Serum matrix metalloproteinase-3 as a novel marker for risk stratification of patients with nonischemic dilated cardiomyopathy

Inhibition of ERK 1/2 pathway downregulates YAP1/TAZ signaling in human cardiomyocytes exposed to hyperglycemic conditions

Hyperglycemia-mediated cardiac dysfunction is an acute initiator in the development of vascular complications, leading to cardiac fibrosis. To investigate the effects of hyperglycemia-mediated changes in cardiomyocytes, cells were cultured in-vitro under normoglycemic (5 mM or 25 mM D-glucose) and hyperglycemic (5 → 50 mM or 25 → 50 mM D-glucose) conditions, respectively. After 24-h of hyperglycemic exposure, cells were collected for RNA-sequencing (RNA-seq) studies to further investigate the differentially expressed genes (DEG) related to inflammation and fibrosis in samples cultured under hyperglycemic-in comparison with normoglycemic-conditions. Western Blotting was done to evaluate the protein expression of YAP1/TAZ under hyperglycemia induced stress conditions, as it is known to be involved in fibrotic and vascular inflammatory-mediated conditions. RNA-seq revealed the DEG of multiple targets including matrix metalloproteinases and inflammatory mediators, whose expression was significantly altered in the 5 → 50 mM in comparison with the 25 → 50 mM condition. Western Blotting showed a significant upregulation of the protein expression of the YAP1/TAZ pathway under these conditions as well (5 → 50 mM). To further probe the relationship between the inflammatory extracellular-signal-regulated kinase (ERK 1/2) and its downstream effects on YAP1/TAZ expression we studied the effect of inhibition of the ERK 1/2 signaling cascade in the 5 → 50 mM condition. The application of an ERK 1/2 inhibitor inhibited the expression of the YAP1/TAZ protein in the 5 → 50 mM condition, and this strategy may be useful in preventing and improving hyperglycemia associated cardiovascular damage and inflammation.

Identification of the molecular mechanisms underlying dilated cardiomyopathy via bioinformatic analysis of gene expression profiles

In the present study, gene expression profiles of patients with dilated cardiomyopathy (DCM) were re-analyzed with bioinformatics tools to investigate the molecular mechanisms underlying DCM. Gene expression dataset GSE3585 was downloaded from Gene Expression Omnibus, which included seven heart biopsy samples obtained from patients with DCM and five healthy controls. Differential analysis was performed using a Limma package in R to screen for differentially expressed genes (DEGs). Functional enrichment analysis was subsequently conducted for DEGs using the Database for Annotation, Visualization and Integration Discovery. A protein-protein interaction (PPI) network was constructed using information from Search Tool for the Retrieval of Interacting Genes software. A total of 89 DEGs were identified in the patients with DCM, including 67 upregulated and 22 downregulated genes. Functional enrichment analysis demonstrated that the downregulated genes predominantly encoded chromosomal proteins and transport-related proteins, which were significantly associated with the biological processes of ‘nucleosome assembly’, ‘chromatin assembly’, ‘protein-DNA complex assembly’, ‘nucleosome organization’ and ‘DNA packaging’ (H1 histone family member 0, histone cluster 1 H1c, histone cluster 1 H2bd and H2A histone family member Z). The upregulated genes detected in the present study encoded secreted proteins or phosphotransferase, which were associated with biological processes including ‘cell adhesion’ [connective tissue growth factor (CTGF)], ‘skeletal system development’ [CTGF and insulin-like growth factor binding protein 3 (IGFBP3)], ‘muscle organ development’ (SMAD7) and ‘regulation of cell migration’ [SMAD7, IGFBP3 and insulin receptor (INSR)]. Notably, signal transducer and activator of transcription 3, SMAD7, INSR, CTGF, exportin 1, IGFBP3 and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha were hub nodes with the higher degree in the PPI network. Therefore, the results of the present study suggested that DEGs may alter the biological processes of ‘nucleosome formation’, ‘cell adhesion’, ‘skeletal system development’, ‘muscle organ development’ and ‘regulation of cell migration’ in the development of DCM.

