Human Apolipoprotein A-I Gene Transfer Reduces the Development of Experimental Diabetic Cardiomyopathy

Abnormal maternal apolipoprotein levels during pregnancy are risk factors for preterm birth in women with dichorionic twin pregnancies: A retrospective study

OBJECTIVE

In singleton-pregnant women, abnormal maternal apolipoprotein levels have been confirmed as a risk factor for preterm birth. However, there are currently no studies on the relationship of the related research in twin-pregnant women.

METHODS

This single-center retrospective study included 743 dichorionic twin-pregnant women who delivered between January 2019 and December 2020. Twins delivered before 37 weeks gestation were categorized as the preterm group, while those delivered at or after 37 weeks gestation were classified as the term group. Maternal serum apolipoprotein A1 (ApoA1) levels, apolipoprotein B (ApoB) levels, and the ApoB/ApoA1 ratio were measured in the first trimester(6-14 weeks), the second trimester(18-28 weeks) and the third trimester(after 28 weeks). We conducted SPSS analysis to evaluate the correlation between ApoA1 levels, ApoB levels, the ApoB/ApoA1 ratio and preterm birth.

RESULTS

Among the 743 included dichorionic twin-pregnant women, 53.57 % (398/743) delivered preterm. Compared with the term group, the ApoA1 levels in the third trimester were lower (p < 0.001), while the Apo B/ApoA1 ratio was higher in the second (p = 0.01) and third trimesters in the preterm group (p = 0.001). When preterm birth was categorized as iatrogenic and spontaneous preterm birth, the results were similar. In the analysis stratified by prepregnancy BMI, a higher risk of preterm birth was associated with low ApoA1 levels and a high Apo B/ApoA1 ratio in the second and third trimesters only among the subgroup of overweight/obese dichorionic twin-pregnant women.

CONCLUSIONS

Low ApoA1 levels and a high Apo B/ApoA1 ratio during the second and third trimesters were associated with a high incidence of preterm birth for overweight/obese dichorionic twin-pregnant women.

Associations Among Biomarkers of Inflammation, Tubular Injury and Lipid Metabolism With Gestational Diabetes Mellitus Status, Microalbuminuria and Retinopathy in the Microalbuminuria and Retinopathy in Gestational Diabetes Study

OBJECTIVES

Pregnancy may be complicated by gestational diabetes mellitus (GDM) and/or microvascular complications like albuminuria, retinopathy and pre-eclampsia. In this study we aimed to identify whether mechanistic pathways associated with microvascular complications are active in pregnant women with GDM or microvascular disease.

METHODS

Urinary albumin excretion and biomarkers of inflammation, lipoprotein metabolism and tubular injury were quantified in 355 pregnant women with and without GDM. Participants underwent fundus photography graded for retinopathy. Adjusted associations between individual biomarkers and each outcome variable of interest, including GDM status, albuminuria and retinopathy, were performed using logistic regression.

RESULTS

After adjusting for age, systolic blood pressure, body mass index and ethnicity, significant associations between GDM status and apolipoprotein A1, interleukin (IL)-6, IL-8, soluble tumour necrosis factor receptor-I and -II (sTNFR-I and -II), vascular endothelial growth factor and von Willebrand factor were observed. Increased high-sensitivity C-reactive protein (hsCRP) and sTNFR-II were associated with higher levels of albuminuria. hsCRP and previous GDM were associated with retinopathy.

CONCLUSION

Mechanistic pathways associated with microvascular complications appear to be active in pregnant women with GDM or microvascular disease.

Cardiac fibroblasts and mechanosensation in heart development, health and disease

The term 'mechanosensation' describes the capacity of cells to translate mechanical stimuli into the coordinated regulation of intracellular signals, cellular function, gene expression and epigenetic programming. This capacity is related not only to the sensitivity of the cells to tissue motion, but also to the decryption of tissue geometric arrangement and mechanical properties. The cardiac stroma, composed of fibroblasts, has been historically considered a mechanically passive component of the heart. However, the latest research suggests that the mechanical functions of these cells are an active and necessary component of the developmental biology programme of the heart that is involved in myocardial growth and homeostasis, and a crucial determinant of cardiac repair and disease. In this Review, we discuss the general concept of cell mechanosensation and force generation as potent regulators in heart development and pathology, and describe the integration of mechanical and biohumoral pathways predisposing the heart to fibrosis and failure. Next, we address the use of 3D culture systems to integrate tissue mechanics to mimic cardiac remodelling. Finally, we highlight the potential of mechanotherapeutic strategies, including pharmacological treatment and device-mediated left ventricular unloading, to reverse remodelling in the failing heart.

Dynamic Resistance Exercise Alters Blood ApoA-I Levels, Inflammatory Markers, and Metabolic Syndrome Markers in Elderly Women

Combined endurance and dynamic-resistance exercise has important anti-inflammatory effects, altering vascular endothelial function, and helping to prevent and treat aging-related metabolic syndrome (MS). We studied changes in 40 elderly women aged ≥ 65 years (control group (no MS), n = 20, mean age: 68.23 ± 2.56 years; MS group, n = 19, mean age: 71.42 ± 5.87 years; one left). The exercise program comprised dynamic-resistance training using elastic bands, three times weekly, for six months. We analyzed body composition, blood pressure, physical fitness, and MS-related blood variables including ApoA-I, antioxidant factors, and inflammatory markers. After the program, the MS group showed significant reductions in waist-hip ratio, waist circumference, diastolic blood pressure, blood insulin, and HOMA-IR, and a significant increase in HSP70 (p < 0.05). Both groups showed significant increases in ApoA-I levels, ApoA-I/HDL-C ratio, SOD2, IL-4, and IL-5 levels (p < 0.05). Active-resistance training-induced changes in ApoA-I were significantly positively correlated with changes in HDL-C and HSP70, and significantly negatively correlated with changes in triglycerides, C-reactive protein, and TNF-α (p < 0.05). Active-resistance training qualitatively altered HDL, mostly by altering ApoA-I levels, relieving vascular inflammation, and improving antioxidant function. This provides evidence that dynamic-resistance exercise can improve physical fitness and MS risk factors in elderly women.

Potential diabetic cardiomyopathy therapies targeting pyroptosis: A mini review

Pyroptosis is primarily considered a pro-inflammatory class of caspase-1- and gasdermin D (GSDMD)-dependent programmed cell death. Inflammasome activation promotes the maturation and release of interleukin (IL)-1β and IL-18, cleavage of GSDMD, and development of pyroptosis. Recent studies have reported that NLRP3 inflammasome activation-mediated pyroptosis aggravates the formation and development of diabetes cardiomyopathy (DCM). These studies provide theoretical mechanisms for exploring a novel approach to treat DCM-associated cardiac dysfunction. Accordingly, this review aims to summarize studies that investigated possible DCM therapies targeting pyroptosis and elucidate the molecular mechanisms underlying NLRP3 inflammasome-mediated pyroptosis, and its potential association with the pathogenesis of DCM. This review may serve as a basis for the development of potential pharmacological agents as novel and effective treatments for managing and treating DCM.

Anti-inflammatory effects of cannabidiol against lipopolysaccharides in cardiac sodium channels

BACKGROUND

Sepsis, caused by a dysregulated host response to infections, can lead to cardiac arrhythmias. However, the mechanisms underlying sepsis-induced inflammation, and how inflammation provokes cardiac arrhythmias, are not well understood. We hypothesized that CBD may ameliorate lipopolysaccharides (LPS)-induced cardiotoxicity via Toll-like receptor 4 (TLR-4) and cardiac sodium channels (Nav1.5).

METHODS AND RESULTS

We incubated human immune cells (THP-1 macrophages) with LPS for 24 hours, then extracted the THP-1 incubation media. ELISA assay showed that LPS (1 or 5 μg/ml), in a concentration-dependent manner, or MPLA (TLR-4 agonist, 5 μg/ml) stimulated the THP-1 cells to release inflammatory cytokines (TNF-α and IL-6). Prior incubation (4 hours) with cannabidiol (CBD: 5 μM) or C34 (TLR-4 antagonist: 5 μg/ml) inhibited LPS and MPLA-induced release of both IL-6 and TNF-α. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) were subsequently incubated for 24 hours in the media extracted from THP-1 cells incubated with LPS, MPLA alone, or in combination with CBD or C34. Voltage-clamp experiments showed a right shift in the voltage dependence of Nav1.5 activation, steady state fast inactivation (SSFI), increased persistent current and prolonged in silico action potential duration in hiSPC-CM incubated in the LPS or MPLA-THP-1 media. Co-incubation with CBD or C34 rescued the biophysical dysfunction caused by LPS and MPLA.

CONCLUSION

Our results suggest that CBD may protect against sepsis-induced inflammation and subsequent arrhythmias through (i) inhibition of the release of inflammatory cytokines, antioxidant and anti-apoptotic effects and/or (ii) direct effect on Nav1.5.

Prognostic significance of metabolomic biomarkers in patients with diabetes mellitus and coronary artery disease

Background

Diabetes mellitus (DM) and coronary artery disease (CAD) constitute inter-related clinical entities. Biomarker profiling emerges as a promising tool for the early diagnosis and risk stratification of either DM or CAD. However, studies assessing the predictive capacity of novel metabolomics biomarkers in coexistent CAD and DM are scarce.

