43 results on '"Young LEA"'
Search Results
2. Spray-Dried Plasma Promotes Broiler Chick Growth by Enhancing Immune Surveillance
- Author
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Blue, Candice E. C., primary, Jababu, Yasin, additional, Ibrahim, Salam A., additional, Minor, Radiah C., additional, Williams, Leonard L., additional, Adetunji, Adedeji O., additional, Ali, Rizwana, additional, Young, Lea S., additional, and Fasina, Yewande O., additional
- Published
- 2023
- Full Text
- View/download PDF
3. Effect of hydrofluorocarbon structure of C3H2F6 isomers on high aspect ratio etching of silicon oxide
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Tak, Hyun Woo, primary, Lee, Hye Joo, additional, Wen, Long, additional, Kang, Byung Jin, additional, Sung, Dain, additional, Bae, Jeong Woon, additional, Kim, Dong Woo, additional, Lee, Wonseok, additional, Lee, Seung Bae, additional, Kim, Keunsuk, additional, Cho, Byeong Ok, additional, Kim, Young Lea, additional, Song, Han Dock, additional, and Yeom, Geun Young, additional
- Published
- 2022
- Full Text
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4. Effect of hydrofluorocarbon structure of C3H2F6 isomers on high aspect ratio etching of silicon oxide
- Author
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Hyun Woo Tak, Hye Joo Lee, Long Wen, Byung Jin Kang, Dain Sung, Jeong Woon Bae, Dong Woo Kim, Wonseok Lee, Seung Bae Lee, Keunsuk Kim, Byeong Ok Cho, Young Lea Kim, Han Dock Song, and Geun Young Yeom
- Subjects
General Physics and Astronomy ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2022
5. Improving patient outcomes: Evidence based on-site coaching of practice nurses
- Author
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Parker, Christina, Edwards, Helen E., Innes-Walker, Karen, Finlayson, Kathleen J., Brooks, Melinda, Young, Lea, Morley, Nicola, Maresco-Pennisi, Diane, Parker, Christina, Edwards, Helen E., Innes-Walker, Karen, Finlayson, Kathleen J., Brooks, Melinda, Young, Lea, Morley, Nicola, and Maresco-Pennisi, Diane
- Abstract
The aim of this project was to evaluate the effectiveness of the implementation of the CWC model on: Health professionals’ knowledge and patients’ satisfaction about evidence based practice in wound management; Patient outcomes (healing and quality of life).
- Published
- 2018
6. Identifying infection in chronic wounds.
- Author
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Young, Lea
- Abstract
There is a myriad of published research and anecdotal information available regarding wound infection, biofilm and antimicrobials. The author reviewed recent literature on chronic wound infections and has provided a concise and simple breakdown aimed at health professionals dealing with chronic wounds to encourage critical appraisal of their current practice and to guide future practice. [ABSTRACT FROM AUTHOR]
- Published
- 2012
7. Legs Get-together: One year on.
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YOUNG, LEA
- Subjects
WOUND care ,ASSOCIATIONS, institutions, etc. ,COMMUNITY health services ,MEMBERSHIP ,ORGANIZATIONAL goals ,SOCIETIES - Abstract
The article focuses on Legs Get-together dance club of the Lindsay Leg Club Foundation (LLCF). Topics discussed include first anniversary of Legs Get-together which is owned by the community nurses who are educated through the Leg Club Foundation education programme, demand of chronic wounds awareness by the Australian Wound Management Association (AWMA) and presence of Ellie Lindsay, founder of Leg Clubs, at the anniversary event of the club.
- Published
- 2014
8. Barnacle.
- Author
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Young, Lea
- Subjects
- BARNACLE (Poem), YOUNG, Clea
- Abstract
Presents the poem "Barnacle," by Clea Young. First Line: Last night, I was yanking; Last Line: roots in the mud.
- Published
- 2005
9. It's time for businesses to get involved with New Orleans public schools.
- Author
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Young, Lea
- Subjects
MENTORING in education ,PUBLIC schools - Abstract
Discusses how the Partnerships in Education (PIE) program helps students from public schools in New Orleans, Louisiana. What type of persons are on the PIE's steering committee; Need for business enterprises to support this program.
- Published
- 1998
10. TgLaforin, a glucan phosphatase, reveals the dynamic role of storage polysaccharides in Toxoplasma gondii tachyzoites and bradyzoites.
