Safety assessment of Rhodobacter azotoformans SY5 for potential application in Chinese mitten crab Eriocheir sinensis

Rhodobacter species are promising beneficial microbes that can improve growth performance, immunity and antioxidant capability in aquatic crustaceans. Yet the safety of Rhodobacter azotoformans for potential application in Chinese mitten crab Eriocheir sinensis is still unclear. In the present study, R. azotoformans SY5, a potential probiotic additive that can significantly improve the growth performance, immunity, antioxidant capability, and disease resistance in E. sinensis, was evaluated for safety through whole genome sequencing, antibiotic resistance, toxic metabolites, virulence, and crab tolerance assays. The results indicated that R. azotoformans SY5 only harboured the acyl carrier protein-encoding gene (acpP) that was universal in probiotic bacteria with the function of bacterial fatty acid biosynthesis, exhibited high susceptibility to aminoglycosides, penicillins, polymyxins, polyphosphates, quinolones, and tetracyclines antimicrobials, and possessed inability to produce hemolysin, hydrogen sulphide, nitrite, ammonia, and phenylpyruvate. In addition, R. azotoformans SY5 showed no pathogenicity for E. sinensis with the seven-day acute intraperitoneal LD50 value of above 6.0 × 109 cfu/ml and 30-day chronic oral LD50 of above 6.0 × 109 cfu/g diet. To our knowledge, this is the first report on the safety of R. azotoformans for potential application in Chinese mitten crabs.

Diagnostic Value of Pulmonary Ultrasound and Arterial Blood Gas Analysis in Acute Patients with Severe Injuries Complicated by Respiratory Failure-A Retrospective Study

Background

To investigate the early application of pulmonary ultrasonography and arterial blood gas analysis in critical patients with severe multiple injuries exacerbated by respiratory failure.

Patients and Methods

The retrospective selection was performed on 81 patients admitted to our critical care unit between January 2020 and January 2021 with severe multiple injuries rendered worse by respiratory failure. Based on the different examination procedures, the patients were categorised into three groups (n=27): group A; diagnosed with pulmonary ultrasonography, group B; diagnosed with arterial blood gas; and group C; diagnosed with both pulmonary ultrasonography and arterial blood gas analyses. Patients were subsequently divided into a survival group (n = 65) and a death group (n = 16). On an annual basis, patients' prognoses were examined in relation to the predictive value of pulmonary ultrasound.

Results

Initial diagnosis, diagnosis, and initial correct treatment times were significantly shorter in groups B and C than group A (P<0.05). In contrast, initial diagnosis time, diagnosis time, and initial correct treatment times were potentially shorter in group C than in group B (P<0.05). Compared to groups B and C, group A had a considerably lower diagnosis rate for the examination methods (P<0.05). The right diaphragm displacement and left diaphragm displacement in the survival group were potentially higher than the LUS score (P < 0.05). In contrast, the survival group's lung ultrasound score (LUS) was considerably lower than the death group's. Statistical analysis showed that the predictive values of right diaphragm displacement, left diaphragm displacement, and mean diaphragm displacement were significant compared with the LUS score. The findings of the receiver operating characteristic curve demonstrated that the right, left, and average diaphragm displacements had high predictive values.

Conclusion

In the early evaluation of patients with severe multiple injuries complicated by respiratory failure, pulmonary ultrasonography combined with arterial blood gas analysis is crucial for the rapid diagnosis and prognosis prediction of patients.

