The balance of serum matrix metalloproteinase-8 and its tissue inhibitor in acute coronary syndrome and its recurrence

Multi-omics landscape of childhood simple obesity: novel insights into pathogenesis and biomarkers discovery

BACKGROUND

The increasing incidence of childhood obesity annually has led to a surge in physical and mental health risks, making it a significant global public health concern. This study aimed to discover novel biomarkers of childhood simple obesity through integrative multi-omics analysis, uncovering their potential connections and providing fresh research directions for the complex pathogenesis and treatment strategies.

METHODS

Transcriptome, untargeted metabolome, and 16 S rDNA sequencing were conducted on subjects to examine transcripts, metabolites in blood, and gut microflora in stool.

RESULTS

Transcriptomic analysis identified 599 differentially expressed genes (DEGs), of which 25 were immune-related genes, and participated in immune pathways such as antimicrobial peptides, neutrophil degranulation, and interferons. The optimal random forest model based on these genes exhibited an AUC of 0.844. The metabolomic analysis examined 71 differentially expressed metabolites (DEMs), including 12 immune-related metabolites. Notably, lauric acid showed an extremely strong positive correlation with BMI and showed a good discriminative power for obesity (AUC = 0.82). DEMs were found to be significantly enriched in four metabolic pathways, namely "Aminoacyl-tRNA biosynthesis", "Valine leucine and isoleucine biosynthesis, and Glycine", "Serine and threonine metabolism", and "Biosynthesis of unsaturated fatty acids". Microbiome analysis revealed 12 differential gut microbiotas (DGMs) at the phylum and genus levels, with p_Firmicutes dominating in the obese group and g_Escherichia-Shigella in the normal group. Subsequently, a Random Forest model was developed based on the DEMs, immune-related DEGs, and metabolites with an AUC value of 0.912. The 14 indicators identified by this model could potentially serve as a set of biomarkers for obesity. The analysis of the inter-omics correlation network found 233 pairs of significant correlations. DEGs BPIFA1, BPI, and SAA1, DEMs Dimethy(tetradecyl)amine, Deoxycholic acid, Pathalic anhydride, and DL-Alanine, and DGMs g_Intestinimonas and g_Turicibacter showed strong connectivity within the network, constituting a large proportion of interactions.

CONCLUSION

This study presents the first comprehensive description of the multi-omics characteristics of childhood simple obesity, recognizing promising biomarkers. Immune-related markers offer a new perspective for researching the immunological mechanisms underlying obesity and its associated complications. The revealed interactions among these biomarkers contribute to a deeper understanding the intricate biological regulatory networks associated with obesity.

Serum MMP-8 and TIMP-1 concentrations in a population-based cohort: effects of age, gender, and health status

Background

Matrix-degrading proteinases and their regulators, such as matrix metalloproteinase 8 (MMP-8) and tissue inhibitor of matrix metalloproteinase 1 (TIMP-1), may contribute to various pathological events. Elevated MMP-8 concentrations have been associated with e.g., cardiovascular diseases and periodontitis. However, there is little knowledge on the physiological concentrations of these molecules in serum, or the effect of demographic or lifestyle factors on their levels.

Design and methods

We investigated the effect of various demographic characteristics and behavioral habits, such as aging, sex, smoking, and BMI, on serum concentrations of MMP-8 and TIMP-1. We used the FINRISK97 cohort (n = 8,446), which has comprehensive information on demographic and lifestyle factors, clinical data, laboratory measurements, and register data available. Further, we investigated the concentrations of MMP-8, TIMP-1, and the MMP-8/TIMP-1 ratio in different age groups of healthy and diseased participants. A t-test was used to compare log-transformed mean levels in different groups and linear regression was used to evaluate the association between MMP-8 and TIMP-1 and selected diseases and background variables.

Results

MMP-8 levels decreased with increasing age in the whole population and for women, while TIMP-1 concentration increased slightly with age for the whole population and both genders separately (p for linear trend <0.001). The concentrations of MMP-8 were lower and TIMP-1 higher in men compared to women (p < 0.001). Additionally, a significant positive association was found for MMP-8 and smoking, CRP, and an inverse association with obesity and fasting time. For TIMP-1, significant positive associations were found with smoking, CRP and obesity, and an inverse association with prevalent diabetes.

Conclusion

The association of serum MMP-8 and TIMP-1 concentrations with cardiometabolic risk is frequently investigated. MMP-8 levels decrease significantly with age and fasting time. In addition, sex, smoking, and obesity are associated with both MMP-8 and TIMP-1 concentrations. These factors should be carefully considered in epidemiological studies on serum MMP-8 and TIMP-1.

