Downregulation of miR-155-5p Improves Mitochondrial Dynamics and Cell Function

Researchers here identify miR-155-5p as a potential target to improve mitochondrial function. This microRNA is upregulated with age, and appears to inhibit mitochondrial fission. That in turn prevents the cellular maintenance process of mitophagy from clearing out worn and damaged mitochondria efficiently enough to prevent loss of function. Since mitochondria provide the chemical energy store molecules that power all cellular operations, this has downstream consequences on cell and tissue function, including higher levels of cellular senescence. Aging impairs the functions of human mesenchymal stem cells (MSCs), thereby severely reducing their beneficial effects on myocardial infarction (MI). MicroRNAs (miRNAs) play crucial roles in regulating the senescence of MSCs; however, the underlying mechanisms remain unclear. Here, we investigated the significance of miR-155-5p in regulating MSC senescence and whether inhibition of miR-155-5p could rejuvenate aged MSCs (AMSCs) to enhance their therapeutic efficacy for MI. Young MSCs (YMSCs) and AMSCs were isolated from young and aged donors, respectively. The cellular senescence of MSCs was evaluated by senescence-associated β-galactosidase (SA-β-gal) staining. Compared with YMSCs, AMSCs exhibited increased cellular senescence as evidenced by increased SA-β-gal activity and decreased proliferative capacity and paracrine effects. The expression of miR-155-5p was much higher in both serum and MSCs from aged donors tha...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs