Bone marrow lacks a transplantable progenitor for smooth muscle type alpha-actin-expressing cells.
While some studies have suggested that hematopoietic stem cells might give rise to other tissue types, others indicate that transdifferentiation would have to be an extremely rare event. We have now exploited smooth muscle type alpha-actin (alphaSMA) promoter-driven green fluorescent protein (GFP) transgenic mice (alphaSMA-GFP mice) for bone marrow transplantation to evaluate their potential to generate donor-type tissues in irradiation chimeras. There was a highly restricted pattern of GFP expression in the transgenic mice, marking bone marrow stromal cells and mesangial cells in the kidney. However, these characteristics were not transferable to wild-type animals given transgenic marrow cells even though hematopoietic cells were largely replaced. Our findings support earlier studies suggesting that the bone marrow microenvironment is difficult to transplant and indicate that hematopoietic stem cells are unlikely to give rise to alphaSMA-expressing progeny.
Yokota
Takafumi
T
Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73190-3048, USA.
Kawakami
Yutaka
Y
Nagai
Yoshinori
Y
Ma
Jian-xing
JX
Tsai
Jen-Yue
JY
Kincade
Paul W
PW
Sato
Sanai
S
D000199:Actins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001853:Bone Marrow / Q000378:metabolism*; D016026:Bone Marrow Transplantation; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D050527:Mesangial Cells / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology* / Q000378:metabolism; D017154:Stromal Cells; D018183:Transplantation Chimera
D000199:Actins; D049452:Green Fluorescent Proteins