Sublethal doses of dinophysistoxin-1 and okadaic acid stimulate secretion of inflammatory factors on innate immune cells: Negative health consequences

© 2016 Elsevier LtdOne of the proposed mechanisms to explain why Diarrhetic Shellfish Poison (DSP) toxins are tumor promoters is founded on the capacity of these toxins to increase TNF-α secretion. Although macrophages are the principal cells in the activation of the inflammatory response, the immune profile that Okadaic acid (OA) and Dinophysistoxin-1 (DTX-1) trigger in these cells has not been fully explored. We have therefore investigated the effect of various concentrations of both toxins on the activity of several inflammatory factors. Our results demonstrate that OA and DTX-1, at sublethal doses, stimulate secretion of inflammatory factors. Nevertheless DTX-1 was more potent than OA in increasing TNF-α and IL-6 as well as their dependent chemokines KC, MCP-1, LIX, MIP-1 α, MIP-1 β and MIP-2. On the other hand, secretion of IFN-γ and the anti-inflammatory cytokines, IL-4 and IL-10, was unaffected. In addition, DTX-1 also raises matrix metalloproteinase-9 (MMP-9) activity. In thi

ATPase and ADPase activities in synovial membrane of equine metacarpophalangeal joint

ATPase and ADPase activities capable of hydrolyzing nucleoside di- and triphosphates in the presence of Ca2+ are present in synovial membrane of metacarpophalangeal joint mainly associated to membrane fractions. These hydrolytic activities have been considered involved in the inflammatory process where ATP and ADP are inflammatory mediators while adenosine counteracts this effect. Both, subcellular localization and kinetic properties of these nucleotidase activities, suggest that could correspond to single enzyme called ATP-diphosphohydrolase or apyrase. The comparison of the activity on ATP-Ca and ADP-Ca from normal and pathological equine synovial membrane did not show significant differences either in the subcellular fraction distribution or in the enrichment of each subcellular fraction. Neither differences on 5′-nucleotidase activity present in the microsomal fraction were observed

Impaired cardiac autophagy in patients developing postoperative atrial fibrillation

Objectives: Postoperative atrial fibrillation (POAF) is a common complication after on-pump heart surgery. Several histologic abnormalities, such as interstitial fibrosis and vacuolization, have been described in atrial samples from patients developing POAF. This ultrastructural remodeling has been associated with the establishment of a proarrhythmic substrate. We studied whether atrial autophagy is activated in patients who develop POAF. Methods: A total of 170 patients in sinus rhythm who had undergone elective coronary artery bypass grafting were included. Systemic inflammatory markers were measured at baseline and 72 hours after surgery. During the procedure, samples of the right atrial appendages were obtained for evaluation of remodeling by light and electron microscopy. Protein ubiquitination and autophagy-related LC3B processing were assessed by Western blot. Results: Of these patients, 22% developed POAF. The level of high-sensitivity C-reactive protein, fibrosis, inflammatio

Trophic factors in cerebrospinal fluid and spinal cord of patients with tropical spastic paraparesis, HIV, and Creutzfeldt-Jakob disease

HTLV-1-associated myelopathy/tropical spastic paraparesis (TSP/HAM) is a chronic CNS disease characterized by axomyelinic degeneration of the long axons of corticospinal tracts. Levels of NGF, NT-3, NT-4/5, BDNF, GDNF, CNTF, and FGF-2 were measured in the cerebrospinal fluid (CSF) of 21 TSP/HAM patients and 20 controls. NGF, BDNF, and FGF-2 levels were also determined in 19 patients with HIV motor cognitive motor syndrome, and in 21 subjects diagnosed with Creutzfeldt Jakob disease (CJD). No significant differences were detected in the concentrations of NGF, BDNF, NT-3, NT-4/5, GDNF, and CNTF in the CSF between TSP/HAM patients and controls. FGF-2 was significantly lower in the CSF of the three groups of patients compared with controls; the HIV group exhibited the lowest values. HIV patients differed from TSP/HAM in their significantly higher levels of NGF and lower levels of BDNF and FGF-2, whereas CJD patients differed only in their higher levels of NGF. Immunohistochemical studies

