Extracellular Matrix Protein-1 as a Mediator of Inflammation-Induced Fibrosis After Myocardial Infarction

Irreversible fibrosis is a hallmark of myocardial infarction (MI) and heart failure. Extracellular matrix protein-1 (ECM-1) is up-regulated in these hearts, localized to fibrotic, inflammatory, and perivascular areas. ECM-1 originates predominantly from fibroblasts, macrophages, and pericytes/vascular cells in uninjured human and mouse hearts, and from M1 and M2 macrophages and myofibroblasts after MI. ECM-1 stimulates fibroblast-to-myofibroblast transition, up-regulates key fibrotic and inflammatory pathways, and inhibits cardiac fibroblast migration. ECM-1 binds HuCFb cell surface receptor LRP1, and LRP1 inhibition blocks ECM-1 from stimulating fibroblast-to-myofibroblast transition, confirming a novel ECM-1-LRP1 fibrotic signaling axis. ECM-1 may represent a novel mechanism facilitating inflammation-fibrosis crosstalk.

Fibulin-3 is necessary to prevent cardiac rupture following myocardial infarction

Despite the high prevalence of heart failure in the western world, there are few effective treatments. Fibulin-3 is a protein involved in extracellular matrix (ECM) structural integrity, however its role in the heart is unknown. We have demonstrated, using single cell RNA-seq, that fibulin-3 was highly expressed in quiescent murine cardiac fibroblasts, with expression highest prior to injury and late post-infarct (from ~ day-28 to week-8). In humans, fibulin-3 was upregulated in left ventricular tissue and plasma of heart failure patients. Fibulin-3 knockout (Efemp1-/-) and wildtype mice were subjected to experimental myocardial infarction. Fibulin-3 deletion resulted in significantly higher rate of cardiac rupture days 3-6 post-infarct, indicating a weak and poorly formed scar, with severe ventricular remodelling in surviving mice at day-28 post-infarct. Fibulin-3 knockout mice demonstrated less collagen deposition at day-3 post-infarct, with abnormal collagen fibre-alignment. RNA-seq on day-3 infarct tissue revealed upregulation of ECM degradation and inflammatory genes, but downregulation of ECM assembly/structure/organisation genes in fibulin-3 knockout mice. GSEA pathway analysis showed enrichment of inflammatory pathways and a depletion of ECM organisation pathways. Fibulin-3 originates from cardiac fibroblasts, is upregulated in human heart failure, and is necessary for correct ECM organisation/structural integrity of fibrotic tissue to prevent cardiac rupture post-infarct.

Paracrine Factors Released by Stem Cells of Mesenchymal Origin and their Effects in Cardiovascular Disease: A Systematic Review of Pre-clinical Studies

Mesenchymal stem cell (MSC) therapy has gained significant traction in the context of cardiovascular repair, and have been proposed to exert their regenerative effects via the secretion of paracrine factors. In this systematic review, we examined the literature and consolidated available evidence for the “paracrine hypothesis”. Two Ovid SP databases were searched using a strategy encompassing paracrine mediated MSC therapy in the context of ischemic heart disease. This yielded 86 articles which met the selection criteria for inclusion in this study. We found that the MSCs utilized in these articles were primarily derived from bone marrow, cardiac tissue, and adipose tissue. We identified 234 individual protective factors across these studies, including VEGF, HGF, and FGF2; which are proposed to exert their effects in a paracrine manner. The data collated in this systematic review identifies secreted paracrine factors that could decrease apoptosis, and increase angiogenesis, cell proliferation, and cell viability. These included studies have also demonstrated that the administration of MSCs and indirectly, their secreted factors can reduce infarct size, and improve left ventricular ejection fraction, contractility, compliance, and vessel density. Furthering our understanding of the way these factors mediate repair could lead to the identification of therapeutic targets for cardiac regeneration.