- Author
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Murphy RD, Troublefield CA, Miracle JS, Young LEA, Tripathi A, Brizzee CO, Dhara A, Patwardhan A, Sun RC, Kooi CWV, Gentry MS, and Sinai AP
- Abstract
The asexual stages of Toxoplasma gondii are defined by the rapidly growing tachyzoite during the acute infection and by the slow growing bradyzoite housed within tissue cysts during the chronic infection. These stages represent unique physiological states, each with distinct glucans reflecting differing metabolic needs. A defining feature of T. gondii bradyzoites is the presence of insoluble storage glucans known as amylopectin granules (AGs) that are believed to play a role in reactivation, but their functions during the chronic infection remain largely unexplored. More recently, the presence of storage glucans has been recognized in tachyzoites where their precise function and architecture have yet to be fully defined. Importantly, the T. gondii genome encodes activities needed for glucan turnover: a glucan phosphatase (TgLaforin; TGME49_205290) and a glucan kinase (TgGWD; TGME49_214260) that catalyze a cycle of reversible glucan phosphorylation required for glucan degradation by amylases. The expression of these enzymes in tachyzoites supports the existence of a storage glucan, evidence that is corroborated by specific labeling with the anti-glycogen antibody IV58B6. Disruption of reversible glucan phosphorylation via a CRISPR/Cas9 knockout (KO) of TgLaforin revealed no growth defects under nutrient-replete conditions in tachyzoites. However, the growth of TgLaforin-KO tachyzoites was severely stunted when starved of glutamine, even under glucose replete conditions. The loss of TgLaforin also resulted in the attenuation of acute virulence in mice accompanied by a lower cyst burden. While the absence of TgLaforin did not impact the size distribution of tissue cysts, bradyzoites within both in vitro generated and in vivo tissue cysts exhibited profound changes in AG levels and morphology. Quantification of relative AG levels using AmyloQuant, an imaging-based application, revealed the starch-excess phenotype associated with the loss of TgLaforin is heterogeneous across tissue cysts and exhibits a temporal profile linked to an emerging AG cycle. Together, these data demonstrate the importance of glucan turnover across the T. gondii asexual cycle. These findings, alongside our previously identified class of small molecules that inhibit TgLaforin, implicate reversible glucan phosphorylation as a legitimate target for the development of new drugs against chronic T. gondii infections., Competing Interests: Conflicts of Interest: none
- Published
- 2024
- Full Text
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11. Determining the N-Glycan and Collagen/Extracellular Matrix Protein Compositions in a Novel Outcome Cohort of Prostate Cancer Tissue Microarrays Using MALDI-MSI.
- Author
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Hartig JP, Bejar K, Young LEA, Grimsley G, Bethard JR, Troyer DA, Hernandez J, Wu JD, Ippolito JE, Ball LE, Gelfond JAL, Johnson-Pais TL, Mehta AS, Leach RJ, Angel PM, and Drake RR
- Abstract
Prostate cancer is a significant health concern, with metastasis posing major clinical challenges and resulting in poor patient outcome. Despite screening and treatment advances, a critical need for novel biomarkers to predict prostate cancer progression at the time of prostatectomy persists. Here, we assessed aberrant N-glycosylation patterns and alterations in extracellular matrix proteins as potential biomarkers of predicting prostate cancer severity in a unique patient outcome cohort. Tissue microarray slides were assembled from primary prostatectomy specimens that were categorized into "no evidence of disease (NED)" and "metastasis (MET)" designations based on >5-year disease progression outcomes. Serial mass spectrometry imaging techniques were performed to analyze N-glycans and extracellular matrix (ECM) components in formalin-fixed paraffin-embedded cores. The results revealed a significant upregulation of bisecting and multi-antennary core fucosylated N-glycans in MET tissues when compared to NED tissues. Alterations in ECM composition in both NED and MET cohorts were observed, particularly in collagen species and the amount of hydroxyproline content. Results suggest a coordinated alteration of ECM protein and glycosylation content in prostate cancer tissues can be predictive for post-prostatectomy disease progression.
- Published
- 2024
- Full Text
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12. Small-molecule inhibition of glycogen synthase 1 for the treatment of Pompe disease and other glycogen storage disorders.
