Anti-EBV antibodies: Roles in diagnosis, pathogenesis, and antiviral therapy.

Epstein-Barr virus (EBV) infection is prevalent in global population and associated with multiple malignancies and autoimmune diseases. During the infection, EBV-harbored or infected cell-expressing antigen could elicit a variety of antibodies with significant role in viral host response and pathogenesis. These antibodies have been extensively evaluated and found to be valuable in predicting disease diagnosis and prognosis, exploring disease mechanisms, and developing antiviral agents. In this review, we discuss the versatile roles of EBV antibodies as important biomarkers for EBV-related diseases, potential driving factors of autoimmunity, and promising therapeutic agents for viral infection and pathogenesis.

Genomic Profiling of Radiation-Induced Sarcomas Reveals the Immunologic Characteristics and Its Response to Immune Checkpoint Blockade.

PURPOSE: Radiation-induced sarcomas (RIS) have a poor prognosis and lack effective treatments. Its genome and tumor microenvironment are not well characterized and need further exploration. EXPERIMENTAL DESIGN: Here, we performed whole-exome sequencing (WES) and mRNA sequencing (mRNA-seq) on patients with RIS and primary sarcomas (WES samples 46 vs. 48, mRNA-seq samples 16 vs. 8, mainly in head and neck), investigated the antitumor effect of programmed cell death protein 1 (PD-1) blockade in RIS patient-derived xenograft models, and analyzed clinical data of patients with RIS treated with chemotherapy alone or combined with an anti-PD-1 antibody. RESULTS: Compared with primary sarcomas, RIS manifested different patterns of copy-number variations, a significantly higher number of predicted strong MHC-binding neoantigens, and significantly increased immune cell infiltration. Clinical data showed that the combinatorial use of chemotherapy and PD-1 blockade achieved a higher objective response rate (36.67% vs. 8.00%; P = 0.003), longer overall survival (31.9 months vs. 14.8 months; P = 0.014), and longer progression-free survival (4.7 months vs. 9.5 months; P = 0.032) in patients with RIS compared with single chemotherapy. CONCLUSIONS: Elevated genomic instability and higher immune cell infiltrations were found in RIS than in primary sarcomas. Moreover, higher efficacy of chemotherapy plus PD-1 blockade was observed in animal experiments and clinical practice. This evidence indicated the promising application of immune checkpoint inhibitors in the treatment of RIS.

Parallel profiling of antigenicity alteration and immune escape of SARS-CoV-2 Omicron and other variants.

SARS-CoV-2 variants have evolved a variety of critical mutations, leading to antigenicity changes and immune escape. The recent emerging SARS-CoV-2 Omicron variant attracted global attention due to its significant resistance to current antibody therapies and vaccines. Here, we profiled the mutations of Omicron and other various circulating SARS-CoV-2 variants in parallel by computational interface analysis and in vitro experimental assays. We identified critical mutations that lead to antigenicity changes and diminished neutralization efficiency of a panel of 14 antibodies due to diverse molecular mechanisms influencing the antigen-antibody interaction. Our study identified that Omicron exhibited extraordinary potency in immune escape compared to the other variants of concern, and explores the application of computational interface analysis in SARS-CoV-2 mutation surveillance and demonstrates its potential for the early identification of concerning variants, providing preliminary guidance for neutralizing antibody therapy.

Experimental Investigation of Synchronous Grouting Material Prepared with Different Mineral Admixtures.

