Recent genome-wide association studies have identified many single nucleotide polymorphisms (SNPs) associated with body mass index (BMI)/generalized obesity. In this study, we aimed to examine the ass Show more
Recent genome-wide association studies have identified many single nucleotide polymorphisms (SNPs) associated with body mass index (BMI)/generalized obesity. In this study, we aimed to examine the associations of identified SNPs with risk of central obesity in a child population from China. We genotyped 11 SNPs (FTO rs9939609, MC4R rs17782313, GNPDA2 rs10938397, BDNF rs6265, FAIM2 rs7138803, NPC1 rs1805081, SEC16B rs10913469, SH2B1 rs4788102, PCSK1rs6235, KCTD15 rs29941, BAT2 rs2844479) in the Chinese children (N = 3502, age range 6-18 years) from the Beijing Child and Adolescent Metabolic Syndrome (BCAMS). Based on the age- and sex- specific waist circumference (WC) standards generated in the BCAMS study, 1196 central obese cases and 2306 controls were identified. Of 11 studied SNPs, four SNPs and genetic risk score (GRS) based on them were statistically significantly associated with central obesity by WC criteria (FTO rs9939609: OR = 1.29, 95%CI = 1.10-1.50, p = 0.001; MC4R rs17782313: OR = 1.27, 95%CI = 1.12-1.44, p = 1.32×10⁻⁴; GNPDA2 rs10938397: OR = 1.22, 95%CI = 1.09-1.37, p = 4.09×10⁻⁴; BDNF rs6265: OR = 1.20, 95%CI = 1.08-1.34, p = 8.86×10⁻⁴; GRS: OR = 1.25, 95%CI 1.16-1.34, p = 2.58×10⁻⁹) after adjustment for sex, age, pubertal stage, physical activity and family history of obesity. Similar observations were made using weight-to-height ratio (WHtR) criterion. However, other SNPs were not associated with central obesity by WC as well as WHtR criterion. Our study replicates the statistically significant association of four SNPs (FTO rs9939609, MC4R rs17782313, GNPDA2 rs10938397, BDNF rs6265) with risk of central obesity in the Chinese children. Show less
Recent genome-wide association studies have identified a few single nucleotide polymorphisms (SNPs), which are associated with body mass index (BMI)/obesity. This study aimed to examine the identified Show more
Recent genome-wide association studies have identified a few single nucleotide polymorphisms (SNPs), which are associated with body mass index (BMI)/obesity. This study aimed to examine the identified associations among a population of Chinese children. Five SNPs (SEC16B rs10913469, SH2B1 rs4788102, PCSK1rs6235, KCTD15 rs29941, BAT2 rs2844479) were genotyped for a group of Chinese children (N = 2849, age range 6-18 years). A total of 1230 obese cases and 1619 controls with normal weight were identified based on the Chinese age- and sex-specific BMI references. Of five studied variants, only two (SEC16B rs10913469, SH2B1 rs4788102) were nominally associated with indices of adiposity and obesity risk in girls and only SEC16B rs10913469 in children at puberty (p < 0·05), while no statistical associations was found for three other variants (PCSK1rs6235, KCTD15 rs29941, BAT2 rs2844479). After false discovery rate (FDR) adjustment for multiple testing, none were statistically significant. Further analysis indicated that the genetic risk score (GRS) was associated with BMI, waist circumference and risk of obesity (defined by BMI) in girls, even after FDR adjustment for multiple testing. However, there was no statistical association of GRS with indices of adiposity and risk of obesity in children at puberty after multiple comparison correction. This study confirmed the synthetic effect of SNPs on the indices of adiposity and risk of obesity in Chinese girls, but failed to replicate the effect of five separate variants. We also did not found cumulative effect of SNPs in children at puberty. Show less
Birth weight reflects prenatal metabolic adaption and has been related to later-life obesity risk. This study aimed to evaluate whether birth weight modifies the effect of genetic susceptibility on ob Show more
Birth weight reflects prenatal metabolic adaption and has been related to later-life obesity risk. This study aimed to evaluate whether birth weight modifies the effect of genetic susceptibility on obesity risk in young Chinese. We recruited 540 young (14-30 years) and obese patients (body mass index, BMI30 kg m(-2)), and 500 age- and sex-matched normal-weight healthy individuals (BMI<23 kg m(-2)). We genotyped 23 BMI-associated genetic variants identified from recent genome-wide association studies (GWAS) in Caucasians with European ancestry with minor allele frequency>0.05 in HapMap Han Chinese in Beijing, China. Six loci, including SEC16B, GNPDA2, BDNF, FTO, MC4R and TMEM160, were significantly associated with obesity risk, with odds ratio from 1.314 to 1.701. The 23 risk loci accounted for 6.38% of the genetic variance in obesity. We created two genetic risk scores (GRSs) by summing the risk alleles of all 23 (GRS1) and 6 obesity-associated (GRS2) genetic variants. Prediction of obesity was significantly improved (P<0.001) when the GRS1 and GRS2 were added to a model with age and gender, with improvement of discrimination for obesity by 0.8% and 2.7%, respectively. In addition, we found that the two GRSs interacted with birth weight in relation to obesity (Pinteraction<0.001). The genetic effect appeared to be more pronounced in individuals with normal range of birth weight (25-75%) than those with either low (<25%) or high (>75%) birth weight. We confirmed the associations of the single-nucleotide polymorphism tagging six loci reported in recent GWAS with obesity in young Chinese. Our data also suggest birth weight may significantly modify genetic susceptibility to obesity risk. Show less
The individuals carrying melanocortin-1 receptor (MC1R) variants, especially those associated with red hair color, fair skin, and poor tanning ability (RHC trait), are more prone to melanoma; however, Show more
