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Featured researches published by Lori Royer.


Arteriosclerosis, Thrombosis, and Vascular Biology | 2002

Increased Atherosclerosis in Hyperlipidemic Mice With Inactivation of ABCA1 in Macrophages

Robert J. Aiello; Dominique Brees; Patricia-Ann Bourassa; Lori Royer; Saralyn Lindsey; Timothy M. Coskran; Mehrdad Haghpassand; Omar L. Francone

The ATP-binding cassette transporter A1 (ABCA1) encodes a membrane protein that promotes cholesterol and phospholipid efflux from cells. Mutations in ABCA1 lead to HDL deficiency and tissue accumulation of macrophages in patients with homozygous Tangier disease. In this study, we examined whether the complete absence of ABCA1 or selected inactivation in macrophages is accompanied by an increase in atherosclerotic lesion progression in hypercholesterolemic apolipoprotein E–deficient (apoE−/−) mice and LDLR receptor–deficient (LDLr−/−) mice. The absence of ABCA1 led to reduced plasma cholesterol levels in both the apoE−/− and LDLr−/− mice, along with severe skin xanthomatosis characterized by marked foamy macrophages and cholesterol ester accumulation. However, the complete absence of ABCA1 did not affect the development, progression, or composition of atherosclerotic lesions in either the LDLr−/− or the apoE−/− mice fed a chow or atherogenic diet. In contrast, bone marrow transplantation studies demonstrated that the selective inactivation of ABCA1 in macrophages markedly increased atherosclerosis and foam cell accumulation in apoE−/−. Taken together, these findings demonstrate that the complete absence of ABCA1 has a major impact on plasma lipoprotein homeostasis, and the proposed antiatherogenic effect resulting from ABCA1 deficiency is compensated by a less atherogenic profile. ABCA1 deficiency in macrophages, however, demonstrates the antiatherogenic properties of ABCA1 independent of plasma lipids and HDL levels.


Arteriosclerosis, Thrombosis, and Vascular Biology | 2005

Increased Cholesterol Deposition, Expression of Scavenger Receptors, and Response to Chemotactic Factors in Abca1-Deficient Macrophages

Omar L. Francone; Lori Royer; Germaine Boucher; Mehrdad Haghpassand; Ann Freeman; Dominique Brees; Robert J. Aiello

Objective—Studies in bone marrow transplanted from ATP-binding cassette transporter A1 (ABCA1)–deficient mice into normal mice provides direct evidence that the absence of leukocyte ABCA1 exerts a marked proatherogenic effect independent of changes in plasma lipids, suggesting that ABCA1 plays a key role in the regulation of cholesterol homeostasis and function of macrophages. Therefore, we examined whether the absence of ABCA1 affects the morphology, properties, and functional activities of macrophages that could be related to the development of atherosclerosis. Methods and Results—We conducted a series of experiments in macrophages isolated from Abca1-deficient and wild-type mice and compared several of their properties that are thought to be related to the development of atherosclerosis. Macrophages isolated from Abca1-deficient mice have an increase in cholesterol content, expression of scavenger receptors, and secretion of chemokines, growth factors, and cytokines, resulting in an increased ability to respond to a variety of chemotactic factors. Conclusion—Our studies indicate that the absence of ABCA1 leads to significant changes in the morphology, properties, and functional activities of macrophages. These changes, together with the proinflammatory condition present in ABCA1-deficient mice and increased reactivity of macrophages to chemotactic factors, play a key role in the development and progression of atherosclerosis.


Journal of Lipid Research | 2008

Phospholipid transfer protein deficiency ameliorates diet-induced hypercholesterolemia and inflammation in mice

Lorraine D. Shelly; Lori Royer; Thomas Sand; Heather Jensen; Yi Luo

Phospholipid transfer protein (PLTP) facilitates the transfer of phospholipids from triglyceride-rich lipoproteins into HDL. PLTP has been shown to be an important factor in lipoprotein metabolism and atherogenesis. Here, we report that chronic high-fat, high-cholesterol diet feeding markedly increased plasma cholesterol levels in C57BL/6 mice. PLTP deficiency attenuated diet-induced hypercholesterolemia by dramatically reducing apolipoprotein E-rich lipoproteins (−88%) and, to a lesser extent, LDL (−40%) and HDL (−35%). Increased biliary cholesterol secretion, indicated by increased hepatic ABCG5/ABCG8 gene expression, and decreased intestinal cholesterol absorption may contribute to the lower plasma cholesterol in PLTP-deficient mice. The expression of proinflammatory genes (intercellular adhesion molecule-1 and vascular cell adhesion molecule-1) is reduced in aorta of PLTP knockout mice compared with wild-type mice fed either a chow or a high-cholesterol diet. Furthermore, plasma interleukin-6 levels are significantly lower in PLTP-deficient mice, indicating reduced systemic inflammation. These data suggest that PLTP appears to play a proatherogenic role in diet-induced hyperlipidemic mice.


