Metformin therapy attenuates pro-inflammatory Microglia by inhibiting NF-κB in cuprizone demyelinating mouse model of multiple Sclerosis

Multiple sclerosis (MS) is a chronic disorder characterized by reactive gliosis, inflammation, and demyelination. Microglia plays a crucial role in the pathogenesis of MS and has the dynamic plasticity to polarize between pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes. Metformin, a glucose-lowering drug, attenuates inflammatory responses by activating adenosine monophosphate protein kinase (AMPK) which suppresses nuclear factor kappa B (NF-κB). In this study, we indirectly investigated whether metformin therapy would regulate microglia activity in the cuprizone (CPZ)-induced demyelination mouse model of MS via measuring the markers associated with pro- and anti-inflammatory microglia. Evaluation of myelin by luxol fast blue staining revealed that metformin treatment (CPZ + Met) diminished demyelination, in comparison to CPZ mice. In addition, metformin therapy significantly alleviated reactive microgliosis and astrogliosis in the corpus callosum, as measured by Iba-1 and GFAP staining. Moreover, metformin treatment significantly downregulated the expression of pro-inflammatory associated genes (iNOS, H2-Aa, and TNF-α) in the corpus callosum, whereas expression of anti-inflammatory markers (Arg1, Mrc1, and IL10) was not promoted, compared to CPZ mice. Furthermore, protein levels of iNOS (pro-inflammatory marker) were significantly decreased in the metformin group, while those of Trem2 (anti-inflammatory marker) were increased. In addition, metformin significantly increased AMPK activation in CPZ mice. Finally, metformin administration significantly reduced the activation level of NF-κB in CPZ mice. In summary, our data revealed that metformin attenuated pro-inflammatory microglia markers through suppressing NF-κB activity. The positive effects of metformin on microglia and remyelination suggest that it could be used as a promising candidate to lessen the incidence of inflammatory neurodegenerative diseases such as MS

Effects of Platelet-Rich Plasma & Platelet-Rich Fibrin with and without Stromal Cell-Derived Factor-1 on Repairing Full-Thickness Cartilage Defects in Knees of Rabbits

Background: The purpose of this study was to create biomaterial scaffolds like platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) containing stromal cell-derived factor-1 (SDF1) as a chemokine to induce hyaline cartilage regeneration of rabbit knee in a full thickness defect. Methods: We created a full thickness defect in the trochlear groove of thirty-six bilateral knees of eighteen mature male rabbits. The knees were randomly divided into six groups (group I: untreated control, group II: PRP, group III: PRF, group IV: Gelatin+SDF1, group V: PRP+SDF1, and group VI: PRF+SDF1). After four weeks, the tissue specimens were evaluated by macroscopic examination and histological grading, immunofluorescent staining for collagen type II, and analyzed for cartilage marker genes by real-time PCR. The data were compared using statistical methods (SPSS 20, Kruskal-Wallis test, Bonferroni post hoc test and P<0.05). Results: Macroscopic evaluations revealed that international cartilage repair society (ICRS) scores of the PRF+SDF1 group were higher than other groups. Microscopic analysis showed that the ICRS score of the PRP group was significantly lower than other groups. Immunofluorescent staining for collagen II demonstrated a remarkable distribution of type II collagen in the Gel+SDF1, PRP+SDF1 and PRF+SDF1 groups compared with other groups. Real-time PCR analysis revealed that mRNA expression of SOX9 and aggrecan were significantly greater in the PRF+SDF1, PRP+SDF1, Gel+SDF1 and PRF groups than the control group (P<0.05). Conclusion: Our results indicate that implantation of PRF scaffold containing SDF1 led to the greatest evaluation scores of full-thickness lesions in rabbits

The roles of Sertoli cells in fate determinations of spermatogonial stem cells

Background: Spermatogenesis is a complex and highly organized process of proliferation and differentiation of spermatogonial stem cells. Spermatogonial stem cells (SSCs) as a unique stem cell have the potential to self-renewal, differentiation and transmit genetic information to the next generation and play a vital role in maintaining fertility. Sertoli cells as the only somatic cells within the seminiferous epithelium play central roles in the formation of niche and balance between self-renewal and differentiation by secrete many growth factors. Given the importance and widespread use of SSCs, particularly in the treatment of infertility, the aim of this study was to create an optimal environment for the proliferation of SSCs. So we decided to study of undifferentiated (ID4) and differentiated (c-Kit) gene expression in SSCs followed by co-culture with Sertoli cells for a one-month. Methods: This experimental study was conducted from November 2013 to December 2014 in Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, on immature NMRI mouse (6-3 days old). Initially, Sertoli cells and SSCs were isolated from neonates mouse testes during the two-step enzymatic digestion characteristics Sertoli cells with vimentin marker and SSCs with promyelocytic leukemia zinc-finger (PLZF) marker were confirmed. Then SSCs were cultured in two groups: co-culture with Sertoli and without co-culture (control). Undifferentiated (ID4) and differentiation (c-Kit) gene expression were evaluated by Real-time PCR technique. Results: Spermatogonial stem cells purity was obtained 66.91% by flow cytometry. The relative expression levels of gene ID4 in co-culture group at the end of each week, compared to the control group showed a significant increase (P<0.05). While the expression of this gene significantly decreased in each group over time (P<0.05). The results of the comparison of the relative expression of c-Kit gene in co-culture group are indicated significant decrease than the control group at the end of each week (P<0.05). In addition, this gene expression was showed significant increase in each group individually over time (P<0.05) ID4 gene expression showed a significant (P<0.05) increase toward the control group, while in the expression of c-Kit was observed a significant (P<0.05) decrease compared with the control group at the end of each week. Conclusion: According to the results of this study, co-culture with Sertoli cells maintains SSCs in the prolifration stage for long-term, so can be used to optimize the culture medium at the clinic

