Reciprocal Multifaceted Interaction Between HDL (High-Density Lipoprotein) and Myocardial Infarction

Clusterin attenuates blood-brain barrier damage and cognitive impairment by inhibiting astrocyte aging in mice with sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is a severe complication of sepsis, however, its exact mechanism remains unknown. This study aimed to evaluate whether clusterin is essential to the development of SAE during the aging process of astrocytes. In the study, septic mice were established with cecal ligation and puncture (CLP) and lipopolysaccharides were applied to astrocytes in vitro. Evan's blue dye was used in vivo to show blood-brain barrier (BBB) permeability. A morris water maze test was conducted to assess cognitive functions of the mice. Clusterin-knockout mice were used to examine the effect of clusterin on sepsis. The astrocytes were transfected with lentivirus expressing clusterin cDNA for clusterin overexpression or pYr-LV-clusterin small hairpin RNA for clusterin knockdown in vitro. The expression of clusterin, p-p53, p21, GDNF, and iNOS was detected. he CLP mice exhibited a higher clusterin expression in hippocampus tissue, aging astrocytes, lower GDNF expression and higher iNOS expression, accompanied with BBB damage and cognitive deficiency. Following clusterin knockout, this pathological process was further enhanced. In vitro, following lipopolysaccharides treatment, astrocytes exhibited increased clusterin, p-p53, p21, iNOS and decreased GDNF. Following clusterin knockdown, the cells exhibited a further increase in p-p53, p21, and iNOS and decrease in GDNF. Clusterin overexpression, however, helped inhibit astrocytes aging and neuroinflammation evidenced by decreased p-p53, p21, iNOS and increased GDNF. The present study has revealed that clusterin may exert its neuroprotective effect by preventing aging in astrocytes, suppressing the secretion of iNOS and promoting GNDF release.

CAV1 Protein Encapsulated in Mouse BMSC-Derived Extracellular Vesicles Alleviates Myocardial Fibrosis Following Myocardial Infarction by Blocking the TGF-β1/SMAD2/c-JUN Axis

Extracellular vesicles (EVs) derived from mouse bone marrow mesenchymal stem cells (mBMSCs) convey the CAV1 protein, influencing the TGF-β1/SMAD2/c-JUN pathway and thus the molecular mechanisms underlying myocardial fibrosis (MF) post-myocardial infarction (MI). Through various experimental methods, including transmission electron microscopy, Nanosight analysis, Western blot, ELISA, and qRT-PCR, we isolated, purified, and identified EVs originating from mBMSCs. Bioinformatics and experimental findings show a reduced expression of CAV1 in myocardial fibrosis tissue. Furthermore, our findings suggest that mBMSC-EVs can deliver CAV1 to cardiac fibroblasts (CFs) and that silencing CAV1 in mBMSC-EVs promotes CF fibrosis. In vivo studies further corroborated these findings. In conclusion, mBMSC-EVs mitigate myocardial fibrosis in MI mice by delivering the CAV1 protein, inhibiting the TGF-β1/SMAD2/c-JUN pathway.

The Essence of Lipoproteins in Cardiovascular Health and Diseases Treated by Photodynamic Therapy

Lipids, together with lipoprotein particles, are the cause of atherosclerosis, which is a pathology of the cardiovascular system. In addition, it affects inflammatory processes and affects the vessels and heart. In pharmaceutical answer to this, statins are considered a first-stage treatment method to block cholesterol synthesis. Many times, additional drugs are also used with this method to lower lipid concentrations in order to achieve certain values of low-density lipoprotein (LDL) cholesterol. Recent advances in photodynamic therapy (PDT) as a new cancer treatment have gained the therapy much attention as a minimally invasive and highly selective method. Photodynamic therapy has been proven more effective than chemotherapy, radiotherapy, and immunotherapy alone in numerous studies. Consequently, photodynamic therapy research has expanded in many fields of medicine due to its increased therapeutic effects and reduced side effects. Currently, PDT is the most commonly used therapy for treating age-related macular degeneration, as well as inflammatory diseases, and skin infections. The effectiveness of photodynamic therapy against a number of pathogens has also been demonstrated in various studies. Also, PDT has been used in the treatment of cardiovascular diseases, such as atherosclerosis and hyperplasia of the arterial intima. This review evaluates the effectiveness and usefulness of photodynamic therapy in cardiovascular diseases. According to the analysis, photodynamic therapy is a promising approach for treating cardiovascular diseases and may lead to new clinical trials and management standards. Our review addresses the used therapeutic strategies and also describes new therapeutic strategies to reduce the cardiovascular burden that is induced by lipids.

