Wanjiang Zhang

NRAMP1, VDR, HLA-DRB1, and HLA-DQB1 Gene Polymorphisms in Susceptibility to Tuberculosis among the Chinese Kazakh Population: A Case-Control Study

Background. To explore the potential role of natural-resistance-associated macrophage protein 1 (NRAMP1) gene, vitamin D receptor (VDR) gene, (human leukocyte antigen, (HLA-DRB1) HLA) -DRB1 gene, and HLA-DQB1 gene polymorphisms in susceptibility to tuberculosis (TB) in the Chinese Kazakh population. Methods. A case-control study was performed on the Chinese Kazak population. Genetic polymorphisms of NRAMP1 gene (3′UTR) and VDR gene (TaqI and FokI) were analysed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing analysis in TB patients and healthy controls. Genetic polymorphisms of HLA-DRB1 gene and HLA-DQB1 gene in the two groups were detected with polymerase chain reaction-sequence-specific primers (PCR-SSPs) technique and sequencing analysis. Results. There was statistically significant difference in the 3′UTR polymorphism between the TB patients and healthy controls in the Chinese Kazak population (P = 0.002; OR = 1.859; 95% CI = 1.182–2.926). Significant difference was observed in the FokI polymorphism between the TB patients and healthy controls (P = 0.001; OR = 1.530; 95% CI = 1.007–2.325). It does not disclose any significant association between the disease and TaqI (P > 0.05). Alleles HLA-DRB1∗04 and HLA-DQB1∗0201 occurred more frequently in patients than in controls (P = 0.011 and 0.002; OR = 1.889 and 1.802; 95% CI = 1.153–3.095 and 1.230–2.639, resp.). Conclusions. Polymorphisms in the NRAMP1 gene, VDR gene, HLA-DRB1 gene, and HLA-DQB1 gene are statistically associated with susceptibility to TB in the Chinese Kazakh population.

Association of the miR-146a, miR-149, miR-196a2 and miR-499 polymorphisms with susceptibility to pulmonary tuberculosis in the Chinese Uygur, Kazak and Southern Han populations

BackgroundSingle nucleotide polymorphisms (SNPs) within precursor microRNAs (miRNAs) can affect miRNAs expression, and may be involved in the pathogenesis of pulmonary tuberculosis (TB). This study aimed to investigate potential associations between the four precursor miRNA SNPs (miR-146a C > G, miR-149 T > C, miR-196a2 T > C, and miR-499 T > C) and susceptibility to pulmonary TB in the Chinese Uygur, Kazak, and Southern Han populations.MethodsA case-control study was performed on Chinese Uygur (n = 662), Kazak (n = 612), and Southern Han (n = 654) populations using the PCR-PFLR method. The allele and genotype frequencies for all populations were analyzed. Linkage disequilibrium was performed, and different models of inheritance were tested.ResultsThe allele and genotype frequencies of the miR-499 SNP were significantly different between the TB patients group and the healthy control group in the Uygur population, and were found to be codominant, dominant, recessive and additive models in association with pulmonary TB. The haplotype CTCC showed significant correlation with pulmonary TB. The allele and genotype frequencies of miR-146a and miR-196a2 SNPs were significantly different between the two groups in the Kazak population. The miR-146a SNP was found to be codominant, recessive and additive models, whereas, the miR-196a2 SNP was found to be codominant, dominant, and additive models in association with pulmonary TB. The haplotypes TCCC and CCCT showed significant correlation with pulmonary TB.ConclusionsThe results suggested that susceptibility to pulmonary TB may be closely related to individual differences caused by genetic factors among different ethnic groups in China.

A novel single nucleotide polymorphism within the NOD2 gene is associated with pulmonary tuberculosis in the Chinese Han, Uygur and Kazak populations

BackgroundThe present study aimed to investigate the genetic polymorphisms in exon 4 of the NOD2 gene in tuberculosis patients and healthy controls, in order to clarify whether polymorphisms in the NOD2 gene is associated with tuberculosis.MethodsA case-control study was performed on the Chinese Han, Uygur and Kazak populations. Exon 4 of the NOD2 gene was sequenced in 425 TB patients and 380 healthy controls to identify SNPs.ResultsThe frequency of T/G genotypes for the Arg587Arg (CGT → CGG) single nucleotide polymorphism (SNP) in NOD2 was found to be significantly higher in the Uygur (34.9%) and Kazak (37.1%) populations than the Han population (18.6%). Also, the frequency of G/G genotypes for the Arg587Arg SNP was significantly higher in the Uyghur (8.3%) and Kazak (5.4%) populations than the Han population (0.9%). Meanwhile, no significant difference was found in the Arg587Arg polymorphism between the tuberculosis patients and healthy controls in the Uyghur and Kazak populations (P > 0.05) whereas, a significant difference was observed in the Arg587Arg polymorphism between the tuberculosis patients and healthy controls in the Han population (P < 0.01). The odd ratio of 2.16 (95% CI = 1.31-3.58; P < 0.01) indicated that the Arg587Arg SNP in NOD2 may be associated with susceptibility to tuberculosis in the Chinese Han population.ConclusionsOur study is the first to demonstrate that the Arg587Arg SNP in NOD2 is a new possible risk factor for tuberculosis in the Chinese Han population, but not in the Uyghur and Kazak populations. Our results may reflect racial differences in genetic susceptibility to tuberculosis.

