Activation of PKC affects the ventricular restitution properties and arrhythmogenesis through L-type Ca+ current.

OBJECTIVE: To investigate the role of protein kinase C (PKC) in action potential duration (APD) restitution and ventricular tachyarrhythmias (VAs). METHODS AND RESULTS: Rabbits hearts were isolated and prepared for Langendorff perfusion technique. The stimuli-extra-stimulus (S1-S2) method and dynamic S1 pacing protocol were performed to construct APD restitution and to induce APD alternans or VA, respectively, at 10 sites throughout the ventricular chamber. Administration of phorbol-12-myristate-13-acetate (PMA) (100 nM) (n = 15) greatly steepened the restitution curves (Smax > 1) (p < .01) at each site compared to the control group (n = 15). Furthermore, treatment with PMA also induced larger spatial dispersions of Smax (p < .05) and decreased the thresholds of the VA and APD alternans (p < .01). However, perfused with the PKC inhibitor, bisindolylmaleimide (BIM) (500 nM) (n = 10), reversibly flattened the APD restitution curves at each site (Smax < 1), decreased the spatial dispersions of Smax, and increased the thresholds of APD alternans and VA. According to the results of patch-clamp, peak amplitude of L-type Ca2+ current was significantly increased by addition of PMA compared with control (CTL) group (p < .05). Antagonize this current with verapamil (n = 10) can fully inhibited the PMA induced increasing of Smax and inducibility of VA and alternans. CONCLUSION: PKC activation increased the dispersion of APD restitution and thus led to occurrence of VA, which possibly related to the increased Ca2+ influx.

Left atrial appendage closure in a patient previously implanted with an interatrial shunt device: a case report.

Patients with previous interatrial shunt device (IASD) implantation may face greater challenges during future left atrial interventional procedures. Herein, we report the first case of left atrial appendage closure (LAAC) in a patient with previous IASD implantation. The patient successfully underwent LAAC using the LAmbre device without complications.

Remedy of a deep downward shift of a valve using double snares and "sandwich" technique.

A 76-year-old man diagnosed with severe pure native aortic regurgitation (PNAR) underwent transcatheter aortic valve replacement (TAVR) due to high surgical risk. The computed tomography angiography showed no calcification and no stenosis of the aortic valve, with an annulus perimeter of 81.1 mm and sinus diameters of 35 to 38 mm.

Biomedical Data Repository Concepts and Management Principles.

The demand for open data and open science is on the rise, fueled by expectations from the scientific community, calls to increase transparency and reproducibility in research findings, and developments such as the Final Data Management and Sharing Policy from the U.S. National Institutes of Health and a memorandum on increasing public access to federally funded research, issued by the U.S. Office of Science and Technology Policy. This paper explores the pivotal role of data repositories in biomedical research and open science, emphasizing their importance in managing, preserving, and sharing research data. Our objective is to familiarize readers with the functions of data repositories, set expectations for their services, and provide an overview of methods to evaluate their capabilities. The paper serves to introduce fundamental concepts and community-based guiding principles and aims to equip researchers, repository operators, funders, and policymakers with the knowledge to select appropriate repositories for their data management and sharing needs and foster a foundation for the open sharing and preservation of research data.

Long-term outcomes in patients with bicuspid valve stenosis and aortic dilation undergoing transcatheter valve implantation.

