Effect of Transcutaneous Electrical Stimulation of Nerves on Blood Pressure and Blood Content of Neuropeptide CGRP and Nitric Oxide in Hypertensive Rats with Metabolic Disturbances.

The development of arterial hypertension in male Wistar rats with fructose-induced metabolic syndrome (12.5% of fructose solution as the only drinking source for 10 weeks) along with impaired glucose tolerance and increased serum concentration of triglycerides and LPO products caused a decrease in the content of serum blood calcitonin gene-related peptide (CGRP). Low-frequency transcutaneous electrical nerve stimulation (1 mA, 2 Hz, 10 min daily for 2 weeks) performed in 8 weeks after the beginning of fructose treatment reduced systolic BP and serum concentration of triglycerides and LPO produces and improved glucose tolerance. After stimulation, CGRP content in rats maintained on fructose diet returned to normal values and the content of nitric oxide metabolites increased. We hypothesize that CGRP and nitric oxide are involved in mechanisms mediating the therapeutic effect of low-frequency transcutaneous electrical nerve stimulation on arterial hypertension developing in metabolic syndrome.

Hypolipidemic effect of mannans from C. albicans serotypes a and B in acute hyperlipidemia in mice.

Mannans, which are biological macromolecules of polysaccharide origin and function as immunomodulators, have been shown to stimulate macrophages in vivo by interaction with the mannose receptor. Thus, they can be used to stimulate macrophages in order to effectively remove circulating atherogenic lipoproteins. Our primary aim was to evaluate the hypolipidemic potential of mannans from C. albicans serotype A (mannan A) and serotype B (mannan B) in a murine model of hyperlipidemia. Mannan A and mannan B were shown to significantly (p<0.05) stimulate both the proliferation (p <0.05) and nitric oxide production of murine peritoneal macrophages in vitro. Pre-treatment of CBA/Lac mice with mannan A prior to induction of hyperlipidemia significantly (p<0.001) reduced serum atherogenic LDL-cholesterol, total cholesterol, and triglycerides. Mannan B exhibited a similar, but more potent, hypolipidemic effect. Electron microscopic analysis of liver revealed a significant (p<0.001) decrease in the volume of lipid droplets when hyperlipidemic mice were pretreated by both mannans. In conclusion, our findings would suggest that both polysaccharide-based biological macromolecules evaluated in the present study, specifically, the natural immunomodulators (mannans A and B), appeared to function as effective lipid-lowering macromolecules, which could potentially serve as adjunct therapy to more conventional hypolipidemic medications such as a statin drug.

Preventing cardiovascular heart disease: Promising nutraceutical and non-nutraceutical treatments for cholesterol management.

Hypercholesterolemia is one of the major risk factors for the development of cardiovascular disease. Atherosclerosis resulting from hypercholesterolemia causes many serious cardiovascular diseases. Statins are generally accepted as a treatment of choice for lowering low-density lipoprotein (LDL) cholesterol, which reduces coronary heart disease morbidity and mortality. Since statin use can be associated with muscle problems and other adverse symptoms, non-adherence and discontinuation of statin therapy often leads to inadequate control of plasma cholesterol levels and increased cardiovascular risk. Moreover, there is compelling evidence on the presence of still considerable residual cardiovascular risk in statin-treated patients. Ezetimibe improves cholesterol-lowering efficacy and provides mild additional cardiovascular protection when combined with statin treatment. Despite a favorable safety profile compared to statins, ezetimibe-induced cholesterol-lowering is modest when used alone. Hence, there is a critical need to identity additional effective hypolipidemic agents that can be used either in combination with statins, or alone, if statins are not tolerated. Thus, hypolipidemic agents such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, apolipoprotein B-100 antisense oligonucleotides, cholesteryl ester transfer protein (CETP) inhibitors, and microsomal triglyceride transfer protein (MTTP) inhibitors, as well as yeast polysaccharides (beta-glucans and mannans) and compounds derived from natural sources (nutraceuticals) such as glucomannans, plant sterols, berberine, and red yeast rice are being used. In this review, we will discuss hypercholesterolemia, its impact on the development of cardiovascular disease (CVD), and the use of yeast polysaccharides, various nutraceuticals, and several therapeutic agents not derived from 'natural' sources, to treat hypercholesterolemia.

