Design, Synthesis, and Biological Evaluation of Retinoic Acid-Related Orphan Receptor γt (RORγt) Agonist Structure-Based Functionality Switching Approach from In House RORγt Inverse Agonist to RORγt Agonist.

Retinoic acid receptor-related orphan receptor γt (RORγt) agonists are expected to provide a novel class of immune-activating anticancer drugs via activation of Th17 cells and Tc17 cells. Herein, we describe a novel structure-based functionality switching approach from in house well-optimized RORγt inverse agonists to potent RORγt agonists. We succeeded in the identification of potent RORγt agonist 5 without major chemical structure change. The biochemical response was validated by molecular dynamics simulation studies that showed a helix 12 stabilization effect of RORγt agonists. These results indicate that targeting helix 12 is an attractive and novel medicinal chemistry strategy for switching existing RORγt inverse agonists to agonists.

Parallel fluorescent probe synthesis based on the large-scale preparation of BODIPY FL propionic acid.

We describe a methodology for quick development of fluorescent probes with the desired potency for the target of interest by using a method of parallel synthesis, termed as Parallel Fluorescent Probe Synthesis (Parallel-FPS). BODIPY FL propionic acid 1 is a widely used fluorophore, but it is difficult to prepare a large amount of 1, which hinders its use in parallel synthesis. Optimization of a synthetic scheme enabled us to obtain 50g of 1 in one batch. With this large quantity of 1 in hand, we performed Parallel-FPS of BODIPY FL-labeled ligands for estrogen related receptor-α (ERRα). An initial trial of the parallel synthesis with various linkers provided a potent ligand for ERRα (Reporter IC50=80nM), demonstrating the usefulness of Parallel-FPS.

Optimization of (2,3-dihydro-1-benzofuran-3-yl)acetic acids: discovery of a non-free fatty acid-like, highly bioavailable G protein-coupled receptor 40/free fatty acid receptor 1 agonist as a glucose-dependent insulinotropic agent.

G protein-coupled receptor 40 (GPR40)/free fatty acid receptor 1 (FFA1) is a free fatty acid (FFA) receptor that mediates FFA-amplified glucose-stimulated insulin secretion in pancreatic ß-cells. We previously identified (2,3-dihydro-1-benzofuran-3-yl)acetic acid derivative 2 as a candidate, but it had relatively high lipophilicity. Adding a polar functional group on 2 yielded several compounds with lower lipophilicity and little effect on caspase-3/7 activity at 30 µM (a marker of toxicity in human HepG2 hepatocytes). Three optimized compounds showed promising pharmacokinetic profiles with good in vivo effects. Of these, compound 16 had the lowest lipophilicity. Metabolic analysis of 16 showed a long-acting PK profile due to high resistance to ß-oxidation. Oral administration of 16 significantly reduced plasma glucose excursion and increased insulin secretion during an OGTT in type 2 diabetic rats. Compound 16 (TAK-875) is being evaluated in human clinical trials for the treatment of type 2 diabetes.

Discovery of phenylpropanoic acid derivatives containing polar functionalities as potent and orally bioavailable G protein-coupled receptor 40 agonists for the treatment of type 2 diabetes.

As part of a program to identify potent GPR40 agonists with drug-like properties suitable for clinical development, the incorporation of polar substituents was explored with the intention of decreasing the lipophilicity of our recently disclosed phenylpropanoic acid derivative 1. This incorporation would allow us to mitigate the cytotoxicity issues observed with compound 1 and enable us to move away from the multifunctional free fatty acid-like structure. Substitutions on the 2',6'-dimethylbiphenyl ring were initially undertaken, which revealed the feasibility of introducing polar functionalities at the biphenyl 4'-position. Further optimization of this position and the linker led to the discovery of several 4'-alkoxybiphenyl derivatives, which showed potent GPR40 agonist activities with the best balance in terms of improved cytotoxicity profiles and favorable pharmacokinetic properties. Among them, 3-{2-fluoro-4-[({4'-[(4-hydroxy-1,1-dioxidotetrahydro-2H-thiopyran-4-yl)methoxy]-2',6'-dimethylbiphenyl-3-yl}methyl)amino]phenyl}propanoic acid (35) exhibited a robust plasma glucose-lowering effect and insulinotropic action during an oral glucose tolerance test in rats with impaired glucose tolerance.

