Lipoprotein(a) induces caspase-1 activation and IL-1 signaling in human macrophages.

Introduction: Lipoprotein(a) (Lp(a)) is an LDL-like particle with an additional apolipoprotein (apo)(a) covalently attached. Elevated levels of circulating Lp(a) are a risk factor for atherosclerosis. A proinflammatory role for Lp(a) has been proposed, but its molecular details are incompletely defined. Methods and results: To explore the effect of Lp(a) on human macrophages we performed RNA sequencing on THP-1 macrophages treated with Lp(a) or recombinant apo(a), which showed that especially Lp(a) induces potent inflammatory responses. Thus, we stimulated THP-1 macrophages with serum containing various Lp(a) levels to investigate their correlations with cytokines highlighted by the RNAseq, showing significant correlations with caspase-1 activity and secretion of IL-1ß and IL-18. We further isolated both Lp(a) and LDL particles from three donors and then compared their atheroinflammatory potentials together with recombinant apo(a) in primary and THP-1 derived macrophages. Compared with LDL, Lp(a) induced a robust and dose-dependent caspase-1 activation and release of IL-1ß and IL-18 in both macrophage types. Recombinant apo(a) strongly induced caspase-1 activation and IL-1ß release in THP-1 macrophages but yielded weak responses in primary macrophages. Structural analysis of these particles revealed that the Lp(a) proteome was enriched in proteins associated with complement activation and coagulation, and its lipidome was relatively deficient in polyunsaturated fatty acids and had a high n-6/n-3 ratio promoting inflammation. Discussion: Our data show that Lp(a) particles induce the expression of inflammatory genes, and Lp(a) and to a lesser extent apo(a) induce caspase-1 activation and IL-1 signaling. Major differences in the molecular profiles between Lp(a) and LDL contribute to Lp(a) being more atheroinflammatory.

SARS-CoV-2 reinfection: Adding insult to dysfunctional endothelium in patients with atherosclerotic cardiovascular disease.

In this short narrative review, we aim at defining the pathophysiological role endothelial dysfunction in the observed COVID-19-associated rise in risk of cardiovascular disease. Variants of the SARS-CoV-2 virus have caused several epidemic waves of COVID-19, and the emergence and rapid spread of new variants and subvariants are likely. Based on a large cohort study, the incidence rate of SARS-CoV-2 reinfection is about 0.66 per 10 000 person-weeks. Both the first infection and reinfection with SARS-CoV-2 increase cardiac event risk, particularly in vulnerable patients with cardiovascular risk factors and the accompanying systemic endothelial dysfunction. By worsening pre-existing endothelial dysfunction, both the first infection and reinfection with ensuing COVID-19 may turn the endothelium procoagulative and prothrombotic, and ultimately lead to local thrombus formation. When occurring in an epicardial coronary artery, the risk of an acute coronary syndrome increases, and when occurring in intramyocardial microvessels, scattered myocardial injuries will ensue, both predisposing the COVID-19 patients to adverse cardiovascular outcomes. In conclusion, considering weakened protection against the cardiovascular risk-enhancing reinfections with emerging new subvariants of SARS-CoV-2, treatment of COVID-19 patients with statins during the illness and thereafter is recommended, partly because the statins tend to reduce endothelial dysfunction.

Obesity-induced changes in cancer cells and their microenvironment: Mechanisms and therapeutic perspectives to manage dysregulated lipid metabolism.

Obesity has been closely related to cancer progression, recurrence, metastasis, and treatment resistance. We aim to review recent progress in the knowledge on the obese macroenvironment and the generated adipose tumor microenvironment (TME) inducing lipid metabolic dysregulation and their influence on carcinogenic processes. Visceral white adipose tissue expansion during obesity exerts systemic or macroenvironmental effects on tumor initiation, growth, and invasion by promoting inflammation, hyperinsulinemia, growth-factor release, and dyslipidemia. The dynamic relationship between cancer and stromal cells of the obese adipose TME is critical for cancer cell survival and proliferation as well. Experimental evidence shows that secreted paracrine signals from cancer cells can induce lipolysis in cancer-associated adipocytes, causing them to release free fatty acids and acquire a fibroblast-like phenotype. Such adipocyte delipidation and phenotypic change is accompanied by an increased secretion of cytokines by cancer-associated adipocytes and tumor-associated macrophages in the TME. Mechanistically, the availability of adipose TME free fatty acids and tumorigenic cytokines concomitant with the activation of angiogenic processes creates an environment that favors a shift in the cancer cells toward an aggressive phenotype associated with increased invasiveness. We conclude that restoring the aberrant metabolic alterations in the host macroenvironment and in adipose TME of obese subjects would be a therapeutic option to prevent cancer development. Several dietary, lipid-based, and oral antidiabetic pharmacological therapies could potentially prevent tumorigenic processes associated with the dysregulated lipid metabolism closely linked to obesity.

