Post-Mortem Immunohistochemical Evidence of β2-Adrenergic Receptor Expression in the Adrenal Gland.

Elvira Ventura Spagnolo,Alessio Asmundo,Cristina Mondello,Domenico Puzzolo,Angela Alibrandi,Gennaro Baldino,Consuelo Malta,Vincenzo Macaione,Luigi Cardia,Letteria Minutoli,Antonio Micali

doi:10.3390/ijms20123065

Elvira Ventura Spagnolo, Alessio Asmundo + Show 9 more

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https://doi.org/10.3390/ijms20123065

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Abstract

The evidence from post-mortem biochemical studies conducted on cortisol and catecholamines suggest that analysis of the adrenal gland could provide useful information about its role in human pathophysiology and the stress response. Authors designed an immunohistochemical study on the expression of the adrenal β2-adrenergic receptor (β2-AR), a receptor with high-affinity for catecholamines, with the aim to show which zones it is expressed in and how its expression differs in relation to the cause of death. The immunohistochemical study was performed on adrenal glands obtained from 48 forensic autopsies of subjects that died as a result of different pathogenic mechanisms using a mouse monoclonal β2-AR antibody. The results show that immunoreactivity for β2-AR was observed in all adrenal zones. Furthermore, immunoreactivity for β2-AR has shown variation in the localization and intensity of different patterns in relation to the original cause of death. To the best of our knowledge, this is the first study that demonstrates β2-AR expression in the human cortex and provides suggestions on the possible involvement of β2-AR in human cortex hormonal stimulation. In conclusion, the authors provide a possible explanation for the observed differences in expression in relation to the cause of death.

Highlights

The adrenal response to stress involves the activation of the sympathoadrenal (SA) system and the hypothalamic–pituitary–adrenocortical (HPA) axis; in this way, homeostasis in emergencies such as “fight or flight” situations is maintained [1]
The study revealed an evident immunoreactivity for β2-adrenergic receptor (β2-adrenergic receptors (ARs)) expressed in the human adrenal gland (Figures 1 and 2)
Hanging: the immunostaining of β2-AR was higher in the glomerulosa, reticularis, and medulla (Figure 1a,c,d), while a lower expression was observed in the fasciculata (Figure 1b)

Summary

Introduction

The adrenal response to stress involves the activation of the sympathoadrenal (SA) system and the hypothalamic–pituitary–adrenocortical (HPA) axis; in this way, homeostasis in emergencies such as “fight or flight” situations is maintained [1]. Scientific evidence has shown that both the SNS and the adrenomedullary system can respond differentially to stress in relation to the type and the intensity of the stressor and to the perception and interpretation of the stress situation [3]. In this setting, the adrenomedullary secretion was associated with the concurrent activation of the HPA axis [4]. Very few studies in forensic pathology have been carried on the adrenal gland, despite it being one of the main organs involved in the stress response, releasing corticosteroids and catecholamines [10,11]. Catecholamines are able to up-regulate the expression of membrane-bound proteins known as adrenergic receptors (ARs), and the β2-AR pathway, in many organs, either in normal [12] or in pathological conditions [13,14], suggesting that the analysis of the molecular change of such receptors could provide information on specific circumstances related to stressful events

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