Expression of vitamin D receptor and cathelicidin in human corneal epithelium cells during fusarium solani infection.

Aim: To observe the expression of vitamin D receptor (VDR) in human specimen and immortalized human corneal epithelium cells (HCEC) when challenged with fusarium solani. Moreover, we decided to discover the pathway of VDR expression. Also, we would like to detect the expression of cathelicidin antimicrobial peptide (CAMP) in the downstream pathway of VDR.

Methods: Immunohistochemistry was used to examine the VDR expression in HCEC from healthy and fungal keratitis patients. Real time quantitative polymerase chain reaction (qPCR) was performed to observe the messenger ribonucleic acid (mRNA) change of VDR when immortalized HCEC were challenged with fusarium solani for different hours. CAMP was detected at both mRNA and protein levels.

Results: We found out that the VDR expression in fusarium solani keratitis patients' specimen was much more than that in healthy people. The mRNA and protein expression of VDR increased when we stimulated HCEC with fusarium solani antigen (P<0.01) and it could be inhibited by toll like receptor 2 (TLR2) monoclonal antibody. The CAMP expression was decreased because of fusarium solani antigen stimulation (P<0.01).

Conclusion: The VDR expression can be increased via TLR2/1-VDR pathway while the CAMP expression is decreased by the stimulation of fusarium solani antigen.