The role of protein synthesis in adrenocorticotrophin action: Effects of cycloheximide and puromycin on the steroidogenic response of isolated adrenocortical cells

The kinetics of the corticosteroidogenic response to adrenocorticotrophin (ACTH) have been investigated using collagenase dispersed adrenocortical cells. Following the addition of ACTH at a concentration that was maximal for steroidogenesis, there was a time-lag of about 3 min before increased steroidogenesis became apparent. This lag was extended (about two-fold) in the presence of a half-maximal concentration of ACTH. Preincubation of cells with submaximal concentrations of both cycloheximide and puromycin extended the time-lag observed following ACTH addition. Increasing doses of cycloheximide or puromycin concomitantly inhibited protein synthesis and steroidogenesis. Moreover cycloheximide, at a dose that halved protein synthesis, also inhibited steroidogenesis by 54–61% for a range of ACTH concentrations (1 × 10⁻⁴ to 1 × 10⁻² I.U./ml).It is concluded that the delay before ACTH-stimulated steroidogenesis is not attributable solely to the time taken for ribosomes to read of from the mRNA strand, the code for protein regulator(s). The results are discussed in terms of steroidogenic mechanisms whereby ACTH either induces de novo protein synthesis or activates a pre-existing, but labile, protein. In this latter scheme the steroidogenic rate observed under various conditions would be directly dependent upon the intracellular level of such an activated protein regulator. The half-life of labile protein, implicated as regulating steroidogenesis, was estimated at 2–4 min in this adrenal cell suspension system.     

Clues for early detection of autoimmune Addison's disease – myths and realities

Background

Early detection of autoimmune Addison's disease (AAD ) is important as delay in diagnosis may result in a life‐threatening adrenal crisis and death. The classical clinical picture of untreated AAD is well‐described, but methodical investigations are scarce.

Objective

Perform a retrospective audit of patient records with the aim of identifying biochemical markers for early diagnosis of AAD .

Material and Methods

A multicentre retrospective study including 272 patients diagnosed with AAD at hospitals in Norway and Sweden during 1978–2016. Scrutiny of medical records provided patient data and laboratory values.

Results

Low sodium occurred in 207 of 247 (84%), but only one‐third had elevated potassium. Other common nonendocrine tests were largely normal. TSH was elevated in 79 of 153 patients, and hypoglycaemia was found in 10%. Thirty‐three per cent were diagnosed subsequent to adrenal crisis, in whom electrolyte disturbances were significantly more pronounced (P < 0.001). Serum cortisol was consistently decreased (median 62 nmol L^?1 [1–668]) and significantly lower in individuals with adrenal crisis (38 nmol L^?1 [2–442]) than in those without (81 nmol L^?1 [1–668], P < 0.001).

Conclusion

The most consistent biochemical finding of untreated AAD was low sodium independent of the degree of glucocorticoid deficiency. Half of the patients had elevated TSH levels. Only a minority presented with marked hyperkalaemia or other nonhormonal abnormalities. Thus, unexplained low sodium and/or elevated TSH should prompt consideration of an undiagnosed AAD , and on clinical suspicion bring about assay of cortisol and ACTH . Presence of 21‐hydroxylase autoantibodies confirms autoimmune aetiology. Anticipating additional abnormalities in routine blood tests may delay diagnosis.

     

Glutamate receptors and the regulation of steroidogenesis in the human adrenal gland: The metabotropic pathway

Background

l-glutamate is a major excitatory neurotransmitter in the mammalian brain. Glutamate receptors have been reported in the rat adrenal cortex and in human aldosterone-producing adenomas (APA). However, details regarding the expression levels and functions of these receptors in human adrenocortical tissues remain unknown.

Methods

The mRNA levels of glutamate receptors were evaluated by qPCR in: 12 normal adrenal cortex (NAC), 11 APA, and 12 cortisol-producing adenoma (CPA) tissues. Protein localization was evaluated by immunohistochemistry for 15 NAC, 5 idiopathic hyperaldosteronism cases, 15 APA and 15 CPA. H295R cells were treated with angiotensin-II or forskolin alone or combined with the GRM2/3 agonist LY354740.

Results

The level of GRM3 mRNA was higher in APA than in CPA (P = 0.0086) or NAC (P = 0.0022). GRM1, IGLUR2, and IGLUR3 were also detected in adrenocortical tissues. When added to angiotensin-II/forskolin treatments, LY354740 decreased aldosterone and cortisol production in H295R cells.

Conclusions

GRM3 is considered to regulate steroidogenesis in adrenocortical tissues.     

Abnormal linear growth in paediatric adrenal diseases: Pathogenesis,prevalence and management

Abnormal adrenal function can interfere with linear growth, potentially causing either acceleration or impairment of growth in paediatric patients. These abnormalities can be caused by direct effects of adrenal hormones, particularly glucocorticoids and sex steroids, or be mediated by indirect mechanisms such as the disturbance of the growth hormone-insulin-like growth factor-1 axis and aromatization of androgens to oestrogens. The early diagnosis and optimal treatment of adrenal disorders can prevent or minimize growth disturbance and facilitate improved height gain. Mechanisms of growth disturbance in the following abnormal states will be discussed; hypercortisolaemia, hyperandrogenaemia and obesity. Prevalence and features of growth disturbance will be discussed in ACTH-dependent and ACTH-independent Cushing's syndrome, adrenocortical tumours, premature adrenarche, congenital adrenal hyperplasia and adrenal insufficiency disorders. Recommendations for management have been included.     