The individuals carrying melanocortin-1 receptor (MC1R) variants, especially those associated with red hair color, fair skin, and poor tanning ability (RHC trait), are more prone to melanoma; however, the underlying mechanism is poorly defined. Here, we report that UVB exposure triggers phosphatase and tensin homolog (PTEN) interaction with wild-type (WT), but not RHC-associated MC1R variants, which protects PTEN from WWP2-mediated degradation, leading to AKT inactivation. Strikingly, the biological consequences of the failure of MC1R variants to suppress PI3K/AKT signaling are highly context dependent. In primary melanocytes, hyperactivation of PI3K/AKT signaling leads to premature senescence; in the presence of BRAF(V600E), MC1R deficiency-induced elevated PI3K/AKT signaling drives oncogenic transformation. These studies establish the MC1R-PTEN axis as a central regulator for melanocytes' response to UVB exposure and reveal the molecular basis underlying the association between MC1R variants and melanomagenesis. Show less
Yan Yang, Bing Liao, Suyun Wang+4 more · 2013 · Proceedings of the National Academy of Sciences of the United States of America · National Academy of Sciences · added 2026-04-24
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 interfe Show more
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
Many tumor suppressors play an important role in the DNA damage pathway. Zinc finger protein 668 (ZNF668) has recently been identified as one of the potential tumor suppressors in breast cancer, but i Show more
Many tumor suppressors play an important role in the DNA damage pathway. Zinc finger protein 668 (ZNF668) has recently been identified as one of the potential tumor suppressors in breast cancer, but its function in DNA damage response is unknown. Herein, we report that ZNF668 is a regulator of DNA repair. ZNF668 knockdown impairs cell survival after DNA damage without affecting the ATM/ATR DNA-damage signaling cascade. However, recruitment of repair proteins to DNA lesions is decreased. In response to IR, ZNF668 knockdown reduces Tip60-H2AX interaction and impairs IR-induced histone H2AX hyperacetylation, thus impairing chromatin relaxation. Impaired chromatin relaxation causes decreased recruitment of repair proteins to DNA lesions, defective homologous recombination (HR) repair and impaired cell survival after IR. In addition, ZNF668 knockdown decreased RPA phosphorylation and its recruitment to DNA damage foci in response to UV. In both IR and UV damage responses, chromatin relaxation counteracted the impaired loading of repair proteins and DNA repair defects in ZNF668-deficient U2OS cells, indicating that impeded chromatin accessibility at sites of DNA breaks caused the DNA repair defects observed in the absence of ZNF668. Our findings suggest that ZNF668 is a key molecule that links chromatin relaxation with DNA damage response in DNA repair control. Show less
The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that is involved in regulating cell-cycle progression. It has been widely studied in yeast and animal cells, but the function Show more
The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that is involved in regulating cell-cycle progression. It has been widely studied in yeast and animal cells, but the function and regulation of the APC/C in plant cells are largely unknown. The Arabidopsis APC/C comprises at least 11 subunits, only a few of which have been studied in detail. APC4 is proposed to be a connector in the APC/C in yeast and animals. Here, we report the functional characterization of the Arabidopsis APC4 protein. We examined three heterozygous plant lines carrying apc4 alleles. These plants showed pleiotropic developmental defects in reproductive processes, including abnormal nuclear behavior in the developing embryo sac and aberrant cell division in embryos; these phenotypes differ from those reported for mutants of other subunits. Some ovules and embryos of apc4/+ plants also accumulated cyclin B protein, a known substrate of APC/C, suggesting a compromised function of APC/C. Arabidopsis APC4 was expressed in meristematic cells of seedlings, ovules in pistils and embryos in siliques, and was mainly localized in the nucleus. Additionally, the distribution of auxin was distorted in some embryos of apc4/+ plants. Our results indicate that Arabidopsis APC4 plays critical roles in female gametogenesis and embryogenesis, possibly as a connector in APC/C, and that regulation of auxin distribution may be involved in these processes. Show less
Fei Wang, Alison B Kohan, Tammy L Kindel+6 more · 2012 · Proceedings of the National Academy of Sciences of the United States of America · National Academy of Sciences · added 2026-04-24
Apolipoprotein A-IV (apoA-IV) is secreted by the small intestine in response to fat absorption. Here we demonstrate a potential role for apoA-IV in regulating glucose homeostasis. ApoA-IV-treated isol Show more
Apolipoprotein A-IV (apoA-IV) is secreted by the small intestine in response to fat absorption. Here we demonstrate a potential role for apoA-IV in regulating glucose homeostasis. ApoA-IV-treated isolated pancreatic islets had enhanced insulin secretion under conditions of high glucose but not of low glucose, suggesting a direct effect of apoA-IV to enhance glucose-stimulated insulin release. This enhancement involves cAMP at a level distal to Ca(2+) influx into the β cells. Knockout of apoA-IV results in compromised insulin secretion and impaired glucose tolerance compared with WT mice. Challenging apoA-IV(-/-) mice with a high-fat diet led to fasting hyperglycemia and more severe glucose intolerance associated with defective insulin secretion than occurred in WT mice. Administration of exogenous apoA-IV to apoA-IV(-/-) mice improved glucose tolerance by enhancing insulin secretion in mice fed either chow or a high-fat diet. Finally, we demonstrate that exogenous apoA-IV injection decreases blood glucose levels and stimulates a transient increase in insulin secretion in KKAy diabetic mice. These results suggest that apoA-IV may provide a therapeutic target for the regulation of glucose-stimulated insulin secretion and treatment of diabetes. Show less
Dietary fat is an important mediator of atherosclerosis and obesity. Despite its importance in mediating metabolic disease, there is still much unknown about dietary fat absorption in the intestine an Show more