The Association Between the Triglyceride to High-Density Lipoprotein Cholesterol Ratio and the Incidence of Type 2 Diabetes Mellitus in the Japanese Population

Abstract Aims: To explore whether the triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C) was independently associated with the risk of incident type 2 diabetes mellitus (T2DM) in a large Japanese cohort. Methods: A secondary analysis was performed using open-access data from a retrospective cohort study. A total of 12,716 eligible participants who had standard medical examinations at the Murakami Memorial Hospital were included in this study. New-onset T2DM was the main outcome during follow-up. The risk of T2DM based on the TG/HDL-C ratio was evaluated using Cox regression analysis and Kaplan-Meier analysis. Subgroup analysis was performed to understand further the significance of the TG/HDL-C ratio in particular populations. To assess the potential of the TG/HDL-C ratio for predicting T2DM, a receiver operating characteristic (ROC) analysis was performed. Results: One hundred fifty new-onset T2DM cases were observed during a median follow-up of 5.39 years. The incidence of T2DM increased with a rise in the TG/HDL-C ratio based on the Kaplan-Meier curves (P < 0.0001). After controlling for potential confounding variables, the TG/HDL-C ratio was positively related to incidence of T2DM (hazard ratio = 1.08, 95% confidence interval: 1.01-1.15, P = 0.0239). In subgroup analysis, those with a body mass index of ≥18.5 and <24 kg/m2 showed a significantly positive relationship. The area under the ROC curve for the TG/HDL-C ratio as a T2DM predictor was 0.684. The optimal TG/HDL-C ratio cutoff value for T2DM was 1.609, with a sensitivity of 54.7% and a specificity of 73.6%. Conclusion: The authors' results showed a significant relationship between the TG/HDL-C ratio and the incidence of T2DM in the Japanese population.

First-Trimester Triglyceride-Glucose Index and Triglyceride/High-Density Lipoprotein Cholesterol are Predictors of Gestational Diabetes Mellitus Among the Four Surrogate Biomarkers of Insulin Resistance

Purpose

This study seeks to assess the potential of early pregnancy Triglyceride Glucose Index (TyG), triglyceride to High-Density Lipoprotein Cholesterol ratio (TG/HDL-c), Low-Density Lipoprotein Cholesterol to High-Density Lipoprotein Cholesterol ratio (LDL-C/HDL-C), and Total Cholesterol to High-Density Lipoprotein Cholesterol ratio (TC/HDL-C) in predicting Gestational Diabetes Mellitus (GDM).

Patients and Methods

A total of 1073 adults singleton pregnant women were enrolled from June 2017 to September 2019. Complete anthropometric data and lipid profiles were measured in the first trimester (before 12 weeks gestation) and a 75g oral glucose tolerance test (OGTT) at 24-28 weeks was performed. Based on OGTT results, participants were categorised into Normal Glucose Tolerance (NGT) group (n=872) and GDM group (n=201). General data, laboratory test results, and surrogate insulin resistance indicators such as TyG index, TG/HDL-C, LDL-C/HDL-C, and TC/HDL-C were documented and compared. To compare differences between the two groups, t-test was used, Spearman correlation analysis and linear regression analysis were performed to establish associations between these indicators and insulin resistance in GDM. Receiver Operating Characteristic (ROC) curves were generated to compare the thresholds of these indicators for predicting GDM during pregnancy and to quantify overall diagnostic accuracy.

Results

Individuals with GDM had higher TyG, TG/HDL-C, and LDL-C/HDL-C levels (P < 0.001), but with no significant difference observed in TC/HDL-C. All four ratios were positively correlated with Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), yet only TyG emerged as an independent risk factor for HOMA-IR. The Area under the Curve (AUC) of TyG index (0.692) was comparable to that of HOMA-IR (0.703). The cut-off points for TyG index, TG/HDL-C, and HOMA-IR in predicting GDM were 7.088, 0.831, and 1.8, respectively. HOMA-IR exhibited the highest sensitivity (79.1%), while TyG index (64.3%) and TG/HDL-C ratio (64.3%) demonstrated better specificity compared to HOMA-IR (56.3%). LDL-C/HDL-C and TC/HDL-C offered no discernible predictive advantage.

Conclusion

Early pregnancy TyG index and TG/HDL-C can aid in identifying pregnant women at risk for GDM, potentially facilitating early and effective intervention to improve prognosis. TyG index exhibited superior predictive capability compared to TG/HDL-C.

