Rho Kinase Type 1 (ROCK1) Promotes Lipopolysaccharide-induced Inflammation in Corneal Epithelial Cells by Activating Toll-Like Receptor 4 (TLR4)-Mediated Signaling.

Abstract

BACKGROUND Rho kinases (ROCKs) are the typical downstream effectors of RhoA, which can regulate corneal epithelial wound healing. In this study, the role of ROCK1 in lipopolysaccharide (LPS)-induced cornea inflammation was investigated. MATERIAL AND METHODS The expression of ROCK1 in human corneal epithelial cells (HCECs) was bilaterally modulated with ROCK1 expression vector and ROCK1 inhibitor Y-27632. The effects of ROCK1 modulation on the inflammatory response, cell viability, cell apoptosis, and cell cycle distribution were detected by ELISA assay, MTT assay, and flow cytometry, respectively. The pathways involved in the effect of ROCK1 in HCECs was preliminarily explained by detecting changes of TLR4-mediated NF-kB and ERK signaling using western blotting and electrophoretic mobility shift assays. RESULTS Overexpression of ROCK1 promoted LPS-induced production of IL-6, IL-8, IL-1β, and TNF-α, and the apoptotic process in HCECs. Augmented inflammation and apoptosis were associated with stronger activation of TLR4-mediated signal transduction; the phosphorylation of IkBa, JNK, ERK1/2, and p38, and nuclear translocation of NF-κB p65 induced by LPS were further increased by overexpression of ROCK1. Inhibition of ROCK1 function by Y-27632 blocked the effect of LPS on HCECs; both LPS-induced inflammation and apoptosis was alleviated by Y-27632, which was associated with suppression of TLR4-mediated NF-κB and ERK signaling. CONCLUSIONS LPS-induced inflammation and apoptosis in HCECs depended on the function of ROCK1, inhibition of which would attenuate impairments on cornea cells due to LPS.

• Authors: Jianying Gong, Linan Guan, Pei Tian, Chao Li, Yi Zhang
• Journal: Medical science monitor : international medical journal of experimental and clinical research (Med Sci Monit) Vol. 24 Pg. 3514-3523 (May 27 2018) ISSN: 1643-3750 [Electronic] United States
• PMID: 29804125 (Publication Type: Journal Article)

Chemical References

• Cytokines
• Lipopolysaccharides
• NF-kappa B
• TLR4 protein, human
• Toll-Like Receptor 4
• ROCK1 protein, human
• rho-Associated Kinases
• rhoA GTP-Binding Protein

Topics

• Apoptosis
• Cell Cycle
• Cell Nucleus (metabolism)
• Cell Survival
• Cytokines (metabolism)
• Epithelial Cells (metabolism, pathology)
• Epithelium, Corneal (pathology)
• Humans
• Inflammation (pathology)
• Lipopolysaccharides
• MAP Kinase Signaling System
• NF-kappa B (metabolism)
• Protein Transport
• Signal Transduction
• Toll-Like Receptor 4 (metabolism)
• rho-Associated Kinases (metabolism)
• rhoA GTP-Binding Protein (metabolism)