Systemic Vulnerability, as Expressed by I-CAM and MMP-9 at Presentation, Predicts One Year Outcomes in Patients with Acute Myocardial Infarction-Insights from the VIP Clinical Study

(1) Background: The prediction of recurrent events after acute myocardial infarction (AMI) does not sufficiently integrate systemic inflammation, coronary morphology or ventricular function in prediction algorithms. We aimed to evaluate the accuracy of inflammatory biomarkers, in association with angiographical and echocardiographic parameters, in predicting 1-year MACE after revascularized AMI. (2) Methods: This is an extension of a biomarker sub-study of the VIP trial (NCT03606330), in which 225 AMI patients underwent analysis of systemic vulnerability and were followed for 1 year. Hs-CRP, MMP-9, IL-6, I-CAM, V-CAM and E-selectin were determined at 1 h after revascularization. The primary end-point was the 1-year MACE rate. (3) Results: The MACE rate was 24.8% (n = 56). There were no significant differences between groups in regard to IL-6, V-CAM and E-selectin. The following inflammatory markers were significantly higher in MACE patients: hs-CRP (11.1 ± 13.8 vs. 5.1 ± 4.4 mg/L, p = 0.03), I-CAM (452 ± 283 vs. 220.5 ± 104.6, p = 0.0003) and MMP-9 (2255 ± 1226 vs. 1099 ± 706.1 ng/mL p = 0.0001). The most powerful predictor for MACE was MMP-9 of >1155 ng/mL (AUC-0.786, p < 0.001) even after adjustments for diabetes, LVEF, acute phase complications and other inflammatory biomarkers. For STEMI, the most powerful predictors for MACE included I-CAM > 239.7 ng/mL, V-CAM > 877.9 ng/mL and MMP-9 > 1393 ng/mL. (4) Conclusions: High levels of I-CAM and MMP-9 were the most powerful predictors for recurrent events after AMI for the overall study population. For STEMI subjects, the most important predictors included increased levels of I-CAM, V-CAM and MMP-9, while none of the analyzed parameters had proven to be predictive. Inflammatory biomarkers assayed during the acute phase of AMI presented a more powerful predictive capacity for MACE than the LVEF.

Causal associations of serum matrix metalloproteinase-8 level with ischaemic stroke and ischaemic stroke subtypes: a Mendelian randomization study

BACKGROUND AND PURPOSE

Elevated serum matrix metalloproteinase-8 (MMP-8) concentrations are associated with high risk of vascular disease, but the causality remains unclear. A two-sample Mendelian randomization (MR) study was performed to examine the causal effect of serum MMP-8 concentrations on the risk of ischaemic stroke, ischaemic stroke subtypes and coronary artery disease.

METHODS

Ten independent single-nucleotide polymorphisms related to serum MMP-8 concentrations were identified as instrumental variables from a genome-wide association study of 6049 European subjects. Genetic association estimates for ischaemic stroke were obtained from the Multiancestry Genome-wide Association Study of Stroke consortium with 446,696 European individuals. The inverse-variance weighted method was applied to assess the causal associations of serum MMP-8 with ischaemic stroke and its subtypes in the main analysis.

RESULTS

No significant causal association was observed for MMP-8 levels with total ischaemic stroke, large artery stroke or cardioembolic stroke. Genetically determined 1 - unit higher log-transformed serum MMP-8 concentration was associated with an increased risk of small vessel stroke (odds ratio 1.25; 95% confidence interval 1.12-1.39; p < 0.001). In secondary analysis, a similar adverse impact was reported for MMP-8 on coronary artery disease (odds ratio 1.05; 95% confidence interval 1.01-1.10; p = 0.017). Sensitivity analyses further confirmed the relationship between serum MMP-8 level and small vessel stroke and coronary artery disease. Mendelian randomization Egger regression showed no evidence of pleiotropic bias.

CONCLUSIONS

High serum MMP-8 concentrations were causally associated with increased risks of small vessel stroke and coronary artery disease. The mechanism underlying the effect of serum MMP-8 on the vascular system requires further investigation.

Combined Effects of MMP-7, MMP-8 and MMP-26 on the Risk of Ischemic Stroke

Ischemic stroke (IS) is multifactorial causation combining with traditional cardiovascular disease (CVD) and genetic risk factors. Combined effects of MMP-7, MMP-8 and MMP-26 on the risk of IS remain incompletely understood. We aimed to assess individual and joint effects for IS risk by weighted genetic risk score (wGRS) from these three genes and traditional CVD risk factors. A case-control study including 500 cases with IS and 500 stroke-free healthy controls frequency-matched with cases by age and sex was conducted. The wGRS was a weighted average of the number of risk genotype across selected SNPs from MMP-7, MMP-8 and MMP-26. Multivariate logistic regression models were used to analyze the relationship between wGRS and risk of IS. A wGRS in the second tertile was associated with a 1.5-fold increased risk of IS compared with the lowest tertile after adjusting for traditional CVD risk factors. Compared to subjects with low genetic and low modifiable CVD risk, those with high genetic and high modifiable CVD risk had the highest risk of IS (adjusted-OR = 5.75). In conclusion, higher wGRS was significantly associated with an increased risk for IS. A significant interaction between genetic and traditional CVD risk factors was also found on the risk of IS.