Methods

This post-hoc analysis of the CorLipid trial (NCT04580173) included 316 patients with CAD and comorbid DM who underwent emergency or elective coronary angiography due to acute or chronic coronary syndrome. Cox regression analyses were performed to identify metabolomic predictors of the primary outcome, which was defined as the composite of major adverse cardiovascular or cerebrovascular events (MACCE: cardiovascular death, myocardial infarction, stroke, major bleeding), repeat unplanned revascularizations and cardiovascular hospitalizations. Linear regression analyses were also performed to detect significant predictors of CAD complexity, as assessed by the SYNTAX score.

Results

After a median 2-year follow up period (IQR = 0.7 years), the primary outcome occurred in 69 (21.8%) of patients. Acylcarnitine ratio C4/C18:2, apolipoprotein (apo) B, history of heart failure (HF), age > 65 years and presence of acute coronary syndrome were independent predictors of the primary outcome in diabetic patients with CAD (aHR = 1.89 [1.09, 3.29]; 1.02 [1.01, 1.04]; 1.28 [1.01, 1.41]; 1.04 [1.01, 1.05]; and 1.12 [1.05–1.21], respectively). Higher levels of ceramide ratio C24:1/C24:0, acylcarnitine ratio C4/C18:2, age > 65 and peripheral artery disease were independent predictors of higher CAD complexity (adjusted β = 7.36 [5.74, 20.47]; 3.02 [0.09 to 6.06]; 3.02 [0.09, 6.06], respectively), while higher levels of apoA1 were independent predictors of lower complexity (adjusted β= − 0.65 [− 1.31, − 0.02]).

Conclusions

In patients with comorbid DM and CAD, novel metabolomic biomarkers and metabolomics-based prediction models could be recruited to predict clinical outcomes and assess the complexity of CAD, thereby enabling the integration of personalized medicine into routine clinical practice. These associations should be interpreted taking into account the observational nature of this study, and thus, larger trials are needed to confirm its results and validate them in different and larger diabetic populations.

Late sodium current: incomplete inactivation triggers seizures, myotonias, arrhythmias, and pain syndromes

Acquired and inherited dysfunction in voltage-gated sodium channels underlies a wide range of diseases. "In addition to the defects in trafficking and expression, sodium channelopathies are also caused by dysfunction in one or several gating properties, for instance activation or inactivation. Disruption of the channel inactivation leads to the increased late sodium current, which is a common defect in seizure disorders, cardiac arrhythmias skeletal muscle myotonia and pain. An increase in late sodium current leads to repetitive action potential in neurons and skeletal muscles, and prolonged action potential duration in the heart. In this topical review, we compare the effects of late sodium current in brain, heart, skeletal muscle, and peripheral nerves. Abstract figure legend Shows cartoon illustration of general Nav channel transitions between (1) resting, (2) open, and (3) fast inactivated states. Disruption of the inactivation process exacerbates (4) late sodium currents. This article is protected by copyright. All rights reserved.

Role of Oxidative Stress in Diabetic Cardiomyopathy

Type 2 diabetes is a redox disease. Oxidative stress and chronic inflammation induce a switch of metabolic homeostatic set points, leading to glucose intolerance. Several diabetes-specific mechanisms contribute to prominent oxidative distress in the heart, resulting in the development of diabetic cardiomyopathy. Mitochondrial overproduction of reactive oxygen species in diabetic subjects is not only caused by intracellular hyperglycemia in the microvasculature but is also the result of increased fatty oxidation and lipotoxicity in cardiomyocytes. Mitochondrial overproduction of superoxide anion radicals induces, via inhibition of glyceraldehyde 3-phosphate dehydrogenase, an increased polyol pathway flux, increased formation of advanced glycation end-products (AGE) and activation of the receptor for AGE (RAGE), activation of protein kinase C isoforms, and an increased hexosamine pathway flux. These pathways not only directly contribute to diabetic cardiomyopathy but are themselves a source of additional reactive oxygen species. Reactive oxygen species and oxidative distress lead to cell dysfunction and cellular injury not only via protein oxidation, lipid peroxidation, DNA damage, and oxidative changes in microRNAs but also via activation of stress-sensitive pathways and redox regulation. Investigations in animal models of diabetic cardiomyopathy have consistently demonstrated that increased expression of the primary antioxidant enzymes attenuates myocardial pathology and improves cardiac function.

HDL Composition, Heart Failure, and Its Comorbidities

Although research on high-density lipoprotein (HDL) has historically focused on atherosclerotic coronary disease, there exists untapped potential of HDL biology for the treatment of heart failure. Anti-oxidant, anti-inflammatory, and endothelial protective properties of HDL could impact heart failure pathogenesis. HDL-associated proteins such as apolipoprotein A-I and M may have significant therapeutic effects on the myocardium, in part by modulating signal transduction pathways and sphingosine-1-phosphate biology. Furthermore, because heart failure is a complex syndrome characterized by multiple comorbidities, there are complex interactions between heart failure, its comorbidities, and lipoprotein homeostatic mechanisms. In this review, we will discuss the effects of heart failure and associated comorbidities on HDL, explore potential cardioprotective properties of HDL, and review novel HDL therapeutic targets in heart failure.

Colchicine prevents disease progression in viral myocarditis via modulating the NLRP3 inflammasome in the cardiosplenic axis

Aim

The acute phase of a coxsackievirus 3 (CVB3)‐induced myocarditis involves direct toxic cardiac effects and the systemic activation of the immune system, including the cardiosplenic axis. Consequently, the nucleotide‐binding oligomerization domain‐like receptor pyrin domain‐containing‐3 (NLRP3) inflammasome pathway is activated, which plays a role in disease pathogenesis and progression. The anti‐inflammatory drug colchicine exerts its effects, in part, via reducing NLRP3 activity, and has been shown to improve several cardiac diseases, including acute coronary syndrome and pericarditis. The aim of the present study was to evaluate the potential of colchicine to improve experimental CVB3‐induced myocarditis.

Methods and results

C57BL6/j mice were intraperitoneally injected with 1 × 10⁵ plaque forming units of CVB3. After 24 h, mice were treated with colchicine (5 μmol/kg body weight) or phosphate‐buffered saline (PBS) via oral gavage (p.o.). Seven days post infection, cardiac function was haemodynamically characterized via conductance catheter measurements. Blood, the left ventricle (LV) and spleen were harvested for subsequent analyses. In vitro experiments on LV‐derived fibroblasts (FB) and HL‐1 cells were performed to further evaluate the anti‐(fibro)inflammatory and anti‐apoptotic effects of colchicine via gene expression analysis, Sirius Red assay, and flow cytometry. CVB3 + colchicine mice displayed improved LV function compared with CVB3 + PBS mice, paralleled by a 4.7‐fold (P < 0.01) and 1.7‐fold (P < 0.001) reduction in LV CVB3 gene expression and cardiac troponin‐I levels in the serum, respectively. Evaluation of components of the NLRP3 inflammasome revealed an increased percentage of apoptosis‐associated speck‐like protein containing a CARD domain (ASC)‐expressing, caspase‐1‐expressing, and interleukin‐1β‐expressing cells in the myocardium and in the spleen of CVB3 + PBS vs. control mice, which was reduced in CVB3 + colchicine compared with CVB3 + PBS mice. This was accompanied by 1.4‐fold (P < 0.0001), 1.7‐fold (P < 0.0001), and 1.7‐fold (P < 0.0001) lower numbers of cardiac dendritic cells, natural killer cells, and macrophages, respectively, in CVB3 + colchicine compared with CVB3 + PBS mice. A 1.9‐fold (P < 0.05) and 4.6‐fold (P < 0.001) reduced cardiac gene expression of the fibrotic markers, Col1a1 and lysyl oxidase, respectively, was detected in CVB3 + colchicine mice compared with CVB3 + PBS animals, and reflected by a 2.2‐fold (P < 0.05) decreased Collagen I/III protein ratio. Colchicine further reduced Col3a1 mRNA and collagen protein expression in CVB3‐infected FB and lowered apoptosis and viral progeny release in CVB3‐infected HL‐1 cells. In both CVB3 FB and HL‐1 cells, colchicine down‐regulated the NLRP3 inflammasome‐related components ASC, caspase‐1, and IL‐1β.

Conclusions

Colchicine improves LV function in CVB3‐induced myocarditis, involving a decrease in cardiac and splenic NLRP3 inflammasome activity, without exacerbation of CVB3 load.

Role of Oxidative Stress in Heart Failure: Insights from Gene Transfer Studies

Under physiological circumstances, there is an exquisite balance between reactive oxygen species (ROS) production and ROS degradation, resulting in low steady-state ROS levels. ROS participate in normal cellular function and in cellular homeostasis. Oxidative stress is the state of a transient or a persistent increase of steady-state ROS levels leading to disturbed signaling pathways and oxidative modification of cellular constituents. It is a key pathophysiological player in pathological hypertrophy, pathological remodeling, and the development and progression of heart failure. The heart is the metabolically most active organ and is characterized by the highest content of mitochondria of any tissue. Mitochondria are the main source of ROS in the myocardium. The causal role of oxidative stress in heart failure is highlighted by gene transfer studies of three primary antioxidant enzymes, thioredoxin, and heme oxygenase-1, and is further supported by gene therapy studies directed at correcting oxidative stress linked to metabolic risk factors. Moreover, gene transfer studies have demonstrated that redox-sensitive microRNAs constitute potential therapeutic targets for the treatment of heart failure. In conclusion, gene therapy studies have provided strong corroborative evidence for a key role of oxidative stress in pathological remodeling and in the development of heart failure.

