Propofol postconditioning ameliorates hypoxia/reoxygenation induced H9c2 cell apoptosis and autophagy via upregulating forkhead transcription factors under hyperglycemia

Background:Administration of propofol,an intravenous anesthetic with antioxidant property,immediately at the onset of post-ischemic reperfusion(propofol postconditioning,P-PostC) has been shown to confer cardioprotection against ischemia–reperfusion(I/R) injury,while the underlying mechanism remains incompletely understood.The forkhead box O(FoxO) transcription factors are reported to play critical roles in activating cardiomyocyte survival signaling throughout the process of cellular injuries induced by oxidative stress and are also involved in hypoxic postconditioning mediated neuroprotection,however,the role of FoxO in postconditioning mediated protection in the heart and in particular in high glucose condition is unknown.Methods:Rat heart-derived H9c2 cells were exposed to high glucose(HG) for 48 h,then subjected to hypoxia/reoxygenation(H/R,composed of 8 h of hypoxia followed by 12 h of reoxygenation) in the absence or presence of postconditioning with various concentrations of propofol(P-PostC) at the onset of reoxygenation.After having identified the optical concentration of propofol,H9c2 cells were subjected to H/R and P-PostC in the absence or presence of FoxO1 or FoxO3a gene silencing to explore their roles in P-PostC mediated protection against apoptotic and autophagic cell deaths under hyperglycemia.Results:The results showed that HG with or without H/R decreased cell viability,increased lactate dehydrogenase(LDH) leakage and the production of reactive oxygen species(ROS) in H9c2 cells,all of which were significantly reversed by propofol(P-PostC),especially at the concentration of 25 μmol/L(P25)(P<0.05,NC vs.HG;HG vs.HG+HR;HG+HR+P12.5 or HG+HR+P25 or HG+HR+P50 vs.HG+HR).Moreover,we found that propofol(P25) decreased H9c2 cells apoptosis and autophagy that were concomitant with increased FoxO1 and FoxO3a expression(P<0.05,HG+HR+P25 vs.HG+HR).The protective effects of propofol(P25) against H/R injury were reversed by silencing FoxO1 or FoxO3a(P<0.05,HG+HR+P25 vs.HG+HR+P25+siRNA-1 or HG+HR+P25+siRNA-5).Conclusions:It is concluded that propofol postconditioning attenuated H9c2 cardiac cells apoptosis and autophagy induced by H/R injury through upregulating FoxO1 and FoxO3a under hyperglycemia.

Caloric restriction-mimetics for the reduction of heart failure risk in aging heart: with consideration of gender-related differences

The literature is full of claims regarding the consumption of polyphenol or polyamine-rich foods that offer some protection from developing cardiovascular disease(CVD). This is achieved by preventing cardiac hypertrophy and protecting blood vessels through improving the function of endothelium. However, do these interventions work in the aged human hearts? Cardiac aging is accompanied by an increase in left ventricular hypertrophy, along with diastolic and systolic dysfunction. It also confers significant cardiovascular risks for both sexes. The incidence and prevalence of CVD increase sharply at an earlier age in men than women. Furthermore, the patterns of heart failure differ between sexes, as do the lifetime risk factors. Do caloric restriction(CR)-mimetics, rich in polyphenol or polyamine, delay or reverse cardiac aging equally in both men and women? This review will discuss three areas:(1) mechanisms underlying age-related cardiac remodeling;(2) gender-related differences and potential mechanisms underlying diminished cardiac response in older men and women;(3) we select a few polyphenol or polyamine rich compounds as the CRmimetics, such as resveratrol, quercetin, curcumin, epigallocatechin gallate and spermidine, due to their capability to extend health-span and induce autophagy. We outline their abilities and issues on retarding aging in animal hearts and preventing CVD in humans. We discuss the confounding factors that should be considered for developing therapeutic strategies against cardiac aging in humans.

Cardiac-targeted PIASy gene silencing mediates deSUMOylation of caveolin-3 and prevents ischemia/reperfusion-induced Na_(v)1.5 downregulation and ventricular arrhythmias

Background:Abnormal myocardial voltage-gated sodium channel 1.5(Nav1.5)expression and function cause lethal ventricular arrhythmias during myocardial ischemia–reperfusion(I/R).Protein inhibitor of activated STAT Y(PIASy)-mediated caveolin-3(Cav-3)small ubiquitin-related modifier(SUMO)modification affects Cav-3 binding to the Nav1.5.PIASy activity is increased after myocardial I/R,but it is unclear whether this is attributable to plasma membrane Nav1.5 downregulation and ventricular arrhythmias.Methods:Using recombinant adeno-associated virus subtype 9(AAV9),rat cardiac PIASy was silenced using intraventricular injection of PIASy short hairpin RNA(shRNA).After two weeks,rat hearts were subjected to I/R and electrocardiography was performed to assess malignant arrhythmias.Tissues from peri-infarct areas of the left ventricle were collected for molecular biological measurements.Results:PIASy was upregulated by I/R(P<0.01),with increased SUMO2/3 modification of Cav-3 and reduced membrane Nav1.5 density(P<0.01).AAV9-PIASy shRNA intraventricular injection into the rat heart down-regulated PIASy after I/R,at both mRNA and protein levels(P<0.05 vs.Scramble-shRNA+I/R group),decreased SUMO-modified Cav-3 levels,enhanced Cav-3 binding to Nav1.5,and prevented I/R-induced decrease of Nav1.5 and Cav-3co-localization in the intercalated disc and lateral membrane.PIASy silencing in rat hearts reduced I/R-induced fatal arrhythmias,which was reflected by a modest decrease in the duration of ventricular fibrillation(VF;P<0.05 vs.Scramble-shRNA+I/R group)and a significantly reduced arrhythmia score(P<0.01 vs.Scramble-shRNA+I/R group).The anti-arrhythmic effects of PIASy silencing were also evidenced by decreased episodes of ventricular tachycardia(VT),sustained VT and VF,especially at the time 5–10 min after ischemia(P<0.05 vs.Scramble-shRNA+IR group).Using in vitro human embryonic kidney 293 T(HEK293T)cells and isolated adult rat cardiomyocyte models exposed to hypoxia/reoxygenation(H/R),we confirmed that increased PIASy promoted Cav-3 modification by SUMO2/3 and Nav1.5/Cav-3 dissociation after H/R.Mutation of SUMO consensus lysine sites in Cav-3(K38R or K144R)altered the membrane expression levels of Nav1.5 and Cav-3 before and after H/R in HEK293T cells.Conclusions:I/R-induced cardiac PIASy activation increased Cav-3 SUMOylation by SUMO2/3 and dysregulated Nav1.5-related ventricular arrhythmias.Cardiac-targeted PIASy silencing mediated Cav-3 deSUMOylation and partially prevented I/R-induced Nav1.5 downregulation in the plasma membrane of cardiomyocytes,and subsequent ventricular arrhythmias in rats.PIASy was identified as a potential therapeutic target for life-threatening arrhythmias in patients with ischemic heart diseases.

