Analysis of Multiple Risk Factors for Seronegative Rate of Anti-Tick-Borne Encephalitis Virus Immunization in Human Serum.

Background and objectives: Tick-borne encephalitis virus (TBEV) infections have been the cause of threatening outbreaks for many years. Apart from several physical and chemical methods to prevent tick bites, active vaccination of people highly exposed to infection is still the most important strategy of prevention. However, in some subjects, the lack of or low response to TBEV antigens is observed. The aim of the current study was to assess the prevalence of seronegative rate for anti-TBEV antibodies and the risk factors for waning immunity. Materials and Methods: 2315 at least primary vaccinated subjects from the high risk group for TBEV infections participated in this study. A commercial enzyme-linked immunosorbent assay (ELISA) test was used for the assessment of anti-TBEV IgG serum level. Results: Data showed that 86.2% of subjects who underwent vaccination were positive for anti-TBEV antibodies within 5 years. As much as 13.8% of subjects that underwent primary or primary and booster vaccination were barely protected after vaccination. Women and subjects under 60 years underwent more effective protection but sex and older age was not a risk factor for being a subject of waning immunity. A logistic regression showed that both a longer time since the vaccination and a lower number of booster doses constantly increased the chance of lost anti-TBEV antibodies. Conclusions: This study demonstrates that the vaccination schedule should be reevaluated. The extension of the interval of booster immunization is risky and all subjects should be surrounded by care consisting of more frequent monitoring of serum antibodies by personalized schedule to adjust the frequency of subsequent doses of booster vaccination.

Cardioprotective effect of MMP-2-inhibitor-NO-donor hybrid against ischaemia/reperfusion injury.

Hypoxic injury of cardiovascular system is one of the most frequent complications following ischaemia. Heart injury arises from increased degradation of contractile proteins, such as myosin light chains (MLCs) and troponin I by matrix metalloproteinase 2 (MMP-2). The aim of the current research was to study the effects of 5-phenyloxyphenyl-5-aminoalkyl nitrate barbiturate (MMP-2-inhibitor-NO-donor hybrid) on hearts subjected to ischaemia/reperfusion (I/R) injury. Primary human cardiac myocytes and Wistar rat hearts perfused using Langendorff method have been used. Human cardiomyocytes or rat hearts were subjected to I/R in the presence or absence of tested hybrid. Haemodynamic parameters of heart function, markers of I/R injury, gene and protein expression of MMP-2, MMP-9, inducible form of NOS (iNOS), asymmetric dimethylarginine (ADMA), as well as MMP-2 activity were measured. Mechanical heart function, coronary flow (CF) and heart rate (HR) were decreased in hearts subjected to I/R Treatment of hearts with the hybrid (1-10 µmol/L) resulted in a concentration-dependent recovery of mechanical function, improved CF and HR. This improvement was associated with decreased tissue injury and reduction of synthesis and activity of MMP-2. Decreased activity of intracellular MMP-2 led to reduced degradation of MLC and improved myocyte contractility in a concentration-dependent manner. An infusion of a MMP-2-inhibitor-NO-donor hybrid into I/R hearts decreased the expression of iNOS and reduced the levels of ADMA. Thus, 5-phenyloxyphenyl-5-aminoalkyl nitrate barbiturate protects heart from I/R injury.

Co-infection with human polyomavirus BK enhances gene expression and replication of human adenovirus.