Changes in collagen metabolism account for ventricular functional recovery following beta-blocker therapy in patients with chronic heart failure

While beta blockade improves left ventricular (LV) function in patients with chronic heart failure (CHF), the mechanisms are not well known. This study aimed to examine whether changes in myocardial collagen metabolism account for LV functional recovery following beta-blocker therapy in 62 CHF patients with reduced ejection fraction (EF). LV function was echocardiographically measured at baseline and 1, 6, and 12 months after bisoprolol therapy along with serum markers of collagen metabolism including C-terminal telopeptide of collagen type I (CITP) and matrix metalloproteinase (MMP)-2. Deceleration time of mitral early velocity (DcT) increased even in the early phase, but LVEF gradually improved throughout the study period. Heart rate (HR) was reduced from the early stage, and CITP gradually decreased. LVEF and DcT increased more so in patients with the larger decreases in CITP (r = -0.33, p < 0.05; r = -0.28, p < 0.05, respectively), and HR (r = -0.31, p < 0.05; r = -0.38, p < 0.05, respectively). In addition, there were greater decreases in CITP, MMP-2 and HR from baseline to 1, 6, or 12 months in patients with above-average improvement in LVEF than in those with below-average improvement in LVEF. Similar results were obtained in terms of DcT. There was no significant correlation between the changes in HR and CITP. In conclusion, improvement in LV systolic/diastolic function was greatest in patients with the larger inhibition of collagen degradation. Changes in myocardial collagen metabolism are closely related to LV functional recovery somewhat independently from HR reduction.

Role of various proteases in cardiac remodeling and progression of heart failure

It is believed that cardiac remodeling due to geometric and structural changes is a major mechanism for the progression of heart failure in different pathologies including hypertension, hypertrophic cardiomyopathy, dilated cardiomyopathy, diabetic cardiomyopathy, and myocardial infarction. Increases in the activities of proteolytic enzymes such as matrix metalloproteinases, calpains, cathepsins, and caspases contribute to the process of cardiac remodeling. In addition to modifying the extracellular matrix, both matrix metalloproteinases and cathepsins have been shown to affect the activities of subcellular organelles in cardiomyocytes. The activation of calpains and caspases has been identified to induce subcellular remodeling in failing hearts. Proteolytic activities associated with different proteins including caspases, calpain, and the ubiquitin-proteasome system have been shown to be involved in cardiomyocyte apoptosis, which is an integral part of cardiac remodeling. This article discusses and compares how the activities of various proteases are involved in different cardiac abnormalities with respect to alterations in apoptotic pathways, cardiac remodeling, and cardiac dysfunction. An imbalance appears to occur between the activities of some proteases and their endogenous inhibitors in various types of hypertrophied and failing hearts, and this is likely to further accentuate subcellular remodeling and cardiac dysfunction. The importance of inhibiting the activities of both extracellular and intracellular proteases specific to distinct etiologies, in attenuating cardiac remodeling and apoptosis as well as biochemical changes of subcellular organelles, in heart failure has been emphasized. It is suggested that combination therapy to inhibit different proteases may prove useful for the treatment of heart failure.

Plasma metalloproteinase-9 and restrictive filling pattern as major predictors of outcome in patients with ischemic cardiomyopathy

OBJECTIVE

Assessment of plasma matrix metalloproteinase-9 (MMP-9) and Doppler markers of increased left ventricular (LV) filling pressure may be added to risk stratify patients with ischemic cardiomyopathy (IC). Therefore, we aimed at investigating the value of plasma MMP-9 and restrictive filling pattern (RFP) in IC patients.

METHODS

Eighty-eight consecutive patients hospitalized for heart failure (LV ejection fraction ≤ 40%) due to IC were enrolled. A complete M-mode and two-dimensional echo-Doppler examination were performed. Patients were defined as having RFP if they had a mitral E wave deceleration time<150 ms. Plasma MMP-9 and N-terminal protype-B natriuretic peptide levels were assessed at the time of the index echocardiogram. The end point was all-cause mortality or hospitalization for worsening HF. Follow-up period was 25 ± 17 months.