Suppression of Mcl‐1 induces apoptosis in mouse peritoneal macrophages infected with Mycobacterium tuberculosis

The effect of myeloid cell leukemia‐1 (Mcl‐1) inhibition on apoptosis of peritoneal macrophages in mice infected with Mycobacterium tuberculosis was investigated and the primary signaling pathway associated with the transcriptional regulation of Mcl‐1 was identified. Real‐time PCR and western blotting indicated that Mcl‐1 transcript and protein expression are upregulated during infection with virulent M. tuberculosis H37Rv and Xinjiang strains but not with attenuated M. tuberculosis strain H37Ra or Bacillus Calmette–Guérin. Mcl‐1 transcript and protein expression were downregulated by specific inhibitors of the Janus kinase/signal transducer and activator of transcription (JAK/STAT), mitogen‐activated protein kinase (MAPK) and phosphoinositol 3‐kinase (PI3K) pathways (AG490, PD98059 and LY294002, respectively). The strongest inhibitor of Mcl‐1 expression was PD98059, the MAPK inhibitor. Flow cytometry demonstrated that the rate of apoptosis in peritoneal macrophages is significantly higher in mice infected with M. tuberculosis and the rate of apoptosis is correlated with the virulence of the strain of M. tuberculosis. Apoptosis was found to be upregulated by AG490, PD98059 and LY294002, whereas inhibition of the MAPK pathway sensitized the infected macrophages to apoptosis. Taken together, these results suggest that specific downregulation of Mcl‐1 significantly increases apoptosis of peritoneal macrophages and that the MAPK signaling pathway is the primary mediator of Mcl‐1 expression.

Single Nucleotide Polymorphisms in P2X7 Gene Are Associated with Serum Immunoglobulin G Responses to Mycobacterium tuberculosis in Tuberculosis Patients

Objective. Our study investigated the association between single nucleotide polymorphisms (SNPs) in P2X7 gene and serum immunoglobulin G (IgG) responses to mycobacterium tuberculosis (MTB) in TB patients. Methods. A total of 103 TB patients were enrolled as case group and 87 healthy individuals at same geographical region as control group. The SNP detection of 1513A>C and -762T>C was performed using PCR-RFLP, and the levels of serum IgG responses to MTB in all subjects were determined. Results. AC and CC of 1513A>C and TC and CC of -762T>C had higher frequencies in case group than in control group. TB patients carrying TC and CC of -762T>C had higher positive rate of IgG responses to MTB than those carrying TT. Additionally, patients carrying TC and CC of -762T>C had more MTB in sputum than those carrying TT. Conclusion. P2X7 SNPs, 1513A>C and -762T>C, may be associated with the susceptibility to tuberculosis, and -762T>C SNP may contribute to the development of MTB. The mutant genotype of -762T>C (TC and CC) may lower human capability of phagocytosis to MTB, leading to an increased morbidity of TB.

A small hairpin RNA targeting myeloid cell leukemia-1 enhances apoptosis in host macrophages infected with Mycobacterium tuberculosis

