Metabonomics reveals drastic changes in anti-inflammatory/pro-resolving polyunsaturated fatty acids-derived lipid mediators in leprosy disease.

Despite considerable efforts over the last decades, our understanding of leprosy pathogenesis remains limited. The complex interplay between pathogens and hosts has profound effects on host metabolism. To explore the metabolic perturbations associated with leprosy, we analyzed the serum metabolome of leprosy patients. Samples collected from lepromatous and tuberculoid patients before and immediately after the conclusion of multidrug therapy (MDT) were subjected to high-throughput metabolic profiling. Our results show marked metabolic alterations during leprosy that subside at the conclusion of MDT. Pathways showing the highest modulation were related to polyunsaturated fatty acid (PUFA) metabolism, with emphasis on anti-inflammatory, pro-resolving omega-3 fatty acids. These results were confirmed by eicosanoid measurements through enzyme-linked immunoassays. Corroborating the repertoire of metabolites altered in sera, metabonomic analysis of skin specimens revealed alterations in the levels of lipids derived from lipase activity, including PUFAs, suggesting a high lipid turnover in highly-infected lesions. Our data suggest that omega-6 and omega-3, PUFA-derived, pro-resolving lipid mediators contribute to reduced tissue damage irrespectively of pathogen burden during leprosy disease. Our results demonstrate the utility of a comprehensive metabonomic approach for identifying potential contributors to disease pathology that may facilitate the development of more targeted treatments for leprosy and other inflammatory diseases.

Comparison between C57Bl/6 and C57Bl/10 mycobacterial mouse pleurisy with respect to cellular migration and nitric oxide production.

Mycobacterium bovis-BCG (BCG) and Mycobacterium leprae (ML) have opposite inflammatory properties. Mycobacteria-induced pleurisy in C57Bl/6 and C57Bl/10 mice was evaluated to establish if their innate responses could be comparable, verifying cellular migration and nitrite production. Kinetic responses after ML or BCG intrathoracic injection were compared in those mice, sharing the H-2(b) MHC haplotype. BCG led to acute eosinophilia and late neutrophilia in both mice. In C57Bl/6 late pleurisy, monocytes and neutrophil recruitment was dose- and iNOS-dependent, inhibited by methotrexate but not by indomethacin. Pleural macrophages released nitrites ex vivo after 7 days of BCG stimulus, without "priming" and blocked by the nitrite inhibitor L-N5-(1-iminoethyl)-ornithine (L-NIO). ML did not induce cellular migration or nitrite production, independent of the mouse strain, timing, or number of bacilli. Although these mycobacteria have high homology, there was no effect of ML on BCG-evoked secondary cellular recruitment. Both C57Black mice trigger similar onset of inflammatory responses to these mycobacteria, so far can alternatively be used in experimental studies.