scholarly journals Effects of CRN04894, a Nonpeptide Orally Bioavailable ACTH Antagonist, on Corticosterone in Rodent Models of ACTH Excess

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A167-A167
Author(s):  
Melissa A Fowler ◽  
Ana Karin Kusnetzow ◽  
Sangdon Han ◽  
Greg Reinhart ◽  
Sun Hee Kim ◽  
...  

Abstract CRN04894 is an orally administered nonpeptide that is a potent and selective antagonist for adrenocorticotropic hormone (ACTH) acting at the melanocortin 2 receptor (MC2R) and is currently under development for the treatment of diseases of ACTH excess such as Cushing’s disease, congenital adrenal hyperplasia, and ectopic ACTH-secreting tumors. Cushing’s disease results from an adenoma derived from pituitary corticotropic cells that secrete excess ACTH, whereas ectopic ACTH syndrome arises from nonpituitary ACTH secreting tumors. Congenital adrenal hyperplasia is a genetic disease that results in cortisol deficiency leading to high levels of ACTH and adrenal androgens. Each of these indications is characterized by high ACTH levels that act on MC2R expressed in the adrenal cortex to drive pathological elevations of adrenally derived steroid hormones. CRN04894 blocks the action of ACTH at MC2R, providing a potential novel treatment for these diseases. Preclinical models of chronic hypercortisolemia include implantation of ACTH-secreting pituitary tumor cells in mice and continuous administration of ACTH via subcutaneously implanted osmotic pumps in rats. These models induce features consistent with human diseases of ACTH excess including hypercortisolemia and hypertrophy of the adrenal glands. We employed both rodent models to examine the pharmacodynamic effects of CRN04894 on corticosterone levels and adrenal gland morphology. In the mouse pituitary tumor model, subcutaneous inoculation of the ACTH-secreting mouse pituitary tumor cell line, AtT-20, into immunodeficient mice resulted in formation of tumors and increased plasma ACTH and corticosterone levels. Repeated daily oral administration of CRN04894 for 14 days dose-dependently and robustly suppressed plasma corticosterone levels in mice with AtT-20 tumors. In the rat model, subcutaneous implantation of osmotic pumps delivering ACTH resulted in increased corticosterone levels, reduction in body weight, and hypertrophy of the adrenal glands after 7 days. Daily oral administration of CRN04894 over 7 days dose-dependently suppressed corticosterone levels, mitigated the effect of ACTH excess on body weight, and rescued the adrenal gland hypertrophy. These findings provide evidence that CRN04894 functions as an effective ACTH antagonist at MC2R to suppress adrenal corticosterone secretion in both mouse and rat models of ACTH excess and hypercortisolemia, thus providing a strong rationale for its potential therapeutic utility in diseases of ACTH excess. This work was supported in part by an SBIR grant from the NIH awarded to Dr. Struthers (R43- DK115245)

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Ana Karin Kusnetzow ◽  
Sangdon Han ◽  
Melissa A Fowler ◽  
Jon Athanacio ◽  
Greg Reinhart ◽  
...  

Abstract Adrenocorticotropic hormone (ACTH) is an important modulator of steroidal hormone synthesis and secretion from the adrenal gland and its selective activity at the melanocortin type 2 receptor (MC2) dictates the synthesis and secretion of cortisol (corticosterone in rats). Excess ACTH action contribute to the pathophysiology of Cushing’s disease (CD), ectopic ACTH secreting tumors (EAS), and Congenital Adrenal Hyperplasia (CAH). Cushing’s disease results from a microadenoma derived from pituitary corticotrophic cells that secretes excess ACTH, whereas EAS arises from nonpituitary ACTH secreting tumors. Excess ACTH action at the adrenal gland and resulting hypercortisolemia presents in a myriad of symptoms that result in high morbidity. CAH results from inactivating mutations in steroid synthesis pathways, resulting in lack of cortisol and aldosterone production. Lack of negative feedback by cortisol at the level of the pituitary causes the over-secretion of ACTH, and overproduction of adrenal androgens, causing significant virilization and reduction in quality of life. We hypothesize that blocking ACTH action directly via a selective MC2 receptor antagonist may provide an important new therapeutic mechanism for these patients. To test this hypothesis, Crinetics launched an iterative medicinal chemistry program to identify potent and selective nonpeptide ACTH antagonists with pharmaceutical and safety characteristics suitable for evaluation in human clinical trials. Unlike most other G protein coupled receptors, MC2 requires the presence of an accessory protein (MRAP) for cell surface expression and recognition of ACTH. Using CHO-K cells stably expressing this MC2-MRAP complex, iterative optimization led to the discovery of multiple chemical classes of highly potent, nonpeptide MC2 receptor selective antagonist leads, which were then further optimized for drug-like characteristics. We identified multiple compounds that exhibit high potency for human and rat MC2 receptors (hMC2 Kb <1 nM), while having no activity at the MC1, MC3, MC4, or MC5 receptors. Leading ACTH antagonists were also evaluated for drug like characteristics, including good stability in liver microsomes, lack of inhibition of cytochromes P450 and the hERG ion channel, and were shown to exhibit good exposure upon oral dosing in both rats and dogs. These ACTH antagonists acutely suppress corticosterone secretion in an ACTH-challenge model in rats. In a 7-day hypercortisolemia model in which rats receive an implanted minipump that continually secretes ACTH, corticosterone levels were decreased, and body weight loss and adrenal hypertrophy were prevented with ACTH antagonist treatment. The culmination of these studies has led to a subset of candidate molecules that are being evaluated in genotoxicity, safety pharmacology, and general toxicology studies to enable evaluation in human clinical trials.


