Increased C-reactive protein expression exacerbates left ventricular dysfunction and remodeling after myocardial infarction

Insight into the Role of the PI3K/Akt Pathway in Ischemic Injury and Post-Infarct Left Ventricular Remodeling in Normal and Diabetic Heart

Despite the significant decline in mortality, cardiovascular diseases are still the leading cause of death worldwide. Among them, myocardial infarction (MI) seems to be the most important. A further decline in the death rate may be achieved by the introduction of molecularly targeted drugs. It seems that the components of the PI3K/Akt signaling pathway are good candidates for this. The PI3K/Akt pathway plays a key role in the regulation of the growth and survival of cells, such as cardiomyocytes. In addition, it has been shown that the activation of the PI3K/Akt pathway results in the alleviation of the negative post-infarct changes in the myocardium and is impaired in the state of diabetes. In this article, the role of this pathway was described in each step of ischemia and subsequent left ventricular remodeling. In addition, we point out the most promising substances which need more investigation before introduction into clinical practice. Moreover, we present the impact of diabetes and widely used cardiac and antidiabetic drugs on the PI3K/Akt pathway and discuss the molecular mechanism of its effects on myocardial ischemia and left ventricular remodeling.

Excess ischemic tachyarrhythmias trigger protection against myocardial infarction in hypertensive rats

Increased level of C-reactive protein (CRP) is a risk factor for cardiovascular diseases, including myocardial infarction and hypertension. Here, we analyzed the effects of CRP overexpression on cardiac susceptibility to ischemia/reperfusion (I/R) injury in adult spontaneously hypertensive rats (SHR) expressing human CRP transgene (SHR-CRP). Using an in vivo model of coronary artery occlusion, we found that transgenic expression of CRP predisposed SHR-CRP to repeated and prolonged ventricular tachyarrhythmias. Excessive ischemic arrhythmias in SHR-CRP led to a significant reduction in infarct size (IS) compared with SHR. The proarrhythmic phenotype in SHR-CRP was associated with altered heart and plasma eicosanoids, myocardial composition of fatty acids (FAs) in phospholipids, and autonomic nervous system imbalance before ischemia. To explain unexpected IS-limiting effect in SHR-CRP, we performed metabolomic analysis of plasma before and after ischemia. We also determined cardiac ischemic tolerance in hearts subjected to remote ischemic perconditioning (RIPer) and in hearts ex vivo. Acute ischemia in SHR-CRP markedly increased plasma levels of multiple potent cardioprotective molecules that could reduce IS at reperfusion. RIPer provided IS-limiting effect in SHR that was comparable with myocardial infarction observed in naïve SHR-CRP. In hearts ex vivo, IS did not differ between the strains, suggesting that extra-cardiac factors play a crucial role in protection. Our study shows that transgenic expression of human CRP predisposes SHR-CRP to excess ischemic ventricular tachyarrhythmias associated with a drop of pump function that triggers myocardial salvage against lethal I/R injury likely mediated by protective substances released to blood from hypoxic organs and tissue at reperfusion.

Upregulated lncRNA Pvt1 may be important for cardiac remodeling at the infarct border zone

Myocardial infarction (MI) is a leading cause of mortality due to progression to ventricular arrhythmias (VAs) or heart failure (HF). Cardiac remodeling at the infarct border zone (IBZ) is the primary contributor for VAs or HF. Therefore, genes involved in IBZ remodeling may be potential targets for the treatment of MI, but the mechanism remains unclear. The present study aimed to explain the molecular mechanisms of IBZ remodeling based on the roles of long non-coding RNAs (lncRNAs). After downloading miRNA (GSE76592) and mRNA/lncRNA (GSE52313) datasets from the Gene Expression Omnibus database, 23 differentially expressed miRNAs (DEMs), 2,563 genes (DEGs) and 168 lncRNAs (DELs) were identified between IBZ samples of MI mice and sham controls. A total of 483 DEGs were predicted to be regulated by 23 DEMs, among which Itgam, Met and TNF belonged to hub genes after five topological parameters were calculated for genes in the protein-protein interaction network. These hub genes-associated DEMs (mmu-miR-181a, mmu-miR-762) can also interact with six DELs (Gm15832, Gas5, Gm6634, Pvt1, Gm14636 and A330023F24Rik) to constitute the competing endogenous RNA (ceRNA) axes. Furthermore, a co-expression network was constructed based on the co-expression pairs between 44 DELs and 297 DEGs, in which Pvt1 and Bst1 were overlapped with the ceRNA network. Thus, Bst1-associated ceRNA (Pvt1-mmu-miR-181a-Bst1) and co-expression (Pvt-Bst1) axes were also pivotal for MI. Accordingly, Pvt1 may be a crucial lncRNA for modification of cardiac remodeling in the IBZ after MI and may function by acting as a ceRNA for miR-181a to regulate TNF/Met/Itgam/Bst1 or by co-expressing with Bst1.

