In the intestinal epithelium, the aberrant regulation of cell/cell junctions leads to intestinal barrier defects, which may promote the onset and enhance the severity of inflammatory bowel disease (IB Show more
In the intestinal epithelium, the aberrant regulation of cell/cell junctions leads to intestinal barrier defects, which may promote the onset and enhance the severity of inflammatory bowel disease (IBD). However, it remains unclear how the coordinated behaviour of cytoskeletal network may contribute to cell junctional dynamics. In this report, we identified ACF7, a crosslinker of microtubules and F-actin, as an essential player in this process. Loss of ACF7 leads to aberrant microtubule organization, tight junction stabilization and impaired wound closure in vitro. With the mouse genetics approach, we show that ablation of ACF7 inhibits intestinal wound healing and greatly increases susceptibility to experimental colitis in mice. ACF7 level is also correlated with development and progression of ulcerative colitis (UC) in human patients. Together, our results reveal an important molecular mechanism whereby coordinated cytoskeletal dynamics contributes to cell adhesion regulation during intestinal wound repair and the development of IBD. Show less
Gliomas are commonly malignant tumors that arise in the human central nervous system and have a low overall five-year survival rate. Previous studies reported that several members of Rab GTPase family Show more
Gliomas are commonly malignant tumors that arise in the human central nervous system and have a low overall five-year survival rate. Previous studies reported that several members of Rab GTPase family are involved in the development of glioma, and abnormal expression of Rab small GTPases is known to cause aberrant tumor cell behavior. In this study, we characterized the roles of Rab21 (Rab GTPase 21), a member of Rab GTPase family, in glioma cells. The study involved downregulation of Rab21 in two glioma cell lines (T98G and U87) through transfection with specific-siRNA. Experiments using the MTT assay, cell cycle analysis, apoptosis assay, real-time PCR and western blot were performed to establish the expression levels of related genes. The results show that downregulation of Rab21 can significantly inhibit cell growth and remarkably induce cell apoptosis in T98G and U87 cell lines. Silencing Rab21 resulted in significantly increased expression of apoptosis-related proteins (caspase7, Bim and Bax) in glioma cells. We inferred that Rab21 silencing can induce apoptosis and inhibit proliferation in human glioma cells, indicating that Rab21 might act as an oncogene and serve as a novel target for glioma therapy. Show less
Genome-wide association studies (GWAS) on Parkinson's disease (PD) have mostly been done in Europeans and Japanese. No study has been done in Han Chinese, which make up nearly a fifth of the world pop Show more
Genome-wide association studies (GWAS) on Parkinson's disease (PD) have mostly been done in Europeans and Japanese. No study has been done in Han Chinese, which make up nearly a fifth of the world population. We conducted the first Han Chinese GWAS analysing a total of 22,729 subjects (5,125 PD cases and 17,604 controls) from Singapore, Hong Kong, Malaysia, Korea, mainland China and Taiwan. We performed imputation, merging and logistic regression analyses of 2,402,394 SNPs passing quality control filters in 779 PD cases, 13,227 controls, adjusted for the first three principal components. 90 SNPs with association P < 10-4 were validated in 9 additional sample collections and the results were combined using fixed-effects inverse-variance meta-analysis. We observed strong associations reaching genome-wide significance at SNCA, LRRK2 and MCCC1, confirming their important roles in both European and Asian PD. We also identified significant (P < 0.05) associations at 5 loci (DLG2, SIPA1L2, STK39, VPS13C and RIT2), and observed the same direction of associations at 9 other loci including BST1 and PARK16. Allelic heterogeneity was observed at LRRK2 while European risk SNPs at 6 other loci including MAPT and GBA-SYT11 were non-polymorphic or very rare in our cohort. Overall, we replicate associations at SNCA, LRRK2, MCCC1 and 14 other European PD loci but did not identify Asian-specific loci with large effects (OR > 1.45) on PD risk. Our results also demonstrate some differences in the genetic contribution to PD between Europeans and Asians. Further pan-ethnic meta-analysis with European GWAS cohorts may unravel new PD loci. Show less
Fa Chen, Baochang He, Lingjun Yan+3 more · 2017 · Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons · Elsevier · added 2026-04-24
The fatty acid desaturase 1 (FADS1) gene variant is a novel susceptibility marker for laryngeal squamous cell carcinoma identified by a recent genome-wide association study, but it is still unclear wh Show more
The fatty acid desaturase 1 (FADS1) gene variant is a novel susceptibility marker for laryngeal squamous cell carcinoma identified by a recent genome-wide association study, but it is still unclear whether this genetic variant continues to influence oral cancer recurrence or death. The purpose of this study was to evaluate the role of FADS1 rs174549 polymorphism and its interaction with postoperative chemoradiotherapy in the prognosis of oral cancer. A prospective cohort study involving 304 oral cancer patients with surgical resection was conducted in Fujian, China. Demographic and clinical data (adjuvant therapy types, histologic types, clinical stage, etc.) were extracted from medical records, and follow-up data were obtained by telephone interviews. We collected 5 to 8 mL of venous blood from all patients for DNA extraction, and rs174549 genotypes were determined by TaqMan assays (Life Technologies, Carlsbad, CA). A Cox proportional hazards model and Kaplan-Meier curve were used to assess the association between FADS1 rs174549 polymorphism and progression-free survival (PFS), as well as overall survival, in oral cancer. Carrying the AA genotype was significantly associated with a decreased risk of PFS: The hazard ratio was 0.52 (95% confidence interval, 0.29 to 0.93) for the codominant model and 0.54 (95% confidence interval, 0.31 to 0.94) for the recessive model. Moreover, better PFS was particularly obvious in patients who had received chemoradiotherapy. A positive multiplicative interaction between FADS1 rs174549 polymorphism and chemoradiotherapy was observed for PFS (P = .036). No significant association was found between FADS1 rs174549 polymorphism and overall survival. Our study suggests, for the first time, that FADS1 rs174549 polymorphism is a potentially independent and favorable factor in predicting oral cancer PFS especially for patients who undergo chemoradiotherapy, and it may serve as a potential target for individualized treatment in the future. Show less
