Concentrations of liver enzymes in plasma are widely used as indicators of liver disease. We carried out a genome-wide association study in 61,089 individuals, identifying 42 loci associated with conc Show more
Concentrations of liver enzymes in plasma are widely used as indicators of liver disease. We carried out a genome-wide association study in 61,089 individuals, identifying 42 loci associated with concentrations of liver enzymes in plasma, of which 32 are new associations (P = 10(-8) to P = 10(-190)). We used functional genomic approaches including metabonomic profiling and gene expression analyses to identify probable candidate genes at these regions. We identified 69 candidate genes, including genes involved in biliary transport (ATP8B1 and ABCB11), glucose, carbohydrate and lipid metabolism (FADS1, FADS2, GCKR, JMJD1C, HNF1A, MLXIPL, PNPLA3, PPP1R3B, SLC2A2 and TRIB1), glycoprotein biosynthesis and cell surface glycobiology (ABO, ASGR1, FUT2, GPLD1 and ST3GAL4), inflammation and immunity (CD276, CDH6, GCKR, HNF1A, HPR, ITGA1, RORA and STAT4) and glutathione metabolism (GSTT1, GSTT2 and GGT), as well as several genes of uncertain or unknown function (including ABHD12, EFHD1, EFNA1, EPHA2, MICAL3 and ZNF827). Our results provide new insight into genetic mechanisms and pathways influencing markers of liver function. Show less
The Δ6 desaturase, encoded by FADS2, plays a crucial role in omega-3 and omega-6 fatty acid synthesis. These fatty acids are essential components of the central nervous system, and they act as precurs Show more
The Δ6 desaturase, encoded by FADS2, plays a crucial role in omega-3 and omega-6 fatty acid synthesis. These fatty acids are essential components of the central nervous system, and they act as precursors for eicosanoid signaling molecules and as direct modulators of gene expression. The polypyrimidine tract binding protein (PTB or hnRNP I) is a splicing factor that regulates alternative pre-mRNA splicing. Here, PTB is shown to bind an exonic splicing silencer element and repress alternative splicing of FADS2 into FADS2 AT1. PTB and FADS2AT1 were inversely correlated in neonatal baboon tissues, implicating PTB as a major regulator of tissue-specific FADS2 splicing. In HepG2 cells, PTB knockdown modulated alternative splicing of FADS2, as well as FADS3, a putative desaturase of unknown function. Omega-3 fatty acids decreased by nearly one half relative to omega-6 fatty acids in PTB knockdown cells compared with controls, with a particularly strong decrease in eicosapentaenoic acid (EPA) concentration and its ratio to arachidonic acid (ARA). This is a rare demonstration of a mechanism specifically altering the cellular omega-3 to omega-6 fatty acid ratio without any change in diet/media. These findings reveal a novel role for PTB, regulating availability of membrane components and eicosanoid precursors for cell signaling. Show less
Forkhead Box M1 (Foxm1) is a transcription factor essential for organ morphogenesis and development of various cancers. Although complete deletion of Foxm1 in Foxm1(-/-) mice caused embryonic lethalit Show more
Forkhead Box M1 (Foxm1) is a transcription factor essential for organ morphogenesis and development of various cancers. Although complete deletion of Foxm1 in Foxm1(-/-) mice caused embryonic lethality due to severe abnormalities in multiple organ systems, requirements for Foxm1 in cardiomyocytes remain to be determined. This study was designed to elucidate the cardiomyocyte-autonomous role of Foxm1 signaling in heart development. We generated a new mouse model in which Foxm1 was specifically deleted from cardiomyocytes (Nkx2.5-Cre/Foxm1(fl/f) mice). Deletion of Foxm1 from cardiomyocytes was sufficient to disrupt heart morphogenesis and induce embryonic lethality in late gestation. Nkx2.5-Cre/Foxm1(fl/fl) hearts were dilated with thinning of the ventricular walls and interventricular septum, as well as disorganization of the myocardium which culminated in cardiac fibrosis and decreased capillary density. Cardiomyocyte proliferation was diminished in Nkx2.5-Cre/Foxm1(fl/fl) hearts owing to altered expression of multiple cell cycle regulatory genes, such as Cdc25B, Cyclin B(1), Plk-1, nMyc and p21(cip1). In addition, Foxm1 deficient hearts displayed reduced expression of CaMKIIδ, Hey2 and myocardin, which are critical mediators of cardiac function and myocardial growth. Our results indicate that Foxm1 expression in cardiomyocytes is critical for proper heart development and required for cardiomyocyte proliferation and myocardial growth. Show less
Protein kinases are intensely studied mediators of cellular signaling, yet important questions remain regarding their regulation and in vivo properties. Here, we use a probe-based chemoprotemics platf Show more
Protein kinases are intensely studied mediators of cellular signaling, yet important questions remain regarding their regulation and in vivo properties. Here, we use a probe-based chemoprotemics platform to profile several well studied kinase inhibitors against >200 kinases in native cell proteomes and reveal biological targets for some of these inhibitors. Several striking differences were identified between native and recombinant kinase inhibitory profiles, in particular, for the Raf kinases. The native kinase binding profiles presented here closely mirror the cellular activity of these inhibitors, even when the inhibition profiles differ dramatically from recombinant assay results. Additionally, Raf activation events could be detected on live cell treatment with inhibitors. These studies highlight the complexities of protein kinase behavior in the cellular context and demonstrate that profiling with only recombinant/purified enzymes can be misleading. Show less
Dental caries is the most common chronic disease in children and a major public health concern due to its increasing incidence, serious health and social co-morbidities, and socio-demographic disparit Show more
