Single-cell RNA sequencing reveals the altered innate immunity in immune checkpoint inhibitor-related myocarditis.

Myocarditis has emerged as a rare but lethal immune checkpoint inhibitor (ICI)-associated toxicity. However, the exact mechanism and the specific therapeutic targets remain underexplored. In this study, we aim to characterise the transcriptomic profiles based on single-cell RNA sequencing from ICI-related myocarditis. Peripheral blood mononuclear cell (PBMC) samples were collected from four groups for single-cell RNA sequencing: (1) patients with newly diagnosed lung squamous cell carcinoma before treatment (Control Group); (2) patients with lung squamous cell carcinoma with PD-1 inhibitor therapy who did not develop myocarditis (PD-1 Group); (3) patients during fulminant ICI-related myocarditis onset (Myocarditis Group); and (4) Patients with fulminant ICI-related myocarditis during disease remission (Recovery Group). Subcluster determination, functional analysis, single-cell trajectory and cell-cell interaction analysis were performed after scRNA-seq. Bulk-RNA sequencing was performed for further validation. Our results revealed the diversity of cellular populations in ICI-related myocarditis, marked by their distinct transcriptional profiles and biological functions. Monocytes, NKs as well as B cells contribute to the regulation of innate immunity and inflammation in ICI-related myocarditis. With integrated analysis of scRNA-seq and bulk sequencing, we identified S100A protein family as a potential serum marker for ICI-related myocarditis. Our study has created a cell atlas of PBMC during ICI-related myocarditis, which would shed light on the pathophysiological mechanism and potential therapeutic targets of ICI-related myocarditis in continuous exploration.

Statins aggravate insulin resistance through reduced blood glucagon-like peptide-1 levels in a microbiota-dependent manner.

Statins are currently the most common cholesterol-lowering drug, but the underlying mechanism of statin-induced hyperglycemia is unclear. To investigate whether the gut microbiome and its metabolites contribute to statin-associated glucose intolerance, we recruited 30 patients with atorvastatin and 10 controls, followed up for 16 weeks, and found a decreased abundance of the genus Clostridium in feces and altered serum and fecal bile acid profiles among patients with atorvastatin therapy. Animal experiments validated that statin could induce glucose intolerance, and transplantation of Clostridium sp. and supplementation of ursodeoxycholic acid (UDCA) could ameliorate statin-induced glucose intolerance. Furthermore, oral UDCA administration in humans alleviated the glucose intolerance without impairing the lipid-lowering effect. Our study demonstrated that the statin-induced hyperglycemic effect was attributed to the Clostridium sp.-bile acids axis and provided important insights into adjuvant therapy of UDCA to lower the adverse risk of statin therapy.

A computational method for predicting nucleocapsid protein in retroviruses.

Nucleocapsid protein (NC) in the group-specific antigen (gag) of retrovirus is essential in the interactions of most retroviral gag proteins with RNAs. Computational method to predict NCs would benefit subsequent structure analysis and functional study on them. However, no computational method to predict the exact locations of NCs in retroviruses has been proposed yet. The wide range of length variation of NCs also increases the difficulties. In this paper, a computational method to identify NCs in retroviruses is proposed. All available retrovirus sequences with NC annotations were collected from NCBI. Models based on random forest (RF) and weighted support vector machine (WSVM) were built to predict initiation and termination sites of NCs. Factor analysis scales of generalized amino acid information along with position weight matrix were utilized to generate the feature space. Homology based gene prediction methods were also compared and integrated to bring out better predicting performance. Candidate initiation and termination sites predicted were then combined and screened according to their intervals, decision values and alignment scores. All available gag sequences without NC annotations were scanned with the model to detect putative NCs. Geometric means of sensitivity and specificity generated from prediction of initiation and termination sites under fivefold cross-validation are 0.9900 and 0.9548 respectively. 90.91% of all the collected retrovirus sequences with NC annotations could be predicted totally correct by the model combining WSVM, RF and simple alignment. The composite model performs better than the simplex ones. 235 putative NCs in unannotated gags were detected by the model. Our prediction method performs well on NC recognition and could also be expanded to solve other gene prediction problems, especially those whose training samples have large length variations.

