[Degradation of proteins by ubiquitin proteasome pathway].

All intracellular and some extracellular proteins are continually degraded and replaced by synthesis of new proteins. Both these processes need to stay in equilibrium since their balance may lead to emergence of diseases. Cells contain many proteolytic systems that ensure highly specific and controlled degradation of proteins.

[Comparative plasma proteomic analysis of patients with multiple myeloma treated with bortezomib-based regimens].

Backgrounds: Recently, the term biomarker has become, especially in connection with the term clinical proteomics, one of the most frequent terms in the field of biomedical research. The aim of this work was to select an appropriate pre-fractionation method of blood plasma prior to a subsequent proteomic analysis of low-abundant fraction of proteins by two dimensional gel electrophoresis (2-DE) and mass spectrometry to improve the resolution of 2-DE maps and protein identification.

Materials And Methods: First, we compared two prefractionation methods (MARS versus ProteoMiner) preceding 2-DE analysis using 10 blood plasma samples.

Impact of nestin analysis in multiple myeloma.

Nestin, a marker of multipotent precursor cells, is an important dynamic structure; its polymerization/depolymerization influences intracellular signaling and participates in key cell processes such as proliferation, migration and cell survival. It is presumed that nestin plays a central role in carcinogenesis. It is suggested that nestin might be a suitable diagnostic and prognostic indicator of malignancy and a potential marker of cancer stem cells.

Sample processing and methodological pitfalls in multiple myeloma research.

In this paper, initial processing of biological material, cell separation algorithms and other procedures are discussed. For samples with initial infiltration of plasma cells > 5%, CD138 MicroBeads and Auto-Magnetic-Activated Cell Sorting program are used. Fluorescence-Activated Cell Sorting is used exclusively for cell populations with low-abundance; these samples are detected using fluorescently labeled antibodies only.

Proteomic analysis in multiple myeloma research.

Multiple myeloma (MM) is an incurable plasma cell (PC) malignancy characterized by the accumulation of monoclonal PCs in the bone marrow. For deeper understanding of the molecular mechanisms involved in the development of this disease, the influence of microenvironment, or the prediction of response of tumor PCs to anti-MM treatment, it is possible to use modern technologies for genomic and proteomic analyses. Due to progress in instrumentation, one of the main tools of proteomic analysis is mass spectrometry in combination with chosen separation techniques.

Optimization of immunomagnetic selection of myeloma cells from bone marrow using magnetic activated cell sorting.

Plasma cells (PCs) enrichment from bone marrow samples of multiple myeloma (MM) patients is frequently performed by immunomagnetic separation (magnetic activated cell sorting, MACS) using anti-CD138 MicroBeads. The aim of our work was to find optimal strategy for immunomagnetic separation of PCs and determine optimal algorithm of separation techniques for samples with various percentage of neoplastic cells. From 2007 to 2008, selection of PCs using separation programs Possels and Posseld(2) was carried out on 234 bone marrow samples obtained from 208 MM patients.

Cardiac remodeling and MMPs on the model of chronic daunorubicin-induced cardiomyopathy in rabbits.

The matrix metalloproteinases (MMPs) play a key role during cardiac remodeling. The aim of the study was to investigate the changes in collagenous proteins and MMPs in the model of non-ischemic, anthracycline-induced chronic cardiomyopathy in rabbits using both biochemical and histological approaches. The study was carried out in three groups of Chinchilla male rabbits: 1) daunorubicin (3 mg/kg, once weekly for 10 weeks), 2) control (saline in the same schedule), 3) daunorubicin with the cardioprotectant dexrazoxane (60 mg/kg, before each daunorubicin).

Regression of left ventricular hypertrophy and aortic remodelling in NO-deficient hypertensive rats: effect of L-arginine and spironolactone.

Aim: We investigated, whether the substrate for nitric oxide (NO) formation -L-arginine - and the aldosterone receptor antagonist - spironolactone - are able to reverse alterations of the left ventricle (LV) and aorta in N(omega)-nitro-L-arginine methyl ester (L-NAME)-induced hypertension.

Methods: Six groups of male adult Wistar rats were investigated: controls after 4 and 7 weeks of experiment, rats treated with L-NAME for 4 weeks and three recovery groups: spontaneous-reversion (4 weeks L-NAME + 3 weeks placebo), spironolactone-induced reversion (4 weeks L-NAME + 3 weeks spironolactone) and L-arginine-induced reversion (4 weeks L-NAME+ 3 weeks L-arginine). Blood pressure was measured by tail-cuff plethysmography.

Pyridoxal isonicotinoyl hydrazone (PIH) and its analogs as protectants against anthracycline-induced cardiotoxicity.

The risk of cardiotoxicity is the main drawback of anthracycline antibiotics. However, these drugs remain among the most effective and frequently used anti cancer drugs. In this study we aimed to assess the cardioprotective effects of aroylhydrazone iron (FE) chelators: pyridoxal isonicotinoyl hydrazone (PIH) and its two analogs: salicyladehyde isonicotinoyl hydrazone (SIH) and pyridoxal o-chlorbenzoyl hydrazone (o-108).

A pilot study of matrix metalloproteinases on the model of daunorubicin-induced cardiomyopathy in rabbits.

Matrix metalloproteinases (MMPs), activated by oxidative stress, play a key role during cardiac remodeling. In the present study we aimed to assess the role of MMPs in experimental cardiomyopathy induced by repeated 10-week administration of daunorubicin (3 mg/kg i.v.

