VCP Phosphorylation-Dependent Interaction Partners Prevent Apoptosis in Helicobacter pylori-Infected Gastric Epithelial Cells

Previous studies have demonstrated that valosin-containing protein (VCP) is associated with H. pylori-induced gastric carcinogenesis. By identifying the interactome of VCP overexpressed in AGS cells using a subtractive proteomics approach, we aimed to characterize the cellular responses mediated by VCP and its functional roles in H. pylori-associated gastric cancer. VCP immunoprecipitations followed by proteomic analysis identified 288 putative interacting proteins, 18 VCP-binding proteins belonged to the PI3K/Akt signaling pathway. H. pylori infection increased the interaction between Akt and VCP, Akt-dependent phosphorylation of VCP, levels of ubiquitinated proteins, and aggresome formation in AGS cells. Furthermore, phosphorylated VCP co-localized with the aggresome, bound ubiquitinated proteins, and increased the degradation of cellular regulators to protect H. pylori-infected AGS cells from apoptosis. Our study demonstrates that VCP phosphorylation following H. pylori infection promotes both gastric epithelial cell survival, mediated by the PI3K/Akt pathway, and the degradation of cellular regulators. These findings provide novel insights into the mechanisms of H. pylori infection induced gastric carcinogenesis.     

Soluble Guanylate Cyclase α1–Deficient Mice: A Novel Murine Model for Primary Open Angle Glaucoma

Primary open angle glaucoma (POAG) is a leading cause of blindness worldwide. The molecular signaling involved in the pathogenesis of POAG remains unknown. Here, we report that mice lacking the α₁ subunit of the nitric oxide receptor soluble guanylate cyclase represent a novel and translatable animal model of POAG, characterized by thinning of the retinal nerve fiber layer and loss of optic nerve axons in the context of an open iridocorneal angle. The optic neuropathy associated with soluble guanylate cyclase α₁–deficiency was accompanied by modestly increased intraocular pressure and retinal vascular dysfunction. Moreover, data from a candidate gene association study suggests that a variant in the locus containing the genes encoding for the α₁ and β₁ subunits of soluble guanylate cyclase is associated with POAG in patients presenting with initial paracentral vision loss, a disease subtype thought to be associated with vascular dysregulation. These findings provide new insights into the pathogenesis and genetics of POAG and suggest new therapeutic strategies for POAG.     

Overexpression of EMMPRIN is associated with lymph node metastasis and advanced stage of non-small cell lung cancer: a retrospective study

Background

Previous studies show that overexpression of EMMPRIN involved in the malignant biological behavior of tumors. This investigation was to disclose the expression status of EMMPRIN in non-small cell lung cancer (NSCLC) and its clinical value for the diagnosis of NSCLC.

Methods

The expression of EMMPRIN was examined using immunohistochemistry and enzyme-linked immunosorbent assay. The clinical value of EMMPRIN was evaluated by drawing a receiver operating characteristic (ROC) curve.

Results

NSCLC tissues and serum exhibited higher expression levels of EMMPRIN than the normal control (p?<?0.05), and the expression of the EMMPRIN was significantly associated with lymphatic invasion and advanced stage of NSCLC (p?<?0.05). ROC curve suggested that the threshold level of serum EMMPRIN for distinguishing NSCLC from control group was 80.3 pg/mL, and displayed a sensitivity of 97.22% and a specificity of 95%. And higher EMMPRIN expression in serum and tissues appeared to be risk factors for NSCLC development (risk ratio =1.56 and 1.1).

Conclusion

Overexpression of EMMPRIN was associated with lymphatic metastasis and advanced stage of NSCLC and test of serum EMMPRIN contributes to the NSCLC diagnosis.