Dietary fat is an important mediator of atherosclerosis and obesity. Despite its importance in mediating metabolic disease, there is still much unknown about dietary fat absorption in the intestine and especially the detailed biological roles of intestinal apolipoproteins involved in that process. We were specifically interested in determining the physiological role of the intestinal apolipoprotein A-IV (A-IV) using A-IV knockout (KO) mice. A-IV is stimulated by fat absorption in the intestine and is secreted on nascent chylomicrons into intestinal lymph. We found that A-IV KO mice had reduced plasma triglyceride (TG) and cholesterol levels and that this hypolipidemia persisted on a high-fat diet. A-IV KO did not cause abnormal intestinal lipid absorption, food intake, or adiposity. Additionally, A-IV KO did not cause abnormal liver TG and cholesterol metabolism, as assessed by measuring hepatic lipid content, lipogenic and cholesterol synthetic gene expression, and in vivo VLDL secretion. Instead, A-IV KO resulted in the secretion of larger chylomicrons from the intestine into the lymph, and those chylomicrons were cleared from the plasma more slowly than wild-type chylomicrons. These data suggest that A-IV has a previously unknown role in mediating the metabolism of chylomicrons, and therefore may be important in regulating plasma lipid metabolism. Show less
To find novel variants and explore potential mechanism of triglyceride metabolism by resequencing apoA5 gene in patients with severe hypertriglyceridemia. The apoA5 gene in the patients with severe hy Show more
To find novel variants and explore potential mechanism of triglyceride metabolism by resequencing apoA5 gene in patients with severe hypertriglyceridemia. The apoA5 gene in the patients with severe hypertriglyceridemia were resequenced, who had been excluded with variants in LPL or apoCII. With constructed apoA5 cDNA expression vectors, transiently expression was observed in vitro and the protein expression was detected by Western blot and (35)S-labeled immunoprecipitation. The mutations of T184S and V153M were found in a patient with heterozygous variants in apoA5, and T184S was not reported before. Both mutant and wild type apoA5 cDNA expression vectors were constructed successfully. Western blot and immunoprecipitation showed they can be expressed in the cell and the mutational apoA5 can be secreted from the cell as well as wild type. A novel mutation in apoA5 was found in a patient with severe hypertriglyceridemia, which has the potential damaging effect for the function of this protein but not the secretion function. It need further study on the interaction of apoA5 and other related proteins. Show less
To investigate the relationship between SNPs reported in previous studies and the blood lipid level in the Tibetan population. Random cluster sampling was employed in 5 areas (Lhasa, Shigatse, Shannan Show more
To investigate the relationship between SNPs reported in previous studies and the blood lipid level in the Tibetan population. Random cluster sampling was employed in 5 areas (Lhasa, Shigatse, Shannan, Nagqu, and Nyingchi). The levels of cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) from blood samples were determined and DNA was extracted for genotyping and statistical analyses. Among 1 318 subjects aged >18 years enrolled in this study, 367 had dyslipidemia with a prevalence of 27.8%, of whom dyslipidemia males accounted for 33.1% and dyslipidemia females -24.5%. Results of the correlation analysis between all SNPs and TG showed that the SNPs of rs714052 and rs964184 were related to the serum TG level. Subjects with rs714052 CC genotype had the lowest TG level, and the highest TG level was found in those with rs714052 TT genotype. The serum TG level in individuals with TC genotype lied in between the above two population groups. Subjects with rs964184 CC genotype had the lowest TG level, and the highest serum TG level was noted in those with rs964184 GG genotype. Several SNPs were found to be related to the serum TG level in the Tibetan population. The APOA5 gene and MLXIPL gene may be closely associated with the serum TG level in this ethnic population group. Show less
The association between polymorphism -1131T/C in the promoter region of apolipoprotein A5 (APOA5) and ischemic stroke and plasma triglyceride (TG) levels remains controversial. To better clarify the a Show more
The association between polymorphism -1131T/C in the promoter region of apolipoprotein A5 (APOA5) and ischemic stroke and plasma triglyceride (TG) levels remains controversial. To better clarify the association between APOA5-1131T/C and risk of ischemic stroke and plasma TG levels, we performed a meta-analysis to examine the allele and genotype of APOA5-1131T/C polymorphism in ischemic stroke cases and controls. Based on the search of PubMed, Embase, MEDLINE, CNKI (National Knowledge Infrastructure) and CBM (Chinese BioMedical Literature Database) databases, we identified and abstracted outcome data from all articles to evaluate the association between APOA5 and ischemic stroke/plasma TG levels. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were performed in dominant model (CC + TC vs. TT), recessive model (CC vs. TC + TT), homozygote comparison (CC vs. TT) and heterozygote comparison (TC vs. TT). The association between dominant model (CC + TC vs. TT) and plasma TG/total cholesterol/high-density lipoprotein cholesterol levels was measured by a weighted mean difference (WMD) with its corresponding 95% CI. To evaluate the ethnicity-specific effects, subgroup analyses were performed by ethnic group. A meta-analysis containing 2,294 ischemic stroke cases and 1,858 controls from 8 case-control studies was performed. The results showed that APOA5-1131T/C polymorphism was significantly associated with ischemic stroke in all comparison models (CC + TC vs. TT, OR = 1.70, 95% CI = 1.24-2.32; CC vs. TC + TT, OR = 1.36, 95% CI = 0.98-1.90; CC vs. TT, OR = 1.73, 95% CI = 1.34-2.23; TC vs. TT, OR = 1.67, 95% CI = 1.19-2.36). On subgroup analysis by ethnicity, similarly significant associations were found in both Asians and Europeans, and the Europeans possessed a higher risk of ischemic stroke, especially in CC versus TT model (OR = 4.47, 95% CI = 1.33-15.06). Significant association between the C allele and elevated TG levels was detected in both ischemic stroke cases and controls; the TG levels were higher in the ischemic stroke cases and controls carrying the APOA5-1131C allele than in the noncarriers (CC + TC vs. TT, cases WMD = 0.43, 95% CI = 0.27-0.59; controls WMD = 0.51, 95% CI = 0.35-0.66). Similar within-group comparison of the total cholesterol and high-density lipoprotein cholesterol levels did not show any difference. Our meta-analysis revealed that the APOA5-1131T/C polymorphism is associated with a significant risk of ischemic stroke and elevated TG levels. The CC genotype and C allele might be a genetic risk factor that increases susceptibility of ischemic stroke and elevates plasma TG levels, and might be a useful target for clinical therapeutic intervention. Show less
