Changes in the activity of connective tissue matrix enzymes in the metabolic syndrome

Vitamin D supplementation has no effect on matrix metalloproteinases-2, -9, and tissue inhibitor matrix metalloproteinase-1 in subjects with metabolic syndrome: A pilot study

The present randomized, double-blind, placebo controlled study aimed to evaluate the effect of vitamin D supplementation on matrix metalloproteinases-2, -9 (MMP-2 and MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in subjects with metabolic syndrome. Forty-six eligible subjects were randomly assigned to either vitamin D or placebo groups for 16 weeks. The participants were asked to take 50,000 IU vitamin D or matching placebo every week. Metabolic and anthropometric indices, serum MMP-2, MMP-9, TIMP-1 and high-sensitivity C-reactive protein (hsCRP) were assessed before and after intervention. Moreover, dietary intake, sun exposure and physical activity were also determined. The trial was registered at http://www.irct.ir (No. IRCT201409033140N14). Participants were 40.20 ± 4.60 y and 45.50% males. Compared to the baseline values, MMP-9 and TIMP-1 concentrations were decreased after 16 weeks in the intervention group (p = 0.03 and p = 0.04, respectively). However, the changes of MMP-2, MMP-9, TIMP-1 and hsCRP in the intervention group were not significant compared to the placebo group (p > 0.05). Furthermore, the metabolic or anthropometric indices between two study groups remained unchanged (p > 0.05). The findings of the present study demonstrated no effect of vitamin D supplementation on MMP-2, MMP-9 and TIMP-1 concentrations in subjects with metabolic syndrome. However, there is a need for more longitudinal trials to investigate the role of vitamin D on atherosclerosis and cardiovascular diseases in subjects with metabolic syndrome.

Metalloproteinases and leptin in vehicle drivers of public service with metabolic syndrome in Armenia, Quindío

OBJECTIVE

To describe the relationship between metalloproteinase (MMP) 2, MMP-9, and leptin in drivers of public service vehicles with metabolic syndrome in the city of Armenia (Quindio, Colombia).

METHODS

Leptin was measured using Millipore ELISA kits. MMP-2 and MMP-9 were measured with ELISA kits from R&D Systems.

RESULTS

Fifty-seven male drivers with metabolic syndrome with a mean age of 45.35years, BMI of 29.81, and an abdominal circumference of 105.75cm were identified. Blood pressure values were 126.5/82.5mmHg. Leptin, MMP-2, and MMP-9 levels were 24.6ng/mL, 28,1ng/mL, and 7.5ng/mL respectively. The relationship between leptin and waist circumference was statistically significant (P<.001). The explained variation (R(2)) in waist circumference, is explained in a 80.12% for the study variables, has a statistically significant association with BMI (P<.001), MMP-2 (P=.01), age (P=.01), SBP (P<.001) and DBP (P<.001). The R(2) of leptin, is explained in a 69.56% for the study variables, has a statistically significant association with BMI (P<.001), MMP-2 (P=.05) and triglycerides (P=.02). The R(2) of MMP-2, explained in 41.82% of the study variables and has a statistically significant association with waist circumference (P=.01), glucose (P=.01) and age (P=.03).

CONCLUSIONS

Statistically significant associations were found between waist circumference and MMP-2; leptin and MMP-2, and MMP-2 and waist circumference and blood glucose.

Impact of peroxisome proliferator-activated receptor γ on angiotensin II type 1 receptor-mediated insulin sensitivity, vascular inflammation and atherogenesis in hypercholesterolemic mice

INTRODUCTION

The angiotensin II type 1 receptor (AT1R) and the peroxisome proliferator-activated receptor γ (PPARγ) have been implicated in the pathogenesis of atherosclerosis. A number of studies have reported that AT1R inhibition or genetic AT1R disruption and PPARγ activation inhibit vascular inflammation and improve glucose and lipid metabolism, underscoring a molecular interaction of AT1R and PPARγ. We here analyzed the hypothesis that vasculoprotective anti-inflammatory and metabolic effects of AT1R inhibition are mediated by PPARγ.

MATERIAL AND METHODS

Female ApoE(-/-)/AT1R(-/-) mice were fedwith a high-fat and cholesterol-rich diet and received continuous treatment with the selective PPARγ antagonist GW9662 or vehicle at a rate of 700 ng/kg/min for 4 weeks using subcutaneously implanted osmotic mini-pumps. Additionally, one group of female ApoE(-/-) mice served as a control group. After treatment for 4 weeks mice were sacrificed and read-outs (plaque development, vascular inflammation and insulinsensitivity) were performed.

