The survival and persistence of Mycobacterium tuberculosis depends on its capacity to manipulate multiple host defense pathways, including the ability to actively inhibit the death by apoptosis of infected host cells. The genetic basis for this anti-apoptotic activity and its implication for mycobacterial virulence have not been demonstrated or elucidated. Using a novel gain-of-function genetic screen, we demonstrated that inhibition of infection-induced apoptosis of macrophages is controlled by multiple genetic loci in M. tuberculosis. Characterization of one of these loci in detail revealed that the anti-apoptosis activity was attributable to the type I NADH-dehydrogenase of M. tuberculosis, and was mainly due to the subunit of this multicomponent complex encoded by the nuoG gene. Expression of M. tuberculosis nuoG in nonpathogenic mycobacteria endowed them with the ability to inhibit apoptosis of infected human or mouse macrophages, and increased their virulence in a SCID mouse model. Conversely, deletion of nuoG in M. tuberculosis ablated its ability to inhibit macrophage apoptosis and significantly reduced its virulence in mice. These results identify a key component of the genetic basis for an important virulence trait of M. tuberculosis and support a direct causal relationship between virulence of pathogenic mycobacteria and their ability to inhibit macrophage apoptosis.

Extracts of Anthemis hyalina (Ah), Nigella sativa (Ns) and peels of Citrus sinensis (Cs) have been used as folk medicine to fight antimicrobial diseases. To evaluate the effect of extracts of Ah, Ns and Cs on the replication of coronavirus (CoV) and on the expression of TRP genes during coronavirus infection, HeLa-CEACAM1a (HeLa-epithelial carcinoembryonic antigen-related cell adhesion molecule 1a) cells were inoculated with MHV-A59 (mouse hepatitis virus–A59) at moi of 30. 1/50 dilution of the extracts was found to be the safe active dose. ELISA kits were used to detect the human IL-8 levels. Total RNA was isolated from the infected cells and cDNA was synthesized. Fluidigm Dynamic Array nanofluidic chip 96.96 was used to analyze the mRNA expression of 21 TRP genes and two control genes. Data was analyzed using the BioMark digital array software. Determinations of relative gene expression values were carried out by using the 2−∆∆Ct method (normalized threshold cycle (Ct) value of sample minus normalized Ct value of control). TCID50/ml (tissue culture infectious dose that will produce cytopathic effect in 50 % of the inoculated tissue culture cells) was found for treatments to determine the viral loads. The inflammatory cytokine IL-8 level was found to increase for both 24 and 48 h time points following Ns extract treatment. TRPA1, TRPC4, TRPM6, TRPM7, TRPM8 and TRPV4 were the genes which expression levels changed significantly after Ah, Ns or Cs extract treatments. The virus load decreased when any of the Ah, Ns or Cs extracts was added to the CoV infected cells with Ah extract treatment leading to undetectable virus load for both 6 and 8hpi. Although all the extract treatments had an effect on IL-8 secretion, TRP gene expression and virus load after CoV infection, it was the Ah extract treatment that showed the biggest difference in virus load. Therefore Ah extract is the best candidate in our hands that contains potential treatment molecule(s).Electronic supplementary materialThe online version of this article (doi:10.1007/s11033-014-3019-7) contains supplementary material, which is available to authorized users.

Nod2 is a pattern recognition receptor that modulates host innate immune responses and protects from inflammation, steatosis, and obesity. Obesity and inflammation are risk factors for hepatocellular carcinoma, however, the role of Nod2 in obesity-dependent hepatic tumorigenesis is not known. Here we tested the hypothesis that Nod2 protects from high fat diet (HFD)-dependent hepatic cancer. We used an obesity-dependent hepatic tumor model. WT and Nod2−/− mice were treated with the carcinogen dimethylbenz[a]anthracene (DMBA) and maintained on HFD. Nod2−/− mice treated with DMBA and maintained on HFD gain significantly more weight and develop more liver tumors than similarly treated WT mice. Livers of Nod2−/− tumorigenic mice had increased expression of genes involved in cell proliferation, immune responses, and cholesterol biosynthesis, increased infiltration of neutrophils, inflammatory monocytes, and T cells, and increased activation of STAT3 and ERK during the later stages of tumorigenesis. Bioinformatic analyses of genes with differential expression predicted an increase in cancer, immune, and cholesterol biosynthesis pathways. In summary, we have identified a novel role for Nod2 and demonstrate that Nod2 protects from HFD-dependent liver malignancy and this protection is accompanied by decreased cell proliferation, inflammation, steroid biosynthesis, neutrophils and macrophages infiltration, and STAT3 and MAPK signaling in the liver.

