Antidyslipidemic potential of a novel farnesoid X receptor antagonist in a hamster model of dyslipidemia: Comparative studies of other nonstatin agents.

We attempted to clarify the therapeutic capability of antagonists of the farnesoid X receptor (FXR), a nuclear receptor that regulates lipid and bile acid metabolism. Herein, we report the antidyslipidemic effects of a novel synthesized FXR antagonist, compound-T1, utilizing a dyslipidemic hamster model. Compound-T1 selectively inhibited chenodeoxycholic acid-induced FXR activation (IC 50, 2.1 nmol·L-1). A hamster model of diet-induced hyperlipidemia was prepared to investigate the antidyslipidemic effects of compound-T1 through comparative studies of the nonstatin lipid-modulating agents ezetimibe, cholestyramine, and torcetrapib. In the hamster model, compound-T1 (6 mg·kg-1·day-1, p.o.) increased the level of plasma high-density lipoprotein (HDL)-cholesterol (+22.2%) and decreased the levels of plasma non-HDL-cholesterol (-43.6%) and triglycerides (-31.1%). Compound-T1 also increased hepatic cholesterol 7α-hydroxylase expression and fecal bile acid excretion, and decreased hepatic cholesterol content. Moreover, the hamster model could reflect clinical results of other nonstatin agents. Torcetrapib especially increased large HDL particles compared with compound-T1. Additionally, in the human hepatoma Huh-7 cells, compound-T1 enhanced apolipoprotein A-I secretion at a concentration close to its IC 50 value for FXR. Our results indicated the usefulness of the hamster model in evaluating FXR antagonists and nonstatin agents. Notably, compound-T1 exhibited beneficial effects on both blood non-HDL-cholesterol and HDL-cholesterol, which are thought to involve enhancement of cholesterol catabolism and apolipoprotein A-I production. These findings aid the understanding of the antidyslipidemic potential of FXR antagonists with a unique lipid and bile acid modulation.

Farnesoid X receptor antagonist exacerbates dyslipidemia in mice.

BACKGROUND: The effects of farnesoid X receptor (FXR) antagonists on plasma lipid profile in mice have not been investigated thus far. The aim of this study was to investigate the antidyslipidemic effects of an FXR antagonist in dyslipidemic mice, and to clarify the mechanisms underlying the lipid modulatory effect. METHODS: Compound-T0 (1-100 mg/kg) was orally administered to C57BL/6J mice fed a Western-type diet or low-density lipoprotein receptor knockout (LDLR-/-) mice fed a Western-type diet for a week, and plasma lipid levels were investigated. Effects on lipid clearance, hepatic triglyceride secretion after Triton WR-1339 challenge, and intestinal lipid absorption were investigated after multiple dosing. RESULTS: Compound-T0 significantly increased plasma level of non-high-density lipoprotein cholesterol in both C57BL/6 and LDLR-/- mice; in addition, it significantly increased plasma triglyceride level in LDLR-/- mice. Compound-T0 failed to enhance the clearance of 3,3'-dioctadecylindocarbocyanine (DiI)-labeled LDL in C57BL/6J mice. Although compound-T0 did not affect triglyceride clearance and hepatic triglyceride secretion, it significantly increased intestinal [3H]cholesterol absorption in LDLR-/- mice. CONCLUSIONS: It was found that the FXR antagonist, compound-T0 exacerbated dyslipidemia in mice because it enhanced intestinal lipid absorption via acceleration of bile acid excretion.

Synthesis and evaluation of hedgehog signaling inhibitor with novel core system.

As we previously reported, N-methylpyrrolo[3,2-c]pyridine derivatives 1 (TAK-441) was discovered as a clinical candidate of hedgehog (Hh) signaling inhibitor by modification of the upper part. We next focused on modification of the lower part including core skeletons to discover new Hh signaling inhibitors with novel core rings. Efforts to find novel chemotypes by using X-ray single crystal structure analysis led to some potent Hh signaling inhibitors (2c, 2d, 2e, 2f) with novel core ring systems, which had benzamide moiety at the 5-position as a key component for potent activity. The suppression of Gli1 expression with these new Hh signaling inhibitors were weaker than that of compound 1 (TAK-441) because of low pharmacokinetic property. We recognized again TAK-441 is a good compound as clinical candidate with good structural and pharmacokinetic advantages.

