Showing 16 results for Mesenchymal Stem Cells
Volume 3, Issue 2 (11-2012)
Abstract
Stem cell therapy has been introduced as an innovative and promising treatment in Ischemic diseases. Mesenchymal stem cells are considered for cell therapy to some extent due to their immunemodulatory, differentiation potential, feasibility of isolation and proliferation properties. Stem cells, after transplantation, often encounter harsh and hypoxic environment in ischemic tissues, which leads to cell death and decreased therapeutic efficiency. On the other hand, the fate of stem cell viability and differentiation is still an ambiguous issue in cell therapy regenerative medicine. To overcome this problem, Hypoxic/Ischemic preconditioning has been reported as a powerful tool with beneficial effects on cell survival. The reported master regulator in this process is a transcription factor known as HIF-1α. This study aimed to over-express HIF-1α in mesenchymal stem cells along with eGFP by using lenti viral vectors. Bisistronic expression of eGFP and HIF-1α provides the possibilities of tracking the transplanted cells and mimicking the hypoxic conditions for genetically modified stem cells for future animal model studies.
Volume 4, Issue 1 (10-2013)
Abstract
Most patients with liver diseases are in the waiting list of liver implantation for a long period of time because of the lack of enough donors. Liver differentiation potential of Mesenchymal Stem Cells (MSCs) is a new perspective in curing these patients. Tissue engineering improves hepatocyte differentiation by coating the culture surfaces with Glycosaminoglycans (GAGs) such as Heparan Sulfate (HS). Cell detachment and death during hepatogenic differentiation hamper the efficiency of cell therapy. This study aims to establish a matrix. mimicking the liver extracellular matrix, which supports the attachment and proliferation potential of MSCs, as well. Collagen was physically coated on polystyrene plates. Collagen-GAG matrix was constructed by covalently immoblizing the HS molecules on collagen by EDC. Cell attachment and proliferation were evaluated by direct cell-counting and MTT methods. GAG presence on collagen was verified by Safranin O staining. Comparisons showed that the highest attachment belonged to collagen, collagen-HS and polystyrene, respectively. Collagen matrix showed also the highest cell proliferation. Collagen-GAG provided more suitable matrix for cell proliferation compared to polystyrene. The results further showed that biomimicked collagen-GAG matrix supports superior attachment and viability for MSCs compared to polystyrene.
Volume 9, Issue 3 (9-2018)
Abstract
Aims: Nitric oxide (NO) plays an important role in maintaining cellular stem status, and the range of electromagnetic fields (EMF) is very deep in contrast to the electric field. The aim of this study was to investigate the effect of electromagnetic field and nitric oxide on the neural differentiation proteins marker and viability of the rat bone marrow mesenchymal stem cells.
Materials and Methods: The present experimental research was conducted on bone marrow mesenchymal stem cells of Vistar rats. For treatments of the cells, high (1mM) and low (10micromolar Deta-NO) concentrations were used as a nitric oxide donor molecule and 50Hz low-frequency electromagnetic field and they were compare with the control group. The cell viability was recorded by MTT assay test, the neural differentiation pathway gene expression was investigated by RT-PCR technique, and the neural differentiation marker protein expression was evaluated by Immunocytochemistry technique. The data were analyzed by one-way ANOVA, using SPSS 13 software.
Findings: After 24 hours of treatment with nitric oxide and EMF, the rate of viability in all groups was significantly decreased compared to the control group. After 48 hours, EMF alone, as well as with low concentration of nitric oxide did not decrease the rate of viability and cell growth increased compared to the control group. In the group treated with high nitric oxide concentration along with EMF, MAP2 protein was expressed in the number of cells more than the control group and the one treated with EMF.
Conclusion: The electromagnetic field, along with its high concentration of nitric oxide, decreases the number of rat bone marrow mesenchymal stem cells and, by increasing cell size, gene expression and neural differentiation proteins marker facilitates their differentiation to nerve-like cells.
Volume 11, Issue 0 (10-2009)
Abstract
Objective: The environmental exposure to Magnetic Fields (MFs) may interact with biological systems. MFs are generated from various sources such as power lines, electric appliances at homes and offices, electrified transportation systems including urban railway systems and diagnostic devices such as Magnetic Resonance Imaging (MRI). There are some scientific evidences that imply the exposure to MFs are hazardous to our health and increases the rate of some cancers like leukemia. The biological consequences of exposure to MFs have been investigated from a variety of endpoints. However, most studies have been performed in vitro and have examined effects on cellular processes and its malfunction; such studies can be used as evidence of effects in vivo.
