Hypercholesterolemia Is Associated With Dysregulation of Lipid Metabolism and Poor Prognosis in Primary Biliary Cholangitis.

BACKGROUND & AIMS: Hypercholesterolemia is frequently diagnosed in patients with primary biliary cholangitis (PBC). However, its association with the prognosis and lipid metabolism is unknown. In this study, we aimed to investigate the prognostic value of baseline total cholesterol (TC) levels in PBC and characterized the associated lipid metabolism. METHODS: Five hundred and thirty-one patients with PBC without prior cirrhosis-related complications were randomly divided into the derivation and validation cohorts at a ratio of 7:3. Complete clinical data were obtained and analyzed. The endpoints were defined as liver-related death, liver transplantation, and cirrhosis-related complications. Lipidomics was performed in 89 patients and 28 healthy controls. RESULTS: Baseline TC was independently associated with poor liver-related outcomes, and adjusted C-statistics were 0.80 (95% confidence interval [CI]: 0.74-0.85) and 0.88 (95% CI: 0.78-0.91) in the derivation and validation cohorts, respectively. The predictive ability of TC for disease outcomes was stable over time and comparable with the Globe score. The 200 mg/dL cut-off optimally divided patients into low- and high-TC groups. A combination of TC and Globe score provided a more accurate stratification of patients into risk subgroups. Lipidomics indicated an up-regulation of lipid families in high-TC patients. Pathway analysis of 66 up-regulated lipids revealed the dysregulation of glycerophospholipid and sphingolipid metabolism in high-TC patients, which were associated with poor liver-related outcomes. CONCLUSIONS: Our results indicate that patients with PBC having baseline TC levels above 200 mg/dL have unique lipidome characteristics and are at a higher risk of poor liver-related outcomes.

Dasatinib plus prednisone as induction and consolidation for adults with Ph-positive acute lymphoblastic leukaemia: A single-arm, multicentre, phase 2 trial.

To reducing chemotherapy-related toxicity, the chemo-free regimens become a new trend of Ph + ALL treatment. Therefore, we conducted a phase 2 trial of dasatinib plus prednisone, as induction (Course I) and early consolidation (Courses II and III) treating newly diagnosed Ph + ALL. The trial was registered at www.chictr.org.cn, ChiCTR2000038053. Forty-one patients were enrolled from 15 hospitals. The complete remission (CR) was 95% (39/41), including two elderly induction deaths. By the end of Course III, 25.6% (10/39) of patients achieved a complete molecular response. With a median follow-up of 15.4 months, 2-year disease-free survival (DFS) were 100% and 33% for patients who receiving haematopoietic stem cell transplantation (HSCT) at CR1 and receiving chemotherapy alone respectively. When censored at time of HSCT, 2-year DFS were 51% and 45% for young and elderly patients (p = 0.987). 2-year overall survival were 45%, 86% and 100% for patients without HSCT, receiving HSCT after relapse and receiving HSCT at CR1 respectively. A total of 12 patients had marrow recurrences and one had CNS relapse, with 38% occurred early (between Courses I and III). IKZF1 gene deletion was shown to be associated with relapse (p = 0.019). This chemo-free induction and early consolidation regimen was efficacious and well-tolerated in de novo Ph + ALL. Allogeneic HSCT conferred definite survival advantage after chemo-free induction.

Effectiveness of Fenofibrate in Treatment-Naive Patients With Primary Biliary Cholangitis: A Randomized Clinical Trial.

