Multifunctional role of microRNAs in mesenchymal stem cell-derived exosomes in treatment of diseases

Mesenchymal stem cells can be replaced by exosomes for the treatment of inflammatory diseases,injury repair,degenerative diseases,and tumors.Exosomes are small vesicles rich in a variety of nucleic acids[including messenger RNA,Long non-coding RNA,microRNA(miRNA),and circular RNA],proteins,and lipids.Exosomes can be secreted by most cells in the human body and are known to play a key role in the communication of information and material transport between cells.Like exosomes,miRNAs were neglected before their role in various activities of organisms was discovered.Several studies have confirmed that miRNAs play a vital role within exosomes.This review focuses on the specific role of miRNAs in MSC-derived exosomes(MSC-exosomes)and the methods commonly used by researchers to study miRNAs in exosomes.Taken together,miRNAs from MSC-exosomes display immense potential and practical value,both in basic medicine and future clinical applications,in treating several diseases.

Effect of microenvironment modulation on stem cell therapy for spinal cord injury pain

Spinal cord injury （SCI） currently ranks second after mental retarda- tion among neurological disorders in terms of cost to society. Pain is a debilitating consequence of SCI related to the nature of the lesion, neurological structures damaged, and secondary pathophysiological changes of surviving tissues （Yezierski, 2005; D＇Angelo et al., 2013）.

Lysine-specific demethylase 1 inhibitor rescues the osteogenic ability of mesenchymal stem cells under osteoporotic conditions by modulating H3K4 methylation

Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulation plays an important role in the developmental origins of osteoporosis; however, few studies have investigated the potential of epigenetic therapy to improve or rescue the osteogenic ability of bone marrow mesenchymal stem cells(BMMSCs) under osteoporotic conditions. Here, we investigated pargyline, an inhibitor of lysine-specific demethylase 1(LSD1), which mainly catalyzes the demethylation of the di- and mono-methylation of H3K4. We demonstrated that 1.5 mmol·Lpargyline was the optimal concentration for the osteogenic differentiation of human BMMSCs. Pargyline rescued the osteogenic differentiation ability of mouse BMMSCs under osteoporotic conditions by enhancing the dimethylation level of H3K4 at the promoter regions of osteogenesis-related genes. Moreover, pargyline partially rescued or prevented the osteoporotic conditions in aged or ovariectomized mouse models, respectively. By introducing the concept of epigenetic therapy into the field of osteoporosis, this study demonstrated that LSD1 inhibitors could improve the clinical practice of MSC-based bone tissue engineering and proposes their novel use to treat osteoporosis.