High-Density Lipoprotein Signaling via Sphingosine-1-Phosphate Receptors Safeguards Spontaneously Hypertensive Rats against Myocardial Ischemia/Reperfusion Injury

BACKGROUND

High-density lipoprotein (HDL) protects against ischemia/reperfusion (I/R) injury via signaling through scavenger-receptor class B type-I (SR-BI) and sphingosine-1-phosphate receptors (S1PRs). We recently reported that HDL protects the hearts of spontaneously hypertensive rats (SHRs) against I/R injury in an SR-BI-dependent manner.

OBJECTIVE

In this study, we examined the role of S1PRs in HDL-induced protection against myocardial I/R injury in hypertensive rats.

METHODS

Hearts from Wistar Kyoto rats (WKYs) and SHRs were subjected to I/R injury using a modified Langendorff system. The hearts were treated with or without HDL in the presence or absence of a receptor- or kinase-specific antagonist. Cardiac hemodynamics and infarct size were measured. Target proteins were analyzed by immunoblotting and ELISA, and nitrite levels were measured using Greis reagent.

RESULTS

HDL protected the hearts of WKYs and SHRs against I/R injury. HDL, however, was more protective in WKYs. HDL protection in SHRs required lipid uptake via SR-BI and S1PR1 and S1PR3 but not S1PR2. The hearts from SHRs expressed significantly lower levels of S1PR3 than the hearts from WKYs. HDL differentially activated mediators of the SAFE and RISK pathways in WKYs and SHRs and resulted in nitric oxide generation. Blockage of these pathways abrogated HDL effects.

CONCLUSIONS

HDL protects against myocardial I/R injury in normotensive and hypertensive rats, albeit to varying degrees. HDL protection in hearts from hypertensive rodents involved SR-BI-mediated lipid uptake coupled with signaling through S1PR1 and S1PR3. The extent of HDL-induced cardiac protection is directly proportional to S1PR3 expression levels. Mechanistically, the safeguarding effects of HDL involved activation of the SAFE and RISK pathways and the generation of nitric oxide.

High-Density Lipoproteins at the Interface between the NLRP3 Inflammasome and Myocardial Infarction

Despite significant therapeutic advancements, morbidity and mortality following myocardial infarction (MI) remain unacceptably high. This clinical challenge is primarily attributed to two significant factors: delayed reperfusion and the myocardial injury resulting from coronary reperfusion. Following reperfusion, there is a rapid intracellular pH shift, disruption of ionic balance, heightened oxidative stress, increased activity of proteolytic enzymes, initiation of inflammatory responses, and activation of several cell death pathways, encompassing apoptosis, necroptosis, and pyroptosis. The inflammatory cell death or pyroptosis encompasses the activation of the intracellular multiprotein complex known as the NLRP3 inflammasome. High-density lipoproteins (HDL) are endogenous particles whose components can either promote or mitigate the activation of the NLRP3 inflammasome. In this comprehensive review, we explore the role of inflammasome activation in the context of MI and provide a detailed analysis of how HDL can modulate this process.

Update of HDL in atherosclerotic cardiovascular disease

Epidemiologic evidence supported an inverse association between HDL (high-density lipoprotein) cholesterol (HDL-C) levels and atherosclerotic cardiovascular disease (ASCVD), identifying HDL-C as a major cardiovascular risk factor and postulating diverse HDL vascular- and cardioprotective functions beyond their ability to drive reverse cholesterol transport. However, the failure of several clinical trials aimed at increasing HDL-C in patients with overt cardiovascular disease brought into question whether increasing the cholesterol cargo of HDL was an effective strategy to enhance their protective properties. In parallel, substantial evidence supports that HDLs are complex and heterogeneous particles whose composition is essential for maintaining their protective functions, subsequently strengthening the "HDL quality over quantity" hypothesis. The following state-of-the-art review covers the latest understanding as per the roles of HDL in ASCVD, delves into recent advances in understanding the complexity of HDL particle composition, including proteins, lipids and other HDL-transported components and discusses on the clinical outcomes after the administration of HDL-C raising drugs with particular attention to CETP (cholesteryl ester transfer protein) inhibitors.

Association between the triglyceride to high-density lipoprotein cholesterol ratio and the risk of gestational diabetes mellitus: a second analysis based on data from a prospective cohort study

Background

Although there is strong evidence linking triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio to insulin resistance and diabetes mellitus, its clinical importance in pregnant women has not been well determined. This study sought to determine the connection between the TG/HDL-C ratio in the first trimester and the eventual onset of gestational diabetes mellitus (GDM).