INTRODUCTION: Primary biliary cholangitis (PBC) is a progressive autoimmune liver disease, and patients with inadequate response to ursodeoxycholic acid (UDCA) treatment show reduced long-term survival. Recent studies have shown that fenofibrate is an effective off-label therapy for PBC. However, prospective studies on biochemical response including the timing of fenofibrate administration are lacking. This study is aimed to evaluate the efficacy and safety of fenofibrate in UDCA treatment-naive patients with PBC. METHODS: A total of 117 treatment-naive patients with PBC were recruited from the Xijing Hospital for a 12-month randomized, parallel, and open-label clinical trial. Study participants were assigned to receive either UDCA standard dose (UDCA-only group) or fenofibrate at a daily dose of 200 mg in addition to UDCA (UDCA-Fenofibrate group). RESULTS: The primary outcome was biochemical response percentage in patients according to the Barcelona criterion at 12 months. In the UDCA-Fenofibrate group, 81.4% (69.9%-92.9%) of patients achieved the primary outcome and 64.3% (51.9%-76.8%) in the UDCA-only group achieved the primary outcome ( P = 0.048). There was no difference between the 2 groups in noninvasive measures of liver fibrosis and biochemical markers other than alkaline phosphatase at 12 months. Creatinine and transaminases levels in the UDCA-Fenofibrate group increased within the first month, then returned to normal, and remained stable thereafter until the end of the study, even in patients with cirrhosis. DISCUSSION: In this randomized clinical trial in treatment-naive patients with PBC, the combination of fenofibrate and UDCA resulted in a significantly higher biochemical response rate. Fenofibrate seemed to be well-tolerated in patients.

MRI-based automatic identification and segmentation of extrahepatic cholangiocarcinoma using deep learning network.

BACKGROUND: Accurate identification of extrahepatic cholangiocarcinoma (ECC) from an image is challenging because of the small size and complex background structure. Therefore, considering the limitation of manual delineation, it's necessary to develop automated identification and segmentation methods for ECC. The aim of this study was to develop a deep learning approach for automatic identification and segmentation of ECC using MRI. METHODS: We recruited 137 ECC patients from our hospital as the main dataset (C1) and an additional 40 patients from other hospitals as the external validation set (C2). All patients underwent axial T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and diffusion-weighted imaging (DWI). Manual delineations were performed and served as the ground truth. Next, we used 3D VB-Net to establish single-mode automatic identification and segmentation models based on T1WI (model 1), T2WI (model 2), and DWI (model 3) in the training cohort (80% of C1), and compared them with the combined model (model 4). Subsequently, the generalization capability of the best models was evaluated using the testing set (20% of C1) and the external validation set (C2). Finally, the performance of the developed models was further evaluated. RESULTS: Model 3 showed the best identification performance in the training, testing, and external validation cohorts with success rates of 0.980, 0.786, and 0.725, respectively. Furthermore, model 3 yielded an average Dice similarity coefficient (DSC) of 0.922, 0.495, and 0.466 to segment ECC automatically in the training, testing, and external validation cohorts, respectively. CONCLUSION: The DWI-based model performed better in automatically identifying and segmenting ECC compared to T1WI and T2WI, which may guide clinical decisions and help determine prognosis.

Trimethoprim-sulfamethoxazole prevents interstitial pneumonitis in B-cell lymphoma patients receiving chemotherapy: a propensity score matching analysis.

B-cell lymphoma is the most prevalent type of non-Hodgkin lymphoma, for which the standard treatment regimen includes rituximab combined with CHOP. However, some patients may develop interstitial pneumonitis (IP), which can be caused by various factors; one of the most important factors is Pneumocystis jirovecii. It is crucial to investigate the pathophysiology of IP and implement preventive measures since IP can be fatal for some people. The data were collected from the First Affiliated Hospital, Zhejiang University School of Medicine, where patients with B-cell lymphoma received the R-CHOP/R-CDOP regimen with or without prophylactic use of trimethoprim-sulfamethoxazole (TMP-SMX). Multivariable logistic regression and propensity score matching (PSM) were used to investigate any potential association. Eight hundred thirty-one patients with B-cell lymphoma were classified into two groups: the non-prophylaxis group without TMP-SMX (n=699) and the prophylaxis group with TMP-SMX (n = 132). IP occurred in 66 patients (9.4%, all in the non-prophylaxis group), with an onset median of three cycles of chemotherapy. Multiple logistic regression analysis demonstrated that IP incidence was associated with pegylated liposome doxorubicin (OR=3.29, 95% CI 1.84-5.90, P<0.001). After utilizing a 1:1 matching algorithm for PSM, 90 patients from each group were obtained. There was a statistical difference between the two cohorts in the IP incidence (non-prophylaxis 12.2% vs prophylaxis 0.0%, P <0.001). The prophylactic use of TMP-SMX could prevent the occurrence of IP whose risk factor was pegylated liposome doxorubicin after chemotherapy for B-cell lymphoma.