Materials and Methods: In this study Bone Marrow Stem Cells were grown in the absence and in the presence of a 15 mT Static Magnetic Field for 5 hours in order to determine any changes in cell cycle progression using the count of cells in different phases. The count of cells in a special phase of cell cycle indicates the length of that phase. The Static Magnetic Field was performed using a locally designed MF generator.
Results: A significant increase in the number of cells in G0/G1 was observed in comparison with the controls. Also the number of cells in G0/G1 in the cells treated with Hydrogen-Peroxide, as an oxidative agent, was significantly increased in Static MF.
Conclusion: Genetic material damages or mal-function of related proteins may cause these halts. Mfs have not enough energy to affect the biological molecules directly but the mechanism of free radical mediators is probable. These kinds of damages (direct or indirect) can permanently bring the cell cycle to a halt.
Volume 12, Issue 2 (1-2022)
Abstract
Graphene-based nanomaterials are being investigated for their biocompatibility and bioactivity, as well as their ability to improve osteogenic differentiation. In this research, the base material, reduced graphene oxide (rGO) sheets, were decorated with hydroxyapatite and strontium (rGO / HAp-Sr) to induce osteogenic differentiation in adipose-derived mesenchymal stem cells. Different techniques were used to determine the properties of the nanocomposite such as diffraction analysis techniques (XRD) and transmission electron microscopy (to evaluate the size and morphology of HAp-Sr on rGO plates), FT-IR (to analyze the nanocomposite functional group), Raman spectroscopy (to investigate possible disorders in nanocomposite structure and number of layers), induced dual plasma emission spectroscopy (to assess atomic concentration of Ca and Sr), zeta potential(electrical potential of the nanocomposite) and MTT (nanocomposite cytotoxicity assessment) were used. The ossification potential of the synthesized nanocomposite was investigated and confirmed using the calcium deposition test in dipose-derived mesenchymal stem cells. According to the obtained results, osteogenic differentiation induction is possible using synthesized nanocomposites without the need for chemical inducers.
Volume 13, Issue 4 (1-2023)
Abstract
Stem cells are characterized by their capacity for self-renewal and their ability to differentiate into specific cell types under the influence of their microenvironment. It is known that matrix chemistry controls stem cell differentiation. Single cell encapsulations of the Mesenchymal stem cells into a semi-permeable microgel, allows a greater control of the stem cell fate. In this study, a chip for single-cell encapsulation was designed and fabricated using microfluidic technology. By using microfluidic chip, human bone marrow mesenchymal stem cells (hBMSCs) are encapsulated inside alginate and alginate-poly-l lysine (PLL) microgels. The results of long-term viability of MSCs inside alginate-PLL microgels, shows a significant increase compared to alginate microgels. Mesenchymal stem cell proliferation in alginate-PLL microgels also increased significantly on days 14 and 21. It seems that PLL improves cell adhesion and function by creating a positively charged matrix. Microscopic studies indicate that the morphology of the cells inside the microgels is spherical. However, the average diameter and volume of cells in microgels containing PLL are smaller than others, which indicates more proliferation and space limitation inside the microgels. Therefore, single cell alginate-PLL microgels provide a suitable substrate in clinical studies for tissue engineering, organ transplantation and cell therapy.
Volume 14, Issue 1 (1-2011)
Abstract
Objective: Zoledronic acid as a main treatment for osteoporosis has an important role in differentiation of mesenchymal stem cells. However, mechanism of osteoblastic differentiation induction by zoledronic acid is not well understood until now. In this research we evaluate zoledronic acid effect on methylation status of RUNX2 and DLX5 promoters.
Materials and Methods: After isolation and expansion of hMSCs from BM, they were pulse treated with 5μM ZA for 3h, and incubated in osteogenic differentiation medium for 3 weeks. DNA was extracted after first, second and third weeks of culture and also from undifferentiated MSCs. After SBS treatment, gene specific methylation analysis for RUNX2 and DLX5 were carried out by MSP using methylated and unmethylated primers.
Results: In the genes RUNX2 and DLX5, M and U primers of MSP amplified promoter regions of undifferentiated and osteoblastic differentiated MSCs. Therefore, methylation status in RUNX2 and DLX5 promoters present incomplete methylation.
