Unraveling a fine balance between ferroptosis, lipid metabolism, and hormonal protection in Leydig cell steroidogenesis
hCG can rescue Leydig cells from certain ferroptotic stresses, but its effectiveness is limited by the need for GPX4 functionality.
Where it sits
this study against the rest of the hcg (human chorionic gonadotropin) corpusSummary and findings
The study investigates ferroptosis in Leydig cells and its impact on steroidogenesis, focusing on the protective role of hCG. Leydig cells exposed to ferroptosis inducers showed downregulated Star expression, but hCG rescued cells from Erastin-induced toxicity. The protection was not effective against GPX4 inhibition by RSL3.
Abstract
Leydig cells (LCs) are essential for male reproductive function due to their role in testosterone synthesis, a process critically dependent on mitochondrial cholesterol transport mediated by the Steroidogenic Acute Regulatory protein (StAR). Despite their importance, LCs are highly sensitive to metabolic and exogenous stressors. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a key link between cellular metabolism and cell fate; however, its role in LCs and steroidogenesis remains poorly understood. In this study, we investigated the induction of ferroptosis in LCs and its impact on their steroidogenic capacity. We evaluated cellular responses to canonical ferroptosis inducers (Erastin and RSL3) alongside the transcriptional regulation of key genes. Our results demonstrate that LCs are vulnerable to ferroptotic stress, which significantly downregulates Star expression. Notably, we uncovered a novel endocrine-metabolic crosstalk: hormonal stimulation via hCG effectively rescues LCs from Erastin-induced toxicity and fully sustains maximal steroidogenesis. However, this hormone-driven cytoprotection fails against direct GPX4 inhibition by RSL3, indicating an absolute reliance on functional GPX4. These mechanistic findings highlight the paradoxical dual role of ACSL4 in Leydig cell biology and are further supported by bioinformatic analysis of public transcriptomic profiles from infertile patients, which reveal a detrimental imbalance in the ACSL4/GPX4 axis. Together, our data position ferroptosis as a critical disruptor of male endocrine function and reveal a hormone-mediated metabolic adaptation that could inform novel therapeutic strategies against oxidative stress in the testis. <h4>Highlights</h4> -Leydig cells exhibit a strong vulnerability to ferroptotic cell death. -Ferroptosis disrupts StAR expression and halts Leydig cell steroidogenesis. -hCG signaling promotes metabolic adaptation against Erastin-induced ferroptosis.
Background
Leydig cells are crucial for testosterone synthesis, which is dependent on mitochondrial cholesterol transport via the Steroidogenic Acute Regulatory protein (StAR). These cells are sensitive to metabolic stress, and ferroptosis, a form of regulated cell death, is linked to cellular metabolism. Understanding ferroptosis in Leydig cells is important for male reproductive health, as it may disrupt steroidogenesis.
Methods
The study used Leydig cells to investigate the effects of ferroptosis inducers Erastin and RSL3 on steroidogenesis. Cellular responses and transcriptional regulation of key genes were evaluated. The role of hCG in rescuing cells from ferroptotic stress was also assessed, alongside bioinformatic analysis of public transcriptomic profiles from infertile patients.
Results
Leydig cells exhibited vulnerability to ferroptotic stress, with significant downregulation of Star expression. Hormonal stimulation via hCG rescued cells from Erastin-induced toxicity, maintaining steroidogenesis. However, hCG did not protect against GPX4 inhibition by RSL3, indicating a reliance on functional GPX4. Bioinformatic analysis revealed an imbalance in the ACSL4/GPX4 axis in infertile patients.
Interpretation
The findings suggest that while hCG can protect Leydig cells from certain ferroptotic stresses, its protective effects are limited by the need for functional GPX4. This highlights the complex interplay between hormonal signaling and cellular metabolism. The study's reliance on cellular models limits its direct applicability to clinical practice, but it provides insights into potential therapeutic strategies for oxidative stress in the testis.
Key findings
- Leydig cells are vulnerable to ferroptotic stress.
- Ferroptosis significantly downregulates Star expression.
- hCG rescues Leydig cells from Erastin-induced toxicity.
- hCG fails to protect against RSL3-induced GPX4 inhibition.
- Bioinformatic analysis shows imbalance in ACSL4/GPX4 axis in infertile patients.
Limitations
- preclinical cellular model
- no direct human data
- limited translation to clinical practice
- reliance on bioinformatic analysis