Development and validation of a model for prediction of septic shock in neonates with sepsis.

PURPOSE: This study aimed to develop and validate a model for prediction of septic shock in neonates with sepsis. MATERIALS AND METHODS: This retrospective study included early-onset septic neonates in the Renmin Hospital of Wuhan University between January 2017 and June 2021. The neonates were divided into the training set and the validation set in a ratio of 7:3, and further categorized into septic shock group and none-shock group according to presence or absence of shock symptoms. RESULTS: A total of 406 septic neonates were enrolled, including 217 in septic shock group. Sex (odds ratio [OR] = 0.092, 95% confidence interval [CI]: 0.012 to 0.683, P = 0.020), C-reactive protein at 6 h (OR = 8.475, 95% CI: 3.154 to 22.774, P < 0.001), serum amyloid A at 6 h (OR = 1.179, 95% CI: 1.094 to 1.269, P < 0.01), white blood cells at 6 h (OR = 0.173, 95% CI: 0.092 to 0.326, P < 0.001), platelets at 6 h (OR = 0.985, 95% CI: 0.975 to 0.995, P < 0.001), and Ca 2+ at 6 h (OR = 1.44x10 11 , 95% CI: 2.70 x10 6 to 7.70 x10 15 , P < 0.001) were identified as independent risk factors for septic shock and were further included in the nomogram. The area under the receiver operator characteristic curve were 0.873 and 0.920 in training and validation sets, respectively. CONCLUSIONS: A predictive model for early diagnosis of septic shock in neonates was developed and initially validated in this study, allowing for timely intervention.

m6A regulator-mediated RNA methylation modification remodels immune microenvironment in dilated cardiomyopathy.

The latest evidence suggested that the onset of dilated cardiomyopathy (DCM) is closely associated with immune microenvironment disturbance. Since N6 -methyladenosine (m6A) RNA methylation impacts on immunocyte function and antitumor immunity, it is predictable that m6A RNA methylation may result in immune microenvironment disorder. Here, we attempted to verify this hypothesis. We used single-sample gene set enrichment analysis (ssGSEA) to investigate the infiltration abundance of immunocytes, single-cell RNA-Seq to identify key m6A regulator, and a doxorubicin (Dox)-induced DCM mouse model to confirm our findings. ssGSEA revealed a higher infiltration abundance of CD8+ T lymphocytes, NK cells, monocytes, and B+ lymphocytes in DCM myocardium tissue. Single-cell RNA-Seq indicated a critical role of IGFBP2 in DCM. Cross-checking analysis hinted an interaction between IGFBP2 and NSUN5, ALYREF, RRP8, and ALKBH3. Mechanically, IGFBP2-mediated RNA methylation deteriorated the immune microenvironment and thus increased the risk of DCM by enhancing CD8+ T lymphocyte, NK cell, monocyte, B+ lymphocyte infiltration and activating check-point, MHC-I, and T cell co-stimulation signaling pathways. In the DCM mouse model, echocardiography indicated a significant reduction in ejection fraction (EF) and fractional shortening (FS) and an increase in left ventricular internal dimensions at systole (LVIDs) and diastole (LVIDd). MASSON staining indicated an increased fibrosis in myocardium tissue. qPCR and immunofluorescence staining indicated a significant increase in mRNA and protein levels of IGFBP2. The present study indicated that IGFBP2-mediated RNA methylation remodeled the immune microenvironment and increased the risk of DCM. IGFBP2 may serve as potential therapeutic target for DCM.

Effects of the genetic variants of alcohol-metabolizing enzymes on lipid levels in Asian populations: a systematic review and meta-analysis.

