Search

Exosomes derived from differentiated P12 cells and MSCs were proved to suppress apoptosis of neuron cells, and phosphatase and tensin homolog pseudogene 1 (PTENP1) was reported to inhibit cell proliferation. In this study, we aimed to investigate the role of PTENP1 in the process of post‐spinal cord injury (SCI) recovery, so as to evaluate the therapeutic effects of exosomes derived from MSCs transfected with PTENP1 short hairpin RNA (shRNA), as a type of novel biomarkers in the treatment of SCI. Electron microscopy was used to observe the morphology of different exosomes. Real‐time polymerase chain reaction and western blot, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assays, flow cytometry, Nissl staining, immunohistochemistry assay, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were conducted to investigate and validate the underlying molecular signaling pathway. PTENP1‐shRNA downregulated PTENP1 and PTEN while upregulating miR‐21 and miR‐19b. PTENP1‐shRNA also accelerated cell apoptosis and reduced cell viability. In addition, PTENP1 reduced the miR‐21 and miR‐19b expression by directly targeting miR‐21 and miR‐19b. Meanwhile, both miR‐21 and miR‐19b reduced the expression of PTEN by directly targeting the 3′‐untranslated region of PTEN. Furthermore, PTEN level and apoptosis index of neuron cells was the highest in the SCI group, while the treatment with exosomes+PTENP1‐shRNA reduced the PTEN expression to a level similar to that in the sham group. Finally, PTENP1 inhibited miR‐21 and miR‐19b expression but upregulated PTEN expression. The upregulation of miR‐21/miR‐19b also suppressed the apoptosis of neuron cells by downregulating the PTEN expression. PTENP1 is involved in the recovery of SCI by regulating the expression of miR‐19b and miR‐21, and exosomes from PTENP1‐shRNA‐transfected cells may be used as a novel biomarker in SCI treatment. [ABSTRACT FROM AUTHOR]

Objectives: Angiotensinogen (AGT) and miR-149-5p were differentially expressed genes in the osteoarthritis (OA), but their functional contribution to this disease is unclear. Our study aimed to illustrate their relevance to OA pathology and chondrocytic inflammation responses., Methods: In this study, a total of 32 healthy donors and 56 OA patients were recruited for cartilage tissues, and interleukin (IL)-6-stimulated human chondrocyte-articular (HC-a) cells were used as an in vitro OA model., Results: RT-qPCR and western blot assays demonstrated that AGT was upregulated in OA cartilage tissues while miR-149-5p was downregulated. Using a loss-of-function assay and inhibitor treatment, we found that AGT knockdown inhibited the increase of IL-1β, matrix metalloproteinase (MMP)-13 and nitrite in IL-6-induced chondrocytes through blocking the renin-angiotensin system (RAS). The prediction (TargetScan) and validation (mutant and luciferase reporter assays) of the interaction between AGT and miR-149-5p indicated that miR-149-5p directly regulated inflammatory responses in OA chondrocytes by binding to AGT. Furthermore, using overexpression and inhibitor treatment experiments, our study proved that JAK2/STAT3 was activated in OA tissues, and AGT regulated OA inflammation via activating the JAK2/STAT3 pathway., Conclusions: Our study demonstrated that AGT, modulated and directly bond by miR-149-5p, promoted the IL-6-induced inflammatory responses in OA via JAK2/STAT3 pathway.