Molecular Mechanism of MiR-136-5p Targeting NF-κB/A20 in the IL-17-Mediated Inflammatory Response after Spinal Cord Injury.

BACKGROUND/AIMS: The pathophysiology of spinal cord injury (SCI) results in serious damage to the human body via an increase in the secondary biological processes imposed by activated astrocytes. Abnormal expression of microRNAs after SCI has become a potential research focus. However, the underlying mechanisms are poorly understood. METHODS: SCI models were established in rats using Allen's method, and the BBB scoring method was employed to assess locomotor function. Lentivirus was used to infect rat astrocytes and SCI rats. Real-time PCR and antibody chip were used to measure gene expression and cytokine secretion. Western blot analysis was employed to detect protein expression. HE staining was used to assess the histological changes in SCI. The immunohistochemical staining of A20 and p-NF-κB in SCI was also analyzed. RESULTS: The in vitro experiment showed that miR-136-5p up-regulated the expression of p-NF-κB by down-regulating the expression of A20 so that astrocytes produced inflammatory factors and chemokines. The in vivo experiment indicated that overexpressed miR-136-5p promoted the production of inflammatory factors, chemokines and p-NF-κB in SCI rats, whereas it inhibited the expression of A20 protein and increased inflammatory cell infiltration and injuries in the spinal cord. CONCLUSION: The current findings indicate that silencing miR-136-5p effectively decreased inflammatory factors and chemokines and protected the spinal cord via NF-κB/A20 signaling in vivo and in vitro. In contrast, overexpression of miR-136-5p had the opposite effect.

The Effects of miR-136-5p-Mediated Regulation of A20 in Astrocytes from Cultured Spinal Cord Cultured Cells In Vitro.

BACKGROUND/AIMS: This study focused on investigating the regulatory mechanism of miR-136-5p in mouse astrocytes stimulated with interleukin-17(IL-17). METHODS: C57BL/6 mouse astrocytes were stimulated with IL-17 (100ng/ml) for various periods of time (0-48 hours) and at various doses (0-200 ng), and the expression levels of inflammatory cytokine and chemokine genes (IL-6, TNF-α, MCP-1, MCP-5 and MIP-2) were then detected by real-time PCR. The expression of the A20 gene was measured with real-time PCR in cells that were stimulated with IL-17 (50 ng/ml) for various periods of time (0-48 hours). C57BL/6 mouse astrocytes were transfected with Ctrl-anti-miR-136-5p or LNA -anti-miR-136-5p for 48 h. Thereafter, the cells were stimulated with or without IL-17 (50ng/ml) for 6 h. The level of A20 protein (TNFα-induced protein 3, TNFAIP3) was detected by Western blot analysis. RESULTS: (1) Compared with the DMEM control group, within six hours, IL-17 stimulation significantly increased the expression levels of inflammatory cytokine and chemokine genes and clearly decreased the expression level of the A20 protein. (2) Without IL-17 stimulation, the expression level of the miR-136-5p gene was significantly decreased, whereas in the miR-136-5p-inhibition group, the A20 protein expression was elevated. IL-17 stimulation slightly decreased the expression of the A20 protein in the miR-136-5p-inhibition group, but it was still slightly higher than in the control group. CONCLUSION: This study demonstrated that miR-136-5p affected the expression of A20 in IL-17-stimulated astrocytes.

Mitochondrial-targeted cyclometalated Ir(III)-5,7-dibromo/dichloro-2-methyl-8-hydroxyquinoline complexes and their anticancer efficacy evaluation in Hep-G2 cells.

Both 8-hydroxyquinoline compounds and iridium (Ir) complexes have emerged as potential novel agents for tumor therapy. In this study, we synthesized and characterized two new Ir(III) complexes, [Ir(L1)(bppy)2] (Br-Ir) and [Ir(L2)(bppy)2] (Cl-Ir), with 5,7-dibromo-2-methyl-8-hydroxyquinoline (HL-1) or 5,7-dichloro-2-methyl-8-hydroxyquinoline as the primary ligand. Complexes Br-Ir and Cl-Ir successfully inhibited antitumor activity in Hep-G2 cells. In addition, complexes Br-Ir and Cl-Ir were localized in the mitochondrial membrane and caused mitochondrial damage, autophagy, and cellular immunity in Hep-G2 cells. We tested the proteins related to mitochondrial and mitophagy by western blot analysis, which showed that they triggered mitophagy-mediated apoptotic cell death. Remarkably, complex Br-Ir showed high in vivo antitumor activity, and the tumor growth inhibition rate was 63.0% (P < 0.05). In summary, our study on complex Br-Ir revealed promising results in in vitro and in vivo antitumor activity assays.

Polygonatum Sibiricum Polysaccharide Promotes Osteoblastic Differentiation Through the ERK/GSK-3ß/ß-Catenin Signaling Pathway In Vitro.

Natural compound polygonatum sibiricum polysaccharide (PSP) has a variety of biological actions such as reducing blood fat, antitumor and antioxidant activities, and enhancing immune function. Our previous study has revealed that PSP can promote osteoblastic (OB) differentiation in bone mesenchymal stem cells by increasing nuclear accumulation of ß-catenin. This study was designed to investigate that PSP can upregulate nuclear ß-catenin, which was prevented by inhibiting the glycogen synthase kinase 3ß (GSK-3ß) activity, by effectively activating Wnt signaling independent of low-density lipoprotein receptor-related protein 5 (LRP5). We showed that PSP reduced the level of GSK-3ß, which phosphorylates and destabilizes nuclear ß-catenin through extracellular signal-regulated kinase (ERK) signaling pathway. Taken together, these findings demonstrate that PSP promotes OB differentiation and mineralization in vitro through the ERK/GSK-3ß/ß-catenin signaling pathways. This study may aid in the development of a therapeutic approach utilizing PSP for the enhancement of bone health and prevention of osteoporosis.