👤 Songren Shu

Recent studies implicate a strong association between elevated plasma branched-chain amino acids (BCAAs) and insulin resistance (IR). However, a causal relationship and whether interrupted BCAA homeostasis can serve as a therapeutic target for diabetes remain to be established experimentally. In this study, unbiased integrative pathway analyses identified a unique genetic link between obesity-associated IR and BCAA catabolic gene expression at the pathway level in human and mouse populations. In genetically obese ( Show less

The aberrant expression of ceroid-lipofuscinosis 3 (CLN3) has been reported in a variety of human malignancies. However, the role of CLN3 in the progression and prognosis of hepatocellular carcinoma (HCC) remains unknown. In this study, we found that CLN3 was frequently upregulated in HCC clinical samples and HCC-derived cell lines and was significantly correlated with an APF serum level ≥20 μg/L, a tumour size ≥5 cm, multiple tumours, and the absence of encapsulation. Kaplan-Meier showed that CLN3 upregulation predicted shorter recurrence-free survival (RFS) and overall survival (OS) time in HCC patients. Cox regression analysis revealed that CLN3 upregulation was an independent risk factor for RFS and OS. A functional study demonstrated that the knockdown of CLN3 expression profoundly suppressed the growth and metastasis of HCC cells both in vitro and in vivo. Mechanistic investigation revealed that the EGFR/PI3K/AKT pathway was essential for mediating CLN3 function. In conclusion, our results provide the first evidence that CLN3 contributes to tumour progression and metastasis and offer a potential prognostic predictor and therapeutic target for HCC. Show less

Melanocortin 4 receptor: (MC4R) and Myostatin (MSTN) are two important growth trait-related genes in animals. In this study, we showed that two SNPs, MC4R-719A>G and MSTN-519C>T, found in the promoters of the MC4R and MSTN genes, respectively, are both associated with growth traits in Spinibarbus hollandi. Furthermore, we observed that there were significant associations between the expression levels of the MC4R and MSTN genes and these two growth trait-related SNPs. The expression level of MC4R gene in brain was lower in GG genotype fish with extremely high growth performance than that in AA genotype fish with extremely low growth performance. Expression level of the MSTN gene in muscle was lower in TT genotype fish with extremely high growth performance than that in CC and CT genotype fish with lower growth performance. The results indicated that these SNPs located in the promoters of MC4R and MSTN are associated with growth-related traits through modification of gene expression levels. The MSTN and MC4R SNPs may have useful application in effective marker-assisted selection aimed to increase output in S. hollandi. Show less

Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer mortality in American women. Normal ovarian physiology is intricately connected to small GTP binding proteins of the Ras superfamily (Ras, Rho, Rab, Arf, and Ran) which govern processes such as signal transduction, cell proliferation, cell motility, and vesicle transport. We hypothesized that common germline variation in genes encoding small GTPases is associated with EOC risk. We investigated 322 variants in 88 small GTPase genes in germline DNA of 18,736 EOC patients and 26,138 controls of European ancestry using a custom genotype array and logistic regression fitting log-additive models. Functional annotation was used to identify biofeatures and expression quantitative trait loci that intersect with risk variants. One variant, ARHGEF10L (Rho guanine nucleotide exchange factor 10 like) rs2256787, was associated with increased endometrioid EOC risk (OR = 1.33, p = 4.46 x 10-6). Other variants of interest included another in ARHGEF10L, rs10788679, which was associated with invasive serous EOC risk (OR = 1.07, p = 0.00026) and two variants in AKAP6 (A-kinase anchoring protein 6) which were associated with risk of invasive EOC (rs1955513, OR = 0.90, p = 0.00033; rs927062, OR = 0.94, p = 0.00059). Functional annotation revealed that the two ARHGEF10L variants were located in super-enhancer regions and that AKAP6 rs927062 was associated with expression of GTPase gene ARHGAP5 (Rho GTPase activating protein 5). Inherited variants in ARHGEF10L and AKAP6, with potential transcriptional regulatory function and association with EOC risk, warrant investigation in independent EOC study populations. Show less

Wnt/β-catenin signaling activity is maintained in homeostasis by an expanding list of molecular determinants. However, the molecular components and the regulatory mechanisms involved in its fine-tuning remain to be determined. Here, we identified C9orf140, a tumor-specific protein, as a novel Axin1-interacting protein by tandem-affinity purification and mass spectrometry. We further showed that C9orf140 is a negative regulator of Wnt/β-catenin signaling in cultured cells as well as in zebrafish embryos. It functions upstream of β-catenin, outcompetes PP2A for binding to Axin1, influences the balance between phosphorylation and de-phosphorylation of β-catenin, and ultimately compromises Wnt3A-induced β-catenin accumulation. Interestingly, Wnt-induced C9orf140 expression via β-catenin. We propose that C9orf140 mediates a negative feedback loop of Wnt/β-catenin signaling by interacting with Axin1. Our results advance the current understanding of the exquisite control of Wnt/β-catenin signaling cascade, and provide evidence of the new role of C9orf140. Show less

