Combined Effect of Insulin-Like Growth Factor-1 and CC Chemokine Ligand 2 on Angiogenic Events in Endothelial Cells

Abstract

Therapeutic angiogenesis may be applied in medical conditions to promote stimulation of angiogenesis. Angiogenesis is a multistep process, which includes endothelial cell proliferation, migration, and tube formation, which is mediated by various angiogenic polypeptides. Thus, studies that elucidate the cellular mechanisms involved in these processes are necessary to develop novel therapeutic strategies. This study investigated the in vitro effects of the pro-angiogenic factors, insulin-like growth factor-1 (IGF-1) and/or chemokine (CC motif) ligand 2 (CCL2), on endothelial cells. Flow cytometry analysis showed that IGF-1 and CCL2 treatment did not interfere with IGF-1 receptor (IGF-1R) expression, but CCL2 treatment increased CCL2 receptor (CCR2) expression. Immunofluorescence analysis revealed that the IGF-1/CCL2 combination induced a greater increase in fibronectin deposition, but the treatments did not alter the expression of the fibronectin receptors, CD49e and CD44. The interaction of fibronectin with cytokines demonstrated that IGF-1/CCL2 promoted changes in intermediate F-actin remodeling that may result in increased endothelial cell adhesion and cell migration mediated by fibronectin. Furthermore, IGF-1/CCL2 stimulated endothelial cells, grown on fibronectin, to form capillary-like structures and intercellular lumina with greater luminal area. These data suggest that IGF-1/CCL2 combination and a fibronectin matrix may contribute to the angiogenesis process to stimulate adhesion, migration, and tube formation by endothelial cells as a result of F-actin remodeling.

Circulating IGF-1 deficiency exacerbates hypertension-induced microvascular rarefaction in the mouse hippocampus and retrosplenial cortex: implications for cerebromicrovascular and brain aging

“…Solid lines represent links supported by existing experimental evidence (see Discussion for details). Dashed lines represent proposed mechanistic links among microvascular injury, regional ischemia, microhemorrhages, neuroinflammation, and cognitive impairment, which should be tested experimentally by future studies that IGF-1 regulates multiple aspects of the angiogenic process, including induction of endothelial cell proliferation, migration, and tube formation (Viana et al 2015).…”

Hypertension impairs neurovascular coupling and promotes microvascular injury: role in exacerbation of Alzheimer’s disease

“…Further studies are warranted to better understand the synergistic roles for AD, hypertension, and aging processes in regulation of microvascular regression. AD patients are typically old, and there is strong evidence that aging itself is associated with dysregulation of multiple aspects of the angiogenic process, including induction of endothelial cell proliferation, migration, and tube formation (Viana et al 2015). In experimental mouse models, hypertension also results in dysregulated expression of pro-and anti-angiogenic genes (Tarantini et al 2016a).…”

Growth hormone modulates in vitro endothelial cell migration and formation of capillary‐like structures

“…This result was accompanied by an increase in the expression levels of VLA-4 and VLA-5 integrins. The augmentation of fibronectin deposition was also demonstrated in tEnd.1 cells treated in vitro with both the insulin-like growth factor-1 (IGF-1) and CCL2, but it did not modulate integrin expression (Viana et al, 2015).…”

“…Together with cell growth, GH also modulated tEnd.1 cell morphology in our study. The augmentation of fibronectin deposition was also demonstrated in tEnd.1 cells treated in vitro with both the insulin-like growth factor-1 (IGF-1) and CCL2, but it did not modulate integrin expression (Viana et al, 2015). Aside the cell shape, cytoskeleton molecules also interact with the extracellular matrix to permit cell adhesion and migration.…”

“…Proliferation assays were conducted as described earlier (Viana et al, 2015). In brief, tEnd.1 cells (2.5 Â 10 4 ) were grown in six-well plates in complete medium at 37 C with 5% CO 2 for 16 h for cellular adhesion.…”