Renoprotective Effect of TP0472993, a Novel and Selective 20-Hydroxyeicosatetraenoic Acid Synthesis Inhibitor, in Mouse Models of Renal Fibrosis.

Kidney fibrosis is considered the essential pathophysiological process for the progression of chronic kidney disease (CKD) toward renal failure. 20-Hydroxyeicosatetraenoic acid (20-HETE) has crucial roles in modulating the vascular response in the kidney and the progression of albuminuria. However, the roles of 20-HETE in kidney fibrosis are largely unexplored. In the current research, we hypothesized that if 20-HETE has important roles in the progression of kidney fibrosis, 20-HETE synthesis inhibitors might be effective against kidney fibrosis. To verify our hypothesis, this study investigated the effect of a novel and selective 20-HETE synthesis inhibitor, TP0472993, on the development of kidney fibrosis after folic acid- and obstructive-induced nephropathy in mice. Chronic treatment with TP0472993 at doses of 0.3 and 3 mg/kg twice a day attenuated the degree of kidney fibrosis in the folic acid nephropathy and the unilateral ureteral obstruction (UUO) mice, as demonstrated by reductions in Masson's trichrome staining and the renal collagen content. In addition, TP0472993 reduced renal inflammation, as demonstrated by markedly reducing interleukin-1ß (IL-1ß) and tumor necrosis factor alpha (TNF-α) levels in the renal tissue. Chronic treatment with TP0472993 also reduced the activity of extracellular signal-regulated kinase 1/2 (ERK1/2) and signal transducer and activator of transcription 3 (STAT3) in the kidney of UUO mice. Our observations indicate that inhibition of 20-HETE production with TP0472993 suppresses the kidney fibrosis progression via a reduction in the ERK1/2 and STAT3 signaling pathway, suggesting that 20-HETE synthesis inhibitors might be a novel treatment option against CKD. SIGNIFICANCE STATEMENT: In this study, we demonstrate that the pharmacological blockade of 20-hydroxyeicosatetraenoic acid (20-HETE) synthesis using TP0472993 suppresses the progression of kidney fibrosis after folic acid- and obstructive-induced nephropathy in mice, indicating that 20-HETE might have key roles in the pathogenesis of kidney fibrosis. TP0472993 has the potential to be a novel therapeutic approach against chronic kidney disease.

Discovery of Novel Pyrazolylpyridine Derivatives for 20-Hydroxyeicosatetraenoic Acid Synthase Inhibitors with Selective CYP4A11/4F2 Inhibition.

20-Hydroxyeicosatetraenoic acid (20-HETE) is one of the major oxidized arachidonic acid (AA) metabolites produced by cytochrome P450 (CYP) 4A11 and CYP4F2 isozymes in the human liver and kidney. Numerous studies have suggested the involvement of 20-HETE in the pathogenesis of renal diseases, and suppression of 20-HETE production by inhibition of CYP4A11 and CYP4F2 may be an attractive therapeutic strategy for renal diseases. At first, we identified methylthiazole derivative 2 as a potent dual inhibitor of CYP4A11 and CYP4F2. An optimization study of a series of derivatives with a molecular weight of around 300 to improve aqueous solubility and selectivity against drug-metabolizing CYPs while maintaining the CYP4A11- and CYP4F2-inhibitory activities led to the identification of acetylpiperidine compound 11c. Compound 11c inhibited 20-HETE production in both human and rat renal microsomes and exhibited a favorable pharmacokinetic profile. Furthermore, 11c also significantly inhibited renal 20-HETE production in Sprague-Dawley rats after oral dosing at 0.1 mg/kg.

Synthesis and Structure-Activity Relationship of C-Phenyl D-Glucitol (TP0454614) Derivatives as Selective Sodium-Dependent Glucose Cotransporter 1 (SGLT1) Inhibitors.

Sodium-glucose cotransporter 1 (SGLT1) is the primary transporter for glucose absorption from the gastrointestinal tract. While C-phenyl D-glucitol derivative SGL5213 has been reported to be a potent intestinal SGLT1 inhibitor for use in the treatment of type 2 diabetes, no SGLT1 selectivity was found in vitro (IC50 29 nM for hSGLT1 and 20 nM for hSGLT2). In this study we found a new method of synthesizing key intermediates 12 by a one-pot three-component condensation reaction and discovered C-phenyl D-glucitol 41j (TP0454614), which has >40-fold SGLT1 selectivity in vitro (IC50 26 nM for hSGLT1 and 1101 nM for hSGLT2). The results of our study have provided new insights into the structure-activity relationships (SARs) of the SGLT1 selectivity of C-glucitol derivatives.

TP0463518, a Novel Prolyl Hydroxylase Inhibitor, Specifically Induces Erythropoietin Production in the Liver.

