👤 Zixiang Ye

Nuclear receptors (NRs) are a class of transcription factors that regulate many cellular functions through manipulation of gene expression and also play important roles in tumorigenesis, proliferation, progression and prognosis in various kinds of cancers according to recent studies. This work aimed to determine the predictive ability of NRs in muscle-invasive bladder cancer (MIBC). A total of 308 MIBC patients with complete clinicopathological and RNASeq data from The Cancer Genome Atlas (TCGA) cohort were collected for filtration. Genes showed clear correlations with overall survival (OS) and recurrence free survival (RFS) were further validated in 123 MIBC patients recruited consecutively from 2008 to 2012 in Fudan University Shanghai Cancer Center (FUSCC) cohort. Cox proportional hazards regression model and Kaplan-Meier plot were used to assess the relative factors. In TCGA cohort, we found that high NR1H3 (HR=0.779, 95% CI: 0.634 - 0.957), NR2C1 (HR=0.673, 95% CI: 0.458 - 0.989) and NR2F6 (HR=0.750, 95% CI: 0.574 - 0.980) expressions were independent factors of favorable OS, while only low NR1H3 (log-rank test, P=0.0076) and NR2F6 (log-rank test, P=0.0395) expressions had the ability to predict poor prognosis for RFS. Further, in FUSCC validating cohort, we confirmed that low NR1H3 expression level was independent factor of poor OS (HR=1.295, 95% CI: 1.064 - 1.576) and it had the ability to predict poor RFS (log-rank test, P=0.0059). Low NR1H3 expression level is an independent prognostic factor of poor OS, and can also predict worse RFS in MIBC patients. Our "TCGA filtrating and local database validating" model can help reveal more prognostic biomarkers and cast a new light in understanding certain gene function in MIBC. Show less

Whole-exome sequencing (WES) has been successful in identifying genes that cause familial Parkinson's disease (PD). However, until now this approach has not been deployed to study large cohorts of unrelated participants. To discover rare PD susceptibility variants, we performed WES in 1148 unrelated cases and 503 control participants. Candidate genes were subsequently validated for functions relevant to PD based on parallel RNA-interference (RNAi) screens in human cell culture and Drosophila and C. elegans models. Assuming autosomal recessive inheritance, we identify 27 genes that have homozygous or compound heterozygous loss-of-function variants in PD cases. Definitive replication and confirmation of these findings were hindered by potential heterogeneity and by the rarity of the implicated alleles. We therefore looked for potential genetic interactions with established PD mechanisms. Following RNAi-mediated knockdown, 15 of the genes modulated mitochondrial dynamics in human neuronal cultures and four candidates enhanced α-synuclein-induced neurodegeneration in Drosophila. Based on complementary analyses in independent human datasets, five functionally validated genes-GPATCH2L, UHRF1BP1L, PTPRH, ARSB, and VPS13C-also showed evidence consistent with genetic replication. By integrating human genetic and functional evidence, we identify several PD susceptibility gene candidates for further investigation. Our approach highlights a powerful experimental strategy with broad applicability for future studies of disorders with complex genetic etiologies. Show less

Ammonia detoxification, which takes place via the hepatic urea cycle, is essential for nitrogen homeostasis and physiological well-being. It has been reported that a reduction in dietary protein reduces urea nitrogen. MicroRNAs (miRNAs) are major regulatory non-coding RNAs that have significant effects on several metabolic pathways; however, little is known on whether miRNAs regulate hepatic urea synthesis. The objective of this study was to assess the miRNA expression profile in a low protein diet and identify miRNAs involved in the regulation of the hepatic urea cycle using a porcine model. Weaned 28-days old piglets were fed a corn-soybean normal protein diet (NP) or a corn-soybean low protein diet (LP) for 30 d. Hepatic and blood samples were collected, and the miRNA expression profile was assessed by sequencing and qRT-PCR. Furthermore, we evaluated the possible role of miR-19b in urea synthesis regulation. There were 25 differentially expressed miRNAs between the NP and LP groups. Six of these miRNAs were predicted to be involved in urea cycle metabolism. MiR-19b negatively regulated urea synthesis by targeting SIRT5, which is a positive regulator of CPS1, the rate limiting enzyme in the urea cycle. Our study presented a novel explanation of ureagenesis regulation by miRNAs. Show less

Long chain polyunsaturated fatty acids (LCPUFA) are bioactive components of membrane phospholipids and serve as substrates for signaling molecules. LCPUFA can be obtained directly from animal foods or synthesized endogenously from 18 carbon precursors via the FADS2 coded enzyme. Vegans rely almost exclusively on endogenous synthesis to generate LCPUFA and we hypothesized that an adaptive genetic polymorphism would confer advantage. The rs66698963 polymorphism, a 22-bp insertion-deletion within FADS2, is associated with basal FADS1 expression, and coordinated induction of FADS1 and FADS2 in vitro. Here, we determined rs66698963 genotype frequencies from 234 individuals of a primarily vegetarian Indian population and 311 individuals from the US. A much higher I/I genotype frequency was found in Indians (68%) than in the US (18%). Analysis using 1000 Genomes Project data confirmed our observation, revealing a global I/I genotype of 70% in South Asians, 53% in Africans, 29% in East Asians, and 17% in Europeans. Tests based on population divergence, site frequency spectrum, and long-range haplotype consistently point to positive selection encompassing rs66698963 in South Asian, African, and some East Asian populations. Basal plasma phospholipid arachidonic acid (ARA) status was 8% greater in I/I compared with D/D individuals. The biochemical pathway product-precursor difference, ARA minus linoleic acid, was 31% and 13% greater for I/I and I/D compared with D/D, respectively. This study is consistent with previous in vitro data suggesting that the insertion allele enhances n-6 LCPUFA synthesis and may confer an adaptive advantage in South Asians because of the traditional plant-based diet practice. Show less