Methods

We performed a secondary analysis of open-access data from a prospective cohort study. This present study included 590 singleton pregnant women at 10-14 weeks who visited the outpatient clinics for prenatal checks and were recorded at Incheon Seoul Women's Hospital and Seoul Metropolitan Government Seoul National University Boramae Medical Center in Korea. A binary logistic regression model, a series of sensitivity analyses, and subgroup analysis were used to examine the relationship between TG/HDL-C ratio and incident GDM. A receiver operating characteristic (ROC) analysis was also conducted to assess the ability of the TG/HDL-C ratio to predict GDM.

Results

The mean age of the included individuals was 32.06 ± 3.80 years old. The mean TG/HDL-C ratio was 1.96 ± 1.09. The incidence rate of GDM was 6.27%. After adjustment for potentially confounding variables, TG/HDL-C ratio was positively associated with incident GDM (OR=1.77, 95%CI: 1.32-2.38, P=0.0001). Sensitivity analyses and subgroup analysis demonstrated the validity of the relationship between the TG/HDL-C ratio and GDM. The TG/HDL-C ratio was a good predictor of GDM, with an area under the ROC curve of 0.7863 (95% CI: 0.7090-0.8637). The optimal TG/HDL-C ratio cut-off value for detecting GDM was 2.2684, with a sensitivity of 72.97% and specificity of 75.05%.

Conclusion

Our results demonstrate that the elevated TG/HDL-C ratio is related to incident GDM. The TG/HDL-C ratio at 10-14 weeks could help identify pregnant women at risk for GDM and may make it possible for them to receive early and effective treatment to improve their prognosis.

Phospholipids, the Masters in the Shadows during Healing after Acute Myocardial Infarction

Phospholipids are major components of cell membranes with complex structures, high heterogeneity and critical biological functions and have been used since ancient times to treat cardiovascular disease. Their importance and role were shadowed by the difficulty or incomplete available research methodology to study their biological presence and functionality. This review focuses on the current knowledge about the roles of phospholipids in the pathophysiology and therapy of cardiovascular diseases, which have been increasingly recognized. Used in singular formulation or in inclusive combinations with current drugs, phospholipids proved their positive and valuable effects not only in the protection of myocardial tissue, inflammation and fibrosis but also in angiogenesis, coagulation or cardiac regeneration more frequently in animal models as well as in human pathology. Thus, while mainly neglected by the scientific community, phospholipids present negligible side effects and could represent an ideal target for future therapeutic strategies in healing myocardial infarction. Acknowledging and understanding their mechanisms of action could offer a new perspective into novel therapeutic strategies for patients suffering an acute myocardial infarction, reducing the burden and improving the general social and economic outcome.

Association of four lipid-derived indicators with the risk of developing type 2 diabetes: a Chinese population-based cohort study

BACKGROUND

Studies have reported that lipid-derived indicators are associated with type 2 diabetes (T2D) in various populations; however, it is unclear which lipid-derived indicators could effectively predict T2D risk. Therefore, this study aimed to explore the association between four lipid-derived indicators and T2D risk.

METHODS

This was a post-hoc analysis from a large cohort that included data from 114,700 Chinese individuals aged 20 years and older from 11 cities and 32 sites. The association between four lipid-derived indicators and T2D risk was determined using Kaplan-Meier (KM) survival curves, Cox regression, and restricted cubic spline analyses. This study used receiver operating characteristic (ROC) curves for assessing the ability of four lipid-derived indicators to accurately predict the development of T2D during follow-up.

RESULTS

This study included a total of 114,700 participants, with a mean age of 44.15. These individuals were followed up for 3.1 years, of which 2668 participants developed T2D. ROC curve analysis showed that TyG was the most robust predictor of 3-year [aera under the ROC (AUC) = 0.77, 95% CI: 0.768, 0.772] and 5-year T2D risk (AUC = 0.763, 95% CI: 0.760, 0.765). In addition, sensitivity analysis showed an association between TyG and an increased incidence of T2D.

CONCLUSIONS

The results suggest that TyG was a superior for predicting the risk of developing T2D in the general Chinese population.

Harnessing the Plasma Proteome to Mirror Current and Predict Future Cardiac Remodeling After Myocardial Infarction

To identify plasma proteins that mirror current and predict future remodeling after myocardial infarction (MI), we retrospectively interrogated plasma proteomes of day (D)0 control (n = 16) and D3 MI (n = 15) from C57BL/6 J mice (20 ± 1 months). A total of 165 unique proteins were correlated with cardiac physiology variables. We prospectively tested the hypothesis that candidates identified retrospectively would predict cardiac physiology at an extended timepoint (D7 MI) in a second cohort of mice (n = 4 ± 1 months). We also examined human plasma from healthy controls (n = 18) and patients 48 h after presentation for MI (n = 41). Retrospectively, we identified 5 strong reflectors of remodeling (all r ≥ 0.60 and p < 0.05). Prospectively, ApoA1, IgA, IL-17E, and TIMP-1 mirrored current and predicted future remodeling. In humans, cytokine-cytokine receptor signaling was the top enriched KEGG pathway for all candidates. In summary, we identified plasma proteins that serve as useful prognostic indicators of adverse remodeling and progression to heart failure.