We aim to validate the effects of glucose-dependent insulinotropic polypeptide (GIP) on fat distribution and glucose metabolism in Han Chinese populations. We genotyped six tag single-nucleotide polym Show more
We aim to validate the effects of glucose-dependent insulinotropic polypeptide (GIP) on fat distribution and glucose metabolism in Han Chinese populations. We genotyped six tag single-nucleotide polymorphisms (SNPs) of GIP and four tag SNPs of glucose-dependent insulinotropic polypeptide receptor (GIPR) among 2884 community-based individuals from Han Chinese populations. Linear analysis was applied to test the associations of these variants with visceral fat area (VFA) and subcutaneous fat area (SFA) quantified by magnetic resonance imaging as well as glucose-related traits. We found that the C allele of rs4794008 of GIP tended to increase the VFA and the VFA/SFA ratio in all subjects (P=0.050 and P=0.054, respectively), and rs4794008 was associated with the VFA/SFA ratio in males (P=0.041) after adjusting for the BMI. The VFA-increasing allele of rs4794008 was not related to any glucose metabolism traits. However, rs9904288 of GIP was associated with the SFA in males as well as glucose-related traits in all subjects (P range, 0.004-0.049), and the GIPR variants displayed associations with both fat- and glucose-related traits. The results could provide the evidence that GIP might modulate visceral fat accumulation via incretin function or independent of incretin. Show less
Mutations in many centriolar protein-encoding genes cause primary microcephaly. Using super-resolution and electron microscopy, we find that the human microcephaly protein, RTTN, is recruited to the p Show more
Mutations in many centriolar protein-encoding genes cause primary microcephaly. Using super-resolution and electron microscopy, we find that the human microcephaly protein, RTTN, is recruited to the proximal end of the procentriole at early S phase, and is located at the inner luminal walls of centrioles. Further studies demonstrate that RTTN directly interacts with STIL and acts downstream of STIL-mediated centriole assembly. CRISPR/Cas9-mediated RTTN gene knockout in p53-deficient cells induce amplification of primitive procentriole bodies that lack the distal-half centriolar proteins, POC5 and POC1B. Additional analyses show that RTTN serves as an upstream effector of CEP295, which mediates the loading of POC1B and POC5 to the distal-half centrioles. Interestingly, the naturally occurring microcephaly-associated mutant, RTTN (A578P), shows a low affinity for STIL binding and blocks centriole assembly. These findings reveal that RTTN contributes to building full-length centrioles and illuminate the molecular mechanism through which the RTTN (A578P) mutation causes primary microcephaly.Mutations in many centriolar protein-encoding genes cause primary microcephaly. Here the authors show that human microcephaly protein RTTN directly interacts with STIL and acts downstream of STIL-mediated centriole assembly, contributing to building full-length centrioles. Show less
Chronic alcohol exposure induces pronounced changes in GPCR-mediated G-protein signaling. Recent microarray and RNA-seq analyses suggest associations between alcohol abuse and the expression of genes Show more
Chronic alcohol exposure induces pronounced changes in GPCR-mediated G-protein signaling. Recent microarray and RNA-seq analyses suggest associations between alcohol abuse and the expression of genes involved in G-protein signaling. The activity of G-proteins (e.g. Gαi/o and Gαq) is negatively modulated by regulator of G-protein signaling (RGS) proteins which are implicated in drugs of abuse including alcohol. The present study used 7days of chronic intermittent ethanol exposure followed by 24h withdrawal (CIE) to investigate changes in mRNA and protein levels of G-protein subunit isoforms and RGS protein subtypes in rat prefrontal cortex, a region associated with cognitive deficit attributed to excessive alcohol drinking. We found that this ethanol paradigm induced differential expression of Gα subunits and RGS subtypes. For example, there were increased mRNA and protein levels of Gαi1/3 subunits and no changes in the expression of Gαs and Gαq subunits in ethanol-treated animals. Moreover, CIE increased the mRNA but not the protein levels of Gαo. Additionally, a modest increase in Gαi2 mRNA level by CIE was accompanied by a pronounced increase in its protein level. Interestingly, we found that CIE increased mRNA and protein levels of RGS2, RGS4, RGS7 and RGS19 but had no effect on the expression of RGS5, RGS6, RGS8, RGS12 or RGS17. Changes in the expression of Gα subunits and RGS subtypes could contribute to the functional alterations of certain GPCRs following chronic ethanol exposure. The present study suggests that RGS proteins may be potential new targets for intervention of alcohol abuse via modification of Gα-mediated GPCR function. Show less
To investigate whether genetic variations on the estrogen metabolic pathway would be associated with risk of Alzheimer's disease (AD). Cross-sectional study. Individuals were recruited at the Memory C Show more
