Biomarkers of extracellular matrix metabolism (MMP-9 and TIMP-1) and risk of stroke, myocardial infarction, and cause-specific mortality: cohort study

Disease types and pathogenic mechanisms induced by PM2.5 in five human systems: An analysis using omics and human disease databases

Atmospheric fine particulate matter (PM2.5) can harm various systems in the human body. Due to limitations in the current understanding of epidemiology and toxicology, the disease types and pathogenic mechanisms induced by PM2.5 in various human systems remain unclear. In this study, the disease types induced by PM2.5 in the respiratory, circulatory, endocrine, and female and male urogenital systems have been investigated and the pathogenic mechanisms identified at molecular level. The results reveal that PM2.5 is highly likely to induce pulmonary emphysema, reperfusion injury, malignant thyroid neoplasm, ovarian endometriosis, and nephritis in each of the above systems respectively. The most important co-existing gene, cellular component, biological process, molecular function, and pathway in the five systems targeted by PM2.5 are Fos proto-oncogene (FOS), extracellular matrix, urogenital system development, extracellular matrix structural constituent conferring tensile strength, and ferroptosis respectively. Differentially expressed genes that are significantly and uniquely targeted by PM2.5 in each system are BTG2 (respiratory), BIRC5 (circulatory), NFE2L2 (endocrine), TBK1 (female urogenital) and STAT1 (male urogenital). Important disease-related cellular components, biological processes, and molecular functions are specifically induced by PM2.5. For example, response to wounding, blood vessel morphogenesis, body morphogenesis, negative regulation of response to endoplasmic reticulum stress, and response to type I interferon are the top uniquely existing biological processes in each system respectively. PM2.5 mainly acts on key disease-related pathways such as the PD-L1 expression and PD-1 checkpoint pathway in cancer (respiratory), cell cycle (circulatory), apoptosis (endocrine), antigen processing and presentation (female urogenital), and neuroactive ligand-receptor interaction (male urogenital). This study provides a novel analysis strategy for elucidating PM2.5-related disease types and is an important supplement to epidemiological investigation. It clarifies the risks of PM2.5 exposure, elucidates the pathogenic mechanisms, and provides scientific support for promoting the precise prevention and treatment of PM2.5-related diseases.

Features of The Dynamics of Profibrotic Markers and Regression of Left Ventricular Hypertrophy After Renal Denervation in Patients With Resistant Hypertension and Stenosing Atherosclerosis of the Coronary Arteries

AIM

To compare the changes in serum concentrations of matrix metalloproteinases (MMPs) and their tissue inhibitor (TIMP) to the dynamics of blood pressure (BP) and parameters of left ventricular hypertrophy (LVH) 6 months after renal denervation (RD) in patients with resistant arterial hypertension (RAH) and complicated coronary atherosclerosis.

MATERIAL AND METHODS

In 22 RAH patients with complicated coronary atherosclerosis (revascularization and/or history of myocardial infarction (MI)), 24-hour BP monitoring, echocardiography, and measurement of blood MMPs and TIMP were performed at baseline and six months after RD. The comparison group consisted of 48 RAH patients without a history of coronary revascularization or MI.

RESULTS

In 6 months after RD, BP was decreased comparably in both groups. In the group of complicated atherosclerosis, there were no significant changes in profibrotic markers or LVH parameters. Thus, at baseline and after 6 months, the values of the studied indicators were the following: left ventricular myocardial mass (LVMM) 233.1±48.1 and 243.0±52.0 g, LVMM index 60.6±14.5 and 62.8±10 .9 g/m2.7, proMMP-1 4.9 [2.1; 7.7] and 3.6 [2.0; 9.4]  ng/ml, MMP-2 290.4 [233.1; 352.5] and 352.2 [277.4; 402.9] ng/ml, MMP-9 220.6 [126.9; 476.7] and 263.5 [82.9; 726.2] ng/ml, TIMP-1 395.7 [124.7; 591.4] and 424.2 [118.2; 572.0] ng/ml, respectively. In the comparison group, on the contrary, there was a significant decrease in LVMM from 273.6±83.3 g to 254.1±70.4 g, LVMM index from 67.1±12.3 to 64.0±14.4 g/m2.7, proMMP-1 from 7.2 [3.6; 11.7] to 5.9 [3.5; 10.9] ng/ml, MMP-2 from 328.9 [257.1; 378.1] to 272.8 [230.2; 343.2] ng/ml, MMP-9 from 277.9 [137.0; 524.0] to 85.5 [34.2; 225.9] ng/ml, and the MMP-9/TIMP-1 ratio from 0.80 [0.31; 1.30] to 0.24 [0.07; 0.76]. The BP dynamics in this group was inversely correlated with MMP-2 at 6 months (r=-0.38), and the MMP-9/TIMP-1 ratio was correlated with LVMM and the LVMM index at baseline (r=0.39 and r=0.39) and at 6 months (r=0.37 and r=0.32). The change in TIMP-1 from 543.9 [277.5; 674.1] to 469.8 [289.7; 643.6] ng/ml was not significant (p=0.060).

CONCLUSION

In RAH patients with complicated coronary atherosclerosis, the dynamics of profibrotic biomarkers and LVH parameters after RD was absent despite the pronounced antihypertensive effect, probably due to the low reversibility of cardiovascular remodeling processes or more complex regulatory mechanisms of the MMP system.

The TIMP protein family: diverse roles in pathophysiology

The tissue inhibitors of matrix metalloproteinases (TIMPs) are a family of four matrisome proteins classically defined by their roles as the primary endogenous inhibitors of metalloproteinases (MPs). Their functions however are not limited to MP inhibition, with each family member harboring numerous MP-independent biological functions that play key roles in processes such as inflammation and apoptosis. Because of these multifaceted functions, TIMPs have been cited in diverse pathophysiological contexts. Herein, we provide a comprehensive overview of the MP-dependent and -independent roles of TIMPs across a range of pathological conditions. The potential therapeutic and biomarker applications of TIMPs in these disease contexts are also considered, highlighting the biomedical promise of this complex and often misunderstood protein family.

A functional MMP-9-1562C>T polymorphism, MMP-9 serum levels and nephrolithiasis risk in a southern Chinese population

Background

The role of matrix metalloproteinase 9 (MMP-9) in the pathophysiology of chronic kidney disease (CKD), which is associated with a nearly two-fold greater risk for urinary calculi compared to people without CKD, has been demonstrated. The aim of the research is to evaluate the association between MMP-9-1562C>T polymorphism, MMP-9 serum levels and nephrolithiasis risk.

Methods

A hospital-based case-control study involving 302 kidney stone patients and 408 controls without kidney stone from southern China was conducted. Sanger sequencing was used to genotype the MMP-9-1562C>T polymorphism. The serum MMP-9 was measured in 105 kidney stone patients and 77 controls by enzyme-linked immunosorbent assay.

Results

Compared to the control group, the CT genotype was more frequent in nephrolithiasis patients (adjusted OR = 1.60, 95% CI = 1.09-2.37: the risk of developing nephrolithiasis in individuals with CT genotype compared to CC genotype). Moreover, there was also a higher frequency of CT/TT genotypes among patients with nephrolithiasis (adjusted OR = 1.49, 95% CI = 1.02-2.19: the risk of developing nephrolithiasis in individuals with CT/TT genotypes compared to CC genotype). The risk remained for the subgroups of patients aged >53, smokers with pack-years of smoking >20, non-drinkers, non-diabetic patients, patients with hypertension, recurrent episodes and calcium oxalate stones (OR = 2.26, 95% CI = 1.31-3.91; OR = 5.47, 95% CI = 1.10-27.30; OR = 1.76, 95% CI = 1.14-2.72; OR = 1.54, 95% CI = 1.03-2.30; OR = 1.97, 95% CI = 1.01-3.82; OR = 1.67, 95% CI = 1.06-2.62; OR = 1.54, 95% CI = 1.02-2.32, respectively). Biochemical parameters did not differ between genotypes. Compared to controls (18.57 ± 5.80 ng/mL), nephrolithiasis patients had significantly higher serum MMP-9 levels (30.17 ± 6.78 ng/mL, p < 0.001). The serum MMP-9 levels of patients with CT/TT genotypes of MMP-9-1562C>T were significantly higher than those with CC genotype (32.00 ± 6.33 vs. 29.13 ± 6.85 ng/mL, p = 0.037).

Conclusion

The MMP-9-1562C>T polymorphism in association with its soluble protein increased the risk of kidney stone, thus suggesting it could be used as a susceptibility biomarker for nephrolithiasis. Further functional studies and larger studies that include environmental exposure data are needed to confirm the findings.

Cytokinopathy with aberrant cytotoxic lymphocytes and profibrotic myeloid response in SARS-CoV-2 mRNA vaccine-associated myocarditis

Rare immune-mediated cardiac tissue inflammation can occur after vaccination, including after SARS-CoV-2 mRNA vaccines. However, the underlying immune cellular and molecular mechanisms driving this pathology remain poorly understood. Here, we investigated a cohort of patients who developed myocarditis and/or pericarditis with elevated troponin, B-type natriuretic peptide, and C-reactive protein levels as well as cardiac imaging abnormalities shortly after SARS-CoV-2 mRNA vaccination. Contrary to early hypotheses, patients did not demonstrate features of hypersensitivity myocarditis, nor did they have exaggerated SARS-CoV-2-specific or neutralizing antibody responses consistent with a hyperimmune humoral mechanism. We additionally found no evidence of cardiac-targeted autoantibodies. Instead, unbiased systematic immune serum profiling revealed elevations in circulating interleukins (IL-1β, IL-1RA, and IL-15), chemokines (CCL4, CXCL1, and CXCL10), and matrix metalloproteases (MMP1, MMP8, MMP9, and TIMP1). Subsequent deep immune profiling using single-cell RNA and repertoire sequencing of peripheral blood mononuclear cells during acute disease revealed expansion of activated CXCR3+ cytotoxic T cells and NK cells, both phenotypically resembling cytokine-driven killer cells. In addition, patients displayed signatures of inflammatory and profibrotic CCR2+ CD163+ monocytes, coupled with elevated serum-soluble CD163, that may be linked to the late gadolinium enhancement on cardiac MRI, which can persist for months after vaccination. Together, our results demonstrate up-regulation in inflammatory cytokines and corresponding lymphocytes with tissue-damaging capabilities, suggesting a cytokine-dependent pathology, which may further be accompanied by myeloid cell-associated cardiac fibrosis. These findings likely rule out some previously proposed mechanisms of mRNA vaccine--associated myopericarditis and point to new ones with relevance to vaccine development and clinical care.