Ginsenoside Rh1, a novel casein kinase II subunit alpha (CK2α) inhibitor, retards metastasis via disrupting HHEX/CCL20 signaling cascade involved in tumor cell extravasation across endothelial barrier.

Tumor cell extravasation across endothelial barrier has been recognized as a pivotal event in orchestrating metastasis formation. This event is initiated by the interactions of extravasating tumor cells with endothelial cells (ECs). Therefore, targeting the crosstalk between tumor cells and ECs might be a promising therapeutic strategy to prevent metastasis. In this study, we demonstrated that Rh1, one of the main ingredients of ginseng, hindered the invasion of breast cancer (BC) cells as well as diminished the permeability of ECs both in vitro and in vivo, which was responsible for the attenuated tumor cell extravasation across endothelium. Noteworthily, we showed that ECs were capable of inducing the epithelial-mesenchymal transition (EMT) and invadopodia of BC cells that are essential for tumor cell migration and invasion through limiting the nuclear translocation of hematopoietically expressed homeobox (HHEX). The decreased nuclear HHEX paved the way for initiating the CCL20/CCR6 signaling axis, which in turn contributed to damaged endothelial junctions, uncovering a new crosstalk mode between tumor cells and ECs. Intriguingly, Rh1 inhibited the kinase activity of casein kinase II subunit alpha (CK2α) and further promoted the nuclear translocation of HHEX in the BC cells, which resulted in the disrupted crosstalk between chemokine (C-C motif) ligand 20 (CCL20) in the BC cells and chemokine (C-C motif) receptor 6 (CCR6) in the ECs. The prohibited CCL20-CCR6 axis by Rh1 enhanced vascular integrity and diminished tumor cell motility. Taken together, our data suggest that Rh1 serves as an effective natural CK2α inhibitor that can be further optimized to be a therapeutic agent for reducing tumor cell extravasation.

Preoperative prediction of the lymphovascular tumor thrombus of colorectal cancer with the iodine concentrations from dual-energy spectral CT.

BACKGROUND: The aim of this study was to explore application value of iodine concentration from dual-energy spectral computed tomography (DESCT) in preoperative prediction of lymphovascular tumor thrombus in patients with colorectal cancer (CRC). METHODS: We finally retrospectively analyzed 50 patients with CRC who underwent abdominal DESCT before receiving any preoperative treatment and underwent surgery to obtain pathological specimens which were stained with hematoxylin-eosin (HE) staining. According to the presence of cancer cell nests in blood vessels and lymphatic vessels, the subjects were divided into the positive group and negative group of lymphovascular tumor thrombus. Two radiologists independently measured the normalized iodine concentration (NIC) values, effective atomic number (Zeff) and CT values of virtual monochromatic images (VMIs) at 40-90 keV of the primary tumors in the arterial phase (AP) and venous phase (VP). Used SPSS 17.0 to calculate the receiver operating characteristic (ROC) curve to evaluate diagnostic value. RESULTS: The patients were divided into lymphovascular tumor thrombus positive group(n = 16) and negative group(n = 34). The values of NIC-AP and NIC-VP in the positive group were 0.17 ± 0.09, 0.51 ± 0.13, respectively. And those in the negative group were 0.15 ± 0.06, 0.43 ± 0.12, respectively. There was significant difference in NIC-VP value between the two groups (p = 0.039), but there was no significant difference in NIC-AP value (p = 0.423). The optimal threshold value of NIC-VP value for diagnosis of lymphovascular tumor thrombus was 0.364. The sensitivity was 68.8% and the specificity was 67.6%. CONCLUSIONS: The NIC-VP value of DESCT can be used to predict the presence or absence of the lymphovascular tumor thrombus in CRC patients before operation, which is helpful to select the best treatment scheme and evaluate its prognosis.

