Pharmacological profile of a new, potent, and long-acting gonadotropin-releasing hormone antagonist: degarelix

We describe the pharmacological profile in rats and monkeys of degarelix (FE200486), a member of a new class of long-acting gonadotropin-releasing hormone (GnRH) antagonists. At single subcutaneous injections of 0.3 to 10 microg/kg in rats, degarelix produced a dose-dependent suppression of the pituitary-gonadal axis as revealed by the decrease in plasma luteinizing hormone (LH) and testosterone levels. Duration of LH suppression increased with the dose: in the rat, significant suppression of LH lasted 1, 2, and 7 days after a single subcutaneous injection of degarelix at 12.5, 50, or 200 microg/kg, respectively. Degarelix fully suppressed plasma LH and testosterone levels in the castrated and intact rats as well as in the ovariectomized rhesus monkey for more than 40 days after a single 2-mg/kg subcutaneous injection. In comparative experiments, degarelix showed a longer duration of action than the recently developed GnRH antagonists abarelix, ganirelix, cetrorelix, and azaline B. The in vivo mechanism of action of degarelix was consistent with competitive antagonism, and the prolonged action of degarelix was paralleled by continued presence of radioimmunoassayable degarelix in the general circulation. In contrast to cetrorelix and similarly to ganirelix and abarelix, degarelix had only weak histamine-releasing properties in vitro. These results demonstrate that the unique and favorable pharmacological properties of degarelix make it an ideal candidate for the management of sex steroid-dependent pathologies requiring long-term inhibition of the gonadotropic axis

Partially purified rabbit gastric lipase: in vitro and in vivo experiments to assess its potential contribution to gastric and intestinal lipolysis

In vitro and in vivo experiments were undertaken to evaluate enzyme-replacement therapy with an acid stable lipase preparation in pancreatic lipase insufficiency. Utilizing an emulsion of [1- 14C] trioleylglycerol, partially purified rabbit gastric lipase exhibited a maximal specific activity of 6.45 μmoles FFA/h, a K m of 80 mM, an optimal peak activities at pH 4.86 and 5.48, and stability in acidic medium. Although preferential lipolysis of medium chain fatty acid ester bonds was evidenced by experiments with a commercial formula (Similac R) containing 28% MCT (C 6−C 8−C 10−C 12), the gastric lipase preparation also displayed ability to split the long chain fatty acid ester bonds in a fine emulsion of triglycerides for IV use (Intralipid R). Triacylglycerol hydrolysis was enhanced either by 4 mM Na-taurocholate or 4 mM Na-glycocholate, and remained unchanged following the addition of these bile salts at 8 mM. These in vitro findings suggested that the gastric lipase preparation was biologically active under the conditions prevailing in the stomach and in the upper small intestine. To investigate its in vivo lipolytic activity exogenous rabbit gastric lipase was added to the stomach of rats with ligated pylorus and oesophagus. With long-chain triacylglycerols as substrate, a 40% increase of ester bond cleavage occurred during 1 h of intragastric incubation, relative to rats from which exogenous enzymes were excluded. Similarly, a level of 40% hydrolysis was reached into the intestine of rats with a diversion of pancreatobiliary secretions. Our studies clearly indicate that hydrolysis of dietary fat may be initiated into the stomach by exogenous gastric lipase preparation and may continue in the upper small intestine. On the basis of these findings, studies in humans with this enzyme preparation appear warranted to define its role in the management of patients with exocrine pancreatic insufficiency who do not respond satisfactorily to currently available enzyme preparations

Cloning and characterization of dipeptidyl peptidase 10, a new member of an emerging subgroup of serine proteases.

