The role of resistance genes expression in meglumine antimoniate non-healing and healing isolates of anthroponotic cutaneous leishmaniasis due to Leishmania tropica

Introduction and Objectives: Anthroponotic cutaneous leishmaniasis (ACL) treatment is being challenged by the emergence of drug resistance against the first line of treatment, pentavalent antimonials (SbV) including meglumine antimoniate. Identification of Sb(V) resistance mechanisms through reliable molecular markers is critical for consolidating strategies to monitor the emergence and spreading of Sb(V) resistance in countries where CL is endemic. The aim of the present study was to assess the expression of AQP1, γ-GCS, MRPA, TDR1 and TR as resistance genes in clinical antimony non-healing and healing L. tropica isolates obtained from patients with ACL for exploring the potential of targeted expression profiling as a surveillance tool for monitoring the Sb(V) unresponsiveness in field isolates. Materials and Methods: The expression of five major antimony resistance-associated genes, i.e., aquaglyceroporin1 (AQP1), γ-glutamylcysteine synthetase (γ-GCS), multidrug resistance protein A (MRPA), trypanothione reductase (TR) and thiol dependent reductase 1 (TDR1) in non-healing and healing Leishmania tropica field isolates was analyzed by quantitative real-time PCR (qPCR) in comparison with sensitive and resistant reference strains. Results: Gene expression analysis showed the down-regulation of AQP1, γ-GCS and TDR1 by 1.9-fold, 1.7-fold and 3.55-fold in non-healing isolates compared to those of healing ones, respectively. Also, the average RNA expression level of MRPA showed an increase of 1.9-fold in the non-healing group. Additionally, a strong positive linear correlation between gene expression of AQP1 and γ-GCS was exhibited in isolates. Negative correlation between the AQP1 and γ-GCS expression level and lesion duration in healing patients, indicated the potential role in diagnosing drug-unresponsive parasites in endemic areas of ACL. Conclusion: Due to the inconclusive outcomes of the resistance in clinical isolates, the expression analysis of a set of influential genes can be beneficial to identify distinctive biomarkers between the antimony non-healing and healing patients.

کلیدواژه ها:

Non-healing and healing patients ، Leishmania tropica ، Resistance genes ، Real-time qPCR