Harnessing the Plasma Proteome to Mirror Current and Predict Future Cardiac Remodeling After Myocardial Infarction

To identify plasma proteins that mirror current and predict future remodeling after myocardial infarction (MI), we retrospectively interrogated plasma proteomes of day (D)0 control (n = 16) and D3 MI (n = 15) from C57BL/6 J mice (20 ± 1 months). A total of 165 unique proteins were correlated with cardiac physiology variables. We prospectively tested the hypothesis that candidates identified retrospectively would predict cardiac physiology at an extended timepoint (D7 MI) in a second cohort of mice (n = 4 ± 1 months). We also examined human plasma from healthy controls (n = 18) and patients 48 h after presentation for MI (n = 41). Retrospectively, we identified 5 strong reflectors of remodeling (all r ≥ 0.60 and p < 0.05). Prospectively, ApoA1, IgA, IL-17E, and TIMP-1 mirrored current and predicted future remodeling. In humans, cytokine-cytokine receptor signaling was the top enriched KEGG pathway for all candidates. In summary, we identified plasma proteins that serve as useful prognostic indicators of adverse remodeling and progression to heart failure.

Assessment of Atherosclerosis in Ischemic Stroke by means of Ultrasound of Extracranial/Intracranial Circulation and Serum, Urine, and Tissue Biomarkers

It is a common practice to take into consideration age, diabetes, smoking, treated and untreated systolic blood pressure, total cholesterol, and high-density lipoprotein cholesterol for the prediction of atherosclerosis and stroke. There are, however, ultrasound markers in use for the assessment of atherosclerosis and the evaluation of stroke risk. Two areas of investigation are of interest: the carotid artery and the intracranial arterial circulation. Again, within the domain of the carotid artery, two ultrasonic markers have attracted our attention: intima media thickness of the carotid artery and the presence of carotid plaque with its various focal characteristics. In the domain of intracranial circulation, the presence of arterial stenosis and the recruitment of collaterals are considered significant ultrasonic markers for the above-mentioned purpose. On the other hand, a series of serum, urine, and tissue biomarkers are found to be related to atherosclerotic disease. Future studies might address the issue of whether the addition of proven ultrasonic carotid indices to the aforementioned serum, urine, and tissue biomarkers could provide the vascular specialist with a better assessment of the atherosclerotic load and solidify their position as surrogate markers for the evaluation of atherosclerosis and stroke risk.

Leukocyte subtypes, gelatinases, and their tissue inhibitors in a group of subjects with asymptomatic carotid atherosclerosis

In a cohort of subjects with asymptomatic carotid atherosclerosis (ACA), we have evaluated the neutrophil and lymphocyte count and their ratio (NLR), the gelatinases (MMP-2 and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2). At baseline, no difference was observed between ACA subjects and subject control group regarding neutrophil and lymphocyte count while was evident in ACA subjects a significant increase in MMP-2, MMP-9 and TIMP-2 associated to a significant decrease in TIMP-1. Dividing the ACA according to the number of cardiovascular risk factors (CRFs) we have observed an increase in lymphocyte count in the subgroup with 3-5 CRFs. Evaluating the leukocyte subtypes according to all the surrogate markers of insulin resistance has been noted, in the subgroups that exceed the medians of these markers, a significant increase in neutrophil and lymphocyte count without any variation of the NLR. Effecting the same evaluation for the MMP/TIMP pattern we observed, instead, that the same subgroups tend to show a decrease in MMP-2 and an increase in MMP-9. No difference instead for TIMP-1 and TIMP-2. The abnormality of the MMP/TIMP pattern, bearing in mind the cardiometabolic clustering present in this cohort of ACA subjects, would induce to use drugs able not only to cure the cardiometabolic risk factors but also to influence the MMP/TIMP profile.

Macrophages secrete murinoglobulin-1 and galectin-3 to regulate neutrophil degranulation after myocardial infarction

Inflammation presides early after myocardial infarction (MI) as a key event in cardiac wound healing. Ischemic cardiomyocytes secrete inflammatory cues to stimulate infiltration of leukocytes, predominantly macrophages and neutrophils. Infiltrating neutrophils degranulate to release a series of proteases including matrix metalloproteinase (MMP)-9 to break down extracellular matrix and remove necrotic myocytes to create space for the infarct scar to form. While neutrophil to macrophage communication has been explored, the reverse has been understudied. We used a proteomics approach to catalogue the macrophage secretome at MI day 1. Murinoglobulin-1 (MUG1) was the highest-ranked secreted protein (4.1-fold upregulated at MI day 1 vs. day 0 pre-MI cardiac macrophages, p = 0.004). By transcriptomics evaluation, galectin-3 (Lgals3) was 2.2-fold upregulated (p = 0.008) in MI day 1 macrophages. We explored the direct roles of MUG1 and Lgals3 on neutrophil degranulation. MUG1 blunted while Lgals3 amplified neutrophil degranulation in response to phorbol 12-myristate 13-acetate or interleukin-1β, as measured by MMP-9 secretion. Lgals3 itself also stimulated MMP-9 secretion. To determine if MUG1 regulated Lgals3, we co-stimulated neutrophils with MUG1 and Lgals3. MUG1 limited degranulation stimulated by Lgals3 by 64% (p < 0.001). In vivo, MUG1 was elevated in the infarct region at MI days 1 and 3, while Lgals3 increased at MI day 7. The ratio of MUG1 to Lgals3 positively correlated with infarct wall thickness, revealing that MUG1 attenuated infarct wall thinning. In conclusion, macrophages at MI day 1 secrete MUG1 to limit and Lgals3 to accentuate neutrophil degranulation to regulate infarct wall thinning.

Pathophysiology of Circulating Biomarkers and Relationship With Vascular Aging: A Review of the Literature From VascAgeNet Group on Circulating Biomarkers, European Cooperation in Science and Technology Action 18216

Impairment of the arteries is a product of sustained exposure to various deleterious factors and progresses with time; a phenomenon inherent to vascular aging. Oxidative stress, inflammation, the accumulation of harmful agents in high cardiovascular risk conditions, changes to the extracellular matrix, and/or alterations of the epigenetic modification of molecules, are all vital pathophysiological processes proven to contribute to vascular aging, and also lead to changes in levels of associated circulating molecules. Many of these molecules are consequently recognized as markers of vascular impairment and accelerated vascular aging in clinical and research settings, however, for these molecules to be classified as biomarkers of vascular aging, further criteria must be met. In this paper, we conducted a scoping literature review identifying thirty of the most important, and eight less important, biomarkers of vascular aging. Herein, we overview a selection of the most important molecules connected with the above-mentioned pathological conditions and study their usefulness as circulating biomarkers of vascular aging.

P2Y12 receptor blockers are anti-inflammatory drugs inhibiting both circulating monocytes and macrophages including THP-1 cells

P₂Y₁₂ blockade improves patient outcomes after myocardial infarction. As well as antithrombotic effects, anti-inflammatory effects may contribute to this beneficial clinical outcome. Here we aimed to identify potential anti-inflammatory effects of P₂Y₁₂ receptor blockers on monocytes and macrophages. Using flow cytometry, migration assays, flow chambers and RNA microarrays, we investigated the effects of adenosine diphosphate (ADP) and P₂Y₁₂ receptor blockers on blood monocytes, THP-1 monocytes and THP-1 monocytes after differentiation to macrophages. P₂Y₁₂ -expressing platelets can form aggregates with monocytes in circulating blood. Mediated by platelets, ADP results in activation of the integrin receptor Mac-1 on blood monocytes, as detected by the conformation-specific single-chain antibody MAN-1. Via the same association with platelets, THP-1 monocyte adhesion to the endothelial intercellular adhesion molecule 1 (ICAM-1) is induced by ADP. P₂Y₁₂ receptor blockers prevent these ADP effects on monocytes. Interestingly, in contrast to THP-1 monocytes, THP-1 monocytes, after differentiation to macrophages, directly expressed the P₂Y₁₂ receptor and consequently ADP was found to be a potent chemoattractant. Again, P₂Y₁₂ receptor blockers antagonised this effect. Accordingly, stimulation of THP-1 macrophages with ADP caused a substantial change in gene expression pattern and upregulation of several genes associated with inflammation and atherogenesis. These data establish novel anti-inflammatory effects of P₂Y₁₂ receptor blockers on monocytes and macrophages, which are expected to contribute to cardiovascular risk reduction.

A High-Cholesterol Diet Increases Toll-like Receptors and Other Harmful Factors in the Rabbit Myocardium: The Beneficial Effect of Statins

Background: A high-cholesterol diet (HCD) induces vascular atherosclerosis through vascular inflammatory and immunological processes via TLRs. The aim of this study is to investigate the mRNA expression of TLRs and other noxious biomarkers expressing inflammation, fibrosis, apoptosis, and cardiac dysfunction in the rabbit myocardium during (a) high-cholesterol diet (HCD), (b) normal diet resumption and (c) fluvastatin or rosuvastatin treatment. Methods: Forty-eight male rabbits were randomly divided into eight groups (n = 6/group). In the first experiment, three groups were fed with HCD for 1, 2 and 3 months. In the second experiment, three groups were fed with HCD for 3 months, followed by normal chow for 1 month and administration of fluvastatin or rosuvastatin for 1 month. Control groups were fed with normal chow for 90 and 120 days. The whole myocardium was removed; total RNA was isolated from acquired samples, and polymerase chain reaction, reverse transcription PCR and quantitative real-time PCR were performed. Results: mRNA of TLRs 2, 3, 4 and 8; interleukin-6; TNF-a; metalloproteinase-2; tissue inhibitor of metalloproteinase-1; tumor protein 53; cysteinyl aspartate specific proteinase-3; and brain natriuretic peptide (BNP) increased in HCD. Statins but not resumption of a normal diet decreased levels of these biomarkers and increased levels of antifibrotic factors. Conclusions: HCD increases the levels of TLRs; inflammatory, fibrotic and apoptotic factors; and BNP in the rabbit myocardium. Atherogenic diets adversely affect the myocardium at a molecular level and are reversed by statins.

