Perivascular location of the MSC niche

<p>It was originally reported that Mesenchymal Stem Cells (MSCs) reside around the microvasculature of their tissue of origin. This was determined via identification of MSCs using the human antibody STRO-1 [1]. However, STRO-1 is not exclusive to MSCs and its expression in hMSCs is gradually lost during culture expansion [2,3]. Within murine bone marrow, a sub-population of nestin+ MSCs has been identified which also occupy a perivascular localisation. Nestin+ MSCs have also been shown to act as the functional components of the HSC niche [4,5], suggesting that the function and phenotype of MSCs may depend on their microenvironment/tissue of origin. MSCs support HSC homeostasis and have anti-proliferative features that are in common with physiological stromal niches [6].</p> <p> </p> <p>[1] Shi S, Gronthos S (2003) Perivascular niche of postnatal mesenchymal stem cells in human bone marrow and dental pulp. J Bone Miner Res 18: 696-704.</p> <p>[2] Kolf CM, Cho E, Tuan RS (2007) Mesenchymal stromal cells. Biology of adult mesenchymal stem cells: regulation of niche, self-renewal and differentiation. Arthritis Res Ther 9: 204.</p> <p>[3] Gronthos S, Zannettino ACW, Hay SJ, Shi ST, Graves SE, et al. (2003) Molecular and cellular characterisation of highly purified stromal stem cells derived from human bone marrow. Journal of Cell Science 116: 1827-1835.</p> <p>[4] Mendez-Ferrer S, Michurina TV, Ferraro F, Mazloom AR, Macarthur BD, et al. (2010) Mesenchymal and haematopoietic stem cells form a unique bone marrow niche. Nature 466: 829-834.</p> <p>[5] Ehninger A, Trumpp A (2011) The bone marrow stem cell niche grows up: mesenchymal stem cells and macrophages move in. J Exp Med 208: 421-428.</p> <p>[6] Uccelli A, Moretta L, Pistoia V (2008) Mesenchymal stem cells in health and disease. Nat Rev Immunol 8: 726-736.