Tight control of cell-cell communication is essential for the generation of a normally patterned embryo. A critical mediator of key cell-cell signaling events during embryogenesis is the highly conserved Wnt family of secreted proteins. Recent biochemical and genetic analyses have greatly enriched our understanding of how Wnts signal, and the list of canonical Wnt signaling components has exploded. The data reveal that multiple extracellular, cytoplasmic, and nuclear regulators intricately modulate Wnt signaling levels. In addition, receptor-ligand specificity and feedback loops help to determine Wnt signaling outputs. Wnts are required for adult tissue maintenance, and perturbations in Wnt signaling promote both human degenerative diseases and cancer. The next few years are likely to see novel therapeutic reagents aimed at controlling Wnt signaling in order to alleviate these conditions.

/pdf/the-wnt-signaling-pathway-in-development-and-disease-z4j8s29ao8.pdf

The Wnt signaling pathway in development and disease.

Wnt/β-catenin signaling: components, mechanisms, and diseases

https://web.stanford.edu/group/nusselab/cgi-bin/wnt/sites/default/files/reviews/Cell%202012%20Clevers.pdf

Wnt/β-catenin signaling and disease.

We have previously reported suggestive linkage of type 2 diabetes mellitus to chromosome 10q. We genotyped 228 microsatellite markers in Icelandic individuals with type 2 diabetes and controls throughout a 10.5-Mb interval on 10q. A microsatellite, DG10S478, within intron 3 of the transcription factor 7-like 2 gene (TCF7L2; formerly TCF4) was associated with type 2 diabetes (P = 2.1 x 10(-9)). This was replicated in a Danish cohort (P = 4.8 x 10(-3)) and in a US cohort (P = 3.3 x 10(-9)). Compared with non-carriers, heterozygous and homozygous carriers of the at-risk alleles (38% and 7% of the population, respectively) have relative risks of 1.45 and 2.41. This corresponds to a population attributable risk of 21%. The TCF7L2 gene product is a high mobility group box-containing transcription factor previously implicated in blood glucose homeostasis. It is thought to act through regulation of proglucagon gene expression in enteroendocrine cells via the Wnt signaling pathway.

Variant of transcription factor 7-like 2 (TCF7L2) gene confers risk of type 2 diabetes.

Since the initial discovery of the oncogenic activity of WNT1 in mouse mammary glands, our appreciation for the complex roles for WNT signalling pathways in cancer has increased dramatically. WNTs and their downstream effectors regulate various processes that are important for cancer progression, including tumour initiation, tumour growth, cell senescence, cell death, differentiation and metastasis. Although WNT signalling pathways have been difficult to target, improved drug-discovery platforms and new technologies have facilitated the discovery of agents that can alter WNT signalling in preclinical models, thus setting the stage for clinical trials in humans.

WNT signalling pathways as therapeutic targets in cancer

http://www2.denizyuret.com/ref/lepourcelet/wntdrug2004.pdf

Small-molecule antagonists of the oncogenic Tcf/β-catenin protein complex

IRL 2500 [N-(3,5-dimethylbenzoyl)-N-methyl-(D)-(4-phenylphenyl)-alany l-L- tryptophan] inhibited the binding of [125I]-endothelin-1 (ET-1) to human ETB (IC50 1.3 +/- 0.2 nM) and ETA (IC50 94 +/- 3 nM) receptors expressed in transfected Chinese hamster ovary (CHO) cells. In in vitro studies, IRL 2500 inhibited the sarafotoxin S6c (STX6c)-mediated contraction of the dog saphenous vein (pKb 7.77) and the STX6c-induced relaxation of the preconstricted rabbit mesenteric artery (pKb 6.92). In the anesthetized rat, IRL 2500 (10 mg/kg, i.v.) inhibited the initial transient decrease in mean arterial pressure (MAP) induced by the ETB-selective agonist IRL 1620 (0.5 nmol/kg, i.v.). IRL 2500 also attenuated the IRL 1620-mediated increase in renal vascular resistance (RVR) in the anesthetized rat. Therefore, IRL 2500 is a potent and selective ETB receptor antagonist that can be used to delineate ET responses mediated by the ETB receptor.

Characterization of a potent and selective endothelin-B receptor antagonist, IRL 2500.

