Experience from a regional percutaneous coronary intervention center: Aiming to assess and improve quality of care.

INTRODUCTION AND OBJECTIVES: Ischemic heart disease is the single most common cause of death in Europe. Mortality in patients presenting with ST-elevation myocardial infarction (STEMI) is associated with many factors, one of which is the time delay to treatment. The purpose of this work is to analyze the coronary pathway in our region in terms of timing, taking into consideration the place of first medical contact (FMC). METHODS: Consecutive patients admitted to our center with STEMI to undergo percutaneous coronary intervention (PCI) between 2013 and 2022 were analyzed. Age, gender, and time delays were collected. Analysis was performed with IBM SPSS version 28 for a significance level of 0.05. RESULTS: We found that non-PCI centers had a significantly greater FMC to diagnosis delay and diagnosis to wire delay compared to other places of origin. Only 2.2% of patients met the 10-min FMC to diagnosis target; 44.8% met the target of 90 min from diagnosis to wire in transferred patients, while 40.6% met the 60-min target for patients admitted to a PCI center. Median patient, electrocardiogram (ECG) and logistic delays are 92.0±146.0 min, 19.0±146.0 min and 15.5±46.3 min, respectively. CONCLUSION: A significant difference between state-of-the-art targets and reality was found, depending on the place of FMC, with the worst delays in non-PCI centers. Patient delay, ECG delay, FMC to diagnosis and logistic delay are identified as key areas in which to intervene.

Netrin-1 blockade inhibits tumour growth and EMT features in endometrial cancer.

Netrin-1 is upregulated in cancers as a protumoural mechanism1. Here we describe netrin-1 upregulation in a majority of human endometrial carcinomas (ECs) and demonstrate that netrin-1 blockade, using an anti-netrin-1 antibody (NP137), is effective in reduction of tumour progression in an EC mouse model. We next examined the efficacy of NP137, as a first-in-class single agent, in a Phase I trial comprising 14 patients with advanced EC. As best response we observed 8 stable disease (8 out of 14, 57.1%) and 1 objective response as RECIST v.1.1 (partial response, 1 out of 14 (7.1%), 51.16% reduction in target lesions at 6 weeks and up to 54.65% reduction during the following 6 months). To evaluate the NP137 mechanism of action, mouse tumour gene profiling was performed, and we observed, in addition to cell death induction, that NP137 inhibited epithelial-to-mesenchymal transition (EMT). By performing bulk RNA sequencing (RNA-seq), spatial transcriptomics and single-cell RNA-seq on paired pre- and on-treatment biopsies from patients with EC from the NP137 trial, we noted a net reduction in tumour EMT. This was associated with changes in immune infiltrate and increased interactions between cancer cells and the tumour microenvironment. Given the importance of EMT in resistance to current standards of care2, we show in the EC mouse model that a combination of NP137 with carboplatin-paclitaxel outperformed carboplatin-paclitaxel alone. Our results identify netrin-1 blockade as a clinical strategy triggering both tumour debulking and EMT inhibition, thus potentially alleviating resistance to standard treatments.

Netrin-1 blockade inhibits tumor associated Myeloid-derived suppressor cells, cancer stemness and alleviates resistance to chemotherapy and immune checkpoint inhibitor.

Drug resistance and cancer relapse represent significant therapeutic challenges after chemotherapy or immunotherapy, and a major limiting factor for long-term cancer survival. Netrin-1 was initially identified as a neuronal navigation cue but has more recently emerged as an interesting target for cancer therapy, which is currently clinically investigated. We show here that netrin-1 is an independent prognostic marker for clinical progression of breast and ovary cancers. Cancer stem cells (CSCs)/Tumor initiating cells (TICs) are hypothesized to be involved in clinical progression, tumor relapse and resistance. We found a significant correlation between netrin-1 expression and cancer stem cell (CSC) markers levels. We also show in different mice models of resistance to chemotherapies that netrin-1 interference using a therapeutic netrin-1 blocking antibody alleviates resistance to chemotherapy and triggers an efficient delay in tumor relapse and this effect is associated with CSCs loss. We also demonstrate that netrin-1 interference limits tumor resistance to immune checkpoint inhibitor and provide evidence linking this enhanced anti-tumor efficacy to a decreased recruitment of a subtype of myeloid-derived suppressor cells (MDSCs) called polymorphonuclear (PMN)-MDSCs. We have functionally demonstrated that these immune cells promote CSCs features and, consequently, resistance to anti-cancer treatments. Together, these data support the view of both a direct and indirect contribution of netrin-1 to cancer stemness and we propose that this may lead to therapeutic opportunities by combining conventional chemotherapies and immunotherapies with netrin-1 interfering drugs.