Two dipeptidyl peptidase IV (DPPIV, DPP4)-related proteins, DPP8 and DPP9, have been identified recently [Abbott, Yu, Woollatt, Sutherland, McCaughan, and Gorrell (2000) Eur. J. Biochem. 267, 6140-6150; Olsen and Wagtmann (2002) Gene 299, 185-193; Qi, Akinsanya, Riviere, and Junien (2002) Patent application WO0231134]. In the present study, we describe the cloning of DPP10, a novel 796-amino-acid protein, with significant sequence identity to DPP4 (32%) and DPP6 (51%) respectively. We propose that DPP10 is a new member of the S9B serine proteases subfamily. The DPP10 gene is located on the long arm of chromosome 2 (2q12.3-2q14.2), close to the DPP4 (2q24.3) and FAP (2q23) genes. The active-site serine residue is replaced by a glycine residue in DPP10, resulting in the loss of DPP activity. The serine residue is also replaced in DPP6, which lacks peptidase activity. DPP8 and DPP9 share an identical active site with DPP4 (Gly-Trp-Ser-Tyr-Gly). In contrast with the previous results suggesting that DPP9 is inactive, we show that DPP9 is a DPP, hydrolysing Ala-Pro-(7-amino-4-methyl-coumarin) with similar pH-specificity and protease-inhibitor-sensitivity to those of DPP4 and DPP8. Northern-blot analysis shows that whereas DPP8 and DPP9 are widely expressed, DPP10 is expressed mainly in the brain and pancreas. DPP6, which has the highest amino acid identity with DPP10, has been shown previously [Nadal, Ozaita, Amarillo, de Miera, Ma, Mo, Goldberg, Misumi, Ikehara, Neubert et al. (2003) Neuron 37, 449-461] to associate with A-type K(+) channel subunits, modulating their transport and function in somatodendritic compartments of neurons. It is possible that DPP10 is involved in similar functions in the brain. Elucidation of the physiological or pathophysiological role of DPP8, DPP9 and DPP10 and characterization of their structure-function relationships will add impetus to the development of inhibitor molecules for pharmacological or therapeutic use

Chronic inhibition of circulating dipeptidyl peptidase IV by FE 999011 delays the occurrence of diabetes in male zucker diabetic fatty rats

Acute suppression of dipeptidyl peptidase IV (DPP-IV) activity improves glucose tolerance in the Zucker fatty rat, a rodent model of impaired glucose tolerance, through stabilization of glucagon-like peptide (GLP)-1. This study describes the effects of a new and potent DPP-IV inhibitor, FE 999011, which is able to suppress plasma DPP-IV activity for 12 h after a single oral administration. In the Zucker fatty rat, FE 999011 dose-dependently attenuated glucose excursion during an oral glucose tolerance test and increased GLP-1 (7-36) release in response to intraduodenal glucose. Chronic treatment with FE 999011 (10 mg/kg, twice a day for 7 days) improved glucose tolerance, as suggested by a decrease in the insulin-to-glucose ratio. In the Zucker diabetic fatty (ZDF) rat, a rodent model of type 2 diabetes, chronic treatment with FE 999011 (10 mg/kg per os, once or twice a day) postponed the development of diabetes, with the twice-a-day treatment delaying the onset of hyperglycemia by 21 days. In addition, treatment with FE 999011 stabilized food and water intake to prediabetic levels and reduced hypertriglyceridemia while preventing the rise in circulating free fatty acids. At the end of treatment, basal plasma GLP-1 levels were increased, and pancreatic gene expression for GLP-1 receptor was significantly upregulated. This study demonstrates that DPP-IV inhibitors such as FE 999011 could be of clinical value to delay the progression from impaired glucose tolerance to type 2 diabetes

Pan-PPAR agonist lanifibranor improves portal hypertension and hepatic fibrosis in experimental advanced chronic liver disease.