Pyroptosis in the Retinal Neurovascular Unit: New Insights Into Diabetic Retinopathy

Diabetic retinopathy (DR) is prevalent among people with long-term diabetes mellitus (DM) and remains the leading cause of visual impairment in working-aged people. DR is related to chronic low-level inflammatory reactions. Pyroptosis is an emerging type of inflammatory cell death mediated by gasdermin D (GSDMD), NOD-like receptors and inflammatory caspases that promote interleukin-1β (IL-1β) and IL-18 release. In addition, the retinal neurovascular unit (NVU) is the functional basis of the retina. Recent studies have shown that pyroptosis may participate in the destruction of retinal NVU cells in simulated hyperglycemic DR environments. In this review, we will clarify the importance of pyroptosis in the retinal NVU during the development of DR.

Melatonin attenuates aortic oxidative stress injury and apoptosis in STZ-diabetes rats by Notch1/Hes1 pathway

Oxidative stress injury is an important link in the pathogenesis of diabetes, and reducing oxidative stress damage caused by long-term hyperglycemia is an important diabetic treatment strategy. Melatonin has been proved to be a free radical scavenger with strong antioxidant activity, and its protective effect on diabetes and the complications has been confirmed. However, the role and potential mechanism of melatonin in oxidative stress injury of diabetic aorta have not been reported. Besides, Notch signaling pathway plays an important role in vascular growth, differentiation, and apoptosis. We speculated that melatonin could improve oxidative stress injury of diabetic aorta through Notch1/Hes1 signaling pathway. STZ-induced diabetic rats and vascular smooth muscle cells (VSMCs) cultured with high glucose were treated with or without melatonin, melatonin receptor antagonist Luzindole, γ-secretase inhibitor DAPT respectively. We found that melatonin could improve the oxidative stress injury of diabetic aorta and reduce the apoptosis of VSMCs. Interestingly, melatonin could activate Notch1 signaling pathway, play an antioxidant role, and reduce the expression of apoptosis-related proteins. However, these protective effects could be largely eliminated by Luzindole or DAPT. We concluded that the repression of Notch1 signaling pathway would inhibit the repair of oxidative stress injury in diabetes. Melatonin could ameliorate oxidative stress injury and apoptosis of diabetic aorta by activating Notch1/Hes1 signaling pathway.

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.

Interventricular Differences of Signaling Pathways-Mediated Regulation of Cardiomyocyte Function in Response to High Oxidative Stress in the Post-Ischemic Failing Rat Heart

Standard heart failure (HF) therapies have failed to improve cardiac function or survival in HF patients with right ventricular (RV) dysfunction suggesting a divergence in the molecular mechanisms of RV vs. left ventricular (LV) failure. Here we aimed to investigate interventricular differences in sarcomeric regulation and function in experimental myocardial infarction (MI)-induced HF with reduced LV ejection fraction (HFrEF). MI was induced by LAD ligation in Sprague-Dawley male rats. Sham-operated animals served as controls. Eight weeks after intervention, post-ischemic HFrEF and Sham animals were euthanized. Heart tissue samples were deep-frozen stored (n = 3-5 heart/group) for ELISA, kinase activity assays, passive stiffness and Ca²⁺-sensitivity measurements on isolated cardiomyocytes, phospho-specific Western blot, and PAGE of contractile proteins, as well as for collagen gene expressions. Markers of oxidative stress and inflammation showed interventricular differences in post-ischemic rats: TGF-β1, lipid peroxidation, and 3-nitrotyrosine levels were higher in the LV than RV, while hydrogen peroxide, VCAM-1, TNFα, and TGF-β1 were increased in both ventricles. In addition, nitric oxide (NO) level was significantly decreased, while FN-1 level was significantly increased only in the LV, but both were unchanged in RV. CaMKII activity showed an 81.6% increase in the LV, in contrast to a 38.6% decrease in the RV of HFrEF rats. Cardiomyocyte passive stiffness was higher in the HFrEF compared to the Sham group as evident from significantly steeper F_passive vs. sarcomere length relationships. In vitro treatment with CaMKIIδ, however, restored cardiomyocyte passive stiffness only in the HFrEF RV, but had no effect in the HFrEF LV. PKG activity was lower in both ventricles in the HFrEF compared to the Sham group. In vitro PKG administration decreased HFrEF cardiomyocyte passive stiffness; however, the effect was more pronounced in the HFrEF LV than HFrEF RV. In line with this, we observed distinct changes of titin site-specific phosphorylation in the RV vs. LV of post-ischemic rats, which may explain divergent cardiomyocyte stiffness modulation observed. Finally, Ca²⁺-sensitivity of RV cardiomyocytes was unchanged, while LV cardiomyocytes showed increased Ca²⁺-sensitivity in the HFrEF group. This could be explained by decreased Ser-282 phosphorylation of cMyBP-C by 44.5% in the RV, but without any alteration in the LV, while Ser-23/24 phosphorylation of cTnI was decreased in both ventricles in the HFrEF vs. the Sham group. Our data pointed to distinct signaling pathways-mediated phosphorylations of sarcomeric proteins for the RV and LV of the post-ischemic failing rat heart. These results implicate divergent responses for oxidative stress and open a new avenue in targeting the RV independently of the LV.

Impact of Syndecan-2-Selected Mesenchymal Stromal Cells on the Early Onset of Diabetic Cardiomyopathy in Diabetic db/db Mice

Background: Mesenchymal stromal cells (MSCs) are an attractive cell type for cell therapy given their immunomodulatory, anti-fibrotic, and endothelial-protective features. The heparin sulfate proteoglycan, syndecan-2/CD362, has been identified as a functional marker for MSC isolation, allowing one to obtain a homogeneous cell product that meets regulatory requirements for clinical use. We previously assessed the impact of wild-type (WT), CD362^-, and CD362⁺ MSCs on local changes in protein distribution in left ventricular (LV) tissue and on LV function in an experimental model of early-onset diabetic cardiomyopathy. The present study aimed to further explore their impact on mechanisms underlying diastolic dysfunction in this model. Materials: For this purpose, 1 × 10⁶ WT, CD362^-, or CD362⁺ MSCs were intravenously (i.v.) injected into 20-week-old diabetic BKS.Cg-m+/+Lepr^db/BomTac, i.e., db/db mice. Control animals (db+/db) were injected with the equivalent volume of phosphate-buffered saline (PBS) alone. After 4 weeks, mice were sacrificed for further analysis. Results: Treatment with all three MSC populations had no impact on blood glucose levels in db/db mice. WT, CD362^-, and CD362⁺ MSC application restored LV nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) levels in db/db mice, which correlated with a reduction in cardiomyocyte stiffness. Furthermore, all stromal cells were able to increase arteriole density in db/db mice. The effect of CD362⁺ MSCs on NO and cGMP levels, cardiomyocyte stiffness, and arteriole density was less pronounced than in mice treated with WT or CD362^- MSCs. Analysis of collagen I and III protein expression revealed that fibrosis had not yet developed at this stage of experimental diabetic cardiomyopathy. All MSCs reduced the number of cardiac CD3⁺ and CD68⁺ cells in db/db mice, whereas only splenocytes from CD362^-- and CD362⁺-db/db mice exhibited a lower pro-fibrotic potential compared to splenocytes from db/db mice. Conclusion: CD362⁺ MSC application decreased cardiomyocyte stiffness, increased myocardial NO and cGMP levels, and increased arteriole density, although to a lesser extent than WT and CD362^- MSCs in an experimental model of early-onset diabetic cardiomyopathy without cardiac fibrosis. These findings suggest that the degree in improvement of cardiomyocyte stiffness following CD362⁺ MSC application was insufficient to improve diastolic function.

CircRNAs in diabetic cardiomyopathy

Diabetic cardiomyopathy is an important irreversible chronic cardiovascular complication in diabetic patients. This condition is described as early diastolic dysfunction, myocardial fibrosis, cardiac hypertrophy, systolic dysfunction and other complex pathophysiological events, which ultimately lead to heart failure. Despite these characteristics, the underlying mechanisms resulting in diabetic cardiomyopathy are still unknown. With the developments in molecular biotechnology, increasing evidence shows that circRNAs play critical roles in the pathogenesis of diabetic cardiomyopathy. The purpose of this review is to summarize recent studies on the role of circRNAs in the pathophysiological process to provide novel prevention and treatment strategies for diabetic cardiomyopathy, oxidative stress, inflammation, endothelial dysfunction, myocardial fibrosis and cell death in diabetic cardiomyopathy.

High-Density Lipoprotein-Targeted Therapies for Heart Failure

The main and common constituents of high-density lipoproteins (HDLs) are apolipoprotein A-I, cholesterol, and phospholipids. Biochemical heterogeneity of HDL particles is based on the variable presence of one or more representatives of at least 180 proteins, 200 lipid species, and 20 micro RNAs. HDLs are circulating multimolecular platforms that perform divergent functions whereby the potential of HDL-targeted interventions for treatment of heart failure can be postulated based on its pleiotropic effects. Several murine studies have shown that HDLs exert effects on the myocardium, which are completely independent of any impact on coronary arteries. Overall, HDL-targeted therapies exert a direct positive lusitropic effect on the myocardium, inhibit the development of cardiac hypertrophy, suppress interstitial and perivascular myocardial fibrosis, increase capillary density in the myocardium, and prevent the occurrence of heart failure. In four distinct murine models, HDL-targeted interventions were shown to be a successful treatment for both pre-existing heart failure with reduced ejection fraction (HFrEF) and pre-existing heart failure with preserved ejection fraction (HFrEF). Until now, the effect of HDL-targeted interventions has not been evaluated in randomized clinical trials in heart failure patients. As HFpEF represents an important unmet therapeutic need, this is likely the preferred therapeutic domain for clinical translation.

