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Salient evidence testifies the link between organophosphorus (OPs) exposure and the formation of free radical oxidants; and it is well accepted that free radicals are one of the basic concerns of senescence. To show the oxidative features of phosalone (PLN) as a key member of OPs, to induce senescence in rat embryonic fibroblast (REF) cells and to demonstrate the beneficial effects of the known antioxidant ellagic acid (EA) in diminishing the PLN-induced toxic effects, the levels of cell viability, oxidative stress markers, inflammatory cytokines, telomerase activity, and the expression of the genes related to senescence were investigated. Our results lend support to the hypothesis that PLN enhances the entire premature senescence parameters of REF cells. This accounts for the mechanistic approval of the role of OPs in induction of senescence in rat fibroblasts. Moreover, incorporation of EA diminished PLN toxicity mainly through suppression of p38 and p53 at gene and protein levels, and tempered the inflammation factors (TNF-α, IL-1β, IL-6 and NF-κB), which further affected cell division. Analysis of cell cycle showed that the percentage of G0/G1 arrest, in REF cells treated by EA was elevated as compared to control and PLN treated cells.

Nerve tissue engineering (NTE) is one of the most promising methods to restore central nerve systems in human health care. Three-dimensional (3D) distribution and growth of cells within the porous scaffold composed of nanofibers are of clinical significance for NTE. In this study, an attempt was made to develop and characterize the use of fibrin gel and human endometrial stem cells (hEnSCs)-derived neuron-like cells simultaneously to support cell behavior especially neuron outgrowth. The structural and mechanical characteristics of fibrin gel scaffold were examined with SEM and rheometer. Also, hEnSCs-derived neuron-like cells were cultured in fibrin gel and were subsequently analyzed with immunofluorescent staining against neuronal markers. In parallel, the survival and growth rates of the cells were determined by MTT assay and neurite extension. At the end, cell-matrix interactions were investigated with SEM and TEM micrographs. Mechanical properties of fabricated scaffold were studied and results indicated appropriate choice of material, SEM and TEM showed excellent integration of cells with nanofibers regarding the relation between cells and fibrin gel. Immunofluorescent staining of fibrin gel after 6 days of cell seeding and culture demonstrated well expanded and incorporated network of neurons. In addition, viability, proliferation, and neuronal growth of seeded cells were analyzed at days 1, 3, and 6. Comparing those results with 2D culture of seeded cells showed positive effect of 3D culture. Taken together, the results suggest that fibrin can provide a suitable, three-dimensional scaffold for neuronal survival and outgrowth for regeneration of the central nervous system.

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Type I diabetes mellitus is a metabolic disease caused by the impairment of pancreatic β-cells mainly mediated through oxidative stress and related apoptosis. Islets transplantation seems a promising treatment for these patients, but during islets transplant, various types of stresses related to the isolation and transplantation procedure compromise the function and viability of islets. We recently hypothesized that the combination of cerium oxide (CeO2) and yttrium oxide (Y2O3) nanoparticles with a potential free radical scavenger behavior should be useful to make isolated islets survive until transplanted. In the present study, oxidative stress-induced apoptosis in isolated rat pancreatic islets exposed to hydrogen peroxide (H2O2) and the protective effects of CeO2 and Y2O3 nanoparticles were investigated. Exposure of islets to H2O2 (50 µm, 2 h) increased intracellular oxidant formation such as reactive oxygen species and subsequently apoptosis and decreased viability, glucose-induced adenosine triphosphate (ATP) production and glucose-stimulated insulin secretion. Pretreatment with CeO2 and/or Y2O3 nanoparticles reduced the oxidant formation and apoptosis and increased viability, glucose-induced ATP production and glucose-stimulated insulin secretion. These results suggest that this combination may protect β-cell apoptosis by improving the oxidative stress-mediated apoptotic pathway.