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Seeley, E. H.

Publications and source records attributed to Seeley, E. H..

8 recordsLinked to original sources

An atlas of the aging glycoproteome reveals how glycosylation modulates autoantibody binding in the brain

N-glycosylation generates substantial molecular diversity, yet how glycan composition varies throughout aging remains poorly understood. We mapped the N-glycoproteome of brain, liver, spleen, kidney, and plasma across nine ages spanning the mouse lifespan, identifying 80,618 unique N-glycopeptides at 9,211 glycosites on 4,391 glycoproteins, together with matched proteomic trajectories (glycoproteinatlas.org). Organ identity was the dominant determinant of glycan composition, but numerous glycosites nevertheless underwent remodeling with age. The brain showed a prominent age-associated increase in short paucimannose glycans, driven in part by the age-associated increase in the glycan-processing enzyme HEXB. In white matter, a hotspot for this change, aging increased the paucimannosylation of Myelin oligodendrocyte glycoprotein (MOG), a major target of central nervous system autoimmunity. We identified MOG-reactive autoantibodies in aged individuals and patients with MOG antibody-associated disease (MOGAD) and showed that the glycan at MOG N60 modulates autoantibody binding. Experimental autoimmune encephalomyelitis (EAE) recapitulated a subset of the age-associated glycosite changes, revealing shared glycosylation signatures between aging and autoimmune targeting of MOG. Together, these findings reveal site-specific N-glycosylation as both a marker of age and a regulator of molecular interactions.

neuroscience↗

Distinct spatiotemporal immunometabolic remodeling following acute traumatic brain injury

Traumatic brain injury induces profound metabolic reprogramming across neurons, astrocytes, and microglia, yet the spatiotemporal organization of these metabolic responses remains poorly understood. Because pyruvate is uniquely positioned in cerebral metabolism by connecting glycolysis, lactate metabolism, and the tricarboxylic acid cycle, we combined matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging with in vivo administration of isotopically labeled pyruvate and immunohistochemistry to characterize cell-type-wise metabolic remodeling in a controlled cortical impact rat model during the acute and subacute phases of injury. TBI induced distinct spatiotemporal immunometabolic remodeling across neuroglial compartments. Microglia- and macrophage-enriched regions exhibited selective accumulation of citrate, succinate, and itaconate, consistent with inflammatory metabolic rewiring. In contrast, astrocyte enriched regions showed increased glutamine and malate abundance, indicative of altered neuron-astrocyte metabolic coupling such as remodeling of the glutamate-glutamine cycle and enhanced anaplerotic metabolism. These metabolic signatures evolved with distinct regional and temporal distributions, identifying compartmentalized metabolic responses. Notably, labeled isotopologues of selected metabolites, including glutamate and citrate derived from administered pyruvate, changed before the corresponding metabolite pools. Together, these findings describe the spatiotemporal landscape of immunometabolic remodeling following acute TBI, uncover metabolically distinct microglial/macrophage and astrocytic responses during secondary brain injury, and identify candidate metabolic pathways for therapeutic intervention and metabolic imaging.

biochemistry↗

Integration of spatial single-cell proteomics and spatial metabolomics reveals tumor microenvironment predictive of immunotherapy response in mucosal melanoma

Mucosal melanoma (MuM) is a rare but aggressive malignancy with limited benefit from immune checkpoint inhibition and few predictive biomarkers. We integrated single-cell spatial proteomics (COMET) and spatial metabolomics (MALDI-IMS) to profile 97 tissue cores from 26 patients treated with PD-1/PD-L1 and/or CTLA-4 inhibitors. We profiled 695,444 cells and resolved 25 cell states across eight major cell types. Cellular neighborhood (CN) analysis revealed distinct tumor- and stromal-associated spatial architectures. Responders were enriched for tumor-associated CNs (invasive tumor and tumor boundary) with close spatial proximity among Ki67 tumor cells, CD163 macrophages, and CD11c dendritic cells (DCs), and increased proliferating/cytotoxic CD8+ T-cell subsets. Non-responders showed stromal CN dominance with reduced immune infiltration. Spatial metabolomics identified lower abundance of indole-derived metabolites and reduced indole/tryptophan pathway activity in responders within tumor and TME regions that tracked with DC/macrophage-enriched spatial contexts. This study advances MuM spatial biology and provides a framework for biomarker-driven immunotherapy strategies. Statement of significanceMucosal melanoma (MuM) responds poorly to immune checkpoint blockade, and predictive biomarkers are limited. Integrated spatial proteomics and metabolomics reveal response-associated tumor-immune neighborhood architecture, stromal contexts linked to immune exclusion, and altered indole/tryptophan metabolism in the microenvironment. These spatial features nominate biomarkers and therapeutic hypotheses to improve immunotherapy for MuM.