To investigate whether genetic variations on the estrogen metabolic pathway would be associated with risk of Alzheimer's disease (AD). Cross-sectional study. Individuals were recruited at the Memory Clinic, Queen Mary Hospital, Hong Kong. Chinese individuals with (n = 426) and without (n = 350) AD. All subjects underwent a standardized cognitive assessment and genotyping of four candidate genes on the estrogen metabolic pathway (estrogen receptor α gene (ESR1), estrogen receptor β gene (ESR2), cytochrome P450 19A1 gene (CYP19A1), cytochrome P450 11A1 gene (CYP11A1)). Apart from consistent results showing an association between apolipoprotein (APO)E and AD, strong evidence of disease associations were found for polymorphisms in ESR2 and CYP11A1 based on the entire data set. For ESR2, significant protective effects were found for A alleles of rs4986938 (permuted P = .02) and rs867443 (permuted P = .02). For CYP11A1, significant risk effects were found for G alleles of rs11638442 (permuted P = .03) and rs11632698 (permuted P = .03). Stratifying subjects according to APOE ε4 status, their genetic effects continued to be significant in the APOE ε4-negative subgroup. Associations between CYP11A1 polymorphisms (rs2279357, rs2073475) and risk of AD were detected in women but not men. Further gene-level analysis confirmed the above association between ESR2 and CYP11A1, and pathway-level analysis highlighted the genetic effect of the estrogen metabolic pathway on disease susceptibility (permuted pathway-level P = .03). Consistent with previous biological findings for sex steroid hormones in the central nervous system, genetic alterations on the estrogen metabolic pathway were revealed in the Chinese population. Confirmation of these present findings in an independent population is warranted to elucidate disease pathogenesis and to explore the potential of hormone therapy in the treatment of AD. Show less
Cancer is a polygenic disease characterized by uncontrolled growth of normal body cells, deregulation of the cell cycle as well as resistance to apoptosis. The spectraplakin protein microtubule actin Show more
Cancer is a polygenic disease characterized by uncontrolled growth of normal body cells, deregulation of the cell cycle as well as resistance to apoptosis. The spectraplakin protein microtubule actin cross-linking factor 1 (MACF1) plays an essential function in various cellular processes, including cell proliferation, migration, signaling transduction and embryo development. MACF1 is also involved in processes such as metastatic invasion in which cytoskeleton organization is a critical element that contributes to tumor progression in various human cancers. Aberrant expression of MACF1 initiates the tumor cell proliferation, and migration and metastasis in numerous cancers, such as breast cancer, colon cancer, lung cancer and glioblastoma. In this review, we summarized the current knowledge of MACF1 and its critical role in different human cancers. This will be helpful for researchers to investigate the novel functional role of MACF1 in human cancers and as a potential target to enhance the efficacy of therapeutic treatment modalities. Show less
Macroautophagy/autophagy is a conserved catabolic process that recycles cytoplasmic material during low energy conditions. BECN1/Beclin1 (Beclin 1, autophagy related) is an essential protein for funct Show more
Macroautophagy/autophagy is a conserved catabolic process that recycles cytoplasmic material during low energy conditions. BECN1/Beclin1 (Beclin 1, autophagy related) is an essential protein for function of the class 3 phosphatidylinositol 3-kinase (PtdIns3K) complexes that play a key role in autophagy nucleation and elongation. Here, we show that AMP-activated protein kinase (AMPK) regulates autophagy by phosphorylating BECN1 at Thr388. Phosphorylation of BECN1 is required for autophagy upon glucose withdrawal. BECN1(T388A), a phosphorylation defective mutant, suppresses autophagy through decreasing the interaction between PIK3C3 (phosphatidylinositol 3-kinase catalytic subunit type 3) and ATG14 (autophagy-related 14). The BECN1(T388A) mutant has a higher affinity for BCL2 than its wild-type counterpart; the mutant is more prone to dimer formation. Conversely, a BECN1 phosphorylation mimic mutant, T388D, has stronger binding to PIK3C3 and ATG14, and promotes higher autophagy activity than the wild-type control. These findings uncover a novel mechanism of autophagy regulation. Show less
Axin-1, a negative regulator of Wnt signaling, is a versatile scaffold protein involved in centrosome separation and spindle assembly in mitosis, but its function in mammalian oogenesis remains unknow Show more
Axin-1, a negative regulator of Wnt signaling, is a versatile scaffold protein involved in centrosome separation and spindle assembly in mitosis, but its function in mammalian oogenesis remains unknown. Here we examined the localization and function of Axin-1 during meiotic maturation in mouse oocytes. Immunofluorescence analysis showed that Axin-1 was localized around the spindle. Knockdown of the Axin1 gene by microinjection of specific short interfering (si)RNA into the oocyte cytoplasm resulted in severely defective spindles, misaligned chromosomes, failure of first polar body (PB1) extrusion, and impaired pronuclear formation. However, supplementing the culture medium with the Wnt pathway activator LiCl improved spindle morphology and pronuclear formation. Downregulation of Axin1 gene expression also impaired the spindle pole localization of γ-tubulin/Nek9 and resulted in retention of the spindle assembly checkpoint protein BubR1 at kinetochores after 8.5 h of culture. Our results suggest that Axin-1 is critical for spindle organization and cell cycle progression during meiotic maturation in mouse oocytes. Show less
Recently, increasing numbers of long noncoding RNAs (lncRNAs), with both oncogenic and tumor-suppressive potential, have been found to be aberrantly expressed in various human cancers. However, the fu Show more
