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Showing 8 results for Baharvand

Hossein Baharvand, Bijan Hatami, Mohammad Massumi,
Volume 10, Issue 1 (Spring 2006)
Abstract

Introduction: To evaluate the cAMP -mediated IBMX (3-IsoButyle -1-Methyl Xanthin) and db-cAMP (dibutyryl cAMP) effects on differentiation of human Embryonic Stem Cells (hESCs) into nerve cells were the objectives of this study. Methods: We have used Royan H1 hESC- derived embryoid bodies with four treatment groups: six days treatment with IBMX (5×10 -4M) and db-cAMP (10 -9M) (referred to as cAMP), retinoic acid (RA, 10 -6M), IBMX + db-cAMP + RA, and control (no treatment). Immunocytochemistry was carried out for neural specific antibodies including β-Tubulin III, Microtubule Associated Protein 2 (MAP-2), Neurofilament Protein-Heavy chain (NF-H), Glial Fibrilary Acidic Protein (GFAP) and Synaptophysin as well as morphological studies. Semiquantitative RT-PCR was also used to evaluate gene expression involved in neurogenesis. Results: In the 4+6+4 days the neuronal process were apparently observed. Immunocytochemical studies using nerve specific antibodies for proteins such as β- Tubulin III, MAP-2, NF-H, GFAP and Synaptophysin showed the presence of these neuronal and astrocyte markers in differentiated cells by cAMP. Evaluation of expression of genes involved in neurogenesis showed that Hash1, Synaptophysin, β-Adrenergic Receptor and Acetylcholine Receptor- which were silent in embryoid bodies - switched on after treatment with cAMP and/or RA. Relative expression of nerve specific genes showed a significant enhancement in expression of Synaptophysin, NFM and β-Adrenergic Receptor during differentiation, which, with the enhancement in cAMP treated groups were more than those treated with RA and control (p < 0.05). Conclusion: In conclusion, this study showed that cAMP could be a neurogenic agent for human embryonic stem cells differentiation.
Reza Moghadasali, Hossein Baharvand, Bahman Zeynali, Masoud Soleimani,
Volume 10, Issue 2 (Summer 2006)
Abstract

Introduction: Embryonic Stem (ES) cells as pluripotent cells derived from the inner cell mass of blastula can differentiate to neural cells in vitro and this property is valuable in studies of neurogenesis and in the generation of donor cells for transplantation. In this regard, the propose of this research, was the study of the role of two important factors in the development of neural system, Fibroblast Growth Factor and Retinoic Acid were used in the study of mouse ESCs differentiation into neural cells. Methods: Royan B1 ESCs were used in this experiment. The formation of embryoid bodies (EBs) within 2days was the key indication of the differentiation process and then the treatment was carried out under the influence of different factors for example retinoic acid and fibroblast growth factor-2 within 4days in cell culture media in 6 groups and finally the EBs were transferred on poly-L-lysine coated dishes within 5 days to promotes the differentiation. Results: The Studying of β-tubulin III, as a marker of neural cells, in neural cells derived from the ESCs used immunocytochemistry method, and the results obtained from statistical analysis of the percentage of neural differentiated colonies, revealed that, retinoic acid is a strong inducer factor which caused the differentiation of ESCs into neural cells and under the influence of combination of fibroblast growth factor and retinoic acid, ESCs differentiated to the neural cells with longer and thicker outgrowth. Conclusion: This experiment showed that under the influence of fibroblast growth factor-2 and retinoic acid there is a possibility to generate an efficient and large numbers of neurons with longer and thicker outgrowth like motor neurons of spinal cord of posterior area which an suitable for transplantation in damaged spinal cord.
Farshad Homayouni Moghadam, Hojatoallah Alaie, Khadije Karbalaie, Somayeh Tanhaei, Mohammad Hossein Nasr Esfahani, Hossein Baharvand,
Volume 11, Issue 3 (Fall 2007)
Abstract

