Genetic overexpression of COMP-Ang1 impairs BM microenvironment and induces senescence of BM HSCs.
Supplemental Angiopoietin 1 (Ang1) exerts its therapeutic potential on microvascular regression-associated diseases, and this potential is linked with the function of hematopoietic stem cells (HSCs). However, the underlying mechanisms of the effect of enhanced angiogenesis on the modulation of HSCs are not yet defined. Here, we generated transgenic mice expressing Cartilage Oligomeric Matrix Protein (COMP)-Ang1 in keratin 14-expressing cells. The mutant animals expressed excessive angiogenic characteristics in the skin and bone marrow (BM) along with redder skin with more numerous and branched vessels compared with their wild-type (WT) littermates. The mutants displayed reduced long bone formation and osteoclast activity than did WT littermates and had fewer CD150+CD48-Lineage-Sca-1+c-Kit+ (LSK) cells in the BM. The mutants also exhibited greater senescence-associated (SA) β-gal activity, p16INK4a protein expression, and superoxide anion levels in CD150+CD48-LSK cells in the BM. Furthermore, transplantation assay revealed that the mutant-derived LSK cells were inferior to the cells derived from WT littermate in inducing competitive repopulating capacity in the recipients. Collectively, our results demonstrate that persistent and prolonged administration of COMP-Ang1 by inducible transgenic expression mediates excessive angiogenesis in the body and impairs BM microenvironment, eventually leading to senescence of BM HSCs.
['Kook|Sung-Ho|SH|', 'Sim|Hyun-Jaung|HJ|', 'Hwang|Jae-Won|JW|', 'Baek|Young-Hyun|YH|', 'Kim|Chun-Chu|CC|', 'Lee|Jeong-Hoon|JH|', 'Cho|Eui-Sic|ES|', 'Lee|Jeong-Chae|JC|']
D042683:Angiopoietin-1 D000818:Animals D001853:Bone Marrow D064236:Cartilage Oligomeric Matrix Protein D060833:Cellular Microenvironment D016922:Cellular Senescence D015870:Gene Expression D006412:Hematopoietic Stem Cells D006801:Humans D008822:Mice, Transgenic D009154:Mutation D018919:Neovascularization, Physiologic D010010:Osteoclasts D011993:Recombinant Fusion Proteins
COMP-Ang1 Senescence Hematopoietic stem cells Angiogenesis Bone marrow