Bile acids inhibit ferroptosis sensitivity through activating farnesoid X receptor in gastric cancer cells.

BACKGROUND: Gastric cancer (GC) is associated with high mortality rates. Bile acids (BAs) reflux is a well-known risk factor for GC, but the specific mechanism remains unclear. During GC development in both humans and animals, BAs serve as signaling molecules that induce metabolic reprogramming. This confers additional cancer phenotypes, including ferroptosis sensitivity. Ferroptosis is a novel mode of cell death characterized by lipid peroxidation that contributes universally to malignant progression. However, it is not fully defined if BAs can influence GC progression by modulating ferroptosis. AIM: To reveal the mechanism of BAs regulation in ferroptosis of GC cells. METHODS: In this study, we treated GC cells with various stimuli and evaluated the effect of BAs on the sensitivity to ferroptosis. We used gain and loss of function assays to examine the impacts of farnesoid X receptor (FXR) and BTB and CNC homology 1 (BACH1) overexpression and knockdown to obtain further insights into the molecular mechanism involved. RESULTS: Our data suggested that BAs could reverse erastin-induced ferroptosis in GC cells. This effect correlated with increased glutathione (GSH) concentrations, a reduced GSH to oxidized GSH ratio, and higher GSH peroxidase 4 (GPX4) expression levels. Subsequently, we confirmed that BAs exerted these effects by activating FXR, which markedly increased the expression of GSH synthetase and GPX4. Notably, BACH1 was detected as an essential intermediate molecule in the promotion of GSH synthesis by BAs and FXR. Finally, our results suggested that FXR could significantly promote GC cell proliferation, which may be closely related to its anti-ferroptosis effect. CONCLUSION: This study revealed for the first time that BAs could inhibit ferroptosis sensitivity through the FXR-BACH1-GSH-GPX4 axis in GC cells. This work provided new insights into the mechanism associated with BA-mediated promotion of GC and may help identify potential therapeutic targets for GC patients with BAs reflux.

Intrinsic Manifold SLIC: A Simple and Efficient Method for Computing Content-Sensitive Superpixels.

Superpixels are perceptually meaningful atomic regions that can effectively capture image features. Among various methods for computing uniform superpixels, simple linear iterative clustering (SLIC) is popular due to its simplicity and high performance. In this paper, we extend SLIC to compute content-sensitive superpixels, i.e., small superpixels in content-dense regions with high intensity or colour variation and large superpixels in content-sparse regions. Rather than using the conventional SLIC method that clusters pixels in , we map the input image to a 2-dimensional manifold , whose area elements are a good measure of the content density in . We propose a simple method, called intrinsic manifold SLIC (IMSLIC), for computing a geodesic centroidal Voronoi tessellation (GCVT)-a uniform tessellation-on , which induces the content-sensitive superpixels in . In contrast to the existing algorithms, IMSLIC characterizes the content sensitivity by measuring areas of Voronoi cells on . Using a simple and fast approximation to a closed-form solution, the method can compute the GCVT at a very low cost and guarantees that all Voronoi cells are simply connected. We thoroughly evaluate IMSLIC and compare it with eleven representative methods on the BSDS500 dataset and seven representative methods on the NYUV2 dataset. Computational results show that IMSLIC outperforms existing methods in terms of commonly used quality measures pertaining to superpixels such as compactness, adherence to boundaries, and achievable segmentation accuracy. We also evaluate IMSLIC and seven representative methods in an image contour closure application, and the results on two datasets, WHD and WSD, show that IMSLIC achieves the best foreground segmentation performance.

PD-1/PD-L1 signal pathway participates in HCV F protein-induced T cell dysfunction in chronic HCV infection.

Programmed cell death-1/programmed cell death-1 ligand 1 (PD-1/PD-L1) inhibitory signal pathway has been verified to be involved in the establishment of persistent viral infections. Blockade of PD-1/PD-L1 engagement to reinvigorate T cell activity is supposed to be a potential therapeutic scheme. Studies have verified the participation of PD-1/PD-L1 in hepatitis C virus (HCV) core protein-regulated immune response. To determine the roles of PD-1/PD-L1 signal pathway in HCV F protein-induced immunoreaction in chronic HCV infection, variations in T cells were examined. The results showed that PD-1 expression on CD8(+) and CD4(+) T cells was increased with HCV F stimulation in both chronic HCV patients and healthy controls, and could be reduced partly by PD-1/PD-L1 blocking. Additionally, by PD-1/PD-L1 blocking, HCV F-induced inhibition of T cell proliferation and promotion of cellular apoptosis were partly or even totally recovered. Furthermore, levels of both Th1 and Th2 cytokines were elevated in the presence of anti-PD-L1 antibody. All these results indicated that PD-1/PD-L1 signal pathway also participates in HCV F protein-induced immunoregulation. PD-1/PD-L1 blocking plays important roles in the restoration of effective functionality of the impaired T cells in chronic HCV patients.