The Role of Pathological Aging in Cardiac and Pulmonary Fibrosis

Aging promotes a range of degenerative pathologies characterized by progressive losses of tissue and/or cellular function. Fibrosis is the hardening, overgrowth and scarring of various tissues characterized by the accumulation of extracellular matrix components. Aging is an important predisposing factor common for fibrotic heart and respiratory disease. Age-related processes such as senescence, inflammaging, autophagy and mitochondrial dysfunction are interconnected biological processes that diminish the regenerative capacity of the aged heart and lung and have been shown to play a crucial role in cardiac fibrosis and idiopathic pulmonary fibrosis. This review focuses on these four processes of aging in relation to their role in fibrosis. It has long been established that the heart and lung are linked both functionally and anatomically when it comes to health and disease, with an ever-expanding aging population, the incidence of fibrotic disease and therefore the number of fibrosis-related deaths will continue to rise. There are currently no feasible therapies to treat the effects of chronic fibrosis therefore highlighting the importance of exploring the processes of aging and its role in inducing and exacerbating fibrosis of each organ. The focus of this review may help to highlight potential avenues of therapeutic exploration

Novel role of extracellular matrix protein 1 (ECM1) in cardiac aging and myocardial infarction

INTRODUCTION

The prevalence of heart failure increases in the aging population and following myocardial infarction (MI), yet the extracellular matrix (ECM) remodeling underpinning the development of aging- and MI-associated cardiac fibrosis remains poorly understood. A link between inflammation and fibrosis in the heart has long been appreciated, but has mechanistically remained undefined. We investigated the expression of a novel protein, extracellular matrix protein 1 (ECM1) in the aging and infarcted heart.

METHODS

Young adult (3-month old) and aging (18-month old) C57BL/6 mice were assessed. Young mice were subjected to left anterior descending artery-ligation to induce MI, or transverse aortic constriction (TAC) surgery to induce pressure-overload cardiomyopathy. Left ventricle (LV) tissue was collected early and late post-MI/TAC. Bone marrow cells (BMCs) were isolated from young healthy mice, and subject to flow cytometry. Human cardiac fibroblast (CFb), myocyte, and coronary artery endothelial & smooth muscle cell lines were cultured; human CFbs were treated with recombinant ECM1. Primary mouse CFbs were cultured and treated with recombinant angiotensin-II or TGF-β1. Immunoblotting, qPCR and mRNA fluorescent in-situ hybridization (mRNA-FISH) were conducted on LV tissue and cells.

RESULTS

ECM1 expression was upregulated in the aging LV, and in the infarct zone of the LV early post-MI. No significant differences in ECM1 expression were found late post-MI or at any time-point post-TAC. ECM1 was not expressed in any resident cardiac cells, but ECM1 was highly expressed in BMCs, with high ECM1 expression in granulocytes. Flow cytometry of bone marrow revealed ECM1 expression in large granular leucocytes. mRNA-FISH revealed that ECM1 was indeed expressed by inflammatory cells in the infarct zone at day-3 post-MI. ECM1 stimulation of CFbs induced ERK1/2 and AKT activation and collagen-I expression, suggesting a pro-fibrotic role.

CONCLUSIONS

ECM1 expression is increased in ageing and infarcted hearts but is not expressed by resident cardiac cells. Instead it is expressed by bone marrow-derived granulocytes. ECM1 is sufficient to induce cardiac fibroblast stimulation in vitro. Our findings suggest ECM1 is released from infiltrating inflammatory cells, which leads to cardiac fibroblast stimulation and fibrosis in aging and MI. ECM1 may be a novel intermediary between inflammation and fibrosis.

The Processes and Mechanisms of Cardiac and Pulmonary Fibrosis

Fibrosis is the formation of fibrous connective tissue in response to injury. It is characterized by the accumulation of extracellular matrix components, particularly collagen, at the site of injury. Fibrosis is an adaptive response that is a vital component of wound healing and tissue repair. However, its continued activation is highly detrimental and a common final pathway of numerous disease states including cardiovascular and respiratory disease. Worldwide, fibrotic diseases cause over 800,000 deaths per year, accounting for ~45% of total deaths. With an aging population, the incidence of fibrotic disease and subsequently the number of fibrosis-related deaths will rise further. Although, fibrosis is a well-recognized cause of morbidity and mortality in a range of disease states, there are currently no viable therapies to reverse the effects of chronic fibrosis. Numerous predisposing factors contribute to the development of fibrosis. Biological aging in particular, interferes with repair of damaged tissue, accelerating the transition to pathological remodeling, rather than a process of resolution and regeneration. When fibrosis progresses in an uncontrolled manner, it results in the irreversible stiffening of the affected tissue, which can lead to organ malfunction and death. Further investigation into the mechanisms of fibrosis is necessary to elucidate novel, much needed, therapeutic targets. Fibrosis of the heart and lung make up a significant proportion of fibrosis-related deaths. It has long been established that the heart and lung are functionally and geographically linked when it comes to health and disease, and thus exploring the processes and mechanisms that contribute to fibrosis of each organ, the focus of this review, may help to highlight potential avenues of therapeutic investigation.

