Microfluidic compartmentalization reveals that ferrostatin-1 restores directional mitochondrial transport in Aβ-challenged neurons

Abstract

Mitochondrial dysfunction is a hallmark of neurodegenerative diseases, including Alzheimer's disease (AD). While ferroptosis has been implicated in AD through iron accumulation and amyloid β (Aβ)-mediated toxicity, its role in mitochondrial regulation remains unclear. Here, we examined whether mitochondrial dysfunction in AD increases neuronal vulnerability to ferroptosis and whether ferroptosis inhibition can preserve mitochondrial network integrity. Primary cortical neurons were cultured in a multi-compartment microfluidic platform that facilitated high-resolution tracking of mitochondrial dynamics using time-lapse microscopy. Prolonged exposure to the ferroptosis inducer erastin disrupted neuronal networks, whereas acute exposure to erastin or Aβ significantly enhanced retrograde mitochondrial transport. These effects were blocked by the ferroptosis inhibitor ferrostatin-1 (Fer-1). Using a novel mitochondrial calcium probe (mt-Fura 2.3 AM), we further demonstrated that Aβ acutely increased mitochondrial calcium, which was ameliorated by Fer-1 and by inhibition of the mitochondrial calcium uniporter with MCUi4. In contrast, Aβ-induced hyperactivity recorded on a microelectrode array was prevented by MCUi4, but not Fer-1. Together, these results show that ferroptotic stress profoundly impacts mitochondrial movement and calcium regulation in neurons. Our multimodal microfluidic approach establishes a direct mechanistic link between ferroptosis, mitochondrial dysfunction, and neuronal vulnerability in AD, offering new insights into therapeutic targeting of ferroptosis in neurodegeneration.