HCV F protein amplifies the predictions of IL-28B and CTLA-4 polymorphisms about the susceptibility and outcomes of HCV infection in Southeast China.

Cytotoxic T lymphocyte associated antigen-4(CTLA-4) is an inhibitory receptor with great value in the progression of hepatitis C virus (HCV) infection related diseases. To determine the potential associations of IL-28B rs12979860 and CTLA-4 rs231775, rs3087243 and rs5742909 polymorphisms with the generation of HCV F protein, susceptibility and outcomes of HCV infection, a total of 375 healthy controls, 219 HCV spontaneous recovered patients and 600 chronic HCV patients from Southeast China were recruited and genotyped in this study. And the relative mRNA levels of CTLA-4 in T cells were detected. Logistic regression analysis showed that rs231775 A allele was associated with significantly higher rate of spontaneous viral clearance in anti-HCV F antibody negative patients (adjusted OR=0.512, P=0.008), but allele A was related to higher mRNA level of CTLA-4 with the generation of HCV F protein. And rs5742909 T allele added up to the risk of HCV infection chronicity significantly in patients with the presence of HCV F protein (adjusted OR=2.698, P=0.003). Also, the rs5742909 CC genotype, along with the presence of HCV F protein, indicated a significantly higher CTLA-4 level than that in anti-HCV F antibody negative patients. The AG+AA genotype of rs3087243 significantly increased the susceptibility to HCV infection in subjects over 56 years old (adjusted OR=1.595, P=0.011). Genotype-genotype interaction between IL-28B rs12979860 and CTLA-4 rs3087243 was found to be significantly associated with increased susceptibility to HCV infection (adjusted OR=1.509, P=0.005). Haplotype analysis in CTLA-4 also showed significant association with the generation of HCV F protein. All these results indicated the importance of IL-28B and CTLA-4 polymorphisms and their associations with HCV F protein in the risk and chronicity of HCV infection in Chinese Han population in Southeast China.

Potential Role of Hepatitis C Virus Alternate Reading Frame Protein in Negative Regulation of T-Bet Gene Expression.

Hepatitis C virus (HCV) is a major cause of chronic liver disease and has led to cirrhosis or hepatocellular carcinoma in a majority of infected individuals. We have previously demonstrated that the HCV alternate reading frame protein (F protein) is related to Th1/Th2 bias in chronic hepatitis C (CHC) patients, and we aimed to explore the relative molecular mechanisms here. A total of 104 cases including CHC patients and healthy donors were enrolled. T-bet and GATA-3 expression levels were analyzed in peripheral blood mononuclear cells (PBMCs). The levels of signal transducer and activator of transcription-1/-6(STAT1/6) and phosphorylated STAT1/6(pSTAT1/6) in PBMCs were measured by Western blotting. Our results showed that the levels of T-bet in PBMCs, as well as the levels of gamma interferon (IFN-γ) in sera, were decreased in anti-F protein antibody seropositive patients compared with anti-F protein antibody seronegative patients, whereas the levels of GATA-3 did not show difference between the two groups. Moreover, the decreased pSTAT1 and increased pSTAT6 were observed in PBMCs by HCV core/F protein stimulation with constant STAT1/6 expression. Taken together, it suggested that T-bet may be involved in Th1/Th2 bias induced by HCV F protein, and the disruption of STAT phosphorylation may participate in this mediation.

Genetic variations of IL-28B and PD-1 are in association with the susceptibility and outcomes of HCV infection in Southeast China.

Programmed cell death-1 (PD-1) is an important co-inhibitory molecule involved in the progression of chronic viral infections. To investigate the associations of three single nucleotide polymorphisms (SNPs) (rs10204525, rs2227982 and rs36084323) in PD-1 and a previously well-inquired SNP rs12979860 in IL-28B with the outcomes of hepatitis C virus (HCV) infection in Southeast China, a total of 375 healthy controls, 219 spontaneous resolved HCV patients and 600 chronic HCV patients were enrolled in this study. The generation of HCV F protein and PD-1 expression on T cells was determined. Multivariate logistic regression analysis showed no association of rs12979860 CC genotype with spontaneous clearance of HCV infection in our subjects. The generation of HCV F protein was significantly related to HCV infection chronicity, but no significant relationship was found between HCV F protein and SNPs in PD-1. The rs10204525 TT genotype was associated with an increased risk of HCV infection chronicity in age ⩽56years subgroup (adjusted OR=0.390, P=3.8×10(-4)). The C allele of rs10204525 played protective roles in females infected with HCV (adjusted OR=0.608, P=0.008). A significant higher percentage of PD-1 expression on T cells was observed in rs10204525 TT genotype when compared to CC genotype (P=0.047). Moreover, a significant genotype-genotype interaction between IL-28B rs12979860 CC and PD-1 rs10204525 TC+CC was found to be associated with higher rates of spontaneous clearance (adjusted OR=0.689, P=0.032). The combined effect of rs12979860 and rs10204525 was of great value in predicting the outcomes of HCV infection. These analyses showed the importance of IL-28B and PD-1 polymorphisms and their interactions in the outcomes of HCV infection in Chinese Han population in Southeast China.