     

Study of human chromosome V

Summary The induction of fragile sites on human chromosomes has been demonstrated under various conditions that cause thymidylate stress, including exposure to uridine. In this study, we examined common fragile site expression by initially exposing peripheral lymphocytes to uridine, followed by repair of the fragile sites with media containing various concentrations of thymidine. Lymphocytes were cultured in medium 199 with 2 mM uridine. At 0.5, 1, 2, 3, 8, 10, 12, and 18 h before harvest, the uridine medium was removed and replaced by medium containing thymidine at various concentrations. Our results demonstrate that the effect of uridine on chromosome fragility can be reversed by low concentrations of thymidine (2 M up to 200 M) and the rescuing effect of thymidine can be achieved if the cells were treated prior to 2–3 h before harvest. No repair was found if thymidine was added to culture within 2 h prior to harvesting, suggesting that packing of chromosomes is also an important factor in the expression and repair of fragile sites.     

Enhancement of the mutagenicity of IQ and MeIQ by nitrite in the Salmonella system.

The fried food mutagens IQ, MeIQ, Glu-P-1 and Trp-P-2 were treated with nitrite at pH 3.0 for 1 h at 37 degrees C. The resulting reaction mixtures were tested for mutagenicity towards Salmonella typhimurium TA97, TA98, TA100 and TA1535. Glu-P-1 and Trp-P-2 were readily converted to weak or non-mutagenic deaminated compounds, whereas IQ and MeIQ were converted to extremely strong mutagenic derivatives in both the presence and the absence of rat liver S9 mix. The mutagenicity of MeIQ in TA98 was enhanced by nitrite up to 3-fold, while that of nitrosated MeIQ was further enhanced by S9 mix up to 15-fold. The nitrosation products of MeIQ were resolved into 7 bands by TLC on silica gel plate. Bands I, III, V and VI were highly mutagenic to both TA98 and TA100. The experimental results suggest that the non-enzymatic formation of direct-acting mutagens from indirect-acting mutagens such as IQ or MeIQ might be physiologically important, especially with regard to the etiology of human gastrointestinal tract tumors.     

杜氏盐藻(Dunalielle salina)盐适应相关蛋白

观察不同盐浓度培养液中生长的杜氏盐藻可溶性蛋白SDS-PAG图谱,发现高盐与低盐相比,其51kD和63kD蛋白含量高,而23kD的蛋白含量则低。高渗骤变后,51kD蛋白的含量减少,而23kD蛋白的含量增加两倍或两倍以上,骤变23h后含量增加已非常明显;低渗骤变后24h,51kD和23kD蛋白的含量变化不明显。另外,有一分子量约为26kD的蛋白在高盐下易降解。分析了这些蛋白与社氏盐藻渗透调节的可能关系。     

CD4+ and CD8+ T Cells Make Discrete Contributions to Demyelination and Neurologic Disease in a Viral Model of Multiple Sclerosis

