Mitochondrial dysfunction and mitochondrial unfolded protein response (UPR^mt): unravelling their roles in autism...

Autism spectrum disorders (ASD) is a complex neurodevelopmental condition characterized by a gamut of impairments in social interaction, communication, and behaviour. Emerging evidence implicates mitochondrial dysfunction, manifested through disruptions in ATP synthesis, mitochondrial DNA (mtDNA) mutations, and heightened oxidative stress, as a significant contributor to the pathophysiology of ASD. Notably, individuals with ASD demonstrate a higher prevalence of mitochondrial disorders compared to the general population, suggesting a potential pathogenic link. However, the relationship between mitochondrial dysfunction and ASD is heterogeneous and varies among individuals, reflecting the disorder's intrinsic complexity. Recent interest in the Mitochondrial Unfolded Protein Response (UPR^mt), which is activated in response to mitochondrial stress and misfolded proteins, underscores its critical role in maintaining mitochondrial integrity. Yet, its specific implications in ASD have been insufficiently investigated. This review aims to consolidate the current literature on UPR^mt-related biomarkers in the context of ASD, elucidating how disruptions in this pathway may exacerbate mitochondrial dysfunction and contribute to ASD pathogenesis. In this narrative review, based on our literature search from academic databases such as PubMed, Scopus, Web of Science, and Google Scholar, and also grey literature, we present a conceptual framework to enhance our understanding of ASD pathophysiology that integrates mitochondrial stress, UPR^mt activation, and neurodevelopmental outcomes. This review aims to expand the existing knowledge of mitochondrial contributions to ASD and identify new research dimensions to explore the mechanisms underlying UPR^mt deregulation in ASD pathophysiology, thereby highlighting the potential therapeutic directions for targeting mitochondria-mediated UPR^mt dysfunction in ASD.