Impairments in endogenous AMPA receptor dynamics correlates with learning deficits in Alzheimer's disease model mice.

AMPA receptors (AMPARs) play a critical role in synaptic plasticity and learning and memory, and dysfunction or dysregulation of AMPARs could lead to various neurological and psychiatric disorders, such as Alzheimer's disease (AD). However, the dynamics and/or longitudinal changes of AMPARs in vivo during AD pathogenesis remain elusive. Here, employing 5xFAD SEP-GluA1 KI mice, we investigated endogenous AMPA receptor dynamics in a whisker deflection-associated Go/No-go learning paradigm. We found a significant increase in synaptosomal AMPA receptor subunits GluA1 in WT mice after learning, while no such changes were detected in 7-mo-old 5xFAD mice. Daily training led to an increase in endogenous spine surface GluA1 in Control mice, while this increase was absent in 5xFAD-KI mice which correlates with its learning defects in Go/No-go paradigm. Furthermore, we demonstrated that the onset of abnormal AMPAR dynamics corresponds temporally with microglia and astrocyte overactivation. Our results have shown that impairments in endogenous AMPA receptor dynamics play an important role in learning deficits in 5xFAD mice and AD pathogenesis.

Knockdown of NR4A1 alleviates doxorubicin-induced cardiotoxicity through inhibiting the activation of the NLRP3 inflammasome.

Doxorubicin (DOX) is a widely used antitumor drug, but its clinical applicability is hampered by the unfortunate side effect of DOX-induced cardiotoxicity (DIC). In our current study, we retrieved three high-throughput sequencing datasets related to DIC from the Gene Expression Omnibus (GEO) datasets. We conducted differential analysis using R (DESeq2) to pinpoint differentially expressed genes (DEGs, and identified 11 genes that were consistently altered in both the control and DOX-treated groups. Notably, our Random Forest analysis of these three GEO datasets highlighted the significance of nuclear receptor subfamily 4 group A member 1 (NR4A1) in the context of DIC. The DOX-induced mouse model and cell model were used for the in vivo and in vitro studies to reveal the role of NR4A1 in DIC. We found that silencing NR4A1 by adeno-associated virus serotype 9 (AAV9) contained shRNA in vivo alleviated the DOX-induced cardiac dysfunction, cardiomyocyte injury and fibrosis. Mechanistically, we found NR4A1 silencing was able to inhibit DOX-induced the cleavage of NLRP3, IL-1ß and GSDMD in vivo. Further in vitro studies have shown that inhibition of NR4A1 suppressed DOX-induced cytotoxicity and oxidative stress through the same molecular mechanism. We prove that NR4A1 plays a critical role in DOX-induced cardiotoxicity by inducing pyroptosis via activation of the NLRP3 inflammasome, and it might be a promising therapeutic target for DIC.

GPX3 is a key cholesterol-related gene associated with prognosis and tumor-infiltrating T cells in colorectal cancer.

High cholesterol is an important factor inducing colorectal cancer (CRC). The study aims to determine the key genes and regulatory mechanism associated with tumor-infiltrating T cells underlying cholesterol-induced CRC. Gene expression data and clinical data from CRCS in The Cancer Genome Atlas (TCGA) were selected for differential expression and survival analysis. A total of 5,815 DEGs and 21 cholesterol-associated KEGG pathways were identified. Subsequently, 128 CRCs and 127 patients without obvious intestinal lesions were recruited to analyze the relationship between GPX3 expression, cholesterol levels, and pathologic condition. The results showed that the expression of cholesterol-related gene GPX3 was negatively associated with cholesterol level, but positively correlated with Ki-67 proliferation index in CRC. The expression of GPX3 was higher in CRC patients who were in poorly differentiated and advanced stage. In addition, a mice model of high-cholesterol diet intervention was constructed to detect the levels of cholesterol and GPX3 in the peripheral blood of mice, and it was found that the expression level of GPX3 in high-cholesterol mice was lower than that in normal diet mice. CD8+ T cells were isolated from the spleen of mice and the T cell surface receptors were detected. It was found that the expression of CD69 in CD8+ T cells of mice interfered with the high-cholesterol diet, while the expression of PD1, TIM-3, and CTLA-4 was increased. CD8+ T cells were co-cultured with MC38 cells to detect the proliferation rate of CRC cells. The results showed that the tumor cell proliferation ratio in the high cholesterol group was higher than that in the control group. Furthermore, GPX3 downstream genes associated with m6A modification and tumor-infiltrating T cells were screened, and a T cell immune-related ceRNA network was constructed. In total, 53 GPX3 downstream genes associated with m6A modification and tumor-infiltrating T cells were identified. A PPI network that contained 45 nodes and 85 interaction pairs was constructed. The ceRNA network, including 39 miRNA-target and 43 lncRNA-miRNA regulatory pairs, was constructed. In conclusion, GPX3 is a potential target for cholesterol regulation of T cell immunity in CRC.

Effect of implantable cardioverter defibrillator on primary prevention of sudden cardiac death in high-risk patients.