Introduction Cholinergic system is one of the important systems of mammalian CNS. Cholinergic neurons distributed in brain and spinal cord and contributed to principal functions like: consciousness, learning and memory, and motor control. In this study we investigated the differentiation potentiality of mouse embryonic stem cells toward cholinergic neurons. The aim of this study was to evaluate the effect of sonic hedgehog (Shh), Retinoic Acid (RA), LIF, IL6 and NGF on differentiation of neural progenitor cells (NPCs), produced by lineage selection method, to cholinergic neurons. Material and methods Royan B1, mouse embryonic stem cells derived from C57BL/6 strain was used to produce aggregates. Aggregates were cultured in serum free medium to produce nestin positive or NPCs, then cell expansion was achieved by treatment with EGF and FGF2. Following withdrawal of EGF and FGF2, the cells were further cultured in presence or absence of differentiation factors in serum containing medium. Relative number of neurons and cholinergic neurons were assessed by immunohistochemical procedure using antibodies against MAP2, B-tubulin3, and ChAT. Results Data obtained show that around 70% of cells were B-tubulin3 positive. We found ChAT immunoreactivity in cultured cells in both treated and control groups. Conclusion This study shows that some of the neurons produced by lineage selection method are cholinergic neurons, and the percentage of cholinergic neurons increased after treatment by Shh, LIF and RA.
Maryam Anjomshoaa, Khadije Karbalaei, Shahnaz Razavi, Mohammad Mardani, Somayeh Tanhaei, Mohammad Hossien Nasr Esfahani, Hossein Baharvand,
Volume 12, Issue 1 (Spring 2008)
Abstract

Introduction: The aim of this study was evaluate the ability of notochord to induce neural induction and/or differentiation of mouse embryonic stem cell to neuron and motor neuron, respectively. Methods: In order to produce embryoid bodies, ES cells line Royan B1 were grown in suspension in the absence of LIF for 4 days. EBs were divided into 4 groups. EBs in group 1 & 2 were further cultured in suspension for 4 days in presence of retinoic acid (RA) while EBs in group 3 and 4 were cultured in absence of RA. Unlike group 2 and 4, EBs in the group 1 and 3 were also co-cultured with notochord for further 4 days. Numbers and type of neurons were assessed for each group. Results: EBs in group 3 and 4 lead to 6 to 5 % neuron production while EBs in the group 1 and 2 lead to 55 and 42% neuron production, respectively. There were only significant difference at P <0.05 between groups 3 and 4 with groups 1 and 2. Assessment of percentage of motor neuron (Hb9 positive) reveals a significant increase in the group 1 compared to group 2. Conclusion: Apparently, co-culture of mouse embryonic stem cells in presence of notochord did not induce neural differentiation of mouse embryonic stem cells, while notochord may direct neural differentiation of mouse embryonic stem cells toward motor neurons
Hossein Azizi, Narges Zare Mehrjerdy, Saeed Kasemi Ashtiani, Mirzakhalil Bahmani, Hossein Baharvand,
Volume 12, Issue 3 (Fall 2008)
Abstract

Introduction: The p19 line of embryonal carcinoma cells develops into neurons, astroglia and fibroblasts after aggregation and exposure to retinoic acid (RA). Dehydroepiandroesteron (DHEA) is a neurosteroid, can increase proliferation of human neural stem cell (NSC) and positively regulated the number of neurons produced. This study was initiated to assess the effect of DHEA on neural progenitor cells derived from p19 embryonal carcinoma stem cells. Methods: p19 cells suspended in DMEM contain 5%FBS into bacterial-greade Petri dishes in the presence RA and DHEA in different concentration for 6 days. Serum concentration decrease to 3% in days 5 and 6. Then collected aggregate and processed for flowcytometry, immunocytochemistery and RT-PCR analysis. Cells were trypsinized for dispersion and replaced in poly L- lysine (10µg/ml) coated tissue culture dishes without RA and DHEA for 4 days. And then difference cells were evaluated by phase contrast microscopy. Results: Flowcytometry analyses of Nestin and Brdu/Nestin showed percent Nestin positive and proliferation Nestin positive cells in different groups DHEA and RA. Brdu/Nestin immunochemistry confirmed proliferation of Nestin positive cells and also RT-PCR analysis show expression of proneural marker and estrogen receptor gens.Result showed that RA +DHEA(1μM) significantly increased the number of Nestin positive and newly formed Nestin positive cells than other groups. Conclusion: Result showed DHEA accompanied RA significantly increased the number of Nestin positive and newly formed Nestin positive cells derived from p19 embryonal carcinoma cells but in comparison to RA cannot induce neural progenitor cells.
Mahboobeh Farokhpour, Khadijeh Karbalaie, Mahmood Etebari, Hamid Mirmohamad Sadeghi, Mohammad Hossein Nasr-Esfahani, Marzieh Nematolahi, Hossein Baharvand,
Volume 12, Issue 3 (Fall 2008)
Abstract