RESULTS

Median value of MMP-9 was 714 ng/ml. On univariate analysis, a number of measurements predicted the composite end point: NYHA class>2, RFP, MMP-9>60.5 ng/ml, LV ejection fraction<27%, anemia, pulmonary pressure ≥ 35 mm Hg, N-terminal protype-B natriuretic peptide>1742 pg/ml, and glomerular filtration rate<60 ml/min/1.73 m(2). Independent variables of outcome were anemia (HR=1.9, p=0.031), and the combination of plasma MMP-9 and RFP (HR=3.2, p=0.004). On Kaplan-Meier survival curves, patients with elevated MMP-9 levels and RFP had the lowest event-free survival rate (log-rank: 29.0, p<0.0001). The net reclassification improvement showed a significant increase in the prediction model when elevated MMP-9 and RFP were added to the base model that included clinical, biochemical and echocardiographic parameters (p<0.0001).

CONCLUSION

MMP-9 levels and RFP have an incremental predictive value to risk classify IC patients.

Osteopontin-stimulated expression of matrix metalloproteinase-9 causes cardiomyopathy in the mdx model of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD), caused by mutations in the dystrophin gene, is a common and lethal form of muscular dystrophy. With progressive disease, most patients succumb to death from respiratory or heart failure, or both. However, the mechanisms, especially those governing cardiac inflammation and fibrosis in DMD, remain less understood. Matrix metalloproteinase (MMPs) are a group of extracellular matrix proteases involved in tissue remodeling in both physiologic and pathophysiologic conditions. Previous studies have shown that MMP-9 exacerbates myopathy in dystrophin-deficient mdx mice. However, the role and the mechanisms of action of MMP-9 in cardiac tissue and the biochemical mechanisms leading to increased levels of MMP-9 in mdx mice remain unknown. Our results demonstrate that the levels of MMP-9 are increased in the heart of mdx mice. Genetic ablation of MMP-9 attenuated cardiac injury, left ventricle dilation, and fibrosis in 1-y-old mdx mice. Echocardiography measurements showed improved heart function in Mmp9-deficient mdx mice. Deletion of the Mmp9 gene diminished the activation of ERK1/2 and Akt kinase in the heart of mdx mice. Ablation of MMP-9 also suppressed the expression of MMP-3 and MMP-12 in the heart of mdx mice. Finally, our experiments have revealed that osteopontin, an important immunomodulator, contributes to the increased amounts of MMP-9 in cardiac and skeletal muscle of mdx mice. This study provides a novel mechanism for development of cardiac dysfunction and suggests that MMP-9 and OPN are important therapeutic targets to mitigating cardiac abnormalities in patients with DMD.

Plasma matrix metalloproteinase-9 better predicts outcome than N-terminal protype-B natriuretic peptide in patients with systolic heart failure and a high prevalence of coronary artery disease

Metalloproteinases have been proposed as biochemical markers of left ventricular (LV) remodeling in systolic heart failure (HF). However, their role in the prognostic stratification of these patients remains controversial. In the present study, we aimed at investigating the value of plasma metalloproteinases-3 and -9 in comparison with N-terminal protype-B natriuretic peptide in patients with systolic HF. One hundred and 27 consecutive patients hospitalized for systolic HF (LV ejection fraction < 45%) were enrolled. Coronary artery disease (CAD) was the aetiology in 67% of the study patients. Plasma metalloproteinases-3 and -9 and N-terminal protype-B natriuretic peptide levels were assessed. A complete echocardiographic and Doppler examination was also performed. Follow-up period was 24-15 months. On univariate analysis, a number of measurements predicted cardiac events in the following order of power: NYHA class >2, LV ejection fraction < 25%, metalloproteinases-9 > 238 ng/ml, mitral E wave deceleration time < 150 ms, N-terminal protype-B natriuretic peptide > 1586 pg/ml and metalloproteinases-3 > 15 ng/ml. However, on multivariate analysis the only independent variables of cardiac events were NYHA class (OR=2.26, p=0.059) and plasma metalloproteinases-9 (OR=2.00, p=0.029). On Kaplan-Meier survival analysis, patients with elevated levels of metalloproteinases-9 exhibited a significantly worse event free-survival at 45 months than those without (21% vs. 54%, log-rank: 13.93, p=0.0002). A worse survival was also observed in patients with elevated N-terminal protype-B natriuretic peptide levels with respect to those without (18% vs. 46%, log-rank: 9.11, p=0.025). Our results demonstrated the value of plasma metalloproteinases-9 levels for prognostication of patients with systolic HF and a high prevalence of CAD.