OBJECTIVE: To investigate the effect of implantable cardioverter defibrillator (ICD) on primary prevention of sudden cardiac death (SCD) in patients with high risk. METHODS: This retrospective analysis included 70 patients who received primary prevention of SCD by ICD implantation in Huzhou Central Hospital from March 2016 to May 2019. Based on survival, 15 patients who died during follow-up were placed into the death group and the 55 patients who survived were set as the survival group. The two groups were compared in terms of sex, age, non-sustained ventricular tachycardia (VT), diastolic pressure, systolic pressure, left ventricular ejection fraction (LVEF), urea nitrogen, serum creatinine, history of diabetes, history of atrial fibrillation, history of myocardial ischemia, history of dilated cardiomyopathy, history of hypertrophic cardiomyopathy, type I Brugada wave and cardiac function classification. Further, we analyzed the proportion of discharge, the survival of patients (Kaplan Meier method), and the risk factors of patient death (Logistic regression). RESULTS: The analysis of baseline data showed that patients in the death group had older age and higher level of serum creatinine than the survival group (P<0.05), and the number of patients with non-sustained VT≥5 times/24 h in the survival group was higher than that in the death group (P<0.05). There was no obvious difference in other baseline indexes between the two groups (P>0.05). In addition, there was no difference in the proportion of patients receiving appropriate/inappropriate discharge (P>0.05) between the two groups. Follow-up data showed that 15 cases (21.43%) of spontaneous VT/ventricular fibrillation events were correctly diagnosed by pacemakers and properly treated by ICD (discharge or antitachycardia pacing (ATP)), while 55 cases (78.57%) received inappropriate ICD treatment. There were 15 patients (21.43%) who died during follow up, including 6 cases of cardiac insufficiency, 1 case of SCD, 2 cases of acute myocardial infarction, 1 case of respiratory failure, and 5 cases of unknown etiology; the survival time was (20.27±7.06) months. Logistic regression analysis showed that age and serum creatinine were the risk factors of patient death. CONCLUSION: Primary prevention with ICD implantation benefits SCD patients. Non persistent VT≥5 times/24 h is a predictive value for ICD implantation in patients receiving primary prevention of SCD. Age and serum creatinine are risk factors for death.

Pre-treatment with galectin-1 attenuates lipopolysaccharide-induced myocarditis by regulating the Nrf2 pathway.

Galectin-1 (Gal-1), a member of a highly conserved family of animal lectins, plays a crucial role in controlling inflammation and neovascularization. However, the potential role of Gal-1 in preventing myocarditis remains uncertain. We aimed to explore the functions and mechanisms of Gal-1 in preventing myocarditis. In vivo, C57/BL6 mice were pre-treated with or without Gal-1 and then exposed to lipopolysaccharide (LPS) to induce myocarditis. Subsequently, cardiac function, histopathology, inflammation, oxidative stress, and apoptosis of myocardial tissues were detected. Following this, qRT-PCR and Western blotting were applied to measure iNOS, COX2, TXNIP, NLRP3 and Caspase-1 p10 expressions. In vitro, H9c2 cells pre-treated with different doses of Gal-1 were stimulated by LPS to induce myocarditis models. CCK8, flow cytometry and reactive oxygen species (ROS) assay were then employed to estimate cell viability, apoptosis and oxidative stress. Furthermore, Nrf2 and HO-1 protein expressions were evaluated by Western blotting in vivo and in vitro. The results showed that in vivo, Gal-1 pre-treatment not only moderately improved cardiac function and cardiomyocyte apoptosis, but also ameliorated myocardial inflammation and oxidative damage in mice with myocarditis. Furthermore, Gal-1 inhibited TXNIP-NLRP3 inflammasome activation. In vitro, Gal-1 pre-treatment prevented LPS-induced apoptosis, cell viability decrease and ROS generation. Notably, Gal-1 elevated HO-1, total Nrf2 and nuclear Nrf2 protein expressions both in vivo and in vitro. In conclusion, pre-treatment with Gal-1 exhibited cardioprotective effects in myocarditis via anti-inflammatory and antioxidant functions, and the mechanism may relate to the Nrf2 pathway, which offered new solid evidence for the use of Gal-1 in preventing myocarditis.

Evaluation of Left Ventricular Systolic Function in Patients with Coronary Microvascular Dysfunction by Three-Dimensional Speckle-Tracking Imaging.

