Focal adhesion kinase-mediated signaling controls the onset of pancreatic cell differentiation.

Signals from the endothelium play a pivotal role in pancreatic lineage commitment. As such, the fate of the epithelial cells relies heavily on the spatiotemporal recruitment of the endothelial cells to the embryonic pancreas. Although it is known that VEGFA secreted by the epithelium recruits the endothelial cells to the specific domains within the developing pancreas, the mechanism that controls the timing of such recruitment is poorly understood. Here, we have assessed the role of focal adhesion kinase (FAK) in mouse pancreatic development based on our observation that the presence of the enzymatically active form of FAK (pFAK) in the epithelial cells is inversely correlated with vessel recruitment. To study the role of FAK in the pancreas, we conditionally deleted the gene encoding focal adhesion kinase in the developing mouse pancreas. We found that homozygous deletion of Fak (Ptk2) during embryogenesis resulted in ectopic epithelial expression of VEGFA, abnormal endothelial recruitment and a delay in endocrine and acinar cell differentiation. The heterozygous mutants were born with no pancreatic phenotype but displayed gradual acinar atrophy due to cell polarity defects in exocrine cells. Together, our findings imply a role for FAK in controlling the timing of pancreatic lineage commitment and/or differentiation in the embryonic pancreas by preventing endothelial recruitment to the embryonic pancreatic epithelium.

Nanomaterials for diabetes: diagnosis, detection and delivery.

537 million people worldwide suffer from diabetes mellitus, a problem of glucose management that is related to a number of major health risks, including cardiovascular diseases. There is a need for new, efficient formulations of diabetic medications to address this condition and its related consequences because existing treatments have a number of drawbacks and limits. This encouraged the development of treatment plans to get around some of these restrictions, like low therapeutic drug bioavailability or patients' disobedience to existing therapies. Approaches based on nanotechnology have a lot of promise to enhance the treatment of diabetic patients. In order to manage blood glucose, this review article highlights recent developments and explores the potential applications of different materials (polymeric, ceramic, dendrimers, etc.) as nanocarriers for the delivery of insulin and other antidiabetic medications. Using an injectable and acid-degradable polymeric network produced by the electrostatic interaction of oppositely charged dextran nanoparticles loaded with insulin and glucose-specific enzymes, we reviewed a glucose-mediated release approach for the self-regulated delivery of insulin, in which, after a degradable nano-network was subcutaneously injected into type 1 diabetic mice,in vivoexperiments confirmed that these formulations improved glucose management. In addition, a discussion of silica-based nanocarriers, their potential for treating diabetes and controlling blood glucose levels, and an explanation of the role of dendrimers in diabetes treatment have been covered. This is done by utilizing the properties of silica nanoparticles, such as their tuneable particle and pore size, surface chemistry, and biocompatibility. The article summarized the significance of nanomaterials and their uses in the diagnosis and treatment of diabetes overall, illuminating the field's potential and outlining its prospects for the future.

Acinar to ß-like cell conversion through inhibition of focal adhesion kinase.

Insufficient functional ß-cell mass causes diabetes; however, an effective cell replacement therapy for curing diabetes is currently not available. Reprogramming of acinar cells toward functional insulin-producing cells would offer an abundant and autologous source of insulin-producing cells. Our lineage tracing studies along with transcriptomic characterization demonstrate that treatment of adult mice with a small molecule that specifically inhibits kinase activity of focal adhesion kinase results in trans-differentiation of a subset of peri-islet acinar cells into insulin producing ß-like cells. The acinar-derived insulin-producing cells infiltrate the pre-existing endocrine islets, partially restore ß-cell mass, and significantly improve glucose homeostasis in diabetic mice. These findings provide evidence that inhibition of the kinase activity of focal adhesion kinase can convert acinar cells into insulin-producing cells and could offer a promising strategy for treating diabetes.

Antidiabetic activity enhancement in streptozotocin + nicotinamide-induced diabetic rats through combinational polymeric nanoformulation.