Correlation between the triglyceride-to-high-density lipoprotein cholesterol ratio and other unconventional lipid parameters with the risk of prediabetes and Type 2 diabetes in patients with coronary heart disease: a RCSCD-TCM study in China

Objective

Type 2 diabetes mellitus (T2DM) is often accompanied by undiagnosed dyslipidemia. Research on the association of unconventional lipid markers with prediabetes (pre-DM) and T2DM simultaneously is limited in coronary heart disease (CHD) patients.

Methods

This study included 28,476 patients diagnosed with CHD. Their lipid levels, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), were measured, and non-traditional lipid parameters were calculated. The patients were divided into three groups based on the diabetic status including normoglycemic (NG), pre-DM, and T2DM. Multiple logistic regression was used to compare the association of TG/HDL-C and other non-traditional lipid parameters with pre-DM and T2DM. The tertiles of TG/HDL-C included T1 (TG/HDL-C < 1.10), T2 (1.10 ≤ TG/HDL-C ≤ 1.89) and T3 (TG/HDL-C > 1.89). Low and high TG/HDL-C was defined with sex-specific cutoff points.

Results

Multiple logistic regression results showed that the non-traditional lipid parameters, including non-HDL-C, LDL-C/HDL-C, TC/HDL-C, non-HDL-C/HDL-C and TG/HDL-C, were all correlated with the risk of pre-DM and T2DM. Meanwhile TG/HDL-C showed the strongest correlation (odds ratio [OR]: 1.19; 95% confidence interval [CI] 1.16–1.23), (OR: 1.36; 95% CI 1.33–1.39). When dividing TG/HDL-C into tertiles, using T1 as a reference, T3 was observed to have the highest association with both pre-DM and T2DM (OR: 1.60; 95% CI 1.48–1.74), (OR: 2.79; 95% CI 2.60–3.00). High TG/HDL-C was significantly associated with pre-DM and T2DM (OR: 1.69; 95% CI 1.52–1.88), (OR: 2.85; 95% CI 2.60–3.12). The association of TG/HDL-C with T2DM and pre-DM existed across different sex, age, smoking, and drinking statuses.

Conclusion

Elevated non-traditional lipid parameters were significantly associated with pre-DM and T2DM in CHD patients, especially TG/HDL-C. High TG/HDL-C was the risk factor with a strong correlation with the risk of pre-DM and T2DM.

High Density Lipoprotein Reduces Blood Pressure and Protects Spontaneously Hypertensive Rats Against Myocardial Ischemia-Reperfusion Injury in an SR-BI Dependent Manner

Background

Hypertension is a key risk factor in the development of cardiovascular diseases. Elevation in blood pressure alters high density lipoprotein (HDL) function and composition. The exact role of HDL in cardiovascular complications observed in hypertension is however not clearly understood. HDL protected against myocardial ischemia/reperfusion (I/R) injury in normotensive rats. Nonetheless, it's not clear if restoration of HDL function and/or composition protects against myocardial I/R injury in spontaneously hypertensive rats (SHR).

Objectives

In this study we tested the effect of HDL treatment on I/R injury in Wistar Kyoto rats (WKY) and SHR and investigated the possible underlying mechanism(s).

Methods

HDL (900 ng/kg/min) or vehicle were continuously administered to 11-week old WKY and SHR for 1 week (chronic treatment). Blood pressure was measured before and after treatment. Hearts were subjected to I/R injury using a modified Langendorff system. Another set of rats were treated with HDL administered at reperfusion (acute treatment) in the presence or absence of scavenger receptor class B type-I (SR-BI) blocking antibody. Cardiac hemodynamics were computed and cardiac enzyme release and infarct size were measured. Total cholesterol (TC) and HDL-cholesterol (HDL-C) were enzymatically assayed. Markers of autophagy and inflammation were detected by immunoblotting and ELISA, respectively.

Results

HDL treatment did not increase TC or HDL-C levels in SHR or WKY, yet it significantly (P &lt; 0.01) reduced systolic and diastolic blood pressure in SHR. Chronic and acute HDL treatment significantly (P &lt; 0.05) protected WKY and SHR against myocardial I/R injury. Chronic HDL treatment was significantly (P &lt; 0.05) more protective in SHR whereas acute HDL treatment induced significantly (P &lt; 0.05) greater protection in WKY. The extent of HDL induced protection was proportional to the expression levels of cardiac SR-BI and blockage of SR-BI completely abolished HDL mediated protection in SHR. Chronic HDL treatment significantly (P &lt; 0.05) reduced markers of autophagy and inflammation in hypertensive rats.

