Role of PNPT1 in cardiomyocyte apoptosis induced by oxygen-glucose deprivation / 南方医科大学学报

OBJECTIVE@#To explore the effect of inhibiting polyribonucleotide nucleotidyl-transferase 1 (PNPT1) on oxygen-glucose deprivation (OGD)-induced apoptosis of mouse atrial myocytes.@*METHODS@#Cultured mouse atrial myocytes (HL-1 cells) with or without OGD were transfected with PNPT1-siRNA or a negative control siRNA (NC-siRNA group), and the cell survival rate was detected using CCK-8 assay. The expression levels of ACTB and TUBA mRNA were detected with qPCR, and the protein expression of PNPT1 was detected with Western blotting. The apoptosis rate of the treated cells was determined with flow cytometry, the mitochondrial membrane potential was detected using JC-1 kit, and the mitochondrial morphology was observed using transmission electron microscope.@*RESULTS@#With the extension of OGD time, the protein expression levels of PNPT1 increased progressively in the cytoplasm of HL-1 cells (P < 0.05). Transfection with PNPT1-siRNA significantly reduced PNPT1 expression in HL-1 cells (P < 0.05). Exposure to OGD significantly enhanced degradation of ACTB and TUBA mRNA (P < 0.05) and markedly increased the apoptosis rate of HL-1 cells (P < 0.05), and these changes were significantly inhibited by transfection with PNPT1-siRNA (P < 0.05), which obviously increased mitochondrial membrane potential and improved mitochondrial morphology of HL-1 cells exposed to OGD.@*CONCLUSION@#Inhibition of PNPT1 improves mitochondrial damage and reduces degradation of apoptotic-associated mRNAs to alleviate OGD-induced apoptosis of mouse atrial myocyte.

Polydeoxyribonucleotides Improve Diabetic Wound Healing in Mouse Animal Model for Experimental Validation

BACKGROUND: Wound healing mechanisms is believed to have effects similar to wound healing disorders in diabetic patients, including abnormal inflammatory cells, angiogenesis disorders, and reduced collagen synthesis. Therefore, reestablishment of structural and promoted angiogenesis could be beneficial to promote wound healing process. OBJECTIVE: Therefore, we investigated whether the polydeoxyribonucleotide (PDRN) that was self-production in Korea, could be useful as an intradermal injection for promoting wound healing. Also, we validate for wound healing effect of PDRN using healing-impaired (db/db) mice. METHODS: In this study, we confirmed the effects of PDRN by creating wound models in in vitro and in vivo model. Using an in vitro wound healing assay, we observed that PDRN stimulated closure of wounded monolayers of human fibroblast cells. PDRN (8.25 mg/ml) or phosphate-buffered saline (0.9% NaCl) was injected once daily into the dermis adjacent to the wound for 12 days after skin injury. RESULTS: Time course observations revealed that mice treated with PDRN showed accelerated wound closure and epidermal and dermal regeneration, enhanced angiogenesis. The wound area and depth decreased at 3, 6, 9, and 12 days after skin injury. Histological evaluation showed an increase of vascular endothelial growth factor, CD31, and collagen fibers in the PDRN group compared with the control group, indicating that PDRN was effective in the treatment of delayed wound healing caused by diabetes. CONCLUSION: This study suggests that our PDRN has a wound healing effect in transgenic animal models with cells and diabetes through angiogenesis.