BACKGROUND: To date, whether ascending aorta dilation (AAD) should be considered a contraindication for transcatheter aortic valve replacement (TAVR) remains a topic of debate.. OBJECTIVE: The study investigated the clinical outcome of TAVR in patients with bicuspid aortic valve stenosis (BAV-AS) complicated by AAD. METHODS: We included patients with BAV-AS who underwent TAVR between 2012 and 2019. We collected patient perioperative clinical data., tracked clinical outcomes for over four years post-TAVR, and obtained echocardiography images one year postoperatively. The Kaplan-Meier method was employed for analyzing both unadjusted and adjusted survival data, which was compared using the log-rank test. COX regression and nomograms were used to assess the impact of AAD on post-TAVR clinical outcomes in patients with aortic stenosis (AS), with all-cause mortality as the primary clinical endpoint. RESULTS: A total of 111 BAV patients were included in this study. Long-term follow-up showed an increased mortality risk in patients with BAV-AAD (adjusted Kaplan-Meier analysis: P = .02/0.001). Cox correlation analysis indicated that age (OR = 1.137; P = .034), AAD (OR = 3.51; P = .038), and postoperative left ventricular pressure (LVSP) (OR: 0.959; P = .044) were predictive factors for mortality more than four years after TAVR in patients with BAV. The area under the curve of the Nomogram predicting long-term survival for the training set of patients based on the above metrics was 0.845 (95% CI: 0.696-0.994). Short-term cardiac ultrasound follow-up showed a more rapid rate of AA expansion (0.29 [0-0.34] vs. -1 [-3.3-1] mm/month, P = .001) and a smaller proportion of AA diameter reduction (7.1% vs. 53.7%, P = .001) in patients who died. CONCLUSIONS: Patients with BAV-AAD-AS treated with TAVR have an increased risk of long-term mortality, and clinical prediction models, including AAD age and postoperative LVSP, may predict long-term patient survival. CONDENSED ABSTRACT: The study investigated the clinical outcome of transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic valve stenosis (BAV-AS) complicated by ascending aorta dilation (AAD). Patients with BAV-AAD-AS treated with TAVR have an increased risk of long-term mortality. AAD, age and postoperative LVSP, may predict long-term patient survival. Short-term cardiac ultrasound follow-up showed a more rapid rate of AA expansion and a smaller proportion of AA diameter reduction in patients who died. A high postoperative AAD expansion rate may indicate an adverse clinical outcome. Surgery regimens for tolerable BAV-AADs and can be considered as a treatment option.

A Novel Swine Model for Inducing Functional Tricuspid Valve Regurgitation.

Functional tricuspid regurgitation (FTR) is the most common TR, although experimental models to effectively study it are scarce; therefore, this study aimed to establish a robust experimental swine model. A swine FTR model was developed using radiofrequency ablation, atrial septostomy, and right atrial volume overload. The baseline and follow-up echocardiography was performed to evaluate the progression FTR and changes in the heart. Autopsy was employed to verify the anatomy of tricuspid valve. One-month post intervention, among the subjects, one (8.3%) exhibited severe FTR, eight (66.7%) exhibited moderate TR, and three (25%) exhibited mild FTR. Each pig developed an atrial septal defect (diameter, 1.5 ± 0.5 cm). The tricuspid annular diameter significantly increased with enlargement of right heart (P < 0.05). No significant difference was found on left heart size and mitral regurgitation. We successfully developed a novel swine FTR model, providing a reliable and effective platform for further research on FTR.

Transcatheter Closure of Atrial Septal Defects with Absent Aortic Rim and the Predictors of Right Atrial Reverse Remodeling: 5 Years Experience in China.

INTRODUCTION: Atrial septal defect (ASD) is one of the most common congenital heart malformations. Although not recommended, a significant proportion of patients with aortic root defects receive ASD closure, some of whom have improved right ventricular function. The study aimed to investigate the safety of interventional therapy in ASD patients with complete aortic rim deficiency and explore the predictors of right atrial (RA) non-reverse remodeling. METHODS: 1,011 patients with ASD who underwent transcatheter closure in the Department of Cardiology, Zhongshan Hospital, affiliated to Fudan University from June 2017 to June 2023 were enrolled in the study. They were divided into a complete aortic rim deficiency group and without absent aortic rim group. Furthermore, patients who had an enlarged RA in the absent aortic rim group were divided into two subgroups according to whether their RA remodeling was reversed post-procedure. Multivariate logistic regression was used to determine the predictors of RA reverse remodeling. RESULTS: During the 1-year follow-up, no major operative complications occurred in all patients with the absence of an aortic rim and a normal edge. After the operation, the right heart remodeling was significantly reversed, multivariate logistic regression analysis was performed, and it was found that no coronary heart disease before an operation, lower plasma creatinine level, and larger RA and RV dimensions were the predictive factors for the reverse of RA remodeling after treatment. CONCLUSION: Transcatheter closure of ASD with complete aortic rim deficiency is safe and feasible. For patients without coronary heart disease, the lower the creatinine value and the lower the tricuspid regurgitation before an operation, the more improvement of RA remodeling after the operation.

