Avaliação da expressão do Liver X receptor (LXR) na leishmaniose tegumentar

Abstract

Evaluation of liver X receptor (LXR) expression in cutaneous leishmaniasis. Background: cutaneous Leishmaniasis is endemic in Brazil, with about 240,000 new cases in the last ten years. Mostly caused by Leishmania braziliensis, it is characterized by cutaneous or mucous lesions, with intense inflammatory infiltrate and few parasites, especially in mucous leishmaniasis. The "liver X receptor" (LXR), a member of the nuclear receptor supefamily , seens to have a prominent role in the regulation of macrophages in infectious processes. Genes inhibited by LXR express proteins with proinflammatory effects, suggesting that these receptors influence the immune response. Objective: evaluate a transcription and an in situ protein expression of LXR in different forms of cutaneous leishmaniasis. Methodology: Samples of lesions from patients with localized cutaneous leishmaniasis (LCL), mucos leishmaniasis (LM), normal skin samples (PN) and normal mucosa (MN) of healthy donors (control) where submitted to a RNAm extraction (LCL = 43, LM = 04. PN = 20, MN = 05). Then the transcripts were analyzed by nanostring for an expression of the hundreds of molecules involved in the immune response. The differently pathways expressed were identified by Ingenuity Pathway Analysis (IPA) software. Protein expression of LXR was evaluated by immunohistochemistry (LCL = 06, LM = 03, MN = 02) using anti-LXRα primary antibody and the marked area was quantified using ImagePro software. Results: (1) the expression of mRNA for LXR was decreased in both LCL and LM compared to controls; (2) there was a trend to lower LXR expression in LCL and LM samples when compared to healthy ones; however, there was no significant statistical difference between the groups. Conclusion: There is a reduction in transcription and translation of LXR in situ in cutaneous leishmaniasis, which may be related to an exacerbated inflammatory response in this disease.