Influence of melatonin and sexual hormones on the expression of proliferating cell nuclear antigen in the adrenal cortex of a seasonal breeder (Lagostomus maximus)

The viscacha (Lagostomus maximus) is a rodent of nocturnal habits, whose physiology and behavior vary according to modifications of environmental signals. The objective of this study is to assess the influence of melatonin and sexual hormones on the viscacha adrenal cortex proliferative activity through the immunohistochemical detection of proliferating cell nuclear antigen (PCNA) along with hormonal determinations. PCNA expression was studied in male viscachas to assess the effect of melatonin administration, castration, and the annual reproductive cycle. In female viscachas, PCNA was studied in nonpregnant and pregnant viscachas. PCNA expression was observed in adrenocortical cells (PCNA-A) and endothelial cells (PCNA-E). Melatonin-administered animals showed a significantly lower number of PCNA-A compared to the control group. No significant difference could be established in the number of PCNA-A and PCNA-E between castrated and control animals. However, the morphometric analysis showed an increase in the size of the cortex of castrated animals, along with other cytological features. Significant differences in serum testosterone levels were observed during the male viscacha reproductive cycle, with the lowest levels encountered during the regression period (winter). Male viscachas exhibited a significantly high number of PCNA-A during late autumn and a high number of PCNA-E during winter. In females, hormonal determinations showed a peak of progesterone and estrogen during mid-pregnancy, along with a notably high number of PCNA-A and an increase in the number of PCNA-E. Our results suggest that proliferation in the adrenal cortex of the viscacha varies in relation to melatonin, sexual hormones, and environmental conditions.     

Cytological diagnosis of bilateral primary adrenal lymphoma with cutaneous involvement

Primary adrenal lymphoma (PAL) is an extremely rare condition. We describe here, a case of bilateral adrenal lymphoma in a 62‐year‐old man. He later developed subcutaneous masses on the hand and the leg. Fine‐needle aspiration cytology from the adrenals and the soft tissue swellings led to a diagnosis of non‐Hodgkin's lymphoma (NHL). Histopathological examination from the lesion on the leg, confirmed the diagnosis to be B‐cell NHL. The case highlights the cytomorphological findings of this unusual case. Awareness of this entity is essential to differentiate it from other common causes of adrenal enlargement and formulate an appropriate treatment.     

Maternal sensitivity and infant autonomic and endocrine stress responses

Background

Early environmental exposures may help shape the development of the autonomic nervous system (ANS) and hypothalamic–pituitary–adrenal (HPA) axis, influencing vulnerability for health problems across the lifespan. Little is known about the role of maternal sensitivity in influencing the development of the ANS in early life.

Aims

To examine associations among maternal sensitivity and infant behavioral distress and ANS and HPA axis reactivity to the Repeated Still-Face Paradigm (SFP-R), a dyadic stress task.

Study design

Observational repeated measures study.

Subjects

Thirty-five urban, sociodemographically diverse mothers and their 6-month-old infants.

Outcome measures

Changes in infant affective distress, heart rate, respiratory sinus arrhythmia (RSA), and T-wave amplitude (TWA) across episodes of the SFP-R were assessed. A measure of cortisol output (area under the curve) in the hour following cessation of the SFP-R was also obtained.

Results

Greater maternal insensitivity was associated with greater infant sympathetic activation (TWA) during periods of stress and tended to be associated with greater cortisol output following the SFP-R. There was also evidence for greater affective distress and less parasympathetic activation (RSA) during the SFP-R among infants of predominantly insensitive mothers.

Conclusions

Caregiving quality in early life may influence the responsiveness of the sympathetic and parasympathetic branches of the ANS as well as the HPA axis. Consideration of the ANS and HPA axis systems together provides a fuller representation of adaptive versus maladaptive stress responses. The findings highlight the importance of supporting high quality caregiving in the early years of life, which is likely to promote later health.     

Cytochrome P450 oxidoreductase deficiency: Rare congenital disorder leading to skeletal malformations and steroidogenic defects

Cytochrome P450 oxidoreductase (POR) deficiency (PORD) is a newly characterized disorder. PORD is caused by homozygous or compound heterozygous mutations in POR encoding an electron donor for several microsomal enzymes such as CYP21A2, CYP17A1, CYP19A1, CYP51A1, and CYP26A1‐C1. Molecular defects of PORD include a Japanese founder mutation p.R457H, as well as various missense, nonsense, frameshift, and splice‐site mutations and exonic deletions. PORD leads to unique skeletal malformations referred to as Antley–Bixler syndrome, in addition to 46,XX and 46,XY disorders of sex development, pubertal failure, adrenal dysfunction, and maternal virilization during pregnancy. Such clinical features are ascribable to impaired activities of the POR‐dependent microsomal enzymes. PORD represents one form of congenital adrenal hyperplasia, although it can occur as a congenital malformation syndrome and a disorder of sex development. Phenotypic severity of PORD is highly variable and only partly depends on the residual activity of the mutant proteins. It is possible that PORD remains undiagnosed in several patients. Detailed hormonal assessment and molecular analysis are useful for diagnosis of PORD.