Cross-talk between microtubules and the linker of nucleoskeleton complex plays a critical role in the adipogenesis of human adipose-derived stem cells

Abstract

BackgroundAdipose-derived stem cells (ASCs) that show multidifferentiation and anti-immune rejection capacities have been widely used in plastic and reconstructive surgery. Previous studies have indicated that mechanical and biophysical interactions between cells and their surrounding environment regulate essential processes, such as growth, survival, and differentiation, and the cytoskeleton system plays an important role in the mechanotransduction. However, the role of mechanical force in the determination of lineage fate is still unclear.MethodsHuman ASCs (hASCs) were obtained from three different donors by liposuction. Adipogenesis and osteogenesis were determined by Oil Red O and Alizarin Red staining, respectively. The mRNA levels of the cytoskeleton system, PPARγ, and C/EBPα were determined by real-time polymerase chain reaction (RT-PCR). The level of cytoskeleton, PPARγ, and C/EBPα protein levels were measured by Western blotting. The morphology of the cytoskeleton system during adipogenesis was observed with confocal microscopy. hASCs were transfected with a SUN2-specific shRNA to knockdown sun2, and a nontargeting shRNA was used as a control.ResultsWe found that disrupting the physiological balance between the cytoskeleton and the linker of the nucleoskeleton and cytoskeleton (LINC) complex (especially SUN2) could impact the adipogenesis of hASCs in vitro. Microtubule (MT) depolymerization with nocodazole (which interferes with the polymerization of MTs) increased the expression of SUN2 and PPARγ, while taxol (an inhibitor of MT disassembly) showed the opposite results. Meanwhile, hASCs with sun2 knockdown overexpressed MTs and decreased PPARγ expression, thereby inhibiting the adipogenesis. Furthermore, knockdown of sun2 changed the structure of perinuclear MTs.ConclusionsWe demonstrated the presence of cross-talk between MT and SUN2, and this cross-talk plays a critical role in the rebalance of the mechanical environment and is involved in the regulation of PPARγ transport during adipogenic differentiation of hASCs.Electronic supplementary materialThe online version of this article (10.1186/s13287-018-0836-y) contains supplementary material, which is available to authorized users.

Lineage Commitment, Signaling Pathways, and the Cytoskeleton Systems in Mesenchymal Stem Cells

“…117 During adipogenic differentiation of adipose-derived MSCs MTs also assemble around the nucleus, form the cobweb-like structure, and later translocate into the peripheral cytoplasm. 118 Disruption of MT array with nocodazole in osteogenic conditions is favorable for the osteogenic differentiation, 18 while disruption of MT array in adipogenic conditions increases the expression of PPAR-gamma and enhances adipogenic commitment. 118 These effects are attributed to the loss of physiological balance between MTs and the linker of the nucleoskeleton and cytoskeleton (LINC) complex, as MT disruption increased the expression of SUN2 (LINC component), and SUN2 knockdown perturbed the structure of the perinuclear MTs in differentiating adipocytes.…”

“…118 Disruption of MT array with nocodazole in osteogenic conditions is favorable for the osteogenic differentiation, 18 while disruption of MT array in adipogenic conditions increases the expression of PPAR-gamma and enhances adipogenic commitment. 118 These effects are attributed to the loss of physiological balance between MTs and the linker of the nucleoskeleton and cytoskeleton (LINC) complex, as MT disruption increased the expression of SUN2 (LINC component), and SUN2 knockdown perturbed the structure of the perinuclear MTs in differentiating adipocytes. 118 MTs interact with LINC through the motor proteins; however, whether the interaction is direct or not remains unknown.…”

“…118 These effects are attributed to the loss of physiological balance between MTs and the linker of the nucleoskeleton and cytoskeleton (LINC) complex, as MT disruption increased the expression of SUN2 (LINC component), and SUN2 knockdown perturbed the structure of the perinuclear MTs in differentiating adipocytes. 118 MTs interact with LINC through the motor proteins; however, whether the interaction is direct or not remains unknown. 119,120 These data suggest the possible regulatory role of MTs in mechanosensory pathways within the cytoplasm and nucleus.…”

“…165 Senescence in vitro decreases osteogenic potential but does not influence adipogenic potential of MSCs. 118 Senescence of MSC could be monitored by the expression of surface markers (CD90 and CD106), 166,167 by analysis of differentiation potential in adipogenic, chondrogenic, and osteogenic assays 168 and by increased autofluorescence. 169 MSCs senescence involves slowdown of actin turnover and diminished antioxidant synthesis, 163 alteration of the differentiation gene expression profile with the continuous decrease of multilineage potential.…”

Expression profile of SYNE3 and bioinformatic analysis of its prognostic value and functions in tumors

“…Since nesprin-3/SYNE3 was initially discovered, it was mostly studied in stem cells. Nesprin-3 was reported to engage in nucleus maintaining [ 8 ], cell migration [ 9 , 10 ] and cell differentiation [ 11 – 13 ]. Recent studies began to focus on its roles in cancer, suggesting that nesprin-3 mediated tumor cell migration in lung cancer [ 14 ] and fibrosarcoma cells [ 15 ].…”