Release of protein as well as activity of MMP-9 from unstable atherosclerotic plaques during percutaneous coronary intervention

Association between NLRP3 inflammasome and periprocedural myocardial injury following elective PCI

Background

Periprocedural myocardial injury (PMI) is a common complication of percutaneous coronary intervention (PCI) associated with poor prognosis. Inflammation has been demonstrated to exert a crucial role in PMI. However, how the inflammation is initiated or sustained in PMI remains elusive.

Methods

RNA-seq in peripheral blood mononuclear cells (PBMCs) from 3 Non-PMI and 6 PMI patients was performed with subsequent bioinformatics analysis. RNA-seq results were verified in a patient cohort. We also established the coronary microembolization (CME) mice model to mimic PMI. The activity of caspase-1 in PBMCs was detected by flow cytometry. The levels of interleukin (IL)-1β, IL-18 and cardiac troponin in plasma were measured by enzyme-linked immunosorbent assay.

Results

We identified a total of 901 differentially expressed genes (DEGs) between Non-PMI and PMI patients. These DEGs participated in several inflammation-related processes. NOD-like receptor signaling pathway was significantly enriched in pathway analysis. All the key genes composed in the NLRP3 inflammasome, including NLRP3, PYCARD, CASP1 and IL1B, were upregulated in PMI patients. The activation of NLRP3 inflammasome was then verified by increased activity of caspase-1 in PBMCs, and elevated levels of IL-1β and IL-18 in plasma in PMI patients. Spearman analysis confirmed tight correlations between caspase-1 activity, IL-1β, IL-18 levels and troponin T level. In addition, caspase-1 activity, IL-1β and IL-18 levels were also enhanced in CME mice.

Conclusions

We discovered that NLRP3 inflammasome was involved in PMI, thus providing evidence supporting the therapeutic value of NLRP3 inflammasome-targeted strategies in PMI.

Characterization of Systemic and Culprit-Coronary Artery miR-483-5p Expression in Chronic CAD and Acute Myocardial Infarction Male Patients

Coronary artery disease (CAD) is the leading cause of mortality worldwide. In chronic and myocardial infarction (MI) states, aberrant levels of circulating microRNAs compromise gene expression and pathophysiology. We aimed to compare microRNA expression in chronic-CAD and acute-MI male patients in peripheral blood vasculature versus coronary arteries proximal to a culprit area. Blood from chronic-CAD, acute-MI with/out ST segment elevation (STEMI/NSTEMI, respectively), and control patients lacking previous CAD or having patent coronary arteries was collected during coronary catheterization from peripheral arteries and from proximal culprit coronary arteries aimed for the interventions. Random coronary arterial blood was collected from controls; RNA extraction, miRNA library preparation and Next Generation Sequencing followed. High concentrations of microRNA-483-5p (miR-483-5p) were noted as 'coronary arterial gradient' in culprit acute-MI versus chronic-CAD (p = 0.035) which were similar to controls versus chronic-CAD (p < 0.001). Meanwhile, peripheral miR-483-5p was downregulated in acute-MI and chronic-CAD, compared with controls (1.1 ± 2.2 vs. 2.6 ± 3.3, respectively, p < 0.005). A receiver operating characteristic curve analysis for miR483-5p association with chronic CAD demonstrated an area under the curve of 0.722 (p < 0.001) with 79% sensitivity and 70% specificity. Using in silico gene analysis, we detected miR-483-5p cardiac gene targets, responsible for inflammation (PLA2G5), oxidative stress (NUDT8, GRK2), apoptosis (DNAAF10), fibrosis (IQSEC2, ZMYM6, MYOM2), angiogenesis (HGSNAT, TIMP2) and wound healing (ADAMTS2). High miR-483-5p 'coronary arterial gradient' in acute-MI, unnoticed in chronic-CAD, suggests important local mechanisms for miR483-5p in CAD in response to local myocardial ischemia. MiR-483-5p may have an important role as a gene modulator for pathologic and tissue repair states, is a suggestive biomarker, and is a potential therapeutic target for acute and chronic cardiovascular disease.