MALDI-IMS as a Tool to Determine the Myocardial Response to Syndecan-2-Selected Mesenchymal Stromal Cell Application in an Experimental Model of Diabetic Cardiomyopathy

PURPOSE

Mesenchymal stromal cells (MSC) are an attractive tool for treatment of diabetic cardiomyopathy. Syndecan-2/CD362 has been identified as a functional marker for MSC isolation. Imaging mass spectrometry (IMS) allows for the characterization of therapeutic responses in the left ventricle. This study aims to investigate whether IMS can assess the therapeutic effect of CD362⁺ -selected MSC on early onset experimental diabetic cardiomyopathy.

EXPERIMENTAL DESIGN

1 × 10⁶ wild type (WT), CD362^- , or CD362⁺ MSC are intravenously injected into db/db mice. Four weeks later, mice are hemodynamically characterized and subsequently sacrificed for IMS combined with bottom-up mass spectrometry, and isoform and phosphorylation analyses of cardiac titin.

RESULTS

Overall alterations of the cardiac proteome signatures, especially titin, are observed in db/db compared to control mice. Interestingly, only CD362⁺ MSC can overcome the reduced titin intensity distribution and shifts the isoform ratio toward the more compliant N2BA form. In contrast, WT and CD362^- MSCs improve all-titin phosphorylation and protein kinase G activity, which is reflected in an improvement in diastolic performance.

CONCLUSIONS AND CLINICAL RELEVANCE

IMS enables the characterization of differences in titin intensity distribution following MSC application. However, further analysis of titin phosphorylation is needed to allow for the assessment of the therapeutic efficacy of MSC.

Cannabidiol protects against high glucose-induced oxidative stress and cytotoxicity in cardiac voltage-gated sodium channels

BACKGROUND AND PURPOSE

Cardiovascular complications are the major cause of mortality in diabetic patients. However, the molecular mechanisms underlying diabetes-associated arrhythmias are unclear. We hypothesized that high glucose could adversely affect Na_v 1.5, the major cardiac sodium channel isoform of the heart, at least partially via oxidative stress. We further hypothesized that cannabidiol (CBD), one of the main constituents of Cannabis sativa, through its effects on Na_v 1.5, could protect against high glucose-elicited oxidative stress and cytotoxicity.

EXPERIMENTAL APPROACH

To test these ideas, we used CHO cells transiently co-transfected with cDNA encoding human Na_v 1.5 α-subunit under control and high glucose conditions (50 or 100 mM for 24 hr). Several experimental and computational techniques were used, including voltage clamp of heterologous expression systems, cell viability assays, fluorescence assays and action potential modelling.

KEY RESULTS

High glucose evoked cell death associated with elevation in reactive oxygen species (ROS) right shifted the voltage dependence of conductance and steady-state fast inactivation, and increased persistent current leading to computational prolongation of action potential (hyperexcitability) which could result in long QT3 arrhythmia. CBD mitigated all the deleterious effects provoked by high glucose. Perfusion with lidocaine (a well-known sodium channel inhibitor with antioxidant effects) or co-incubation of Tempol (a well-known antioxidant) elicited protection, comparable to CBD, against the deleterious effects of high glucose.

CONCLUSION AND IMPLICATIONS

These findings suggest that, through its favourable antioxidant and sodium channel inhibitory effects, CBD may protect against high glucose-induced arrhythmia and cytotoxicity.

Speckle-tracking echocardiography combined with imaging mass spectrometry assesses region-dependent alterations

Left ventricular (LV) contraction is characterized by shortening and thickening of longitudinal and circumferential fibres. To date, it is poorly understood how LV deformation is altered in the pathogenesis of streptozotocin (STZ)-induced type 1 diabetes mellitus-associated diabetic cardiomyopathy and how this is associated with changes in cardiac structural composition. To gain further insights in these LV alterations, eight-week-old C57BL6/j mice were intraperitoneally injected with 50 mg/kg body weight STZ during 5 consecutive days. Six, 9, and 12 weeks (w) post injections, echocardiographic analysis was performed using a Vevo 3100 device coupled to a 30-MHz linear-frequency transducer. Speckle-tracking echocardiography (STE) demonstrated impaired global longitudinal peak strain (GLS) in STZ versus control mice at all time points. 9w STZ animals displayed an impaired global circumferential peak strain (GCS) versus 6w and 12w STZ mice. They further exhibited decreased myocardial deformation behaviour of the anterior and posterior base versus controls, which was paralleled with an elevated collagen I/III protein ratio. Additionally, hypothesis-free proteome analysis by imaging mass spectrometry (IMS) identified regional- and time-dependent changes of proteins affecting sarcomere mechanics between STZ and control mice. In conclusion, STZ-induced diabetic cardiomyopathy changes global cardiac deformation associated with alterations in cardiac sarcomere proteins.

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.

Lipoprotein modulation of proteinuric renal injury

High-density lipoprotein (HDL) and its main protein, apolipoprotein AI (apoAI), have established benefits in various cells, but whether these cytoprotective effects of HDL pertain to renal cells is unclear. We investigated the in vitro consequences of exposing damaged podocytes to normal apoAI, HDL, and apoAI mimetic (L-4F), and the in vivo effects of L-4F on kidney and atherosclerotic injury in a podocyte-specific injury model of proteinuria. In vitro, primary mouse podocytes were injured by puromycin aminonucleoside (PAN). Cellular viability, migration, production of reactive oxygen species (ROS), apoptosis, and the underlying signaling pathway were assessed. In vivo, we used a proteinuric model, Nphs1-hCD25 transgenic (NEP25⁺) mice, which express human CD25 on podocytes. Podocyte injury was induced by using immunotoxin (LMB2) and generated a proteinuric atherosclerosis model, NEP25⁺:apoE^-/- mice, was generated by mating apoE-deficient (apoE^-/-) mice with NEP25⁺ mice. Animals received L-4F or control vehicle. Renal function, podocyte injury, and atherosclerosis were assessed. PAN reduced podocyte viability, migration, and increased ROS production, all significantly lessened by apoAI, HDL, and L-4F. L-4F attenuated podocyte apoptosis and diminished PAN-induced inactivation of Janus family protein kinase-2/signal transducers and activators of transcription 3. In NEP25⁺ mice, L-4F significantly lessened overall proteinuria, and preserved podocyte expression of synaptopodin and cell density. Proteinuric NEP25⁺:apoE^-/- mice had more atherosclerosis than non-proteinuric apoE^-/- mice, and these lesions were significantly decreased by L-4F. Normal human apoAI, HDL, and apoAI mimetic protect against podocyte damage. ApoAI mimetic provides in vivo beneficial effects on podocytes that culminate in reduced albuminuria and atherosclerosis. The results suggest supplemental apoAI/apoAI mimetic may be a novel candidate to lessen podocyte damage and its complications.

Role of Pyroptosis in Cardiovascular Diseases and its Therapeutic Implications

Pyroptotic cell death or pyroptosis is characterized by caspase-1-dependent formation of plasma membrane pores, leading to the release of pro-inflammatory cytokines and cell lysis. Pyroptosis tightly controls the inflammatory responses and coordinates antimicrobial host defenses by releasing pro-inflammatory cellular contents, such as interleukin (IL)-1β and IL-18, and consequently expands or sustains inflammation. It is recognized as an important innate immune effector mechanism against intracellular pathogens. The induction of pyroptosis is closely associated with the activation of the NOD-like receptor 3 (NLRP3) inflammasome which has been linked to key cardiovascular risk factors including hyperlipidemia, diabetes, hypertension, obesity, and hyperhomocysteinemia. Emerging evidence has indicated pyroptosis as an important trigger and endogenous regulator of cardiovascular inflammation. Thus, pyroptosis may play an important role in the pathogenesis of cardiovascular diseases. Design of therapeutic strategies targeting the activation of NLRP3 inflammasome and pyroptosis holds promise for the treatment of cardiovascular diseases.

Tetrahydrocurcumin Ameliorates Diabetic Cardiomyopathy by Attenuating High Glucose-Induced Oxidative Stress and Fibrosis via Activating the SIRT1 Pathway

Hyperglycemia-induced oxidative stress and fibrosis play a crucial role in the development of diabetic cardiomyopathy (DCM). Tetrahydrocurcumin (THC), a major bioactive metabolite of natural antioxidant curcumin, is reported to exert even more effective antioxidative and superior antifibrotic properties as well as anti-inflammatory and antidiabetic abilities. This study was designed to investigate the potential protective effects of THC on experimental DCM and its underlying mechanisms, pointing to the role of high glucose-induced oxidative stress and interrelated fibrosis. In STZ-induced diabetic mice, oral administration of THC (120 mg/kg/d) for 12 weeks significantly improved the cardiac function and ameliorated myocardial fibrosis and cardiac hypertrophy, accompanied by reduced reactive oxygen species (ROS) generation. Mechanically, THC administration remarkably increased the expression of the SIRT1 signaling pathway both in vitro and in vivo, further evidenced by decreased downstream molecule Ac-SOD2 and enhanced deacetylated production SOD2, which finally strengthened antioxidative stress capacity proven by repaired activities of SOD and GSH-Px and reduced MDA production. Additionally, THC treatment accomplished its antifibrotic effect by depressing the ROS-induced TGFβ1/Smad3 signaling pathway followed by reduced expression of cardiac fibrotic markers α-SMA, collagen I, and collagen III. Collectively, these finds demonstrated the therapeutic potential of THC treatment to alleviate DCM mainly by attenuating hyperglycemia-induced oxidative stress and fibrosis via activating the SIRT1 pathway.

