[High-density lipoproteins as a form of daunorubicin transport in hepatoma cells of mice].

The efficiency of using high-density lipoproteins (HDLPs) as the transport form of an antineoplastic drug daunorubicin (rubomycin hydrochloride, daunoxome) has been shown on the culture of HA-1 hepatoma cells of mice. The use of HDLPs in a complex with daunorubicin led to an increase in the efficiency of drug transport and cytotoxic action with respect to tumor cells in comparison with hepatocytes of healthy animals.

[Influence of isoniazid complex with A-I apolipoprotein on activity of lysosomal enzymes in mice with tuberculous inflammation model].

It is established that isoniazid (isonicotinic acid hydrazide) can interact with A-I apolipoprotein to form a complex, which can be considered as the transport form of the preparation. The use of this complex for the treatment of mice with BCG-induced tuberculous inflammation led to an increase in the free activities of acid phosphatase and cathepsin D in the liver, which was decreased under the action of mycobacteria and the free form of isoniazid. The isoniazid complex with A-I apolipoprotein exhibited more expressed anti-inflammatory effect (estimated by the activity of chitotriosidase in blood serum) as compared to the free drug.

[The analysis of interaction between lipoproteins and steroid hormones].

Using the methods of ultracentrifugation, gel-filtration and fluorescence quenching, we demonstrated, that plasma lipoproteins bind steroid hormones and can therefore play a role of their active transport form in an organism. High density lipoproteins have revealed the highest affinity to steroids for. It has been found, that protein component of lipoproteins takes part in the formation of lipoprotein-steroid complex. The apolipoprotein A-I, the main protein component of high density lipoproteins, is responsible for binding of steroid hormones. The calculated constants formation of the complexes of lipoproteins with steroid hormones testifies to specificity of linkage. The results obtained allow to considering real opportunity of transfer of steroid hormones into cell by a receptor-mediated endocytosis in structure of lipoproteins complexes.

[Role of tumor-associated macrophages in the regulation of protein biosynthesis in Ehrlich carcinoma cells].

The paper discusses the role of peritoneal macrophages in uptake and metabolic degradation of high-density proteins of lipoproteins in mice with Ehrlich ascites carcinoma. These processes were found to be influenced by cortisol. Distinctions in spectra of endocellular proteins in tumor-associated macrophages and peritoneal ones in intact mice were identified and, in particular, relative to apolipoprotein E level. Our study demonstrated participation of macrophages in tumor cell-mediated regulation of protein biosynthesis rate under the influence of high-density lipoproteins and cortisol. Apolipoprotein E may play a role of mediator of negative feedback in the mechanism of accelerating protein biosynthesis in tumor cells.

[Mechanisms of interaction of tetrahydrocortisol and its complex with apolipoprotein A-I and DNA regulatory cis-elements of CC(GCC)5/GG(CGG)5 type].

An IR-spectroscopy study of the mechanism of interaction between duplex CC(GCC)5/GG (CGG)5Li2 and tetrahydrocortisol or tetrahydrocortisol-apolipoprotein A-I complex revealed the formation of hydrogen bonds between the OH group of the tetrahydrocortisol A-ring and the C=0 group of cytosine or guanine. Tetrahydrocortisol forms hydrogen bonds with the PO2-group of the duplex and with the OH-group of monosaccharide. The interaction of tetrahydrocortisol and apolipoprotein A-I with the duplex occurs at the same active site, namely, with the C=O-group of bases. The order --> order structural transition takes place in the duplex under the action of tetrahydrocortisol. The order --> disorder structural transition takes place in the duplex under the action of tetrahydrocortisol-apolipoprotein A-I complex.

[Effect of apolipoprotein A-1 containing steroid hormones on DNA and protein biosynthesis in cells of ascitic hepatoma HA-1].

