%0 Journal Article
%T Wnt1 Accelerates an Ex Vivo Expansion of Human Cord Blood CD34+CD38£¿ Cells
%A Kamonnaree Chotinantakul
%A Patcharee Prasajak
%A Wilairat Leeanansaksiri
%J Stem Cells International
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/909812
%X Cord blood hematopoietic stem cells (CB-HSCs) transplantation has been increasing gradually with facing the limitation of insufficient quantity of HSCs in each CB unit. Therefore, efficient expansion methods which can maintain stem cell characteristics are needed. In this study, umbilical CB-CD34+ cells were cultured in two different cytokine cocktails: 4 factors (4F£¿=£¿Flt3-L, SCF, IL-6, and TPO) and 5 factors (5F£¿=£¿Wnt1£¿+£¿4F) in both serum and serum-free media. The data revealed that the best condition to accelerate an expansion of CD34+CD38£¿ cells was serum-free culture condition supplemented with 5F (5F KSR). This condition yielded 24.3£¿¡À£¿2.1 folds increase of CD34+CD38£¿ cells. The expanded cells exhibited CD34+ CD38£¿ CD133+ CD71low CD33low CD3£¿ CD19£¿ markers, expressed nanog, oct3/4, c-myc, and sox2 genes, and maintained differentiation potential into lymphoid, erythroid and myeloid lineages. The achievement of CD34+CD38£¿ cells expansion may overcome an insufficient quantity of the cells leading to the improvement of the stem cell transplantation. Altogether, our findings highlight the role of Wnt1 and the new culture condition in stimulating hematopoietic stem/progenitor cells expansion which may offer a new therapeutic avenue for cord blood transplantation, regenerative medicine, stem cell bank applications, and other clinical applications in the future. 1. Introduction Hematopoietic stem cells (HSCs, CD34+CD38£¿) obtained from umbilical cord blood (UCB) have been studied extensively in stem cell research for advanced cellular therapies [1]. Cord blood (CB) contains HSCs expressing low immunogenicity which render CB to be the promised source of stem cells for transplantation [2]. Moreover, CB transplantation displays advantages over bone marrow and mobilized peripheral blood transplantations in the aspects of noninvasive collect procedure, richness in hematopoietic stem/progenitor content [3], and lower incidence of acute graft-versus-host disease [4]. However, the quantity of HSCs is limited in a single CB unit and may raise the risk of engraftment failure, especially in the adult transplantation [5]. Thus, an increase in HSCs population without changing in their phenotype and losing their repopulating ability is required for successful clinical transplantation. These obstacles, therefore, constitute a challenge to researchers to overcome. The majority of publications aim to expand CD34+ cells rather than CD34+CD38£¿ cells expansion. However, CD34+CD38£¿ cells indeed conserve more primitive HSCs population, which contain more efficiency to
%U http://www.hindawi.com/journals/sci/2013/909812/