Association Between Inflammatory Markers and Myocardial Fibrosis

Inflammation promotes adverse ventricular remodeling. T1 mapping has been used to noninvasively assess interstitial myocardial fibrosis. We examined the association of baseline markers of systemic inflammation with interstitial myocardial fibrosis measured by extracellular volume fraction (ECV) and native T1 mapping at 10-year follow-up in the MESA (Multi-Ethnic Study of Atherosclerosis). Seven hundred seventy-two participants had complete baseline data and underwent cardiac magnetic resonance imaging. All analyses were stratified by sex. Multivariable linear regression models were constructed to assess the associations of baseline CRP (C-reactive protein), IL (interleukin)-6, and fibrinogen with native T1 time and ECV. Longer native T1 times and higher percentages of ECV represent increasing myocardial fibrosis. A 1-SD increment of log-transformed IL-6 levels was associated with 0.4% higher ECV in men (β=0.4; P=0.05). CRP and fibrinogen were not associated to ECV. A 1-SD increment in the log-transformed CRP levels was associated with 4.9 ms higher native T1 (β=4.9; P=0.03). In women, the inflammatory markers did not demonstrate association with native T1 nor ECV. Higher IL-6 and CRP levels are associated with increased interstitial myocardial fibrosis assessed by cardiac magnetic resonance in men. However, no inflammatory markers were associated to myocardial fibrosis in women.

Association Between Acute Inflammatory Response and Infarct Size in Stemi Patients Undergoing Primary PCI

Background: The inflammatory response of the immune system plays a major role in the period following an acute myocardial infarction (MI), as it coordinates the formation of the fibrous scar tissue that replaces the infarcted myocardial cells and ultimately leads to healing and remodeling of the affected zone. Along with other pro- and anti-inflammatory cytokines and acute phase proteins, interleukin-6 (IL-6) and C-reactive protein (CRP) are associated with the extent of the infarct size (IS) and may serve as predictors for remodeling and adverse left ventricular (LV) function. Material and methods: A single-center, non-randomized, observational prospective study was conducted, which included 75 patients with primary revascularized ST-elevation myocardial infarction (STEMI). High-sensitivity CRP (hs-CRP) serum levels were determined on day 1 and day 5 following the acute event. IL-6 was also determined on day 1. All patients underwent cardiac magnetic resonance imaging (CMR) at 1-month follow-up with determination of LV function and quantification of the scar tissue using late gadolinium enhancement imaging. The patients were divided into 2 groups based on baseline hs-CRP values. Results: Patients with higher baseline hs-CRP levels presented significantly higher infarct size (p = 0.0003), higher transmural extent (p <0.0001), lower LV ejection fraction (p = 0.0024), end-systolic (p = 0.0021) and end-diastolic (p = 0.0065) volumes. Small IS (<10%) recorded the lowest levels of hs-CRP, while IS >20% presented the highest levels of hs-CRP, at baseline and day 5 (p = 0.4 and 0.001). IL-6 levels were also associated with the magnitude of infarct scar: 2.17 pg/mL for IS <10%, 15.52 pg/mL for IS between 10% and 20%, and 24.52 pg/mL for IS >20%, p = 0.002. Conclusion: hs-CRP and IL-6 serum levels following an MI are correlated with IS, transmurality extent of the scar tissue, as well as with altered systolic and diastolic LV function determined by CMR at 1-month follow-up.

A multi-site coronary sampling study on CRP in non-STEMI: Novel insights into the inflammatory process in acute coronary syndromes

BACKGROUND AND AIMS

Inflammation has become a key element in cardiovascular disease, and recently, new anti-inflammatory interventions have shown promising results. In this context, CRP levels have been thoroughly studied in vitro and in animals, but studies in humans are scarce and insights into its release, site(s) of production and uptake are not uniform.

METHODS

We performed a biomarker study with multi-site sampling in the coronary circulation, in non-ST elevation MI (NSTEMI) patients with coronary angiography and right-sided catheterisation. Trans-lesional gradients were obtained by sampling distal to the culprit lesion, in patients with a suitable anatomy. To asses trans-cardiac gradients, blood was sampled from the systemic circulation, coronary sinus (CS) and great cardiac vein. Concentrations of CRP were measured with a high-sensitivity assay.

RESULTS

In 42 patients, a median systemic venous CRP concentration of 4.97 mg/L was observed. There was no evidence of a trans-lesional gradient (4.59 mg/L versus 4.56 mg/L, p = 0.278; n = 14). A significant decrease in CRP concentration was observed between systemic arterial and CS samples (4.88 mg/L versus 4.44 mg/L; p < 0.001; n = 42). This trans-cardiac gradient was irrespective of time of presentation, infarct size and culprit lesion location. The gradient was not only driven by blood that ran through the injured myocardium, but also by lower CRP concentrations in the coronary veins that drain non-infarcted myocardium.

CONCLUSIONS

In the context of NSTEMI, we observed a trans-cardiac decrease in CRP, which may indicate the first human in vivo proof of a net CRP uptake by the myocardium, with a role for CRP both in the injured and adjacent myocardium.