Endocrinology | 2011

Aldosterone Production in Human Adrenocortical Cells Is Stimulated by High-Density Lipoprotein 2 (HDL2) through Increased Expression of Aldosterone Synthase (CYP11B2)

Yewei Xing; Anthony Cohen; George H. Rothblat; Sandhya Sankaranarayanan; Ginny Weibel; Lori Royer; Omar L. Francone; William E. Rainey

Adrenal aldosterone production is regulated by physiological agonists at the level of early and late rate-limiting steps. Numerous studies have focused on the role of lipoproteins including high-density lipoprotein (HDL) as cholesterol providers in this process; however, recent research suggests that HDL can also act as a signaling molecule. Herein, we used the human H295R adrenocortical cell model to study the effects of HDL on adrenal aldosterone production and CYP11B2 expression. HDL, especially HDL2, stimulated aldosterone synthesis by increasing expression of CYP11B2. HDL treatment increased CYP11B2 mRNA in both a concentration- and time-dependent manner, with a maximal 19-fold increase (24 h, 250 μg/ml of HDL). Effects of HDL on CYP11B2 were not additive with natural agonists including angiotensin II or K(+). HDL effects were likely mediated by a calcium signaling cascade, because a calcium channel blocker and a calmodulin kinase inhibitor abolished the CYP11B2-stimulating effects. Of the two subfractions of HDL, HDL2 was more potent than HDL3 in stimulating aldosterone and CYP11B2. Further studies are needed to identify the active components of HDL, which regulate aldosterone production.


Bioorganic & Medicinal Chemistry | 2008

Effects of modifications of the linker in a series of phenylpropanoic acid derivatives : Synthesis, evaluation as PPARα/γ dual agonists, and X-ray crystallographic studies

Agustin Casimiro-Garcia; Christopher F. Bigge; Jo Ann Davis; Teresa Padalino; James Pulaski; Jeffrey F. Ohren; Patrick McConnell; Christopher D. Kane; Lori Royer; Kimberly A. Stevens; Bruce Auerbach; Wendy Collard; Christine McGregor; Stephen A. Fakhoury; Robert P. Schaum; Hairong Zhou

A new series of alpha-aryl or alpha-heteroarylphenyl propanoic acid derivatives was synthesized that incorporate acetylene-, ethylene-, propyl-, or nitrogen-derived linkers as a replacement of the commonly used ether moiety that joins the central phenyl ring with the lipophilic tail. The effect of these modifications in the binding and activation of PPARalpha and PPARgamma was first evaluated in vitro. Compounds possessing suitable profiles were then evaluated in the ob/ob mouse model of type 2 diabetes. The propylene derivative 40 and the propyl derivative 53 demonstrated robust plasma glucose lowering activity in this model. Compound 53 was also evaluated in male Zucker diabetic fatty rats and was found to achieve normalization of glucose, triglycerides, and insulin levels. An X-ray crystal structure of the complex of 53 with the PPARgamma-ligand-binding domain was obtained and discussed in this report.


Bioorganic & Medicinal Chemistry | 2009

Synthesis and evaluation of novel α-heteroaryl-phenylpropanoic acid derivatives as PPARα/γ dual agonists

Agustin Casimiro-Garcia; Christopher F. Bigge; Jo Ann Davis; Teresa Padalino; James Pulaski; Jeffrey F. Ohren; Patrick McConnell; Christopher D. Kane; Lori Royer; Kimberly A. Stevens; Bruce Auerbach; Wendy Collard; Christine McGregor; Kun Song

The synthesis of a new series of phenylpropanoic acid derivatives incorporating an heteroaryl group at the alpha-position and their evaluation for binding and activation of PPARalpha and PPARgamma are presented in this report. Among the new compounds, (S)-3-{4-[3-(5-methyl-2-phenyl-oxazol-4-yl)-propyl]-phenyl}-2-1,2,3-triazol-2-yl-propionic acid (17j), was identified as a potent human PPARalpha/gamma dual agonist (EC(50)=0.013 and 0.061 microM, respectively) with demonstrated oral bioavailability in rat and dog. 17j was shown to decrease insulin levels, plasma glucose, and triglycerides in the ZDF female rat model. In the human apolipoprotein A-1/CETP transgenic mouse model 17j produced increases in hApoA1 and HDL-C and decreases in plasma triglycerides. The increased potency for binding and activation of both PPAR subtypes observed with 17j when compared to previous analogs in this series was explained based on results derived from crystallographic and modeling studies.


Proceedings of the National Academy of Sciences of the United States of America | 2000

High density lipoprotein deficiency and foam cell accumulation in mice with targeted disruption of ATP-binding cassette transporter-1

John D. McNeish; Robert J. Aiello; Deborah J. Guyot; Tom Turi; Christopher A. Gabel; Charles E. Aldinger; Kenneth L. Hoppe; Marsha L. Roach; Lori Royer; Jeffery de Wet; Cyril Broccardo; Giovanna Chimini; Omar L. Francone


Journal of Lipid Research | 1997

Expression of human lecithin : cholesterol acyltransferase in transgenic mice: effects on cholesterol efflux, esterification, and transport

Omar L. Francone; Mehrdad Haghpassand; J A Bennett; Lori Royer; J McNeish


Biochemistry | 2003

Abnormal Phospholipid Composition Impairs HDL Biogenesis and Maturation in Mice Lacking Abca1

Omar L. Francone; Papasani V. Subbaiah; Arie van Tol; Lori Royer; Mehrdad Haghpassand


Atherosclerosis | 2003

Enhanced efflux of cholesterol from ABCA1-expressing macrophages to serum from type IV hypertriglyceridemic subjects

Natalie Fournier; Omar L. Francone; George H. Rothblat; Dominique Goudouneche; Michèle Cambillau; Ginny Kellner-Weibel; Peggy Robinet; Lori Royer; Nicole Moatti; Alain Simon; Jean-Louis Paul

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