Acute coronary syndromes (ACSs) are clinically cardiovascular events associated with dyslipidemia in common. Single nucleotide polymorphisms (SNPs) and haplotypes in the APOA1/C3/A5 gene cluster are a Show more
Acute coronary syndromes (ACSs) are clinically cardiovascular events associated with dyslipidemia in common. Single nucleotide polymorphisms (SNPs) and haplotypes in the APOA1/C3/A5 gene cluster are associated with diabetes and familial combined hyperlipidaemia (FCH). Little is known about whether the polymorphisms in these genes affect lipid homeostasis in patients with ACSs. The present paper aimed to examine these associations with 4 SNPs in the APOA1 -75G > A, the APOC3 -455T > C, and APOA5 -1131T > C, c.553G > T variant to ACSs in Chinese Han. Chinese Han of 229 patients with ACSs and 254 unrelated controls were analyzed. Four SNPs in APOA1/C3/A5 cluster were genotyped and lipid was determined. Our data show that minor allelic frequencies of APOC3 -455T > C, APOA5 -1131T > C, and c.553G > T polymorphisms in patients with ACSs were significantly higher than control group (P < 0.05). Furthermore, the 3 polymorphic sites were strongly of linkage disequilibrium, and minor alleles of 3 SNP sites had higher TG level than wild alleles (P < 0.05), APOC3 -455C and APOA5 c.553T allele carriers also had lower level of HDL-C. The minor alleles of APOC3 -455T > C, APOA5 -1131T > C, and c.553G > T polymorphisms are closely associated with ACSs. Show less
The severe forms of hypertriglyceridaemia (HTG) are caused by mutations in genes that lead to the loss of function of lipoprotein lipase (LPL). In most patients with severe HTG (TG > 10 mmol L(-1) ), Show more
The severe forms of hypertriglyceridaemia (HTG) are caused by mutations in genes that lead to the loss of function of lipoprotein lipase (LPL). In most patients with severe HTG (TG > 10 mmol L(-1) ), it is a challenge to define the underlying cause. We investigated the molecular basis of severe HTG in patients referred to the Lipid Clinic at the Academic Medical Center Amsterdam. The coding regions of LPL, APOC2, APOA5 and two novel genes, lipase maturation factor 1 (LMF1) and GPI-anchored high-density lipoprotein (HDL)-binding protein 1 (GPIHBP1), were sequenced in 86 patients with type 1 and type 5 HTG and 327 controls. In 46 patients (54%), rare DNA sequence variants were identified, comprising variants in LPL (n = 19), APOC2 (n = 1), APOA5 (n = 2), GPIHBP1 (n = 3) and LMF1 (n = 8). In 22 patients (26%), only common variants in LPL (p.Asp36Asn, p.Asn318Ser and p.Ser474Ter) and APOA5 (p.Ser19Trp) could be identified, whereas no mutations were found in 18 patients (21%). In vitro validation revealed that the mutations in LMF1 were not associated with compromised LPL function. Consistent with this, five of the eight LMF1 variants were also found in controls and therefore cannot account for the observed phenotype. The prevalence of mutations in LPL was 34% and mostly restricted to patients with type 1 HTG. Mutations in GPIHBP1 (n = 3), APOC2 (n = 1) and APOA5 (n = 2) were rare but the associated clinical phenotype was severe. Routine sequencing of candidate genes in severe HTG has improved our understanding of the molecular basis of this phenotype associated with acute pancreatitis and may help to guide future individualized therapeutic strategies. Show less
Histone deacetylase (HDAC) plays an important role in the deacetylation of histone, which can alter gene expression patterns and affect cell behavior associated with malignant transformation. The aims Show more
Histone deacetylase (HDAC) plays an important role in the deacetylation of histone, which can alter gene expression patterns and affect cell behavior associated with malignant transformation. The aims of this study were to investigate the relationships between HDAC1, HDAC2, clinicopathologic characteristics, patient prognosis and apoptosis, to clarify the mechanism of upregulation of the Axis inhibitor Axin (an important regulator of the Wnt pathway) by X-radiation and to elucidate the effect of siRNA on radiation therapy of non-small cell lung cancer (NSCLC). HDAC1 and HDAC2 expression levels were measured by immunohistochemistry and reverse transcription PCR. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling and fluorescence activated cell sorting. BE1 cells expressing Axin were exposed to 2 Gy of X-radiation. Expression of HDAC1 and that of HDAC2 were correlated, and significantly higher in NSCLC tissues than in normal lung tissues (P < 0.05). HDAC1 and HDAC2 expression was correlated with pTNM stage and negatively correlated with differentiation of NSCLC and apoptotic index (P < 0.05). The prognosis of patients with low expression of HDAC1 and HDAC2 was better than that of those with high expression. X-radiation and siRNA inhibited HDAC1 and HDAC2 expression in NSCLC cells and Axin levels were significantly higher in BE1 cells. X-radiation and siRNA inhibit expression of HDAC1 and HDAC2, weaken the inhibitory effect of HDAC on Axin, upregulate Axin expression and induce apoptosis of lung cancer cells. Inhibition of HDAC1 and HDAC2 is a means of enhancing the radiosensitivity of NSCLC. Show less
Zhiqiang Li, Yeqi Wang, Min Zhang+4 more · 2012 · The Journal of biological chemistry · American Society for Biochemistry and Molecular Biology · added 2026-04-24
The Motin family proteins can regulate cell polarity, cell mobility, and proliferation during embryonic development by controlling distinct signaling pathways. In this study, we demonstrate that amotl Show more