Advance in the pharmacological effects of quercetin in modulating oxidative stress and inflammation related disorders.

Numerous pharmacological effects of quercetin have been illustrated, including antiinflammation, antioxidation, and anticancer properties. In recent years, the antioxidant activity of quercetin has been extensively reported, in particular, its impacts on glutathione, enzyme activity, signaling transduction pathways, and reactive oxygen species (ROS). Quercetin has also been demonstrated to exert a striking antiinflammatory effect mainly by inhibiting the production of cytokines, reducing the expression of cyclooxygenase and lipoxygenase, and preserving the integrity of mast cells. By regulating oxidative stress and inflammation, which are regarded as two critical processes involved in the defense and regular physiological operation of biological systems, quercetin has been validated to be effective in treating a variety of disorders. Symptoms of these reactions have been linked to degenerative processes and metabolic disorders, including metabolic syndrome, cardiovascular, neurodegeneration, cancer, and nonalcoholic fatty liver disease. Despite that evidence demonstrates that antioxidants are employed to prevent excessive oxidative and inflammatory processes, there are still concerns regarding the expense, accessibility, and side effects of agents. Notably, natural products, especially those derived from plants, are widely accessible, affordable, and generally safe. In this review, the antioxidant and antiinflammatory abilities of the active ingredient quercetin and its application in oxidative stress-related disorders have been outlined in detail.

Dess-Martin Periodinane-Mediated Oxidative Coupling Reaction of Isoquinoline with Benzyl Bromide.

Dess-Martin periodinane (DMP) is a broadly applicable oxidant in chemical synthesis. In this work, an efficient and convenient synthesis of N-substituted isoquinolinone derivatives mediated by DMP was achieved through the oxidative coupling reaction of functionalized isoquinoline with readily available benzyl bromide, which is a metal-free, mild, and practical method for synthesizing isoquinoline-1,3-dione or isoquinoline-1,3,4-trione derivatives in excellent yields. The H2O18-labeling experiment was performed to gain insight into the possible mechanism for this reaction.

Fenofibrate normalizes alkaline phosphatase and improves long-term outcomes in patients with advanced primary biliary cholangitis refractory to ursodeoxycholic acid.

BACKGROUND: Although patients with advanced liver disease have been included in studies evaluating fibrates for the treatment of primary biliary cholangitis (PBC), the frequency of biochemical responses and adverse effects for this group of patients was not reported separately and comprehensively. AIMS: to evaluate the efficacy and safety of additional fenofibrate therapy in patients with advanced and ursodeoxycholic acid (UDCA)-refractory PBC. METHODS: Patients were analyzed retrospectively to determine the clinical therapeutic effects of UDCA with additional fenofibrate therapy versus continued UDCA monotherapy. The liver transplantation (LT)-free survival and the alkaline phosphatase (ALP) normalization rates were estimated using Cox regression analyses and Kaplan-Meier plots with inverse probability of treatment weighting (IPTW). RESULTS: A total of 118 patients were included: 54 received UDCA alone and 64 received UDCA in combination with fenofibrate therapy. In the fenofibrate and UDCA groups, 37% and 11% of patients with advanced and UDCA-refractory PBC, respectively, achieved ALP normalization (P=0.001). Additional fenofibrate therapy improved both LT-free survival and ALP normalization rate after IPTW (hazard ratio [HR]: 0.23, 95% confidence interval [CI]: 0.07-0.75, P=0.015; and HR: 11.66, 95% CI: 5.02-27.06, P=0.001, respectively). These effects were supported by parallel changes in the rates of liver decompensation and histologic progression, and the United Kingdom (UK)-PBC and Globe risk scores. During the follow-up period, serum levels of ALP and aminotransferase decreased significantly, while total bilirubin, albumin, platelet, serum creatinine, and estimated glomerular filtration rate remained stable in fenofibrate-treated participants. No fenofibrate-related significant adverse events were observed in our cohort. CONCLUSIONS: Additional fenofibrate therapy significantly improved LT-free survival and ALP normalization in patients with advanced and UDCA-refractory PBC. Furthermore, adding-on fenofibrate therapy appeared to be safe and well tolerated in this population.