Metastatic Infiltration of Nervous Tissue and Periosteal Nerve Sprouting in Multiple Myeloma-Induced Bone Pain in Mice and Human.

Multiple myeloma (MM) is a neoplasia of B plasma cells that often induces bone pain. However, the mechanisms underlying myeloma-induced bone pain (MIBP) are mostly unknown. Using a syngeneic MM mouse model, we show that periosteal nerve sprouting of calcitonin gene-related peptide (CGRP+) and growth associated protein 43 (GAP43+) fibers occurs concurrent to the onset of nociception and its blockade provides transient pain relief. MM patient samples also showed increased periosteal innervation. Mechanistically, we investigated MM induced gene expression changes in the dorsal root ganglia (DRG) innervating the MM-bearing bone of male mice and found alterations in pathways associated with cell cycle, immune response and neuronal signaling. The MM transcriptional signature was consistent with metastatic MM infiltration to the DRG, a never-before described feature of the disease that we further demonstrated histologically. In the DRG, MM cells caused loss of vascularization and neuronal injury, which may contribute to late-stage MIBP. Interestingly, the transcriptional signature of a MM patient was consistent with MM cell infiltration to the DRG. Overall, our results suggest that MM induces a plethora of peripheral nervous system alterations that may contribute to the failure of current analgesics and suggest neuroprotective drugs as appropriate strategies to treat early onset MIBP.SIGNIFICANCE STATEMENT Multiple myeloma (MM) is a painful bone marrow cancer that significantly impairs the quality of life of the patients. Analgesic therapies for myeloma-induced bone pain (MIBP) are limited and often ineffective, and the mechanisms of MIBP remain unknown. In this manuscript, we describe cancer-induced periosteal nerve sprouting in a mouse model of MIBP, where we also encounter metastasis to the dorsal root ganglia (DRG), a never-before described feature of the disease. Concomitant to myeloma infiltration, the lumbar DRGs presented blood vessel damage and transcriptional alterations, which may mediate MIBP. Explorative studies on human tissue support our preclinical findings. Understanding the mechanisms of MIBP is crucial to develop targeted analgesic with better efficacy and fewer side effects for this patient population.

Confined migration promotes cancer metastasis through resistance to anoikis and increased invasiveness.

Mechanical stress is known to fuel several hallmarks of cancer, ranging from genome instability to uncontrolled proliferation or invasion. Cancer cells are constantly challenged by mechanical stresses not only in the primary tumour but also during metastasis. However, this latter has seldom been studied with regards to mechanobiology, in particular resistance to anoikis, a cell death programme triggered by loss of cell adhesion. Here, we show in vitro that migrating breast cancer cells develop resistance to anoikis following their passage through microporous membranes mimicking confined migration (CM), a mechanical constriction that cancer cells encounter during metastasis. This CM-induced resistance was mediated by Inhibitory of Apoptosis Proteins, and sensitivity to anoikis could be restored after their inhibition using second mitochondria-derived activator of caspase (SMAC) mimetics. Anoikis-resistant mechanically stressed cancer cells displayed enhanced cell motility and evasion from natural killer cell-mediated immune surveillance, as well as a marked advantage to form lung metastatic lesions in mice. Our findings reveal that CM increases the metastatic potential of breast cancer cells.

Δ40p53 isoform up-regulates netrin-1/UNC5B expression and potentiates netrin-1 pro-oncogenic activity.

