TNF-α evokes blood-brain barrier dysfunction through activation of Rho-kinase and neurokinin 1 receptor

Gao, Xin; Bayraktutan, Ulvi

Abstract

Ischaemic stroke, accompanied by neuroinflammation, impairs blood–brain barrier (BBB) integrity through a complex mechanism involving activation of both RhoA/Rho kinase/myosin light chain-2 and neurokinin 1 receptor (NK1R). Using an in vitro model of human BBB composed of brain microvascular endothelial cells (BMEC), astrocytes and pericytes, this study examined the potential contributions of these elements to BBB damage induced by elevated availability of pro-inflammatory cytokine, TNF-α. Treatment of human BMECs with TNF-α significantly enhanced RhoA activity and the protein expressions of Rho kinase and phosphorylated Ser19MLC-2 while decreasing that of NK1R. Pharmacological inhibition of Rho kinase by Y-27632 and NK1R by CP96345 neutralised the disruptive effects of TNF-α on BBB integrity and function as ascertained by reversal of decreases in transendothelial electrical resistance and increases in paracellular flux of low molecular weight permeability marker, sodium fluorescein, respectively. Suppression of RhoA activation, mitigation of actin stress fibre formation and restoration of plasma membrane localisation of tight junction protein zonula occludens-1 appeared to contribute to the barrier-protective effects of both Y-27632 and CP96345. Attenuation of TNF-α-mediated increases in NK1R protein expression in BMEC by Y-27632 suggests that RhoA/Rho kinase pathway acts upstream to NK1R. In conclusion, specific inhibition of Rho kinase in cerebrovascular conditions, accompanied by excessive release of pro-inflammatory cytokine TNF-α, helps preserve endothelial cell morphology and inter-endothelial cell barrier formation and may serve as an important therapeutic target.

Citation

Gao, X., & Bayraktutan, U. (2023). TNF-α evokes blood-brain barrier dysfunction through activation of Rho-kinase and neurokinin 1 receptor. Immunobiology, 228(5), Article 152706. https://doi.org/10.1016/j.imbio.2023.152706

• Journal Article Type: Article
• Acceptance Date: Jul 4, 2023
• Online Publication Date: Jul 12, 2023
• Publication Date: 2023-09
• Deposit Date: Jul 13, 2023
• Publicly Available Date: Jul 13, 2024
• Journal: Immunobiology
• Print ISSN: 0171-2985
• Electronic ISSN: 1878-3279
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 228
• Issue: 5
• Article Number: 152706
• DOI: https://doi.org/10.1016/j.imbio.2023.152706
• Keywords: TNF-α; Brain microvascular endothelial cells; Neurokinin 1 receptor; RhoA; Rho kinase; Blood-brain barrier; Cytoskeleton
• Public URL: https://nottingham-repository.worktribe.com/output/22999432
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0171298523045084