Non-small-cell lung cancer (NSCLC) has been recognized as a highly heterogeneous disease with phenotypic and genotypic diversity in each subgroup. While never-smoker patients with NSCLC have been well studied through next generation sequencing, we have yet to recognize the potentially unique molecular features of young never-smoker patients with NSCLC. In this study, we conducted whole genome sequencing (WGS) to characterize the genomic alterations of 36 never-smoker Chinese patients, who were diagnosed with lung adenocarcinoma (LUAD) at 45 years or younger. Besides the well-known gene mutations (e.g., TP53 and EGFR), our study identified several potential lung cancer-associated gene mutations that were rarely reported (e.g., HOXA4 and MST1). The lung cancer-related copy number variations (e.g., EGFR and CDKN2A) were enriched in our cohort (41.7%, 15/36) and the lung cancer-related structural variations (e.g., EML4-ALK and KIF5B-RET) were commonly observed (22.2%, 8/36). Notably, new fusion partners of ALK (SMG6-ALK) and RET (JMJD1C-RET) were found. Furthermore, we observed a high prevalence (63.9%, 23/36) of potentially targetable genomic alterations in our cohort. Finally, we identified germline mutations in BPIFB1 (rs6141383, p.V284M), CHD4 (rs74790047, p.D140E), PARP1 (rs3219145, p.K940R), NUDT1 (rs4866, p.V83M), RAD52 (rs4987207, p.S346*), and MFI2 (rs17129219, p.A559T) were significantly enriched in the young never-smoker patients with LUAD when compared with the in-house noncancer database (p < 0.05). Our study provides a detailed mutational portrait of LUAD occurring in young never-smokers and gives insights into the molecular pathogenesis of this distinct subgroup of NSCLC. Show less

Most patients with hypertrophic cardiomyopathy have single-gene autosomal dominant mutations in loci that encode for sarcomeric proteins. The aim of this study was to determine whether pathogenic mutations were present by whole-exome sequencing (WES) in two families with hypertrophic cardiomyopathy (HCM) that presented during adolescence. Blood samples and clinical data were collected from individuals in two families with HCM. DNA was extracted. Mutations were identified using whole-exome sequencing (WES), and the genotypes of family members were identified using Sanger sequencing. Compound heterozygous mutations in the MYBPC3 gene (c.659A > G, p.Tyr220Cys; c.772G > A, p.Glu258Lys,NM₀₀₀₂₅₆, Family 1), (c.873delG, p. Ile292PhefsTer8; c.3G > A, p.Met1?, NM₀₀₀₂₅₆, Family 2) were identified by WES. Patient 1 carried the maternally inherited c.659A > G mutation and the paternally inherited c.772G > A mutation. Patient 2 carried the maternally inherited frameshift mutation c.873delG and the paternally inherited mutation c.3G > A. Two families with HCM presenting during adolescence (age of onset is about 11 years old) demonstrated compound heterozygous mutations in the MYBPC3 gene. These findings suggested an association of MYBPC3 mutations with the early onset of symptoms and worsened prognoses. Our study highlights the importance of genetic screening of all family members in cases of HCM. Show less

The class III PI3-kinase (PIK3C3) is an enzyme responsible for the generation of phosphatidylinositol 3-phosphate (PI3P), a critical component of vesicular membrane. Here, we report that PIK3C3 deficiency in zebrafish results in intestinal injury and inflammation. In pik3c3 mutants, gut tube forms but fails to be maintained. Gene expression analysis reveals that barrier-function-related inflammatory bowel disease (IBD) susceptibility genes (e-cadherin, hnf4a, ttc7a) are suppressed, while inflammatory response genes are stimulated in the mutants. Histological analysis shows neutrophil infiltration into mutant intestinal epithelium and the clearance of gut microbiota. Yet, gut microorganisms appear dispensable as mutants cultured under germ-free condition have similar intestinal defects. Mechanistically, we show that PIK3C3 deficiency suppresses the formation of PI3P and disrupts the polarized distribution of cell-junction proteins in intestinal epithelial cells. These results not only reveal a role of PIK3C3 in gut homeostasis, but also provide a zebrafish IBD model. Show less