Netrin-1, a secreted protein recently characterized as a relevant cancer therapeutic target, is the antiapoptotic ligand of the dependence receptors deleted in colorectal carcinoma and members of the UNC5H family. Netrin-1 is overexpressed in several aggressive cancers where it promotes cancer progression by inhibiting cell death induced by its receptors. Interference of its binding to its receptors has been shown, through the development of a monoclonal neutralizing antinetrin-1 antibody (currently in phase II of clinical trial), to actively induce apoptosis and tumor growth inhibition. The transcription factor p53 was shown to positively regulate netrin-1 gene expression. We show here that netrin-1 could be a target gene of the N-terminal p53 isoform Δ40p53, independent of full-length p53 activity. Using stable cell lines, harboring wild-type or null-p53, in which Δ40p53 expression could be finely tuned, we prove that Δ40p53 binds to and activates the netrin-1 promoter. In addition, we show that forcing immortalized human skeletal myoblasts to produce the Δ40p53 isoform, instead of full-length p53, leads to the up-regulation of netrin-1 and its receptor UNC5B and promotes cell survival. Indeed, we demonstrate that netrin-1 interference, in the presence of Δ40p53, triggers apoptosis in cancer and primary cells, leading to tumor growth inhibition in preclinical in vivo models. Finally, we show a positive correlation between netrin-1 and Δ40p53 gene expression in human melanoma and colorectal cancer biopsies. Hence, we propose that inhibition of netrin-1 binding to its receptors should be a promising therapeutic strategy in human tumors expressing high levels of Δ40p53.

Targeting netrin-3 in small cell lung cancer and neuroblastoma.

The navigation cue netrin-1 is well-documented for its key role in cancer development and represents a promising therapeutic target currently under clinical investigation. Phase 1 and 2 clinical trials are ongoing with NP137, a humanized monoclonal antibody against netrin-1. Interestingly, the epitope recognized by NP137 in netrin-1 shares 90% homology with its counterpart in netrin-3, the closest member to netrin-1 in humans, for which little is known in the field of cancer. Here, we unveiled that netrin-3 appears to be expressed specifically in human neuroblastoma (NB) and small cell lung cancer (SCLC), two subtypes of neuroectodermal/neuroendocrine lineages. Netrin-3 and netrin-1 expression are mutually exclusive, and the former is driven by the MYCN oncogene in NB, and the ASCL-1 or NeuroD1 transcription factors in SCLC. Netrin-3 expression is correlated with disease stage, aggressiveness, and overall survival in NB. Mechanistically, we confirmed the high affinity of netrin-3 for netrin-1 receptors and we demonstrated that netrin-3 genetic silencing or interference using NP137, delayed tumor engraftment, and reduced tumor growth in animal models. Altogether, these data support the targeting of netrin-3 in NB and SCLC.

Creatinine variation improves Zwolle score in selecting low-risk patients after ST-segment elevation myocardial infarction.

BACKGROUND: The Zwolle score is recommended to identify ST-segment elevation myocardial infarction (STEMI) patients with low-risk eligible for early discharge. Our aim was to ascertain if creatinine variation (Δ-sCr) would improve Zwolle score in the decision-making of early discharge after primary percutaneous coronary intervention (PCI). METHODS AND RESULTS: A total of 3296 patients with STEMI that underwent primary PCI were gathered from the Portuguese Registry on Acute Coronary Syndromes. A Modified-Zwolle score, including Δ-sCr, was created and compared with the original Zwolle score. Δ-sCr was also compared between low (Zwolle score ≤3) and non-low-risk patients (Zwolle score >3). The primary endpoint is 30-day mortality and the secondary endpoints are in-hospital mortality and complications. Thirty-day mortality was 1.5% in low-risk patients (35 patients) and 9.2% in non-low-risk patients (92 patients). The Modified-Zwolle score had a better performance than the original Zwolle score in all endpoints: 30-day mortality (area under curve 0.853 versus 0.810, P < 0.001), in-hospital mortality (0.889 versus 0.845, P < 0.001) and complications (0.728 versus 0.719, P = 0.037). Reclassification of patients lead to a net reclassification improvement of 6.8%. Additionally, both original Zwolle score low-risk patients and non-low-risk patients who had a Δ-sCr ≥0.3 mg/dl had higher 30-day mortality (low-risk: 1% versus 6.6%, P < 0.001; non-low-risk 4.4% versus 20.7%, P < 0.001), in-hospital mortality and complications. CONCLUSION: Δ-sCr enhanced the performance of Zwolle score and was associated with higher 30-day mortality, in-hospital mortality and complications in low and non-low-risk patients. This data may assist the selection of low-risk patients who will safely benefit from early discharge after STEMI.