The strong male predominance in Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) remains inadequately explained, but sex hormones might be involved. We hypothesized that single nucleotide polymorphisms (SNPs) in the androgen pathway influence risk of developing BE and EAC. This genetic-epidemiological analysis included 14 studies from Australia, Europe and North America. Polymorphisms in 16 genes coding for the androgen pathway were analyzed using a gene-based approach: versatile gene-based test association study. This method evaluates associations between a trait and all SNPs within a specific gene rather than each SNP marker individually as in a conventional GWAS. The data were stratified for sex, body-mass index, waist-to-hip ratio, tobacco smoking and gastroesophageal reflux status. Included were data from 1,508 EAC patients, 2,383 BE patients and 2,170 control participants. SNPs within the gene CYP17A1 were associated with risk of BE in the sexes combined (p = 0.002) and in males (p = 0.003), but not in females separately (p = 0.3). This association was found in tobacco smokers (p = 0.003) and in BE patients without reflux (p = 0.004), but not in nonsmokers (p = 0.2) or those with reflux (p = 0.036). SNPs within JMJD1C were associated with risk of EAC in females (p = 0.001). However, none of these associations replicated in a subsequent sample. Fourteen other genes studied did not reach statistically significant levels of association with BE, EAC or the combination of BE and EAC, after correcting for the number of genes included in the analysis. In conclusion, genetic variants in the androgen-related genes CYP17A1 and JMJD1C might be associated with risk of BE and EAC, respectively, but replication data with larger sample sizes are needed. Show less

Determination of the exogenous factors that regulate differentiation of neural stem/progenitor cells into neurons, oligodendrocytes and astrocytes is an important step in the clinical therapy of spinal cord injury (SCI). The Notch pathway inhibits the differentiation of neural stem/progenitor cells and Lingo-1 is a strong negative regulator for myelination and axon growth. While Lingo-1 shRNA and N-[N-(3, 5-difluorophenacetyl)-1-alanyl]-S-Phenylglycinet-butylester (DAPT), a Notch pathway inhibitor, have been used separately to help repair SCI, the results have been unsatisfactory. Here we investigated and elucidated the preliminary mechanism for the effect of Lingo-1 shRNA and DAPT on neural stem/progenitor cells differentiation. We found that neural stem/progenitor cells from E14 rat embryos expressed Nestin, Sox-2 and Lingo-1, and we optimized the transduction of neural stem/progenitor cells using lentiviral vectors encoding Lingo-1 shRNA. The addition of DAPT decreased the expression of Notch intracellular domain (NICD) as well as the downstream genes Hes1 and Hes5. Expression of NeuN, CNPase and GFAP in DAPT treated cells and expression of NeuN in Lingo-1 shRNA treated cells confirmed differentiation of neural stem/progenitor cells into neurons, oligodendrocytes and astrocytes. These results revealed that while Lingo-1 shRNA and Notch signaling inhibitor DAPT both promoted differentiation of neural stem cells into neurons, only DAPT was capable of driving neural stem/progenitor cells differentiation into oligodendrocytes and astrocytes. Since we were able to show that both Lingo-1 shRNA and DAPT could drive neural stem/progenitor cells differentiation, our data might aid the development of more effective SCI therapies using Lingo-1 shRNA and DAPT. Show less

Primary liver cancer is one of the most common and aggressive human malignancies worldwide. As numerous studies have revealed that WW domain containing E3 Ub‑protein ligase 2 (WWP2) exerts cancer‑specific functions, the present study assessed the role of WWP2 in liver cancer. WWP2 was revealed to be significantly overexpressed in liver cancer tissues compared with paired normal tissues at the mRNA as well as at the protein level. Furthermore, small interfering RNA-mediated WWP2 knockdown in liver cancer cell lines was demonstrated to inhibit cell proliferation, cause cell cycle arrested in G1 phase and to induce apoptosis as revealed by a Cell Counting Kit-8 assay and flow cytometric analysis. In addition, western blot analysis revealed that WWP2 knockdown significantly increased the expression of apoptosis-associated markers caspase‑7, caspase‑8 and B-cell lymphoma 2 (Bcl-2)-associated X in liver cancer cell lines, while Bcl‑2 was significantly decreased. In conclusion, the present study suggested that WWP2 may exert important functions in the over‑proliferation and evasion of apoptosis of liver cancer, likely through regulating the expression of apoptosis-associated markers. Furthermore, WWP2 may represent a novel diagnostic marker and molecular therapeutic target for liver cancer. Show less

