Julio F. Marchini

Macrophage-Derived Matrix Vesicles An Alternative Novel Mechanism for Microcalcification in Atherosclerotic Plaques

Rationale: We previously showed that early calcification of atherosclerotic plaques associates with macrophage accumulation. Chronic renal disease and mineral imbalance accelerate calcification and the subsequent release of matrix vesicles (MVs), precursors of microcalcification. Objective: We tested the hypothesis that macrophage-derived MVs contribute directly to microcalcification. Methods and Results: Macrophages associated with regions of calcified vesicular structures in human carotid plaques (n=136 patients). In vitro, macrophages released MVs with high calcification and aggregation potential. MVs expressed exosomal markers (CD9 and TSG101) and contained S100A9 and annexin V. Silencing S100A9 in vitro and genetic deficiency in S100A9−/− mice reduced MV calcification, whereas stimulation with S100A9 increased calcification potential. Externalization of phosphatidylserine after Ca/P stimulation and interaction of S100A9 and annexin V indicated that a phosphatidylserine-annexin V-S100A9 membrane complex facilitates hydroxyapatite nucleation within the macrophage-derived MV membrane. Conclusions: Our results support the novel concept that macrophages release calcifying MVs enriched in S100A9 and annexin V, which contribute to accelerated microcalcification in chronic renal disease. # Novelty and Significance {#article-title-18}Rationale: We previously showed that early calcification of atherosclerotic plaques associates with macrophage accumulation. Chronic renal disease and mineral imbalance accelerate calcification and the subsequent release of matrix vesicles (MVs), precursors of microcalcification. Objective: We tested the hypothesis that macrophage-derived MVs contribute directly to microcalcification. Methods and Results: Macrophages associated with regions of calcified vesicular structures in human carotid plaques (n=136 patients). In vitro, macrophages released MVs with high calcification and aggregation potential. MVs expressed exosomal markers (CD9 and TSG101) and contained S100A9 and annexin V. Silencing S100A9 in vitro and genetic deficiency in S100A9−/− mice reduced MV calcification, whereas stimulation with S100A9 increased calcification potential. Externalization of phosphatidylserine after Ca/P stimulation and interaction of S100A9 and annexin V indicated that a phosphatidylserine-annexin V-S100A9 membrane complex facilitates hydroxyapatite nucleation within the macrophage-derived MV membrane. Conclusions: Our results support the novel concept that macrophages release calcifying MVs enriched in S100A9 and annexin V, which contribute to accelerated microcalcification in chronic renal disease.

MicroRNA-26a regulates pathological and physiological angiogenesis by targeting BMP/SMAD1 signaling

Rationale: The rapid induction and orchestration of new blood vessels are critical for tissue repair in response to injury, such as myocardial infarction, and for physiological angiogenic responses, such as embryonic development and exercise. Objective: We aimed to identify and characterize microRNAs (miR) that regulate pathological and physiological angiogenesis. Methods and Results: We show that miR-26a regulates pathological and physiological angiogenesis by targeting endothelial cell (EC) bone morphogenic protein/SMAD1 signaling in vitro and in vivo. MiR-26a expression is increased in a model of acute myocardial infarction in mice and in human subjects with acute coronary syndromes. Ectopic expression of miR-26a markedly induced EC cycle arrest and inhibited EC migration, sprouting angiogenesis, and network tube formation in matrigel, whereas blockade of miR-26a had the opposite effects. Mechanistic studies demonstrate that miR-26a inhibits the bone morphogenic protein/SMAD1 signaling pathway in ECs by binding to the SMAD1 3′-untranslated region, an effect that decreased expression of Id1 and increased p21WAF/CIP and p27. In zebrafish, miR-26a overexpression inhibited formation of the caudal vein plexus, a bone morphogenic protein-responsive process, an effect rescued by ectopic SMAD1 expression. In mice, miR-26a overexpression inhibited EC SMAD1 expression and exercise-induced angiogenesis. Furthermore, systemic intravenous administration of an miR-26a inhibitor, locked nucleic acid-anti–miR-26a, increased SMAD1 expression and rapidly induced robust angiogenesis within 2 days, an effect associated with reduced myocardial infarct size and improved heart function. Conclusions: These findings establish miR-26a as a regulator of bone morphogenic protein/SMAD1-mediated EC angiogenic responses, and that manipulating miR-26a expression could provide a new target for rapid angiogenic therapy in ischemic disease states.

