Knockdown of long noncoding RNA SAN rejuvenates aged adipose-derived mesenchymal stem cells via miR-143-3p/ADD3 axis

Abstract: Background Senescent adipose-derived stem cells (ASCs) exhibit reduced therapeutic efficacy during wound healing. Transcriptional regulation factors including long non-coding RNAs (lncRNAs) reportedly play essential roles in stem cell aging. However, the mechanisms by which lncRNAs influence mesenchymal stem cell aging have not been investigated. Methods The lncRNA senescence-associated non-coding RNA (SAN) was identified among differentially expressed lncRNAs in ASCs obtained from old and young volunteer donors. ASCs with overexpression or knockdown of SAN and ADD3 were constructed by lentiviral transduction. Proliferation, migration, and cellular senescence were investigated in ASCs, as were the angiogenic effects on endothelial cells and promigratory effects on fibroblasts stimulated with conditioned medium (CM) from ASCs. Dual-luciferase assays were performed to characterize RNA interactions. The therapeutic effects of SAN-depleted aged ASCs were evaluated in a skin injury model. Results The lncRNA SAN (NONHSAT035482.2) was upregulated in aged ASCs and functioned to regulate cellular senescence in ASCs. lncRNA SAN knockdown and ADD3 silencing in ASCs led to ASC functional enhancement and the inhibition of cellular senescence; it also promoted the effects of CM on endothelial cells and fibroblasts. Mechanistic analysis showed that SAN serves as a sponge for miR-143-3p, thereby regulating the expression of γ-adducin (ADD3); moreover, ADD3 silencing could rejuvenate senescent ASCs. The application of SAN-depleted aged ASCs accelerated the skin wound closure, compared with transplantation of aged ASCs. Conclusion The lncRNA SAN mediates ASC senescence by regulating the miR-143-3p/ADD3 pathway, providing a potential target for rejuvenation of senescent ASCs and enhancement of wound repair.