Dental caries is the most common chronic disease in children and a major public health concern due to its increasing incidence, serious health and social co-morbidities, and socio-demographic disparities in disease burden. We performed the first genome-wide association scan for dental caries to identify associated genetic loci and nominate candidate genes affecting tooth decay in 1305 US children ages 3-12 yrs. Affection status was defined as 1 or more primary teeth with evidence of decay based on intra-oral examination. No associations met strict criteria for genome-wide significance (p < 10E-7); however, several loci (ACTN2, MTR, and EDARADD, MPPED2, and LPO) with plausible biological roles in dental caries exhibited suggestive evidence for association. Analyses stratified by home fluoride level yielded additional suggestive loci, including TFIP11 in the low-fluoride group, and EPHA7 and ZMPSTE24 in the sufficient-fluoride group. Suggestive loci were tested but not significantly replicated in an independent sample (N = 1695, ages 2-7 yrs) after adjustment for multiple comparisons. This study reinforces the complexity of dental caries, suggesting that numerous loci, mostly having small effects, are involved in cariogenesis. Verification/replication of suggestive loci may highlight biological mechanisms and/or pathways leading to a fuller understanding of the genetic risks for dental caries. Show less
To investigate the potential role of synthetic liver X receptors (LXRs) agonists T0901317 in lung of rats with acute lung injury induced by lipopolysaccharide (LPS). Rats infused with LPS served as ac Show more
To investigate the potential role of synthetic liver X receptors (LXRs) agonists T0901317 in lung of rats with acute lung injury induced by lipopolysaccharide (LPS). Rats infused with LPS served as acute lung injury (ALI) models. Specific mRNA was quantified by semi-quantitative reverse transcription polymerase (RT-PCR) and protein expression by western blotting. Inflammatory cytokine and MPO activity assays were studied by ELISA. Histopathology analysis was evaluated by hematoxylin and eosin. The expressions of LXRα and LXRβ were gradually decreased after LPS challenge. T0901317 pretreatment efficiently reduced the production of TNF-α, IL-1β, and IL-6, while elevated the level of IL-10 in BALF of rats with ALI. T0901317 also decreased the number of inflammatory cells and the concentration of total proteins in the BALF. Compared with the LPS group, rats with ALI which were pretreated with T0901317 had lower pulmonary tissue MPO activity and lightened histopathologic changes of lung. Furthermore, the expressions of NF-κB and ICAM-1 were markedly reduced after T0901317 administration. The expressions of LXRs were significantly decreased and synthetic agonist T0901317 suppresses lung inflammatory responses and lightened histopathologic changes of lung in rats with ALI. The mechanisms of this action for T0901317 may associate with the inhibition of NF-κB activation and downregulation of adhesion molecules ICAM-1 gene. Show less
In the previous experiment, we found that there was a different response between E3 rats and DA.1U rats to high-fat-diet-induced metabolic syndrome (HFD-MetS). The aim of this study was to explore the Show more
In the previous experiment, we found that there was a different response between E3 rats and DA.1U rats to high-fat-diet-induced metabolic syndrome (HFD-MetS). The aim of this study was to explore the cause and molecular mechanism of the genetic difference in susceptibility to metabolic syndrome in E3 rats as compared with DA.1U rats. Firstly, a 12-week HFD-MetS model in E3 and DA.1U rats was carried out and assessed. Then, the expression of key insulin signaling molecules, metabolic nuclear receptors, metabolic key enzymes and histone deacetylases (Hdacs) was determined by different methods. Finally, the effects of overexpression and disruption of Hdac3 on metabolic nuclear receptors were analyzed in CBRH-7919 cells and primarily-hepatic cells from DA.1U and E3 rats. We found that E3 rats were susceptible, while DA.1U rats were resisted to HFD-MetS. The expression of liver X receptor α,β (LXR-α,β), farnesoid X receptor (FXR), peroxisome proliferator activated receptor γ (PPAR-γ) and cholesterol 7α-hydroxylase (CYP7A1) increased markedly in DA.1U rat liver, whereas they decreased significantly in E3 rats. The expression of Hdac3 increased by HFD treatment in both E3 and DA.1U rat livers, but the constitutive Hdac3 expression was lower in DA.IU rat liver than in E3 rat liver. Importantly, overexpression of Hdac3 could downregulate the expression of LXR-α, PPAR-γ and CYP7A1 in both CBRH-7919 cells and primarily cultured hepatic cells from DA.IU rats. On the contrary, disruption of Hdac3 by shRNA upregulated the expression of LXR-α, PPAR-γ and CYP7A1 in both CBRH-7919 cells and primarily cultured hepatic cells from E3 rats. The results suggested that a high constitutive expression of Hdac3 inhibiting the expression of PPAR-γ, LXR-α and CYP7A1 in liver contributes to HFD-MetS in E3 rats. Show less
Atherogenesis is a long-term process that involves inflammatory response coupled with metabolic dysfunction. Foam cell formation and macrophage inflammatory response are two key events in atherogenesi Show more