Immunocompromised patients are susceptible to multiple viral infections. Relevant interactions between co-infecting viruses might result from viral regulatory genes which trans-activate or repress the expression of host cell genes as well as the genes of any co-infecting virus. The aim of the current study was to show that the replication of human adenovirus 5 is enhanced by co-infection with BK polyomavirus and is associated with increased expression of proteins including early region 4 open reading frame 1 and both the large tumor antigen and small tumor antigen. Clinical samples of whole blood and urine from 156 hematopoietic stem cell transplant recipients were tested. We also inoculated adenocarcinomic human alveolar basal epithelial cells with both human adenovirus 5 and BK polyomavirus to evaluate if co-infection of viruses affected their replication. Data showed that adenovirus load was significantly higher in the plasma (mean 7.5 x 103 ± 8.5 x 102 copies/ml) and urine (mean 1.9 x 103 ± 8.0 x 102 copies/ml) of samples from patients with co-infections, in comparison to samples from patients with isolated adenovirus infection. In vitro co-infection led to an increased (8.6 times) expression of the adenovirus early region 4 open reading frame gene 48 hours post-inoculation. The expression of the early region 4 open reading frame gene positively correlated with the expression of BK polyomavirus large tumor antigen (r = 0.90, p < 0.0001) and small tumor antigen (r = 0.83, p < 0.001) genes. The enhanced expression of the early region 4 open reading frame gene due to co-infection with BK polyomavirus was associated with enhanced adenovirus, but not BK polyomavirus, replication. The current study provides evidence that co-infection of adenovirus and BK polyomavirus contributes to enhanced adenovirus replication. Data obtained from this study may have significant importance in the clinical setting.

An efficient method for isolation of representative and contamination-free population of blood platelets for proteomic studies.

To date, there has been no ideal method for blood platelet isolation which allows one to obtain a preparation devoid of contaminations, reflecting the activation status and morphological features of circulating platelets. To address these requirements, we have developed a method which combines the continuous density gradient centrifugation with washing from PGI2-supplemented platelet-rich plasma (PRP). We have assessed the degree of erythrocyte and leukocyte contamination, recovery of platelets, morphological features, activation status, and reactivity of isolated platelets. Using our protocol, we were able to get a preparation free from contaminations, representing well the platelet population prior to the isolation in terms of size and activity. Besides this, we have obtained approximately 2 times more platelets from the same volume of blood compared to the most widely used method. From 10 ml of whole citrated blood we were able to get on average 2.7 mg of platelet-derived protein. The method of platelet isolation presented in this paper can be successfully applied to tests requiring very pure platelets, reflecting the circulating platelet state, from a small volume of blood.

Subthreshold nitric oxide synthase inhibition improves synergistic effects of subthreshold MMP-2/MLCK-mediated cardiomyocyte protection from hypoxic injury.

Injury of myocardium during ischaemia/reperfusion (I/R) is a complex and multifactorial process involving uncontrolled protein phosphorylation, nitration/nitrosylation by increased production of nitric oxide and accelerated contractile protein degradation by matrix metalloproteinase-2 (MMP-2). It has been shown that simultaneous inhibition of MMP-2 with doxycycline (Doxy) and myosin light chain kinase (MLCK) with ML-7 at subthreshold concentrations protects the heart from contractile dysfunction triggered by I/R in a synergistic manner. In this study, we showed that additional co-administration of nitric oxide synthase (NOS) inhibitor (1400W or L-NAME) in subthreshold concentrations improves this synergistic protection in the model of hypoxia-reoxygenation (H-R)-induced contractile dysfunction of cardiomyocytes. Isolated cardiomyocytes were subjected to 3 min. of hypoxia and 20 min. of reoxygenation in the presence or absence of the inhibitor cocktails. Contractility of cardiomyocytes was expressed as myocyte peak shortening. Inhibition of MMP-2 by Doxy (25-100 µM), MLCK by ML-7 (0.5-5 µM) and NOS by L-NAME (25-100 µM) or 1400W (25-100 µM) protected myocyte contractility after H-R in a concentration-dependent manner. Inhibition of these activities resulted in full recovery of cardiomyocyte contractility after H-R at the level of highest single-drug concentration. The combination of subthreshold concentrations of NOS, MMP-2 and MLCK inhibitors fully protected cardiomyocyte contractility and MLC1 from degradation by MMP-2. The observed protection with addition of L-NAME or 1400W was better than previously reported combination of ML-7 and Doxy. The results of this study suggest that addition of NOS inhibitor to the mixture of inhibitors is better strategy for protecting cardiomyocyte contractility.