Failed Apoptosis Enhances Melanoma Cancer Cell Aggressiveness.

Triggering apoptosis remains an efficient strategy to treat cancer. However, apoptosis is no longer a final destination since cancer cells can undergo partial apoptosis without dying. Recent evidence shows that partial mitochondrial permeabilization and non-lethal caspase activation occur under certain circumstances, although it remains unclear how failed apoptosis affects cancer cells. Using a cancer cell model to trigger non-lethal caspase activation, we find that melanoma cancer cells undergoing failed apoptosis have a particular transcriptomic signature associated with focal adhesions, transendothelial migration, and modifications of the actin cytoskeleton. In line with this, cancer cells surviving apoptosis gain migration and invasion properties in vitro and in vivo. We further demonstrate that failed apoptosis-associated gain in invasiveness is regulated by the c-Jun N-terminal kinase (JNK) pathway, whereas its RNA sequencing signature is found in metastatic melanoma. These findings advance our understanding of how cell death can both cure and promote cancer.

Netrin-1 and Its Receptor DCC Are Causally Implicated in Melanoma Progression.

Deleted in colorectal cancer (DCC), the receptor for the multifunctional cue netrin-1, acts as a tumor suppressor in intestinal cancer and lung metastasis by triggering cancer cell death when netrin-1 is lowly expressed. Recent genomic data highlighted that DCC is the third most frequently mutated gene in melanoma; we therefore investigated whether DCC could act as a melanoma tumor suppressor. Reexpressing DCC in human melanoma cell lines promoted tumor cell death and tumor growth inhibition in xenograft mouse models. Genetic silencing of DCC prodeath activity in a BRAFV600E mouse model increased the proportion of mice with melanoma, further supporting that DCC is a melanoma tumor suppressor. Netrin-1 expression was elevated in melanoma compared with benign melanocytic lesions. Upregulation of netrin-1 in the skin cells of a BRAFV600E-mutated murine model reduced cancer cell death and promoted melanoma progression. Therapeutic antibody blockade of netrin-1 combined with dacarbazine increased overall survival in several mouse melanoma models. Together, these data support that interfering with netrin-1 could be a viable therapeutic approach in patients with netrin-1-expressing melanoma. SIGNIFICANCE: Netrin-1 and its receptor DCC regulate melanoma progression, suggesting therapeutic targeting of this signaling axis as a viable option for melanoma treatment.

New-Onset Atrial Fibrillation in St-Segment Elevation Myocardial Infarction: Predictors and Impact on Therapy And Mortality / Fibrilação Auricular de Novo no Infarto Agudo do Miocárdio com Supradesnível do Segmento ST: Preditores e Impacto na Terapêutica e Mortalidade

Abstract Backgrund: New-onset atrial fibrillation complicating acute myocardial infarction represents an important challenge, with prognostic significance. Objective: To study the incidence, impact on therapy and mortality, and to identify predictors of development of new-onset atrial fibrillation during hospital stay for ST-segment elevation myocardial infarction. Methods: We studied all patients with ST-elevation myocardial infarction included consecutively, between 2010 and 2017, in a Portuguese national registry and compared two groups: 1 - no atrial fibrillation and 2 - new-onset atrial fibrillation. We adjusted a logistic regression model data analysis to assess the impact of new-onset atrial fibrillation on in-hospital mortality and to identify independent predictors of its development. A p value < 0.05 was considered significant. Results: We studied 6325 patients, and new-onset atrial fibrillation was found in 365 (5.8%). Reperfusion was successfully accomplished in both groups with no difference regarding type of reperfusion. In group 2, therapy with beta-blockers and angiotensin-conversion enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs) was less frequent, 20.6% received anticoagulation at discharge and 16.1% were on triple therapy. New-onset atrial fibrillation was associated with more in-hospital complications and mortality. However, it was not found as an independent predictor of in-hospital mortality. We identified age, prior stroke, inferior myocardial infarction and complete atrioventricular block as independent predictors of new-onset atrial fibrillation. Conclusion: New-onset atrial fibrillation remains a frequent complication of myocardial infarction and is associated with higher rate of complications and in-hospital mortality. Age, prior stroke, inferior myocardial infarction and complete atrioventricular block were independent predictors of new onset atrial fibrillation. Only 36.7% of the patients received anticoagulation at discharge.