Cystatin C as a Marker of Progressing Cardiovascular Events during Coronary Heart Disease.

The role of cystatin C, an inhibitor of cysteine proteases, as an alternative and potent predictor of acute cardiovascular events in coronary heart disease (CHD) patients was examined and compared to that of other markers of cardiorenal abnormalities. The patients with CHD demonstrated elevated serum cystatin C, especially in cases with serious risk of cardiovascular complications. In comparison with other indicators of cardiorenal dysfunction, cystatin C can be viewed as an alternative predictor of cardiovascular complications, although its sensitivity is inferior to that of high-sensitivity C-reactive protein and natriuretic peptide.

Effects of Anti-CD206 Antibodies on Macrophage Functions in Male CBF1 Mice with Lipidemia.

The effects of anti-CD208 antibodies (mannose receptor) on functional characteristics of peritoneal macrophages were studied in intact mice and mice with lipidemia induced by poloxamer-407. Lipidemia was associated with suppression of phagocytosis and increase in spontaneous proliferative potential and NO production by macrophages. Anti-CD206 antibodies suppressed NO production by macrophages in mice with lipidemia.

Hypolipidemic Effect of Mannan in Mice with Acute Lipemia Induced by Poloxamer 407.

We studied biological effects of mannan, a polysaccharide immunomodulator from C. albicans, that interacts with mannose receptor in vivo. It is shown that preliminary administration of mannan (5 times in a dose of 50 mg/kg or 2 times in a dose of 100 mg/kg) to mice with acute lipemia induced by lipase inhibitor poloxamer 407 (300 mg/kg) reduces the serum concentrations of atherogenic LDL, cholesterol, and triglycerides. Administration of mannan to intact mice and animals with acute lipemia reduces triglyceride concentration and causes labilization of lysosomal membranes in the liver. Serum activity of chitotriosidase, a marker of macrophage activation, was elevated in mice with acute lipemia treated with mannan. Thus, mannan from C. albicans is a promising hypolipidemic polysaccharide compound, similar by its activity to ß-glycan, a component of LPS.

Depression of Macrophages Modifies Serum Lipid Profile in Hyperlipidemia.

Suppression of functional activity of macrophages by gadolinium chloride, suppressing the macrophage population and the endocytosis velocity, was studied in vivo. Injection of GdCl3 led to an increase in serum cholesterol concentration. Preliminary injection of GdCl3 to mice with lipidemia 24 h before poloxamer 407 reduced the concentrations of triglycerides and LDL during marked depression of macrophages (in 24 h). Macrophage repopulation (days 5, 7) was associated with development of a trend to an increase of triglyceride and LDL levels. lectron microscopic study of Kupffer cells after injection of poloxamer 407 and its combination with gadoliniun chloride detected the intralysosomal accumulation syndrome in these cells (formation of auto- and heterophagolysosomes). Activity of cathepsin B, characteristic of macrophages, reduced 24 h after injections of GdCl3 and poloxamer 407 alone and restored in response to their combination.

[A Therapeutic Target for Inhibition of Neurodegeneration: Autophagy].

The role of autophagy in cell survival and suppression of neurodegeneration was considered. We discussed its involvement in Alzheimer's, Parkinson's, and Huntington's diseases connected with accumulation of amy- loid-ß, α-synuclein, and huntingtin, respectively. Autophagy is reduced in these diseases and in aging as well to various extent. Elimination of accumulated toxic proteins and structures is performed by autophagy mech- anisms (chaperon-mediated autophagy, macroautophagy, selected autophagy) in an interaction with ubiqui- tin-proteasome system. In many cases activation of mTOR-dependent autophagy and mTOR-independent regulatory pathways lead to the therapeutic effect of inhibition of neurodegeneration in cell cultures and an- imal models. Some autophagy enhancers such as resveratrol, metformin, rilmenidine, lithium, and curcumin are tested now in clinical trials.

Cellular Composition of the Spleen and Changes in Splenic Lysosomes in the Dynamics of Dyslipidemia in Mice Caused by Repeated Administration of Poloxamer 407.

