Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) Is Increased in Human Left Ventricle after Acute Myocardial Infarction

Theranostic Contribution of Extracellular Matrix Metalloprotease Inducer-Paramagnetic Nanoparticles Against Acute Myocardial Infarction in a Pig Model of Coronary Ischemia-Reperfusion

Rapid screening and accurate diagnosis of acute myocardial infarction are critical to reduce the progression of myocardial necrosis, in which proteolytic degradation of myocardial extracellular matrix plays a major role. In previous studies, we found that targeting the extracellular matrix metalloprotease inducer (EMMPRIN) by injecting nanoparticles conjugated with the specific EMMPRIN-binding peptide AP9 significantly improved cardiac function in mice subjected to ischemia/reperfusion.

Ivabradine induces cardiac protection by preventing cardiogenic shock-induced extracellular matrix degradation

INTRODUCTION AND OBJECTIVES

Ivabradine reduces heart rate by blocking the I(f) current and preserves blood pressure and stroke volume through unknown mechanisms. Caveolin-3 protects the heart by forming protein complexes with several proteins, including extracellular matrix (ECM)-metalloproteinase-inducer (EMMPRIN) and hyperpolarization-activated cyclic nucleotide-gated channel 4 (HN4), a target of ivabradine. We hypothesized that ivabradine might also exert cardioprotective effects through inhibition of ECM degradation.

METHODS

In a porcine model of cardiogenic shock, we studied the effects of ivabradine on heart integrity, the levels of MMP-9 and EMMPRIN, and the stability of caveolin-3/HCN4 protein complexes with EMMPRIN.

RESULTS

Administration of 0.3 mg/kg ivabradine significantly reduced cardiogenic shock-induced ventricular necrosis and expression of MMP-9 without affecting EMMPRIN mRNA, protein, or protein glycosylation (required for MMP activation). However, ivabradine increased the levels of the caveolin-3/LG-EMMPRIN (low-glycosylated EMMPRIN) and caveolin-3/HCN4 protein complexes and decreased that of a new complex between HCN4 and high-glycosylated EMMPRIN formed in response to cardiogenic shock. We next tested whether caveolin-3 can bind to HCN4 and EMMPRIN and found that the HCN4/EMMPRIN complex was preserved when we silenced caveolin-3 expression, indicating a direct interaction between these 2 proteins. Similarly, EMMPRIN-silenced cells showed a significant reduction in the binding of caveolin-3/HCN4, which regulates the I(f) current, suggesting that, rather than a direct interaction, both proteins bind to EMMPRIN.

CONCLUSIONS

In addition to inhibition of the I(f) current, ivabradine may induce cardiac protection by inhibiting ECM degradation through preservation of the caveolin-3/LG-EMMPRIN complex and control heart rate by stabilizing the caveolin-3/HCN4 complex.

Basigin rs8259 Polymorphism Confers Decreased Risk of Chronic Heart Failure in a Chinese Population

Left ventricular remodeling is an essential risk factor contributing to the pathogenesis of chronic heart failure (CHF). Basigin (BSG) promotes cardiovascular inflammation and myocardial remodeling processes by induction of extracellular matrix metalloproteinases and inflammatory cytokines. BSG rs8259 polymorphism was associated with BSG expression and risk of acute coronary syndrome. Therefore, we investigated whether rs8259 polymorphism contributes to risk and prognosis of CHF in Chinese patients. In total 922 adult patients with CHF and 1107 matched healthy controls were enrolled. BSG rs8259 polymorphism was genotyped using PCR-restriction fragment length polymorphism. Whole blood BSG mRNA expression data from Genotype-Tissue Expression project was accessed. Evaluation of follow-up data was performed in only 15.2% (140) of the patients with CHF. BSG rs8259 TT genotype was associated with a decreased risk of CHF (OR = 0.83, 95% CI = 0.72–0.96, p = 0.010), especially in patients with hypertension (OR = 0.80, 95% CI = 0.68–0.95, p = 0.011) and coronary heart disease (OR = 0.81, 95% CI = 0.69–0.96, p = 0.013) after adjustment for multiple cardiovascular risk factors. Rs8259 T allele was associated with decreased BSG mRNA in whole blood from 338 healthy normal donors (p = 1.31 × 10⁻⁶). However, rs8259 polymorphism failed to exhibit an association with cardiovascular mortality (p = 0.283). BSG rs8259 polymorphism may contribute to decreased risk of CHF in a Chinese Han population.