Counter- regulatory renin–angiotensin system in cardiovascular disease

The renin–angiotensin system is an important component of the cardiovascular system. Mounting evidence suggests that the metabolic products of angiotensin I and II — initially thought to be biologically inactive — have key roles in cardiovascular physiology and pathophysiology. This non- canonical axis of the renin–angiotensin system consists of angiotensin 1–7 , angiotensin 1–9, angiotensin- converting enzyme 2, the type 2 angiotensin II receptor (AT2R), the proto- oncogene Mas receptor and the Mas- related G protein- coupled receptor member D. Each of these components has been shown to counteract the effects of the classical renin– angiotensin system. This counter- regulatory renin–angiotensin system has a central role in the pathogenesis and development of various cardiovascular diseases and, therefore, represents a potential therapeutic target. In this Review , we provide the latest insights into the complexity and interplay of the components of the non- canonical renin–angiotensin system, and discuss the function and therapeutic potential of targeting this system to treat cardiovascular disease.Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) FONDAP 15130011 FONDECYT 1161739 FONDECYT 11181000 FONDECYT 1140713 Puente Pontificia Universidad Catolica de Chile P1705/2017 Bayer AG (Program Grants4Targets) 2017-08-2260 National Council for Scientific and Technological Development (CNPq) 310515/2015-

Insulin/NFκB protects against ischemia-induced necrotic cardiomyocyte death

In the heart, insulin controls key functions such as metabolism, muscle contraction and cell death. However, all studies have been focused on insulin action during reperfusion. Here we explore the cardioprotective action of this hormone during ischemia. Rat hearts were perfused ex vivo with an ischemia/reperfusion Langendorff model in absence or presence of insulin. Additionally, cultured rat cardiomyocytes were exposed to simulated ischemia in the absence or presence of insulin. Cytoprotective effects were measured by myocardial infarct size, trypan blue exclusion, released LDH and DNA fragmentation by flow cytometry. We found that insulin protected against cardiac ischemia ex vivo and in vitro. Moreover, insulin protected cardiomyocytes from simulated ischemia by reducing necrotic cell death. Protective effects of insulin were dependent of Akt and NFκB. These novel results show that insulin reduces ischemia-induced cardiomyocyte necrosis through an Akt/NF-κB dependent mechanism. These novel findings clarify the role of insulin during ischemia and further support its use in early GIK perfusion to treat myocardial infarction

Preoperative soluble VCAM-1 contributes to predict late mortality after coronary artery surgery

Background Soluble vascular cell adhesion molecule-1 has been associated with long-term cardiovascular mortality in patients with stable coronary artery disease and to the development of new atrial fibrillation in subjects with cardiovascular risk factors but no evidence of cardiac disease. Hypothesis Preoperative soluble vascular cell adhesion molecule-1 predicts the risk of future all-cause death and cardiovascular death among patients submitted to elective coronary artery bypass surgery. Methods From a cohort of 312 patients who underwent elective coronary artery bypass surgery prospectively followed for a median of 6.7 years, we evaluated the prognostic role of preoperative soluble vascular cell adhesion molecule-1, inflammatory markers, CHA2DS2-VASc score and development of postoperative atrial fibrillation (POAF). Univariable and multivariable Cox regression analyses were performed to establish an association of these parameters with long term all-cause death and cardiovascular death. Results During 2112 person-years of follow-up, we observed 41 deaths, 10 were cardiovascular deaths. Independently increased levels of preoperative soluble vascular cell adhesion molecule-1, POAF, and CHA2DS2-VASc score were associated with all-cause mortality. After multivariate adjustment, elevated preoperative soluble vascular cell adhesion molecule-1 and POAF were the only independent predictors of all-cause death. Also, preoperative soluble vascular cell adhesion molecule-1, POAF, and CHA2DS2-VASc score resulted in being independent predictors of cardiovascular mortality. Conclusions Increased circulating levels of preoperative soluble vascular cell adhesion molecule-1, together with POAF and CHA2DS2-VASc score, were significantly associated with future all-cause death and cardiovascular death among patients submitted to coronary artery bypass surgery.Agencia Nacional de Ciencia y Desarrollo (Chile) FONDECYT 1141137 1100801 1181147 FONDAP 1513001