Conclusion: Methyltion patterns of RUNX2 and DLX5 don’t change during zoledronic acid osteoblastic differentiation of MSCs. Our findings show that zoledronic acid does not induce osteoblastic differentiation via epigenetic mechanisms. Therefore, zoledronic acid can induce osteoblastic differentiation in a manner independent from DNA epigenetic changes.
Volume 14, Issue 2 (6-2011)
Abstract
Objective: Evaluating the effects of p-benzoquinone and hydroquinone on the RUNX2 expression and osteoblastic differentiation of human marrow derived mesenchymal stem cells (MSCs).
Materials and Methods: Bone marrow MSCs obtained by cultivating marrow mononuclear cells, were exposed to 10μM of either p-benzoquinone or hydroquinone. Following chemical treatment, RUNX2 gene expression was assessed by Real-time RT PCR 1, 6, 24 and 48 hours later and osteogenic differentiation was analyzed using alizarin red and alkaline phosphatase staining methods on days 7 and 14 after ostegenic induction.
Results: RUNX2 expression was significantly elevated (up to approximately 8 times) due to chemical exposure but the applied chemicals exert no considerable effect on MSCs osteogenic differentiation.
Conclusion: According to the literature, despite the necessity of RUNX2 overexpression on the induction of osteogenic differentiation, but it is not sufficient for osteogenesis to occure so increase in RUNX2 expression observed in our study is not the indicator of the induced osteogenic differentiation. Instead, this elevated expression could be the sign of increased activity of the canonical Wnt signaling pathway thereby its involvement in the development of AML due to exposure to benzene and its metabolites. Moreover, this augmented expression of RUNX2 in MSCs can indicate the
RUNX2 overexpression in myeloid progenitors as an expected similar effect of exposure to benzene and its metabolites to contribute in myeloid malignancies developed due to benzene exposure.
Volume 14, Issue 4 (3-2012)
Abstract
Objective: This study investigated the effects of adipose-derived mesenchymal stem cells (MSCs) and conditioned medium injection on cell infiltration in the brains of an experimental C57BL/6 mice model of autoimmune encephalomyelitis (EAE).
Methods: EAE was induced with myelin oligodendrocyte glycoprotein (35-55 peptides) in 20 mice. MSCs were obtained from the adipose tissue of C57BL/6 mice and cultured with Eagle’s minimum essential medium/alpha medium (DMEM) after removal of non-adherent cells. After 2 to 3 passages, 15 days after induction of EAE, 4 groups (n=5) of C57BL/6 mice were treated as follows: i) MSCs were injected intraperitoneally, ii) MSCs were injected intravenously, iii) conditioned medium was administrated intraperitoneally, and iv) the control group received no treatment. After day 60, the mice brains were removed and the effect of adipose-tissue MSCs and administration of conditioned medium was investigated.
Results: Leukocyte infiltration and clinical scores were significantly reduced in animals that received MSC and conditioned medium compared to untreated animals. Body weight increased significantly in the treated groups compared to the control group. Percentage of survival also increased in the animals that received MSCs and conditioned medium as compared to the control group.
Conclusion: MSCs had immunomodulatory and neurogenerative functions which reduced leukocyte infiltration and improved clinical scores in the EAE animals that received MSC and conditioned medium compared to untreated animals with EAE.
Volume 17, Issue 4 (1-2015)
Abstract
Objective:More similarity to in vivo medium may help to increase the proliferation and differentiation of cells at in vitro condition. The present study has investigated the effect of a dynamic mediumand nano hydroxyapatite (nHA) presence on proliferation and differentiation of mesenchymal stem cells (MSCs) to bone cells using electrospun polycaprolactone (PCL) scaffolds. Methods: We prepared PCL and PCL-nHA scaffolds by electrospinning. After static culturing of the scaffolds with MSCs, the scaffolds in a 14-day period, they were divided into two groups of static and dynamic cultures. The dynamic culture scaffolds were placed on a shaker. Cell proliferation and differentiation at days 3, 7 and 14 were investigated by MTT, and the calcium and alkaline phosphatase assays. Results: The obtained results from the MTT assay on day 14 showed an increase of 1.1 times in cell proliferation in the dynamic culture compared to the static culture. During this period, the calcium content produced by cells in the dynamic culture at day 14 were 1.23 times higher for the PCL scaffold and 1.46 times higher for the PCL-nHA scaffold compared to the static culture. Alkaline phosphatase levels for the dynamic state PCL scaffold were 1.24 times more and for the PCL-nHA scaffold they were 1.28 times more compared to the static culture at day 14. Conclusion: The obtained results from dynamic culture, showed higher proliferation and differentiation of stem cells to bone for both PCL and PCL-nHA scaffolds compared to the static culture. The amount of cell proliferation and differentiation in the scaffolds that contained nHA was more than scaffolds that did not have nHA.