Relationship of High-Density Lipoprotein-Associated Arylesterase Activity to Systolic Heart Failure in Patients with and without Type 2 Diabetes

High-density lipoprotein (HDL) confers protection against cardiovascular disease partly attributable to its robust anti-oxidant activities, which is largely impaired in diabetic conditions. In this study, we analyzed the anti-oxidant activity of HDL, as represented by the arylesterase activity of paraoxonase 1 (PON1) in HDL particles, in 216 consecutive HF patients with (n = 79) or without (n = 137) type 2 diabetes, and age- and gender-matched 112 diabetic and 189 non-diabetic non-HF controls. We found arylesterase activity was significantly decreased in patients with than without HF, and was further decreased when comorbid with diabetes. After adjusting for conventional risk factors and apolipoprotein A-I levels, arylesterase activity remained correlated positively with left ventricular ejection fraction in diabetic (r = 0.325, P = 0.020) but not non-diabetic patients (r = 0.089, P = 0.415), and negatively with NT-proBNP and NYHA functional class in both subgroups. In regression analyses, a higher risk of HF was observed in diabetic than non-diabetic patients when having low arylesterase activities. In conclusion, our data demonstrate that impaired serum arylesterase activity in patients with HF is further reduced when comorbid with diabetes. The relationship of impaired arylesterase activity to HF is especially enhanced in diabetic patients.

Effective Treatment of Diabetic Cardiomyopathy and Heart Failure with Reconstituted HDL (Milano) in Mice

The risk of heart failure (HF) is prominently increased in patients with type 2 diabetes mellitus. The objectives of this study were to establish a murine model of diabetic cardiomyopathy induced by feeding a high-sugar/high-fat (HSHF) diet and to evaluate the effect of reconstituted HDL_Milano administration on established HF in this model. The HSHF diet was initiated at the age of 12 weeks and continued for 16 weeks. To investigate the effect of reconstituted HDL_Milano on HF, eight intraperitoneal administrations of MDCO-216 (100 mg/kg protein concentration) or of an identical volume of control buffer were executed with a 48-h interval starting at the age of 28 weeks. The HSHF diet-induced obesity, hyperinsulinemia, and type 2 diabetes mellitus. Diabetic cardiomyopathy was present in HSHF diet mice as evidenced by cardiac hypertrophy, increased interstitial and perivascular fibrosis, and decreased myocardial capillary density. Pressure-volume loop analysis indicated the presence of both systolic and diastolic dysfunction and of decreased cardiac output in HSHF diet mice. Treatment with MDCO-216 reversed pathological remodelling and cardiac dysfunction and normalized wet lung weight, indicating effective treatment of HF. No effect of control buffer injection was observed. In conclusion, reconstituted HDL_Milano reverses HF in type 2 diabetic mice.

Successful treatment of established heart failure in mice with recombinant HDL (Milano)

BACKGROUND AND PURPOSE

The pleiotropic properties of HDL may exert beneficial effects on the myocardium. The effect of recombinant HDLMilano on established heart failure was evaluated in C57BL/6 mice.

EXPERIMENTAL APPROACH

Mice were subjected to transverse aortic constriction (TAC) or sham operation at the age of 14 weeks. Eight weeks later, TAC and sham mice were each randomized into three different groups. Reference groups were killed at day 56 after the operation for baseline analysis. Five i.p. injections of recombinant HDLMilano (MDCO-216), 100 mg·kg-1 , or an equivalent volume of control buffer were administered with a 48 h interval starting at day 56. Endpoint analyses in the control buffer groups and in the MDCO-216 groups were executed at day 65.

KEY RESULTS

Lung weight in MDCO-216 TAC mice was 25.3% lower than in reference TAC mice and 27.9% lower than in control buffer TAC mice and was similar in MDCO-216 sham mice. MDCO-216 significantly decreased interstitial fibrosis and increased relative vascularity compared to reference TAC mice and control buffer TAC mice. The peak rate of isovolumetric relaxation in MDCO-216 TAC mice was 30.4 and 36.3% higher than in reference TAC mice and control buffer TAC mice respectively. Nitro-oxidative stress and myocardial apoptosis were significantly reduced in MDCO-216 TAC mice compared to control buffer TAC mice.

CONCLUSIONS AND IMPLICATIONS

MDCO-216 improves diastolic function, induces regression of interstitial fibrosis and normalizes lung weight in mice with established heart failure. Recombinant HDL may emerge as a treatment modality in heart failure.

Hepatocyte-Specific SR-BI Gene Transfer Corrects Cardiac Dysfunction in Scarb1 -Deficient Mice and Improves Pressure Overload-Induced Cardiomyopathy

Objective—

We investigated the hypothesis that HDL (high-density lipoprotein) dysfunction in Scarb1 −/− mice negatively affects cardiac function both in the absence and in the presence of pressure overload. Second, we evaluated whether normalization of HDL metabolism in Scarb1 −/− mice by hepatocyte-specific SR-BI (scavenger receptor class B, type I) expression after E1E3E4-deleted adenoviral AdSR-BI (E1E3E4-deleted adenoviral vector expressing SR-BI protein in hepatocytes) transfer abrogates the effects of total body SR-BI deficiency on cardiac structure and function.

Approach and Results—

Transverse aortic constriction (TAC) or sham operation was performed at the age of 14 weeks, 2 weeks after saline injection or after gene transfer with AdSR-BI or with the control vector Adnull. Mortality rate in Scarb1 −/− TAC mice was significantly increased compared with wild-type TAC mice during 8 weeks of follow-up (hazard ratio, 2.02; 95% CI, 1.14–3.61). Hepatocyte-specific SR-BI gene transfer performed 2 weeks before induction of pressure overload by TAC potently reduced mortality in Scarb1 −/− mice (hazard ratio, 0.329; 95% CI, 0.180–0.600). Hepatocyte-specific SR-BI expression abrogated increased cardiac hypertrophy and lung congestion and counteracted increased myocardial apoptosis and interstitial and perivascular fibrosis in Scarb1 −/− TAC mice. Scarb1 −/− sham mice were, notwithstanding the absence of detectable structural heart disease, characterized by systolic and diastolic dysfunction and hypotension, which were completely counteracted by AdSR-BI transfer. Furthermore, AdSR-BI transfer abrogated increased end-diastolic pressure and diastolic dysfunction in Scarb1 −/− TAC mice. Increased oxidative stress and reduced antioxidant defense systems in Scarb1 −/− mice were rescued by AdSR-BI transfer.

Conclusions—

The detrimental effects of SR-BI deficiency on cardiac structure and function are nullified by hepatocyte-specific SR-BI transfer, which restores HDL metabolism.

Exogenous Pancreatic Kallikrein Improves Diabetic Cardiomyopathy in Streptozotocin-Induced Diabetes

Aims: To evaluate the protective effects of exogenous pancreatic kallikrein (PKK) treatment on diabetic cardiomyopathy (DCM) and explore the underlying mechanisms. Methods and Results: Streptozotocin (STZ)-induced diabetic rats, a type 1 diabetic model, were treated with either PKK or saline for 12 weeks. Non-diabetic rats were used as controls. PKK administration attenuated the mitochondria swelling, Z line misalignments, myofibrosis and interstitial collagen accumulation in diabetic myocardial tissue. The oxidative stress imbalance including increased nitrotyrosine, decreased anti-oxidative components such as nuclear receptor nuclear factor like 2 (Nrf2), glutathione peroxidase 1(GPx-1), catalase (CAT) and superoxide dismutase (SOD), were recovered in the heart of PKK-treated diabetic rats. In diabetic rats, protein expression of TGF-β1 and accumulation of collagen I in the heart tissues was decreased after PKK administration. Markers for inflammation were decreased in diabetic rats by PKK treatment. Compared to diabetic rats, PKK reversed the degradation of IκB-α, an inhibitive element of heterotrimer nuclear factor kappa B (NF-κB). The endothelial nitric oxide synthase (eNOS) protein and myocardial nitrate/nitrite were impaired in the heart of diabetic rats, which, however, were restored after PKK treatment. The sarcoplasmic reticulum Ca²⁺-ATPase 2 (SERCA2) and phospholamban (PLN) were mishandled in diabetic rats, while were rectified in PKK-treated diabetic rats. The plasma NT-proBNP level was increased in diabetic rats while was reduced with PKK treatment. Conclusion: PKK protects against DCM via reducing fibrosis, inflammation, and oxidative stress, promoting nitric oxide production, as well as restoring the function of the calcium channel.

Andrographolide Ameliorates Diabetic Cardiomyopathy in Mice by Blockage of Oxidative Damage and NF-κB-Mediated Inflammation

Andrographolide (Andro), a major bioactive component obtained from Andrographis paniculata Nees, has exerted wide antioxidant as well as cytoprotective properties. However, whether Andro treatment could retard the progress of diabetic cardiomyopathy (DCM) remains unknown. In this study, we evaluated the effects of Andro against diabetes-induced myocardial dysfunction and explored the underlying mechanism in STZ-induced diabetic mice. As a result, treatment with Andro dose dependently suppressed cardiac inflammation and oxidative stress, accompanied by decreasing cardiac apoptosis, which subsequently ameliorated cardiac fibrosis and cardiac hypertrophy. Further, Andro blocked hyperglycemia-triggered reactive oxygen species (ROS) generation by suppressing NADPH oxidase (NOX) activation and augmenting nuclear factor erythroid 2-related factor 2 (Nrf2) expression both in vitro and in vivo. Our results suggest that the cardioprotective effects afforded by Andro treatment involve the modulation of NOX/Nrf2-mediated oxidative stress and NF-κB-mediated inflammation. The present study unravels the therapeutic potential of Andro in the treatment of DCM by attenuating oxidative stress, inflammation, and apoptosis.

