Cell Journal (Yakhteh)
Year:2017 | Volume:18 | Issue:4|Papers Count:14

Satellite cells (SCs) are the most abundant skeletal muscle stem cells. They are widely recognized for their contributions to maintenance of muscle mass, regeneration and hypertrophy during the human life span. These cells are good candidates for cell therapy due to their self-renewal capabilities and presence in an undifferentiated form. Presently, a significant gap exists between our knowledge of SCs behavior and their application as a means for human skeletal muscle tissue repair and regeneration. Both physiological and pathological stimuli potentially affect SCs activation, proliferation, and terminal differentiation - the former category being the focus of this article.Activation of SCs occurs following exercise, post-training micro-injuries, and electrical stimulation. Exercise, as a potent and natural stimulus, is at the center of numerous studies on SC activation and relevant fields. According to research, different exercise modalities end with various effects. This review article attempts to picture the state of the art of the SCs life span and their engagement in muscle regeneration and hypertrophy in exercise.

Approximately 5-10% of all thyroid cancers are medullary thyroid carcinomas (MTC). MTC is mainly sporadic in nature, but 20-30% of cases are hereditary. Genetic testing for hereditary MTC is very important for the patient and his family, but the patients must be receiving appropriate genetic counseling. About 98% of patients with hereditary MTC have germline mutations in exons 10, 11, 13, 14, 15, 16 and intron 16 of the RE arrangement during transfection (RET) proto-oncogene, but the etiology of the more frequent sporadic form of MTC (sMTC) is not well understood. Recently, it has been reported that apparently sporadic MTC may involve point mutations in BRAF and RAS genes, with an overall prevalence of almost 10%. Also alteration and abnormal expression of mi RNA has been described in MTC. In this review, we attempted to mention some mutations and molecular changes in sporadic and hereditary MTC pathogenesis.

Objective: Today, esophageal cancer (EC) has become one of the most common cancer types in China. Therefore, new drug and therapeutic strategies are urgently needed to improve postoperative survival rate of patients with EC. As a food additive, several lines of evidence have shown that citric acid can be served as glycolysis suppressor to inhibit growth of some tumor cells. However, little is known about the effect of this organic acid on the growth of human esophageal carcinoma cell line, EC109.Materials and Methods: In this experimental study, cell proliferation rate was determined using MTT assay. Apoptotic morphological changes were evaluated by fluorescent microscopy using Hoechst 33258 staining. Cell apoptosis rate and mitochondrial membrane potential (MMP) were detected using flow-cytometry. Effect of citric acid on cellular membrane permeability was assessed by measuring lactate dehydrogenase (LDH) activity, using LDH assay kit.Results: Compared to the control group, there was a marked decrease in cells proliferation when the cells were treated with higher citric acid concentrations (800, 1600 mg/ml). Typical apoptotic morphology of EC109 cells was observed upon treatment with citric acid, such as chromatin condensation and appearance of apoptotic body. Cell apoptotic indexes were significantly increased (P<0.01) after treatment with citric acid at the concentration of 400-1600 mg/ml. Extracellular LDH activity and loss of MMP in all of the treated groups were significantly higher than control (P<0.05), in a dose-dependent manner. Conclusion: These results suggest that citric acid prevents EC109 cell growth by inhibiting cell proliferation and inducing apoptosis, which perhaps offers some theoretical guidance for its application in EC treatment.