Circulating matrix metalloproteinase-3 and metalloproteinase-9 and tissue Doppler measures of diastolic dysfunction to risk stratify patients with systolic heart failure

Abnormal matrix metalloproteinase (MMP) activity and diastolic dysfunction may affect left ventricular (LV) remodeling and prognosis, but it is not known whether the combined evaluation of MMP-3 and MMP-9 and variables of diastolic dysfunction are useful for the risk stratification of patients with systolic heart failure (HF). Therefore, this study was designed to assess the value of combining circulating levels of MMPs and tissue Doppler measures of LV diastolic dysfunction to risk-stratify patients with systolic HF. Consecutive patients with systolic HF due to either ischemic or nonischemic cardiomyopathy (n = 134) and LV ejection fractions <45% were submitted to complete echocardiographic and Doppler examinations. The ratio of mitral E peak velocity and averaged e' velocity (E/e') was calculated. Plasma levels of MMP-3 and MMP-9 were measured at the time of index echocardiography. All-cause mortality was defined as the end point. The mean LV ejection fraction was 28 +/- 9%. There was a total of 32 deaths during follow-up (24 +/- 14 months). Several clinical, biochemical, Doppler, and echocardiographic parameters were associated with the outcome on univariate Cox regression analysis. After statistical adjustment for the potentially confounding factors by multivariate analysis, E/e' (hazard ratio 1.11, p = 0.0028), ejection fraction (hazard ratio 0.92, p = 0.017), and MMP-9 (hazard ratio 1.01, p = 0.027) remained significant independent predictors of the end point. Kaplan-Meier curves showed that survival was worse in patients with E/e' ratios >/=13 and MMP-9 levels >89.9 ng/mL (p <0.0001). In conclusion, the assessment of circulating MMP levels and tissue Doppler measures of LV diastolic dysfunction may improve the prognostic stratification of patients with systolic HF.

Emerging concepts in cardiac matrix biologyThis article is one of a selection of papers published in a special issue on Advances in Cardiovascular Research

The cardiac extracellular matrix, far from being merely a static support structure for the heart, is now recognized to play central roles in cardiac development, morphology, and cell signaling. Recent studies have better shaped our understanding of the tremendous complexity of this active and dynamic network. By activating intracellular signal cascades, the matrix transduces myocardial physical forces into responses by myocytes and fibroblasts, affecting their function and behavior. In turn, cardiac fibroblasts and myocytes play active roles in remodeling the matrix. Coupled with the ability of the matrix to act as a dynamic reservoir for growth factors and cytokines, this interplay between the support structure and embedded cells has the potential to exert dramatic effects on cardiac structure and function. One of the clearest examples of this occurs when cell–matrix interactions are altered inappropriately, contributing to pathological fibrosis and heart failure. This review will examine some of the recent concepts that have emerged regarding exactly how the cardiac matrix mediates these effects, how our collective vision of the matrix has changed as a result, and the current state of attempts to pharmacologically treat fibrosis.

Time-course of health status in patients with rheumatoid arthritis during the first year of treatment with infliximab

OBJECTIVES

A longitudinal study was performed to examine changes in health status in comparison with rheumatoid arthritis (RA) inflammation in patients with RA during the first 54 weeks of infliximab (IFX) treatment.

METHODS

Health status in active RA patients (n=13) was assessed monthly using the Arthritis Impact Measurement Scale 2 (AIMS2) and the VAS-GH during the first year of IFX treatment. Simultaneously, RA activity was assessed using inflammation markers, MMP-3 and the Disease Activity Score in 28 joints (DAS-28) based on CRP [DAS-28(CRP)] and ESR[DAS-28(ESR)].