Waste sediment generated during tunnel construction is applied to prepare synchronous grouting material, where the influences of fly ash, slag powder, and bentonite on the rheological properties (such as consistency, fluidity, setting time, drainage rate, and stone rate) are studied. The results show that adding fly ash content increases the initial consistency, setting time, and fluidity of grouting material, but also increases its drainage rate and decreases its stone rate. The addition of slag powder results in a slight increase in the setting time and fluidity of the grouting material, yet a decrease in the initial consistency value. In contrast, with the addition of bentonite, both the initial consistency and fluidity of the grouting material decrease. Finally, the optimal mix ratio of high-performance and low-cost grouting materials is fixed to be 30% fly ash, 50% slag powder, and 10% bentonite. Therefore, the fluidity of grouting material can be 170 mm, with an initial consistency of 122 mm, setting time of 1050 min, stone rate of 96.2%, drainage rate of 1.5%, and 28-day compressive strength of 8.3 MPa.

NR4A1 counteracts JNK activation incurred by ER stress or ROS in pancreatic ß-cells for protection.

Sustained hyperglycaemia and hyperlipidaemia incur endoplasmic reticulum stress (ER stress) and reactive oxygen species (ROS) overproduction in pancreatic ß-cells. ER stress or ROS causes c-Jun N-terminal kinase (JNK) activation, and the activated JNK triggers apoptosis in different cells. Nuclear receptor subfamily 4 group A member 1 (NR4A1) is an inducible multi-stress response factor. The aim of this study was to explore the role of NR4A1 in counteracting JNK activation induced by ER stress or ROS and the related mechanism. qPCR, Western blotting, dual-luciferase reporter and ChIP assays were applied to detect gene expression or regulation by NR4A1. Immunofluorescence was used to detect a specific protein expression in ß-cells. Our data showed that NR4A1 reduced the phosphorylated JNK (p-JNK) in MIN6 cells encountering ER stress or ROS and reduced MKK4 protein in a proteasome-dependent manner. We found that NR4A1 increased the expression of cbl-b (an E3 ligase); knocking down cbl-b expression increased MKK4 and p-JNK levels under ER stress or ROS conditions. We elucidated that NR4A1 enhanced the transactivation of cbl-b promoter by physical association. We further confirmed that cbl-b expression in ß-cells was reduced in NR4A1-knockout mice compared with WT mice. NR4A1 down-regulates JNK activation by ER stress or ROS in ß-cells via enhancing cbl-b expression.

NR4A1 retards adipocyte differentiation or maturation via enhancing GATA2 and p53 expression.

Nuclear receptor subfamily 4 group A member 1 (NR4A1) is an orphan nuclear receptor with diverse functions. It has been reported that NR4A1, as a transcriptional activator, is implicated in glucose and lipid metabolism. The aim of this study was to investigate the regulatory role of NR4A1 in adipogenesis and explore the underlying mechanisms. Quantitative real-time PCR and Western blotting were used to analyse the expression of genes involved in synthesis and mobilization of fats in vivo and in vitro. Dual-luciferase reporter assay was conducted to study the regulatory mechanisms of NR4A1. Our data from in vivo study confirmed that NR4A1 knockout (KO) mice fed with high-fat diet were more prone to obesity, and gene expression levels of PPARγ and FAS were increased in KO mice compared to controls; our data from in vitro study showed that NR4A1 overexpression in 3T3-L1 pre-adipocytes inhibited adipogenesis. Moreover, NR4A1 enhanced GATA binding protein 2 (GATA2) expression, which in turn inhibited peroxisome proliferator-activated receptor γ (PPARγ); NR4A1 inhibited sterol regulatory element binding transcription factor 1 (SREBP1) and its downstream gene fatty acid synthase (FAS) by up-regulating p53. NR4A1 inhibits the differentiation and lipid accumulation of adipocytes by enhancing the expression of GATA2 and p53.

Baicalin protects against thrombin induced cell injury in SH-SY5Y cells.

