Understanding the OMA1-DELE1-HRI Axis and PINK1-parkin-mediated Mitophagy in Parkinson’s Disease

INTRODUCTION: Mitochondrial dysfunction plays a crucial role in the pathogenesis of Parkinson's disease (PD). PINK1-Parkin-mediated mitophagy is a quality-control system for mitochondria that protects neurons by getting rid of damaged mitochondria. The OMA1-DELE1-HRI axis has recently been recognized as a vital regulatory checkpoint that limits excessive mitophagy and prevents metabolic failure during mitochondrial stress. The aim of this review is to analyze the mechanistic interplay between the PINK1-Parkin pathway and the OMA1-DELE1-HRI signaling axis. This study aims to synthesize current research on the influence of the stress-response pathway on the initiation of mitophagy, maintenance of mitochondrial homeostasis, and neuronal survival in PD. METHODS: A comprehensive literature review was conducted of molecular, genetic, and pharmacological studies on OMA1, DELE1, and HRI. A thorough analysis of data from kinome-wide screening assays, genetic knockdown experiments, multi-omics profiling, and structural biology studies was performed to elucidate the regulatory interactions between HRI and PINK1 under mitochondrial stress conditions. RESULT: The OMA1-DELE1-HRI pathway stops PINK1 from being stable by controlling how mitochondria make proteins and how they respond to stress. This inhibition serves as a metabolic safeguard that regulates mitophagy levels, preventing harmful overactivation. HRI seems to change PINK1-dependent mitophagy while having little effect on other pathways that clear things at the same time. This suggests that HRI has different substrate preferences and signaling specificity. DISCUSSION: The OMA1-DELE1-HRI axis is an important negative regulator of mitophagy that PINK1 and Parkin mediate. It stops too much mitochondrial clearance and metabolic failure in Parkinson's disease. This mechanism preserves bioenergetic homeostasis and promotes neuronal survival, suggesting that HRI is a promising therapeutic target. Inhibitors like ISRIB or heme mimetics may selectively restore mitophagy, thereby enhancing neuroprotection and enabling precision therapies guided by biomarkers such as phosphorylated eIF2. CONCLUSION: The OMA1-DELE1-HRI axis is a distinctive regulatory mechanism for mitochondrial quality control, significantly impacting neuroprotection in Parkinson's disease. Understanding its dual role in controlling mitophagy and maintaining bioenergetic homeostasis opens new possibilities for targeted drug development. Subsequent research should focus on structural and pharmacological modifications of HRI to enhance mitophagy while preventing mitochondrial depletion.