Mycobacterium lepraeinduces a tolerogenic profile in monocyte-derived dendritic cells via TLR2 induction of IDO
JOURNAL OF LEUKOCYTE BIOLOGY
Authors: Oliveira, Jessica A. P.; Gandini, Mariana; Sales, Jorgenilce S.; Fujimori, Sergio K.; Barbosa, Mayara G. M.; Frutuoso, Valber S.; Moraes, Milton O.; Sarno, Euzenir N.; Pessolani, Maria C., V; Pinheiro, Roberta O.
Abstract
The enzyme IDO-1 is involved in the first stage of tryptophan catabolism and has been described in both microbicidal and tolerogenic microenvironments. Previous data from our group have shown that IDO-1 is differentially regulated in the distinctive clinical forms of leprosy. The present study aims to investigate the mechanisms associated with IDO-1 expression and activity in human monocyte-derived dendritic cells (mDCs) after stimulation with irradiatedMycobacterium lepraeand its fractions.M. lepraeand its fractions induced the expression and activity of IDO-1 in human mDCs. Among the stimuli studied, irradiatedM. lepraeand its membrane fraction (MLMA) induced the production of proinflammatory cytokines TNF and IL-6 whereas irradiatedM. lepraeand its cytosol fraction (MLSA) induced an increase in IL-10. We investigated if TLR2 activation was necessary for IDO-1 induction in mDCs. We observed that in cultures treated with a neutralizing anti-TLR2 antibody, there was a decrease in IDO-1 activity and expression induced byM. lepraeand MLMA. The same effect was observed when we used a MyD88 inhibitor. Our data demonstrate that coculture of mDCs with autologous lymphocytes induced an increase in regulatory T (Treg) cell frequency in MLSA-stimulated cultures, showing thatM. lepraeconstituents may play opposite roles that may possibly be related to the dubious effect of IDO-1 in the different clinical forms of disease. Our data show thatM. lepraeand its fractions are able to differentially modulate the activity and functionality of IDO-1 in mDCs by a pathway that involves TLR2, suggesting that this enzyme may play an important role in leprosy immunopathogenesis.
Astragaloside IV protects human cardiomyocytes from hypoxia/reoxygenation injury by regulating miR-101a
MOLECULAR AND CELLULAR BIOCHEMISTRY
Authors: Wu, Yang; Fan, Zongjing; Chen, Zhengju; Hu, Jiqiang; Cui, Jie; Liu, Yang; Wang, Yao; Guo, Bin; Shen, Juan; Xie, Liandi
Abstract
Astragaloside IV (AS/IV) is one of the extracted components from the traditional Chinese medicine Astragalus which has been demonstrated to have potential capacity for anti-inflammation activity and for treating cardiovascular disease. Our purpose was to determine the function and underlying molecular mechanism of AS/IV in hypoxia/reoxygenation (H/R) injured in cardiomyocytes. Differentially expressed genes (DEGs) were screened using bioinformatic analysis, and the molecular targeting relationship was verified by the dual-luciferase report system. H/R injured cardiomyocytes were employed to explore the effect of AS/IV. QRT-PCR and Western blot analysis were applied to detect the expression of mRNA and proteins, respectively. Additionally, superoxide dismutase (SOD), lactic dehydrogenase (LDH) and MDA (malondialdehyde) levels were detected to determine the oxidative damage. Cell viability was assessed by CCK-8, and flow cytometry was used to evaluate cell apoptosis ratio. TGFBR1 and TLR2 were selected as DEGs. Additionally, AS/IV could enhance cell proliferation and upregulated miR-101a expression, which suppressed TGFBR1 and TLR2 expression in H/R injured cardiomyocytes. Moreover, the results of Western blot exhibited that the downstream genes (p-ERK and p-p38) in the MAPK signaling pathway were suppressed, which meant AS/IV could inhibit this pathway in H/R injured cardiomyocytes. Overall, this study demonstrated AS/IV could attenuate H/R injury in human cardiomyocytes via the miR-101a/TGFBR1/TLR2/MAPK signaling pathway axis, which means that it could serve as a possible alternate for H/R treatment.