The Cardiac Microenvironment Instructs Divergent Monocyte Fates and Functions in Myocarditis

Two types of monocytes, Ly6C^hi and Ly6C^lo, infiltrate the heart in murine experimental autoimmune myocarditis (EAM). We discovered a role for cardiac fibroblasts in facilitating monocyte-to-macrophage differentiation of both Ly6C^hi and Ly6C^lo cells, allowing these macrophages to perform divergent functions in myocarditis progression. During the acute phase of EAM, IL-17A is highly abundant. It signals through cardiac fibroblasts to attenuate efferocytosis of Ly6C^hi monocyte-derived macrophages (MDMs) and simultaneously prevents Ly6C^lo monocyte-to-macrophage differentiation. We demonstrated an inverse clinical correlation between heart IL-17A levels and efferocytic receptor expressions in humans with heart failure (HF). In the absence of IL-17A signaling, Ly6C^hi MDMs act as robust phagocytes and are less proinflammatory, whereas Ly6C^lo monocytes resume their differentiation into MHCII⁺ macrophages. We propose that MHCII⁺Ly6C^lo MDMs are associated with the reduction of cardiac fibrosis and prevention of the myocarditis sequalae.

Hou et al. show that cardiac fibroblasts facilitate infiltrating Ly6C^hi and Ly6C^lo monocytes to become macrophages. IL-17A trans-signaling through cardiac fibroblasts increases MerTK shedding and promotes a pro-inflammatory and pro-tissue remodeling gene expression profile in Ly6C^hi monocyte-derived macrophages. Paradoxically, IL-17A signaling through cardiac fibroblasts can substantially inhibit Ly6C^lo monocyte-to-macrophage differentiation.

Association of Circulating Tissue Inhibitor of Metalloproteinases-1 and Procollagen Type III Aminoterminal Peptide Levels With Incident Heart Failure and Chronic Kidney Disease

Background Tissue inhibitor of metalloproteinases-1 ( TIMP -1) and procollagen type III aminoterminal peptide are established circulating markers of extracellular matrix remodeling and associated with cardiovascular disease. The association of both biomarkers with incident congestive heart failure and chronic kidney disease ( CKD ) in the community is not well studied. Methods and Results We measured plasma total TIMP -1 and procollagen type III aminoterminal peptide levels in 922 Framingham participants (mean age, 57 years; 57% women) and related both biomarkers to the risk of incident CKD and congestive heart failure in multivariable-adjusted Cox regression models. Plasma total TIMP -1 levels were positively associated with risk of incident CKD (164 events; hazard ratio per 1 SD in log-biomarker, 1.90; 95% CI , 1.53-2.37) in multivariable models, including adjustments for left ventricular mass, C-reactive protein, and B-type natriuretic peptide levels. The association of total TIMP -1 with risk of congestive heart failure was statistically significant in an age- and sex-adjusted model, but was attenuated upon adjustment for conventional risk factors. Blood procollagen type III aminoterminal peptide levels were not related to the risk of CKD or congestive heart failure. Conclusions Higher baseline levels of total TIMP -1 conferred an increased risk for incident CKD , independent of conventional risk factors and circulating biomarkers of chronic systemic inflammation and neurohormonal activation. Our prospective observations in a large community-based sample support the role of matrix remodeling in the pathogenesis of CKD .

Molecular signatures of atherosclerotic plaques: An up-dated panel of protein related markers

Atherosclerosis remains the leading cause of ischemic syndromes such as myocardial infarction or brain stroke, mainly promoted by plaque rupture and subsequent arterial blockade. Identification of vulnerable or high-risk plaques constitutes a major challenge, being necessary to identify patients at risk of occlusive events in order to provide them with appropriate therapies. Clinical imaging tools have allowed the identification of certain structural indicators of prone-rupture plaques, including a necrotic lipidic core, intimal and adventitial inflammation, extracellular matrix dysregulation, and smooth muscle cell depletion and micro-calcification. Additionally, alternative approaches focused on identifying molecular biomarkers of atherosclerosis have also been applied. Among them, proteomics has provided numerous protein markers currently investigated in clinical practice. In this regard, it is quite uncertain that a single molecule can describe plaque rupture, due to the complexity of the process itself. Therefore, it should be more accurate to consider a set of markers to define plaques at risk. Herein, we propose a selection of 76 proteins, from classical inflammatory to recently related markers, all of them identified in at least two proteomic studies analyzing unstable atherosclerotic plaques. Such panel could be used as a prognostic signature of plaque instability.

Elevated circulating metalloproteinase 7 predicts recurrent cardiovascular events in patients with carotid stenosis: a prospective cohort study

BACKGROUND

Major adverse cardiovascular events are the main cause of morbidity and mortality over the long term in patients undergoing carotid endarterectomy. There are few reports assessing the prognostic value of markers of inflammation in relation to the risk of cardiovascular disease after carotid endarterectomy. Here, we aimed to determine whether matrix metalloproteinases (MMP-1, MMP-2, MMP-7, MMP-9 and MMP-10), tissue inhibitor of MMPs (TIMP-1) and in vivo inflammation studied by ¹⁸F-FDG-PET/CT predict recurrent cardiovascular events in patients with carotid stenosis who underwent endarterectomy.

METHODS

This prospective cohort study was carried out on 31 consecutive patients with symptomatic (23/31) or asymptomatic (8/31) severe (> 70%) carotid stenosis who were scheduled for carotid endarterectomy between July 2013 and March 2016. In addition, 26 healthy controls were included in the study. Plasma and serum samples were collected 2 days prior to surgery and tested for MMP-1, MMP-2, MMP-7, MMP-9, MMP-10, TIMP-1, high-density lipoprotein, low-density lipoprotein, high-sensitivity C-reactive protein and erythrocyte sedimentation rate. ¹⁸F-FDG-PET/CT focusing on several territories' vascular wall metabolism was performed on 29 of the patients because of no presurgical availability in 2 symptomatic patients. Histological and immunohistochemical studies were performed with antibodies targeting MMP-10, MMP-9, TIMP-1 and CD68.

RESULTS

The patients with carotid stenosis had significantly more circulating MMP-1, MMP-7 and MMP-10 than the healthy controls. Intraplaque TIMP-1 was correlated with its plasma level (r = 0.42 P = .02) and with ¹⁸F-FDG uptake (r = 0.38 P = .05). We did not find any correlation between circulating MMPs and in vivo carotid plaque metabolism assessed by ¹⁸F-FDG-PET. After a median follow-up of 1077 days, 4 cerebrovascular, 7 cardiovascular and 11 peripheral vascular events requiring hospitalization were registered. Circulating MMP-7 was capable of predicting events over and above the traditional risk factors (HR = 1.15 P = .006). When the model was associated with the variables of interest, the risk predicted by ¹⁸F-FDG-PET was not significant.

CONCLUSIONS

Circulating MMP-7 may represent a novel marker for recurrent cardiovascular events in patients with moderate to severe carotid stenosis. MMP-7 may reflect the atherosclerotic burden but not plaque inflammation in this specific vascular territory.

The Association of Matrix Metalloproteinases with Chronic Kidney Disease and Peripheral Vascular Disease: A Light at the End of the Tunnel?

: Chronic Kidney Disease (CKD) represents a risk factor for fatal and nonfatal cardiovascular (CV) events, including peripheral vascular disease (PVD). This occurs because CKD encompasses several factors that lead to poor prognoses, mainly due to a reduction of the estimated glomerular filtration rate (eGFR), the presence of proteinuria, and the uremic inflammatory milieu. The matrix metalloproteinases (MMPs) are a group of zinc-containing endopeptidases implicated in extracellular matrix (ECM) remodeling, a systemic process in tissue homeostasis. MMPs play an important role in cell differentiation, angiogenesis, inflammation, and vascular damage. Our aim was to review the published evidence regarding the association between MMPs, PVD, and CKD to find possible common pathophysiological mechanisms. MMPs favor ECM deposition through the glomeruli, and start the shedding of cellular junctions and epithelial-mesenchymal transition in the renal tubules. MMP-2 and -9 have also been associated with the presence of systemic vascular damage, since they exert a pro-inflammatory and proatherosclerotic actions. An imbalance of MMPs was found in the context of PVD, where MMPs are predictors of poor prognoses in patients who underwent lower extremity revascularization. MMP circulating levels are increased in both conditions, i.e., that of CKD and PVD. A possible pathogenic link between these conditions is represented by the enhanced production of transforming growth factor-β that worsens vascular calcifications and atherosclerosis and the development of proteinuria in patients with increased levels of MMPs. Proteinuria has been recognized as a marker of systemic vascular damage, and this may explain in part the increase in CV risk that is manifest in patients with CKD and PVD. In conclusion, MMPs can be considered a useful tool by which to stratify CV risk in patients with CKD and PVD. Further studies are needed to investigate the causal-relationships between MMPs, CKD, and PVD, and to optimize their prognostic and predictive (in response to treatments) roles.

Tissue Inhibitor of Matrix Metalloproteinase 1 Increases With Ageing and Can Be Associated With Stroke ― Nested Case-Control Study ―

Background: Increase of collagen in the extracellular matrix occurs with ageing. We investigated whether a collagen marker, tissue inhibitor of matrix metalloproteinase 1 (TIMP-1), was associated with risk of stroke.

Methods and Results: In a nested case-control study of 953 subjects from the general population, we evaluated determinants of TIMP-1 level and stroke risk. Mean subject age was 65.7±8.6 years (53.0% men); TIMP-1 was 72.4±28.2 pg/mL in the control group and 75.3±30.9 pg/mL in the stroke group. The relationship between TIMP-1 quartile and stroke was J-curved. Subjects in the highest TIMP-1 quartile (≥89 ng/mL) had a significantly higher OR of stroke (59–72 ng/mL; OR, 1.90; 95% CI: 1.09–3.31, P=0.023) than those in the second TIMP-1 quartile, and this tended toward significance even after adjusting for confounding factors (P=0.059). Elevation of serum TIMP-1 became more marked after age 65 years. On multiple linear regression analysis, significant determinants of TIMP-1 were older age (B=0.21 per 1 year; 95% CI: 0.52–1.07, P<0.001) and higher systolic blood pressure (SBP; B=0.19 per 1 mmHg, 95% CI: 0.08–0.42, P=0.004).