Genetic Variants Contributing to Circulating Matrix Metalloproteinase 8 Levels and Their Association With Cardiovascular Diseases: A Genome-Wide Analysis

BACKGROUND

Matrix metalloproteinase 8 (MMP-8) is a proinflammatory enzyme expressed mainly by neutrophils. Elevated serum and plasma concentrations of MMP-8 are associated with the risk for and outcome of cardiovascular diseases (CVDs). The origin of circulating MMP-8 is not completely clear.

METHODS AND RESULTS

We performed a genome-wide association study of serum MMP-8 levels in 2 populations comprising altogether 6049 individuals. Moreover, we studied whether MMP-8-associated variants are linked to increased risk of CVDs and overall mortality in >20 000 subjects. The strongest association with serum MMP-8 was found in locus 1q31.3, containing the gene for complement factor H (lead single nucleotide polymorphism: rs800292; P=2.4×10^-35). In functional experiments, activation of the alternative pathway of complement in the carriers of rs800292 minor allele (Ile62 in factor H) led to decreased release of MMP-8 from neutrophils compared with the major allele (Val62 in factor H). Another association was detected in 1q21.3, containing genes S100A8, S100A9, and S100A12 (strongest association: rs1560833; P=5.3×10^-15). The minor allele of rs1560833 was inversely associated with CVD (odds ratio [95% confidence interval]: 0.90 [0.82-0.99]; P=0.032) and the time to incident CVD event (hazard ratio [95% confidence interval]: 0.91 [0.84-0.99]; P=0.032) in men but not in women.

CONCLUSIONS

According to our results, the activation of the alternative pathway of the complement system strongly contributes to serum MMP-8 concentration. Genetic polymorphism in S100A9-S100A12-S100A8 locus affects serum and plasma MMP-8 and shows a suggestive association with the risk of CVDs. Our results show that genetic variation determines a significant portion of circulating MMP-8 concentrations.

Inflammatory biomarkers in saliva and serum of patients with rheumatoid arthritis with respect to periodontal status

OBJECTIVE

To study prospectively the association of salivary and serum matrix metalloproteinase (MMP)-8, tissue inhibitor of MMPs (TIMP)-1 and interleukin (IL)-6 with periodontal and systemic inflammation in rheumatoid arthritis (RA). We hypothesized that biomarker concentrations reflect inflammation.

METHODS

Fifty three early untreated RA (ERA) and 28 chronic RA (CRA) patients, underwent rheumatological and dental examinations at baseline and one year later after starting first conventional or biological disease modifying antirheumatic drug. We included 43 control subjects. Saliva and serum samples were analyzed for MMP-8, TIMP-1 and IL-6. Periodontal health was assessed by bleeding on probing (BOP), pocket depth (PD) and periodontal inflammatory burden index (PIBI); RA disease activity was assessed by disease activity score DAS28. Joint destruction was analyzed by the modified Sharp-van der Heijde (SHS) method.

RESULTS

Serum MMP-8 (p < .001; p < .001) and IL-6 (p < .001; p = .002) were significantly higher in CRA vs. other study groups during the study. Salivary MMP-8 (p = .010) and IL-6 (p = .010) were significantly higher in ERA vs. other study groups at baseline. Salivary MMP-8 was associated with periodontal parameters.

CONCLUSION

Elevated serum concentrations of MMP-8 and IL-6 in CRA patients reflected chronic RA, while elevated salivary concentrations of MMP-8 levels in ERA patients reflected increased periodontal inflammation. Key messages Concentrations of inflammatory biomarkers in serum and saliva were different between patients with RA and healthy controls. Concentrations of MMP-8 and of IL-6 in serum were elevated in patients with chronic RA reflecting joint inflammation and the burden of established RA. Concentrations of MMP-8 in saliva was elevated already at the early stage of RA and the level of salivary MMP-8 was associated with poor periodontal health both in patients with early and in those with chronic RA.

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.

