» Articles » PMID: 37047812

C1q/TNF-Related Proteins 1, 6 and 8 Are Involved in Corneal Epithelial Wound Closure by Targeting Relaxin Receptor RXFP1 In Vitro

Overview
Journal Int J Mol Sci
Publisher MDPI
Date 2023 Apr 13
PMID 37047812
Authors
Affiliations
Soon will be listed here.
Abstract

Inadequate wound healing of ocular surface injuries can lead to permanent visual impairment. The relaxin ligand-receptor system has been demonstrated to promote corneal wound healing through increased cell migration and modulation of extracellular matrix formation. Recently, C1q/tumor necrosis factor-related protein (CTRP) 8 was identified as a novel interaction partner of relaxin receptor RXFP1. Additional data also suggest a role for CTRP1 and CTRP6 in RXFP1-mediated cAMP signaling. However, the role of CTRP1, CTRP6 and CTRP8 at the ocular surface remains unclear. In this study, we investigated the effects of CTRP1, CTRP6, and CTRP8 on epithelial ocular surface wound closure and their dependence on the RXFP1 receptor pathway. CTRP1, CTRP6, and CTRP8 expression was analyzed by RT-PCR and immunohistochemistry in human tissues and cell lines derived from the ocular surface and lacrimal apparatus. In vitro ocular surface wound modeling was performed using scratch assays. We analyzed the effects of recombinant CTRP1, CTRP6, and CTRP8 on cell proliferation and migration in human corneal and conjunctival epithelial cell lines. Dependence on RXFP1 signaling was established by inhibiting ligand binding to RXFP1 using a specific anti-RXFP1 antibody. We detected the expression of CTRP1, CTRP6, and CTRP8 in human tissue samples of the cornea, conjunctiva, meibomian gland, efferent tear ducts, and lacrimal gland, as well as in human corneal, conjunctival, and meibomian gland epithelial cell lines. Scratch assays revealed a dose-dependent increase in the closure rate of surface defects in human corneal epithelial cells after treatment with CTRP1, CTRP6, and CTRP8, but not in conjunctival epithelial cells. Inhibition of RXFP1 fully attenuated the effect of CTRP8 on the closure rate of surface defects in human corneal epithelial cells, whereas the CTRP1 and CTRP6 effects were not completely suppressed. Conclusions: Our findings demonstrate a novel role for CTRP1, CTRP6, and CTRP8 in corneal epithelial wound closure and suggest an involvement of the relaxin receptor RXFP1 signaling pathway. This could be a first step toward new approaches for pharmacological and therapeutic intervention.

References
1.
Rodriguez S, Lei X, Petersen P, Tan S, Little H, Wong G . Loss of CTRP1 disrupts glucose and lipid homeostasis. Am J Physiol Endocrinol Metab. 2016; 311(4):E678-E697. PMC: 5241556. DOI: 10.1152/ajpendo.00087.2016. View

2.
Klonisch T, Glogowska A, Thanasupawat T, Burg M, Krcek J, Pitz M . Structural commonality of C1q TNF-related proteins and their potential to activate relaxin/insulin-like family peptide receptor 1 signalling pathways in cancer cells. Br J Pharmacol. 2016; 174(10):1025-1033. PMC: 5406291. DOI: 10.1111/bph.13559. View

3.
Hansson G . Inflammation, atherosclerosis, and coronary artery disease. N Engl J Med. 2005; 352(16):1685-95. DOI: 10.1056/NEJMra043430. View

4.
Shen L, Wang S, Ling Y, Liang W . Association of C1q/TNF-related protein-1 (CTRP1) serum levels with coronary artery disease. J Int Med Res. 2019; 47(6):2571-2579. PMC: 6567692. DOI: 10.1177/0300060519847372. View

5.
Ferlin A, Menegazzo M, Gianesello L, Selice R, Foresta C . Effect of relaxin on human sperm functions. J Androl. 2011; 33(3):474-82. DOI: 10.2164/jandrol.110.012625. View