Esmolol inhibits cognitive impairment and neuronal inflammation in mice with sepsis-induced brain injury

Sepsis is a potentially fatal organ failure resulting from a dysregulated host response to infection. It can be a substantial financial burden on families and society due to the high cost of medical care. The study aims to investigate the protective roles of Esmolol in mice with sepsis-induced brain injuries against cognitive dysfunction and neuronal inflammation. Male C57BL/6J mice were intraperitoneally injected with LPS (10 mg/kg, L2630, Sigma) to establish a septic encephalopathy model. Esmolol (15 mg/kg/h, HY-B1392, MedChemExpress) was subcutaneously infused using osmotic mini-pumps for 6 h before LPS injection. Morris water maze and novel object recognition tests evaluated LPS-induced cognitive impairment and behavioral phenotypes. Cytokines and protein expression were assessed using ELISA assay and RT-qPCR. Esmolol treatment potentially improved cognitive impairment in septic mice. Esmolol administration markedly diminished the abnormal hippocampal neuronal structure, and the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α was significantly downregulated in the hippocampal tissue. Esmolol treatment significantly reduced apoptotic TUNEL-positive cells and reversed the related gene expression (BAX and BCL-2). The effects of esmolol on the reactive oxidative species and oxidative stress markedly reduce malondialdehyde MDA content and increase superoxide dismutase and catalase in hippocampal tissues. In addition, esmolol significantly reduced the percentage and density of Iba-1 + microglia in septic mice. Our results demonstrated that esmolol potentially improved cognitive impairment and neuronal inflammation in mice with sepsis-induced brain injury.

Association between plasma homocysteine levels and pancreatic islet beta-cell function in the patients with type 2 diabetes mellitus: a cross-sectional study from China

BACKGROUND

This study sought to investigate the association between plasma homocysteine (HCY) levels and pancreatic islet beta-cell function in type 2 diabetes mellitus (T2DM) patients.

METHODS

430 hospitalized T2DM patients were enrolled in this cross-sectional study from December 2013 to December 2016. All participants were requested to complete a detailed questionnaire and undergo anthropometric measurements. Blood samples were collected from all participants. A 75-g oral glucose tolerance test (OGTT) was performed to diagnose T2DM in each individual, and an insulin releasing test (IRT) was used to calculate selected parameters for glucose, insulin, and C-peptide. Linear correlation and multivariate regression analyses were performed to assess the association between serum HCY concentration and these parameters.

RESULTS

Patients were divided into the following subgroups based on quartiles of serum HCY levels: Group Q1: <17.03 µmol/L; Group Q2: 17.03-19.50 µmol/L; Group Q3: 19.5-24.7 µmol/L; and Group Q4: >24.7 µmol/L. The levels of fasting blood glucose (FBG), 2 h postprandial blood glucose (2hPBG), glycated hemoglobin A1c (HbA1c), fasting C-peptide and fasting insulin increased significantly as HCY levels increased (P<0.05). The area under the curves (AUCs) of serum glucose and insulin in IRT increased significantly and that of serum C-peptide decreased as HCY levels increased (P<0.05). The levels of Homeostasis Model Assessment-β (HOMA-β), Modified Beta-cell function Index (MBCI), Disposal Index (DI), C-peptide immunoreactivity (CPR), Insulinogenic Index 30 (IGI 30), and Secretory Units of Islets in Transplantation (SUIT) decreased as HCY levels increased. An inverse linear correlation was found between HOMA-β, MBCI, DI, CPR, IGI 30, SUIT 0 h, and HCY plasma concentration (R2, 0.539, 0.569, 0.500, 0.676, 0.579, and 0.588, respectively; P<0.001), and this association was independent of many confounders, such as age, gender, body mass index, glucose and insulin levels, and HbA1c.

CONCLUSIONS

Serum HCY levels were inversely related to the parameters for pancreatic islet beta-cell function. Thus, the insulin releasing function of beta cells in the pancreas can be well elucidated by plasma HCY concentration.

Proteomics of Tear in Inactive Thyroid-Associated Ophthalmopathy

BACKGROUND

Thyroid-associated ophthalmopathy (TAO), one of the most common orbital diseases in adults, seriously reduces patients' quality of life. Although human tear proteomics identified many abnormal expressed proteins and proposed several pathogeneses of TAO, most of these studies focused on the active stage or mixed types in TAO. In this study we identified significantly changed proteins and preliminary revealed the potential signalling pathways and mechanisms of TAO with the late, inactive stage.