Conclusions

We demonstrate a novel anti-hypertensive and a cardioprotective effect of HDL against myocardial I/R injury in SHR, the magnitude of which is directly related to the expression levels of cardiac SR-BI. Mechanistically, chronic HDL treatment protected SHR hearts by reducing autophagy and inflammation.

Post-ST-Segment-Elevation Myocardial Infarction Platelet Reactivity Is Associated With the Extent of Microvascular Obstruction and Infarct Size as Determined by Cardiac Magnetic Resonance Imaging

Background

Despite optimized medical management and techniques of primary percutaneous coronary intervention, a substantial proportion of patients with ST‐segment–elevation myocardial infarction (STEMI) display significant microvascular damage. Thrombotic microvascular obstruction (MVO) has been implicated in the pathogenesis of microvascular and subsequent myocardial damage attributed to distal embolization and microvascular platelet plugging. However, there are only scarce data regarding the effect of platelet reactivity on MVO.

Methods and Results

We prospectively evaluated 105 patients in 2 distinct periods (2012–2013 and 2016–2018) who presented with first ST‐segment–elevation myocardial infarction and underwent primary percutaneous coronary intervention. All patients were treated with dual antiplatelet therapy (DAPT). Blood samples were analyzed for platelet reactivity, and cardiac magnetic resonance imaging scans were evaluated for late gadolinium enhancement and MVO. DAPT suboptimal response was defined as hyporesponsiveness to either aspirin or P2Y12 receptor inhibitor agents and demonstrated in 31 patients (29.5%) of the current cohort. Suboptimal platelet response to DAPT was associated with a significantly greater extent of MVO when expressed as a percentage of the left ventricular mass, left ventricular scar, and the number of myocardial left ventricular segments showing MVO (P<0.01 for each). Adjusted multivariable logistic regression model revealed that suboptimal response to DAPT is significantly associated with both greater late gadolinium enhancement (P<0.01) and MVO extent (odds ratio, 3.7 [95% CI, 1.3–10.5]; P=0.01). Patients with a greater extent of MVO were more likely to sustain major adverse cardiovascular events at a 1‐year follow‐up (37% versus 11%; P<0.01).

Conclusions

In patients undergoing primary percutaneous coronary intervention for ST‐segment–elevation myocardial infarction, platelet reactivity in response to DAPT is a key predictor of the extent of both myocardial and microvascular damage.

Role of high-density lipoproteins in cardioprotection and in reverse remodeling: Therapeutic implications

Cardioprotection includes all mechanisms that contribute to preservation of the heart by reducing or even preventing myocardial damage. High-density lipoproteins (HDLs) are circulating multimolecular platforms that exert a multitude of effects on cardiomyocytes and nonmyocyte cells in the myocardium leading to preservation of cardiac structure and function. Animal intervention studies applying HDL-targeted therapies have provided consistent evidence that HDLs protect against ischemia-reperfusion injury, leading to smaller myocardial infarctions, and that HDLs attenuate infarct expansion and cardiac remodeling post-myocardial infarction. These beneficial effects of HDLs are not restricted to prevention of development of ischemic cardiomyopathy but also apply to prevention of pathological hypertrophy and adverse remodeling in the presence of diabetes or in the presence of pressure overload. Moreover, HDLs can induce reverse remodeling characterized by a reduction of cardiac hypertrophy, a decrease of myocardial fibrosis, a regression of capillary rarefaction, and a restoration of cardiac function. HDL-targeted interventions are an effective treatment for heart failure in animal models. In conclusion, whereas protective effects of HDLs on coronary arteries remain essentially unproven till now, the potential for clinical translation of HDL-targeted interventions in prevention of cardiomyopathy and in treatment of heart failure is supported by consistent evidence from animal intervention studies.

Serum levels of small HDL particles are negatively correlated with death or lung transplantation in an observational study of idiopathic pulmonary fibrosis

BACKGROUND

Serum lipoproteins, such as high density lipoproteins (HDL), may influence disease severity in idiopathic pulmonary fibrosis (IPF). Here, we investigated associations between serum lipids and lipoproteins and clinical endpoints in IPF.