Genome-wide profiling of DNA methylome and transcriptome reveals epigenetic regulation of Urechis unicinctus response to sulfide stress.

Sulfide is a well-known environmental pollutant that can have detrimental effects on most organisms. However, few metazoans living in sulfide-rich environments have developed mechanisms to tolerate and adapt to sulfide stress. Epigenetic mechanisms, including DNA methylation, have been shown to play a vital role in environmental stress adaptation. Nevertheless, the precise function of DNA methylation in biological sulfide adaptation remains unclear. Urechis unicinctus, a benthic organism inhabiting sulfide-rich intertidal environments, is an ideal model organism for studying adaptation to sulfide environments. In this study, we conducted a comprehensive analysis of the DNA methylome and transcriptome of U. unicinctus after exposure to 50 µM sulfide. The results revealed dynamic changes in the DNA methylation (5-methylcytosine) landscape in response to sulfide stress, with U. unicinctus exhibiting elevated DNA methylation levels following stress exposure. Integrating differentially expressed genes (DEGs) and differentially methylated regions (DMRs), we identified a crucial role of gene body methylation in predicting gene expression. Furthermore, using a DNA methyltransferase inhibitor, we validated the involvement of DNA methylation in the sulfide stress response and the gene regulatory network influenced by DNA methylation. The results indicated that by modulating DNA methylation levels during sulfide stress, the expression of glutathione S-transferase, glutamyl aminopeptidase, and cytochrome c oxidase could be up-regulated, thereby facilitating the metabolism and detoxification of exogenous sulfides. Moreover, DNA methylation was found to regulate and enhance the oxidative phosphorylation pathway, including NADH dehydrogenase, isocitrate dehydrogenase, and ATP synthase. Additionally, DNA methylation influenced the regulation of Cytochrome P450 and macrophage migration inhibitory factor, both of which are closely associated with oxidative stress and stress resistance. Our findings not only emphasize the role of DNA methylation in sulfide adaptation but also provide novel insights into the potential mechanisms through which marine organisms adapt to environmental changes.

Targeting Macrophages: Therapeutic Approaches in Diabetic Kidney Disease.

Diabetes is not solely a metabolic disorder but also involves inflammatory processes. The immune response it incites is a primary contributor to damage in target organs. Research indicates that during the initial phases of diabetic nephropathy, macrophages infiltrate the kidneys alongside lymphocytes, initiating a cascade of inflammatory reactions. The interplay between macrophages and other renal cells is pivotal in the advancement of kidney disease within a hyperglycemic milieu. While M1 macrophages react to the inflammatory stimuli induced by elevated glucose levels early in the disease progression, their subsequent transition to M2 macrophages, which possess anti-inflammatory and tissue repair properties, also contributes to fibrosis in the later stages of nephropathy by transforming into myofibroblasts. Comprehending the diverse functions of macrophages in diabetic kidney disease and regulating their activity could offer therapeutic benefits for managing this condition.

Identification of the principal neuropeptide MIP and its action pathway in larval settlement of the echiuran worm Urechis unicinctus.

BACKGROUND: Larval settlement and metamorphosis represent critical events in the life history of marine benthic animals. Myoinhibitory peptide (MIP) plays a pivotal role in larval settlement of marine invertebrates. However, the molecular mechanisms of MIP involved in this process are not well understood. RESULTS: In this study, we evaluated the effects of thirteen MIP mature peptides on triggering the larval settlement of Urechis unicinctus (Xenopneusta, Urechidae), and determined that MIP2 was the principal neuropeptide. Transcriptomic analysis was employed to identify differentially expressed genes (DEGs) between the MIP2-treated larvae and normal early-segmentation larvae. Both cAMP and calcium signaling pathways were enriched in the DEGs of the MIP2-treated larvae, and two neuropeptide receptor genes (Spr, Fmrfar) were up-regulated in the MIP2-treated larvae. The activation of the SPR-cAMP pathway by MIP2 was experimentally validated in HEK293T cells. Furthermore, fourteen cilia-related genes, including Tctex1d2, Cfap45, Ift43, Ift74, Ift22, Cav1 and Mns1, etc. exhibited down-regulated expression in the MIP2-treated larvae. Whole-mount in situ hybridization identified two selected ciliary genes, Tctex1d2 and Cfap45, were specially expressed in circumoral ciliary cells of the early-segmentation larvae. Knocking down Tctex1d2 mRNA levels by in vivo RNA interference significantly increased the larval settlement rate. CONCLUSION: Our findings suggest that MIP2 inhibits the function of the cilia-related genes, such as Tctex1d2, through the SPR-cAMP-PKA pathway, thereby inducing larval settlement in U. unicinctus. The study contributes important data to the understanding of neuropeptide regulation in larval settlement.