[Establishment of a short-form screening test for malnutrition in a newly developed comprehensive geriatric assessment initiative named 'Dr. SUPERMAN'].

AIM: Assessment of the nutritional state is important in comprehensive geriatric assessment (CGA). Several standardized screening tests for malnutrition are available such as the Mini-Nutritional Assessment (MNA) and MNA-Short Form (MNA-SF). However, it takes more than 10 minutes to perform the MNA-SF alone. We have developed a CGA initiative named 'Dr. SUPERMAN', which is designed to accomplish CGA within 10 minutes. In this study, we evaluated a short-form screening test for malnutrition preceding the MNA. METHODS: The MNA-SF, which consists of 6 items (A-F), was administered to 163 elderly outpatients (mean age: 83.4 years, 80 men) with various diseases. Using the results of the MNA-SF score (normal ≥ 12 and abnormal ≤ 11) as a gold standard, the sensitivity, specificity, and positive predictive values (PPVs) of each item were calculated and the best combination of 2 items for identifying malnutrition among the elderly outpatients was selected. According to the combination of 2 items (item B: weight loss during the last 3 months; item F: body mass index (BMI)/calf circumference (CC) in cm), they were divided into 2 groups: the normal control (NC) group (neither items B nor F) and the malnutrition/at risk (MN) group (either items B or D, or both). Findings of the clinical feature, anthropometric measurement, and nutritional biomarker between the 2 groups were examined to clarify the characteristics of each. RESULTS: The MNA-SF score was distributed as follows: 3-7 in 12 cases, 8-11 in 68 cases, and 12-14 in 83 cases. Based on the MNA-SF score, the combination of items B and F revealed the highest sensitivity (91.3%), specificity (63.9%), and PPV (70.9%), resulting in 103 cases in the MN group and 60 cases in the NC group. A high frequency of anorexia, living alone, hypoprealbuminemia, lymphocytopenia, and dehydration was observed in the MN group, whereas a high frequency of leg edema was observed in the NC group. Cases showing a positive wall-occiput test, which compelled the alternation of CC with BMI, accounted for 24% of all cases. CONCLUSIONS: The combination of 'weight loss during the last 3 months' and initial BMI ≥ 23/CC <31 cm along with a positive wall-occiput test was a useful and valuable SF screening test for malnutrition in elderly outpatients.

Discovery of the investigational drug TAK-441, a pyrrolo[3,2-c]pyridine derivative, as a highly potent and orally active hedgehog signaling inhibitor: modification of the core skeleton for improved solubility.

We recently reported the discovery of the novel pyrrolo[3,2-c]quinoline-4-one derivative 1 as a potent inhibitor of Hedgehog (Hh) pathway signaling. However, the PK evaluation of 1 at high dosage (100 mg/kg) revealed the C(max) value 3.63 µg/mL, likely due to poor solubility of this compound. Efforts to improve solubility by reducing the aromatic ring count of the core system led to N-methylpyrrolo[3,2-c]pyridine derivative 11. Further optimization of the 3-alkoxy group led to compound 11d with acceptable solubility and potent Hh inhibitory activity. Compound 11d suppressed transcription factor Gli1 mRNA expression in tumor-associated stromal tissue and inhibited tumor growth (treatment/control ratio, 3%) in a mouse medulloblastoma allograft model owing to the improved PK profile based on increased solubility. Compound 11d (TAK-441) is currently in clinical trials for the treatment of advanced solid tumors.

Discovery of pyrrolo[3,2-c]quinoline-4-one derivatives as novel hedgehog signaling inhibitors.

The Hedgehog (Hh) signaling pathway plays a significant role in the regulation of cell growth and differentiation during embryonic development. Since activation of the Hh signaling pathway is implicated in several types of human cancers, inhibitors of this pathway could be promising anticancer agents. Using high throughput screening, thieno[3,2-c]quinoline-4-one derivative 9a was identified as a compound of interest with potent in vitro activity but poor metabolic stability. Our efforts focused on enhancement of in vitro inhibitory activity and metabolic stability, including core ring conversion and side chain optimization. This led to the discovery of pyrrolo[3,2-c]quinoline-4-one derivative 12b, which has a structure distinct from previously reported Hh signaling inhibitors. Compound 12b suppressed stromal Gli1 mRNA expression in a murine model and demonstrated antitumor activity in a murine medulloblastoma allograft model.