Selenium Deficiency Influences the Gene Expressions of Heat Shock Proteins and Nitric Oxide Levels in Neutrophils of Broilers

The aim of the present study was to investigate the effects of selenium (Se) deficiency on the expressions of heat shock proteins (Hsp90, 70, 60, 40, and 27) and nitric oxide (NO) levels in neutrophils of broilers. One hundred eighty 1-day-old broilers were randomly assigned into two groups and were fed on a low-Se diet (0.008 mg/kg Se) or a control diet (0.2 mg/kg Se), respectively. Then, the messenger RNA (mRNA) levels of Hsp90, 70, 60, 40, and 27, induced nitric oxide synthase (iNOS), and NO levels were examined. The results showed that Se deficiency increased the mRNA levels of Hsps and iNOS and induced higher level of NO in chicken neutrophils (P?iNOS had the biggest correlation with Hsp60, which indicated that Hsp60 might play an important function in inhibiting the production of NO, and the correlation coefficient between Hsp60 and Hsp70 was over 0.9, which indicated that they might have a synergistic effect. These results suggested that the level of NO and Hsp expression levels in neutrophils can be influenced by Se deficiency. And Hsp40 might play the crucial protective role in neutrophils induced by Se deficiency.     

Apparent Reduction of ADAM10 in Scrapie-Infected Cultured Cells and in the Brains of Scrapie-Infected Rodents

It has been described that A disintegrin and metalloproteinase (ADAM10) may involve in the physiopathology of prion diseases, but the direct molecular basis still remains unsolved. In this study, we confirmed that ADAM10 was able to cleave recombinant human prion protein in vitro. Using immunoprecipitation tests (IP) and immunofluorescent assays (IFA), reliable molecular interaction between the native cellular form of PrP (PrP^C) and ADAM10 was observed not only in various cultured neuronal cell lines but also in brain homogenates of healthy hamsters and mice. Only mature ADAM10 (after removal of its prodomain) molecules showed the binding activity with the native PrP^C. Remarkably more prion protein (PrP)-ADAM10 complexes were detected in the membrane fraction of cultured cells. In the scrapie-infected SMB cell model, the endogenous ADAM10 levels, especially the mature ADAM10, were significantly decreased in the fraction of cell membrane. IP and IFA tests of prion-infected SMB-S15 cells confirmed no detectable PrP-ADAM10 complex in the cellular lysates and PrP-ADAM10 co-localization on the cell surface. Furthermore, we demonstrated that the levels of ADAM10 in the brain homogenates of scrapie agent 263K-infected hamsters and agent ME7-infected mice were also almost diminished at the terminal stage, showing time-dependent decreases during the incubation period. Our data here provide the solid molecular basis for the endoproteolysis of ADAM10 on PrP molecules and interaction between ADAM10 and PrP^C. Obvious loss of ADAM10 during prion infection in vitro and in vivo highlights that ADAM10 may play essential pathophysiological roles in prion replication and accumulation.     

Quercetin Potentiates the Antitumor Activity of Rituximab in Diffuse Large B-Cell Lymphoma by Inhibiting STAT3 Pathway

STAT3 pathway plays an important role in the growth of diffuse large B-cell lymphoma (DLBCL) cells. Here we investigated the antitumor activity of Quercetin, a flavonoid compound, in combination with rituximab in DLBCL cell lines in vitro. We found that Quercetin synergistically enhanced rituximab-induced growth inhibition and apoptosis in DLBCL cell lines. Moreover, we found Quercetin exerted inhibitory activity against STAT3 pathway and downregulated the expression of survival genes. These results suggest that combining the Quercetin with rituximab may present an attractive and potentially effective way for the treatment of DLBCL.     

Polymorphism of DNA Repair Gene xrcc1 and Lung Cancer Risk

The current large-scale meta-analysis was performed to reach a reliable conclusion on the association between X-ray repair cross-complementing 1 (xrcc1) rs1799782 and the development of lung cancer. Studies that investigated the association between rs1799782 and lung cancer risk were identified by searching PubMed. We calculated odds ratio (OR) with corresponding 95 % confidence interval (CI) for Trp/Trp vs Arg/Arg, Trp/Trp + Arg/Trp vs Arg/Arg, and Trp/Trp vs Arg/Trp + Arg/Arg contrast models. Combining all 25 studies, we yielded three summary ORs: 1.07 (95 % CI 0.92–1.23) for Trp/Trp vs Arg/Arg, 0.93 (95 % CI 0.87–1.00) for Trp/Trp + Arg/Trp vs Arg/Arg, and 1.08 (95 % CI 0.94–1.25) for Trp/Trp vs Arg/Trp + Arg/Arg, suggesting rs1799782 was not associated with overall risk of lung cancer. Strikingly, a significantly deceased risk was found among Caucasian populations (Trp/Trp + Arg/Trp vs Arg/Arg, OR = 0.86, 95 % CI 0.76–0.97). This study confirms that xrcc1 rs1799782 may lower the risk of lung cancer among Caucasians.     