RESULTS

Using AT1R deficient ApoE(-/-) mice (ApoE(-/-)/AT1R(-/-) mice) we found decreased cholesterol-induced endothelial dysfunction and atherogenesis compared to ApoE(-/-) mice. Inhibition of PPARγ by application of the specific PPARγ antagonist GW9662 significantly abolished the anti-atherogenic effects of AT1R deficiency in ApoE(-/-)/AT1R(-/-) mice (plaque area as % of control: ApoE(-/-): 39 ±5%; ApoE(-/-)/AT1R(-/-): 17 ±7%, p = 0.044 vs. ApoE(-/-); ApoE(-/-)/AT1R(-/-) + GW9662: 31 ±8%, p = 0.047 vs. ApoE(-/-)/AT1R(-/-)). Focusing on IL6 as a pro-inflammatory humoral marker we detected significantly increased IL-6 levels in GW9662-treated animals (IL-6 in pg/ml: ApoE(-/-): 230 ±16; ApoE(-/-)/AT1R(-/-): 117 ±20, p = 0.01 vs. ApoE(-/-); ApoE(-/-)/AT1R(-/-) + GW9662: 199 ±20, p = 0.01 vs. ApoE(-/-)/AT1R(-/-)), while the anti-inflammatory marker IL-10 was significantly reduced after PPARγ inhibition in GW9662 animals (IL-10 in pg/ml: ApoE(-/-): 18 ±4; ApoE(-/-)/AT1R(-/-): 55 ±12, p = 0.03 vs. ApoE(-/-); ApoE(-/-)/AT1R(-/-) + GW9662: 19 ±4, p = 0.03 vs. ApoE(-/-)/AT1R(-/-)). Metabolic parameters of glucose homeostasis (glucose and insulin tolerance test) were significantly deteriorated in ApoE(-/-)/AT1R(-/-) mice treated with GW9662 as compared to vehicle-treated ApoE(-/-)/AT1R(-/-) mice. Systolic blood pressure and plasma cholesterol levels were similar in all groups.

CONCLUSIONS

Genetic disruption of the AT1R attenuates atherosclerosis and improves endothelial function in an ApoE(-/-) mouse model of hypercholesterolemia-induced atherosclerosis via PPARγ, indicating a significant role of PPARγ in reduced vascular inflammation, improvement of insulin sensitivity and atheroprotection of AT1R deficiency.

Effect of elastin-derived peptides on the production of tissue inhibitor of metalloproteinase-1, -2, and -3 and the ratios in various endothelial cell lines

Tissue inhibitors of metalloproteinases (TIMPs) control the activity of metalloproteinases. Elastin-derived peptides (EDPs) are generated as a result of the degradation of elastin fibers. The EDPs bind to the elastin receptor and exert numerous biological effects. The aim of the present study was to compare the production of TIMP-1, TIMP-2 and TIMP-3 and their ratios in human endothelial cells (ECs) derived from three clinically important vascular localizations (coronary arteries, aorta and iliac artery), and evaluate the influence of a well-known EDP, κ-elastin. The highest concentration of TIMP-1 was identified in the aortic ECs, while the lowest concentration was observed in the ECs derived from the coronary artery. The opposite pattern was observed for TIMP-2 production. When the TIMP-3 concentration was analyzed in the three EC lines, no statistically significant differences were observed. Application of κ-elastin was found to decrease the TIMP-1 concentration in the aortic ECs, while an increase in the TIMP-1 concentration was observed in the ECs derived from the iliac artery. The most significant decrease in TIMP-2 concentration following κ-elastin administration was observed in the ECs obtained from the coronary arteries. Furthermore, the highest concentration of κ-elastin resulted in an increase in TIMP-3 production in the ECs derived from the coronary arteries. The following ratios of the TIMP concentrations were calculated: TIMP-1/TIMP-2, TIMP-1/TIMP-3 and TIMP-2/TIMP-3. Each ratio presented different values for the ECs obtained from the various localizations. In the majority of cases, the addition of κ-elastin did not significantly change these proportions. Therefore, these indicators may be characteristic features that can be used to describe ECs in various clinically important vascular localizations.

Evaluation of plasma MMP-8, MMP-9 and TIMP-1 identifies candidate cardiometabolic risk marker in metabolic syndrome: results from double-blinded nested case-control study

AIMS

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are dysregulated in metabolic syndrome (MetS) and associated with atherosclerosis and cardiovascular disease (CVD). Previous studies on the association between MMPs/TIMPs and MetS are controversial. We aimed to evaluate circulating MMP-8, MMP-9 and TIMP-1 in a group of MetS individuals and healthy controls to find the potential marker associated with MetS and its components.