Rabbit plaque models closely resembling lesions in human coronary artery disease.

BACKGROUND: A suitable animal model is required to investigate plaque biology. Here, we examined 6 rabbit models of plaque generated by balloon injury and sequential combinations of normal and high-cholesterol diets. METHODS AND RESULTS: Fifty-eight male Japanese White rabbits were used. Lipid-rich macrophages accumulated in the center of the intima, and smooth muscle cells were located on the luminal side of the intima (similar to stable plaques in human coronary arteries) of a model in which balloon injury was followed by a normal diet for 4 weeks and then by a high-cholesterol diet for 4 weeks. Extending the high-cholesterol diet for a further 4 weeks increased accumulation of lipid-rich macrophages, diminished the amounts of elastic fibers and smooth muscle cells in the intima and caused the expression of matrix metalloproteinase-9 and tissue factor. All of these features are characteristic of unstable plaques. Moreover, quantitative analysis revealed that matrix metalloproteinase-9 expression and elastic-fiber content inversely correlated with statistical significance (R(2) = 0.52, p = 0.0003). CONCLUSION: A high-cholesterol diet for 0 to 8 weeks after a normal diet for the first 4 weeks following balloon injury induced various arterial lesions resembling the diffuse intimal thickening, as well as stable and unstable plaques that accumulate in human coronary arteries. The present models might be useful for plaque studies.

Adrenal androgen dehydroepiandrosterone sulfate inhibits vascular remodeling following arterial injury.

Recent epidemiologic studies have suggested that serum dehydroepiandrosterone sulfate (DHEAS) levels have a significant inverse correlation with the incidence of cardiovascular diseases. However, direct evidence for the association with DHEAS and vascular disorders has not yet been explored. DHEAS significantly reduced neointima formation 28 days after surgery without altering other serum metabolite levels in a rabbit carotid balloon injury model. Immunohistochemical analyses revealed the reduction of proliferating cell nuclear antigen (PCNA) index and increase of TdT-mediated dUTP-biotin Nick End Labeling (TUNEL) index, expressing differentiated vascular smooth muscle cell (VSMC) markers in the media 7 days after surgery. In vitro, DHEAS exhibited inhibitory effects on VSMC proliferation and migration activities, inducing G1 cell cycle arrest with upregulation of one of the cyclin dependent kinase (CDK) inhibitors p16(INK4a) and apoptosis with activating peroxisome proliferator-activated receptor (PPAR)-alpha in VSMCs. DHEAS inhibits vascular remodeling reducing neointima formation after vascular injury via its effects on VSMC phenotypic modulation, functions and apoptosis upregulating p16(INK4a)/activating PPARalpha. DHEAS may play a pathophysiological role for vascular remodeling in cardiovascular disease.

Asymptomatic acute ischemic stroke after primary percutaneous coronary intervention in patients with acute coronary syndrome might be caused mainly by manipulating catheters or devices in the ascending aorta, regardless of the approach to the coronary artery.

BACKGROUND: Asymptomatic acute ischemic stroke (aAIS) following primary percutaneous coronary intervention (p-PCI) in patients with acute coronary syndrome (ACS) has not been studied in detail. METHODS AND RESULTS: Of 75 patients who underwent p-PCI, 26 (34.7%) developed aAIS as determined by diffusion-weighted magnetic resonance imaging (MRI). Including the approach to the coronary artery (via lower limb or right upper limb), 23 factors were compared between patients with (n=26) and without (n=49) aAIS. Age, hypertension, smoking, plasma glucose levels, Killip grade, right coronary artery (RCA) as culprit vessel, percutaneous coronary intervention (PCI) time, and the frequency of device insertion into the coronary artery differed in a statistically significant manner. However, multivariate analysis showed that the RCA (odds ratio 3.477) and the frequency of device insertion (1.375) were independent factors linked to the incidence of aAIS. Moreover, anterior or posterior location and left or right cerebral circulation of aAIS were equivalent in both approaches. CONCLUSIONS: Cranial MRI images following emergency PCI revealed that 34.7% of the patients with ACS had aAIS that might be caused by manipulating the catheter or devices in the ascending aorta, micro-air bubble embolism during injection, or micro-thrombus embolism derived from the ACS lesions during the PCI procedure.