Coronary microcirculatory dysfunction in hypercholesterolemic patients with COVID-19: potential benefit from cholesterol-lowering treatment.

Patients with hypercholesterolemia often have coronary microvascular dysfunction (CMD). Viral infections, such as the SARS-CoV-2 infection, may also result in CMD. Three non-randomized studies have shown significant beneficial effects of statins on CMD in non-infected patients. Similarly, in SARS-CoV-2 - infected patients one beneficial mechanism of action of statins may be the amelioration of endothelial dysfunction, which is a major driver of CMD. Apart from statins, lipoprotein apheresis and PCSK9 inhibitors can also improve or even reverse CMD. The potential reversal of CMD by using effective cholesterol-lowering medications during and after COVID-19 infection, especially in hypercholesterolemic COVID-19 patients, is important.KEY MESSAGESCoronary microvascular dysfunction (CMD) is common in patients hospitalized with SARS-CoV-2 infectionThree nonrandomized studies in non-infected patients are showing the beneficial effects of statin treatment on CMDEffective cholesterol-lowering medication during and after SARS-CoV-2 infection, especially in hypercholesterolemic COVID-19 patients, is of great significance.

Familial hypercholesterolemia: The nexus of endothelial dysfunction and lipoprotein metabolism in COVID-19.

PURPOSE OF REVIEW: Patients with heterozygous familial hypercholesterolemia (HeFH) are at increased risk for COVID-19 cardiovascular complications in the acute phase of the infection. Elevated levels of LDL-C and often lipoprotein(a) are present from birth and lead to endothelial dysfunction, which is aggravated by a direct viral attack of the endothelial cells and their exposure to the toxic levels of circulating proinflammatory and prothrombotic mediators during the hyperinflammatory reaction typical of COVID-19. RECENT FINDINGS: Evidence to date shows the benefit of lipid-lowering therapy in patients with COVID-19. In HeFH patients who are at much higher cardiovascular risk, the focus should, therefore, be on the effective lowering of LDL-C levels, the root cause of the greater cardiovascular vulnerability to COVID-19 infection in these patients. The ongoing use of statins and other lipid-lowering therapies should be encouraged during the ongoing COVID pandemic to mitigate the risk of cardiovascular complications from COVID-19, particularly in HeFH patients. SUMMARY: Epidemiologic registry data show that the incidence of myocardial infarction is increased in SARS-CoV-2-infected HeFH patients. There is a need to study whether the risk for acute cardiovascular events is increased in the long-term and if there are changes in lipid metabolism after SARS-CoV infection(s) in patients with HeFH.

Maleficent Comrades: War in Ukraine and COVID-19.

Infectious diseases and war are maleficent comrades. This reality applies equally well to the war in Ukraine and the current coronavirus disease 2019 (COVID-19) pandemic. Europe is facing a huge refugee crisis and potentially the conflict could worsen the COVID-19 pandemic. Initially, 2 major countries of concern are Poland, which has taken the majority of refugees, and Moldova, which has taken a very large number of refugees on a per capita basis. However, the concern extends to the rest of Europe because of the mobility of refugees beyond the first country they enter. Vaccinating, infection control, and boosting refugees should be a priority. However, complete prevention of COVID-19 is very complex because of other issues related to the success of prevention.

Lymphatic vessels are present in human saccular intracranial aneurysms.