METHODS

243 MetS individuals participated in a nested case-control design, of whom 63 were excluded (study subjects for analysis n=180; 87 MetS cases, 93 controls). We employed the International Diabetes Federation criteria using national waist circumference cutoffs for case definition. Anthropometric and biochemical measurements were done using standard methods.

RESULTS

Plasma MMP-8, TIMP-1, tumor necrosis factor-alpha (TNF-α), highly sensitive C-reactive protein (hs-CRP) and MMP-8/TIMP-1 ratio were significantly higher in MetS cases (P for all < 0.05). Each component of MetS except raised fasting plasma glucose positively correlated with MMP-8 and numbers of MetS components increased with higher MMP-8. In all regression models, MMP-8 was a significant predictor of MetS and in the final model the relationship persisted even after adjusting for pro-inflammatory cytokines hs-CRP and TNF-α (odds ratio=6.008, 95% confidence interval: 1.612-22.389, P=0.008).

CONCLUSION

Strong associations of MMP-8 with components of MetS in univariate, bivariate and multivariate models suggest plasma MMP-8 as a potential cardiometabolic risk marker for MetS. Higher MMP-8 in MetS is possibly mediated through mechanisms both dependent and independent of chronic low grade inflammation.

Significance of impaired serum gelatinases activities in metabolic syndrome

Introduction:

A consortium of metabolic risk factors accelerate the onset of diabetes, heart disease, stroke, and certain cancers. Proteolytic enzymes like matrix metalloproteinases (MMP) are regulated by a group of endogenous proteins called tissue inhibitors of metalloproteinases (TIMP). These TIMPs binds to active and alternate sites of activated MMPs and facilitate regulation. Impaired expression of MMPs may have a significant contribution in the pathogenesis of many tissues-destructive processes like tumor progression and cardiovascular and metabolic disorders.

Materials and Methods:

This case control study lays stress on the possible role of impaired levels of circulating MMP-2 and 9 in metabolic syndrome (MetS). The age, sex-matched 388 subjects with 190 newly diagnosed patients, and 198 healthy controls were recruited. To screen the patients with MetS, biochemical analysis of patients for impaired glucose level, hypertension, body mass index (BMI), and lipid profile was performed. The circulating level of MMP-2 and -9 in serum was analyzed by enzyme-linked immunosorbent assay (ELISA) in all patients and control.

Results:

All metabolic risk factors were statistically significant (P < 0.01) in patients against control group. The serum MMP-2 and -9 level was significantly higher (P < 0.001) in patients having MetS as compared with control group.

Conclusions:

Similar trend was observed in gender wise analysis of serum MMP level. Higher MMP level alteration observed in male patients as compared with female patients.

Thrombin inhibition by dabigatran attenuates atherosclerosis in ApoE deficient mice

INTRODUCTION

Atherosclerosis is a chronic inflammatory disease characterized by endothelial cell damage, infiltration, proliferation and accumulation of macrophages, lymphocytes and transformed vascular smooth muscle cells within the vascular wall and procoagulation processes involving activation of plasmatic coagulation events and platelets. Numerous studies suggested a close interaction between thrombin action and atherogenesis, but possibly underlying mechanisms are multiple and specific treatment options were missing until now.

MATERIAL AND METHODS

Atherosclerosis prone 12 weeks old ApoE(-/-) mice were fed a cholesterol rich diet for 4 weeks and were concomitantly treated orally with placebo or the thrombin inhibitor dabigatran (1.2 g/kg/day).

RESULTS

The thrombin time (HEMOCLOT(®)) was significant extended in dabigatran treated animals. Vascular oxidative stress was significantly reduced during thrombin inhibition, as assessed by L012 chemiluminescence in aortic segments (212 ±84 vs. 69 ±21 RLU/s/mg dry weight, p = 0.048). Organ chamber experiments of isolated aortic rings showed that dabigatran treatment significantly improved endothelium-derived vasorelaxation (p < 0.001). Dabigatran treated mice developed less atherosclerotic lesions (6.2 ±0.2% vs. 9 ±1.1%, p = 0.037) and showed less infiltration of atherosclerotic lesions with macrophages (2.59 ±0.3% vs. 5.14 ±0.7%, p = 0.0046), as determined by systematic histological and immunohistological analyses of the aortic root. Blood pressure, body weight and food intake were not altered by the treatment.

CONCLUSIONS

The thrombin inhibitor dabigatran reduces vascular oxidative stress and inflammation, improves endothelial function and decreases atherosclerosis in mice.

