Allahbakhshian Farsani M, Amirizadeh N, Forouzandeh M, Soleimani M, Pourfatholah A A. TGF-bReceptor2 knocked down by SiRNA increases cord blood CD34+ HSCs self-renewal. mjms 2011; 14 (1) :1-15
URL:
http://mjms.modares.ac.ir/article-30-5944-en.html
1- Department of Hematology and Blood Banking, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran
2- Assistant Professor, Department of Hematology, Research Center of Iranian Blood Transfusion Organization, Tehran, Iran
3- Associated Professor, Department of Biotechnology, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran
4- Assistant Professor, Department of Hematology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
5- Professor, Department of Immunology, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran
Abstract: (10248 Views)
Objective: Nowadays, cord blood Hematopoietic stem cells (HSCs) are known as a valuable source for bone marrow transplantation but unfortunately their insufficient number is a limiting factor for using them in adult bone marrow transplantation. Cord blood HCSs expansion is an approach to overcome this problem, by inducing their self-renewal. TGF-b signaling pathway is a key inhibitory agent for HSCs self-renewal. In this study, we tried to enhance self-renewal of long term culture initiating cell by inhibiting TGFbR2 expression.
Materials and Methods: CD34+ HSCs were isolated from cord blood units with MACS column. SiRNA against TGFbR2 was transfected by Lipofectamine™ RNAiMAX as transfection reagent. HSCs were cultured in IMDM medium containing 10% FBS and early acting cytokines (Flt3L, SCF, Tpo) for 8 days. Then we evaluated TGFbR2 expression by QRT-PCR. The CD34+ subpopulation of cultured cells were examined by flow cytometry on the 8th day. Finally the expanded cells were evaluated for the presence of early hematopoietic stem cells by LT-CIC and clonogenic assays.
Results: According to our results, TGFbR2 down regulation increases CD34+ subpopulation of HSCs. In addition, LT-CIC assay showed an enhancement in primitive hematopoietic stem cell capable of self-renewal.
Conclusion: All in all, it seems that positive regulators have attracted more attention in the field of HSCs expansion while negative regulators have same importance in self-renewal process of HSCs and their inhibition can be a beneficial tool for enhancement of HSCs self-renewa.
Article Type:
Original Manuscipt |
Subject:
Hematology Received: 2011/02/12 | Accepted: 2011/02/28