Prolyl hydroxylase (PHD) 1/2/3 pan inhibitors are known to potentially induce erythropoietin (EPO) production in both the kidney and liver. The 2-[[1-[[6-(4-chlorophenoxy)pyridin-3-yl]methyl]-4-hydroxy-6-oxo-2,3-dihydropyridine-5-carbonyl]amino]acetic acid (TP0463518) is a novel PHD 1/2/3 pan inhibitor; however, the main source of EPO production after TP0463518 administration remained to be investigated. We examined the effect of TP0463518 in inducing EPO production in the kidney and liver by measuring the hypoxia-inducible factor 2α (HIF-2α), EPO mRNA, and serum EPO levels in normal and bilaterally nephrectomized rats. Furthermore, we examined whether liver-derived EPO improved anemia in 5/6 nephrectomized (5/6 Nx) rats. TP0463518 scarcely increased the HIF-2α and EPO mRNA expression levels in the kidney cortex, whereas oral administration of TP0463518 at 40 mg/kg dramatically increased the HIF-2α level from 0.27 to 1.53 fmol/mg and the EPO mRNA expression level by 1300-fold in the livers of healthy rats. After administration of TP0463518 at 20 mg/kg, the total EPO mRNA expression level in the whole liver was 22-fold that in the whole kidney. In bilaterally nephrectomized rats, TP0463518 raised the serum EPO concentration from 0 to 180 pg/ml at 20 mg/kg. Furthermore, repeated administration of TP0463518 at 10 mg/kg increased the reticulocyte count in 5/6 Nx rats on day 7 and raised the hemoglobin level on day 14. The present study revealed that TP0463518 specifically induced EPO production in the liver and improved anemia. The characteristic feature of TP0463518 would lead to not only a more detailed understanding of the PHD-HIF2α-EPO pathway in erythropoiesis, but a new therapeutic alternative for renal anemia. SIGNIFICANCE STATEMENT: Prolyl hydroxylase (PHD) 1/2/3 pan inhibitors are known to potentially induce erythropoietin (EPO) production in both the kidney and liver; however, their effects on renal EPO production have been shown to vary depending on the experimental conditions. The authors found that 2-[[1-[[6-(4-chlorophenoxy)pyridin-3-yl]methyl]-4-hydroxy-6-oxo-2,3-dihydropyridine-5-carbonyl]amino]acetic acid (TP0463518), a PHD 1/2/3 pan inhibitor, specifically induced EPO production in the liver and that the liver-derived EPO was pharmacologically effective. Investigation of the effects of TP0463518 may pave the way for the development of a new therapeutic alternative for renal anemia patients.

SGL5213, a novel and potent intestinal SGLT1 inhibitor, suppresses intestinal glucose absorption and enhances plasma GLP-1 and GLP-2 secretion in rats.

Sodium-glucose cotransporter 1 (SGLT1) is the primary transporter for glucose absorption from digested nutrients in the gastrointestinal tract. Intestinal SGLT1 inhibition reduces post-prandial hyperglycemia and enhances the increase of plasma glucagon-like peptide-1 (GLP-1) levels. SGL5213 is a novel and potent intestinal SGLT1 inhibitor. This study characterizes the pharmacological profiles of SGL5213 in rodents. Orally administered SGL5213 was hardly absorbed and its distribution was restricted to the gastrointestinal lumen. SGL5213 significantly improved post-prandial hyperglycemia in streptozotocin (STZ)-induced diabetic rats at doses of 1 mg/kg or more. After the oral administration of starch, SGL5213 increased the amount of residual glucose in the small intestine at 1-3 h and in the cecum and colon at 3-9 h by inhibiting glucose absorption and allowing the unabsorbed glucose to be delivered into the lower-gastrointestinal tract. In the vehicle group, the plasma total GLP-1 (tGLP-1) and tGLP-2 levels increased at 15 min and the plasma total glucose-dependent insulinotropic polypeptide (tGIP) level increased at 1 h after meal loading. SGL5213 at doses of 0.1 mg/kg or more enabled the plasma levels of tGLP-1 and tGLP-2 to be retained for a period of 1-6 h, compared with the vehicle group. In contrast, SGL5213 at doses of 0.3 mg/kg or more suppressed the plasma tGIP elevation after meal loading. This study demonstrated for the first time that an intestinal SGLT1 inhibitor enhanced post-prandial plasma GLP-2 secretion. These results suggest that SGL5213 might exhibit a useful pharmacological efficacy through the physiological actions of GLP-1 and GLP-2.

TP0463518, a novel inhibitor for hypoxia-inducible factor prolyl hydroxylases, increases erythropoietin in rodents and monkeys with a good pharmacokinetics-pharmacodynamics correlation.