The role and clinical implication of the WWP2 E3 ubiquitin ligase in liver cancer are poorly understood. In the current study, we investigated the expression level of WWP2 and its functions in cell adhesion, invasion, and migration in liver cancer. We used real-time PCR to detect the expression of WWP2 in liver cancer and adjacent samples from the People's Hospital of Lishui and also analyzed The Cancer Genome Atlas (TCGA) RNA-seq data by bioinformatics. Migration and invasion were detected by transwell analysis. We detected a strong WWP2 expression in tumor tissues of the People's Hospital of Lishui, and the survival rate was significantly higher in patients with lower WWP2-expressing tumors. WWP2 small hairpin RNA (shRNA) lentivirus stably infected cells (shWWP2), Huh7, showed slower growth speed compared with scramble control-infected cells in a xenograft mouse model. Knockdown of WWP2 Huh7 and BEL-7404 cells demonstrated a reduction in adhesion, invasion, and migration. Gene set enrichment analysis (GSEA) showed that WWP2 is positively correlated to cancer-related pathways including the chemokine signaling pathway. WWP2 also regulated MMP-9, caspase-9, CXCR3, and CCR5 expression in liver cancer cells. In addition, knockdown of CXCR3 and CCR5 significantly inhibited cell proliferation, adhesion, invasion, and migration in Huh7 and BEL-7404 cells. Our data suggest that targeting of WWP2 may be a therapeutic strategy for liver cancer treatment. Show less

Apolipoprotein A5 (APOA5) is associated with plasma triglyceride (TG) levels, a risk factor for coronary heart disease (CHD). This study explored the association between CHD and the APOA5 rs662799 polymorphism. We collected 1,521 samples (783 CHD patients and 738 controls) for this case-control study. Meta-analysis was performed using Review Manager Software and Stata Software. Significant differences were observed between CHD cases and controls at the level of both genotype (χ2 = 8.964, df = 2, P = 0.011) and allele (χ2 = 9.180, df = 1, P = 0.002, OR = 1.275, 95% CI = 1.089-1.492). A breakdown analysis by gender showed a significant association of APOA5 rs662799 with CHD in males (χ2 = 7.770, df = 1, P = 0.005; OR = 1.331, 95% CI = 1.088-1.628). An additional meta-analysis using 21378 cases and 28428 controls established that rs662799 is significantly associated with CHD (P < 0.00001). Both our case-control study and meta-analysis confirm a significant association between APOA5 rs662799 and CHD. In addition, our results suggest a male-specific association between the APOA5 rs662799 polymorphism and CHD. Show less

Genetic variants within the BUD13-APOA5 gene region are known to be associated with high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) levels. Recent studies suggest that single nucleotide polymorphisms (SNPs) within this region affect HDL-C response to statin-fibrate combination therapy and low-density lipoprotein cholesterol (LDL-C) response to statin therapy. We hypothesized that SNPs within the BUD13-APOA5 region are associated with TG, HDL-C, and LDL-C response to statin therapy. We examined 1520 observations for 1086 patients from the Personalized Medicine Research Project, a large biorepository at the Marshfield Clinic Research Foundation, who had received statin therapy and been previously genotyped for polymorphisms in the 11q23 chromosomal region. A significant differential response to statin therapy was observed for 3 SNPs. The minor allele at rs11605293 significantly attenuated TG-lowering response to pravastatin (P = 0.000159), whereas the minor allele at rs12806755 was associated with a similar response to lovastatin (P = 0.000192). Genotypes at rs947990 significantly attenuated LDL-C reduction to atorvastatin therapy (P = 0.000668) with some patients with the minor allele having LDL-C increase after therapy. No SNPs within the BUD13-APOA5 region were associated with a significant effect on HDL-C reduction in response to statin therapy. In conclusion, this study suggests that common SNPs within the BUD13-APOA5 can affect TG and LDL-C response to statin therapy in a North American population. Show less

Controversy exists on the benefits versus harms of n-6 polyunsaturated fatty acids (n-6 PUFA). Although n-6 PUFA demonstrates anti-atherosclerotic properties, survival following cardiac remodeling may be compromised. We hypothesized that n-6 PUFA like linoleic acid (LA) or other downstream PUFAs like γ-linolenic acid or arachidonic acid alter the transforming growth factor-β (TGFβ)-collagen axis in the heart. Excess dietary LA increased the collagen I/III ratio in the mouse myocardium, leading to cardiac "stiffening" characterized by impaired transmitral flow indicative of early diastolic dysfunction within 5 weeks. In vitro, LA under TGFβ1 stimulation increased collagen I and lysyl oxidase (LOX), the enzyme that cross-links soluble collagen resulting in deposited collagen. Overexpression of fatty acid desaturase 2 (fads2), which metabolizes LA to downstream PUFAs, reduced collagen deposits, LOX maturation, and activity with LA, whereas overexpressing fads1, unrelated to LA desaturation, did not. Furthermore, fads2 knockdown by RNAi elevated LOX activity and collagen deposits in fibroblasts with LA but not oleic acid, implying a buildup of LA for aggravating such pro-fibrotic effects. As direct incubation with γ-linolenic acid or arachidonic acid also attenuated collagen deposits and LOX activity, we concluded that LA itself, independent of other downstream PUFAs, promotes the pro-fibrotic effects of n-6 PUFA. Overall, these results attempt to reconcile opposing views of n-6 PUFA on the cardiovascular system and present evidence supporting a cardiac muscle-specific effect of n-6 PUFAs. Therefore, aggravation of the collagen I/III ratio and cardiac stiffening by excess n-6 PUFA represent a novel pathway of cardiac lipotoxicity caused by high n-6 PUFA diets. Show less