Atherogenesis is a long-term process that involves inflammatory response coupled with metabolic dysfunction. Foam cell formation and macrophage inflammatory response are two key events in atherogenesis. Adipocyte enhancer-binding protein 1 (AEBP1) has been shown to impede macrophage cholesterol efflux, promoting foam cell formation, via peroxisome proliferator-activated receptor (PPAR)-γ1 and liver X receptor α (LXRα) downregulation. Moreover, AEBP1 has been shown to promote macrophage inflammatory responsiveness by inducing nuclear factor (NF)-κB activity via IκBα downregulation. Lipopolysaccharide (LPS)-induced suppression of pivotal macrophage cholesterol efflux mediators, leading to foam cell formation, has been shown to be mediated by AEBP1. Herein, we showed that AEBP1-transgenic mice (AEBP1(TG)) with macrophage-specific AEBP1 overexpression exhibit hyperlipidemia and develop atherosclerotic lesions in their proximal aortas. Consistently, ablation of AEBP1 results in significant attenuation of atherosclerosis (males: 3.2-fold, P = 0.001 [en face]), 2.7-fold, P = 0.0004 [aortic roots]; females: 2.1-fold, P = 0.0026 [en face], 1.7-fold, P = 0.0126 [aortic roots]) in the AEBP1(-/-)/low-density lipoprotein receptor (LDLR )(-/-) double-knockout (KO) mice. Bone marrow (BM) transplantation experiments further revealed that LDLR (-/-) mice reconstituted with AEBP1(-/-)/LDLR (-/-) BM cells (LDLR (-/-)/KO-BM chimera) display significant reduction of atherosclerosis lesions (en face: 2.0-fold, P = 0.0268; aortic roots: 1.7-fold, P = 0.05) compared with control mice reconstituted with AEBP1(+/+)/LDLR (-/-) BM cells (LDLR (-/-)/WT-BM chimera). Furthermore, transplantation of AEBP1(TG) BM cells with the normal apolipoprotein E (ApoE) gene into ApoE (-/-) mice (ApoE (-/-)/TG-BM chimera) leads to significant development of atherosclerosis (males: 2.5-fold, P = 0.0001 [en face], 4.7-fold, P = 0.0001 [aortic roots]; females: 1.8-fold, P = 0.0001 [en face], 3.0-fold, P = 0.0001 [aortic roots]) despite the restoration of ApoE expression. Macrophages from ApoE (-/-)/TG-BM chimeric mice express reduced levels of PPARγ1, LXRα, ATP-binding cassette A1 (ABCA1) and ATP-binding cassette G1 (ABCG1) and increased levels of the inflammatory mediators interleukin (IL)-6 and tumor necrosis factor (TNF)-α compared with macrophages of control chimeric mice (ApoE (-/-)/NT-BM ) that received AEBP1 nontransgenic (AEBP1(NT) ) BM cells. Our in vivo experimental data strongly suggest that macrophage AEBP1 plays critical regulatory roles in atherogenesis, and it may serve as a potential therapeutic target for the prevention or treatment of atherosclerosis. Show less
The nuclear receptor retinoid X receptor (RXR) functions potently in the regulation of homeostasis and cell development, while rexinoids as RXR agonists have proved their therapeutic potential in the Show more
The nuclear receptor retinoid X receptor (RXR) functions potently in the regulation of homeostasis and cell development, while rexinoids as RXR agonists have proved their therapeutic potential in the treatment of metabolic diseases and cancer. Here, the natural product bigelovin was identified as a selective RXRα agonist. Interestingly, this compound could not transactivate RXRα:RXRα homodimer but could enhance the transactivation of RXRα:peroxisome proliferator-activated receptor γ heterodimer and repress that of RXRα:liver X receptor (LXR) α heterodimer, while it had no effects on RXRα:farnesoid X receptor heterodimer. Considering that the effective role of LXR response element involved transactivation of sterol regulatory element-binding protein-1c mediated by RXRα:LXRα in triglyceride elevation, such LXR response element repressing by bigelovin has obviously addressed its potency for further research. Moreover, our determined crystal structure of the bigelovin-activated RXRα ligand-binding domain with the coactivator human steroid receptor coactivator-1 peptide revealed that bigelovin adopted a distinct binding mode. Compared with the known RXR ligands, bigelovin lacks the acidic moiety in structure, which indicated that the acidic moiety rendered little effects on RXR activation. Our results have thereby provided new insights into the structure-based selective rexinoids design with bigelovin as a potential lead compound. Show less
Although widely prescribed for their potent antiinflammatory actions, glucocorticoid drugs (e.g., dexamethasone) cause undesirable side effects that are features of the metabolic syndrome, including h Show more
Although widely prescribed for their potent antiinflammatory actions, glucocorticoid drugs (e.g., dexamethasone) cause undesirable side effects that are features of the metabolic syndrome, including hyperglycemia, fatty liver, insulin resistance, and type II diabetes. Liver x receptors (LXRs) are nuclear receptors that respond to cholesterol metabolites and regulate the expression of a subset of glucocorticoid target genes. Here, we show LXRβ is required to mediate many of the negative side effects of glucocorticoids. Mice lacking LXRβ (but not LXRα) were resistant to dexamethasone-induced hyperglycemia, hyperinsulinemia, and hepatic steatosis, but remained sensitive to dexamethasone-dependent repression of the immune system. In vivo, LXRα/β knockout mice demonstrated reduced dexamethasone-induced expression of the key hepatic gluconeogenic gene, phosphoenolpyruvate carboxykinase (PEPCK). In perfused liver and primary mouse hepatocytes, LXRβ was required for glucocorticoid-induced recruitment of the glucocorticoid receptor to the PEPCK promoter. These findings suggest a new avenue for the design of safer glucocorticoid drugs through a mechanism of selective glucocorticoid receptor transactivation. Show less
Obesity is a serious health concern for children and adolescents, particularly in Western societies, where its incidence is now considered to have reached epidemic proportions. A number of genetic det Show more