Baicalin, an extract from the dried root of Scutellaria baicalensis Georgi, was shown to be neuroprotective. However, the precise mechanisms are incompletely known. In this study, we determined the effect of baicalin on thrombin induced cell injury in SH-SY5Y cells, and explored the possible mechanisms. SH-SY5Y cells was treated with thrombin alone or pre-treated with baicalin (5, 10, 20 µM) for 2 h followed by thrombin treatment. Cells without thrombin and baicalin treatment were used as controls. Cell viability was detected by MTT assay. Cell apoptosis was analyzed by flow cytometry. Real-time PCR was performed to determine the mRNA expression of protease-activated receptor-1 (PAR-1). Western blotting was conducted to determine the protein expression of PAR-1, Caspase-3 and NF-κB. Baicalin reduced cell death following thrombin treatment in a dose-dependent manner, with concomitant inhibition of NF-κB activation and suppression of PAR-1 expression. In addition, baicalin reduced Caspase-3 expression. The above findings indicated that baicalin prevents against cell injury after thrombin stimulation possibly through inhibition of PAR-1 expression and NF-κB activation.

Urinary methylmalonic acid as an indicator of early vitamin B12 deficiency and its role in polyneuropathy in type 2 diabetes.

The rising incidence of diabetes and its negative impact on quality of life highlights the urgent need to develop biomarkers of early nerve damage. Measurement of total vitamin B12 has some limitations. We want to determine the levels of urinary methylmalonic acid and its relationships with serum vitamin B12 and polyneuropathy. The 176 Chinese patients with Type 2 diabetes mellitus were divided into 3 groups according to the levels of vitamin B12. A gas chromatography mass spectrometric technique was used to determine blood methylmalonic acid and urinary methylmalonic acid. The diagnosis of distal diabetic polyneuropathy was based on the determination of bilateral limb sensory and motor nerve conduction velocity and amplitude with electromyogram. Multiple regression analysis revealed that urinary methylmalonic acid/creatinine, blood methylmalonic acid, and so forth were variables that influenced diabetic polyneuropathy significantly. Nerve sensory conduction velocity and nerve amplitude in the group of urinary methylmalonic acid/creatinine >3.5 mmol/mol decreased significantly. Superficial peroneal nerve sensory and motor conduction velocity and ulnar nerve compound motor active potential amplitude were inversely correlated with urinary methylmalonic acid/creatinine. Urinary methylmalonic acid correlates with serum vitamin B12 levels in person with diabetes and is a sensitive marker of early polyneuropathy.

Baicalin attenuates brain edema in a rat model of intracerebral hemorrhage.

Baicalin is a flavonoid compound purified from the roots of Scutellaria baicalensis, which possesses multiple biological activities. Previous studies have shown that baicalin is protective in ischemic cerebral diseases. The aim of the present study was to examine the effects of baicalin on brain injury in a rat model of intracerebral hemorrhage (ICH) and to explore the possible mechanisms. Intracerebral hemorrhage was induced in male Wistar rats by injection of 0.5 U collagenaseVII to the caudate nucleus. Sham operation rats were injected with equal volume of saline. After the induction of ICH, the rats were randomly divided into four groups and administered with different dose of baicalin (0, 25, 50, or 100 mg/kg in saline) through peritoneal injection. The brain tissues around the hemorrhage areas were collected on days 1, 3, and 5 after treatment. Brain edema was analyzed by desiccation method; the metalloproteinase-9 (MMP-9) protein and mRNA expression were determined by western blotting and real time RT-PCR, respectively. Nuclear factor-κB (NF-κB) protein expression was analyzed by western blotting. IL-1ß and IL-6 levels were determined by enzyme-linked immunosorbent assay. Blood-brain barrier permeability was determined by Evans blue leakage method. The results showed that baicalin reduced brain edema following ICH in a dose-dependent manner, with concomitant inhibition of NF-κB activation and suppression of MMP-9 expression. In addition, baicalin also reduced IL-1ß and IL-6 production, as well as blood-brain barrier permeability. The above results indicated that baicalin prevents against perihematomal edema development after intracerebral hemorrhage possibly through an anti-inflammatory mechanism.

Renal lymphatic ligation aggravates renal dysfunction through induction of tubular epithelial cell apoptosis in mononephrectomized rats.

