HIF-PHD inhibitor desidustat ameliorates iron deficiency anemia.

Iron deficiency anemia is caused by many pathological conditions like chronic kidney disease (CKD), inflammation, malnutrition and gastrointestinal abnormality. Current treatments that are erythropoiesis stimulating agents (ESAs) and iron supplementation are inadequate and often lead to tolerance and/or toxicity. Desidustat, a prolyl hydroxylase (PHD) inhibitor, is clinically used for the treatment of anemia with CKD. In this study, we investigated the effect of desidustat on iron deficiency anemia (IDA). IDA was induced in C57BL6/J mice by iron deficient diet feeding. These mice were then treated with desidustat (15 mg/kg, PO) and FeSO4 (20 mg/kg) for five weeks and effect of the treatment on hematology, iron homeostasis, and bone marrow histology was observed. Effect of desidustat on iron metabolism in inflammation (LPS)-induced iron deficiency was also assessed. Both, Desidustat and FeSO4, increased MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin), hemoglobin, and HCT (hematocrit) in blood and increased iron in serum, liver, and spleen. Desidustat increased MCHC (mean corpuscular hemoglobin concentration) while FeSO4 treatment did not alter it. FeSO4 treatment significantly increased iron deposition in liver, and spleen, while desidustat increased iron in circulation and demonstrated efficient iron utilization. Desidustat increased iron absorption, serum iron and decreased hepcidin without altering tissue iron, while FeSO4 increased serum and tissue iron by increasing hepcidin in LPS-induced iron deficiency. Desidustat increased erythroid population, especially iron-dependent polychromatic normoblasts and orthochromatic normoblasts, while FeSO4 did not improve cell architecture. PHD inhibition by desidustat improved iron utilization in iron deficiency anemia, by efficient erythropoiesis.

Microsomal triglyceride transfer protein inhibitor lomitapide-induced liver toxicity is ameliorated by Triiodothyronine treatment following improved bile homeostasis and ß-oxidation.

Dyslipidemia or its severe version like familial hypercholesterolemia causes a high risk for cardiovascular diseases. Lomitapide, a microsomal triglyceride transfer protein inhibitor, is approved to treat familial hypercholesterolemia, associated with liver fat accumulation. In this work, we investigated the effect of the combination of lomitapide and triiodothyronine (T3) in Zucker fatty rats. Lomitapide (1 mg/kg, PO), or T3 (13 µg/kg, PO), or their combination, were given to these rats once daily for fourteen days. Body weight and food intake were recorded once daily during the treatment period. Serum and hepatic lipids, glucose tolerance, serum aminotransferases, bile fluids, hepatic gene expression, and liver histology were assessed at the end of the treatment. Lomitapide treatment reduced body weight, food intake, glucose intolerance, and serum lipids, and elevated serum aminotransferases and liver lipids. When combined with T3, lomitapide showed an enhanced reduction in body weight, food intake, serum cholesterol, serum LDL, and glucose intolerance. The combination treatment increased bile flow rate and biliary cholesterol excretion rate. Combining T3 with lomitapide attenuated the elevation of serum aminotransferases and liver lipids. Hepatic ABCB11, ABCG5, ABCG8, CYP7A1, CPT1, and ACOX1 expressions were increased with combination treatment. Histological analysis indicated that T3 attenuated hepatic fat accumulation caused by lomitapide. These data suggests that combining lomitapide with T3 may reduce lomitapide-induced hepatic toxicity and provide additional benefits in obesity and glucose intolerance.

Discovery of novel, potent and orally efficacious inhibitor of neutral amino acid transporter B0AT1 (SLC6A19).

Amino acid restriction by inhibition of neutral amino acid transporter, B0AT1 (SLC6A19) activity has been recently shown to improve glyceamic control by upregulating glucagon like peptide (GLP1) and fibroblast growth factor (FGF21) in mice. Hence, pharmacological inhibition of B0AT1 is expected to treat type-2 diabetes and related disorder. In this study, rationally designed trifluoromethyl sulfonyl derivatives were identified as novel, potent and orally bioavailable B0AT1 inhibitors. Compound 39 was found to be nanomolar potent (IC50: 0.035 µM) B0AT1 inhibitor with excellent pharmacokinetic profile (%F: 66) in mice and efficacious in vivo in diet induced obese (DIO) mice model.