Re-entry circuit in ventricular tachycardia due to focal fatty-fibrosis in a patient with myotonic dystrophy.

A 69-year-old man with a recurrent ventricular tachycardia (VT) was admitted. The patient was diagnosed as myotonic dystrophy type 1 (DM1) and DNA analysis revealed 1,800 CTG-repeat expansion in the myotonic dystrophy protein kinase (DMPK) gene. Ultrasonic cardiogram (UCG), left ventriculogram (LVG) and magnetic resonance imaging (MRI) did not show any abnormal sign including fatty infiltration. But, endomyocardial biopsy obtained from ventricular outflow tract revealed severe fatty infiltration and interstitial fibrosis. Radiofrequency catheter ablation at the biopsy site could eliminate VT, so it was strongly suggested that the re-entry circuit was formed by focal fatty-fibrosis. Careful observation should be continued for a long period.

Axillo-axillary bypass for in-stent restenosis in Takayasu arteritis.

We report a patient with Takayasu arteritis (TA) who initially received stent placement (SP) following percutaneous transluminal balloon angioplasty for stenotic lesion of the left subclavian artery and subsequently had recurrent in-stent restenosis three times. Every time restenosis occurred, percutaneous transluminal rotational arterectomy (RA) was performed. After all, the patient underwent axillo-axillary bypass and has remained asymptomatic for 10 months after the surgery. We suggest that surgical treatment is beneficial for in-stent restenosis in patient with Takayasu arteritis.

Different migratory and proliferative properties of smooth muscle cells of coronary and femoral artery.

In the human coronary arteries, the intima begins to thicken from early adolescence and shows progressive thickening with age. We compared the response to vascular injury of the coronary and femoral arteries using a canine model. Both incorporation of 5-bromo-2'-deoxyuridine (BrdU) and neointimal formation after balloon injury were significantly greater in the coronary artery than in the femoral artery. Also, the proliferative and migratory activities of coronary smooth muscle cells (SMCs) were significantly greater than those of femoral SMCs in vitro. The level of phosphorylated myosin light chain (phospho-MLC) was higher in coronary SMCs than in femoral SMCs. Y-27632, a specific inhibitor of Rho-kinase, significantly inhibited the PDGF-induced migration of both coronary and femoral SMCs. In contrast, the migration of coronary SMCs, but not femoral SMCs, was inhibited by ML-9, a specific inhibitor of myosin light chain kinase (MLCK). These findings suggest that the contribution of Rho-kinase and MLCK differs between the different arteries. They also suggest that a neointima develops more easily in the coronary artery than in the femoral artery because of the greater proliferative and migratory activity of coronary SMCs. Differential activation of MLC might partly explain the increased proliferation and migration of coronary SMCs.

Successful catheter interventional therapy for acute coronary syndrome secondary to kawasaki disease in young adults.

Acute coronary syndrome occurred in 2 young adults who had a history of Kawasaki disease (KD), but few other coronary risk factors. The first patient was a 27-year-old male with acute myocardial infarction without stenosis detected by coronary arteriography 4 years earlier. Emergency coronary arteriography showed occlusion of the right coronary artery. Aspiration-thrombectomy and rescue balloon angioplasty were successfully performed. The second patient was a 32-year-old male with unstable angina. Right coronary arteriography showed total occlusion with severe calcification. Left coronary arteriography showed 99% stenosis at the proximal site of the circumflex artery, and a directional coronary atherectomy was performed. Histological examination of a specimen from this site revealed a lipid core, macrophages, and smooth muscle cells. Restenosis was not observed on follow-up coronary arteriography after 5-6 months in either case. The coronary stenosis in each case was probably caused by accelerated atherosclerosis at the site without aneurysm as it seemed to be 'normal' on arteriography. Conventional catheter intervention was effective treatment. The sequelae of KD should be recognized as independent coronary risk factors.