Objective: Phthalates, which are commonly used to render plastics into soft and flexible materials, have also been determined as developmental and reproductive toxicants in human and animals. The purpose of this study was to evaluate the effect of mono-(2-ethylhexyl) phthalate (MEHP) and di-(2-ethylhexyl) phthalate (DEHP) oral administrations on maturation of mouse oocytes, apoptosis and gene transcription levels. Materials and Methods: In this experimental study, immature oocytes recovered from Naval Medical Research Institute (NMRI) mouse strain (6-8 weeks), were divided into seven different experimental and control groups. Control group oocytes were retrieved from mice that received only normal saline. The experimental groups I, II or III oocytes were retrieved from mice treated with 50, 100 or 200 ml DEHP (2.56 mM) solution, respectively. The experimental groups IV, V or VI oocytes were retrieved from mouse exposed to 50, 100 or 200 ml MEHP (2.56 mM) solution, respectively. Fertilization and embryonic development were carried out in OMM and T6 medium. Apoptosis was assessed by annexin V-FITC/Dead Cell Apoptosis Kit, with PI staining. In addition, the mRNA levels of Pou5f1, Ccna1 and Asah1 were examined in oocytes. Finally, mouse embryo at early blastocyst stage was stained with acridine-orange (AO) and ethidium-bromide (EB), in order to access their viability.Results: The proportion of oocytes that progressed up to metaphase II (MII) and 2-cells embryo formation stage was significantly decreased by exposure to MEHP or DEHP, in a dose-dependent manner. Annexin V and PI positive oocytes showed greater quantity in the treated mice than control. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) revealed that expression levels of Pou5f1, Asah1 and Ccna1 were significantly lower in the treated mouse oocytes than control. The total cell count for blastocyst developed from the treated mouse oocytes was lower than the controls.Conclusion: These results indicate that oral administration of MEHP and DEHP could negatively affect mouse oocyte meiotic maturation and development in vivo, suggesting that phthalates could be risk factors for mammalians’ reproductive health. Additionally, phthalate-induced changes in Pou5f1, Asah1 and Ccna1 transcription level could explain in part, the reduced developmental ability of mouse-treated oocytes.

Objective: Despite the huge efforts, chronic kidney disease (CKD) remains as an unsolved problem in medicine. Many studies have shown a central role for transforming growth factor beta-1 (TGFb-1) and its downstream signaling cascades in the pathogenesis of CKD. In this study, we have reanalyzed a microarray dataset to recognize critical signaling pathways controlled by TGFb-1.Materials and Methods: This study is a bioinformatics reanalysis for a microarray data. The GSE23338 dataset was downloaded from the gene expression omnibus (GEO) database which assesses the mRNA expression profile of TGFb-1 treated human kidney cells after 24 and 48 hours incubation. The protein interaction networks for differentially expressed (DE) genes in both time points were constructed and enriched. In addition, by network topology analysis, genes with high centrality were identified and then pathway enrichment analysis was performed with either the total network genes or with the central nodes.Results: We found 110 and 170 genes differentially expressed in the time points 24 and 48 hours, respectively. As the genes in each time point had few interactions, the networks were enriched by adding previously known genes interacting with the differentially expressed ones. In terms of degree, betweenness, and closeness centrality parameters 62 and 60 nodes were considered to be central in the enriched networks of 24 hours and 48 hours treatment, respectively. Pathway enrichment analysis with the central nodes was more informative than those with all network nodes or even initial DE genes, revealing key signaling pathways.Conclusion: We introduced a method for the analysis of microarray data that integrates the expression pattern of genes with their topological properties in protein interaction networks. This holistic novel approach allows extracting knowledge from raw bulk omics data.

Objective: CRISPR/Cas9 technology provides a powerful tool for targeted modification of genomes. In this system, a donor DNA harboring two flanking homology arms is mostly used for targeted insertion of long exogenous DNA. Here, we introduced an alternative design for the donor DNA by incorporation of a single short homology arm into a circular plasmid. Materials and Methods: In this experimental study, single homology arm donor was applied along with a single guide RNA (sgRNA) specific to the homology region, and either Cas9 or its mutant nickase variant (Cas9n). Using Pdx1 gene as the target locus the functionality of this system was evaluated in MIN6 cell line and murine embryonic stem cells (ESCs).Results: Both wild type Cas9 and Cas9n could conduct the knock-in process with this system. We successfully applied this strategy with Cas9n for generation of Pdx1GFP knock-in mouse ESC lines. Altogether, our results demonstrated that a combination of a single homology arm donor, a single guide RNA and Cas9n is capable of precisely incorporating DNA fragments of multiple kilo base pairs into the targeted genomic locus.Conclusion: While taking advantage of low off-target mutagenesis of the Cas9n, our new design strategy may facilitate the targeting process. Consequently, this strategy can be applied in knock-in or insertional inactivation studies.