Effects of Acute Colchicine Administration Prior to Percutaneous Coronary Intervention: COLCHICINE-PCI Randomized Trial

BACKGROUND

Vascular injury and inflammation during percutaneous coronary intervention (PCI) are associated with increased risk of post-PCI adverse outcomes. Colchicine decreases neutrophil recruitment to sites of vascular injury. The anti-inflammatory effects of acute colchicine administration before PCI on subsequent myocardial injury are unknown.

METHODS

In a prospective, single-site trial, subjects referred for possible PCI (n=714) were randomized to acute preprocedural oral administration of colchicine 1.8 mg or placebo.

RESULTS

Among the 400 subjects who underwent PCI, the primary outcome of PCI-related myocardial injury did not differ between colchicine (n=206) and placebo (n=194) groups (57.3% versus 64.2%, P=0.19). The composite outcome of death, nonfatal myocardial infarction, and target vessel revascularization at 30 days (11.7% versus 12.9%, P=0.82), and the outcome of PCI-related myocardial infarction defined by the Society for Cardiovascular Angiography and Interventions (2.9% versus 4.7%, P=0.49) did not differ between colchicine and placebo groups. Among 280 PCI subjects in a nested inflammatory biomarker substudy, the primary biomarker end point, change in interleukin-6 concentrations did not differ between groups 1-hour post-PCI but increased less 24 hours post-PCI in the colchicine (n=141) versus placebo group (n=139; 76% [-6 to 898] versus 338% [27 to 1264], P=0.02). High-sensitivity C-reactive protein concentration also increased less after 24 hours in the colchicine versus placebo groups (11% [-14 to 80] versus 66% [1 to 172], P=0.001).

CONCLUSIONS

Acute preprocedural administration of colchicine attenuated the increase in interleukin-6 and high-sensitivity C-reactive protein concentrations after PCI when compared with placebo but did not lower the risk of PCI-related myocardial injury. Registration: URL: https://www.clinicaltrials.gov; Unique Identifiers: NCT02594111, NCT01709981.

Association of genetic polymorphisms in matrix metalloproteinase-9 and coronary artery disease in the Chinese Han population: a case-control study

OBJECTIVE

Matrix metalloproteinase-9 (MMP-9) plays an important role in inflammation and matrix degradation involved in atherosclerosis and plaque rupture. The T allele of rs3918242 has been reported to lead to a high promoter activity and associate with the extent of coronary artery disease (CAD). And some studies have reported that the G allele of rs17576 might be associated with CAD. The aim of this study was to assess the association between the polymorphisms of the MMP-9 gene and CAD in the Chinese Han population.

METHODS

This case-control study comprised 258 CAD cases and 153 controls from the Chinese Han Population. The genomic DNA of MMP-9 was isolated from whole blood. Polymerase chain reaction-based restriction fragment length polymorphism was used to determine the rs3918242 and rs17576 genotypes in the MMP-9 gene and the total serum levels of MMP-9 were measured using enzyme-linked immunosorbent assay in both case and control groups.

RESULTS

Analysis of MMP-9 gene polymorphisms showed that the frequencies of the T allele and CT+TT genotypes of rs3918242 were significantly higher in the case group than in the control group (p<0.05). However, the distribution of variant genotypes of rs17576 did not differ between the case and control groups (p>0.05). The total serum level of MMP-9 was significantly higher in the case group than in the control group (p<0.05). The subjects carrying T alleles in the CAD group had higher average serum MMP-9 levels compared with CC genotypes (p<0.05).

CONCLUSIONS

Our results suggest that the single-nucleotide polymorphism of rs3918242 in the MMP-9 gene is associated with CAD and high serum levels of MMP-9 are also associated with CAD in the Chinese Han population. Therefore, genetic variation of rs3918242 may participate in the development of CAD through influencing MMP-9 expression.

