OMG! A proteomic determinant of neurodegenerative resiliency

Abstract Background Biofluid proteomics can enhance our understanding of the neurodegenerative mechanisms underlying Alzheimer’s disease and related dementias (ADRDs). Oligodendrocyte myelin glycoprotein (OMG) is a brain-specific protein implicated in myelination, but its potential mechanistic, biomarker, and therapeutic roles in ADRDs requires further elucidation. Methods After detecting an inverse association between its abundance in peripheral circulation and cortical amyloid deposition in two community-based cohorts, the current study characterized OMG’s role in ADRDs with high-throughput proteomics from sixteen independent cohorts. Data included a variety of cross-sectional and longitudinal community-based and clinical cohorts from North America, Europe, and Asia, and incorporated complementary biofluids, biospecimens, and proteomic platforms. Statistical analyses were conducted separately in each cohort. Results We detected lower plasma OMG in individuals with cortical amyloid deposition, compromised brain structure, dementia, and multiple sclerosis, as well as in individuals who developed dementia over 7- to 20-year follow-up periods. OMG’s CSF and brain proteomic signatures reflected broader neuroprotective mechanisms, especially axonal structural integrity, and two-sample Mendelian randomization causally implicated OMG as protective against multiple neurodegenerative diseases. Conclusions Our findings implicate OMG as a mechanistic determinant of neurodegenerative resiliency among older adults, which is reliably captured by its abundance in peripheral circulation