PATIENTS AND METHODS

Tears from TAO patients (n=6) with a CAS score < 3 and 6 control healthy subject were collected. The pooled tears were further fractionated using high pH reversed-phase chromatography, then submitted to LC-MS/MS and subsequent bioinformatic analysis.

RESULTS

Proteomic profiling identified 107 significantly changed proteins between the inactive stage of TAO patients and healthy cases. Among these proteins, 62 were upregulated, and 45 were downregulated in TAO cases compared to healthy individuals. Enrichment analysis revealed that the immune system, cell cycle, metabolism (carbohydrate metabolism and metabolism of cofactors and vitamins), protein synthesis and degradation might play a vital role in the progress of inactive TAO. The present investigation represents the first proteomic tear study of TAO patients in the inactive stage.

CONCLUSION

The results shed light on the differences between inactive TAO patients and healthy cases, thus enabling us to understand better the molecular mechanisms and potential targets for the treatment of inactive TAO.

Investigation on Potential of Novel Carrier System Containing Silver and Gold Nanoparticles for Burn Surgery: Evaluation in Rat Model

The main aim of the study was to optimization and evaluation of a suitable dosage form i.e., tropical gel containing silver and gold nanoparticles which are synthesized by green synthesis as this is the rapid and better alternative to chemical synthesis. For burn injury systemic route of administration is not suitable due to damaged skin hence tropical route selected to provide controlled effects, low systemic toxicity and easy application. Silver nanoparticles were synthesized by green synthesis by use of neem leaves and gold nanoparticles by Aloe vera. Characterization was done by UV spectroscopy, particle size distribution, TEM and zeta potential. Gel was formulated by simple mixing and stirring method and evaluated for color, homogeneity, Spreadability, viscosity, in vitro release, antimicrobial study and in vivo study. In this study, the combination of Carbopol 934 P and HPMC (ratio 1:3) was found to be ideal formulation (Formulation F5) with optimum viscosity and Spread-ability i.e., 4459 cP and 5.7 gmcm/sec resp. in vitro release was found to be 98.66% in 12 hours. in vitro antimicrobial study and in vivo study on rat showed maximum effects than standard formulations. From this study it can be concluded that, tropical gel is the superior dosage form containing silver and gold nanoparticles which acts as the antimicrobial agents and is effective in treatment of burn surgery.

Circular RNA expression profiles and features in NAFLD mice: a study using RNA-seq data

Background

Nonalcoholic fatty liver disease (NAFLD) is primarily characterized by the hepatic cholesterol accumulation. Circular RNA (circRNA), one of noncoding RNA, involves in many liver diseases progression. However, no recent studies on circRNA expression profiles in NAFLD have been reported previously.

Methods

A NAFLD mouse model was constructed by providing high-fat diet (HFD) for 32 weeks. The circRNAs expression profile in normal mice and NAFLD mice were determined using high-output RNA sequencing method and bioinformatics methods, while the differentially expressed circRNAs were confirmed using Sanger sequencing and qRT-PCR. The circRNA-miRNA network was also predicted. The biological functions of circRNAs were annotated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG).

Results

The results demonstrated the successful construction of NAFLD mice model by immunohistology and serology assay. In total, 93 dysregulated circRNAs were observed, including 57 upregulated circRNAs and 36 downregulated circRNAs, in the NAFLD group. The circRNA-miRNA network revealed the complex interaction between circRNAs and its potential miRNA targets in NAFLD. The characteristic of tissue-specific expression in circRNA was demonstrated. The differentially expressed circRNAs with important biological function were also annotated using GO and KEGG. Both DDAH1 and VAV3 genes were found to be associated with the NAFLD development.

Conclusions

Taken together, this study demonstrated the circRNAs expression profile and features in NAFLD, which may provide potential biological markers for the pathogenesis of NAFLD.

