Permanent cystathionine-?-Synthase gene knockdown promotes inflammation and oxidative stress in immortalized human adipose-derived mesenchymal stem cells, enhancing their adipogenic capacity

In the present study, we aimed to investigate the impact of permanent cystathionine-?-Synthase (CBS) gene knockdown in human telomerase reverse transcriptase (hTERT) immortalized human adipose-derived mesenchymal stem cells (ASC52telo) and in their capacity to differentiate into adipocytes. CBS gene KD in ASC52telo cells led to increased cellular inflammation (IL6, CXCL8, TNF) and oxidative stress markers (increased intracellular reactive oxygen species and decreased reduced glutathione levels) in parallel to decreased H2S production and rejuvenation (LC3 and SIRT1)-related gene expression. In addition, CBS gene KD in ASC52telo cells resulted in altered mitochondrial respiratory function, characterised by decreased basal respiration (specifically proton leak) and spare respiratory capacity, without significant effects on cell viability and proliferation. In this context, shCBS-ASC52telo cells displayed enhanced adipogenic (FABP4, ADIPOQ, SLC2A4, CEBPA, PPARG)-, lipogenic (FASN, DGAT1)- and adipocyte (LEP, LBP)-related gene expression markers, decreased expression of proinflammatory cytokines, and increased intracellular lipid accumulation during adipocyte differentiation compared to control ASC52telo cells. Otherwise, the increased adipogenic potential of shCBS-ASC52telo cells was detrimental to the ability to differentiate into osteogenic linage. In conclusion, this study demonstrated that permanent CBS gene KD in ASC52telo cells promotes a cellular senescence phenotype with a very increased adipogenic potential, promoting a non-physiological enhanced adipocyte differentiation with excessive lipid storage.