Endocrine Abstracts

Background: Sepsis is a life-threatening inflammatory condition and a leading cause of death in hospitals. It arises when a microbial infection triggers prolonged and uncontrolled systemic inflammation resulting in progressing organ dysfunction. Recent experimental data suggest a possible involvement of ferroptosis – an iron-dependent form of regulated necrosis – in sepsis-mediated damage of many vital organs. However, its role in adrenal gland dysfunction and/or damage during systemic inflammation hasn’t been studied so far.

Objectives: The aim of this project is to elucidate whether septic conditions such as enhanced inflammation and steroidogenesis impact ferroptosis activation in the adrenal glands.

Methods: The human adrenocortical cells, NCI-H295R, were either treated with forskolin or inflammatory cytokines (TNFα, IL-6, IFNγ) in vitro for 24–48 h. After that time, expression of ferroptosis-relevant genes and proteins was analyzed by qPCR and western blot, respectively. In addition, necrosis induction (via Annexin V and PI staining) as well as lipid peroxidation were analyzed to study ferroptosis induction during those conditions. Potential ferroptosis induction in the adrenals was additionally evaluated in vivo using wildtype mice treated with LPS.

Results: The major molecules involved in the suppression (glutathione peroxidase 4; GPX4), and induction (long-chain-fatty-acid-CoA ligase 4; ACSL4) of ferroptosis were strongly expressed in human and mouse adrenal glands, with the adrenal cortex being the major expression site. Enhanced steroidogenesis or treatment with cytokines led to enhanced ACSL4 expression and/or reduction of GPX4 in NCI-H295R cells. Similar results were observed in vivo. Furthermore, the same treatments led to an increased necrotic cell death of NCI-H295R cells, as well as induction of phospholipid peroxidation which was mitigated when the cells were treated with the ferroptosis inhibitor Ferrostatin-1.

Conclusions: Altogether, these results suggest that enhanced inflammation and steroidogenesis may sensitize adrenal cells to necrosis. However, additional experiments are required to further verify ferroptosis involvement.