Biomarkers of Cardiac Injury: An Update

Effect of Pesticide Vinclozolin Toxicity Exposure on Cardiac Oxidative Stress and Myocardial Damage

(1) Background: Vinclozolin is a popular fungicide used in fruit, ornamental plants, and vegetable crops. It has recently been seen that prolonged exposure to VZN can cause human or animal health damage to various organs, but little is known to date about its cardiovascular effects. In this study, we addressed the chronic effects of VZN on the myocardium and the enzymes involved in the cardiovascular function. (2) Methods: The animals were divided into four groups: group 1 served as the control, group 2 received 1 mg/kg of VZN by gavage, group 3 received 30 mg/kg of VZN by gavage, and group 4 received 100 mg/kg of VZN by gavage, for 30 days. (3) Results: Results showed that 100 mg/kg VZN markedly increased the plasma concentration of cardiac markers (CK-MB, cTnT, ANP, BNP). Moreover, compared to the control group, VZN treatment decreased the activity of SOD, CAT, and GPx, and downregulated the mRNA expression levels of Nrf2. Furthermore, collagen deposition was amplified owing to 100 mg/kg VZN cardiotoxicity. This harmful effect was confirmed by a histological study using hematoxylin and eosin (H&E) and Masson's trichrome staining. (4) Conclusion: Overall, our results proved the cardiotoxicity caused by chronic exposure to VZN.

Post-ischemic Myocardial Inflammatory Response: A Complex and Dynamic Process Susceptible to Immunomodulatory Therapies

Following acute occlusion of a coronary artery causing myocardial ischemia and implementing first-line treatment involving rapid reperfusion, a dynamic and balanced inflammatory response is initiated to repair and remove damaged cells. Paradoxically, restoration of myocardial blood flow exacerbates cell damage as a result of myocardial ischemia-reperfusion (MI-R) injury, which eventually provokes accelerated apoptosis. In the end, the infarct size still corresponds to the subsequent risk of developing heart failure. Therefore, true understanding of the mechanisms regarding MI-R injury, and its contribution to cell damage and cell death, are of the utmost importance in the search for successful therapeutic interventions to finally prevent the onset of heart failure. This review focuses on the role of innate immunity, chemokines, cytokines, and inflammatory cells in all three overlapping phases following experimental, mainly murine, MI-R injury known as the inflammatory, reparative, and maturation phase. It provides a complete state-of-the-art overview including most current research of all post-ischemic processes and phases and additionally summarizes the use of immunomodulatory therapies translated into clinical practice.

Effects of short duration high intensity competition on cardiac and cell damage biomarkers

The purpose of this study was to investigate the cardiac biomarkers like cardiac troponin T (cTnT), cardiac troponin I, and creatine kinase-MB (CK-MB) and the cell damage biomarkers including creatine phosphokinase (CPK), C-reactive protein (CRP), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in response to a short-duration high-intensity competition with correction of the post-exercise raw data with the plasma volume loss in trained athletes. Thirty-two male athletes (age, 26.9±4.7 years) competed in 8 min high-intensity competition. The competition items included: running for 400 meters; three-stage deadlifting; bar pulling up; and 30 kg kettlebell swinging. Venous blood samples were obtained before and immediately after the competition and biomarkers analysed. Plasma volume changes were estimated from haemoglobin and haematocrit readings before and after the competition. A significant increase was shown immediately after the competition compared to resting in cTnT, AST, ALT, CPK, and CRP (P<0/001). CK-MB showed no significant difference. When raw data were corrected for plasma volume loss, CPK showed a significant increase (P<0.001), and LDH and CK-MB a significant decrease (P<0.001), however cTnT, AST, ALT and CRP showed no significant difference. The plasma volume loss can affect the response of cardiac and cellular damage biomarkers to exercise. High-intensity competition for 8 min did not elevate the cardiac biomarkers, but elevated the muscle biomarkers.

Angiotensin-converting enzyme 2 (ACE2): COVID 19 gate way to multiple organ failure syndromes

BACKGROUND

Globally, the current medical emergency for novel coronavirus 2019 (COVID-19) leads to respiratory distress syndrome and death.

PURPOSE

This review highlighted the effect of COVID-19 on systemic multiple organ failure syndromes. This review is intended to fill a gap in information about human physiological response to COVID-19 infections. This review may shed some light on other potential mechanisms and approaches in COVID -19 infections towards systemic multiorgan failure syndromes.

FINDING

SARS-CoV-2 intervened mainly in the lung with progression to pneumonia and acute respiratory distress syndrome (ARDS) via the angiotensin-converting enzyme 2(ACE2) receptor. Depending on the viral load, infection spread through the ACE2 receptor further to various organs such as heart, liver, kidney, brain, endothelium, GIT, immune cell, and RBC (thromboembolism). This may be aggravated by cytokine storm with the extensive release of proinflammatory cytokines from the deregulating immune system.

CONCLUSION

The widespread and vicious combinations of cytokines with organ crosstalk contribute to systemic hyper inflammation and ultimately lead to multiple organ dysfunction (Fig. 1). This comprehensive study comprises various manifestations of different organs in COVID-19 and may assist the clinicians and scientists pertaining to a broad approach to fight COVID 19.

Post-Myocardial Infarction Ventricular Remodeling Biomarkers-The Key Link between Pathophysiology and Clinic

Studies in recent years have shown increased interest in developing new methods of evaluation, but also in limiting post infarction ventricular remodeling, hoping to improve ventricular function and the further evolution of the patient. This is the point where biomarkers have proven effective in early detection of remodeling phenomena. There are six main processes that promote the remodeling and each of them has specific biomarkers that can be used in predicting the evolution (myocardial necrosis, neurohormonal activation, inflammatory reaction, hypertrophy and fibrosis, apoptosis, mixed processes). Some of the biomarkers such as creatine kinase-myocardial band (CK-MB), troponin, and N-terminal-pro type B natriuretic peptide (NT-proBNP) were so convincing that they immediately found their place in the post infarction patient evaluation protocol. Others that are related to more complex processes such as inflammatory biomarkers, atheroma plaque destabilization biomarkers, and microRNA are still being studied, but the results so far are promising. This article aims to review the markers used so far, but also the existing data on new markers that could be considered, taking into consideration the most important studies that have been conducted so far.

Cardioprotective Effects of Atorvastatin Are Mediated Through PPARγ in Paraquat-Exposed Rats

BACKGROUND

Paraquat poisoning is one of leading intoxication worldwide without an effective antidote and treatment protocol. Among the other organs, cardiotoxicity of paraquat has been frequently reported.

AIM

The protective effects of atorvastatin (STN) on paraquat-induced cardiotoxicity and the role of peroxisome proliferator-activated receptors γ in the mediation of STN effects were investigated.

METHODS

Forty-two male Wistar rats were aliquoted into control or test groups. The animals in test groups in addition of paraquat received saline normal (PQ), pioglitazone (PGT), atorvastatin (STN), PGT + STN, PGT + GW9662, and/or STN + GW9662 for 14 days.