An infection of human adenovirus 31 affects the differentiation of preadipocytes into fat cells, its metabolic profile and fat accumulation.

The primary issue undertaken in this study was to test the hypothesis that preadipocytes would have intrinsically elevated propensity to differentiate into mature adipocytes due to HAdV31 infection. To prove that, the metabolic and molecular mechanisms responsible for HAdV31-induced adipogenesis were examined. 3T3L1 cells (mouse embryonic fibroblast, adipose like cell line) were used as a surrogate model to analyze an increased proliferation, differentiation, and maturation of preadipocytes infected with human adenovirus. An expression of E4orf1, C/EBP-ß, PPAR-γ, GAPDH, aP2, LEP, and fatty acid synthase genes, intracellular lipid accumulation as well as cytokine release from the fat cells were assessed. Data showed that HAdV31 increased an expression of C/EBP-ß and PPAR-γ genes leading to an enhanced differentiation of preadipocytes into fat cells. Besides, overexpression of GAPDH and fatty acid synthase, and decreased expression of leptin caused an increased accumulation of intracellular lipids. Secretion of TNF-α and IL-6 from HAdV31-infected cells was strongly decreased, leading to unlimited virus replication. The results obtained from this study provided the evidences that HAdV31, likewise previously documented HAdV36, is a subsequent human adenovirus affecting the differentiation and lipid accumulation of 3T3L1 cells.

Adenovirus type 9 enhances differentiation and decreases cytokine release from preadipocytes.

The hypothesis was that preadipocytes would have intrinsically elevated propensity to differentiate into mature adipocytes due to AdV9 infection. To test this hypothesis, the metabolic and molecular mechanisms responsible for AdV9-induced adipogenesis were examined. An association between anti-AdV9 antibodies and human obesity was also identified. 3T3L1 cells were used as a surrogate model to analyze the preadipocyte proliferation, differentiation, and maturation. An expression of E4orf1, C/EBP-ß, PPAR-γ, GAPDH, aP2, LEP and fatty acid synthase gene, intracellular lipid accumulation and cytokine release were assessed. The presence of anti-AdV antibodies, serum lipids, plasma leptin, and CRP was evaluated in 204 obese and non-obese patients. AdV9-infected cells accumulated more intracellular lipids in comparison to uninfected controls. AdV9 enhanced an expression of C/EBP-ß and PPAR-γ leading to an increased differentiation of preadipocytes. Overexpression of aP2 and fatty acid synthase, and decreased expression of leptin confirmed an increased accumulation of intracellular lipids due to AdV infection. Secretion of TNF-α and IL-6 from AdV9-inoculated cells was decreased strongly. About 24.5% of prevalence of anti-AdV9 antibodies was reported in the study group. AdV9-infected subjects presented higher body weights, BMIs, WHR, and central obesity. The presence of anti-AdV9 antibodies was associated with changes in serum lipids level but neither elevated CRP nor decreased leptin levels were related to obesity due to AdV infection. Data obtained from this study provide the evidences that AdV9 is a second adenovirus, which has an influence on differentiation and lipid accumulation of 3T3L1 cells.

Lack of adenovirus DNA in mediastinal adipose tissue of obese/overweight adults with cardiovascular disorders?

Mediastinal adipose tissue can be found on the anterior surface of pericardial sac below the remnants of the thymus. On the basis of previous studies describing adenoviruses (AdVs) as a causative factor of obesity, the causative relation between the presence of AdVs and an increased accumulation of mediastinal adipose tissue was studied. The study included 25 obese/overweight subjects with cardiac disorders. Specimens from fat deposits from the anterior mediastinum were collected during cardiac surgery procedures. Afterwards, PCR was used to detect AdV-DNA. No AdV-DNA could be detected in adipose tissue. An association between an excessive accumulation of mediastinal adipose tissue and an AdV-infection in the development of accompanying cardiac disorders was excluded.

CD117 (c-kit) expression on CD34+ cells participates in the cytogenetic response to imatinib in patients with chronic myeloid leukemia in the first chronic phase.