Saccular intracranial aneurysm (sIA) rupture leads to subarachnoid haemorrhage and is preceded by chronic inflammation and atherosclerotic changes of the sIA wall. Increased lymphangiogenesis has been detected in atherosclerotic extracranial arteries and in abdominal aortic aneurysms, but the presence of lymphatic vessels in sIAs has remained unexplored. Here we studied the presence of lymphatic vessels in 36 intraoperatively resected sIAs (16 unruptured and 20 ruptured), using immunohistochemical and immunofluorescence stainings for lymphatic endothelial cell (LEC) markers. Of these LEC-markers, both extracellular and intracellular LYVE-1-, podoplanin-, VEGFR-3-, and Prox1-positive stainings were detected in 83%, 94%, 100%, and 72% of the 36 sIA walls, respectively. Lymphatic vessels were identified as ring-shaped structures positive for one or more of the LEC markers. Of the sIAs, 78% contained lymphatic vessels positive for at least one LEC marker. The presence of LECs and lymphatic vessels were associated with the number of CD68+ and CD163+ cells in the sIA walls, and with the expression of inflammation indicators such as serum amyloid A, myeloperoxidase, and cyclo-oxygenase 2, with the presence of a thrombus, and with the sIA wall rupture. Large areas of VEGFR-3 and α-smooth muscle actin (αSMA) double-positive cells were detected in medial parts of the sIA walls. Also, a few podoplanin and αSMA double-positive cells were discovered. In addition, LYVE-1 and CD68 double-positive cells were detected in the sIA walls and in the thrombus revealing that certain CD68+ macrophages are capable of expressing LEC markers. This study demonstrates for the first time the presence of lymphatic vessels in human sIA walls. Further studies are needed to understand the role of lymphatic vessels in the pathogenesis of sIA.

Tankyrase Inhibition Attenuates Cardiac Dilatation and Dysfunction in Ischemic Heart Failure.

Hyperactive poly(ADP-ribose) polymerases (PARP) promote ischemic heart failure (IHF) after myocardial infarction (MI). However, the role of tankyrases (TNKSs), members of the PARP family, in pathogenesis of IHF remains unknown. We investigated the expression and activation of TNKSs in myocardium of IHF patients and MI rats. We explored the cardioprotective effect of TNKS inhibition in an isoproterenol-induced zebrafish HF model. In IHF patients, we observed elevated TNKS2 and DICER and concomitant upregulation of miR-34a-5p and miR-21-5p in non-infarcted myocardium. In a rat MI model, we found augmented TNKS2 and DICER in the border and infarct areas at the early stage of post-MI. We also observed consistently increased TNKS1 in the border and infarct areas and destabilized AXIN in the infarct area from 4 weeks onward, which in turn triggered Wnt/ß-catenin signaling. In an isoproterenol-induced HF zebrafish model, inhibition of TNKS activity with XAV939, a TNKSs-specific inhibitor, protected against ventricular dilatation and cardiac dysfunction and abrogated overactivation of Wnt/ß-catenin signaling and dysregulation of miR-34a-5p induced by isoproterenol. Our study unravels a potential role of TNKSs in the pathogenesis of IHF by regulating Wnt/ß-catenin signaling and possibly modulating miRNAs and highlights the pharmacotherapeutic potential of TNKS inhibition for prevention of IHF.

Cholesterol-lowering drugs for high-risk hypercholesterolemia patients with COVID-19 while on Paxlovid™ therapy.

Paxlovid™ is a promising antiviral oral medication for patients at a high risk of a severe form of COVID-19. Regarding COVID-19 patients who have hypercholesterolemia and are at high or very high risk for an acute atherothrombotic cardiovascular event, we are highlighting patients with heterozygous familial hypercholesterolemia as an example of severe hypercholesterolemia. Unfortunately, the concomitant use of Paxlovid and a statin, which is highly dependent on cytochrome P4507A (CYP3A) for clearance, may result in significant drug interactions. Since an abrupt withdrawal of statin use may cause serious negative rebound effects on the cardiovascular system, it is essential to continue statin treatment also during the 5-day Paxlovid treatment period. During Paxlovid treatment, simvastatin and lovastatin need to be substituted with another statin, such as pravastatin or fluvastatin, while a reduction of the dose of atorvastatin and rosuvastatin is recommended.

Alterations of Cardiac Protein Kinases in Cyclic Nucleotide-Dependent Signaling Pathways in Human Ischemic Heart Failure.

