[Long-Chain Free Fatty Acids Influence Lipid Accumulation, Lysosome Activation and Glycolytic Shift in Various Cells In Vitro].

Hydrophobic molecules may be toxic when present in excess. When dissolved in membranes, hydrophobic molecules disrupt membrane function. Studies on the effects of free fatty acids (FFA) on cultured cells contradict each other. Here we describe the effects of FFA on various human cells in culture. The addition of long-chain FFA (oleic, palmitic, linoleic, linolenic, etc.) to cultured cells led to lipid accumulation in hepatocytes and muscle cells, initiation of autophagy, and uncoupling of oxidative phosphorylation. Although treated cells increase their oxygen consumption, metabolic shifts in favor of glycolysis were observed. All these effects were expressed to varying degrees in different cells and with the addition of different FFAs. The mechanisms of these FFA effects are discussed, as well their practical implications.

Generation of iPS Cells from Human Hair Follice Dermal Papilla Cells.

Dermal papilla (DP) cells are unique regional stem cells of the skin that induce formation of a hair follicle and its regeneration cycle. DP are multipotent stem cells; therefore we supposed that the efficiency of DPC reprogramming could exceed that of dermal fibroblasts reprogramming. We generated induced pluripotent stem cells from human DP cells using lentiviral transfection with Oct4, Sox2, Klf4, and c-Myc, and cultivation of cells both in a medium supplemented with valproic acid and at a physiological level of oxygen (5%). The efficiency of DP cells reprogramming was ~0.03%, while the efficiency of dermal fibroblast reprogramming under the same conditions was ~0.01%. Therefore, we demonstrated the suitability of DP cells as an alternative source of iPS cells.