Prebiotics improve osteoporosis indicators in a preclinical model: systematic review with meta-analysis.

Context: Studies using experimental models have demonstrated that prebiotics are involved in antiosteoporotic mechanisms.

Objective: This study was conducted to determine the impact of supplementation with prebiotics in the basal diet of ovariectomized rats with induced osteoporosis as a preclinical model.

Methods: A comprehensive systematic search was carried out in the electronic databases PubMed, Science Direct, Web of Science, Scielo, and Google through March 2022 for studies that investigated the impact of prebiotics on bone mineral density (BMD), bone mineral content (BMC), and bone biomechanics.

Molecular pathways involved in the antineoplastic effects of calcitriol on insulinoma cells.

We have previously reported that in tumorigenic pancreatic beta-cells, calcitriol exerts a potent antitumorigenic effect by inducing apoptosis, cell growth inhibition, and reduction of solid beta-cell tumors. Here we have studied the molecular pathways involved in the antineoplastic activity of calcitriol on mouse insulinoma beta TC(3) cells, mouse insulinoma beta TC expressing or not expressing the oncogene p53, and beta TC-tet cells overexpressing or not the antiapoptotic gene Bcl2. Our results indicate that calcitriol-induced apoptosis was dependent on the function of p53 and was associated with a biphasic increase in protein levels of transcription factor nuclear factor-kappa B.

Effects of carboxypeptidase E overexpression on insulin mRNA levels, regulated insulin secretion, and proinsulin processing of pituitary GH3 cells transfected with a furin-cleavable human proinsulin cDNA.

We recently developed two rat pituitary GH3 cell clones engineered to secrete human insulin (InsGH3). InsGH3 cells convert proinsulin into mature insulin, which is partially stored into a readily releasable pool of secretory granules. The efficiency of these processes, however, is relatively low in these cells, either in vitro or in vivo.

Secretory defects induced by immunosuppressive agents on human pancreatic beta-cells.

Despite the considerable interest for islet and pancreas transplantation, remarkably little is known about the direct effects of immunosuppressive drugs on human beta-cell function. We measured different insulin secretory parameters and insulin gene expression of human islets cultured for 5 days in the presence of mycophenolate mofetil (MMF), cyclosporin A (CsA), tacrolimus (FK506) or a mixture of 3 cytokines. Basal insulin release after exposure to cytokines and FK506 was significantly higher than in control islets.

Antitumorigenic and antiinsulinogenic effects of calcitriol on insulinoma cells and solid beta-cell tumors.

Malignant insulinoma is a rare form of cancer with a poor prognosis because of metastatic dissemination and untreatable hypoglycemia. Effective chemotherapy of patients who are not cured by surgery is needed. Calcitriol has known anticancer properties on different neoplastic cell lines, but no data are available regarding its activity on tumorigenic pancreatic beta-cells.