It is well known that glucagon-like peptide 1 (GLP-1) has antidiabetic action. It has 2 distinct functions, an insulinotropic effect dependent on GLP-1 receptor (GLP-1R) and an insulinomimetic effect independent of GLP-1R. However, use of GLP-1 in vivo is limited by its short half-life. Therefore, our lab designed PGLP-1, a novel 2-function candidate peptide as a potential substitute. Using a streptozotocin-induced hyperglycemic mouse model, we demonstrated in vitro and in vivo that PGLP-1 had insulinotropic actions dependent on GLP-1R and insulinomimetic functions independent of GLP-1R. PGLP-1 treatment increased islet b-cell mass, plasma insulin, and C-peptide levels and Ki-67-immunoreactive b-cell numbers, verifying that PGLP-1 can work as a short GLP-1R agonist, similar to commercially available exendin-4. Additionally, PGLP-1 improved insulin sensitivity, inhibited gluconeogenesis by increasing expression of AMPK and receptor subfamily 0, group B, member 2 (SHP), and inhibited body weight loss by inhibiting b-oxidation, suggesting that PGLP-1 had insulinomimetic action. Taken together, these data indicated that PGLP-1, as a dual-function peptide, improved glycemic control and inhibited body weight loss, suggesting it could be useful for type 1 diabetes mellitus patients as an adjunctive therapy to
The main challenge of anticancer drugs is poor tumor targeting. Now cellular carriers are widely investigated to deliver anticancer agents. As an ideal cellular candidate, human umbilical cord derived mesenchymal stem cells (hUC-MSCs) possess inherent tropism potential to tumor. Here, we constructed hUC-MSCs carrying transferrin-inspired-nanoparticles that contain doxorubicin(hUC-MSCs-Tf-inspired-NPs) to achieve enhanced anti-tumor efficacy and made an evaluation. Results represented that hUC-MSCs-Tf-inspired-NPs not only exhibit the controlled-release property of Tf-inspired-NPs, but also integrate tumor tropism and penetrative abilities of MSCs. The tumor volume of nude mice bearing breast cancer MCF-7 treated with hUC-MSCs-Tf-inspired-NPs, was remarkably reduced compared to those treated with free drug or Tf-inspired-NPs. Thus, Tf-inspired-NPs loaded hUC-MSCs have a potential to deliver anticancer drugs.
Glucagon-like peptide 1 (GLP-1) has recently received significant attention as an efficacious way to treat diabetes mellitus. However, the short half-life of the peptide limits its clinical application in diabetes. In our previous study, a novel GLP-1 analog (PGLP-1) with a longer half-life was synthesized and evaluated. Herein, we prepared the PGLP-1-loaded poly(d,l-lactide- co-glycolide) microspheres to achieve long-term effects on blood glucose control. The incorporation of zinc ion into the formulation can effectively decrease the initial burst release, and a uniform drug distribution was obtained, in contrast to native PGLP-1 encapsulated microspheres. We demonstrated that the solubility of the drug encapsulated in microspheres played an important role in in vitro release behavior and drug distribution inside the microspheres. The Zn-PGLP-1 microspheres had a prominent acute glucose reduction effect in the healthy mice. A hypoglycemic effect was observed in the streptozotocin (STZ) induced diabetic mice through a 6-week treatment of Zn-PGLP-1-loaded microspheres. Meanwhile, the administration of Zn-PGLP-1 microspheres led to the β-cell protection and stimulation of insulin secretion. The novel GLP-1 analog-loaded sustained microspheres may greatly improve patient compliance along with a desirable safety feature.
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