RESULTS

PGT and STN lowered lipid peroxidation rate, nitric oxide concentration, and activity of myeloperoxidase and CK/MB in the heart. PGT and STN protected from thiol molecules reduction and PQ-induced histopathological injuries. STN regulated the PQ-induced upregulation of COX-II expression in the heart. All STN-related protective effects were reversed by GW9662 as PPARγ antagonist.

CONCLUSIONS

These data suggest a cardioprotective effect for STN against the PQ-induced inflammation and oxidative stress. The pharmacologic approach of these findings indicates that STN through PPARγ pathway lowered the PQ-induced cardiotoxicity.

The Preventive role of Regular Physical Training in Ventricular Remodeling, Serum Cardiac Markers, and Exercise Performance Changes in Breast Cancer in Women Undergoing Trastuzumab Therapy-An REH-HER Study

Cardiotoxicity is known as a severe clinical problem in oncological practice that reduces the options for cancer therapy. Physical exercise is recognized as a well-established protective measure for many heart and cancer diseases. In our study, we hypothesized that supervised and moderate-intensity exercise training would prevent heart failure and its consequences induced by trastuzumab therapy. The aim of this study was to examine the effect of physical training on ventricular remodeling, serum cardiac markers, and exercise performance in women with human epidermal growth receptor 2 (HER2+) breast cancer (BC) undergoing trastuzumab therapy. This was a prospective, randomized, clinical controlled trial. Forty-six BC women were randomized into either an intervention group (IG) or a control group (CG). An exercise program (IG) was performed after 3–6 months of trastuzumab therapy at 5 d/week (to 80% maximum heart rate (HRmax)) for 9 weeks. We then evaluated their cardiac function using echocardiography, a 6-Minute Walk Test (6MWT), and plasma parameters (C-reactive protein (CRP), myoglobin (MYO), interleukin-6 (IL-6), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatine kinase (CK)). After the physical training program, we did not observe any significant changes in the left ventricular (LV) ejection fraction (LVEF) and 6MWT (p > 0.05) in the IG compared to the CG (decrease p < 0.05). The differences in the blood parameters were not significant (p < 0.05). To conclude, moderate-intensity exercise training prevented a decrease in the LVEF and physical capacity during trastuzumab therapy in HER2+ BC. Further research is needed to validate our results.

In vivo anti-hypercholesterolemic effect of buttermilk, milk fat globule membrane and Enterococcus faecium FFNL-12

The present study was undertaken to evaluate the hypocholesterolemic activity of buttermilk, milk fat globule membrane (MFGM) and Enterococcus faecium FFNL-12 in rat model. Thirty-sixth male Abino rats were divided into six groups. The first one (coded as G1) was fed a standard diet containing 10% corn oil as fat source while remaining five (coded G2 to G6) were fed hypercholesterolemic diets in which oil was replaced with animal grease. Animals subjected to treatment G1 served as healthy control while those in G2 were assigned as hypocholesterolemic animals which did not receive any treatment. The remaining experimental groups were designed to assess the hypocholesterolemic effect of intragastric adminstartion of dose of 109 CFU/Kg body weight of Enterococcus faecium FFNL-12 (G3), Enterococcus faecium FFNL-12/butter milk (G4), buttermilk (G5) and milk fat globule membrane (MFGM). After four weeks, animals were evaluated in relation to growth, fecal pH, organs weight, serum lipid profile, antioxidant activity of liver tissue, liver and heart function and liver histopathological architecture. Results revealed that animals fed hypercholesterolemic diet (G2-G6) had significantly lower faecal pH and liver weight compared with those fed standard diet (G1). Treatments applied to animals fed hypercholesterolemic diet with the above mentioned additions (G3 to G6) appeared to improve both cardiac and hepatic functions, serum lipid profile and glucose concentration and liver histopathological architecture compared with animals subjected to G2 treatment. In most cases, treatment with MFGM appeared to be the most effective to avoid adverse effects associated to feeding hypercholesterolemic diet. MFGM fraction as well as E. faecium FFNL-12/buttermilk combination were effective in reducing serum lipids and glucose levels to the normal range. This combination also had potential antioxidant activity and ability to improve liver and heart functions.

Prevalence, patterns and factors associated with hypertensive crises in Mulago hospital emergency department; a cross-sectional study

Background

Hypertension is increasing in sub-Saharan Africa (SSA) and it's the single most important modifiable stroke risk factor, yet it's control is not routinely emphasized.

The prevalence, pattern and factors associated with hypertensive urgencies and emergencies in Uganda is not well established. A cross-sectional study, was conducted between November 2015 and February 2016, using a complete clinical examination and pre-tested standardized questionnaire subjects were enrolled. The prevalence of hypertensive crises and associations of demographic and clinical factors determined using logistic regression.

Results

The prevalence of hypertensive crises was 5.1%, (203/4000) of all admissions at the medical section of the accident and emergency ward of Mulago National Referral Hospital. The hypertensive urgencies and emergencies accounted for 32.5% and 67.5% respectively among study subjects with hypertension. Among those with hypertensive crises, 41.1% were aged 45–65 years and half were female. Self-reported compliance was significantly different between those with hypertensive crisis compared to non-hypertensive crisis with OR; (95% CI) 52.4; (24.5 — 111.7), p-value =<0.001. Acute stroke was the commonest hypertensive emergency.

Conclusion

Hypertensive emergencies are common and significantly associated with poor compliance to prescribed anti-hypertensive drugs. Acute stroke is the commonest presentation in our setting.

Circulating MiR-17-5p, MiR-126-5p and MiR-145-3p Are Novel Biomarkers for Diagnosis of Acute Myocardial Infarction

Ischemic heart disease including myocardial infarction (MI) is a major cause of mortality and morbidity worldwide. In order to manage the acute myocardial infarction (AMI) outbreaks, novel biomarkers for risk prediction are needed. Recent studies have shown that circulating microRNAs (miRNAs) are promising biomarkers for cardiovascular diseases prediction. This study aimed to determine the possibility of circulating miRNAs used as biomarkers for AMI. The dynamic expression levels of miRNAs were examined before and after percutaneous coronary intervention (PCI) in patients. Circulating miR-17-5p, miR-126-5p, and miR-145-3p were selected and validated in 29 patients with AMI and 21 matched controls by quantitative real-time PCR. The expression levels of plasma miR-17-5p, miR-126-5p, and miR-145-3p were significantly increased in AMI patients. Receiver Operating Characteristic (ROC) analysis indicated that miR-17-5p, miR-126-5p, and miR-145-3p showed considerable diagnostic efficiency for AMI. Furthermore, we demonstrated that the combination of these three miRNAs managed to provide more accurate diagnosing of AMI.