ATP-binding cassette transporter A1 (ABCA1), ATP-binding cassette transporter G1 (ABCG1), and scavenger receptor-B1 (SR-B1) promote cholesterol efflux from cells to lipid-poor apolipoprotein A-I and play an important role in the development of atherosclerosis. Liver X receptor (LXRα) and peroxisome proliferator-activated receptor-gamma (PPARγ) operate as cholesterol sensors, which may protect from cholesterol overload by stimulating cholesterol efflux from cells to high-density lipoprotein through ABCA1, ABCG1, and SR-B1. Propofol administration is associated with cardiovascular protective effects, including anti-inflammatory and antioxidant properties. Here, we examined the effect of propofol on ABCA1, ABCG1, and SR-B1 expression and explored whether PPARγ and LXRα were involved in the regulation of propofol-induced ABCA1, ABCG1, and SR-B1 expression in THP-1 macrophage-derived foam cells. Propofol significantly increased expression levels of ABCA1, ABCG1, and SR-B1 in a time-dependent manner. Cellular cholesterol content was decreased while cholesterol efflux was increased by propofol treatment. Moreover, PPARγ and LXRα were up-regulated by propofol treatment. In addition, the up-regulated expression of ABCA1, ABCG1, and SR-B1 by propofol was significantly abolished by both PPARγ siRNA and LXRα siRNA in THP-1 macrophage-derived foam cells. These results provide evidence that propofol up-regulates expression of ABCA1, ABCG1, and SR-B1 through the PPARγ/LXRα pathway in THP-1 macrophage-derived foam cells. Show less

The primary cilium plays critical roles in vertebrate development and physiology, but the mechanisms underlying its biogenesis remain poorly understood. We investigated the molecular function of C2 calcium-dependent domain containing 3 (C2cd3), an essential regulator of primary cilium biogenesis. We show that C2cd3 is localized to the centriolar satellites in a microtubule- and Pcm1-dependent manner; however, C2cd3 is dispensable for centriolar satellite integrity. C2cd3 is also localized to the distal ends of both mother and daughter centrioles and is required for the recruitment of five centriolar distal appendage proteins: Sclt1, Ccdc41, Cep89, Fbf1, and Cep164. Furthermore, loss of C2cd3 results in failure in the recruitment of Ttbk2 to the ciliary basal body as well as the removal of Cp110 from the ciliary basal body, two critical steps in initiating ciliogenesis. C2cd3 is also required for recruiting the intraflagellar transport proteins Ift88 and Ift52 to the mother centriole. Consistent with a role in distal appendage assembly, C2cd3 is essential for ciliary vesicle docking to the mother centriole. Our results suggest that C2cd3 regulates cilium biogenesis by promoting the assembly of centriolar distal appendages critical for docking ciliary vesicles and recruiting other essential ciliogenic proteins. Show less

Global quantification of the single amino-acid variations (SAAVs) is essential to investigate the roles of SAAVs in disease progression. However, few efforts have been made on this issue due to the lack of high -throughput approach. Here we presented a strategy by integration of the stable isotope dimethyl labeling with variation-associated database search to globally quantify the SAAVs at the first time. A protein database containing 87,745 amino acid variant sequences and 73,910 UniProtKB/Swiss-Prot canonical protein entries was constructed for database search, and higher energy collisional dissociation combined with collision-induced dissociation fragmentation modes were applied to improve the quantification coverage of SAAVs. Compared with target proteomics in which only a few sites could be quantified, as many as 282 unique SAAVs sites were quantified between hepatocellular carcinoma (HCC) and normal human liver tissues by our strategy. The variation rates in different samples were evaluated, and some interesting SAAVs with significant increase normalized quantification ratios, such as T1406N in CPS1 and S197R in HTATIP2, were observed to highly associate with HCC progression. Therefore, the newly developed strategy enables the large-scale comparative analysis of variations at the protein level and holds a promising future in the research related to variations. Show less

Abnormal expression of solute carrier family 34 (sodium phosphate), member 2 (SLC34A2) in the lung may induce abnormal alveolar type II (AT II) cells to transform into lung adenocarcinoma cells, and may also be important in biological process of lung adenocarcinoma. However, at present, the effects and molecular mechanisms of SLC34A2 in the initiation and progression of lung cancer remain to be elucidated. To the best of our knowledge, the present study revealed for the first time that the expression levels of SLC34A2 were downregulated in the A549 and H1299 lung adenocarcinoma cell lines. Further investigation demonstrated that the elevated expression of SLC34A2 in A549 cells was able to significantly inhibit cell viability and invasion in vitro. In addition, 10 upregulated genes between the A549‑P‑S cell line stably expressing SLC34A2 and the control cell line A549‑P were identified by microarray analysis and quantitative polymerase chain reaction, including seven tumor suppressor genes and three complement genes. Furthermore, the upregulation of complement gene C3 and complement 4B preproprotein (C4b) in A549‑P‑S cells was confirmed by ELISA analysis and was identified to be correlated with recovering Pi absorption in A549 cells by the phosphomolybdic acid method by enhancing the expression of SLC34A2. Therefore, it was hypothesized that the mechanisms underlying the effect of SLC34A2 on A549 cells might be associated with the activation of the complement alternative pathway (C3 and C4b) and upregulation of the expression of selenium binding protein 1, thioredoxin‑interacting protein, PDZK1‑interacting protein 1 and dual specificity protein phosphatase 6. Downregulation of SLC34A2 may primarily cause abnormal AT II cells to escape from complement‑associated immunosurveillance and abnormally express certain tumor‑suppressor genes inducing AT II cells to develop into lung adenocarcinoma. The present study further elucidated the effects and mechanisms of SLC34A2 in the generation and development of lung cancer. Show less

