G-CSF Protects Human Brain Vascular Endothelial Cells Injury Induced by High Glucose, Free Fatty Acids and Hypoxia through MAPK and Akt Signaling

Abstract

Granulocyte-colony stimulating factor (G-CSF) has been shown to play a neuroprotective role in ischemic stroke by mobilizing bone marrow (BM)-derived endothelial progenitor cells (EPCs), promoting angiogenesis, and inhibiting apoptosis. Impairments in mobilization and function of the BM-derived EPCs have previously been reported in animal and human studies of diabetes where there is both reduction in the levels of the BM-derived EPCs and its ability to promote angiogenesis. This is hypothesized to account for the pathogenesis of diabetic vascular complications such as stroke. Here, we sought to investigate the effects of G-CSF on diabetes-associated cerebral vascular defect. We observed that pretreatment of the cultured human brain vascular endothelial cells (HBVECs) with G-CSF largely prevented cell death induced by the combination stimulus with high glucose, free fatty acids (FFA) and hypoxia by increasing cell viability, decreasing apoptosis and caspase-3 activity. Cell ultrastructure measured by transmission electron microscope (TEM) revealed that G-CSF treatment nicely reduced combination stimulus-induced cell apoptosis. The results from fluorescent probe Fluo-3/AM showed that G-CSF greatly suppressed the levels of intracellular calcium ions under combination stimulus. We also found that G-CSF enhanced the expression of cell cycle proteins such as human cell division cycle protein 14A (hCdc14A), cyclinB and cyclinE, inhibited p53 activity, and facilitated cell cycle progression following combination stimulus. In addition, activation of extracellular signal-regulated kinase1/2 (ERK1/2) and Akt, and deactivation of c-Jun N terminal kinase (JNK) and p38 were proved to be required for the pro-survival effects of G-CSF on HBVECs exposed to combination stimulus. Overall, G-CSF is capable of alleviating HBVECs injury triggered by the combination administration with high glucose, FFA and hypoxia involving the mitogen-activated protein kinases (MAPK) and Akt signaling cascades. G-CSF may represent a promising therapeutic agent for diabetic stroke.

Neuroprotective effect of tanshinone IIA weakens spastic cerebral palsy through inflammation, p38MAPK and VEGF in neonatal rats

“…The inhibition of p38MAPK can inhibit the transcription of NF-κB (33). Major biological functions following the activation of p38MAPK include generating and activating various inflammatory cytokines, including TNF-α, IL-1β, IL-6 and IL-8 (34). Macrophages at the ischemic core can be found with activated P38MAPK, indicating that p38MAPK may be involved in the inflammatory responses when cerebral ischemic injury occurs (32).…”

Effect of Granulocyte-Colony Stimulating Factor on Endothelial Cells and Osteoblasts

“…Early in the 1990s, in vitro studies have shown that G-CSF (100 ng/mL) had direct stimulatory actions on mature vascular endothelial cells, by showing positive effect on cell migration, proliferation in culture, and capillary-like tube formation on Matrigel culture in vitro [ 6 ]. A recent study has demonstrated that G-CSF are capable of enhancing the expression of multiple cell cycle proteins of endothelial cells and preventing cell death by increasing cell viability, decreasing apoptosis and caspase-3 activity [ 17 ]. Besides the potential of G-CSF on angiogenesis, recent studies have further demonstrated its ability of mobilizing mesenchymal stem cells (MSC), from which osteoblasts were derived, into peripheral blood [ 18 ].…”

“…Based on the differentiation of endothelial cells, tube formation assay replicates many steps in angiogenic process, including cell adhesion, migration, protease activity, alignment, and tube formation [ 11 ]. It has been reported that low concentration of G-CSF demonstrated a favorable effect on proliferation and migration through certain pathways [ 17 , 23 ]. However, the mechanism of the interaction during tube formation remains unclear.…”

Subcellular proteomic approach for identifying the signaling effectors of protein kinase C-β2 under high glucose conditions in human umbilical vein endothelial cells

“…Previous studies have demonstrated that high glucose levels affect vascular endothelial cell proliferation, however, the role of PKC isoforms in cell proliferation remains to be fully elucidated ( 45 – 47 ). Flow cytometric analysis was used to determine which phase of the cell cycle was affected by high glucose exposure, as well as the effect PKC-β 2 had on cell proliferation and the cell cycle.…”