[Mechanism of active ingredients in Periploca forrestii compound against rheumatoid arthritis based on integrative metabolomics and network pharmacology].

In this study, an ultra-performance liquid chromatography-quadrupole time-of-flight high resolution mass spectrometer(UPLC-Q-TOF-HRMS) was used to investigate the effects of the active ingredients in Periploca forrestii compound on spleen metabolism in rats with collagen-induced arthritis(CIA), and its potential anti-inflammatory mechanism was analyzed by network pharmacology. After the model of CIA was successfully established, the spleen tissues of rats were taken 28 days after administration. UPLC-Q-TOF-HRMS chromatograms were collected and analyzed by principal component analysis(PCA), orthogonal partial least squares discriminant analysis(OPLS-DA), and MetPA. The results showed that as compared with the blank control group, 22 biomarkers in the spleen tissues such as inosine, citicoline, hypoxanthine, and taurine in the model group increased, while 9 biomarkers such as CDP-ethanolamine and phosphorylcholine decreased. As compared with the model group, 21 biomarkers such as inosine, citicoline, CDP-ethanolamine, and phosphorylcholine were reregulated by the active ingredients in P. forrestii. Seventeen metabolic pathways were significantly enriched, including purine metabolism, taurine and hypotaurine metabolism, glycerophospholipid metabolism, and cysteine and methionine metabolism. Network pharmacology analysis found that purine metabolism, glycerophospholipid metabolism, and cysteine and methionine metabolism played important roles in the pathological process of rheumatoid arthritis. This study suggests that active ingredients in P. forrestii compound can delay the occurrence and development of inflammatory reaction by improving the spleen metabolic disorder of rats with CIA. The P. forrestii compound has multi-target and multi-pathway anti-inflammatory mechanism. This study is expected to provide a new explanation for the mechanism of active ingredients in P. forrestii compound against rheumatoid arthritis.

Comprehensive evaluation of the effects of long-term cryopreservation on peripheral blood mononuclear cells using flow cytometry.

Human peripheral blood mononuclear cells (PBMCs) originate from hematopoietic stem cells in the bone marrow, which mainly includes lymphocytes (T cells, B cells, and natural killer cells) and monocytes. Cryopreserved PBMCs providing biobank resources are crucial for clinical application or scientific research. Here, we used flow cytometry to explore the influence of long-term cryopreservation on the quality of PBMCs with the aim of providing important evidence for the effective utilization of biobank resources. The PBMCs were isolated from the peripheral blood, which was collected from volunteers in the hospital. After long-term cryopreservation in liquid nitrogen, we analyzed the changes in cell numbers, viability, and multiple subtypes of PBMCs and studied the apoptosis, proliferation, activation, function, and status of T cells in comparison with freshly isolated PBMCs by flow cytometry, and then further tracked the effects of long-term cryopreservation on the same sample. Although the different cell types in the PBMCs dynamically changed compared with those in the freshly isolated samples, PBMC recovery and viability remained stable after long-term cryopreservation, and the number of most innate immune cells (e.g., monocytes and B cells) was significantly reduced compared to that of the freshly isolated PBMCs or long-term cryopreserved PBMCs; more importantly, the proportion of T cell subtypes, apoptosis, proliferation, and functional T cells, except for Tregs, were not affected by long-term cryopreservation. However, the proportions of activated T, naïve T, central memory T, effector T, and effector memory T cells dynamically changed after long-term cryopreservation. This article provides important evidence for the effective utilization of biobank resources. Long-term cryopreserved PBMCs can be partly used as biological resources for clinical research or basic studies, but the effect of cryopreservation on PBMCs should be considered when selecting cell samples, especially in research relating to activating or inhibiting function.

