A Class of Disulfide Compounds Suppresses Ferroptosis by Stabilizing GPX4.

Ferroptosis is a nonapoptotic form of cell death characterized by iron-dependent lipid peroxidation and has been implicated in multiple pathological conditions. Glutathione peroxidase 4 (GPX4) plays an essential role in inhibiting ferroptosis by eliminating lipid peroxide using glutathione (GSH) as a reductant. In this study, we found Ellman's reagent DTNB and a series of disulfide compounds, including disulfiram (DSF), an FDA-approved drug, which protect cells from erastin-induced ferroptosis. Mechanistically, DTNB or DSF is conjugated to multiple cysteine residues in GPX4 and disrupts GPX4 interaction with HSC70, an adaptor protein for chaperone mediated autophagy, thus preventing GPX4 degradation induced by erastin. In addition, DSF ameliorates concanavalin A induced acute liver injury by suppressing ferroptosis in a mouse model. Our work reveals a novel regulatory mechanism for GPX4 protein stability control. We also discover disulfide compounds as a new class of ferroptosis inhibitors and suggest therapeutic repurposing of DSF in treating ferroptosis-related diseases.

MRGAT: Multi-Relational Graph Attention Network for knowledge graph completion.

One of the most effective ways to solve the problem of knowledge graph completion is embedding-based models. Graph neural networks (GNNs) are popular and promising embedding models which can exploit and use the structural information of neighbors in knowledge graphs. The current GNN-based knowledge graph completion methods assume that all neighbors of a node have equal importance. This assumption which cannot assign different weights to neighbors is pointed out in our study to be unreasonable. In addition, since the knowledge graph is a kind of heterogeneous graph with multiple relations, multiple complex interactions between nodes and neighbors can bring challenges to the effective message passing of GNNs. We then design a multi-relational graph attention network (MRGAT) which can adapt to different cases of heterogeneous multi-relational connections and then calculate the importance of different neighboring nodes through a self-attention layer. The incorporation of self-attention mechanism into the network with different node weights optimizes the network structure, and therefore, significantly results in a promotion of performance. We experimentally validate the rationality of our models on multiple benchmark knowledge graphs, where MRGAT achieves the best performance on various evaluation metrics including MRR score, Hits@ score compared with other state-of-the-art baseline models.

A GWAS-supported variant interacting with diabetes predicts risk of atherothrombotic stroke in Han Chinese population.

BACKGROUND: A recent genome-wide association study has identified that rs4376531 variant conferred risk of atherothrombotic stroke (AS) in a Japanese population. This study was to explore the association in Han Chinese population. METHODS: A total of 1036 cases and 643 healthy controls were enrolled. We genotyped rs4376531 variant with SNPscan. Multivariate logistic regression analysis was used to determine the association of genetic variation with risk of AS. Interaction analysis was examined by SNPStats web tool. RESULTS: After adjusting for gender, age, body mass index (BMI), hypertension, diabetes and smoking, compared with CC genotype, we observed that GC and GG/GC genotypes were associated with a significantly decreased risk of AS (OR = 0.76, 95% CI = 0.58-0.99 and OR = 0.76, 95% CI = 0.58-0.98, respectively). The decreased risk was more obvious among subgroups with high BMI (OR = 0.63, 95% CI = 0.45-0.88), no hypertension (OR = 0.66, 95% CI = 0.46-0.94), diabetes (OR = 0.33, 95% CI = 0.17-0.64), and smoking (OR = 0.65, 95% CI = 0.44-0.95) in the dominant model (GG/GC vs CC). Interaction analysis also revealed that compared with non-diabetic patients with CC genotype, diabetic patients with CC genotype had a 4.48-fold (OR = 4.48; 95% CI = 2.98-6.72) increased risk of AS. CONCLUSION: Our data suggested that GC and GG/GC of rs4376531 contributed to a decreased risk of AS while CC genotype, interacting with diabetes, increased the stroke risk in Han Chinese population.

Preparation and application of magnetic molecularly imprinted nanoparticles for separation and purification of protein / 西安交通大学学报(医学版)

Objective To develop a novel strategy for separation and purification of target protein by magnetic molecularly imprinted nanoparticles . Methods Fe3 O4 nanoparticles were synthesized through a hydrothermal method .A sol-gel technique was adopted to prepare imprinting layers .The adsorption capability of magnetic molecularly imprinted nanoparticles was investigated by kinetic , isothermal , and selective binding experiments .Results The imprinted nanomaterials could reach equilibrium within 30 min . The adsorption capacity was 44 .51 mg/g .The imprinting factor and selectivity coefficient were 3 .50 and 2 .92 ,respectively .The resulting imprinted polymers could selectively separate and enrich bovine hemoglobin from a bovine blood sample . Conclusion The prepared imprinted nanomaterials with good specific adsoprtion ability can provide an effective strategy for separation and purification of target protein .

Progress in application of affinity chromatography inpharmaceutical analysis / 西安交通大学学报(医学版)

Affinity chromatography (AC)is a type of liquid chromatography that makes use of biological-like interactions for separation and specific analysis of bioactive components. It has been widely used as a high-throughput screening method for the separation,screening and purification of the target molecules from complex samples with advantages such as high selectivity and high recovery efficiency.This article summarizes the biological effects of affinity chromatography, molecular imprinting chromatography, and dye ligands affinity chromatography.The review also encompasses the application of AC in the separation of chiral drugs,screening of active components,purification of target protein,and mechanism of the drug-protein interaction.Moreover,the prospects of its applications are also discussed.