Atorvastatin attenuates plaque vulnerability by downregulation of EMMPRIN expression via COX-2/PGE2 pathway

Extracellular matrix metalloproteinase inducer (EMMPRIN) reportedly has a key regulatory role in matrix metalloproteinase (MMP) activities and the progression of atherosclerosis. Statins, which are anti-atherosclerotic pharmacological agents, are widely applied in clinical settings. The aim of the present study was to investigate the pharmaceutical effect of atorvastatin on EMMPRIN expression in atherosclerotic plaques. An atherosclerotic mouse model was established using apoliprotein E-deficient (ApoE^−/−) mice raised on a high-fat diet. Additionally, a low (5 mg/kg/day) or high dosage (10 mg/kg/day) of atorvastatin suspension was administered orally for eight weeks, beginning on week 7 or 11 respectively. The effects of atorvastatin on atherosclerotic plaque formation and EMMPRIN expression were subsequently determined. The THP-1 cell line was used to investigate the effect of atorvastatin on EMMPRIN expression in vitro. The results demonstrated that the high-fat diet led to vulnerable plaques (VPs) and increased EMMPRIN expression in VPs in ApoE^−/− mice. Atorvastatin treatment decreased EMMPRIN expression in the aortas and plaques of ApoE^−/− mice. In vitro, oxidized low-density lipoprotein (ox-LDL) induced the expression of cyclooxygenase-2 (COX-2) and EMMPRIN in THP-1 macrophages, and atorvastatin inhibited ox-LDL-induced expression of PGE2, EMMPRIN and COX-2 in THP-1 macrophages. Therefore, the present data indicated that atorvastatin treatment reduces the vulnerability of atherosclerotic plaques and expression of EMMPRIN, and that the inhibitory effect of atorvastatin on EMMPRIN may occur via the COX-2/PGE2 signaling pathway in macrophages.

EMMPRIN-Targeted Magnetic Nanoparticles for In Vivo Visualization and Regression of Acute Myocardial Infarction

Inhibition of extracellular matrix (ECM) degradation may represent a mechanism for cardiac protection against ischemia. Extracellular matrix metalloproteinase inducer (EMMPRIN) is highly expressed in response to acute myocardial infarction (AMI), and induces activation of several matrix metalloproteinases (MMPs), including gelatinases MMP-2 and MMP-9. We targeted EMMPRIN with paramagnetic/fluorescent micellar nanoparticles conjugated with the EMMPRIN binding peptide AP-9 (NAP9), or an AP-9 scrambled peptide as a negative control (NAPSC). We found that NAP9 binds to endogenous EMMPRIN in cultured HL1 myocytes and in mouse hearts subjected to ischemia/reperfusion (IR). Injection of NAP9 at the time of or one day after IR, was enough to reduce progression of myocardial cell death when compared to Control and NAPSC injected mice (infarct size in NAP9 injected mice: 32%±6.59 vs Control: 46%±9.04 or NAPSC injected mice: 48%±7.64). In the same way, cardiac parameters were recovered to almost healthy levels (LVEF NAP9 63% ± 7.24 vs Control 42% ± 4.74 or NAPSC 39% ± 6.44), whereas ECM degradation was also reduced as shown by inhibition of MMP-2 and MMP-9 activation. Cardiac magnetic resonance (CMR) scans have shown a signal enhancement in the left ventricle of NAP9 injected mice with respect to non-injected, and to mice injected with NAPSC. A positive correlation between CMR enhancement and Evans-Blue/TTC staining of infarct size was calculated (R:0.65). Taken together, these results point to EMMPRIN targeted nanoparticles as a new approach to the mitigation of ischemic/reperfusion injury.

