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Background: Pentavalent antimonial has been a drug of choice against leishmaniasis, despite the emergence of treatment failure. Identification of resistance markers is urgently needed to design new therapeutic strategies. Iron-Superoxide dismutases (Fe-SODs) are antioxidant enzymes contributing to detoxify reactive oxygen species to prevent a cell from oxidative stress. Since antimonial compounds induce oxidative stress, in this survey, the expression of SOD genes was investigated to identify their expression pattern in clinical resistant isolates. Methods: This cross-sectional survey was done in Mashhad City, northeast of Iran during 2014 to 2019. The RNA expression level of mitochondrial (SODA) and glycosomal (SODB) superoxide dismutase was investigated in 25 antimony responsive (n=15) and unresponsive (n=10) anthroponotic cutaneous leishmaniasis (ACL) patients. Total RNA extraction and cDNA synthesis, the qRT-PCR approach was utilized to investigate the relative RNA expression level. Results: The transcript level of SODs was over-expressed in the most resistant isolates. Gene expression analysis demonstrated the over-expression of SODA and B by a factor of 3.8 and 4.81, respectively, in resistance isolates vs. sensitive ones. Conclusion: Aberrant expression of SODA/B in unresponsive parasites could potentially implicate in detoxifying antimony-induced oxidative stress. Moreover, SODs might be considered as potential predictive markers of the response to antimonials in ACL patients in endemic areas. [ABSTRACT FROM AUTHOR]

Pentavalent antimonials remain the treatment of choice for all the clinical forms of leishmaniasis. The increasing rates of antimony resistance are becoming a serious health problem in treatment of anthroponotic cutaneous leishmaniasis (ACL). Accordingly, unraveling molecular markers is crucial for improving medication strategies and monitoring of drug-resistant parasites. Different studies have suggested the importance of genes involved in trypanothione metabolism and drug transport. In this regard, present study was designed to investigate the RNA expression level of five genes including γ-GCS, ODC, TRYR (involved in trypanothione metabolism), AQP1 (acts in drug uptake) and MRPA (involved in sequestration of drug) in sensitive and resistant Leishmania tropica isolates. Seven antimony-resistant and seven antimony-sensitive L. tropica clinical isolates were collected from ACL patients. Drug sensitivity test was performed on the samples as well as reference strains; afterwards, gene expression analysis was performed on clinical isolates by quantitative real-time PCR. The results revealed that the average expression level of AQP1 gene was decreased (0.47-fold) in resistant isolates compared to sensitive ones whereas MRPA (2.45), γ-GCS (2.1) and TRYR (1.97) was upregulated in resistant isolates. The average expression of ODC (1.24-fold) gene was not different significantly between sensitive and resistant isolates. Our findings suggest that AQP1, MRPA, GSH1 and TRYR can be considered as potential molecular markers for screening of antimony resistance in some L. tropica clinical isolates. [ABSTRACT FROM AUTHOR]

Background: Cutaneous leishmaniasis (CL) is one of the world health problems. Leishmania major is the etiological agent of zoonotic cutaneous leishmaniasis (ZCL). Promastigote and amastigote are two morphological forms of Leishmania parasites that express different proteins and p27 is an important gene encoding cytochrome c oxidase (COX) component. P27 gene expresses a 27 kDa protein that essential in ATP synthesis. This study aimed to compare p27 gene expression in promastigote and amastigote forms in Iranian strain of L. major (MRHO/IR/75/ER). Methods: This study was conducted in 2015. Clinical isolates of CL patients from north, center, west and south parts of Iran were collected and identified by PCRRFLP. After RNA extraction of promastigotes and amastigotes and cDNA synthesis, the expression level of p27 gene was compared by real-time RT-PCR. Results: By comparison of expression level between amastigote and promastigote forms of Iranian strain of L. major, up-regulation of p27 gene (2.73 fold) was observed in amastigotes. Moreover, there was no significant difference in p27 gene expression between L. major isolates. Conclusion: p27 gene and protein can be considered as a target in recombinant vaccine production and treatment process. [ABSTRACT FROM AUTHOR]