CONTEXT: Emerging evidence indicates that variants of alcohol-metabolizing enzymes may influence lipid metabolism. OBJECTIVE: This study aimed to investigate whether the rs671 and rs1229984 variants affect lipid levels in East Asian individuals. DATA SOURCES: PubMed, Foreign Medical Journal Service, Embase, Cochrane Library, Scopus, MEDLINE, Web of Science, Web of Knowledge, Wanfang, and Chinese Biomedical Literature databases were searched until December 31, 2021. DATA EXTRACTION: Meta-analyses of studies that examined the effects of alcohol-metabolizing enzyme variants on lipid levels, as well as the interaction with alcohol intake, were selected. Data extraction was conducted independently by two investigators and confirmed by the third. DATA ANALYSIS: In total, 86 studies (179 640 individuals) were analyzed. The A allele of rs671 (a functional variant in the ALDH2 gene) was linked to higher levels of low-density lipoprotein cholesterol (LDL-C) and lower levels of triglycerides and high-density lipoprotein cholesterol. In contrast, the A allele of the rs1229984 (a functional variant in the ADH2 gene) was associated only with lower levels of LDL-C. The effects of rs671 and rs1229984 on lipid levels were much stronger in Japanese than in Chinese individuals and in males than in females. Regression analysis indicated that the effects of rs671 on lipid levels were independent of alcohol intake in an integrated East Asian population (ie, Japanese, Chinese, and Korean individuals). Intriguingly, alcohol intake had a statistical influence on lipid levels when the sample analyzed was restricted to Japanese individuals or to males. CONCLUSIONS: The rs671 and rs1229984 variants of alcohol-metabolizing enzymes have significant effects on lipid levels and may serve as genetic markers for lipid dyslipidemia in East Asian populations. Circulating lipid levels in Japanese individuals and in males were modulated by the interaction between rs671 and alcohol intake.

Fatty acid-binding protein 5 aggravates pulmonary artery fibrosis in pulmonary hypertension secondary to left heart disease via activating wnt/ß-catenin pathway.

INTRODUCTION: Pulmonary hypertension secondary to left heart disease (PH-LHD) is a common and fatal disease. However, no effective therapeutic targets have been identified. OBJECTIVES: Here, we set out to illustrate the functional role and underlying mechanisms of fatty acid-binding protein 5 (FABP5) in PH-LHD development. METHODS: We performed a systematic analysis of datasets GSE84704 and GSE16624 to identify differentially expressed genes and then constructed protein-protein interaction network for significant modules. Potential target genes in the modules were validated by RT-qPCR and western blot in a PH-LHD mouse model. PH-LHD or sham mice were treated with FABP5 antagonist SBFI-26 or DMSO for 28 days. The role of FABP5 on cardiac function was determined by echocardiography, its impact on pulmonary vascular remodelling were evaluated with right heart catheter, histological analysis and western blot. In vitro, primary pulmonary adventitial fibroblasts were used to investigate the pro-fibrotic mechanisms involving in FABP5. RESULTS: FABP5 was the only one dramatically upregulated along with increased protein expression in the established PH-LHD mouse model. Inhibition of FABP5 by SBFI-26 injection abrogated pulmonary artery remodelling in PH-LHD and improved cardiac function. In vitro, SBFI-26 or FABP5 siRNA blunted the TGF-ß1-induced fibrotic response in cultured pulmonary adventitial fibroblasts. Mechanistically, FABP5 knockdown inhibited GSK3ß phosphorylation and increased ß-catenin phosphorylation. The wnt/ß-catenin agonist SKL2001 diminished the antifibrotic effect of FABP5 knockdown on pulmonary adventitial fibroblasts under TGF-ß1 stimulation. CONCLUSION: FABP5 is an important mediator of pulmonary artery remodelling and a potential therapeutic target for PH-LHD.

The Clinical Trial Outcomes of Med-Zenith PT-Valve in the Treatment of Patients With Severe Pulmonary Regurgitation.