The Motin family proteins can regulate cell polarity, cell mobility, and proliferation during embryonic development by controlling distinct signaling pathways. In this study, we demonstrate that amotl2 knockdown in zebrafish wild-type embryos results in embryonic dorsalization, and this effect can be antagonized by co-knockdown of the dorsal inducer β-catenin2. Overexpression of amotl2 in masterblind (mbl) homozygous embryos, in which canonical Wnt signaling is up-regulated due to an axin1 mutation, transforms eyeless phenotype into smaller eyes, whereas co-knockdown of amot, amotl1, and amotl2 leads to development of smaller eyes in mbl heterozygotes. In cultured mammalian cells, Motin family members all possess the ability to attenuate Wnt/β-catenin signaling. Focusing on Amotl2, we show that Amotl2 can associate with and trap β-catenin in the Rab11-positive recycling endosomes, and as a result, the amount of β-catenin in the cytosol and nucleus is reduced. Thus, our findings provide novel insights into functions of Motin family members and regulation of Wnt/β-catenin signaling. Show less
Wei-feng Tan, Lan-lan Wang, Qi Li+4 more · 2012 · Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology · added 2026-04-24
To further investigate the biological function of human novel gene CTRP4 by constructing the prokaryotic expression vector of human CTRP4, inducing the expression of and purifying hCTRP4-his protein i Show more
To further investigate the biological function of human novel gene CTRP4 by constructing the prokaryotic expression vector of human CTRP4, inducing the expression of and purifying hCTRP4-his protein in E.coli, and preparing polyclonal antibody against human CTRP4. Human CTRP4 gene was amplified by PCR, digested with enzymes, and subcloned into a his-tagged prokaryotic expression vector to generate a recombinant plasmid named pET-32a-hCTRP4. The pET-32a-hCTRP4 was transformed into E.coli BL21(DE3). The hCTRP4-his fusion protein was induced by IPTG, purified by Ni-NTA purification system, and analyzed by SDS-PAGE. The recombinant vector pcDNA3.1-myc/his(-)B-hCTRP4 expressing full-length human CTRP4 and purified prokaryotic protein hCTRP4 were used to immunize BALB/c mice to produce polyclonal antibody. The anti-serum was purified and the characteristics of the antibody were identified by ELISA, Western blotting, immunofluorescence cytochemistry and immunohistochemistry. The prokaryotic expression vector of pET-32a-hCTRP4 was constructed successfully. hCTRP4-his fusion protein was expressed in E.coli BL21(DE3) after IPTG induction. The titer of the anti-serum reached 1:20 000, and its specificity was proved by Western blotting. The results of immunofluorescence cytochemistry and immunohistochemistry indicated that CTRP4 was mainly localized in the cytoplasm of hepatic cells. hCTRP4-his fusion protein can be successfully expressed in E.coli. A specific polyclonal antibody against human CTRP4 has been successfully prepared. Show less
A dynamic balance between targeted transport and endocytosis is critical for polarized cell growth. However, how actin-mediated endocytosis is regulated in different growth modes remains unclear. Here Show more
A dynamic balance between targeted transport and endocytosis is critical for polarized cell growth. However, how actin-mediated endocytosis is regulated in different growth modes remains unclear. Here we report differential regulation of cortical actin patch dynamics between the yeast and hyphal growth in Candida albicans. The mechanism involves phosphoregulation of the endocytic protein Sla1 by the cyclin-dependent kinase (CDK) Cdc28-Cln3 and the actin-regulating kinase Prk1. Mutational studies of the CDK phosphorylation sites of Sla1 revealed that Cdc28-Cln3 phosphorylation of Sla1 enhances its further phosphorylation by Prk1, weakening Sla1 association with Pan1, an activator of the actin-nucleating Arp2/3 complex. Sla1 is rapidly dephosphorylated upon hyphal induction and remains so throughout hyphal growth. Consistently, cells expressing a phosphomimetic version of Sla1 exhibited markedly reduced actin patch dynamics, impaired endocytosis, and defective hyphal development, whereas a nonphosphorylatable Sla1 had the opposite effect. Taken together, our findings establish a molecular link between CDK and a key component of the endocytic machinery, revealing a novel mechanism by which endocytosis contributes to cell morphogenesis. Show less
Shiyao Wang · 2012 · Advances in experimental medicine and biology · Springer · added 2026-04-24
Juvenile neuronal ceroid lipofuscinoses (JNCL) is the most common type of the neuronal ceroid lipofuscinoses (NCLs), a group of pediatric neurodegenerative diseases. In this chapter the genetic and bi Show more
Juvenile neuronal ceroid lipofuscinoses (JNCL) is the most common type of the neuronal ceroid lipofuscinoses (NCLs), a group of pediatric neurodegenerative diseases. In this chapter the genetic and biochemical basis, pathogenesis, clinical features, histopathological features, diagnosis and therapeutic strategies of the JNCL are reviewed. The premature death of the patients and subnormal life quality are inevitable due to the lack of understanding of pathogenesis and limitation in treatment. Hence we are still a long way to conquer the disease. Show less
Fabiana Quagliarini, Yan Wang, Julia Kozlitina+7 more · 2012 · Proceedings of the National Academy of Sciences of the United States of America · National Academy of Sciences · added 2026-04-24
Angiopoietin-like proteins (ANGPTLs) play major roles in the trafficking and metabolism of lipids. Inactivation of ANGPTL3, a gene located in an intron of DOCK7, results in very low levels of LDL-chol Show more
Angiopoietin-like proteins (ANGPTLs) play major roles in the trafficking and metabolism of lipids. Inactivation of ANGPTL3, a gene located in an intron of DOCK7, results in very low levels of LDL-cholesterol (C), HDL-C and triglyceride (TAG). We identified another ANGPTL family member, ANGPTL8, which is located in the corresponding intron of DOCK6. A variant in this family member (rs2278426, R59W) was associated with lower plasma LDL-C and HDL-C levels in three populations. ANGPTL8 is expressed in liver and adipose tissue, and circulates in plasma of humans. Expression of ANGPTL8 was reduced by fasting and increased by refeeding in both mice and humans. To examine the functional relationship between the two ANGPTL family members, we expressed ANGPTL3 at physiological levels alone or together with ANGPTL8 in livers of mice. Plasma TAG level did not change in mice expressing ANGPTL3 alone, whereas coexpression with ANGPTL8 resulted in hypertriglyceridemia, despite a reduction in circulating ANGPTL3. ANGPTL8 coimmunoprecipitated with the N-terminal domain of ANGPTL3 in plasma of these mice. In cultured hepatocytes, ANGPTL8 expression increased the appearance of N-terminal ANGPTL3 in the medium, suggesting ANGPTL8 may activate ANGPTL3. Consistent with this scenario, expression of ANGPTL8 in Angptl3(-/-) mice failed to promote hypertriglyceridemia. Thus, ANGPTL8, a paralog of ANGPTL3 that arose through duplication of an ancestral DOCK gene, regulates postprandial TAG and fatty acid metabolism by controlling activation of its progenitor, and perhaps other ANGPTLs. Inhibition of ANGPTL8 provides a new therapeutic strategy for reducing plasma lipoprotein levels. Show less
