Determination of Changes in the Expression of MIR-212 and EGFR Genes in Clinical Samples from Areas Infected with Trichophyton rubrum Compared with Non-Infected Areas

Skin infections with dermatophytes (dermatophytosis) are common human fungal infections, the most common cause of which is Trichophyton rubrum. Antimicrobial peptides (AMPs), which have potential anti-microbial effects, are affected by epidermal growth factor receptor (EGFR) gene. Elevated expression of this gene in skin cells activates AMPs and prevents cloning of dermatophytes in keratinocytes. However, mRNA of EGFR gene is muted with increased expression of microRNAs (miRNAs), in particular miR-212. Therefore, EGFR inhibition may have a negative impact on AMP localization in dermatophyte-infected keratinocytes. This study aimed to determine the changes in the expression of miR-212 and EGFR genes in cutaneous tissues affected by T. rubrum compared to their healthy margins. The number of samples in this study was estimated to be 72. The fungus was cultivated on Sabouraud Dextrose Agar medium. Isolation and optimization of total RNA and synthesis and optimization of cDNA for the EGFR and miR-212 genes were performed. Amplification of these target genes was performed using real-time polymerase chain reaction (RT-PCR). In data aggregation and analysis, changes in expression of the target genes were calculated via 2-ΔΔCt ratio. P value was considered < 0.05. In samples infected with T. rubrum, miR-212 significantly reduced the expression of EGFR gene, and in these samples, the expression of miR-212 gene was eight times higher compared to the expression of the EGFR gene. In control samples, the expression of miR-212 was much lower than that of the EGFR gene. By enhancing the expression of miR-212 in this study, the function of EGFR gene mRNA was turned off, leading to the reduction of AMPs, and in turn, the colonization of T. rubrum and creation of dermatophytosis on the skin.