Fast skeletal troponin I, but not the slow isoform, is increased in patients under statin therapy: a pilot study

Introduction

Statin therapy is often associated with muscle complaints and increased serum creatine kinase (CK). However, although essential in determining muscle damage, this marker is not specific for skeletal muscle. Recent studies on animal models have shown that slow and fast isoforms of skeletal troponin I (ssTnI and fsTnI, respectively) can be useful markers of skeletal muscle injury. The aim of this study was to evaluate the utility of ssTnI and fsTnI as markers to monitor the statin-induced skeletal muscle damage.

Materials and methods

A total of 51 patients (14 using and 37 not using statins) admitted to the intensive care unit of the University of Ferrara Academic Hospital were included in this observational study. Serum activities of CK, aldolase, alanine aminotransferase and myoglobin were determined by spectrophotometric assays or routine laboratory analysis. Isoforms ssTnI and fsTnI were determined by commercially available ELISAs. The creatine kinase MB isoform (CK-MB) and cardiac troponin I (cTnI) were evaluated as biomarkers of cardiac muscle damage by automatic analysers.

Results

Among the non-specific markers, only CK was significantly higher in statin users (P = 0.027). Isoform fsTnI, but not ssTnI, was specifically increased in those patients using statins (P = 0.009) evidencing the major susceptibility of fast-twitch fibres towards statins. Sub-clinical increase in fsTnI, but not CK, was more frequent in statin users (P = 0.007). Cardiac markers were not significantly altered by statins confirming the selectivity of the effect on skeletal muscle.

Conclusions

Serum fsTnI could be a good marker for monitoring statin-associated muscular damage outperforming traditional markers.

Functionalization of polyacrylamide for nanotrapping positively charged biomolecules

Engineering new materials which are capable of trapping biomolecules in nanoscale quantities, is crucial in order to achieve earlier diagnostics in different diseases. This article demonstrates that using free radical copolymerization, polyacrylamide can be successfully functionalized with specific synthons for nanotrapping positively charged molecules, such as numerous proteins, through electrostatic interactions due to their negative charge. Specifically, two functional random copolymers, acrylamide/acrylic acid (1) and acrylamide/acrylic acid/N-(pyridin-4-yl-methyl)acrylamide (2), whose negative net charges differ in their water solutions, were synthetized and their ability to trap positively charged proteins was studied using myoglobin as a proof-of-concept example. In aqueous solutions, copolymer 1, whose net charge for a 100 chain fragment (Q_{pH 6}/M) is −1.323 × 10⁻³, interacted with myoglobin forming a stable monodisperse nanosuspension. In contrast, copolymer 2, whose value of Q_{pH 6}/M equals −0.361 × 10⁻³, was not able to form stable particles with myoglobin. Nevertheless, thin films of both copolymers were grown using a dewetting process, which exhibited nanoscale cavities capable of trapping different amounts of myoglobin, as demonstrated by bimodal AFM imaging. The simple procedures used to build protein traps make this engineering approach promising for the development of new materials for biomedical applications where trapping biomolecules is required.

Engineering new materials which are capable of trapping biomolecules in nanoscale quantities, is crucial in order to achieve earlier diagnostics in different diseases.

Dragon's Blood exerts cardio-protection against myocardial injury through PI3K-AKT-mTOR signaling pathway in acute myocardial infarction mice model

ETHNOPHARMACOLOGICAL RELEVANCE

Dragon's Blood (DB), the red resin of Dracaena cochinchinensis (Lour.) S. C., has been used in traditional Chinese medicine to treat acute myocardial infarction (AMI) for centuries. Evidence indicated that DB may exert cardio-protective effect by inhibiting inflammatory response during myocardial infarction. However, its pharmaceutical mechanism is still to be elucidated.

AIM OF THE STUDY

Due to its potential anti-inflammatory effect, Dragon's Blood extract (DBE) was applied on AMI mice model in this study and its mechanism on inflammation via PI3K-AKT-mTOR signaling pathway was to be validated.

MATERIALS AND METHODS

AMI mice model was established by ligation of left anterior descending (LAD) arteries. DBE was administered for 7 days before the surgery. Heart function was evaluated by 2D echocardiography. Levels of CK-MB and LDH1 in serum as well as TXB2, 6-keto-PGF1α and ET-1 in plasma were detected. Level of IL-6 in cardiac tissues was quantified by ELISA. Expressions of key proteins in PI3K-AKT-mTOR signaling pathway were detected by Western blot.

RESULTS

The result demonstrated that DBE could improve heart function in AMI mice model. Meanwhile, it could also regulate levels of CK-MB and LDH1, and restore balance between TXB2 and 6-keto-PGF1α. Further study suggested that DBE could inhibit inflammation and regulate expressions of key proteins in IL-6-JAK2/STAT3 pathway in cardiac tissue. Western blot results validated that DBE could activate PI3K-AKT-mTOR signaling pathway, thereby regulating the expressions of its downstream targets, including VEGF, COX2 and PPARγ.

CONCLUSION

DBE exerts cardio-protective efficacy by activating JAK2-STAT3 and PI3K-AKT-mTOR pathways in cardiac tissue. These findings provide insight into the pharmacological mechanism of DBE and validate the beneficial effects of DBE in the clinical application for AMI.

Maternal Allopurinol Prevents Cardiac Dysfunction in Adult Male Offspring Programmed by Chronic Hypoxia During Pregnancy

Integrating functional and molecular levels, we investigated the effects of maternal treatment with a xanthine oxidase inhibitor on the programming of cardiac dysfunction in adult offspring using an established rat model of hypoxic pregnancy. Female Wistar rats were divided into normoxic or hypoxic (13% O₂) pregnancy±maternal allopurinol treatment (30 mg kg^-1 d^-1). At 4 months, hearts were isolated from 1 male per litter per outcome variable to determine cardiac function and responses to ischemia-reperfusion in a Langendorff preparation. Sympathetic dominance, perfusate CK (creatine kinase) and LDH (lactate dehydrogenase) and the cardiac protein expression of the β₁-adrenergic receptor, the M₂ Ach receptor (muscarinic type-2 acetylcholine receptor), and the SERCA2a (sarcoplasmic reticulum Ca²⁺ ATPase 2a) were determined. Relative to controls, offspring from hypoxic pregnancy showed elevated left ventricular end diastolic pressure (+34.7%), enhanced contractility (dP/dt_max, +41.6%), reduced coronary flow rate (-21%) and an impaired recovery to ischemia-reperfusion (left ventricular diastolic pressure, area under the curve recovery -19.1%; all P<0.05). Increased sympathetic reactivity (heart rate, +755.5%; left ventricular diastolic pressure, +418.9%) contributed to the enhanced myocardial contractility ( P<0.05). Perfusate CK (+431%) and LDH (+251.3%) and the cardiac expression of SERCA2a (+71.4%) were also elevated ( P<0.05), further linking molecular markers of cardiac stress and injury to dysfunction. Maternal allopurinol restored all functional and molecular indices of cardiac pathology. The data support a link between xanthine oxidase-derived oxidative stress in hypoxic pregnancy and cardiac dysfunction in the adult offspring, providing a target for early intervention in the developmental programming of heart disease.