Progress in application of affinity chromatography inpharmaceutical analysis / 西安交通大学学报(医学版)

Affinity chromatography (AC)is a type of liquid chromatography that makes use of biological-like interactions for separation and specific analysis of bioactive components. It has been widely used as a high-throughput screening method for the separation,screening and purification of the target molecules from complex samples with advantages such as high selectivity and high recovery efficiency.This article summarizes the biological effects of affinity chromatography, molecular imprinting chromatography, and dye ligands affinity chromatography.The review also encompasses the application of AC in the separation of chiral drugs,screening of active components,purification of target protein,and mechanism of the drug-protein interaction.Moreover,the prospects of its applications are also discussed.

Peptidylation for the determination of low-molecular-weight compounds by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Determination of low-molecular-weight compounds by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has been a great challenge in the analytical research field. Here we developed a universal peptide-based derivatization (peptidylation) strategy for the sensitive analysis of low-molecular-weight compounds by MALDI-TOF-MS. Upon peptidylation, the molecular weights of target analytes increase, thus avoiding serious matrix ion interference in the low-molecular-weight region in MALDI-TOF-MS. Since peptides typically exhibit good signal response during MALDI-TOF-MS analysis, peptidylation endows high detection sensitivities of low-molecular-weight analytes. As a proof-of-concept, we analyzed low-molecular-weight compounds of aldehydes and thiols by the developed peptidylation strategy. Our results showed that aldehydes and thiols can be readily determined upon peptidylation, thus realizing the sensitive and efficient determination of low-molecular-weight compounds by MALDI-TOF-MS. Moreover, target analytes also can be unambiguously detected in biological samples using the peptidylation strategy. The established peptidylation strategy is a universal strategy and can be extended to the sensitive analysis of various low-molecular-weight compounds by MALDI-TOF-MS, which may be potentially used in areas such as metabolomics.

Value of contrast-enhanced ultrasound in preoperative evaluation for hilar cholangiocarcinoma / 中华医学超声杂志（电子版）

Objective To evaluate the value of contrast-enhanced ultrasound (CEUS) in preoperative classification for hilar cholangiocarcinoma. Methods Forty-six patients with 46 hilar cholangiocarcinoma were diagnosed by surgical pathology in Zhongshan Hospital of Fudan University from January 2007 to April 2013. The echogenicity difference on conventinal ultrasound and CEUS were compared with chi-square test. The accuracy of conventinal ultrasound and CEUS for evaluating invaded bile duct, detective rates for portal vein invasion and displaying rate of metastatic hilar lymph nodes were compared with chi-square test or Fisher’s Exact test according to the golden standard of operative exploration. Results On CEUS, 82.6%(38/46) and 91.3%(42/46) hilar cholangiocarcinoma were hypoechoic in portal vein phase and delayed phase respectively, while 63.0%(29/46) hilar cholangiocarcinoma were isoechoic on conventinal ultrasound with vague margin. The clearly displaying rates were 37.0%(17/46), 84.8%(39/46) and 91.3%(42/46) in conventinal ultrasound, portal vein and delayed phase of CEUS and the echogenicity was signiifcantly different. The evaluation accuracy of hilar cholangiocarcinoma invading bile duct was improved from 80.4%(37/46, conventinal ultrasound) to 100%(46/46, CEUS) significantly (χ2=7.882,P=0.005). Portal vein invasion were found in 9 cases during operative exploration and the detective rates on conventinal ultrasound and CEUS were 78%(7/9) and 89%(8/9) without signiifcant difference (P=1.000). Metastatic hilar lymph nodes were found in 8 cases and the displaying rates on conventinal ultrasound and CEUS were the same (75%, 6/8) without signiifcant difference (P=1.000). Conclusions CEUS could signiifcantly improve the clearly displaying rate of hilar cholangiocarcinoma and improve the evaluation accuracy for invaded bile duct comparing with conventinal ultrasound.

Correlation Analysis between EBV and Hp Infection and Gastric Cancer / 天津医药

Objective To investigate the correlation between Epstein-Barrvirus (EBV) and H.pylori (Hp) infection and gastric cancer. Methods The EBV infection was examined by polymerase chain reaction (PCR) and in situ hybridiza-tion (ISH) in 100 samples of gastric cancer tissue and 82 samples of gastritis tissue. The Hp infection was detected by PCR. The correlation between EBV and Hp infection and clinical and pathological features was analyzed in patients with gastric cancer. Results The positive rates of EBV and Hp were significantly higher in gastric cancer tissues than those in gastritis tissues (9.0%vs 0 and 56.0%vs 40.2%, P＜0.05). There was significantly higher infection rate in EBV in cardia gastric can-cer than that of gastric cancer (16.3%vs 2.0%,P＜0.05). There were significantly higher infection rates in EBV and Hp in poorly differentiated carcinoma than those of well-differentiated carcinoma (15.7%vs 2.0%and 66.7%vs 44.9%, P＜0.05). There were no significant differences in EBV and Hp infection between gender, age, nationality and lymph node metastasis (P>0.05). There was no significant difference in Hp infection between different parts of gastric cancer. There was no correla-tion between EBV and Hp infection in gastric cancer tissues (r=0.137, P>0.05). Conclusion EBV and Hp infection are two independent factors in the development of gastric cancer, and both of them are associated with the malignant evolution of gastric cancer.