Recently, increasing numbers of long noncoding RNAs (lncRNAs), with both oncogenic and tumor-suppressive potential, have been found to be aberrantly expressed in various human cancers. However, the function of lncRNAs in hepatocellular carcinoma (HCC) progression remains largely unknown. In this study, we performed a comprehensive microarray analysis of lncRNA expression using human HCC specimens. After validation in 119 human HCC tissues, we identified a novel tumor suppressor lncRNA, CPS1 intronic transcript 1 (CPS1-IT1). To elucidate the clinical significance of CPS1-IT1 in HCC, correlations between CPS1-IT1 levels, clinical parameters, and survival outcomes were analyzed. In vitro and in vivo functional assays were also performed to dissect the potential underlying mechanisms. Expression of CPS1-IT1 was significantly decreased in 73% of HCC tissues, and patients with low CPS1-IT1 expression had poor survival outcomes. Furthermore, in vitro functional assays indicated that CPS1-IT1 significantly reduced cell proliferation, migration and invasion capacities through reduced Hsp90 binding to and activation of HIF-1α, thereby suppressing the epithelial-mesenchymal transition (EMT). An in vivo animal model also demonstrated the tumor suppressor role of CPS1- IT1 via decreased tumor growth and metastasis. In conclusion, lncRNA CPS1-IT1 acts as a tumor suppressor in HCC by reducing HIF-1α activation and suppressing EMT. The findings of this study establish a function for CPS1-IT1 in HCC progression and suggest its potential as a new prognostic biomarker and target for HCC therapy. Show less
Epidemiological studies suggest that levels of n-3 and n-6 long-chain polyunsaturated fatty acids are associated with risk of cardio-metabolic outcomes across different ethnic groups. Recent genome-wi Show more
Epidemiological studies suggest that levels of n-3 and n-6 long-chain polyunsaturated fatty acids are associated with risk of cardio-metabolic outcomes across different ethnic groups. Recent genome-wide association studies in populations of European ancestry have identified several loci associated with plasma and/or erythrocyte polyunsaturated fatty acids. To identify additional novel loci, we carried out a genome-wide association study in two population-based cohorts consisting of 3521 Chinese participants, followed by a trans-ethnic meta-analysis with meta-analysis results from 8962 participants of European ancestry. Four novel loci (MYB, AGPAT4, DGAT2 and PPT2) reached genome-wide significance in the trans-ethnic meta-analysis (log10(Bayes Factor) ≥ 6). Of them, associations of MYB and AGPAT4 with docosatetraenoic acid (log10(Bayes Factor) = 11.5 and 8.69, respectively) also reached genome-wide significance in the Chinese-specific genome-wide association analyses (P = 4.15 × 10(-14) and 4.30 × 10(-12), respectively), while associations of DGAT2 with gamma-linolenic acid (log10(Bayes Factor) = 6.16) and of PPT2 with docosapentaenoic acid (log10(Bayes Factor) = 6.24) were nominally significant in both Chinese- and European-specific genome-wide association analyses (P ≤ 0.003). We also confirmed previously reported loci including FADS1, NTAN1, NRBF2, ELOVL2 and GCKR. Different effect sizes in FADS1 and independent association signals in ELOVL2 were observed. These results provide novel insight into the genetic background of polyunsaturated fatty acids and their differences between Chinese and European populations. Show less
Exostosin glycosyltransferase (EXT) 1 and EXT2 have been identified as causative genes in osteochondroma; however, it is not known whether these genes are also involved in condylar osteochondromas. Th Show more
Exostosin glycosyltransferase (EXT) 1 and EXT2 have been identified as causative genes in osteochondroma; however, it is not known whether these genes are also involved in condylar osteochondromas. The aim of this study was to identify EXT1 and EXT2 mutations in patients with non-hereditary osteochondromas of the mandibular condyle. DNA was obtained from resected tissues (cartilage cap) of 12 patients with solitary condylar osteochondromas. The exons, 3',5'-untranslated regions and intron-exon boundaries of EXT1 and EXT2 were amplified by polymerase chain reaction and the products were sequenced directly. Through direct sequencing, four genetic variations of EXT1 in 4 cases and three variations of EXT2 in 5 cases were identified. The intronic alteration of the EXT2 gene, occurring in 2 cases, was novel, whereas the other alterations had been previously reported. Nonsense somatic mutations were detected in tumor DNA. Our study extended the mutational spectrum in EXT1 and EXT2 and may facilitate a better understanding of the pathophysiology of condylar osteochondromas. Show less
Targeting leukemia-initiating cells (LICs) is the key to eradicating leukemia and preventing its relapse. Recent studies have indicated that metabolic regulation may play a critical role in the mainte Show more
Targeting leukemia-initiating cells (LICs) is the key to eradicating leukemia and preventing its relapse. Recent studies have indicated that metabolic regulation may play a critical role in the maintenance of stemness in LICs, although the detailed mechanisms are poorly understood. Herein, we provide intriguing evidence showing that a glucose-responsive transcription factor, carbohydrate responsive element binding protein (ChREBP), served as a tumor suppressor rather than an oncogene, as previously described, to inhibit the development of acute myeloid leukemia by promoting the differentiation of LICs. Using an MLL-AF9-induced murine leukemia model, we demonstrated that the deletion of ChREBP resulted in the blockage of the differentiation of LICs and significantly reduced survival in ChREBP-null leukemic mice. However, ChREBP was not required for the normal repopulation abilities of hematopoietic stem cells. ChREBP promoted leukemia cell differentiation through the direct inhibition of RUNX1 or the transactivation of TXNIP to downregulate the RUNX1 level and ROS generation. Moreover, knockdown of ChREBP in human leukemia THP1 cells led to markedly enhanced proliferation and decreased differentiation upon PMA treatment. Collectively, we unraveled an unexpected role of ChREBP in leukemogenesis, which may provide valuable clues for developing novel metabolic strategies for leukemia treatment. Show less