Conclusions: TIMP-1 increased with ageing and with SBP, and can be associated with stroke.

Compound Danshen Dripping Pill Inhibits Retina Cell Apoptosis in Diabetic Rats

Scope: Diabetic retinopathy (DR) is a severe microvascular complication of diabetes. Previous clinical trials have shown that Compound Danshen Dripping Pill (CDDP) improves DR symptoms. However, the mechanism involved remains unclear.

Procedures: Rats fed a high-fat diet and injected with streptozotocin (STZ) were used as an experimental type 2 diabetes rodent model. CDDP was administered to two groups of diabetic rats at 0.2 and 0.4 g/kg/day via gastric gavage for 12 weeks. After the 12 weeks of treatment, retinal function was evaluated by electroretinography (ERG). Histological staining and TdT-mediated dUTP nick-end labeling (TUNEL) assays were also performed. Retinal genome expression was determined by gene array.

Results: We found that CDDP moderated ERG and histological abnormalities in diabetic rats, independent of blood glucose level. A gene array showed that CDDP changed 262 genes significantly in the diabetic retina. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that differentially expressed genes in the CDDP-treated groups were involved mainly in the apoptosis pathway. Moreover, CDDP reduced the number of TUNEL-positive cells in the diabetic retinas. CDDP prevented the reduction in Bcl-2 expression and the increase in BCL-2 associated X (Bax) and caspase-3 (Casp3) expression in diabetic rats.

Conclusion: Our results suggest that CDDP exerts its neuroprotective functions by inhibiting cell apoptosis in diabetic rats.

Fibrosis as measured by the biomarker, tissue inhibitor metalloproteinase-1, predicts mortality in Age Gene Environment Susceptibility-Reykjavik (AGES-Reykjavik) Study

Background

Fibrosis is a key pathological process in many chronic inflammatory disease states.

Aims

We hypothesized that tissue inhibitor metalloproteinase-1 and matrix metalloproteinase-9 (TIMP-1 and MMP-9), biomarkers of fibrosis, would predict all-cause mortality and we assessed the incremental value of these biomarkers when adjusting for clinical and other biomarkers.

Methods

The cohort included 5511 community-dwelling participants in the AGES-Reykjavik Study. The baseline Cox proportional hazards regression model was based on the Framingham Risk Score variables; we added TIMP-1, MMP-9, serum high-sensitivity C-reactive protein (hsCRP), and estimated glomerular filtration rate (eGFR). The primary outcome was all-cause 10-year mortality. Cause of death was categorized as cardiovascular death (CVD), cancer death, and other causes.

Results

Participants averaged 76 years and 43% were male. Ten-year mortality was 41% (2263 deaths). Of these, 915 (16.6%) died of cardiovascular disease (CVD), 543 (9.9%) with cancer, and 805 (14.6%) from other causes. For 10-year mortality, age was the strongest predictor (log likelihood χ2 = 798.7, P < 0.0001), followed by TIMP-1 (χ2 = 125.2, P < 0.0001), female gender, current smoker, diabetes mellitus, total cholesterol, eGFR (χ2 16.7, P < 0.0001), body mass index, and hsCRP (χ2 11.3, P = 0.0008) in that order. TIMP-1 and hsCRP had the highest continuous net reclassification improvement over the baseline model for 5-year survival [net reclassification index (NRI) 0.28 and 0.19, respectively, both P < 0.0001] and for 10-year survival (NRI 0.19 and 0.11, respectively, both statistically significant).

Conclusion

TIMP-1 is the strongest predictor of all-cause mortality after age. The metabolic pathways regulating extracellular matrix homeostasis and fibrogenic processes appear pathologically relevant and are prognostically important.

The Perineuronal 'Safety' Net? Perineuronal Net Abnormalities in Neurological Disorders

Perineuronal nets (PNN) are extracellular matrix (ECM) assemblies that preferentially ensheath parvalbumin (PV) expressing interneurons. Converging evidence indicates that PV cells and PNN are impaired in a variety of neurological disorders. PNN development and maintenance is necessary for a number of processes within the CNS, including regulation of GABAergic cell function, protection of neurons from oxidative stress, and closure of developmental critical period plasticity windows. Understanding PNN functions may be essential for characterizing the mechanisms of altered cortical excitability observed in neurodegenerative and neurodevelopmental disorders. Indeed, PNN abnormalities have been observed in post-mortem brain tissues of patients with schizophrenia and Alzheimer’s disease. There is impaired development of PNNs and enhanced activity of its key regulator matrix metalloproteinase-9 (MMP-9) in Fragile X Syndrome, a common genetic cause of autism. MMP-9, a protease that cleaves ECM, is differentially regulated in a number of these disorders. Despite this, few studies have addressed the interactions between PNN expression, MMP-9 activity and neuronal excitability. In this review, we highlight the current evidence for PNN abnormalities in CNS disorders associated with altered network function and MMP-9 levels, emphasizing the need for future work targeting PNNs in pathophysiology and therapeutic treatment of neurological disorders.

Tissue inhibitor of metalloproteinases 1 enhances rod survival in the rd1 mouse retina

Retinitis pigmentosa (RP), an inherited retinal degenerative disease, is characterized by a progressive loss of rod photoreceptors followed by loss of cone photoreceptors. Previously, when tissue inhibitor of metalloproteinase 1 (TIMP1), a key extracellular matrix (ECM) regulator that binds to and inhibits activation of Matrix metallopeptidase 9 (MMP9) was intravitreal injected into eyes of a transgenic rhodopsin rat model of RP, S334ter-line3, we discovered cone outer segments are partially protected. In parallel, we reported that a specific MMP9 and MMP2 inhibitor, SB-3CT, interferes with mechanisms leading to rod photoreceptor cell death in an MMP9 dependent manner. Here, we extend our initial rat studies to examine the potential of TIMP1 as a treatment in retinal degeneration by investigating neuroprotective effects in a classic mouse retinal degeneration model, rdPde6b-/- (rd1). The results clearly demonstrate that intravitreal injections of TIMP1 produce extended protection to delay rod photoreceptor cell death. The mean total number of rods in whole-mount retinas was significantly greater in TIMP-treated rd1 retinas (postnatal (P) 30, P35 (P<0.0001) and P45 (P<0.05) than in saline-treated rd1 retinas. In contrast, SB-3CT did not delay rod cell death, leading us to further investigate alternative pathways that do not involve MMPs. In addition to inducing phosphorylated ERK1/2, TIMP1 significantly reduces BAX activity and delays attenuation of the outer nuclear layer (ONL). Physiological responses using scotopic electroretinograms (ERG) reveal b-wave amplitudes from TIMP1-treated retinas are significantly greater than from saline-treated rd1 retinas (P<0.05). In later degenerative stages of rd1 retinas, photopic b-wave amplitudes from TIMP1-treated rd1 retinas are significantly larger than from saline-treated rd1 retinas (P<0.05). Our findings demonstrate that TIMP1 delays photoreceptor cell death. Furthermore, this study provides new insights into how TIMP1 works in the mouse animal model of RP.

Proteolytic biomarkers are related to prognosis in COPD- report from a population-based cohort

BACKGROUND

The imbalance between proteases and anti-proteases is considered to contribute to the development of COPD. Our aim was to evaluate the protease MMP-9, the antiprotease TIMP-1 and the MMP-9/TIMP-1-ratio as biomarkers in relation to prognosis. Prognosis was assessed as lung function decline and mortality. This was done among subjects with COPD in a population-based cohort.

METHODS

In 2005, clinical examinations including spirometry and peripheral blood sampling, were made in a longitudinal population-based cohort. In total, 1542 individuals participated, whereof 594 with COPD. In 2010, 1031 subjects participated in clinical examinations, and 952 subjects underwent spirometry in both 2005 and 2010. Serum MMP-9 and TIMP-1 concentrations were measured with enzyme linked immunosorbent assay (ELISA). Mortality data were collected from the Swedish national mortality register from the date of examination in 2005 until 31st December 2010.

RESULTS

The correlation between biomarkers and lung function decline was similar in non-COPD and COPD, but only significant for MMP-9 and MMP-9/TIMP-1-ratio in non-COPD. Mortality was higher in COPD than non-COPD (16% vs. 10%, p = 0.008). MMP-9 concentrations and MMP-9/TIMP-1 ratios in 2005 were higher among those who died during follow up, as well as among those alive but not participating in 2010, when compared to those participating in the 2010-examination. In non-COPD, male sex, age, burden of smoking, heart disease and MMP-9/TIMP-1 ratio were associated with increased risk for death, while increased TIMP-1 was protective. Among those with COPD, age, current smoking, increased MMP-9 and MMP-9/TIMP-1 ratio were associated with an increased risk for death.

CONCLUSIONS

The expected association between these biomarkers and lung function decline in COPD was not confirmed in this population-based study, probably due to a healthy survivor effect. Still, it is suggested that increased proteolytic imbalance may be of greater prognostic importance in COPD than in non-COPD.

Serum matrix metalloproteinase-8, tissue inhibitor of metalloproteinase and myeloperoxidase in ischemic stroke

BACKGROUND AND AIMS

Matrix metalloproteinase (MMP)-8 and myeloperoxidase (MPO) may contribute to cerebral damage in acute ischemic stroke. We tested the hypothesis that levels of MPO, MMP-8 and the ratio between MMP-8 and its regulator, tissue inhibitor of metalloproteinase (TIMP-1), are increased in acute ischemic stroke and its etiologic subgroups and they correlate with stroke severity.

METHODS

In a cross-sectional case-control study, serum concentrations of MMP-8, MPO and TIMP-1 were assessed within 24 h after admission in 470 first-ever ischemic stroke patients and 809 age- and sex-matched controls, randomly selected from the population. Odds ratios (OR) per decade of log transformed dependent variables were calculated and adjusted for age, sex and vascular risk factors.