Innate and adaptive immunity in atherosclerosis

Atherosclerosis is a chronic inflammatory disorder of the large and medium-size arteries characterized by the subendothelial accumulation of cholesterol, immune cells, and extracellular matrix. At the early onset of atherogenesis, endothelial dysfunction takes place. Atherogenesis is further triggered by the accumulation of cholesterol-carrying low-density lipoproteins, which acquire properties of damage-associated molecular patterns and thereby trigger an inflammatory response. Following activation of the innate immune response, mainly governed by monocytes and macrophages, the adaptive immune response is started which further promotes atherosclerotic plaque formation. In this review, an overview is given describing the role of damage-associated molecular patterns, NLRP3 inflammasome activation, and innate and adaptive immune cells in the atherogenesis process.

Dietary butylated hydroxytoluene improves lipid metabolism, antioxidant and anti-apoptotic response of largemouth bass (Micropterus salmoides)

A 10-week growth trail was conducted to investigate the efficacy and tolerance of dietary butylated hydroxytoluene (BHT) by evaluating inflammation, apoptosis and hepatic disease related to oxidative stress in largemouth bass (Micropterus salmoides). Four experimental diets were prepared with BHT supplement levels of 0 (B0), 150 (B150), 300 (B300) and 1500 (B1500) mg/kg, in which B150 was at the maximum recommended level established by European Union Regulation, and the B300 and B1500 levels were 2 and 10-fold of B150, respectively. Each diet was fed to 6 replicates with 30 largemouth bass (initial body weight, IBW = 6.20 ± 0.01 g) in each tank. The BHT inclusion level did not affect the specific growth rate, but fish in the B150 group showed the lowest feed conversion rate (P < 0.05). BHT inclusion significantly decreased the levels of plasma TC, TG, LDL, ALT and AKP, and increased the (HDL-C)/TC ratio (P < 0.05). Plasma MDA was significantly decreased in the B150 group and GSH-Px was extremely enhanced in each BHT inclusion group (P < 0.05). Hepatic T-AOC was significantly enhanced and O₂^- was significantly decreased in each BHT inclusion group compared to the B0 group (P < 0.05), as well as hepatic MDA was significantly decreased in B1500 group (P < 0.05). Dietary BHT inclusion down-regulated the hepatic mRNA levels of inflammation, apoptosis and fibrosis related genes, including TNFα, TGF-β1, α-SMA, IL8, IL11β and caspase-9. Moreover, BHT could improve hepatic lipid metabolism via up-regulating the mRNA levels of APOA1, CYP7A1, CYP8B1, and down-regulating the mRNA levels of PPAR-γ and APOB. Histological examination of the liver morphology with H&E and Sirius Red staining showed that BHT inclusion decreased necrotic degenerative changes and collagen deposition in largemouth bass. An immunofluorescence examination revealed significantly decreased cleaved caspase-3 signals in the BHT groups. In conclusion, the results demonstrated that ROS induces hepatic cell apoptosis and fibrosis via the intrinsic pathway of apoptosis by activating caspase-9 in the mitochondria and then initiates apoptosis by activating caspase-3. Consuming 2.32-23.80 mg/kg·bw/d (150-1500 mg/kg in diet) of BHT effectively improved the plasma and hepatic lipid metabolism, antioxidant response as well as reduced ROS production, protecting hepatic cells from injury. It is implied that even a 10-fold increase of the maximum level of BHT (150 mg/kg) is safe for the largemouth bass.

Abnormal cannabidiol confers cardioprotection in diabetic rats independent of glycemic control

Chronic GPR18 activation by its agonist abnormal cannabidiol (trans-4-[3-methyl-6-(1-methylethenyl)-2-cyclohexen-1-yl]-5-pentyl-1,3-benzenediol; abn-cbd) improves myocardial redox status and function in healthy rats. Here, we investigated the ability of abn-cbd to alleviate diabetes-evoked cardiovascular pathology and the contribution of GPR18 to this effect. Four weeks after diabetes induction by streptozotocin (STZ, 55mg/kg; i.p), male Wistar rats received abn-cbd, the GPR18 antagonist (1,3-dimethoxy-5-methyl-2-[(1R,6R)-3-methyl-6-(1-methylethenyl)-2-,cyclohexen-1-yl]benzene;O-1918), their combination (100µg/kg/day, i.p, each) or their vehicle for 2 weeks. Abn-cbd had no effect on diabetes-evoked cardiac hypertrophy or impaired glycemic control (hyperglycemia and hypoinsulinemia), but alleviated the associated reductions in left ventricular (LV) contractility (dP/dt_max) and relaxation (dP/dt_min) indices, and the increases in LV end diastolic pressure (LVEDP) and cardiac vagal dominance. Abn-cbd also reversed myocardial oxidative stress by restoring circulating and cardiac nitric oxide (NO) and adiponectin (ADN) levels and enhancing GPR18 expression and phosphorylation of Akt, ERK1/2 and eNOS in diabetic rats' hearts. Concurrent GPR18 blockade (O-1918) abrogated all favorable effects of abn-cbd in diabetic rats. Collectively, the current findings present evidence for abn-cbd alleviation of diabetes-evoked cardiovascular anomalies likely via GPR18 dependent restoration of cardiac adiponectin-Akt-eNOS signaling and the diminution of myocardial oxidative stress.

Heart Failure with Preserved Ejection Fraction and Future Pharmacological Strategies: a Glance in the Crystal Ball

PURPOSE OF REVIEW

The current definition of heart failure is mainly based on an inappropriate measure of cardiac function, i.e., left ventricular ejection fraction (LVEF). The initial sole entity, heart failure with reduced ejection fraction (HFrEF, LVEF <40%), was complemented by the addition of heart failure with preserved ejection fraction (HFpEF, LVEF ≥50%) and most recently, heart failure with mid-range ejection fraction (HFmrEF, LVEF 40-49%). Initially, HFpEF was believed to be a purely left ventricular diastolic dysfunction. Pathophysiological concepts of HFpEF have changed considerably during the last years. In addition to intrinsic cardiac mechanisms, the heart failure pathogenesis is increasingly considered as driven by non-cardiac systemic processes including metabolic disorders, ischemic conditions, and pro-inflammatory/pro-fibrotic or immunological alterations. Presentation and pathophysiology of HFpEF is heterogeneous, and its management remains a challenge since evidence of therapeutic benefits is scarce. Up to now, there are no therapies improving survival in patients with HFpEF.

RECENT FINDINGS

Several results from clinical and preclinical interventions targeting non-cardiac mechanisms or non-pharmacological interventions including new anti-diabetic or anti-inflammatory drugs, mitochondrial-targeted anti-oxidants, anti-fibrotic strategies, microRNases incl. antagomirs, cell therapeutic options, and high-density lipoprotein-raising strategies are promising and under further investigation. This review addresses mechanisms and available data of current best clinical practice and novel approaches towards HFpEF.

The role and function of HDL in patients with diabetes mellitus and the related cardiovascular risk

BACKGROUND

Diabetes mellitus (DM) is a major public health problem which prevalence is constantly raising, particularly in low- and middle-income countries. Both diabetes mellitus types (DMT1 and DMT2) are associated with high risk of developing chronic complications, such as retinopathy, nephropathy, neuropathy, endothelial dysfunction, and atherosclerosis.

METHODS

This is a review of available articles concerning HDL subfractions profile in diabetes mellitus and the related cardiovascular risk. In this review, HDL dysfunction in diabetes, the impact of HDL alterations on the risk diabetes development as well as the association between disturbed HDL particle in DM and cardiovascular risk is discussed.

RESULTS

Changes in the amount of circulation lipids, including triglycerides and LDL cholesterol as well as the HDL are frequent also in the course of DMT1 and DMT2. In normal state HDL exerts various antiatherogenic properties, including reverse cholesterol transport, antioxidative and anti-inflammatory capacities. However, it has been suggested that in pathological state HDL becomes "dysfunctional" which means that relative composition of lipids and proteins in HDL, as well as enzymatic activities associated to HDL, such as paraoxonase 1 (PON1) and lipoprotein-associated phospholipase 11 (Lp-PLA2) are altered. HDL properties are compromised in patients with diabetes mellitus (DM), due to oxidative modification and glycation of the HDL protein as well as the transformation of the HDL proteome into a proinflammatory protein. Numerous studies confirm that the ability of HDL to suppress inflammatory signals is significantly reduced in this group of patients. However, the exact underlying mechanisms remains to be unravelled in vivo.

CONCLUSIONS

The understanding of pathological mechanisms underlying HDL dysfunction may enable the development of therapies targeted at specific subpopulations and focusing at the diminishing of cardiovascular risk.