Resumo Fundamento: A fibrilação auricular de novo no contexto de infarto agudo do miocárdio representa um importante desafio com potencial impacto prognóstico. Objetivo: Determinar a incidência, impacto na terapêutica e mortalidade, e identificar possíveis preditores do aparecimento de fibrilação auricular de novo durante o internamento por infarto agudo do miocárdio com supradesnivelamento do segmento ST. Métodos: Estudamos todos os pacientes com infarto agudo do miocárdio com supradesnivelamento do segmento ST inseridos consecutivamente de 2010 a 2017 num registro nacional português e comparamos dois grupos: 1 - sem fibrilação auricular; 2- com fibrilação auricular de novo. Efetuamos análise com modelo de regressão logística para avaliar o impacto de fibrilação auricular de novo na mortalidade intra-hospitalar e identificar preditores independentes para o seu aparecimento. Para teste de hipóteses, considerou-se significativo p < 0,05. Resultados: Estudamos 6325 pacientes, dos quais 365 (5.8%) apresentaram fibrilação auricular de novo. Não houve diferença no número de pacientes reperfundidos nem na estratégia de reperfusão. No grupo 2, terapêutica com betabloqueadores e IECA/ARA foi menos frequente, 20.6% tiveram alta sob anticoagulação oral e 16.1% sob terapêutica tripla. A fibrilação auricular de novo associou-se a maior incidência de complicações e mortalidade intra-hospitalar, mas não foi preditor independente de mortalidade intra-hospitalar. Identificamos idade, acidente vascular cerebral prévio, infarto inferior e bloqueio auriculoventricular completo como preditores independentes de fibrilação auricular de novo. Conclusões: A fibrilação auricular de novo continua sendo uma complicação frequente do infarto agudo do miocárdio, estando associada a aumento das complicações e mortalidade intra-hospitalar. Apenas 36.7% desses pacientes teve alta sob anticoagulação.

New-Onset Atrial Fibrillation in St-Segment Elevation Myocardial Infarction: Predictors and Impact on Therapy And Mortality.

BACKGRUND: New-onset atrial fibrillation complicating acute myocardial infarction represents an important challenge, with prognostic significance. OBJECTIVE: To study the incidence, impact on therapy and mortality, and to identify predictors of development of new-onset atrial fibrillation during hospital stay for ST-segment elevation myocardial infarction. METHODS: We studied all patients with ST-elevation myocardial infarction included consecutively, between 2010 and 2017, in a Portuguese national registry and compared two groups: 1 - no atrial fibrillation and 2 - new-onset atrial fibrillation. We adjusted a logistic regression model data analysis to assess the impact of new-onset atrial fibrillation on in-hospital mortality and to identify independent predictors of its development. A p value < 0.05 was considered significant. RESULTS: We studied 6325 patients, and new-onset atrial fibrillation was found in 365 (5.8%). Reperfusion was successfully accomplished in both groups with no difference regarding type of reperfusion. In group 2, therapy with beta-blockers and angiotensin-conversion enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs) was less frequent, 20.6% received anticoagulation at discharge and 16.1% were on triple therapy. New-onset atrial fibrillation was associated with more in-hospital complications and mortality. However, it was not found as an independent predictor of in-hospital mortality. We identified age, prior stroke, inferior myocardial infarction and complete atrioventricular block as independent predictors of new-onset atrial fibrillation. CONCLUSION: New-onset atrial fibrillation remains a frequent complication of myocardial infarction and is associated with higher rate of complications and in-hospital mortality. Age, prior stroke, inferior myocardial infarction and complete atrioventricular block were independent predictors of new onset atrial fibrillation. Only 36.7% of the patients received anticoagulation at discharge.

Cancer-Associated Fibroblasts Produce Netrin-1 to Control Cancer Cell Plasticity.

