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Because of its safety record and multiple novel mechanisms of action, minocycline may be a valuable cardioprotective agent to ameliorate cardiac dysfunction and cell loss associated with I/R injury.

a b s t r a c tFlavonoids exhibit a variety of beneficial effects in cardiovascular diseases. Although their therapeutic properties have been attributed mainly to their antioxidant action, they have additional protective mechanisms such as inhibition of signal transducer and activator of transcription 1 (STAT1) activation. Here, we have investigated the cardioprotective mechanisms of strong antioxidant flavonoids such as quercetin, myricetin and delphinidin. Although all of them protect the heart from ischemia/reperfusion-injury, myricetin and delphinidin exert a more pronounced protective action than quercetin by their capacity to inhibit STAT1 activation. Biochemical and computer modeling analysis indicated the direct interaction between STAT1 and flavonoids with anti-STAT1 activity.

BackgroundAlthough originally described as a survival mechanism, it is unknown whether and to what extent autophagy is implicated in the terminal stages of heart failure. Here, we studied magnitude and evolution of autophagy in patients with intractable heart failure.Material/MethodsMyocardial samples were obtained from 22 patients with ischemic cardiomyopathy and idiopathic dilated cardiomyopathy who were undergoing cardiac transplantation. Hearts from 11 patients who died from non-cardiac causes were used as control samples. Autophagy was evaluated by immunostaining with a monoclonal microtubule associated protein light chain 3 (LC3)-II antibody, while the relationship of autophagy with apoptosis and oncosis was assessed by double staining with TUNEL (terminal deoxynucleotidyl transferase – mediated deoxyuridine triphosphate nick end labeling) assay and complement 9 (C9) immunological staining, respectively. In addition, several necroptotic markers, including RIP1 and RIP3 (receptor interacting protein kinase 1 and 3), anti-C3 (cleaved-caspase-3), and anti-NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) were assessed by immunohistochemistry.ResultsAnti-LC3-II staining was detected in 8.7±1.6% of the heart failure patient heart samples and in 1.2±0.3% of control patient heart samples. Vacuole formation started at one nuclear pole, before becoming bipolar and involving the cytosol. Subsequently, the autophagic process extended also to the nuclei, which underwent a progressive vacuolization and disintegration, assuming a peculiar “strawberry like appearance”. Myocytes with extensive vacuole formation exhibited nuclear degeneration, which was associated with TUNEL, C3, C9, RIP1, and RIP3 positive staining. Conversely, myocytes with less extensive vacuole formation showed RIP1 and NF-κB positive staining, though not positivity for other cell death markers.ConclusionsAutophagy was extensively detected in end-stage heart failure and its progression, resulted in secondary cell death, with occurrence of oncosis and necroptosis exceeding that of apoptosis. Conversely, activation of the RIP1/NF-κB pathway was associated with cell survival.

Background: Many patients who have been suffering by Covid-19 suffer of long-Covid syndrome, with symptoms of fatigue and muscular weakness that characterize post-acute sequelae SARS-CoV-2 infection (PASC). However, there is limited knowledge about the molecular pathophysiology, and about the serum profile of these patients.Methods: We studied the blood serum profile of 75 selected patients, with previous confirmed Covid-19, 2 months after hospital discharge, who reported new-onset fatigue, muscle weakness and/or dyspnea not present prior to the virus infection and independently from concomitant diseases and/or clinical conditions.Results: All patients had very high serum concentrations of ferritin and D-Dimer. 87 and 72% of patients had clinically significant low levels of hemoglobin and albumin, respectively. Seventy three percentage had elevations in erythrocyte sedimentation rate and CRP. Twenty seven percentage had elevations in LDH.Conclusions: The co-existence of patient symptoms along with blood markers of coagulation, protein disarrangement and inflammation suggests ongoing alterations in the metabolism, promoting an inflammatory/hypercatabolic state which maintains a vicious circles implicated in the persistence of PASC. The persistence of altered D-Dimer levels raises the possibility of long-term risks of thromboembolic disease. All these markers levels should be accurately evaluated in the long-term follow-up, with individualized consideration for prophylactic nutritional, anti-inflammatory and/or anticoagulant therapy if indicated.