Mental health nurses can increase capability and capacity in primary care by educating practice nurses: an evaluation of an education programme in England

Most people with a mental health problem in England are cared for by clinicians in primary care who may have had little or no training in this area. Our aim was to develop an accessible education programme which was appropriate to the learning needs of this workforce. A survey of the mental health and well-being training needs and preferred learning methods of practice nurses was undertaken, then a programme of education was developed by a primary care mental health expert. Teaching was delivered by mental health nurses who were trained as educators. Both the practice nurses and mental health nurses felt their clinical practice would improve as a result of being involved in this programme. To sustain the learning, mental health nurses were supported by attending and then leading their own action learning sets. This model of education can be adapted and used by health organizations both nationally and internationally. Research is required to find out whether training practice nurses using this programme has an impact on patients.

Pilot of BRAF mutation analysis in indeterminate, suspicious and malignant thyroid FNA cytology

BACKGROUND

BRAF V600E mutation has been reported to show a high specificity for papillary thyroid carcinoma (PTC). Using this marker to upgrade 'indeterminate' or 'suspicious' thyroid fine needle aspiration (FNA) cytology to 'malignant' could potentially allow one-stage therapeutic total thyroidectomy.

METHODS

For a 14-month period, FNA cytology specimens in the Thy3-5 categories, which are the UK equivalents of indeterminate (Thy3a, atypical; Thy3f, follicular), suspicious for malignancy (Thy4) and malignant (Thy5) in the Bethesda System, underwent BRAF mutation testing by melt curve analysis. The results were correlated with histology.

RESULTS

We tested 123 cytology specimens of which 12 (9.8%) failed. The BRAF mutation rate in the remainder was 16.2% (18/111), with 93 showing the wild-type. Seventeen mutations were V600E and one was non-V600E. The rate of mutation increased significantly (P < 0.0001 if Thy3a and Thy3f were combined) with the cytology category: 1/42 Thy3a (2.4%), 1/36 Thy3f (2.8%), 4/15 Thy4 (26.7%), 12/18 Thy5 (66.7%). All BRAF mutations correlated with PTC on histology, except for one recurrent PTC without histology. One mutation-positive case with Thy3a cytology showed the target lesion to be a 10-mm follicular adenoma on histology with an immediately adjacent 4-mm micro-PTC, in a patient who did not require total thyroidectomy.

CONCLUSION

BRAF mutational analysis by melt curve analysis is feasible in routine thyroid cytology, and in our series had a 100% specificity for PTC in subsequent histology. The application of BRAF analysis could be useful for indeterminate cytology, but we suggest that it would be most appropriate and cost-effective for Thy4/suspicious cases, for which it could enable one-stage therapeutic surgery in the context of multidisciplinary discussion. In contrast, the sensitivity is low and there is no role for avoiding diagnostic thyroid surgery if wild-type BRAF is found.

Comparison of five clustering algorithms to classify phytoplankton from flow cytometry data

BACKGROUND

Artificial neural networks (ANNs) have been shown to be valuable in the analysis of analytical flow cytometric (AFC) data in aquatic ecology. Automated extraction of clusters is an important first stage in deriving ANN training data from field samples, but AFC data pose a number of challenges for many types of clustering algorithm. The fuzzy k-means algorithm recently has been extended to address nonspherical clusters with the use of scatter matrices. Four variants were proposed, each optimizing a different measure of clustering "goodness."

METHODS

With AFC data obtained from marine phytoplankton species in culture, the four fuzzy k-means algorithm variants were compared with each other and with another multivariate clustering algorithm based on critical distances currently used in flow cytometry.

RESULTS

One of the algorithm variants (adaptive distances, also known as the Gustafson--Kessel algorithm) was found to be robust and reliable, whereas the others showed various problems.

CONCLUSIONS

The adaptive distances algorithm was superior in use to the clustering algorithms against which it was tested, but the problem of automatic determination of the number of clusters remains to be addressed.

