Changes in the Expression of Regulatory MicroRNAs – miR-21 and miR-155 – in Gut-Associated Lymphoid Tissue Cells of Rats with Streptozotocin-Induced Diabetes and After the Administration of a Non-Selective TNF-A Blocker

Introduction: The development of type 1 diabetes can be triggered by genetic predisposition as well as changes occurring in the gut-associated lymphoid tissue. This study aimed to investigate the transcriptional activity of the miR-21 and miR-155 genes in gut-associated lymphoid tissue cells of rats with streptozotocin-induced diabetes, both untreated and treated with pentoxifylline, a non-specific blocker of TNF-α. Material and Methods: Experimental diabetes mellitus was induced by singleintraperitoneal administration of streptozotocin at a dose of 50 mg/kg body weight. Pentoxifylline was administrated orally at a dose of 9 mg/kg body weight for 2 or 4 weeks from the first day of streptozotocin-induced diabetes. The expression of miR-21 and miR155 genes was studied using real-time quantitative polymerase chain reaction. Results: Streptozotocin-induced diabetes led to the transcriptional induction of the miR-21 and miR155 genes. Pentoxifylline administration to the experimental animals led to the 3-fold downward trend of miR-21 gene expression on day 28 of the experiment. Conclusions: The expression of miR-21 and miR155 genes in immune cells may be used as markers of several autoimmune pathologies progression such as type 1 diabetes due to their effect on the balance of pro- and anti-inflammatory factors.