Role of mineralocorticoid receptor antagonists in kidney diseases.

Mineralocorticoid receptor (MR) antagonists, for example, spironolactone and eplerenone, are in clinical use to treat hypertension. Increasing evidence suggests that mineralocorticoid receptor activation causes the pathogenesis and progression of chronic kidney disease. Aldosterone-induced MR activation increases inflammation, fibrosis, and oxidative stress in the kidney. MR antagonists (MRAs) have demonstrated therapeutic actions in chronic kidney disease (CKD), diabetic nephropathy (DN), renal fibrosis, and drug-induced renal injury in preclinical and clinical studies. We have summarized and discussed these studies in this review. The nonsteroidal MRA, esaxerenone, recently received approval for the treatment of hypertension. It has also shown a positive therapeutic effect in phase 3 clinical trials in patients with DN. Other nonsteroidal MRA such as apararenone, finerenone, AZD9977, and LY2623091 are in different clinical trials in patients with hypertension suffering from renal or hepatic fibrotic diseases. Hyperkalemia associated with MRA therapy has frequently led to the discontinuation of the treatment. The new generation nonsteroidal MRAs like esaxerenone are less likely to cause hyperkalemia at therapeutic doses. It appears that the nonsteroidal MRAs can provide optimum therapeutic benefit for patients suffering from kidney diseases.

Prolyl hydroxylase inhibitor desidustat protects against acute and chronic kidney injury by reducing inflammatory cytokines and oxidative stress.

Chronic kidney disease (CKD) is associated with activated inflammatory responses. Desidustat, a prolyl hydroxylase (PHD) inhibitor is useful for treatment of anemia associated with CKD, but its effect on the inflammatory and fibrotic changes in CKD is not evaluated. In this study, we investigated the effect of desidustat on the inflammatory and fibrotic changes in preclinical models of acute and chronic kidney injury. Acute kidney injury was induced in male Sprague Dawley rats by ischemia-reperfusion, in which effect of desidustat (15 mg/kg, PO) was estimated. In a separate experiment, male C57 mice were treated with adenine for 14 days to induce CKD. These mice were treated with desidustat (15 mg/kg, PO, alternate day) treatment for 14 days, with adenine continued. Desidustat prevented elevation of serum creatinine, urea, IL-1ß, IL-6, and kidney injury molecule-1 (KIM-1), and elevated the erythropoietin levels in rats that were subjected to acute kidney injury. Mice treated with adenine developed CKD and anemia, and desidustat treatment caused improvement in serum creatinine, urea, and also improved hemoglobin and reduced hepatic and serum hepcidin. A significant reduction in IL-1ß, IL-6, myeloperoxidase (MPO) and oxidative stress was observed by desidustat treatment. Desidustat treatment also reduced renal fibrosis as observed by histological analysis and hydroxyproline content. Desidustat treatment reduced the renal fibrosis and inflammation along with a reduction in anemia in preclinical models of kidney injury, which may translate to protective effects in CKD patients.

Coagonist of glucagon-like peptide-1 and glucagon receptors ameliorates nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is often associated with obesity and type 2 diabetes. Coagonists of glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR) are under clinical investigation for the treatment of obesity and type 2 diabetes. In this study, we have demonstrated the effect of a balanced coagonist in the treatment of NAFLD using mouse models. GLP-1R agonist exendin-4, glucagon, and coagonist (Aib2 C24 chimera2) were administered to C57BL6/J mice, in which NAFLD was induced by carbon tetrachloride (CCl4) treatment after high-fat diet (HFD) feeding, and choline-deficient, L-amino-acid-defined HFD (CDAHFD) feeding. Repeated dose administration of coagonist significantly attenuated liver inflammation and steatosis induced by acute and long-term treatment with CCl4 in HFD-fed mice. Coagonist markedly attenuated the CDAHFD-induced expression of TIMP-1, MMP-9, TNF-α, MCP-1, COL1A1, and α-SMA. It also inhibited progression of hepatic steatosis and fibrosis in mice. Exendin-4 was better than glucagon, but coagonist was most effective in reduction of hepatic inflammation as well as steatosis. Coagonist of GLP-1R and GCGR improved NAFLD in C57BL6/J mice. This effect is mediated by reduction in lipotoxicity and inflammation in liver.