Long non-coding RNAs (lncRNAs) have been shown to be critical biomarkers or therapeutic targets for human diseases. However, only a small number of lncRNAs were screened and characterized. Here, we id Show more
Long non-coding RNAs (lncRNAs) have been shown to be critical biomarkers or therapeutic targets for human diseases. However, only a small number of lncRNAs were screened and characterized. Here, we identified 15 lncRNAs, which are associated with fatty liver disease. Among them, APOA4-AS is shown to be a concordant regulator of Apolipoprotein A-IV (APOA4) expression. APOA4-AS has a similar expression pattern with APOA4 gene. The expressions of APOA4-AS and APOA4 are both abnormally elevated in the liver of ob/ob mice and patients with fatty liver disease. Knockdown of APOA4-AS reduces APOA4 expression both in vitro and in vivo and leads to decreased levels of plasma triglyceride and total cholesterol in ob/ob mice. Mechanistically, APOA4-AS directly interacts with mRNA stabilizing protein HuR and stabilizes APOA4 mRNA. Deletion of HuR dramatically reduces both APOA4-AS and APOA4 transcripts. This study uncovers an anti-sense lncRNA (APOA4-AS), which is co-expressed with APOA4, and concordantly and specifically regulates APOA4 expression both in vitro and in vivo with the involvement of HuR. Show less
Although major depressive disorder (MDD) has low heritability, a genome-wide association study in humans has recently implicated type 3 adenylyl cyclase (AC3; ADCY3) in MDD. Moreover, the expression l Show more
Although major depressive disorder (MDD) has low heritability, a genome-wide association study in humans has recently implicated type 3 adenylyl cyclase (AC3; ADCY3) in MDD. Moreover, the expression level of AC3 in blood has been considered as a MDD biomarker in humans. Nevertheless, there is a lack of supporting evidence from animal studies. We employed multiple approaches to experimentally evaluate if AC3 is a contributing factor for major depression using mouse models lacking the Adcy3 gene. We found that conventional AC3 knockout (KO) mice exhibited phenotypes associated with MDD in behavioral assays. Electroencephalography/electromyography recordings indicated that AC3 KO mice have altered sleep patterns characterized by increased percentage of rapid eye movement sleep. AC3 KO mice also exhibit neuronal atrophy. Furthermore, synaptic activity at cornu ammonis 3-cornu ammonis 1 synapses was significantly lower in AC3 KO mice, and they also exhibited attenuated long-term potentiation as well as deficits in spatial navigation. To confirm that these defects are not secondary responses to anosmia or developmental defects, we generated a conditional AC3 floxed mouse strain. This enabled us to inactivate AC3 function selectively in the forebrain and to inducibly ablate it in adult mice. Both AC3 forebrain-specific and AC3 inducible knockout mice exhibited prodepression phenotypes without anosmia. This study demonstrates that loss of AC3 in mice leads to decreased neuronal activity, altered sleep pattern, and depression-like behaviors, providing strong evidence supporting AC3 as a contributing factor for MDD. Show less
Autophagy is an important catabolic process, which sustains intracellular homeostasis and lengthens cell survival under stress. Here we identify the ankyrin-repeat-containing, SH3-domain-containing, a Show more
Autophagy is an important catabolic process, which sustains intracellular homeostasis and lengthens cell survival under stress. Here we identify the ankyrin-repeat-containing, SH3-domain-containing, and proline-rich region-containing protein 2 (ASPP2), a haploinsufficient tumor suppressor, as a molecular regulator of starvation-induced autophagy in hepatocellular carcinoma (HCC). ASPP2 expression is associated with an autophagic response upon nutrient deprivation and downregulation of ASPP2 facilitates autophagic flux, whereas overexpression of ASPP2 blocks this starvation-induced autophagy in HCC cells. Mechanistically, ASPP2 inhibits autophagy through regulating BECN1 transcription and formation of phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3) complex. Firstly, ASPP2 inhibits p65/RelA-induced transcription of BECN1, directly by an ASPP2-p65/RelA-IκBα complex which inhibits phosphorylation of IκBα and the translocation of p65/RelA into the nucleus. Secondly, ASPP2 binds to BECN1, leading to decreased binding of PIK3C3 and UV radiation resistance-associated gene (UVRAG), and increased binding of Rubicon in PIK3C3 complex. Downregulation of ASPP2 enhances the pro-survival and chemoresistant property via autophagy in HCC cells in vitro and in vivo. Decreased ASPP2 expression was associated with increased BECN1 and poor survival in HCC patients. Therefore, ASPP2 is a key regulator of BECN1-dependent autophagy, and decreased ASPP2 may contribute to tumor progression and chemoresistance via promoting autophagy. Show less
White blood cells play diverse roles in innate and adaptive immunity. Genetic association analyses of phenotypic variation in circulating white blood cell (WBC) counts from large samples of otherwise Show more
