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Shedlock, C.

Publications and source records attributed to Shedlock, C..

3 recordsLinked to original sources

A multi-organ spatial metabolomic atlas of exercising mice reveals neuronal Complex I as a convergent and sufficient axis for tau pathology reduction in PS19

We constructed a spatially resolved metabolomic atlas of long-term exercise across six major organs in wild-type mice: brain, heart, lung, liver, kidney, and skeletal muscle, cataloguing 224 metabolic features and revealing coordinated inter-organ remodeling. Surprisingly, the brain showed particularly pronounced region-specific adaptation. Because pathological tau associates with synaptic mitochondria from early stages of tauopathy, we extended this multi-organ spatial metabolomic approach to PS19 mice and found that exercise reduced over 70% of observable tau pathology in PS19 hippocampus and restored the mitochondrial-related metabolome. Integrated proteomic and spatial metabolomic analyses identified NADH dehydrogenase Complex I as the convergent node. To test this finding biologically, we expressed the yeast NADH dehydrogenase, Ndi1, in PS19 neurons in the absence of exercise. This increased cerebral antioxidants, restored shuttle-linked metabolites, and reduced tau pathology. Increasing NADH dehydrogenase activity through NDI1 reproduces the core anti-tau and metabolic effects of exercise. These findings provide a molecular mechanism for how exercise may prevent or slow tau pathology accumulation, complementing the human-cohort literature linking exercise to delayed cognitive decline.

neuroscience↗

Metabolic Coherence of the Mouse Brain

The brains metabolic demands are well established, but how metabolism is coordinated across anatomically distinct regions remains poorly understood. Here, using matrix-assisted laser desorption/ionization (MALDI) imaging integrated with the Allen Brain Atlas and optimal transport-based computational analysis, we map the spatial metabolome across twelve major mouse brain divisions. We define an optimal-transport-derived inter-regional metabolite similarity metric and refer to it as metabolic coherence. This structure is largely preserved in an amyloid mouse model of Alzheimers disease despite widespread changes in individual metabolite and lipid levels. Individual metabolites and lipids shift in a coordinated manner across regions, sustaining inter-regional relationships even as absolute levels change in patterns indicative of mitochondrial dysfunction. To test whether the coherence metric is responsive to local intervention, we targeted the left hippocampus of mice from this model via lentiviral shHIF1 knockdown or neuronal AAV-mediated AOX expression. Both interventions were associated with metabolite normalization at the injection site. More importantly, normalization extended across distal regions sharing high metabolic similarity with the hippocampus and was accompanied by improved social memory in a single behavioral assay. Gene modulation and amyloid plaque reduction localized to the injection site.

neuroscience↗

Hyper-Glycosylation as a Central Metabolic Driver of Alzheimers Disease

Alzheimers disease (AD) is a neurodegenerative disorder characterized by devastating degenerative decline. Metabolic disruptions are widely observed, yet their involvement in the molecular etiology of AD remains underexplored. Utilizing spatial metabolomics, lipidomics, and glycomics in both mouse models and human post-mortem samples, we identified a hyper-glycosylation phenotype as a hallmark of AD. To investigate the underlying mechanisms and whether the observed effect was a driver of the observed decline, we developed an advanced spatial isotopic tracing pulse-chase method to study the dynamics of N-linked glycans. Our analysis revealed enhanced glycan biosynthesis in AD mouse models. Based on these findings, we performed genetic and dietary interventions to modulate glycan biosynthesis. Genetic knockdown of glycan biosynthetic enzymes ameliorated the hyper-glycosylation and improved cognitive and behavioral outcomes in AD mice. In contrast, oral glucosamine supplementation drove hyper-glycosylation and exacerbated cognitive and behavioral deficits. To assess the clinical relevance of these findings, we conducted a retrospective analysis of a large population of patients with mild cognitive impairment (MCI), AD, and Alzheimers Disease Related Dementias (ADRD) stratified by glucosamine use, leveraging electronic health records. Consistently, glucosamine supplementation was associated with increased mortality in AD and ADRD patient cohorts, and significantly elevated progression from MCI to AD compared to age-matched controls. Collectively, our findings establish hyper-glycosylation as a pathological driver of AD and highlight glycan metabolism as an actional target in the fight against AD.

neuroscience↗