Placenta-Derived Adherent Stromal Cells Improve Diabetes Mellitus-Associated Left Ventricular Diastolic Performance

Left ventricular (LV) diastolic dysfunction is among others attributed to cardiomyocyte stiffness. Mesenchymal stromal cells (MSC) have cardiac-protective properties. We explored whether intravenous (i.v.) application of PLacenta-eXpanded (PLX) MSC-like cells (PLX) improves LV diastolic relaxation in streptozotocin (STZ)-induced diabetic mice and investigated underlying mechanisms. Diabetes mellitus was induced by STZ application (50 mg/kg body weight) during five subsequent days. One week after the first STZ injection, PLX or saline were i.v. applied. Two weeks later, mice were hemodynamically characterized and sacrificed. At this early stage of diabetic cardiomyopathy with low-grade inflammation and no cardiac fibrosis, PLX reduced LV vascular cell adhesion molecule-1, transforming growth factor-β1, and interferon-γ mRNA expression, induced the percentage of circulating regulatory T cells, and decreased the splenic pro-fibrotic potential in STZ mice. STZ + PLX mice exhibited higher LV vascular endothelial growth factor mRNA expression and arteriole density versus STZ mice. In vitro, hyperglycemic PLX conditioned medium restored the hyperglycemia-impaired tube formation and adhesion capacity of human umbelical vein endothelial cells (HUVEC) via increasing nitric oxide (NO) bioavailability. PLX further induced the diabetes-downregulated activity of the NO downstream protein kinase G, as well as of protein kinase A, in STZ mice, which was associated with a raise in phosphorylation of the titin isoforms N2BA and N2B. Concomitantly, the passive force was lower in single isolated cardiomyocytes from STZ + PLX versus from STZ mice, which led to an improvement of LV diastolic relaxation. We conclude that i.v. PLX injection improves diabetes mellitus-associated diastolic performance via decreasing cardiomyocyte stiffness. Stem Cells Translational Medicine 2017;6:2135-2145.

Selective HDL-Raising Human Apo A-I Gene Therapy Counteracts Cardiac Hypertrophy, Reduces Myocardial Fibrosis, and Improves Cardiac Function in Mice with Chronic Pressure Overload

Epidemiological studies support an independent inverse association between high-density lipoprotein (HDL) cholesterol levels and heart failure incidence. The effect of selective HDL-raising adeno-associated viral serotype 8-human apolipoprotein (apo) A-I (AAV8-A-I) gene transfer on cardiac remodeling induced by transverse aortic constriction (TAC) was evaluated in C57BL/6 low-density lipoprotein receptor-deficient mice. Septal wall thickness and cardiomyocyte cross-sectional area were reduced by 16.5% (p < 0.001) and by 13.8% (p < 0.01), respectively, eight weeks after TAC in AAV8-A-I mice (n = 24) compared to control mice (n = 39). Myocardial capillary density was 1.11-fold (p < 0.05) higher and interstitial cardiac fibrosis was 45.3% (p < 0.001) lower in AAV8-A-I TAC mice than in control TAC mice. Lung weight and atrial weight were significantly increased in control TAC mice compared to control sham mice, but were not increased in AAV8-A-I TAC mice. The peak rate of isovolumetric contraction was 1.19-fold (p < 0.01) higher in AAV8-A-I TAC mice (n = 17) than in control TAC mice (n = 29). Diastolic function was also significantly enhanced in AAV8-A-I TAC mice compared to control TAC mice. Nitro-oxidative stress and apoptosis were significantly reduced in the myocardium of AAV8-A-I TAC mice compared to control TAC mice. In conclusion, selective HDL-raising human apo A-I gene transfer potently counteracts the development of pressure overload-induced cardiomyopathy.

Acute effects of reducing sitting time in adolescents: a randomized cross-over study

BACKGROUND

Levels of sitting among adolescents are high, especially during the school day. The acute cognitive and health consequences associated with prolonged sitting are poorly understood in adolescents. This randomized crossover design study examined the acute effects of a simulated school day with reduced sitting or usual sitting on adolescents' cognitive function and cardiometabolic biomarkers.

METHODS

Eighteen healthy school aged adolescents were recruited from the community to the study (11 males; 7 females; mean age [SD] = 13.5 ± 0.9 years). Two protocols were developed to simulate an adolescent school day, the amount of time spent sitting was manipulated reflecting: a 'typical' day (65% of the time spent sitting with two sitting bouts sitting >20 min) and a 'reduced sitting' day (adolescents sat for 50% less time with no bouts of sitting >20 mins). The order that participants were exposed to each condition was randomized (via random number generator). Participants were not fully blinded as they could observe the difference between conditions. Energy intake and moderate to vigorous physical activity (MVPA) were standardized for both conditions and monitored for 48 h post-condition for compensatory effects. Cognitive (working memory) and cardiometabolic outcomes (lipids, glucose, insulin, IL-6, apo-A1, apo-B, blood pressure,) were assessed pre and post for both conditions, BMI and body fat were assessed on the morning of the intervention. Data were analyzed using linear mixed models. Standardised effect sizes were calculated.

RESULTS

Compared with the typical school day, the reduced sitting day demonstrated significant positive effects for apoB/apoA-1 ratio (adjusted difference ± SD) -0.02 ± 0.03; P = 0.03; effect size [Cohen's d] = -0.67. Findings for total cholesterol -0.19 ± 0.27; P = 0.28; d = -0.71; HDL cholesterol -0.23 ± 0.50; P = 0.12 d = -0.66; and total cholesterol/HDL ratio 0.25 ± 0.53; P = 0.25; d = 0.51 and for cognition 0.64 ± 0.15; P = 0.15; d = 0.54 were non-significant. There were no compensatory changes in participant energy expenditure or energy intake for 48 h post intervention.

CONCLUSION

Reducing school day sitting time in adolescents' resulted in significant improvements in apoB/apoA-1 ratio with medium effect sizes for total cholesterol, HDL cholesterol and total cholesterol/HDL ratio. Cognitive function results showed the equivalent of a 6 month improvement in effective mental-attentional capacity.

TRIAL REGISTRATION

The trial was registered as a clinical trial with the Australian and New Zealand Clinical Trials Registry ( ACTRN12614001064695 ) on the 3rd of October 2014 - registered retrospectively.

CX3CR1 knockout aggravates Coxsackievirus B3-induced myocarditis

Studies on inflammatory disorders elucidated the pivotal role of the CX3CL1/CX3CR1 axis with respect to the pathophysiology and diseases progression. Coxsackievirus B3 (CVB3)-induced myocarditis is associated with severe cardiac inflammation, which may progress to heart failure. We therefore investigated the influence of CX3CR1 ablation in the model of acute myocarditis, which was induced by inoculation with 5x105 plaque forming units of CVB3 (Nancy strain) in either CX3CR1-/- or C57BL6/j (WT) mice. Seven days after infection, myocardial inflammation, remodeling, and titin expression and phosphorylation were examined by immunohistochemistry, real-time PCR and Pro-Q diamond stain. Cardiac function was assessed by tip catheter. Compared to WT CVB3 mice, CX3CR1-/- CVB3 mice exhibited enhanced left ventricular expression of inflammatory cytokines and chemokines, which was associated with an increase of immune cell infiltration/presence. This shift towards a pro-inflammatory immune response further resulted in increased cardiac fibrosis and cardiomyocyte apoptosis, which was reflected by an impaired cardiac function in CX3CR1-/- CVB3 compared to WT CVB3 mice. These findings demonstrate a cardioprotective role of CX3CR1 in CVB3-infected mice and indicate the relevance of the CX3CL1/CX3CR1 system in CVB3-induced myocarditis.

Inflammation - Cause or Consequence of Heart Failure or Both?

PURPOSE OF REVIEW

With the intention to summarize the currently available evidence on the pathophysiological relevance of inflammation in heart failure, this review addresses the question whether inflammation is a cause or consequence of heart failure, or both.

RECENT FINDINGS

This review discusses the diversity (sterile, para-inflammation, chronic inflammation) and sources of inflammation and gives an overview of how inflammation (local versus systemic) can trigger heart failure. On the other hand, the review is outlined how heart failure-associated wall stress and signals released by stressed, malfunctioning, or dead cells (DAMPs: e.g., mitochondrial DNA, ATP, S100A8, matricellular proteins) induce cardiac sterile inflammation and how heart failure provokes inflammation in various peripheral tissues in a direct (inflammatory) and indirect (hemodynamic) manner. The crosstalk between the heart and peripheral organs (bone marrow, spleen, gut, adipose tissue) is outlined and the importance of neurohormonal mechanisms including the renin angiotensin aldosteron system and the ß-adrenergic nervous system in inflammation and heart failure is discussed. Inflammation and heart failure are strongly interconnected and mutually reinforce each other. This indicates the difficulty to counteract inflammation and heart failure once this chronic vicious circle has started and points out the need to control the inflammatory process at an early stage avoiding chronic inflammation and heart failure. The diversity of inflammation further addresses the need for a tailored characterization of inflammation enabling differentiation of inflammation and subsequent target-specific strategies. It is expected that the characterization of the systemic and/or cardiac immune profile will be part of precision medicine in the future of cardiology.