Serum MMP-9 Diagnostics, Prognostics, and Activation in Acute Coronary Syndrome and Its Recurrence

Matrix metalloproteinase (MMP)-9 is crucial in atherosclerotic plaque rupture and tissue remodeling after a cardiac event. The balance between MMP-9 and endogenous inhibitor, tissue inhibitors of matrix metalloproteinase 1 (TIMP-1), is important in acute coronary syndrome (ACS). This is an age- and gender-matched case-control study of ACS (N = 669). Patients (45.7%) were resampled after recovery, and all were followed up for 6 years. The molecular forms of MMP-9 were investigated by gelatin zymography. Diagnostically, MMP-9 and the MMP-9/TIMP-1 molar ratio were associated with ACS (OR 5.81, 95% CI 2.65–12.76, and 4.96, 2.37–10.38). The MMP-9 concentrations decreased 49% during recovery (p < 0.001). The largest decrease of these biomarkers between acute and recovery phase (ΔMMP-9) protected the patients from major adverse cardiac events, especially the non-fatal events. The fatal events were associated with in vitro activatable MMP-9 levels (p = 0.028). Serum MMP-9 and the MMP-9/TIMP-1 molar ratio may be valuable in ACS diagnosis and prognosis. High serum MMP-9 activation potential is associated with poor cardiovascular outcome.

HLA, infections and inflammation in early stages of atherosclerosis in children with type 1 diabetes

AIMS

This prospective study focuses on risk factors for arterial damage in children with type 1 diabetes (T1D).

METHODS

Eighty children and adolescents with T1D were investigated twice, approximately 2 years apart, for carotid artery intima-media thickness (cIMT) and compliance (CAC), flow-mediated dilatation (FMD) of the brachial artery, and plasma levels of matrix metalloproteinase (MMP)-8. All subjects were genotyped for HLA. The number of respiratory tract infections (RTI) during the past year was obtained by a questionnaire in 56 patients.

RESULTS

cIMT progression, defined as percentage (%) change of cIMT from baseline, correlated inversely with the % changes of both CAC (p = 0.04, r = - 0.3; n = 62) and FMD (p = 0.03, r = - 0.3; n = 47). In multivariate analysis, RTI frequency correlated significantly with cIMT progression irrespective of age, diabetes duration, BMI, and HbA1c (p = 0.03, r = 0.3). When patients were divided in relation to RTI, the association of DQ2/8 with cIMT progression remained significant in patients with over three infections/year (p = 0.04, r = 0.3). During follow-up, the group of DQ2/8 patients with hsCRP > 1 mg/l showed significantly higher levels of plasma MMP-8 than the non-DQ2/8 group.

CONCLUSIONS

The diabetes-risk genotype DQ2/8 and systemic inflammation contribute to pro-atherosclerotic vascular changes in children and adolescents with T1D.

Matrix metalloproteinase-8 and tissue inhibitor of matrix metalloproteinase-1 predict incident cardiovascular disease events and all-cause mortality in a population-based cohort

Background Extracellular matrix degrading proteases and their regulators play an important role in atherogenesis and subsequent plaque rupture leading to acute cardiovascular manifestations. Design and methods In this prospective cohort study, we investigated the prognostic value of circulating matrix metalloproteinase-8, tissue inhibitor of matrix metalloproteinase-1 concentrations, the ratio of matrix metalloproteinase-8/ tissue inhibitor of matrix metalloproteinase-1 and, for comparison, myeloperoxidase and C-reactive protein concentrations for incident cardiovascular disease endpoints. The population-based FINRISK97 cohort comprised 7928 persons without cardiovascular disease at baseline. The baseline survey included a clinical examination and blood sampling. During a 13-year follow-up the endpoints were ascertained through national healthcare registers. The associations of measured biomarkers with the endpoints, including cardiovascular disease event, coronary artery disease, acute myocardial infarction, stroke and all-cause death, were analysed using Cox regression models. Discrimination and reclassification models were used to evaluate the clinical implications of the biomarkers. Results Serum tissue inhibitor of matrix metalloproteinase-1 and C-reactive protein concentrations were associated significantly with increased risk for all studied endpoints. Additionally, matrix metalloproteinase-8 concentration was associated with the risk for a coronary artery disease event, myocardial infarction and death, and myeloperoxidase concentration with the risk for cardiovascular disease events, stroke and death. The only significant association for the matrix metalloproteinase-8/ tissue inhibitor of matrix metalloproteinase-1 ratio was observed with the risk for myocardial infarction. Adding tissue inhibitor of matrix metalloproteinase-1 to the established risk profile improved risk discrimination of myocardial infarction ( p=0.039) and death (0.001). Both matrix metalloproteinase-8 (5.2%, p < 0.001) and tissue inhibitor of matrix metalloproteinase-1 (12.9%, p < 0.001) provided significant clinical net reclassification improvement for death. Conclusions Serum matrix metalloproteinase-8 and tissue inhibitor of matrix metalloproteinase-1 can be considered as biomarkers of incident cardiovascular disease events and death.