Nitazoxanide inhibits osteosarcoma cells growth and metastasis by suppressing AKT/mTOR and Wnt/ß-catenin signaling pathways.

Osteosarcoma (OS) is the most prevalent malignant bone tumor with poor prognosis. Developing new drugs for the chemotherapy of OS has been a focal point and a major obstacle of OS treatment. Nitazoxanide (NTZ), a conventional anti-parasitic agent, has got increasingly noticed because of its favorable antitumor potential. Herein, we investigated the effect of NTZ on human OS cells in vitro and in vivo. The results obtained in vitro showed that NTZ inhibited the proliferation, migration and invasion, arrested cell cycle at G1 phase, while induced apoptosis of OS cells. Mechanistically, NTZ suppressed the activity of AKT/mTOR and Wnt/ß-catenin signaling pathways of OS cells. Consistent with the results in vitro, orthotopic implantation model of 143B OS cells further confirmed that NTZ inhibited OS cells growth and lung metastasis in vivo. Notably, NTZ caused no apparent damage to normal cells/tissues. In conclusion, NTZ may inhibit tumor growth and metastasis of human OS cells through suppressing AKT/mTOR and Wnt/ß-catenin signaling pathways.

Pharmacological manipulation of Ezh2 with salvianolic acid B results in tumor vascular normalization and synergizes with cisplatin and T cell-mediated immunotherapy.

Tumor vasculature is characterized by aberrant structure and function, resulting in immune suppressive profiles of tumor microenvironment (TME) through limiting immune cell infiltration into tumors. The defective vascular perfusion in tumors also impairs the delivery and efficacy of chemotherapeutic agents. Targeting abnormal tumor blood vessels has emerged as an effective therapeutic strategy to improve the outcome of chemotherapy and immunotherapy. In this study, we demonstrated that Salvianolic acid B (SalB), one of the major ingredients of Salvia miltiorriza elicited vascular normalization in the mouse models of breast cancer, contributing to improved delivery and response of chemotherapeutic agent cisplatin as well as attenuated metastasis. Moreover, SalB in combination with anti-PD-L1 blockade retarded tumor growth, which was mainly due to elevated infiltration of immune effector cells and boosted delivery of anti-PD-L1 into tumors. Mechanistically, tumor cell enhancer of zeste homolog 2 (Ezh2)-driven cytokines disrupted the endothelial junctions with diminished VE-cadherin expression, which could be rescued in the presence of SalB. The restored vascular integrity by SalB via modulating the interactions between tumor cells and endothelial cells (ECs) offered a principal route for achieving vascular normalization. Taken together, our data elucidated that SalB enhanced sensitivity of tumor cells to chemotherapy and immunotherapy through triggering tumor vascular normalization, providing a potential therapeutic strategy of combining SalB and chemotherapy or immunotherapy for patients with breast cancer.

Novel bioactive hybrid Celecoxib-HDAC Inhibitor, induces apoptosis in human acute lymphoblastic leukemia cells.

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children. Here, we exploited the synergy between histone deacetylase inhibitors (HDACi) and cyclooxygenase 2 (COX-2) inhibitors by generating and testing a series of hybrid Celecoxib-HDAC inhibitors (selenium-containing analogues of Celecoxib) on ALL cells, of which compound 11 exhibited significant inducement to kill NALM6 cells with an average IC50 of 9.95 ± 0.44 µM compared with control Celecoxib at 28.58 ± 1.44 µM and inhibited NALM6 cells growth via the inhibition of the cell cycle in G2 phase. Furthermore, compound 11 induced apoptosis by activating PARP cleavage. Taken together, compound 11 possessed the potential to be developed further as a chemotherapeutic agent for ALL.