We studied the effect of dyslipidemia induced by poloxamer 407 (300 mg/kg twice a week for 30 days) on cellular composition of the spleen and splenocyte lysosomes in mice. Changes in blood lipid profile included elevated concentrations of total cholesterol, aterogenic LDL, and triglycerides most pronounced in 24 h after the last poloxamer 407 injection; gradual normalization of lipid profile was observed in 4 days (except triglycerides) and 10 days. The most pronounced changes in the spleen (increase in organ weight and number of cells, inhibition in apoptosis, and reduced accumulation of vital dye acridine orange in lysosomes) were detected on day 4; on day 10, the indices returned to normal. Cathepsin D activity in the spleen also increased at these terms. The relationship between changes in the cellular composition of the spleen and dynamics of serum lipid profile in mice in dyslipidemia caused by repeated administrations of relatively low doses of poloxamer 407 is discussed.

Ratio of Active Matrix Metalloproteinases and Proenzymes during Growth and Metastasizing of Mouse Lewis Lung Adenocarcinoma.

Ratio between proMMP and active MMP was studied in the dynamics of growth of the Lewis lung adenocarcinoma with lung metastasis. It was shown that tumor growth is associated with an increase in the content of proMMP (day 20; terminal stage), but the level of active MMP in tumor tissue did not signifi cantly change. The development of lung metastasis was accompanied by accumulation of active MMP (days 7, 15, and 20) and a decrease in the content of pro-MMP (days 7, and 20) in comparison with the control. In the spleen of these mice (metastasis-free organ), an increase in the levels of proMMP (day 20) and especially active MMP (days 7, 15, and 20) were found. The results suggest that tumor development shifts the proportion between active MMP and proenzymes in the tumor, lungs with metastasis, and spleen without metastasis.

Serum cystatin C and chitotriosidase in acute P-407 induced dyslipidemia: Can they serve as potential early biomarkers for atherosclerosis?

In an attempt to better understand potential biomarkers for, and the role of macrophages in, the development of atherosclerosis, the toxicologic, and any therapeutic pharmacologic effects of carboxymethylated ß-glucan, gadolinium chloride, and poloxamer 407 were studied in mice for their capacity to perturb serum lipids, cystatin C, and chitotriosidase-1. Gadolinium and carboxymethylated ß-glucan dosed separately to control mice had no effect on serum lipids, whereas carboxymethylated ß-glucan, but not gadolinium, exerted a significant (p<0.01) and unexpected hypolipidemic effect in poloxamer 407-induced hyperlipidemic mice. An acute hyperlipidemic state (∼4 days), induced with poloxamer 407 administration alone, resulted in a significant (p<0.01) time-dependent decrease and increase in serum cystatin C and chitotriosidase, respectively. Carboxymethylated ß-glucan administration to hyperlipidemic mice significantly (p<0.05) increased the serum concentration of cystatin C, but significantly (p<0.01) decreased chitotriosidase activity, when each was compared to mice treated with poloxamer 407 only. Gadolinium administration caused a significant decrease in serum chitotriosidase activity in both controls (p<0.01) and poloxamer 407-induced hyperlipidemic (p<0.001) mice, but had no effect on the concentration of cystatin C in either controls or poloxamer 407-induced hyperlipidemic mice. Gadolinium administration resulted in both morphological and functional changes to liver macrophages, which included incorporation of excess lipids, especially when simultaneously administered with poloxamer 407. It is suggested that serum cystatin C and chitotriosidase may represent potential early biomarkers for eventual atherosclerosis in the poloxamer 407-induced mouse model of atherogenesis, and that two compounds known to either increase (carboxymethylated ß-glucan) or decrease (gadolinium chloride) the number of macrophages in vivo were able to modulate serum chitotriosidase activity, This, in turn, would appear to support the premise that serum chitotriosidase activity may be a more sensitive indicator of macrophage involvement than cystatin C in the context of future atherosclerosis.

Role of changes in serum chitotriosidase activity in mice under conditions of hyperlipidemia and lipid-lowering effect of carboxymethylated (1-3)-ß-D-glycan.