Subclinical inflammation associated with prolonged TIMP-1 upregulation and arterial stiffness after gestational diabetes mellitus: a hospital-based cohort study

BACKGROUND

Gestational diabetes mellitus (GDM) has significant implications for the future health of the mother. Some clinical studies have suggested subclinical inflammation and vascular dysfunction after GDM. We aimed to study whether concentrations of high-sensitivity C-reactive protein (hsCRP), tissue inhibitor of metalloproteinase-1 (TIMP-1), matrix metalloproteinase-8 (MMP-8) and -9, as well as values of arterial stiffness differ between women with and without a history of GDM a few years after delivery. We also investigated possible effects of obesity on the results.

METHODS

We studied two cohorts-120 women with a history of GDM and 120 controls-on average 3.7 years after delivery. Serum concentrations of hsCRP were determined by immunonephelometric and immunoturbidimetric methods, MMP-8 by immunofluorometric assay, and MMP-9 and TIMP-1 by enzyme-linked immunosorbent assays. Pulse wave velocity (PWV) was determined using the foot-to-foot velocity method from carotid and femoral waveforms by using a SphygmoCor device. Arterial compliance was measured non-invasively by an HDI/PulseWave™CR-2000 arterial tonometer. All 240 women were also included in subgroup analyses to study the effect of obesity on the results. Multiple linear regression analyses were performed with adjustment for confounding factors.

RESULTS

PWV after pregnancy complicated by GDM was significantly higher than after normal pregnancy, 6.44 ± 0.83 (SD) vs. 6.17 ± 0.74 m/s (p = 0.009). Previous GDM was also one of the significant determinants of PWV in multiple linear regression analyses. On the other hand, compliance indices of both large (p = 0.092) and small (p = 0.681) arteries did not differ between the study cohorts. Serum TIMP-1 levels were significantly increased after previous GDM (p = 0.020). However, no differences were found in the serum levels of MMP-8, MMP-9 or hsCRP. In subgroup analyses, there were significantly higher concentrations of hsCRP (p = 0.015) and higher PWV (p < 0.001) among obese women compared with non-obese ones.

CONCLUSIONS

PWV values were significantly higher after GDM compared with normoglycemic pregnancies and were associated with prolonged TIMP-1 upregulation. Cardiovascular risk factors were more common in participants with high BMI than in those with previous GDM.

Low MMP-8/TIMP-1 reflects left ventricle impairment in takotsubo cardiomyopathy and high TIMP-1 may help to differentiate it from acute coronary syndrome

BACKGROUND

Matrix metalloproteinase 8 (MMP-8) is the most potent type-I collagen protease. Such collagen mainly constitutes the transient fibrosis in takotsubo cardiomyopathy (TTC) endomyocardial biopsies. High MMP-8 and tissue-inhibitor of matrix metalloproteinase-1 (TIMP-1) levels are implicated in acute coronary syndrome (ACS). We compared MMP-8 and TIMP-1 levels in consecutive TTC and ACS patients, and their association to TTC severity.

METHODS AND RESULTS

In 45 acute serum samples of TTC, 2072 ACS and 1000 controls, TIMP-1 differed between ACS 146.7ng/mL (115.0-186.3) (median (interquartile range)), TTC 115.7 (94.3-137.7) and controls 80.9 (73.2-90.4), (p<0.0001). MMP-8 levels were similar between ACS and TTC. In receiver-operating characteristics analysis, TIMP-1 differentiated TTC from ACS with an area under the curve (AUC) of 0.679 (p<0.0001) surpassing troponin T (TnT) at 0.522 (p = 0.66). Compared to other differing factors (age, sex, smoking), TIMP-1 improved diagnostic specificity and sensitivity from AUC of 0.821 to 0.844 (p = 0.007). The MMP8/TIMP-1 molar ratio differentiated normal ejection fraction (EF) at 0.27 (0.13-0.51) from decreased EF<50% at 0.08 (0.05-0.20), (p = 0.04) in TTC, but not in ACS.

CONCLUSIONS

Even with other differing factors considered, TIMP-1 differentiated TTC from ACS better than TnT. In TTC, the low MMP-8/TIMP-1 molar ratio may reflect decreased proteolysis and increased transient fibrosis, perhaps in part explaining the left-ventricle impairment.

Association of MMP-8 with obesity, smoking and insulin resistance

BACKGROUND

Obesity has been recognized as a state of subclinical inflammation resulting in a loss of insulin receptors and decreased insulin sensitivity. We here studied in vivo the role of circulating matrix metalloproteinase-8 (MMP-8) among young healthy twin adults. Also, in vitro analysis of the cleavage of human insulin receptor (INSR) by MMP-8 was investigated as well its inhibition by doxycycline and other MMP-8 inhibitor, Ilomastat/GM6001, which are broad-spectrum MMP inhibitors.

