Characterization of C-X-C chemokine receptor type 5 in the cornea and role in the inflammatory response after corneal injury

• Published in: Experimental eye research 2023-01, Vol.226, p.109312, Article 109312
• Main Authors: Balne, Praveen K., Gupta, Suneel, Landon, Keele M., Sinha, Nishant R., Hofmann, Alexandria C., Hauser, Nicholas, Sinha, Prashant R., Huang, Hu, Kempuraj, Duraisamy, Mohan, Rajiv R.
• Format: Article
• Language: English
• Subjects: Alkali injury; Alkalies; Animals; Burns, Chemical - metabolism; Cornea; Cornea - metabolism; Corneal fibrosis; Corneal inflammation; Corneal Injuries - metabolism; CXCR5; Endothelial Cells - metabolism; Eye Burns - metabolism; Humans; Inflammation - metabolism; Mice; Mice, Inbred C57BL; Receptors, Chemokine - metabolism; RNA, Messenger - genetics; RNA, Messenger - metabolism; Vascular Endothelial Growth Factor A - metabolism; Vascular Endothelial Growth Factors
• ISSN: 0014-4835; 1096-0007; 1096-0007
• DOI: 10.1016/j.exer.2022.109312

C-X-C chemokine receptor type 5 (CXCR5) regulates inflammatory responses in ocular and non-ocular tissues. However, its expression and role in the cornea are still unknown. Here, we report the expression of CXCR5 in human cornea in vitro and mouse corneas in vivo, and its functional role in corneal inflammation using C57BL/6J wild-type (CXCR5+/+) and CXCR5-deficient (CXCR5−/−) mice, topical alkali injury, clinical eye imaging, histology, immunofluorescence, PCR, qRT-PCR, and western blotting. Human corneal epithelial cells, stromal fibroblasts, and endothelial cells demonstrated CXCR5 mRNA and protein expression in PCR, and Western blot analyses, respectively. To study the functional role of CXCR5 in vivo, mice were divided into four groups: Group-1 (CXCR5+/+ alkali injured cornea; n = 30), Group-2 (CXCR5−/− alkali injured cornea; n = 30), Group-3 (CXCR5+/+ naïve cornea; n = 30), and Group-4 (CXCR5−/− naïve cornea; n = 30). Only one eye was wounded with alkali. Clinical corneal evaluation and imaging were performed before and after injury. Mice were euthanized 4 h, 3 days, or 7 days after injury, eyes were excised and used for histology, immunofluorescence, and qRT-PCR. In clinical eye examinations, CXCR5−/− mouse corneas showed ocular health akin to the naïve corneas. Alkali injured CXCR5+/+ mouse corneas showed significantly increased mRNA (p