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.

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.

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.

[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.