The interaction of Mycobacterium tuberculosis (Mtb) with host cell death signaling pathways is characterized by an initial anti-apoptotic phase followed by a pro-necrotic phase to allow for host cell exit of the bacteria. The bacterial modulators regulating necrosis induction are poorly understood. Here we describe the identification of a transcriptional repressor, Rv3167c responsible for regulating the escape of Mtb from the phagosome. Increased cytosolic localization of MtbΔRv3167c was accompanied by elevated levels of mitochondrial reactive oxygen species and reduced activation of the protein kinase Akt, and these events were critical for the induction of host cell necrosis and macroautophagy. The increase in necrosis led to an increase in bacterial virulence as reflected in higher bacterial burden and reduced survival of mice infected with MtbΔRv3167c. The regulon of Rv3167c thus contains the bacterial mediators involved in escape from the phagosome and host cell necrosis induction, both of which are crucial steps in the intracellular lifecycle and virulence of Mtb.

Aim: The expression differences of SCN8A (which encodes type VIII alpha subunit of voltage gated sodium channel) and NDUFC2 (which encodes C2 subunit of Complex I enzyme in oxidative phosphorylation) genes were evaluated in paired colorectal cancer (CRC) tissues which was relied on our partial transcriptome analysis data in cancer cell lines. Materials and Methods: A total of 62 paired tissues of CRC patients (34 male, 28 female) were included in the study. The mRNA levels of SCN8A and NDUFC2 genes were determined by using real-time PCR (qRT-PCR and semiquantitative PCR). Results: SCN8A gene expression level was significantly lower in tumor tissues (p = 0.0128) and in the patients with the age below 45 years (p = 0.0049). There were also meaningful relationships between the gender, grade of CRC, tumor location, histopathological classification, and SCN8A expression. There was no NDUFC2 differential expression. However, the tumors taken from right colon had significantly lower NDUFC2 expression. Conclusion: Although the voltage gated sodium channels (VGSCs) and Complex I (CI) were associated to a number of diseases including different types of cancers, the different subunits of CI and individual members of VGSCs seem to be cancer type-specific in varying proportions.

Long non-coding RNAs (lncRNAs) are found to play crucial roles in several biological processes and have been associated with many complex human diseases including cancers. Several lines of evidences indicate that lncRNAs deregulated in many cancer tissues. In this particular study, differential expression of long intergenic non-coding RNA 663 (LINC00663) was demonstrated in various cancer cell lines and healthy human tissues by using RT-PCR and qPCR methods. While expression level of LINC00663 was most prominent in thyroid gland and uterus, it is least expressed in skeletal muscle tissues. Moreover, LINC00663 was found to be differentially expressed in various cancer cells. Particularly, its expression was highly diminished in DU-145, PC3, HGC-27, CRL-1469, A549, MCF7, and BCPAP cancer cells. Also, LINC00663 expression was most prominent in A172 glioblastoma cells. Additionally, a novel splice variant of LINC00663 RNA was also detected. The sequence and Basic Local Alignment Search Tool (BLAST) analysis results revealed the presence of a novel exonic region between exons 2 and 3. Subsequently, five potential splice variants showing high level of variation have been identified. Secondary structures of these variants with minimum free energy were also demonstrated. Furthermore, putative microRNA (miRNA) binding sites to these variants have been shown. In conclusion, LINC00663 was shown to be differentially expressed in various human tissues and cancer cell lines. Also, LINC00663 undergoes alternative splicing and the novel exonic region alters its secondary structure and its interactions with potential targeting miRNAs. The role of LINC00663 in cancer formation further needs to be investigated with a wide range of studies.