The rate of DNA and protein biosynthesis in murine hepatoma HA-1 was accelerated when steroid hormones, containing a reduced delta4,3-keto group in the A-ring, were used in combination with apolipoprotein A-1. That was demonstrated for apolipoprotein A-1 complexes with dehydroepiandrosterone, dehydroepiandrosterone sulfate and tetrahydrocortisol. Apolipoprotein A-1 complexes serve as a vehicle for steroids penetration into cells to influence protein biosynthesis.

[Interaction of tetrahydrocortisol-apolipoprotein A-I complex with eukaryotic DNA and with single-stranded oligonucleotides]. / Vzaimodeistvie kompleksa tetragidrokortizol-apolipoprotein A-I c éukarioticheskoi DNK i odnotsepochechnymi oligonukleotidami.

The complex formed by tetrahydrocortisol (THC) and apolipoprotein A-I (ApoAI) specifically interacts with eukaryotic DNA from rat liver. Taken together, physical and chemical data and the results of small-angle X-ray scattering analysis show that interaction of the THC-ApoAI complex with eukaryotic DNA results in deformation of the DNA double helix. Single-stranded fragments were demonstrated to cause deformation of the double helix. In this state DNA forms complexes with DNA-dependent RNA polymerase. This interaction is cooperative and of saturating type; up to six enzyme molecules bind with one DNA molecule. The putative site of complex binding with DNA is the sequence CC(GCC)n found in many genes including the human ApoAI gene. An oligonucleotide of this type was synthesized. Its association constant (Ka) was 1.66 x 10(6) M-1. Substitution of THC with cortysol considerably decreases the Ka. We suggest that THC interacting with GC pairs of the binding site forms hydrogen bonds with cytosine, inducing rupture of the bonds within the complementary nucleic base pair.

[Interaction of eukaryotic DNA with apolipoprotein A-I and its complexes with glucocorticoids]. / Vzaimodeistvie éukarioticheskoi DNK s apolipoproteinom A-I i ego kompleksami s gliukokortikoidami.

A biochemically active complex of apolipoprotein A-I with tetrahydrocortisol was revealed, which increases gene expression in hepatocytes. It was shown by the method of fluorescent probe that titration of rat liver DNA by the apolipoprotein A-I-tetrahydrocortisol complex leads to the appearance of single-stranded fragments. The effect of the complex on the secondary structure of native DNA was confirmed by the method of small-angle X-ray scattering. It was shown that approximately 54 apolipoprotein A-I molecules carrying tetrahydrocortisol as a ligand bind to one molecule of isolated native DNA, inducing a break of hydrogen bonds between the pair of nitrous bases. It is concluded that the cooperative effect of high-density lipoproteins and cortisol in the regulation of gene expression in hepatocytes with the participation of resident liver macrophages is accomplished by a new biochemical mechanism. This mechanism makes itself evident as a result of the interaction of DNA with the apolipoprotein A-I-tetrahydrocortisol complex, the appearance of single-stranded DNA regions in binding sites, and subsequent initiation of gene transcription.

Enzyme-linked immunosorbent assay for apolipoproteins A-I and B in the urine of patients with nephrotic syndrome. / Tverdofaznyi immunofermentnyi analiz apolipoproteinov A-I i B v moche liudei s nefroticheskim sindromom.

Enzyme-linked immunosorbent assay (ELISA) has been used for measuring apolipoproteins A-I and B in the urine. ApoB is absent in urine of healthy subjects, and apoA-I is determined in trace quantity. In patients with chronic glomerulonephritis quantity of apoA-I in urine was 117 times as much as in control group. ApoB is present in urine of patients in considerable quantity (1528 +/- 315 micrograms/l). The ELISA method for determining apoA-I and apoB in urine makes it possible to evaluate the gravity of pathological process in kidney.

[Anomalous change in the specific conductivity in lipoproteins at around physiologic temperatures]. / Anomal'noe izmenenie udel'noi élektroprovodnosti v lipoproteinakh v oblasti fiziologicheskoi temperatury.

