Vinculin Is Indispensable for Repopulation by Hematopoietic Stem Cells, Independent of Integrin Function

Abstract

Vinculin is a highly conserved actin-binding protein that is localized in integrin-mediated focal adhesion complexes. Although critical roles have been proposed for integrins in hematopoietic stem cell (HSC) function, little is known about the involvement of intracellular focal adhesion proteins in HSC functions. This study showed that the ability of c-Kit ؉ Sca1 ؉ Lin ؊ HSCs to support reconstitution of hematopoiesis after competitive transplantation was severely impaired by lentiviral transduction with short hairpin RNA sequences for vinculin. The potential of these HSCs to differentiate into granulocytic and monocytic lineages, to migrate toward stromal cellderived factor 1␣, and to home to the bone marrow in vivo were not inhibited by the loss of vinculin. However, the capacities to form long term culture-initiating cells and cobblestone-like areas were abolished in vinculin-silenced c-KitIn contrast, adhesion to the extracellular matrix was inhibited by silencing of talin-1, but not of vinculin. Whole body in vivo luminescence analyses to detect transduced HSCs confirmed the role of vinculin in long term HSC reconstitution. Our results suggest that vinculin is an indispensable factor determining HSC repopulation capacity, independent of integrin functions.

Magnesium modification of a calcium phosphate cement alters bone marrow stromal cell behavior via an integrin-mediated mechanism

“…Vinculin, a highly conserved actin-binding protein, is frequently used as a marker for focal adhesion formation and integrinmediated cell-ECM interactions [45,46], and was examined through immunocytochemical staining. Intriguing results showed the expressions of vinculin and focal adhesion as well as the intracellular F-actin were highly enhanced on 5(10)MCPC surfaces and suppressed on CPC and 20MCPC.…”

Intra‐articular injection of mesenchymal stem cells expressing coagulation factor ameliorates hemophilic arthropathy in factor VIII‐deficient mice

“…The fates of transduced cells in identical recipient mice in vivo were directly assessed by measuring luciferase activities derived from the transduced cells (IVIS Imaging System and L iving I mage software; Xenogen, Alameda, CA, USA), as previously described [20].…”

Biophysical regulation of hematopoietic stem cells

“…[84][85][86][87][88] As described for anchorage-dependent cells, it has also been shown for HSCs § that adhesion to the ECM is talin-dependent. 89 HSCs are assumed to express kindlin-3 (synonym: FERMT3), because this member of the kindlin family is specifically found in hematopoietic cells and platelets, including hematopoietic organs during murine fetal development and bone marrow mononuclear cells in adult mice. 90,91 Following the engagement of talin and kindlin, vinculin binds to talin and fosters the clustering of multiple activated integrins.…”