Identification of phenylsulfone-substituted quinoxaline (WYE-672) as a tissue selective liver X-receptor (LXR) agonist.

A series of phenyl sulfone substituted quinoxaline were prepared and the lead compound 13 (WYE-672) was shown to be a tissue selective LXR Agonist. Compound 13 demonstrated partial agonism for LXRbeta in kidney HEK-293 cells but did not activate Gal4 LXRbeta fusion proteins in huh-7 liver cells. Although 13 showed potent binding affinity to LXRbeta (IC(50) = 53 nM), it had little binding affinity for LXRalpha (IC(50) > 1.

Improvement of physiochemical properties of the tetrahydroazepinoindole series of farnesoid X receptor (FXR) agonists: beneficial modulation of lipids in primates.

In an effort to develop orally active farnesoid X receptor (FXR) agonists, a series of tetrahydroazepinoindoles with appended solubilizing amine functionalities were synthesized. The crystal structure of the previously disclosed FXR agonist, 1 (FXR-450), aided in the design of compounds with tethered solubilizing functionalities designed to reach the solvent cavity around the hFXR receptor. These compounds were soluble in 0.

Circulating cytokine levels in prostate cancer patients undergoing radiation therapy: influence of neoadjuvant total androgen suppression.

Background: The purpose of this study was to investigate the immunological impact of combining neoadjuvant total androgen suppression (TAS) with radiotherapy (xRT) in the treatment of prostate cancer by monitoring blood cytokine levels.

Patients And Methods: Participants were stage I-II prostate cancer patients receiving xRT alone (n=18) or TAS+xRT (n=19) under the procedures outlined in RTOG protocols #94-08 and #94-13. Peripheral blood samples were collected immediately prior to TAS (xRT+TAS group), immediately prior to xRT, 24 hours after initiation of xRT, and weekly during xRT.

Pyrrole[2,3-d]azepino compounds as agonists of the farnesoid X receptor (FXR).

Pyrrole[2,3-d]azepines have been identified as potent agonists of the farnesoid X receptor (FXR). Based on the planar X-ray crystal structure of WAY-362450 1 in the ligand binding domain and molecular modeling studies, non-planar reduced compounds were designed which led to agonists that exhibit high aqueous solubility and retain moderate in vitro potency.

LXR ligand lowers LDL cholesterol in primates, is lipid neutral in hamster, and reduces atherosclerosis in mouse.

Liver X receptors (LXRs) are ligand-activated transcription factors that coordinate regulation of gene expression involved in several cellular functions but most notably cholesterol homeostasis encompassing cholesterol transport, catabolism, and absorption. WAY-252623 (LXR-623) is a highly selective and orally bioavailable synthetic modulator of LXR, which demonstrated efficacy for reducing lesion progression in the murine LDLR(-/-) atherosclerosis model with no associated increase in hepatic lipogenesis either in this model or Syrian hamsters. In nonhuman primates with normal lipid levels, WAY-252623 significantly reduced total (50-55%) and LDL-cholesterol (LDLc) (70-77%) in a time- and dose-dependent manner as well as increased expression of the target genes ABCA1/G1 in peripheral blood cells.

Radioprotection of murine gastrointestinal epithelium by interleukin-1alpha involves down-regulation of the apoptotic response.

Background: Interleukin-1alpha (IL-1) is known to radioprotect the gastrointestinal tract, but the mechanism by which this protection occurs remains unclear. These studies were undertaken to investigate whether the radioprotective potential of IL-1 may be linked to an ability to reduce apoptosis within the gastrointestinal crypts.

Materials And Methods: IL-1 was administered to C57Bl/6 mice 24 hours prior to receiving 8 Gy abdominal X-irradiation (xRT).

Activation of farnesoid X receptor prevents atherosclerotic lesion formation in LDLR-/- and apoE-/- mice.

The role of farnesoid X receptor (FXR) in the development of atherosclerosis has been unclear. Here, LDL receptor (LDLR(-/-)) or apolipoprotein E (apoE(-/-)) female or male mice were fed a Western diet and treated with a potent synthetic FXR agonist, WAY-362450. Activation of FXR blocked diet-induced hypertriglyceridemia and elevations of non-HDL cholesterol and produced a near complete inhibition of aortic lesion formation.

