Reciprocal regulation of endothelial-mesenchymal transition by MAPK7 and EZH2 in intimal hyperplasia and coronary artery disease.

Endothelial-mesenchymal transition (EndMT) is a form of endothelial dysfunction wherein endothelial cells acquire a mesenchymal phenotype and lose endothelial functions, which contributes to the pathogenesis of intimal hyperplasia and atherosclerosis. The mitogen activated protein kinase 7 (MAPK7) inhibits EndMT and decreases the expression of the histone methyltransferase Enhancer-of-Zeste homologue 2 (EZH2), thereby maintaining endothelial quiescence. EZH2 is the catalytic subunit of the Polycomb Repressive Complex 2 that methylates lysine 27 on histone 3 (H3K27me3). It is elusive how the crosstalk between MAPK7 and EZH2 is regulated in the endothelium and if the balance between MAPK7 and EZH2 is disturbed in vascular disease. In human coronary artery disease, we assessed the expression levels of MAPK7 and EZH2 and found that with increasing intima/media thickness ratio, MAPK7 expression decreased, whereas EZH2 expression increased. In vitro, MAPK7 activation decreased EZH2 expression, whereas endothelial cells deficient of EZH2 had increased MAPK7 activity. MAPK7 activation results in increased expression of microRNA (miR)-101, a repressor of EZH2. This loss of EZH2 in turn results in the increased expression of the miR-200 family, culminating in decreased expression of the dual-specificity phosphatases 1 and 6 who may repress MAPK7 activity. Transfection of endothelial cells with miR-200 family members decreased the endothelial sensitivity to TGFß1-induced EndMT. In endothelial cells there is reciprocity between MAPK7 signaling and EZH2 expression and disturbances in this reciprocal signaling associate with the induction of EndMT and severity of human coronary artery disease.

MicroRNA-374b induces endothelial-to-mesenchymal transition and early lesion formation through the inhibition of MAPK7 signaling.

Endothelial-mesenchymal transition occurs during intimal hyperplasia and neointima formation via mechanisms that are incompletely understood. Endothelial MAPK7 signaling is a key mechanosensitive factor that protects against endothelial-mesenchymal transition, but its signaling activity is lost in vessel areas that are undergoing pathological remodeling. At sites of vascular remodeling in mice and pigs, endothelial MAPK7 signaling was lost. The TGFß-induced microRNA-374b targets MAPK7 and its downstream effectors in endothelial cells, and its expression induces endothelial-mesenchymal transition. Gain-of-function experiments, where endothelial MAPK7 signaling was restored, precluded endothelial-mesenchymal transition. In human coronary artery disease, disease severity is associated with decreased MAPK7 expression levels and increased miR-374b expression levels. Endothelial-mesenchymal transition occurs in intimal hyperplasia and early lesion formation and is governed in part by microRNA-374b-induced silencing of MAPK7 signaling. Restoration of MAPK7 signaling abrogated these pathological effects in endothelial cells expressing miR-374b. Thus, our data suggest that the TGFß-miR-374b-MAPK7 axis plays a key role in the induction of endothelial-mesenchymal transition during intimal hyperplasia and early lesion formation and might pose an interesting target for antiatherosclerosis therapy. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Allogeneic pASC transplantation in humanized pigs attenuates cardiac remodeling post-myocardial infarction.

Cell therapy repair strategies using adult mesenchymal stromal cells have shown promising evidence to prevent cardiac deterioration in rodents even in the absence of robust differentiation of the cells into cardiomyocytes. We tested whether increasing doses of porcine adipose-tissue derived mesenchymal stem cells (pASCs) increase cardiac tissue perfusion in pigs post-myocardial infarction (MI) receiving angiotensin-converting-enzyme inhibitor (ACE inhibitors) and Beta-blockers similarly to patients. Female pigs were subjected to MI induction by sponge permanent occlusion of left circumflex coronary artery (LCx) generating approximately 10% of injured LV area with minimum hemodynamic impact. We assessed tissue perfusion by real time myocardial perfusion echocardiography (RTMPE) using commercial microbubbles before and following pASCs treatment. Four weeks after the occlusion of the left circumflex artery, we transplanted placebo or pASCs (1, 2 and 4x106 cells/Kg BW) into the myocardium. The highest dose of pASCs increased myocardial vessel number and blood flow in the border (56% and 3.7-fold, respectively) and in the remote area (54% and 3.9-fold, respectively) while the non-perfused scar area decreased (up to 38%). We also found an increase of immature collagen fibers, although the increase in total tissue collagen and types I and III was similar in all groups. Our results provide evidence that pASCs-induced stimulation of tissue perfusion and accumulation of immature collagen fibers attenuates adverse remodeling post-MI beyond the normal beneficial effects associated with ACE inhibition and beta-blockade.