Co-exposure of silica nanoparticles and methylmercury induced cardiac toxicity in vitro and in vivo

The released nanoparticles into environment can potentially interact with pre-existing pollution, maybe causing higher toxicity. As such, assessment of their joint toxic effects is necessary. This study was to investigate the co-exposure cardiac toxicity of silica nanoparticles (SiNPs) and methylmercury (MeHg). Factorial design was used to determine the potential joint action type. In vitro study, human cardiomyocytes (AC16) were exposed to SiNPs and MeHg alone or the combination. Higher toxicity was observed on cell viability, cell membrane damage in co-exposure compared with single exposure and control. The co-exposure enhanced the ROS, MDA generation and reduced the activity of SOD and GSH-Px. In addition, the co-exposure induced much higher cellular apoptotic rate in AC16. In vivo study, after SD rats exposed to SiNPs and MeHg and their mixture by intratracheal instillation for 30days, pathological changes (myocardial interstitial edema) of heart were occurred in co-exposure compared with single exposure and control. Moreover obvious ultra-structural changes, including myofibril disorder, myocardial gap expansion, and mitochondrial damage were observed in co-exposure group. The activity of myocardial enzymes, including CK-MB, ANP, BNP and cTnT, were significantly elevated in co-exposure group of rat serum. Meanwhile, the cardiac injury-linked proteins expression showed an increase in SERCA2 and decreased levels of cTnT, ANP and BNP in co-exposure group. Factorial design analysis demonstrated that additive and synergistic interactions were responsible for the co-exposure cardiac toxicity in vitro and vivo. In summary, our results showed severe cardiac toxicity induced by co-exposure of SiNPs and MeHg in both cardiomycytes and heart. It will help to clarify the potential cardiovascular toxicity in regards to combined exposure pollutions.

Canonical PI3Kγ signaling in myeloid cells restricts Trypanosoma cruzi infection and dampens chagasic myocarditis

Chagas disease is caused by infection with the protozoan Trypanosoma cruzi (T. cruzi) and is an important cause of severe inflammatory heart disease. However, the mechanisms driving Chagas disease cardiomyopathy have not been completely elucidated. Here, we show that the canonical PI3Kγ pathway is upregulated in both human chagasic hearts and hearts of acutely infected mice. PI3Kγ-deficient mice and mutant mice carrying catalytically inactive PI3Kγ are more susceptible to T. cruzi infection. The canonical PI3Kγ signaling in myeloid cells is essential to restrict T. cruzi heart parasitism and ultimately to avoid myocarditis, heart damage, and death of mice. Furthermore, high PIK3CG expression correlates with low parasitism in human Chagas’ hearts. In conclusion, these results indicate an essential role of the canonical PI3Kγ signaling pathway in the control of T. cruzi infection, providing further insight into the molecular mechanisms involved in the pathophysiology of chagasic heart disease.

Trypanosoma cruzi infection causes Chagas disease, but mechanisms underlying pathogenesis are unclear. Here, Silva et al. show that canonical PI3Kγ signaling in myeloid cells restricts T. cruzi infection in mice and that high PIK3CG expression correlates with low parasite levels in human Chagas’ hearts.

Evaluation of Cardiac Toxicity Biomarkers in Rats from Different Laboratories

There is a great need for improved diagnostic and prognostic accuracy of potential cardiac toxicity in drug development. This study reports the evaluation of several commercially available biomarker kits by 3 institutions (SRI, Eli Lilly, and Pfizer) for the discrimination between myocardial degeneration/necrosis and cardiac hypertrophy as well as the assessment of the interlaboratory and interplatform variation in results. Serum concentrations of natriuretic peptides (N-terminal pro-atrial natriuretic peptide [NT-proANP] and N-terminal pro-brain natriuretic peptide [NT-proBNP]), cardiac and skeletal troponins (cTnI, cTnT, and sTnI), myosin light chain 3 (Myl3), and fatty acid binding protein 3 (FABP3) were assessed in rats treated with minoxidil (MNX) and isoproterenol (ISO). MNX caused increased heart-to-body weight ratios and prominent elevations in NT-proANP and NT-proBNP concentrations detected at 24-hr postdose without elevation in troponins, Myl3, or FABP3 and with no abnormal histopathological findings. ISO caused ventricular leukocyte infiltration, myocyte fibrosis, and necrosis with increased concentrations of the natriuretic peptides, cardiac troponins, and Myl3. These results reinforce the advantages of a multimarker strategy in elucidating the underlying cause of cardiac insult and detecting myocardial tissue damage at 24-hr posttreatment. The interlaboratory and interplatform comparison analyses also showed that the data obtained from different laboratories and platforms are highly correlated and reproducible, making these biomarkers widely applicable in preclinical studies.

An experimental ovine Theileriosis: The effect of Theileria lestoquardi infection on cardiovascular system in sheep

The malignant ovine theileriosis is caused by Theileria lestoquardi, which is highly pathogenic in sheep. Theileriosis involves different organs in ruminants, but the effect of the disease on the cardiovascular system is unclear. To understand the pathogenesis of T. lestoquardi on the cardiovascular system, Baluchi breed sheep were infected with the mentioned parasite by releasing unfed adults of Hyalomma anatolicum anatolicum, which were infected with T. lestoquardi. The infected sheep were clinically examined on days 0, 2, 5, 7, 10, 12, 14, 17, and 21, and the blood samples were collected for biochemical parameters measurement. At termination of the experiment, the infected sheep were euthanized and pathological examinations of heart tissue were conducted. During experimental infection of sheep with T. lestoquardi, activities of cardiac troponin I (cTnI), lactate dehydrogenase, and aspartate aminotransferase, were significantly increased (P˂0.05), while a conspicuous decrease (P˂0.05) was observed in creatine phosphokinase activities. Alterations made in biochemical factors almost coincided with the presence of piroplasm in the blood and schizont in lymph nodes. Maximum and minimum of parasitemia in the sheep stood between 3.3% and 0.28%, respectively. In addition, electrocardiography revealed sinus tachycardia, sinus arrhythmia, sino-atrial block and ST-elevation, atrial premature beat, and alteration in QRS and in T waves' amplitude. Heart histopathological examination showed hyperemia, infiltration of mononuclear inflammatory cells into interstitial tissue, endocarditis, and focal necrosis of cardiac muscle cells. In addition, in one of the sheep, definite occurrence of infarction was observed. The results indicate that T. lestoquardi infection has devastating pathological impacts on the cardiovascular system of sheep. Furthermore, measurement of the cTnI amount is a useful biochemical factor for diagnosis and for better understanding of the severity and progression of the disease and its effects on cardiac tissue.

