Search published articles


Showing 9 results for Differentiation

Nemati Sh, Zare Mehrjerdi N, Baharvand H,
Volume 67, Issue 8 (11-2009)
Abstract

Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background: Human bone marrow mesenchymal stem cells (hMSCs) can differentiate into several types of mesenchymal cells, including osteocytes, chondrocytes, and adipocytes, but can also differentiate into non-mesenchymal cells, such as neural cells, under appropriate experimental conditions. Until now, many protocols for inducing neuro-differentiation in MSCs in vitro have been reported. In this study, we induced differentiation into neural phenotype in the hMSCs population by new protocol. In this treatment, hMSCs could express neural markers more than other reports, associating with remarkable morphological modifications. 
Methods: The Bone marrow specimens were aspirated from the iliac crest of normal men. hMSCs were isolated and cultured in DMEM containing 15% FBS. Between 4-8 passages conversion of hMSCs into neurosphere-like structures and induction this cells to nerve precursors in the low-attachment plastic bacterial dishes with bFGF, EGF & RA were initiated. After seven days terminal neural differentiation was initiated by plating the cells on poly-L-ornithin and Laminin coated dishes. Cells were differentiated for 7-14 days. We used flowcytometry and immunocytochemistry analysis for assessment of specific neural stem cell markers in induced cells.
Results: Flowcytometery analysis showed that after induction, 90±2.52 percent of the cells will express neuronal marker Nestin and about 41±1 percent of the cells will express Tuj-1 and about 67±1.05 percent of the cells will express GFAP. Immunocytochemistry and morphologically modifications revealed the same results.
Conclusion: Results showed that hMSCs treatment with bFGF, EGF & RA the number of Tuj1 neurons. These data confirmed that hMSCs can exhibit neuronal differentiation potential in vitro, depending on the protocols of inducement.


Bakhtiari M, Mansouri K, Mostafaie A, Sadeghi Y, Mozafari H, Ghorbani R, Rezaei Tavirani M,
Volume 68, Issue 9 (12-2010)
Abstract

Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background: Skin-derived precursors (SKPs) are a type of progenitor cells extracted from mammalian dermal tissue and can be differentiate to neural and mesodermal lineage in vitro. These cells can introduce an accessible autologos source of neural precursor cells for treatment of different neurodegenerative diseases. This research was done in order to set up isolation, culture, proliferation and differentiation of human skin derived precursors (hSKPs).
Methods: Human foreskin samples were cut into smaller pieces and cultured in proliferation medium after enzymatic digestion. To induce neural differentiation, cells were cultured in neural differentiation medium after fifth passage. We used immunocytochemistry and RT-PCR for characterization of the cells. Neuron and glial cell differentiation potential was assessed by immunofloresence using specific antibodies. The experiments were carried out in triplicate.
Results: After differentiation, βΙΙΙ- tubulin and neurofilament-M positive cells were observed that are specific markers for neurons. Moreover, glial fibrillary acid protein (GFAP) and S100 positive cells were identified that are markers specifically express in glial cells. Detected neurons and glials were also confirmed by their morphologic characterizations.
Conclusion: Our results demonstrated that skin-derived precursors obtained from human foreskin can exhibit neuronal and glial differentiation potential in vitro, depending on the protocols of induction.


Ganji Fatemeh, Abruon Saeid, Baharvand Hossein, Ebrahimi Marzieh, Aghdami Nasser,
Volume 70, Issue 3 (6-2012)
Abstract

Background: Human embryonic stem cells (hESCs) are capable of self-renewal and large-scale expansion. They also have the capacity to differentiate into a variety of cell types including liver, cardiac and neuron cells. However, it is not yet clear whether hESCs can differentiate to hemangioblasts under in-vitro conditions. Hemangioblasts are bipotential progenitors that can generate hematopoietic lineages and endothelial cells. The aim of this study was to identify the potential of human Royan H5 embryonic stem cells in differentiating into hemangioblast cells.

Methods: HESCs were cultured at suspension system in DMEM/F12 supplemented with bFGF. 7-day old cells differentiated into blast cells under defined condition consisting of hematopoietic cytokines including BMP4, VEGF, etc. Blast cell markers kinase insert domain receptor (KDR), CD31, and CD34 were evaluated by flow cytometry and blast gene expressions (TAL-1, Runx-1 and CD34) were detected by qRT-PCR. Clonogenic assays were performed in semisolid medium by colony forming unit-assays.