Enhanced expression and activity of chitotriosidase in humans is regarded as a marker of atherosclerosis. However, it remains unclear, whether this increase is related to lipemia or enhanced secretion of the enzyme by activated macrophages in the atherosclerotic plaques. It was shown that acute lipemia in mice caused by single administration of poloxamer 407 (P-407) in a dose of 300 mg/kg is accompanied by an increase in serum chitotriosidase activity (24 h) that correlated with elevated content of total cholesterol and triglycerides. Preliminary administration of (1-3)-ß-D-glycan prevented the P-407-induced increase in chitotriosidase activity, probably due to the hypolipidemic action of (1-3)-ß-D-glycan. The relationship between changes in chitotriosidase activity with atherogenic fractions and subfractions of serum lipoproteins during lipemia is discussed.

Activation of cathepsins B and L in mouse lymphosarcoma tissue under the effect of cyclophosphamide is associated with apoptosis induction and infiltration by mononuclear phagocytes.

We analyzed activities of lysosomal cystein cathepsins B and L in mouse LS lymphosarcoma and its drug-resistant RLS 40 strain and their correlations with the dynamics of the percentage of cells with fragmented DNA and CD14 (+) phagocytes over 3 days after cyclophosphamide injection. LS regression and inhibition of RLS 40 growth after cyclophosphamide injection were paralleled by an increase in cathepsins B and L activities in tumor tissues. The antitumor effect of cyclophosphamide associated with apoptosis intensity and protease activities were significantly higher in LS. Positive correlations between activities of cathepsins B and L and the LS tissue content of cells with fragmented DNA and CD14 (+) phagocytes and negative correlations thereof with tumor weight were detected. It seems that the increase in cathepsins B and L activities in LS tissues was caused by cyclophosphamide induction of apoptosis and depended on the level of tumor cell infiltration with mononuclear phagocytes.

Comparative characteristics of lipemia models induced by injections of Triton WR-1339 and poloxamer 407 in mice.

Lipemia modeled by injections of Triton WR-1339 (500 mg/kg) and poloxamer 407 (500 mg/kg) to mice were compared. LP fraction and subfraction compositions were compared by small-angle X-ray scattering on a diffractometer. Both compounds in the same dose caused a sharp increase in serum concentrations of total cholesterol (CH) and triglycerides (TG), the increases in response to poloxamer 407 being more pronounced. The differences in the models consisted in the levels of atherogenic fractions: CH-VLDL (subfractions CH-VLDL1-2) and CH-LDL, which were higher under the effect of poloxamer 407. Similar increases were observed for atherogenic fractions: TG-VLDL (subfractions TG-VLDL1-2) and TG-LDL (subfractions TG-LDL1-3). A specific feature of the model induced by poloxamer 407 was elevation of the concentrations of antiatherogenic CH-HDL and TG-HDL (subfractions CH-HDL2 and TG-HDL2). Both models exhibited high similarity, but changes in atherogenic fractions were more pronounced under the effect of poloxamer 407.

Tissue inhibitors of matrix metalloproteinases 1 and 2 and matrix metalloproteinase activity in the serum and lungs of mice with lewis lung carcinoma.

We studied the content of tissue inhibitors of matrix metalloproteinases 1 and 2 (TIMP-1 and TIMP-2) and activities of matrix metalloproteinases (MMP) in the serum and lungs of mice with Lewis lung carcinoma metastasizing into the lung. Metastasizing was associated with increased serum content of TIMP-1 and TIMP-2 (only on day 20 at the terminal stage of the tumor process). These data confirm the hypothesis on pro-tumorigenic role of TIMP-1 in the serum. Locally, the development of metastases was associated with a decrease in TIPM-1 concentration (day 7), an increase in TIMP-2 concentration (days 7 and 20), and elevated activity of MMP at all terms of the study (days 7, 15, and 20). Increased concentration of TIMP-2 in the lungs (but not in the serum) can be regarded as an indicator of Lewis lung carcinoma metastasizing.

[Effect of statins on activity of matrix metalloproteases and serum concentration of cystatin C in patients with various risk of development of ischemic heart disease and in patients after coronary artery bypass surgery].