Vascular effects of glycoprotein130 ligands--part II: biomarkers and therapeutic targets

Glycoprotein130 (gp130) ligands are defined by the use of the common receptor subunit gp130 and comprise interleukin (IL)-6, oncostatin M (OSM), IL-11, leukemia inhibitory factor (LIF), cardiotrophin-1 (CT-1), cardiotrophin-like cytokine (CLC), ciliary neurotrophic factor (CNTF), IL-27 and neuropoietin (NP). In part I of this review we addressed the pathophysiological functions of gp130 ligands with respect to the vascular wall. In part II of this review on the vascular effects of gp130 ligands we will discuss data about possible use of these molecules as biomarkers to predict development or progression of cardiovascular diseases. Furthermore, the possibility to modulate circulating levels of gp130 ligands or their tissue expression by specific antibodies, soluble gp130 protein, renin-angiotensin-aldosterone system (RASS) inhibitors, statins, agonists of peroxisome proliferator-activated receptors (PPAR), hormone replacement therapy, nonsteroidal anti-inflammatory drugs (NSAID) or lifestyle modulating strategies are presented. Recent knowledge about the application of recombinant cytokines from the gp130 cytokine family as therapeutic agents in obesity or atherosclerosis is also summarized. Thus the purpose of this review is to cover a possible usefulness of gp130 ligands as biomarkers and targets for therapy in cardiovascular pathologies.

Evaluating oxidative stress in human cardiovascular disease: methodological aspects and considerations

Oxidative stress is a key feature in atherogenesis, since reactive oxygen species (ROS) are involved in all stages of the disease, from endothelial dysfunction to atheromatic plaque formation and rupture. It is therefore important to identify reliable biomarkers allowing us to monitor vascular oxidative stress status. These may lead to improved understanding of disease pathogenesis and development of new therapeutic strategies. Measurement of circulating biomarkers of oxidative stress is challenging, since circulation usually behaves as a separate compartment to the individual structures of the vascular wall. However, measurement of stable products released by the reaction of ROS and vascular/circulating molecular structures is a particularly popular approach. Serum lipid hydroperoxides, plasma malondialdehyde or urine F2-isoprostanes are widely used and have a prognostic value in cardiovascular disease. Quantification of oxidative stress at a tissue level is much more accurate. Various chemiluminescence and high performance liquid chromatography assays have been developed over the last few years, and some of them are extremely accurate and specific. Electron spin resonance spectroscopy and micro-electrode assays able to detect ROS directly are also widely used. In conclusion, measurement of circulating biomarkers of oxidative stress is valuable, and some of them appear to have predictive value in cardiovascular disease. However, these biomarkers do not necessarily reflect intravascular oxidative stress and therefore cannot be used as therapeutic targets or markers to monitor pharmacological treatments in clinical settings. Measurement of vascular oxidative stress status is still the only reliable way to evaluate the involvement of oxidative stress in atherogenesis.

The trouble with translational medicine

Increasingly more reports in the literature are reflecting on the hurdles of effective translation from promising results of biomedical research into useful therapeutics. A recurrent theme is that good intentions are frustrated by extrinsic factors upon which 'translationalists' have little control. It is possible that the problem resides, at least in part, within the translational community itself, which has failed to prioritize the steps required to approach the problem systematically. Most importantly, there is disproportionate emphasis on bench-to-bedside efforts, rather than confronting a priori the need to increase the understanding of human pathophysiology. Thus, therapeutic concepts based on experimental conditions that may not and indeed often do not represent the nature of human genetics lead to drug development that is not sufficiently applicable to the human condition. The damage is then amplified when these ill-fated concepts are tested in clinical trials at great cost. The use of surrogate biomarkers that could allow early assessment of efficacy currently requires long-term assessment of clinical benefit. This can delay by years or decades essential feedback about clinical efficacy. Moreover, scant effort is applied to learning whether a drug has achieved its biological endpoint, or why it failed its clinical endpoint. Thus, the feedback loop is not only delayed, but is often uninformative. As a consequence, researchers continue to produce novel therapeutic candidates based on experimental models without the essential benefit of lessons learned from previous failures. Biomedical research will succeed when drug development is guided by experience gained through informative clinical trials with the purpose of not only testing the effectiveness of treatment but also providing mechanistic insights into the differences between expected and observed results. This can only be achieved through the courageous effort of the research community to change the way biomedical research is funded, published and rewarded.

