P2Y13 receptor regulates HDL metabolism and atherosclerosis in vivo.

High-density lipoprotein (HDL) is known to protect against atherosclerosis by promoting the reverse cholesterol transport. A new pathway for the regulation of HDL-cholesterol (HDL-c) removal involving F1-ATPase and P2Y13 receptor (P2Y13R) was described in vitro, and recently in mice. However, the physiological role of F1-ATPase/P2Y13R pathway in the modulation of vascular pathology i.e. in the development of atherosclerotic plaques is still unknown. We designed a specific novel agonist (CT1007900) of the P2Y13R that caused stimulation of bile acid secretion associated with an increased uptake of HDL-c in the liver after single dosing in mice. Repeated dose administration in mice, for 2 weeks, stimulated the apoA-I synthesis and formation of small HDL particles. Plasma samples from the agonist-treated mice had high efflux capacity for mobilization of cholesterol in vitro compared to placebo group. In apoE-/- mice this agonist induced a decrease of atherosclerotic plaques in aortas and carotids. The specificity of P2Y13R pathway in those mice was assessed using adenovirus encoding P2Y13R-shRNA. These results demonstrate that P2Y13R plays a pivotal role in the HDL metabolism and could also be a useful therapeutic agent to decrease atherosclerosis. In this study, the up-regulation of HDL-c metabolism via activation of the P2Y13R using agonists could promote reverse cholesterol transport and promote inhibition of atherosclerosis progression in mice.

Influence of various central moieties on the hypolipidemic properties of long hydrocarbon chain diols and diacids.

A series of long (11-15) hydrocarbon chain diols and diacids with various central functional groups and terminal gem-dimethyl or -methyl/aryl substituents was synthesized and evaluated in both in vivo and in vitro assays for its potential to favorably alter lipid disorders including metabolic syndrome. Compounds were assessed for their effects on the de novo incorporation of radiolabeled acetate into lipids in primary cultures of rat hepatocytes, as well as for their effects on lipid and glycemic variables in obese female Zucker fatty rats, Crl:(ZUC)-faBR. The most active compounds were hydroxyl-substituted symmetrical diacids and diols with a 13-atom chain and terminal gem-dimethyl substituents. Furthermore, biological activity was enhanced by central substitution with O, C=O, S, S=O compared to the methylene analogues and was diminished for compounds with central functional groups such as carbamate, ester, urea, acetylmethylene, and hydroxymethylene.

Long hydrocarbon chain keto diols and diacids that favorably alter lipid disorders in vivo.

Keto-substituted hydrocarbons with 11-19 methylene and bis-terminal hydroxyl and carboxyl groups have been synthesized and evaluated in both in vivo and in vitro assays for their potential to favorably alter lipid disorders including metabolic syndrome. Compounds were assessed for their effects on the de novo incorporation of radiolabeled acetate into lipids in primary cultures of rat hepatocytes as well as for their effects on lipid and glycemic variables in obese female Zucker fatty rats [Crl:(ZUC)-faBR] following 1 and 2 weeks of oral administration. The most active compounds were found to be symmetrical with four to five methylene groups separating the central ketone functionality and the gem dimethyl or methyl/aryl substituents. Furthermore, biological activity was found to be greatest in both in vivo and in vitro assays for the tetramethyl-substituted keto diacids and diols (e.g., 10c, 10g, 14c), and the least active were shown to be the bis(arylmethyl) derivatives (e.g., 10e, 10f, 14f). Compound 14c dose-dependently elevated HDL-cholesterol, reduced triglycerides, and reduced NEFA, with a minimum effective dose of 30 mg/kg/day. Compound 1 g dose-dependently modified non-HDL-cholesterol, triglycerides, and nonesterified fatty acids, with a minimum effective dose of 10 mg/kg/day. At this dose, compound 10g elevated HDL-cholesterol levels 2-3 times higher than pretreatment levels, and a dose-dependent reduction of fasting insulin and glucose levels was observed.

Long hydrocarbon chain ether diols and ether diacids that favorably alter lipid disorders in vivo.

Long hydrocarbon chain ethers with bis-terminal hydroxyl or carboxyl groups have been synthesized and evaluated for their potential to favorably alter lipid disorders including metabolic syndrome. Compounds were assessed for their effects on the de novo incorporation of radiolabeled acetate into lipids in primary cultures of rat hepatocytes as well as for their effects on lipid and glycemic variables in female obese Zucker fatty rats following 1 and 2 weeks of daily oral administration. The most active compounds were found to be symmetrical with four to five methylene groups separating the central ether functionality and the gem dimethyl or methyl/aryl substituents. Biological activity was found to be greatest for tetramethyl-substituted ether diols (e.g., 28 and 31), while bis(arylmethyl) derivatives (e.g., 10, 11, and 27), diethers (e.g., 49, 50, and 56), and diphenyl ethers (e.g., 35 and 36) were the least active. For the most biologically active compound 28, we observed as much as a 346% increase in serum HDL-cholesterol and a 71% reduction in serum triglycerides at the highest dose administered (100 mg/kg) after 2 weeks of treatment. For compound 31 we observed a 69% reduction in non-HDL-cholesterol, accompanied by a 131% increase in HDL-cholesterol and an 84% reduction in serum triglycerides under the same treatment conditions.