Thakur Shilpa, More Deepti, Rahat Beenish, Khanduja Krishan Lal, Kaur Jyotdeep
Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India.
Department of Biophysics, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India.
Mol Cell Biochem. 2016 Jan;411(1-2):151-60. doi: 10.1007/s11010-015-2577-x. Epub 2015 Oct 3.
Excessive alcohol consumption and dietary folate inadequacy are the main contributors leading to folate deficiency (FD). The present study was planned to study regulation of folate transport in conditions of FD and ethanol exposure in human embryonic kidney cell line. Also, the reversible nature of effects mediated by ethanol exposure and FD was determined by folate repletion and ethanol removal. For ethanol treatment, HEK293 cells were grown in medium containing 100 mM ethanol, and after treatment, one group of cells was shifted on medium that was free from ethanol. For FD treatment, cells were grown in folate-deficient medium followed by shifting of one group of cells on folate containing medium. FD as well as ethanol exposure resulted in an increase in folate uptake which was due to an increase in expression of folate transporters, i.e., reduced folate carrier, proton-coupled folate transporter, and folate receptor, both at the mRNA and protein level. The effects mediated by ethanol exposure and FD were reversible on removal of treatment. Promoter region methylation of folate transporters remained unaffected after FD and ethanol exposure. As far as transcription rate of folate transporters is concerned, an increase in rate of synthesis was observed in both ethanol exposure and FD conditions. Additionally, mRNA life of folate transporters was observed to be reduced by FD. An increased expression of folate transporters under ethanol exposure and FD conditions can be attributed to enhanced rate of synthesis of folate transporters.
过量饮酒和膳食叶酸摄入不足是导致叶酸缺乏（FD）的主要因素。本研究旨在探讨在人胚肾细胞系中，FD和乙醇暴露条件下叶酸转运的调节机制。此外，通过叶酸补充和乙醇去除来确定乙醇暴露和FD介导的效应的可逆性。对于乙醇处理，将HEK293细胞培养在含有100 mM乙醇的培养基中，处理后，将一组细胞转移至不含乙醇的培养基中。对于FD处理，将细胞培养在叶酸缺乏的培养基中，然后将一组细胞转移至含叶酸的培养基中。FD以及乙醇暴露均导致叶酸摄取增加，这是由于叶酸转运蛋白（即还原型叶酸载体、质子偶联叶酸转运体和叶酸受体）在mRNA和蛋白质水平的表达增加所致。乙醇暴露和FD介导的效应在去除处理后是可逆的。FD和乙醇暴露后，叶酸转运蛋白的启动子区域甲基化未受影响。就叶酸转运蛋白的转录速率而言，在乙醇暴露和FD条件下均观察到合成速率增加。此外，FD可使叶酸转运蛋白的mRNA寿命缩短。乙醇暴露和FD条件下叶酸转运蛋白表达增加可归因于叶酸转运蛋白合成速率的提高。