Influence of acute and chronic kidney failure in rats on the disposition and pharmacokinetics of ZYAN1, a novel prolyl hydroxylase inhibitor, for the treatment of chronic kidney disease-induced anemia.

1. ZYAN1 is a prolyl hydroxylase inhibitor in clinical development for treatment of anemia associated with chronic kidney disease (CKD). We evaluated the effect of acute and chronic kidney impairment on the pharmacokinetics of ZYAN1 in rat models. 2. Cisplatin (2.5, 5 and 7.5 mg/kg) was used to induce acute kidney injury (AKI), and five-sixth and total nephrectomy was used to induce chronic kidney injury (CKI) in male Wistar rats. All groups received a single 15 mg/kg oral dose of ZYAN1. Blood/urine samples were analyzed for ZYAN1 to assess peak concentration (Cmax), area under the concentration-time curve (AUCinf), total body clearance (CL/F) and elimination half-life (T1/2). 3. Cmax and AUCinf were not significantly different in the various AKI groups or in five-sixth nephrectomized rats, as compared to control rats. Recovery of ZYAN1 in urine was reduced; the impact on the CL/F was minimal. There was a 2-fold increase in AUCinf with reduction in CL/F in total nephrectomized rats. T1/2 was longer for ZYAN1 in the severe AKI/five-sixth nephrectomy rats and total nephrectomy rats as compared to control rats. 4. Based on the rodent data it may be inferred that PK of ZYAN1 in CKD patients may be minimally affected.

Central GLP-1 receptor activation improves cholesterol metabolism partially independent of its effect on food intake.

Glucagon-like peptide-1 (GLP-1) receptor agonists modulate lipid metabolism, apart from controlling glucose homeostasis. We investigated the role of central GLP-1 receptor (GLP-1R) agonism in regulation of hepatic lipid metabolism in cholesterol-fed hamsters. Cholesterol-fed hamsters were treated by intracerebroventricular (i.c.v.) route with exendin-4, as acute or repeated dose regimen and compared with hamsters pair-fed to the exendin-treated hamsters and with hamsters co-treated with GLP-1 antagonist exendin-9. Effect of acute treatment was observed on food intake, tyloxapol-induced hypertriglyceridemia, and corn oil induced post prandial lipemia. Plasma and hepatic lipids and changes in the expression of hepatic genes involved in lipid metabolism were assessed after chronic administration. Acute, as well as repeated dose, treatment of exendin-4 showed significant changes in hepatic lipids, circulating fatty acids, triglycerides, LDL, and cholesterol. Expression of SREBP-1c was reduced while that of LDLR and CYP7A1 was increased after the repeated dose treatment, and there was no change in HMG CoA reductase. These changes were blocked by co-treatment of exendin-9, and not replicated by pair feeding to the significant extent. Central GLP-1 receptor activation showed profound effects on peripheral lipid metabolism, which were partially independent of its effect on food intake.

Design, synthesis and biological evaluation of novel aminomethyl-piperidones based DPP-IV inhibitors.

A series of novel aminomethyl-piperidones were designed and evaluated as potential DPP-IV inhibitors. Optimized analogue 12v ((4S,5S)-5-(aminomethyl)-1-(2-(benzo[d][1,3]dioxol-5-yl)ethyl)-4-(2,5-difluorophenyl)piperidin-2-one) showed excellent in vitro potency and selectivity for DPP-IV over other serine proteases. The lead compound 12v showed potent and long acting antihyperglycemic effects (in vivo), along with improved pharmacokinetic profile.

Cannabinoid receptor 1 antagonist treatment induces glucagon release and shows an additive therapeutic effect with GLP-1 agonist in diet-induced obese mice.

