Qi Wan,Hui Chen,Xiaolei Li,Lianqi Yan,Yu Sun,Jingcheng Wang
Fibroblast proliferation is considered to be a major cause in the process of epidural fibrosis formation. Autophagy is a tightly-regulated catabolic process in charge of degrading intracellular components. Although autophagy has been associated with fibrosis of different tissues, the effect of autophagy on epidural fibrosis is still unknown. The aim of this study was to investigate the function and mechanism of autophagy induced by Artesunate (ART), a classical antimalarial agent extracted from the Chinese medicinal herb. In vitro, the effect of ART on inducing fibroblast autophagy was evaluated via LC3 immunofluorescent staining , Transmission Electron Microscopy (TEM) and western blotting analysis. Moreover, the effect of ART on inhibiting fibroblast proliferation was investigated by CCK-8 assay, EdU incorporation assay, flow cytometry and western blotting analysis. Results indicated that ART could induce autophagy and inhibit proliferation in fibroblasts. The inhibitory effect of ART on fibroblast proliferation was associated with the upregulation of p53 and p21 waf1/cip1 proteins. Intriguingly, 3-MA, a classical autophagy inhibitor, attenuated ART-induced p53/p21 waf1/cip1 pathway activation and fibroblast proliferation inhibition. In vivo, the effect of ART on reducing epidural fibrosis was detected by histological macroscopic assessment, hydroxyproline content analysis, histological and immunohistochemical staining. The results revealed that ART had significant suppressive effects on epidural fibrosis following laminectomy in rats. In conclusion, this research demonstrated that ART could inhibit fibroblast proliferation and reduce epidural fibrosis formation after laminectomy, and the potential mechanism might through autophagy cascade-mediated p53/p21 waf1/cip1 pathway. It might provide a novel reagent for reducing epidural fibrosis after spinal laminectomy surgery.
Background Cellular senescence refers to a condition where cells permanently cease division while maintaining metabolic activity. Doxorubicin (Dox) is known as an agent of induction of cellular senescence. This study aimed to explore the potential role of human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-Exo) in mitigating Dox induced senescent. Method NIH3T3 cells were treated by various concentrations of Dox with or without hucMSC-Exo, cell morphology, viability, migration, senescence-associated SA-β-Gal staining were monitored. Cellular senescence was induced in C57BL/6J mice via administration of 5 mg/kg Doxorubicin, followed by treatment with hucMSC-Exo or metformin. Assessments included body weight, liver and kidney weight, colon length, SA-β-Gal staining of kidney and skin, molecular biomarkers of aging such as p16 INK4A , p53, and p21 Waf1/Clip1 to evaluate senescence status. Result We found that after the treatment of exosomes or metformin improved several aging-related phenotypes in both mouse and cellular models, including increases in body weight, liver and kidney weights, and the reduction of SA-β-Gal positive cells in kidney and skin tissues as well as cell models. At the molecular level, hucMSC-Exo resulted in the downregulation of inflammatory factors and senescence markers in liver and kidney tissues as well as cell models. Conclusion Our study demonstrates hucMSC-Exo may ameliorate Dox induced senescence either in NIH3T3 cells or in mice.