MiR-34a suppression targets Nampt to ameliorate bone marrow mesenchymal stem cell senescence by regulating NAD+-Sirt1 pathway

Stem Cell Research & Therapy

Huan Wang¹  Cao Ma²  Yan Li³  Yue Yang⁴  Yingai Shi⁵  Haiying Zhang⁵  Yulin Li⁵  Yanan Sun⁵  Xu He⁵  Hui Sun⁵  Xiao Yu⁵  Xingyu Gao⁵  Chenchen Pi⁶ 

[1] Department of Pathology, The First Affiliated Hospital, Henan University of Chinese Medicine, 450000, Henan, China;Department of Pathology, Zhongda Hospital, School of Medicine, Southeast University, 210009, Nanjing, China;Division of Orthopedics and Biotechnology, Department for Clinical Intervention and Technology (CLINTEC), Karolinska Institute, Stockholm, Sweden;Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, 610072, Chengdu, China;The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xin Min Street, Changchun, Jilin Province, People’s Republic of China;The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, 126 Xin Min Street, Changchun, Jilin Province, People’s Republic of China;The First Hospital, and Institute of Immunology, Jilin University, 130021, Changchun, China;

关键词: Mesenchymal stem cell;    Senescence;    miRNA;    miR-34a;    Nampt;    Regulation;   

DOI  :  10.1186/s13287-021-02339-0

来源: Springer

【 摘 要 】

BackgroundExpansion-mediated replicative senescence and age-related natural senescence have adverse effects on mesenchymal stem cell (MSC) regenerative capability and functionality, thus severely impairing the extensive applications of MSC-based therapies. Emerging evidences suggest that microRNA-34a (miR-34a) has been implicated in the process of MSC senescence; however, the molecular mechanisms with regard to how miR-34a influencing MSC senescence remain largely undetermined.MethodsMiR-34a expression in MSCs was evaluated utilizing RT-qPCR. The functional effects of miR-34a exerting on MSC senescence were investigated via gene manipulation. Relevant gene and protein expression levels were analyzed by RT-qPCR and western blot. Luciferase reporter assays were applied to confirm that Nampt is a direct target of miR-34a. The underlying regulatory mechanism of miR-34a targeting Nampt in MSC senescence was further explored by measuring intracellular NAD+ content, NAD+/NADH ratio and Sirt1 activity.ResultsIn contrast to Nampt expression, miR-34a expression incremented in senescent MSCs. MiR-34a overexpression in young MSCs resulted in senescence-associated characteristics as displayed by senescence-like morphology, prolonged cell proliferation, declined osteogenic differentiation potency, heightened senescence-associated-β-galactosidase activity, and upregulated expression levels of the senescence-associated factors. Conversely, miR-34a suppression in replicative senescent and natural senescent MSCs contributed to diminished senescence-related phenotypic features. We identified Nampt as a direct target gene of miR-34a. In addition, miR-34a repletion resulted in prominent reductions in Nampt expression levels, NAD+ content, NAD+/NADH ratio, and Sirt1 activity, whereas anti-miR-34a treatment exerted the opposite effects. Furthermore, miR-34a-mediated MSC senescence was evidently rescued following the co-treatment with Nampt overexpression.ConclusionThis study identifies a significant role of miR-34a playing in MSC replicative senescence and natural senescence via targeting Nampt and further mediating by NAD+-Sirt1 pathway, carrying great implications for optimal strategies for MSC therapeutic applications.

【 授权许可】

CC BY