Zeinab Neshati

Comparative Analysis of Chemokine Receptor's Expression in Mesenchymal Stem Cells Derived from Human Bone Marrow and Adipose Tissue

Mesenchymal stem cells (MSCs) are considered as promising candidates for new clinical trials of cell therapies. Bone marrow (BM) was the first source reported to contain MSCs; however, using it may be detrimental due to the highly invasive aspiration procedures. More recently, adipose tissue, attainable by a less invasive method, has been introduced as an alternative source of MSCs. So far, MSCs derived from these two sources have been compared in different characters; however, one of the main properties, i.e., the expression of chemokine receptors, has been ignored in these comparisons. In the present study, human MSCs were derived from bone marrow and adipose tissues and characterized by their expression of some cell surface antigens and also differentiation capacity. The expression of five selected chemokine receptors, which seems to be important in cell homing, was also compared. Semiquantitative reverse transcription-polymerase chain reaction method was used to assess gene expression levels of these chemokine receptors. Our results indicate that expression of these receptors in human MSCs, derived from adipose tissue, was higher than MSCs from bone marrow. Chemokine receptors and their ligands and adhesion molecules play an important role in tissue-specific homing of leukocytes and have also been implicated in trafficking of hematopoietic precursors into and through tissues. Therefore, MSCs from adipose tissue may show a better migration and homing capacity and they might be a better candidate for therapeutic purposes.

Hematopoietic MicroRNA-126 Protects against Renal Ischemia/Reperfusion Injury by Promoting Vascular Integrity

Ischemia/reperfusion injury (IRI) is a central phenomenon in kidney transplantation and AKI. Integrity of the renal peritubular capillary network is an important limiting factor in the recovery from IRI. MicroRNA-126 (miR-126) facilitates vascular regeneration by functioning as an angiomiR and by modulating mobilization of hematopoietic stem/progenitor cells. We hypothesized that overexpression of miR-126 in the hematopoietic compartment could protect the kidney against IRI via preservation of microvascular integrity. Here, we demonstrate that hematopoietic overexpression of miR-126 increases neovascularization of subcutaneously implanted Matrigel plugs in mice. After renal IRI, mice overexpressing miR-126 displayed a marked decrease in urea levels, weight loss, fibrotic markers, and injury markers (such as kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin). This protective effect was associated with a higher density of the peritubular capillary network in the corticomedullary junction and increased numbers of bone marrow-derived endothelial cells. Hematopoietic overexpression of miR-126 increased the number of circulating Lin(-)/Sca-1(+)/cKit(+) hematopoietic stem and progenitor cells. Additionally, miR-126 overexpression attenuated expression of the chemokine receptor CXCR4 on Lin(-)/Sca-1(+)/cKit(+) cells in the bone marrow and increased renal expression of its ligand stromal cell-derived factor 1, thus favoring mobilization of Lin(-)/Sca-1(+)/cKit(+) cells toward the kidney. Taken together, these results suggest overexpression of miR-126 in the hematopoietic compartment is associated with stromal cell-derived factor 1/CXCR4-dependent vasculogenic progenitor cell mobilization and promotes vascular integrity and supports recovery of the kidney after IRI.

Differentiation of mesenchymal stem cells to insulin-producing cells and their impact on type 1 diabetic rats.

Cell therapy is thought to be a possible approach for treatment of diabetes. Cells with the ability to differentiate into insulin-producing cells (IPCs) would provide an unlimited source of islet cells for transplantation. In this study, the differentiation capacity of rat bone-marrow-derived mesenchymal stem cells (MSCs) to IPCs and the feasibility of using them for reversal of hyperglycemia were investigated. In vitro studies indicated that treatment of cells with high glucose concentration, nicotinamide and β-mercaptoethanol resulted to differentiated cells, which had characteristics of IPCs including spherical, grape-like morphology, secretion of insulin, and being positive for dithizone. To test the in vivo function of differentiated MSCs, they were injected into the spleen of diabetic rats. It was shown that diabetic rats who received IPCs, significantly reduced the glucose level, in response to intraperitoneal glucose tolerance (IPGT) test. These results indicate that MSCs are capable of in vitro differentiation into functional IPCs, which can reverse hyperglycemia in rat model of diabetes.

Systemic transplantation of mesenchymal stem cells can reduce cognitive and motor deficits in rats with unilateral lesions of the neostriatum

Abstract Huntington’s disease (HD) is an inherited neurodegenerative disorder that usually occurs in the third or fourth decades of life. Stem cell therapy is one of the approaches for HD treatment. Since mesenchymal stem cells (MSCs) have the ability to migrate into the lesioned site, we transplanted rat bone marrow-derived MSCs intravenously, following unilateral intrastriatal lesion made by quinolinic acid (QA) in Wistar rats. QA administration caused widespread neuropathological deficits similar to those found in HD, including impairments in motor and cognitive functions. Animals receiving MSCs exhibited significant improvement in motor and cognitive performance compared with sham group animals that did not receive cells. Animals were tested by apomorphine-induced rotations, beam walk, cylinder and hang wire tests at different times after cell transplantation. Results indicate that systemic transplantation of MSCs can significantly reduce the behavioral abnormalities of these animals. This method of systemic injection has a great advantage over invasive surgical techniques for transplantation of cells at the lesioned site.