Toxicity effects of chlorantraniliprole in zebrafish (Danio rerio) involving in liver function and metabolic phenotype.

Chlorantraniliprole (CAP), a representative bisamide insecticide, is widely used in rice fields around the world, posing potential toxicity risks to aquatic organisms. In this study, we examined the effects of exposure to CAP on growth and metabolic phenotype of zebrafish (Danio rerio) and oxidative stress and apoptosis in the liver of zebrafish (Danio rerio). First, we identified that CAP had a low bioaccumulation in zebrafish. Subsequently, growth phenotype analysis revealed that CAP could significantly increase liver weight and liver index in zebrafish. In addition, we found that CAP exposure could cause significant changes in indicators of oxidative stress, resulting in a significant increase in the content of malondialdehyde (MDA), causing oxidative stress in the liver of zebrafish. Meanwhile, the expression levels of apoptosis-related genes were also significantly changed and apoptosis was promoted in the liver of zebrafish with CAP exposure. Importantly, the results of metabolomics analysis shown that CAP exposure could significantly disrupt the metabolic phenotype of zebrafish, interfering with multiple metabolic pathways, mainly including valine, leucine and isoleucine biosynthesis and degradation, alanine, aspartate and glutamate metabolism and d-glutamine and D-glutamate metabolism. Last but not least, correlation analysis identified strong links between changes in liver function involving oxidative stress and apoptosis and changes in metabolic phenotype of zebrafish following CAP exposure. In brief, these results indicate that potential environmental risks of CAP to aquatic organisms should receive more attention.

Insights into the conformation changes of SARS-CoV-2 spike receptor-binding domain on graphene.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been widely spread in the world, causing more than two million deaths and seriously threatening human life. Effective protection measures are important to prevent the infection and spreading of the virus. To explore the effects of graphene on the virus adsorption and its biological properties, the adsorption process of the receptor binding domain (RBD) of SARS-CoV-2 on graphene has been investigated by molecular dynamics simulations in this paper. The results show that RBD can be quickly adsorbed onto the surface of graphene due to π - π stacking and hydrophobic interactions. Residue PHE486 with benzene ring has stronger adsorption force and the maximum contact area with graphene. Graphene significantly affects the secondary structure of RBD area, especially on the three key sites of binding with human ACE2, GLY476, PHE486 and ASN487. The binding free energy of RBD and graphene shows that the adsorption is irreversible. Undoubtedly, these changes will inevitably affect the pathogenicity of the virus. Therefore, this study provides a theoretical basis for the application of graphene in the protection of SARS-CoV-2, and also provides a reference for the potential application of graphene in the biomedical field.

Crystal Structure of Human CD47 in Complex with Engineered SIRPα.D1(N80A).

Background: Targeting the CD47/SIRPα signaling pathway represents a novel approach to enhance anti-tumor immunity. However, the crystal structure of the CD47/SIRPα has not been fully studied. This study aims to analyze the structure interface of the complex of CD47 and IMM01, a novel recombinant SIRPα-Fc fusion protein. Methods: IMM01-Fab/CD47 complex was crystalized, and diffraction images were collected. The complex structure was determined by molecular replacement using the program PHASER with the CD47-SIRPαv2 structure (PDB code 2JJT) as a search model. The model was manually built using the COOT program and refined using TLS parameters in REFMAC from the CCP4 program suite. Results: Crystallization and structure determination analysis of the interface of IMM01/CD47 structure demonstrated CD47 surface buried by IMM01. Comparison with the literature structure (PDB ID 2JJT) showed that the interactions of IMM01/CD47 structure are the same. All the hydrogen bonds that appear in the literature structure are also present in the IMM01/CD47 structure. These common hydrogen bonds are stable under different crystal packing styles, suggesting that these hydrogen bonds are important for protein binding. In the structure of human CD47 in complex with human SIRPα, except SER66, the amino acids that form hydrogen bonds are all conserved. Furthermore, comparing with the structure of PDB ID 2JJT, the salt bridge interaction from IMM01/CD47 structure are very similar, except the salt bridge bond between LYS53 in IMM01 and GLU106 in CD47, which only occurs between the B and D chains. However, as the side chain conformation of LYS53 in chain A is slightly different, the salt bridge bond is absent between the A and C chains. At this site between chain A and chain C, there are a salt bridge bond between LYS53 (A) and GLU104 (C) and a salt bridge bond between HIS56 (A) and GLU106 (C) instead. According to the sequence alignment results of SIRPα, SIRPß and SIRPγ in the literature of PDB ID 2JJT, except ASP100, the amino acids that form common salt bridge bonds are all conserved. Conclusion: Our data demonstrated crystal structure of the IMM01/CD47 complex and provides a structural basis for the structural binding interface and future clinical applications.