MATERIALS AND METHODS

We analysed serum MMP-8 levels by a time-resolved immunofluorometric assay in obese (n = 34), overweight (n = 76) and normal weight (n = 130) twin individuals. The effect of MMP-8 on INSR and the effects of synthetic MMP-8 inhibitors, doxycycline and Ilomastat/GM6001, were studied by SDS-PAGE.

RESULTS

We found that in obese individuals relative to normal weight individuals, the serum MMP-8 levels and MMP-8/TIMP-1 ratio were significantly increased (P = 0·0031 and P = 0·031, respectively). Among normal weight and obese individuals, also smoking significantly increases serum MMP-8 and MMP-8/TIMP-1 ratio. In vitro, we found that INSR was degraded by MMP-8 and this was inhibited by doxycycline and Ilomastat/GM6001.

CONCLUSIONS

Obesity associated with elevated circulating MMP-8 found among young adults may contribute to progression of insulin resistance by cleaving INSR. This INSR cleavage by MMP-8 can be inhibited by synthetic MMP-8 inhibitors such as doxycycline. In addition to obesity, also smoking independently explained increased MMP-8 levels. Our results suggest that MMP-8 is an essential mediator in systemic subclinical inflammatory response in obesity, and a potential drug target.

Practical implications of novel serum ELISA-assay for matrix metalloproteinase-8 in acute cardiac diagnostics

Matrix metalloproteinases (MMPs) play a major role in inflammatory processes as they degrade extracellular proteins and modify immune responses. Inflammation is the driving factor in atherogenesis and MMPs, particularly MMP-8, has been linked to atherosclerotic plaque progression. MMP-8 is shown to be strongly associated with cardiovascular diseases (CVDs) and its complications thus providing a potential marker to identify patients at risk. Previously, laborious and expensive immunofluorometric assay (IFMA) was needed to reliably detect MMP-8 levels in serum. In this study, we compared a novel in-house ELISA-assay, dentoELISA, to the standard IFMA in determination of serum MMP-8 concentrations. As a cheaper and non-laborious assay, ELISA proved to be diagnostically as sensitive and specific as the IFMA. ROC statistics showed highly similar areas under the curve for both assays (0.779 versus 0.781). Furthermore, the concentrations measured by ELISA correlated significantly with concentrations determined with IFMA (r = 0.881, P < 0.001). In our study population, MMP-8 levels were significantly higher in the acute coronary syndrome patients (n = 2071) in comparison to reference population without significant coronary artery disease (n = 653). With this background, MMP-8-ELISA could provide interesting new approaches to novel CVD diagnostics.

Neutrophil proteolytic activation cascades: a possible mechanistic link between chronic periodontitis and coronary heart disease

Cardiovascular diseases are chronic inflammatory diseases that affect a large segment of society. Coronary heart disease (CHD), the most common cardiovascular disease, progresses over several years and affects millions of people worldwide. Chronic infections may contribute to the systemic inflammation and enhance the risk for CHD. Periodontitis is one of the most common chronic infections that affects up to 50% of the adult population. Under inflammatory conditions the activation of endogenous degradation pathways mediated by immune responses leads to the release of destructive cellular molecules from both resident and immigrant cells. Matrix metalloproteinases (MMPs) and their regulators can activate each other and play an important role in immune response via degrading extracellular matrix components and modulating cytokines and chemokines. The action of MMPs is required for immigrant cell recruitment at the site of inflammation. Stimulated neutrophils represent the major pathogen-fighting immune cells that upregulate expression of several proteinases and oxidative enzymes, which can degrade extracellular matrix components (e.g. MMP-8, MMP-9 and neutrophil elastase). The activity of MMPs is regulated by endogenous inhibitors and/or candidate MMPs (e.g. MMP-7). The balance between MMPs and their inhibitors is thought to mirror the proteolytic burden. Thus, neutrophil-derived biomarkers, including myeloperoxidase, may activate proteolytic destructive cascades that are involved in subsequent immune-pathological events associated with both periodontitis and CHD. Here, we review the existing studies on the contribution of MMPs and their regulators to the infection-related pathology. Also, we discuss the possible proteolytic involvement and role of neutrophil-derived enzymes as an etiological link between chronic periodontitis and CHD.