Bone Marrow–Derived Kruppel-Like Factor 10 Controls Reendothelialization in Response to Arterial Injury

Objective—The objective of this study was to investigate the role of Kruppel-like factor (KLF) 10, a zinc-finger transcription factor, in bone marrow (BM)–derived cell responses to arterial endothelial injury. Accumulating evidence indicates that BM-derived progenitors are recruited to sites of vascular injury and contribute to endothelial repair. Approach and Results—In response to carotid artery endothelial denudation, KLF10 mRNA expression was markedly increased in both BM and circulating lin− progenitor cells. To examine the specific role of KLF10 in arterial reendothelialization, we used 2 models of endothelial denudation (wire- and thermal-induced injury) of the carotid artery in wild-type (WT) and KLF10−/− mice. WT mice displayed higher areas of reendothelialization compared with KLF10−/− mice after endothelial injury using either method. BM transplant studies revealed that reconstitution of KLF10−/− mice with WT BM fully rescued the defect in reendothelialization and increased lin−CD34+kinase insert domain receptor+ progenitors in the blood and injured carotid arteries. Conversely, reconstitution of WT mice with KLF10−/− BM recapitulated the defects in reendothelialization and peripheral cell progenitors. The media from cultured KLF10–/– BM progenitors was markedly inefficient in promoting endothelial cell growth and migration compared with the media from WT progenitors, indicative of defective paracrine trophic effects from KLF10–/– BM progenitors. Finally, BM-derived KLF10−/− lin− progenitors from reconstituted mice had reduced CXC-chemokine receptor 4 expression and impaired migratory responses. Conclusions—Collectively, these observations demonstrate a protective role for BM-derived KLF10 in paracrine and homing responses important for arterial endothelial injury and highlight KLF10 as a possible therapeutic target to promote endothelial repair in vascular disease states.

The H region HTBF gene mediates terbinafine resistance in Leishmania major

The H region HTBF gene mediates terbinafine resistance in Leishmania major Julio F.M. Marchini a, Angela K. Cruz a, Stephen M. Beverley b, Luiz R.O. Tosi a,∗ a Departamento de Biologia Celular e Molecular e Bioagentes Patogenicos, Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo, Ave. Bandeirantes, 3900, 14049-900 Ribeirao Preto—SP, Brazil b Department of Molecular Microbiology, Washington University Medical School, 660 South Euclid Ave., St. Louis, MO 63110, USA

Very late outcomes of drug-eluting stents coated with biodegradable polymers: insights from the 5-year follow-up of the randomized PAINT trial

BACKGROUND Few studies have examined the very long-term outcomes after implantation of drug-eluting stents (DES) coated with biodegradable polymers (BP). This report presents the 5-year clinical follow-up of patients treated with BP-DES in the randomized PAINT trial. METHODS The PAINT study is a prospective, multicenter randomized controlled trial that allocated 274 patients for treatment with two BP-DES formulations [paclitaxel-eluting stents (PES) or sirolimus-eluting stents (SES)] or bare metal stents (BMS) in a 1:2:2 ratio, respectively. The primary end-point of this sub-study was defined as the composite of the major cardiac adverse events (MACE) cardiac death, myocardial infarction (MI) or ischemia-driven target vessel revascularization (TVR) at 5 years. RESULTS The 5-year MACE rates were different among the groups: 35.3%, 22.5% and 16.9% for BMS, PES and SES, respectively (P<0.05 for both DES vs. bare stent comparisons). The primary end-point was mainly driven by TVR: 31.8%, 14.1% and 12.2% for bare stents, PES and SES, respectively (P<0.05 for both DES vs. bare stent comparisons). The incidence of stent thrombosis (ST) was null for BMS during the entire follow-up. There was no definite or probable ST in the SES group after the second year, while one patient (1.0%) presented with a definite ST episode in the PES group between 4 and 5 years. CONCLUSIONS The tested biodegradable-polymer coated stents releasing either paclitaxel or sirolimus, compared with same bare metal platform, sustained their effectiveness in reducing combined major adverse cardiac events and re-intervention without an increase in ST during 5 years of follow-up.

Refeeding syndrome, an undiagnosed and forgotten potentially fatal condition.

Refeeding syndrome (RFS) has been well described but is also a frequently forgotten and undiagnosed complication in clinical practice, which, if untreated, may lead to death. Patients who are more prone to developing RFS are those with at least one of the following conditions: BMI <16 kg/m2, a recent unintentional weight loss >15%, very little nutritional intake for >10 days, and/or low plasma concentrations of potassium, phosphate or magnesium before feeding; and those with at least two of the following conditions: BMI <18.5 kg/m2, a recent weight loss >10%, very little nutritional intake for >5 day, and/or a history of alcohol abuse or drug use, including insulin, chemotherapy or diuretics. We report here a patient who, after undergoing intestinal resection (short gut syndrome), presented diarrhoea, weight loss and protein–energy malnutrition. After nutritional assessment, the nutritional support team decided to feed the patient by the parenteral route. After 16 h of parenteral nutrition, the patient developed supraventricular tachycardia, hypomagnesaemia and hypocalcaemia, and RFS was diagnosed and managed. After intestinal adaptation, the patient is currently able to maintain his nutritional status with nutrition therapy by the oral route.