Neurogenesis in the developing neocortex relies on the ability of radial glial progenitor cells (RGCs) to switch from proliferative to differentiative neuron-generating divisions, but the molecular me Show more
Neurogenesis in the developing neocortex relies on the ability of radial glial progenitor cells (RGCs) to switch from proliferative to differentiative neuron-generating divisions, but the molecular mechanisms that control this switch in a correct temporal manner are not well understood. Here, we show that DOCK7, a member of the DOCK180 family of proteins, regulates RGC proliferation versus differentiation. Silencing of DOCK7 in RGCs of developing mouse embryos impedes neuronal differentiation and maintains cells as cycling progenitors. In contrast, DOCK7 overexpression promotes RGC differentiation to basal progenitors and neurons. We further present evidence that DOCK7 influences neurogenesis by controlling apically directed interkinetic nuclear migration of RGCs. DOCK7 exerts its effects by antagonizing the microtubule growth-promoting function of the centrosome-associated protein TACC3. Thus, DOCK7 interaction with TACC3 controls interkinetic nuclear migration and the genesis of neurons from RGCs during cortical development. Show less
In Xenopus, the functional kidney of the tadpole, the pronephros, forms from the kidney field, which is specified at completion of gastrulation. Specification of the kidney field requires retinoic aci Show more
In Xenopus, the functional kidney of the tadpole, the pronephros, forms from the kidney field, which is specified at completion of gastrulation. Specification of the kidney field requires retinoic acid (RA) signalling during gastrulation, while fibroblast growth factor (FGF) signals inhibit should be inhibit this process. We have analysed the functional interactions taking place during gastrulation between RA and FGF signals in the lateral marginal zone (LMZ), that is in the environment of unspecified pronephric mesoderm precursors. Inhibition of FGF receptor (FGFR) signalling with SU5402 does not significantly affect expression of genes encoding RA metabolism enzymes and RA receptor-α in LMZ explants. Furthermore, SU5402 has no effect on the expression of hoxa1, a major RA target in the LMZ, showing that FGF is not antagonising RA in the LMZ. Disruption of RA signalling affects FGF ligand production to some extent, especially FGF8b, but the strongest effect is the down-regulation of the mitogen-activated protein kinase phosphatase-3 (MKP3)-encoding gene, mkp3. A strong up-regulation of mkp3 occurs in response to exogenous RA. This effect is reduced in a context of FGFR inhibition, suggesting that RA and FGF signals are co-operating upstream of mkp3. Mkp3 knockdown results in an inhibition of the kidney field markers pax8 and lhx1 and in a defective development of the pronephros. FGF is not negatively influencing pronephric specification by antagonising RA signalling. Functional interactions between RA and FGF rather take place at the level of the transcriptional regulation of mkp3, indicating that RA may antagonise FGF signalling at the level of the extracellular signal-regulated kinase (Erk) pathway. A fine tuning of Erk signalling by MKP3 is important for the proper establishment of the kidney field. Show less
γ-Secretase inhibitors (GSIs) are being investigated for their potential to modify the progression of Alzheimer disease based on their ability to regulate amyloid-β (Aβ) accumulation. BMS-708163 (avag Show more
γ-Secretase inhibitors (GSIs) are being investigated for their potential to modify the progression of Alzheimer disease based on their ability to regulate amyloid-β (Aβ) accumulation. BMS-708163 (avagacestat) is an oral GSI designed for selective inhibition of Aβ synthesis currently in development for the treatment of mild to moderate and predementia AD. In addition to the desired effect on Aβ synthesis, GSIs affect Notch processing, which is thought to mediate some toxic adverse effects reported with this drug class. Avagacestat produced up to 190-fold greater selectivity for Aβ synthesis than Notch processing in preclinical studies and may therefore produce less toxic adverse events than other less selective compounds. Presented here are the results of the first in-human study for this new GSI compound. The goal of this study was to assess the tolerability profile, pharmacokinetic properties, and effects on pharmacodynamic markers (Aβ, trefoil factor family 3 protein, dual specificity phosphatase 6, and hairy and enhancer of split-1) of single, oral doses of avagacestat in healthy, young, male volunteers. This was a multicenter, randomized, double-blind, placebo-controlled, single-ascending dose study in 8 healthy young men (age, 18-45 years) per dosing panel. Each study participant was randomized to receive a single dose of placebo (n = 2) or avagacestat (n = 6 for each dose) as an oral solution in 1 of 9 sequential dose panels (0.3, 1.5, 5, 15, 50, 100, 200, 400, and 800 mg). For determination of avagacestat, blood samples were obtained before dosing and for up to 144 hours after dosing. For participants in the 800-mg avagacestat dose panel, additional samples were obtained at 216, 312, and 648 hours. For 40-amino acid isoform of Aβ (Aβ(1-40)) assessment, plasma samples were collected before avagacestat administration and up to 72 hours after dosing. Avagacestat concentrations peaked quickly after oral administration and then had a biphasic decrease in concentrations with a prolonged terminal phase. Exposures were proportional with doses up to 200 mg. Avagacestat was well tolerated at single oral doses up to 800 mg, with a biphasic effect on plasma Aβ(1-40). Adverse events were predominately mild to moderate in severity with no evidence of dose dependence up to 200 mg. Results from this single-ascending dose study suggest that avagacestat was tolerated at a single-dose range of 0.3 to 800 mg and suitable for further clinical development. Show less
