Abstract: BACKGROUND: Connexin 43 is also known as Gja1 protein. Gja1 recombinant lentivirus may improve bladder contractile dysfunction in diabetes.
OBJECTIVE: To establish a guinea pig model of diabetic cystopathy, study the way of transurethral infusion of Gja1 recombinant lentiviral drugs, and observe the effect on the expression of connexin 43 protein and mRNA on the surface of detrusor muscle cells in the damaged bladder. 
METHODS: Eighty healthy guinea pigs of similar age and body mass were selected, 15 of which were randomly selected and conventionally fed and the remaining 65 were given intraperitoneal injection of 1% streptozotocin (200 mg/kg) to establish a guinea pig model of diabetic cystopathy. Urodynamics screening was performed to identify guinea pigs with diabetic cystopathy, which were further randomized into three groups: blank group (n=12), control group (n=12) and experimental group (n=12). The blank group was perfused with 0.2 mL of phosphate buffered saline, the control group was perfused with 0.2 mL of empty recombinant lentivirus, and the experimental group was perfused with 0.2 mL of Gja1 recombinant lentivirus. Three guinea pigs from each group were killed at each observation time point (2, 7, 14, and 28 days) after transfection. Expression and distribution of connexin 43 protein in the bladder were observed by immunohistochemical staining, and the protein and mRNA levels of connexin 43 were detected by western blot and qRT-PCR assays, respectively, 
RESULTS AND CONCLUSION: After transurethral infusion of Gja1 recombinant lentivirus, the expression levels of connexin 43 protein and mRNA were significantly higher in the experimental group than the blank and control groups (P < 0.01, P < 0.01), and the best expression levels of connexin 43 protein and mRNA were found at 14 days after transfection with Gja1 recombinant lentivirus. There were no significant differences in the expression levels of connexin 43 protein and mRNA between the blank and control groups (P > 0.01). To conclude, Gja1 gene via transurethral perfusion can stably express in bladder tissue and up-regulate the expression of connexin 43 at protein and mRNA levels, which may be beneficial to repair damaged signal transduction and exchange pathways between cells.

Key words: Gja1 gene, recombinant lentivirus, diabetic cystopathy, connexin 43