RESULTS

Levels of MMP-8 (OR 4.9; 95% CI 3.4-7.2), MMP-8/TIMP-1 ratio (3.0; 2.2-4.1) and MPO (6.6; 4.0-11.0) were independently associated with ischemic stroke. MMP-8 levels differed between etiologic stroke subgroups (p = 0.019, ANOVA), with higher levels in cardioembolic stroke and stroke due to large vessel disease, and lower levels in microangiopathic stroke. MMP-8, MMP-8/TIMP-1 ratio and MPO (p < 0.001) concentrations showed positive associations with stroke severity independent of stroke etiology.

CONCLUSIONS

Concentrations of serum neutrophil markers are increased after ischemic stroke and associate with stroke severity and etiology. The value of these biomarkers in diagnostics and prognostics is worth being evaluated.

Spinal Cord Injury Causes Systolic Dysfunction and Cardiomyocyte Atrophy

Individuals with spinal cord injury (SCI) have been shown to exhibit systolic, and to a lesser extent, diastolic cardiac dysfunction. However, previous reports of cardiac dysfunction in this population are confounded by the changing loading conditions after SCI and as such, whether cardiac dysfunction per se is present is still unknown. Therefore, our aim was to establish if load-independent cardiac dysfunction is present after SCI, to understand the functional cardiac response to SCI, and to explore the changes within the cellular milieu of the myocardium. Here, we applied in vivo echocardiography and left-ventricular (LV) pressure-volume catheterization with dobutamine infusions to our Wistar rodent model of cardiac dysfunction 5 weeks following high (T2) thoracic contusion SCI, while also examining the morphological and transcriptional alterations of cardiomyocytes. We found that SCI significantly impairs systolic function independent of loading conditions (end-systolic elastance in control: 1.35 ± 0.15; SCI: 0.65 ± 0.19 mm Hg/μL). The reduction in contractile indices is accompanied by a reduction in width and length of cardiomyocytes as well as alterations in the LV extracellular matrix. Importantly, we demonstrate that the reduction in the rate (dP/dtmax) of LV pressure rise can be offset with beta-adrenergic stimulation, thereby experimentally implicating the loss of descending sympatho-excitatory control of the heart as a principle cause of LV dysfunction in SCI. Our data provide evidence that SCI induces systolic cardiac dysfunction independent of loading conditions and concomitant cardiomyocyte atrophy that may be underpinned by changes in the genes regulating the cardiac extracellular matrix.

Progression and Characterization of the Accelerated Atherosclerosis in Iliac Artery of New Zealand White Rabbits: Effect of Simvastatin

OBJECTIVE

Although atherosclerosis is described in New Zealand White rabbit's iliac artery, yet details of time-dependent atherosclerosis progression are not well known. Further, a well characterized accelerated model of atherosclerosis is also required for the screening of candidate drugs to target specific steps of atherosclerosis development. The present study extensively characterizes the time-dependent plaque composition and functional responses of the atherosclerosis in rabbit iliac artery and its modification by simvastatin.

METHODS

Atherosclerosis was induced with a combination of balloon injury and atherogenic diet (AD) (1% cholesterol, 6% peanut oil) in rabbit's iliac artery. Atherosclerosis progression was evaluated on days 8, 10, 15, 21, 35, and 56 after AD feeding. The plaque characterization was done using histology, real-time reverse transcription-polymerase chain reaction, and vasoreactivity experiments. The standard anti-hyperlipidemic drug, simvastatin (5 mg·kg·d), was used to investigate its effect on atherosclerotic changes.

RESULTS

Plasma lipids were elevated in a progressive manner after AD feeding from days 8 to 56. Similarly, arterial lipids, Monocyte Chemoattractant Protein-1 (MCP-1) level along with infiltration of macrophages in the lesion area were also increased from day 15 onward. This resulted in a significant increase in the plaque area and intimal-medial thickness ratio in contrast to normal animals. Inflammatory milieu was observed with a significant increase in expression of pro-inflammatory regulators like MCP-1, Tumor Necrosis Factor-α (TNF-α) and Vascular Cell Adhesion Molecule-1 (VCAM-1), whereas anti-inflammatory cytokine interleukin 10 decreased as disease progressed. Endothelial dysfunction was also observed, specifically Acetylcholine (ACh)-induced vasorelaxation was reduced from day 8 onward, whereas the phenylephrine-induced vasoconstriction response was progressively reduced from day 15 in the iliac artery. Ground substances including proteoglycans, α-actin, and collagen content along with metalloproteinase-9 and Tissue inhibitor of metalloproteinases-1 (TIMP-1) inhibitors were significantly augmented at later time points, day 21 onward. Simvastatin treatment for 35 days, at a dose having no significant effect on plasma lipid levels, significantly reduced atherosclerotic progression as evident by reduced macrophage content, inflammatory burden, and extracellular matrix component like proteoglycans and metalloproteinase-9.

CONCLUSIONS

The authors observed that AD feeding with balloon injury in the rabbit iliac artery accelerated the progression of atherosclerosis and exhibited predominant features of type III human lesion within 8 weeks (56 days). Simvastatin treatment for 35 days exhibited anti-atherosclerotic efficacy without significantly lowering the circulating lipids. The current study thus provides an insight into the time-dependent atherosclerotic progression in rabbit iliac artery and highlights its utility for anti-atherosclerotic evaluation of the candidate drugs.

Urine Arsenic and Arsenic Metabolites in U.S. Adults and Biomarkers of Inflammation, Oxidative Stress, and Endothelial Dysfunction: A Cross-Sectional Study

BACKGROUND

Arsenic (As) exposure has been associated with increased risk for cardiovascular disease (CVD) and with biomarkers of potential CVD risk and inflammatory processes. However, few studies have evaluated the effects of As on such biomarkers in U.S. populations, which are typically exposed to low to moderate As concentrations.

OBJECTIVES

We investigated associations between As exposures and biomarkers relevant to inflammation, oxidative stress, and CVD risk in a subset of participants from the New Hampshire Health Study, a population with low to moderate As exposure (n=418).

METHODS

Associations between toenail As, total urine As (uAs), and %uAs metabolites [monomethyl (%uMMA^V), dimethyl (%uDMA^V), and inorganic (%iAs) species] and plasma biomarkers, including soluble plasma vascular and cellular adhesion molecules (VCAM-1 and ICAM-1, respectively), matrix metalloproteinase-9 (MMP-9), tumor necrosis factor-α, plasminogen activator inhibitor-1 (PAI-1), and urinary oxidative stress marker 15-F_2t-isoprostane (15-F_2t-IsoP), were evaluated using linear regression models.

RESULTS

Covariate-adjusted estimates of associations with a doubling of urinary As suggested an 8.8% increase in 15-F_2t-IsoP (95% CI: 3.2, 14.7), and a doubling of toenail As was associated with a 1.7% increase in VCAM-1 (95% CI: 0.2, 3.2). Additionally, a 5% increase in %uMMA was associated with a 7.9% increase in 15-F_2t-IsoP (95% CI: 2.1, 14.1), and a 5% increase in %uDMA was associated with a 2.98% decrease in 15-F_2t-IsoP [(95% CI: -6.1, 0.21); p=0.07]. However, in contrast with expectations, a doubling of toenail As was associated with a 2.3% decrease (95% CI: -4.3, -0.3) in MMP-9, and a 5% increase in %uMMA was associated with a 7.7% decrease (95% CI: -12.6, -2.5) in PAI-1.

CONCLUSION

In a cross-sectional study of U.S. adults, we observed some positive associations of uAs and toenail As concentrations with biomarkers potentially relevant to CVD pathogenesis and inflammation, and evidence of a higher capacity to metabolize inorganic As was negatively associated with a marker of oxidative stress. https://doi.org/10.1289/EHP2062.

Collagen turnover biomarkers and systemic right ventricle remodeling in adults with previous atrial switch procedure for transposition of the great arteries

Background

Myocardial fibrosis is a potential pathophysiological mechanism leading to systemic right ventricular (SRV) deterioration. We hypothesize that circulating levels of collagen deposition markers are elevated in patients with SRV remodeling and this elevation may have a predictive value.

Methods

We prospectively evaluated 56 patients with D-TGA after the atrial switch procedure (mean age 25.6 ± 4.8, range 18–37 years; 67% males). Serum levels of procollagen type III amino-terminal propeptide (PIIINP), collagen type I carboxy-terminal telopeptide (CITP), procollagen type I N-terminal propeptide (PINP), matrix metalloproteinase (MMP 1, MMP 9) and a tissue inhibitor of matrix metalloproteinase (TIMP 1) and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) were measured and compared with healthy controls. The relationship between these serum markers, echocardiographic and cardiac magnetic resonance parameters and the outcome at a follow-up of 61 months (range, 24–85 months) was determined.

Results

Compared with the healthy control group, the study group had significantly higher levels of TIMP1, PIIINP, CITP, PINP and NT-pro-BNP (p<0.05, each). The levels of PIIINP and CITP were significantly higher among patients with an SRV mass index above the mean value. The level of PIIINP was significantly higher among patients with an SRV EDV index above the mean value. CITP was significantly elevated in SRV late gadolinium enhanced (LGE) positive patients, compared to patients without SRV LGE. MMP9 and TIMP1 predicted an adverse clinical outcome on univariate Cox proportional hazard survival analysis in addition to well proven predictors of outcome (SRV EF and NYHA).

Conclusions

We demonstrated a pattern of altered collagen turnover adversely related with the indices of SRV remodeling and an adverse clinical outcome in patients with SRV.

Plasma matrix metalloproteinases are associated with incident cardiovascular disease and all-cause mortality in patients with type 1 diabetes: a 12-year follow-up study

Background

Altered regulation of extracellular matrix remodeling by matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP) may contribute to vascular complications in type 1 diabetes. We investigated associations between plasma MMP-1, -2, -3, -9, -10 and TIMP-1, and cardiovascular events and all-cause mortality in type 1 diabetic patients.

Methods

We prospectively followed 337 type 1 diabetic patients [mean age 41.4 years (9.6), 39% female], 170 with and 167 without diabetic nephropathy, with median follow-up of 12.3 years. Survival analyses were applied to investigate differences in plasma MMP-1, -2, -3, -9, -10, and TIMP-1-levels in patients with and without a cardiovascular event and in those who died vs survivors. All analyses were adjusted for age, sex, duration of diabetes, HbA1c, nephropathy and for other conventional cardiovascular risk factors.