Dysregulated Arginine Metabolism in Young Patients with Chronic Persistent Asthma and in Human Bronchial Epithelial Cells.

BACKGROUND: Recent metabolomics studies have found circulatory metabolism alterations in patients with asthma, indicating that altered metabolites played a significant role in asthma. However, the regulatory mechanisms in asthma, especially in young chronic persistent asthma remain underexplored. METHODS: In this study, a prospective cohort of 162 patients diagnosed of asthma admitted to the First Affiliated Hospital of Xi'an Jiaotong University from January 2018 to December 2019 was used to perform a nested case-control study. Among them, we included 30 patients with chronic persistent asthma between 20 to 35 years old; 30 health control with evenly distributed age and sex were then recruited. Nontargeted metabolomics was applied to identify serum metabolic profiles and altered metabolic pathways. RESULTS: In vitro, human bronchial epithelial cells (HBECs) line BEAS-2B with the addition of L-citrulline and/or asymmetric dimethylarginine (ADMA) model was utilized and the concentrations of nitric oxide (NO) metabolites were tested to evaluate the therapeutic potential of L-citrulline. The young patients with chronic persistent asthma displayed dysregulated serum metabolic profiles, especially enriched in arginine metabolism. The ratio of L-citrulline to ornithine is associated with blood eosinophil count. In vitro, adding L-citrulline could reverse ADMA-mediated reduction of NOx at lower L-arginine concentration (25 µM), but was ineffective in the higher L-arginine concentration (100 µM) media. CONCLUSIONS: The arginine metabolism balance is of vital importance during the pathogenesis and progression of chronic asthma. L-citrulline could be a powerful approach to restore airway NO production, potentially exhibiting therapeutic benefits among young patients with chronic asthma.

Interplay Between Gut Microbiota and Amino Acid Metabolism in Heart Failure.

Heart failure (HF) is a complex clinical syndrome of which the incidence is on the rise worldwide. Cardiometabolic disorders are associated with the deterioration of cardiac function and progression of HF. Recently, there has been renewed interest in gut microbiota (GM) and its metabolites in the cardiovascular disease. HF-caused hypoperfusion could increase intestinal permeability, and a "leaky" bowel leads to bacterial translocation and make its metabolites more easily enter the circulation. Considerable evidence shows that the composition of microbiota and amino acids (AAs) has been altered in HF patients, and AAs could serve as a diagnostic and prognostic biomarker in HF. The findings indicate that the gut-amino acid-HF axis may play a key role in the progression of HF. In this paper, we focus on the interrelationship between the AA metabolism and GM alterations during the development of heart failure. We also discuss the potential prognostic and therapeutic value of the gut-amino acid-HF axis in the cortex of HF.

Targeted metabolomic analysis of plasma fatty acids in acute myocardial infarction in young adults.

BACKGROUND AND AIMS: Acute myocardial infarction (AMI) in young adults has distinct clinical features and risk profile as compared with that in elder adults. The pathophysiologic mechanism of AMI in young adults remains unclear. In this study, we used targeted metabolomics to measure metabolic profile and analyzed plasma fatty acids levels in young adults with AMI, seeking to determine whether circulating fatty acid metabolism was correlated with the occurrence of AMI in young adults. METHODS AND RESULTS: Consecutive young and elder patients admitted to hospital for AMI were enrolled. Plasma samples of all participants were obtained after overnight fast and then measured using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) based targeted metabolomic platform. A total of 201 plasma metabolites were measured using UPLC-MS/MS. Several plasma fatty acids were significantly altered in young AMI patients compared with control or elder AMI patients, which also showed significant prediction value for AMI in young adults. Percentage of short chain fatty acids (SCFAs) was decreased and long chain increased in AMI as compared with control. Moreover, alpha-linolenic acid and linoleic acid metabolism (ALALAM) pathway metabolites were gradually increased in control, young, and elder AMI patients. Altered fatty acid correlation network further identified fatty acid metabolism disorder in AMI in young adults. CONCLUSION: By utilizing targeted metabolomic technique, we have found several altered fatty acids and respective pathways that show diagnostic value for AMI in young adults. SCFA and long-chain fatty acid (LCFA) were differentially altered in AMI patients.