BackgroundCarfilzomib (CFZ) is a new proteasome inhibitor used for the treatment of multiple myeloma. Besides heart failure, angina and myocardial ischemia occurred following administration of CFZ, which is not contraindicated in patients with recent myocardial infarction/unstable angina excluded from the safety trials.Aim of StudyTo test the effects of CFZ (10− 9 to 10− 7 mol/L) on vascular tone and reactivity in the isolated rabbit heart and aorta.Methods and ResultsCFZ administered by bolus injection to the isolated heart increased coronary perfusion pressure (CPP) at all tested concentrations and mildly raised left ventricular pressure and heart rate, only at the highest concentration. Addition of CFZ directly into the organ bath increased the basal tone of isolated aortic strips with contraction plateau reached after 10 min. This spasmogenic effect doubled following ablation of the endothelium. Pretreatment with CFZ amplified the vasospastic action exerted by KCl, noradrenaline (NA) and angiotensin II (A) on aortic strips, and impaired vasodilation following administration of nitroglycerin (NTG) and nifedipine (NFP) on the contraction plateau induced by KCl, NA and A. Aortic strips pretreated with CFZ exhibited impaired relaxation, as compared to untreated strips, following administration of acetylcholine (Ach), an endothelium-dependent vasodilating agent, on the plateau of NA contraction (p < 0.05).ConclusionsCFZ increased CPP, resting vasoconstricting tone and the spasmogenic effect of different agents. Preincubation with CFZ decreased the anti-spasmogenic activity of NTG and NFP, as well as reduced by over 50% the vasodilating effect of Ach, suggesting that CFZ can impair vasodilation via an endothelium dependent mechanism. Further studies are warranted to establish its clinical safety in patients with known CAD and prior history of coronary spasm.

BackgroundIL-17A and IL-17F are pro-inflammatory cytokines which induce the expression of several cytokines, chemokines and matrix metalloproteinases (MMPs) in target cells. IL-17 cytokines have recently attracted huge interest due to their pathogenic role in diseases such as arthritis and inflammatory bowel disease although a role for IL-17 cytokines in myocardial infarction (MI) has not previously been described.MethodsIn vivo MI was performed by coronary artery occlusion in the absence or presence of a neutralizing IL-17 antibody for blocking IL-17 actions in vivo. IL-17 signaling was also assessed in isolated primary cardiomyocytes by Western blot, mRNA expression and immunostaining.ResultsExpression of IL-17A, IL-17F and the IL-17 receptor (IL-17RA) were all increased following MI. Expression of several IL-17 target genes, including Cxcl1, Cxcl2, IL-1β, iNOS and IL-6 was also upregulated following MI. In addition, IL-17A promoted the expression of Cxcl1 and IL-6 in isolated cardiomyocytes in a MAPK and PI(3)K-dependent manner. IL-17A and ischaemia/reperfusion (I/R) injury were found to have an additive effect on Cxcl1 expression, suggesting that IL-17 may enhance myocardial neutrophil recruitment during MI. Moreover, protein levels of both IL-17R and IL-17A were enhanced following in vivo MI. Finally, blocking IL-17 signaling in vivo reduced the levels of apoptotic cell death markers following in vivo MI.ConclusionsThese data imply that the expression of IL-17 cytokines and their receptor are elevated during myocardial I/R injury and may play a fundamental role in post infarct inflammatory and apoptotic responses.

Deep insight into the complex mechanisms of myocardial ischemia-reperfusion injury has been attained in the past years. Minocycline is a second-generation tetracycline with US FDA approval for clinical use in various infections. Lately, several noninfectious cytoprotective activities of minocycline have been discovered as well. There now exists encouraging evidence of its protective role in cardiovascular pathology and its activity against myocardial ischemia-reperfusion injury. In this article, an overview of the major mechanisms involved in myocardial ischemia-reperfusion injury is presented. This is followed by an analysis of the mechanisms by which minocycline exerts its cytoprotective role and of studies that have been conducted in order to analyze minocycline, along with a review of the scope and limitations of its role as a cytoprotective agent.