Results

After adjustment for potential confounders, higher MMP-2 plasma levels were significantly associated with higher incidence of cardiovascular events [HR 1.49 (95% CI 1.11; 1.99)], and higher plasma levels of MMP-1 [1.38 (1.07; 1.78)], MMP-2 [1.60 (1.19; 2.15)] and MMP-3 [1.39 (1.05; 1.85)] were associated with all-cause mortality. All associations were independent of low-grade inflammation and endothelial dysfunction as estimated by plasma markers. Associations between MMP-2 and cardiovascular events and between MMP-3 and mortality were attenuated after further adjustment for eGFR and changes in eGFR.

Conclusions

Higher levels of MMP-2 are associated with CVD and higher MMP-1, -2 and -3 with all-cause mortality. In addition, associations between MMP-2 and CVD, and MMP-3 and mortality were attenuated after adjustment for eGFR while both MMPs were associated with eGFR decline, indicating a possible mediating role of eGFR.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0539-1) contains supplementary material, which is available to authorized users.

Plasma levels of matrix metalloproteinase 9 in patients undergoing off-pump coronary artery bypass grafting

BACKGROUND

Matrix metalloproteinase 9 (MMP9) has recently emerged as a risk predictor in patients with cardiovascular diseases. However, little is known about the significance of increased plasma MMP9 in patients with perioperative myocardial injury. We aimed to investigate the role of MMP9 in the occurrence of myocardial injury during off-pump coronary artery bypass grafting (OPCAB).

METHODS

A total of 34 consecutive patients with coronary artery diseases (CAD) were recruited in this prospective, observational study. All patients were operated for OPCAB surgery. Serial blood samples were collected preoperatively and 12 hours after surgery. MMP9, together with cardiac troponin I (cTnI), creatinine kinase myocardial b fraction (CK-MB), C-reactive protein (CRP), and N-terminal pro B-type natriuretic peptide (NT-proBNP) levels in plasma were measured at each time-point.

RESULTS

MMP9 levels increased significantly at 12 hours after surgery, attaining nearly 2 times the baseline levels (P=0.0001). There was a significant correlation between preoperative (pre-OP) circulating levels of MMP9 and the left ventricular ejection fraction (LVEF) (r=0.48; P=0.004) as well as European System for Cardiac Operative Risk Evaluation (EuroSCORE) II (r=0.43; P=0.012). Patients were in New York Heart Association (NYHA) functional class III or IV heart failure showed a significantly higher MMP9 levels (1,348.0±337.2 vs. 630.4±93.0 ng/L, P=0.012) as compared to the patients in NYHA functional class I and II. No significant correlation was observed between MMP9 and age (P=0.612), serum creatinine (P=0.185), CRP (P=0.207), NT-proBNP (P=0.058). A significant correlation was observed in these data between the post-OP MMP9 and cTnI (r=0.35; P=0.003).

CONCLUSIONS

Our study first established a connection between MMP9 and OPCAB procedure, suggesting that MMP9 could be a novel biomarker for identifying perioperative myocardial injury in patients undergoing OPCAB.

Pathological and molecular analyses of atherosclerotic lesions in ApoE-knockout mice

The establishment of consistent and reliable methods for the analysis of atherosclerosis molecular pathways and for testing the efficiency of new therapeutics is of utmost importance. Here, we fed ApoE-knockout (KO) mice with high-fat diet to for 16 weeks to induce atherosclerosis. Atherosclerotic lesions in mice were methodically investigated using pathologic analyses and molecular biology tools. These lesions were histopathologically classified into three categories: early, progressive, and combined lesions. Immunohistochemical analyses showed that both F4/80 (macrophage marker) and tenascin-C are expressed in these lesions. Real-time PCR analysis conducted using formalin-fixed paraffin-embedded tissues with atherosclerotic lesions demonstrated an increase in the levels of many inflammatory chemokines, including Cxcl16, while antibody arrays performed using frozen atherosclerotic tissue samples showed elevated TIMP-1 expression. Subsequent immunohistochemical analyses showed that the expression of CXCL16, TIMP-1, MMP-9, MMP-8, and LOX-1 is localized in the atherosclerotic lesions. We confirmed that the expression of these proteins is localized to atherosclerotic lesion, which suggests their roles in the development of the lesions in ApoE-KO mice. Therefore, this mouse model represents an appropriate tool for elucidating molecular mechanisms underlying the development of atherosclerosis, and a model for the evaluation of therapeutic efficiency of novel drugs.

Gelatinases and their tissue inhibitors in a group of subjects with obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is associated with an elevated risk of cardiovascular events and stroke. Matrix metalloproteinases (MMPs) are endopeptidases involved in extracellular matrix degradation and then in the development and progression of cardiovascular diseases. Our aim was to evaluate plasma levels of gelatinases (MMP-2 and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2) in a group of subjects with OSAS. We enrolled 48 subjects (36 men and 12 women; mean age 49.7 ± 14.68 yrs) with OSAS diagnosed with a 1-night cardiorespiratory study and then we subdivided these subjects into two subgroups according to the apnea/hypopnea index (AHI): Low (L = 21 subjects with AHI <30) and High (H = 27 subjects with AHI >30). We measured plasma concentration of the gelatinases and their inhibitors using ELISA kits. We observed a significant increase in plasma concentration of MMP-9, MMP-2, TIMP-1 and TIMP-2 in the entire group of OSAS subjects and in the two subgroups, with higher levels in the H in comparison with the L subgroup. In the whole group of OSAS subjects we also noted a significant decrease in MMP-9/TIMP-1 ratio in comparison with normal controls. Only MMP-9 was significantly correlated with the severity of the disease, expressed as AHI, with the oxygen desaturation index and also with the mean oxygen saturation. MMPs pattern is altered in OSAS and significantly influenced by the severity of the disease; it probably contributes to the vascular remodeling that leads to the atherosclerotic disease and cardiovascular complications.

Plasma thrombin-cleaved osteopontin as a potential biomarker of acute atherothrombotic ischemic stroke

We investigated whether thrombin-cleaved osteopontin N-terminal is useful as a blood biomarker of acute atherothrombotic ischemic stroke. Acute ischemic stroke patients were prospectively evaluated with brain magnetic resonance imaging and cardiac evaluations for etiological diagnosis according to the Trial of Org 10172 in Acute Stroke Treatment classification. They were divided into the atherothrombotic and non-atherothrombotic groups. Thrombin-cleaved osteopontin N-terminal, osteopontin, matrix metalloproteinase-9, S100B, C-reactive protein and D-dimer levels were measured from blood samples collected at admission. After excluding patients who met the exclusion criteria or had stroke of other/undetermined etiology, 60 of the 100 patients initially enrolled were included in the final analysis. The ischemic stroke subtypes were atherothrombotic (n=28, 46.7%), cardioembolic (n=19, 31.7%) and lacunar (n=13, 21.7%). Thrombin-cleaved osteopontin N-terminal and matrix metalloproteinase-9 levels were significantly higher in the atherothrombotic than in the non-atherothrombotic group (median (interquartile range): 5.83  (0.0-8.6 ) vs. 0.0  (0.0-3.3) pmol l^-1, P=0.03 and 544   (322-749 ) vs. 343   (254-485) ng ml^-1, P=0.01, respectively). After adjustment for the prevalence of hypertension, diabetes and dyslipidemia, thrombin-cleaved osteopontin N-terminal levels of >5.47 pmol l^-1 (odds ratio, 16.81; 95% confidence interval, 3.53-80.10) and matrix metalloproteinase-9 levels of >605.5 ng ml^-1 (6.59; 1.77-24.60) were identified as independent predictors of atherothrombosis. Within 3 h from stroke onset, only thrombin-cleaved osteopontin N-terminal independently predicted atherothrombosis and thus may add valuable, time-sensitive diagnostic information in the early evaluation of ischemic stroke, especially the atherothrombotic subtype.

Periodontal diseases and carotid intima-media thickness in Bangladesh

AIM

To evaluate the relationship between periodontal diseases and subclinical atherosclerosis in a younger and lean South Asian population.

METHODS

We conducted a cross-sectional study in 917 subjects (mean age 46 years and mean body mass index 21.1 kg/m² ) from the Health Effects of Arsenic Longitudinal Study in Bangladesh. Multivariate linear regression models were used to assess the associations between multiple clinical measures of periodontal diseases and carotid intima-media thickness (IMT).

RESULTS

Mean attachment loss (AL) and percentage of sites with AL ≥ 4 mm (% AL ≥ 4) were associated with increased IMT. The IMT was 20.0-μm (95% CI: 2.2, 37.8) and 26.5-μm (95% CI: 8.9, 44.1) higher in subjects in the top quartile of mean AL (>3.72 mm) and % AL ≥ 4 (>58.4%), respectively, compared to those in the bottom quartile. In a subset of 366 subjects, mean AL was positively associated with plasma levels of matrix metalloproteinase-9 (p < 0.05) and soluble intercellular adhesion molecule-1 (p < 0.01).

CONCLUSIONS

Attachment loss was associated with subclinical atherosclerosis in this young and lean Bangladeshi population. Future prospective studies are needed to confirm this association.

Knockout of the Prostaglandin E2 Receptor Subtype 3 Promotes Eccentric Cardiac Hypertrophy and Fibrosis in Mice

Background:

Prostaglandin E2 receptor subtype 3 (EP3), a Gi protein-coupled receptor activated by prostaglandin E2, plays a particular role in cardioprotection. This study aimed to investigate the impact of EP3 deletion on cardiac remodeling and further elucidate the related involvement of possible signaling pathways.