The STIM1 inhibitor ML9 disrupts basal autophagy in cardiomyocytes by decreasing lysosome content

Stromal-interaction molecule 1 (STIM1)-mediated store-operated Ca2+ entry (SOCE) plays a key role in mediating cardiomyocyte hypertrophy, both in vitro and in vivo. Moreover, there is growing support for the contribution of SOCE to the Ca2+ overload associated with ischemia/reperfusion injury. Therefore, STIM1 inhibition is proposed as a novel target for controlling both hypertrophy and ischemia/reperfusion-induced Ca2+ overload. Our aim was to evaluate the effect of ML9, a STIM1 inhibitor, on cardiomyocyte viability. ML9 was found to induce cell death in cultured neonatal rat cardiomyocytes. Caspase-3 activation, apoptotic index and release of the necrosis marker lactate dehydrogenase to the extracellular medium were evaluated. ML9-induced cardiomyocyte death was not associated with increased intracellular ROS or decreased ATP levels. Moreover, treatment with ML9 significantly increased levels of the autophagy marker LC3-II, without altering Beclin1 or p62 protein levels. However, treatment with ML9 followed by bafilomycin-A1 did not produce further increases in LC3-II content. Furthermore, treatment with ML9 resulted in decreased LysoTracker (R) Green staining. Collectively, these data suggest that ML9-induced cardiomyocyte death is triggered by a ML9-dependent disruption of autophagic flux due to lysosomal dysfunction.FONDECYT, Chile 3150545 FONDAP 1513001

Angiotensin-(1-9) reduces cardiovascular and renal inflammation in experimental renin-independent hypertension

© 2018 Elsevier Inc. Hypertension-induced cardiovascular and renal damage can be mediated by activation of the renin-angiotensin-aldosterone system. There are different factors beyond renin-angiotensin-aldosterone system involved in hypertension and renal damage. Inflammation has emerged as an important mediator of hypertension and cardiovascular and kidney damage. Angiotensin-(1-9), a peptide of the renin-angiotensin system, counter-regulates both the physiological and pathological actions of angiotensin II. Recent data has shown that angiotensin-(1-9) protects the heart and blood vessels from adverse cardiovascular remodeling in experimental models of hypertension and/or heart failure and reduces cardiac fibrosis in stroke-prone, spontaneously hypertensive rats. These effects are mediated by the angiotensin II type 2 receptor (AT2R). However, it remains unknown whether angiotensin-(1-9) also has an anti-inflammatory effect. In the present study, we investigate whether angiotensin-(1

Pro-fibrotic effect of oxidized LDL in cardiac myofibroblasts

Inflammatory signals associated with cardiac diseases trigger trans-differentiation of cardiac fibroblasts to cardiac myofibroblasts. Cardiac myofibroblasts are the main cell type involved in the development of cardiac fibrosis, a diffuse and disproportionate accumulation of collagen in the myocardium. Although the role of the scavenger like-lectin receptor LOX-1 was previously investigated in cardiac fibroblasts and fibrosis, the involvement of the LOX-1 ligand -oxidized low-density lipoprotein (oxLDL)- on cardiac myofibroblast function still remains unexplored. In the present work, we investigated the effect of oxLDL/LOX-1 on fibrotic markers and cardiac myofibroblast function. Our in vitro results showed that oxLDL increased cardiac myofibroblast proliferation, triggered an increase in the synthesis of collagen type I and fibronectin containing extra domain A, and stimulated collagen type I secretion. oxLDL also decreased cardiac myofibroblast migration, collagen gel contraction and cell area, without modifying alpha-smooth muscle actin protein levels. These effects were dependent on LOX-1, because LOX-1 knockdown abolished oxLDL effects. Collectively these data showed that oxLDL has important modulatory effects on cardiac myofibroblast function.Agencia Nacional de Investigación y Desarrollo (ANID), Chile Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT) CONICYT FONDECYT 1140713 Universidad de Chile ENL022/17 Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) 21140144 FONDAP 1513001