Biomarkers and mortality in severe Chagas cardiomyopathy

BACKGROUND

Chagas cardiomyopathy is a chronic sequela of infection by the parasite, Trypanosoma cruzi. Advanced cardiomyopathy is associated with a high mortality rate, and clinical characteristics have been used to predict mortality risk. Though multiple biomarkers have been associated with Chagas cardiomyopathy, it is unknown how these are related to survival.

OBJECTIVES

This study aimed to identify biomarkers associated with mortality in individuals with severe Chagas cardiomyopathy in an urban Bolivian hospital.

METHODS

The population included individuals with and without T. cruzi infection recruited in an urban hospital in Santa Cruz, Bolivia. Baseline characteristics, electrocardiogram findings, medications, and serum cardiac biomarker levels (B-type natriuretic peptide [BNP], N-terminal pro-B-type natriuretic peptide [NT-proBNP], creatine kinase-myocardial band [CK-MB], troponin I, matrix metalloproteinase [MMP]-2, MMP-9, tissue inhibitor of metalloproteinases [TIMP] 1 and 2, transforming growth factor [TGF] beta 1 and 2) were ascertained. Echocardiograms were performed on those with cardiac symptoms or electrocardiogram abnormalities at baseline. Participants were contacted approximately 1 year after initial evaluation; deaths were reported by family members. Receiver-operating characteristic curves (ROC) were used to optimize cutoff values for each marker. For markers with area under the curve (AUC) >0.55, Cox proportional hazards models were performed to determine the hazards ratio (HR) and 95% confidence interval (CI) for the association of each marker with mortality.

RESULTS

The median follow-up time was 14.1 months (interquartile range 12.5, 16.7). Of 254 individuals with complete cardiac data, 220 (87%) had follow-up data. Of 50 patients with severe Chagas cardiomyopathy at baseline, 20 (40%) had died. Higher baseline levels of BNP (HR: 3.1, 95% CI: 1.2 to 8.4), NT-proBNP (HR: 4.4, 95% CI: 1.8 to 11.0), CK-MB (HR: 3.3, 95% CI: 1.3 to 8.0), and MMP-2 (HR: 4.2, 95% CI: 1.5 to 11.8) were significantly associated with subsequent mortality.

CONCLUSIONS

Severe Chagas cardiomyopathy is associated with high short-term mortality. BNP, NT-proBNP, CK-MB, and MMP-2 have added predictive value for mortality, even in the presence of decreased ejection fraction and other clinical signs of congestive heart failure.

Selection of DNA aptamers against Human Cardiac Troponin I for colorimetric sensor based dot blot application

Troponin T and I are ideal markers which are highly sensitive and specific for myocardial injury and have shown better efficacy than earlier markers. Since aptamers are ssDNA or RNA that bind to a wide variety of target molecules, the purpose of this research was to select an aptamer from a 79bp single-stranded DNA (ssDNA) random library that was used to bind the Human Cardiac Troponin I from a synthetic nucleic acids library by systematic evolution of ligands exponential enrichment (Selex) based on several selection and amplification steps. Human Cardiac Troponin I protein was coated onto the surface of streptavidin magnetic beads to extract specific aptamer from a large and diverse random ssDNA initial oligonucleotide library. As a result, several aptamers were selected and further examined for binding affinity and specificity. Finally TnIApt 23 showed beast affinity in nanomolar range (2.69nM) toward the target protein. A simple and rapid colorimetric detection assay for Human Cardiac Troponin I using the novel and specific aptamer-AuNPs conjugates based on dot blot assay was developed. The detection limit for this protein using aptamer-AuNPs-based assay was found to be 5ng/ml.

Quantitative proteomics for cardiac biomarker discovery using isoproterenol-treated nonhuman primates

To identify new cardiac biomarkers, a quantitative proteomic analysis has been performed on serum and heart tissue proteins from three species of nonhuman primates following isoproterenol (ISO) treatment. Three serum proteins--serum amyloid A (SAA), α-1-acid glycoprotein (A1AG), and apolipoprotein A-1 (Apo A1)--were consistently identified as changed and remained altered 72 h post dose in all three species post ISO treatment, indicating the potential of including these proteins in preclinical or clinical evaluation of drug-induced cardiac injury. Furthermore, proteomic analysis of heart tissue proteins following ISO treatment demonstrated detrimental effects on calcium signaling and energy generation in cardiac myocytes. It is worth noting that cardiac troponins were not identified in serum but were identified as altered in heart tissue lysate along with other cardiac-specific proteins. This strategy for cardiac biomarker discovery by proteomic screening of heart tissue proteins, followed by verification in serum samples using immunoassays or targeted mass spectrometry, could be applied in future biomarker studies.

High sensitivity troponins and conventional troponins at the bedside

The continuing advances in the biochemical research for the discovering an ideal biomarker for diagnosing myocardial injury have led to discovery cardiac Troponin, a biochemical gold standard for myocardial necrosis. Further with advances in the immunoassay techniques, the 99th percentile cutoff value of cardiac troponin required for the diagnosis of myocardial infarction decreased, with the latest available ultrasensitive cardiac troponin assay capable of measuring level as low as 0.005 ng/ml. Troponin have both diagnostic as well as prognostic significance in myocardial necrosis, but the cut off value by 99th percentile rule is useful only when applied to patients with a high pretest probability of Acute Coronary Syndrome(ACS) and also the results must be interpreted in the context of clinical history, ECG findings, and possibly cardiac imaging to establish the correct diagnosis. As cardiac troponins are also elevated in other cardiac conditions such as cardiomyopaties, the serial monitoring of the cardiac troponin level along with the absolute value would help to differentiate myocardial infarction from these many varied conditions, with the interval of serial assay being reduced to 3 hours. The aim of this review is to complement the advantages, to emphasize on proper interpretation of positive results, to appraise the challenges faced with the available cardiac troponin assays and need for further research to overcome them and build up the most ideal cardiac marker for diagnosing the myocardial infarction.

The decrease of NAD(P)H:quinone oxidoreductase 1 activity and increase of ROS production by NADPH oxidases are early biomarkers in doxorubicin cardiotoxicity

CONTEXT

Doxorubicin cardiotoxicity displays a complex and multifactorial progression.

OBJECTIVE

Identify early biochemical mechanisms leading to a sustained imbalance of cellular bioenergetics.

METHODS

Measurements of the temporal evolution of selected biochemical markers after treatment of rats with doxorubicin (20 mg/kg body weight).

RESULTS

Doxorubicin treatment increased lipid oxidation, catalase activity and production of H₂O₂ by Nox-NADPH oxidases, and down-regulated

NAD(P)H

quinone oxidoreductase-1 prior eliciting changes in reduced glutathione, protein carbonyls and protein nitrotyrosines. Alterations of mitochondrial and myofibrillar bioenergetics biomarkers were detected only after this oxidative imbalance was established.

