EST12 regulates Myc expression and enhances anti-mycobacterial inflammatory response via RACK1-JNK-AP1-Myc immune pathway.

c-Myc (Myc) is a well-known transcription factor that regulates many essential cellular processes. Myc has been implicated in regulating anti-mycobacterial responses. However, its precise mechanism in modulating mycobacterial immunity remains elusive. Here, we found that a secreted Rv1579c (early secreted target with molecular weight 12 kDa, named EST12) protein, encoded by virulent Mycobacterium tuberculosis (M.tb) H37Rv region of deletion (RD)3, induces early expression and late degradation of Myc protein. Interestingly, EST12-induced Myc was further processed by K48 ubiquitin proteasome degradation in E3 ubiquitin ligase FBW7 dependent manner. EST12 protein activates JNK-AP1-Myc signaling pathway, promotes Myc binding to the promoters of IL-6, TNF-α and iNOS, then induces the expression of pro-inflammatory cytokines (IL-6 and TNF-α)/inducible nitric oxide synthase (iNOS)/nitric oxide (NO) to increase mycobacterial clearance in a RACK1 dependent manner, and these effects are impaired by both Myc and JNK inhibitors. Macrophages infected with EST12-deficiency strain (H37RvΔEST12) displayed less production of iNOS, IL-6 and TNF-α. In conclusion, EST12 regulates Myc expression and enhances anti-mycobacterial inflammatory response via RACK1-JNK-AP1-Myc immune pathway. Our finding provides new insights into M.tb-induced immunity through Myc.

Detection of circulating Mycobacterium tuberculosis-specific DNA by droplet digital PCR for vaccine evaluation in challenged monkeys and TB diagnosis.

Mycobacterium tuberculosis (M. tb) is emerging as a more serious pathogen due to the increased multidrug-resistant TB and co-infection of human immunodeficiency virus (HIV). The development of an effective and sensitive detection method is urgently needed for bacterial load evaluation in vaccine development, early TB diagnosis, and TB treatment. Droplet digital polymerase chain reaction (ddPCR) is a newly developed sensitive PCR method for the absolute quantification of nucleic acid concentrations. Here, we used ddPCR to quantify the circulating virulent M. tb-specific CFP10 (10-kDa culture filtrate protein, Rv3874) and Rv1768 DNA copy numbers in the blood samples from Bacille Calmette-Guerin (BCG)-vaccinated and/or virulent M. tb H37Rv-challenged rhesus monkeys. We found that ddPCR was more sensitive compared to real-time fluorescence quantitative PCR (qPCR), as the detection limits of CFP10 were 1.2 copies/µl for ddPCR, but 15.8 copies/µl for qPCR. We demonstrated that ddPCR could detect CFP10 and Rv1768 DNA after 3 weeks of infection and at least two weeks earlier than qPCR in M.tb H37Rv-challenged rhesus monkey models. DdPCR could also successfully quantify CFP10 and Rv1768 DNA copy numbers in clinical TB patients' blood samples (active pulmonary TB, extrapulmonary TB (EPTB), and infant TB). To our knowledge, this study is the first to demonstrate that ddPCR is an effective and sensitive method of measuring the circulating CFP10 and Rv1768 DNA for vaccine development, bacterial load evaluation in vivo, and early TB (including EPTB and infant TB) diagnosis as well.

Ficolin-A/2, acting as a new regulator of macrophage polarization, mediates the inflammatory response in experimental mouse colitis.

Human ficolin-2 (FCN-2) and mouse ficolin-A (FCN-A, a ficolin-2-like molecule in mouse) are activators of the lectin complement pathway, present in normal plasma and usually associated with infectious diseases, but little is known about the role of FCN-A/2 in inflammatory bowel disease (IBD). In our present study, we found that patients with IBD exhibited much higher serum FCN-2 levels than healthy controls. In the dextran sulphate sodium-induced acute colitis mouse model, FCN-A knockout mice showed much milder disease symptoms with less histological damage, lower expression levels of pro-inflammatory cytokines [interleukin-6 (IL-6), IL-1ß and tumour necrosis factor-α (TNF-α)], chemokines (CXCL1/2/10 and CCL4) and higher levels of the anti-inflammatory cytokine IL-10 compared with wild-type mice. We demonstrated that FCN-A/2 exacerbated the inflammatory pathogenesis of IBD by stimulating M1 polarization through the TLR4/MyD88/MAPK/NF-κB signalling pathway in macrophages. Hence, our data suggest that FCN-A/2 may be used as a novel therapeutic target for IBD.

MiR-141 targets ZEB2 to suppress HCC progression.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Increasing evidence suggests that microRNAs (miRNAs) are associated with HCC tumorigenesis. The present study was designed to define the role of miR-141 in HCC. The expression of miR-141 was significantly decreased in four HCC cell lines. Overexpression of miR-141 suppressed both the growth and the motility of HCC cells. Furthermore, we identified zinc finger E-box binding homeobox 2 (ZEB2) as a target of miR-141 and miR-141 functioned as a tumor suppressor via ZEB2 targeting in HCC. These data provide a novel potential therapeutic target for HCC treatment.

Synthesis and anti-HIV activity of [ddN]-[ddN] dimers and benzimidazole nucleoside dimers.

In an attempt to combine the HIV-inhibitory capacity of different 2',3'-dideoxynucleoside (ddN) analogs, we have designed and synthesized several dimers of [AZT]-[AZT] and [AZT]-[d4T]. In addition, we also synthesized the dimers of 1-(1H-benzimidazol-1-yl)-1-deoxy-beta-D-ribofuranose. The in vitro anti-HIV activity of these compounds on a pseudotype virus, pNL4-3.Luc.R-E-, in the 293T cells has been determined. Among these compounds, 2,2'-(propane-1,3-diyl)bis[1-(beta-D-ribofuranosyl)-1H-benzimidazole] showed the highest anti-HIV activity with similar effect as AZT.