Mogoltacin enhances vincristine cytotoxicity in human transitional cell carcinoma (TCC) cell line

Bladder cancer is the second common cancer of the genitourinary system throughout the world and intravesical chemotherapy is usually used to reduce tumour recurrence and progression. Human transitional cell carcinoma (TCC) is an epithelial-like adherent cell line originally established from primary bladder carcinoma. Here we report the effect of mogoltacin, a sesquiterpene coumarin from Ferula badrakema on TCC cells. Mogoltacin was isolated from the fruits of F. badrakema, using silica gel column chromatography and preparative thin layer chromatography. Mogoltacin did not have any significant cytotoxicity effect on neoplastic TCC cells at 16, 32, 64, 128, 200 and 600 microg ml(-1) concentrations. In order to analyse its combination effect, TCC cells were cultured in the presence of various combining concentrations of mogoltacin and vincristine. Cells were then observed for morphological changes (by light microscopy) and cytotoxicity using MTT assay. The effect of mogoltacin on vincristine toxicity was studied after 24, 48 and 72 h of drug administration. The results of MTT assay showed that mogoltacin can significantly enhance the cytotoxicity of vincristine and confirmed the morphological observations. Results revealed that combination of 40 microg ml(-1) vincristine with 16 microg ml(-1) mogoltacin increased the cytotoxicity of vincristine after 48 h by 32.8%.

Constitutively Active Acetylcholine-Dependent Potassium Current Increases Atrial Defibrillation Threshold by Favoring Post-Shock Re-Initiation

Electrical cardioversion (ECV), a mainstay in atrial fibrillation (AF) treatment, is unsuccessful in up to 10–20% of patients. An important aspect of the remodeling process caused by AF is the constitutive activition of the atrium-specific acetylcholine-dependent potassium current (IK,ACh → IK,ACh-c), which is associated with ECV failure. This study investigated the role of IK,ACh-c in ECV failure and setting the atrial defibrillation threshold (aDFT) in optically mapped neonatal rat cardiomyocyte monolayers. AF was induced by burst pacing followed by application of biphasic shocks of 25–100 V to determine aDFT. Blocking IK,ACh-c by tertiapin significantly decreased DFT, which correlated with a significant increase in wavelength during reentry. Genetic knockdown experiments, using lentiviral vectors encoding a Kcnj5-specific shRNA to modulate IK,ACh-c, yielded similar results. Mechanistically, failed ECV was attributed to incomplete phase singularity (PS) removal or reemergence of PSs (i.e. re-initiation) through unidirectional propagation of shock-induced action potentials. Re-initiation occurred at significantly higher voltages than incomplete PS-removal and was inhibited by IK,ACh-c blockade. Whole-heart mapping confirmed our findings showing a 60% increase in ECV success rate after IK,ACh-c blockade. This study provides new mechanistic insight into failing ECV of AF and identifies IK,ACh-c as possible atrium-specific target to increase ECV effectiveness, while decreasing its harmfulness.

Cardiomyogenic differentiation of human adipose-derived mesenchymal stem cells transduced with Tbx20-encoding lentiviral vectors

Ischemic heart disease often results in myocardial infarction and is the leading cause of mortality and morbidity worldwide. Improvement in the function of infarcted myocardium is a main purpose of cardiac regenerative medicine. One possible way to reach this goal is via stem cell therapy. Mesenchymal stem cells (MSCs) are multipotent stromal cells that can differentiate into a variety of cell types but display limited cardiomyogenic differentiation potential. Members of the T‐box family of transcription factors including Tbx20 play important roles in heart development and cardiomyocyte homeostasis. Therefore, in the current study, we investigated the potential of Tbx20 to enhance the cardiomyogenic differentiation of human adipose‐derived MSCs (ADMSCs). Human ADMSCs were transduced with a bicistronic lentiviral vector encoding Tbx20 (murine) and the enhanced green fluorescent protein (eGFP) and analyzed 7 and 14 days post transduction. Transduction of human ADMSCs with this lentiviral vector increased the expression of the cardiomyogenic differentiation markers ACTN1, TNNI3, ACTC1, NKX2.5, TBX20 (human), and GATA4 as revealed by RT‐qPCR. Consistently, immunocytological results showed elevated expression of α‐actinin and cardiac troponin I in these cells in comparison to the cells transduced with control lentiviral particles coding for eGFP alone. Accordingly, forced expression of Tbx20 exerts cardiomyogenic effects on human ADMSCs by increasing the expression of cardiomyogenic differentiation markers at the RNA and protein level.

Transduced Mesenchymal Stem Cells and Cardiomyogenic Differentiation

Vajiheh Neshati1*, Bibi Sedigheh Fazly Bazzaz1,2*, Majid Mojarrad3,4, Zeinab Neshati5 and Mohammad Amin Kerachian3,4 1Biotechnology Research Center, Faculty of medicine, Institute of Pharmaceutical Technology, Mashhad University of Medical Sciences, Mashhad, Iran 2School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran 3Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran 4Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran 5Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran *Corresponding author: Fazly Bazzaz BS, Biotechnology Research Center, Institute of Pharmaceutical Technology, Mashhad University of Medical Sciences, Mashhad, Iran, Tel: +985138823251; E-mail: fazlis@mums.ac.ir