Objective: Nearly 2/3 of patients with dilated right ventricular outflow tract (RVOT) were excluded from pulmonary valves transplantation due to the lack of size-matched valves. Here, we explored the safety and efficacy of the Med-Zenith PT-Valve for the treatment of patients with severe pulmonary regurgitation. Methods: 22 Patients with severe PR (grade 3+,4+) were enrolled based on the anatomical features of native RVOT and the valve design. The immediate, 3-months and 1-year post-procedural follow-up data were analyzed. Results: The baseline mean systolic diameters in the distal main pulmonary artery (MPA), MPA sinus junction, MPA sinus, pulmonary annulus, RVOT aneurysm and muscular outlet measured with computed tomography were 33.6 ± 6.1, 34.0 ± 5.8, 37.9 ± 6.0, 32.4 ± 7.3, 41.9 ± 9.3, and 34.4 ± 8.0 mm, respectively. The PT-Valve landing zone was set within these levels. Successful valve implantations were achieved in all patients without noticeable device malposition, coronary artery compression, pulmonary branch obstruction or paravalvular leak during follow-ups. Post-procedural pulmonary artery diastolic pressure increased from 5.8 ± 3.1 to 11.3 ± 2.5 mmHg. In the 3-month and 1-year follow-up, the right ventricular end diastolic volume index reduced from the baseline 181.6 ± 29.0 to 143.7 ± 29.7 ml/m2 and 123.4 ± 31.2 ml/m2, and the trans-pulmonary valve gradient decreased from 25.6 ± 22.2 to 10.64 ± 3.54 mmHg and 11.16 ± 3.0 mmHg, respectively. The 6-min walk distance increased from 416.6 ± 97.9 to 455.9 ± 64.6 m and 467.8 ± 61.2 m, respectively. Conclusion: This clinical trial revealed favorable outcomes for the safety, efficacy and feasibility of the Med-Zenith PT-Valve in the treatment of severe PR with significantly enlarged RVOT.

Exploration of dilated cardiomyopathy for biomarkers and immune microenvironment: evidence from RNA-seq.

BACKGROUND: The pathogenic mechanism of dilated cardiomyopathy (DCM) remains to be defined. This study aimed to identify hub genes and immune cells that could serve as potential therapeutic targets for DCM. METHODS: We downloaded four datasets from the Gene Expression Omnibus (GEO) database: GSE141910, GSE3585, GSE42955 and GSE79962. Weighted gene coexpression network analysis (WGCNA) and differential expression analysis were performed to identify gene panels related to DCM. Meanwhile, the CIBERSORT algorithm was used to estimate the immune cells in DCM tissues. Multiple machine learning approaches were used to screen the hub genes and immune cells. Finally, the diagnostic value of the hub genes was assessed by receiver operating characteristic (ROC) analysis. An experimental mouse model of dilated cardiomyopathy was used to validate the bioinformatics results. RESULTS: FRZB and EXT1 were identified as hub biomarkers, and the ROC curves suggested an excellent diagnostic ability of the above genes for DCM. In addition, naive B cells were upregulated in DCM tissues, while eosinophils, M2 macrophages, and memory CD4 T cells were downregulated in DCM tissues. The increase in two hub genes and naive B cells was validated in animal experiments. CONCLUSION: These results indicated that FRZB and EXT1 could be used as promising biomarkers, and eosinophils, M2 macrophages, resting memory CD4 T cells and naive B cells may also affect the occurrence of DCM.

Genetic support of a causal relationship between iron status and atrial fibrillation: a Mendelian randomization study.

BACKGROUND: Atrial fibrillation is the most common arrhythmia disease. Animal and observational studies have found a link between iron status and atrial fibrillation. However, the causal relationship between iron status and AF remains unclear. The purpose of this investigation was to use Mendelian randomization (MR) analysis, which has been widely applied to estimate the causal effect, to reveal whether systemic iron status was causally related to atrial fibrillation. METHODS: Single nucleotide polymorphisms (SNPs) strongly associated (P < 5 × 10-8) with four biomarkers of systemic iron status were obtained from a genome-wide association study involving 48,972 subjects conducted by the Genetics of Iron Status consortium. Summary-level data for the genetic associations with atrial fibrillation were acquired from the AFGen (Atrial Fibrillation Genetics) consortium study (including 65,446 atrial fibrillation cases and 522,744 controls). We used a two-sample MR analysis to obtain a causal estimate and further verified credibility through sensitivity analysis. RESULTS: Genetically instrumented serum iron [OR 1.09; 95% confidence interval (CI) 1.02-1.16; p = 0.01], ferritin [OR 1.16; 95% CI 1.02-1.33; p = 0.02], and transferrin saturation [OR 1.05; 95% CI 1.01-1.11; p = 0.01] had positive effects on atrial fibrillation. Genetically instrumented transferrin levels [OR 0.90; 95% CI 0.86-0.97; p = 0.006] were inversely correlated with atrial fibrillation. CONCLUSION: In conclusion, our results strongly elucidated a causal link between genetically determined higher iron status and increased risk of atrial fibrillation. This provided new ideas for the clinical prevention and treatment of atrial fibrillation.

