# HUWE1 regulates mitophagy to protect dopaminergic neurons from 6-OHDA- and MPP⁺-induced neurotoxicity

## TL;DR

This study shows that HUWE1 helps protect brain cells from damage linked to Parkinson's disease by managing mitochondrial health.

## Contribution

The study identifies HUWE1 as a novel regulator of mitophagy in dopaminergic neurons under neurotoxic stress.

## Key findings

- HUWE1 depletion increases vulnerability of dopaminergic neurons to 6-OHDA and MPP⁺ toxicity.
- Overexpression of HUWE1 preserves mitochondrial integrity and promotes mitophagy under stress.
- BL-918 treatment activates HUWE1-mediated mitophagy and reduces neurotoxic effects.

## Abstract

Parkinson’s disease (PD) is characterized by dopaminergic neuronal loss, often associated with mitochondrial dysfunction and impaired mitophagy. Here, we investigated the role of HUWE1, an E3 ubiquitin ligase, in regulating mitophagy and neuronal survival in a cellular PD model. HUWE1 promoted mitophagy, whereas its depletion sensitized SH-SY5Y cells to 6-hydroxydopamine (6-OHDA)- and 1-methyl-4-phenylpyridinium (MPP⁺)-induced cytotoxicity and mitochondrial dysfunction. Notably, both toxins downregulated HUWE1, suggesting that loss of HUWE1 contributes to dopaminergic vulnerability. Conversely, HUWE1 overexpression preserved mitochondrial integrity and enhanced mitophagy under neurotoxic stress. Importantly, BL-918, a ULK1 activator that promotes AMBRA1 recruitment, facilitated HUWE1-mediated mitophagy in SH-SY5Y cells. BL-918 treatment significantly attenuated 6-OHDA- and MPP⁺-induced neurotoxicity and protected mitochondrial function via HUWE1 activation. Collectively, these findings identify HUWE1 as a key mechanistic regulator of mitophagy linked to dopaminergic neuronal vulnerability, and provide a conceptual framework for future investigations examining its role in PD–relevant model systems.

Highlights

• HUWE1 is an E3 ubiquitin ligase that regulates mitophagy in dopaminergic neurons.

• Neurotoxicity induced by 6-OHDA or MPP+ reduces HUWE1 expression, thereby inhibiting mitophagy in dopaminergic neurons.

• Overexpression or activation of HUWE1 promotes the clearance of damaged mitochondria under neurotoxic stress.

• BL-918 enhances HUWE1-mediated mitophagy and mitigates neurotoxin-induced mitochondrial dysfunction in dopaminergic neurons.