A double-blind, placebo-controlled trial of nefazodone in the treatment of patients hospitalized for major depression

BACKGROUND

There are few published placebo-controlled clinical trials demonstrating the efficacy of the newer antidepressants in markedly or severely depressed hospitalized patients. This study demonstrates the efficacy of nefazodone compared with placebo in the treatment of patients hospitalized for major depression.

METHOD

Nefazodone and placebo treatment were compared in a 6-week trial of 120 patients hospitalized for DSM-III-R diagnosed major depression (without psychosis) at 2 study centers. Efficacy was evaluated using standard psychiatric rating scales, and patients were monitored for safety.

RESULTS

Nefazodone treatment resulted in a significant reduction (p < .01) of the 17-item Hamilton Rating Scale for Depression (HAM-D-17) total score compared with placebo from the end of the first treatment week through the end of the study (-12.2 nefazodone vs. -7.7 placebo). At the end of the trial, significantly more nefazodone-treated patients (50%) than placebo-treated patients (29%) had responded, as indicated by their Clinical Global Impressions-Improvement score (p = .021) or by a > or = 50% reduction in their HAM-D-17 scores (p = .017). Significantly more patients treated with nefazodone (36%) than placebo-treated patients (14%) had a HAM-D-17 score < or = 10 at the end of treatment (p = .004). Significant treatment differences (p < .01) in favor of nefazodone were also seen in the Montgomery-Asberg Depression Rating Scale; the HAM-D retardation, anxiety, and sleep disturbance factors; and HAM-D item 1 (depressed mood). Patients with dysthymia in addition to major depression also showed significant improvement (p < .05) when treated with nefazodone, with significant differences in response rates seen as early as week 2 and through the end of the trial. The mean nefazodone dose was 491 mg/day at the end of week 2 and 503 mg/day at the end of treatment. Nefazodone was well tolerated, and the number of patients discontinuing owing to adverse events was small, with no significant safety issues noted in either treatment group. Fewer nefazodone-treated than placebo-treated patients discontinued owing to lack of efficacy.

CONCLUSION

Nefazodone was superior to placebo in the treatment of marked to severe major depression in patients requiring hospitalization. The clinical benefit of nefazodone was evident as early as the first week of treatment as judged by several measures of efficacy, with significant differences from placebo sustained throughout the trial.

Survey of the diet of Pima Indians using quantitative food frequency assessment and 24-hour recall. Diabetic Renal Disease Study

OBJECTIVE

A dietary survey was conducted in the Gila River Indian Community in Arizona using two methods of dietary assessment--24-hour recall and quantitative food frequency (QFF) assessment--to determine the usual intake of the population.

DESIGN

Interviews were conducted by Pima women who were trained and monitored by a research dietitian. Energy and nutrient intake were calculated using a computerized dietary database that included specific Pima foods.

SUBJECTS

An age- and sex-stratified sample of 575 Pima Indians (273 men, 302 women) aged 18 to 74 years participated in the study.

STATISTICAL ANALYSES

Spearman correlations were used to compare the results of the two survey methods for energy and each nutrient. Intraclass correlations were used to measure reproducibility.

RESULTS

According to the 24-hour recall, mean reported energy intakes within decades of age were 95% to 112% of those in the US population for Pima women, and 76% to 94% of those in the US population for Pima men. Total energy intake assessed using QFF was 30% higher in men and 33% higher in women than the intake assessed using the 24-hour recall method.

CONCLUSIONS

A large dietary survey conducted using lay interviewers in a Native-American community was as reproducible as studies conducted in the general US population. The Pima diet was distributed among the major nutrients in a proportion similar to the US diet.

Therapeutic dose range of nefazodone in the treatment of major depression

The therapeutic dose range of nefazodone for treatment of major depression was examined in a series of placebo-controlled efficacy studies carried out during phase 2 and 3 premarketing clinical evaluation. Nefazodone is a new antidepressant drug with pharmacologic effects on both serotonin and norepinephrine neurotransmitters. The usual starting dose of nefazodone for depressed patients, unless they are being switched from a serotonin selective reuptake inhibitor (SSRI), is 100 mg. b.i.d. A lower starting dose is recommended for elderly patients or patients being treated with an SSRI. Following assessment of the patient's clinical response after the first week of therapy, the daily dose should be adjusted upward for most patients. In the efficacy studies, the majority of patients were being maintained on a dose of 300 to 500 mg daily at the end of the acute treatment period. The side effects of nefazodone most often related to dosage were sedation, nausea, and visual symptoms. Imipramine-treated patients, on the other hand, had a high incidence of dry mouth, constipation, and asthenia. In these studies, nefazodone was found to be effective and well tolerated by patients, the majority of whom were being maintained at a 300- to 500-mg/day dose, following an initial starting dose of 100 mg b.i.d.

