ResearchPad - translational-studies-on-adrenocortical-function-in-health-and-disease https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[OR19-05 Steroid:Corticosteroid-Binding Globulin Interactions; Effects of Neutrophil Elastase Cleavage, Pyrexia and Acidosis]]> https://www.researchpad.co/article/elastic_article_7050 Context Corticosteroid-binding globulin (CBG) transports cortisol and other steroid hormones1,2. High-affinity CBG (haCBG) undergoes proteolysis of the reactive centre loop (RCL) by neutrophil elastase (NE) at inflammatory sites, liberating immunomodulatory cortisol and altering conformation to low-affinity CBG (laCBG). Pyrexia reduces CBG:cortisol binding affinity, an interaction at the RCL is speculated3. Objective To measure the equilibrium binding constants of a panel of steroids to glycosylated haCBG and laCBG over temperature and pH ranges mimicking the pathophysiological conditions of septic shock. Design Surface plasmon resonance was used to determine the binding profiles of 19 steroid ligands to haCBG and laCBG at temperatures 25°C, 37°C and 39°C and pH 7.4 and 7.0. The RCL-recognizing 9G12 antibody was used to assess cleavage and epitope availability of the RCL across conditions. Results A 4–8 fold reduction in affinity for cortisol, cortisone, corticosterone, 11-deoxycortisol, progesterone, 17-hydroxyprogesterone and prednisolone occurred with NE-mediated haCBG-to-laCBG conversion, cortisol expectedly displayed the highest binding affinity. Binding affinity consistently decreased at higher temperatures and at acidic pH for both haCBG and laCBG. 9G12 antibody RCL binding was preserved for haCBG across temperatures. Conclusions These studies reveal that steroid binding to CBG is selective and in all cases reduced upon NE-mediated haCBG-to-laCBG transition. Moreover, reduced CBG:cortisol binding affinity at elevated temperature occurs with an intact and accessible RCL epitope, suggesting a non-RCL mechanism for the delivery of anti-inflammatory cortisol in pyrexia. Synergy of NE cleavage and pyrexia/acidosis may serve for local inflammatory site cortisol delivery and increase free cortisol. These findings demonstrate the modifiable hormone binding characteristics of CBG in (patho-)physiological conditions, supporting its significance in cortisol delivery in obviating systemic inflammation and multiorgan-organ failure in patients with septic shock and its association with mortality4.

1. Pemberton PA, Stein PE, Pepys MB, et al. Hormone binding globulins undergo serpin conformational change in inflammation. Nature. 1988;336(6196):257–258.

2. Pugeat MM, Dunn JF, Nisula BC. Transport of steroid hormones: interaction of 70 drugs with testosterone-binding globulin and corticosteroid-binding globulin in human plasma. J Clin Endocrinol Metab. 1981;53(1):69–75.

3. Cameron A, Henley D, Carrell R, et al. Temperature-responsive release of cortisol from its binding globulin: a protein thermocouple. J Clin Endocrinol Metab. 2010;95(10):4689–4695.

4. Meyer EJ, Nenke MA, Rankin W, et al. Total and high-affinity corticosteroid-binding globulin depletion in septic shock is associated with mortality. Clin Endocrinol (Oxf). 2019;90(1):232–240.

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<![CDATA[OR19-02 Luteinizing Hormone/Human Chorionic Gonadotropin Receptor Protein Expression in Adrenocortical Progenitor Cells, Aldosterone Producing Cell Clusters and Adrenal Adenomas Derived from Postmenopausal Women]]> https://www.researchpad.co/article/N6bb9f86b-70cf-42c3-85cb-26ce076683d0 Objective/Background

Adrenal pathologies are more common in women than men. Embryologically the adrenals and gonads develop from the adrenogenital ridge with differential migration and differentiation. We hypothesized that in adult females there are adrenocortical progenitor cells that express the LH/hCG-R and proliferate in response to elevated LH. Indeed, several case reports demonstrated LH/hCG-R expression in adrenal secretory tumors in postmenopausal and pregnant females. In aging adults, nests of cells known as aldosterone-producing cell clusters (APCCs) that may be precursors to aldosterone producing adenomas are frequently detected. We retrospectively studied the immunohistochemical expression of LH/hCG-R in normal adrenals, adrenal adenomas and APCCs in archival specimens derived from post-menopausal women.

Methods

Archival specimens from adrenal adenomas derived from 23 women >55 years of age were examined. Clinical data was obtained in a blinded fashion and hormonal data was available in 9/23 cases; 6/9 were secreting cortisol and 3/9 adenomas were secreting aldosterone. In addition, 6 samples derived from a repository of normal adrenal tissues from deceased kidney donors (1 male, and 5 postmenopausal females) were studied. All specimens were immunostained for LH/hCG-R and the adrenal stem cell marker DLK1 that facilitates the maintenance of an undifferentiated phenotype. The normal adrenal tissues were also stained for aldosterone synthase (CYP11B2) to detect APCCs. The slides were reviewed and graded by a pathologist in a blinded fashion.