EGFR-AKT-mTOR activation mediates epiregulin-induced pleiotropic functions in cultured osteoblasts

Epidermal growth factor (EGF) receptor (EGFR) emerges as an essential molecule for the regulating of osteoblast cellular functions. In the current study, we explored the effect of epiregulin, a new EGFR ligand, on osteoblast functions in vitro, and studied the underlying mechanisms. We found that epiregulin-induced EGFR activation in both primary osteoblasts and osteoblast-like MC3T3-E1 cells. Meanwhile, epiregulin activated AKT-mammalian target of rapamycin (mTOR) and Erk-mitogen-activated protein kinase (MAPK) signalings in cultured osteoblasts, which were blocked by EGFR inhibitor AG1478 or monoclonal antibody against EGFR (anti-EGFR). Further, in primary and MC3T3-E1 osteoblasts, epiregulin promoted cell proliferation and increased alkaline phosphatase activity, while inhibiting dexamethasone (Dex)-induced cell death. Such effects by epiregulin were largely inhibited by AG1478 or anti-EGFR. Notably, AKT-mTOR inhibitors, but not Erk inhibitors, alleviated epiregulin-induced above pleiotropic functions in osteoblasts. Meanwhile, siRNA depletion of Sin1, a key component of mTOR complex 2 (mTORC2), also suppressed epiregulin-exerted effects in MC3T3-E1 cells. Together, these results suggest that epiregulin-induced pleiotropic functions in cultured osteoblasts are mediated through EGFR-AKT-mTOR signalings.     

Identification of nucleolus-localized PTEN and its function in regulating ribosome biogenesis

The tumor suppressor PTEN is a lipid phosphatase that is found mutated in different types of human cancers. PTEN suppresses cell proliferation by inhibiting the PI3K-Akt signaling pathway at the cell membrane. However, PTEN is also demonstrated to localize in the cell nucleus where it exhibits tumor suppressive activity via a different, unknown mechanism. In this study we report that PTEN also localizes to the nucleolus and that nucleolar PTEN plays an important role in regulating nucleolar homeostasis and maintaining nucleolar morphology. Overexpression of nuclear PTEN in PTEN null cells inhibits Akt phosphorylation and reduces cell size. Knockdown of PTEN in PTEN positive cells leads to nucleolar morphologic changes and an increase in the proportion of cells with a greater number of nucleoli. In addition, knockdown of PTEN in PTEN positive cells increased ribosome biogenesis. These findings expand current understanding of function and relevance of nuclear localized PTEN and provide a foundation for the development of novel therapies targeting PTEN.     

Mechanism of bFGF-binding Peptide Reversing Adriamycin Resistance in Human Gastric Cancer Cells

Development of drug resistance is a challenging problem in cancer chemotherapy. It has been shown that basic fibroblast growth factor (bFGF) plays an important role in an epigenetic mechanism of drug resistance. We have isolated a bFGF binding peptide P7 with inhibitory activity against bFGF-induced proliferation of human gastric cancer cells by screening a phage display library. In this study, we found that P7 peptide also has efficacy of reversing bFGF-induced resistance to Adriamycin (ADM) in human gastric cancer cells. Further investigations with SGC-7901 cells revealed that inhibition of Akt activation triggered by bFGF, and reversal of bFGF-induced up-regulation of Bcl-2 and XIAP and down-regulation of Bax, contribute to P7 peptide counteracting the anti-apoptotic effect of bFGF, and further reversing bFGF-induced resistance to ADM. The results suggested that the bFGF-binding peptide may have therapeutic potential of drug resistance in gastric cancer.     