Stent Thrombosis: Understanding and Managing a Critical Problem

Opinion statementCoronary artery stent thrombosis (ST), defined as the thrombotic occlusion of a stented segment, is an infrequent but serious complication of percutaneous coronary intervention (PCI). The clinical consequences of ST are severe, because acute stent occlusion results in myocardial infarction and death in up to 45% of cases. Specific patient and procedural characteristics increase the risk of ST, but optimized interventional techniques and antiplatelet therapies have the potential to decrease ST and improve cardiovascular outcomes following PCI.

An Algorithm for use of Prasugrel (Effient) in Patients Undergoing Cardiac Catheterization and Percutaneous Coronary Intervention

An algorithm for use of Prasugrel (Effient) in patients undergoing cardiac catheterization and percutaneous coronary intervention at the Brigham and Womens Hospital is presented. Our algorithm, which is in the process of being implemented, is consistent with published and generally accepted standards of care and is based on data from the pivotal Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis in Myocardial Infarction (TRITON-TIMI) 38, which compared clopidogrel with prasugrel in acute coronary syndrome patients undergoing percutaneous coronary intervention. Areas of focus include analysis of the benefit of prasugrel over clopidogrel in acute coronary syndrome patients and appropriate selection of patients for prasugrel treatment.

Avaliação a médio prazo do controle de fatores de risco de doença cardiovascular em coorte prospectiva de pacientes de alto risco tratados por intervenção coronária percutânea

INTRODUCAO: A prevencao secundaria apos intervencao coronaria percutânea (ICP) e fundamental para melhorar a sobrevida livre de eventos e consiste principalmente no controle de fatores de risco. Analisou-se a prevencao secundaria de pacientes de alto risco, incluidos prospectivamente no estudo Sequence Variation in Platelet Aggregation in Response to Clopidogrel and aspirin (SPARC). METODOS: Foram arrolados 187 pacientes consecutivos entre dezembro de 2009 e fevereiro de 2011, tratados por ICP com stent e avaliados em retornos ambulatoriais de 30 dias, 3 meses, 6 meses e 12 meses quanto ao controle de hipertensao arterial, disglicemia, dislipidemia e tabagismo, e medidas terapeuticas respectivas. RESULTADOS: Houve aumento significativo de pacientes com controle pressorico (29%; P = 0,02), que cessaram tabagismo (18%; P = 0,003), e que receberam hipolipemiantes (19%; P < 0,0001) entre a internacao para ICP e o primeiro retorno apos o procedimento. Esse melhora do controle de fatores de risco refletiu-se em reducao do escore de risco de Framingham medio observado no mesmo periodo (9,9%; P < 0,0001). Durante seguimento de ate 12 meses o ganho atingido na internacao para ICP se manteve para todos os fatores de risco. CONCLUSOES: Observou-se efeito importante relativamente a internacao indice para ICP, com aumento da prescricao de medicamentos para controle de fatores de risco e alcance de metas. Esse estudo identifica relevante janela de oportunidade para priorizacao do controle de fatores de risco na internacao inicial, quando ganhos expressivos sao observados e mantidos. Mas tambem explicita que esforcos adicionais sao necessarios para expandir o beneficio da prevencao secundaria no seguimento a medio prazo de pacientes tratados por ICP.

Low educational status, smoking, and multidisciplinary team experience predict hospital length of stay after bariatric surgery.

Objective The objective of the present study was to identify new risk factors associated with longer hospitalization following bariatric surgery. Methods Patient clinical, social, and biochemical data in addition to multidisciplinary team experience were analyzed in a cohort that included all patients undergoing bariatric surgery at our hospital. The primary outcome was length of hospital stay (LOS). Mortality was recorded to validate the obesity surgery mortality risk score (OS-MRS). Results This study included 299 sequential patients, 41 ± 10 years of age, and BMI of 50 ± 8 kg/m2 who underwent bariatric surgery. Two thirds (196) of patients were hypertensive, a third (86) were diabetic and a third (91) were current or former smokers. Overall, LOS was 8 ± 5 days. The predictors of a longer LOS were smoking (P < 0.05) and less multidisciplinary team experience (P < 0.05). Looking at only the last three years of data, LOS was 6 ± 5 days, and the predictors of a longer LOS were low educational attainment (P < 0.02) and smoking (P < 0.01) but not team experience. The global mortality was 2.6%, with the OS-MRS identifying a high-risk group. Conclusion Excluding the initial learning phase, longer LOS independent predictors were patient low educational attainment and smoking. These predictors can help guide care to reduce complications.