Hydrodynamics-based transfection of the combination of betacellulin and neurogenic differentiation 1 DNA ameliorates hyperglycemia in mice with streptozotocin-induced diabetes

Background: The biohazards caused by the viral delivery of pancreatic transcription factors, including neurogenic differentiation 1 (Neurod1) and Betacellulin (Btc), to the murine liver limit application of this procedure in reversing diabetes. We aimed to evaluate the feasibility of hydrodynamics-based transfection (HBT) with Neurod1 and Btc in improving hyperglycemia. Methods: Murine hepatocellular carcinoma (Hepa1-6) cells were transfected with the combination of Neurod1-expressing plasmid, pcDNA3.1/V5-His A (pcDNA)-Neurod1, and Btc-expressing plasmid, pcDNA3.1/V5-His A (pcDNA)-Btc. Hepatic delivery of a combination of pcDNA-Neurod1 and pcDNA-Btc (experimental group) or pcDNA (control group) to mice with streptozocin-induced diabetes was achieved by HBT. The sequential serum glucose and alanine aminotransferase (ALT) levels were assessed. Results: On day 3 after transfection, the transfection efficiencies of pcDNA-Btc and pcDNA-Neurod1 in the Hepa1-6 cells were 20% and 8%, respectively; respective values in the mouse livers were 30% and 10%. At 1 week after HBT, aside from hepatic expression of insulin, the experimental mice had a significantly lower sugar level (8-14 days after HBT, P values ranged from 0.034 to <0.001) than the control mice; the difference remained for 1 week but diminished afterward. The ALT levels and the body weight change were not different between the two groups. No mortality was noted in both groups. Conclusions: The hypoglycemic effect of Neurod1 and Btc delivered by HBT was transient and associated with negligible complications. In studies on the short-term hypoglycemic effects of Neurod1 and Btc in vivo, HBT is a potential alternative to viral delivery of Neurod1 and Btc to the murine liver.