Netrin-1 is upregulated in a large fraction of human neoplasms. In multiple animal models, interference with netrin-1 is associated with inhibition of tumor growth and metastasis. Although netrin-1 upregulation was initially described in cancer cells, we report here that in the human colorectal cancer database, the expression of netrin-1 and its receptor UNC5B correlates with a cancer-associated fibroblasts (CAF) signature. Both colon and lung CAF secreted netrin-1 when cocultured with respective cancer cells, and netrin-1 upregulation in CAF was associated with increased cancer cell stemness. Pharmacologic inhibition of netrin-1 with a netrin-1-mAb (Net1-mAb) abrogated the CAF-mediated increase of cancer stemness both in coculture experiments and in mice. Net-1-mAb inhibited intercellular signaling between CAF and cancer cells by modulating CAF-mediated expression of cytokines such as IL6. Together these data demonstrate that netrin-1 is upregulated not only in cancer cells but also in cancer-associated stromal cells. In addition to its direct activity on cancer cells, inhibition of netrin-1 may reduce proneoplastic CAF-cancer cell cross-talk, thus inhibiting cancer plasticity. SIGNIFICANCE: Netrin-1, a navigation cue during embryonic development, is upregulated in cancer-associated fibroblasts and regulates cancer cell stemness.

Left main and/or three-vessel disease in patients with non-ST-segment elevation myocardial infarction and low-risk GRACE score: Prevalence, clinical outcomes and predictors.

INTRODUCTION: A low-risk GRACE score identifies patients with a lower incidence of major cardiac events, however it can erroneously classify patients with severe coronary artery disease as low-risk. We assessed the prevalence, clinical outcomes and predictors of left main and/or three-vessel disease (LM/3VD) in non-ST-elevation acute myocardial infarction (NSTEMI) patients with a GRACE score of ≤108 at admission. METHODS: Using data from the Portuguese Registry on Acute Coronary Syndromes, 1196 patients with NSTEMI and a GRACE score of ≤108 who underwent coronary angiography were studied. Independent predictors of LM/3VD and its impact on in-hospital complications and one-year mortality were retrospectively analyzed. RESULTS: LM/3VD was present in 18.2% of patients. Its prevalence was higher in males and associated with hypertension, diabetes, previous myocardial infarction, heart failure and peripheral arterial disease (PAD). Although there were no differences in in-hospital complications, these patients had higher mortality (0.9 vs. 0.0%) and more major adverse cardiac and cerebrovascular events (MACCE) (4.1 vs. 2.5%, p=0.172), and higher one-year mortality (2.4 vs. 0.5%, p=0.005). Independent predictors of LM/3VD were age (OR 1.03; 95% CI 1.01-1.0, p=0.003), male gender (OR 2.56; 95% CI 1.56-4.17, p<0.001), heart rate (1.02; 95% CI 1.01-1.03, p<0.001), PAD (OR 3.21; 95% CI 1.47-7.00, p<0.001) and heart failure (OR 3.38; 95% CI 1.02-11.15, p=0.046). CONCLUSIONS: LM/3VD was found in one in five patients. These patients had a tendency for higher in-hospital mortality and more MACCE, and higher one-year mortality. Simple clinical variables could help predict this severe coronary anatomy.

Hey1- and p53-dependent TrkC proapoptotic activity controls neuroblastoma growth.

The neurotrophin-3 (NT-3) receptor tropomyosin receptor kinase C (TrkC/NTRK3) has been described as a dependence receptor and, as such, triggers apoptosis in the absence of its ligand NT-3. This proapoptotic activity has been proposed to confer a tumor suppressor activity to this classic tyrosine kinase receptor (RTK). By investigating interacting partners that might facilitate TrkC-induced cell death, we have identified the basic helix-loop-helix (bHLH) transcription factor Hey1 and importin-α3 (karyopherin alpha 4 [KPNA4]) as direct interactors of TrkC intracellular domain, and we show that Hey1 is required for TrkC-induced apoptosis. We propose here that the cleaved proapoptotic portion of TrkC intracellular domain (called TrkC killer-fragment [TrkC-KF]) is translocated to the nucleus by importins and interacts there with Hey1. We also demonstrate that Hey1 and TrkC-KF transcriptionally silence mouse double minute 2 homolog (MDM2), thus contributing to p53 stabilization. p53 transcriptionally regulates the expression of TrkC-KF cytoplasmic and mitochondrial interactors cofactor of breast cancer 1 (COBRA1) and B cell lymphoma 2-associated X (BAX), which will subsequently trigger the intrinsic pathway of apoptosis. Of interest, TrkC was proposed to constrain tumor progression in neuroblastoma (NB), and we demonstrate in an avian model that TrkC tumor suppressor activity requires Hey1 and p53.