Objectives: Impaired protein kinase signaling is a hallmark of ischemic heart disease (IHD). Inadequate understanding of the pathological mechanisms limits the development of therapeutic approaches. We aimed to identify the key cardiac kinases and signaling pathways in patients with IHD with an effort to discover potential therapeutic strategies. Methods: Cardiac kinase activity in IHD left ventricle (LV) and the related signaling pathways were investigated by kinomics, transcriptomics, proteomics, and integrated multi-omics approach. Results: Protein kinase A (PKA) and protein kinase G (PKG) ranked on top in the activity shift among the cardiac kinases. In the IHD LVs, PKA activity decreased markedly compared with that of controls (62% reduction, p = 0.0034), whereas PKG activity remained stable, although the amount of PKG protein increased remarkably (65%, p = 0.003). mRNA levels of adenylate cyclases (ADCY 1, 3, 5, 9) and cAMP-hydrolysing phosphodiesterases (PDE4A, PDE4D) decreased significantly, although no statistically significant alterations were observed in that of PKGs (PRKG1 and PRKG2) and guanylate cyclases (GUCYs). The gene expression of natriuretic peptide CNP decreased remarkably, whereas those of BNP, ANP, and neprilysin increased significantly in the IHD LVs. Proteomics analysis revealed a significant reduction in protein levels of "Energy metabolism" and "Muscle contraction" in the patients. Multi-omics integration highlighted intracellular signaling by second messengers as the top enriched Reactome pathway. Conclusion: The deficiency in cAMP/PKA signaling pathway is strongly implicated in the pathogenesis of IHD. Natriuretic peptide CNP could be a potential therapeutic target for the modulation of cGMP/PKG signaling.

Continuation of fibrate therapy in patients with metabolic syndrome and COVID-19: a beneficial regime worth pursuing.

Based on separate protective mechanisms related to lipid metabolism, viral cell entry and inflammation, fibrate treatment might be advantageous among patients who have been taking fibrates before SARS-CoV-2 infection and continue taking them during the infection. Based on published data on hospitalized COVID-19 patients, we recommend that the clinicians should ask their patients with metabolic syndrome who are already taking fibrates to continue fibrate treatment during the COVID-19 illness. This recommendation applies to both outpatients and hospitalized patients. However, results from the ongoing randomized controlled trials (RCTs) using fenofibrate treatment for the prevention or treatment of COVID-19 have yet to prove that fenofibrate is clinically significant for this indication.KEY MESSAGESThe role of fibrates as a repurpose to treat SARS-CoV-2 is under investigation in at least three ongoing RCTs.Obesity, diabetes, hypertension and dyslipidaemia, individually or clustered as a discrete phenotype, the metabolic syndrome, typically associate with a more severe course of COVID-19.Fibrate treatment seems to be most advantageous among patients who have been taken fibrates before SARS-CoV-2 infection and are continuing to take them during the infection.We recommend that the clinicians encourage their patients who are already taking fibrate to continue using the drug throughout the COVID-19 illness.

Glutamine synthetase in human carotid plaque macrophages associates with features of plaque vulnerability: An immunohistological study.

BACKGROUND AND AIMS: Glutamine synthetase (GLUL), the sole generator of glutamine, is a metabolic nexus molecule also involved in atherosclerosis. We recently demonstrated a 2.2-fold upregulation of GLUL mRNA in stroke-causing carotid plaques when compared with plaques from asymptomatic patients. Here we compared in the same cohort GLUL mRNA expression with plaque gross morphology, and the colocalization of immunodetectable GLUL protein with histopathological changes and molecular and mechanical mediators linked to plaque development. METHODS: Endarterectomy specimens from 19 asymptomatic and 24 stroke patients were sectioned longitudinally and immunostained for GLUL, CD68, α-smooth muscle actin, iron, heme oxygenase-1 and CD163, and graded semiquantitatively in every 1 mm2. The amounts of cholesterol clefts and erythrocytes were graded. The fibrous cap thickness within each 1 mm2 area was measured. The association between the local pathological findings was analyzed by a hierarchical mixed modelling approach. RESULTS: The previously found correlation between GLUL mRNA and clinical symptomatology was supported by the increased GLUL mRNA in diseased tissue and increased local GLUL immunoreactivity in areas with multiple different atherosclerotic changes. A longer symptom-to-operation time correlated with lower GLUL mRNA (Rs = -0.423, p=0.050) but few outliers had a significantly higher GLUL mRNA levels, which persisted throughout the post-symptomatic period. Plaque ulceration associated with 1.8-fold higher GLUL mRNA (p=0.006). Macrophages were the main GLUL immunoreactive cells. GLUL immunostaining colocalized with erythrocytes, iron, CD163, and heme oxygenase-1. The correlations between local variables were consistent in both asymptomatic and stroke-causing plaques. An inverse correlation was found between the fibrous cap thickness and local GLUL immunoreactivity (p=0.012). Considerable variability in interplaque expression pattern of GLUL was present. CONCLUSIONS: Our results link connect macrophage GLUL expression with carotid plaque features characterizing plaque vulnerability.