Abnormal Cannabidiol protects pancreatic beta cells in mouse models of experimental Type 1 diabetes

Background and PurposeThe atypical cannabinoid Abn-CBD was reported to improve the inflammatory status in preclinical models of several pathologies including autoimmune diseases. However, its potential for autoimmune diabetes, i.e. type 1 diabetes (T1D), is unknown. Experimental ApproachWe used two mouse models of T1D, streptozotocin (STZ)-injected and non-obese diabetic (NOD) mice. Eight-to-ten-week-old male C57Bl6/J mice were pre-treated with Abn-CBD (1mg/kg of body weight) or vehicle for 1 week, following STZ treatment, and euthanized 1 week later. Six-week-old female NOD mice were treated with Abn-CBD (0.1-1mg/kg) or vehicle for 12 weeks and then euthanized. Blood, pancreas, pancreatic lymph nodes and circulating T cells were collected and processed for analysis. Glycemia was also monitored. Key ResultsAbn-CBD decreased circulating proinflammatory cytokines, ameliorated islet inflammation and the autoimmune attack, showing a 2-fold decrease in CD8+ T cells infiltration and reduced Th1/Th2 ratio in pancreatic lymph nodes of STZ-injected mice. Mechanistically, Abn-CBD reduced intra-islet phospho-NF-{kappa}B and TXNIP. Concomitant reduction of islet cell apoptosis and intra-islet fibrosis were observed in Abn-CBD pre-treated mice compared to vehicle. In NOD mice, Abn-CBD reduced the expression of Ifng, Il21, Tnfa and Il10 while increased Il4 in circulating CD4+ T cells compared to vehicle, reducing the severity of insulitis and improving glucose tolerance. Conclusion and ImplicationsAltogether, we found that Abn-CBD reduces intra-islet inflammation and delays the progression of insulitis in mouse models of T1D, preserving healthy functional islets. Hence, Abn-CBD and related compounds emerge as new candidates to develop pharmacological strategies to treat early stages of T1D. WHAT IS ALREADY KNOWN- Phytocannabinoids such as cannabidiol (CBD) have anti-inflammatory and glucose-lowering properties - The CBD derivative Abn-CBD ameliorates inflammation in various diseases and modulates beta cell function WHAT THIS STUDY ADDS- Abn-CBD reduces systemic and pancreatic inflammation in mice models of type 1 diabetes - Abn-CBD prevents beta cell damage and loss during type 1 diabetes onset CLINICAL SIGNIFICANCE- Synthetic cannabinoids emerge as potential treatment for type 1 diabetes