The effects of dehydroepiandrosterone (DHEA) supplementation on body composition and blood pressure: A meta-analysis of randomized clinical trials

Dehydroepiandrosterone (DHEA) supplementation has been anecdotally considered as a tool to improve body composition and health status. We aimed to verify the impact of DHEA supplementation on traditional measurements of body composition and blood pressure (BP) due to their clinical applicability. A meta-analysis of randomized clinical trials was conducted based on the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Regarding anthropometric characteristics, DHEA supplementation did not change body weight (weighted mean difference (WMD): -0.16 kg, 95% CI: -1.02 to 0.70, p = 0.72) or body mass index (WMD: -0.18 kg/m², 95% CI: -0.48 to 0.12, p = 0.24), but increased lean body mass (WMD: 0.45 kg, 95% CI: 0.15 to 0.75, p = 0.004) and decreased fat mass (WMD: -0.85%, 95% CI: -1.18 to -0.51, p = 0.000), when compared to control groups. Neither systolic (WMD: 0.98 mm Hg, 95% CI: -2.31 to 4.29, p = 0.56) nor diastolic BP were significantly changed (WMD: -1.62 mm Hg, 95% CI: -5.49 to 2.24, p = 0.49). Our findings demonstrate that DHEA supplementation increased lean body mass and decreased fat mass, but debate persists when translating the results into clinical benefit. Lastly, DHEA supplementation had a neutral effect on BP.

PolyMet-HA nanocomplexs regulates glucose uptake by inhibiting SHIP2 activity

Metformin, the first-line drug to treat type 2 diabetes, inhibits mitochondrial glycerolphosphate dehydrogenase in the liver to suppress gluconeogenesis. The major adverse effects caused by metformin were lactic acidosis and gastrointestinal discomfort. Therefore, there is need to develop a strategy with excellent permeability and appropriate retention effects.In this study, we synthesized a simple and biocompatible PolyMetformin (denoted as PolyMet) through conjugation of PEI_1.8K with dicyandiamide, and then formed PolyMet-hyaluronic acid (HA) nanocomplexs by electrostatic self-assembly of the polycationic PolyMet and polyanionic hyaluronic acid (HA). Similar to metformin, the PolyMet-HA nanocomplexs could reduce the catalytic activity of the recombinant SHIP2 phosphatase domain in vitro. In SHIP2-overexpressing myotubes, PolyMet-HA nanocomplexes ameliorated glucose uptake by downregulating glucose transporter 4 endocytosis. PolyMet-HA nanocomplexes also could restore Akt signaling and protect the podocyte from apoptosis induced by SHIP2 overexpression. In essence, the PolyMet-HA nanocomplexes act similarly to metformin and increase glucose uptake, and maybe have a potential role in the treatment of type 2 diabetes.

In Vitro Reconstitution of Autophagosome-Lysosome Fusion

SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) proteins are a highly regulated class of membrane proteins lying in the center of membrane fusion. In conjunction with accessory proteins, SNAREs drive efficient merger of two distinct lipid bilayers into one interconnected structure. This chapter describes our fluorescence resonance energy transfer (FRET)-based proteoliposome fusion assays for the roles of various SNARE proteins, accessory proteins, and effects of different lipid compositions on membrane fusion involved in autophagy.

Species differences for stereoselective metabolism of ethofumesate and its enantiomers in vitro

1. The stereoselective metabolism of ethofumesate (ETO) and its enantiomers in rabbit and rat liver microsomes have been studied by chiral high-performance liquid chromatography (HPLC) method. Two metabolites were detected in both liver microsomes in the presence of beta-nicotinamide adenine dinucleotide phosphate (NADPH). 2. The T(1/2) of (+)-ETO and (-)-ETO in rabbit liver microsomes were 12.2 and 4.7 min of rac-ETO and 25.9 and 6.7 of ETO enantiomers. However, the T(1/2) of (+)-ETO and (-)-ETO in rat liver microsomes were 5.3 and 5.9 min of rac-ETO and 7.8 and 10.6 of ETO enantiomers. The stereoselective selectivity is similar to the in vivo study. 3. After incubation of ETO enantiomers, stereoselectivity was present in the formation of ETO-OH enantiomer in rabbit liver microsomes, but stereoselectivity was not evident in rat liver microsomes. 4. There was no chiral inversion from the (+)-ETO to (-)-ETO or inversion from (-)-ETO to (+)-ETO in both rabbit and rat liver microsomes.