Pyroptosis Patterns Are Involved in Immune Microenvironment Regulation of Dilated Cardiomyopathy.

The importance of cell pyroptosis in immunity regulation is becoming increasingly obvious, especially in diseases of the cardiovascular system. Nevertheless, it is unknown whether the pyroptosis signalling pathway is involved in the immune microenvironment regulation of dilated cardiomyopathy (DCM). Therefore, the purpose of the study was to investigate the influence of pyroptosis on the immune environment in dilated cardiomyopathy. We found that expression of 19 pyrolysis-related genes (PRGs) in DCM samples was altered compared to healthy samples. Subsequently, based on these 12 hub pyrolysis-related genes, we developed a classifier that can distinguish between healthy samples and DCM samples. Among the hub pyrolysis-related genes, RT-PCR analyses demonstrated that five of them exhibited significant differential expression in DCM. Interestingly, we observed that immune characteristics are correlated with pyroptosis: higher expression of GSDMD is positively correlated with infiltrating activated pDCs; GSDMD is negatively correlated with Tregs; CASP1 is positively related to parainflammation; and CASP9 is negatively related to the type II IFN response. In addition, distinct pyroptosis-mediated patterns were identified, and immune characteristics under distinct patterns were revealed: pattern B mediates an active immune response, and pattern A leads to a relatively mild immune response to DCM. We also compared the biological functions between these patterns. Compared with pattern A, pattern B had more abundant pathways, such as the NOTCH signalling pathway and pentose phosphate pathway. In summary, this study proves the important influence of pyrolysis on the immune microenvironment of dilated cardiomyopathy and provides new clues for understanding the pathogenesis of dilated cardiomyopathy.

Association between Circulating Antioxidants and Longevity: Insight from Mendelian Randomization Study.

BACKGROUND: Antioxidants attracted long-standing attention as promising preventive agents worldwide. Previous observational studies have reported that circulating antioxidants are associated with reduced mortality; however, randomized clinical trials indicate neutral or harmful impacts. The association of long-term circulating antioxidant exposure with longevity is still unclear. OBJECTIVES: We aim to determine whether long-term circulating antioxidant exposure is causally associated with longevity in the general population using the two-sample Mendelian randomization (MR) design. METHODS: Genetic instruments for circulating antioxidants (ascorbate, lycopene, selenium, beta-carotene, and retinol) and antioxidant metabolites (ascorbate, alpha-tocopherol, gamma-tocopherol, and retinol) were identified from the largest up-to-date genome-wide association studies (GWASs). Summary statistics of these instruments with individual survival to the 90th vs. 60th percentile age (11,262 cases and 25,483 controls) and parental lifespan (N = 1,012,240 individuals) were extracted. The causal effect was estimated using the inverse-variance weighted method in the main analysis and complemented by multiple sensitivity analyses to test the robustness of results. RESULTS: We found that genetically determined higher concentration of circulating retinol (vitamin A) metabolite was casually associated with a higher odds of longevity (OR, 1.07; 95% CI, 1.02-1.13; P < 0.01) and increased parental lifespan (lifespan years per 10-fold increase: 0.17; 95% CI, 0.07-0.27; P < 0.01). Present evidence did not support a causal impact of circulating ascorbate (vitamin C), tocopherol (vitamin E), lycopene, selenium or beta-carotene on life expectancy. No evidence was identified to show the pleiotropic effects had biased the results. CONCLUSIONS: Long-term higher exposure to retinol metabolite is causally associated with longevity in the general population. Future MR analyses could assess the current findings further by utilizing additional genetic variants and greater samples from large-scale GWASs.

Cardiac Infiltration as the First Manifestation of Acute Lymphoblastic Leukemia: A Systematic Review.

Cardiac symptoms or signs as the first manifestations in acute lymphoblastic leukemia patients are sporadically reported which lead to misdiagnosis or delayed diagnosis due to lack of clinical experience and improper diagnosis procedures. Here, we documented the clinical features, procedures of diagnosis, treatments, and outcomes from the so-far reported 30 lymphoblastic leukemia cases that initially presented as cardiac problems and provided management recommendations based on the experiences and lessons learned from these patients to help physicians avoid misdiagnosis and improper treatment.