Hypocalcemia is an important metabolic disease of dairy cows during the transition period, although the effect of hypocalcemia on biological function in dairy cows remains unknown. In this study, proteomic, mass spectrum, bioinformatics and western blotting were employed to identify differentially expressed proteins related to serum Ca concentration. Serum samples from dairy cows were collected at three time points: 3rd days before calving (day -3), the day of calving (day 0), and 3rd days after calving (day +3). According to the Ca concentration on day 0, a total of 27 dairy cows were assigned to one of three groups (clinical, subclinical, and healthy). Samples collected on day -3 were used for discovery of differentially expressed proteins, which were separated and identified via proteomic analysis and mass spectrometry. Bioinformatics analysis was performed to determine the function of the identified proteins (gene ontology and pathway analysis). The differentially expressed proteins were verified by western blot analysis. There were 57 differential spots separated and eight different proteins were identified. Vitamin D-binding protein precursor (group-specific component, GC), alpha-2-macroglobulin (A2M) protein, and apolipoprotein A-IV were related to hypocalcemia by bioinformatics analysis. Due to its specific expression (up-regulated in clinical hypocalcemia and down-regulated in subclinical hypocalcemia), A2M was selected for validation. The results were consistent with those of proteomic analysis. A2M was as an early detection index for distinguishing clinical and subclinical hypocalcemia. The possible pathogenesis of clinical hypocalcemia caused by GC and apolipoprotein A-IV was speculated. The down-regulated expression of GC was a probable cause of the decrease in calcium concentration. Show less

Neuronal regeneration and axonal regrowth mechanisms in the injured mammalian central nervous system are largely unknown. As part of a major pathway for inhibiting axonal regeneration, activated neuronal glycosylphosphatidylinositol-anchored Nogo receptor (NgR) interacts with LINGO-1 and p75NTR to form a complex at the cell surface. However, it was found in our previous report that upregulation of NgR stimulated by injury plays a key role in neuronal regeneration in the neonatal cortex freeze-lesion model, but its downstream signalling remains elusive. In the present study, the novel regulatory role of NgR in a serine-threonine kinase WNK1 was identified. NgR's transcriptional regulation of WNK1 was identified by RT-qPCR and semiquantitative western blot after the overexpression or knockdown of NgR, and the regulation is specific to WNK1, which is not the same for its family members, WNK2, WNK3 and WNK4. Furthermore, NgR inhibition by NEP fails to affect WNK1, which indicates that WNK1 functions outside of the Nogo-A/NgR pathway. By performing a proliferation, migration and axonal extension assay, we also identified that overexpressed NgR critically regulated these processes and impairment by overexpressing NgR was rescued with coexpression of WNK1, indicating the partial role of WNK1 in NgR-mediated morphological regulation. Our study identifies a separation of functions for the NgR-regulated WNK1 in mediating proliferation, migration and axonal extension in PC12 cells as well as a specific regulatory role between NgR and WNK1 that is important for recovery from central nervous system injury. Show less

In this study, we aimed to clinically and genetically characterize LVNC patients and investigate the prevalence of variants in known and novel LVNC disease genes. Left ventricular non-compaction cardiomyopathy (LVNC) is an increasingly recognized cause of heart failure, arrhythmia, thromboembolism, and sudden cardiac death. We sought here to dissect its genetic causes, phenotypic presentation and outcome. In our registry with follow-up of in the median 61 months, we analysed 95 LVNC patients (68 unrelated index patients and 27 affected relatives; definite familial LVNC = 23.5%) by cardiac phenotyping, molecular biomarkers and exome sequencing. Cardiovascular events were significantly more frequent in LVNC patients compared with an age-matched group of patients with non-ischaemic dilated cardiomyopathy (hazard ratio = 2.481, P = 0.002). Stringent genetic classification according to ACMG guidelines revealed that TTN, LMNA, and MYBPC3 are the most prevalent disease genes (13 patients are carrying a pathogenic truncating TTN variant, odds ratio = 40.7, Confidence interval = 21.6-76.6, P < 0.0001, percent spliced in 76-100%). We also identified novel candidate genes for LVNC. For RBM20, we were able to perform detailed familial, molecular and functional studies. We show that the novel variant p.R634L in the RS domain of RBM20 co-segregates with LVNC, leading to titin mis-splicing as revealed by RNA sequencing of heart tissue in mutation carriers, protein analysis, and functional splice-reporter assays. Our data demonstrate that the clinical course of symptomatic LVNC can be severe. The identified pathogenic variants and distribution of disease genes-a titin-related pathomechanism is found in every fourth patient-should be considered in genetic counselling of patients. Pathogenic variants in the nuclear proteins Lamin A/C and RBM20 were associated with worse outcome. Show less

The adipokine adipocyte fatty acid-binding protein (A-FABP) has been implicated in obesity-related cardio-metabolic complications. Here we show that A-FABP increases thermogenesis by promoting the conversion of T4 to T3 in brown adipocytes. We find that A-FABP levels are increased in both white (WAT) and brown (BAT) adipose tissues and the bloodstream in response to thermogenic stimuli. A-FABP knockout mice have reduced thermogenesis and whole-body energy expenditure after cold stress or after feeding a high-fat diet, which can be reversed by infusion of recombinant A-FABP. Mechanistically, A-FABP induces the expression of type-II iodothyronine deiodinase in BAT via inhibition of the nuclear receptor liver X receptor α, thereby leading to the conversion of thyroid hormone from its inactive form T4 to active T3. The thermogenic responses to T4 are abrogated in A-FABP KO mice, but enhanced by A-FABP. Thus, A-FABP acts as a physiological stimulator of BAT-mediated adaptive thermogenesis. Show less