Obesity is a serious health concern for children and adolescents, particularly in Western societies, where its incidence is now considered to have reached epidemic proportions. A number of genetic determinants of adult BMI have already been established through genome wide association studies (GWAS), most recently from the GIANT meta-analysis of such datasets combined. In this current study of European Americans, we examined the 32 loci detected in that GIANT study in the context of common childhood obesity within a cohort of 1,097 cases (defined as BMI ≥95th percentile), together with 2,760 lean controls (defined as BMI <50th percentile), aged between 2 and 18 years old. Nine of these single-nucleotide polymorphims (SNPs) yielded at least nominal evidence for association with common childhood obesity, namely at the FTO, TMEM18, NRXN3, MC4R, SEC16B, GNPDA2, TNNI3K, QPCTL, and BDNF loci. However, overall 28 of the 32 loci showed directionally consistent effects to that of the adult BMI meta-analysis. We conclude that among the 32 loci that have been reported to associate with adult BMI in the largest meta-analysis of BMI to date, at least nine also contribute to the determination of common obesity in childhood in European Americans, as demonstrated by their associations in our pediatric cohort. Show less
Large-scale genome-wide association studies (GWAS) have identified many loci associated with body mass index (BMI), but few studies focused on obesity as a binary trait. Here we report the results of Show more
Large-scale genome-wide association studies (GWAS) have identified many loci associated with body mass index (BMI), but few studies focused on obesity as a binary trait. Here we report the results of a GWAS and candidate SNP genotyping study of obesity, including extremely obese cases and never overweight controls as well as families segregating extreme obesity and thinness. We first performed a GWAS on 520 cases (BMI>35 kg/m(2)) and 540 control subjects (BMI<25 kg/m(2)), on measures of obesity and obesity-related traits. We subsequently followed up obesity-associated signals by genotyping the top ∼500 SNPs from GWAS in the combined sample of cases, controls and family members totaling 2,256 individuals. For the binary trait of obesity, we found 16 genome-wide significant signals within the FTO gene (strongest signal at rs17817449, P = 2.5 × 10(-12)). We next examined obesity-related quantitative traits (such as total body weight, waist circumference and waist to hip ratio), and detected genome-wide significant signals between waist to hip ratio and NRXN3 (rs11624704, P = 2.67 × 10(-9)), previously associated with body weight and fat distribution. Our study demonstrated how a relatively small sample ascertained through extreme phenotypes can detect genuine associations in a GWAS. Show less
The association of small, ubiquitin-related modifier-specific isopeptidases (also known as sentrin-specific proteases, or SENPs) with nuclear pore complexes (NPCs) is conserved in eukaryotic organisms Show more
The association of small, ubiquitin-related modifier-specific isopeptidases (also known as sentrin-specific proteases, or SENPs) with nuclear pore complexes (NPCs) is conserved in eukaryotic organisms ranging from yeast to mammals. However, the functional significance of this association remains poorly understood, particularly in mammalian cells. In this study, we have characterized the molecular basis for interactions between SENP2 and NPCs in human cells. Using fluorescence recovery after photobleaching, we demonstrate that SENP2, although concentrated at the nuclear basket, is dynamically associated with NPCs. This association is mediated by multiple targeting elements within the N-terminus of SENP2 that function cooperatively to mediate NPC localization. One of these elements consists of a high-affinity nuclear localization signal that mediates indirect tethering to FG-repeat-containing nucleoporins through karyopherins. A second element mediates interactions with the Nup107-160 nucleoporin subcomplex. A third element consists of a nuclear export signal. Collectively, our findings reveal that SENP2 is tethered to NPCs through a complex interplay of interactions with nuclear import and export receptors and nucleoporins. Disruption of these interactions enhances SENP2 substrate accessibility, suggesting an important regulatory node in the SUMO pathway. Show less
The L27 (LIN-2/LIN-7) domain is a protein-protein interaction module capable of assembling proteins into biologically important complexes. Pals1 contains two L27 domains: the first, L27N, interacts wi Show more
The L27 (LIN-2/LIN-7) domain is a protein-protein interaction module capable of assembling proteins into biologically important complexes. Pals1 contains two L27 domains: the first, L27N, interacts with PATJ, and the second, L27C, interacts with MALS, forming a tripartite complex that plays a crucial role in the establishment and maintenance of cell polarity. To provide a better understanding of the mechanism of assembly of this tripartite complex, four different L27(PATJ)-(L27N,L27C)(Pals1)-L27(MALS) constructs were cloned, expressed, purified and crystallized. Crystals of tripartite complex 1 of L27(PATJ)-(L27N,L27C)(Pals1)-L27(MALS) diffracted to 2.05 Å resolution. These crystals belonged to either space group P6(1)22 or P6(5)22, with unit-cell parameters a = b = 145.2, c = 202.5 Å. Assuming the presence of four molecules in the asymmetric unit, a Matthews coefficient of 2.69 Å(3) Da(-1) was calculated, corresponding to a solvent content of 54.25%. 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 Show more
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
Sox9 is a direct transcriptional activator of cartilage-specific extracellular matrix genes and has essential roles in chondrogenesis. Mutations in or around the SOX9 gene cause campomelic dysplasia o Show more
Sox9 is a direct transcriptional activator of cartilage-specific extracellular matrix genes and has essential roles in chondrogenesis. Mutations in or around the SOX9 gene cause campomelic dysplasia or Pierre Robin Sequence. However, Sox9-dependent transcriptional control in chondrogenesis remains largely unknown. Here we identify Wwp2 as a direct target of Sox9. Wwp2 interacts physically with Sox9 and is associated with Sox9 transcriptional activity via its nuclear translocation. A yeast two-hybrid screen using a cDNA library reveals that Wwp2 interacts with Med25, a component of the Mediator complex. The positive regulation of Sox9 transcriptional activity by Wwp2 is mediated by the binding between Sox9 and Med25. In zebrafish, morpholino-mediated knockdown of either wwp2 or med25 induces palatal malformation, which is comparable to that in sox9 mutants. These results provide evidence that the regulatory interaction between Sox9, Wwp2 and Med25 defines the Sox9 transcriptional mechanisms of chondrogenesis in the forming palate. Show less