White blood cells play diverse roles in innate and adaptive immunity. Genetic association analyses of phenotypic variation in circulating white blood cell (WBC) counts from large samples of otherwise healthy individuals can provide insights into genes and biologic pathways involved in production, differentiation, or clearance of particular WBC lineages (myeloid, lymphoid) and also potentially inform the genetic basis of autoimmune, allergic, and blood diseases. We performed an exome array-based meta-analysis of total WBC and subtype counts (neutrophils, monocytes, lymphocytes, basophils, and eosinophils) in a multi-ancestry discovery and replication sample of ∼157,622 individuals from 25 studies. We identified 16 common variants (8 of which were coding variants) associated with one or more WBC traits, the majority of which are pleiotropically associated with autoimmune diseases. Based on functional annotation, these loci included genes encoding surface markers of myeloid, lymphoid, or hematopoietic stem cell differentiation (CD69, CD33, CD87), transcription factors regulating lineage specification during hematopoiesis (ASXL1, IRF8, IKZF1, JMJD1C, ETS2-PSMG1), and molecules involved in neutrophil clearance/apoptosis (C10orf54, LTA), adhesion (TNXB), or centrosome and microtubule structure/function (KIF9, TUBD1). Together with recent reports of somatic ASXL1 mutations among individuals with idiopathic cytopenias or clonal hematopoiesis of undetermined significance, the identification of a common regulatory 3' UTR variant of ASXL1 suggests that both germline and somatic ASXL1 mutations contribute to lower blood counts in otherwise asymptomatic individuals. These association results shed light on genetic mechanisms that regulate circulating WBC counts and suggest a prominent shared genetic architecture with inflammatory and autoimmune diseases. Show less
Gastric cancer is not a single disease, and its subtype classification is still evolving. Next-generation sequencing studies have identified novel genetic drivers of gastric cancer, but their use as m Show more
It is generally recognized that the inflammatory reaction in glia is one of the important pathological factors in brain ischemic injury. Our previous study has revealed that opening ATP-sensitive pota Show more
It is generally recognized that the inflammatory reaction in glia is one of the important pathological factors in brain ischemic injury. Our previous study has revealed that opening ATP-sensitive potassium (K-ATP) channels could attenuate glial inflammation induced by ischemic stroke. However, the detailed mechanisms are not well known. Primary cultured astrocytes separated from C57BL/6 mice were subjected to oxygen-glucose deprivation (OGD); cellular injuries were determined via observing the changes of cellular morphology and cell viability. MicroRNA (miR) and messenger RNA (mRNA) level was validated by real-time PCR. The interaction between microRNA and the target was confirmed via dual luciferase reporter gene assay. Expressions of proteins and inflammatory cytokines were respectively assessed by western blotting and enzyme-linked immunosorbent assay. OGD resulted in astrocytic damage, which was prevented by K-ATP channel opener nicorandil. Notably, we found that OGD significantly downregulated miR-7 and upregulated Herpud2. Our further study proved that miR-7 targeted Herpud2 3'UTR, which encoded endoplasmic reticulum (ER) stress protein-HERP2. Correspondingly, our results showed that OGD increased the levels of ER stress proteins along with significant elevations of pro-inflammatory cytokines, including tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β). Pretreatment with nicorandil could remarkably upregulate miR-7, depress the ER-related protein expressions including glucose-regulated protein 78 (GRP78), C/EBP-homologous protein (CHOP), and Caspase-12, and thereby attenuate inflammatory responses and astrocytic damages. These findings demonstrate that opening K-ATP channels protects astrocytes against OGD-mediated neuroinflammation. Potentially, miR-7-targeted ER stress acts as a key molecular brake on neuroinflammation. Show less
Multiple osteochondromas (MO), also known as hereditary multiple exostoses, is an autosomal dominant bone disorder. Mutations in exostosin glycosyl transferase‑1 (EXT1) and exostosin glycosyl transfer Show more
Multiple osteochondromas (MO), also known as hereditary multiple exostoses, is an autosomal dominant bone disorder. Mutations in exostosin glycosyl transferase‑1 (EXT1) and exostosin glycosyl transferase‑2 (EXT2), including missense, nonsense, frameshift and splice‑site mutations, account for up to 80% of reported cases. The proteins EXT1 and EXT2 form a hetero‑oligomeric complex that functions in heparan sulfate proteoglycan biosynthesis. A heterozygous EXT2 mutation, c.939+1G>T, was identified in a five‑generation 33‑member MO family, and was present in all 13 affected members. The mutation results in deletion of exon 5 in the mRNA, producing a frameshift that leads to a premature termination codon. The present study extends the mutational spectrum of EXT2. Show less
5-Hydroxytryptamine (5-HT), a neurotransmitter and vasoactive factor, has been reported to promote proliferation of serum-deprived hepatocellular carcinoma (HCC) cells but the detailed intracellular m Show more
5-Hydroxytryptamine (5-HT), a neurotransmitter and vasoactive factor, has been reported to promote proliferation of serum-deprived hepatocellular carcinoma (HCC) cells but the detailed intracellular mechanism is unknown. As Wnt/β-catenin signalling is highly dysregulated in a majority of HCC, this study explored the regulation of Wnt/β-catenin signalling by 5-HT. The expression of various 5-HT receptors was studied by quantitative real-time polymerase chain reaction (qPCR) in HCC cell lines as well as in 33 pairs of HCC tumours and corresponding adjacent non-tumour tissues. Receptors 5-HT1D (21/33, 63.6%), 5-HT2B (12/33, 36.4%) and 5-HT7 (15/33, 45.4%) were overexpressed whereas receptors 5-HT2A (17/33, 51.5%) and 5-HT5 (30/33, 90.1%) were reduced in HCC tumour tissues. In vitro data suggests 5-HT increased total β-catenin, active β-catenin and decreased phosphorylated β-catenin protein levels in serum deprived HuH-7 and HepG2 cells compared to control cells under serum free medium without 5-HT. Activation of Wnt/β-catenin signalling was evidenced by increased expression of β-catenin downstream target genes, Axin2, cyclin D1, dickoppf-1 (DKK1) and glutamine synthetase (GS) by qPCR in serum-deprived HCC cell lines treated with 5-HT. Additionally, biochemical analysis revealed 5-HT disrupted Axin1/β-catenin interaction, a critical step in β-catenin phosphorylation. Increased Wnt/β-catenin activity was attenuated by antagonist of receptor 5-HT7 (SB-258719) in HCC cell lines and patient-derived primary tumour tissues in the presence of 5-HT. SB-258719 also reduced tumour growth in vivo. This study provides evidence of Wnt/β-catenin signalling activation by 5-HT and may represent a potential therapeutic target for hepatocarcinogenesis. Show less
