Basic Fibroblast Growth Factor Reduces Permeability and Apoptosis of Human Brain Microvascular Endothelial Cells in Response to Oxygen and Glucose Deprivation Followed by Reoxygenation via the Fibroblast Growth Factor Receptor 1 (FGFR1)/ERK Pathway

Abstract

The study was supported by the Foundation of the Program of Technology of Education Committee of Chongqing (No. KJQN201800122) and the Program of Technology of Science and Technology Committee of Yuzhong District in Chongqing (No. 20180131) Background: Disruption of the blood-brain barrier (BBB) is a mechanism in the pathogenesis of traumatic brain injury. Basic fibroblast growth factor (bFGF) is expressed in angiogenesis, neurogenesis, and neuronal survival. This study aimed to investigate the role of bFGF in vitro in human brain microvascular endothelial cells (HBMECs) challenged by oxygen-glucose deprivation/reperfusion (OGD/R). Material/Methods: HBMECs were cultured in glucose-free medium and an environment with <0.5% oxygen in an anaerobic chamber. Immunocytochemistry, Western blot, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to measure the protein and mRNA expression levels of bFGF, tight junction, adherens junction, apoptotic proteins, and matrix metalloproteinases (MMPs). The effects of bFGF on the viability of HBMECs was evaluated using the cell counting kit-8 (CCK-8) assay. Cell apoptosis was evaluated using the TUNEL assay, and endothelial permeability was quantified using a transwell migration assay with fluorescein isothiocyanate (FITC) conjugated with dextran. The effects of bFGF were evaluated following inhibition of fibroblast growth factor receptor 1 (FGFR1) with PD173074 and inhibition of ERK with PD98059. Results: Following OGD/R of HBMECs, bFGF significantly reduced cell permeability and apoptosis and significantly inhibited the down-regulation of the expressions of proteins associated with tight junctions, adherens junctions, apoptosis and matrix metalloproteinases (MMPs). The effects of bFGF were mediated by the activation of FGFR1 and ERK, as they were blocked by FGFR1 and ERK inhibitors. Conclusions: Permeability and apoptosis of HBMECs challenged by OGD/R were reduced by bFGF by activation of the FGFR1 and the ERK pathway.

Concentration‐dependent duality of bFGF in regulation of barrier properties of human brain endothelial cells

“…Several studies investigated effects of exogenous bFGF administration on BBB integrity. All reports published hitherto demonstrated protective role of exogenous bFGF against BBB disruption occurring after intracerebral haemorrhage (Huang et al, 2012), traumatic brain injury (Wang et al, 2016), oxygen glucose deprivation (Chen et al, 2019;Lin et al, 2018) and mannitol-induced hyperosmotic shock (Linville et al, 2020). In consequence, it was proposed that bFGF preserves AJs by suppressing the RhoA and ROCK by FGFR-induced activation of the PI3K-Akt-Rac1 signalling pathway (Huang et al, 2012).…”

A steroid‑induced osteonecrosis model established using an organ‑on‑a‑chip platform

“…Apoptosis involves the activation, expression and regulation of a series of genes and it differs from cell necrosis in morphology and biochemistry. The caspase family is a cysteine protease system with a specific aspartic cysteine that is a key player in apoptosis ( 17 , 18 ). To date, ≥14 caspase members have been implicated in apoptosis in mammals.…”

Concentration-dependent duality of bFGF in regulation of barrier properties of human brain endothelial cells

“…Several studies investigated effects of exogenous bFGF administration on the BBB integrity. All reports published hitherto demonstrated protective role of exogenous bFGF against BBB disruption occurring after intracerebral haemorrhage [6], traumatic brain injury [26], oxygen glucose deprivation [27,28] and mannitol-induced hyperosmotic shock [29]. In consequence, it was proposed that bFGF preserves AJs by suppressing the RhoA and ROCK by FGFR-induced activation of the PI3K-Akt-Rac1 signalling pathway [6].…”