AIMS: To further explore the mechanisms of apoptosis in mononephrectomized rats with renal lymph circulation disorder. METHODS: Animals were divided into three groups: rats with left renal lymph ligation and right nephrectomy (KL), rats with only right nephrectomy (KN) and sham-operated rats (sham). 24-h proteinuria and serum creatinine level were monitored. Indexes of oxidative stress were measured. Renal apoptosis was examined. Further biochemical analysis was provided using real-time PCR, western blot and Elisa techniques. RESULTS: Our results showed that renal lymphatic ligation induced renal tubular epithelial cell apoptosis and aggravated renal dysfunction in mononephrectomized rats. In addition, renal lymphatic ligation increased the activities of caspase-3, caspase-8 and caspase-9. Further investigation of mechanisms showed that renal lymphatic ligation up-regulated Fas expression, increased the ratio of Bax/Bcl-2, and also increased the levels of reactive oxygen species (ROS), malondialdehyde (MDA) while reducing superoxide dismutase (SOD) activity. CONCLUSION: These results indicated that disturbance of renal lymphatic circulation might lead to tubular epithelial cell apoptosis through activation of intrinsic and extrinsic apoptotic pathways, suggestive of an essential role of renal lymphatic circulation in the maintenance of tubular integrity and function.

Association of toll-like receptor 4 polymorphisms with type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is characterized by a chronic low-grade inflammatory state. Toll-like receptor 4 (TLR4) is a critical mediator of innate immunity. Polymorphisms in TLR4 gene have been shown to be associated with impaired inflammatory response. Here, we investigated the association of TLR4 polymorphisms with T2DM. Four TLR4 polymorphisms (+986A/G, +1196C/T, +3725G/C, and +11367G/C) were genotyped in a total number of 822 T2DM patients and 835 healthy controls. Results showed that the +986A/G and +1196C/T polymorphisms did not exist in the Han Chinese population. The prevalence of TLR4 +3725GC and CC genotypes were significantly decreased in T2DM cases than in controls (odds ratio (OR) = 0.62, 95 % confidence interval (CI) = 0.50-0.78, p = 3.48 × 10(-5), and OR = 0.36, 95 % CI = 0.22-0.59, p = 1.55 × 10(-5), respectively). Also, the frequency of TLR4 +3725C allele was significantly lower in T2DM patients (p = 2.46 × 10(-9)). When analyzing the TLR4 +11367G/C polymorphism, the +11367CC genotype revealed lower numbers in patients compared to healthy controls (OR = 0.46, 95 % CI = 0.27-0.78, p = 0.0032). Analysis of the clinical features on the control subjects demonstrated no correlations between these TLR4 polymorphisms and sex, age, body mass index, etc. (p > 0.05). In conclusion, these data indicate that TLR4 +3725G/C and +11367G/C polymorphisms may be novel protective factors against T2DM in the Chinese population.

Dipeptidyl peptidase-IV is a potential molecular biomarker in diabetic kidney disease.

The present study was designed to identify the changes in microvesicle-dipeptidyl peptidase-IV (DPP IV) levels in human urine and serum, and to determine whether there were correlations with the severity of diabetic kidney disease (DKD). A total of 127 patients with type 2 diabetes mellitus (T2DM) were divided into three groups according to the urinary albumin/ creatinine ratio (UACR): microalbuminuria group (n = 50); macroalbuminuria group (n = 34) and normoalbuminuria group (n = 43), and 34 age- and sex-matched non-diabetic healthy subjects were selected as controls. Microvesicle-bound DPP IV and free urinary DPP IV were separated by a filtra-centrifugation method. The total microvesicles were captured by a specific monoclonal antibody, AD-1. DPP IV activity was determined by measuring the cleavage of chromogenic free 4-nitroaniline from Gly-Pro-p-nitroanilide at 405 nm with an ELISA plate reader. DPP IV protein levels were determined by ELISA and Western blot. Our results showed that the microvesicle-bound type was the major form of DPP IV in urine; the urinary microvesicle-DPP IV excretion of each T2DM group was significantly higher compared with controls. The urinary microvesicle-DPP IV level was positively correlated with UACR in patients with T2DM. These findings suggest that the urinary level of microvesicle-bound DPP IV is associated with the severity of DKD.