CONCLUSIONS

NAD(P)H

quinone oxidoreductase-1 activity and increase of hydrogen peroxide production by NADPH oxidases are early biomarkers in doxorubicin cardiotoxicity.

Infusion of foam sclerosants results in a distance-dependent procoagulant activity, haemoconcentration and elevation of D-dimer levels

Objective

To investigate the biological effects of foam sclerotherapy in vivo.

Materials and methods

Ultrasound-guided sclerotherapy was performed using a 3% sodium tetradecyl sulphate or polidocanol. A total of 15 mL of foam was injected. Samples were collected from antecubital veins, target saphenous veins and the adjoining deep veins before, immediately after and 1 hour after the procedure. Saphenous vein samples were also taken sequentially at set 15 cm intervals. Clotting times, D-dimer, cell counts and biochemical parameters were measured. D-dimer levels were repeated one week later.

Results

Forty procedures were performed. Systemic clotting times were not affected by the procedure. Injection of 0.5 mL of foam 5 cm away from the relevant junctions resulted in procoagulant activity in the adjoining deep veins (sodium tetradecyl sulphate) and the target saphenous veins (sodium tetradecyl sulphate and polidocanol). The procoagulant effect in the target veins reached a peak at 15 cm but normalised at 45 cm. D-dimer levels were significantly increased 1 hour after treatment with either agent and remained elevated one week later. Sodium tetradecyl sulphate and to a lesser degree polidocanol induced biochemical changes consistent with haemoconcentration.

Conclusion

Infusion of foam sclerosants results in a distance-dependent procoagulant activity in the exposed vessels. Foam sclerotherapy results in haemoconcentration and elevation of D-dimer.

Serum biomarkers reveal long-term cardiac injury in isoproterenol-treated African green monkeys

The assessment of cardiac toxicity is a major challenge in both drug development and clinical trials, and numerous marketed pharmaceuticals have been removed from the market due to unpredicted cardiac effects. Serum troponins are widely used indicators of cardiac injury; however, they are short-lived and have not been validated in preclinical animal models. In this study, we have used filter-aided sample preparation (FASP) and tandem mass tag (TMT) labeling to investigate serum protein alterations in isoproterenol-treated African green monkeys. Our results showed that the combination of FASP and TMT labeling provided highly reproducible and efficient sample preparation, which enables us to identify and quantify serum proteins with high confidence. We focused on the proteins that exhibit long-term alteration upon isoproterenol injection and discovered nine proteins exhibiting significant changes at 48 and 72 h postdosing. We further chose three proteins, serum amyloid A (SAA), frutose biphosphate aldolase A (FBAA), and fetuin A, for validation using enzyme-linked immunosorbent assay (ELISA). The serum concentration of SAA showed a ∼ 50 fold increase, while concentration of FBAA and fetuin A exhibited a significant decrease accompanying isoproterenol-induced cardiotoxicity. This work provides valuable insights for multimarker evaluation of long-term cardiac injury.

Proteomic profiling of tissue-engineered blood vessel walls constructed by adipose-derived stem cells

Adipose-derived stem cells (ASCs) can differentiate into smooth muscle cells and have been engineered into elastic small diameter blood vessel walls in vitro. However, the mechanisms involved in the development of three-dimensional (3D) vascular tissue remain poorly understood. The present study analyzed protein expression profiles of engineered blood vessel walls constructed by human ASCs using methods of two-dimensional gel electrophoresis (2DE) and mass spectrometry (MS). These results were compared to normal arterial walls. A total of 1701±15 and 1265±26 protein spots from normal and engineered blood vessel wall extractions were detected by 2DE, respectively. A total of 20 spots with at least 2.0-fold changes in expression were identified, and 38 differently expressed proteins were identified by 2D electrophoresis and ion trap MS. These proteins were classified into seven functional categories: cellular organization, energy, signaling pathway, enzyme, anchored protein, cell apoptosis/defense, and others. These results demonstrated that 2DE, followed by ion trap MS, could be successfully utilized to characterize the proteome of vascular tissue, including tissue-engineered vessels. The method could also be employed to achieve a better understanding of differentiated smooth muscle protein expression in vitro. These results provide a basis for comparative studies of protein expression in vascular smooth muscles of different origin and could provide a better understanding of the mechanisms of action needed for constructing blood vessels that exhibit properties consistent with normal blood vessels.

Cardiac markers: profile in rats experimentally infected with Toxocara canis

The aim of this study was to evaluate the profile of the enzymes creatine kinase (CK), creatine kinase MB (CK-MB) and lactate dehydrogenase (LDH) in Wistar rats infected with 250 (GI, n = 24) or 1000 (GII, n = 24) Toxocara canis eggs. Animals were evaluated on days 7, 15, 30, 60, 120 and 180 post-infection (DPI). Only the GI rats showed an increase in CK and CK-MB, at 15 and 30 DPI, respectively. Anti-Toxocara spp. antibodies were detected by ELISA in infected animals. Despite of the presence of eosinophilic infiltrate in the heart of three infected animals, none larva was recovered from the organ neither by acid digestion nor by Baermann procedure. Eosinophilia was observed in both groups but there was no significant difference in the eosinophil counts between GI and GII (p = 0.2239). It is possible to consider that cardiac lesion is an eventual finding in murine model for toxocariasis.

Gene expression profiles following intracoronary injection of mesenchymal stromal cells using a porcine model of chronic myocardial infarction

BACKGROUND AIMS

We evaluated the therapeutic potential of injection of in vitro differentiated bone marrow mesenchymal stromal cells (MSC) using a swine model.

METHODS AND RESULTS

Myocardial infarction was induced by coronary occlusion. Three groups (n = 5 each) were analyzed: one group received an injection of 17.8 ± 9.3 × 10(6) 5-azacytidine-treated allogeneic MSC 1 month after infarction; a placebo group received an injection of medium; and controls were kept untreated. After 4 weeks, heart samples were taken from three infarcted areas, interventricular septa, ventricles and atria. Gene expression profiles of genes related to contractility (Serca2a), fibrosis (Col1a1), cardiomyogenesis (Mef2c, Gata4 and Nkx2.5) and mobilization of stem cells (Sdf1, Cxcr4 and c-kit) were compared by quantitative real-time PCR (qRT-PCR). Gene expression profiles varied in different heart areas. Thus Serca2a expression was reduced in infarcted groups in all heart regions except for the left ventricles, where Col1a1 was overexpressed. The expression of genes related to cardiomyogenesis decreased in the infarcted zones and left atria compared with healthy hearts. Interestingly, increased expression of Cxcr4 was detected in infarcted regions of MSC-treated pigs compared with the placebo group.

CONCLUSIONS

Infarction induced changes in expression of genes involved in various biologic processes. Genes involved in cardiomyogenesis were downregulated in the left atrium. The intracoronary injection of MSC resulted in localized changes in the expression of Cxcr4.

