# Transcriptomic Investigation of FoxM1-Mediated Neuroprotection by hAEC-Derived Exosomes in an In Vitro Ischemic Stroke Model

## TL;DR

This study explores how exosomes from human amniotic cells protect brain cells in stroke models, with a focus on the role of the FoxM1 protein.

## Contribution

The study identifies FoxM1 as a key mediator of the neuroprotective effects of amniotic cell-derived exosomes in ischemic stroke.

## Key findings

- Exosomes from human amniotic epithelial cells reduced inflammation, cell death, and oxidative stress in stroke models.
- FoxM1 was found to be crucial for the protective effects of exosomes, as its knockdown reversed these benefits.
- The study suggests that these exosomes could be a promising cell-free therapy for ischemic stroke.

## Abstract

Stroke is a leading cause of death and long-term disability worldwide, most commonly occurring when a blockage cuts off blood flow to the brain. This lack of oxygen and nutrients can cause widespread brain cell death and permanent damage. Unfortunately, current treatments must be administered very early and often cannot reverse damage once it has occurred. In this study, we explored a novel therapeutic strategy using tiny particles called exosomes, which are naturally released by human amniotic epithelial cells from the placenta after birth. These exosomes can carry beneficial signals to injured brain cells. We employed a laboratory in vitro stroke model to simulate brain injury and tested how these exosomes affected neuronal and immune cells. Our results showed that the exosomes reduced harmful inflammation, prevented cell death, and supported cell recovery. We also discovered that a specific protein, called FoxM1, plays a crucial role in mediating these protective effects. This research suggests that exosomes derived from amniotic cells may offer a safe and effective new treatment to help the brain heal after a stroke, potentially improving patient outcomes and reducing the burden of this disease on families and healthcare systems.

Human amniotic epithelial cell-derived exosomes (hAECs-Exos) are nanoscale extracellular vesicles with neuroprotective, regenerative, and anti-inflammatory properties, presenting a promising cell-free therapeutic approach for ischemic stroke. This study investigated the protective effects of hAECs-Exos against ischemic injury and explored the underlying molecular mechanisms. An optimized oxygen-glucose deprivation/reoxygenation (OGD/R) model was established in murine hippocampal HT22 neurons and BV2 microglial cells to simulate ischemic conditions. hAECs-Exos were successfully isolated and characterized via transmission electron microscopy, nanoparticle tracking analysis, and Western blotting. Confocal microscopy confirmed efficient exosome uptake by both cell types. Functional analyses revealed that hAECs-Exos significantly improved cell viability, suppressed pro-inflammatory cytokine release, alleviated oxidative stress, and modulated apoptosis-related proteins. RNA sequencing identified Forkhead box protein M1 (FoxM1) as a significantly upregulated transcription factor following hAECs-Exos treatment. Further experiments demonstrated that knockdown of FoxM1 in hAECs abolished the beneficial effects of exosomes on the viability of HT22 and BV2 cells and on the suppression of inflammation, oxidative stress, and apoptosis. These findings indicate that hAECs-Exos confer neuroprotection through FoxM1-dependent mechanisms. Together, our results highlight the therapeutic potential of hAECs-Exos as a safe, effective, and clinically translatable strategy for ischemic stroke treatment, warranting future validation in vivo and rescue experiments to fully elucidate FoxM1’s causal role.