Apolipoprotein A-IV (apoA-IV) in the brain potently suppresses food intake. However, the mechanisms underlying its anorexigenic effects remain to be identified. We first examined the effects of apoA-IV on cellular activities in hypothalamic neurons that co-express agouti-related peptide (AgRP) and neuropeptide Y (NPY) and in neurons that express pro-opiomelanocortin (POMC). We then compared anorexigenic effects of apoA-IV in wild-type mice and in mutant mice lacking melanocortin 4 receptors (MC4Rs; the receptors of AgRP and the POMC gene product). Finally, we examined expression of apoA-IV in mouse hypothalamus and quantified its protein levels at fed versus fasted states. We demonstrate that apoA-IV inhibited the firing rate of AgRP/NPY neurons. The decreased firing was associated with hyperpolarized membrane potential and decreased miniature excitatory postsynaptic current. We further used c-fos immunoreactivity to show that intracerebroventricular (i.c.v.) injections of apoA-IV abolished the fasting-induced activation of AgRP/NPY neurons in mice. Further, we found that apoA-IV depolarized POMC neurons and increased their firing rate. In addition, genetic deletion of MC4Rs blocked anorexigenic effects of i.c.v. apoA-IV. Finally, we detected endogenous apoA-IV in multiple neural populations in the mouse hypothalamus, including AgRP/NPY neurons, and food deprivation suppressed hypothalamic apoA-IV protein levels. Our findings support a model where central apoA-IV inhibits AgRP/NPY neurons and activates POMC neurons to activate MC4Rs, which in turn suppresses food intake. Show less

In the injured adult mammalian central nervous system (CNS), the failure of axonal regeneration is thought to be attributed, at least in part, to various myelin-associated inhibitors (MAIs), such as Nogo, myelinassociated glycoprotein (MAG), and oligodendrocyte-myelin glycoprotein (OMgp) around the damaged site. Interestingly, these three structurally different inhibitors share two common receptors, Nogo-66 receptor (NgR) and paired immunoglobulin-like receptor B (PirB), and transduce the inhibitory signal into neurons via their complex combinant and co-receptors, such as p75 neurotrophin receptor (p75NTR), Nogo receptor-interacting protein 1 (LINGO-1), and TROY. Accordingly, targeting of the whole myelin or just portions by immunization has been proved to be neuroprotective and is able to promote regeneration in the injured spinal cords. In the past few years, vaccine approaches were initially achieved and could induce the production of antibodies against inhibitors in myelin to block the inhibitory effects and promote functional recovery in spinal cord injury (SCI) models by immunizing with MAIs, such as purified myelin, spinal cord homogenates, or their receptors with the concept of protective autoimmunity formulated. However, for safety consideration, further work is necessary before the immunotherapy strategies can be adopted to treat human injured spinal cords. Show less

Smooth muscle 22α (SM22α) is involved in stress fiber formation and enhances contractility in vascular smooth muscle cells (VSMCs). In many cases, SM22α acts as an adapter protein to assemble signaling complexes and regulate signaling, but whether SM22α regulates contractile signaling induced by angiotensin II (AngII) remains unclear. To address this issue, we established a hypertension model of Sm22α(-/-) mice, and demonstrated that hypertension induced by AngII was attenuated in Sm22α(-/-) mice. A decreased vasoconstriction was observed in aortic rings from Sm22α(-/-) mice. Furthermore, loss of SM22α resulted in a reduced contractile response to AngII in VSMCs in vitro. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) induced by AngII was impaired following depletion of SM22α, in parallel with a reduced contractility. The decay of ERK1/2 activity was associated with increased expression of mitogen-activated protein kinase phosphatase 3 (MKP3). Inhibition of MKP3 activity rescued ERK1/2 activity. SM22α depletion caused an enhanced interaction of MKP3 with ERK1/2, and a reduced ubiquitination and degradation of MKP3. Knockdown of SM22α extended the half-life of MKP3. In conclusion, SM22α promotes AngII-induced contraction by maintenance of ERK1/2 signaling cascades through facilitating ubiquitination and degradation of MKP3. The vasoconstriction is attenuated in aortic rings from Sm22α(-/-) mice. MKP3 mediates dephosphorylation of ERK1/2 in AngII-induced VSMC contraction. SM22α inhibits the interaction of ERK1/2 with MKP3. SM22α promotes ubiquitination and degradation of MKP3. SM22α facilitates AngII-induced contraction by maintenance of ERK1/2 signaling. Show less