The proteome of human brain after ischemic stroke

Although stroke is among the most common causes of death and chronic disability worldwide, the proteome of the ischemic human brain remains unknown. Only a few studies have investigated the ischemic brain proteome in rodent stroke models. We performed a proteomic study of the human brain after ischemic stroke using a 2-dimensional differential gel electrophoresis-based proteomic approach. In brain samples from 6 deceased stroke patients and 3 control subjects, there was an average of 1,442 ± 231 protein spots in the gels. Changes of at least 1.5-fold in the relative expression of 132 protein spots between different cerebral areas (infarct core, peri-infarct, and contralateral tissue) were identified (p < 0.05); 39 of these were successfully identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Among the identified protein spots, we validated the results of 10 proteins by Western blot and determined the cellular localization in brain parenchyma for 3 of the identified proteins: dihydropyrimidinase-related protein 2, vesicle-fusing ATPase, and Rho dissociation inhibitor 1. These results contribute to understanding the processes that follow cerebral ischemia; moreover, some of the identified proteins may be therapeutic targets or biologic markers for determining the diagnosis and prognosis of stroke.

Current role of ischemia-modified albumin in routine clinical practice

BACKGROUND

Ischemia-modified albumin has been proposed as a useful rule-out marker for the diagnosis of acute coronary syndrome in the emergency department.

OBJECTIVE

To perform a review of ischemia-modified albumin use in the clinical practice.

METHODS

We performed a comprehensive literature search by using electronic bibliographic databases.

CONCLUSION

Although the main limitation of ischemia-modified albumin at present is its low specificity, it may be a useful test to rule out acute coronary syndrome from low to moderate pre-test probability conditions with negative cardiac troponins and a negative ECG.

Biochemical markers of muscular damage

Muscle tissue may be damaged following intense prolonged training as a consequence of both metabolic and mechanical factors. Serum levels of skeletal muscle enzymes or proteins are markers of the functional status of muscle tissue, and vary widely in both pathological and physiological conditions. Creatine kinase, lactate dehydrogenase, aldolase, myoglobin, troponin, aspartate aminotransferase, and carbonic anhydrase CAIII are the most useful serum markers of muscle injury, but apoptosis in muscle tissues subsequent to strenuous exercise may be also triggered by increased oxidative stress. Therefore, total antioxidant status can be used to evaluate the level of stress in muscle by other markers, such as thiobarbituric acid-reactive substances, malondialdehyde, sulfhydril groups, reduced glutathione, oxidized glutathione, superoxide dismutase, catalase and others. As the various markers provide a composite picture of muscle status, we recommend using more than one to provide a better estimation of muscle stress.

Automated heart-type fatty acid-binding protein assay for the early diagnosis of acute myocardial infarction

We compared an automated quantitative heart-type fatty acid-binding protein (H-FABP) assay with other cardiac-marker assays to examine its usefulness as an early diagnostic marker of acute myocardial infarction (AMI). Serum samples for cardiac troponin T (cTnT), creatine kinase-MB isozyme (CK-MB), myoglobin, and H-FABP were obtained from 64 patients with AMI and 53 patients with other conditions (control group). H-FABP was measured by using 2 immunoassays, the H-FABP enzyme-linked immunosorbent assay (ELISA; Biocheck, Foster City, CA) and the H-FABP latex turbidimetric immunoassay (LTIA; HBI, Anyang, Korea). Sensitivities of assays for cTnT, CK-MB, myoglobin, H-FABP (by ELISA), H-FABP (by LTIA), and electrocardiogram (ECG) for the diagnosis of AMI at hospital admission were 39.1%, 59.4%, 64.1%, 68.7%, 70.3%, and 54.7%, respectively. Specificities of cTnT, CK-MB, myoglobin, H-FABP (by ELISA), H-FABP (by LTIA), and ECG were 98.1%, 71.7%, 81.1%, 77.4%, 90.6%, and 92.5%, respectively. The automated H-FABP (by LTIA) is superior to cTnT, CK-MB, myoglobin, and H-FABP (by ELISA) tests for the diagnosis of AMI in patients admitted within 4 hours from the onset of chest pain.

The use of proteomics to identify novel therapeutic targets for the treatment of disease

The completion of the Human Genome Project has revealed a multitude of potential avenues for the identification of therapeutic targets. Extensive sequence information enables the identification of novel genes but does not facilitate a thorough understanding of how changes in gene expression control the molecular mechanisms underlying the development and regulation of a cell or the progression of disease. Proteomics encompasses the study of proteins expressed by a population of cells, and evaluates changes in protein expression, post-translational modifications, protein interactions, protein structure and splice variants, all of which are imperative for a complete understanding of protein function within the cell. From the outset, proteomics has been used to compare the protein profiles of cells in healthy and diseased states and as such can be used to identify proteins associated with disease development and progression. These candidate proteins might provide novel targets for new therapeutic agents or aid the development of assays for disease biomarkers. This review provides an overview of the current proteomic techniques available and focuses on their application in the search for novel therapeutic targets for the treatment of disease.

Cardiac isoform of alpha 2 macroglobulin: a marker of cardiac involvement in pediatric HIV and AIDS

Cardiac involvement in children with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) is known but less often considered. Our objectives were to determine cardiac manifestations in pediatric HIV/AIDS and estimate the cardiac isoform of alpha-2 macroglobulin [CA2M] among them. We recruited 67 pediatric HIV/AIDS patients, 37 with cardiac involvement (group A) and 30 without (group B); 30 cardiac patients without HIV infection (group C); and 30 healthy control subjects without any comorbid illness (group D). Their sociodemographic and clinical information were collected along with echocardiogram and blood for CA2M. Patterns of cardiac involvement in HIV/AIDS (group A) were pericardial effusion, left ventricular dysfunction, pulmonary hypertension, and cardiomyopathy and observed in 43, 30, 16, and 11% of subjects, respectively. CA2M levels among groups A, B, C, and D were 132.67 +/- 5.01, 41.25 +/- 3.33, 65.99 +/- 2.48 and 29.59 +/- 2.76 microgm/ml, respectively. It was elevated significantly in group A (P = 0.001; 95% confidence interval [CI] 87.27-95.55) compared with group B and was independent of sex and CD4 count among HIV/AIDS subjects. Although CA2M was elevated in HIV-negative patients with cardiac involvement, it was much less than in HIV/AIDS subjects with cardiac involvement (P = 0.001; 95% CI 62.54-70.82). Because CA2M is a cardiac biomarker, further research with larger population is needed to ascertain the role of CA2M as a diagnostic/therapeutic/prognostic marker in cardiac patients with and without HIV infection.