Administration of the Mitochondrial Permeability Transition Pore Inhibitor, TRO40303, prior to Primary Percutaneous Coronary Intervention, Does Not Affect the Levels of Pro-Inflammatory Cytokines or Acute-Phase Proteins

Objectives: In the MITOCARE study, reperfusion injury was not prevented after administration of the mitochondrial permeability transition pore (mPTP) opening inhibitor, TRO40303, in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). The effects of TRO40303 on pro-inflammatory cytokines and acute-phase proteins were assessed. Methods: STEMI patients (n = 163, mean age 62 years) with chest pain within 6 h before admission for pPCI were randomized to intravenous bolus of TRO40303 (n = 83) or placebo (n = 80) prior to reperfusion. We tested whether the groups differed in levels of IL-1β, IL-6, IL-10, TNF, and high-sensitive C-reactive protein at various time points (0, 12, and 72 h) after PCI. Further, potential differences between groups in the change of biomarker levels between 0 and 72 h, 0 and 12 h, and 12 and 72 h were tested. Results: There were no statistically significant differences between the two groups, neither in levels of pro-inflammatory cytokines nor in levels of acute-phase proteins, and there were no statistically significant differences in the change of biomarker levels between the groups considering the time intervals from 0 to 72 h, from 0 to 12 h, and from 12 to 72 h. Conclusion: The administration of the mPTP, TRO40303, prior to reperfusion does not alter the pharmacokinetics of pro-inflammatory cytokines or acute-phase proteins during the first 72 h after PCI.

Novel role of platelet reactivity in adverse left ventricular remodelling after ST-segment elevation myocardial infarction: The REMODELING Trial

The role of platelet-leukocyte interaction in the infarct myocardium still remains unveiled. We aimed to determine the linkage of platelet activation to post-infarct left ventricular remodelling (LVR) process. REMODELING was a prospective, observational, cohort trial including patients (n = 150) with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. Patients were given aspirin plus clopidogrel therapy (600 mg loading and 75 mg daily). Platelet reactivity (PRU: P2Y12 Reaction Units) was assessed with VerifyNow P2Y12 assay on admission. Transthoracic echocardiography was performed on admission and at one-month follow-up. The primary endpoint was the incidence of LVR according to PRU-based quartile distribution. LVR was defined as a relative ≥ 20 % increase in LV end-diastolic volume (LVEDV) between measurements. Adverse LVR was observed in 36 patients (24.0 %). According to PRU quartile, LVR rate was 10.8 % in the first, 23.1 % in the second, 27.0 % in the third, and 35.1 % in the fourth (p = 0.015): the optimal cut-off of PRU was ≥ 248 (area under curve: 0.643; 95 % confidence interval: 0.543 to 0.744; p = 0.010). LVR rate also increased proportionally according to the level of high sensitivity-C reactive protein (hs-CRP) (p = 0.012). In multivariate analysis, the combination of PRU (≥ 248) and hs-CRP (≥ 1.4 mg/l) significantly increased the predictive value for LVR occurrence by about 21-fold. In conclusion, enhanced levels of platelet activation and inflammation determined the incidence of adverse LVR after STEMI. Combining the measurements of these risk factors increased risk discrimination of LVR. The role of intensified antiplatelet or anti-inflammatory therapy in post-infarct LVR process deserves further study.

Infectious Complications and Immune/Inflammatory Response in Cardiogenic Shock Patients: A Prospective Observational Study

INTRODUCTION

Patients with cardiogenic shock (CS) are at a high risk of developing infectious complications; however, their early detection is difficult, mainly due to a frequently occurring noninfectious inflammatory response, which accompanies an extensive myocardial infarction (MI) or a postcardiac arrest syndrome. The goal of our prospective study was to describe infectious complications in CS and the immune/inflammatory response based on a serial measurement of several blood-based inflammatory biomarkers.

METHODS

Eighty patients with CS were evaluated and their infections were monitored. Inflammatory markers (C-reactive protein, procalcitonin, pentraxin 3, presepsin) were measured seven times per week. The control groups consisted of 11 patients with ST segment elevation myocardial infarction without CS and without infection, and 22 patients in septic shock.

RESULTS

Infection was diagnosed in 46.3% of patients with CS; 16 patients developed an infection within 48 h. Respiratory infection was most common, occurring in 33 out of 37 patients. Infection was a significant or even the main reason of death only in 3.8% of all patients with CS, and we did not find statistically significant difference in 3-month mortality between group of patients with CS with and without infection. There was no statistically significant prolongation of the duration of mechanical ventilation associated with infection. Strong inflammatory response is often in patients with CS due to MI, but we found no significant difference in the course of the inflammatory response expressed by evaluated biomarkers in patients with CS with and without infection. We found a strong relationship between the elevated inflammatory markers (sampled at 12 h) and the 3-month mortality: the area under the curve of receiver operating characteristic ranged between 0.683 and 0.875.

CONCLUSION

The prevalence of infection in patients with CS was 46.3%, and respiratory tract infections were the most common type. Infections did not prolong statistically significantly the duration of mechanical ventilation and did not increase the prevalence of hospital mortality in this high-risk CS population. CS due to acute myocardial infarction was accompanied by a strong and highly variable inflammatory response, but it did not reach the intensity of the inflammatory response observed in patients with septic shock. An extensive immune/inflammatory response in patients with CS is linked to a poor prognosis.

