Expression and Externalization of Annexin 1 in the Adrenal Gland: Structure and Function of the Adrenal Gland in Annexin 1-Null Mutant Mice

Abstract

Annexin 1 (ANXA1) is a member of the annexin family of phospholipid- and calcium-binding proteins with a well demonstrated role in early delayed (30 min to 3 h) inhibitory feedback of glucocorticoids in the hypothalamus and pituitary gland. This study used adrenal gland tissue from ANXA1-null transgenic mice, in which a beta-galactosidase (beta-Gal) reporter gene was controlled by the ANXA1 promoter, and wild-type control mice to explore the potential role of ANXA1 in adrenal function. RT-PCR and Western blotting revealed strong expression of ANXA1 mRNA and protein in the adrenal gland. Immunofluorescence labeling of ANXA1 in wild-type and beta-Gal expression in ANXA1-null adrenals localized intense staining in the outer perimeter cell layers. Immunogold electron microscopy identified cytoplasmic and nuclear ANXA1 labeling in outer cortical cells and capsular cells. Exposure of adrenal segments in vitro to dexamethasone (0.1 mum, 3 h) caused an increase in the amount of ANXA1 in the intracellular compartment and attached to the surface of the cells. The N-terminal peptide ANXA1(Ac2-26) inhibited corticosterone release. Corticosterone release was significantly greater from ANXA1-null adrenal cells compared with wild type in response to ACTH (10 pm to 5 nm). In contrast, basal and ACTH-stimulated aldosterone release from ANXA1-null adrenal cells was not different from wild type. Morphometry studies demonstrated that ANXA1 null adrenal glands were smaller than wild-type, and the cortical/medullary area ratio was significantly reduced. These results suggest ANXA1 is a regulator of adrenocortical size and corticosterone secretion.

60 YEARS OF NEUROENDOCRINOLOGY: Glucocorticoid dynamics: insights from mathematical, experimental and clinical studies

“…Interestingly, ANXA1 is also expressed in the adrenal cortex, and as observed in other tissue, its expression and activity is regulated by CORT (Davies et al 2007). Remarkably, the same study also showed that ACTH stimulation of isolated adrenal gland obtained from ANXA1-null mice exhibited a greater CORT response compared to adrenal obtained from WT mice, suggesting an involvement of ANXA1 in the inhibition of CORT synthesis.…”

Changes in granulosa cells' gene expression associated with increased oocyte competence in bovine

“…ANXA1 expression is stimulated by 17b-estradiol, in the anterior pituitary in vivo (Davies et al 2007a(Davies et al , 2007b. ANXA1 has an effect on cell growth, differentiation, apoptosis, membrane fusion, endocytosis, and exocytosis (John et al 2004).…”

A highly sensitive immunofluorometric assay for the measurement of aldosterone in small sample volumes: validation in mouse serum

“…To demonstrate this, we carried out a study including pharmacological intervention with dexamethasone suppression as well as stimulation with an ACTH analog (Synacthen). ACTH is thought to be an acute regulator of aldosterone synthesis in stress situations (Muller 1995, Davies et al 2007. To demonstrate that there were clear increases and decreases in the production of aldosterone under the circumstances of the study and to make sure that there was definite hyper-and hypoplasia of the adrenal gland under stimulation and suppression we used a previously established protocol (Coll et al 2006).…”

“…Currently, there is a lack of longitudinal and systematic studies addressing adrenal gland growth and function as well as circulating aldosterone concentrations in mouse models. Plasma concentrations of corticosterone are relatively high and are therefore unproblematic to measure in mice (Weber et al 1999, Coll et al 2004, Wang et al 2004, Karpac et al 2005, Lee et al 2005, Sausbier et al 2005, Schmidt et al 2006, Davies et al 2007), whereas measurement of aldosterone can be problematic due to the low concentrations found in plasma and the limited amounts which can be collected from mice when repeated measurements must be carried out.…”