BACKGROUND: Chronic myeloid leukemia (CML) biology seemed to be perfectly explored especially at the beginning of the tyrosine kinase inhibitors era. Later years with imatinib and second-generation tyrosine kinase inhibitors showed a variety of resistance mechanisms and it became obvious that the bcr-abl chimeric gene is not the only enemy to fight. Some studies assumed the decreased rate of programmed cell death (apoptotic) to be the primary mechanism by which BCR-ABL affects expansion of the leukemic clone in CML. Therefore, the aim of this study was to investigate the role of c-kit inhibition in treatment response. METHODS: Cytogenetic analysis, real-time quantitative reverse-transcriptase polymerase chain reaction, flow-cytometric analysis and imatinib serum level quantification were applied. RESULTS: The percentage of CD34+ cells expressing c-kit (CD117) isolated from bone marrow samples of 54 CML patients treated with standard-dose imatinib was significantly lower among imatinib responders. The fraction of apoptotic CD34+CD117+ cells in this patient group was significantly higher than in nonresponders. CONCLUSION: To achieve optimal treatment response in CML patients, the elimination of CD34+CD117+ may be necessary through an apoptotic pathway.

[Diagnostic utility of RHD-gene detection in maternal plasma in the prophylaxis of feto-maternal Rh-incompatibility]. / Diagnostyczna przydatnosc detekcji genu RHD w osoczu ciezarnych w profilaktyce konfliktu matczyno-plodowego na tle antygenu D z ukladu Rh.

OBJECTIVES: The aim of the study was analytical validation of prenatal noninvasive fetal RHD detection in maternal plasma and the preliminary assessment of its clinical utility Introduction of this noninvasive test into routine diagnostic use is important for more rational and safe immunoprophylaxis. MATERIAL AND METHODS: RHD gene was detected using real-time PCR. Primers and probes complementary to sequence on exons 7 and 10 were chosen. Samples with RHD-negative results were examined with additional tests to confirm the proper isolation of cell-free fetal DNA (cffDNA). For male fetuses, the presence of fetal DNA was confirmed by detection of the male genetic marker (SRY gene) using Quantifiler Duo kit. In the case of SRY-negative result we used mini SGM test, which is based on the detection of short-tandem repeat polymorphism differences between maternal and fetal DNA. RESULTS: Diagnostic accuracy of RHD test was 96.82%, while diagnostic value of SRY determination was lower (87.50%). Mini SGM test was able to confirm the presence of fetal DNA in 77% of the cases. CONCLUSIONS: Effectiveness of the proposed procedure of prenatal noninvasive RHD determination and cffDNA confirmation is high, on condition proper control samples and suitable verifying tests are used.

Proteomic analysis of right and left cardiac ventricles under aerobic conditions and after ischemia/reperfusion.

Ischemia/reperfusion (I/R) injury is a major consequence of a cardiovascular intervention. The study of changes of the left and right ventricle proteomes from hearts subjected to I/R may be a key to revealing the pathological mechanisms underlying I/R-induced heart contractile dysfunction. Isolated rat hearts were perfused under aerobic conditions or subjected to 25 min global ischemia and 30 min reperfusion. At the end of perfusion, right and left ventricular homogenates were analyzed by 2DE. Contractile function and coronary flow were significantly reduced by I/R. 2DE followed by mass spectrometry identified ten protein spots whose levels were significantly different between aerobic left and right ventricles, eight protein spots whose levels were different between aerobic and I/R left ventricle, ten protein spots whose levels were different between aerobic and I/R right ventricle ten protein spots whose levels were different between the I/R groups. Among these protein spots were ATP synthase beta subunit, myosin light chain 2, myosin heavy chain fragments, peroxiredoxin-2, and heat shock proteins, previously associated with cardiovascular disease. These results reveal differences between proteomes of left and right ventricle both under aerobic conditions and in response to I/R that contribute to a better understanding of I/R injury.