ADENOSINE DEAMINASE ACTIVITY AND SERUM C-REACTIVE PROTEIN AS PROGNOSTIC MARKERS OF CHAGAS DISEASE SEVERITY

Chagas disease is a public health problem worldwide. The availability of diagnostic tools to predict the development of chronic Chagas cardiomyopathy is crucial to reduce morbidity and mortality. Here we analyze the prognostic value of adenosine deaminase serum activity (ADA) and C-reactive protein serum levels (CRP) in chagasic individuals. One hundred and ten individuals, 28 healthy and 82 chagasic patients were divided according to disease severity in phase I (n = 35), II (n = 29), and III (n = 18). A complete medical history, 12-lead electrocardiogram, chest X-ray, and M-mode echocardiogram were performed on each individual. Diagnosis of Chagas disease was confirmed by ELISA and MABA using recombinant antigens; ADA was determined spectrophotometrically and CRP by ELISA. The results have shown that CRP and ADA increased linearly in relation to disease phase, CRP being significantly higher in phase III and ADA at all phases. Also, CRP and ADA were positively correlated with echocardiographic parameters of cardiac remodeling and with electrocardiographic abnormalities, and negatively with ejection fraction. CRP and ADA were higher in patients with cardiothoracic index ≥ 50%, while ADA was higher in patients with ventricular repolarization disturbances. Finally, CRP was positively correlated with ADA. In conclusion, ADA and CRP are prognostic markers of cardiac dysfunction and remodeling in Chagas disease.

Characterization of a Cardiorenal-like Syndrome in Aged Chimpanzees (Pan troglodytes)

Cardiorenal syndrome involves disease and dysfunction of the heart that leads to progressive renal dysfunction. This study investigated the relationship between cardiac and renal disease in 91 aged chimpanzees at the Alamogordo Primate Facility by evaluation of the medical histories, metabolic parameters, functional measurements of the cardiovascular system, clinical pathology, and histopathology focused on the heart and kidney. Cardiac fibrosis was the most frequent microscopic finding in 82 of 91 animals (90%), followed by glomerulosclerosis with tubulointerstitial fibrosis in 63 of 91 (69%). Cardiac fibrosis with attendant glomerulosclerosis and tubulointerstitial fibrosis was observed in 58 of 91 animals (63%); there was a statistically significant association between the 2 conditions. As the severity of cardiac fibrosis increased, there was corresponding increase in severity of glomerulosclerosis with tubulointerstitial fibrosis. Altered metabolic, cardiovascular, and clinical pathology parameters indicative of heart and kidney failure were commonly associated with the moderate to severe microscopic changes, and concurrent heart and kidney failure were considered the cause of death. The constellation of findings in the chimpanzees were similar to cardiorenal syndrome in humans.

Prognostic value of pentraxin-3 level in patients with STEMI and its relationship with heart failure and markers of oxidative stress

OBJECTIVE

Pentraxin-3 (PTX3) appears to have a cardioprotective effect through a positive influence against postreperfusion damage. This study assesses the prognostic value of PTX3 level and its relationship with clinical parameters and markers of oxidative stress and nitric oxide metabolism in patients with ST-elevation myocardial infarction (STEMI).

METHODS

Plasma/serum levels of several biomarkers of inflammation and oxidative stress and nitrite/nitrate were assessed upon admission and 24 h after STEMI onset in patients treated by primary percutaneous coronary intervention.

RESULTS

ROC analysis showed that plasma PTX3 at 24 h was a strong predictor of 30-day and 1-year mortality and independent predictor of combined end-point of left ventricle dysfunction or mortality in 1 year. The inflammatory response expressed by PTX3 had a significant relationship with age, heart failure, infarct size, impaired flow in the infarct-related artery, and renal function and positively correlated with neopterin, TNF-α, 8-hydroxy-2'-deoxyguanosine, and nitrite/nitrate.

CONCLUSIONS

Plasma PTX3 at 24 h after STEMI onset is a strong predictor of 30-day and 1-year mortality. PTX3 as a single biomarker is comparable with currently used scoring systems (TIMI or GRACE) or B-type natriuretic peptide. PTX3 is also an independent predictor of combined end-point of left ventricle dysfunction or mortality in 1 year.

Recognition functions of pentameric C-reactive protein in cardiovascular disease

C-reactive protein (CRP) performs two recognition functions that are relevant to cardiovascular disease. First, in its native pentameric conformation, CRP recognizes molecules and cells with exposed phosphocholine (PCh) groups, such as microbial pathogens and damaged cells. PCh-containing ligand-bound CRP activates the complement system to destroy the ligand. Thus, the PCh-binding function of CRP is defensive if it occurs on foreign pathogens because it results in the killing of the pathogen via complement activation. On the other hand, the PCh-binding function of CRP is detrimental if it occurs on injured host cells because it causes more damage to the tissue via complement activation; this is how CRP worsens acute myocardial infarction and ischemia/reperfusion injury. Second, in its nonnative pentameric conformation, CRP also recognizes atherogenic low-density lipoprotein (LDL). Recent data suggest that the LDL-binding function of CRP is beneficial because it prevents formation of macrophage foam cells, attenuates inflammatory effects of LDL, inhibits LDL oxidation, and reduces proatherogenic effects of macrophages, raising the possibility that nonnative CRP may show atheroprotective effects in experimental animals. In conclusion, temporarily inhibiting the PCh-binding function of CRP along with facilitating localized presence of nonnative pentameric CRP could be a promising approach to treat atherosclerosis and myocardial infarction. There is no need to stop the biosynthesis of CRP.