Recent meta-analysis of genome-wide association studies in European descent samples identified novel loci influencing glucose and insulin related traits. In the current study, we aimed to evaluate the Show more
Recent meta-analysis of genome-wide association studies in European descent samples identified novel loci influencing glucose and insulin related traits. In the current study, we aimed to evaluate the association between these loci and traits related to glucose metabolism in the Chinese. We genotyped seventeen single nucleotide polymorphisms (SNPs) from fifteen loci including GIPR, ADCY5, TCF7L2, VPS13C, DGKB, MADD, ADRA2A, FADS1, CRY2, SLC2A2, GLIS3, PROX1, C2CD4B, SLC30A8 and IGF1 in 6,822 Shanghai Chinese Hans comprising 3,410 type 2 diabetic patients and 3,412 normal glucose regulation subjects. MADD rs7944584 showed strong association to type 2 diabetes (p = 3.5×10(-6), empirical p = 0.0002) which was not observed in the European descent populations. SNPs from GIPR, TCF7L2, CRY2, GLIS3 and SLC30A8 were also associated with type 2 diabetes (p = 0.0487∼2.0×10(-8)). Further adjusting age, gender and BMI as confounders found PROX1 rs340874 was associated with type 2 diabetes (p = 0.0391). SNPs from DGKB, MADD and SLC30A8 were associated with fasting glucose while PROX1 rs340874 was significantly associated with OGTT 2-h glucose (p = 0.0392∼0.0014, adjusted for age, gender and BMI), the glucose-raising allele also showed association to lower insulin secretion. IGF1 rs35767 showed significant association to both fasting and 2-h insulin levels as well as insulin secretion and sensitivity indices (p = 0.0160∼0.0035, adjusted for age, gender and BMI). Our results indicated that SNPs from GIPR, TCF7L2, DGKB, MADD, CRY2, GLIS3, PROX1, SLC30A8 and IGF1 were associated with traits related to glucose metabolism in the Chinese population. Show less
Obesity is globally prevalent and highly heritable, but its underlying genetic factors remain largely elusive. To identify genetic loci for obesity susceptibility, we examined associations between bod Show more
Obesity is globally prevalent and highly heritable, but its underlying genetic factors remain largely elusive. To identify genetic loci for obesity susceptibility, we examined associations between body mass index and ∼ 2.8 million SNPs in up to 123,865 individuals with targeted follow up of 42 SNPs in up to 125,931 additional individuals. We confirmed 14 known obesity susceptibility loci and identified 18 new loci associated with body mass index (P < 5 × 10⁻⁸), one of which includes a copy number variant near GPRC5B. Some loci (at MC4R, POMC, SH2B1 and BDNF) map near key hypothalamic regulators of energy balance, and one of these loci is near GIPR, an incretin receptor. Furthermore, genes in other newly associated loci may provide new insights into human body weight regulation. Show less
To search for a new method of screening for molecular targets for androgen-dependent prostate cancer. We collected tissue samples and paired serum samples from 3 cases of androgen-dependent prostate c Show more
To search for a new method of screening for molecular targets for androgen-dependent prostate cancer. We collected tissue samples and paired serum samples from 3 cases of androgen-dependent prostate cancer (ADPC) treated by surgical resection, and included another 3 samples of benign prostatic hyperplasia (BPH) tissue and normal human serum in the control group. The total proteins extracted were separated and transmembrane by two-dimensional gel electrophoresis, followed by hybridization with the sera of the patients with ADPC and those with hormone-independent prostate cancer (HIPC) as the primary antibodies. The differentially expressed proteins were compared by Western blot, analyzed by MALDI-TOF-MS mass spectrography, and verified by RT-PCR and Western blot following bioinformatic identification. This modified method exhibited a significantly better effect in displaying differentially expressed proteins, by which 12 differentially expressed protein spots were identified, including Beclin1, glutathione S-transferase P (GSTP1-1), ZBTB7, dihydrodiol dehydrogenase 2 (DDH), enolase (ENO1), glucose-dependent insulin-releasing peptide receptor (GIPR), Mn-superoxide dismutase (MnSOD), phosphoglycerate mutase 1 (PGAM1), amino-peptidyl-prolyl cistrons isomerase (PPIA), and phospholipid-PE-binding protein (PEBP). The mRNA and protein expressions of Beclin1 were significantly down-regulated in androgen-dependent prostate cancer tissues. This modified serum-guided immunoblotting technique has provided a new method for clarifying the molecular mechanisms of the occurrence and progression of HIPC, in which Beclin1-mediated autophagy may play a key role. Show less
to explore the potential role of apolipoprotein A5 (apoA5) on the hypertriglyceridemia (HTG)-lowering effects of statin. twenty-four Sprague-Dawley rats were randomized into 3 groups: (1) control grou Show more