Objective: Autism is a neurodevelopmental disorder characterized by difficulty in verbal and non-verbal communication, impaired social interaction, and restricted and repetitive behavior. It has been recently introduced as a multigenic disorder with significant epigenetic effects on its pathology. Recently, epigenetic silencing of retinoic acid receptorrelated orphan receptor alpha (RORα) gene (which has an essential role in neural tissue development) was shown to have occurred in autistic children due to methylation of its promoter region. This may thus explain a significant part of the molecular pathogenesis of autism. Therefore, we aimed to confirm this finding by implementing a case-control (experimental) study in the population of Isfahan. Materials and Methods: The methylation status of a 136 bp sequence of a GpG island (encompassing 13 CpG sites) in the RORA promoter region (positions -200 to -64) as an experimental study was examined in the lymphocyte cells of 30 autistic children after sodium bisulfite treatment using the melting curve analysis-methylation (MCA-Meth) assay compared with normal children. Also, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis was used to estimate the level of mRNA transcripts and to evaluate MCA-Meth analysis results.Results: This study revealed no methylation in the examined promoter regions in both autistic and normal children, with the melting curve of all studied samples being comparable to that of the non-methylated control. The results of MCA-Meth analysis were also consistent with qRT-PCR results. We therefore observed no significant difference in the levels of RORα transcripts in the blood lymphocytes between autistic and healthy children. Conclusion: The methylation of the RORA promoter region may not be considered as a common epigenetic risk factor for autism in all populations. Hence, the molecular pathogenesis of autism remains unclear in the population investigated.

Objective: Low-frequency stimulation (LFS) exerts suppressive effects in kindled animals. It is believed that overstimulated glutamatergic and decreased GABAergic transmission have long been associated with seizure activity. In this study, we investigated the effect of electrical LFS on different parameters of spontaneous excitatory and inhibitory post-synaptic currents (sEPSCs and sIPSCs) in hippocampal CA1 pyramidal cells in kindled animals. Materials and Methods: In this experimental study, rats were kindled by electrical stimulation of the hippocampal CA1 area in a semi-rapid manner (12 stimulations/day). The animals were considered fully kindled when they showed stage 5 seizures on three consecutive days. One group of animals received LFS 4 times at 30 seconds, 6 hours, 18 and 24 hours following the last kindling stimulation. Each LFS consisted of 4 packages at 5 minutes intervals. Each package of LFS consisted of 200 pulses at 1 Hz and each monophasic square wave pulse duration was 0.1 millisecond. At 2-3 hours post-LFS, acute hippocampal slices were prepared and a whole cell patch clamp recording was performed in all animals to measure the different parameters of sEPSCs and sIPSCs. Results: In kindled animals, the inter-event interval (as an index of occurrence) of sEPSCs decreased, whereas sIPSC increased. In addition, the decay time constant of sIPSCs as an index of the duration of its activity decreased compared to the control group. There was no significant difference in other parameters between the kindled and control groups. Application of LFS in kindled animals prevented the observed changes. There was no significant difference between the measured parameters in kindled+LFS and control groups. Conclusion: LFS application may prevent seizure-induced increase in the occurrence of sEPSCs and seizure-induced decrease in occurrence and activity duration of sIPSCs.

Objective: Extracellular deposition of the beta-amyloid (Ab) peptide, which is the main finding in the pathophysiology of Alzheimer’s disease (AD), leads to oxidative damage and apoptosis in neurons. Melissa officinalis (M. officinalis) is a medicinal plant from the Lamiaceae family that has neuroprotective activity. In the present study we have investigated the protective effect of the acidic fraction of M. officinalis on Ab-induced oxidative stress and apoptosis in cultured cerebellar granule neurons (CGN). Additionally, we investigated a possible role of the nicotinic receptor.Materials and Methods: This study was an in vitro experimental study performed on mice cultured CGNs. CGNs were pre-incubated with different concentrations of the acidic fraction of M. officinalis for 24 hours, followed by incubation with Ab for an additional 48 hours. CGNs were also pre-incubated with the acidic fraction of M. officinalis and mecamylamin, followed by incubation with Ab. We used the 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyltetrazolium bromide (MTT) assay to measure cell viability. Acetylcholinesterase (AChE) activity, reactive oxygen species (ROS) production, lipidperoxidation, and caspase-3 activity were measured after incubation. Hochst/annexin V- fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining was performed to detect apoptotic cells.Results: The acidic fraction could protect CGNs from Ab-induced cytotoxicity. Mecamylamine did not abolish the protective effect of the acidic fraction. AChE activity, ROS production, lipid peroxidation, and caspase-3 activity increased after Ab incubation. Preincubation with the acidic fraction of M. officinalis ameliorated these factors and decreased the number of apoptotic cells.Conclusion: Our results indicated that the protective effect of the acidic fraction of M. officinalis was not mediated through nicotinic receptors. This fraction could protect CGNs through antioxidant and anti-apoptotic activities.