Review of the risk factors for SARS-CoV-2 transmission

The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)pandemic,which has lasted for nearly a year,has made people deeply aware of the strong transmissibility and pathogenicity of SARS-CoV-2 since its outbreak in December 2019.By December 2020,SARS-CoV-2 had infected over 65 million people globally,resulting in more than 1 million deaths.At present,the exact animal origin of SARS-CoV-2 remains unclear and antiviral vaccines are now undergoing clinical trials.Although the social order of human life is gradually returning to normal,new confirmed cases continue to appear worldwide,and the majority of cases are sporadic due to environmental factors and lax self-protective consciousness.This article provides the latest understanding of the epidemiology and risk factors of nosocomial and community transmission of SARS-CoV-2,as well as strategies to diminish the risk of transmission.We believe that our review will help the public correctly understand and cope with SARS-CoV-2.

Serum Soluble Vascular Endothelial Growth Factor Receptor 1 as a Potential Biomarker of Hepatopulmonary Syndrome

Background and Aims:The results of basic research implicate the vascular endothelial growth factor(VEGF)family as a potential target of hepatopulmonary syndrome(HPS).However,the negative results of anti-angiogenetic therapy in clinical studies have highlighted the need for markers for HPS.Therefore,we aimed to determine whether VEGF family members and their receptors can be potential biomarkers for HPS through clinical and experimental studies.Methods:Clinically,patients with chronic liver disease from two medical centers were enrolled and examined for HPS.Patients were divided into HPS,intrapulmonary vascular dilation[positive contrast-enhanced echocardiography(CEE)and normal oxygenation]and CEE-negative groups.Baseline information and perioperative clinical data were compared between HPS and non-HPS patients.Serum levels of VEGF family members and their receptors were measured.In parallel,HPS rats were established by common bile duct ligation.Liver,lung and serum samples were collected for the evaluation of pathophysiologic changes,as well as the expression levels of the above factors.Results:In HPS rats,all VEGF family members and their receptors underwent significant changes;however,only soluble VEGFR1(sFlt-1)and the sFlt-1/placental growth factor(PLGF)ratio were changed in almost the same manner as those in HPS patients.Furthermore,through feature selection and internal and external validation,sFlt-1 and the sFlt-1/PLGF ratio were identified as the most important variables to distinguish HPS from non-HPS patients.Conclusions:Our results from animal and human studies indicate that sFlt-1 and the sFlt-1/PLGF ratio in serum are potential markers for HPS.

A Simple and Quick Screening Method for Intrapulmonary Vascular Dilation in Cirrhotic Patients Based on Machine Learning

Background and Aims:Screening for hepatopulmonary syndrome in cirrhotic patients is limited due to the need to perform contrast enhanced echocardiography(CEE)and arterial blood gas(ABG)analysis.We aimed to develop a simple and quick method to screen for the presence of intrapulmonary vascular dilation(IPVD)using noninvasive and easily available variables with machine learning(ML)algorithms.Methods:Cirrhotic patients were enrolled from our hospital.All eligible patients underwent CEE,ABG analysis and physical examination.We developed a twostep model based on three ML algorithms,namely,adaptive boosting(termed AdaBoost),gradient boosting decision tree(termed GBDT)and eXtreme gradient boosting(termed Xgboost).Noninvasive variables were input in the first step(the NI model),and for the second step(the NIBG model),a combination of noninvasive variables and ABG results were used.Model performance was determined by the area under the curve of receiver operating characteristics(AUCROCs),precision,recall,F1-score and accuracy.Results:A total of 193 cirrhotic patients were ultimately analyzed.The AUCROCs of the NI and NIBG models were 0.850(0.738–0.962)and 0.867(0.760–0.973),respectively,and both had an accuracy of 87.2%.For both negative and positive cases,the recall values of the NI and NIBG models were both 0.867(0.760–0.973)and 0.875(0.771–0.979),respectively,and the precisions were 0.813(0.690–0.935)and 0.913(0.825–1.000),respectively.Conclusions:We developed a two-step model based on ML using noninvasive variables and ABG results to screen for the presence of IPVD in cirrhotic patients.This model may partly solve the problem of limited access to CEE and ABG by a large numbers of cirrhotic patients.