Teratogenic effects of Origanum Vulgare extract in mice fetals

Background: A number of studies on reproduction have mentioned Origanum Vulgare extract’s ability to reduce mortality rates and improve fertility rates. However, other studies have suggested that it is possible to use Origanum Vulgare extract to induce abortion. The aim of this study was to investigate the effect of different doses of Origanum Vulgare on embryo survival and macroscopic abnormalities in mice.Methods: In this study, 24 mice Balb/c female weighting approximately 25-30 g were divided into 4 groups. Origanum Vulgare extract was prepared; different concentrations (2.5, 12.5, and 25 mg in 0.25 ml distilled water) were administered, by oral gavage, to three experimental groups of mice between day 6 (starting gastrulation) until day 15 of pregnancy (end of organogenesis). The control group consisted of six mice that received 0.25 ml of distilled water daily. On day 16 of study, pregnant mice were anesthetized by chloroform and fetuses were removed and stained with Alcian Blue, Alizarin Red s and microwave irradiation. Morphological and skeletal abnormalities were investigated by light and stereomicroscopes.Results: The results of this study showed that high doses of the Origanum Vulgare extract significantly decreased the mean number of embryos (100.5, P>0.05), mean number of live embryos (70.5, P>0.05) in each mouse and resulted in significant reduction in mean weight(11848 mg, P>0.05) and crown-rump length(11.90.23 mm, P>0.05) and the overall size of fetuses compared to control group, whereas there was no significant difference between the groups receiving low dose of Origanum Vulgare extract with control group. In addition, under the effect of the Origanum Vulgare extract the subcutaneous bleeding seemed (20.1, P>0.05) significantly more frequent compared to the control group. Conclusion: Origanum Vulgare extract did not have any positive effect on fetal development; and high dosages led to an increased incidence rate of abortion and fetal malformations in the fetuses of women who received it

Differentiation of Adipose-derived Stem Cells into Schwann Cell Phenotype in Comparison with Bone Marrow Stem Cells

Objective(s)Bone marrow is the traditional source of human multipotent mesenchymal stem cells (MSCs), but adipose tissue appears to be an alternative and more readily available source. In this study, rat adipose-derived stem cells (ADSCs) were induced to differentiate into Schwann-like cells and compared with rat bone marrow stem cells (BMSCs) for their Schwann-like cells differentiation potential. Materials and MethodsBMSCs and ADSCs were characterized for expression of MSCs-specific markers, osteogenic and adipogenic differentiation. They were induced to differentiate into Schwann-like cells and analyzed for expression of the Schwann specific markers. The immunocytochemical differentiation markers were S-100 and real time quantitative Real-time polymerase chain reaction (RT-PCR) markers were S100, P75 and glial fibrillary acidic protein (GFAP). 3-(4, 5-Dimethylthiazol- 2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and Annexin V-Fluorescein isothiocyanate (FITC)/ Propidium iodide (PI) double labeling method were employed to detect early stage cell apoptosis.ResultsBMSCs and ADSCs showed similarities in expression of the MSC-specific markers, osteogenic and adipogenic differentiation. Both quantitative RT-PCR and immunocytochemical analysis demonstrated that BMSCs and ADSCs had equal expression of the Schwann-specific markers following Schwann-like cells differentiation. However, gene expression of P75 was higher in BMSCs compared with ADSCs. MTT assay and flow cytometry found that of the total BMSCs and ADSCs in the culture medium, 20% to 30% of the cells died, but the remaining cell population remained strongly attached to the substrate and differentiated.ConclusionComparative analysis showed that Schwann-like cell differentiation potential of ADSCs was slightly decreased in comparison with BMSCs. Therefore, BMSCs are more favorable choice than ADSCs for tissue engineering

Progesterone Enhanced Remyelination in the Mouse Corpus Callosum After Cuprizone Induced Demyelination

Background: Progesterone as a sex steroid hormone is thought to affect and prevent demyelination, but its role in promoting myelin repair is far less investigated. In this study, remyelinating potential of progesterone in corpus callosum was evaluated on an experimental model of MS. Methods: In this experimental study, adult male C57BL/6 mice were fed with 0.2% (w/w) cuprizone in ground breeder chow ad libitum for 6 weeks. At day zero, after cuprizone removal, mice were divided randomly into two groups: (a) placebo group, which received saline pellet implant, (b) progesterone group, which received progesterone pellet implant. Some mice of the same age were fed with their normal diet to serve as the healthy control group. Two weeks after progesterone administration, Myelin content was assessed by Luxol-fast blue staining. The myelin basic protein (MBP) and proteolipid protein (PLP) expression were assessed using Western blot analysis and the changes in the number of oligodendrocytes and oligodendroglial progenitor cells were assessed by immunohistochemistry (IHC) and flow cytometry. Results: Luxol-fast blue staining revealed enhanced remyelination in the progesterone group when compared with the placebo group. Densitometry measurements of immunoblots demonstrated that MBP and PLP proteins contents were significantly increased in the progesterone group compared with the placebo group. Flow cytometry and IHC analysis showed increases in Olig2 and O4 cells in the progesterone group compared with the placebo group. Conclusion: Overall, our results indicate that progesterone treatment can stimulate myelin production and that it may provide a feasible and practical way for remyelination in diseases such as multiple sclerosis

Intentos de reforma en la universidad de Valladolid durante el reinado de Carlos IV

Actas de la I Reunión Científica de la Asociación Española de Historia Moderna, Madrid, 11 al 13 de diciembre de 1989Peer reviewe