cancer biology↗

Loss of the Coronary Artery Disease Risk Gene Leiomodin1 in Vascular Smooth Muscle Cells Triggers Rapid Onset Coronary Atherosclerosis

BackgroundAtherosclerosis is the primary underlying cause of coronary artery disease (CAD). Leiomodin1 is a vascular smooth muscle cell (VSMC)-restricted CAD risk gene whose role in coronary artery pathophysiology is unknown. Global loss of Leiomodin1 causes lethal neonatal visceral myopathy, requiring unique approaches for study in VSMCs. MethodsSeveral distinct Leiomodin1 mutant mouse models were generated by clustered regularly interspaced short palindromic repeats (CRISPR). Control (Lmod1WT) and VSMC-restricted Lmod1 knockout (Lmod1SMKO) mice were subjected to various atherogenic regimens. Atherosclerosis and LMOD1 expression in mouse and human coronary arteries were assessed by histopathology and confocal immunofluorescence microscopy. Coronary arteries from Lmod1WT and Lmod1SMKO mice were analyzed with assorted stains and antibodies, immunogold lineage tracing, spatial metabolomics/transcriptomics, and single-cell RNA sequencing (scRNA-seq). Mouse aortic SMCs from Lmod1WT and Lmod1SMKO mice were subjected to lipid loading with lentiviruses expressing wild-type Lmod1, a nucleation deficient Leiomodin1 (Lmod1ND), or a short hairpin RNA (shRNA) targeting Thrombospondin (Thbs1). ResultsUnder atherogenic conditions, Lmod1SMKO mice displayed unremarkable vessels in several organs but developed diffuse and occlusive coronary atherosclerosis. No such disease was observed in Lmod1WT mice. Time-course studies documented lipid insudation and VSMC foam cell formation in the coronary arteries of Lmod1SMKO mice as early as six days post-regimen. Immunogold lineage tracing demonstrated 46% of coronary plaque cells being of VSMC origin, with most showing evidence of lipid uptake. An intronic deletion of Lmod1, containing a conserved region where the single nucleotide variant associated with CAD exists, showed attenuated LMOD1 expression; heterozygous Lmod1SMKO mice, with a similar reduction in LMOD1, showed no CAD. Spatial metabolomics uncovered multiple lipid species within coronary atheromata of Lmod1SMKO mice, and spatial/scRNA-seq of similar coronary lesions disclosed altered lipid pathways with a consistent elevation in Thbs1. In vitro mechanistic studies revealed lipid accumulation in Lmod1SMKO VSMCs that was rescued by Lmod1WT, Lmod1ND, and Thbs1 shRNA. VSMC-restricted expression of Lmod1ND in mice resulted in negligible coronary atherosclerosis. ConclusionsUnder proatherogenic conditions, Lmod1SMKO mice present with rapidly manifesting coronary atherosclerosis that appears to be independent of the actin nucleation function of LMOD1. Targeting Thbs1 represents a viable strategy to mitigate VSMC foam cell formation. Clinical PerspectiveO_ST_ABSWhat is new?C_ST_ABSO_LIVascular smooth muscle cell (VSMC) loss of Leiomodin1 (Lmod1) causes diffuse and occlusive coronary atherosclerosis in mice, with little or no such disease in other vascular beds. C_LIO_LIA novel immunogold lineage tracing assay shows VSMC migration to the intima as early as six days following an atherogenic regimen, and quantitative studies demonstrate that 46% of coronary plaque cells are of SMC origin. C_LIO_LIThe coronary phenotype appears to be independent of LMOD1s actin nucleation activity, but VSMC lipid uptake is thrombospondin-dependent. C_LI What are the clinical implications?O_LILMOD1 is an annotated smooth muscle cell-restricted risk allele for human coronary artery disease (CAD), offering new insight into the role of smooth muscle cells in atherogenesis. C_LIO_LIThe rapidly manifesting CAD phenotype in Lmod1 knockout mice enables expedited testing of novel therapeutics to mitigate disease progression. C_LIO_LINew insight into LMOD1 pathobiology will help inform further SNV interrogation of the LMOD1 locus for CAD risk in patients. C_LI