Results: The hESCs (Royan H5) had the capacity of differentiating into hemangioblast cells. We could detect colonies that expressed 79%±12.5 KDR+, 5.6%±2.8 CD31+-CD34+ and 6%±2.12 KDR+-CD31+ on day 8 in the hESCs. Up-regulation of TAL-1, Runx-1 and CD34 occurred during hemangioblast commitment (P≤0.05 and P≤0.01, respectively). Moreover, hemangioblast cells generated mixed-type and endothelial-like colonies in semi-solid media.

Conclusion: Our results showed that hESCs (Royan H5) were able to differentiate into hemangioblasts under in-vitro conditions. The hemangioblasts had the potential to generate two non-adherent (Mixed-type) and adherent (endothelial-like) cell populations.


Sanambar Sadighi , Ahad Khoshzban , Amir Hossein Tavakoli , Ramin Khatib Semnani, Zahra Sobhani , Nayer Dadashpur Majidabad,
Volume 72, Issue 1 (4-2014)
Abstract

Background: Currently, autologous and allogeneic adipose tissues represent a ubiqui-tous source of material for fat reconstructive therapies. However, these approaches are limited, and often accompanied by a 40-60% reduction in graft volume following transplantation, limited proliferative capacity of mature adipocytes for ex vivo expansion, and extensive adipocyte damage encountered when harvested with conventional liposuction techniques. Recently, cell-based approaches utilizing adipogenic progenitor cells for fat tissue engineering have been developed and were reported to promote both short-term in vivo adipogenesis and to repair defect sites. The aim of this study was to isolate stem cells from fat tissue than examine the growth of stem cells by invitro tests. Methods: For human adipose stem cell isolation (hASC), subcutaneous adipose tissue sites were obtained from female subjects undergoing elective procedures. Tissues were washed 3-4 times in phosphate buffered saline (PBS) and suspended in an equal volume of PBS supplemented with 1% FCS and 0.1% collagenase type I. The tissue was placed in an agitated water bath at 37 1C. The supernatant containing mature adipocytes, was aspirated. Portions of the SVF were suspended in DMEM medium. hASCs were selected based on their ability to adhere to tissue culture plastic and subsequently expanded to 75-90% confluence. Adipose stem cells were isolated and cultured on DMEM. To assess mesenchymal origin of stem cells we used flow-cytomery technique as well as differentiation to osteocyte and chondrocyte lines. Results: The nature of the mesenchymal cells was confirmed by flow -cytometry tech-niques, based on the expression of CD90, CD105, CD166, and lack of expression of hematopoietic markers of CD34, CD31, and CD45. The successful differentiation of our stem cells to osteocyte, chondrocyte had been showed by specific Alizarin-Red and Toluidine-blue staining of cells. Conclusion: Although we have not the results of in vivo tests to support in vivo adipo-genesis either alone or in combination with natural or synthetic matrix, the results showed that stem cells isolation from adipose tissue was successful, and we provided an environment for differentiation of stem cells.
Mohammad Reza Noori Daloii , Arash Salmaninejad , Mina Tabrizi ,
Volume 72, Issue 7 (10-2014)
Abstract

Differentiated cells can change to embryonic stem cells by reprograming. Generation of induced pluripotent stem cells (iPSCs) has revolutionized the field of regenerative and personalized medicine. iPSCs can self-renew and differentiate into many cell types. iPSC cells offer a potentially unlimited source for targeted differentiation. Through the expression of a set of transcription factors, iPSCs can be generated from different kinds of embryonic and adult cells. This technology for the first time enabled the researchers to take differentiated cells from an individual, and convert them to another cell type of interest, which is particularly to that person. When the set of master transcription factors containing OCT4, SOX2, KLF4, and MYC is expressed ectopically in somatic cells, the transcriptional network is propelled to organize itself in such a way as to maintenance a pluripotent state. Since iPSCs are similar to Embryonic Stem Cell (ESC), they can be considered as sources for modeling different diseases. iPSCs which are induced from somatic cells of patient can be useful for screening and drugs selection, and also introduce treatment via grafting the cells. Although this technology has been successful in different fields, the tumorigenesis of viral vectors during induction of reprogramming is a major challenge. Nevertheless, iPSCs are valuable for clinical applications and research. By discovery of these cells many challenges related to the safety, efficacy, and bioethics of ESCs are solved. Pluripotency is defined in two aspect of functional and molecular, by which functional regards the capacity of cell is generate three kinds of embryonic layers and germ line, and molecular aspect regards the identifying of molecules and genes that support functional features. Identification of these genes has been placed at the center of fields related to development and stem cell research. In this review, we discuss the process of generation of these cells, as well as required genes and factors for pluripotency, and also current progress in generation of iPSCs utilizing tens of reliable and new studies.
Sharif Moradi , Hossein Baharvand ,
Volume 72, Issue 8 (11-2014)
Abstract