Known genetic loci explain only a small proportion of the familial relative risk of colorectal cancer (CRC). We conducted a genome-wide association study of CRC in East Asians with 14,963 cases and 31,945 controls and identified 6 new loci associated with CRC risk (P = 3.42 × 10(-8) to 9.22 × 10(-21)) at 10q22.3, 10q25.2, 11q12.2, 12p13.31, 17p13.3 and 19q13.2. Two of these loci map to genes (TCF7L2 and TGFB1) with established roles in colorectal tumorigenesis. Four other loci are located in or near genes involved in transcriptional regulation (ZMIZ1), genome maintenance (FEN1), fatty acid metabolism (FADS1 and FADS2), cancer cell motility and metastasis (CD9), and cell growth and differentiation (NXN). We also found suggestive evidence for three additional loci associated with CRC risk near genome-wide significance at 8q24.11, 10q21.1 and 10q24.2. Furthermore, we replicated 22 previously reported CRC-associated loci. Our study provides insights into the genetic basis of CRC and suggests the involvement of new biological pathways. Show less

Recognition of viral double-stranded RNA by Toll-like receptor 3 (TLR3) triggers activation of the transcription factors NF-κB and interferon regulated factor 3, leading to induction of type I interferons and proinflammatory cytokines. TIR-domain-containing adapter-inducing interferon-β (TRIF) is an adapter protein required for TLR3-mediated signaling. Here we identified the E3 ubiquitin ligase WW domain-containing protein 2 (WWP2) as a TRIF-associated protein by biochemical purification. WWP2 mediated K48-linked ubiquitination and degradation of TRIF upon TLR3 activation. Overexpression of WWP2 inhibited TLR3-mediated NF-κB and interferon regulated factor 3 activation, whereas knockdown of WWP2 had opposite effects. We generated Wwp2-deficient mice to further investigate the roles of Wwp2 in innate immune responses. Consistently, production of IFN-β, CCL5, TNFα, and IL-6 in response to the TLR3 ligand poly(I:C) was elevated in Wwp2(-/-) macrophages and Wwp2-deficient mice exhibited increased susceptibility to poly(I:C)-induced death than the control littermates. Our findings suggest that WWP2 negatively regulates TLR3-mediated innate immune and inflammatory responses by targeting TRIF for ubiquitination and degradation. Show less

Multiple genetic loci associated with obesity or body mass index (BMI) have been identified through genome-wide association studies conducted predominantly in populations of European ancestry. We performed a meta-analysis of associations between BMI and approximately 2.4 million SNPs in 27,715 east Asians, which was followed by in silico and de novo replication studies in 37,691 and 17,642 additional east Asians, respectively. We identified ten BMI-associated loci at genome-wide significance (P < 5.0 × 10(-8)), including seven previously identified loci (FTO, SEC16B, MC4R, GIPR-QPCTL, ADCY3-DNAJC27, BDNF and MAP2K5) and three novel loci in or near the CDKAL1, PCSK1 and GP2 genes. Three additional loci nearly reached the genome-wide significance threshold, including two previously identified loci in the GNPDA2 and TFAP2B genes and a newly identified signal near PAX6, all of which were associated with BMI with P < 5.0 × 10(-7). Findings from this study may shed light on new pathways involved in obesity and demonstrate the value of conducting genetic studies in non-European populations. Show less

The reticulon protein Nogo-A is an important regulator of neurite growth, axonal plasticity, and cell migration in the central nervous system. Previous studies have shown markedly elevated levels of Nogo-A in human temporal lobe epilepsy. In the present study, we examined the expression pattern of the Nogo-A system in cortical lesions of pediatric patients with tuberous sclerosis complex and focal cortical dysplasia type IIb. These disorders are characterized by malformations of cortical development and are frequently associated with intractable epilepsy. We found that the messenger RNA and protein levels of the Nogo-A receptor (NgR) and the downstream targets of Nogo-A, LINGO-1, TROY, and RhoA but not P75 were upregulated in the cortices of patients compared with autopsy control samples. Immunohistochemical analyses indicated that Nogo-A and NgR were strongly expressed in misshapen cells, particularly dysmorphic neurons, balloon cells, and giant cells. TROY was diffusely expressed in the malformations of cortical development. Most of theNogo-A/NgR-positive misshapen cells were colabeled with neuronal rather than astrocytic markers. Taken together, our results suggestthat the activation of Nogo-A via the NgR/LINGO-1/TROY signal transduction pathways, but not NgR/LINGO-1/P75, may be involved in the development and/or seizure activity of cortical lesions in tuberous sclerosis complex and focal cortical dysplasia type IIb. Show less