Cannabinoid 1 (CB1) receptor antagonists reduce body weight and improve insulin sensitivity. Preclinical data indicates that an acute dose of CB1 antagonist rimonabant causes an increase in blood glucose. A stable analog of glucagon-like peptide 1 (GLP-1), exendin-4 improves glucose-stimulated insulin secretion in pancreas, and reduces appetite through activation of GLP-1 receptors in the central nervous system and liver. We hypothesized that the insulin secretagogue effect of GLP-1 agonist exendin-4 may synergize with the insulin-sensitizing action of rimonabant. Intraperitoneal as well as intracerebroventricular administration of rimonabant increased serum glucose upon glucose challenge in overnight fasted, diet-induced obese C57 mice, with concomitant rise in serum glucagon levels. Exendin-4 reversed the acute hyperglycemia induced by rimonabant. The combination of exendin-4 and rimonabant showed an additive effect in the food intake, and sustained body weight reduction upon repeated dosing. The acute efficacy of both the compounds was additive for inducing nausea-like symptoms in conditioned aversion test in mice, whereas exendin-4 treatment antagonized the effect of rimonabant on forced swim test upon chronic dosing. Thus, the addition of exendin-4 to rimonabant produces greater reduction in food intake owing to increased aversion, but reduces the other central nervous system side effects of rimonabant. The hyperglucagonemia induced by rimonabant is partially responsible for enhancing the antiobesity effect of exendin-4.

The Perspective of Using Flow Cytometry for Unpuzzling Hypoxia-Inducible Factors Signalling.

Hypoxia-inducible factors (HIFs) are transcription factors that are responsible for adapting to the changes in oxygen levels in the cellular environment. HIF activity determines the expression of cellular proteins that control the development and physiology of the cells and pathophysiology of a disease. Understanding the role of specific HIF (HIF-1-3) in cellular function is essential for development of the HIF-targeted therapies. In this review, we have discussed the use of flow cytometry in analysing HIF function in cells. Proper understanding of HIF-signalling will help to design pharmacological interventions HIF-mediated therapy. We have discussed the role of HIF-signalling in various diseases such as cancer, renal and liver diseases, ulcerative colitis, arthritis, diabetes and diabetic complications, psoriasis, and wound healing. We have also discussed protocols that help to decipher the role of HIFs in these diseases that would eventually help to design promising therapies.

Age-related changes in hematological and biochemical profiles of Wistar rats.

BACKGROUND: Wistar rats are extensively used as the model for assessing toxicity and efficacy in preclinical research. Hematological and biochemical laboratory data are essential for evaluating specific variations in the physiological and functional profile of a laboratory animal. Establishing hematological and biochemical reference values for Wistar (han) rats at various age intervals was the goal of this work. Male and female Wistar rats (n = 660) of ages 6-8 weeks, 10-14 weeks and > 6 months were used in the experiment. Blood and serum were collected from these rats under fasting conditions. RESULTS: We observed that the majority of hematological and biochemical parameters were significantly influenced by sex and age. Hematological changes were significantly correlated to aging were increased red blood cells, hemoglobin, hematocrit, neutrophils, monocytes and eosinophils in both sexes, as well as decreased platelet, mean corpuscular volume, mean corpuscular hemoglobin and lymphocytes in both sexes. White blood cells of male rats were considerably higher than those of female rats in all age ranges. For biochemistry, increase in glucose, total protein and creatinine were seen in both sexes, along with increases in urea in females and alanine aminotransferase in males. Age was significantly associated with decreased alkaline phosphatase in both sexes. CONCLUSIONS: When using Wistar rats as a model, these reference values may be useful in evaluating the results.

HIF Stabilizer Desidustat Protects against Complement-Mediated Diseases.

Complement cascade is a defence mechanism useful for eliminating pathogenic microorganisms and damaged cells. However, activation of alternative complement system can also cause inflammation and promote kidney and retinal disease progression. Inflammation causes tissue hypoxia, which induces hypoxia-inducible factor (HIF) and HIF helps the body to adapt to inflammation. In this study, we investigated the effect of HIF stabilizer desidustat in complement-mediated diseases. Oral administration of desidustat (15 mg/kg) was effective to reduce the kidney injury in mice that was induced by either lipopolysaccharide (LPS), doxorubicin or bovine serum albumin (BSA)-overload. Complement activation-induced membrane attack complex (MAC) formation and factor B activity were also reduced by desidustat treatment. In addition, desidustat was effective against membranous nephropathy caused by cationic BSA and retinal degeneration induced by sodium iodate in mice. C3-deposition, proteinuria, malondialdehyde, and interleukin-1ß were decreased and superoxide dismutase was increased by desidustat treatment in cBSA-induced membranous nephropathy. Desidustat specifically inhibited alternative complement system, without affecting the lectin-, or classical complement pathway. This effect appears to be mediated by inhibition of factor B. These data demonstrate the potential therapeutic value of HIF stabilization by desidustat in treatment of complement-mediated diseases.