On the origin of matrix metalloproteinase-2 and -9 in blood platelets.

To date, several matrix metalloproteinases (MMPs) have been identified in human platelets. In most research studies, the platelets are obtained using the isolation method from plasma by centrifugation and washing. The metalloproteinase content in the platelets can be affected by the isolation technique and the leukocyte contamination. In this work, we studied the influence of the isolation method on the detection of platelet MMPs and explore the expression of these enzymes in megakaryoblastic MEG-01 cells. We investigated the expression of mRNAs encoding for MMP-2 and -9 in platelets and MEG-01 cells. Using gelatin zymography and western blotting, we examined the expression and release of MMP-2 and 9 by platelets and MEG-01 cells and checked whether the amount of the released MMPs depends on the volume of tested platelet and leukocyte contamination. To investigate the MMP-2 expression profile, we used zymography and flow cytometry. Platelets, in contrast to the MEG-01 cells, neither contain mRNA for MMP-2 nor -9. The platelets contain pro-MMP-2 and release it during the activation. The population of uncontaminated (leukocytes<0.02%) platelets contained no MMP-9 or the active form of MMP-2. We have observed that the activity of MMP-2 in platelet lysate is proportional to their mean volume and that the MMP-2 activity may not be detected if very small platelets are examined. We conclude that the detection of gelatinases in platelets depends on platelet isolation techniques and the degree of leukocyte contamination.

Improved real-time PCR assay for detection and quantification of all 54 known types of human adenoviruses in clinical samples.

BACKGROUND: Detection and quantification of adenoviruses (AdVs) causing life-threatening complications are important abilities in recognition of infection and management of immunocompromised patients. Due to the rapid increase in the number of known AdV types, most commercial tests for detection and identification of AdVs are outdated. MATERIAL/METHODS: We designed an improved, easier and faster real-time quantitative polymerase chain reaction (RQ-PCR) method for detection and quantification of 54 types of human AdVs. A wide validation effort was undertaken to ensure confidence in highly sensitive and specific detection of AdVs in compromised patients. The validation process included evaluation of the method's suitability and reliability for use in routine diagnostics. RESULTS: Due to high sensitivity (9.2×10² copies/ml) and broad dynamic range (7 log) we are able to detect specific viral DNA in large amounts of cell-free body fluids. The new assay is characterized by high precision and low variation within and between individual virus tests (CV=0.036%, CV=1.29%), low bias error (4%) and no cross-reactivity with other pathogens. CONCLUSIONS: The implementation of this new assay in clinical and laboratory practice provides a rapid, reliable and less laborious method for detection and monitoring of AdV replication in immunocompromised patients. Moreover, it offers the ability to distinguish between active and latent infection and assess treatment efficiency.

Matrix Metalloproteinase-2 Inhibition in Acute Ischemia-Reperfusion Heart Injury-Cardioprotective Properties of Carvedilol.

Matrix metalloproteinase 2 (MMP-2) is activated in hearts upon ischemia-reperfusion (IR) injury and cleaves sarcomeric proteins. It was shown that carvedilol and nebivolol reduced the activity of different MMPs. Hence, we hypothesized that they could reduce MMPs activation in myocytes, and therefore, protect against cardiac contractile dysfunction related with IR injury. Isolated rat hearts were subjected to either control aerobic perfusion or IR injury: 25 min of aerobic perfusion, followed by 20 min global, no-flow ischemia, and reperfusion for 30 min. The effects of carvedilol, nebivolol, or metoprolol were evaluated in hearts subjected to IR injury. Cardiac mechanical function and MMP-2 activity in the heart homogenates and coronary effluent were assessed along with troponin I content in the former. Only carvedilol improved the recovery of mechanical function at the end of reperfusion compared to IR injury hearts. IR injury induced the activation and release of MMP-2 into the coronary effluent during reperfusion. MMP-2 activity in the coronary effluent increased in the IR injury group and this was prevented by carvedilol. Troponin I levels decreased by 73% in IR hearts and this was abolished by carvedilol. Conclusions: These data suggest that the cardioprotective effect of carvedilol in myocardial IR injury may be mediated by inhibiting MMP-2 activation.