The Activity of a Hexameric M17 Metallo-Aminopeptidase Is Associated With Survival of Mycobacterium tuberculosis.

Mycobacterium tuberculosis is one of the most prevalent human pathogens causing millions of deaths in the last years. Moreover, tuberculosis (TB) treatment has become increasingly challenging owing to the emergence of multidrug resistant M. tuberculosis strains. Thus, there is an immediate need for the development of new anti-TB drugs. Proteases appear to be a promising approach and may lead to shortened and effective treatments for drug-resistant TB. Although the M. tuberculosis genome predicts more than 100 genes encoding proteases, only a few of them have been studied. Aminopeptidases constitute a set of proteases that selectively remove amino acids from the N-terminus of proteins and peptides and may act as virulence factors, essential for survival and maintenance of many microbial pathogens. Here, we characterized a leucine aminopeptidase of M. tuberculosis (MtLAP) as a cytosolic oligomeric metallo-aminopeptidase. Molecular and enzymatic properties lead us to classify MtLAP as a typical member of the peptidase family M17. Furthermore, the aminopeptidase inhibitor bestatin strongly inhibited MtLAP activity, in vitro M. tuberculosis growth and macrophage infection. In murine model of TB, bestatin treatment reduced bacterial burden and lesion in the lungs of infected mice. Thus, our data suggest that MtLAP participates in important metabolic pathways of M. tuberculosis necessary for its survival and virulence and consequently may be a promising target for new anti-TB drugs.

Spontaneous coronary artery dissection: Still a lot to learn.

Non-atherosclerotic spontaneous coronary artery dissection (SCAD) is an uncommon but probably underdetected pathological substrate for acute coronary syndrome. Clinical associations have been noted, like female gender and young age, but its pathophysiology is not yet fully understood. In this report we describe the case of a 50-year-old woman, without cardiovascular risk factors presenting with non-ST segment elevation myocardial infarction, in whom SCAD was diagnosed. Treatment was initially conservative but due to aggravation of the dissection she eventually underwent a complex percutaneous coronary intervention, requiring implantation of multiple stents, but with a good clinical outcome. The procedure was guided by optical coherence tomography (OCT). Carefully analyzing the combined pictures of OCT and angiography, the dissection appeared to be filled with a clear fluid, but not contrast.

Acute kidney injury in acute coronary syndromes - An important multifactorial consequence.

INTRODUCTION: Acute kidney injury (AKI) is a pathological phenomenon with a negative impact on outcomes in different clinical scenarios. Its mechanism in acute coronary syndrome (ACS) is not completely understood, and measures to prevent it are not uniform. We set out to study the incidence, clinical relevance, predictors and possible implications for patient management of AKI in ACS. METHODS: Using data from a multicenter national registry on ACS, we retrospectively analyzed predictors of AKI and its impact on outcomes (in-hospital complications and one-year mortality). All ACS types were included. AKI was defined as an increase in serum creatinine of ≥0.3 mg/dl (≥26.4 µmol/l) and/or by ≥1.5 times baseline. RESULTS: A total of 7808 ACS patients were included in the analysis, 1369 (17.5%) of whom developed AKI. AKI was shown to be an independent predictor of in-hospital major bleeding (odds ratio [OR] 2.09; 95% confidence interval [CI] 1.19-3.64; p=0.01), mortality (OR 4.72; 95% CI 2.94-7.56; p<0.001) and one-year mortality (hazard ratio 2.01; 95% CI 1.51-2.68; p<0.001). The incidence of AKI was associated with older age, history of hypertension, renal failure and stroke/transient ischemic attack, Killip class >1 on admission and left ventricular ejection fraction <50%. Performance of coronary angiography or angioplasty were not associated with AKI. Diuretics during admission were predictors of AKI only in patients in Killip class 1. CONCLUSIONS: AKI is an important finding in ACS, with a significant impact on hard clinical endpoints such as in-hospital and one-year mortality. It is associated with easily identifiable clinical factors and an invasive strategy does not increase its incidence.