Misfolded proteins of the endoplasmic reticulum (ER) are retrotranslocated to the cytosol and degraded by the proteasome via a process termed ER-associated degradation (ERAD). The precise mechanism of retrotranslocation is unclear. Here, we use several lumenal ERAD substrates targeted for degradation by the ubiquitin ligase HRD1 including SHH (sonic hedgehog) and NHK (null Hong Kong α1-antitrypsin) to study the geometry, organization, and regulation of the HRD1-containing ERAD machinery. We report a new HRD1-associated membrane protein named HERP2, which is homologous to the previously identified HRD1 partner HERP1. Despite sequence homology, HERP2 is constitutively expressed in cells, whereas HERP1 is highly induced by ER stress. We find that these proteins are required for efficient degradation of both glycosylated and nonglycosylated SHH proteins as well as NHK. In cells depleted of HERPs, SHH proteins are largely trapped inside the ER with a fraction of the stabilized SHH protein bound to the HRD1-SEL1L ligase complex. Ubiquitination of SHH is significantly attenuated in the absence of HERPs, suggesting a defect in retrotranslocation. Both HERP proteins interact with HRD1 through a region located in the cytosol. However, unlike its homolog in Saccharomyces cerevisiae, HERPs do not regulate HRD1 stability or oligomerization status. Instead, they help recruit DERL2 to the HRD1-SEL1L complex. Additionally, the UBL domain of HERP1 also seems to have a function independent of DERL2 recruitment in ERAD. Our studies have revealed a critical scaffolding function for mammalian HERP proteins that is required for forming an active retrotranslocation complex containing HRD1, SEL1L, and DERL2. Show less

Recent large-scale genome-wide association studies have identified multiple loci robustly associated with BMI, predominantly in European ancestry (EA) populations. However, associations of these loci with obesity and related traits have not been well described in Chinese Hans. This study aimed to investigate whether BMI-associated loci are, individually and collectively, associated with adiposity-related traits and obesity in Chinese Hans and whether these associations are modified by physical activity (PA). We genotyped 28 BMI-associated single nucleotide polymorphisms (SNPs) in a population-based cohort including 2,894 unrelated Han Chinese. Genetic risk score (GRS), EA and East Asian ancestry (EAA) GRSs were calculated by adding BMI-increasing alleles based on all, EA and EAA identified SNPs, respectively. Interactions of GRS and PA were examined by including the interaction-term in the regression model. Individually, 26 of 28 SNPs showed directionally consistent effects on BMI, and associations of four loci (TMEM18, PCSK1, BDNF and MAP2K5) reached nominal significance (P<0.05). The GRS was associated with increased BMI, trunk fat and body fat percentages; and increased risk of obesity and overweight (all P<0.05). Effect sizes (0.11 vs. 0.17 kg/m2) and explained variance (0.90% vs. 1.45%) of GRS for BMI tended to be lower in Chinese Hans than in Europeans. The EA GRS and EAA GRS were associated with 0.11 and 0.13 kg/m2 higher BMI, respectively. In addition, we found that PA attenuated the effect of the GRS on BMI (Pinteraction = 0.022). Our observations suggest that the combined effect of obesity-susceptibility loci on BMI tended to be lower in Han Chinese than in EA. The overall, EA and EAA GRSs exert similar effects on adiposity traits. Genetic predisposition to increased BMI is attenuated by PA in this population of Han Chinese. Show less

A better understanding of the molecular mechanisms that regulate adipose tissue-derived stromal cell (ADSC) differentiation could provide new insight into some adipose-tissue-related disease. The differentiation of ADSCs into adipocytes is a complex physiological process that includes clonal expansion, growth arrest, and terminal differentiation. Here the role of microRNA-143 (miR-143) during ADSC adipogenic differentiation was systematically investigated. We found that miR-143 expression was transiently decreased after adipogenic induction while increased from day 3 and peaked on day 7 after induction. We show for the first time that the role of miR-143 is not consistent in the differentiation process. The regulatory role depends on the differentiation stage that miR-143 acts on. When miR-143 is overexpressed during the clonal expansion stage, the adipogenic differentiation of ADSCs is inhibited, whereas the overexpression of miR-143 during the growth arrest stage or terminal differentiation stage promotes differentiation. Further we firstly demonstrate that miR-143 plays the modulational role by directly repressing MAP2K5, a key member of the MAPKK family in the MAPK signaling pathway. These findings suggest that miR-143 plays an important role in adipose tissue formation, with special implications for some metabolic disease in which the amount and/or function of adipose tissue is altered. Show less