Coculture with primary visceral rat adipocytes from control but not streptozotocin-induced diabetic animals increases glucose uptake in rat skeletal muscle cells: role of adiponectin.

We developed a coculture system comprising primary rat adipocytes and L6 rat skeletal muscle cells to allow investigation of the effects of physiologically relevant mixtures of adipokines. We observed that coculture, or adipocyte-conditioned media, increased glucose uptake in muscle cells. An adipokine that could potentially mediate this effect is adiponectin, and we demonstrated that small interfering RNA-mediated knockdown of adiponectin receptor-2 in muscle cells reduced the uptake of glucose upon coculture with primary rat adipocytes. Analysis of coculture media by ELISA indicated total adiponectin concentration of up to 1 microg/ml, and Western blotting and gel filtration analysis demonstrated that the adipokine profile was hexamer greater than high molecular weight much greater than trimer. We used the streptozotocin-induced rat model of diabetes and found that high-molecular-weight adiponectin levels decreased in comparison with control animals and this correlated with the fact that diabetic rat-derived primary adipocytes in coculture did not stimulate glucose uptake to the same extent as control adipocytes. Coculture induced phosphorylation of AMP-activated protein kinase (T172) and interestingly also insulin receptor substrate-1 (Y612) and Akt (T308 & S473), which could be attenuated after adiponectin receptor-2-small interfering RNA treatment. In summary, we believe that this coculture system represents an excellent model to study the effects of primary adipocyte-derived adipokine mixtures on skeletal muscle metabolism, and here we have established that in the context of physiologically relevant mixtures of adipokines, adiponectin may be an important determinant of positive cross talk between adipocytes and skeletal muscle.

Heparin suppresses lipid raft-mediated signaling and ligand-independent EGF receptor activation.

Heparin is well known to suppress vascular smooth muscle cell (VSMC) proliferation, and attempts to exploit this therapeutically have led to recognition of multiple pathways for heparin's anti-mitogenic actions. At low concentrations (ca. 1 microg.ml(-1)), these suppressive effects may reflect physiological activities of endogenous heparan sulfates, and appear to be rapid responses to extracellular or cell surface-associated heparin. Because heparin has been shown to influence expression of caveolin proteins, and caveolae/lipid rafts are critical structures modulating cell signaling, we examined the effect of heparin on signaling involving cholesterol-rich membrane microdomains. The VSMC line PAC-1 activates the MAP kinase Erk in response to the cholesterol-sequestering agents methyl-beta-cyclodextrin and nystatin. This follows a temporal sequence that involves Ras-GTP activation of MEK, and is independent of PKC, Src, and PI3 kinase. However, ligand-independent phosphorylation of the EGF receptor (EGFR) by removal of cholesterol precedes Ras activation, and the EGFR kinase inhibitor AG1478 blocks Erk phosphorylation, supporting occurrence of the signaling sequence EGFR-Ras-MEK-Erk. Phosphorylation of EGFR occurs predominantly in caveolin-rich microdomains as identified by Western blotting of fractions from density gradient centrifugation of membranes prepared under detergent-free conditions. In these situations, heparin inhibits phosphorylation of EGFR on the Src-dependent site Tyr(845), but not the autophosphorylation of Tyr(1173), and decreases Ras activation and Erk phosphorylation. We conclude that heparin can suppress Erk signaling in VSMC with effects on site-specific phosphorylation of EGFR localized in caveolin-enriched lipid rafts.