A synthetic farnesoid X receptor (FXR) agonist promotes cholesterol lowering in models of dyslipidemia.

The nuclear hormone receptor farnesoid X receptor (FXR) plays a critical role in the regulation of bile acid, triglyceride (TG), and cholesterol homeostasis. WAY-362450 (FXR-450/XL335) is a potent synthetic FXR agonist as characterized in luciferase reporter assays and in mediating FXR target gene regulation in primary human and immortalized mouse hepatocytes. In vivo, WAY-362450 dose dependently decreased serum TG levels after 7 days of oral dosing in western diet-fed low-density lipoprotein receptor-/- mice and in the diabetic mouse strains KK-Ay and db/db comparable to that achieved with the peroxisome proliferator activated receptor-alpha agonist, fenofibrate.

Indazole-based liver X receptor (LXR) modulators with maintained atherosclerotic lesion reduction activity but diminished stimulation of hepatic triglyceride synthesis.

A series of substituted 2-benzyl-3-aryl-7-trifluoromethylindazoles were prepared as LXR modulators. These compounds were partial agonists in transactivation assays when compared to 1 (T0901317) and were slightly weaker with respect to potency and efficacy on LXRalpha than on LXRbeta. Lead compounds in this series 12 (WAY-252623) and 13 (WAY-214950) showed less lipid accumulation in HepG2 cells than potent full agonists 1 and 3 (WAY-254011) but were comparable in efficacy to 1 and 3 with respect to cholesterol efflux in THP-1 foam cells, albeit weaker in potency.

Discovery and implementation of transcriptional biomarkers of synthetic LXR agonists in peripheral blood cells.

Background: LXRs (Liver X Receptor alpha and beta) are nuclear receptors that act as ligand-activated transcription factors. LXR activation causes upregulation of genes involved in reverse cholesterol transport (RCT), including ABCA1 and ABCG1 transporters, in macrophage and intestine. Anti-atherosclerotic effects of synthetic LXR agonists in murine models suggest clinical utility for such compounds.

Loss of small heterodimer partner expression in the liver protects against dyslipidemia.

Multiple studies suggest increased conversion of cholesterol to bile acids by cholesterol 7alpha-hydroxylase (CYP7A1) protects against dyslipidemia and atherosclerosis. CYP7A1 expression is repressed by the sequential activity of two nuclear hormone receptors, farnesoid X receptor (FXR) and small heterodimer partner (SHP). Here we demonstrate 129 strain SHP(-/-) mice are protected against hypercholesterolemia resulting from either a cholesterol/cholic acid (chol/CA) diet or from hypothyroidism.

Inhibition of the CaM-kinases augments cell death in response to oxygen radicals and oxygen radical inducing cancer therapies in MCF-7 human breast cancer cells.

Many cancer treatments induce cell death through lethal oxidative stress. Oxidative stress also induces the activation of the calcium/calmodulin-dependent kinases (CaM-Ks), CaM-KII and CaM-KIV. In turn, the CaM-Ks are known to induce the activation of antiapoptotic signaling pathways, such as Akt, ERK, and NF-kappaB in many different cell types.

The nuclear hormone receptor farnesoid X receptor (FXR) is activated by androsterone.

Farnesoid X receptor (FXR) uses bile acids as endogenous ligands. Here, we demonstrate that androsterone, a metabolic product of testosterone, is also an FXR ligand. Treatment of castrated male mice with androsterone induced expression of the FXR target gene small heterodimer partner (SHP).

Response of T lymphocyte populations in prostate cancer patients undergoing radiotherapy: influence of neoajuvant total androgen suppression.

Background: This study sought to better define the immunological impact of combining neoadjuvant total androgen suppression (TAS) with radiotherapy (xRT) in treating prostate cancer.