pathology↗

AADAT-Driven Metabolic Control of Malate and CoQ10 Shapes Immune Evasion in Triple-Negative Breast Cancer

Compared to other subtypes of breast cancer, triple-negative breast cancers (TNBC) have fewer treatment options and exhibit a worse prognosis. Through integrated transcriptomic, metabolomic, immunohistochemical, spatial, and clinical analyses, we identify the mitochondrial enzyme, -aminoadipate aminotransferase (AADAT) as a previously unrecognized metabolic immune checkpoint in TNBC. AADAT mRNA and protein were significantly upregulated in human TNBC, and high AADAT expression was associated with reduced intra-tumoral CD8 T-cell density and inferior survival. Genetic silencing of AADAT in orthotopic murine TNBC models curtailed primary tumor growth and distant metastasis in a CD8 T-cell-dependent manner, enhanced effector T-cell activation, and sensitized tumors to dual PD-1/CTLA-4 blockade. Mechanistically, unbiased metabolomics showed increased malate levels after AADAT knockdown. Additionally, 4-hydroxyphenylpyruvate, an essential precursor for coenzyme Q10(CoQ10) biosynthesis, decreased following AADAT knockdown, suggesting an impaired mitochondrial electron transport chain. CoQ10 supplementation restored metabolic balance and reversed malate accumulation caused by AADAT knockdown, indicating that AADAT helps maintain CoQ10-supported redox homeostasis, thereby preventing malate buildup and export. Notably, malate addition directly boosted CD8 T-cell oxidative metabolism, increased the NAD/NADH ratio and reactive oxygen species, and augmented TNF- and IFN-{gamma} production. In vivo, malate supplementation in drinking water phenocopied AADAT knockdown, restored the response to paclitaxel plus anti-PD-1 therapy in multiple independent syngeneic TNBC models with de novo or acquired resistance to immunotherapy, reduced tumor burden, and prolonged survival. In patient cohorts, higher spatially clustered intra-tumoral malate is associated with co-localization of functional CD8 T cells, decreased exhausted T-cell neighborhoods, and superior post-chemotherapy outcomes. These data position AADAT as a central metabolic orchestrator of immune escape in TNBC and nominate oral malate as a readily translatable adjuvant to reverse chemo-immunotherapy resistance in TNBC. Statement of SignificanceAADAT defines a metabolic-immune axis driving immune evasion and therapy resistance in triple-negative breast cancer. Blocking AADAT or administering oral malate reactivates CD8 T-cell immunity and sensitizes chemo-immunotherapy-resistant tumors to these agents. These findings uncover a readily translatable metabolic vulnerability with potential to improve outcomes for patients with aggressive breast cancer subtypes.

cancer biology↗

Downregulation of LATS1/2 Drives Endothelial Senescence-Associated Stemness (SAS) and Atherothrombotic Lesion Formation