Dietary phytosterols have been successfully used for lowering cholesterol levels, which correlates with the fact that some phytosterols are able to act as liver X receptor (LXR) agonists. Sargassum fusiforme is an edible marine seaweed well-known for its antiatherosclerotic function in traditional Chinese medicine. In this study, seven phytosterols including fucosterol (1), saringosterol (2), 24-hydroperoxy-24-vinyl-cholesterol (3), 29-hydroperoxy-stigmasta-5,24(28)-dien-3β-ol (4), 24-methylene-cholesterol (5), 24-keto-cholesterol (6), and 5α,8α-epidioxyergosta-6,22-dien-3β-ol (7) were purified and evaluated for their actions on LXR-mediated transcription using a reporter assay. Among these phytosterols, 2 was the most potent compound in stimulating the transcriptional activities of LXRα by (3.81±0.15)-fold and LXRβ by (14.40±1.10)-fold, respectively. Two epimers of 2, 24(S)-saringosterol (2a) and 24(R)-saringosterol (2b), were subsequently separated by semipreparative high-performance liquid chromatography. Interestingly, 2a was more potent than 2b in LXRβ-mediated transactivation ((3.50±0.17)-fold vs (1.63±0.12)-fold) compared with control. Consistently, 2a induced higher expression levels of LXR target genes including key players in reverse cholesterol transport in six cell lines. These data along with molecular modeling suggested that 2a acts as a selective LXRβ agonist and is a potent natural cholesterol-lowering agent. This study also demonstrated that phytosterols in S. fusiforme contributed to the well-known antiatherosclerotic function. Show less

Transcriptional coregulators are important components of nuclear receptor (NR) signaling machinery and provide additional mechanisms for modulation of NR activity. Expression of a mutated nuclear corepressor 1 (NCoR1) that lacks 2 NR interacting domains (NCoRΔID) in the liver leads to elevated expression of genes regulated by thyroid hormone receptor (TR) and liver X receptor (LXR), both of which control hepatic cholesterol metabolism. Here, we demonstrate that expression of NCoRΔID in mouse liver improves dietary cholesterol tolerance in an LXRα-independent manner. NCoRΔID-associated cholesterol tolerance was primarily due to diminished intestinal cholesterol absorption as the result of changes in the composition and hydrophobicity of the bile salt pool. Alterations of the bile salt pool were mediated by increased expression of genes encoding the bile acid metabolism enzymes CYP27A1 and CYP3A11 as well as canalicular bile salt pump ABCB11. We have determined that these genes are regulated by thyroid hormone and that TRβ1 is recruited to their regulatory regions. Together, these data indicate that interactions between NCoR1 and TR control a specific pathway involved in regulation of cholesterol metabolism and clearance. Show less

miR-200b has been reported to be a tumor suppressor and a promising therapeutic target in cancer. miR-200b has been associated with epithelial-mesenchymal transition and chemo-resistance in cancer. The aim of this study is to investigate the expression of miR-200b, its prognostic roles and its potential targets in breast cancer. qRT-PCR was used to detect miR-200b expression in breast cancer tissues and cell lines. In situ hybridization of miR-200b on tissue microarray including 134 breast cancer samples was used to evaluate its prognostic role. Novel targets of miR-200b in breast cancer were predicted and confirmed by luciferase reporter assay and western bloting. Immunohistochemical staining was used for protein detection. The biological effects of miR-200b in breast cancer cells were further confirmed by ectopic expression of its mimics followed by MTT assay and invasion test. miR-200b was downregulated in breast cancer tissues and cell lines and its low-expression correlated with poor outcome in breast cancer patients. Members of RAB family, RAB21, RAB23, RAB18 and RAB3B were predicted to be the targets of miR-200b. The luciferase reporter assay was performed to certificate this prediction. The expressions of RAB21, RAB23, RAB18 and RAB3B were suppressed by transfection of miR-200b in breast cancer cells. Over-expression of miR-200b or knock-down of RAB21, RAB23, RAB18 and RAB3B inhibited breast cancer cell proliferation and invasion in vitro. Our study provides evidence that miR-200b is a prognostic factor in breast cancer targeting multiple members of RAB family. MiR-200b could be a potential therapeutic target in breast cancer. Show less

Previous studies have shown that apolipoprotein A5 (APOA5) gene variants are genetic determinants of the concentration of triglycerides, which are a known risk factor for coronary heart disease (CHD). Using the standardized coronary angiography method, 290 CHD patients and 198 non‑CHD controls were recruited from Ningbo Lihuili Hospital. In addition, 331 unrelated healthy volunteers were recruited as healthy controls from Ningbo Ximen Community residents. Three variants of the APOA5 gene, S19W, ‑1131T>C and 553G>T, were analyzed for their association with CHD. Under a dominant inheritance model, ‑1131CT>C was shown to be a CHD risk factor (P=0.030; OR, 1.422; 95% CI, 1.036‑1.952). The single nucleotide polymorphism, 553G>T, was found to correlate with the severity of CHD in males (P=0.032). Meta‑analysis showed that ‑1131T>C was significantly associated with CHD (P<0.0001). By contrast, negative correlations with CHD were observed for S19W and 553G>T. In the present case‑control study, APOA5 gene variants were not found to correlate with the risk of CHD in the populations studied; however, ‑1131CT>C was shown to be a CHD risk factor under a dominant inheritance model. Meta‑analysis showed a significant contribution of ‑1131T>C to the risk of CHD, implying an ethnic difference in APOA5 gene variants. Show less