Identification of cardiac myosin-binding protein C as a candidate biomarker of myocardial infarction by proteomics analysis

Acute myocardial infarction (AMI) is a common cause of death for which effective treatments are available provided that diagnosis is rapid. The current diagnostic gold standards are circulating cardiac troponins I and T. However, their slow release delays diagnosis, and their persistence limits their utility in the identification of reinfarction. The aim was to identify candidate biomarkers of AMI. Isolated mouse hearts were perfused with oxygenated protein-free buffer, and coronary effluent was collected after ischemia or during matched normoxic perfusion. Effluents were analyzed using proteomics approaches based on one- or two-dimensional initial separation. Of the 459 proteins identified after ischemia with one-dimensional separation, 320 were not detected in the control coronary effluent. Among these were all classic existing biomarkers of AMI. We also identified the cardiac isoform of myosin-binding protein C in its full-length form and as a 40-kDa degradation product. This protein was not detected in the other murine organs examined, increased markedly with even trivial myocardial infarction, and could be detected in the plasma after myocardial infarction in vivo, a profile compatible with a biomarker of AMI. Two-dimensional fluorescence DIGE of ischemic and control coronary effluents identified more than 200 asymmetric spots verified by swapping dyes. Once again existing biomarkers of injury were confirmed as well as posttranslational modifications of antioxidant proteins such as peroxiredoxins. Perfusing hearts with protein-free buffers provides a platform of graded ischemic injury that allows detailed analysis of protein release and identification of candidate cardiac biomarkers like myosin-binding protein C.

The relationship between ASAT, CKMB, Troponin-T and mortality after cardiac surgery

OBJECTIVE

To investigate the relationship between ASAT, CKMB, troponin-T and mortality after cardiac surgery.

DESIGN

ASAT, CKMB and TnT were analysed in 116 patients. Correlation, sensitivity, specificity and predictive values for permanent myocardial injury (defined as TnT > or = 2.0 microg/l postoperative day four) were calculated. In the second part our clinical protocol (ASAT on postoperative day 1 and TnT on day 3-4 in patients with ASAT above 2.5 microkat/l) was evaluated. Mortality was compared between patients with ASAT < 2.5 microkat/l (ASAT-), 2. ASAT > or = 2.5 microkat/l and TnT < 2.0 microg/l (ASAT+/TnT-) and 3. ASAT > or = 2.5 microkat/l and TnT > or = 2.0 microg/l (ASAT+/TnT+).

RESULTS

Both ASAT and CKMB had irrespectively of cut-off level, low positive and high negative predictive value of permanent myocardial injury. Early and mid-term mortality did not differ significantly between ASAT- and ASAT+/TnT- patients.

CONCLUSIONS

ASAT and CKMB can be used to exclude but not to diagnose permanent myocardial injury after cardiac surgery. Increased postoperative ASAT in the absence of increased TnT is not associated with worse clinical outcome than after normal postoperative ASAT.

Proteome and system ontology of hemorrhagic shock: exploring early constitutive changes in postshock mesenteric lymph

BACKGROUND

Postshock mesenteric lymph (PSML) is the mechanistic link between splanchnic ischemia reperfusion (IR) and remote organ injury. We hypothesize that an unbiased inspection of the proteome of PSML will reveal previously unrecognized aberrations in systems biology provoked by hemorrhage-induced mesenteric IR injury in vivo.

METHODS

Shock was induced in male Sprague-Dawley rats by controlled hemorrhage, and the mesenteric duct was cannulated for lymph collection. Preshock and postshock lymph were collected for differential in-gel electrophoresis (DIGE)-based proteomics. Proteins that increased or decreased in relative concentration > or =1.5-fold were selected for trypsin digestion and analysis by mass spectrometry (MS).

RESULTS

Evidence of tissue injury was detected by an increase in cell/tissue proteins in PSML. Components of coagulation were depleted, whereas products of hemolysis were increased. Haptoglobin was decreased, which supports an early postshock hemolytic process. Interestingly, several protective protease inhibitors were decreased in PSML. The unexpected findings were an increase in alpha-enolase (a key glycolitic enzyme and cell-surface plasminogen binding receptor, +2.4-fold change) and increased major urinary protein (MUP, a sex-specific lipid-binding protein, +17.1-fold change) in PSML.

CONCLUSION

A proteomic evaluation of PSML revealed evidence of several shock-associated processes: protein release from tissue injury, depletion of coagulation factors and evidence of hemolysis, depletion of protective protease inhibitors, and an increase in abundance of lipid carriers. These results suggest that constitutive changes in the proteome of PSML may provide novel insights into the complex pathophysiology of postshock systems biology.

Role of pro-/anti-inflammatory cytokines and their correlation with established risk factors in South Indians with coronary artery disease

Cytokines are responsible for the modulation of immunological and inflammatory processes and play a significant role in the pathogenesis of coronary artery disease. We estimated the levels of pro-/anti-inflammatory cytokines in South Indian patients with coronary artery disease. The study population comprised of groups 1-3: 100 patients each with acute myocardial infarction, unstable angina, and stable angina, respectively, and group 4 (100 healthy controls). Cytokine levels (interleukin-6, interleukin-8, interleukin-10, and tumor necrosis factor-alpha) were estimated by enzyme-linked immunosorbent assay (ELISA). Interleukin-6, interleukin-8, and tumor necrosis factor-alpha levels were significantly higher in patients from groups 1 and 2, than in group 3 and controls. Acute myocardial infarction patients exhibited higher serum levels of interleukin-10 compared with other groups and control subjects. Patients with unstable angina had significantly lower interleukin-10 concentrations than those with stable angina. The ratios of pro-/anti-inflammatory cytokines in all the study groups increased significantly when patients with unstable angina were compared to other groups. In patients with acute myocardial infarction, interleukin-10 and tumor necrosis factor-alpha levels showed significant correlation with established risk factors such as body mass index, blood pressure, and lipid levels. Acute myocardial infarction patients show elevation in proinflammatory and anti-inflammatory cytokines, while unstable angina is associated with low levels of serum interleukin-10. Higher levels of anti-inflammatory cytokine interleukin-10 may be needed to provide protection in unstable angina. These cytokines are markers of coronary artery disease and may be used for the identification of high-risk patients with unstable angina/acute myocardial infarction.

Absolute quantification of cardiac troponin T by means of liquid chromatography/triple quadrupole tandem mass spectrometry

A liquid chromatography/tandem mass spectrometric method for absolute quantification of cardiac troponin T (cTnT) in mouse heart tissue is presented. Even in such a complex biological sample, the multiple reaction monitoring acquisition mode allowed the selective and sensitive determination of a specific peptide, obtained by cTnT enzymatic digestion. The concentration of this cTnT-specific peptide was considered as a representation of the concentration of its parent protein. Quantification was carried out by means of the matrix-matched calibration curve, constructed by adding the synthetic standard of the target peptide and another synthetic structurally analogous peptide as internal standard. Method identification limit and method quantification limit were estimated as 60 and 110 ng of cTnT per mg of total extracted proteins, respectively. The developed label-free approach has been applied for the absolute quantitation of cTnT because of its diagnostic and prognostic value as cardiac disease marker. However, the method could be of general application, since it requires only the synthesis of two suitable peptides, a protein tryptic cleavage product and an internal standard.