CGS 35601 is a potent triple inhibitor of endothelinconverting enzyme-1, neutral endopeptidase 24.11, and angiotensinconverting enzyme. It inhibited the activities of these three enzymes with IC50 values of 55, 2 and 22 nM, respectively. In conscious rats, CGS 35601 suppressed the big endothelin-1-induced pressor response by 82% and 72% at 30 and 120 minutes, respectively, following injection at a dose of 10 mg/kg, intravenously. At the same dose, CGS 35601 increased plasma atrial natriuretic peptide (ANP) immunoreactivity by 170% for up to 4 hours in conscious rats infused with ANP, and it inhibited the angiotensin I-induced pressor response by 74-94% within the first 2 hours after dosing. Similar in vivo activities were also observed with its orally active prodrug, CGS 37808. This compound blocked the big endothelin-1- induced pressor response by 71% and 67% at 30 and 120 minutes, respectively, after an oral dose of 10 mgEq/kg in conscious rats. It also increased plasma ANP immunoreactivity by 103% for up to 4 hours and inhibited the angiotensin I-induced pressor response by an average of 49% within the first 4 hours after the same dosing regimen. By suppressing the biosyntheses of endothelin-1 and angiotensin II, two potent vasoconstrictors, while simultaneously potentiating the circulating levels of ANP, a vasorelaxant and diuretic, CGS 35601 and CGS 37808 may represent novel agents for the treatment of cardiovascular and renal diseases.

CGS 35601 and its orally active prodrug CGS 37808 as triple inhibitors of endothelin-converting enzyme-1, neutral endopeptidase 24.11, and angiotensin-converting enzyme.

Endothelins (ETs) are potent vasoconstrictors and have been implicated in the pathogenesis of various cardiovascular and renal diseases. In contrast, atrial natriuretic peptide (ANP) is a potent vasorelaxant and diuretic agent, which is mainly degraded by neutral endopeptidase 24.11 (NEP) in vivo . Thus, compounds that can suppress the biosynthesis of ETs by inhibiting endothelin converting enzymes (ECEs), which catalyse the final step of post-translational processing of the vasoconstrictors, while simultaneously potentiating the levels of ANP by inhibiting NEP may have novel therapeutic utility. Through targeted screening of our compound library and subsequent optimization, CGS 34226 was identified as a potent, dual inhibitor of ECE-1 and NEP, inhibiting the enzymes with respective IC 50 values of 11 and 4.6nM. In vivo , CGS 34226 suppressed the big endothelin-1 (big ET-1)-induced pressor response dose-dependently. At 15 and 90min after an intravenous dose of 30mg/kg in anaesthetized rats, this compound inhibited the big ET-1-induced effect by 79% and 65% respectively. In addition, CGS 34226 increased plasma ANP immunoreactivity by 120% up to 4h after an intravenous dose of 10mg/kg in conscious rats infused with ANP at a rate of 450ng/kg per min, intravenously. These results show that CGS 34226 is a potent dual inhibitor of ECE-1 and NEP in vitro and in vivo and that the compound may represent a novel agent for the treatment of cardiovascular and renal dysfunction.

CGS 34226, a thiol-based dual inhibitor of endothelin converting enzyme-1 and neutral endopeptidase 24.11.

The purpose of this study was to examine the pharmacologic properties of CGS 35066, a novel aminophosphonate inhibitor of endothelin-converting enzyme-1 (ECE-1). CGS 35066 inhibited the activity of human ECE-1 and rat kidney neutral endopeptidase 24.11 (NEP) in vitro with IC50 values of 22 +/- 0.9 nM and 2.3 +/- 0.03 microM, respectively. The in vivo effects of CGS 35066 were characterized in conscious, catheterized rats. At 30 and 120 min after treatment with vehicle, big endothelin-1 (big ET-1, 0.3 nmol/kg i.v.) produced increases in mean arterial pressure (MAP) of 982 +/- 31 and 992 +/- 43 mmHg x min (area under the curve), respectively. Doses of 0.3, 1.0, 3.0 and 10.0 mg/kg i.v., of CGS 35066 blocked these pressor responses by 61 +/- 7, 78 +/- 4, 93 +/- 4 and 98 +/- 2% at 30 min (p < 0.05 compared with vehicle controls, all doses), and by 29 +/- 7, 63 +/- 5, 63 +/- 5 and 84 +/- 10% at 120 min (p < 0.05, all doses). In contrast, the pressor effect (58 +/- 6 mmHg) of angiotensin-I (300 ng/kg i.v.) was unaffected by the ECE-1 inhibitor (10 mg/kg i.v.) indicating the absence of activity against angiotensin-converting enzyme. In rats infused with atrial natriuretic peptide (ANP), CGS 35066, at 1 mg/kg, had no effect on plasma irANP; however, irANP levels were doubled at a dose of 30 mg/kg. These results demonstrate that CGS 35066 is the most potent and selective ECE inhibitor identified to date.

Charles W. Bruseo

Papers

Small-molecule antagonists of the oncogenic Tcf/β-catenin protein complex

Characterization of a potent and selective endothelin-B receptor antagonist, IRL 2500.

CGS 35601 and its orally active prodrug CGS 37808 as triple inhibitors of endothelin-converting enzyme-1, neutral endopeptidase 24.11, and angiotensin-converting enzyme.

CGS 34226, a thiol-based dual inhibitor of endothelin converting enzyme-1 and neutral endopeptidase 24.11.

Pharmacological properties of CGS 35066, a potent and selective endothelin-converting enzyme inhibitor, in conscious rats.