Ginkgo suppresses atherosclerosis through downregulating the expression of connexin 43 in rabbits

INTRODUCTION

Ginkgo biloba extract (GBE) EGb761 is widely used for cardiovascular prevention. Here, we investigated the effects of GBE on atherosclerotic lesion development in rabbits with a high-fat diet.

MATERIAL AND METHODS

Forty New Zealand white male rabbits were randomly divided into four groups. The first two were the normal diet group (C) and the high-fat group (HF). The remaining two groups were those who received a high cholesterol diet supplemented with either the standard drug (simvastatin 2 mg/kg/day) or GBE (3 mg/kg/day). At 12 weeks, histopathological and chemical analyses were performed.

RESULTS

Plasma lipid measurement showed that GBE inhibited high-fat diet-induced increase of serum triglyceride (TG), total cholesterol (TC), and low density lipoprotein cholesterol (LDL-C) by 59.1% (0.9 ±0.2 4 mmol/l vs. 2.2 ±0.4 mmol/l), 18.2% (31.1 ±1.4 mmol/l vs. 38.0 ±0.4 mmol/l) and 15% (28.9 ±1.3 mmol/l vs. 34.0±1.0 mmol/l), respectively, at 12 weeks (p < 0.01). The en face Sudan IV-positive lesion area of the aorta in the GBE group (51.7 ±3.1%) was significantly lower compared with that in the HF group (88.2 ±2.2%; p < 0.01). The mean atherosclerotic lesion area of the GBE group was reduced by 53.2% compared with the HF group (p < 0.01). Immunohistochemistry and western blot analysis showed that GBE markedly suppressed high-fat diet-induced upregulation of connexin 43 (Cx43) in rabbits (p < 0.01).

CONCLUSIONS

Thus, our study revealed that GBE prevented atherosclerosis progress through modulating plasma lipid, suppressing atherosclerotic lesion development, and attenuating the expression of Cx43 protein.

Comprehensive insight into immune regulatory mechanisms and vascular wall determinants of atherogenesis - emerging perspectives of immunomodulation

For many years atherosclerosis was believed to be the passive accumulation of cholesterol in vessel walls. Today the picture is more complex, as immune processes occur in atherogenesis. Considerable attention is focused on the particular role of adaptive immune responses orchestrated by T cell subsets. Since the role of Th1/Th2 balance and Th1 cell domination in atherogenesis is already known, the involvement of regulatory T lymphocytes and recently described Th17 cells raises new concerns. On one hand, each of these cells may specifically drive responses of vascular wall tissues and immune cells; however, they are subject to the control of a plethora of tissue- and pathogen-derived agents. Due to ineffective tissue regeneration, remodeling of the vascular wall occurs. The understanding of the immune regulatory network gives perspectives of innovative immunomodulatory therapies of atherosclerosis and the prevention of its complications, such as coronary artery disease.

Proof of Concept: Matrix metalloproteinase inhibitor decreases inflammation and improves muscle insulin sensitivity in people with type 2 diabetes

Background

Obesity is a state of subclinical inflammation resulting in loss of function of insulin receptors and decreased insulin sensitivity. Inhibition of the inflammatory enzymes, matrix metalloproteinases (MMPs), for 6 months in rodent models restores insulin receptor function and insulin sensitivity.

Methods

This 12-week double-blind, randomized, placebo (PL)-controlled proof-of-concept study was performed to determine if the MMP inhibitor (MMPI), doxycycline, decreased global markers of inflammation and enhanced muscle insulin sensitivity in obese people with type 2 diabetes (DM2). The study included non-DM2 controls (n = 15), and DM2 subjects randomized to PL (n = 13) or doxycycline 100 mg twice daily (MMPI; n = 11). All participants were evaluated on Day 1; MMPI and PL groups were also evaluated after 84 days of treatment.

Results

There was a significant decrease in inflammatory markers C-reactive protein (P < 0.05) and myeloperoxidase (P = 0.01) in the MMPI but not PL group. The MMPI also significantly increased skeletal muscle activated/total insulin signaling mediators: 3’phosphoinositide kinase-1 (PDK1) (p < 0.03), protein kinase B (PKB/Akt) (p < 0.004), and glycogen synthase kinase 3ß (GSK3ß) (p < 0.03).

Conclusions

This study demonstrated short term treatment of people with diabetes with an MMPI resulted in decreased inflammation and improved insulin sensitivity. Larger, longer studies are warranted to determine if doxycycline can improve glucose control in people with diabetes.

Trial Registration

Clinicaltrials.gov NCT01375491