Scharner D, Rössig L, Carmona G, Chavakis E, Urbich C, Fischer A, Kang TB, Wallach D, Chiang YJ, Deribe YL, Dikic I, Zeiher AM, Dimmeler S. Caspase-8 is involved in neovascularization-promoting progenitor cell functions.
Arterioscler Thromb Vasc Biol 2009;
29:571-8. [PMID:
19122169 DOI:
10.1161/atvbaha.108.182006]
[Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE
Endothelial progenitor cells (EPCs) comprise a heterogeneous population of cells, which improve therapeutic neovascularization after ischemia. The neovascularization-promoting potential of progenitor cells depends on survival and retention of the infused cells to the tissue. Caspases mediate apoptosis but are also involved in other critical biological processes. Therefore, we aimed to address the role of caspases in proangiogenic cells.
METHODS AND RESULTS
The caspase-8 inhibitor zIETD abrogated the ex vivo formation of EPCs, inhibited EPC adhesion and migration, and reduced their capacity to improve neovascularization in vivo. Consistently, cells isolated from caspase-8-deficient mice exhibited a reduced capacity for enhancing neovascularization when transplanted into mice after hindlimb ischemia. Because inhibition of Caspase-8 reduced the adhesion and homing functions of EPCs, we further determined the surface expression of integrins and receptors involved in cell recruitment to ischemic tissues. Pharmacological inhibition of caspase-8 and genetic depletion of caspase-8 reduced the expression of the fibronectin receptor subunits alpha5 and beta1 and the SDF-1 receptor CXCR4. Moreover, we identified the E3 ubiquitin ligase Cbl-b, which negatively regulates integrin and receptor-mediated signaling, as a potential Caspase-8 substrate.
CONCLUSIONS
In summary, our data demonstrate a novel apoptosis-unrelated role of caspase-8 in proangiogenic cells.
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