to explore the potential role of apolipoprotein A5 (apoA5) on the hypertriglyceridemia (HTG)-lowering effects of statin. twenty-four Sprague-Dawley rats were randomized into 3 groups: (1) control group (n = 8), with no special treatment; (2) HTG group (n = 8), treated with 10% fructose water for 6 weeks; (3) statin group (n = 8), treated with 10% fructose water for 2 weeks and cotreated with atorvastatin 10 mg×kg(-1)×d(-1) for another 4 weeks. Body weight, fasting plasma lipids and the hepatic expressions of apoA5 and peroxisome proliferator activated receptor (PPAR)α were determined. In separate in vitro experiments, we tested the effects of atorvastatin on TG and the expressions of apoA5 and PPARα in HepG2 cells. (1) at 6 weeks, plasma TG was higher in rats in HTG group than in controls, which was significantly reduced in statin group (both P < 0.05). (2) Rat hepatic apoA5 expression in HTG group was significantly lower than in control group and was significantly higher in statin group than in HTG group (both P < 0.05). (3) Similarly, rat PPARα mRNA expression in HTG group was lower than in control group and was higher in statin group than in HTG group (both P < 0.05). (4) Statin significantly upregulated the expressions of apoA5 and PPARα and decreased TG in HepG2 cells. The above effects induced by statin was blocked in the presence of PPARα inhibitor. upregulation of apoA5 expression contributes to TG lowering effect of statin via PPARα signaling pathway. Show less
The neighboring position of apolipoprotein A-I (apoA-I) and apolipoprotein A-V (apoA-V) gene and the modulation of apoA-V on the concentrations, size and maturation of high density lipoprotein (HDL) m Show more
The neighboring position of apolipoprotein A-I (apoA-I) and apolipoprotein A-V (apoA-V) gene and the modulation of apoA-V on the concentrations, size and maturation of high density lipoprotein (HDL) may indicate a special relationship between apoA-V and HDL. To assess the effects of apoA-V on HDL structure and related functions in vitro, a series of recombinant HDL (rHDL) were synthesized in vitro with various mass ratios of recombinant apoA-I: apoA-V. An increase in apoA-V in rHDL resulted in enhanced lipid-binding ability, increased phospholipid content and larger particle size. Furthermore, the lipid-free and lipid-bound apoA-V in rHDL showed antioxidant capacity against low density lipoprotein (LDL) in vitro. In THP-1 derived macrophages, apoA-V of rHDL was shown to have no influence on the uptake of oxidized LDL (oxLDL) and intracellular lipid accumulation. Thus, the addition of apoA-V to rHDL resulted in changes in several rHDL properties, including increased lipid-binding ability, phospholipid content, particle size and antioxidant capacity. These alterations may explain the modulation of apoA-V on HDL in vivo and the beneficial functions of apoA-V on atherosclerosis. Show less
Genetic studies might provide new insights into the biological mechanisms underlying lipid metabolism and risk of CAD. We therefore conducted a genome-wide association study to identify novel genetic Show more
Genetic studies might provide new insights into the biological mechanisms underlying lipid metabolism and risk of CAD. We therefore conducted a genome-wide association study to identify novel genetic determinants of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides. We combined genome-wide association data from 8 studies, comprising up to 17 723 participants with information on circulating lipid concentrations. We did independent replication studies in up to 37 774 participants from 8 populations and also in a population of Indian Asian descent. We also assessed the association between single-nucleotide polymorphisms (SNPs) at lipid loci and risk of CAD in up to 9 633 cases and 38 684 controls. We identified 4 novel genetic loci that showed reproducible associations with lipids (probability values, 1.6×10(-8) to 3.1×10(-10)). These include a potentially functional SNP in the SLC39A8 gene for HDL-C, an SNP near the MYLIP/GMPR and PPP1R3B genes for LDL-C, and at the AFF1 gene for triglycerides. SNPs showing strong statistical association with 1 or more lipid traits at the CELSR2, APOB, APOE-C1-C4-C2 cluster, LPL, ZNF259-APOA5-A4-C3-A1 cluster and TRIB1 loci were also associated with CAD risk (probability values, 1.1×10(-3) to 1.2×10(-9)). We have identified 4 novel loci associated with circulating lipids. We also show that in addition to those that are largely associated with LDL-C, genetic loci mainly associated with circulating triglycerides and HDL-C are also associated with risk of CAD. These findings potentially provide new insights into the biological mechanisms underlying lipid metabolism and CAD risk. Show less
As a newly described member of the apolipoprotein gene family, apolipoprotein A5 (APOA5) has been suggested to play a key role in the triglyceride metabolism in both human and mice. The aim of this st Show more
As a newly described member of the apolipoprotein gene family, apolipoprotein A5 (APOA5) has been suggested to play a key role in the triglyceride metabolism in both human and mice. The aim of this study was to identify the porcine (Sus scrofa) APOA5 gene, determine its mRNA and its mutations that are associated with lipid accumulation. The porcine APOA5 cDNA was amplified by reverse transcriptase polymerase chain reaction using the information of the mouse or other mammals. It had been determined that the open reading frame of the porcine APOA5 gene consists of 1092 bp, which encodes a predicted protein composed of 363 amino acids with a similarity to bovine (80.43%) and to human (78.47%). The expression analysis indicated that the porcine APOA5 gene was expressed in hypophysis, fat and liver. Twelve single nucleotide polymorphisms (SNPs), including 4 SNPs in the 5' end, 1 SNP in second intron, 1 SNP in third exon and 6 SNPs in the 3' end, were identified in the porcine APOA5 gene and genotyped on the Jinhua × Pietrain F2 reference population, it had revealed that the SNP of C1834T was significantly associated with average backfat thickness and leaf fat weight (P < 0.01 and P < 0.05, respectively). In conclusion, this study has got basic information of the porcine APOA5 gene and provides evidence that the APOA5 gene could be a potential candidate gene for fat deposition. Show less