Upregulation of EMMPRIN (OX47) in Rat Dorsal Root Ganglion Contributes to the Development of Mechanical Allodynia after Nerve Injury

Matrix metalloproteinases (MMPs) are widely implicated in inflammation and tissue remodeling associated with various neurodegenerative diseases and play an important role in nociception and allodynia. Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) plays a key regulatory role for MMP activities. However, the role of EMMPRIN in the development of neuropathic pain is not clear. Western blotting, real-time quantitative RT-PCR (qRT-PCR), and immunofluorescence were performed to determine the changes of messenger RNA and protein of EMMPRIN/OX47 and their cellular localization in the rat dorsal root ganglion (DRG) after nerve injury. Paw withdrawal threshold test was examined to evaluate the pain behavior in spinal nerve ligation (SNL) model. The lentivirus containing OX47 shRNA was injected into the DRG one day before SNL. The expression level of both mRNA and protein of OX47 was markedly upregulated in ipsilateral DRG after SNL. OX47 was mainly expressed in the extracellular matrix of DRG. Administration of shRNA targeted against OX47 in vivo remarkably attenuated mechanical allodynia induced by SNL. In conclusion, peripheral nerve injury induced upregulation of OX47 in the extracellular matrix of DRG. RNA interference against OX47 significantly suppressed the expression of OX47 mRNA and the development of mechanical allodynia. The altered expression of OX47 may contribute to the development of neuropathic pain after nerve injury.

Impact of artificial capnothorax on coagulation in patients during video-assisted thoracoscopic esophagectomy for squamous cell carcinoma

BACKGROUND

Compared with the lung isolation using double-lumen endobronchial tube intubation, the artificial capnothorax using single-lumen endotracheal tube intubation has shown to be a safe, more convenient, and cost-effective procedure for thoracoscopic esophagectomy. However, the impact of capnothorax on coagulation is not well defined. Herein, we evaluate the impact of a capnothorax on coagulation and fibrinolysis in patients who undergoing thoracoscopic esophagectomy.

METHODS

Between March 2014 and August 2014, 24 patients underwent thoracoscopic esophagectomies for esophageal cancer with the procedure of artificial capnothorax (group P); we also performed 24 thoracoscopic esophagectomy cases without using capnothorax (group N). The demographics and arterial blood gas, as well as the parameters of coagulation and fibrinolysis, of the two groups were analyzed.

RESULTS

The pH value of group P after CO2 insufflation was significantly lower than in group N (P < 0.05), and the partial pressure of carbon dioxide (PaCO2) was significantly increased compared with group N (P < 0.05). The R and K values after CO2 insufflation were significantly longer than before anesthesia (P < 0.05), and both α angle and MA value after CO2 insufflation were significantly lower than those before anesthesia (P < 0.05). No significant differences in R value, K value, α angle, or MA value were observed between pre-anesthesia and termination of capnothorax. No significant difference in LY30 data was found between different groups (P > 0.05).

CONCLUSION

Artificial capnothorax in patients receiving endoscopic resection of esophageal carcinoma had a significant impact on coagulation. These patients showed significant impairments in coagulation not observed in patients without artificial capnothorax.

Interleukin 18 and extracellular matrix metalloproteinase inducer cross-regulation: implications in acute myocardial infarction

Circulating interleukin-18 (IL-18) is thought to promote atherosclerosis and cardiovascular complications such as plaque rupture. Atherosclerosis is also characterized by smooth muscle cell migration, a consequence of extracellular matrix (ECM) degradation regulated by metalloproteinases (MMPs). Because extracellular matrix metalloproteinase inducer (EMMPRIN) has been shown to promote plaque instability by inducing ECM degradation and MMP synthesis, we investigated whether a cross-regulatory interaction exists between IL-18 and EMMPRIN in human monocytes. EMMPRIN levels in monocytes were markedly greater in 20 patients with acute myocardial infarction (AMI) compared with 20 patients with stable angina pectoris or 20 healthy volunteers (control group). The levels of IL-18 and MMP-9 in serum were also significantly greater in the AMI group in comparison with the other 2 groups. IL-18 levels positively correlated with increased levels of EMMPRIN in monocytes. In vitro, the expression of EMMPRIN was increased in monocytes cultured with IL-18, and IL-18 secretion was augmented in monocytes cultured with EMMPRIN. Gene silencing of EMMPRIN by small interfering RNA reduced monocyte secretion of both IL-18 and MMP-9. In the present study, cross-regulation between IL-18 and EMMPRIN in monocytes was demonstrated. This interaction may amplify the inflammatory cascade and be responsible for increased monocytic MMP-9 serum levels in atherosclerosis, contributing to atherosclerotic plaque destabilization and subsequent AMI.