Objective: Induced pluripotent stem cells are generated from somatic cells by direct reprogramming. These reprogrammed pluripotent cells have different applications in biomedical fields such as regenerative medicine. Although viral vectors are widely used for efficient reprogramming, they have limited applications in the clinic due to the risk for immunogenicity and insertional mutagenesis. Accordingly, we designed and developed a small, non-integrating plasmid named pLENSO/Zeo as a 2A-mediated polycistronic expression vector.Materials and Methods: In this experimental study, we developed a single plasmid which includes a single expression cassette containing open reading frames of human LIN28, NANOG, SOX2 and OCT4 along with an EGFP reporter gene. Each reprogramming factor is separated by an intervening sequence that encodes a 2A self-processing peptide. The reprogramming cassette is located downstream of a CMV promoter. The vector is easily propagated in the E. coli GT115 strain through a CpG-depleted vector backbone. We evaluated the stability of the constructed vector bioinformatically, and its ability to stoichiometric expression of the reprogramming factors using quantitative molecular methods analysis after transient transfection into HEK293 cells.Results: In the present study, we developed a nonviral episomal vector named pLENSO/ Zeo. Our results demonstrated the general structural stability of the plasmid DNA. This relatively small vector showed concomitant, high-level expression of the four reprogramming factors with similar titers, which are considered as the critical parameters for efficient and consistent reprogramming.Conclusion: According to our experimental results, this stable extrachromosomal plasmid expresses reliable amounts of four reprogramming factors simultaneously. Consequently, these promising results encouraged us to evaluate the capability of pLENSO/Zeo as a simple and feasible tool for generation of induced pluripotent stem cells from primary cells in the future.

Objective: This study aimed to evaluate the levels of two oxidative stress (OS) markers including lipid peroxide (LPO) and total antioxidant capacity (TAC) in both serum and follicular fluid (FF) of women with endometriosis after puncture.Materials and Methods: In this cross-sectional study, a total number of sixty-three women younger than 40 years old with laparoscopy (gold standard for endometriosis diagnosis) indication underwent in vitro fertilization (IVF) program in the Royan Institute, Tehran, Iran from September 2013 to October 2014. About forty-three patients were diagnosed with endometriosis after laparoscopy. Blood and FF from the leading follicle in each stimulated ovary were obtained at the time of egg retrieval; samples were centrifuged and frozen until assessment. At the time of sample assessment, serum and FF samples were evaluated for the levels of LPO and TAC on spectrophotometery.Results: We observed that women with endometriosis had significantly higher LPO and lower TAC levels in the serum and FF as compared with the control group (P<0.05). Conclusion: It has observed that FF of women with endometriosis, regardless of disease stage, increases the proliferation power of endometrial cells in vitro, we presume that inflammatory reactions-induced OS in ovary may be responsible for proliferation induction ability in FF obtained from women with endometriosis.