Matrix metalloproteinase-9 functional promoter polymorphism 1562C>T increased risk of early-onset coronary artery disease

The Matrix metalloproteinase-9 functional promoter polymorphism 1562C>T may be considered an important genetic determinant of early-onset coronary artery disease (ECAD). In this study, association between MMP-9 1562C>T allele with plasma MMP-9 activity, homocysteine and lipid-lipoproteins level and ECAD in Iranian subjects was investigated. This case-control study consisted of 53 ECAD patients (age < 55 years) and unrelated late-onsets CAD (age>70 years) who angiographically had at least 50% stenosis. MMP-9 1562C>T polymorphism was detected by PCRRFLP, plasma MMP-9 activity, serum lipid and homocysteine levels were determined by gelatin gel zymography, enzyme assay and by HPLC, respectively. The presence of MMP-9 1562C>T allele was found to be associated with ECAD (OR=3.2, P=0.001). The ECAD patients with MMP-9 1562C>T allele had higher MMP-9 activity (P=0.001), LDL-C (P=0.045), TC (P=0.02) and homocysteine (P=0.01) levels than the LCAD subjects. MMP-9 1562C>T allele is a risk factor for ECAD. The carriers of this allele have high levels of MMP-9 activity, LDL-C, TC and homocysteine (P=0.01), thus, are more likely to develop myocardial infarction and CAD at young age (less than 55 years).

Effect of Qingre Quyu Granule (清热祛瘀颗粒) on stabilizing plaques in the brachiocephalic artery of apolipoprotein E deficient mice

OBJECTIVE

To investigate the effect of Qingre Quyu Granule (清热祛瘀颗粒, QRQYG) on stabilizing vulnerable plaques in apolipoprotein E (ApoE) deficient mice.

METHODS

Seventy-two male ApoE deficient mice were given a high-fat diet from 6 weeks of age. At the 16th week, all the mice were randomized into 3 groups: the QRQYG group, the simvastatin group, and the control group. Sixteen weeks after administration of 0.9 g/kg QRQYG, 3 mg/kg simvastatin or 10 mg/kg sodium chloride per day to the respective groups, the animals were euthanized. The pathological morphologic changes in the vulnerable plaques were evaluated, the matrix metalloprotease-9 (MMP-9) expression was measured by immunohistofluorescence, the soluble intercellular adhesion molecule 1 (ICAM-1) was determined by ELISA, the nuclear factor kappaB (NF-κB) subunit p65 was measured by quantitative RT-PCR, and, finally, thrombospondin-1 (TSP-1) was determined by the immunohistochemical method.

RESULTS

The plaque cross-sectional area in the brachiocephalic artery (23.7%, P<0.01), the lipid core of the plaque (43.1%±3.1%), and the number of buried fibrotic caps of the plaque were significantly decreased in the QRQYG group compared to the control group (both P<0.01); furthermore, the thickness of the fibrotic cap of the plaque increased and the intra-plaque hemorrhage of the plaque decreased. The serum soluble ICAM-1 (27.1±5.1 μg/mL), the protein expression of MMP-9 and TSP-1 and the p65 mRNA expression increased in the QRQYG group in comparison with the control group (P<0.05 or P<0.01).

CONCLUSION

QRQYG could stabilize the vulnerable plaque through inhibition of the inflammatory response.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Role of matrix metalloproteinases and their tissue inhibitors as potential biomarkers of left ventricular remodelling in the athlete's heart