The goal of our study is to investigate the combined contribution of 10 genetic variants to diabetes susceptibility. Bibliographic databases were searched from 1970 to Dec 2012 for studies that reported on genetic association study of diabetes. After a comprehensive filtering procedure, 10 candidate gene variants with informative genotype information were collected for the current meta-anlayses. Using the REVMAN software, odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the combined contribution of the selected genetic variants to diabetes. A total of 37 articles among 37,033 cases and 54,716 controls were involved in the present meta-analyses of 10 genetic variants. Three variants were found to be significantly associated with type 1 diabetes (T1D): NLRP1 rs12150220 (OR = 0.71, 95% CI = 0.55-0.92, P = 0.01), IL2RA rs11594656 (OR = 0.86, 95% CI = 0.82-0.91, P<0.00001), and CLEC16A rs725613 (OR = 0.71, 95% CI = 0.55-0.92, P = 0.01). APOA5 -1131T/C polymorphism was shown to be significantly associated with of type 2 diabetes (T2D, OR = 1.27, 95% CI = 1.03-1.57, P = 0.03). No association with diabetes was showed in the meta-analyses of other six genetic variants, including SLC2A10 rs2335491, ATF6 rs2070150, KLF11 rs35927125, CASQ1 rs2275703, GNB3 C825T, and IL12B 1188A/C. Our results demonstrated that IL2RA rs11594656 and CLEC16A rs725613 are protective factors of T1D, while NLRP1 rs12150220 and APOA5 -1131T/C are risky factors of T1D and T2D, respectively. Show less

Little is known about the associations of FADS1 genetic variants with circulating levels of PUFA and lipids in Asian populations who have a different dietary pattern and dyslipidemia prevalence compared with Western populations. In a population-based sample of 3,210 unrelated Han Chinese living in Beijing and Shanghai, we examined a FADS1 genetic variant, rs174550, in relation to blood PUFA and lipid levels. C-allele of rs174550 was significantly associated with levels of erythrocyte PUFAs in upstream and downstream pathways of delta-5 desaturase (D5D) (P ≤ 0.003). Moreover, rs174550 C-allele was associated with a lower HDL cholesterol level (P = 0.02) in total population and a higher triglyceride level (P = 0.0002) in Beijing residents. Interestingly, erythrocyte levels of 18:2n-6 and 18:3n-3 modified the effect of rs174550 on HDL cholesterol level: stronger associations between rs174550 C-allele and lower HDL cholesterol levels were exhibited when erythrocyte 18:2n-6 or 18:3n-3 level was low (P for interaction = 0.02 and 0.03, respectively). These data suggested that FADS1 genetic variant was associated with circulating PUFA and lipid levels and that its effect on HDL cholesterol might depend on PUFA status in the Han Chinese population. Show less

The effects of red clover extract and its bioactive components, biochanin A and formononetin, on the blood glucose and lipid levels of streptozotocin (STZ) induced-diabetic mice were investigated. Male diabetic C57BL/6 mice were induced by multiple low-dose STZ administration and then treated with red clover extract or isoflavones for a period of 3 weeks. Red clover extract had no significant effect on lowering the blood glucose levels of STZ-diabetic mice. Similarly, biochanin A and formononetin exerted no hypoglycemic effect. However, the serum triglycerides, total cholesterols and low-density lipoprotein-cholesterol levels for STZ-diabetic mice receiving red clover extract were significantly lower than that of untreated STZ-diabetic mice. In addition, treatment with biochanin A or formononetin significantly ameliorated these lipid profiles in diabetic mice. The mRNA expression of two target genes transcriptionally regulated by peroxisome proliferator-activated receptor (PPAR) α were determined by semi-quantitative RT-PCR and biochanin A or formononetin were found to significantly down-regulate hepatic APOC3 expression, whereas they had no significant effect on hepatic APOA5 expression. Thus we conclude that red clover extract and biochanin A or formononetin significantly ameliorate the lipid profiles of STZ-diabetic mice and these effects are achieved at least in part by activating hepatic PPARα. Show less

To investigate the association between the polymorphisms of fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2) and elongation of very long chain fatty acids like 2 (ELOVL2) gene and coronary artery disease (CAD) in a Chinese Han population. Three single nucleotide polymorphisms (SNPs) from these genes were genotyped using PCR-based restriction fragment length polymorphism analysis in 199 CAD cases and 192 controls of Han Chinese origin. rs174556 in the FADS1 gene showed allelic (P=0.002) and genotypic (P=0.030) association with the disease, while there was no disease association for the other two SNPs. The frequency of rs174556 minor allele (T) was significantly higher in the case group than the control group. The trans phase gene-gene interaction analysis showed that the combined genotype of rs174556 (T/T) and rs3756963 (T/T) was weakly associated with the disease (P=0.043). rs174556 in the FADS1 gene is very likely to be associated with CAD in the Chinese Han population. Show less