PTEN is a lipid phosphatase that converts phosphatidylinositol 3,4,5-phosphate (PIP3) to phosphatidylinositol 4,5-phosphate (PIP2) and plays a critical role in the regulation of tumor growth. PTEN is Show more
PTEN is a lipid phosphatase that converts phosphatidylinositol 3,4,5-phosphate (PIP3) to phosphatidylinositol 4,5-phosphate (PIP2) and plays a critical role in the regulation of tumor growth. PTEN is subject to regulation by a variety of post-translational modifications, including phosphorylation on a C-terminal cluster of four Ser/Thr residues (380, 382, 383, and 385) and ubiquitylation by various E3 ligases, including NEDD4-1 and WWP2. It has previously been shown that C-terminal phosphorylation of PTEN can increase its cellular half-life. Using in vitro ubiquitin transfer assays, we show that WWP2 is more active than NEDD4-1 in ubiquitylating unphosphorylated PTEN. The mapping of ubiquitylation sites in PTEN by mass spectrometry showed that both NEDD4-1 and WWP2 can target a broad range of Lys residues in PTEN, although NEDD4-1 versus WWP2 showed a stronger preference for ubiquitylating PTEN's C2 domain. Whereas tetraphosphorylation of PTEN did not significantly affect its ubiquitylation by NEDD4-1, it inhibited PTEN ubiquitylation by WWP2. Single-turnover and pull-down experiments suggested that tetraphosphorylation of PTEN appears to weaken its interaction with WWP2. These studies reveal how the PTEN E3 ligases WWP2 and NEDD4-1 exhibit distinctive properties in Lys selectivity and sensitivity to PTEN phosphorylation. Our findings also provide a molecular mechanism for the connection between PTEN Ser/Thr phosphorylation and PTEN's cellular stability. Show less
PI3Kδ has been found to be over-expressed in B-Cell-related malignancies. Despite the clinical success of the first selective PI3Kδ inhibitor, CAL-101, inhibition of PI3Kδ itself did not show too much Show more
PI3Kδ has been found to be over-expressed in B-Cell-related malignancies. Despite the clinical success of the first selective PI3Kδ inhibitor, CAL-101, inhibition of PI3Kδ itself did not show too much cytotoxic efficacy against cancer cells. One possible reason is that PI3Kδ inhibition induced autophagy that protects the cells from death. Since class III PI3K isoform PIK3C3/Vps34 participates in autophagy initiation and progression, we predicted that a PI3Kδ and Vps34 dual inhibitor might improve the anti-proliferative activity observed for PI3Kδ-targeted inhibitors. We discovered a highly potent ATP-competitive PI3Kδ/Vps34 dual inhibitor, PI3KD/V-IN-01, which displayed 10-1500 fold selectivity over other PI3K isoforms and did not inhibit any other kinases in the kinome. In cells, PI3KD/V-IN-01 showed 30-300 fold selectivity between PI3Kδ and other class I PI3K isoforms. PI3KD/V-IN-01 exhibited better anti-proliferative activity against AML, CLL and Burkitt lymphoma cell lines than known selective PI3Kδ and Vps34 inhibitors. Interestingly, we observed FLT3-ITD AML cells are more sensitive to PI3KD/V-IN-01 than the FLT3 wt expressing cells. In AML cell inoculated xenograft mouse model, PI3KD/V-IN-01 exhibited dose-dependent anti-tumor growth efficacies. These results suggest that dual inhibition of PI3Kδ and Vps34 might be a useful approach to improve the PI3Kδ inhibitor's anti-tumor efficacy. Show less
Leucine-rich repeat and immunoglobulin domain-containing protein (LINGO)-1 is expressed in neural stem cells, and its neutralization results in sustained neuronal immaturity. Thus, targeted inhibition Show more
Leucine-rich repeat and immunoglobulin domain-containing protein (LINGO)-1 is expressed in neural stem cells, and its neutralization results in sustained neuronal immaturity. Thus, targeted inhibition of LINGO-1 via RNA interference may enhance transplanted neural stem cell survival and neuronal differentiation in vivo. Furthermore, LINGO-1 RNA interference in neural stem cells represents a potential therapeutic strategy for spinal cord injury. Department of Spine Surgery, First Affiliated Hospital of Sun Yat-sen University. Translational Medicine Center Research Laboratory, First Affiliated Hospital of Sun Yat-sen University. Female Sprague-Dawley rats. The animals were divided into three groups that underwent laminectomy and complete spinal cord transection accompanied by transplantation of control-RNA interference-treated or LINGO-1-RNA interference-treated neural stem cells at the injured site in vivo. In vitro, neural stem cells were divided into four groups for the following treatments: control, control RNA interference lentivirus, LINGO-1 RNA interference lentivirus and LINGO-1 complementary DNA lentivirusand the Key Projects of the Natural Science Foundation of Guangdong Province (No. S2013020012818). Neural stem cells in each treatment group were examined for cell survival and neuronal differentiation in vitro and in vivo via immunofluorescence and Western blot analysis. Axonal regeneration and tissue repair were assessed via retrograde tracing using Fluorogold, electron microscopy, hematoxylin-eosin staining and MRI. Rats were also examined for functional recovery based on the measurement of spinal cord-evoked potentials and the Basso-Beattie-Bresnahan score. LINGO-1-RNA interference-treated neural stem cell transplantation increased tissue repair and functional recovery of the injured spinal cord in rats. Similarly, LINGO-1 RNA interference increased neural stem cell survival and neuronal differentiation in vitro. The mechanism underlying the effect of LINGO-1 RNA interference on the injured rat spinal cord may be that the significant inhibition of LINGO-1 expression in neural stem cells inactivated the RhoA and Notch signaling pathways, which act downstream of LINGO-1. Our findings indicate that transplantation of LINGO-1-RNA interference-treated neural stem cells facilitates functional recovery after spinal cord injury and represents a promising potential strategy for the repair of spinal cord injury. Show less