The gradually increasing changes in a human hyperlipidemic diet along with chronic stress might play an important role in the increased numbers of fatty liver. This study investigated the effects of Ilex asprella root decoction on related genes of lipid metabolism in chronic stress in hyperlipidemic fatty liver in rats. Forty-eight male Wistar rats were randomly divided into four groups: normal control group, model control group, simvastatin group, and Ilex asprella root group. To establish chronic stress and hyperlipidemic fatty liver models in rats, the levels of serum lipids, glucose, liver index, insulin (INS), insulin resistant (IR) index, adiponectin, superoxide dismutase (SOD), glutathione peroxidase (GSH-pX), glutathione (GSH), liver X receptor (LXR), and sterol responsive element binding protein (SREBP)-1c in rats were measured. When compared to the normal control group, the levels of serum lipids, glucose, liver index, INS, IR index, and GSH in the model control group significantly increased (P < 0.01). The protein levels of LXRα and SREBP-1c increased (P < 0.05), and the serum adiponectin and the SOD and GSH-pX decreased significantly (P < 0.01). When compared to the model control group, the levels of serum lipids, glucose, liver index, INS, IR index, SOD, and GSH-pX in the simvastatin group and Ilex asprella root group increased in varying degrees (P < 0.01 or 0.05); the serum adiponectin and GSH decreased (P < 0.05), while the protein levels of LXRα and SREBP-1c decreased in varying degrees (P < 0.01 or 0.05). When compared to the simvastatin group, the IR index and protein levels of LXRα in the Ilex asprella root group decreased (P < 0.05), and the serum adiponectin and SOD increased (P < 0.05). The Ilex asprella root decoction has some protective effects on regulating the related genes of lipid metabolism caused by chronic stress and hyperlipidemic fatty liver in rats. Show less

Genetic variation may influence chemotherapy response and overall survival in cancer patients. We conducted a genome-wide scan in 535 advanced-stage non-small cell lung cancer (NSCLC) patients from two independent cohorts (307 from Nanjing and 228 from Beijing). A replication was carried out on an independent cohort of 340 patients from Southeastern China followed by a second validation on 409 patients from the Massachusetts General Hospital (Boston, MA). Consistent associations with NSCLC survival were identified for five single-nucleotide polymorphisms (SNP) in Chinese populations with P values ranging from 3.63 × 10(-5) to 4.19 × 10(-7) in the additive genetic model. The minor allele of three SNPs (rs7629386 at 3p22.1, rs969088 at 5p14.1, and rs3850370 at 14q24.3) were associated with worse NSCLC survival while 2 (rs41997 at 7q31.31 and rs12000445 at 9p21.3) were associated with better NSCLC survival. In addition, rs7629386 at 3p22.1 (CTNNB1) and rs3850370 at 14q24.3 (SNW1-ALKBH1-NRXN3) were further replicated in the Caucasian population. In this three-stage genome-wide association studies, we identified five SNPs as markers for survival of advanced-stage NSCLC patients treated with first-line platinum-based chemotherapy in Chinese Han populations. Two of these SNPs, rs7629386 and rs3850370, could also be markers for survival among Caucasian patients. Show less

Obesity is a well-established risk factor for endometrial cancer, the most common gynecologic malignancy. Recent genome-wide association studies (GWAS) have identified multiple genetic markers for obesity. The authors evaluated the association of obesity-related single nucleotide polymorphisms (SNPs) with endometrial cancer using GWAS data from their recently completed study, the Shanghai Endometrial Cancer Genetics Study, which comprised 832 endometrial cancer cases and 2,049 controls (1996-2005). Thirty-five SNPs previously associated with obesity or body mass index (BMI; weight (kg)/height (m)(2)) at a minimum significance level of ≤5 × 10(-7) in the US National Human Genome Research Institute's GWAS catalog (http://genome.gov/gwastudies) and representing 26 unique loci were evaluated by either direct genotyping or imputation. The authors found that for 22 of the 26 unique loci tested (84.6%), the BMI-associated risk variants were present at a higher frequency in cases than in population controls (P = 0.0003). Multiple regression analysis showed that 9 of 35 BMI-associated variants, representing 7 loci, were significantly associated (P ≤ 0.05) with the risk of endometrial cancer; for all but 1 SNP, the direction of association was consistent with that found for BMI. For consistent SNPs, the allelic odds ratios ranged from 1.15 to 1.29. These 7 loci are in the SEC16B/RASAL, TMEM18, MSRA, SOX6, MTCH2, FTO, and MC4R genes. The associations persisted after adjustment for BMI, suggesting that genetic markers of obesity provide value in addition to BMI in predicting endometrial cancer risk. Show less

Apolipoprotein A-V (apoA-V), a minor protein associated with lipoproteins, has a major effect on triacylglycerol (TG) metabolism. We investigated whether apoA-V complexed with phospholipid in the form of a reconstituted high-density lipoprotein (rHDL) has potential utility as a therapeutic agent for treatment of hypertriglyceridemia (HTG) when delivered intravenously. Intravenous injection studies were performed in genetically engineered mouse models of severe HTG, including apoav-/- and gpihbp1-/- mice. Administration of apoA-V rHDL to hypertriglyceridemic apoav-/- mice resulted in a 60% reduction in plasma TG concentration after 4 hours. This decline can be attributed to enhanced catabolism/clearance of very-low-density lipoprotein (VLDL), where VLDL TG and cholesterol were reduced ≈60%. ApoA-V that associated with VLDL after injection was also rapidly cleared. Site-specific mutations in the heparin-binding region of apoA-V (amino acids 186 to 227) attenuated apoA-V rHDL TG-lowering activity by 50%, suggesting that this sequence element is required for optimal TG-lowering activity in vivo. Unlike apoav-/- mice, injection of apoA-V rHDL into gpihbp1-/- mice had no effect on plasma TG levels, and apoA-V remained associated with plasma VLDL. Intravenously injected apoA-V rHDL significantly lowers plasma TG in an apoA-V deficient mouse model. Its intravenous administration may have therapeutic benefit in human subjects with severe HTG, especially in cases involving apoA-V variants associated with HTG. Show less