Myeloid cell leukemia-1 (Mcl-1) plays an important role in various cell survival pathways. Some studies indicated that the expression of Mcl-1 was upregulated in host cells during infection with the virulent Mycobacterium tuberculosis strain, H37Rv. The present study was designed to investigate the effect of inhibiting Mcl-1 expression both in vivo and in vitro on apoptosis of host macrophages infected with M. tuberculosis using a small hairpin (sh)RNA. Mcl-1 expression was detected by the real time-polymerase chain reaction, western blotting, and immunohistochemistry. Flow cytometry and transmission electron microscopy were used to measure host macrophage apoptosis. We found elevated Mcl-1 levels in host macrophages infected with M. tuberculosis H37Rv. The expression of Mcl-1 was downregulated efficiently in H37Rv-infected host macrophages using shRNA. Knockdown of Mcl-1 enhanced the extent of apoptosis in H37Rv-infected host macrophages significantly. The increased apoptosis correlated with a decrease in M. tuberculosis colony forming units recovered from H37Rv-infected cells that were treated with Mcl-1-shRNA. Reducing Mcl-1 accumulation by shRNA also reduced accumulation of the anti-apoptotic gene, Bcl-2, and increased expression of the pro-apoptotic gene, Bax, in H37Rv-infected host macrophages. Our results showed that specific knockdown of Mcl-1 expression increased apoptosis of host macrophages significantly and decreased the intracellular survival of a virulent strain of M. tuberculosis. These data indicate that interference with Mcl-1 expression may provide a new avenue for tuberculosis therapy.

A novel HLA-DRB1 allele, DRB1*16:36 identified in a Chinese individual from the Xinjiang region

A novel class II human leukocyte antigen allele HLA-DRB1*16:36 is described.

Identification of key genes and pathways using bioinformatics analysis in septic shock children

Background and hypothesis Sepsis is still one of the reasons for serious infectious diseases in pediatric intensive care unit patients despite the use of anti-infective therapy and organ support therapy. As it is well-known, the effect of single gene or pathway does not play a role in sepsis. We want to explore the interaction of two more genes or pathways in sepsis patients for future works. We hypothesize that the discovery from the available gene expression data of pediatric sepsis patients could know the process or improve the situation. Methods and results The gene expression profile dataset GSE26440 of 98 septic shock samples and 32 normal samples using whole blood-derived RNA samples were generated. A total of 1,108 upregulated and 142 downregulated differentially expressed genes (DEGs) were identified in septic shock children using R software packages. The Gene Ontology (GO) enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were analyzed using DAVID software; Gene Set Enrichment Analysis method was also used for enrichment analysis of the DEGs. The protein-protein interaction (PPI) network and the top 10 hub genes construction of the DEGs were constructed via plug-in Molecular Complex Detection and cytoHubba of Cytoscape software. From the PPI network, the top 10 hub genes, which are all upregulated DEGs in the septic shock children, were identified as GAPDH, TNF, EGF, MAPK3, IL-10, TLR4, MAPK14, IL-1β, PIK3CB, and TLR2. Some of them were involved in one or more significant inflammatory pathways, such as the enrichment of tumor necrosis factor (TNF) pathway in the activation of mitogen-activated protein kinase activity, toll-like receptor signaling pathway, nuclear factor-κB signaling pathway, PI3K-Akt signaling pathway, and TNF signaling pathway. These findings support future studies on pediatric septic shock.

Effect of early fluid resuscitation combined with low dose cyclophosphamide on intestinal barrier function in severe sepsis rats

To investigate the effect of early fluid resuscitation on intestinal microecology in rats with severe sepsis. The severe sepsis model used was mainly cecal ligation perforation (CLP) model. Male SD rats were randomly divided into five groups: sham, CLP, CLP + normal saline (NS), CLP + cyclophosphamide (CTX), and CLP + NS + CTX. (1) The levels of IL-6, IL-10, and TNF-α in peripheral blood were measured by ELISA. (2) The expression of occludin/β-action in colonic tissue of mice was examined by Western Blot. (3) The intestinal permeability was measured by FD70 detection. (4) The length of the chorionic membrane was measured by colon histopathological staining. (5) The intestinal epithelial cell apoptosis was measured with the apoptosis index. (1) The rat model of severe sepsis was successfully replicated, and the 7-day survival rate of sepsis mice in each group was analyzed. (2) The expression level of splenic junction protein and the pathological damage in colonic tissue of the severe sepsis mice was significantly different between sham, CLP, CTX, NS, and NS + CTX (P < 0.05). The expression of tight junction protein in the NS + CTX mice was the highest, and the pathological damage was the smallest. (3) The colonic tissue apoptosis and intestinal permeability in the severe sepsis mice were compared with those of the colon tissues (P < 0.05). (4) The expression levels of IL-6, IL-10, and TNF-α in peripheral blood were significantly increased after severe sepsis (P < 0.01). The expression of IL-6 and TNF-alpha in each treatment group decreased (P < 0.05), while the expression of IL-10 in NS + CTX group increased significantly (P < 0.01). (1) We successfully replicated the rat model of severe sepsis. (2) Early fluid intervention and cyclophosphamide treatment can significantly improve the 7-day survival rate of the sepsis mice. (3) The fluid resuscitation and cyclophosphamide can delay intestinal damage to the intestinal tract barrier function and play a protective role.