Anti-inflammatory strategies for ventricular remodeling following ST-segment elevation acute myocardial infarction

Acute myocardial infarction (AMI) leads to molecular, structural, geometric, and functional changes in the heart in a process known as ventricular remodeling. An intense organized inflammatory response is triggered after myocardial ischemia and necrosis and involves all components of the innate immunity, affecting both cardiomyocytes and noncardiomyocyte cells. Inflammation is triggered by tissue injury; it mediates wound healing and scar formation and affects ventricular remodeling. Many therapeutic attempts aimed at reducing inflammation in AMI during the past 3 decades presented issues of impaired healing or increased risk of cardiac rupture or failed to show any additional benefit in addition to standard therapies. More recent strategies aimed at selectively blocking one of the key factors upstream rather than globally suppressing the response downstream have shown some promising results in pilot trials. We herein review the pathophysiological mechanisms of inflammation and ventricular remodeling after AMI and the results of clinical trials with anti-inflammatory strategies.

Hypoxia activates muscle-restricted coiled-coil protein (MURC) expression via transforming growth factor-β in cardiac myocytes

The expression of MURC (muscle-restricted coiled-coil protein), a hypertrophy-regulated gene, increases during pressure overload. Hypoxia can cause myocardial hypertrophy; however, how hypoxia affects the regulation of MURC in cardiomyocytes undergoing hypertrophy is still unknown. The aim of the present study was to test the hypothesis that hypoxia induces MURC expression in cardiomyocytes during hypertrophy. The expression of MURC was evaluated in cultured rat neonatal cardiomyocytes subjected to hypoxia and in an in vivo model of AMI (acute myocardial infarction) to induce myocardial hypoxia in adult rats. MURC protein and mRNA expression were significantly enhanced by hypoxia. MURC proteins induced by hypoxia were significantly blocked after the addition of PD98059 or ERK (extracellular-signal-regulated kinase) siRNA 30 min before hypoxia. Gel-shift assay showed increased DNA-binding activity of SRF (serum response factor) after hypoxia. PD98059, ERK siRNA and an anti-TGF-β (transforming growth factor-β) antibody abolished the SRF-binding activity enhanced by hypoxia or exogenous administration of TGF-β. A luciferase promoter assay demonstrated increased transcriptional activity of SRF in cardiomyocytes by hypoxia. Increased βMHC (β-myosin heavy chain) and BNP (B-type natriuretic peptide) protein expression and increased protein synthesis was identified after hypoxia with the presence of MURC in hypertrophic cardiomyocytes. MURC siRNA inhibited the hypertrophic marker protein expression and protein synthesis induced by hypoxia. AMI in adult rats also demonstrated increased MURC protein expression in the left ventricular myocardium. In conclusion, hypoxia in cultured rat neonatal cardiomyocytes increased MURC expression via the induction of TGF-β, SRF and the ERK pathway. These findings suggest that MURC plays a role in hypoxia-induced hypertrophy in cardiomyocytes.

Association between lectin complement pathway initiators, C-reactive protein and left ventricular remodeling in myocardial infarction-a magnetic resonance study

BACKGROUND

Lectin complement pathway (LP) activation is an important mechanism in myocardial ischemia reperfusion injury (IRI). LP is activated via the recognition molecules mannose-binding lectin (MBL), ficolins-2 and-3 and is regulated by MBL/Ficolin-associated Protein-1 (MAP-1). Also, C-reactive protein (CRP) and ficolin-2 interact in vitro, but the role of the ficolins in IRI is unknown.

METHODS AND RESULTS

In 55 patients with ST segment elevation myocardial infarction, we investigated the association of LP components and CRP in plasma samples with left ventricular (LV) end systolic and diastolic volumes (ESV and EDV) and infarct size, assessed by cardiac magnetic resonance early at 1-3 days after primary percutaneous coronary intervention and at 6 months follow-up. Opposed to MBL, ficolin-3 and MAP-1, ficolin-2 levels were low at baseline. At baseline, ficolin-2>median was associated with ESV and EDV increases by 7.83 ml/m(2) (p=0.004) and 14.04 ml/m(2) (p<0.001). MBL and MAP-1 were not associated with LV dilatation, yet ficolin-2 and MBL worked synergistically and the combination of their levels>median was associated with ESV (11.21 ml/m(2); p=0.017) and EDV increases (14.72 ml/m(2); p=0.006). MAP-1median had the greatest LV dilatation (17.61 ml/m(2)). The ficolin-2 × CRP interaction variable was positively associated with infarct size and inversely associated with EDV change over 6 months (p=0.006). There was no interaction between CRP and the other LP molecules.

CONCLUSION

The LP initiator molecule ficolin-2 and combinations of ficolin-2, MBL and MAP-1 are associated with LV dilatation after myocardial infarction. Interaction of ficolin-2 and CRP was associated with infarct size and LV remodeling, indicating a potential role for LP and LP-pentraxin cross-activation in IRI and LV remodeling.

