Altered miRNA expression in the lesions of cutaneous leishmaniasis caused by L. major and L. tropica with insights into apoptosis regulation.

Leishmaniasis is a vector-borne infectious disease that affects many subtropical countries. Leishmania (L.) major and L. tropica are among the old-world causative agents and cause cutaneous leishmaniasis (CL). The parasite utilizes various mechanisms to evade host immune responses and facilitate intracellular survival. Among these mechanisms, apoptosis inhibition through altering the host cell miRNA expression profile plays a significant role in parasite survival and infection progression. Based on the in-silico analysis through the miRDB database and literature review, miR-4795-3p, miR-6785-5p, miR-5011-5p, and miR-155-5p were selected as miRNAs regulating apoptosis-related genes. The expression of selected miRNAs was evaluated in the skin biopsy lesions collected from L. tropica and L. major-infected patients by qRT-PCR. Our results showed that miR-155-5p, miR-5011-5p, and miR-6785-5p were significantly upregulated (P < 0.05) in L. tropica-infected patients. Similar expression patterns for miR-155-5p and miR-6785-5p, but with a higher magnitude, were found in the lesions of CL patients infected with L. major. Additionally, miR-4795-3p expression level was downregulated in this group. The KEGG pathway analysis indicated that these miRNAs target several pathways that play key roles during leishmaniasis. The results underscore that further investigation is needed to better understand the regulatory roles of these miRNAs in CL infection.