Genetic Changes during Differentiation of Spermatogonial Stem Cells into Oligoprogenitor Cells

BACKGROUND AND OBJECTIVE: The culture of spermatogonial cells and the production of embryonic stem cells (ES-like cells), suggest these cells as a sufficient new source for cell therapy and for the treatment of diseases, including neurodegenerative diseases. The aim of this study is to evaluate the pattern of genetic changes during differentiation of spermatogonial cells into oligodendrocyte precursor cells. METHODS: In this experimental study, spermatogonial cells were isolated from the testicles of 2 – 6 days old newborn mice (6 – 10 mice each time) through two stages of enzymatic digestion. The cells were divided into three groups of quasi-embryonic stem cells, neuro-progenitive and oligodendrocyte precursor. Specific markers stra8, mvh, piwil2, C-myc, Nanog, NF68, Nestin, Olig2, and NG2 were evaluated using Real Time-PCR and immunocytochemistry method at each differentiation step. FINDINGS: Molecular evaluations showed that increase in Nestin gene expression in neuronal precursor cells was 1.3 times more than quasi-embryonic stem cells. In the molecular evaluations at the end of the second stage of differentiation, it was determined that culture at the end of the induction steps resulted in a significant increase in the expression of the genes of Olig2 and NG2 and decrease in the expression of Nestin gene (p<0.05). Molecular evaluations showed that this increase in oligodendrocyte-like cells was respectively 1.4 and 1.6 times more than neuronal precursor cells. CONCLUSION: In this study, it was demonstrated that quasi-embryonic stem cells have the potential to express the NF68 and Nestin neuron markers. The quasi-embryonic stem cells of NG2 and Olig2 genes were expressed in the cells after the induction stage

Melatonin ameliorates testes against forced treadmill exercise training on spermatogenesis in rats

INTRODUCTION: It is well documented that some forced exercises can have bad effects on the genital system. Melatonin is a potent antioxidant that is effective in reducing the physical stress

In vitro and in vivo evaluations of three-dimensional hydroxyapatite/silk fibroin nanocomposite scaffolds

In this study, three-dimensional hydroxyapatite/silk fibroin (HAp/SF) nanocomposite scaffolds were successfully prepared through layer solvent casting combined with the freeze-drying technique for tissue engineering applications. Various SF aqueous concentrations, ranging from 2.5 to 10, were used to control the physicochemical properties of the prepared scaffolds. Biologic responses of the rat bone marrow stromal cells (rBMSCs) to the HAp/SF scaffolds were examined by culturing the cells within them. In addition, biodegradation and biocompatibility of the scaffolds were evaluated in vitro and in vivo, respectively. Among the prepared scaffolds, HAp/SF-2.5 was the most brittle sample and showed porous structure with lowest mechanical properties. The average pore diameters were 350 ± 67 and 112 ± 89 μm and decreased with the increase in the SF concentration from 5 to 10, respectively. The pores formed in the scaffolds, made up of the 5 SF, were more uniform and regular than those of the scaffolds made up of 5 and 10 SF. The HAp/SF scaffolds did not change the rBMSCs viability and were not cytotoxic compared with the control sample. The scanning electron microscopy micrographs showed that the cells migrated into the pores and well attached to the scaffolds and their cytoplasm was extended in all directions, indicating a promising cell adhesion, high biocompatibility, and no cytotoxicity of the HAp/SF-5 nanocomposite scaffolds. Subcutaneous implantation of the HAp/SF-5 scaffolds in rat models suggested an excellent biocompatibility. All data obtained from this study suggest the potential use of the HAp/SF-5 for hard tissue engineering. © 2014 International Union of Biochemistry and Molecular Biology, Inc

Chitosan-intercalated montmorillonite/Poly (Vinyl alcohol) nanofibers as a platform to guide neuron-like differentiation of human dental pulp stem cells

In this study, we present a novel chitosan-intercalated montmorillonite/poly(vinyl alcohol) (OMMT/PVA) nanofibrous mesh as a microenvironment for guiding differentiation of human dental pulp stem cells (hDPSCs) toward neuronlike cells. The OMMT was prepared through ion exchange reaction between the montmorillonite (MMT) and chitosan. The PVA solutions containing various concentrations of OMMT were electrospun to form 3D OMMT-PVA nanofibrous meshes. The biomechanical and biological characteristics of the nanofibrous meshes were evaluated by ATR-FTIR, XRD, SEM, MTT, and LDH specific activity, contact angle, and DAPI staining. They were carried out for mechanical properties, overall viability, and toxicity of the cells. The hDPSCs were seeded on the prepared scaffolds and induced with neuronal specific differentiation media at two differentiation stages (2 days at preinduction stage and 6 days at induction stage). The neural differentiation of the cells cultured on the meshes was evaluated by determining the expression of Oct-4, Nestin, NF-M, NF-H, MAP2, and βIII-tubulin in the cells after preinduction, at induction stages by real-time PCR (RT-PCR) and immunostaining. All the synthesized nanofibers exhibited a homogeneous morphology with a favorable mechanical behavior. The population of the cells differentiated into neuronlike cells in all the experimental groups was significantly higher than that in control group. The expression level of the neuronal specific markers in the cells cultured on 5% OMMT/PVA meshes was significantly higher than the other groups. This study demonstrates the feasibility of the OMMT/PVA artificial nerve graft cultured with hDPSCs for regeneration of damaged neural tissues. These fabricated matrices may have a potential in neural tissue engineering applications.We express our sincere thanks to Dr. Ali Samadikuchaksaraei for providing helpful comments on this work. The project was funded by Mazandaran University of Medical Sciences (Grant No. 2580). S.C.K. presently holds ERA Chair Full Professor position at the 3B’s Research Group, University of Minho, Portugal, supported by the European Union Framework Programme for Research and Innovation Horizon 2020 under grant agreement n° 668983 − FoReCaST.info:eu-repo/semantics/publishedVersio