Apolipoprotein A-V (apoA-V), secreted solely by the liver, is a low abundance protein that strongly influences plasma triglyceride (TG) levels. In vitro, in transfected hepatoma cell lines apoA-V is largely retained within the cell in association with cytosolic lipid droplets (LD). To evaluate if this is true in vivo, in the present study the amount of apoA-V in the plasma compartment versus liver tissue was determined in APOA5 transgenic (Tg) mice. The majority of total apoA-V ( approximately 80%) was in the plasma compartment. Injection of APOA5 Tg mice with heparin increased plasma apoA-V protein levels by approximately 25% indicating the existence of a heparin-releasable pool. Intrahepatic apoA-V was associated with LD isolated from livers of wild type (WT) and APOA5 Tg mice. Furthermore, livers from APOA5 Tg mice contained significantly higher amounts of TG than livers from WT or apoa5 knockout mice suggesting that apoA-V influences intrahepatic TG levels. Show less

We have identified the transforming acidic coiled-coil protein-3 (Tacc3) as a binding partner for Notch4/Int3 and were able to show that it binds to the intracellular domain (ICD) of all members of the Notch receptor family. Members of the Tacc family reside at the centrosomes and associates with microtubules. Recent studies suggest that Tacc3 also contributes to the regulation of gene transcription. Tacc3 specifically interacts with the Notch4/Int3 CDC10/Ankyrin repeats and to a lesser extent, with residues C-terminal to these repeats in the ICD. Dual label immunofluorescence of mouse mammary tissue shows Tacc3 co-localizes with the Notch3 ICD. Co-immunoprecipitation of endogenous Notch and Tacc3 proteins from NIH3T3 cell extracts, lung and mammary gland confirms that these two proteins interact under physiological conditions. In addition, knock down of Tacc3 in NIH3T3 cells leads to the up-regulation of Hey2, a target gene for Notch signaling. The affinity of Tacc3 binding to Notch4/Int3 ICD is similar to that between Rbpj and Notch4/Int3 ICD. Notch4/Int3 ICD-Tacc3 interaction results in the inhibition of transcription from a Hes1-Luciferase reporter vector in COS-1 cells. The inhibition was reversed in these cells by increasing the levels of Rbpj. Taken together, these results suggest that Tacc3 is a negative regulator of the Notch signaling pathway. Show less

Recent genome-wide association (GWA) studies have identified 18 genetic loci for obesity. Using directly observed and imputed GWA genotyping data on approximately 5,000 Chinese women (1996-2007), the authors evaluated 17 single nucleotide polymorphisms (SNPs) that represent 17 distinct obesity loci. Two SNPs near the BAT2 and MC4R genes and 3 SNPs within the FTO, SEC16B, and SH2B1 genes were significantly associated with body mass index (weight (kg)/height (m)(2)), body weight, and the prevalence of obesity. The per-allele increase in body mass index ranged from 0.16 units (BAT2) to 0.38 units (SH2B1). Odds ratios for obesity ranged from 1.46 (95% confidence interval (CI): 1.12, 1.92) for BAT2 to 2.16 (95% CI: 1.39, 3.37) for MC4R. A genetic risk score calculated by summing the number of risk-increasing alleles that each woman carried at these 5 loci was significantly associated with the prevalence of obesity. Women carrying 5 or more risk alleles had a 3.13-fold (95% CI: 2.06, 4.77) higher prevalence of obesity than women carrying 1 or no risk alleles. Results from this study extend some previous GWA findings to Chinese women and show the need for additional studies to identify susceptibility loci in Chinese and other Asian populations. Show less

Recent human genetics studies have revealed that common variants of the TCF7L2 (T-cell factor 7-like 2, formerly known as TCF4) gene are strongly associated with type 2 diabetes mellitus (T2DM). We have shown that TCF7L2 expression in the beta-cells is correlated with function and survival of the insulin-producing pancreatic beta-cell. In order to understand how variations in TCF7L2 influence diabetes progression, we investigated its mechanism of action in the beta-cell. We show robust differences in TCF7L2 expression between healthy controls and models of T2DM. While mRNA levels were approximately 2-fold increased in isolated islets from the diabetic db/db mouse, the Vancouver Diabetic Fatty (VDF) Zucker rat and the high fat/high sucrose diet-treated mouse compared with the non-diabetic controls, protein levels were decreased. A similar decrease was observed in pancreatic sections from patients with T2DM. In parallel, expression of the receptors for glucagon-like peptide 1 (GLP-1R) and glucose-dependent insulinotropic polypeptide (GIP-R) was decreased in islets from humans with T2DM as well as in isolated human islets treated with siRNA to TCF7L2 (siTCF7L2). Also, insulin secretion stimulated by glucose, GLP-1 and GIP, but not KCl or cyclic adenosine monophosphate (cAMP) was impaired in siTCF7L2-treated isolated human islets. Loss of TCF7L2 resulted in decreased GLP-1 and GIP-stimulated AKT phosphorylation, and AKT-mediated Foxo-1 phosphorylation and nuclear exclusion. Our findings suggest that beta-cell function and survival are regulated through an interplay between TCF7L2 and GLP-1R/GIP-R expression and signaling in T2DM. Show less

