MicroRNAomic Transcriptomic Analysis Reveal Deregulation of Clustered Cellular Functions in Human Mesenchymal Stem Cells During in Vitro Passaging

Senotherapeutics for mesenchymal stem cell senescence and rejuvenation

Mesenchymal stem cells (MSCs) are susceptible to replicative senescence and senescence-associated functional decline, which hampers their use in regenerative medicine. Senotherapeutics are drugs that target cellular senescence through senolytic and senomorphic functions to induce apoptosis and suppress chronic inflammation caused by the senescence-associated secreted phenotype (SASP), respectively. Therefore, senotherapeutics could delay aging-associated degeneration. They could also be used to eliminate senescent MSCs during in vitro expansion or bioprocessing for transplantation. In this review, we discuss the role of senotherapeutics in MSC senescence, rejuvenation, and transplantation, with examples of some tested compounds in vitro. The prospects, challenges, and the way forward in clinical applications of senotherapeutics in cell-based therapeutics are also discussed.

5-Azacytidine pretreatment confers transient upregulation of proliferation and stemness in human mesenchymal stem cells

Successful outcomes of cell-based therapeutic is highly-dependent on quality and quantity of the cells. Epigenetic modifiers are known to modulate cell fates via reprogramming, hence it is plausible to use them in enhancing the plasticity of mesenchymal stem cells. In this study, we aimed to study the effects of 5-Azacytidine (5-AzaCR), an epigenetic modifier, pretreatment on mesenchymal stem cells-derived from Wharton's Jelly (WJMSCs) fates. WJMSCs were pretreated with 5-AzaCR for 24 h and subsequently cultured in culture media mixtures. The proliferative and stemness characteristics of the pretreated WJMSCs were assessed through morphological and gene expression analyses. Results showed that cells pretreated with 5 μM to 20 μM of 5-AzaCR showed to acquire higher proliferative state transiently when cultured in embryonic-mesenchymal stem cell (ESC-MSC) media, but not in MSC medium alone, and this coincides with significant transitional upregulation of stemness transcription factors. 5-AzaCR pretreatment has potential to confer initial induction of higher state of stemness and proliferation in WJMSCs, influenced by the culture media.

Epigenetic Regulation in Mesenchymal Stem Cell Aging and Differentiation and Osteoporosis

Mesenchymal stem cells (MSCs) are a reliable source for cell-based regenerative medicine owing to their multipotency and biological functions. However, aging-induced systemic homeostasis disorders in vivo and cell culture passaging in vitro induce a functional decline of MSCs, switching MSCs to a senescent status with impaired self-renewal capacity and biased differentiation tendency. MSC functional decline accounts for the pathogenesis of many diseases and, more importantly, limits the large-scale applications of MSCs in regenerative medicine. Growing evidence implies that epigenetic mechanisms are a critical regulator of the differentiation programs for cell fate and are subject to changes during aging. Thus, we here review epigenetic dysregulations that contribute to MSC aging and osteoporosis. Comprehending detailed epigenetic mechanisms could provide us with a novel horizon for dissecting MSC-related pathogenesis and further optimizing MSC-mediated regenerative therapies.