Hypertriglyceridemia is associated insulin resistance in obese people. Recently identified apolipoprotein A5 (apoA5) is involved in triglyceride (TG) metabolism. This study was to investigate the role Show more
Hypertriglyceridemia is associated insulin resistance in obese people. Recently identified apolipoprotein A5 (apoA5) is involved in triglyceride (TG) metabolism. This study was to investigate the role of apoA5 in insulin resistance-related hypertriglyceridemia in obesity. 682 participants including 340 non-obese individuals and 342 obese individuals were recruited in this study. Plasma apoA5 levels were measured. The insulin resistance in participants was assessed by homeostasis model assessment of insulin resistance (HOMA-IR). An insulin resistant and hypertriglyceridemic rat model was established by high-fructose diet with obese Zucker rats as positive controls. Besides, two insulin resistant models in vitro were induced by insulin and tumor necrosis factor-alpha (TNFalpha) in HepG2 cells. Obese participants had lower plasma apoA5 levels. Plasma apoA5 levels were inversely correlated with TG, body mass index and HOMA-IR in humans. Furthermore, hepatic and plasma apoA5 reduced in fructose-fed rats whereas no significant changes of apoA5 were observed in obese Zucker rats. In addition, treatment of HepG2 cells with insulin and TNFalpha decreased apoA5 expression and increased TG content. Thus, decreased apolipoprotein A5 is implicated in insulin resistance-related hypertriglyceridemia in obesity. Show less
Nonalcoholic fatty liver disease is associated with hepatic insulin resistance and type 2 diabetes mellitus. Whether this association has a genetic basis is unknown. In 95 healthy Asian Indian men, a Show more
Nonalcoholic fatty liver disease is associated with hepatic insulin resistance and type 2 diabetes mellitus. Whether this association has a genetic basis is unknown. In 95 healthy Asian Indian men, a group known to have a high prevalence of nonalcoholic fatty liver disease, we genotyped two single-nucleotide polymorphisms (SNPs) in the gene encoding apolipoprotein C3 (APOC3) that are known to be associated with hypertriglyceridemia (rs2854116 [T-455C] and rs2854117 [C-482T]). Plasma apolipoprotein C3 concentrations, insulin sensitivity, and hepatic triglyceride content were measured. We also measured plasma triglyceride concentrations and retinyl fatty acid ester absorption as well as plasma triglyceride clearance after oral and intravenous fat-tolerance tests. Liver triglyceride content and APOC3 genotypes were also assessed in a group of 163 healthy non-Asian Indian men. Carriers of the APOC3 variant alleles (C-482T, T-455C, or both) had a 30% increase in the fasting plasma apolipoprotein C3 concentration, as compared with the wild-type homozygotes. They also had a 60% increase in the fasting plasma triglyceride concentration, an increase by a factor of approximately two in the plasma triglyceride and retinyl fatty acid ester concentrations after an oral fat-tolerance test, and a 46% reduction in plasma triglyceride clearance. The prevalence of nonalcoholic fatty liver disease was 38% among variant-allele carriers and 0% among wild-type homozygotes (P<0.001). The subjects with nonalcoholic fatty liver disease had marked insulin resistance. A validation study involving non-Asian Indian men confirmed the association between APOC3 variant alleles and nonalcoholic fatty liver disease. The polymorphisms C-482T and T-455C in APOC3 are associated with nonalcoholic fatty liver disease and insulin resistance. Show less
A significant relationship has been noted between the lipid profile and atherosclerotic coronary artery disease (CAD) using invasive coronary angiography. We tested the hypothesis that the severity of Show more
A significant relationship has been noted between the lipid profile and atherosclerotic coronary artery disease (CAD) using invasive coronary angiography. We tested the hypothesis that the severity of CAD as determined by a non-invasive method, multi-detector row computed tomography (MDCT), is also associated with lipidemic factors. The subjects included 195 consecutive patients who underwent coronary angiography using MDCT because of suspected CAD. The number of significantly stenosed vessels (VD) as evaluated by MDCT, platelet-activating factor acetylhydrolase (PAF-AH), free cholesterol (FC), phospholipid (PL), remnant-like lipoprotein particle-cholesterol (RLP-C), apolipoprotein (apo)-B, apo-C3, apo-E, and highly-sensitive C-reactive protein were determined. The subjects were divided into diabetes mellitus (DM) and non-DM groups. The HDL-associated PAF-AH level in the DM group was significantly lower than that in the non-DM group. The VD determined by MDCT was significantly associated with hypertension, administration of angiotensin II type 1 receptor blocker, high-density lipoprotein cholesterol (HDL-C), HDL-associated (H)-HDL, H-PL, H-FC and RLP-C. Multivariate analysis revealed that VD determined by MDCT was most closely correlated with HDL-C. Lower levels of HDL-C may be an indicator for and provide additional information regarding the severity of CAD compared with other lipidemic factors. Show less
Taeil Kim, Shwetha Pazhoor, Musheng Bao+8 more · 2010 · Proceedings of the National Academy of Sciences of the United States of America · National Academy of Sciences · added 2026-04-24
Toll-like receptor 9 (TLR9) senses microbial DNA and triggers type I IFN responses in plasmacytoid dendritic cells (pDCs). Previous studies suggest the presence of myeloid differentiation primary resp Show more