Hypoxia-inducible factor prolyl hydroxylases (PHDs) inhibitor stabilizes hypoxia inducible factor alpha, which increases erythropoietin (EPO) expression via the hypoxia response element. Therefore, PHDs inhibitors have been developed as novel therapeutic agents for anemia. Here, we characterize the in vitro and in vivo pharmacological profiles of TP0463518, 2-[[1-[[6-(4-chlorophenoxy)pyridin-3-yl]methyl]-4-hydroxy-6-oxo-2,3-dihydropyridine-5-carbonyl]amino]acetic acid, a novel potent PHDs inhibitor. TP0463518 competitively inhibited human PHD2 with a Ki value of 5.3 nM. TP0463518 also inhibited human PHD1/3 with IC50 values of 18 and 63 nM as well as monkey PHD2 with an IC50 value of 22 nM. In normal mice and rats, TP0463518 significantly increased the serum EPO levels at doses of 5 and 20 mg/kg, respectively. The correlation factors for serum EPO and the serum TP0463518 levels were 0.95 in mice and 0.92 in rats. TP0463518 also increased the serum EPO level in 5/6 nephrectomized chronic kidney disease model rats at a dose of 10 mg/kg, with a correlation factor for serum EPO and the serum TP0463518 levels of 0.82. Finally, the effect of TP0463518 in monkeys was investigated. TP0463518 was promptly removed with a half-life of 5.2 h and increased the area under the curve (AUC) of EPO at a dose of 5 mg/kg. The EPO and TP0463518 levels were also correlated. These results suggest that TP0463518 induces endogenous EPO with a strong pharmacokinetic-pharmacodynamic correlation and may contribute to desirable hemoglobin control in patients with renal anemia.

Discovery of novel 2-[(4-hydroxy-6-oxo-2,3-dihydro-1H-pyridine-5-carbonyl)amino]acetic acid derivatives as HIF prolyl hydroxylase inhibitors for treatment of renal anemia.

Prolyl hydroxylase domain-containing protein (PHD) inhibitors are useful as orally administered agents for the treatment of renal anemia. Based on the common structures of known PHD inhibitors, we found novel PHD inhibitor 1 with a 2-[(4-hydroxy-6-oxo-2,3-dihydro-1H-pyridine-5-carbonyl)amino]acetic acid motif. The PHD2-inhibitory activity, lipophilicity (CLogP), and PK profiles (hepatocyte metabolism, protein binding, and/or elimination half-life) of this inhibitor were used as the evaluation index to optimize the structure and eventually discovered clinical candidate 42 as the suitable compound. Compound 42 was demonstrated to promote the production of erythropoietin (EPO) following oral administration in mice and rats. The predicted half-life of this compound in humans was 1.3-5.6 h, therefore, this drug may be expected to administer once daily with few adverse effects caused by excessive EPO production.

Discovery of novel (4-piperidinyl)-piperazines as potent and orally active acetyl-CoA carboxylase 1/2 non-selective inhibitors: F-Boc and triF-Boc groups are acid-stable bioisosteres for the Boc group.

Novel (4-piperidinyl)-piperazine derivatives were synthesized and evaluated as ACC1/2 non-selective inhibitors. Optimization of the substituents on the nitrogen of the piperidine ring led to the identification of the fluorine substituted tert-butoxycarbonyl group. Advanced analog, 1,1,1-trifluoro-2-methylpropan-2-yl 4-{4-[(2-amino-6-methyl-1-benzothiophen-3-yl)carbonyl]piperazin-1-yl}piperidine-1-carboxylate (12c) showed potent inhibitory activities in enzyme-assay and cell-based assays. Compound 12c also exhibited reduction of hepatic de novo fatty acid synthesis in rats after oral administration.

Design and synthesis of disubstituted (4-piperidinyl)-piperazine derivatives as potent acetyl-CoA carboxylase inhibitors.

Acetyl-CoA carboxylases (ACCs), the rate limiting enzymes in de novo lipid synthesis, play important roles in modulating energy metabolism. The inhibition of ACC has demonstrated promising therapeutic potential for treating obesity and type 2 diabetes mellitus in transgenic mice and preclinical animal models. We describe herein the structure-based design and synthesis of a novel series of disubstituted (4-piperidinyl)-piperazine derivatives as ACC inhibitors. Our structure-based approach led to the discovery of the indole derivatives 13i and 13j, which exhibited potent in vitro ACC inhibitory activity.

(4-Piperidinyl)-piperazine: a new platform for acetyl-CoA carboxylase inhibitors.

Acetyl-CoA carboxylases (ACCs), the rate limiting enzymes in de novo lipid synthesis, play important roles in modulating energy metabolism. The inhibition of ACC has demonstrated promising therapeutic potential for treating obesity and type 2 diabetes mellitus in transgenic mice and preclinical animal models. We describe herein the synthesis and structure-activity relationships of a series of disubstituted (4-piperidinyl)-piperazine derivatives as a new platform for ACC1/2 non-selective inhibitors.