Studying Signaling Pathway Activation in TRAIL-Resistant Macrophage-Like Acute Myeloid Leukemia Cells.

Acute myeloid leukemia (AML) is a malignant neoplasm characterized by extremely low curability and survival. The inflammatory microenvironment and maturation (differentiation) of AML cells induced by it contribute to the evasion of these cells from effectors of antitumor immunity. One of the key molecular effectors of immune surveillance, the cytokine TRAIL, is considered a promising platform for developing selective anticancer drugs. Previously, under in vitro conditions of the inflammatory microenvironment (a three-dimensional high-density culture of THP-1 AML cells), we demonstrated the emergence of differentiated macrophage-like THP-1ad clones resistant to TRAIL-induced death. In the present study, constitutive activation of proinflammatory signaling pathways, associated transcription factors, and increased expression of the anti-apoptotic BIRC3 gene were observed in TRAIL-resistant macrophage-like THP-1ad AML cells. For the first time, a bioinformatic analysis of the transcriptome revealed the main regulator, the IL1B gene, which triggers proinflammatory activation and induces resistance to TRAIL in THP-1ad macrophage-like cells.

Study of Biointegration and Elastic-Strength Properties of a New Xenopericardium-Based Biomaterial for Reconstructive Cardiovascular Surgery.

We analyzed biocompatibility, elastic-strength properties, and biointegration potential of a new biomaterial made of xenopericardium for reconstructive cardiovascular surgery. The biomaterial manufactured by the proposed technology demonstrated high biocompatibility and biointegration potential and its elastic-strength properties 2-4-fold surpassed that of native pericardium. The obtained results attested to good prospects of using the proposed technology for preparing biomaterials for reconstructive cardiovascular surgery.

Chronic Alcohol Intoxication Is Not Accompanied by an Increase in Calpain Proteolytic Activity in Cardiac Muscle of Rats.

Enzymatic activity of Ca2+-dependent calpain proteases as well as the content and gene expression of µ-calpain (activated by micromolar calcium ion concentrations), calpastatin (inhibitor of calpains), and titin (substrate for calpains) were investigated in cardiac muscles of rats subjected to chronic alcoholization for 3 and 6 months. There was no increase in the "heart weight/body weight" parameter indicating development of heart hypertrophy in the alcoholized rats, while a decreasing trend was observed for this parameter in the rats after 6-month modeling of alcoholic cardiomyopathy, which indicated development of atrophic changes in the myocardium. Fluorometric measurements conducted using the Calpain Activity Assay Kit did not reveal any changes in total calpain activity in protein extracts of cardiac muscles of the rats alcoholized for 3 and 6 months. Western blot analysis did not show reliable changes in the contents of µ-calpain and calpastatin, and SDS-PAGE did not reveal any decrease in the titin content in the myocardium of rats after the chronic alcohol intoxication. Autolysis of µ-calpain was also not verified, which could indicate that proteolytic activity of this enzyme in myocardium of chronically alcoholized rats is not enhanced. Using Pro-Q Diamond staining, changes in phosphorylation level of titin were not detected in cardiac muscle of rats after chronic alcoholization during three and six months. A decrease in µ-calpain and calpastatin mRNA content (~1.3-fold, p ≤ 0.01 and ~1.9-fold, p ≤ 0.01, respectively) in the myocardium of rats alcoholized for 3 months and decrease in calpastatin mRNA (~1.4-fold, p ≤ 0.01) in animals alcoholized for 6 months was demonstrated using real-time PCR. These results indicate negative effect of chronic alcohol intoxication on expression of the abovementioned genes.

[Inhibition of NF-kB Activation Decreases Resistance in Acute Myeloid Leukemia Cells to TRAIL-induced Apoptosis in Multicellular Aggregates].

Suppression of resistance in acute myeloid leukemia cells to TRAIL-induced apoptosis in multicellular aggregates, was studied using small molecule inhibitors of the activation of the transcription factor NF-kB - NF-k9 Activation Inhibitor IV and JSH-23 at non-toxic concentrations. NF-kB Activation Inhibitor IV and JSH-23 reduced resistance in the acute myeloid leukemia cells in multicellular aggregates to cytotoxic action of recombinant protein izTRAIL. It is shown that the use of these inhibitors decreased the phosphorylation of the RelA (p65) as a main marker activation of the transcription factor NF-kB. We discuss a possible reason for increasing resistance in acute myeloid leukemia cells to TRAIL-induced apoptosis in multicellular aggregates.

[Study of cytotoxicity of fullerene C60 derivatives].

We investigated the cytotoxicity of the fullerene C60 derivatives. We showed that complexes of C60 fullerene with polyvinylpyrrolidone (m.w. of polyvinylpyrrolidone 10000 and 25000), C60-NO2-proline and C60-alanine had no toxic effect on HEp-2 cells. Sodium salt of polycarboxylic derivative of fullerene C60 exerted a pronounced toxic effect on this cell culture.

Fullerenolates: metallated polyhydroxylated fullerenes with potent anti-amyloid activity.

It has been revealed for the first time that sodium fullerenolate Na(4)[C(60)(OH)(∼30)] (NaFL), a water soluble polyhydroxylated [60]fullerene derivative, destroys amyloid fibrils of the Aß(1-42) peptide in the brain and prevents their formation in in vitro experiments. The cytotoxicity of NaFL was found to be negligibly low with respect to nine different culture cell lines. At the same time, NaFL showed a very low acute toxicity in vivo. The maximal tolerable dose (MTD) and LD50 for NaFL correspond to 1000 mg kg(-1) and 1800 mg kg(-1), respectively, as revealed by in vivo tests in mice using intraperitoneal drug injection. The observed pronounced anti-amyloid activity and low toxicity of NaFL make it a very promising lead drug for the development of potent fullerene-based therapeutic approaches for the treatment of amyloidoses, such as Alzheimer's disease and others.

[The role of recipient cells in the mechanism of pathological calcification of heart valve and vascular transplants].

It was found using the model of subcutaneous implantation in rats that the calcification of the aorta wall occurs by two mechanisms of which one is dependent on, and the other independent of the migration of recipient cells to the transplant.