The influence of autologous bone marrow stem cell transplantation on matrix metalloproteinases in patients treated for acute ST-elevation myocardial infarction

Background. Matrix metalloproteinase-9 (MMP-9), regulated by tissue inhibitor of metalloproteinase-9 (TIMP-1) and the extracellular matrix metalloproteinase inducer (EMMPRIN), contributes to plaque instability. Autologous stem cells from bone marrow (mBMC) treatment are suggested to reduce myocardial damage; however, limited data exists on the influence of mBMC on MMPs. Aim. We investigated the influence of mBMC on circulating levels of MMP-9, TIMP-1, and EMMPRIN at different time points in patients included in the randomized Autologous Stem-Cell Transplantation in Acute Myocardial Infarction (ASTAMI) trial (n = 100). Gene expression analyses were additionally performed. Results. After 2-3 weeks we observed a more pronounced increase in MMP-9 levels in the mBMC group, compared to controls (P = 0.030), whereas EMMPRIN levels were reduced from baseline to 2-3 weeks and 3 months in both groups (P < 0.0001). Gene expression of both MMP-9 and EMMPRIN was reduced from baseline to 3 months. MMP-9 and EMMPRIN were significantly correlated to myocardial injury (CK: P = 0.005 and P < 0.001, resp.) and infarct size (SPECT: P = 0.018 and P = 0.008, resp.). Conclusion. The results indicate that the regulation of metalloproteinases is important during AMI, however, limited influenced by mBMC.

Translating Koch's postulates to identify matrix metalloproteinase roles in postmyocardial infarction remodeling: cardiac metalloproteinase actions (CarMA) postulates

The first matrix metalloproteinase (MMP) was described in 1962; and since the 1990s, cardiovascular research has focused on understanding how MMPs regulate many aspects of cardiovascular pathology from atherosclerosis formation to myocardial infarction and stroke. Although much information has been gleaned by these past reports, to a large degree MMP cardiovascular biology remains observational, with few studies homing in on cause and effect relationships. Koch's postulates were first developed in the 19th century as a way to establish microorganism function and were modified in the 20th century to include methods to establish molecular causality. In this review, we outline the concept for establishing a similar approach to determine causality in terms of MMP functions. We use left ventricular remodeling postmyocardial infarction as an example, but this approach will have broad applicability across both the cardiovascular and the MMP fields.

Matrix as an interstitial transport system

The extracellular matrix (ECM) is best known for its function as a structural scaffold for the tissue and more recently as a microenvironment to sequester growth factors and cytokines allowing for rapid and localized changes in their activity in the absence of new protein synthesis. In this review, we explore this and additional new aspects of ECM function in mediating cell-to-cell communications. Fibrillar and nonfibrillar components of ECM can limit and facilitate the transport of molecules through the extracellular space while also regulating interstitial hydrostatic pressure. In turn, transmembrane communications via molecules, such as ECM metalloproteinase inducer, thrombospondins, and integrins, can further mediate cell response to extracellular cues and affect ECM composition and tissue remodeling. Other means of cell-to-cell communication include extracellular microRNA transport and its contribution to gene expression in target cells and the nanotube formation between distant cells, which has recently emerged as a novel conduit for intercellular organelle sharing thereby influencing cell survival and function. The information summarized and discussed here are not limited to the cardiovascular ECM but encompass ECM in general with specific references to the cardiovascular system.