Bahman Vahidi, Esmaeel Rahimpour, Zahra Mollahoseini,
Volume 17, Issue 7 (9-2017)
Abstract
Stem cells due to their ability of self-renewing and the potential of differentiating to different cell lineages are the ideal choices in regenerative tissue engineering. Under cyclic loading, these cells could differentiate to those kind of cells that experience similar conditions inside the body, like osteocytes and chondrocytes. In this research, the purpose is to investigate the effect of the 10 percent cyclic strain with the frequency of 1 Hertz on the mechanical response of a single mesenchymal stem cell cultured in a fibrin hydrogel block, using the finite element method and considering the role of integrins and implementing the Simo’s hyper-viscoelastic model for the cytoskeleton as long as the uniaxial loading leads the cell to differentiate toward Fibrochondrocyte. The results of presented model show that the averages of the circumferential, radial and shear stresses are 240, 260 and 140 Pascal, respectively and corresponding forces are 24, 45 and 15 Pico-Newton. The results imply that stresses and forces generated inside the cytoskeleton are large enough to elicit a different response from the cell. This research results can be very effective for better designing of biological experiments.
Volume 18, Issue 3 (10-2015)
Abstract
Objective: The use of stem cells, particularly mesenchymal stem cells (MSCs), with genes and various growth factors as treatments for myocardial infarction and various other diseases is highly regarded. However these cells meet with inflammation and a hypoxic environment in the target tissue. Hence, treatment with factors that increase the resistance of these stem cells is of importance. Stem cells also can be used as carriers for gene therapy. The aim of the present research is to produce VEGF expressing MSCs. We investigate the effect of stromal derived factor 1 on MSC survival in order to use these cells in a future rat myocardial infarction model.
Methods: MSCs were purified from young male rats by aspirating the cavity of femurs and tibias. After characterization, MSCs were transduced with VEGF using lipofectamine. Expression and function of VEGF was confirmed. Next, we treated MSCs with SDF1α at various time points. The effect of this chemokine was investigated using the LDH assay and by viable cell counts.
Results: The experiments confirmed the production and function of VEGF by MSCs. The LDH levels decreased significantly in SDF1α treated MSCs. Cell viability increased significantly in the presence of this chemokine.
Conclusion: Treatment of MSCs with the SDF1α chemokine has increased the survival of these cells. These MSCs are proper candidates for increasing angiogenesis and for further analysis in a rat model of myocardial infarction.
Volume 19, Issue 1 (5-2016)
Abstract
Objective: In the present study we investigated the effect of a dynamic culture in a shake flask bioreactor (SFB) on the proliferation and differentiation to osteoblasts for human mesenchymal stem cells (hMSCs) cultured on multilayered electrospun PCL-nHA scaffolds.
Methods: First, we prepared PCL-nHA scaffolds by electrospinning. After culturing the hMSCs on the scaffolds in a static state, the seeded scaffolds were divided into two groups (static and SFB culture) and incubated up to 21 days. We assessed biocompatibility and cell differentiation by the MTT, calcium, and alkaline phosphatase (ALP) assays on days 7, 14, and 21.
Results: The MTT assay evaluated hMSCs proliferation rate on the scaffold layers. There was greater cell proliferation (optical density values) on the layers in the bioreactor (OD=2.18) compared to the static state condition (OD=1.68) on day 21. In order to study osteogenic differentiation, we determined the amount of calcium deposition and ALP activity. We observed a 1.6-fold greater level of calcium deposition for the dynamic culture compared to the static culture, which showed increased cell differentiation within the bioreactor on day 21. The ALP results showed that during 14 days, ALP activity within the bioreactor was 1.55-fold higher than the static culture.
Conclusion: The SFB culture displayed a higher proliferation and differentiation of stem cells on PCL-nHA multilayered scaffolds compared to the static state condition.
