Cell-based therapies suggest novel treatments to overcome the complication of the current therapeutic approaches in diabetes mellitus type 1. Replacement of the destroyed pancreatic islet β-cells by appropriate alternative cells needs an efficient approach to differentiate the cells into viable and functional insulin producing cells. Small non-coding RNA molecules, microRNAs (miRNA), have critical roles in post-transcriptional regulation of gene expression. Therefore, they can direct the cells toward β-cell like cells and control islet β-cell development. Previous reports showed the manipulation of the miRNA expression on islet β-cell differentiation and regeneration. Likewise, the regulation of epithelial to mesenchymal transi-tion by the miR-30 family and the miR-200 family may be a useful approach to conduct islet β-cell development. Investigation of stem cells differentiation showed that the dynamic expression patterns of miR-375 and miR-7 are similar to developing human fetal pancreas while dynamic expression of miR-146a and miR-34a occurred during the differentiation. Moreover, miR-342 and its both targets, FOXA2 and MAFB, are found in β-cell differentiation and maturation. Because miRNAs can target specific transcription factors during islet β-cell development and differentiation, they could be offerred as alternative regenerative treatment for diabetes mellitus. Considering that the application of these non-coding RNAs remains limited in the literature, in this review article, we present an overview of the roles of miRNAs in the islet β-cell development, focusing on the application of different miRNAs in the experimental protocols.

Islets transplantation, as a treatment of type 1 diabetes, faces challenges, including the loss of islets in the process of isolation and pre-transplantation due to cellular stresses-induced apoptosis. Accordingly, the optimization of culture plays a decisive role in the transplantation success. In this study, we evaluated the effect of nobiletin on the cultured human islets. Isolated human islets were treated by different concentrations of nobiletin and cultured for 24 and 72 hours. Then, the islets viability, apoptosis, insulin and C-peptide secretion, and apoptosis markers were evaluated. Also, the production of reactive oxygen species (ROS), hypoxia inducible factor 1 alpha (HIF-1α), and its target genes in the islets were examined. Our findings showed that the islets were encountered with hypoxia and oxidative stress after isolation and during culture. These insults induced apoptosis and reduced viability during culture period. Moreover, the secretion of insulin and C-peptide decreased. Nobiletin treatments significantly improved the islets survival through reduction of HIF-1α and ROS production and suppression of apoptosis, along with increased islets function. Islet protective effect of nobiletin might be related to its anti-oxidant, anti-apoptotic and insulinotropic properties. Hence, in order to achieve viable and functional islets for clinical transplantation, the application of nobiletin during pre-transplantation period is useful.

We systematically collected eligible data to measure the effect of CYP3A5*1 expression on personalized tacrolimus therapy. Six databases were searched for studies on adult liver transplant recipients and donors of liver graft which reported tacrolimus dose requirement, trough blood concentration, and/or concentration/dose (C/D) ratio in expressers and nonexpressers of CYP3A5*1. Eligible data were pooled by meta-analysis. Sixteen observational studies (1309 recipients, 1044 donors of liver graft) were included in the analyses. Tacrolimus C/D ratio was lower, and the dose was higher in recipient expressers of CYP3A5*1 and/or carriers of expresser liver graft at 1-4 weeks and 2-4, 6, and 12 months post-transplantation. Tacrolimus blood concentration was lower at the first two weeks. Pair expressers were affected by about twofold, and the effect was different between ethnic groups. CYP3A5*1 expression in recipients increased tacrolimus required dose by 0.023 at first, 0.022 at third, and 0.012 mg/kg/day at sixth month. Its expression in graft tissue increased tacrolimus required dose by 0.024 at first, 0.035 at third, and 0.032 mg/kg/day at sixth month. Considering CYP3A5*1 polymorphism can be helpful in individualization of tacrolimus efficient dose prior to administration, and it can remove initial high-risk lag time (over/underdose period before reaching target blood level) at first few days post-transplantation.

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