Medical Management of Pulmonary Arterial Hypertension: Current Approaches and Investigational Drugs.

Pulmonary arterial hypertension (PAH) is a malignant pulmonary vascular syndrome characterized by a progressive increase in pulmonary vascular resistance and pulmonary arterial pressure, which eventually leads to right heart failure and even death. Although the exact mechanism of PAH is not fully understood, pulmonary vasoconstriction, vascular remodeling, immune and inflammatory responses, and thrombosis are thought to be involved in the development and progression of PAH. In the era of non-targeted agents, PAH had a very dismal prognosis with a median survival time of only 2.8 years. With the deep understanding of the pathophysiological mechanism of PAH as well as advances in drug research, PAH-specific therapeutic drugs have developed rapidly in the past 30 years, but they primarily focus on the three classical signaling pathways, namely the endothelin pathway, nitric oxide pathway, and prostacyclin pathway. These drugs dramatically improved pulmonary hemodynamics, cardiac function, exercise tolerance, quality of life, and prognosis in PAH patients, but could only reduce pulmonary arterial pressure and right ventricular afterload to a limited extent. Current targeted agents delay the progression of PAH but cannot fundamentally reverse pulmonary vascular remodeling. Through unremitting efforts, new therapeutic drugs such as sotatercept have emerged, injecting new vitality into this field. This review comprehensively summarizes the general treatments for PAH, including inotropes and vasopressors, diuretics, anticoagulants, general vasodilators, and anemia management. Additionally, this review elaborates the pharmacological properties and recent research progress of twelve specific drugs targeting three classical signaling pathways, as well as dual-, sequential triple-, and initial triple-therapy strategies based on the aforementioned targeted agents. More crucially, the search for novel therapeutic targets for PAH has never stopped, with great progress in recent years, and this review outlines the potential PAH therapeutic agents currently in the exploratory stage to provide new directions for the treatment of PAH and improve the long-term prognosis of PAH patients.

PCSK9 Inhibition Regulates Infarction-Induced Cardiac Myofibroblast Transdifferentiation via Notch1 Signaling.

Increasing evidence suggests that PCSK9 inhibition protects cardiomyocytes against ischemia-reperfusion injury after myocardial infarction. However, it is not clear whether PCSK9 inhibitor (PCSK9i) affects cardiac fibroblasts (CFs) activation after MI. In this study we used SBC-115076, an antagonist of PCSK9, to investigate the role of PCSK9i in the conversion of CFs to cardiac myofibroblasts (CMFs) after MI and provided a basic for its clinical application in cardiac fibrosis after MI. In vivo study, PCSK9i was injected into mice 4 days after MI. Cardiac function and degree of fibrosis were evaluated by echocardiographic and tissue staining after treatment. Western blot showed that PCSK9i treatment decreases expression of α-SMA, collagen and increases expression of Notch1 in border infarct area. Vitro studies showed that PCSK9i decreased the degree of fibrosis, migration, and collagen fiber deposition in CFs. Confocal microscopy imaging also showed that hypoxia contributes to the formation of α-SMA stress filaments, and PCSK9i alleviated this state. Moreover, overexpression of Notch1 further suppress the activation of CFs under hypoxia. These results revealed that SBC-115076 ameliorates cardiac fibrosis and ventricular dysfunction post-myocardial infarction through inhibition of the differentiation of cardiac fibroblasts to myofibroblasts via Notch1/Hes1 signaling.

Insights into the Molecular Mechanisms of NRF2 in Kidney Injury and Diseases.