Expression of TNF-α, IFN-γ, TGF-β, and IL-4 in the Spinal Tuberculous Focus and Its Impact on the Disease

To investigate the expression of TNF-α, IFN-γ, TGF-β, and IL-4 in the spinal tuberculous focus and its relationship with the lesions type, severity, and bone destruction. The pathological samples of patients with spinal tuberculosis (TB) were divided into hyperplasia group and necrosis group according to their intra-operative and post-operative pathological findings. Normal bone tissues were taken as the control group. Pathology and expression of TNF-α, IFN-γ, TGF-β, and IL-4 in different tissues were compared among these three groups using immunohistochemical staining, quantitative image analysis, and measurement of bone tissue. 286 granulomas observed in the 14 samples in the hyperplasia group, which included 84 necrotizing and 202 non-necrotizing granulomas. As for the 20 samples in the necrosis group, there were 356 necrotizing and 186 non-necrotizing granulomas among all the 542 granulomas. The proportion of necrotizing granulomas in the necrosis group was significantly higher than that of the hyperplasia group. By inter-group comparison, expression of TNF-α, IFN-γ of granulomas in the hyperplasia group was significantly higher than that of the necrosis group, while the expression of TGF-β, IL-4 of granulomas in the necrosis group was significantly higher than that of the hyperplasia group. Also, expression of IFN-γ of non-necrotizing granulomas was significantly higher than that of necrotizing granulomas in the hyperplasia group, and expression of TGF-β in necrotizing granulomas was significantly higher than that of non-necrotizing granulomas in the necrosis group. The lesions were mainly bone resorption in the hyperplasia group, whereas mostly necrotic bones accompanied by local fibrosis in the necrosis group. Expression levels of TNF-α, IFN-γ in the hyperplasia group have a positive correlation to bone loss, whereas expression levels of TGF-β, IL-4 in the necrosis group have a positive correlation to the bone formation. The high expressions of TNF-α, IFN-γ in the spinal tuberculous focus were associated with protective immune cells. TGF-β and IL-4 were related to allergic lesions, fibrosis and osteogenesis. Expression imbalance of TNF-α, IFN-γ, TGF-β, and IL-4 might aggravate the allergy of TB.     

Mutations in microRNA Binding Sites of CEP Genes Involved in Cancer

The CEP genes play a pivotal role in the replication of the cell. CEP family proteins form the major constituents of the centrosome and play a prominent role in centriole biogenesis and in cell replication. Alteration in CEP genes will result in disruption of cell cycle that may in turn cause cancer. In our study, we found that 16 of the CEP genes are a potential target to miRNA that binds to complementary sequences in 3′untranslated regions (UTR) of mRNA and stop them from translation. Single nucleotide polymorphisms (SNPs) occurring naturally in such miRNA binding site can alter the miRNA: mRNA interaction and can significantly alter gene expression. We developed a systematic computational pipeline that integrates data from well-established databases, followed stringent selection criteria and identified a panel of 44 high-confidence SNPs that may impair miRNA target sites in the 3′UTR of 16 genes. Further we performed expression analysis to shed light on the potential tissues that might be affected by mutation, enrichment analysis to find the metabolic functions of the gene, and network analysis to highlight the important interactions of CEP genes with other genes to provide insight that complex network will be disturbed upon mutation. In this study, we explored and prioritised the SNPs in CEP gene which could act as a potential target in centrosome-associated human disease. Our analysis would provide a thoughtful insight to wet lab researches to understand the expression pattern of CEP genes and binding phenomenon of mRNA and miRNA upon mutation, which is responsible for inhibition of translation process at genomic levels.     

Ribosomal RNA contents of maize genotypes with different ribosomal RNA gene numbers

Ribosomal RNA (rRNA) contents were determined in 16 maize genotypes whose individual rRNA gene numbers varied from 5000 to 23,000 per 2C nucleus. Analytical polyacrylamide gel electrophoresis of total RNA showed that no obvious relation existed between rRNA gene number and rRNA content. Only two of nine common inbred lines contained more rRNA than W-23, the inbred with the lowest rRNA gene number. Two of four lines with altered protein content (due to long-term experimental selection) had rRNA contents significantly reduced from those of W-23. A line with an apparent duplication of the nucleolus organizer region of chromosome 6 (called 2-NOR) was expected to possess an elevated quantity of rRNA because it possesses a larger nucleolus; however, we produced a 2-NOR isogenic version and found no difference in rRNA content. The rRNA genes in maize are distributed throughout the NOR-heterochromatin and the NOR-secondary constriction portions of the NOR. The absence of an obvious correlation between rRNA gene number and cellular rRNA content may reflect the presence of a large number of rRNA genes in an inactive state, at least during the stage of growth examined in these experiments.     