Elevated matrix metalloproteinase-8 in saliva and serum in polycystic ovary syndrome and association with gingival inflammation

This study aimed to investigate the levels of matrix metalloproteinase-8 (MMP-8) and tissue inhibitors of MMP-1 (TIMP-1) in saliva and serum samples of women with polycystic ovary syndrome (PCOS; n = 80) and matched systemically healthy controls ( n = 45), with varying degrees of gingival inflammation. Salivary levels of MMP-8 and the MMP-8/TIMP-1 ratio were significantly elevated in women with PCOS, who also exhibited more gingivitis than systemically healthy women. No major changes were observed in salivary TIMP-1 levels with regard to PCOS. Serum levels of MMP-8 and the MMP-8/TIMP-1 ratio were significantly higher in women with PCOS, irrespective of the presence of gingivitis, while there were no differences in TIMP-1 levels. A positive correlation was indicated between probing depth, bleeding on probing, plaque index and salivary or serum MMP-8 levels or MMP-8/TIMP-1 ratio in the case of PCOS, while a negative such correlation was revealed for TIMP-1 in systemically healthy women. Increased levels of MMP-8 in saliva and serum seem to be more pronounced in women with PCOS, and potentiated in the presence of gingival inflammation. Alterations in MMP/TIMP system triggered by local and systemic inflammation may be implicated in the pathogenesis of PCOS, or the deterioration of its clinical presentation.

The effect of prolonged systemic doxycycline therapy on serum tissue degrading proteinases in coronary bypass patients: a randomized, double-masked, placebo-controlled clinical trial

OBJECTIVE

Serum matrix metalloproteinases (MMP-8, MMP-7) and their regulators may be associated with the risk of incident cardiovascular disease events. Doxycycline can be used as matrix metalloproteinase (MMP) inhibitor independent of its antimicrobial activity. We aimed to investigate serum inflammatory biomarkers during 4 months of doxycycline therapy in coronary bypass patients.

MATERIALS AND METHODS

Thirty-one non-smoking men who had previous coronary bypass surgery were randomly assigned to receive placebo or 100 mg doxycycline daily for 4 months. Serum samples were collected at baseline before the treatment, and at 2, 4, and 10 months. Serum levels of MMP-7, tissue inhibitor of matrix metalloproteinase (TIMP)-1, myeloperoxidase, and neutrophil elastase were analyzed with enzyme-linked immunosorbent assay, MMP-8 by immunofluorometric assay, and C-reactive protein by rate nephelometry.

RESULTS

At baseline, no significant differences existed between the two groups. Serum levels of MMP-8, MMP-7, and MMP-8/TIMP-1 were and remained lower (p = 0.034, p = 0.041, and NS) in the doxycycline group relative to the placebo group at 4 months of follow-up.

CONCLUSIONS

Doxycycline decreases the systemic inflammatory burden in patients with myocardial infarction and especially down-regulates MMP-7, MMP-8, and MMP-8/TIMP-1. Doxycycline might prevent or reduce the risk of secondary myocardial infarctions by providing a systemic anti-proteolytic and -inflammatory shield.

The relationship between matrix metalloproteinases (MMP-3, -8, -9) in serum and peripheral lymphocytes (CD8+ , CD56+ ) in Down syndrome children with gingivitis

BACKGROUND AND OBJECTIVE

Altered immune response may be a major contributor to periodontal disease in Down syndrome. This study investigated the relationship between peripheral lymphocytes and matrix metalloproteinases (MMPs) in serum in Down syndrome children with gingivitis.

MATERIAL AND METHODS

Children with Down syndrome (n = 10) and healthy controls (n = 10) were clinically and radiographically examined during dental treatment under general anaesthesia. Peripheral blood and gingival crevicular fluid were collected from each subject and concentrations were determined: serum MMP-2, -3, -8 and -9; serum tissue inhibitors of metalloproteinases (TIMP) -1, -2 and -3; and gingival crevicular fluid. Leukocytes were isolated from peripheral blood and the relative amounts (%) of the various cell phenotypes were analysed using flow cytometry. In addition, peripheral blood cells were treated with Porphyromonas gingivalis lipopolysaccharide and levels of MMPs and TIMPs measured.

RESULTS

Concentrations of MMP-3, MMP-8 and TIMP-1 in serum were significantly higher (p < 0.05) in the Down syndrome group compared to the controls. When peripheral blood leukocytes were cultured in the presence or absence of P. gingivalis lipopolysaccharide, MMP-8 levels were significantly (p < 0.05) higher in the Down syndrome group compared to controls. Children with Down syndrome exhibited significant positive correlations between CD8(+) T cells and MMP-8 (r = 0.630; p = 0.050), between CD8(+) T cells and MMP-9 (r = 0.648; p = 0.043), and between CD56(+) NK cells and MMP-3 (r = 0.828; p = 0.003) compared to controls.

CONCLUSIONS

The positive relationship of serum MMP-3, -8 and -9 with immune cells in children with Down syndrome may facilitate migration of CD8(+) T cells and CD56(+) NK cells into the periodontal tissue, which may contribute to the increased degradation of periodontal tissue in individuals with Down syndrome.

Prognostic value of serum MMP-8, -9 and TIMP-1 in patients with hepatocellular carcinoma

AIM

Prediction of prognosis in hepatocellular carcinoma (HCC) is difficult. The aim of this study was to evaluate the prognostic value of serum MMP-8, -9, -13, and TIMP-1 in patients with HCC.

