Macrophages Treated with VEGF and PDGF Exert Paracrine Effects on Olfactory Ensheathing Cell Function

Abstract

Glial cell transplantation using olfactory ensheathing cells (OECs) holds a promising approach for treating spinal cord injury (SCI). However, integration of OECs into the hostile acute secondary injury site requires interaction and response to macrophages. Immunomodulation of macrophages to reduce their impact on OECs may improve the functionality of OECs. Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF), known for their immunomodulatory and neuroprotective functions, have provided improved outcomes in SCI animal models. Thus, VEGF and PDGF modulation of the SCI microenvironment may be beneficial for OEC transplantation. In this in vitro study, the effect of VEGF and PDGF on macrophages in an inflammatory condition was tested. Combined VEGF + PDGF reduced translocation nuclear factor kappa B p65 in macrophages without altering pro-inflammatory cytokines. Further, the ability of OECs to phagocytose myelin debris was assessed using macrophage-conditioned medium. Conditioned medium from macrophages incubated with PDGF and combined VEGF + PDGF in inflammatory conditions promoted phagocytosis by OECs. The growth factor treated conditioned media also modulated the expression of genes associated with nerve repair and myelin expression in OECs. Overall, these results suggest that the use of growth factors together with OEC transplantation may be beneficial in SCI therapy.

Neurotrophic and immunomodulatory effects of olfactory ensheathing cells as a strategy for neuroprotection and regeneration

“…Specifically, both PDGF and VEGF/PDGF reduced pro-inflammatory cytokines (i.e., TNF) by decreasing NF-κB translocation, promoting phagocytosis of myelin debris. For this reason, administering growth factors before OEC transplantation could improve transplant success and neural recovery ( 125 ).…”

The Effect of Aerobic Training and Octopamine Supplement on Gene Expression Levels of VEGF and PDGFR in the Heart Tissue of Rats Exposed to Deep Fried Oil

“…Several angiogenic factors have been identified so far, but much attention has been paid to vascular endothelial growth factor (VEGF) and plate-derived growth factor (PDGF) (6). VEGF, as the most important angiogenic factor, causes proliferation of endothelial cells, migration and cell differentiation (6).…”

“…Several angiogenic factors have been identified so far, but much attention has been paid to vascular endothelial growth factor (VEGF) and plate-derived growth factor (PDGF) (6). VEGF, as the most important angiogenic factor, causes proliferation of endothelial cells, migration and cell differentiation (6). Also, platelet-derived growth factor (PDGF) plays a role in collagen synthesis, production of extracellular matrix components, and contraction, and is also an angiogenesis regulatory factor (7).…”