Embryonic stem cells are pluripotent stem cells which have the ability to indefinitely self-renew and differentiate into all differentiated cells of the body. Regarding their two main properties (unlimited self-renewal and multi-lineage differentiation), these cells have various biomedical applications in basic research and cell based therapy. Because the transplantation of differentiated cells that are derived from embryonic stem cells is allogenic, they face the problem of immune rejection following the transplantation of embryonic stem cell-derived cells into patients. In 2006, researchers from Japan reported the derivation of a new type of pluripotent stem cells which could overcome the problem of immune rejection that is associated with the application of embryonic stem cells. They designated these cells as induced pluripotent stem (iPS) cells, because their production was ‘induced’ from differentiated somatic cells using a combination of four embryonic stem cell-associated transcription factors. Importantly, these pluripotent stem cells exhibit all the key features of embryonic stem cells including unlimited self-renewal and multi-lineage differentiation potential, and can pass the most stringent test of pluripotency which is known as the tetraploid (4n) complementation. Hence, in addition to bypassing the problem of immune rejection, iPS cells have all of the potential applications of embryonic stem cells, including in developmental studies, toxicology research, drug discovery and disease modeling. Also, considering that they could be generated from patient’s own cells, iPS cells hold great promise in the future of patient-specific cell replacement therapies using pluripotent stem cells. In this review article, we will present a comprehensive review on the how and why of the generation of iPS cell from somatic cells of the body and discuss how they should be characterized in terms of morphologically, pluripotent stem cell behavior, and the molecular signature. In addition, their medical applications as well as some of the considerations and future challenges in their use will be discussed.
Mohammad Miryounesi , Zeinab Jamali , Masoumeh Razipour , Elahe Alavinejad , Mohammad Hossein Modarressi ,
Volume 72, Issue 11 (2-2015)
Abstract

Background: About 15% of couples have fertility problems and male factor in fertility accounts for half of the cases. In vitro generation of germ cells introduces a novel approach to male infertility and provides an effective system in gene tracking studies, however many aspects of this process have remained unclear. We aimed to promote mouse embryonic stem cells (mESCs) differentiation into germ cells and evaluate its effectiveness with tracking the expression of the Testis specific 10 (Tsga10) during this process. Methods: This is an in vitro study that was performed in department of Medical Genetics in Tehran University of Medical Sciences from February 2012 to March 2013. Mouse embryonic stem cells were cultured on mouse embryonic fibroblast as feeder layer. Then mESCs were differentiated into germ cells in the presence of Retinoic Acid. Based on developmental schedule of the postnatal testis, samples were taken on the 7th, 12th and 25th days of the culture and were subjected to expression analysis of a panel of germ cell specific genes (Stra8 as pre-meiotic, Dazl and Sycp3‌ as meiotic and Protamin1 and Spata19 as Post-meiotic). Expression of Testis Specific Gene 10 (Tsga10) at RNA and protein levels was then analyzed. Results: It was shown that transition of embryonic stem cells from mitosis to meiosis occurred between 7th and 12th days of mESC culture and post-meiotic gene expression did not occur until 25th day of the culture. Results showed low level of Tsga10 expression in undifferentiated stem cells. During transition from meiotic to post-meiotic phase, Tsga10 expression increased in 6.6 folds. This finding is in concordance with in vivo changes during transition from pre-pubertal to pubertal stage. Localization of processed and unprocessed form of the related protein was similar to those in vivo as well. Conclusion: Expression pattern of Tsga10, as a gene with critical function in spermatogenesis, is similar during in vitro and in vivo germ cell generation. The results suggest that in vitro derived germ cells could be a trusted model to study genes behavior during spermatogenesis.
Homa Mohseni Kouchesfahani , Somayeh Ebrahimi-Barough , Jafar Ai , Azam Rahimi ,
Volume 74, Issue 12 (3-2017)
Abstract