Bisphenol A (BPA) is a potential endocrine disruptor. It has been shown that it reduces serum testosterone level in rodents after exposure. However, the mechanism is unclear. The object of the present study is to investigate the effects of BPA on human and rat steroidogenic enzymes including P450 17α-hydroxylase/17,20-lyase (CYP17A1), 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3). Human and rat testis microsomes were exposed to various concentrations of BPA (10(-8)-10(-4)M). BPA inhibited human and rat 3β-HSD, CYP17A1 and 17β-HSD3 activities. The half maximal inhibitory concentrations (IC(50)s) of BPA for human and rat testis 3β-HSD were 7.92±1.03 and 26.49±3.03 μM (200 μM pregnenolone), respectively. The IC(50)s for human and rat CYP17A1 (1 μM progesterone) were 18.99±3.75 and 64.67±4.04 μM, respectively. BPA was a weak HSD17B3 inhibitor with IC(50)s of about 100 μM (200 nM androstenedione). BPA also concentration-dependently inhibited testosterone production by rat Leydig cells. In conclusion, BPA is an inhibitor for 3β-HSD, CYP17A1 and 17β-HSD3. Human 3β-HSD and CYP17A1 are more sensitive to BPA than rat 3β-HSD and CYP17A1. Show less

To evaluate the protective effect of intravitreal injection of exendin-4 analogue (E4a) in early diabetic retinopathy (DR) and to explore its possible mechanism. Forty Sprague-Dawley rats were divided into three groups: normal (N), diabetic (D), and E4a-treated diabetic rats (E4a). Diabetes was induced by streptozotocin. Rats in the E4a group were treated with E4a (0.1 μg/2μL/eye), whereas the N and D groups were treated with the equivalent volume of normal saline. Electroretinography was performed at 1 month and 3 months after diabetes onset. Thicknesses and cell counts in each layer of the retina were evaluated. The concentration of glutamate was measured by high-performance liquid chromatography (HPLC). Expressions of glucagon-like peptide-1 receptor (GLP-1R) and GLAST (excitatory amino acid transporter) were detected at mRNA and protein levels and verified by immunohistochemistry in vitro and in vivo. The rMc-1 cells were cultured under high-glucose medium (25 mM), which mimicked diabetic conditions. Effects of E4a (10 μg/mL) were also tested in the rMc-1 culture system. E4a prevented the reduction in b-wave amplitude and oscillatory potential amplitude caused by diabetes. It also prevented the cell loss of outer nuclear layer and inner nuclear layer; the thickness and cell count in the outer nuclear layer were decreased in 1-month diabetic rats. The concentration of glutamate in the retina was higher in diabetic rats and was significantly reduced in the E4a-treated group. Consistent with such changes, retinal GLP-1R and GLAST expression were reduced in the diabetic retina but upregulated in E4a-treated rats. No improvement was found in the retina in both functional and morphologic parameters 3 months after treatment. Intravitreal administration of E4a can prevent the retina, functionally and morphologically, from the insults of diabetes in rats. GLP-1R and GLAST were proved to exist in the rat retina, and their lowered expressions in the diabetic retina might be related to retinal damage by increasing the retinal glutamate. E4a might protect the retina by reducing the glutamate level through upregulating GLP-1R and GLAST, as observed in retinal Müller cells in this study, but this protective effect was transient. Thus, this could be a potential approach for the treatment of DR. Show less

Colorectal cancer (CRC) is the third most common cancer in the world. Early diagnosis of colorectal cancer is the key to reducing the death rate of CRC patients. Predicting the response to current therapeutic modalities of CRC will also have a great impact on patient care. This review summarizes recent advances and patents in biomarker discovery in CRC under five major categories; including genomic changes, expression changes, mutations, epigenetic changes and microRNAs. The interesting patents include: 1) a patent for a method to differentiate normal exfoliated cells from cancer cells based on whether they were subjected to apoptosis and DNA degradation; 2) A model (PM-33 multiple molecular marker model) based on expression changes of up-regulation of the MDM2, DUSP6, and NFl genes down-regulation of the RNF4, MMD and EIF2S3 genes, which achieved an 88% sensitivity, and an 82% specificity for CRC diagnosis; 3) gene mutations in PTEN, KRAS, PIK3CA for predicting the response to anti-EGFR therapies, a common drug used for CRC treatment; 4) patents on epigenetic changes of ITGA4, SEPT9, ALX4, TFAP2E FOXL2, SARM1, ID4 etc. and many key miRNAs. Finally, future directions in the fields were commented on or suggested, including the combination of multiple categories of biomarkers and pathway central or network-based biomarker panels. Show less

Lung cancer is one of the most devastating diseases worldwide. RGS17 is previously shown to be over-expressed in human lung adenocarcinomas and plays an important role in lung tumor growth. Here we have identified a miRNA, has-mir-182, involved in the regulation of RGS17 expression through two conserved sites located in its 3' UTR region. Consistently, endogenous RGS17 expression level is regulated by hsa-mir-182 in human lung cancer cell lines. Similar to the knockdown of RGS17, ectopic expression of hsa-mir-182 significantly inhibits lung cancer cell proliferation and anchorage-independent cell growth, which can be rescued by re-expression of RGS17. Taken together, these data have provided the first evidence of miRNA regulation of RGS17 expression in lung cancer. Show less