Staphylococcus aureus is one of the most important pathogen that causes community acquired and nosocomial infections worldwide. Phagocytosis by macrophages plays an important role in the first line defense against infections caused by S.aureus. On the other hand, the conducted studies have indicated that cigarette smoke has negative effects on both innate and acquired immune responses. The aim of this study was to investigate the effects of cigarette smoke on macrophage viability and their capacity of S.aureus phagocytosis. For this purpose THP-1 cell lines (human leukemic monocyte cell culture) were used and after the differentiation of the cells with PMA (phorbol myristate acetate) treatment, the macrophages were exposed to cigarette smoke extract (CSE) for 2- and 4-hours at concentrations of 1%, 5%, 10%, 25%, and 50%. Afterwards, the cells were stained with propidium iodide and the viability of the cells was analyzed by a flow cytometer. Two different methods were used to investigate the effect of CSE on the phagocytosis of S.aureus. The first one was the classical bacteriological method, in which macrophages were exposed to CSE for 2 hours in five different concentrations and were infected with 100 MOI (multiplicity of infection) S.aureus. After 1 hour of incubation, macrophages were lysed with PBS-0.1% Triton X-100 and plated on Luria-Bertani (LB) agar following serial dilutions. Newly formed colonies were counted and the number of bacteria phagocytosed were evaluated as colony forming units (CFU). The second method for the detection of phagocytosis was flow cytometric analysis in which SYBR(®) Green-labeled bacteria were used. To confirm that the macrophages were infected, bacteria were stained with SYBR(®) Green and macrophages were analyzed following infection via flow cytometry. Macrophages were exposed to 10% and 50% CSE and infected with bacteria stained with SYBR(®) Green. The level of phagocytosis was analyzed by flow cytometry in terms of median fluorescence intensity. Macrophage death rate was 24% and 30% following 2-hour exposure to 25% and 50% CSE, respectively, while 4-hour exposure increased death rate to 38% and 51%, respectively (p< 0.001). At 10% and higher concentrations of CSE, cell death increased with an average of 1.5-fold between 2- and 4-hour exposures (p< 0.05). Macrophages were successfully infected (99.8%) with SYBR(®) Green-stained S.aureus. Phagocytosis of S.aureus by macrophages decreased significantly upon exposure to 10% or more CSE concentrations (p< 0.0001). Median fluorescence intensity, which indicates phagocytosed bacterial cell number, decreased with no statistical significance when macrophages exposed to 10% and 50% CSE were infected with SYBR(®) Green-stained S.aureus. The results of this study revealed that, macrophage viability and phagocytosis of S.aureus were reduced depending on CSE concentration and time of exposure. In addition, it was shown that, SYBR(®) Green dye is a proper stain for the flow cytometric analysis of bacteria that were phagocytosed by macrophages.

Nod2 is involved in innate immunity to bacteria, regulation of metabolism, and sensitivity to cancer. Nod2 polymorphism is associated with breast cancer, but the role of Nod2 in the development and progression of breast cancer is unknown. Here, we tested the hypothesis that Nod2 protects mice from breast cancer using the 4T1 orthotopic model of mammary tumorigenesis. We demonstrate that Nod2−/− mice have higher incidence and larger tumors than WT mice. Detailed analysis of the tumor transcriptome showed that Nod2−/− mice had increased expression of genes that promote DNA replication and cell division and decreased expression of genes required for lipolysis, lipogenesis, and steroid biosynthesis compared with WT mice. Nod2−/− mice also had lower expression of genes required for adipogenesis and higher delipidation than WT mice. The tumors in Nod2−/− mice had decreased expression of genes associated with PPARα/γ signaling, increased activation of STAT3, decreased activation of STAT5, and no change in the activation of ERK compared with WT mice. Thus, we demonstrate that Nod2 protects mice from the 4T1 orthotopic breast tumor, and that tumors in Nod2−/− mice have higher DNA replication, cell cycling and delipidation than WT mice.