To detect gene mutations associated with hypertrophic cardiomyopathy (HCM) in Chinese patients and possible correlations between genotype and phenotype. Twenty-one unrelated patients with hypertrophic cardiomyopathy were studied. The clinical data including symptoms, physical examination, echocardiography and electrocardiography were collected. The full ecoding exons of cardiac myosin-binding protein C gene (cMYBPC3) were amplified with PCR and the products were sequenced. Two mutations were identified in probands from two families. One mutation was frame shift mutation Pro1208fs in the exon 32 of the cMYBPC3 gene. Pro1208fs mutation was identified in a 59 years old female patient with familial hypertrophic cardiomyopathy. Symptom onset was late and a favorable clinical course was evidenced in this patient. Another mutation was missence mutation Gly507Arg in the exon 17 of the MYBPC3 gene identified in a 24 years old male patient. Diffuse thickness of left ventricular wall, impaired diastolic function and enlarged left atria were evidenced in echocardiography. No mutation was identified in the 80 control healthy individuals. cMYBPC3 might be the disease-causing genes in Chinese patients with hypertrophic cardiomyopathy. Show less

We have previously mapped a major susceptibility locus influencing familial lung cancer risk to chromosome 6q23-25. However, the causal gene at this locus remains undetermined. In this study, we further refined this locus to identify a single candidate gene, by fine mapping using microsatellite markers and association studies using high-density single nucleotide polymorphisms (SNP). Six multigenerational families with five or more affected members were chosen for fine-mapping the 6q linkage region using microsatellite markers. For association mapping, we genotyped 24 6q-linked cases and 72 unrelated noncancer controls from the Genetic Epidemiology of Lung Cancer Consortium resources using the Affymetrix 500K chipset. Significant associations were validated in two independent familial lung cancer populations: 226 familial lung cases and 313 controls from the Genetic Epidemiology of Lung Cancer Consortium, and 154 familial cases and 325 controls from Mayo Clinic. Each familial case was chosen from one high-risk lung cancer family that has three or more affected members. A region-wide scan across 6q23-25 found significant association between lung cancer susceptibility and three single nucleotide polymorphisms in the first intron of the RGS17 gene. This association was further confirmed in two independent familial lung cancer populations. By quantitative real-time PCR analysis of matched tumor and normal human tissues, we found that RGS17 transcript accumulation is highly and consistently increased in sporadic lung cancers. Human lung tumor cell proliferation and tumorigenesis in nude mice are inhibited upon knockdown of RGS17 levels. RGS17 is a major candidate for the familial lung cancer susceptibility locus on chromosome 6q23-25. Show less

The expression of apolipoprotein A-V (apoA-V) in hepatoma cells results in homing of this protein to intracellular lipid droplets. When hepatoma cells transfected with a full-length apoA-V-green fluorescent protein fusion protein were cultured in medium that was not supplemented with oleic acid (OA), intracellular lipid droplet size and number were reduced compared with those of cells supplemented with OA. Confocal microscopy studies revealed that apoA-V associates with lipid droplets under both conditions. To define the structural requirements for apoA-V lipid droplet association, hepatoma cells were transfected with a series of C-terminal truncated apoA-V variants. Confocal microscopy analysis revealed that, in a manner similar to mature full-length apoA-V (343 amino acids), truncation variants apoA-V(1-292), apoA-V(1-237), and apoA-V(1-191) associated with lipid droplets, while apoA-V(1-146) did not. Western blot analysis of the relative abundance of apoA-V in cell lysates versus conditioned medium indicated that apoA-V variants associated with lipid droplets were poorly secreted while apoA-V(1-146) was efficiently secreted. Ultracentrifugation of conditioned medium revealed that, unlike full-length apoA-V, which associates with lipoproteins, apoA-V(1-146) was present solely in the lipoprotein-deficient fraction. Deletion of the N-terminal signal peptide from apoA-V resulted in an inability of the protein to be secreted into the medium, although it associated with lipid droplets. Taken together, these data suggest that the C terminus of apoA-V is essential for lipid droplet association in transfected hepatoma cells and lipoprotein association in conditioned medium while the signal peptide is required for extracellular trafficking of this protein. Show less