Xuezhikang alleviates lipid accumulation via AMPK activation in hepatocellular steatosis model

Abstract Xuezhikang (XZK) is an extract of Chinese red yeast rice. It has multiple protective effects in cardiovascular systems. However, the underlying mechanism by which XZK affects free fatty acid (FFA)-induced lipogenesis in hepatocellular steatosis model is still unknown. Herein, we investigated this mechanism in HepG2 cells. The HepG2 cells were treated with palmitate acid (PA) to induce lipogenesis. Then the PA-induced HepG2 cells were subsequently treated with XZK. After 24 h of treatment, we determined the intracellular triglyceride (TG) contents and average areas of lipid droplets. To study the involvement of AMPK signaling pathway, we pre-treated the PA-induced HepG2 cells with Compound C, an AMPK inhibitor, before XZK treatment. Expressions of p-AMPK and AMPK were determined by Western blot. The results showed that XZK decreased TG content and lipid accumulation in hepatocellular steatosis model. Compound C abolished the effects of XZK. These results demonstrated for the first time that XZK protects hepatocytes against lipid accumulation induced by free fatty acids. Its effects may be mediated by the activation of AMPK pathway.

Detection of an anti-angina therapeutic module in the effective population treated by a multi-target drug Danhong injection: a randomized trial.

It's a challenge for detecting the therapeutic targets of a polypharmacological drug from variations in the responsed networks in the differentiated populations with complex diseases, as stable coronary heart disease. Here, in an adaptive, 31-center, randomized, double-blind trial involving 920 patients with moderate symptomatic stable angina treated by 14-day Danhong injection(DHI), a kind of polypharmacological drug with high quality control, or placebo (0.9% saline), with 76-day following-up, we firstly confirmed that DHI could increase the proportion of patients with clinically significant changes on angina-frequency assessed by Seattle Angina Questionnaire (ΔSAQ-AF ≥ 20) (12.78% at Day 30, 95% confidence interval [CI] 5.86-19.71%, P = 0.0003, 13.82% at Day 60, 95% CI 6.82-20.82%, P = 0.0001 and 8.95% at Day 90, 95% CI 2.06-15.85%, P = 0.01). We also found that there were no significant differences in new-onset major vascular events (P = 0.8502) and serious adverse events (P = 0.9105) between DHI and placebo. After performing the RNA sequencing in 62 selected patients, we developed a systemic modular approach to identify differentially expressed modules (DEMs) of DHI with the Zsummary value less than 0 compared with the control group, calculated by weighted gene co-expression network analysis (WGCNA), and sketched out the basic framework on a modular map with 25 functional modules targeted by DHI. Furthermore, the effective therapeutic module (ETM), defined as the highest correlation value with the phenotype alteration (ΔSAQ-AF, the change in SAQ-AF at Day 30 from baseline) calculated by WGCNA, was identified in the population with the best effect (ΔSAQ-AF ≥ 40), which is related to anticoagulation and regulation of cholesterol metabolism. We assessed the modular flexibility of this ETM using the global topological D value based on Euclidean distance, which is correlated with phenotype alteration (r2: 0.8204, P = 0.019) by linear regression. Our study identified the anti-angina therapeutic module in the effective population treated by the multi-target drug. Modular methods facilitate the discovery of network pharmacological mechanisms and the advancement of precision medicine. (ClinicalTrials.gov identifier: NCT01681316).

Right ventricular contractility as a potential independent evaluation parameter in pulmonary hypertension.

BACKGROUND: Pulmonary artery hypertension (PAH) is a common disease with high disability and mortality rates, and can lead to right heart failure. We aimed to evaluate the capability of right ventricular pressure-volume coupling parameters, end-systolic elastance (Ees), right ventricular afterload (Ea), and arterial elastance (Ees/Ea) for assessing right ventricular performance during the chronic development of PAH. METHODS: Thirty-six PAH patients were enrolled in this study. We reported the cutoff values of the right ventricular pressure-volume coupling parameters in the progression of PAH and their relations with other pressure-volume loop measurements in both the right and left ventricles. RESULTS: Ees and normalised Ees (Ees/Ea) calculated from the pressure method performed better than ones from the volume method in correlation with mean pulmonary arterial pressure and mean right arterial pressure. The cutoff sets of Ees and Ees/Ea were capable of grouping pulmonary hypertension patients which were well supported by their significant correlation with several key right ventricular hemodynamic parameters. Additionally, the normalised Ees was able to reflect the changes in left ventricular function during the deterioration of PAH. CONCLUSION: Ees and Ees/Ea are promising independent reference parameters for assessing ventricular function in progressing PAH patients.

