Nitric oxide resistance in Leishmania (Viannia) braziliensis involves upregulation of glucose consumption, glutathione metabolism and increased abundance of proteins with S-nitrosoglutathione reductase activity

ABSTRACT: In American Tegumentary Leishmaniasis (ATL) production of cytokines, reactive oxygen species (ROS) and nitric oxide (•NO) by host’ macrophages normally lead to parasite death. However, some Leishmania (Viannia) braziliensis strains evade those microbicidal mechanisms, exhibiting a resistance profile. L. braziliensis NO-resistant strains cause more lesions and are frequently more resistant to antimonial treatment than NO-susceptible strains, suggesting that NO-resistant parasites are endowed with specific mechanisms of survival and persistence. To tests this, we analysed the effect of pro- and antioxidant molecules on the infectivity in vitro of L. braziliensis strains exhibiting polar phenotypes of resistance or susceptibility to •NO. In addition, we conducted an unbiased and comprehensive quantitative mass spectrometry-based proteomics analysis of those parasites. In vitro infection showed that NO-resistant parasites were more infective to peritoneal macrophages even in the presence of high levels of ROS and RNS, suggesting that parasite’s responses to oxidative and nitrosative stress are differentially regulated in resistant and susceptible strains. Principal component analysis of the absolute protein concentration values demonstrated a clear differentiation between NO-resistant and NO-susceptible parasites supporting the hypothesis that there are natural intrinsic differences at molecular level among L. braziliensis strains. Besides, upon •NO exposure, there is a rapid modulation of resistant parasites’ proteome involving a significant increase in their total protein content. Accordingly, after •NO stimulus, NO-resistant parasites increased glutathione (GSH) metabolism by upregulating enzymes involved in GSH biosynthesis and activity, as well as by increasing the absolute concentration of proteins with S-nitrosoglutathione reductase activity, whereas NO-susceptible did not. In addition, NO-resistant parasites showed increased glucose consumption, and elevated concentration levels of hexokinase (HK) and glucose-6-phosphate dehydrogenase (G6PDH) abundance after nitrosative challenge, all of which can contribute to NADPH pool maintenance and fuel the reducing conditions for the recovery of GSH upon NO exposure. Thus, the upregulation of glucose consumption and GSH-mediated redox capability may explain the natural resistance of L. braziliensis against •NO-mediated damage. Data are available via ProteomeXchange with identifier

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Leishmania Braziliensis

SUBMITTER: Jacek Wisniewski  

LAB HEAD: Jacek R Wisniewski

PROVIDER: PXD029462 | Pride | 2022-04-04

REPOSITORIES: Pride