RESULTS

Serum CRP and ESR decreased significantly from 2.14+/-0.52mg/dL and 56.9+/-6.96mm/h, respectively, at baseline to 0.24+/-0.11mg/dL and 31.6+/-4.39mm/h, respectively, at 2 weeks after initiation of IFX. Other inflammatory markers and MMP-3 were also suppressed significantly after 2 weeks of IFX treatment. DAS-28(CRP) and DAS-28(ESR) were also significantly decreased after 2 weeks and suppression of both DAS values remained significant until 54 weeks of IFX treatment. After initiation of IFX, patient-reported general health also showed a significant improvement based on the changes in the six summary component scores on the AIMS2 (physical, affect, symptom, role, social interaction, and patient satisfaction). These scores all improved progressively until 14-18 weeks after initiation of IFX treatment, and then exhibited a temporary but insignificant exacerbation. The six components of the physical score also improved in a time-dependent manner until 14-18 weeks, but the scores for walking and bending, hand and finger function, arm function, self-care, and household tasks showed significant exacerbation at 22-30 weeks. The score for mobility level did not show this change.

CONCLUSION

IFX treatment significantly improved both RA disease activity and health status in active RA patients. Time-dependent improvement of ADL until 14-18 weeks after initiation of IFX treatment, as reflected in the six components of the physical score, might have contributed to the temporary exacerbation of health status thereafter in these patients.

Cytokines and matrix metalloproteinases as potential biomarkers in chronic heart failure

Heart failure (HF) is accompanied by the upregulation of bioactive signaling molecules, known as cytokines, and a family of downstream proteases, matrix metalloproteinases (MMPs). It is now apparent that these molecules contribute to adverse myocardial remodeling during HF. Elevated levels of cytokines and MMPs exist in the myocardium and can subsequently spill over into the systemic circulation. The purpose of this article is to examine clinical studies of HF that have quantified levels of different types of cytokines, MMPs and endogenous tissue inhibitors of MMPs in relation to this disease process. HF is a complex syndrome that can develop from various etiologies and can be characterized into two distinct phenotypes: systolic and diastolic. This article will present recent clinical studies that have identified significant differences between the cytokine and MMP circulating profile of systolic and diastolic HF patients. In general, elevated levels of cytokines and MMPs exist in systolic HF patients when compared with diastolic HF patients, whereas diastolic HF patients have elevated levels of cytokines and MMPs when compared with controls. Therefore, future studies distinguishing between HF phenotypes may provide more consistent results in determining possible analytes to be used as biomarkers. Furthermore, this article will emphasize why standardization of analytical techniques and establishment of referent cytokine and MMP levels are necessary if these analytes are to be used as biomarkers for the diagnosis, prognosis and evaluation of treatment in the context of HF.

Circulating matrix metalloproteinase-8 (MMP-8) and MMP-9 are increased in chronic periodontal disease and decrease after non-surgical periodontal therapy

BACKGROUND

Periodontal disease shares risk factors with cardiovascular diseases and other systemic inflammatory diseases. The present study was designed to assess the circulating matrix metalloproteinases (MMPs) from chronic periodontal disease patients and, subsequently, after periodontal therapy.

METHODS

We compared the plasma concentrations of MMP-2, MMP-3, MMP-8, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2, and total gelatinolytic activity in patients with periodontal disease (n=28) with those of control subjects (n=22) before and 3 months after non-surgical periodontal therapy.

RESULTS

Higher plasma MMP-3, MMP-8, and MMP-9 concentrations were found in periodontal disease patients compared with healthy controls (all P<0.05), whereas MMP-2, TIMP-1, and TIMP-2 levels were not different. Treatment decreased plasma MMP-8 and MMP-9 concentrations by 35% and 39%, respectively (both P<0.02), while no changes were found in controls. MMP-2, MMP-3, TIMP-1, and TIMP-2 remained unaltered in both groups. Plasma gelatinolytic activity was higher in periodontal disease patients compared with controls (P<0.001) and decreased after periodontal therapy (P<0.05).

CONCLUSIONS

This study showed increased circulating MMP-8 and MMP-9 levels and proteolytic activity in periodontal disease patients that decrease after periodontal therapy. The effects of periodontal therapy suggest that it may attenuate inflammatory chronic diseases.