在骨髓中形成造血干細胞小生境的細胞身份一直不清楚?，F(xiàn)在,，Paul Frenette及其同事識別出,，表達nestin的間葉干細胞為形成小生境的細胞,。這些細胞與造血干細胞有密切物理關(guān)系,，表達高水平的參與干細胞維護的基因，它們的刪除會降低造血先祖細胞的骨髓尋的(homing)功能,。
這項工作顯示,，骨髓中的干細胞小生境是兩種截然不同的體干細胞(somatic stem-cell)類型之間的一種伙伴關(guān)系。（生物谷Bioon.com）
生物谷近期特別推薦會議：
2010細胞治療研究進展與臨床應(yīng)用前沿研討會 www.Cell-therapies.net 2010年9月23日-25日天津召開
第一屆腫瘤基礎(chǔ)和轉(zhuǎn)化醫(yī)學(xué)國際研討會 www.cancerasia.org 2010年10月12日-10月15日上海召開
生物谷推薦原文出處：
Nature doi:10.1038/nature09262
Mesenchymal and haematopoietic stem cells form a unique bone marrow niche
Simón Méndez-Ferrer,Tatyana V. Michurina,Francesca Ferraro,Amin R. Mazloom,Ben D. MacArthur,Sergio A. Lira,David T. Scadden,Avi Ma’ayan,Grigori N. Enikolopov& Paul S. Frenette
The cellular constituents forming the haematopoietic stem cell (HSC) niche in the bone marrow are unclear, with studies implicating osteoblasts, endothelial and perivascular cells. Here we demonstrate that mesenchymal stem cells (MSCs), identified using nestin expression, constitute an essential HSC niche component. Nestin+ MSCs contain all the bone-marrow colony-forming-unit fibroblastic activity and can be propagated as non-adherent ‘mesenspheres’ that can self-renew and expand in serial transplantations. Nestin+ MSCs are spatially associated with HSCs and adrenergic nerve fibres, and highly express HSC maintenance genes. These genes, and others triggering osteoblastic differentiation, are selectively downregulated during enforced HSC mobilization or β3 adrenoreceptor activation. Whereas parathormone administration doubles the number of bone marrow nestin+ cells and favours their osteoblastic differentiation, in vivo nestin+ cell depletion rapidly reduces HSC content in the bone marrow. Purified HSCs home near nestin+ MSCs in the bone marrow of lethally irradiated mice, whereas in vivo nestin+ cell depletion significantly reduces bone marrow homing of haematopoietic progenitors. These results uncover an unprecedented partnership between two distinct somatic stem-cell types and are indicative of a unique niche in the bone marrow made of heterotypic stem-cell pairs.