METHODS

Clinical data and serum lipids were analyzed from a discovery cohort (59 IPF subjects, 56 healthy volunteers) and validated using an independent, multicenter cohort (207 IPF subjects) from the Pulmonary Fibrosis Foundation registry. Associations between lipids and clinical endpoints (FVC, forced vital capacity; 6MWD, 6 min walk distance; GAP (Gender Age Physiology) index; death or lung transplantation) were examined using Pearson's correlation and multivariable analyses.

RESULTS

Serum concentrations of small HDL particles (S-HDLP_NMR), measured by nuclear magnetic resonance (NMR) spectroscopy, correlated negatively with the GAP index in the discovery cohort of IPF subjects. The negative correlation of S-HDLP_NMR with GAP index was confirmed in the validation cohort of IPF subjects. Higher levels of S-HDLP_NMR were associated with lower odds of death or its competing outcome, lung transplantation (OR of 0.9 for each 1 μmol·L^-1 increase in S-HDLP_NMR, p<0.05), at 1, 2, and 3 years from study entry in a combined cohort of all IPF subjects.

CONCLUSIONS

Higher serum levels of S-HDLP_NMR are negatively correlated with the GAP index, as well as with lower observed mortality or lung transplantation in IPF subjects. These findings support the hypothesis that S-HDLP_NMR may modify mortality risk in patients with IPF.

Silencing CircHIPK3 Sponges miR-93-5p to Inhibit the Activation of Rac1/PI3K/AKT Pathway and Improves Myocardial Infarction-Induced Cardiac Dysfunction

The ceRNA network involving circular RNAs (circRNAs) is essential in the cardiovascular system. We investigated the underlying ceRNA network involving circHIPK3 in myocardial infarction (MI). After an MI model was established, cardiac function was verified, and myocardial tissue damage in mice with MI was evaluated. A hypoxia model of cardiomyocytes was used to simulate MI in vivo, and the expression of and targeting relationships among circHIPK3, miR-93-5p, and Rac1 were verified. The apoptosis of cardiomyocyte was identified. Gain- and loss-of-functions were performed to verify the ceRNA mechanism. The MI-modeled mice showed cardiac dysfunction and enlarged infarct size. CircHIPK3 was highly expressed in mouse and cell models of MI. Silencing circHIPK3 reduced infarct size, myocardial collagen deposition, and myocardial apoptosis rate and improved cardiac function. CircHIPK3 sponged miR-93-5p, and miR-93-5p targeted Rac1. Overexpression of miR-93-5p inhibited MI-induced cardiomyocyte injury and eliminated the harmful effect of circHIPK3. CircHIPK3 acted as ceRNA to absorb miR-93-5p, thus promoting the activation of the Rac1/PI3K/AKT pathway. We highlighted that silencing circHIPK3 can upregulate miR-93-5p and then inhibit the activation of Rac1/PI3K/Akt pathway, which can improve MI-induced cardiac dysfunction.

Neutrophil-Mediated Cardiac Damage After Acute Myocardial Infarction: Significance of Defining a New Target Cell Type for Developing Cardioprotective Drugs

Significance: Acute myocardial infarction (AMI) is a leading cause of death worldwide. Post-AMI survival rates have increased with the introduction of angioplasty as a primary coronary intervention. However, reperfusion after angioplasty represents a clinical paradox, restoring blood flow to the ischemic myocardium while simultaneously inducing ion and metabolic imbalances that stimulate immune cell recruitment and activation, mitochondrial dysfunction and damaging oxidant production. Recent Advances: Preclinical data indicate that these metabolic imbalances contribute to subsequent heart failure through sustaining local recruitment of inflammatory leukocytes and oxidative stress, cardiomyocyte death, and coronary microvascular disturbances, which enhance adverse cardiac remodeling. Both left ventricular dysfunction and heart failure are strongly linked to inflammation and immune cell recruitment to the damaged myocardium. Critical Issues: Overall, therapeutic anti-inflammatory and antioxidant agents identified in preclinical trials have failed in clinical trials. Future Directions: The versatile neutrophil-derived heme enzyme, myeloperoxidase (MPO), is gaining attention as an important oxidative mediator of reperfusion injury, vascular dysfunction, adverse ventricular remodeling, and atrial fibrillation. Accordingly, there is interest in therapeutically targeting neutrophils and MPO activity in the setting of heart failure. Herein, we discuss the role of post-AMI inflammation linked to myocardial damage and heart failure, describe previous trials targeting inflammation and oxidative stress post-AMI, highlight the potential adverse impact of neutrophil and MPO, and detail therapeutic options available to target MPO clinically in AMI patients.