Methods and Results:

The animals used were EP3 receptor knockout (EP3KO) mice and wild-type (WT) litter mate controls at 16-18 weeks old. The high-resolution echocardiography and weight index indicated that eccentric cardiac hypertrophy might occur in EP3KO mice, which were having worse cardiac function than WT litter mates. Isolated adult myocytes from EP3KO hearts showed spontaneous lengthening. Cardiac fibrosis was observed in EP3KO mice through Masson trichrome staining. The elevated messenger RNA (mRNA) level in matrix genes and the reduced mRNA, protein, and activity levels of matrix metalloproteinase 2 (MMP-2) indicated an increased synthesis and suppressed degradation of matrix collagen in EP3KO mice. The phosphorylation level of extracellular signal-regulated kinase (ERK) 1/2 protein was reduced in the cardiac tissue of EP3KO mice, accompanied by no significant change in the protein level of total ERK1/2, total p38, phospho-p38, glycogen synthase kinase-3β (GSK3β), phospho-GSK3β, and calcineurin (CaN) as well as CaN activity.

Conclusion:

EP3 knockout in cardiac tissues could induce eccentric cardiac hypertrophy and cardiac fibrosis at 16-18 weeks old. These effects of EP3 knockout might be regulated through inactivating MAPK/ERK pathway and affecting the MMP-2 expression. Overall, PGE2-EP3 is necessary to maintain the normal growth and development of the heart.

Evidence that periodontal treatment improves biomarkers and CVD outcomes

AIM

The aim of this review was to critically appraise the evidence on the impact of periodontal treatment of cardiovascular diseases (CVDs) biomarkers and outcomes.

METHODS

A systematic search was performed in Cinhal, Cochrane, Embase and Medline for relevant articles up to July 2012. Duplicate screening and reference hand searching were performed. Data were then summarized and evidence graded in tables.

RESULTS

The search resulted in: (a) no evidence on the effects of periodontal therapy on subclinical atherosclerosis, serum levels of CD40 ligand, serum amyloid A and monocyte chemoattractant protein-1, (b) limited evidence on the effects of periodontal therapy on arterial blood pressure, leucocyte counts, fibrinogen, tissue necrosis factor-α, sE-selectin, von Willebrand factors, d-dimers, matrix metalloproteinases, oxidative stress and CVD events, and (c) moderate evidence suggesting a negligible effect of periodontal therapy in reducing interleukin-6 and lipids levels, whilst a positive effect in reducing serum C-reactive protein levels and improving endothelial function.

CONCLUSIONS

Periodontal therapy triggers a short-term inflammatory response followed by (a) a progressive and consistent reduction of systemic inflammation and (b) an improvement in endothelial function. There is however limited evidence that these acute and chronic changes will either increase or reduce CVD burden of individuals suffering from periodontitis in the long term.

Evidence that periodontal treatment improves biomarkers and CVD outcomes

AIM

The aim of this review was to critically appraise the evidence on the impact of periodontal treatment of cardiovascular diseases (CVDs) biomarkers and outcomes.

METHODS

A systematic search was performed in Cinhal, Cochrane, Embase and Medline for relevant articles up to July 2012. Duplicate screening and reference hand searching were performed. Data were then summarized and evidence graded in tables.

RESULTS

The search resulted in: (a) no evidence on the effects of periodontal therapy on subclinical atherosclerosis, serum levels of CD40 ligand, serum amyloid A and monocyte chemoattractant protein-1, (b) limited evidence on the effects of periodontal therapy on arterial blood pressure, leucocyte counts, fibrinogen, tissue necrosis factor-a, sE-selectin, von Willebrand factors, d-dimers, matrix metalloproteinases, oxidative stress and CVD events, and (c) moderate evidence suggesting a negligible effect of periodontal therapy in reducing interleukin-6 and lipids levels, whilst a positive effect in reducing serum C-reactive protein levels and improving endothelial function.

CONCLUSIONS

Periodontal therapy triggers a short-term inflammatory response followed by (a) a progressive and consistent reduction of systemic inflammation and (b) an improvement in endothelial function. There is however limited evidence that these acute and chronic changes will either increase or reduce CVD burden of individuals suffering from periodontitis in the long term.

Association of Matrix Metalloproteinase 9 C-1562T Polymorphism with Genetic Susceptibility to Myocardial Infarction: A Meta-Analysis

BACKGROUND

Myocardial infarction (MI) is the major cause of death by disease in the world. Many studies have identified the associations between matrix metalloproteinase 9 (MMP9) C-1562T polymorphisms and MI. However, the results remain inconclusive. To clarify the role of MMP9 C-1562T polymorphism in MI risk, we conducted a systematic review and large-scale meta-analysis.

METHODS

Studies published between January 2005 and March 2014 were obtained from the electronic databases PubMed, Medline, and Embase. The odds ratios (ORs) with 95% CIs were calculated for comparisons of the alleles and genotypes in the overall population and in ethnicity subgroups to measure the strength of genetic associations.

RESULTS

A total of 7 related studies, including 3952 MI cases and 4977 healthy control subjects were included in our meta-analysis. Our results show a statistically significant association between T allele and MI in the overall population (OR = 1.23; 95% CI, 1.02-1.48; P = 0.03). The risk of MI was also significantly higher in patients carrying the T allele (TC + TT genotypes) than in those with the CC genotype (P < 0.05). In stratified analysis by ethnicity, we found the T allele was strongly associated with MI in white populations, whereas in Asian populations there appeared no significant association.

CONCLUSIONS

Our data show that the MMP9 C-1562T polymorphism is a risk factor associated with increased MI susceptibility in the total population and white populations, although no significant association was observed in Asians populations. Further studies with larger sample sizes and assessing gene-gene and gene-environment interactions are required.

Functional measures, inflammatory markers and endothelin-1 as predictors of 360-day survival in centenarians

Centenarians represent a rapidly growing population. To better characterize this specific age group, we have performed a cross-sectional study to observe associations between functional measures and a range of biochemical markers, including inflammatory markers and their significance as predictors of 360-day survival. Medical history and physical and functional assessment (Mini-Mental State Examination (MMSE), Katz Index (activities of daily living, ADL) and Barthel Index (Barthel Index) of Activities of Daily Living, and Lawton Instrumental Activities of Daily Living Scale (Lawton IADL)) were conducted on 86 101.9 ± 1.2-year-old (mean ± SD) subjects (70 women, 16 men). Blood tests were performed on 84 subjects of whom 43 also had extended biomarker assessment. As a reference group 30 51.8 ± 5.0-year old healthy subjects (20 women, 10 men) were recruited. The centenarians received follow-up phone calls. Fifty-two centenarians (60 %) survived ≥360 days. Longer survival was associated with higher MMSE (hazard ratio, HR = 0.934, 95 % confidence interval (CI) 0.896-0.975, P = .002), ADL (HR = 0.840, 95 % CI 0.716-0.985, P = .032), Barthel Index (HR = 0.988, 95 % CI 0.977-0.999, P = .026), and albumin level (HR .926, 95 % CI 0.870-0.986, P .016) and with lower white blood cell (WBC) (HR = 1.161, 95 % CI 1.059-1.273, P = .001), C-reactive protein (CRP) (HR = 1.032, 95 % CI 1.014-1.050, P < .001), IL-6 (HR = 1.182, 95 % CI 1.047-1.335, P = .007), and endothelin-1 (ET-1) level (HR = 3.711, 95 % CI 1.233-11.169, P = .020). Centenarians had higher 360-day survival probability with MMSE ≥13 (P < .001), ADL ≥1 (P < .001), Barthel Index ≥15 (P < .001), Lawton IADL ≥10 points (P = .009), WBC <8.3 G/L (P = .039), CRP <10 mg/L (P < .001), IL-6 <6 pg/mL (P .002), and ET-1 <1.1 pg/mL (P .007). Our results indicate that functional measures, inflammatory markers, and endothelin-1 are predictors of 360-day survival in centenarians.

Plasma Matrix Metalloproteinase-9 Levels Predict First-Time Coronary Heart Disease: An 8-Year Follow-Up of a Community-Based Middle Aged Population

BACKGROUND

The enzyme in matrix metalloproteinase (MMP)-9 has been suggested to be an important determinant of plaque degradation. While several studies have shown elevated levels in patients with coronary heart disease, results in prospective population based studies evaluating MMP-9 in relation to first time coronary events have been inconclusive. As of today, there are four published studies which have measured MMP-9 in serum and none using plasma. Measures of MMP-9 in serum have been suggested to have more flaws than measures in plasma.

AIM

To investigate the independent association between plasma levels of MMP-9 and first-time incidence of coronary events in an 8-year follow-up.

MATERIAL AND METHODS

428 men and 438 women, aged 45-69 years, free of previous coronary events and stroke at baseline, were followed-up. Adjustments were made for sex, age, socioeconomic position, behavioral and cardiovascular risk factors, chronic disease at baseline, depressive symptoms, interleukin-6 and C-reactive protein.

RESULTS

53 events were identified during a risk-time of 6 607 person years. Hazard ratio (HR) for MMP-9 after adjustment for all covariates were HR = 1.44 (1.03 to 2.02, p = 0.033). Overall, the effect of adjustments for other cardiovascular risk factors was low.

CONCLUSION

Levels of plasma MMP-9 are independently associated with risk of first-time CHD events, regardless of adjustments. These results are in contrast to previous prospective population-based studies based on MMP-9 in serum. It is essential that more studies look at MMP-9 levels in plasma to further evaluate the association with first coronary events.

TGF-β1 and TIMP-4 regulate atrial fibrosis in atrial fibrillation secondary to rheumatic heart disease

To investigate the involvement of transforming growth factor-β1 (TGF-β1) and tissue inhibitor of metalloproteinase 4 (TIMP-4) in influencing the severity of atrial fibrosis in rheumatic heart disease (RHD) patients with atrial fibrillation (AF). The degree of myocardial fibrosis was evaluated using Masson staining. The expression levels of TGF-β1, TIMP-4, matrix metalloproteinase-2 (MMP-2), type I collagen, and type III collagen were estimated by Western blot analysis. Additionally, TGF-β1 and TIMP-4 mRNA levels were quantified by qRT-PCR. The effect of TGF-β1 stimulation on TIMP-4 expression was assessed by in vitro stimulation of freshly isolated human atrial fibroblasts with recombinant human TGF-β1, followed by Western blot analysis to detect changes in TIMP-4 levels. Masson stain revealed that the left atrial diameter and collagen volume fraction were obviously increased in AF patients, compared to sinus rhythm (SR) controls (both P < 0.05). Western blot analysis showed significantly elevated levels of the AF markers MMP-2, type I collagen, and type III collagen in the AF group, in comparison to the SR controls (all P < 0.05). In the AF group, TGF-β1 expression was relatively higher, while TIMP-4 expression was apparently lower than the SR group (all P < 0.05). TIMP-4 expression level showed a negative association with TGF-β1 expression level (r = -0.98, P < 0.01) and TGF-β1 stimulation of atrial fibroblasts led to a sharp decrease in TIMP-4 protein level. Increased TGF-β1 expression and decreased TIMP-4 expression correlated with atrial fibrosis and ECM changes in the atria of RHD patients with AF. Notably, TGF-β1 suppressed TIMP-4 expression, suggesting that selective TGF-β1 inhibitors may be useful therapeutic agents.