We compared new non-lipid atherosclerosis indexes related to inflammation and macrophage stimulation (serum concentration of cystatin C, matrix metalloproteases and chitotriosidase activity) with common inflammatory (high sensitivity C reactive protein) and lipid markers in elderly persons and patients with atherosclerosis and ischemic heart disease who have undergone coronary bypass surgery.

Chitotriosidase activity in the blood serum and organs of mice of various strains under the influence of chitin.

Mouse chitotriosidase cleaving chitin belongs to the family of mammalian chitinases, whose biological functions are poorly understood. Chitotriosidase activity in mouse serum was shown to be much higher than in humans. The following interstrain differences were revealed in mouse chitotriosidase activity: GR>C57Bl/6>BALB/c>A/Sn>CBA. Chitotriosidase activity in CBA mice was lowest and practically did not differ from that in C3H/He and ICR mice. No sex-related differences were found in enzyme activity. Hybrids of opposite strains CBA and C57Bl/6 were characterized by dominant inheritance of this sign (elevated activity of chitotriosidase in the serum). Intragastric administration of chitin in a single dose of 100 mg/kg was followed by a decrease in chitotriosidase activity in the lungs, but not in the blood serum and homogenate of gastric cells from CBA mice. These data indicate that intragastric administration of chitin does not induce chitotriosidase in mice.

Fractional composition of blood serum lipoproteins in mice and rats with Triton WR 1339-induced lipemia.

We compared fractional composition of blood serum lipoproteins (LP) in female ICR mice and Wistar rats induced by single administration of a nonionic detergent Triton WR 1339 in doses of 300 and 500 mg/kg. Lipemia in animals of both species was characterized by a sharp increase in the concentration of cholesterol and, particularly, of triglycerides in blood serum lipoproteins by the 24th hour after administration of the detergent. We revealed a significant increase in the concentrations of atherogenic VLDL cholesterol (due to VLDL2), intermediate density lipoproteins, and LDL. These changes were more pronounced in rats. The model of lipemia can be used to study the role of fractional composition of lipoproteins and, particularly, of triglycerides in the pathogenesis of atherosclerosis. Moreover, this model holds much promise for evaluation of the efficiency of hypolipidemic drugs (statins and fibrates) in normalizing the increased level of atherogenic cholesterol of VLDL and LDL.

Changes in tissue metalloproteinase inhibitor-1 and matrix metalloproteinases during tumor development and metastasizing in mice.

Tissue inhibitor of matrix metalloproteinases type 1, inhibiting the majority of matrix metalloproteinases, can both suppress and stimulate tumor growth. The concentrations and activities of tissue matrix metalloproteinase inhibitor-1 were measured in C57Bl/6 mice during progression and metastasizing of Lewis lung adenocarcinoma. Activities of matrix metalloproteinases in tumor tissue of mice were lower than in liver and lung tissues of intact animals. Serum concentration of tissue inhibitor increased significantly during the development of Lewis lung adenocarcinoma. Macrophage depression (injection of gadolinium chloride associated with a decrease in metastasis number) decreased serum concentration of tissue inhibitor, but it did not attain the control level observed in intact mice. These findings attest to a pleiotropic antitumor effect of tissue matrix metalloproteinase inhibitor-1 reflecting disorders in matrix metalloproteinase regulation during the progress of Lewis lung adenocarcinoma in mice.

[Effect of macrophage stimulators on development of selective depression of liver macrophage in vivo].

A single administration of zymosan (50 mg/kg) and chito-carboxymethylated glucan (25 mg/kg) to mice was shown to improve the selective liver macrophage depression induced by gadolinium chloride (7.5 mg/kg, intravenous administration). Both beta-1,3-glucans (ChitoCMG and CMG) studied revealed the signs of liver macrophage stimulation: increased number and phagocytic activity of liver macrophages and increased serum chitotriosidase activity. The model of selective liver macrophage depression was characterized by decreased activity of serum chitotriosidase. ChitoCMG as well as zymosan increased the uptake of gadolinium by liver cells during preliminary (before gadolinium chloride) administration of beta-1,3-glucans. It was concluded that the model of selective liver macrophagedepression is useful for studying the protective effects of biological response modifiers such as polysaccharides (beta-1,3-glucans) in vivo.