Surveillance of transcriptomes in basic military trainees with normal, febrile respiratory illness, and convalescent phenotypes

Gene expression profiles permit analysis of host immune response at the transcriptome level. We used the Pax gene Blood RNA (PAX) System and Affymetrix microarrays (HG-U133A&B) to survey profiles in basic military trainees and to classify them as healthy, febrile respiratory illness (FRI) without adenovirus, FRI with adenovirus, and convalescent from FRI with adenovirus. We assessed quality metrics of RNA processing for microarrays. Class prediction analysis discovered nested sets of transcripts that could categorize the phenotypes with optimized accuracy of 99% (nonfebrile vs febrile, P<0.0005), 87% (healthy vs convalescent, P=0.001), and 91% (febrile without vs with adenovirus, P<0.0005). The discovered set for classification of nonfebrile vs febrile patients consisted of 40 transcripts with functions related to interferon induced genes, complement cascades, and TNF and IL1 signaling. The set of seven transcripts for distinguishing healthy vs convalescent individuals included those associated with ribosomal structure, humoral immunity, and cell adhesion. The set of 10 transcripts for distinguishing FRI without vs with adenovirus had functions related to interferon induced genes, IL1 receptor accessory protein, and cell interactions. These results are the first in vivo demonstration of classification of infectious diseases via host signature transcripts and move us towards using the transcriptome in bio-surveillance.

Impaired glucose-stimulated insulin secretion, enhanced intraperitoneal insulin tolerance, and increased beta-cell mass in mice lacking the p110gamma isoform of phosphoinositide 3-kinase

Phosphoinositide 3-kinase (PI3 kinase) has been implicated in G protein-coupled receptor regulation of pancreatic beta-cell growth and glucose-stimulated insulin secretion. The G protein-activated p110gamma isoform of PI3 kinase was detected in insulinoma cells, mouse islets, and human islets. In 7- to 10-wk-old mice, knockout of p110gamma reduced the plasma insulin response to ip glucose injection and impaired first and second phase glucose-stimulated insulin secretion from pancreata perfused ex vivo. The p110gamma -/- mice responded to preinjection with the glucagon-like peptide-1 receptor agonist exendin 4, such that plasma glucose and insulin responses to ip glucose injection were not different from wild types. Mice lacking p110gamma were not diabetic and were only slightly glucose intolerant (ip glucose injection) compared with wild types, in part due to enhanced responsiveness to insulin as determined by an ip insulin tolerance test. Despite severely reduced insulin secretion in these animals, the p110gamma -/- mice had greater pancreatic insulin content, and an increased beta-cell mass due to beta-cell hypertrophy. These surprising results suggest that the G protein-coupled p110gamma isoform of PI3 kinase is not central to the development or maintenance of sufficient beta-cell mass but positively regulates glucose-stimulated insulin secretion.

X protein of hepatitis B virus modulates cytokine and growth factor related signal transduction pathways during the course of viral infections and hepatocarcinogenesis

Hepatitis B virus produces chronic infections of the liver leading to cirrhosis and hepatocellular carcinoma. The X protein of hepatitis B virus (HBx) is a multifunctional protein that can interact with p53 but can also influence a variety of signal transduction pathways within the cell. In most instances this small viral protein favors cell survival and probably initiates hepatocarcinogenesis. HBx upregulates the activity of a number of transcription factors including NF-kappa B, AP-1, CREB, and TBP. However, the majority of HBx is localized to the cytoplasm where it interacts with and stimulates protein kinases such as protein kinase C, Janus kinase/STAT, IKK, PI-3-K, stress-activated protein kinase/Jun N-terminal kinase, and protein kinase B/Akt. This small viral protein can localize to the mitochondrion. HBx may act as an adaptor or kinase activator to influence signal transduction pathways. This review will attempt to analyze the involvement of HBx in signal transduction pathways during hepatitis B viral infections and hepatocellular carcinoma development.