Glycoursodeoxycholic acid ameliorates diet-induced metabolic disorders with inhibiting endoplasmic reticulum stress.

Recent studies reveal that bile acid metabolite composition and its metabolism are changed in metabolic disorders, such as obesity, type 2 diabetes and metabolic associated fatty liver disease (MAFLD), yet its role and the mechanism remain largely unknown. In the present study, metabolomic analysis of 163 serum and stool samples of our metabolic disease cohort was performed, and we identified glycoursodeoxycholic acid (GUDCA), glycine-conjugated bile acid produced from intestinal bacteria, was decreased in both serum and stool samples from patients with hyperglycemia. RNA-sequencing and quantitative PCR results indicated that GUDCA alleviated endoplasmic reticulum (ER) stress in livers of high fat diet (HFD)-fed mice without alteration of liver metabolism. In vitro, GUDCA reduced palmitic acid induced-ER stress and -apoptosis, as well as stabilized calcium homeostasis. In vivo, GUDCA exerted effects on amelioration of HFD-induced insulin resistance and hepatic steatosis. In parallel, ER stress and apoptosis were decreased in GUDCA-treated mice as compared with vehicle-treated mice in liver. These findings demonstrate that reduced GUDCA is an indicator of hyperglycemia. Supplementation of GUDCA could be an option for the treatment of diet-induced metabolic disorders, including insulin resistance and hepatic steatosis, with inhibiting ER stress.

HDL-C/apoA-I Ratio Is Associated with the Severity of Coronary Artery Stenosis in Diabetic Patients with Acute Coronary Syndrome.

BACKGROUND: Emerging evidence demonstrates that the lipid metabolism in acute coronary syndrome (ACS) patients with type 2 diabetes mellitus (T2DM) differs from nondiabetic patients. However, the distinct lipid profiles and their relationships with the severity of coronary artery stenosis and prognosis in patients with T2DM remain elusive. METHOD AND RESULT: This single-center, prospective cohort study enrolled 468 patients diagnosed with ACS undergoing coronary angiography, consisting of 314 non-DM and 154 DM patients. The HDL-C/apoA-I ratio was significantly higher in DM patients with a multivessel (≥3 affected vessels) lesion than a single-vessel (1-2 affected vessels) lesion. Regression analyses showed that the HDL-C/apoA-I ratio was positively correlated to the number of stenotic coronary arteries in DM patients but not non-DM patients. However, Kaplan-Meier survival analysis revealed no significant difference in the major adverse cardiovascular event rate regarding different HDL-C/apoA-I levels in DM or non-DM ACS patients at the end of the 2-year follow-up. CONCLUSION: A higher HDL-C/apoA-I ratio is associated with increased severity of coronary artery stenosis in DM patients with ACS but not with the rate of major adverse cardiovascular events at the end of the 2-year follow-up.

The gut microbiota is associated with clinical response to statin treatment in patients with coronary artery disease.