Comparison of outcomes of high-flow nasal cannula and noninvasive positive-pressure ventilation in patients with hypoxemia and various APACHE II scores after extubation.

AIMS: The study aimed to compare and analyze the outcomes of high-flow nasal cannula (HFNC) and noninvasive positive-pressure ventilation (NPPV) in the treatment of patients with acute hypoxemic respiratory failure (AHRF) who had extubation after weaning from mechanical ventilation. METHODS: A total 120 patients with AHRF were enrolled into this study. These patients underwent tracheal intubation and mechanical ventilation. They were organized into two groups according to the score of Acute Physiologic Assessment and Chronic Health Evaluation II (APACHE II); group A: APACHE II score <12; group B: 12⩽ APACHE II score <24. Group A had 72 patients and patients given HFNC were randomly assigned to subgroup I while patients given NPPV were assigned to subgroup II (36 patients in each subgroup). Group B had 48 patients and patients given HFNC were randomly assigned to subgroup I while patients given NPPV were assigned to subgroup II (24 patients in each subgroup). General information, respiratory parameters, endpoint event, and comorbidities of adverse effect were compared and analyzed between the two subgroups. RESULTS: The incidence of abdominal distension was significantly higher in patients treated with NPPV than in those treated with HFNC in group A (19.44% versus 0, p = 0.005) and group B (25% versus 0, p = 0.009). There was no significant difference between the HFNC- and NPPV-treated patients in blood pH, oxygenation index, partial pressure of carbon dioxide, respiratory rate, and blood lactic acid concentration in either group (p > 0.05). Occurrence rate of re-intubation within 72 h of extubation was slightly, but not significantly, higher in NPPV-treated patients (p > 0.05). CONCLUSION: There was no significant difference between HFNC and NPPV in preventing respiratory failure in patients with AHRF with an APACHE II score <24 after extubation. However, HFNC was superior to NPPV with less incidence of abdominal distension.The reviews of this paper are available via the supplemental material section.

The Clinical Characteristics and Risk Factors of Severe COVID-19.

OBJECTIVE: We aim to investigate the clinical characteristics and risk factors for the severe cases of coronavirus disease 2019 (COVID-19) in comparison with the non-severe patients. METHODS: We searched PubMed, EMBASE, Web of Science, and CNKI to collect all relevant studies published before July 26, 2020, and a total of 30 papers were included in this meta-analysis. RESULTS: In the severe COVID-19 patients, 60% (95% CI = 56-64%) were male, 25% (95% CI = 21-29%) were over 65 years old, 34% (95% CI = 24-44%) were obese, and 55% (95% CI = 41-70%) had comorbidities. The most prevalent comorbidities were hypertension (34%, 95% CI = 25-44%), diabetes (20%, 95% CI = 15-25%), and cardiovascular disease (CVD; 12%, 95% CI = 9-16%). The most common blood test abnormalities were elevated C-reactive protein (CRP; 87%, 82-92%), decreased lymphocyte count (68%, 58-77%), and increased lactate dehydrogenase (69%, 95% CI = 57-81%). In addition, abnormal laboratory findings revealing organ dysfunctions were frequently observed in the severe cases, including decrease in albumin (43%, 95% CI = 24-63%) and increase in aspartate aminotransferase (47%, 95% CI = 38-56%), alanine aminotransferase (28%, 95% CI = 16-39%), troponin I/troponin T (TnI/TnT; 29%, 95% CI = 13-45%), and serum Cr (SCr; 10%, 95% CI = 5-15%). CONCLUSION: The male, elderly and obese patients and those with any comorbidities, especially with hypertension, diabetes, and CVD, were more likely to develop into severe cases. But the association between hypertension, diabetes, CVD, and severity of COVID-19 was declined by the increase of age. A significant elevation in cardiac TnI/TnT, the hepatic enzymes, and SCr and the reduction in lymphocytes with elevated CRPs are important markers for the severity. Specific attention should be given to the elderly male and obese patients and those with indications of severe immune injury in combination with bacterial infection and indication of multi-organ dysfunction or damages.