BackgroundAtherothrombosis, the main event leading to acute coronary syndrome (ACS), is strongly linked to disturbed blood flow (d-flow) regions. Although the involvement of the Hippo pathway and its kinases Large Tumor Suppressor Kinase 1and 2 (LATS 1 and 2) in mechanical stress responses is known, the mechanisms by which d-flow simultaneously induces senescence, proliferation, and atherothrombosis remain unclear. MethodsThe role of endothelial cells (EC)-specific LATS1/2 was examined using EC specific knock-out (EKO) mice in a partial left carotid ligation (PLCL) model. Plaque spatial multi-omics analysis was performed by integrating imaging mass cytometry, sequential immunofluorescence (COMET), and spatial metabolomics at the single-cell level in human and mouse atherosclerotic plaques. ResultsIn tamoxifen-inducible Lats1homo(-/-) /Lats2 homo(-/-) EC-specific knockout (EKO) mice, deletion of LATS1/2 induced by tamoxifen led to fatal outcomes, characterized by severe systemic edema and markedly increased vascular permeability. In contrast, Lats1het(+/-)/Lats2 homo(-/-)-EKO mice survived and developed atherothrombotic plaques exhibiting neovascularization even without further additional dietary or genetic intervention. Spatial proteomics analysis revealed that LATS1/2 depletion in ECs triggered a senescence-associated stemness (SAS) phenotype, primarily driven by CD38 upregulation. Complementary spatial metabolomics profiling demonstrated a significant increase in sulfite and taurine within LATS1/2-deficient plaques, indicating lowered sulfite oxidase (SUOX) activity. Mechanistically, CD38 upregulation was found to suppress SUOX expression, induce the reverse mode of mitochondrial complex V, and increase succinate dehydrogenase (SDH) activity along with ATP consumption. Paradoxically, despite ATP depletion, this metabolic disturbance enhanced glutamate metabolism and the tricarboxylic acid (TCA) cycle, sustaining EC proliferation under energetically stressed conditions. The combined effect of LATS1/2 deletion and CD38 activation established a unique EC phenotype defined by increased SAS, leading to proliferation, senescence, and eventual cell death. These pathological processes culminated in the formation of atherothrombotic plaques, which were attenuated by inhibition of CD38. Notably, a similar phenotype--marked by metabolically active ECs--was observed in human atherothrombotic plaques, suggesting translational relevance. ConclusionLoss of LATS1/2 in ECs induces SAS state that promotes excessive EC proliferation, senescent cell accumulation, and the development of structurally fragile, leaky neo vessels--hallmarks of atherothrombotic lesions. CD38-mediated SUOX deficiency further amplifies this pathological process by inducing mitochondrial dysfunction, depleting ATP, and triggering compensatory upregulation of glutamate and TCA cycle metabolism. These findings identify a novel LATS1/2-CD38-SUOX axis in ECs that orchestrates SAS-driven atherothrombosis. Targeting CD38 may represent a promising therapeutic strategy to mitigate vascular dysfunction and plaque instability in high-risk ACS patients. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=191 HEIGHT=200 SRC="FIGDIR/small/660635v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@149d313org.highwire.dtl.DTLVardef@1c0988borg.highwire.dtl.DTLVardef@15efec9org.highwire.dtl.DTLVardef@1a96e03_HPS_FORMAT_FIGEXP M_FIG C_FIG Under normal physiological conditions, LATS1/2 and Lamin A work together to suppress CD38 expression. Lamin A binds directly to the CD38 promoter to repress transcription, and LATS1/2 interact with Lamin A to reinforce this suppression. This collaboration helps maintain low CD38 activity and preserves cellular NAD levels. However, under disturbed flow (d-flow), both LATS1/2 and Lamin A are downregulated. The loss of this dual repression leads to increased CD38 NADase expression. Elevated CD38 accelerates NAD consumption, causing NAD depletion--a hallmark of cellular senescence. Reduced NAD disrupts key metabolic and stress-response pathways, contributing to the onset of the senescent state. At the same time, CD38 suppresses sulfite oxidase (SUOX), leading to sulfite accumulation and mitochondrial redox imbalance. This shift activates the reverse mode of mitochondrial Complex V, which decreases ATP production and increases mitochondrial ROS, intensifying metabolic and oxidative stress in endothelial cells (ECs). In response, ECs compensate by upregulating succinate dehydrogenase (SDH), enhancing TCA cycle activity and glutamate metabolism. This metabolic adaptation provides the biosynthetic building blocks needed for cell growth and proliferation. As a result, ECs adopt a paradoxical phenotype: they show classical features of stress-induced senescence (such as NAD depletion, oxidative stress, and cell cycle arrest signals), while simultaneously undergoing metabolic activation and proliferation, also mediated by YAP. This defines a non-canonical endothelial program known as senescence-associated stemness (SAS), characterized by the formation of abnormal, proliferative, yet fragile neovessels. These dysfunctional vessels contribute to atherothrombosis, setting this process apart from the more stable lesions typical of conventional atherosclerosis.

