Dan Wang1, Feng Wang1, Kai-Hu Shi1, Hui Tao1, Yang Li1, Rui Zhao1, Han Lu1, Wenyuan Duan1, Bin Qiao1, Shi-Min Zhao2, Hongyan Wang2, Jian-Yuan Zhao2. 1. From Obstetrics and Gynecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China (D.W., Y.L., R.Z., H.L., S.-M.Z., H.W., J.-Y.Z.); Key Laboratory of Reproduction Regulation of NPFPC, Institute of Reproduction and Development and Children's Hospital of Fudan University, Fudan University, Shanghai, China (D.W., F.W., Y.L., R.Z., S.-M.Z., H.W., J.-Y.Z.); MOE Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, China (S.-M.Z., H.W., J.-Y.Z.); Department of Cardiothoracic Surgery, Second Hospital of Anhui Medical University, Anhui Medical University, Hefei, China (K.-H.S., H.T.); Cardiovascular Research Center, Anhui Medical University, Hefei, China (K.-H.S., H.T.); Institute of Cardiovascular Disease, General Hospital of Jinan Military Region, Jinan, China (W.D., B.Q.); Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China (S.M.-Z., J.-Y.Z.); and Department of Neonatology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China (D.W.). 2. From Obstetrics and Gynecology Hospital of Fudan University, State Key Laboratory of Genetic Engineering, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China (D.W., Y.L., R.Z., H.L., S.-M.Z., H.W., J.-Y.Z.); Key Laboratory of Reproduction Regulation of NPFPC, Institute of Reproduction and Development and Children's Hospital of Fudan University, Fudan University, Shanghai, China (D.W., F.W., Y.L., R.Z., S.-M.Z., H.W., J.-Y.Z.); MOE Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, China (S.-M.Z., H.W., J.-Y.Z.); Department of Cardiothoracic Surgery, Second Hospital of Anhui Medical University, Anhui Medical University, Hefei, China (K.-H.S., H.T.); Cardiovascular Research Center, Anhui Medical University, Hefei, China (K.-H.S., H.T.); Institute of Cardiovascular Disease, General Hospital of Jinan Military Region, Jinan, China (W.D., B.Q.); Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, China (S.M.-Z., J.-Y.Z.); and Department of Neonatology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China (D.W.). zhaosm@fudan.edu.cn wanghy@fudan.edu.cn zhaojy@fudan.edu.cn.
Abstract
BACKGROUND: Folate deficiency is an independent risk factor for congenital heart disease (CHD); however, the maternal plasma folate level is paradoxically not a good diagnostic marker. Genome-wide surveys have identified variants of nonfolate metabolic genes associated with the plasma folate level, suggesting that these genetic polymorphisms are potential risk factors for CHD. METHODS: To examine the effects of folate concentration-related variations on CHD risk in the Han Chinese population, we performed 3 independent case-control studies including a total of 1489 patients with CHD and 1745 control subjects. The expression of the Fidgetin (FIGN) was detected in human cardiovascular and decidua tissue specimens with quantitative real-time polymerase chain reaction and Western blotting. The molecular mechanisms were investigated by luciferase reporter assays, surface plasmon resonance, and chromatin immunoprecipitation. FIGN-interacting proteins were confirmed by tandem affinity purification and coimmunoprecipitation. Proteasome activity and metabolite concentrations in the folate pathway were quantified with a commercial proteasome activity assay and immunoassays, respectively. RESULTS: The +94762G>C (rs2119289) variant in intron 4 of the FIGN gene was associated with significant reduction in CHD susceptibility (P=5.1×10-14 for the allele, P=8.5×10--13 for the genotype). Analysis of combined samples indicated that CHD risks in individuals carrying heterozygous (GC) or homozygous (CC) genotypes were reduced by 44% (odds ratio [OR]=0.56; 95% confidence interval [CI]=0.47-0.67) and 66% (OR=0.34; 95% CI=0.23-0.50), respectively, compared with those with the major GG genotype. Minor C allele carriers who had decreased plasma folate levels exhibited significantly increased FIGN expression because the transcription suppressor CREB1 did not bind the alternative promoter of FIGN isoform X3. Mechanistically, increased FIGN expression led to the accumulation of both reduced folate carrier 1 and dihydrofolate reductase via inhibition of their proteasomal degradation, which promoted folate absorption and metabolism. CONCLUSIONS: We report a previously undocumented finding that decreased circulating folate levels induced by increased folate transmembrane transport and utilization, as determined by the FIGN intronic variant, serves as a protective mechanism against CHD. Our results may explain why circulating folate levels do not have a good diagnostic value.
BACKGROUND:Folate deficiency is an independent risk factor for congenital heart disease (CHD); however, the maternal plasma folate level is paradoxically not a good diagnostic marker. Genome-wide surveys have identified variants of nonfolate metabolic genes associated with the plasma folate level, suggesting that these genetic polymorphisms are potential risk factors for CHD. METHODS: To examine the effects of folate concentration-related variations on CHD risk in the Han Chinese population, we performed 3 independent case-control studies including a total of 1489 patients with CHD and 1745 control subjects. The expression of the Fidgetin (FIGN) was detected in human cardiovascular and decidua tissue specimens with quantitative real-time polymerase chain reaction and Western blotting. The molecular mechanisms were investigated by luciferase reporter assays, surface plasmon resonance, and chromatin immunoprecipitation. FIGN-interacting proteins were confirmed by tandem affinity purification and coimmunoprecipitation. Proteasome activity and metabolite concentrations in the folate pathway were quantified with a commercial proteasome activity assay and immunoassays, respectively. RESULTS: The +94762G>C (rs2119289) variant in intron 4 of the FIGN gene was associated with significant reduction in CHD susceptibility (P=5.1×10-14 for the allele, P=8.5×10--13 for the genotype). Analysis of combined samples indicated that CHD risks in individuals carrying heterozygous (GC) or homozygous (CC) genotypes were reduced by 44% (odds ratio [OR]=0.56; 95% confidence interval [CI]=0.47-0.67) and 66% (OR=0.34; 95% CI=0.23-0.50), respectively, compared with those with the major GG genotype. Minor C allele carriers who had decreased plasma folate levels exhibited significantly increased FIGN expression because the transcription suppressor CREB1 did not bind the alternative promoter of FIGN isoform X3. Mechanistically, increased FIGN expression led to the accumulation of both reduced folate carrier 1 and dihydrofolate reductase via inhibition of their proteasomal degradation, which promoted folate absorption and metabolism. CONCLUSIONS: We report a previously undocumented finding that decreased circulating folate levels induced by increased folate transmembrane transport and utilization, as determined by the FIGN intronic variant, serves as a protective mechanism against CHD. Our results may explain why circulating folate levels do not have a good diagnostic value.
Authors: Matthew Dapas; Frederick T J Lin; Girish N Nadkarni; Ryan Sisk; Richard S Legro; Margrit Urbanek; M Geoffrey Hayes; Andrea Dunaif Journal: PLoS Med Date: 2020-06-23 Impact factor: 11.069
Authors: Rachel L Leon; Imran N Mir; Christina L Herrera; Kavita Sharma; Catherine Y Spong; Diane M Twickler; Lina F Chalak Journal: Pediatr Res Date: 2021-04-16 Impact factor: 3.953