Immunogenicity of recombinant GA733-2E antigen (CO17-1A, EGP, KS1-4, KSA, Ep-CAM) in gastro-intestinal carcinoma patients

Targeting the GA733 antigen (also known as CO17-1A, EGP, KS1-4, KSA, Ep-CAM) by monoclonal antibody CO17-1A or anti-idiotypic antibodies mimicking the CO17-1A or GA733 epitope has induced prolonged survival and specific immune responses to the antigen, respectively, in colorectal cancer (CRC) patients. In pre-clinical studies in mice and rabbits, recombinant baculovirus-derived GA733-2E antigen was superior to anti-idiotypic antibodies at modulating specific immune responses. Our aim was to evaluate the immunogenicity and potential toxicity of alum-precipitated GA733-2E in a phase I trial in patients with resected CRC or pancreatic cancer. Six patients with advanced pancreatic carcinoma and 6 with CRC Dukes' stage A, B or C received between 4 and 7 doses of alum-precipitated GA733-2E at 50, 200 or 800 microg/dose at monthly intervals. Antibody binding to GA733-2E or antigen-positive CRC cells was determined, as were antigen-specific proliferative, cytolytic T-lymphocyte and delayed-type hypersensitivity responses. Six of the 12 patients developed antigen-specific humoral immune responses after immunotherapy, and 8 developed cellular immune responses. The overall immune response rate, including patients with humoral and/or cellular immune responses, was 83%. Median overall survival of the CRC and pancreatic cancer patients was 39.8 and 11.2 months, respectively. Following 18 years of single-epitope targeting of the GA733 antigen, immunization of patients against multiple epitopes of the antigen frequently induces an immune response in the absence of significant toxicity, despite relatively widespread expression of this antigen on normal epithelial cells.

X protein of hepatitis B virus inhibits Fas-mediated apoptosis and is associated with up-regulation of the SAPK/JNK pathway

The X protein from a chronic strain of hepatitis B virus (HBx) was determined to inhibit Fas-mediated apoptosis and promote cell survival. Fas-mediated apoptosis is the major cause of hepatocyte damage during liver disease. Experiments demonstrated that cell death caused by anti-Fas antibodies was blocked by the expression of HBx in human primary hepatocytes and mouse embryo fibroblasts. This effect was also observed in mouse erythroleukemia cells that lacked p53, indicating that protection against Fas-mediated apoptosis was independent of p53. Components of the signal transduction pathways involved in this protection were studied. The SAPK/JNK pathway has previously been suggested to be a survival pathway for some cells undergoing Fas-mediated apoptosis, and kinase assays showed that SAPK activity was highly up-regulated in cells expressing the HBx protein. Normal mouse fibroblasts expressing HBx were protected from death, whereas identical fibroblasts lacking the SEK1 component from the SAPK pathway succumbed to Fas-mediated apoptosis, whether HBx was present or not. Assays showed that caspase 3 and 8 activities and the release of cytochrome c from mitochondria were inhibited, in the presence of HBx, following stimulation with anti-Fas antibodies. Coprecipitation and confocal immunofluorescence microscopy experiments demonstrated that HBx localizes with a cytoplasmic complex containing MEKK1, SEK1, SAPK, and 14-3-3 proteins. Finally, mutational analysis of HBx demonstrated that a potential binding region for 14-3-3 proteins was essential for induction of SAPK/JNK activity and protection from Fas-mediated apoptosis.