Background: The bioactive compounds glycyrrhizin (GL) and thymoquinone (TQ) have been reported for antidiabetic activity in pure and nanoformulation (NF) form. However, the antidiabetic effect of a combined nanoformulation of these two has not been reported in the literature. Here, a combinational nanomedicine approach was investigated to enhance the antidiabetic effects of the two bioactive compounds of GL and TQ (GT), in type 2 diabetic rats in reference to metformin. Methods: Two separately prepared NFs of GL (using polymeric nanoparticles) and TQ (using polymeric nanocapsules) were mixed to obtain a therapeutic cargo of nanomedicine and then characterized with respect to particle size, stability, morphology, chemical interaction, and in vivo behavior. Additionally, NFs were evaluated for their cytotoxic effect on Vero cell lines compared to the pure form. This nanomedicine was administered orally, both independently and in combination (pure form or NF) for 21 successive days to type 2 diabetic rats and the effect assessed in term of body weight, fasting blood-glucose level, and various biochemical parameters (such as lipid-profile parameters and HbA1c). Results: When these nanomedicines were applied in combined rather than individual forms, significant decreases in blood glucose and HbA1c and significant improvements in body weight and lipid profile were observed, despite them containing lower amounts than the pure forms. The treatment of diabetic rats with GL and TQ, when administered independently in either pure or NF forms, did not lead to favorable trends in any studied parameters. Conclusion: The administration of combined GT NFs exhibited significant improvement in studied parameters. Improvements in antidiabetic activity could have been due to a synergistic effect of combined NFs, leading to enhanced absorption of NFs and lesser cytotoxic effects compared to pure bioactive compounds. Therefore, GT NFs demonstrated potential as a new medicinal agent for the management of diabetes.

Improvement of antihyperglycemic activity of nano-thymoquinone in rat model of type-2 diabetes.

Thymoquinone is a bioactive constituent of Nigella sativa seeds. It has been reported to possess antihyperglycemic effect in rats. However, the effect of nanoformulation (NF) of thymoquinone has not been reported in literature. So, the present study was designed with the aim to investigate the effect of nanoformulation of thymoquinone in streptozotocin-nicotinamide induced type-2 diabetic rats and compare its effect with pure bioactive compound as well as metformin, a standard antidiabetic drug. It is the first study reporting the use of thymoquinone NF against diabetes. Polymeric nanocapsules (NCs) of thymoquinone and metformin were prepared by nanoprecipitation method using gum rosin, a biocompatible polymer. Box-Behnken statistical analysis tool was used for the optimization of polymer and other excipients. The NCs were then characterized with respect to particle size, stability, morphology, and in vitro drug dissolution profiles. Furthermore, thymoquinone (20, 40 & 80 mg/kg), metformin (150 mg/kg) and their nanoformulations (20, 40 & 80 mg/kg for thymoquinone and 80 mg/kg for metformin) per se were administered for 21 successive days to type-2 diabetic rats. Body weight and blood glucose levels were measured every week for 3 weeks. Serum lipid profile and glycosylated hemoglobin were estimated on 22nd day. The nanocapsules were stable, spherical in shape and size was less than 100 nm. Thymoquinone-and metformin-loaded NCs showed sustained release profile as compared to their pure forms. Oral administration of thymoquinone, metformin and their nanoformulations significantly decreased blood glucose level and glycated haemoglobin; and improved the lipid profile of diabetic rats as compared to diabetic control rats. Thymoquinone-loaded NCs (containing 10, 20 and 40 mg of thymoquinone) produced dose-dependent antihyperglycemic effect and this effect was comparable to thymoquinone and metformin. In conclusion, thymoquinone nanocapsules (actually containing half of the doses of thymoquinone) produced better antihyperglycemic effect in type-2 diabetic rats as compared to thymoquinone alone.

Evaluation of anti-diabetic activity of glycyrrhizin-loaded nanoparticles in nicotinamide-streptozotocin-induced diabetic rats.

Glycyrrhizin is an active constituent of the roots and rhizomes of Glycyrrhiza glabra and has anti-hyperglycemic effects. In this study, nanoparticles (NPs) loaded with glycyrrhizin or metformin were evaluated in vivo for their anti-hyperglycemic potency towards type-II diabetes in rats. The NPs were produced via the ionotropic gelation method using the biocompatible polymers chitosan and gum arabic. The polymer concentration was optimized using the 32 factorial method to acquire both minimum particle size and maximum encapsulation efficiency. The NPs were then characterized with respect to particle size, encapsulation efficiency, stability, chemical interactions, and in vitro drug dissolution profiles using spectroscopic and microscopic analysis. Furthermore, glycyrrhizin and metformin and their nanoformulations were administered for 21 successive days to diabetic rats. Glycyrrhizin-loaded NPs had significant anti-diabetic effects even though they contained approximately one quarter of the dosage relative to the pure form.