Effects of 25-hydroxy vitamin D on T lymphocyte subsets and sputum smear conversion during antituberculosis treatment.

OBJECTIVES: This study aimed to explore the effects of 25-hydroxy vitamin D (25[OH]D) on T lymphocyte subsets and sputum smear conversion during antituberculosis (TB) treatment. METHODS: A total of 120 newly diagnosed patients with active pulmonary TB were collected and classified into vitamin D sufficiency group, vitamin D insufficiency group, and vitamin D deficiency group according to serum 25(OH)D levels. The clinical data and sputum smear conversion were collected and serum 25(OH)D and T lymphocyte subsets were also measured and compared. RESULTS: Our data showed that 25(OH)D levels reached the lowest point at two months of anti-TB treatment. Significant differences existed in the increase of CD4+ and CD8+ T cells on the basis of vitamin D levels. The vitamin D sufficiency group had a significantly higher increase of CD4+ T cells during six months of anti-TB treatment and CD8+ T cells after four months of anti-TB treatment than the other groups. Vitamin D had no effect on the time-to-sputum smear conversion (vitamin D sufficiency group: adjusted hazard ratio: 1.27, 95% confidence interval [CI]: 0.78-2.06); vitamin D insufficiency group: adjusted hazard ratio: 1.05, 95% CI: 0.63-1.75)]. CONCLUSION: Through null effects on sputum smear conversion, vitamin D may have a beneficial effect on the increase of CD4+ and CD8+ T cells during anti-TB treatment.

MicroRNA­502­3p promotes Mycobacterium tuberculosis survival in macrophages by modulating the inflammatory response by targeting ROCK1.

Tuberculosis (TB) is caused by Mycobacterium tuberculosis (M. tuberculosis) infection and has the highest mortality rate of any single infectious disease worldwide. The aim of the present study was to investigate the function of microRNA (miR)­502­3p in M. tuberculosis­infected macrophages. The Gene Expression Omnibus database was used to analyze miR­502­3p expression in patients with TB and healthy individuals. THP­1 and RAW 264.7 cells were transfected with miR­502­3p mimic, miR­502­3p inhibitor, pcDNA3.1­ROCK1 or their negative controls. The expression levels of miR­502­3p and inflammatory cytokines were evaluated using reverse transcription­quantitative PCR. The colony­forming unit assay was performed to assess the survival of M. tuberculosis in macrophages, and Toll­like receptor (TLR)4/NF­κB signaling pathway­associated protein expression levels were detected by western blotting. The nuclear translocation of NF­κB p65 was detected via immunocytochemistry. TargetScan was used to predict the binding sites between miR­502­3p and ROCK1. The interaction between miR­502­3p and Rho­associated coiled­coil­forming protein kinase 1 (ROCK1) was confirmed using a dual­luciferase reporter assay; ROCK1 was demonstrated to be a direct target gene of miR­502­3p. Results from the present study demonstrated that miR­502­3p expression was significantly increased during M. tuberculosis infection in macrophages. Upregulation of miR­502­3p expression levels significantly enhanced the survival of intracellular M. tuberculosis. IL­6, TNF­α, and IL­1ß mRNA expression levels were significantly upregulated during M. tuberculosis infection but were downregulated by miR­502­3p overexpression. Moreover, miR­502­3p mimics transfection significantly downregulated TLR4/NF­κB signaling pathway­associated protein expression and significantly reduced nuclear transcription of NF­κB in M. tuberculosis­infected macrophages. ROCK1 overexpression reversed the miR­502­3p inhibitory effect on cytokine production in M. tuberculosis­infected macrophages. In conclusion, miR­502­3p/ROCK1 may serve an anti­inflammatory role and may improve the survival of M. tuberculosis within macrophages, which may provide a promising therapeutic target for TB.

Phosphorylated STAT3 suppresses microRNA-19b/1281 to aggravate lung injury in mice with type 2 diabetes mellitus-associated pulmonary tuberculosis.

Type 2 diabetes mellitus (T2DM) is a risk factor for pulmonary tuberculosis (PTB) and increased mortality. This work focused on the functions of phosphorylated STAT3 in lung injury in mouse with T2DM-associated PTB and the molecules involved. A mouse model with T2DM-PTB was induced by administrations of streptozotocin, nicotinamide and mycobacterium tuberculosis (Mtb). A pSTAT3-specific inhibitor AG-490 was given into mice and then the lung injury in mice was observed. The molecules involved in AG-490-mediated events were screened out. Altered expression of miR-19b, miR-1281 and NFAT5 was introduced to identify their involvements and roles in lung injury and PTB severity in the mouse model. Consequently, pSTAT3 expression in mice with T2DM-associated PTB was increased. Down-regulation of pSTAT3 by AG-490 prolonged the lifetime of mice and improved the histopathologic conditions, and inhibited the fibrosis, inflammation, Mtb content and number of apoptotic epithelial cells in mouse lung tissues. pSTAT3 transcriptionally suppressed miR-19b/1281 expression to up-regulate NFAT5. Inhibition of miR-19b/1281 or up-regulation of NFAT5 blocked the protective roles of AG-490 in mouse lung tissues. To conclude, this study evidenced that pSTAT3 promotes NFAT5 expression by suppressing miR-19b/1281 transcription, leading to lung injury aggravation and severity in mice with T2DM-associated PTB.

Expression of autophagy-related genes in cerebrospinal fluid of patients with tuberculous meningitis.

The expression of autophagy-related genes in cerebrospinal fluid of patients with tuberculous meningitis (TBM) and their clinical significance in patients with TBM was investigated. Sixty patients with TBM (observation group) and twenty healthy volunteers during the same period (control group) were selected and the cerebrospinal fluid was collected. The expression levels of p62, Beclin1 and LC3-II genes in cerebrospinal fluid were detected via semi-quantitative reverse transcription-polymerase chain reaction and patients in observation group were divided into high expression and normal or low expression group on the basis of LC3-II expression levels. On the other hand, the contents of inflammatory factors interleukin-6, -10 (IL-6, -10), and tumor necrosis factor-α (TNF-α) were detected using the enzyme-linked immunosorbent assay kit. The mRNA levels of p62, Beclin1 and LC3-II in cerebrospinal fluid of patients in observation were significantly higher than those in the control group (P<0.01). TUNEL assay showed that the apoptosis level of cerebro-spinal fluid in high expression was obviously lower than that in normal or low expression group (P<0.01); the content of IL-6 and TNF-α in cerebrospinal fluid in high expression was significantly lower than those in normal or low expression group (P<0.01); the content of IL-10 in cerebrospinal fluid in high expression was obviously higher than that in normal or low expression group (P<0.01). Correlation analysis revealed that LC3-II was positively correlated with IL-10, but negatively correlated with IL-6 and TNF-α. The mRNA levels of p62, Beclin1 and LC3-II in cerebrospinal fluid of patients with TBM are increased, there is a correlation between expression levels of autophagy-related genes and inflammatory factors, and the high expression of autophagy-related genes may have a protective effect on patients with TBM.