BACKGROUND AIMS In advanced chronic liver disease (ACLD), de-regulated hepatic necroinflammatory processes play a key role in the development of liver microvascular dysfunction, fibrogenesis, and increased hepatic vascular tone, resulting in progression of ACLD and portal hypertension. Given the current lack of an effective treatment, we aimed at characterizing the effects of the pan-peroxisome proliferator-activated receptors (pan-PPAR) agonist lanifibranor in two pre-clinical models of ACLD, as well as in liver cells from patients with ACLD. METHODS Cirrhotic rats (thioacetamide or common bile duct ligation; TAA or cBDL) randomly received lanifibranor (100mg/kg/day, po) or vehicle for 14 days (n=12/group). PPAR expression, systemic and hepatic hemodynamics, presence of ascites, liver sinusoidal endothelial cells (LSEC) phenotype, hepatic stellate cells (HSC) activation, serum transaminases and albumin, hepatic macrophage infiltration, cytokine expression, and liver fibrosis were determined. Hepatic cells were isolated from livers from cirrhotic patients and their phenotype was evaluated after treatment with lanifibranor or vehicle. RESULTS TAA-cirrhotic rats receiving lanifibranor showed significantly lower portal pressure than vehicle-treated animals (-15%) without decreasing portal blood flow, indicating improved hepatic vascular resistance. Moreover, lanifibranor-treated TAA-rats showed decreased ascites, improved phenotype of LSEC and HSC, ameliorated hepatic microvascular function, reduced hepatic inflammation, and significant fibrosis regression (-32%). These findings were confirmed in the cBDL rat model, as well as in human liver cells from cirrhotic patients, which exhibited a phenotypic improvement upon treatment with lanifibranor. CONCLUSIONS This study demonstrates that lanifibranor exerts clear beneficial effects in pre-clinical models of decompensated cirrhosis, which lead to amelioration in fibrosis and portal hypertension. Our results in human hepatic cells isolated from cirrhotic patients further encourage its clinical evaluation for the treatment of ACLD

Odiparcil, a potential glycosaminoglycans clearance therapy in mucopolysaccharidosis VI—Evidence from in vitro and in vivo models

International audienceMucopolysaccharidoses are a class of lysosomal storage diseases, characterized by enzymatic deficiency in the degradation of specific glycosaminoglycans (GAG). Pathological accumulation of excess GAG leads to multiple clinical symptoms with systemic character, most severely affecting bones, muscles and connective tissues. Current therapies include periodic intravenous infusion of supplementary recombinant enzyme (Enzyme Replacement Therapy-ERT) or bone marrow transplantation. However, ERT has limited efficacy due to poor penetration in some organs and tissues. Here, we investigated the potential of the β-D-xyloside derivative odiparcil as an oral GAG clearance therapy for Maroteaux-Lamy syndrome (Mucopolysaccharidosis type VI, MPS VI). In vitro, in bovine aortic endothelial cells, odiparcil stimulated the secretion of sulphated GAG into culture media, mainly of chondroitin sulphate (CS) /dermatan sulphate (DS) type. Efficacy of odiparcil in reducing intracellular GAG content was investigated in skin fibroblasts from MPS VI patients where odiparcil was shown to reduce efficiently the accumulation of intracellular CS with an EC50 in the range of 1 μM. In vivo, in wild type rats, after oral administrations, odiparcil was well distributed, achieving μM concentrations in MPS VI disease-relevant tissues and organs (bone, cartilage, heart and cornea). In MPS VI Arylsulphatase B deficient mice (Arsb-), after chronic oral administration, odiparcil consistently stimulated the urinary excretion of sulphated GAG throughout the treatment period and significantly reduced tissue GAG accumulation in liver and kidney. Furthermore, odiparcil diminished the pathological cartilage thickening observed in trachea and femoral growth plates of MPS VI mice. The therapeutic efficacy of odiparcil was similar in models of early (treatment starting in juvenile, 4 weeks old mice) or established disease (treatment starting in adult, 3 months old mice). Our data demonstrate that odiparcil effectively diverts the synthesis of cellular glycosaminoglycans into secreted soluble species and this effect can be used for reducing cellular and tissue GAG accumulation in MPS VI models. Therefore, our data reveal the potential of odiparcil as an oral GAG clearance therapy for MPS VI patients