Introduction: Doxorubicin is frequently used for treatment of several types of cancer. Doxorubicin cardiac toxicity has limited the use of this drug. Corticosteroids may prevent doxorubicin induced cardiotoxicity. Therefore the aim of this study was to evaluate mouse embryonic stem cells derived cardiomyocytes as a model to evaluate the effect of Doxorubicin and dexamethasone. Methods: Mouse embryonic stem cells derived cardiomyocytes were treated with different concentration of doxorubicin for 24 hours and the results were compared with control group. In order to exam effect of dexamethasone on cardiotoxicity, mouse embryonic stem cells derived cardiomyocytes were either exposed to 0.1, 1 or 10 µM dexamethasone 24 hours prior exposure to doxorubicin or expose to dexamethasone 24 hours before and during exposure to doxorubicin . Each group were compared with only doxorubicin or dexamethasone treated cells. Results: 5µM doxorubicin was selected as the lowest dose that ceased heart beats in more than 50% of Mouse embryonic stem cells derived cardiomyocytes. Results revealed that 10 µM dexamethasone for 24 hours before treatment with doxorubicin has protective effect on doxorubicin induced cardiotoxicity. Conclusion: The overall results obtained in this model are in accordance with previous literature. Thus suggesting that mouse embryonic stem cells derived cardiomyocytes is a suitable model for assessment of cardio toxic effects of drugs. Key words: Stem cell, Cardiomyocyte, Doxorubicin, Dexamethasone
Sahar Kiani, Javad Mirnajafi-Zadeh, Ebrahim Shahbazi, Hossein Baharvand,
Volume 14, Issue 4 (Winter 2011)
Abstract

Introduction: Human embryonic stem cells (hESCs) are pluripotent cells that can proliferate and differentiate to many cell types. Their electrophysiological properties have not yet been chracterzed. In this study, the passive properties (such as resting membrane potential, input resistance and capacitance) and the contribution of delayed rectifier K+ channel currents to the membrane conductance of hESCs was investigated. Methods: hESC (Royan H6 line) was used in this study. Cells were cultured with feeder free culture method. To study the electrophysiological properties of these cells, we used whole cell patch clamp technique in a voltage clamp mode. Ionic currents were recorded by stimulating the cells with depolarizing steps from -90 mV to +50 mV. For pharmacological determination of these currents, potassium channel blockers such as tetraethyl ammonium (TEA a delayed rectifier K+ channel blocker) and 4-aminopyridine (4-AP as an A-type K+ channel blocker) were used. Results: The resting membrane potential of hESCs was -8.66± 0.87 mV, the input resistance was 11.943 ± 0.23 MΩ and the membrane capacitance was 1.46 ± 0.55 nF. In voltage clamp experiments, some outward currents were recorded in hESCs that were progressively increased with positive voltages. These outward currents were inhibited by TEA but not 4-AP. These channels did not show inactivation and their current were recorded from -60 mV. The mean conductance of these channels was 11.81 ± 0.45 pS at -60 mV and 141.4 ± 10.97 pS at +50 mV. There were no inward currents in hESCc.
Shiva Khezri, Mohammad Javan, Hossein Baharvand, Saeed Semnanian,
Volume 15, Issue 2 (Summer 2011)
Abstract

Introduction: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease. In the present study, we investigated the response of subventricular zone (SVZ) adult stem cells in the experimental autoimmune encephalomyelitis (EAE), an animal model of MS, and also the differentiation fate of these stem cells. Methods: Mice were immunized with MOG peptide emulsified in complete Freund's adjuvant (CFA) and pertussis toxin (PT). Control mice received CFA and PT. To study SVZ stem cells migration, mice received seven i.p. injections of BrdU at 2-h intervals on the day before EAE induction. Demyelination was studied using specific staining with luxol fast blue. The number of BrdU+ cells in SVZ and olfactory bulb (OB) was counted using immunohistochemical staining. To understand the fate of the stem cells, NG2 marker was used to detect oligodendrocyte precursors. Results: Lumbar spinal cord of EAE animals showed significant demyelination and the volume of demyelinated areas was increased on days 14 to 21 post lesion. In the EAE group, more Brdu+ cells were observed in the OB compared to the SVZ. The number of Brdu+/NG2 + cells in OB was significantly increased after EAE induction. Conclusion: The demyelinating context of EAE promotes the migration of SVZ stem cells to the OB. These cells mostly differentiate to oligodendrocyte precursors and may contribute to myelin repair.

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