Restoring Akt1 Activity in Outgrowth Endothelial Cells From South Asian Men Rescues Vascular Reparative Potential

Abstract

Recent data suggest reduced indices of vascular repair in South Asian men, a group at increased risk of cardiovascular events. Outgrowth endothelial cells (OEC) represent an attractive tool to study vascular repair in humans and may offer potential in cell-based repair therapies. We aimed to define and manipulate potential mechanisms of impaired vascular repair in South Asian (SA) men. In vitro and in vivo assays of vascular repair and angiogenesis were performed using OEC derived from SA men and matched European controls, prior defining potentially causal molecular mechanisms. SA OEC exhibited impaired colony formation, migration, and in vitro angiogenesis, associated with decreased expression of the proangiogenic molecules Akt1 and endothelial nitric oxide synthase (eNOS). Transfusion of European OEC into immunodeficient mice after wire-induced femoral artery injury augmented reendothelialization, in contrast with SA OEC and vehicle; SA OEC also failed to promote angiogenesis after induction of hind limb ischemia. Expression of constitutively active Akt1 (E17KAkt), but not green fluorescent protein control, in SA OEC increased in vitro angiogenesis, which was abrogated by a NOS antagonist. Moreover, E17KAkt expressing SA OEC promoted re-endothelialization of wire-injured femoral arteries, and perfusion recovery of ischemic limbs, to a magnitude comparable with nonmanipulated European OEC. Silencing Akt1 in European OEC recapitulated the functional deficits noted in SA OEC. Reduced signaling via the Akt/eNOS axis is causally linked with impaired OEC-mediated vascular repair in South Asian men. These data prove the principle of rescuing marked reparative dysfunction in OEC derived from these men.

Endothelial SHIP2 Suppresses Nox2 NADPH Oxidase–Dependent Vascular Oxidative Stress, Endothelial Dysfunction, and Systemic Insulin Resistance

“…Knockdown of SHIP2 in human umbilical vein ECs (HUVECs) (PromoCell, Heidelberg, Germany) was performed with short hairpin RNA (shRNA) transduction using a lentivirus vector (catalog #SHCLNV-NM001567; Sigma-Aldrich) as previously described (17). HUVECs were transduced with a multiplicity of infection of 10 and incubated at 37°C for 4 days prior to analysis.…”

TRPC3‐mediated Ca2+ signals as a promising strategy to boost therapeutic angiogenesis in failing hearts: The role of autologous endothelial colony forming cells

“…At the same way, reconstituting Akt1 activity in ECFCs isolated from South Asian men reversed their inherited reduced reparative capacity in a mouse model of hindlimb ischemia (Cubbon et al, ). In this case, autologous ECFCs were transduced with a self‐inactivating lentiviral vector (Cubbon et al, ). Intriguingly, we also have demonstrated that ECFCs may be reliably transfected with lentiviral vectors encoding for the Ca 2+ ‐sensitive probe aequorin (Lim, Bertoli, Sorgato, & Moccia, ).…”

“…More recently, ECFCs engineered with an adenovirus expressing either Akt or heme-oxygenase-1 (HO-1) led to enhanced neovascularisation, improved cardiac performance and reduced myocardial fibrosis in a mouse model of AMI (Brunt et al, 2012). At the same way, reconstituting Akt1 activity in ECFCs isolated from South Asian men reversed their inherited reduced reparative capacity in a mouse model of hindlimb ischemia (Cubbon et al, 2014). In this case, autologous ECFCs were transduced with a selfinactivating lentiviral vector (Cubbon et al, 2014).…”

Human endothelial colony-forming cells in regenerative therapy: A systematic review of controlled preclinical animal studies

“…ECFCs were derived predominantly from human umbilical cord blood (n = 55; 83%) while remaining studies expanded ECFCs from peripheral blood (n = 11; 17%) of healthy adult volunteers. [11][12][13][14][15][16][17][18][19][20][21] One study used ECFCs collected from human placenta. 22 Most (n = 59, 89%) studies administered ECFCs while 12 studies also included experiments with derivative products such as extracellular vesicles (ie, exosomes [23][24][25][26][27] or microvesicles 11,28 ), and/or conditioned media 7,[29][30][31][32] (Table 1).…”