Results

Expression of LH/hCG-R was demonstrated in both normal and adenomatous tissues in all 23 specimens. The staining in adenomas was heterogeneous, with clusters of densely stained LH/hCG-R positive cells in all specimens. There were less densely stained clusters in normal adjacent adrenocortical tissue that was most prominent in the subcapsular, zona glomerulosa region, an area where the putative adrenal cortical stem cells are found as well as the zona reticularis. Double staining for the stem cell marker DLK1 and LH/hCG-R confirmed that these cells represent adrenocortical progenitor cells. CYP 11B2 immunohistochemistry of normal adrenals demonstrated cell foci dipping from the capsule into the zona fasciculata classified as APCCs that co-expressed cytoplasmic LH/hCGR.

Conclusion

Adrenal adenomas and APCCs derived from postmenopausal women exhibited heterogeneous but strong immunohistochemical expression of LH/hCG-R in all samples. Interestingly, DLK1-positive adrenocortical stem cells in the subcapsular zone also expressed LH/hCG-R. These data may provide insights into the female predominance of adrenal pathologies, particularly in postmenopausal women with high LH levels. The LH/hCG-R may be a viable target for treatment of adrenal adenomas in postmenopausal women.

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<![CDATA[OR19-04 Glucocorticoid Production in the Nervous and Immune Systems: Evidence for a Local HPA Axis Homolog]]> https://www.researchpad.co/article/N6c4f949b-5cc2-4dc7-bb32-9a3c26365508 <![CDATA[OR19-07 Metformin Inhibits Activation of the Melanocortin Receptor 2 and 3 in Vitro, a Possible Mechanism for Its Anti-Androgenic and Weight Balancing Effects in Vivo]]> https://www.researchpad.co/article/N1b3597e1-74de-49c7-9469-3617581f9d47 <![CDATA[OR19-02 Luteinizing Hormone/Human Chorionic Gonadotropin Receptor Protein Expression in Adrenocortical Progenitor Cells, Aldosterone Producing Cell Clusters and Adrenal Adenomas Derived from Postmenopausal Women]]> https://www.researchpad.co/article/Ncfa511f3-b05f-492c-b9c6-b4d7d40634c6

Abstract

Objective/Background

Adrenal pathologies are more common in women than men. Embryologically the adrenals and gonads develop from the adrenogenital ridge with differential migration and differentiation. We hypothesized that in adult females there are adrenocortical progenitor cells that express the LH/hCG-R and proliferate in response to elevated LH. Indeed, several case reports demonstrated LH/hCG-R expression in adrenal secretory tumors in postmenopausal and pregnant females. In aging adults, nests of cells known as aldosterone-producing cell clusters (APCCs) that may be precursors to aldosterone producing adenomas are frequently detected. We retrospectively studied the immunohistochemical expression of LH/hCG-R in normal adrenals, adrenal adenomas and APCCs in archival specimens derived from post-menopausal women.

Methods

Archival specimens from adrenal adenomas derived from 23 women >55 years of age were examined. Clinical data was obtained in a blinded fashion and hormonal data was available in 9/23 cases; 6/9 were secreting cortisol and 3/9 adenomas were secreting aldosterone. In addition, 6 samples derived from a repository of normal adrenal tissues from deceased kidney donors (1 male, and 5 postmenopausal females) were studied. All specimens were immunostained for LH/hCG-R and the adrenal stem cell marker DLK1 that facilitates the maintenance of an undifferentiated phenotype. The normal adrenal tissues were also stained for aldosterone synthase (CYP11B2) to detect APCCs. The slides were reviewed and graded by a pathologist in a blinded fashion.

Results

Expression of LH/hCG-R was demonstrated in both normal and adenomatous tissues in all 23 specimens. The staining in adenomas was heterogeneous, with clusters of densely stained LH/hCG-R positive cells in all specimens. There were less densely stained clusters in normal adjacent adrenocortical tissue that was most prominent in the subcapsular, zona glomerulosa region, an area where the putative adrenal cortical stem cells are found as well as the zona reticularis. Double staining for the stem cell marker DLK1 and LH/hCG-R confirmed that these cells represent adrenocortical progenitor cells. CYP 11B2 immunohistochemistry of normal adrenals demonstrated cell foci dipping from the capsule into the zona fasciculata classified as APCCs that co-expressed cytoplasmic LH/hCGR.

Conclusion

Adrenal adenomas and APCCs derived from postmenopausal women exhibited heterogeneous but strong immunohistochemical expression of LH/hCG-R in all samples. Interestingly, DLK1-positive adrenocortical stem cells in the subcapsular zone also expressed LH/hCG-R. These data may provide insights into the female predominance of adrenal pathologies, particularly in postmenopausal women with high LH levels. The LH/hCG-R may be a viable target for treatment of adrenal adenomas in postmenopausal women.

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<![CDATA[OR19-03 Effects of Nonpeptide Orally Bioavailable ACTH Antagonists on Adrenal Gland Size and Function in Rats]]> https://www.researchpad.co/article/Nf388758f-ad2d-4d55-b971-80de512563a6 <![CDATA[OR19-01 IHC-Guided Capture of Adrenocortical Zones from Archival Formalin-Fixed, Paraffin-Embedded Adrenal Tissue Allows the Study Of RNA Expression Profiles]]> https://www.researchpad.co/article/Nf90aacb3-c418-4097-aec7-1bf9debe72b6 <![CDATA[OR19-06 Sepsis-Induced Critical Illness in Mice Alters Key Regulators of ACTH Production and Secretion Within the Anterior Pituitary Gland]]> https://www.researchpad.co/article/N84bcb49a-32f3-43ec-8621-9803efc7847e