Studying the temperature dependence of conductivity sigma of rat and human lipoproteins and apoprotein A-I fractions revealed an anomalous region in the range of temperatures (35-38) +/- 0.5 degree C. The activation energy delta H and temperature coefficient sigma (delta sigma/delta T) on both sides of Tc and the heat of transition (delta H of transition) were calculated. In high-density human lipoproteins and apoA-I, the delta H value was found to be very low. Some mechanisms of interaction of hydrocortizone with high-density lipoproteins and apoA-I were studied by using IR-spectroscopy and conductometry were studied. It was found that the hormone considerably increases the portion of alpha-helices and beta-structures in these proteins (coil<-->alpha-helix and coil<-->beta-structure transitions). In this case, delta H value of the transition increases 13-fold; in addition, the abnormal region in apoA-I shifts 1-2 degrees C downwards. The anomalous changes in conductivity in the range of physiological temperatures in all lipoprotein fractions including apoA-I are probably related to structural phase transitions both in proteins and in phospholipids. Since the delta H value of the transition in human high-density lipoproteins is small, it is assumed that, in phospholipids of these particles, an orientation transition of the A<-->C smectic type takes place, which is assigned to the second-order phase transition. The structural transition in apoA-I can probably also be assigned to the second-order phase transition since the enthalpia of the transition is very small; presumably, this transition is related to changes in symmetry due to changes in the secondary structure (coil<-->beta-tructure transition).

[Effect of plasma lipoproteins and apolipoprotein A-I on lipopolysaccharide-induced production of reactive oxygen metabolites by Kupffer cells of the rat]. / Vliianie plazmennykh lipoproteinov i apolipoproteina A-I na lipopolisakharid-indutsirovannuiu produktsiiu reaktivnykh metabolitov kisloroda kupferovskimi kletkami krys.

The effects of plasma lipoproteins on LPS-induced production of reactive oxygen intermediates (ROI) in Kupffer cells isolated from livers of zymosan-treated rats, have been studied. ROI production was low in normal Kupffer cells but increased 18-fold by LPS in Kupffer cells from zymosan-treated rats. However, preincubation of LPS with rat serum, low density lipoproteins, high density lipoproteins (HDL3) and apolipoprotein A-I (apoA-I) decreased the LPS-induced production of ROI by 1.2-, 1.3-, 2.8-, and 1.5-fold, respectively. In contrast, very low density lipoproteins and HDL2 had no significant effect on the LPS-induced production of ROI. These results provide evidence for LPS-HDL3 complex formation and suggest that HDL3 and apoA-I play an important role in host defense against endotoxemia and infection.

[The receptor-mediated endocytosis of complexes of colloidal gold with high-density lipoproteins by the sinusoidal cells of the isolated rat liver]. / Retseptor-oposredovannyi éndotsitoz kompleksov kolloidnogo zolota s lipoproteinami vysokoi plotnosti sinusoidal'nymi kletkami izolirovannoi pecheni krys.

Rat hepatic sinusoidal cells absorption of native high-density lipoproteins was studied by electron microscope. Visualization of the endocytosis process was achieved by binding of lipoprotein particles and colloidal gold. The study was carried out on isolated liver perfusing by oxygenated nutritional media which consist of colloidal gold-lipoproteins conjugates. Electron microscope analysis testifies that high-density lipoproteins are absorbed by hepatic sinusoidal cells by means of receptor endocytosis. Both Kupffer cells and endothelial cells have such receptors. Lipoproteins of this class reach hepatic cells in Disse's space through the endothelium, i.e. transcellularly unlike low-density lipoproteins which penetrate paracellularly--through the fenestrae and intracellular contact's ares.

[Lipid biosynthesis and metabolism of native and acetylated low density lipoproteins in macrophages stimulated by zymosan in vivo and in vitro]. / Biosintez lipidov i metabolizm nativnykh i atetilirovannykh lipoproteidov nizkoi plotnosti v makrofagakh, stimulirovannykh zimozanom in vivo i in vitro.