Redox is a constant phenomenon in organisms. From the signaling pathway transduction to the oxidative stress during the inflammation and disease process, all are related to reduction-oxidation (redox). Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor targeting many antioxidant genes. In non-stressed conditions, NRF2 maintains the hemostasis of redox with housekeeping work. It expresses constitutively with basal activity, maintained by Kelch-like-ECH-associated protein 1 (KEAP1)-associated ubiquitination and degradation. When encountering stress, it can be up-regulated by several mechanisms to exert its anti-oxidative ability in diseases or inflammatory processes to protect tissues and organs from further damage. From acute kidney injury to chronic kidney diseases, such as diabetic nephropathy or glomerular disease, many results of studies have suggested that, as a master of regulating redox, NRF2 is a therapeutic option. It was not until the early termination of the clinical phase 3 trial of diabetic nephropathy due to heart failure as an unexpected side effect that we renewed our understanding of NRF2. NRF2 is not just a simple antioxidant capacity but has pleiotropic activities, harmful or helpful, depending on the conditions and backgrounds.

Discovery of compounds that reactivate p53 mutants in vitro and in vivo.

The tumor suppressor p53 is the most frequently mutated protein in human cancer. The majority of these mutations are missense mutations in the DNA binding domain of p53. Restoring p53 tumor suppressor function could have a major impact on the therapy for a wide range of cancers. Here we report a virtual screening approach that identified several small molecules with p53 reactivation activities. The UCI-LC0023 compound series was studied in detail and was shown to bind p53, induce a conformational change in mutant p53, restore the ability of p53 hotspot mutants to associate with chromatin, reestablish sequence-specific DNA binding of a p53 mutant in a reconstituted in vitro system, induce p53-dependent transcription programs, and prevent progression of tumors carrying mutant p53, but not p53null or p53WT alleles. Our study demonstrates feasibility of a computation-guided approach to identify small molecule corrector drugs for p53 hotspot mutations.

New Insights into the Treatment of Glomerular Diseases: When Mechanisms Become Vivid.

Treatment for glomerular diseases has been extrapolated from the experience of other autoimmune disorders while the underlying pathogenic mechanisms were still not well understood. As the classification of glomerular diseases was based on patterns of juries instead of mechanisms, treatments were typically the art of try and error. With the advancement of molecular biology, the role of the immune agent in glomerular diseases is becoming more evident. The four-hit theory based on the discovery of gd-IgA1 gives a more transparent outline of the pathogenesis of IgA nephropathy (IgAN), and dysregulation of Treg plays a crucial role in the pathogenesis of minimal change disease (MCD). An epoch-making breakthrough is the discovery of PLA2R antibodies in the primary membranous nephropathy (pMN). This is the first biomarker applied for precision medicine in kidney disease. Understanding the immune system's role in glomerular diseases allows the use of various immunosuppressants or other novel treatments, such as complement inhibitors, to treat glomerular diseases more reasonable. In this era of advocating personalized medicine, it is inevitable to develop precision medicine with mechanism-based novel biomarkers and novel therapies in kidney disease.

Relationship Between Serum Concentration of Adrenomedullin and Myocardial Ischemic T Wave Changes in Patients With Lung Cancer.

Background: Patients with lung cancer are at increased risk for the development of cardiovascular diseases. Molecular markers for early diagnosis of cardiac ischemia are of great significance for the early prevention of cardiovascular events in patients with lung cancer. By evaluating the relationship between adrenomedullin (ADM) and myocardial ischemic T wave changes, the clinical value of circulating ADM as a predictor of myocardial ischemia in patients with lung cancer is confirmed. Methods: We enrolled patients with lung cancer and healthy people from 2019 to 2021 and extracted a detailed ECG parameter. After adjustment for potential confounders, logistic regression was used to assess the association of clinical data. We performed analyses on differences in T wave between patients with lung cancer and healthy people, and the relationship between T wave and ADM among patients with lung cancer. Receiver operator characteristic (ROC) curves were drawn to confirm the diagnostic value of biomarkers. Results: After adjusting for potential confounders, the incidence of T wave inversion or flattening in patients with lung cancer was higher than in healthy people (OR: 3.3228, P = 0.02). Also, further analysis of the data of lung cancer patients revealed that the ADM in lung cancer patients with T wave inversion or flat was higher than those with normal T wave (189.8 ± 51.9 vs. 131.9 ± 38.4, p < 0.001). The area under the ROC curve was 0.8137. Conclusion: Among the patients with lung cancer, serum ADM concentration is associated with the incidence of the abnormal T wave. ADM might be a potentially valuable predictor for heart ischemia in patients with lung cancer.