Following intracerebral infection with Theiler’s murine encephalomyelitis virus (TMEV), susceptible strains of mice (SJL and PLJ) develop virus persistence and demyelination similar to that found in human multiple sclerosis. Resistant strains of mice (C57BL/6) clear virus and do not develop demyelination. To resolve the controversy about the role of CD4⁺ and CD8⁺ T cells in the development of demyelination and neurologic deficits in diseases of the central nervous system, we analyzed TMEV infection in CD4- and CD8-deficient B6, PLJ, and SJL mice. Genetic deletion of either CD4 or CD8 from resistant B6 mice resulted in viral persistence and demyelination during the chronic stage of disease. Viral persistence and demyelination were detected in all strains of susceptible background. Although genetic deletion of CD8 had no effect on the extent of demyelination in susceptible strains, deletion of CD4 dramatically increased the degree of demyelination observed. Whereas strains with deletions of CD4 showed severe neurologic deficits, mice with deletions of CD8 showed minimal or no deficits despite demyelination. In all strains, deletion of CD4 but not CD8 resulted in a decreased delayed-type hypersensitivity response to viral antigen. We conclude that each T-cell subset makes a discrete and nonredundant contribution to protection from viral persistence and demyelination in resistant strains. In contrast, in susceptible strains, CD8⁺ T cells do not provide protection against chronic demyelinating disease. Furthermore, in persistent TMEV infection of the central nervous system, neurologic deficits appear to result either from the absence of a protective class II-restricted immune response or from the presence of a pathogenic class I-restricted response.Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system (CNS) in humans. MS lesions are characterized by foci of inflammation, myelin destruction, and formation of astrocytic scars known as plaques. The presence of CD4⁺ T cells, CD8⁺ T cells (11), and macrophages in lesions suggests that pathogenesis is immunologically mediated; however, the specific contribution of specific cell types remains unknown (12, 44, 45). Although the etiology of MS is unknown, virus infection is the only epidemiological factor consistently associated with clinical exacerbation (43), and beta interferon, a cytokine with multiple known antiviral properties (46), is the only therapeutic agent definitively shown to decrease exacerbation and limit disability in MS (46). Therefore, the study of viral models of demyelination is extremely relevant.Theiler’s murine encephalomyelitis virus (TMEV), a picornavirus, induces a pathological and clinical disease similar to MS (24). Intracerebral infection with the Daniel strain (DA) of TMEV induces transient, acute neuronal polioencephalitis followed by chronic white matter demyelination and neurologic deficits in mice with susceptible (H-2^f,p,q,r,s,v) major histocompatibility complex (MHC) haplotypes (15, 32). Mice with resistant (H-2^b,d,k) MHC haplotypes recover from the acute disease with no obvious long-term sequelae or demyelination. Although TMEV infection of severely immunodeficient SCID mice results in severe neuronal encephalitis and death within approximately 2 weeks, these mice do not develop demyelination in the spinal cord white matter (38). However, when the immune systems of SCID mice are reconstituted by the adoptive transfer of splenocytes from immunocompetent mice or splenocytes treated with antibodies to CD4 or CD8, infection with TMEV results in chronic demyelination (38). These data indicate that similar to human MS, myelin destruction in chronic TMEV infection is immunologically mediated and requires contributions from both CD4⁺ and CD8⁺ T cells.Various reports have implicated both MHC class I- and class II-restricted cells in the pathogenesis of TMEV infection. CD4⁺ T cells have been implicated by studies demonstrating that demyelination is decreased following treatment with antibodies to CD4 (47) or I-A (34), is increased by adoptive transfer of a CD4⁺ T-cell line specific for VP2 capsid protein (9), and, in some studies, correlates with the development of a CD4-mediated delayed-type hypersensitivity (DTH) response against virus antigen (5). Furthermore, β₂-microglobulin-deficient mice, which are deficient in MHC class I, CD8⁺ T cells, and natural killer cells, develop demyelinating disease (6, 16, 28). In contrast, a role for CD8⁺ T cells has been suggested by studies demonstrating that susceptibility to demyelination maps genetically to MHC class I (H-2D) (1, 35), differential expression of MHC class I in the CNS correlates with disease susceptibility (1), and depletion of CD8⁺ T cells diminishes demyelination (41). Myelin destruction and neurologic deficits develop in TMEV-infected Aβ⁰ mice which are deficient in functional MHC class II and CD4⁺ T cells (20). Of interest, both class I and class II-deficient mice share the resistant (H-2^b) haplotype. This suggests that although multiple studies have implicated CD4⁺ and CD8⁺ T cells in the pathogenesis of TMEV infection, each of these components of the immune response is independently required for maintenance of resistance to demyelination.In order to definitively establish the contribution of CD4⁺ and CD8⁺ T cells to demyelination and neurologic deficits, mice lacking surface expression of CD4 or CD8 were backcrossed onto genetically resistant C57BL/6 (H-2^b) and susceptible SJL (H-2^s) and PLJ (H-2^u) strains. In this report, we confirm that both CD4⁺ and CD8⁺ T cells are required for protection from viral persistence and demyelination in resistant strains of mice. We also demonstrate that genetic deletion of CD8 does not significantly affect the degree of demyelination or survival in susceptible strains; however, genetic deletion of CD4 greatly increases the degree of demyelination and worsens clinical disease. Of interest, genetic deletion of CD8 greatly reduces neurologic deficits in animals with demyelination.