BACKGROUND: The structure and composition of the gut microbiota influence patients' response to therapeutic interventions. It is also known that the response to statin treatment can vary greatly from one patient to another, suggesting a possible connection between microbiome composition and response to statins. In the present study, we aim to explore the influence of the microbiome composition on the response to statin treatment among patients with coronary artery disease (CAD). METHODS: A prospective cohort of 836 CAD patients enrolled from January 2016 to December 2017 was used to perform a nested case-control study. We divided 110 CAD patients into two groups according to their response to statins (good response group and poor response group) and compared their gut microbiota. RESULTS: Our analysis reveals no significant difference in microbiome between the two groups. However, significant differences were found in the relative proportion of numerous genera between GR and PR groups. Most remarkably, we could observe that a poor response to statin treatment correlates to a significant decrease in the abundance of beneficial bacteria for the lipid metabolism (Akkermansia muciniphila (A. muciniphila) and Lactobacillus) and a significant increase in the abundance of bacteria (Holdemanella and Facecallibacterium). CONCLUSIONS: Gut microbiota structure is associated with the response to statin. Our results suggest that manipulation of the gut microbiota composition can be an interesting and effective treatment strategy to blood lipid control among CAD patients.

Clinically relevant high levels of human C-reactive protein induces endothelial dysfunction and hypertension by inhibiting the AMPK-eNOS axis.

Successful treatment of resistant hypertension accompanied by elevated human C-reactive protein (hCRP) remains a key challenge in reducing the burden of cardiovascular diseases. It is still unclear whether clinically relevant high-level hCRP is merely a marker or a key driver of hypertension. Here, we investigated the role and mechanism of clinically relevant high level of hCRP in hypertension. Elevated blood pressure was observed in all three hCRP overexpression models, including adeno-associated virus 9 (AAV9)-transfected mice, AAV9-transfected rats and hCRP transgenic (hCRPtg) rats. hCRPtg rats expressing clinically relevant high-level hCRP developed spontaneous hypertension, cardiac hypertrophy, myocardial fibrosis and impaired endothelium-dependent relaxation. Mechanistically, studies in endothelial nitric oxide (NO) synthase (eNOS) knockout mice transfected with AAV9-hCRP and phosphoproteomics analysis of hCRP-treated endothelial cells revealed that hCRP inhibited AMP-activated protein kinase (AMPK)-eNOS phosphorylation pathway. Further, activation of AMPK by metformin normalized endothelial-dependent vasodilation and decreased the blood pressure of hCRPtg rats. Our results show that clinically relevant high-level hCRP induces hypertension and endothelial dysfunction by inhibiting AMPK-eNOS signaling, and highlight hCRP is not only an inflammatory biomarker but also a driver of hypertension. Treatment with metformin or a synthetic AMPK activator may be a potential strategy for vaso-dysfunction and hypertension in patients with high hCRP levels.

Altered exosomal microRNA profiles in bronchoalveolar lavage fluid can mediate metabolism in patients with Acinetobacter baumannii ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia (VAP) is a major public health problem and is most commonly caused by Acinetobacter baumannii (Ab) infection. In our study, we investigated the profiles of exosomal microRNAs (miRNAs) extracted from the bronchoalveolar lavage fluid (BALF) and serum of patients with Acinetobacter baumannii ventilator-associated pneumonia (Ab-VAP). We also examined the serum metabolomic profiles of these patients. Our aim was to study the associations between lung tissue-derived exosomal miRNAs and changes in global metabolism in patients with Ab-VAP. METHODS: Consecutively sampled patients admitted to an intensive care unit (ICU) for pulmonary infection treatment were enrolled in this study. Demographic information and biochemical measurements were collected. Serum samples were obtained following overnight fasting on admission. Bronchoscopies were performed and BALF samples were collected from each patient. Exosomes were extracted using kits from System Biosciences (SBI) and miRNA sequencing was performed. Non-targeted metabolomics were used to express metabolic profiles. RESULTS: We found significant changes in the miRNA profiles of patients with Ab-VAP; these changes occurred in both BALF exosomal miRNA and serum exosomal miRNA. Gene Ontology analysis further identified the function of miRNA in system metabolism. Serum metabolomic profiles and ratios of biological significance were found to be differentially regulated in Ab-VAP patients. This differential regulation was correlated with the differential expression of miRNAs. CONCLUSIONS: Our data summarizes the dysregulation of serum metabolism and exosomal miRNA excretion that occurs in Ab-VAP patients. The correlation found between BALF exosomal miRNA and dysregulated metabolism, as indicated by the irregular expression of metabolites in the cellular metabolic pathway, highlights potential biomarkers for the diagnosis and treatment of Ab infection.

