One of the causes of diabetes in infants is the defect of the insulin gene (INS). Gene mutations can lead to proinsulin misfolding, an increased endoplasmic reticulum (ER) stress and possible beta-cell apoptosis. In humans, the mechanisms underlying beta-cell failure remain unclear. We generated induced pluripotent stem cells (iPSCs) from a patient diagnosed with neonatal diabetes mellitus carrying the INS mutation in the 2nd intron (c.188-31G>A) and engineered isogenic CRISPR/Cas9 mutation-corrected cell lines. Differentiation into beta-like cells demonstrated that mutation led to the emergence of an ectopic splice site within the INS and appearance of the abnormal RNA transcript. Isogenic iPSC lines differentiated into beta-like cells showed a clear difference in formation of organoids at pancreatic progenitor stage of differentiation. Moreover, MIN6 insulinoma cell line expressing mutated cDNA demonstrated significant decrease in proliferation capacity and activation of ER stress and unfolded protein response (UPR)-associated genes. These findings shed light on the mechanism underlying the pathogenesis of monogenic diabetes.

The aim of this study was to synthesize, characterize, and investigate the biomedical effects of nanoscale cerium phosphate obtained via different synthesis techniques, as well as to evaluate the influence of various CePO₄ concentrations on cells involved in skin structure regeneration (human mesenchymal stem cells, keratinocytes, and fibroblasts) and establish their antioxidant properties. Methods and Results: Cerium(III) orthophosphate was obtained by precipitation with ammonium dihydrogen phosphate from a nitrate solution. By changing the initial concentrations of the solutions and the drying and annealing temperatures, the best conditions for obtaining nanosized phosphate powders were established. The structure of rhabdophane was obtained by X-ray diffraction analysis, and the particle sizes were measured by transmission electron microscopy. The particle sizes ranged from 2 to 10 nm in the transverse direction and 20 to 50 nm in the longitudinal direction. Studies on cell lines have shown a high level of safety, as well as the regenerative potential of CePO₄ nanoparticles, which have a stimulating effect on the proliferation of MSCs at concentrations of 10⁻² to 10⁻³ M for 48 h after application and stimulate the metabolism of human keratinocytes and fibroblasts at a wide range of concentrations (10⁻³ to 10⁻⁵ M). A dose-dependent antioxidant effect of small CePO₄ nanoparticles at a concentration of 10⁻² to 10⁻⁵ has been established, which is stronger than ascorbic acid. Conclusions: A method for obtaining cerium phosphate nanoparticles with beneficial biomedical effects was developed. The non-cytotoxicity and regenerative potential of CePO₄ were established at a wide range of concentrations on different cell lines that are involved in the healing of skin wounds, as were their antioxidant properties.