Matrix metalloproteinase (MMP)-9: a proximal biomarker for cardiac remodeling and a distal biomarker for inflammation

Adverse cardiac remodeling following myocardial infarction (MI) remains a significant cause of congestive heart failure. Additional and novel strategies that improve our ability to predict, diagnose, or treat remodeling are needed. Numerous groups have explored single and multiple biomarker strategies to identify diagnostic prognosticators of remodeling progression, which will improve our ability to promptly and accurately identify high-risk individuals. The identification of better clinical indicators should further lead to more effective prediction and timely treatment. Matrix metalloproteinase (MMP-9) is one potential biomarker for cardiac remodeling, as demonstrated by both animal models and clinical studies. In animal MI models, MMP-9 expression significantly increases and is linked with inflammation, diabetic microvascular complications, extracellular matrix degradation and synthesis, and cardiac dysfunction. Clinical studies have also established a relationship between MMP-9 and post-MI remodeling and mortality, making MMP-9 a viable candidate to add to the multiple biomarker list. By definition, a proximal biomarker shows a close relationship with its target disease, whereas a distal biomarker exhibits non-targeted disease modifying outcomes. In this review, we explore the ability of MMP-9 to serve as a proximal biomarker for cardiac remodeling and a distal biomarker for inflammation. We summarize the current molecular basis and clinical platform that allow us to include MMP-9 as a biomarker in both categories.

Inflammatory activation: cardiac, renal, and cardio-renal interactions in patients with the cardiorenal syndrome

Although inflammation is a physiologic response designed to protect us from infection, when unchecked and ongoing it may cause substantial harm. Both chronic heart failure (CHF) and chronic kidney disease (CKD) are known to cause elaboration of several pro-inflammatory mediators that can be detected at high concentrations in the tissues and blood stream. The biologic sources driving this chronic inflammatory state in CHF and CKD are not fully established. Traditional sources of inflammation include the heart and the kidneys which produce a wide range of pro-inflammatory cytokines in response to neurohormones and sympathetic activation. However, growing evidence suggests that non-traditional biomechanical mechanisms such as venous and tissue congestion due to volume overload are also important as they stimulate endotoxin absorption from the bowel and peripheral synthesis and release of pro-inflammatory mediators. Both during the chronic phase and, more rapidly, during acute exacerbations of CHF and CKD, inflammation and congestion appear to amplify each other resulting in a downward spiral of worsening cardiac, vascular, and renal functions that may negatively impact patients' outcome. Anti-inflammatory treatment strategies aimed at attenuating end organ damage and improving clinical prognosis in the cardiorenal syndrome have been disappointing to date. A new therapeutic paradigm may be needed, which involves different anti-inflammatory strategies for individual etiologies and stages of CHF and CKD. It may also include specific (short-term) anti-inflammatory treatments that counteract inflammation during the unsettled phases of clinical decompensation. Finally, it will require greater focus on volume overload as an increasingly significant source of systemic inflammation in the cardiorenal syndrome.

Effects of heme oxygenase-1 upregulation on blood pressure and cardiac function in an animal model of hypertensive myocardial infarction

In this study, we evaluate the effect of HO-1 upregulation on blood pressure and cardiac function in the new model of infarct spontaneous hypertensive rats (ISHR). Male spontaneous hypertensive rats (SHR) at 13 weeks (n = 40) and age-matched male Wistar (WT) rats (n = 20) were divided into six groups: WT (sham + normal saline (NS)), WT (sham + Co(III) Protoporphyrin IX Chloride (CoPP)), SHR (myocardial infarction (MI) + NS), SHR (MI + CoPP), SHR (MI + CoPP + Tin Mesoporphyrin IX Dichloride (SnMP)), SHR (sham + NS); CoPP 4.5 mg/kg, SnMP 15 mg/kg, for six weeks, one/week, i.p., n = 10/group. At the sixth week, echocardiography (UCG) and hemodynamics were performed. Then, blood samples and heart tissue were collected. Copp treatment in the SHR (MI + CoPP) group lowered blood pressure, decreased infarcted area, restored cardiac function (left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), +dp/dt_max, (−dp/dt_max)/left ventricular systolic pressure (LVSP)), inhibited cardiac hypertrophy and ventricular enlargement (downregulating left ventricular end-systolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD) and heart weight/body weight (HW/BW)), lowered serum CRP, IL-6 and Glu levels and increased serum TB, NO and PGI2 levels. Western blot and immunohistochemistry showed that HO-1 expression was elevated in the SHR (MI + CoPP) group, while co-administration with SnMP suppressed the benefit functions mentioned above. In conclusion, HO-1 upregulation can lower blood pressure and improve post-infarct cardiac function in the ISHR model. These functions may be involved in the inhibition of inflammation and the ventricular remodeling process and in the amelioration of glucose metabolism and endothelial dysfunction.

Value of C-reactive protein in predicting left ventricular remodelling in patients with a first ST-segment elevation myocardial infarction

OBJECTIVE

To assess the value of C-reactive protein (CRP) in predicting postinfarct left ventricular remodelling (LVR).

METHODS

We measured in-hospital plasma CRP concentrations in patients with a first ST-segment elevation myocardial infarction (STEMI).

