Transcriptome and open chromatin analysis reveals the process of myocardial cell development and key pathogenic target proteins in Long QT syndrome type 7.

OBJECTIVE: Long QT syndrome type 7 (Andersen-Tawil syndrome, ATS), which is caused by KCNJ2 gene mutation, often leads to ventricular arrhythmia, periodic paralysis and skeletal malformations. The development, differentiation and electrophysiological maturation of cardiomyocytes (CMs) changes promote the pathophysiology of Long QT syndrome type 7(LQT7). We aimed to specifically reproduce the ATS disease phenotype and study the pathogenic mechanism. METHODS AND RESULTS: We established a cardiac cell model derived from human induced pluripotent stem cells (hiPSCs) to the phenotypes and electrophysiological function, and the establishment of a human myocardial cell model that specifically reproduces the symptoms of ATS provides a reliable platform for exploring the mechanism of this disease or potential drugs. The spontaneous pulsation rate of myocardial cells in the mutation group was significantly lower than that in the repair CRISPR group, the action potential duration was prolonged, and the Kir2.1 current of the inward rectifier potassium ion channel was decreased, which is consistent with the clinical symptoms of ATS patients. Only ZNF528, a chromatin-accessible TF related to pathogenicity, was continuously regulated beginning from the cardiac mesodermal precursor cell stage (day 4), and continued to be expressed at low levels, which was identified by WGCNA method and verified with ATAC-seq data in the mutation group. Subsequently, it indicated that seven pathways were downregulated (all p < 0.05) by used single sample Gene Set Enrichment Analysis to evaluate the overall regulation of potassium-related pathways enriched in the transcriptome and proteome of late mature CMs. Among them, the three pathways (GO: 0008076, GO: 1990573 and GO: 0030007) containing the mutated gene KCNJ2 is involved that are related to the whole process by which a potassium ion enters the cell via the inward rectifier potassium channel to exert its effect were inhibited. The other four pathways are related to regulation of the potassium transmembrane pathway and sodium:potassium exchange ATPase (p < 0.05). ZNF528 small interfering (si)-RNA was applied to hiPSC-derived cardiomyocytes for CRISPR group to explore changes in potassium ion currents and growth and development related target protein levels that affect disease phenotype. Three consistently downregulated proteins (KCNJ2, CTTN and ATP1B1) associated with pathogenicity were verificated through correlation and intersection analysis. CONCLUSION: This study uncovers TFs and target proteins related to electrophysiology and developmental pathogenicity in ATS myocardial cells, obtaining novel targets for potential therapeutic candidate development that does not rely on gene editing.

Aggressive versus controlled fluid resuscitation in acute pancreatitis: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Early fluid resuscitation is one of the fundamental treatments for acute pancreatitis (AP), but there is no consensus on the optimal fluid rate. This systematic review and meta-analysis aimed to compare the efficacy and safety of aggressive vs. controlled fluid resuscitation (CFR) in AP. METHODS: The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and Web of Science databases were searched up to September 30, 2022, for randomized controlled trials (RCTs) comparing aggressive with controlled rates of early fluid resuscitation in AP patients without organ failure on admission. The following keywords were used in the search strategy: "pancreatitis," "fluid therapy,""fluid resuscitation,"and "randomized controlled trial." There was no language restriction. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to assess the certainty of evidence. Trial sequential analysis (TSA) was used to control the risk of random errors and assess the conclusions. RESULTS: A total of five RCTs, involving 481 participants, were included in this study. For primary outcomes, there was no significant difference in the development of severe AP (relative risk [RR]: 1.87, 95% confidence interval [CI] 0.95-3.68; P = 0.07; n = 437; moderate quality of evidence) or hypovolemia (RR: 0.98, 95% CI: 0.32-2.97; P = 0.97; n = 437; moderate quality of evidence) between the aggressive and CFR groups. A significantly higher risk of fluid overload (RR: 3.25, 95% CI: 1.53-6.93; P <0.01; n = 249; low quality of evidence) was observed in the aggressive fluid resuscitation (AFR) group than the controlled group. Additionally, the risk of intensive care unit admission ( P = 0.02) and the length of hospital stay ( P <0.01) as partial secondary outcomes were higher in the AFR group. TSA suggested that more studies were required to draw precise conclusions. CONCLUSION: For AP patients without organ failure on admission, CFR may be superior to AFR with respect to both efficacy and safety outcomes. REGISTRATION: PROSPERO; https://www.crd.york.ac.uk/PROSPERO/ ; CRD 42022363945.

Cardiomyopathies in China: A 2018-2019 state-of-the-art review.

Cardiomyopathies are diseases of the cardiac muscle and are often characterized by ventricular dilation, hypertrophy, and cardiac arrhythmia. Patients with cardiomyopathies often experience sudden death and cardiac failure and require cardiac transplantation during the course of disease progression. Early diagnosis, differential diagnosis, and genetic consultation depend on imaging techniques, genetic testing, and new emerging diagnostic tools such as serum biomarkers. The molecular genetics of cardiomyopathies has been widely studied recently. The discovery of mechanisms underlying heterogeneity and overlapping of the phenotypes of cardiomyopathies has revealed the existence of disease modifiers, and this has led to the emergence of novel disease-modifying therapy. This 2018-2019 state-of-the-art review outlines the pathogenesis, diagnosis, and treatment of cardiomyopathies in China.

Establishment of an induced pluripotent stem cell line PUMCHi004-A from a hereditary transthyretin amyloid cardiomyopathy patient with transthyretin (TTR) p.Asp38Asn mutation.

Hereditary transthyretin amyloid cardiomyopathy is cardiac involvement in systemic transthyretin amyloidosis. For the first time, we generated induced pluripotent stem cell (iPSC) line of hATTR-CM carrying the TTR mutation p.Asp38Asn. We isolated peripheral blood mononuclear cells from the patient's peripheral blood. The reprogramming of PBMCs achieved a pluripotent state by the transfection of non-integrated episomal vectors. We demonstrated pluripotency with the presence of cell surface markers, the expression of pluripotency-related genes and the ability to form teratoma composed of three germ layers in vivo. This iPSC line is a useful model for studying the pathogenic mechanism of TTR p.Asp38Asn mutation.