Materials And Methods: Subjects selected (n = 37) were stage I-II prostate cancer patients meeting the eligibility requirements for RTOG protocols 94-08 or 94-13. Flow cytometric monitoring of circulating T helper (Th), T suppressor/cytotoxic (Ts), natural killer (NK) and B lymphocytes was performed weekly.

Bile acid signaling through FXR induces intracellular adhesion molecule-1 expression in mouse liver and human hepatocytes.

Previous studies have demonstrated a dramatic induction of inflammatory gene expression in livers from mice fed a high-fat, high-cholesterol diet containing cholate after 3-5 wk. To determine the contribution of cholate in mediating these inductions, C57BL/6 mice were fed a chow diet supplemented with increasing concentrations of cholic acid (CA) for 5 days. A dose-dependent induction in the hepatic levels of TNF-alpha, VCAM-1, ICAM-1, and SAA-2 mRNA were observed.

Improved methods for extracting RNA from exfoliated human colonocytes in stool and RT-PCR analysis.

In order to diagnose colon cancer at an earlier, more localized stage, there is a need to develop diagnostic markers (genes) which can detect early patterns of gene expression in exfoliated colonocytes shed in the stool during routine screening for this disease. An RNA-based detection is more pertinent than either a DNA-based or a protein-based method as a screening procedure, but it has not been widely used as a cancer screen because of the difficulty of handling and stabilizing the RNA molecule. We describe a method that permits extraction of intact nondegraded total RNA from human colonocytes in stool and from normal and malignant colon tissues (which were employed for comparison with stool).

Murine hematopoietic stem cell and stromal responses to clinically-related, fractionated radiotherapy (FxRT).

The response of the blood-forming and supportive stromal compartments of the marrow to a localized, fractionated course of radiotherapy [FxRT; 2.0 Gy (q24 h x 5)-->74 Gy] was examined in the C57Bl/6 mouse using the hematopoietic progenitor and the cobblestone-forming cell (CAFC) assays as end-points for the blood-forming compartment and the long-term bone marrow culture (LTBMC) to assess stromal integrity. Both during and subsequent to FxRT, hematopoietic activity in the irradiated femur was significantly dampened, although an abortive attempt at recovery was observed subsequent to the completion of FxRT.

Estrogen receptor alpha regulates expression of the orphan receptor small heterodimer partner.

Hormonal status can influence diverse metabolic pathways. Small heterodimer partner (SHP) is an orphan nuclear receptor that can modulate the activity of several transcription factors. Estrogens are here shown to directly induce expression of the SHP in the mouse and rat liver and in human HepG2 cells.

Global transcription profiling of estrogen activity: estrogen receptor alpha regulates gene expression in the kidney.

Estrogen receptors (ERs) are expressed in numerous organs, although only a few organs are considered classical targets for estrogens. We have completed a systematic survey of estrogen regulation of approximately 10,000 genes in 13 tissues from wild-type and ERbetaKO mice treated sc with vehicle or 17beta-estradiol (E2) for 6 wk. The uterus and pituitary had the greatest number of genes regulated by E2, whereas the kidney had the third largest number of regulated genes.

Estrogen receptors alpha and beta have similar activities in multiple endothelial cell pathways.

The presence of both estrogen receptor alpha (ERalpha) and ERbeta in vascular cells has greatly increased the complexity of potential estrogen regulatory pathways in the cardiovascular system. Here, human umbilical vein endothelial cells were engineered using adenovirus vectors to express either ERalpha or ERbeta. The activities of ERalpha and ERbeta were compared in three distinct gene regulatory pathways, including inhibition of IL-1beta induction of E-selectin expression, inhibition of basal endothelin-1 production, and the ability to induce two matrix-stabilizing enzymes: tissue transglutaminase and a novel member of the lysyl oxidase family.

Estrogen receptor alpha inhibits IL-1beta induction of gene expression in the mouse liver.

Estrogens have been suggested to modulate several inflammatory processes. Here, we show that IL-1beta treatment induced the expression of approximately 75 genes in the liver of ovariectomized mice. 17alpha-Ethinyl estradiol (EE) pretreatment reduced the IL-1beta induction of approximately one third of these genes.