We describe a convenient and simple continuous spectrophotometric method for the determination of mitogen-activated protein kinase (MAPK) kinase activity with its protein substrate. The assay relies o Show more
We describe a convenient and simple continuous spectrophotometric method for the determination of mitogen-activated protein kinase (MAPK) kinase activity with its protein substrate. The assay relies on the measurement of phosphoprotein product generated in the first step of the MAPK kinase reaction. Dephosphorylation of the phosphoprotein is coupled to a MAPK phosphatase to generate phosphate, which is then used as the substrate of purine nucleoside phosphorylase to catalyze the N-glycosidic cleavage of 2-amino 6-mercapto 7-methyl purine ribonucleoside. Of the reaction products ribose 1-phosphate and 2-amino 6-mercapto 7-methylpurine, the latter has a high absorbance at 360nm relative to the nucleoside and, hence, provides a spectrophotometric signal that can be continuously followed. In the presence of excess phosphatase, the phosphorylated protein substrate molecules undergo dephosphorylation almost immediately after their formation; the steady-state use of the resultant inorganic phosphate is a reflection of the constant initial velocity of the exchange reaction. The validity of this method has been confirmed by using it to measure the activities of MEK1 (MAPK/ERK kinase 1) and MKK6 (MAPK kinase 6) toward their physiological substrates. Our findings of the MAPK kinases in the current study provide evidence that the substrate binding affinities of this subfamily of protein kinases are at the submicromolar concentration. Show less
Prior studies on the biology and therapeutic application of human stem cells in human malignancies have reported mixed results. Some evidence shows the use of stem cell transplantation is an important Show more
Prior studies on the biology and therapeutic application of human stem cells in human malignancies have reported mixed results. Some evidence shows the use of stem cell transplantation is an important tool in the treatment of several hematologic and non-hematologic malignancies while some others suggest both human stem cells and mature stromal cells can contribute to the development and growth of human malignancies. Aiming to provide more evidence on this controversial issue, we investigated the effect of cell fusion of mesenchymal stem cells with esophageal carcinoma cells on tumorigenesis. Results suggest that artificial fusion of human umbilical cord mesenchymal stem cells with esophageal carcinoma cells resulted in hybrids with declined cell growth, increased apoptosis and suppressed tumorigenicity. The comparison of gene expression profiles of human mesenchymal stem cells, esophageal carcinoma cells and hybrids indicated that fusion induced activation of apoptosis. Furthermore, the expression of DUSP6/MKP3 in MAPK pathway increased strikingly and the exogenous overexpression confirmed the growth suppression. Our results demonstrate fusion of human mesenchymal stem cells with esophageal carcinoma cells induced apoptosis and benign transdifferentiation rather than reprogramming to cancer stem cells. Show less
Ischemic stroke is a devastating disease with a complex pathophysiology. Galangin is a natural flavonoid isolated from the rhizome of Alpina officinarum Hance, which has been widely used as an antioxi Show more
Ischemic stroke is a devastating disease with a complex pathophysiology. Galangin is a natural flavonoid isolated from the rhizome of Alpina officinarum Hance, which has been widely used as an antioxidant agent. However, its effects against ischemic stroke have not been reported and its related neuroprotective mechanism has not really been explored. In this study, neurological behavior, cerebral infarct volumes and the improvement of the regional cortical blood flow (rCBF) were used to evaluate the therapeutic effect of galangin in rats impaired by middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia. Furthermore, the determination of mitochondrial function and Western blot of apoptosis-related proteins were performed to interpret the neuroprotective mechanism of galangin. The results showed that galangin alleviated the neurologic impairments, reduced cerebral infarct at 24 h after MCAO and exerted a protective effect on the mitochondria with decreased production of mitochondrial reactive oxygen species (ROS). These effects were consistent with improvements in the membrane potential level (Dym), membrane fluidity, and degree of mitochondrial swelling in a dose-dependent manner. Moreover, galangin significantly improved the reduced rCBF after MCAO. Western blot analysis revealed that galangin also inhibited apoptosis in a dose-dependent manner concomitant with the up-regulation of Bcl-2 expression, down-regulation of Bax expression and the Bax/Bcl-2 ratio, a reduction in cytochrome c release from the mitochondria to the cytosol, the reduced expression of activated caspase-3 and the cleavage of poly(ADP-ribose) polymerase (PARP). All these data in this study demonstrated that galangin might have therapeutic potential for ischemic stroke and play its protective role through the improvement in rCBF, mitochondrial protection and inhibiting caspase-dependent mitochondrial cell death pathway for the first time. Show less
During normal development primordial germ cells (PGCs) derived from the epiblast are the precursors of spermatogonia and oogonia. In culture, PGCs can be induced to dedifferentiate to pluripotent embr Show more