Proteome analysis of acute kidney injury - Discovery of new predominantly renal candidates for biomarker of kidney disease.

The main bottleneck in studies aiming to identify novel biomarkers in acute kidney injury (AKI) has been the identification of markers that are organ and process specific. Here, we have used different tissues from a controlled porcine renal ischemia/reperfusion (I/R) model to identify new, predominantly renal biomarker candidates for kidney disease. Urine and serum samples were analyzed in pre-ischemia, ischemia (60min) and 4, 11 and 16h post-reperfusion, and renal cortex samples after 24h of reperfusion. Peptides were analyzed on the Q-Exactive™. In renal cortex proteome, we observed an increase in the synthesis of proteins in the ischemic kidney compared to the contralateral, highlighted by transcription factors and epithelial adherens junction proteins. Intersecting the set of proteins up- or down-regulated in the ischemic tissue with both serum and urine proteomes, we identified 6 proteins in the serum that may provide a set of targets for kidney injury. Additionally, we identified 49, being 4 predominantly renal, proteins in urine. As prove of concept, we validated one of the identified biomarkers, dipeptidyl peptidase IV, in a set of patients with diabetic nephropathy. In conclusion, we identified 55 systemic proteins, some of them predominantly renal, candidates for biomarkers of renal disease. BIOLOGICAL SIGNIFICANCE: The main bottleneck in studies aiming to identify novel biomarkers in acute kidney injury (AKI) has been the identification of markers that are predominantly renal. In fact, putative biomarkers for this condition have also been identified in a number of other clinical scenarios, such as cardiovascular diseases, chronic kidney failure or in patients being treated in intensive care units from a number of conditions. Here we propose a comprehensive, sequential screening procedure able to identify and validate potential biomarkers for kidney disease, using kidney ischemia/reperfusion as a paradigm for a kidney pathological event.

Pesquisa de coliformes totais e termotolerantes em mãos de manipuladores da merenda escolar da rede municipal de ensino de Marialva, PR / Research of total and thermotolerant coliforms in the hands of school lunch handlers of the municipal school network of Marialva, PR

A alimentação dentro dos padrões higiênicos satisfatórios é essencial para a saúde, sendo que uma redução na fiscalização pode resultar em ocorrência de doenças veiculadas por alimentos (DVA's). A prevalência de bactérias indicadoras de contato com fezes nas mãos pode ser usada no monitoramento do comportamento dos manipuladores de alimentos em relação à higiene. A fim de avaliar as condições de fabricação da merenda escolar, foi realizada uma pesquisa identificando-se a presença de coliformes nas mãos destes profissionais, em escolas da rede municipal de ensino de Marialva - Paraná. No presente estudo foram avaliadas 24 amostras de lavagem de mãos, das quais 23 (95,83%) apresentaram- -se positivas para coliformes totais e 14 (58,33%) para coliformes termotolerantes. Através da aplicação de um checklist foi possível constatar hábitos não higiênicos, levando a concluir que um maior controle sanitário de pessoal deve ser empregado.

Catheter-based induction of renal ischemia/reperfusion in swine: description of an experimental model.

Several techniques to induce renal ischemia have been proposed: clamp, PVA particles, and catheter-balloon. We report the development of a controlled, single-insult model of unilateral renal ischemia/reperfusion (I/R) without contralateral nephrectomy, using a suitable model, the pig. This is a balloon-catheter-based model using a percutaneous, interventional radiology procedure. One angioplasty balloon-catheter was placed into the right renal artery and inflated for 120 min and reperfusion over 24 h. Serial serums were sampled from the inferior vena cava and urine was directly sampled from the bladder throughout the experiment, and both kidneys were excised after 24 h of reperfusion. Analyses of renal structure and function were performed by hematoxylin-eosin/periodic Acid-Schiff, serum creatinine (SCr), blood urea nitrogen (BUN), fractional excretion of ions, and glucose, SDS-PAGE analysis of urinary proteins, and serum neutrophil gelatinase-associated lipocalin (NGAL). Total nitrated protein was quantified to characterize oxidative stress. Acute tubular necrosis (ATN) was identified in every animal, but only two animals showed levels of SCr above 150% of baseline values. As expected, I/R increased SCr and BUN. Fractional sodium, potassium, chloride, and bicarbonate excretion were modulated during ischemia. Serum-nitrated proteins and NGAL had two profiles: decreased with ischemia and increased after reperfusion. This decline was associated with increased protein excretion during ischemia and early reperfusion. Altogether, these data show that the renal I/R model can be performed by percutaneous approach in the swine model. This is a suitable translational model to study new early renal ischemic biomarkers and pathophysiological mechanisms in renal ischemia.