Optogenetic cytosol acidification of mammalian cells using an inward proton-pumping rhodopsin.

Ion gradients are a universal form of energy, information storage and conversion in living cells. Advances in optogenetics inspire the development of novel tools towards control of different cellular processes with light. Rhodopsins are perspective tools for optogenetic manipulation of ion gradients in cells and subcellular compartments, controlling pH of the cytosol and intracellular organelles. The key step of the development of new optogenetic tools is evaluation of their efficiency. Here, we used a high-throughput quantitative method for comparing efficiency of proton-pumping rhodopsins in Escherichia coli cells. This approach allowed us to show that an inward proton pump xenorhodopsin from Nanosalina sp. (NsXeR) is a powerful tool for optogenetic control of pH of mammalian subcellular compartments. Further, we demonstrate that NsXeR can be used for fast optogenetic acidification of the cytosol of mammalian cells. This is the first evidence of optogenetic cytosol acidification by an inward proton pump at physiological pH values. Our approach offers unique opportunities to study cellular metabolism at normal and pathological conditions and might help to understand the role of pH dysregulation in cellular dysfunctions.

[The influence of cytoflavin on the recovery of cognitive function in elderly people with alcohol abuse]. / Vliyanie tsitoflavina na vosstanovlenie kognitivnykh funktsii u stradayushchikh alkogolizmom pozhilykh lits.

AIM: To assess effects and to study an influence of cytoflavin on the changes of cognitive functions in the complex treatment of elderly patients with alcoholism. MATERIAL AND METHODS: A prospective cohort randomized parallel study was carried out in the group of 74 elderly patients with alcoholism. RESULTS AND CONCLUSION: Significant positive changes (p<0.05) in the clinical/neurological status of patients was observed during the optimized and combined treatment with the inclusion of cytoflavin in the treatment scheme. There was a rapid and marked improvement in the indices of neuropsychological tests compared to the patients of the comparison group.