Impact of depression and/or anxiety on patients with percutaneous coronary interventions after acute coronary syndrome: a protocol for a real-world prospective cohort study.

INTRODUCTION: Acute coronary syndrome (ACS) is one of the leading causes of death. Depression and/or anxiety after ACS is common. Studies from developed countries have reported that the occurrence of anxiety or depression after ACS might increase the risk of cardiovascular events and mortality. However, the results varied, and are limited in developing countries. Therefore, well designed large-scale real-world study is needed to make further clarification. The main objective of this study is to evaluate whether depression or anxiety could affect the prognosis of patients with percutaneous coronary intervention (PCI) post-ACS. METHOD AND ANALYSIS: The study is a prospective, multicentre, cohort study, which will be performed at 12 large hospitals in northwest China and led by the First Affiliated Hospital of Xi'an Jiaotong University. A total of 5000 patients with PCI post-ACS will be enrolled and followed up for 2 years. Their depression and anxiety status will be evaluated with the Patient Health Questionnaire-9 or Generalised Anxiety Disorder-7 Assessment scales during the follow-up. A Cox proportional hazard model will be used to determine if depression/anxiety after PCI increase the risk of cardiovascular events. The impact of antidepression or antianxiety treatment on the cardiac prognosis will be explored as well among the patients with ACS who received the treatment after PCI. ETHICS AND DISSEMINATION: This study has been approved by the ethics committee of the First Affiliated Hospital of Xi'an Jiaotong University (approval number: XJTU1AF2016LSL-036). The results will be published in research articles or conference papers. TRIAL REGISTRATION NUMBER: NCT03057691.

Clinical characteristics and protective factors in patients with acute myocardial infarction undergoing in-hospital myocardial free wall rupture: a single-center, retrospective analysis.

Myocardial free wall rupture (MFWR) refers to laceration of the heart ventricle or atria, which is a rare but fatal complication of acute myocardial infarction (AMI). In this study, we aim to identify the clinical characteristics and protective factors of free wall rupture after myocardial infarction. This is a single-center, retrospective observational analysis. The study screened all patients admitted to the cardiology department of the First Affiliated Hospital of Xi'an Jiaotong University between January 2013 and April 2018. The biochemical, clinical, angiographic and echocardiographic features of these patients were then collected and analyzed. Among the 5946 screened patients with AMI, 23 patients with a diagnosis of MFWR after AMI were enrolled in the present study. 18 (78.3%) patients were diagnosed with acute ST segment elevated myocardial infarction and the remaining 5 (21.7%) have acute non-ST segment elevated myocardial infarction. Early-phase MFWR happened in 12 (52.2%) and late-phase accounted for 8 (34.8%) in total. Late-phase MFWR had lower left ventricle ejection fraction value (45.8%±5.6% vs 63.0±3.8%, p<0.001) as compared with early-phase. Patients who survived from MFWR has higher ACE inhibitor/angiotensin II receptor blocker (ACEI/ARB) and ß-blocker coverage in the in-hospital treatment of AMI (ACEI/ARB: 100.0% vs 35.3%, p=0.014; ß-blocker: 100.0% vs 47.1%, p=0.048). The present study provides evidence for better understanding of the clinical characteristics and protective functions in MFWR after AMI. Reduced cardiac function is correlated with higher incidence of later phase free wall rupture. Higher ACEI/ARB and ß-blocker coverage in the AMI treatment strategy is associated with lower MFWR incidence.