Human PBMC-derived dendritic cells transduced with an adenovirus vectorinduce cytotoxic T-lymphocyte responses against a vector-encoded antigen in vitro

Dendritic cells (DC) are among the most potent antigen-presenting cells known and play an important role in the initiation of antigen-specific T-lymphocyte responses. Several recent studies have demonstrated that DC expressing vector-encoded tumor-associated antigens can induce protective and therapeutic immunity in murine cancer models. In the current study we set out to examine in vitro the utility of adenovirus vectors in the transduction of human DC for the induction of antigen-specific T-lymphocyte responses against a defined vector-encoded antigen. DC were derived from the adherent fraction of PBMC by culture in defined medium containing GM-CSF and IL-4. A replication-defective E1/E3-deleted type 5 adenovirus vector encoding bacterial beta-galactosidase (beta-gal) under the transcriptional control of a CMV promoter was used to transduce DC at multiplicities of infection (MOI) up to 1000. While high MOI were required to achieve efficient transduction there was no significant effect on DC morphology, immunophenotype or potency in allogeneic lymphocyte proliferation assays. Furthermore, transduced DC-induced antigen-specific CTL activity against adenoviral proteins and more significantly, the vector-encoded antigen beta-gal. These data clearly demonstrate the potential of adenovirus vectors in anticancer DC vaccine strategies and provide an important link between existing animal data and human clinical application.

[Recursion formula of energy levels for 2p(3)3s and 2p(3)3d of O I isoelectronic series]

Based on the perturbation expansion and the observed energy levels for 2p(3)3s and 2p(3)3d of O I -like ions, a recursion formula for the energy levels has been derived. It is found that this method is considerably simple and accurate.

Complement-mediated cytotoxicity and inhibition of ligand binding to hepatocytes by woodchuck hepatitis virus-induced autoantibodies to asialoglycoprotein receptor

Hepadnavirus invasion in woodchucks has been identified as a potent inducer of autoantibodies against asialoglycoprotein receptor (anti-ASGPR), a molecule essentially unique to hepatocytes that mediate clearance of desialylated serum proteins. We evaluated the possible pathogenetic importance of anti-ASGPR triggered by woodchuck hepatitis virus (WHV), using anti-ASGPR-reactive serum immunoglobulins (Igs) from five animals with different stages of WHV hepatitis or self-limited WHV infection and isolated woodchuck hepatocytes or HepG2 cells as targets. The results revealed that WHV-induced anti-ASGPR can specifically inhibit asialoglycoprotein recognition by both homologous and heterologous liver cells, as tested in an asialofetuin (ASFN)-binding radioassay. However, the extent of the interference significantly varied (from 85% inhibition to none) for anti-ASGPR with similar titer from different animals, indicating a high degree of heterogeneity in the ASGPR epitope specificity and in the potential biological effects of these autoantibodies. The WHV-triggered anti-ASGPR also induced complement-mediated hepatocytolysis in a microculture tetrazolium (MTT) assay, which ranged from 8.9% +/- 0.3% to 33.6% +/- 3.6% (mean +/- SD) for different animals and target cell numbers. This cytopathic effect was strictly ASGPR-specific, complement-dependent, and was not related to the anti-ASGPR ability to inhibit ligand-hepatocyte binding. Our findings indicate that among pathways by which anti-ASGPR autoimmunity could cause liver damage, hepadnavirus-induced anti-ASGPR might impair hepatocytes by both disrupting clearance of desialylated proteins and activation of the complement-mediated cytolysis. These cytopathic effects might contribute to the pathogenesis, aggravate severity, and prolong recovery from liver injury in viral hepatitis.

Molecular replacement studies on crystal structure of DesB1-B2 Despentapeptide (B26-B30) insulin

Using the crystal structure of Despentapeptide (B26-B30) insulin (DPI as the search model, the crystal structure of DesB1-B2 Despentapeptide (B26-B30) insulin (DesB1-2 DPI) has been studied by the molecular replacement method. There is one DesB1-2 DPI molecule in each crystallographic asymmetric unit. The cross rotation function search and the translation function search show apparent peaks and thus determine the orientation and position of DesB1-2 DPI molecule in the cell respectively. The subsequent three-dimensional structural rebuilding and refinement of DesB1-2 DPI molecule confirm the results by molecular replacement method.