Volume 19, Issue 2 (9-2016)
Abstract
Nowadays fertility and survival of generation highly considered in societies and male infertility raised as a major attitude for community health around the world. 14% of young couples in Europe have infertility problems. In Iranian couples the rate of infertility is higher than world standards and is about 20.2%. Hormonal factors, genetics and psychological problems cause 40-50 % of infertility in men. Since cancer patients are increasing progressively in industrialized societies and anti-cancer treatments highly eliminate the germ cells, so following cancer treatment reduce male fertility. Distinguish of primordial germ cells, recognition of their migration and also understanding of effective factors in differentiation of them can extended new ways for primary studies that follow production of germ cells from other cell sources like mesenchymal stem cells (MSC). Hence finding a way to distinguish germ cells from mesenchymal stem cells, preservation and proliferation of them in culture system can provide a base for spermatogenesis in vitro culture. Isolation and differentiation of germ cells from different cell sources such as umbilical cord using morphogens (Bone morphogenesis protein and Retinoic Acid) is an efficient method for infertility research. In this study some effective factors in differentiation of umbilical cord mesenchymal stem cells to germ cells has been investigated.
Volume 19, Issue 3 (11-2016)
Abstract
Objective: Cell-derived microvesicles are described as a new mechanism for cell-to-cell communication. Stem cell-derived exosomes have been described as a new mechanism for the paracrine effects of mesenchymal stem cells (MSCs). In this regard, exosomes may play a relevant role in the intercellular communication between MSCs and tumor cells.
Methods: Exosomes were purified from the conditioned medium of MSCs by differential centrifugation. Exosome size and morphology were examined by scanning electron microscope and sized with dynamic light scattering (DLS). Western blot analysis confirmed the exosomes by using CD9 as a marker. Purified exosomes were labeled with a PKH26 red fluorescent labeling kit. The labeled exosomes were incubated with SKOV3 ovarian tumor cells for 12 h at 37°C, and we used an inverted fluorescence microscope to monitor cellular uptake.
Results: Scanning electron microscopy revealed that the purified MSCs-derived exosomes had a spherical shape with a diameter of approximately 30-100 nm. Exosome size measurement by dynamic light scattering analysis also showed a single bell-shaped size distribution with a peak of ~80 nm. Western blot analysis also demonstrated the presence of CD9 (a representative marker of exosomes) in the purified exosomes. These data confirmed that the vesicles isolated from MSCs-conditioned media were the exosomes based on their size and presence of the protein marker CD9. Florescent microscopy showed that PKH26-labeled exosomes could be taken up by SKOV3 tumor cells with high efficiency.
Conclusion: Our approach for isolation, characterization and cellular uptake of exosomes derived from MSCs is valuable and a prerequisite for future studies that intend to discover exosome function in tumor cells. The ability to study the biology of exosome uptake in cancer cells could provide opportunities for functional studies of these natural nanovesicles and their contents in cancer therapy.
Volume 21, Issue 2 (7-2018)
Abstract
Aims: Growth factor (GFs) delivery with the certain concentration and release kinetic is one of the main challenges in tissue engineering. The aim of this study was the preparation and characterization of smart poly (N-isopropylacrylamide) nanoparticles containing vascular endothelial growth factor for induction of angiogenesis in human bone marrow-derived mesenchymal stem cells.
Materials and Methods: In this exprimental study, two different formulations of temperature-sensitive Poly (N-isopropylacrylamide) (PNIPAM) nanoparticles (NPs) were synthesized by free radical polymerization technique. Nanoprecipitation and diffusion methods were used to load the vascular endothelial growth factor (VEGF) in PNIPAM NPs. The effects of released VEGF on the differentiation of human bone marrow stem cells (hBMSCs) into endothelial cells in angiogenic, osteogenic, and 50% angiogenic-osteogenic culture medium were investigated, using flow cytometry and light microscope. Statistical analysis was performed, using the GraphPad Prism 6 software.
Findings: The nanoprecipitation process caused polymer degradation due to using the organic N, N-Dimethylacetamide solvent. The cumulative VEGF released after 72hours for 70%. A total of 10ng/ml VEGF released from PNIPAM nanoparticles, in 2D culture with cell density of 3×104 hBMSCs, after 7 days, leading to the endothelial differentiation, capillary-like tube formation, and expression of 20% vWF as angiogenic marker.
Conclusion: The PNIPAM NPs have the potential to load and release the angiogenic GFs for induction of angiogenesis in hBMSCs and in osteogenic medium.