Ubiquitin C-terminal hydrolase L1 (UCHL1) regulates post-myocardial infarction cardiac fibrosis through glucose-regulated protein of 78 kDa (GRP78).

Abnormal cardiac fibrosis indicates cardiac dysfunction and poor prognosis in myocardial infarction (MI) patients. Many studies have demonstrated that the ubiquitin proteasome system (UPS) plays a significant role in the pathogenesis of fibrosis. Ubiquitin C-terminal hydrolase L1 (UCHL1), a member of the UPS, is related to fibrosis in several heart diseases. However, whether UCHL1 regulates cardiac fibrosis following MI has yet to be determined. In the present study, we found that UCHL1 was dramatically increased in infarct hearts and TGF-ß1-stimulated cardiac fibroblasts (CFs). Inhibition of UCHL1 with LDN57444 (LDN) reversed the myocardial fibrosis in post-MI heart and improved cardiac function. Treatment of LDN or UCHL1 siRNA abolished the TGF-ß1-induced fibrotic response of CFs. We further identified GRP78 as an interactor of UCHL1 through screening using immunoprecipitation-mass spectrometer. We determined that UCHL1 interacted with glucose-regulated protein of 78 kDa (GRP78) and prompted GRP78 degradation via ubiquitination. Furthermore, we found that GRP78 was upregulated after UCHL1 knockdown and that the GRP78 inhibitor HA15 diminished the antifibrotic function exerted by UCHL1 knockdown in CFs stimulated with TGF-ß1. This suggests that UCHL1 regulates cardiac fibrosis post MI through interactions with GRP78. This work identifies that the UCHL1-GRP78 axis is involved in cardiac fibrosis after MI.

DiOHF Protects Against Doxorubicin-Induced Cardiotoxicity Through ERK1 Signaling Pathway.

Doxorubicin (DOX) is an effective anticancer agent. Its clinical use is, however, limited due to its detrimental side effects, especially the cardiotoxicity caused by ROS, mitochondrial dysfunction and apoptosis. 3',4'-dihydroxyflavonol (DiOHF) is a recently developed potent synthetic flavonoid which has been reported to exert anti-oxidative activity in myocardial ischemia-reperfusion injury and maintain the normal mitochondrial function. The aim of this study was to explore the protective effects of DiOHF on the DOX-induced cardiotoxicity. We established DOX-induced cardiotoxicity in H9C2 cells by incubation with 1 µM DOX and in BALB/c mice by DOX injection. DiOHF effectively prevented and reversed the DOX-induced cardiotoxicity, including ROS production, mitochondrial dysfunction, and apoptosis. The DOX-induced cardiotoxicity was accompanied by ERK1/2 activation and abolished by the silence of ERK1, rather than ERK2. Furthermore, DOX treatment in mice induced an increase in serum CK-MB level and myocardial fibrosis with a reduction in left ventricular (LV) function. These detrimental effects were blunted by DiOHF administration. Conclusion: DiOHF suppresses and reverses the DOX-induced cardiotoxicity by inhibiting ROS release, stabilizing mitochondrial function and reducing apoptosis through activation of the ERK1 signaling.

Chronic CaMKII inhibition reverses cardiac function and cardiac reserve in HF mice.