Spontaneous, L-arginine-induced and spironolactone-induced regression of protein remodeling of the left ventricle in L-NAME-induced hypertension.

N(G)-nitro-L-arginine-methyl ester (L-NAME)-induced hypertension is associated with protein remodeling of the left ventricle. The aim of the study was to show, whether aldosterone receptor blocker spironolactone and precursor of NO-production L-arginine were able to reverse the protein rebuilding of the left ventricle. Six groups of male Wistar rats were investigated: control 4 (4 weeks placebo), L-NAME (4 weeks L-NAME), spontaneous-regression (4 weeks L-NAME + 3 weeks placebo), spironolactone-regression (4 weeks L-NAME + 3 weeks spironolactone), L-arginine-regression (4 weeks L-NAME + 3 weeks arginine), control 7 (7 weeks placebo).

In vitro and in vivo examination of cardiac troponins as biochemical markers of drug-induced cardiotoxicity.

Cardiac troponin T (cTnT) and troponin I (cTnI) are becoming acknowledged as useful biochemical markers of drug-induced cardiotoxicity. In this study we examined the release kinetics of cTnT and cTnI using an in vitro model of isolated rat neonatal ventricular cardiomyocytes (NVCM, 72h treatment with 0.1-3microM of daunorubicin) and compared it with data from a rabbit model of chronic anthracycline-induced cardiomyopathy in vivo (3mg/kg of daunorubicin weekly, 10 weeks).

Evaluation of ECG time intervals in a rabbit model of anthracycline-induced cardiomyopathy: a useful tool for assessment of cardioprotective agents.

The aim of this study was to analyze the ECG time intervals in the course of the development of chronic anthracycline cardiomyopathy in rabbits. Furthermore, this approach was employed to study the effects of a model cardioprotective drug (dexrazoxane) and two novel iron chelating compounds--salicylaldehyde isonicotinoyl hydrazone (SIH) and pyridoxal 2-chlorobenzoyl hydrazone (o-108). Repeated daunorubicin administration induced a significant and progressive prolongation of the QRS complex commencing with the eighth week of administration.

Iron chelation-afforded cardioprotection against chronic anthracycline cardiotoxicity: a study of salicylaldehyde isonicotinoyl hydrazone (SIH).

Pyridoxal-derived aroylhydrazone iron chelators have been previously shown as effective cardioprotectants against chronic anthracycline cardiotoxicity. In this study we focused on a novel salicylaldehyde analogue (salicylaldehyde isonicotinoyl hydrazone, SIH), which has been recently demonstrated to possess marked and dose-dependent protective effects against oxidative injury of cardiomyocytes. Therefore, in the present study the cardioprotective potential of SIH against daunorubicin (DAU) cardiotoxicity was assessed in vitro (isolated rat ventricular cardiomyocytes; DAU 10 microM, 48 h exposure) as well as in vivo (chronic DAU-induced cardiomyopathy in rabbits; DAU 3mg/kg, i.

Early detection of anthracycline cardiotoxicity in a rabbit model: left ventricle filling pattern versus troponin T determination.

Anthracycline cardiotoxicity represents a serious risk of anticancer chemotherapy. The aim of the present pilot study was to compare the potential of both the left ventricular (LV) filling pattern evaluation and cardiac troponin T (cTnT) plasma levels determination for the early detection of daunorubicin-induced cardiotoxicity in rabbits. The echocardiographic measurements of transmitral LV inflow as well as cTnT determinations were performed weekly for 10 weeks in daunorubicin (3 mg/kg weekly) and control groups (n=5, each).

Cardioprotective effects of a novel iron chelator, pyridoxal 2-chlorobenzoyl hydrazone, in the rabbit model of daunorubicin-induced cardiotoxicity.

Iron chelation is the only pharmacological intervention against anthracycline cardiotoxicity whose effectiveness has been well documented both experimentally and clinically. In this study, we aimed to assess whether pyridoxal 2-chlorobenzoyl hydrazone (o-108, a strong iron chelator) can provide effective protection against daunorubicin (DAU)-induced chronic cardiotoxicity in rabbits. First, using the HL-60 leukemic cell line, it was shown that o-108 has no potential to blunt the antiproliferative efficacy of DAU.

Myocardial regulatory proteins and heart failure.

Cardiac troponin T (cTnT) and cardiac troponin I (cTnI) are considered to be the most specific and sensitive biochemical markers of myocardial damage. Troponins have been studied in a wide range of clinical settings, including heart failure; however, there are few data on the role of regulatory proteins in the pathogenesis of heart failure, although a few interesting hypotheses have been proposed. A considerable body of evidence favours the view that alteration of the myocardial thin filament is the primary event leading to defective contractility of the failing myocardium, while the changes in Ca(2+) handling are a compensatory response.

Troponin as a marker of myocardiac damage in drug-induced cardiotoxicity.

Cardiac troponins T and I (cTnT and cTnI) are becoming the serum biomarkers of choice for monitoring potential drug-induced myocardial injury in both clinical and preclinical studies. The utility of cardiac troponins has been mainly demonstrated following the administration of antineoplastic drugs and beta-sympathomimetics, although the routine use of these markers in the monitoring in patients who received anthracyclines therapy is far from settled. Unlike the previous markers, which suffered from numerous shortages, the main advantages of cardiac troponins are their high specificity and sensitivity, wide diagnostic window and the possibility to use commercially available assays in clinical settings as well as in a broad range of laboratory animals.