The aim of the present study was to verify whether plasma MMPs (matrix metalloproteinases) and TIMPs (tissue inhibitors of MMPs) could be used as potential markers of paraphysiological remodelling in the athlete's heart, and to correlate these matrix parameters with echocardiographic signs of LV (left ventricular) remodelling. Plasma MMP-2 and MMP-9 were measured by zymography, and TIMP-1 and TIMP-2 were measured by ELISA in 42 veteran marathoners with AH (athlete's heart), and in 25 sedentary healthy subjects (CTL). All subjects were submitted to a clinical examination and two-dimensional colour Doppler echocardiography together with the measurement of circulating NT-proBNP (N-terminal pro-B-type natriuretic peptide); GGT (gamma-glutamyl transpeptidase) was evaluated as a marker of cardiovascular disease. Veteran athletes had a significant elevation in LV dimensions and calculated LV mass index. Diastolic and systolic functions were normal for both groups. MMP-9 levels were significantly lower in AH than in CTL subjects (56.9+/-4.3 compared with 119.4+/-21.5 m-units/l, P<0.01). There were significant differences in MMP-2 between the two groups, with a down-regulation in the AH subjects (182.5+/-16.8 units/ml in CTL compared with 117.1+/-9.1 units/ml in AH, P<0.01). MMP-2 and MMP-2/TIMP-2 were inversely correlated with myocardial indices of hypertrophy in AH and CTL subjects. AH and CTL subjects showed similar TIMP values. The results of the present study indicate that MMPs and TIMPs could represent potential biomarkers of adaptive heart remodelling in the athletes. In addition, the inverse correlation of the MMP-2/TIMP-2 system with echocardiographic signs of myocardial hypertrophy could represent a new diagnostic and prognostic indicator useful in the evaluation of cardiovascular risk in athletes.

The monocyte/macrophage as a therapeutic target in atherosclerosis

It is now clear that the monocyte/macrophage has a crucial role in the development of atherosclerosis. This cell appears to be involved in all stages of atherosclerotic plaque development and is increasingly seen as a candidate for therapeutic intervention and as a potential biomarker of disease progression and response to therapy. The main mechanisms related to the activity of the monocyte/macrophage that have been targeted for therapy are those that facilitate recruitment, cholesterol metabolism, inflammatory activity and oxidative stress. There is also increasing evidence that there is heterogeneity within the monocyte/macrophage population, which may have important implications for plaque development and regression. A better insight into how specific phenotypes may influence plaque progression should facilitate the development of novel methods of imaging and more refined treatments.

Co-cultures of human coronary smooth muscle cells and dimethyl sulfoxide-differentiated HL60 cells upregulate ProMMP9 activity and promote mobility-modulation by reactive oxygen species

Vascular cells and leukocytes, involved in the development of atherosclerosis, produce cytokines and/or reactive oxygen species (ROS) and matrix metalloproteinases (MMPs) implicated in cell mobility. We investigated by co-culture experiments the effects of human coronary smooth muscle cells (HCSMC) on MMPs characteristics and mobility of neutrophil-like dimethyl sulfoxide-differentiated HL60 cells (not equal HL60). The effects of superoxide dismutase (SOD) and catalase were also analyzed. All the studied MMP2 characteristics remained unchanged. HCSMC stimulated MMP9 protein level, activity and mobility of not equal HL60 cells and expressed and secreted a variety of cytokines implicated in atherosclerosis. SOD and catalase increased MMP9 expression, protein level and activity of not equal HL60, but migration of not equal HL60 cells was only decreased by catalase, demonstrating that ROS are more efficient in modulating MMP9 activity of not equal HL60 than their mobility. Finally, HCSMC being able to stimulate not equal HL60, their co-cultures may represent an in vitro approach to study cellular interactions occurring in vivo during atherosclerosis.

Inflammation dampened by gelatinase A cleavage of monocyte chemoattractant protein-3

Tissue degradation by the matrix metalloproteinase gelatinase A is pivotal to inflammation and metastases. Recognizing the catalytic importance of substrate-binding exosites outside the catalytic domain, we screened for extracellular substrates using the gelatinase A hemopexin domain as bait in the yeast two-hybrid system. Monocyte chemoattractant protein-3 (MCP-3) was identified as a physiological substrate of gelatinase A. Cleaved MCP-3 binds to CC-chemokine receptors-1, -2, and -3, but no longer induces calcium fluxes or promotes chemotaxis, and instead acts as a general chemokine antagonist that dampens inflammation. This suggests that matrix metalloproteinases are both effectors and regulators of the inflammatory response.