RESULTS

LVR was present at 6 months in 27.8% of 198 patients. CRP concentration rose during the first 24 h, mainly in LVR group. The prevalence of LVR was higher in patients from the highest quartile of CRP concentrations at 24 h as compared to those from any other quartile (odds ratio (OR) 3.48, 95% confidence interval (95% CI) 1.76-6.88). Multivariate analysis identified CRP concentration at 24 h (OR for a 10 mg/L increase 1.29, 95% CI 1.04-1.60), B-type natriuretic peptide at discharge (OR for a 100 pg/mL increase 1.21, 95% CI 1.05-1.39), body mass index (OR for a 1 kg/m(2) increase 1.10, 95% CI 1.01-1.21), and left ventricular end-diastolic volume (OR for a 1 mL increase 0.98, 95% CI 0.96-0.99) as independent predictors of LVR. The ROC analysis revealed a limited discriminative value of CRP (area under the curve 0.61; 95% CI 0.54-0.68) in terms of LVR prediction.

CONCLUSIONS

Measurement of CRP concentration at 24 h after admission possesses a significant but modest value in predicting LVR after a first STEMI.

Usefulness of C-reactive protein as a marker of early post-infarct left ventricular systolic dysfunction

Objective

To assess the usefulness of in-hospital measurement of C-reactive protein (CRP) concentration in comparison to well-established risk factors as a marker of post-infarct left ventricular systolic dysfunction (LVSD) at discharge.

Materials and methods

Two hundred and four consecutive patients with ST-segment-elevation myocardial infarction (STEMI) were prospectively enrolled into the study. CRP plasma concentrations were measured before reperfusion, 24 h after admission and at discharge with an ultra-sensitive latex immunoassay.

Results

CRP concentration increased significantly during the first 24 h of hospitalization (2.4 ± 1.9 vs. 15.7 ± 17.0 mg/L; p < 0.001) and persisted elevated at discharge (14.7 ± 14.7 mg/L), mainly in 57 patients with LVSD (2.4 ± 1.8 vs. 25.0 ± 23.4 mg/L; p < 0.001; CRP at discharge 21.9 ± 18.6 mg/L). The prevalence of LVSD was significantly increased across increasing tertiles of CRP concentration both at 24 h after admission (13.2 vs. 19.1 vs. 51.5 %; p < 0.0001) and at discharge (14.7 vs. 23.5 vs. 45.6 %; p < 0.0001). Multivariate analysis demonstrated CRP concentration at discharge to be an independent marker of early LVSD (odds ratio of 1.38 for a 10 mg/L increase, 95 % confidence interval 1.01–1.87; p < 0.04).

Conclusion

Measurement of CRP plasma concentration at discharge may be useful as a marker of early LVSD in patients after a first STEMI.

CRP promotes MMP-10 expression via c-Raf/MEK/ERK and JAK1/ERK pathways in cardiomyocytes

C-reactive protein (CRP) was reported to be a predictor for left ventricular (LV) remodeling. Matrix metalloproteinase (MMP)-10 participates in the LV remodeling process. However, the intrinsic relationship between CRP and MMP-10 in cardiomyocytes remains unclear. The purpose of this study is to observe whether CRP may promote MMP-10 expression, and if so, to clarify signaling pathways to be involved in CRP-induced MMP-10 expression in cardiomyocytes. We observed in cultured cardiomyocytes that CRP at a dose of 5 μg/ml increased MMP-10 expression and activity in a time-dependent manner, as measured by real-time polymerase chain reaction (PCR), western blots, and casein zymography analysis. We hypothesized that signal pathways of mitogen-activated protein kinases (MAPKs) and Janus kinases (JAKs)/signal transducers and activators of transcription (STATs) might be involved in CRP-induced MMP-10 expression. Our results showed that CRP markedly activated c-Raf/MEK/ERK and JAK1/ERK signaling pathways but not JAK1/STAT3 signaling pathway by using the phosphor-specific antibodies against these pathways, and blockages of c-Raf/MEK/ERK and JAK1/ERK signaling pathways by the specific ERK1/2 inhibitor U0126 and JAK1 inhibitor piceatannol could significantly decrease CRP-induced MMP-10 expression. In addition, we demonstrated that the DNA binding sites of AP-1 and STAT3 in the nucleus of cardiomyocytes mediated CRP-induced MMP-10 expression. In conclusion, we demonstrated that CRP promoted MMP-10 expression and activity in cardiomyocytes, and clarified that c-Raf/MEK/ERK and JAK1/ERK signaling pathways were involved in MMP-10 expression regulation via activation of DNA binding sites for AP-1 and STAT3 in cardiomyocytes. Our findings suggest that CRP acts as a predictor for LV remodeling might be associated with its promotion effect on MMP-10 expression and activity.

C-reactive protein promotes diabetic kidney disease in a mouse model of type 1 diabetes

AIMS/HYPOTHESIS

Although C-reactive protein (CRP) has been implicated as a risk factor in diabetes, its pathogenic importance in diabetic kidney disease (DKD) remains unclear. The present study investigated the potential role of CRP in DKD.

METHODS

Diabetes was induced by streptozotocin in human CRP transgenic and wild-type mice for assessment of kidney injury at 24 weeks by real-time PCR, immunohistochemistry and western blot analysis. In vitro, the pathogenic effect of CRP was investigated using human kidney tubular epithelial cells cultured with high glucose and/or CRP.

