Rab32 connects ER stress to mitochondrial defects in multiple sclerosis

Area of Science:

• Neuroscience
• Cell Biology
• Pathology

Background:

• Endoplasmic reticulum (ER) stress is a key feature of neurodegenerative diseases like multiple sclerosis (MS).
• The unfolded protein response (UPR) and mitochondrial dysfunction are linked via mitochondria-associated membranes (MAMs).
• Rab32, a GTPase regulating MAMs, mitochondrial dynamics, and apoptosis, was investigated for its role in ER stress and mitochondrial dysfunction.

Purpose of the Study:

• To investigate the association of Rab32 with ER stress and mitochondrial dysfunction in the context of MS.
• To determine if Rab32 is a target of the UPR.

Main Methods:

• Assessed Rab32 expression in MS and experimental autoimmune encephalomyelitis (EAE) tissues.
• Observed mitochondrial morphology in primary neurons.
• Monitored neuronal cell survival following increased Rab32 expression.

Main Results:

• Rab32 and MAM protein induction correlated with ER stress markers in MS and EAE central nervous system (CNS) tissues.
• Rab32 was identified as a novel UPR target, induced by acute brain inflammation.
• Elevated Rab32 expression impaired neurite length, altered mitochondrial morphology, and accelerated neuronal apoptosis/necroptosis.

Conclusions:

• ER stress is linked to Rab32 upregulation during MS progression.
• Rab32 contributes to mitochondrial dysfunction and neuronal death in MS.