FEBS Letters ◽  
1978 ◽  
Vol 90 (2) ◽  
pp. 353-356 ◽  
Author(s):  
H. Scherrer ◽  
S. Benjannet ◽  
P.D. Pezalla ◽  
M. Bourassa ◽  
N.G. Seidah ◽  
...  

2014 ◽  
Vol 122 (03) ◽  
Author(s):  
UJ Knappe ◽  
C Jaspers ◽  
D Buschsieweke ◽  
R Salbeck ◽  
W Saeger ◽  
...  

1969 ◽  
Vol 60 (4) ◽  
pp. 657-668 ◽  
Author(s):  
Frances J. Thomas ◽  
A. W. Steinbeck

ABSTRACT A modified method for the estimation of urinary pregnanetriol, pregnanetriol, pregnanetriolone, Δ5-pregnenetriol and tetrahydro S was investigated. The steroids, separated by chromatography, were measured quantitatively, tetrahydro S by reaction with blue tetrazolium and the other three as acetaldehydogenic substances. The excretion of these steroids was studied in suspected instances of adrenal and/or ovarian disease. Urinary pregnanetriol and tetrahydro S levels were normal in Cushing's syndrome, secondary adrenocortical carcinoma, the Stein-Leventhal syndrome, idiopathic hirsutism and hypertension. Tetrahydro S was doubtfully elevated in an instance of ectopic ACTH Cushing's syndrome. Pregnanetriol excretion was elevated in untreated cases of congenital adrenal hyperplasia and after treatment in some. Pregnanetriolone was found in all patients with congenital adrenal hyperplasia, including those receiving cortisone. Pregnanetriolone was also detected in Cushing's syndrome, secondary adrenocortical carcinoma, the Stein-Leventhal syndrome, ectopic ACTH Cushing's syndrome and suspected congenital adrenal hyperplasia. Δ5-pregnenetriol was present as a glucuronide in the Stein-Leventhal syndrome and idiopathic hirsutism. The diagnostic implications of these results are discussed.


2019 ◽  
Author(s):  
Meenakshi Parsad ◽  
Emily Phisaklea ◽  
Victoria Reay ◽  
Livoon Chong

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2124
Author(s):  
Franziska Keßler ◽  
Angelika Grümpel-Schlüter ◽  
Christian Looft ◽  
Stefanie Petow

It is difficult to objectively assess the chronic effects of housing systems on livestock and particularly on laying hens. However, this seems to be important in the context of animal welfare. Therefore, we conducted the present study in order to compare the effect of two different housing conditions, single cage (SC) and floor pen (FP), on the morphology of the adrenal gland. A higher amount of interrenal cells, which secrete stress hormones, can lead to a difference in the relation of adrenal and interrenal cells, which could be interpreted as an indication of chronic stress. For this purpose, adrenal glands were extracted, prepared, stained and examined by microscopy, and total area of the cut, total area of interrenal cells and total area of adrenal cells were measured. As a result, all laying hens had a higher percentage of interrenal cells than adrenal cells (FP: interrenal cells/adrenal cells = 78.37%/21.63%; SC: 80.00%/20.00%). The median of adrenal–interrenal ratio did not differ significantly (FP = 0.2503, SC = 0.2499), while the variation of the ratio between laying hens in FP and SC showed a slight tendency of a higher ratio in adrenal glands of FP (p < 0.0870). Body weight and adrenal–interrenal ratio were significantly negatively correlated in laying hens in FP (rS = −0.943, p < 0.0048) but not in SC (rS = −0.162, p = 0.7283). There was no significant correlation between body weight and total cell area for interrenal cells or adrenal cells. Body weight was significantly lower for laying hens kept in SC than for laying hens kept in FP (p < 0.0001). Due to the present results, it can be concluded that keeping laying hens in single cages can have a negative effect on body weight.