Inhibition of Thrombin-Activated Fibrinolysis Inhibitor Increases Survival in Experimental Kidney Fibrosis

Uncontrolled diabetes, inflammation, and hypertension are key contributors to progressive renal fibrosis and subsequent loss of renal function. Reduced fibrinolysis appears to be a feature of ESRD, but its contribution to the fibrotic program has not been extensively studied. Here, we show that in patients with CKD, the activity levels of serum thrombin-activated fibrinolysis inhibitor and plasmin strongly correlated with the degree of renal function impairment. We made similar observations in rats after subtotal nephrectomy and tested whether pharmacologic inhibition of thrombin-activated fibrinolysis inhibitor with UK-396082 could reduce renal fibrosis and improve renal function. Compared with untreated animals, UK-396082-treated animals had reduced glomerular and tubulointerstitial fibrosis after subtotal nephrectomy. Renal function, as measured by an increase in creatinine clearance, was maintained and the rate of increase in proteinuria was reduced in UK-396082-treated animals. Furthermore, cumulative survival improved from 16% to 80% with inhibition of thrombin-activated fibrinolysis inhibitor. Taken together, these data support the importance of the fibrinolytic axis in regulating renal fibrosis and point to a potentially important therapeutic role for suppression of thrombin-activated fibrinolysis inhibitor activity.

Serum tissue inhibitor of matrix metalloproteinase-1 levels are associated with mortality in patients with malignant middle cerebral artery infarction

Background

In the last years, circulating matrix metalloproteinases (MMP)-9 levels have been associated with functional outcome in ischemic stroke patients. However the prognostic value of circulating levels of tissue inhibitor of matrix metalloproteinases (TIMP)-1 and MMP-10 in functional outcome of ischemic stroke patients has been scarcely studied. In addition, to our knowledge, serum MMP-9, MMP-10 and TIMP-1 levels in patients with malignant middle cerebral artery infarction (MMCAI) for mortality prediction have not been studied, and these were the objectives of this study.

Methods

This was a multicenter, observational and prospective study carried out in six Spanish Intensive Care Units. We included patients with severe MMCAI defined as Glasgow Coma Scale (GCS) lower than 9. We measured circulating levels of MMP-9, MMP-10, TIMP-1, in 50 patients with severe MMCAI at diagnosis and in 50 healthy subjects. Endpoint was 30-day mortality.

Results

Patients with severe MMCAI showed higher serum levels of MMP-9 (p = 0.001), MMP-10 (p < 0.001), and TIMP-1 (p = 0.02) than healthy subjects. Non-surviving MMCAI patients (n = 26) compared to survivor ones (n = 24) showed higher circulating levels of TIMP-1 (p < 0.001), MMP-10 (p = 0.02) and PAI-1(p = 0.02), and lower MMP-9 levels (p = 0.04). Multiple binomial logistic regression analysis showed that serum TIMP-1 levels > 239 ng/mL are associated with 30-day mortality (OR = 5.82; 95 % CI = 1.37-24.73; P = 0.02) controlling for GCS and age. The area under the curve for TIMP-1 as predictor of 30-day mortality was 0.81 (95 % CI = 0.67-0.91; P < 0.001). We found an association between circulating levels of TIMP-1 and MMP-10 (rho = 0.45; P = 0.001), plasminogen activator inhibitor (PAI)-1 (rho = 0.53; P < 0.001), and tumor necrosis factor (TNF)-alpha (rho = 0.70; P < 0.001).

Conclusions

The most relevant and new findings of our study, were that serum TIMP-1 levels in MMCAI patients were associated with mortality, and could be used as a prognostic biomarker of mortality in MMCAI patients.

Analysis of Gene Expression During the Development of Congestive Heart Failure After Myocardial Infarction in Rat Models

Our study aimed to investigate the gene expression at different myocardial infarction (MI) phases and to understand the development mechanisms of congestive heart failure (CHF) after MI. Dataset GSE1957 including 24 samples of rat left ventricles at 1-day post MI or sham operation and 7-day post MI or sham operation was downloaded from Gene Expression Ominibus. The data were normalized with an affyPLM package and differentially expressed genes (DEGs) were identified with a Linear Models for Microarray Data package. Heat maps of the DEGs were constructed using Cluster 3.0. GO (Gene Ontology) enrichment analysis of the DEGs was performed in Database for Annotation, Visualization, and Integrated Discovery. A protein-protein interaction (PPI) network was constructed by Biomolecular Interaction Network Database and visualized by Cytoscape, and a subnetwork was analyzed using plugin ClusterONE in Cytoscape. A total of 5 DEGs at 1-day post-MI, 5 DEGs at 7-day post-MI, and 7 DEGs between the MI and sham groups at 1-day and 7-day post-MI were identified. For the GO category analysis, DEGs at 1-day post-MI were enriched in response to cytokine stimulus. DEGs at 7-day post-MI were enriched in response to inorganic substance and chemical homeostasis. DEGs between 1-day and 7-day post-MI including CDK2 and CDC20 were significantly enriched in mitosis. CDK2, ANXA1, CDC20, and AQP2 were included in the PPI network, and CDK2 was the only DEG included in the subnetwork. In conclusion, the induction of DEGs at 7-day post-MI might participate in the response to a hormone and endogenous stimulus to regulate the development of CHF after MI.

The effects of age and gender on plasma levels of 63 cytokines

Cytokines play important roles as regulators of cell functions, and over the last decades a number of cytokine assays have been developed. The aim of the present study was to investigate the effects of age and gender on a large number of cytokines. Plasma samples were collected from 33 healthy blood donors. The samples were analyzed using a multiplex proximity extension assay (PEA) allowing simultaneous measurement of 92 cytokines and four technical controls. Biomarkers with less than 80% quantitative results were excluded leaving 63 cytokines that were analyzed for the effects of gender and age. The plasma level of three of the investigated biomarkers (DNER, MCP-4 and MMP-10) were found to be significantly different for the two genders (adjusted p-value<0.05), and 15 of the biomarkers (CCL11, CCL25, CDCP1, CSF-1, CXCL11, CXCL9, FGF-23, Flt3L, HGF, IL-10RB, MCP-3, MCP-4, MMP-10, OPG, VEGF-A) were significantly associated with age. This study reveals the effects of age and gender on a large number of cytokine assays. CXCL5 and TNFB were significantly higher in females, while the other markers with significant gender-dependent differences were higher in males. For the markers that were significantly associated with age, only CXCL6 was found to decrease with age, while the other biomarkers increased with age.

Role of MMP-2 and MMP-9 in resistance to drug therapy in patients with resistant hypertension

Background

Despite the increased evidence of the important role of matrix metalloproteinases (MMP-9 and MMP‑2) in the pathophysiology of hypertension, the profile of these molecules in resistant hypertension (RHTN) remains unknown.

Objectives

To compare the plasma levels of MMP-9 and MMP-2 and of their tissue inhibitors (TIMP-1 and TIMP-2, respectively), as well as their MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios, between patients with controlled RHTN (CRHTN, n=41) and uncontrolled RHTN (UCRHTN, n=35). In addition, the association of those parameters with clinical characteristics, office blood pressure (BP) and arterial stiffness (determined by pulse wave velocity) was evaluate in those subgroups.

Methods

This study included 76 individuals diagnosed with RHTN and submitted to physical examination, electrocardiogram, and laboratory tests to assess biochemical parameters.

Results

Similar values of MMP-9, MMP-2, TIMP-1, TIMP-2, and MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios were found in the UCRHTN and CRHTN subgroups (P>0.05). A significant correlation was found between diastolic BP (DBP) and MMP-9/TIMP-1 ratio (r=0.37; P=0.02) and DPB and MMP-2 (r=-0.40; P=0.02) in the UCRHTN subgroup. On the other hand, no correlation was observed in the CRHTN subgroup. Logistic regression models demonstrated that MMP-9, MMP-2, TIMP-1, TIMP-2 and their ratios were not associated with the lack of BP control.

Conclusion

These findings suggest that neither MMP-2 nor MMP-9 affect BP control in RHTN subjects.

Genetic relationship between serum pregnancy-associated plasma protein-A gene polymorphism and ischemic cerebrovascular disease in a Northern Han Chinese population

The present study recruited 193 patients with ischemic cerebrovascular disease from Inpatient and Outpatient Departments at the Affiliated Hospital of Qingdao University Medical College, China from August 2008 to May 2010, as well as 120 healthy volunteers from the Medical Examination Center at the Affiliated Hospital of Qingdao University Medical College, China, who served as controls for this study. Patients and control subjects were from the Han population in northern China. Enzyme- linked immunosorbent assay analysis revealed increased levels of serum pregnancy-associated plasma protein-A (PAPP-A) in ischemic cerebrovascular disease patients compared with healthy controls. In addition, the patients exhibited greater frequency of genotype CC and C alleles in a missense A/C (Tyr/Ser) polymorphism (dbSNP: rs7020782) of exon 14 in the PAPP-A gene. Multiple-factor logistic regression analysis on correction of age, gender, history of smoking, hypertension, diabetes mellitus, hypercholesteremia, and ischemic stroke family history showed that the risk for ischemic cerebrovascular disease in the population without the A allele at the A/C genetic locus in exon 14 of the PAPP-A was 2-folds greater than the population expressing the A allele. These experimental findings suggested that ischemic cerebrovascular disease correlated with the C allele in exon 14 of PAPP-A. In addition, the A allele is likely a protective gene; individuals carrying the A allele were less prone to ischemic cerebrovascular disease compared with individuals without the A allele.