Complete mitochondrial genome of Gobiobotia intermedia (Cypriniformes, Cyprinidae).

The complete mitochondrial genome of the Cyprinid fish Gobiobotia intermedia (Cypriniformes, Cyprinidae) was determined. The complete mitogenome sequence has 16,608 bp and contains the usual 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA (tRNA) genes and a non-coding control region, as those found in other vertebrates, with the gene order identical to that of typical vertebrates. The overall base composition of the heavy strand shows T 26.08%, C 27.25%, A 27.57% and G 19.11%, apparently with a slight AT bias.

Clinical study of autologous cytokine-induced killer cells for the treatment of elderly patients with diffuse large B-cell lymphoma.

To evaluate the effectiveness and safety of autologous cytokine-induced killer (CIK) cells in elderly patients with diffuse large B-cell lymphoma. Peripheral blood mononuclear cells (PBMC) were isolated from nine elderly patients with diffuse large B-cell lymphoma. PBMCs were augmented by priming with interferon gamma (IFN-γ) followed by IL-2 and monoclonal antibody (mAb) against CD3. Autologous CIK cells (range 5 × 10(9)-1 × 10(10)) were then infused back to individual patients; infusion was repeated every 4 weeks for 32 weeks (eight cycles). Patients were assessed for changes in lymphocyte subgroup, tumor-related biological parameters, imaging characteristics, the condition of remission, quality of life (QOL), and survival. Prior to CIK infusion, two patients were in complete remission and seven patients were in partial remission. After autologous CIK cell transfusions, the proportion of CD3+, CD3+CD8+, and CD3+CD56+ cells were significantly increased compared with baseline (P < 0.05); whereas serum levels of ß2-microglobulin and LDH were significantly decreased (P < 0.05). The lymphoma symptoms were reduced and QOL was improved (P < 0.05) in all patients. All patients achieved complete remission at study endpoint. No adverse reactions were reported. Autologous CIK cell immunotherapy is safe and efficacious for the treatment of elderly patients with diffuse large B-cell lymphoma.

Microsatellite DNA variation of the gametophyte clones isolated from introduced Laminaria japonica (Phaeophyta) and L. longissima of China and varieties derived from them.

The variation of 90 Laminaria gametophyte clones representing the introduced Laminaria japonica (Group 1) and Laminaria longissima (Group 2), the varieties of L. japonica (Group 3) and the varieties derived from interspecific hybrids (Group 4) was determined with 18 microsatellite markers. The allelic diversity and Nei's gene diversity of Group 1 were significantly higher than those of Group 2 (2.9 vs. 1.8 and 0.414 vs. 0.161, respectively), demonstrating that the variation of the introduced L. japonica is richer than that of L. longissima. Both allelic diversity and Nei's gene diversity of Group 3 were lower than those of Group 1, indicating that only a portion of variation of L. japonica was incorporated into the varieties of L. japonica. Significant genetic differentiation was detected between four groups and between female (Population 1) and male (Population 2) gametophyte clones in each group. The variation among groups accounted for 39.95%, while that among populations accounted for 21.65% of the total. The genetic distance between Group 1 and Group 4 was obviously longer than that between Group 2 and Group 4 (0.686 vs. 0.291), indicating that maternal gametophyte clone contributed more variation to the hybrids than the paternal gametophyte clone did.

Purification and characterization of hatching enzyme from shrimp Penaeus chinensis.

By using Penaeus chorion as a specific substrate, the hatching enzyme (HE) from Penaeus chinensis was purified by gel-filtration and ion-exchange chromatography, and characterized in terms of its molecular weight and enzymatic properties in this study. It was found that the molecular weight of Penaeus HE is about 43.0 kDa in SDS-PAGE. The Penaeus HE had obvious choriolytic activity, which was optimal at pH 6.0 and temperature of 40 degrees C, respectively. The Km value of the HE for casein was 7.47 mg ml(-1). The HE activity was almost completely inhibited by SBTI, p-APMSF, bestatin, and NEM, greatly inhibited by ovomucoid, TLCK, IAM, chymostatin, and PMSF, and slightly inhibited by pepstatin A, TPCK, LBTI, and leupeptin. These results indicate that the HE is most probably a trypsin-type serine protease. Besides of these, the HE was extremely sensitive to EDTA, Zn2+, Ca2+, Mg2+, and Cu2+. Combined with the results that the EDTA-pretreated HE activity could be perfectly recovered by Zn2+, it is indicated that shrimp HE is most probably a kind of Zn-metalloprotease.