Toll-like receptor 9 (TLR9) senses microbial DNA and triggers type I IFN responses in plasmacytoid dendritic cells (pDCs). Previous studies suggest the presence of myeloid differentiation primary response gene 88 (MyD88)-dependent DNA sensors other than TLR9 in pDCs. Using MS, we investigated C-phosphate-G (CpG)-binding proteins from human pDCs, pDC-cell lines, and interferon regulatory factor 7 (IRF7)-expressing B-cell lines. CpG-A selectively bound the aspartate-glutamate-any amino acid-aspartate/histidine (DExD/H)-box helicase 36 (DHX36), whereas CpG-B selectively bound DExD/H-box helicase 9 (DHX9). Although the aspartate-glutamate-alanine-histidine box motif (DEAH) domain of DHX36 was essential for CpG-A binding, the domain of unknown function 1605 (DUF1605 domain) of DHX9 was required for CpG-B binding. DHX36 is associated with IFN-alpha production and IRF7 nuclear translocation in response to CpG-A, but DHX9 is important for TNF-alpha and IL-6 production and NF-kappaB activation in response to CpG-B. Knocking down DHX9 or DHX36 significantly reduced the cytokine responses of pDCs to a DNA virus but had no effect on the cytokine responses to an RNA virus. We further showed that both DHX9 and DHX36 are localized within the cytosol and are directly bound to the Toll-interleukin receptor domain of MyD88 via their helicase-associated domain 2 and DUF domains. This study demonstrates that DHX9/DHX36 represent the MyD88-dependent DNA sensors in the cytosol of pDCs and suggests a much broader role for DHX helicases in viral sensing. Show less
Retinoic Acid Receptor Responder (RARRES1) initially identified as a novel retinoic acid receptor regulated gene in the skin is a putative tumor suppressor of unknown function. RARRES1 was knocked dow Show more
Retinoic Acid Receptor Responder (RARRES1) initially identified as a novel retinoic acid receptor regulated gene in the skin is a putative tumor suppressor of unknown function. RARRES1 was knocked down in immortalized human prostatic epithelial cell line PWR-1E cells and differential protein expression was identified using differential in-gel electrophoresis (DIGE) followed by matrix-assisted laser desorption ionization (MALDI) mass spectrometry and western Blot analysis excluding highly abundant proteins routinely identified in almost all proteomics projects. Knock-down of RARRES1: 1- down-regulates PP2A, an enzyme involved in the negative regulation of the growth hormone-stimulated signal transduction pathways; 2- down-regulates Valosin-containing protein causing impaired autophagy; 3- up-regulates the tumor suppressor disks large 2; 4- up-regulates Ankrd26 that belongs to the POTE family of genes that are highly expressed in cancer patients with poor outcome; and 5- down-regulates EB1, a protein that is involved in spindle dynamics and chromosome alignment during mitosis. Show less
It has been reported that N-methyl-D-aspartate receptor (NMDAR)-triggered neurotoxicity is related to excessive Ca(2+) loading and an increase in nitric oxide (NO) concentration. However, the molecula Show more
It has been reported that N-methyl-D-aspartate receptor (NMDAR)-triggered neurotoxicity is related to excessive Ca(2+) loading and an increase in nitric oxide (NO) concentration. However, the molecular mechanisms that underlie these events are not completely understood. NMDARs and neuronal NO synthase each binds to the scaffolding protein postsynaptic density (PSD)-93 through its PDZ domains. In this study, we determined whether PSD-93 plays a critical role in NMDAR/Ca(2+)/NO-mediated neurotoxicity. We found that the targeted disruption of the PSD-93 gene attenuated the neurotoxicity triggered by NMDAR activation, but not by non-NMDAR activation, in cultured mouse cortical neurons. PSD-93 deficiency reduced the amount of NMDAR subunits NR2A and NR2B in synaptosomal fractions from the cortical neurons and significantly prevented NMDA-stimulated increases in cyclic guanosine 3',5'-monophosphate and Ca(2+) loading in the cortical neurons. These findings indicate that PSD-93 deficiency could block NMDAR-triggered neurotoxicity by disrupting the NMDAR-Ca(2+)-NO signaling pathway and reducing expression of synaptic NR2A and NR2B. Since NMDARs, Ca(2+), and NO play a critical role during the development of brain trauma, seizures, and ischemia, the present work suggests that PSD-93 might contribute to molecular mechanisms of neuronal damage in these brain disorders. Show less
Mutations in the TSC1 and TSC2 genes lead to tuberous sclerosis complex (TSC), which is characterized clinically by mental retardation, epilepsy, and benign tumors affecting multiple tissues. Numerous Show more
Mutations in the TSC1 and TSC2 genes lead to tuberous sclerosis complex (TSC), which is characterized clinically by mental retardation, epilepsy, and benign tumors affecting multiple tissues. Numerous components of the TSC protein complex remain uncharacterized. Here we report the purification of the TSC1 complex under physiological conditions using a proteomic strategy. We purified the TSC1 protein complex using a tandem affinity purification method and identified a protein complex containing 139 components. Two known binding proteins of TSC1 (TSC2 and DOCK7) were identified along with other new potential partners, which cover reported and novel TSC1 functional categories. Bioinformatics and biochemical methods were used to evaluate the observed protein-protein interactions. A comparative analysis with a published expression proteomics/genomics study of TSC1 revealed more than 20 common candidates that might be functionally relevant. The data set provides new directions in which to expand our knowledge of the functions of TSC1 and the mechanisms of TSC. The results are highly reliable, which is reflected by the identification of a few reported partners of TSC1 and many TSC1/2-regulated proteins. Interestingly, many new functional categories were identified, such as DNA repair, which provide novel hints to the function of TSC1. Moreover, a few neuronal disease-related proteins that might regulate the normal functions of neurons were identified. Thus, the results suggest that many of the new interactions should be biologically significance. It will be interesting to further investigate the regulatory mechanisms of these components. Show less