Effect of the Rho kinase inhibitor Y-27632 on the proteome of hearts with ischemia-reperfusion injury.

Growing attention has been given to the role of the Rho kinase pathway in the development of heart disease and ischemia/reperfusion (I/R) injury. Y-27632 is a Rho kinase inhibitor demonstrated to protect against I/R injury, but the exact mechanism by which it does so remains to be elucidated. The goal of this project was to determine new targets by which Y-27632 can protect the heart against I/R injury. Isolated rat hearts were perfused under aerobic conditions or subjected to I/R in the presence or absence of Y-27632. Administration of Y-27632 (1 µM) before ischemia and during the first 10 min of reperfusion resulted in complete recovery of cardiac function. 2-D electrophoresis followed by MS identified four proteins whose levels were affected by Y-27632 treatment. Lactate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase were significantly increased in the Y-27632 treated group, while creatine kinase was normalized to control levels. In addition, we found increased level of two different molecular fragments of ATP synthase, which were normalized by Y-27632. This increase suggests that during ischemia ATP synthase is subjected to degradation. The changes in metabolic enzymes' levels and their regulation by Y-27632 suggest that the cardioprotective effect of Y-27632 involves increased energy production.

PCR diagnostics and monitoring of adenoviral infections in hematopoietic stem cell transplantation recipients.

After stem cell transplantation, human patients are prone to life-threatening opportunistic infections with a plethora of microorganisms. We report a retrospective study on 116 patients (98 children, 18 adults) who were transplanted in a pediatric bone marrow transplantation unit. Blood, urine and stool samples were collected and monitored for adenovirus (AdV) DNA using polymerase chain reaction (PCR) and real-time PCR (RT-PCR) on a regular basis. AdV DNA was detected in 52 (44.8%) patients, with mortality reaching 19% in this subgroup. Variables associated with adenovirus infection were transplantations from matched unrelated donors and older age of the recipient. An increased seasonal occurrence of adenoviral infections was observed in autumn and winter. Analysis of immune reconstitution showed a higher incidence of AdV infections during periods of low T-lymphocyte count. This study also showed a strong interaction between co-infections of AdV and BK polyomavirus in patients undergoing hematopoietic stem cell transplantations.

A drug cocktail for protecting against ischemia-reperfusion injury.

Ischemia followed by reperfusion (I/R) of cardiomyocytes causes release of a large amount of inducible nitric oxide (NO) synthase (iNOS) followed by an increase of asymmetric dimethylarginine (ADMA). ADMA disrupts NO signaling by switching of the NOS activity from NO to the production of reactive oxygen species (ROS). Previously, we have shown that pretreatment of the hearts by co-administration of sub-threshold concentrations of doxycycline, a matrix metalloproteinase (MMPs) inhibitor, ML-7 an inhibitor of myosin light-chain kinase (MLCK) and L-NAME a non-selective NOS inhibitor protects the heart against I/R injury. In this study, we replaced the L-NAME with 1400W (selective inhibitor of iNOS) in the drug cocktail that was Langendorff-perfused into the hearts of Wistar rats before (prevention) or after (treatment) the induction of I/R. This pre-treatment resulted in full protection of contractility, decreased production of iNOS and ADMA and normalized the bioavailability of NO in the I/R hearts. Thus, the formulated drug cocktail protects the heart from I/R injury.

L-NAME improves doxycycline and ML-7 cardioprotection from oxidative stress.