Silica nanoparticles induce oxidative stress and inflammation of human peripheral blood mononuclear cells

In the present study, the effects of 10- or 100-nm silica oxide (SiO₂) NPs on human peripheral blood mononuclear cells (PBMC) were examined. Cytotoxic effects and oxidative stress effects, including glutathione (GSH) depletion, the formation of protein radical species, and pro-inflammatory cytokine responses, were measured. PBMC exposed to 10-nm NP concentrations from 50 to 4,000 ppm showed concentration-response increases in cell death; whereas, for 100-nm NPs, PBMC viability was not lost at <500 ppm. Interestingly, 10-nm NPs were more cytotoxic and induced more oxidative stress than 100-nm NPs. Immunoelectron micrographs show the cellular distribution of GSH and NPs. As expected based on the viability data, the 10-nm NPs disturbed cell morphology to a greater extent than did the 100-nm NPs. Antibody to the radical scavenger, 5,5-dimethyl-1-pyrroline N-oxide (DMPO), was used for Western blot analysis of proteins with radicals; more DMPO proteins were found after exposure to 10-nm NPs than 100-nm NPs. Examination of cytokines (TNF-α, IL-1ra, IL-6, IL-8, IL-1β, and IFN-γ) indicated that different ratios of cytokines were expressed and released after exposure to 10- and 100-nm NPs. IL-1β production was enhanced by 10- and 100-nm NPs;, the cytotoxicity of the NPs was associated with an increase in the IL-1β/IL-6 ratio and 100-nm NPs at concentrations that did not induce loss of cell viability enhanced IL-1β and IL-6 to an extent similar to phytohemagglutinin (PHA), a T cell mitogen. In conclusion, our results indicate that SiO₂ NPs trigger a cytokine inflammatory response and induce oxidative stress in vitro, and NPs of the same chemistry, but of different sizes, demonstrate differences in their intracellular distribution and immunomodulatory properties, especially with regard to IL-1β and IL-6 expression.     

Key enzymes of degradation and angiogenesis as factors of tumor progression for squamous-cell cervical carcinoma

Destruction of the connective tissue matrix (CTM) and angiogenesis are the two processes playing a key role in tumor progression. Matrix metalloproteinases (MMPs) play a leading role in processes of tissue destruction. Tissue collagenases MMP-1 and MT1-MMP hydrolyze fibrillar collagens constituting the base of CTM and enable tumor invasion. Gelatinases A and B (MMP-2 and MMP-9) hydrolyze type IV collagen which is the main component of basal membranes and contribute to the development of metastases. Endogenous activators and inhibitors are involved in the regulation of expression and activity of these enzymes. MMP-9 was shown to release vascular endothelial growth factor (VEGF), the principal inductor of angiogenesis, bound to CTM. Angiotensin-converting enzyme (ACE) is involved in the induction of VEGF synthesis and stimulation of endothelial cell proliferation mediated by angiotensin II (AII) and its type 1 receptor (AT1R). Experiments reported in the present article addressed the distinctive features of expression of key degradation and angiogenesis enzymes in squamous cell carcinoma (SCC) of the cervix. MMP-1, MT1-MMP, MMP-2, and MMP-9 and their endogenous regulators TIMP-1 and TIMP-2, as well as ACE, were the objects of research. Experiments were performed with clinical specimens including tumor tissue samples, for which presence or absence of metastasis to regional lymph nodes was taken into account, and morphologically normal tissue samples. Increased expression of MMP-1, MT1-MMP, and MMP-9 and decreased expression of TIMP-1 and TIMP-2 were shown to make the principal contribution to the destructive (invasive) potential of cervical carcinomas; the effect of changes in MMP-2 expression was less pronounced. Dramatically increased expression of MMP-1 and MMP-9 was evident in metastasizing tumors. ACE activity in tumor samples was generally higher than activity in normal tissue. Substantial expression of MMP-1, MMP-2, MMP-9, and ACE was detected in morphologically normal tissue adjacent to the tumor; this can contribute to increased destructive potential of a tumor. The data reported are important for understanding the mechanisms of tumor progression, have prognostic value, and may affect the choice of individual therapeutic strategy for the patients.