Objective: The present study aimed to simultaneously evaluate the association between expression of three potential factors [post-acrosomal sheath WW domain-binding protein (PAWP), phospholipase Cζ (PLCζ), and truncated form of the kit receptor (TR-KIT)] as candidates of oocyte activation with fertilization rate and early embryonic development.Materials and Methods: In this experimental study, semen samples were collected from 35 intra-cytoplasmic sperm injection (ICSI) candidates and analyzed according to World Health Organization criteria (2010). Each sample was divided into two parts. The first part was processed for insemination by density-gradient centrifugation (DGC) and the second part was prepared for assessment of sperm morphology (Papanicolaou staining), DNA fragmentation [transferase dUTP nick end labeling (TUNEL)], and three Sperm-borne oocyte-activating factor (s) (SOAFs)-PLCζ, PAWP, and TR-KIT.Results: Significant positive correlations existed between the percentages of PLCζ, PAWP, and TR-KIT with fertilization rate. In addition, significant negative correlations existed between the percentage of DNA fragmentation with the percentages of PLCζ and PAWP. We did not find a relationship between percentages of PLCζ, PAWP, and TR-KIT with embryo quality and pregnancy rate (P>0.05). There was a significant negative correlation between percentage of DNA fragmentation with fertilization and embryo quality.Conclusion: Oocyte activation was associated with the studied sperm factors (PAWP, PLCζ, and TR-KIT). These factors might hold the potential to be considered as diagnostic factors in the assessment of semen samples to evaluate their potential to induce oocyte activation. In addition, we observed a significant association between DNA fragmentation with fertilization, as well as embryo quality and expression of PAWP and PLCζ, which indicated that men with high degrees of DNA fragmentation might require artificial oocyte activation. Whether such action should take place, and its cost and benefits should be evaluated in the future.

Objective: In this study, we sought to better understand the immunoregulatory function of stem cells derived from human exfoliated deciduous teeth (SHED). We studied the role of the interferon gamma (IFN-γ)-indoleamine 2,3-dioxygenase (IDO)-axis in immunoregulation of SHED compared to bone marrow derived mesenchymal stem cells (BMMSCs) under the same conditions.Materials and Methods: In this cross-sectional study, recently isolated human T cells were stimulated either by mitogen or inactivated allogeneic peripheral blood mononuclear cells (PBMCs). These T cells were subsequently co-cultured with, either SHED or BMMSCs in the presence or absence of 1-methyl-tryptophan (1-MT) or neutralizing antihuman-IFN-γ antibodies. In all co-cultures we evaluated lymphocyte activation as well as IDO activity.Results: SHED, similar to conventional BMMSCs, had anti-proliferative effects on stimulated T cells and reduced their cytokine production. This property of SHED and BMMSCs was changed by IFN-γ neutralization. We detected IDO in the immunosuppressive supernatant of all co-cultures. Removal of IDO decreased the immunosuppression of BMMSCs. Conclusion: SHED, like BMMSCs, produced the IDO enzyme. Although IFN-γ is one of inducer of IDO production in SHED, these cells were not affected by IFN-γ in the same manner as BMMSCs. Unlike BMMSCs, the IDO enzyme did not contribute to their immunosuppression and might have other cell-type specific roles.

Objective: Pulp and periodontal tissues are well-known sources of mesenchymal stem cells (MSCs) that provide a promising place in tissue engineering and regenerative medicine. The molecular mechanisms underlying commitment and differentiation of dental stem cells that originate from different dental tissues are not fully understood. In this study, we have compared the expression levels of pluripotency factors along with immunological and developmentally-related markers in the culture of human dental pulp stem cells (hDPSCs), human dental follicle stem cells (hDFSCs), and human embryonic stem cells (hESCs).Materials and Methods: In this experimental study, isolated human dental stem cells were investigated using quantitative polymerase chain reaction (qPCR), immunostaining, and fluorescence-activated cell sorting (FACS). Additionally, we conducted gene ontology (GO) analysis of differentially expressed genes and compared them between dental stem cells and pluripotent stem cells.Results: The results demonstrated that pluripotency (OCT4 and SOX2) and immunological (IL-6 and TLR4) factors had higher expressions in hDFSCs, with the exception of the JAGGED-1/NOTCH1 ratio, c-MYC and NESTIN which expressed more in hDPSCs. Immunostaining of OCT4, SOX2 and c-MYC showed cytoplasmic and nucleus localization in both groups at similar passages. GO analysis showed that the majority of hDFSCs and hDPSCs populations were in the synthesis (S) and mitosis (M) phases of the cell cycle, respectively. Conclusion: This study showed different status of heterogeneous hDPSCs and hDFSCs in terms of stemness, differentiation fate, and cell cycle phases. Therefore, the different behaviors of dental stem cells should be considered based on clinical treatment variations.