molecular biology↗

Enhanced dynamic covalent chemistry for the controlled release of small molecules and biologics from a nanofibrous peptide hydrogel platform

Maintaining safe and potent pharmaceutical drug levels is often challenging. Multidomain peptides (MDPs) assemble into supramolecular hydrogels with a well-defined, highly porous nanostructure that makes them attractive for drug delivery, yet their ability to extend release is typically limited by rapid drug diffusion. To overcome this challenge, we developed self-assembling boronate ester release (SABER) MDPs capable of engaging in dynamic covalent bonding with payloads containing boronic acids (BAs). As examples, we demonstrate that SABER hydrogels can prolong the release of five BA-containing small-molecule drugs as well as BA-modified insulin and antibodies. Pharmacokinetic studies revealed that SABER hydrogels extended the therapeutic effect of ganfeborole from days to weeks, preventing Mycobacterium tuberculosis growth better than repeated oral administration in an infection model. Similarly, SABER hydrogels extended insulin activity, maintaining normoglycemia for six days in diabetic mice after a single injection. These results suggest that SABER hydrogels present broad potential for clinical translation.

bioengineering↗

Spatially Resolved Metabolites in Stable and Vulnerable Human Atherosclerotic Plaques Identified by Mass Spectrometry Imaging

Impairments in carbohydrate, lipid, and amino acid metabolism drive features of plaque instability. However, where these impairments occur within the atheroma remains largely unknown. Therefore, we sought to characterize the spatial distribution of metabolites within stable and unstable atherosclerosis in both the fibrous cap and necrotic core. Atherosclerotic tissue specimens were scored based on the Stary classification scale and subdivided into stable and unstable atheromas. After performing mass spectrometry imaging (MSI) on these samples, we identified over 850 metabolite-related peaks. Using MetaboScape, METASPACE, and HMDB, we confidently annotated 170 of these metabolites and found over 60 of these were different between stable and unstable atheroma. We then integrated these results with an RNA-sequencing dataset comparing stable and unstable human atherosclerosis. Upon integrating our MSI results with the RNA-seq dataset, we discovered that pathways related to lipid metabolism and long-chain fatty acids were enriched in stable plaques, whereas reactive oxygen species, aromatic amino acid, and tryptophan metabolism were increased in unstable plaques. Acylcarnitines and acylglycines were increased in stable plaques whereas tryptophan metabolites were enriched in unstable plaques. Evaluating spatial differences in stable plaques revealed lactic acid in the necrotic core, whereas pyruvic acid was elevated in the fibrous cap. In unstable plaques, 5-hydroxyindole-acetic acid was enriched in the fibrous cap. Our work herein represents the first step to defining an atlas of metabolic pathways involved in plaque destabilization in human atherosclerosis. We anticipate this will be a valuable resource and open new avenues of research in cardiovascular disease. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=199 SRC="FIGDIR/small/494038v1_ufig1.gif" ALT="Figure 1"> View larger version (59K): org.highwire.dtl.DTLVardef@111368org.highwire.dtl.DTLVardef@1112d99org.highwire.dtl.DTLVardef@c8cdb2org.highwire.dtl.DTLVardef@13895d6_HPS_FORMAT_FIGEXP M_FIG C_FIG

pathology↗