Matrix metalloproteinase-2 (MMP-2) mediated degradation of myosin light chain 1 (MLC1) and troponin I (TnI) contributes to myocardial ischemia/reperfusion (I/R) injury. Modifications of MLC1 triggered by oxidative stress are mediated by myosin light chain kinase (MLCK), nitric oxide synthase (NOS), and MMP-2. Previous studies have shown that inhibiting both MLCK and MMP-2 protects against I/R injury. Here, we hypothesized that the addition of NOS inhibitor (L-NAME) at subprotective concentration to the mixture of subprotective concentrations of ML-7 and doxycycline (Doxy), will increase a synergistic cardioprotection of Doxy and ML-7 during I/R. Isolated rat hearts were subjected to global ischemia without or with administration of the mixture of inhibitors. Markers of I/R injury were measured in hearts and coronary effluents. Addition of L-NAME to the mixture of Doxy and ML-7 led to full recovery of heart contractility in comparison to combination of Doxy and ML-7. Improved heart contractility was associated with reduced degradation of TnI and MLC1. The combined administration of NOS, MMP-2 and MLCK inhibitors provides a novel strategy to protect heart from I/R injury.

Low frequency electromagnetic field decreases ischemia-reperfusion injury of human cardiomyocytes and supports their metabolic function.

Electromagnetic field at extremely low frequencies plays a significant role in the physiological function of human tissues and systems. It is shown that electromagnetic field inhibits production of reactive oxygen species which are involved in heart injury triggered by oxidative stress. We hypothesize that low frequency electromagnetic field protects function of cardiac cells from ischemia-reperfusion injury. Human cardiac myocytes, endothelial cells, and cardiac fibroblast underwent ischemia-reperfusion conditions in the presence or in the absence of low frequency electromagnetic field. LDH and MMP-2 activities (as markers of cell injury), and cell metabolic activity (by fluorescein diacetate staining) were measured to determine the protective role of low frequency electromagnetic field. Our data showed that short courses of low frequency electromagnetic field protect cardiac cells from cellular damage and preserve their metabolic activity during ischemia-reperfusion. This study demonstrates the possibility to use of low frequency electromagnetic field as strategy for the prevention or therapy of ischemia-reperfusion injury. Impact statement In our study, we showed that LF-EMF may be protective for heart during ischemia-reperfusion (I/R). Following is the short description of the main findings: (a) the response to the I/R injury was different for endothelial cells, fibroblasts, and cardiomyocytes; (b) I/R decreases MMP-2 activity in cardiac myocytes and fibroblasts;

Carvedilol Inhibits Matrix Metalloproteinase-2 Activation in Experimental Autoimmune Myocarditis: Possibilities of Cardioprotective Application.

AIMS: Acute myocarditis is a potentially lethal inflammatory heart disease that frequently precedes the development of dilated cardiomyopathy and subsequent heart failure. At present, there is no effective standardized therapy for acute myocarditis, besides the optimal care of heart failure and arrhythmias in accordance with evidence-based guidelines and specific etiology-driven therapy for infectious myocarditis. Carvedilol has been shown to be cardioprotective by reducing cardiac pro-inflammatory cytokines present in oxidative stress in certain heart diseases. However, effects of carvedilol administration in acute myocarditis with its impact on matrix metalloproteinases' (MMPs) activation have not been elucidated. METHODS AND RESULTS: Carvedilol in 3 doses (2, 10, and 30 mg/kg) was given daily to 3 study groups of rats (n = 8) with experimental autoimmune myocarditis by gastric gavage for 3 weeks. In comparison to untreated rats (n = 8) with induced myocarditis, carvedilol significantly prevented the left ventricle enlargement and/or systolic dysfunction depending on the dose in study groups. Performed zymography showed enhanced MMP-2 activity in untreated rats, while carvedilol administration reduced alterations. This was accompanied by prevention of troponin I release and myofilaments degradation in cardiac muscle tissue. Additionally, severe inflammatory cell infiltration was detected in the nontreated group. Carvedilol in all doses tested, had no impact on severity of inflammation. The severity of inflammation did not differ between study groups and in relation to the untreated group. CONCLUSIONS: The protective effects of carvedilol on heart function observed in the acute phase of experimental autoimmune myocarditis seem to be associated with its ability to decrease MMP-2 activity and subsequently prevent degradation of myofilaments and release of troponin I while not related to suppression of inflammation.