Mapping Atheroprotective Functions and Related Proteins/Lipoproteins in Size Fractionated Human Plasma

HDL has been shown to possess a variety of cardio-protective functions, including removal of excess cholesterol from the periphery, and inhibition of lipoprotein oxidation. It has been proposed that various HDL subparticles exist, each with distinct protein and lipid compositions, which may be responsible for HDL's many functions. We hypothesized that HDL functions will co-migrate with the operational lipoprotein subspecies when separated by gel filtration chromatography. Plasma from 10 healthy male donors was fractionated and the protein composition of the phospholipid containing fractions was analyzed by mass spectrometry (MS). Each fraction was evaluated for its proteomic content as well as its ability to promote cholesterol efflux and protect low density lipoprotein (LDL) from free radical oxidation. For each function, several peaks of activity were identified across the plasma size gradient. Neither cholesterol efflux or LDL antioxidation activity correlated strongly with any single protein across the fractions. However, we identified multiple proteins that had strong correlations (r values >0.7, p < 0.01) with individual peaks of activity. These proteins fell into diverse functional categories, including those traditionally associated with lipid metabolism, as well as alternative complement cascade, innate immunity and clotting cascades and immunoglobulins. Additionally, the phospholipid and cholesterol concentration of the fractions correlated strongly with cholesterol efflux (r = 0.95 and 0.82 respectively), whereas the total protein content of the fractions correlated best with antioxidant activity across all fractions (r = 0.746). Furthermore, two previously postulated subspecies (apoA-I, apoA-II and apoC-1; as well as apoA-I, apoC-I and apoJ) were found to have strong correlations with both cholesterol efflux and antioxidation activity. Up till now, very little has been known about how lipoprotein composition mediates functions like cholesterol efflux and antioxidation.

Coronary arterial BK channel dysfunction exacerbates ischemia/reperfusion-induced myocardial injury in diabetic mice

The large conductance Ca(2+)-activated K(+) (BK) channels, abundantly expressed in coronary artery smooth muscle cells (SMCs), play a pivotal role in regulating coronary circulation. A large body of evidence indicates that coronary arterial BK channel function is diminished in both type 1 and type 2 diabetes. However, the consequence of coronary BK channel dysfunction in diabetes is not clear. We hypothesized that impaired coronary BK channel function exacerbates myocardial ischemia/reperfusion (I/R) injury in streptozotocin-induced diabetic mice. Combining patch-clamp techniques and cellular biological approaches, we found that diabetes facilitated the colocalization of angiotensin II (Ang II) type 1 receptors and BK channel α-subunits (BK-α), but not BK channel β1-subunits (BK-β1), in the caveolae of coronary SMCs. This caveolar compartmentation in vascular SMCs not only enhanced Ang II-mediated inhibition of BK-α but also produced a physical disassociation between BK-α and BK-β1, leading to increased infarct size in diabetic hearts. Most importantly, genetic ablation of caveolae integrity or pharmacological activation of coronary BK channels protected the cardiac function of diabetic mice from experimental I/R injury in both in vivo and ex vivo preparations. Our results demonstrate a vascular ionic mechanism underlying the poor outcome of myocardial injury in diabetes. Hence, activation of coronary BK channels may serve as a therapeutic target for cardiovascular complications of diabetes.

Apolipoprotein A-I gene transfer exerts immunomodulatory effects and reduces vascular inflammation and fibrosis in ob/ob mice

Background

Obesity is associated with vascular inflammation, fibrosis and reduced high-density lipoproteins (HDL)-cholesterol. We aimed to investigate whether adenoviral gene transfer with human apolipoprotein (apo) A-I (Ad.A-I), the main apo of HDL, could exert immunomodulatory effects and counteract vascular inflammation and fibrosis in ob/ob mice.

Methods

Ad.A-I transfer was performed in 8 weeks (w) old ob/ob mice, which were sacrificed 7 w later. The aorta was excised for mRNA analysis and the spleen for splenocyte isolation for subsequent flow cytometry and co-culture with murine fibroblasts. HDL was added to mononuclear cells (MNC) and fibroblasts to assess their impact on adhesion capacity and collagen deposition, respectively.

Results

Ad.A-I led to a 1.8-fold (p < 0.05) increase in HDL-cholesterol versus control ob/ob mice at the day of sacrifice, which was paralleled by a decrease in aortic TNF-α and VCAM-1 mRNA expression. Pre-culture of MNC with HDL decreased their adhesion to TNF-α-activated HAEC. Ad.A-I exerted immunomodulatory effects as evidenced by a downregulation of aortic NOD2 and NLRP3 mRNA expression and by a 12 %, 6.9 %, and 15 % decrease of the induced proliferation/activity of total splenic MNC, CD4+, and CD8+ cells in ob/ob Ad.A-I versus control ob/ob mice, respectively (p < 0.05). Ad.A-I further reduced aortic collagen I and III mRNA expression by 62 % and 66 %, respectively (p < 0.0005), and abrogated the potential of ob/ob splenocytes to induce the collagen content in murine fibroblasts upon co-culture. Finally, HDL decreased the TGF-ß1-induced collagen deposition of murine fibroblasts in vitro.

Conclusions

Apo A-I transfer counteracts vascular inflammation and fibrosis in ob/ob mice.

Electronic supplementary material

The online version of this article (doi:10.1186/s12950-016-0131-6) contains supplementary material, which is available to authorized users.

High-density lipoprotein cholesterol (HDL-C) in cardiovascular disease: effect of exercise training

Decreases in high-density lipoprotein cholesterol (HDL-C) levels are associated with an increased risk of coronary artery disease (CAD), whereas increased HDL-C levels are related to a decreased risk of CAD and myocardial infarction. Although HDL prevents the oxidation of low-density lipoprotein under normal conditions, it triggers a structural change, inhibiting antiarteriosclerotic and anti-inflammatory functions, under pathological conditions such as oxidative stress, inflammation, and diabetes. HDL can transform into various structures based on the quantitative reduction and deformation of apolipoprotein A1 and is the primary cause of increased levels of dysfunctional HDL, which can lead to an increased risk of CAD. Therefore, analyzing the structure and components of HDL rather than HDL-C after the application of an exercise training program may be useful for understanding the effects of HDL.

HDL mimetic peptide CER-522 treatment regresses left ventricular diastolic dysfunction in cholesterol-fed rabbits

OBJECTIVES

High-density lipoprotein (HDL) infusions induce rapid improvement of experimental atherosclerosis in rabbits but their effect on ventricular function remains unknown. We aimed to evaluate the effects of the HDL mimetic peptide CER-522 on left ventricular diastolic dysfunction (LVDD).

METHODS

Rabbits were fed with a cholesterol- and vitamin D2-enriched diet until mild aortic valve stenosis and hypercholesterolemia-induced LV hypertrophy and LVDD developed. Animals then received saline or 10 or 30mg/kg CER-522 infusions 6 times over 2weeks. We performed serial echocardiograms and LV histology to evaluate the effects of CER-522 therapy on LVDD.

RESULTS

LVDD was reduced by CER-522 as shown by multiple parameters including early filling mitral deceleration time, deceleration rate, Em/Am ratio, E/Em ratio, pulmonary venous velocities, and LVDD score. These findings were associated with reduced macrophages (RAM-11 positive cells) in the pericoronary area and LV, and decreased levels of apoptotic cardiomyocytes in CER-522-treated rabbits. CER-522 treatment also resulted in decreased atheromatous plaques and internal elastic lamina area in coronary arteries.

CONCLUSIONS

CER-522 improves LVDD in rabbits, with reductions of LV macrophage accumulation, cardiomyocyte apoptosis, coronary atherosclerosis and remodelling.

Decreased expression of the APOA1-APOC3-APOA4 gene cluster is associated with risk of Alzheimer's disease

Background

Apolipoprotein is genetically associated with the risk of Alzheimer’s disease (AD). The APOA1, APOC3, and APOA4 genes are closely linked and located on human chromosome 11. Therefore, this gene cluster may be related to the risk of AD.

Patients and methods

A total of 147 AD patients and 160 healthy controls were randomly recruited from June 2013 to August 2014. APOA1, APOC3, and APOA4 levels were measured using real-time quantitative reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay.

Results

APOA1, APOC3 and APOA4 levels were significantly lower in AD patients than controls (P<0.01). APOA1, APOC3, and APOA4 levels were negatively related with the severities of AD determined by Clinical Dementia Rating scores (P<0.01). APOA1, APOC3, and APOA4 levels showed a negative relation with Montgomery–Åsberg Depression Rating Scale scores and a positive relation with RAND 36-item health-survey scores (P<0.01). There was a decreased trend for levels of APOA1, APOC3, and APOA4 in AD patients.

Conclusion

Low levels of APOA1, APOC3, and APOA4 are associated with risk of AD. APOA1, APOC3, and APOA4 should be developed as combined drugs for the therapy of AD.

High-density lipoproteins reduce palmitate-induced cardiomyocyte apoptosis in an AMPK-dependent manner

Palmitate has been implicated in the induction of cardiomyocyte apoptosis via reducing the activity of 5' AMP-activated protein kinase (AMPK). We sought to evaluate whether high-density lipoproteins (HDLs), known for their cardioprotective features and their potential to increase AMPK activity, can reduce palmitate-induced cardiomyocyte apoptosis and whether this effect is AMPK-dependent. Therefore, cardiomyocytes were isolated from adult Wistar rat hearts via perfusion on a Langendorff-apparatus and cultured in free fatty acid-free BSA control medium or 0.5 mM palmitate medium in the presence or absence of HDL (5 μg protein/ml) with or without 0.1 μM of the AMPK-inhibitor compound S for the analysis of Annexin V/propidium, genes involved in apoptosis and fatty acid oxidation, and cardiomyocyte contractility. We found that HDLs decreased palmitate-induced cardiomyocyte apoptosis as indicated by a reduction in Annexin V-positive cardiomyocytes and an increase in Bcl-2 versus Bax ratio. Concomitantly, HDLs increased the palmitate-impaired expression of genes involved in fatty acid oxidation. Furthermore, HDLs improved the palmitate-impaired cardiomyocyte contractility. All effects were mediated in an AMPK-dependent manner, concluding that HDLs reduce palmitate-induced cardiomyocyte apoptosis, resulting in improved cardiomyocyte contractility through a mechanism involving AMPK.