AIMS: The present study was to explore the impact of KN93 - a specific inhibitor of CaMKII - on cardiac function and cardiac reserve in HF mice. MAIN METHODS: We have generated pressure-overload HF mice using modified transverse aortic constriction (TAC) method. For acute inhibition (AI) experiment, HF mice were randomly divided into HF group, HF + KN93 AI group and HF + KN92 AI group, using sham mice as control. Mice in HF + KN93 AI group and HF + KN92 AI group were injected with CaMKII inhibitor KN93 or its inactive analogue KN92 on post-TAC day 15, while mice in HF group and Sham group were treated with saline. For chronic inhibition (CI) experiment, mice were injected daily with KN93, KN92 or saline for one week. At baseline and after isoproterenol (Iso) injection, in vivo cardiac function was assessed by echocardiography and left ventricular pressure-volume catheter. KEY FINDINGS: Acute inhibition of CaMKII leads to decreased -dP/dtmin, increased EF, FS, longitudinal strain, longitudinal strain rate, ESPVR, dP/dtmax-EDV, PRSW, Tau and EDPVR, and unaltered reactivity to Iso in HF mice. Chronic inhibition results in increased EF, FS, longitudinal strain, longitudinal strain rate, ESPVR, dP/dtmax-EDV and PRSW, without alteration in -dP/dtmin, Tau and EDPVR. In addition, chronic inhibition reverses the effect of Iso on HF mice. SIGNIFICANCE: Although acute CaMKII inhibition can repair systolic function in HF mice, it also exacerbates the diastolic function, whereas chronic inhibition improves both systolic function and cardiac reserve to ß-adrenergic stimulation without impairing diastolic function.

Identification of potentially critical genes in the development of heart failure after ST-segment elevation myocardial infarction (STEMI).

Heart failure (HF) remains a common complication after acute ST-segment elevation myocardial infarction (STEMI). Here, we aim to identify critical genes related to the developed HF in patients with STEMI using bioinformatics analysis. The microarray data of GSE59867, including peripheral blood samples from nine patients with post-infarct HF and eight patients without post-infarct HF, were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between HF and non-HF groups were screened by LIMMA package. Functional enrichment analyses of DEGs were conducted, followed by construction of a protein-protein interaction (PPI) network. The dynamic messenger RNA (mRNA) level of the hub genes during the follow-up was analyzed to further elucidate their role in HF development. A total of 58 upregulated and 75 downregulated DEGs were screen out. They were mainly enriched in biological processes about inflammatory response, extracellular matrix organization, response to cAMP, immune response, and positive regulation of cytosolic calcium ion concentration. Pathway analysis revealed that the DEGs were also involved in hematopoietic cell lineage, pathways in cancer, and extracellular matrix-receptor interaction. In the PPI network consisting of 58 nodes and 72 interactions, CXCL8 (degree = 15), THBS1 (degree = 8), FOS (degree = 7), and ITGA2B (degree = 6) were identified as the hub genes. In the comparison of patients with and without post-infarct HF, the mRNA level of these hub genes were all higher within 30 days but reached similar at 6 months after STEMI. In conclusion, CXCL8, THBS1, FOS, and ITGA2B may play important roles in the development of HF after acute STEMI.

Kv4.3 expression abrogates and reverses norepinephrine-induced myocyte hypertrophy by CaMKII inhibition.

BACKGROUND: Down-regulation of Kv4.3 protein is a general feature of cardiac hypertrophy. Based on our recent studies, we propose that Kv4.3 reduction may be a hypertrophic stimulator. OBJECTIVE: We tested whether Kv4.3 expression can prevent or reverse cardiac hypertrophy induced by norepinephrine (NE). METHODS AND RESULTS: Incubation of 20 µM NE in cultured neonatal rat ventricular myocytes (NRVMs) for 48 h and 96 h induced myocyte hypertrophy in a time-dependent manner, characterized by progressive increase in cell size, protein/DNA ratio, ANP and BNP, along with an progressive increase in the activity of CaMKII and calcineurin and reduction of Kv4.3 mRNA and proteins. Interestingly, PKA-dependent phosphorylation of phospholamban (PLB) at Ser16 was increased at 48 h but reduced to the basal level at 96 h NE incubation. CaMKII inhibitors KN93 and AIP blunted NE-induced hypertrophic response and caused regression of hypertrophy, which is associated with a reduction of CaMKII activity and calcineurin expression. Kv4.3 expression completely suppressed the development of NE-induced hypertrophy and led to a regression in the hypertrophic myocytes. These effects were accompanied by a reduction in CaMKII autophosphorylation, PLB phosphorylation at Thr-17 without changing PLB phosphorylation at Ser-16. NFATc3 was also reduced by Kv4.3 expression. CONCLUSIONS: Our results demonstrated that Kv4.3 reduction is an important mediator in cardiac hypertrophy development via excessive CaMKII activation and that Kv4.3 expression is likely a potential therapeutic strategy for prevention and reversion of adrenergic stress-induced cardiac hypertrophy.