Apigenin-6-C-glucoside ameliorates MASLD in rodent models via selective agonism of adiponectin receptor 2.

Adiponectin plays key roles in energy metabolism and ameliorates inflammation, oxidative stress, and mitochondrial dysfunction via its primary receptors, adiponectin receptors -1 and 2 (AdipoR1 and AdipoR2). Systemic depletion of adiponectin causes various metabolic disorders, including MASLD; however adiponectin supplementation is not yet achievable owing to its large size and oligomerization-associated complexities. Small-molecule AdipoR agonists, thus, may provide viable therapeutic options against metabolic disorders. Using a novel luciferase reporter-based assay here, we have identified Apigenin-6-C-glucoside (ACG), but not apigenin, as a specific agonist for the liver-rich AdipoR isoform, AdipoR2 (EC50: 384 pM) with >10000X preference over AdipoR1. Immunoblot analysis in HEK-293 overexpressing AdipoR2 or HepG2 and PLC/PRF/5 liver cell lines revealed rapid AMPK, p38 activation and induction of typical AdipoR targets PGC-1α and PPARα by ACG at a pharmacologically relevant concentration of 100 nM (reported cMax in mouse; 297 nM). ACG-mediated AdipoR2 activation culminated in a favorable modulation of key metabolic events, including decreased inflammation, oxidative stress, mitochondrial dysfunction, de novo lipogenesis, and increased fatty acid ß-oxidation as determined by immunoblotting, QRT-PCR and extracellular flux analysis. AdipoR2 depletion or AMPK/p38 inhibition dampened these effects. The in vitro results were recapitulated in two different murine models of MASLD, where ACG at 10 mg/kg body weight robustly reduced hepatic steatosis, fibrosis, proinflammatory macrophage numbers, and increased hepatic glycogen content. Together, using in vitro experiments and rodent models, we demonstrate a proof-of-concept for AdipoR2 as a therapeutic target for MASLD and provide novel chemicobiological insights for the generation of translation-worthy pharmacological agents.

Co-agonist of glucagon and GLP-1 reduces cholesterol and improves insulin sensitivity independent of its effect on appetite and body weight in diet-induced obese C57 mice.

Dual agonism of glucagon and glucagon-like peptide-1 (GLP-1) receptors reduce body weight without inducing hyperglycemia in rodents. However, the effect of a co-agonist on insulin sensitivity and lipid metabolism has not been thoroughly assessed. Diet-induced obese (DIO) mice received 0.5 mg·kg(-1) of co-agonist or 2.5 mg·kg(-1) of glucagon or 8 µg·kg(-1) of exendin-4 by subcutaneous route, twice daily, for 28 days. A separate group of mice was pair-fed to the co-agonist-treated group for 28 days. Co-agonist treatment reduced food intake and reduced body weight up to 28 days. In addition, it reduced leptin levels and increased fibroblast growth factor 21 (FGF21) levels in plasma, when compared with control and pair-fed groups. Co-agonist treatment decreased triglyceride levels in serum and liver and reduced serum cholesterol, mainly due to reduction in low-density lipoprotein (LDL) cholesterol. These changes were not seen with pair-fed controls. Co-agonist treatment improved glucose tolerance and increased insulin sensitivity, as observed during glucose and insulin-tolerance test, hyperinsulinemic clamp, and reduced gluconeogenesis, as observed in pyruvate-tolerance test. The effects on insulin sensitivity and lipid levels are mostly independent of the food intake or body weight lowering effect of the co-agonist.

Uncovering Novel Therapeutic Targets for Parkinson's Disease.