[Laparoscopic Common Bile Duct Exploration for Treatment of Common Bile Duct Stones:Clinical Analysis of 158 Cases].

Objective To evaluate the safety and effectiveness of laparoscopic common bile duct exploration in the treatment of common bile duct stones. Methods A retrospective analysis was conducted for 158 patients with cholecystolithiasis and choledocholithiasis admitted to the Number One Hospital of Zhangjiakou from January 2015 to December 2019.The patients were assigned into three groups according to the diameters of cystic duct and common bile duct,degrees of abdominal infection and tissue edema,and operation method.Group A(16 cases):laparoscopic cholecystectomy,transcystic choledochoscopic exploration for stone removal;Group B(94 cases):laparoscopic cholecystectomy,common bile duct incision exploration combined with choledochoscopy for stone removal,T tube drainage;Group C(48 cases):laparoscopic cholecystectomy,common bile duct incision exploration combined with choledochoscopy for stone removal,primary closure of the common bile duct.The operation time,residual rate of stones,and complication(bleeding,bile leakage,and wound infection) rate were compared between groups. Results The operation time of groups A,B,and C was(95.1±14.7),(102.2±18.1),(110.1±16.4) minutes,respectively,which showed no statistical difference between each other(F=0.020,P=0.887).One case in group A had residual stones,while no residual stone appeared in groups B and C.The overall stone clearance rate was 99.4% and the overall complication rate was 1.9%.There was no perioperative death. Conclusion It is generally safe and effective to carry out laparoscopic cholecystectomy and common bile duct exploration for stone removal in suitable populations.

Inflammation and DNA Methylation-Dependent Down-Regulation of miR-34b-5p Mediates c-MYC Expression and CRL4DCAF4 E3 Ligase Activity in Colitis-Associated Cancer.

miRNAs, a well-known group of noncoding RNAs, contribute to the pathogenesis of multiple diseases, including colitis-associated cancer (CAC). Our recent findings indicate that proinflammatory cytokines up-regulate c-MYC level, which subsequently activates cullin 4A and 4B (CUL4A/4B) and CRL4DCAF4 E3 ligases and promotes ubiquitination of suppression of tumorigenicity 7 in CAC. Herein, we identified and proved that miR-34b-5p can directly target c-MYC. In vitro oncogenic phenotype analyses and in vivo tumor formation assay indicated that miR-34b-5p overexpression could markedly decrease cell proliferation, colony formation, cell invasion, and tumor volumes. Overexpression of c-MYC in vitro could reverse the oncogenic phenotypes caused by miR-34b-5p up-regulation. In addition, the down-regulation of miR-34b-5p in CAC was dependent on the coregulation of the inflammatory microenvironment and DNA methylation. Collectively, our findings demonstrate that intracellular inflammation and DNA hypermethylation suppress miR-34b-5p expression, which limits its inhibitory effect on c-MYC and initiates the downstream events, including the induction of CRL4DCAF4 E3 ligase activity. The activated CRL4DCAF4 E3 ligase ubiquitinates suppression of tumorigenicity 7 and results in its degradation, eventually leading to the CAC tumorigenesis.