Recently, a large-scale meta-analysis of genome-wide association study (GWAS) data identified several new risk loci that can modulate the risk of Parkinson's disease (PD). These associations have yet Show more
Recently, a large-scale meta-analysis of genome-wide association study (GWAS) data identified several new risk loci that can modulate the risk of Parkinson's disease (PD). These associations have yet to be examined in PD patients in Chinese or Asian population. Because ethnic-specific effect is an important concern for GWAS analysis, we genotyped single-nucleotide polymorphisms in the new genetic loci, GCH1 (rs11158026), SIPA1L2 (rs10797576), VPS13C (rs2414739), and MIR4697 (rs329648), to investigate their associations with risk of PD in Taiwan. Another single-nucleotide polymorphism GCH1 rs7155501, previously identified by GWAS listed at the top 20 genes in PDGene database was also included. A total of 1151 study subjects comprising 598 patients with PD and 553 unrelated healthy controls were recruited. The frequency of minor allele (C allele) of GCH1 rs11158026 was found to be significantly higher in PD cases than in controls (p = 0.003). The CC genotype of rs11158026 increased PD risk compared to TT genotype (odds ratio [OR] = 1.29, 95% confidence interval [CI] = 1.09, 1.53, p = 0.004). Under additive model, the GCH1 rs11158026 increased the risk of developing PD (OR = 1.30, 95% CI = 1.10, 1.54, p = 0.002). In recessive model, the genotype TT of MIR4697 rs329648 marginally decreased the PD risk (OR = 0.62, 95% CI = 0.43, 0.90, p = 0.01). The PD patients demonstrated similar genotypic and allelic frequencies in GCH1 rs7155501, SIPA1L2 rs10797576, and VPS13C rs2414739 with the controls. These findings suggest that the GCH1 and MIR4697 but not SIPA1L2 and VPS13C are genetic loci influencing risk of PD in Taiwan. Show less
The association between nonalcoholic fatty liver disease (NAFLD) and apolipoprotein C3 gene (APOC3) promoter region single-nucleotide polymorphisms (SNPs) rs2854117 and rs2854116 is controversial. The Show more
The association between nonalcoholic fatty liver disease (NAFLD) and apolipoprotein C3 gene (APOC3) promoter region single-nucleotide polymorphisms (SNPs) rs2854117 and rs2854116 is controversial. The aim of this study was to investigate the relationship between other polymorphisms of APOC3 and NAFLD in Chinese. Fifty-nine liver biopsy-proven NAFLD patients and 72 healthy control subjects were recruited to a cohort representing Chinese Han population. The polymorphisms in the exons and flanking regions of APOC3 and patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 polymorphisms were genotyped. Among the five SNPs (rs4225, rs4520, rs5128, rs2070666, and rs2070667) in APOC3, only rs2070666 (c.179 + 62 T/A) was significantly different in genotype and allele frequency (both p < 0.01) between groups of NAFLD and control. After adjusting for sex, age, serum triglycerides, total cholesterol, body mass index, and the PNPLA3 rs738409 polymorphism, the APOC3 rs2070666 A allele was an independent risk factor for NAFLD with an odds ratio (OR) of 3.683 and 95 % confidence interval (CI) of 1.037-13.084. The APOC3 rs2070666 A allele was linked to the fourth quartile of the controlled attenuation parameter values (OR 2.769, 95 % CI 1.002-7.651) in 131 subjects, and also linked to the significant histological steatosis (OR 4.986, 95 % CI 1.020-24.371), but neither to liver stiffness measurement values nor to hepatic histological activity and fibrosis in NAFLD patients. The APOC3 rs2070666 A allele is a risk factor for NAFLD independent of obesity, dyslipidemia, and PNPLA3 rs738409, and it might contribute to increased liver fat content in Chinese Han population. Show less
Valeriana jatamansi Jones, a plant with heart-shaped leaves in the Valeriana genus of Valerianaceae, is widely used in Chinese folk medicine. Iridoid is an important constituent of V. jatamansi that c Show more
Valeriana jatamansi Jones, a plant with heart-shaped leaves in the Valeriana genus of Valerianaceae, is widely used in Chinese folk medicine. Iridoid is an important constituent of V. jatamansi that contributes to the pharmacological efficacy of the herb. This study aims to investigate the regulation of lipid metabolism and its mechanism of the iridoids rich fraction in V. jatamansi (IRFV). A high fat diet was used to establish the hyperlipidemia rat model, with 2mg/kg/d of simvastatin as a positive control, fed with 7.5, 15, and 30mg/kg/d of IRFV for 20days to investigate the lipid regulation activity and mechanism of IRFV. Body weight, liver index, total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) in both serum and liver, as well as total bile acid (TBA), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in serum were measured. The lipoprotein lipase (LPL) and hepatic lipase (HL) activities and the apoprotein A5 (ApoA5), peroxisome proliferator-activated receptor α (PPAR-α), sterol regulatory element-binding proteins (SREBP-1c), and liver X receptor α (LXR-α) protein expressions were observed. Liver pathology was described through hematoxylin-eosin (HE) staining. Compared with the model group, three different IRFV dosages can slow down the weight gain of rats, reduce the contents of TG, and increase the contents of HDL-C in serum. Low IRFV dosage can significantly reduce the AST and ALT contents in serum, liver index, and the TG contents in liver, enhance LPL activity. Medium IRFV dosage can significantly decrease the TG and LDL-C contents in liver. High IRFV dosage can significantly reduce LDL-C, TBA, AST, and ALT contents in serum, and enhance HL activity. Three different IRFV dosages can significantly increase the ApoA5 and PPAR-α protein expression and decrease the SREBP-1c protein expression. Furthermore, the LXR-α protein expression decreased in low- and high-dose groups. Liver tissue pathological observation showed that IRFV can improve cell degeneration to a certain extent. These results strongly suggest that IRFV play significant roles in regulating lipid metabolism, the mechanism may be related to the increased ApoA5 protein expression. Show less