Intravenous sotalol for the termination of supraventricular tachycardia and atrial fibrillation and flutter: a multicenter, randomized, double-blind, placebo-controlled study. Sotalol Multicenter Study Group

Sotalol is an antiarrhythmic agent with combined beta-blocking and class III antiarrhythmic properties. This study was designed to assess the safety and efficacy of sotalol in terminating supraventricular tachycardia (SVT), atrial fibrillation (AFib), and atrial flutter (AFl). Ninety-three patients with spontaneous or induced SVT (n = 45) or AF (AFib or AFl; n = 48) with a ventricular rate of > or = 120 beats/min were studied. In the first phase, the double-blind phase, patients were randomly assigned to receive placebo or intravenous (i.v.) sotalol, 1.0 or 1.5 mg/kg. If SVT or AF did not convert to sinus rhythm or if the ventricular rate did not slow to < 100 beats/min within 30 minutes, patients then entered the second phase, the open-label phase, which also lasted 30 minutes, and were given 1.5 mg/kg iv sotalol. In the SVT group, during the double-blind phase conversion to sinus rhythm occurred in 2 (14%) of 14 of patients who received placebo, 10 (67%) of 15 who received sotalol, 1.0 mg/kg (p < 0.05 vs placebo), and 10 (67%) of 15 who received 1.5 mg/kg sotalol (p < 0.05 vs placebo); during the open-label phase, 1.5 mg/kg i.v. sotalol converted 7 (41%) of 17 of patients. In the AF group, during the double-blind phase conversion to sinus rhythm occurred in 2 (14%) of 14 of patients who received placebo, 2 (11%) of 18 who received 1.0 mg/kg sotalol (p not significant [NS] vs placebo), and 2 (13%) of 16 who received 1.5 mg/kg sotalol (p = NS vs placebo); in these groups, a > 20% reduction of ventricular rate without conversion to sinus rhythm occurred in 0 (0%) of 14, 13 (72%) of 18 (p < 0.05 vs placebo), and 12 (75%) of 16 of patients (p < 0.05 vs placebo), respectively; during the open-label phase, 1.5 mg/kg i.v. sotalol converted 7 (30%) of 23 of patients. The most common adverse events were hypotension and dyspnea. During the double-blind phase they occurred in 10% of patients who received placebo, 9% of those who received 1.0 mg/kg i.v. sotalol (p = NS vs placebo), and 10% of those who received 1.5 mg/kg i.v. sotalol (p = NS vs placebo). Most of these events were mild to moderate, but all were transient and clinically manageable.(ABSTRACT TRUNCATED AT 400 WORDS)

Glomerular function in Pima Indians with noninsulin-dependent diabetes mellitus of recent onset

Differential solute clearances were used to characterize glomerular function in 20 Pima Indians with noninsulin-dependent diabetes mellitus (NIDDM) of less than 3 yr duration. 28 Pima Indians with normal glucose tolerance served as controls. In the diabetic group, the glomerular filtration rate (GFR, iothalamate clearance) exceeded the control value by 15% (140 +/- 6 vs. 122 +/- 5 ml/min, P less than 0.01). A corresponding 12% increase in renal plasma flow (RPF) was not statistically significant and did not account fully for the observed hyperfiltration, suggesting a concomitant elevation of the ultrafiltration pressure or coefficient. The median albumin excretion ratio in NIDDM exceeded control by almost twofold (10.1 vs. 5.8 mg/g creatinine), a trend which just failed to achieve statistical significance (P = 0.06). Fractional clearances of dextrans of broad size distribution were also elevated in diabetic subjects, significantly so for larger dextrans of between 48 and 60 A radius. A theoretical analysis of dextran transport through a heteroporous membrane revealed glomerular pores in NIDDM to be uniformly shifted towards pores of larger size than in controls. We conclude that an impairment of barrier size selectivity combined with high GFR elevates the filtered protein load in NIDDM of recent onset. We propose that enhanced transglomerular trafficking of protein may predispose to sclerosis of glomeruli in those Pima Indians with NIDDM who ultimately develop diabetic nephropathy.