METHODS

Pre-treatment serum samples from 134 patients with HCC were retrospectively analyzed. The serum concentration of MMP-8 was analyzed with immunofluorometric assay (IFMA), and those of MMP-9, MMP-13, and TIMP-1 were determined by enzyme-linked immunosorbent assays (ELISA). Clinical data were retrieved from patient records and survival data obtained from Statistics Finland.

RESULTS

The overall cumulative disease-specific survival was 69% at 1 year, 50% at 2 years, and 33% at 5 years. Kaplan-Meier overall survival analysis showed that patients with low concentrations of serum MMP-8 or TIMP-1 had a statistically significantly better overall survival than patients with high concentrations of serum MMP-8 or TIMP-1 (P=0.013 and P=0.003). Interestingly, the overall survival in patients with high MMP-9/TIMP-1 ratio was statistically significantly better than in those patients with low MMP-9/TIMP-1 ratio (P=0.004).

CONCLUSION

Our results suggest that serum MMP-8, TIMP-1, and the ratio of MMP-9/TIMP-1 might be useful adjuncts as predictors of prognosis in patients with HCC.

Salivary biomarkers for detection of systemic diseases

Background and Objective

Analysis of inflammatory biomarkers in saliva could offer an attractive opportunity for the diagnosis of different systemic conditions specifically in epidemiological surveys. The aim of this study was to investigate if certain salivary biomarkers could be used for detection of common systemic diseases.

Materials and Methods

A randomly selected sample of 1000 adults living in Skåne, a county in the southern part of Sweden, was invited to participate in a clinical study of oral health. 451 individuals were enrolled in this investigation, 51% women. All participants were asked to fill out a questionnaire, history was taken, a clinical examination was made and stimulated saliva samples were collected. Salivary concentrations of IL-1β, -6, -8, TNF-α, lysozyme, MMP-8 and TIMP-1 were determined using ELISA, IFMA or Luminex assays.

Results

Salivary IL-8 concentration was found to be twice as high in subjects who had experience of tumour diseases. In addition, IL-8 levels were also elevated in patients with bowel disease. MMP-8 levels were elevated in saliva from patients after cardiac surgery or suffering from diabetes, and muscle and joint diseases. The levels of IL-1β, IL-8 and MMP-8, as well as the MMP-8/TIMP-1 ratio were higher in subjects with muscle and joint diseases.

Conclusion

Biomarkers in saliva have the potential to be used for screening purposes in epidemiological studies. The relatively unspecific inflammatory markers used in this study can not be used for diagnosis of specific diseases but can be seen as markers for increased systemic inflammation.

Role of matrix metalloproteinase-8 in atherosclerosis

Plaque rupture is the main cause of acute myocardial infarction and stroke. Atherosclerotic plaques have been described to be vulnerable and more prone to rupture when they are characterized by thin, highly inflamed, and collagen-poor fibrous caps and contain elevated levels of proteases, including metalloproteinases (MMPs). Initiation of collagen breakdown in plaques requires interstitial collagenases, a MMP subfamily consisting of MMP-1, MMP-8, and MMP-13. Previous reports demonstrated that MMP-1 and MMP-13 might be overexpressed in both human and experimental atherosclerosis. Since neutrophils have been only recently reported in atherosclerotic plaques, the role of MMP-8 (formerly known as “neutrophil collagenase”) was only marginally evaluated. In this paper, we will update and comment on evidence of the most relevant regulatory pathways and activities mediated by MMP-8 in atherogenesis.

Comparison of localized versus systemic levels of Matrix metalloproteinases (MMPs), its tissue inhibitors (TIMPs) and cytokines in tuberculous and non-tuberculous pleuritis patients

The interaction of Matrix metalloproteinases (MMPs), its tissue inhibitors (TIMPs) and pro-inflammatory cytokines in response to Mycobacterium tuberculosis (MTB) infection is important to understand the immune response at the site of infection. We compared the levels of MMPs, TIMPs and cytokines in plasma (BL) and pleural fluid (PF) of tuberculosis (TB) and non tuberculosis (NTB) patients. Comparison between BL and PF showed significantly higher levels of MMP-1, TIMP-1 and -3 in TB PF; of MMP-7, -8, -9 in BL of both groups. Also, levels of MMP-1,-8,-9 and TIMP-3 were significantly higher in TB PF compared to NTB. Cytokines INF-γ, TNF-α, and IL-6 significantly increased in PF of both groups. A positive correlation of MMPs with TIMPs in TB, MMP-1 and -9 with IL-6 in TB PF and MMP-9 with IFN-γ in NTB PF was observed. This study implicates the possible usage of MMPs as bio-markers aiding diagnosis in TB pleuritis.