MSC-Exos Restore Hippocampal Neuron Morphology After Stress via Wnt5a Pathway

Chronic stress is a significant clinical concern, known to inflict structural damage on the brain. The hippocampus, a region central to memory formation and emotional regulation, is particularly vulnerable [1, 2]. Sustained exposure to stress hormones can impair the intricate architecture of hippocampal neurons, specifically by reducing dendritic branching and degrading synaptic plasticity, the cellular foundations of cognition [3]. These morphological deficits are increasingly linked to the pathophysiology of depressive disorders and neurodegenerative conditions, creating an urgent need for therapies that can restore neuronal integrity [4, 5]. While mesenchymal stem cells have regenerative potential, their direct use is complicated by logistical and immunological hurdles [6, 7]. An alternative strategy focuses on mesenchymal stem cell-derived exosomes (MSC-Exos), which are nanoscale vesicles that carry a cargo of proteins and nucleic acids, facilitating intercellular communication and tissue repair without transplanting whole cells [8, 6, 9].