IL-10 negatively regulates oxLDL-P38 pathway inhibited macrophage emigration

Comparative interleukins and chemokines analysis of mice mesenchymal stromal cells infected with Mycobacterium tuberculosis H37Rv and H37Ra

Inflammatory pathways involving Mesenchymal stromal cells (MSCs) play an important role in Mycobacterium tuberculosis (Mtb) infection. H37Rv (Rv) is a standard virulent strain, however, H37Ra (Ra) is a strain with reduced virulence. Interleukins and chemokines production are known to promote inflammation resistance in mammalian cells and is recently reported to regulate mycobacterial immunopathogenesis via inflammatory responses. MSCs are very important cells during Mtb infection. However, the different expressions of interleukins and chemokines in the process of Mtb-infected MSCs between Ra and Rv remain unclear. We used the techniques of RNA-Seq, Q-RT-PCR, ELISA, and Western Blotting. We have shown that Rv infection significantly increased mRNA expressions of Mndal, Gdap10, Bmp2, and Lif, thereby increasing more differentiation of MSCs compared with Ra infection in MSCs. Further investigation into the possible mechanisms, we found that Rv infection enhanced more inflammatory response (Mmp10, Mmp3, and Ptgs2) through more activation of the TLR2-MAP3K1-JNK pathway than did Ra infection in MSCs. Further action showed that Rv infection enhanced more Il1α, Il6, Il33, Cxcl2, Ccl3, and Ackr3 production than did Ra infection. Rv infection showed more expressions of Mmp10, Mmp3, Ptgs2, Il1α, Il6, Il33, Cxcl2, Ccl3, and Ackr3 possibly through more active TLR2-MAP3K1-JNK pathway than did Ra infection in MSCs. MSCs may therefore be a new candidate for the prevention and treatment of tuberculosis.

Sirt1 activation negatively regulates overt apoptosis in Mtb-infected macrophage through Bax

Apoptotic pathways play an important role in Mycobacterium tuberculosis-infected macrophages. Sirt1 is a member of the deacetylase family that is known to promote apoptosis resistance in many mammalian cells. However, the apoptotic role of Sirt1 in the process of M. tuberculosis infection remains unclear. With the help of mouse macrophage samples, 129/Sv background mice, and PBMCs-derived macrophages from healthy controls and patients with tuberculosis, we have shown that M. tuberculosis infection reduced Sirt1 mRNA and protein expression, however, increased Bax mRNA and protein expression. Further, we found that resveratrol, a Sirt1 activator, inhibited M. tuberculosis-induced Bax expression. Thus, it seems that Sirt1 acts as a novel regulator of apoptosis signaling in M. tuberculosis infection via its effects on Bax. Sirt1 activation may therefore be a new candidate for the prevention and treatment of tuberculosis.

Sirtuin inhibits M. tuberculosis -induced apoptosis in macrophage through glycogen synthase kinase-3β

Apoptotic and inflammatory pathways play important roles in Mycobacterium tuberculosis-infected macrophages. Sirt1 is a member of the deacetylase family that is known to promote apoptosis resistance in mammalian cells and was recently reported to regulate mycobacterial immunopathogenesis via inflammatory responses. However, the apoptotic role of Sirt1 in the process of M. tuberculosis infection remains unclear. With the help of mouse peritoneal macrophage samples, we have shown that resveratrol, a Sirt1 activator, inhibited M. tuberculosis-induced apoptosis in peritoneal macrophages. Further, we found that Sirt1 activation prompted M. tuberculosis induced GSK3β phosphorylation. Further investigation into the possible mechanisms of action showed that Sirt1 directly interacted with GSK3β and enhanced GSK3β phosphorylation by promoting its deacetylation. Sirt1 activation inhibited M. tuberculosis growth. Thus, it seemed that Sirt1 acted as a novel regulator of apoptosis signaling in M. tuberculosis infection via its direct effects on GSK3β. Sirt1 may therefore be a new candidate for the prevention and treatment of tuberculosis.

The Effects of High Mobility Group Box-1 Protein on Peripheral Treg/Th17 Balance in Patients with Atherosclerosis

BACKGROUND

Atherosclerosis (AS) is defined as chronic inflammation of the vessel wall. The major objective of the this study was to explore the mechanism of Treg/Th17 imbalance and the role of high mobility group box-1 protein (HMGB1) on the balance in AS.

METHODS

We detected the apoptotic ratios of Treg and Th17 cells in peripheral blood mononuclear cells (PBMCs) from subjects with AS and normal coronary arteries (NCA) by flow cytometry. The effects of recombinant HMGB1 (rHMGB1) on the proportion, apoptosis and differentiation of Treg and Th17 cells were analyzed using flow cytometry, qRT-PCR and ELISA.

RESULTS

The frequencies of apoptotic Treg cells in the PBMCs from the subjects with AS were significantly higher than in those with NCA (p < 0.01). Stimulation of rHMGB1 obviously increased the level of Th17 cells and acid- related orphan receptor C (RORC) mRNA, and markedly decreased Treg cell frequency and the mRNA expression of factor forkhead family protein 3 (Foxp3) in the PBMCs. rHMGB1 played an obvious role in elevating Treg cell apoptosis ratio (p < 0.01). rHMGB1 treatment significantly decreased Treg cell ratio and IL-10 level, and increased Th17 cell ratio and IL-17A level induced from naïve CD4+ T cells.

CONCLUSIONS

HMGB1 may modulate Treg/Th17 balance in patients with AS through inducing Treg cell apoptosis and promoting cell differentiation of Th17.