Enhancement of matrix metalloproteinase 2 and 9 inhibitory action of minocycline by aspirin: an approach to attenuate outcome of acute myocardial infarction in diabetes

BACKGROUND AND AIMS

Diabetes is a risk factor for exacerbated outcome after acute myocardial infarction (AMI) and doubles the risk of mortality after MI. Increased levels of MMP-2 and MMP-9 in diabetes cause vascular remodelling, which leads to cardiovascular complications of diabetes. We hypothesized that inhibition of MMP-2 and MMP-9 can reduce worsening of myocardial ischemia in diabetic patients. Further, we hypothesized that minocycline induced MMP-2 and MMP-9 inhibition will be potentiated by aspirin and the combination of both drugs will prevent worsening of MI in diabetic patients. In the present study, efficacy of combination of minocycline and aspirin to attenuate exacerbation of myocardial ischemia/reperfusion (I/R) injury in diabetic rats was evaluated.

METHODS

Diabetes was induced in male Wistar rats by streptozotocin (55 mg/kg i.p.). Three weeks after diabetes induction, rats were treated with minocycline (50 mg/kg, p.o.), aspirin (50 mg/kg, p.o.), or minocycline (50 mg/kg, p.o.) plus aspirin (50 mg/kg, p.o.) for a period of 3 weeks. At the end of week 6, I/R injury was induced by ligating the left anterior descending coronary artery for 30 min followed by 2 h reperfusion.

RESULTS

Percentage infarct volume, arrhythmias, mortality, collagen level and MMP-2 and MMP-9 level were significantly increased in vehicle-treated diabetic group when compared with normoglycemic rats. Treatment with a combination of minocycline and aspirin decreased percentage infarct volume, arrhythmias, mortality and collagen level when compared with vehicle-treated diabetic controls and showed reduced levels of MMP-2 and MMP-9.

CONCLUSIONS

Results of the present study suggest that the combination of minocycline and aspirin prevent worsening of AMI in diabetic rats.

The effects and mechanism of ginsenoside Rg1 on myocardial remodeling in an animal model of chronic thromboembolic pulmonary hypertension

Background

Recent studies haveshown that ginsenoside Rg1, extracted from the dry roots of Panax notoginseng as a traditional Asian medicine, plays an anti-fibrosis role in myocardial remodeling. However, the mechanism still remains unclear. In the present study, we investigate the effect of ginsenoside Rg1on the collagenic remodeling of myocardium in chronic thromboembolic pulmonary hypertension (CTEPH), and its potential mechanism.

Methods

A rat model of CTEPH was established by injecting thrombi through the jugular vein wice in2 weeks. Four weeks later, four groups (Group A: normal rats + normal saline; Group B: normal rats + Rg1; Group C: CTEPH model + normal saline; Group D: CTEPH model + Rg1) were established. Normal saline and Rg1 were administrated by intraperitoneal injection. Ineach group, we measured the hemodynamic parameters, as well as the right ventricle to left ventricle (RV/LV) thickness ratio. Myocardial tissue sections of the RV were stained by hematoxylin-eosin +gentian violet and the morphological characteristics were observed by light microscopy. The matrix metalloproteinases (MMP) -2 and −9 were detected by the western blot.

Results

Compared with Group A and Group B, the right ventricular systolic pressure was significantly increased in Group C and significantly decreased in Group D. Compared with Group A and Group B, the RV/LV thickness ratio of the rats was significantly higher in Group C and Group D. There was significant fibrosis with collagen in Group C compared with Group A and Group B, and less significant changes in Group D were observed compared with those in Group C. The expression of MMP-2 and MMP-9 exhibited a significant decrease in Group C and was also significantly decreased in Group D compared withGroup A and Group B. Also, a negative linear relationship was shown between collagen-I and the expression of MMP-2 and MMP-9.

Conclusions

Our animal study showed that ginsenoside Rg1 positively affects myocardial remodeling and pulmonary hemodynamics in CTEPH. Upregulation of the expression of MMP-2 and MMP-9 could explain the beneficial effects of ginsenoside Rg1 in CTEPH.