Lipoproteins and lipids in cardiovascular disease: from mechanistic insights to therapeutic targeting

With cardiovascular disease being the leading cause of morbidity and mortality worldwide, effective and cost-efficient therapies to reduce cardiovascular risk are highly needed. Lipids and lipoprotein particles crucially contribute to atherosclerosis as underlying pathology of cardiovascular disease and influence inflammatory processes as well as function of leukocytes, vascular and cardiac cells, thereby impacting on vessels and heart. Statins form the first-line therapy with the aim to block cholesterol synthesis, but additional lipid-lowering drugs are sometimes needed to achieve low-density lipoprotein (LDL) cholesterol target values. Furthermore, beyond LDL cholesterol, also other lipid mediators contribute to cardiovascular risk. This review comprehensively discusses low- and high-density lipoprotein cholesterol, lipoprotein (a), triglycerides as well as fatty acids and derivatives in the context of cardiovascular disease, providing mechanistic insights into their role in pathological processes impacting on cardiovascular disease. Also, an overview of applied as well as emerging therapeutic strategies to reduce lipid-induced cardiovascular burden is provided.

Sphingosine-1-Phosphate Receptor Modulator, FTY720, Improves Diastolic Dysfunction and Partially Reverses Atrial Remodeling in a Tm-E180G Mouse Model Linked to Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a genetic cardiovascular disorder, primarily involving mutations in sarcomeric proteins. HCM patients present with hypertrophy, diastolic dysfunction, and fibrosis, but there is no specific treatment. The sphingosine-1-phosphate receptor modulator, FTY720/fingolimod, is approved for treatment of multiple sclerosis. We hypothesize that modulation of the sphingosine-1-phosphate receptor by FTY720 would be of therapeutic benefit in sarcomere-linked HCM.

METHODS

We treated mice with an HCM-linked mutation in tropomyosin (Tm-E180G) and nontransgenic littermates with FTY720 or vehicle for 6 weeks. Compared with vehicle-treated, FTY720-treated Tm-E180G mice had a significant reduction in left atrial size (1.99±0.19 [n=7] versus 2.70±0.44 [n=6] mm; P<0.001) and improvement in diastolic function (E/A ratio: 2.69±0.38 [n=7] versus 5.34±1.19 [n=6]; P=0.004) as assessed by echocardiography.

RESULTS

Pressure-volume relations revealed significant improvements in the end-diastolic pressure volume relationship, relaxation kinetics, preload recruitable stroke work, and ejection fraction. Detergent-extracted fiber bundles revealed a significant decrease in myofilament Ca²⁺-responsiveness (pCa₅₀=6.15±0.11 [n=13] versus 6.24±0.06 [n=14]; P=0.041). We attributed these improvements to a downregulation of S-glutathionylation of cardiac myosin binding protein-C in FTY720-treated Tm-E180G mice and reduction in oxidative stress by downregulation of NADPH oxidases with no changes in fibrosis.

CONCLUSIONS

This is the first demonstration that modulation of S1PR results in decreased myofilament-Ca²⁺-responsiveness and improved diastolic function in HCM. We associated these changes with decreased oxidative modification of myofilament proteins via downregulation of NOX2. Our data support the hypothesis that modification of sphingolipid signaling may be a novel therapeutic approach in HCM.

HDL therapy today: from atherosclerosis, to stent compatibility to heart failure

Epidemiologically, high-density lipoprotein (HDL) cholesterol levels have been inversely associated to cardiovascular (CV) events, although a Mendelian Randomisation Study had failed to establish a clear causal role. Numerous atheroprotective mechanisms have been attributed to HDL, the main being the ability to promote cholesterol efflux from arterial walls; anti-inflammatory effects related to HDL ligands such as S1P (sphingosine-1-phosphate), resolvins and others have been recently identified. Experimental studies and early clinical investigations have indicated the potential of HDL to slow progression or induce regression of atherosclerosis. More recently, the availability of different HDL formulations, with different phospholipid moieties, has allowed to test other indications for HDL therapy. Positive reports have come from studies on coronary stent biocompatibility, where the use of HDL from different sources reduced arterial cell proliferation and thrombogenicity. The observation that low HDL-C levels may be associated with an enhanced risk of heart failure (HF) has also suggested that HDL therapy may be applied to this condition. HDL infusions or apoA-I gene transfer were able to reverse heart abnormalities, reduce diastolic resistance and improve cardiac metabolism. HDL therapy may be effective not only in atherosclerosis, but also in other conditions, of relevant impact on human health.Key messagesHigh-density lipoproteins have as a major activity that of removing excess cholesterol from tissues (particularly arteries).Knowledge on the activity of high-density lipoproteins on health have however significantly widened.HDL-therapy may help to improve stent biocompatibility and to reduce peripheral arterial resistance in heart failure.