INTRODUCTION: The objective of this study is to evaluate the left ventricular systolic function of patients with coronary microvascular dysfunction (CMD) using the three-dimensional speckle-tracking imaging (3D-STI) technique. METHODS: From June 2018 to June 2019,72 subjects from Huzhou Central Hospital were enrolled, including 42 CMD in-patients with typical chest pain or chest tightness and positive treadmill exercise stress test, but without coronary stenosis on coronary angiography, (the CMD group) and another 30 healthy individuals who were undergoing physical examinations in an outpatient clinic (the control group). Using 3D-STI technique, the global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS), global area strain (GAS), and left ventricle were measured. RESULTS: Compared with the control group, GLS and GAS were significantly reduced in the CMD group (P<0.05), while GRS and GCS were similar in both groups (P>0.05). Univariate logistic regression analysis showed that GLS and GAS were the influencing factors of CMD. For the diagnosis of CMD, the area under the receiver operating characteristic (ROC) curve of GLS was 0.883, and the area under the ROC curve of GAS was 0.875. GAS of -29.3% (log-rank test chi-square=34.245, P<0.001) was a strong predictor of major adverse cardiac events. CONCLUSION: 3D-STI technique has obvious advantages in the evaluation of the left ventricular systolic function for CMD patients. Moreover, 3D-STI parameters, especially GLS and GAS, can detect the early abnormal changes in the ischaemic myocardium. Being timelier and more sensitive than echocardiography, 3D-STI should be recommended for clinical application.

A broad and potent IgM antibody against tetra-EV-As induced by EVA71 and CVA16 co-immunization.

OBJECTIVE: To determine the potent and broad neutralizing monoclonal antibody (mAb) against enterovirus A (EV-A) in vitro and in vivo induced by enterovirus A71(EVA71) and coxsackievirus 16 (CVA16) co-immunization. METHODS: The mAb was Generated by co-immunization with EVA71 and CVA16 through hybridomas technology. The characteristics and neutralizing ability of mAb were analysed in vitro and in mice. RESULTS: We screened three mAb, the IgM antibody M20 and IgG antibody B1 and C31. All three antibodies showed cross-reactivity against tetra-EV-As. However, M20 showed potent and broad neutralizing ability against tetra-EV-As than B1 and C31. Meanwhile, M20 provided cross-antiviral efficacy in tetra-EV-As orally infected mice. Moreover, M20 binds to a conserved neutralizing epitope within the GH loop of tetra-EV-As VP1. CONCLUSIONS: M20 and its property exhibited potent and broad antiviral activity against tetra-EV-As, and that is expected to be a potential preventive and therapeutic candidate against EV-As.

Evaluation of Left Ventricular Systolic Function in Patients with Coronary Microvascular Dysfunction by Three-Dimensional Speckle-Tracking Imaging

Abstract Introduction: The objective of this study is to evaluate the left ventricular systolic function of patients with coronary microvascular dysfunction (CMD) using the three-dimensional speckle-tracking imaging (3D-STI) technique. Methods: From June 2018 to June 2019,72 subjects from Huzhou Central Hospital were enrolled, including 42 CMD in-patients with typical chest pain or chest tightness and positive treadmill exercise stress test, but without coronary stenosis on coronary angiography, (the CMD group) and another 30 healthy individuals who were undergoing physical examinations in an outpatient clinic (the control group). Using 3D-STI technique, the global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS), global area strain (GAS), and left ventricle were measured. Results: Compared with the control group, GLS and GAS were significantly reduced in the CMD group (P<0.05), while GRS and GCS were similar in both groups (P>0.05). Univariate logistic regression analysis showed that GLS and GAS were the influencing factors of CMD. For the diagnosis of CMD, the area under the receiver operating characteristic (ROC) curve of GLS was 0.883, and the area under the ROC curve of GAS was 0.875. GAS of -29.3% (log-rank test chi-square=34.245, P<0.001) was a strong predictor of major adverse cardiac events. Conclusion: 3D-STI technique has obvious advantages in the evaluation of the left ventricular systolic function for CMD patients. Moreover, 3D-STI parameters, especially GLS and GAS, can detect the early abnormal changes in the ischaemic myocardium. Being timelier and more sensitive than echocardiography, 3D-STI should be recommended for clinical application.

[Expression and purification of rabies virus glycoprotein and analysis of its specific binding capacity to memory B cells].

We aimed to express and purify three rabies virus glycoproteins with different tags and sizes. After analyzing their binding function, we wish to obtain a rabies virus glycoprotein with higher affinity and ability to specifically bind memory B cells. Experiments were carried out to express full length, as well as the ectodomain RVG by gene engineering method. Combined with the antibody of CD19 and CD27, the candidate protein labeling with fluorescence was used to analyze its binding function. Flow cytometry was used to detect the anti-rabies virus specific memory B cells in PBMCs, and confirm the binding ability between the candidate proteins and anti-rabies virus-specific memory B cells. We successfully constructed three expression vectors pGEX-5X-1-RVG, pET28a-RVG and pET30a-G. Three glycoproteins GST-RVG, His-RVG and His-G were obtained by optimized expression and purification conditions. The antigen specificity of purified GST-RVG, His-RVG and His-G were identified by Western blotting and ELISA. The affinity of these three purified glycoproteins to anti-rabies virus antibody were detected by competitive ELISA. Anti-rabies virus specific memory B cells in positive PBMCs gained from people who had ever been injected with the vaccine can be detected by flow cytometry. Thus, we got a recombinant rabies virus glycoprotein that had high-affinity and could sort antigen specific memory B cells.