During normal development primordial germ cells (PGCs) derived from the epiblast are the precursors of spermatogonia and oogonia. In culture, PGCs can be induced to dedifferentiate to pluripotent embryonic germ (EG) cells in the presence of various growth factors. Several recent studies have now demonstrated that spermatogonial stem cells (SSCs) can also revert back to pluripotency as embryonic stem (ES)-like cells under certain culture conditions. However, the potential dedifferentiation of SSCs into PGCs or the potential generation of oocytes from SSCs has not been demonstrated before. We report that mouse male SSCs can be converted into oocyte-like cells in culture. These SSCs-derived oocytes (SSC-Oocs) were similar in size to normal mouse mature oocytes. They expressed oocyte-specific markers and gave rise to embryos through parthenogenesis. Interestingly, the Y- and X-linked testis-specific genes in these SSC-Oocs were significantly down-regulated or turned off, while oocyte-specific X-linked genes were activated. The gene expression profile appeared to switch to that of the oocyte across the X chromosome. Furthermore, these oocyte-like cells lost paternal imprinting but acquired maternal imprinting. Our data demonstrate that SSCs might maintain the potential to be reprogrammed into oocytes with corresponding epigenetic reversals. This study provides not only further evidence for the remarkable plasticity of SSCs but also a potential system for dissecting molecular and epigenetic regulations in germ cell fate determination and imprinting establishment during gametogenesis. Show less
Multiple osteochondroma (MO) is an autosomal dominant disease characterized by abnormal skeleton development: one or more exostoses localized mainly at the end of long bones. Three pathogenic gene loc Show more
Multiple osteochondroma (MO) is an autosomal dominant disease characterized by abnormal skeleton development: one or more exostoses localized mainly at the end of long bones. Three pathogenic gene loci have been identified and cloned: EXT1, 2, and 3. Only EXT1 and 2 mutations were reported to cause MO. Here, we report on a large Chinese family with MO and a disease-causing mutation in EXT. We extracted DNA from peripheral blood samples of 25 family members, 9 with MO. Polymerase chain reaction and direct DNA sequencing of the entire coding regions of EXT1 and 2 for the nine patients revealed a novel pathogenic mutation, insertion of a T in exon 2 (c.72-73 insT) of EXT2. Our results extend the mutational spectrum of MO and can help with genetic counseling and prenatal diagnosis for this family. Show less
Daniel C Kraushaar, Sumit Rai, Eduard Condac+6 more · 2012 · The Journal of biological chemistry · American Society for Biochemistry and Molecular Biology · added 2026-04-24
Heparan sulfate (HS) has been implicated in regulating cell fate decisions during differentiation of embryonic stem cells (ESCs) into advanced cell types. However, the necessity and the underlying mol Show more
Heparan sulfate (HS) has been implicated in regulating cell fate decisions during differentiation of embryonic stem cells (ESCs) into advanced cell types. However, the necessity and the underlying molecular mechanisms of HS in early cell lineage differentiation are still largely unknown. In this study, we examined the potential of EXT1(-/-) mouse ESCs (mESCs), that are deficient in HS, to differentiate into primary germ layer cells. We observed that EXT1(-/-) mESCs lost their differentiation competence and failed to differentiate into Pax6(+)-neural precursor cells and mesodermal cells. More detailed analyses highlighted the importance of HS for the induction of Brachyury(+) pan-mesoderm as well as normal gene expression associated with the dorso-ventral patterning of mesoderm. Examination of developmental cell signaling revealed that EXT1 ablation diminished FGF and BMP but not Wnt signaling. Furthermore, restoration of FGF and BMP signaling each partially rescued mesoderm differentiation defects. We further show that BMP4 is more prone to degradation in EXT1(-/-) mESCs culture medium compared with that of wild type cells. Therefore, our data reveal that HS stabilizes BMP ligand and thereby maintains the BMP signaling output required for normal mesoderm differentiation. In summary, our study demonstrates that HS is required for ESC pluripotency, in particular lineage specification into mesoderm through facilitation of FGF and BMP signaling. Show less
A recent genome-wide association study in Caucasians revealed that three loci (rs174547 in fatty acid desaturase 1 (FADS1), rs2338104 near mevalonate kinase/methylmalonic aciduria, cobalamin deficienc Show more
A recent genome-wide association study in Caucasians revealed that three loci (rs174547 in fatty acid desaturase 1 (FADS1), rs2338104 near mevalonate kinase/methylmalonic aciduria, cobalamin deficiency, cblB type (MVK/MMAB) and rs10468017 near hepatic lipase (LIPC)) influence the plasma concentrations of high-density lipoprotein-cholesterol (HDL-C) and triglycerides (TG). However, there are few reports on the associations between these polymorphisms and plasma lipid concentrations in Chinese individuals. This study aimed to evaluate the associations between these three polymorphisms with HDL-C and TG concentrations, as well as coronary heart disease (CHD) susceptibility in Chinese individuals. We conducted a population-based case-control study in Chinese individuals to evaluate the associations between these three polymorphisms and HDL-C and TG concentrations, and also evaluated their associations with susceptibility to CHD. Genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism assays and TaqMan genotyping assays. We found significant differences in TG and HDL-C concentrations among the TT, TC and CC genotypes of FADS1 rs174547 (P=0.017 and 0.003, respectively, multiple linear regression). The CC variant of rs174547 was significantly associated with hyperlipidemia compared with the TT variant (adjusted odds ratio (OR)=1.71, 95% confidence intervals (CI): 1.16-2.54). The FADS1 rs174547 CC variant was also associated with significantly increased CHD risk compared with the TT and TC variant (adjusted OR=1.53, 95%CI: 1.01-2.31), and the effect was more evident among nonsmokers and females. The polymorphisms rs2338104 and rs10468017 did not significantly influence HDL-C or TG concentrations in this Chinese population. rs174547 in FADS1 may contribute to the susceptibility of CHD by altering HDL-C and TG levels in Chinese individuals. Show less