Background: Small molecule Purmorphamin (PMA) is the agonist of smoothened protein in Sonic hedgehog (Shh) signaling pathway. Effect of purmorphamin small molecule on differentiation of mesenchymal cells into bone tissue has been studied previously. Use of Shh causes progression of neural differentiation, and the differentiated cells express specific neural markers. Neurofilament (NF) and acetylcholine esterase (Chat) are specific markers of motor neurons and their expression in differentiated cells indicates their conversion into motor neurons. The aim of this study was to evaluate the ability of PMA to differentiate the human endometrial stem cells (hEnSCs) into motor neurons.

Methods: This analytical study was done in Tehran University of Medical Sciences laboratory on September of 2015. In this study hEnSCs were enzymatically extracted from endometrial tissue. After third passages, the flow cytometry was done for mesenchymal stem cells markers. The mesenchymal stem cells were divided into control and differentiated groups. FBS 10%+DMEM/F12 was added to the culture medium of control group and the differentiating group was treated with differentiating medium containing N2, PMA, DMEM/F12, FBS, B27, IBMX, 2ME, FGF2, RA, BDNF. After 21 days immunocytochemistry (ICC) test was done for the expression of NF and Chat proteins and Real-time PCR analysis for expression of neural markers such as NF, Chat, Nestin and GFAP (as glial marker) at mRNA level.

Results: The flow cytometry analysis showed that hEnSCs were positive for mesenchymal markers CD90, CD105 and CD146 and negative for endothelial marker CD31, and hematopoietic marker CD34. The immunocytochemistry and Real time-PCR results showed that the cells treated with PMA expressed motor neuron markers of NF and Chat.

Conclusion: According to the results of this study, it can be concluded that small molecule PMA has the potency to induce the differentiation of hEnSCs into neural cells, specifically motor neurons by activating Shh signaling pathway.


Mohsen Sheykhhasan , Mahdieh Ghiasi ,
Volume 75, Issue 9 (12-2017)
Abstract

Stem cells are undifferentiated biological cells that can differentiate into more specialized cells and divide (through mitosis) to produce more stem cells (self-renew). In mammals, there are two broad types of stem cells: embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells, which are found in various tissues. Mesenchymal stem cells (MSCs) are multipotent cells that are called as one of the most adult stem cells. Due to their highly proliferative potential and their suitable self-renewal capacity, these cells have provided a powerful and promising source for use in the field of regenerative medicine. Also, mesenchymal stem cells are known for their important properties involving multilineage differentiation potential, trophic factor secretion and localization along various organs and tissues. So that MSCs can differentiate into a variety of cell lineages, including: Osteoblasts (bone cells), chondrocytes (cartilage cells), adipocytes (fat cells), myocytes (muscle cells), hepatocytes (liver cells) and endothelial cells. Efficacy of differentiated MSCs to regenerate cells in the injured tissues requires the ability to maintain the differentiation toward the desired cell fate. Since MSCs represent an attractive source for autologous transplantation, cellular and molecular signaling pathways and micro-environmental changes have been studied in order to understand the role of cytokines, chemokines, and transcription factors on the differentiation of MSCs. The differentiation of MSC into a mesenchymal lineage is genetically manipulated and promoted by specific transcription factors associated with a particular cell lineage. Recent studies have explored the integration of transcription factors, including Runx2, Sox9, PPARγ, MyoD, GATA4, and GATA6 in the differentiation of MSCs. Therefore, the overexpression of a single transcription factor in MSCs may promote trans-differentiation into specific cell lineage, which can be used for treatment of some diseases. In this review, we critically discussed and evaluated the role of transcription factors and related signaling pathways that affect the differentiation of MSCs toward adipocytes, chondrocytes, osteocytes, skeletal muscle cells, cardiomyocytes, and smooth muscle cells.
 


Page 1 from 1     

© 2024 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by : Yektaweb