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Introduction: This study aimed to investigate the effect of muscle-derived stem cell (MDSC) exosomes with overexpressed miR-214 on the regeneration and repair of rat sciatic nerve after crush injury and its molecular mechanism. Methods: First, primary MDSCs, Schwann cells (SCs) and dorsal root ganglion (DRG) neurons were isolated and cultured, and the characteristics of MDSCs-derived exosomes were identified by molecular biology and immunohistochemistry. NC mimics and miR-214 mimics were transfected to obtain exo-NC and exo-miR-214. An in vitro co-culture system was established to determine the effect of exo-miR-214 on nerve regeneration. The restoration of sciatic nerve function of rats by exo-miR-214 was evaluated by walking track analysis. Immunofluorescence for NF and S100 was used to detect the regeneration of axon and myelin sheath in injured nerve. The Starbase database was used to analyze the downstream target genes of miR-214. QRT-PCR and dual luciferase reporter assays were used to validate the miR-214 and PTEN interaction relationship. And the expression of the JAK2/STAT3 pathway-related proteins in sciatic nerve tissues were detected by western blot. Results: The above experiments showed that MDSCs-derived exosomes with overexpressed miR-214 was found to promote the proliferation and migration of SCs, increase the expression of neurotrophic factors, promote axon extension of DRG neurons and positively affect the recovery of nerve structure and function. In addition, PTEN was a target gene of miR-214. Exo-miR-214 can significantly inhibit the expression level of PTEN, increase the protein expression levels of p-JAK2 and p-STAT3 and the ratio of p-JAK2/JAK2 and p-STAT3/STAT3, also MDSCs-derived exosomes with overexpressed miR-214 can reduce the occurrence of denervated muscle atrophy. Conclusion: In summary, the MDSCs-derived exosomes with overexpressed miR-214 is involved in peripheral nerve regeneration and repair in rats after sciatic nerve crush injury to activate the JAK2/ STAT3 pathway by targeting PTEN.
RESUMO
Recent studies have demonstrated that lncRNAs play an important role in cancers, particularly osteosarcoma. ZFAS1 is a newly identified and characterized lncRNA linked to a variety of cancers. The role of ZFAS1 in osteosarcoma is mainly unknown. This study discovered that ZFAS1 was upregulated in osteosarcoma patient tissues, which correlates with elevated SRSF3 protein levels. Higher levels of ZFAS1 or SRSF3 were linked to a poor prognosis of osteosarcoma. ZFAS1 knockdown decreased SRSF3 protein levels but had a negligible effect on SRSF3 mRNA expression. Further research indicated that ZFAS1 could bind to the SRSF3 protein directly and prevent degrading. Functional studies revealed that ZFAS1 knockdown inhibited osteosarcoma cell proliferation as measured by the CCK-8 assay, colony formation assay, and Ki-67 immunofluorescence staining. Furthermore, ZFAS1 knockdown reduced the expression of PCNA, CDK1, CDK4, and CDK6, increasing p53 and p16. IT has also been observed that ZFAS1 knockdown inhibited osteosarcoma cell migration and invasion as measured by the wound healing assay and the trans-well assay with or without Matrigel.Furthermore, exogenous SRSF3 expression in ZFAS1-depleted osteosarcoma cells restored SRSF3 expression while simultaneously inhibiting cell proliferation and metastasis. Our findings show that ZFAS1 plays an essential role in osteosarcoma progression by stabilizing the SRSF3 protein. Our study provides novel insight into the role of ZFAS1 in osteosarcoma. ZFAS1 has the potential to be used as a prognostic biomarker as well as a therapeutic target in the treatment of osteosarcoma.
