation. In rat hearts, this expression is down-regulated after birth, concurrent with terminal differentiation of cardiomyocytes. In the developing vasculature, CHF1 first appears in the dorsal aorta at day 9.0, which precedes the reported expression of smooth muscle cell markers, and persists into adulthood. In an in vitro system of smooth muscle cell differentiation, CHF1 mRNA was barely detectable in undifferentiated cells but was induced highly in differentiated smooth muscle cells. To determine whether CHF1 might affect the function of ARNT, we performed transfection studies. Co-transfection of CHF1 inhibited ARNT/EPAS1-dependent transcription by 85%, and this inhibition is dose-dependent. In electrophoretic mobility studies, CHF1 inhibited the binding of the ARNT/EPAS1 heterodimer to its target site. Our data suggest that CHF1 functions as a transcriptional repressor and may play an important role in cardiovascular development. Show less