Expression of basigin in the early phase of acute myocardial ischemia in rats

Basigin may be involved in cardiovascular disease. In our previous study, suppression subtractive hybridization results indicated that basigin may be associated with the early phase of acute myocardial ischemia (AMI) within 1 h. However, little is known regarding the expression of basigin in the early phase of AMI. The aim of the present study was to evaluate the temporal and spatial expression patterns of basigin mRNA and protein levels in AMI in rats. We constructed an AMI model in rats that received left anterior descending coronary artery ligation for 0, 15, 30, 60, 120 or 240 min. Real‑time quantitative PCR and in situ hybridization (ISH) were conducted to reveal the basigin mRNA levels in the early ischemic myocardium (EIM) and non‑ischemic myocardium (NIM). The expression levels of basigin protein were detected using western blot analysis and immunohistochemistry. The expression levels of basigin mRNA and protein significantly changed in the EIM as early as 30 min from ischemia, and the changes continued to be present throughout the ischemic period (P<0.05). The expression levels of basigin mRNA were significantly reduced, whilst those of the protein underwent a significant ~2-fold increase in the EIM. However, there were no significant differences in the basigin mRNA or protein expression levels from 0‑240 min in the NIM (P>0.05). We failed to detect a signal for basigin mRNA in the myocardium by ISH. Our findings indicated that basigin may be involved in acute myocardial ischemia following continual ischemia for >30 min.

Human matrix metalloproteinases: an ubiquitarian class of enzymes involved in several pathological processes

Human matrix metalloproteinases (MMPs) belong to the M10 family of the MA clan of endopeptidases. They are ubiquitarian enzymes, structurally characterized by an active site where a Zn(2+) atom, coordinated by three histidines, plays the catalytic role, assisted by a glutamic acid as a general base. Various MMPs display different domain composition, which is very important for macromolecular substrates recognition. Substrate specificity is very different among MMPs, being often associated to their cellular compartmentalization and/or cellular type where they are expressed. An extensive review of the different MMPs structural and functional features is integrated with their pathological role in several types of diseases, spanning from cancer to cardiovascular diseases and to neurodegeneration. It emerges a very complex and crucial role played by these enzymes in many physiological and pathological processes.

The extracellular matrix metalloproteinase inducer EMMPRIN is a target of nitric oxide in myocardial ischemia/reperfusion

Nitric oxide (NO) is an important defense against myocardial ischemia/reperfusion (I/R) injury. Although matrix metalloproteinase (MMP)-mediated necrosis of cardiac myocytes is well characterized, the role of inducible NO synthase (iNOS)-derived NO in this process is poorly understood. I/R injury was increased in iNOS-deficient mice and in mice treated with 1400 W (a pharmacological iNOS inhibitor) and was associated with significantly increased expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and EMMPRIN-associated MMPs. Transcriptional activity of an EMMPRIN luciferase promoter reporter expressed in cardiac myocytes was inhibited by NO in a cGMP-dependent manner, and this transcriptional inhibition was abolished by mutation of a putative E2F site. Consistent with these findings, EMMPRIN null mice, in which iNOS is normally induced, are partially protected against I/R injury. Pharmacological inhibition of iNOS in EMMPRIN null mice had no additional protective effect, suggesting that EMMPRIN is a downstream target of NO. Administration of anti-EMMPRIN neutralizing antibodies partly reduced the excess heart damage and MMP-9 expression induced by I/R in iNOS null mice, indicating that regulation of EMMPRIN is an important mechanism of NO-mediated cardioprotection.

Temporal and spatial expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases following myocardial infarction

Following a myocardial infarction (MI), the homeostatic balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) is disrupted as part of the left ventricle (LV) response to injury. The full complement of responses to MI has been termed LV remodeling and includes changes in LV size, shape and function. The following events encompass the LV response to MI: (1) inflammation and LV wall thinning and dilation, (2) infarct expansion and necrotic myocyte resorption, (3) accumulation of fibroblasts and scar formation, and (4) endothelial cell activation and neovascularization. In this review, we will summarize MMP and TIMP roles during these events, focusing on the spatiotemporal localization and MMP and TIMP effects on cellular and tissue-level responses. We will review MMP and TIMP structure and function, and discuss specific MMP roles during both the acute and chronic phases post-MI, which may provide insight into novel therapeutic targets to limit adverse remodeling in the MI setting.