The effects of zymosan on lipid metabolism in mouse peritoneal macrophages (MPM) in vitro and in vivo were studied with special reference to the following parameters: i) 14C-oleate incorporation into cholesteryl esters (CE), triglycerides (TG), and phospholipids (PL) in MPM incubated with low density lipoproteins (LDL) and acetylated LDL; ii) cholesteryl-14C-oleate-acetyl LDL uptake and 125I-acetyl LDL degradation; iii) oxidative modification of LDL. Zymosan administered to mice caused significant stimulation of 14C-oleate incorporation into CE, TG, and PL with no effect on 3H-cholesterol (Ch) incorporation into CE or 3H-glycerol incorporation into TG and PL in MPM. The 14C-oleate incorporation into cellular lipids was unaffected by 18-hour incubation of MPM with zymosan (100-500 micrograms/ml) but increased after incubation of unstimulated MPM with blood serum and peritoneal fluid harvested harvested from zymosan-treated mice. One possible explanation of this phenomenon is oleyl-CoA formation induction in cytokine-stimulated MPM in vivo. Zymosan decreased the Ch-14C-oleate-acetyl LDL uptake, 125I-acetyl LDL degradation, and Ch esterification in the presence of acetyl LDL in MPM both in vitro and in vivo. An increase in Ch esterification after incubation of MPM with zymosan for 6-18 hours in the presence of LDL was accompanied by an increase in lipid peroxidation of LDL and its electrophoretic mobility. The data obtained suggest that the macrophage acetyl LDL receptor pathway may be inhibited by zymosan and that cytokines released from zymosan-stimulated cells may influence the generation of foam cells.

[Quantitative characteristics of interactions of blood lipoproteins and steroid hormones]. / Kolichestvennaia kharakteristika vzaimodeistviia lipoproteinov syvorotki krovi so steroidnymi gormonami.

Human and serum lipoproteins interaction with steroid hormones (corticosterone and hydrocortisone) were studied. Methods of fluorescence quenching titration and equilibrium dialysis were used for quantitative evaluation of VLDL, LDL and HDL glucocorticoids binding ability. Association constants were found to be 0.6-2.0 x 10 M for corticosterone and 4.0-8.0 x 10 M for hydrocortisone. The number of binding sites ranged from 3 to 300 for different classes of lipoproteins. Our data suggest high specificity of serum lipoproteins binding with corticosterone and hydrocortisone.

[Detection of apoprotein A-1 immunoreactivity in chromatin of rat hepatocytes]. / Obnaruzhenie apoprotein A-1-immunoreaktivnosti v khromatine iader gepatotsit krys.

The binding of 125I-labeled lipoproteins to subcellular structures of rat hepatocytes was studied. The protein component of HDL, LDL, and VLDL was found in large and small membranes, nuclei, mitochondria, lysosomes, microsomes, and cell cytosol. The presence in liver nuclear chromatin of proteins immunochemically related to apoA-1 was demonstrated by solid phase immunoenzymatic analysis, dot immunoanalysis, and immunoelectroblotting. The apoprotein A-1 immunoreactivity was detected in transcriptionally inactive total chromatin, transcriptionally active chromatin, and nuclear matrix. The specific apoA-1 immunoreactivity of transcriptionally active chromatin and nuclear matrix was two times as low as that of total and transcriptionally inactive chromatin. Immunoelectroblotting revealed two proteins possessing an apoA-1 immunoreactivity (M(r) 28 and 14 kDa). The 28 kDa protein was found in transcriptionally active chromatin and nuclear matrix, while the 14 kDa one--only in transcriptionally inactive chromatin. the roles of apoproteins in lipid transport to nuclei and the maintenance of chromatin in a transcriptionally active state are discussed.