RESULTS

We found that CRP transgenic mice developed much more severe diabetic kidney injury than wild-type mice, as indicated by a significant increase in urinary albumin excretion and kidney injury molecule-1 abundance, enhanced infiltration of macrophages and T cells, and upregulation of pro-inflammatory cytokines (IL-1β, TNFα) and extracellular matrix (collagen I, III and IV). Enhanced renal inflammation and fibrosis in CRP transgenic mice was associated with upregulation of CRP receptor, CD32a, and over-activation of the TGF-β/SMAD and nuclear factor κB signalling pathways. In vitro, CRP significantly upregulated pro-inflammatory cytokines (IL-1β, TNFα, monocyte chemoattractant protein-1 [MCP-1]) and pro-fibrotic growth factors (TGF-β1, connective tissue growth factor [CTGF]) via CD32a/64. CRP was induced by high glucose, which synergistically promoted high glucose-mediated renal inflammation and fibrosis.

CONCLUSIONS/INTERPRETATION

CRP is not only a biomarker, but also a mediator in DKD. Enhanced activation of TGF-β/SMAD and nuclear factor κB signalling pathways may be the mechanisms by which CRP promotes renal inflammation and fibrosis under diabetic conditions.

Overexpression of human C-reactive protein exacerbates left ventricular remodeling in diabetic cardiomyopathy

BACKGROUND

C-reactive protein (CRP) is known to be a pathogenic agent in the cardiovascular system. However, the effect of CRP on heart failure has not been elucidated. The effect of human CRP on cardiac dysfunction induced by diabetes mellitus (DM) using human CRP-overexpressing transgenic mice (CRP-Tg) was examined.

METHODS AND RESULTS

DM was induced in male wild-type mice (Wt/DM) and CRP-Tg (CRP/DM) by an injection of streptozotocin. Non-diabetic wild-type mice (Wt/Con) and CRP-Tg (CRP/Con) served as controls. Echocardiography and hemodynamic measurements 6 weeks after injection showed lower fractional shortening and left ventricular (LV) dP/dt max in CRP/DM compared with Wt/DM. Myocardial mRNA levels of interleukin-6, tumor necrosis factor-α, plasminogen activator inhibitor-1, angiotensin type 1 receptor, angiotensinogen, NADPH oxidase subunits (p47(phox), gp91(phox)), glutathione peroxidase-3. and connective tissue growth factor were increased in CRP/DM compared with Wt/DM. Nuclear staining of 8-hydroxydeoxyguanosine was also increased in CRP/DM compared with Wt/DM. CRP/DM was associated with increased terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling positive cells and a higher ratio of Bax/Bcl-2 proteins compared with Wt/DM. The extent of cardiac fibrosis assessed by Sirius red staining and immunohistochemical staining for collagen type 1 was significantly increased in CRP/DM compared with Wt/DM.

CONCLUSIONS

Overexpression of human CRP exacerbates LV dysfunction and remodeling in diabetic cardiomyopathy, possibly through enhancement of the inflammation, renin-angiotensin system, and oxidative stress.

C-Reactive Protein Overexpression Exacerbates Pressure Overload–Induced Cardiac Remodeling Through Enhanced Inflammatory Response

Serum C-reactive protein (CRP) elevation predicts the development of heart failure in patients with hypertension. CRP activates macrophages and enhances oxidative stress. We hypothesize that CRP itself has a pathogenic role in the development of pressure overload–induced cardiac remodeling. Transgenic mice with human CRP overexpression (CRPtg) and nontransgenic littermates (CON) were subjected to transverse aortic constriction (TAC/CRPtg and TAC/CON) or sham operation (Sham/CRPtg and Sham/CON). One week after operation, in TAC/CRPtg, myocardial mRNA levels of interleukin (IL)-6, CD68, glutathione peroxidase-3 (GPx3), 47-kDa α-subunit of nicotinamide adenine dinucleotide phosphate oxidase (p47 phox ), and collagen-I, the number of infiltrating Mac-2–positive macrophages, nuclear localization of phosphorylated NF-κB/p65 (p-p65) in cardiomyocytes, nuclear NF-κB-DNA-binding activity, and reactive oxygen species (ROS) content were increased compared to those in TAC/CON. Cardiac fibrosis was more prominent in TAC/CRPtg compared to TAC/CON. Four weeks after operation, heart and lung weights, cardiomyocyte cross-sectional area, and the extent of cardiac fibrosis were greater in TAC/CON than in Sham/CON, and these differences were further augmented in TAC/CRPtg compared to TAC/CON. Left ventricular (LV) fractional shortening was less and LV end-diastolic pressure was higher in TAC/CRPtg than in TAC/CON. Myocardial mRNA levels of angiotensin type 1 receptor, atrial natriuretic factor, IL-6, GPx3, p47 phox , collagen-I, and transforming growth factor (TGF)-β1, the protein level of TGF-β1, and the numbers of Mac-2–positive macrophages and p-p65–positive cells were higher in TAC/CRPtg than in TAC/CON. In conclusion, CRP itself may have a pathogenic role in the development of pressure overload–induced cardiac remodeling, possibly through enhanced inflammation and oxidative stress.