Neuregulin-1ß Alleviates Sepsis-Induced Skeletal Muscle Atrophy by Inhibiting Autophagy via AKT/mTOR Signaling Pathway in Rats.

BACKGROUND: Several studies have shown that excessive protein degradation is a major cause of skeletal muscle atrophy induced by sepsis, and autophagy is the main pathway participating in protein degradation. However, the role of autophagy in sepsis is still controversial. Previously, we found that neuregulin-1ß (NRG-1ß) alleviated sepsis-induced diaphragm atrophy through the phosphatidylinositol-3 kinase signaling pathway. Akt/mechanistic target of rapamycin (mTOR) is a classic signaling pathway to regulate autophagy, which maintains intracellular homeostasis. This study aimed to investigate whether NRG-1ß could alleviate sepsis-induced skeletal muscle atrophy by regulating autophagy. METHODS: L6 rat myoblast cells were differentiated using 2% fetal bovine serum into myotubes, which were divided into four groups: Con group treated with normal serum; Sep group treated with septic serum to form a sepsis cell model; septic serum + NRG-1ß (SN) group treated with septic serum for 24 h followed by injection with NRG-1ß and incubation for another 48 h; and serum+NRG-1ß+LY294002 group, in which the PI3K inhibitor LY294002 was added 30 min before NRG-1ß, and other treatments were similar to those in SN group. Effects of NRG-1ß were also evaluated in vivo using Sprague-Dawley (SD) rats, in which sepsis was induced by cecal ligation and puncture (CLP). RESULTS: In L6 myotubes treated with septic serum, the expression of autophagy-related proteins UNC-51 like kinase 1, p-Beclin-1, and Beclin-1, and the ratio of LC3B II/I were highly increased, while protein p62 expression was decreased, indicating that autophagy was excessively activated. Moreover, NRG-1 expression was decreased, as detected by confocal immunofluorescence and western blotting. Upon exogenous addition of NRG-1ß, autophagy was inhibited by the activation of Akt/mTOR signaling pathway, and cell viability was also increased. These effects disappeared in the presence of LY294002. In SD rats, sepsis was induced by CLP. NRG-1ß was shown to inhibit autophagy in these rats via the Akt/mTOR pathway, leading to increased body weight of the septic SD rats and alleviation of atrophy of the tibialis anterior muscle. CONCLUSION: NRG-1ß could alleviate sepsis-induced skeletal muscle atrophy by inhibiting autophagy via the AKT/mTOR signaling pathway.

Association of angiotensin-converting enzyme inhibitors or angiotensin II receptor antagonists use with risk of atrial fibrillation after pacemaker implantation among very old patients.

It remains unknown whether and to what extend the angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) can play a role in the development of atrial fibrillation (AF) after pacemaker implantation in very old patients. Therefore, we aimed to investigate the association between oral ACEIs or ARBs and the risk of developing AF in very old patients after pacemaker implantation. Patients above 80 years old with pacemaker implantation and without baseline history of AF were included and their real-world information about ACEIs or ARBs use was extracted from electronic medical records. New AF cases were confirmed via the records of outpatient visits. The multivariable Cox proportional-hazards model was used to evaluate the associations between oral ACEIs or ARBs and risk of AF after pacemaker implantation. Among a total of 388 identified patients aged 80 to 98 years, 118 used ACEIs, 174 had ARBs therapy, and 115 AF were identified after pacemaker implantation during a median follow-up time of 3.1 years. After adjustment for potential confounders, patients with daily use of ARBs had a relatively lower risk of AF after pacemaker implantation (HR: 0.627, 95% CI: 0.425, 0.926; P = 0.019) compared with those non-users, whereas ACEIs therapy didn't show a significant relation with AF risk (HR: 1.335, 95% CI: 0.894, 1.995; P = 0.157). In conclusion, for very old patients with a permanent pacemaker, daily use of oral ARBs was associated with a relative lower risk of AF after pacemaker implantation, however, daily use of ACEIs was not related with AF risk.