Targeting amino acids metabolic profile to identify novel metabolic characteristics in atrial fibrillation.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia whose incidence is on the rise globally. However, the pathophysiologic mechanism of AF remains poorly understood and there has been a lack of circulatory markers to diagnose and predict prognosis of AF. In the present study, by measuring metabolic profile and analyzing plasma amino acid levels in AF patients, we sought to determine whether amino acid metabolism was correlated to the occurrence of AF. Methods: Consecutive patients admitted to hospital for AF were enrolled. Plasma samples were obtained after overnight fast and a profile of 61 amino acids was then measured using gas chromatography/mass spectrometry (GC/MS). Results: Twenty-three AF and thirty-seven control patients were enrolled in the study. A number of plasma amino acids were altered in AF, which showed significant prediction value for AF. Intriguingly, circulating 4-hydroxypyrrolidine-2-carboxylic was gradually lowered with the persistence of AF. Plasma amino acid levels were more strongly correlated with each other in AF as compared with control. Conclusion: By utilizing non-target metabolic profile surveys, we have found a number of altered amino acids, which exhibit diagnostic value for AF. Enhanced amino acids correlation network further identified AF as a metabolism disorder.

Correlation of Triiodothyronine Level with In-Hospital Cardiac Function and Long-Term Prognosis in Patients with Acute Myocardial Infarction.

OBJECTIVE: The pathophysiologic mechanism of how thyroid function is related to the development and prognosis of acute myocardial infarction (AMI) remains under explored, and there has been a lack of clinical investigations. In this study, we investigate the relationship between triiodothyronine (T3) level and cardiac ejection fraction (EF) as well as probrain natriuretic peptide (NT-proBNP) on admission and subsequent prognosis in AMI patients. METHODS: We measured admission thyroid function, NT-proBNP, and EF by echocardiography in 345 patients diagnosed with AMI. Simple and multiregression analyses were performed to investigate the correlation between T3 level and EF as well as NT-proBNP. Major adverse cardiovascular events (MACE), including new-onset myocardial infarction, acute heart failure, and cardiac death, were documented during the follow-up. 248 participants were separated into three groups based on T3 and free triiodothyronine (FT3) levels for survival analysis during a 2-year follow-up. RESULTS: 345 patients diagnosed with AMI were included in the initial observational analysis. 248 AMI patients were included in the follow-up survival analysis. The T3 levels were found to be significantly positively correlated with EF (R square = 0.042, P < 0.001) and negatively correlated with admission NT-proBNP levels (R square = 0.059, P < 0.001), which is the same with the correlation between FT3 and EF (R square = 0.053, P < 0.001) and admission NT-proBNP levels (R square = 0.108, P < 0.001). Kaplan-Meier survival analysis revealed no significant difference with regard to different T3 or FT3 levels at the end of follow-up. CONCLUSIONS: T3 and FT3 levels are moderately positively correlated with cardiac function on admission in AMI patients but did not predict a long-time survival rate. Further studies are needed to explain whether longer-term follow-up would further identify the prognosis effect of T3 on MACE and all-cause mortality.

The effect of substrate stiffness on cancer cell volume homeostasis.

Existing studies on the mechanism of cell volume regulation are mainly relevant to ion channels and osmosis in extracellular fluid. Recently, accumulating evidence has shown that cellular mechanical microenvironment also influences the cell volume. Herein, we investigated the regulation of substrate stiffness on the cell volume homeostasis of MCF-7 cells and their following migration behaviors. We found that cell volume increases with increasing substrate stiffness, which could be affected by blocking the cell membrane anion permeability and dopamine receptor. In addition, the cell migration is significantly inhibited by decreasing the cell volume using tamoxifen and such inhibition effect on migration is enhanced by increasing substrate stiffness. The cell membrane anion permeability might be the linker between cellular mechanical microenvironment and cellular volume homeostasis regulation. This work revealed the regulation of substrate stiffness on cell volume homeostasis for the first time, which would provide a new perspective into the understanding of cancer metastasis and a promising anti-cancer therapy through regulation of cell volume homeostasis.