Virus-induced anti-asialoglycoprotein receptor autoimmunity in experimental hepadnaviral hepatitis

The relationship between hepatitis virus invasion and emergence of liver-specific autoantibodies against asialoglycoprotein receptor (anti-ASGPR) and the occurrence patterns, prognostic value, and specificity of these autoantibodies toward polypeptides of host ASGPR were investigated in experimental viral hepatitis in the woodchuck system. Sequential sera (n = 231) obtained before and after inoculation with woodchuck hepatitis virus (WHV) from animals which resolved acute infection (n = 7) or developed chronic hepatitis (n = 6) were tested for anti-ASGPR using radio and enzyme-immunodetection assays. In addition, the outcome of WHV hepatitis was analyzed in 30 other woodchucks whose preinoculation sera were tested for anti-ASGPR. The receptor subunit specificity of virus-induced anti-ASGPR was determined by Western blotting and compared with that of anti-ASGPR raised in woodchucks challenged with a heterologous (rabbit) receptor. The results revealed that WHV infection triggered anti-ASGPR in all except one of the initially autoantibody nonreactive animals (eight of nine; 89.9%). Once induced, anti-ASGPR were detectable throughout the entire follow-up independent of histological severity of liver damage or the outcome of hepatitis. In healthy WHV-naive woodchucks, anti-ASGPR occurred at low titers in approximately one third of the animals. Importantly, woodchucks reactive for anti-ASGPR before WHV inoculation developed chronic hepatitis with a significantly greater frequency (55.5%) than those autoantibody negative (15.6%; P < .05). In contrast to anti-ASGPR elicited by immunization with a heterologous receptor, which initially recognized only the ASGPR 40-kd polypeptide, anti-ASGPR emerging after virus invasion reacted with both the ASGPR 40- and 47-kd subunits from the moment of their appearance. This study provides the first direct evidence that hepatitis virus in the natural host triggers autoantibodies against a unique hepatocyte antigen and shows that anti-ASGPR autoimmunity existing before virus infection is associated with a high rate of progression to chronic disease in experimental hepadnaviral hepatitis.

Composition, antigenic properties and hepatocyte surface expression of the woodchuck asialoglycoprotein receptor

We have purified woodchuck hepatic asialoglycoprotein receptor (ASGPR) by ligand affinity chromatography and have identified it as a heterooligomeric complex comprised of two subunits with molecular masses of 40 and 47 kD, designated as woodchuck hepatic lectin 1 and 2 (WHL1 and WHL2), respectively. With the help of antisera generated against the soluble, bioactive woodchuck and rabbit ASGPRs and anti-subunit monospecific antibodies, distinct antigenic specificity of each of the ASGPR polypeptide subunits and interspecies immunologic cross-reactivity of the receptor polypeptides displaying comparable molecular masses were documented. In contrast to the purified woodchuck receptor, WHL2 antigenic reactivity was not identifiable in woodchuck hepatocyte plasma membranes unless the intact membranes were exposed to an asialylated ligand or a soluble membrane fraction was incubated with anti-receptor antibody. These findings imply that both WHL1 and WHL2 are expressed on the hepatocyte surface and contribute to ligand binding, since antibody specific to either subunit blocks ligand attachment. Our results also indicate that ligand binding modifies antigenic properties of the membrane expressed ASGPR.

[Analysis of outer membrane proteins from eight strains of Campylobacter in SDS-PAGE]

The outer membrane proteins (OMPs) from 8 strains of Campylobacter, including 5 reference strains and 3 local strains, were isolated and examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that the population distributions of molecular weight of OMPs from different species and sources were alike based on the Rank Sum Test analysis. The number of bands of major OMP was around 2-3, the molecular weight of which varied from 33-68 kd. Moreover, three C. jejuni local strains isolated from patients in China showed common characteristics of OMPs to the reference strains. It is suggested that the OMPs of Campylobacter are of a conservative and stable structure.