Parkinson's disease (PD) is the second most prevailing progressive disorder leading to neurodegeneration, typically in people above 65 years of age. Motor clinical manifestations of PD appear in a much later stage and include rigidity, tremors, akinesia, and gait dysfunction. There are also nonmotor symptoms like GI and olfactory dysfunction. However, they cannot be considered for diagnosis of the disease, as they are unspecific. PD pathogenesis is mainly characterized by deposits of inclusion bodies on dopaminergic (DA) neurons in substantia nigra pars compacta region (SNpc) of the brain. The major component of these inclusion bodies, are α-synuclein aggregates. α-Synuclein undergoes misfolding and oligomerization to form aggregates and fibrils. These aggregates gradually propagate PD pathology. Other prominent features of this pathological development include mitochondrial dysfunction, neuroinflammation, oxidative stress, and impaired autophagy. These all contribute to neuronal degeneration. Besides this, there are many underlying factors which influence these processes. These factors comprise molecular proteins and signaling cascades. In this review, we have listed out underexplored molecular targets that may aid in development of neoteric and advanced therapeutics.

Long-acting peptidomimetics based DPP-IV inhibitors.

Pyrrolidine based peptidomimetics are reported as potent and selective DPP-IV inhibitors for the treatment of T2DM. Compounds 16c and 16d showed excellent in vitro potency and selectivity towards DPP-IV and the lead compound 16c showed sustained antihyperglycemic effects, along with improved pharmacokinetic profile.

Discovery of liver selective non-steroidal glucocorticoid receptor antagonist as novel antidiabetic agents.

Series of benzyl-phenoxybenzyl amino-phenyl acid derivatives (8a-q) are reported as non-steroidal GR antagonist. Compound 8g showed excellent h-GR binding and potent antagonistic activity (in vitro). The lead compound 8g exhibited significant oral antidiabetic and antihyperlipidemic effects (in vivo), along with liver selectivity. These preliminary results confirm discovery of potent and liver selective passive GR antagonist for the treatment of T2DM.

Discovery of potent, selective and orally bioavailable triaryl-sulfonamide based PTP1B inhibitors.

A novel series of pTyr mimetics containing triaryl-sulfonamide derivatives (5a-r) are reported as potent and selective PTP1B inhibitors. Some of the test compounds (5o and 5p) showed excellent selectivity towards PTP1B over various PTPs, including TCPTP (in vitro). The lead compound 5o showed potent antidiabetic activity (in vivo), along with improved pharmacokinetic profile. These preliminary results confirm discovery of highly potent and selective PTP1B inhibitors for the treatment of T2DM.

Inhibition of 11ß-hydroxysteroid dehydrogenase 1 by carbenoxolone affects glucose homeostasis and obesity in db/db mice.

1. One of the major causes of metabolic syndrome is elevated 11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD1) in the liver and adipose tissue. High 11ß-HSD1 expression contributes significantly to the diabetic phenotype in db/db mice. The purpose of the present study was to test the effect of the pharmacological inhibition of 11ß-HSD1 inhibition by carbenoxolone in db/db mice, a genetic model of diabetes. 2. Inhibition of 11ß-HSD1 by carbenoxolone was evaluated in liver homogenates obtained from untreated mice. At 0.4, 0.8, 1.6 and 3.2 µmol/L, carbenoxolone reduced the conversion of cortisone to cortisol by 21%, 48%, 82% and 95%, respectively. 3. In another series of experiments in which female db/db mice were dosed orally with carbenoxolone (10, 25 and 50 mg/kg, twice daily) for 10 days, dose-dependent decreases were observed in 11ß-HSD1 activity in the brain, adipose and liver. In the case of 10 mg/kg carbenoxolone, the effects were not significant. In addition, the bodyweight of female db/db mice was reduced by 10% and 13% following treatment with 10 and 50 mg/kg carbenoxolone, respectively. Carbenoxolone treatment dose-dependently improved fat mass, energy expenditure, the serum lipid profile, serum leptin and insulin and glucose tolerance. Furthermore, 50 mg/kg carbenoxolone reduced both phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) activity in the liver by 75% and 52%, respectively. These decreases were associated with increased glucokinase protein expression and activity in the liver. 4. Carbenoxolone inhibition of 11ß-HSD1 in the liver, adipose and brain significantly improves the symptoms of metabolic syndrome in db/db mice. These improvements can be attributed to increased energy expenditure, decreased activity of the gluconeogenic enzymes PEPCK and G6Pase in the liver and improved glucokinase function in the liver and pancreas.