2007 ◽  
Vol 51 (8) ◽  
pp. 1329-1338 ◽  
Author(s):  
Andrea Utz ◽  
Beverly M.K. Biller

Adrenocorticotropin hormone (ACTH)-dependent Cushing's syndrome is most often due to a pituitary corticotroph adenoma, with ectopic ACTH-secreting tumors representing approximately 15% of cases. Biochemical and radiological techniques have been established to help distinguish between these two entities, and thus aid in the localization of the neoplastic lesion for surgical resection. The test that offers the highest sensitivity and specificity is bilateral inferior petrosal sinus sampling (BIPSS). BIPSS is an interventional radiology procedure in which ACTH levels obtained from venous drainage very near the pituitary gland are compared to peripheral blood levels before and after corticotropin hormone (CRH) stimulation. A gradient between these two locations indicates pituitary Cushing's, whereas the absence of a gradient suggests ectopic Cushing's. Accurate BIPSS results require hypercortisolemia to suppress normal corticotroph ACTH production and hypercortisolemia at the time of the BIPSS to assure excessive ACTH secretion. In some cases, intrapituitary gradients from side-to-side can be helpful to localize small corticotroph adenomas within the sella. BIPSS has rare complications and is considered safe when performed at centers with experience in this specialized technique.


1956 ◽  
Vol 184 (2) ◽  
pp. 351-355 ◽  
Author(s):  
Frederick W. Maire ◽  
Harry D. Patton

The pulmonary edema which follows preoptic lesions in rats is prevented by antecedent bilateral section of the splanchnic nerves. Intravenous epinephrine in doses exceeding 0.0125 mg/100 gm body weight causes fatal lung edema in rats comparable to that produced by preoptic lesions. Moreover, extracted pressor amines from rat adrenal glands cause lung edema, often fatal, when injected into the donor or into intact rats. However, adrenal demedullation does not prevent lung edema following preoptic lesions. Hence the protective effect of splanchnectomy against preoptic lesions is not wholly due to adrenal denervation. It is tentatively suggested that preoptic lung edema results from overloading of the pulmonary circuit owing to splanchnic mediated constriction of visceral venous reservoirs. Liver and spleen weights of animals dying from preoptic lung edema were significantly less than normal.


2007 ◽  
Vol 135 (1-2) ◽  
pp. 31-37 ◽  
Author(s):  
Zorana Penezic ◽  
Milos Zarkovic ◽  
Svetlana Vujovic ◽  
Miomira Ivovic ◽  
Biljana Beleslin ◽  
...  

Introduction: Diagnosis and differential diagnosis of Cushing?s syndrome (CS) remain considerable challenge in endocrinology. For more than 20 years, CRH has been widely used as differential diagnostic test. Following the CRH administration, the majority of patients with ACTH secreting pituitary adenoma show a significant rise of plasma cortisol and ACTH, whereas those with ectopic ACTH secretion characteristically do not. Objective The aim of our study was to assess the value of CRF test for differential diagnosis of CS using the ROC (receiver operating characteristic) curve method. Method A total of 30 patients with CS verified by pathological examination and postoperative testing were evaluated. CRH test was performed within diagnostic procedures. ACTH secreting pituitary adenoma was found in 18, ectopic ACTH secretion in 3 and cortisol secreting adrenal adenoma in 9 of all patients with CS. Cortisol and ACTH were determined -15, 0, 15, 30, 45, 60, 90 and 120 min. after i.v. administration of 100?g of ovine CRH. Cortisol and ACTH were determined by commercial RIA. Statistical data processing was done by ROC curve analysis. Due to small number, the patients with ectopic ACTH secretion were excluded from test evaluation by ROC curve method. Results In evaluated subgroups, basal cortisol was (1147.3?464.3 vs. 1589.8?296.3 vs. 839.2?405.6 nmol/L); maximal stimulated cortisol (1680.3?735.5 vs. 1749.0?386.6 vs. 906.1?335.0 nmol/L); and maximal increase as a percent of basal cortisol (49.1?36.9 vs. 9.0?7.6 vs. 16.7?37.3 %). Consequently, basal ACTH was (100.9 ?85.0 vs. 138.0?123.7 vs. 4.8?4.3 pg/mL) and maximal stimulated ACTH (203.8 ?160.1 vs. 288.0?189.5 vs. 7.4?9.2 pg/mL). For cortisol, determination area under ROC curve was 0.815?0.083 (CI 95% 0.652-0.978). For cortisol increase cut-off level of 20%, test sensitivity was 83%, with specificity of 78%. For ACTH, determination area under ROC curve was 0.637?0.142 (CI 95% 0.359-0.916). For ACTH increase cut-off level of 30%, test sensitivity was 70%, with specificity of 57%. Conclusion Determination of cortisol and ACTH levels in CRH test remains reliable tool in differential diagnosis of Cushing?s syndrome.


Sign in / Sign up

Export Citation Format

Share Document