- Author
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Ullman JC, Mellem KT, Xi Y, Ramanan V, Merritt H, Choy R, Gujral T, Young LEA, Blake K, Tep S, Homburger JR, O'Regan A, Ganesh S, Wong P, Satterfield TF, Lin B, Situ E, Yu C, Espanol B, Sarwaikar R, Fastman N, Tzitzilonis C, Lee P, Reiton D, Morton V, Santiago P, Won W, Powers H, Cummings BB, Hoek M, Graham RR, Chandriani SJ, Bainer R, DePaoli-Roach AA, Roach PJ, Hurley TD, Sun RC, Gentry MS, Sinz C, Dick RA, Noonberg SB, Beattie DT, Morgans DJ Jr, and Green EM
- Subjects
- Mice, Animals, Glycogen Synthase metabolism, Glycogen Synthase pharmacology, Mice, Knockout, Glycogen metabolism, Muscle, Skeletal metabolism, Enzyme Replacement Therapy methods, Glycogen Storage Disease Type II drug therapy
- Abstract
Glycogen synthase 1 (GYS1), the rate-limiting enzyme in muscle glycogen synthesis, plays a central role in energy homeostasis and has been proposed as a therapeutic target in multiple glycogen storage diseases. Despite decades of investigation, there are no known potent, selective small-molecule inhibitors of this enzyme. Here, we report the preclinical characterization of MZ-101, a small molecule that potently inhibits GYS1 in vitro and in vivo without inhibiting GYS2, a related isoform essential for synthesizing liver glycogen. Chronic treatment with MZ-101 depleted muscle glycogen and was well tolerated in mice. Pompe disease, a glycogen storage disease caused by mutations in acid α glucosidase (GAA), results in pathological accumulation of glycogen and consequent autophagolysosomal abnormalities, metabolic dysregulation, and muscle atrophy. Enzyme replacement therapy (ERT) with recombinant GAA is the only approved treatment for Pompe disease, but it requires frequent infusions, and efficacy is limited by suboptimal skeletal muscle distribution. In a mouse model of Pompe disease, chronic oral administration of MZ-101 alone reduced glycogen buildup in skeletal muscle with comparable efficacy to ERT. In addition, treatment with MZ-101 in combination with ERT had an additive effect and could normalize muscle glycogen concentrations. Biochemical, metabolomic, and transcriptomic analyses of muscle tissue demonstrated that lowering of glycogen concentrations with MZ-101, alone or in combination with ERT, corrected the cellular pathology in this mouse model. These data suggest that substrate reduction therapy with GYS1 inhibition may be a promising therapeutic approach for Pompe disease and other glycogen storage diseases.
- Published
- 2024
- Full Text
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13. Utilizing multimodal mass spectrometry imaging for profiling immune cell composition and N-glycosylation across colorectal carcinoma disease progression.
- Author
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Young LEA, Nietert PJ, Stubler R, Kittrell CG, Grimsley G, Lewin DN, Mehta AS, Hajar C, Wang K, O'Quinn EC, Angel PM, Wallace K, and Drake RR
- Abstract
Colorectal cancer (CRC) stands as a leading cause of death worldwide, often arising from specific genetic mutations, progressing from pre-cancerous adenomas to adenocarcinomas. Early detection through regular screening can result in a 90% 5-year survival rate for patients. However, unfortunately, only a fraction of CRC cases are identified at pre-invasive stages, allowing progression to occur silently over 10-15 years. The intricate interplay between the immune system and tumor cells within the tumor microenvironment plays a pivotal role in the progression of CRC. Immune cell clusters can either inhibit or facilitate tumor initiation, growth, and metastasis. To gain a better understanding of this relationship, we conducted N-glycomic profiling using matrix-assisted laser desorption-ionization mass spectrometry imaging (MALDI-MSI). We detected nearly 100 N-glycan species across all samples, revealing a shift in N-glycome profiles from normal to cancerous tissues, marked by a decrease in high mannose N-glycans. Further analysis of precancerous to invasive carcinomas showed an increase in pauci-mannose biantennary, and tetraantennary N-glycans with disease progression. Moreover, a distinct stratification in the N-glycome profile was observed between non-mucinous and mucinous CRC tissues, driven by pauci-mannose, high mannose, and bisecting N-glycans. Notably, we identified immune clusters of CD20
+ B cells and CD3/CD44+ T cells distinctive and predictive with signature profiles of bisecting and branched N-glycans. These spatial N-glycan profiles offer potential biomarkers and therapeutic targets throughout the progression of CRC., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Young, Nietert, Stubler, Kittrell, Grimsley, Lewin, Mehta, Hajar, Wang, O’Quinn, Angel, Wallace and Drake.)- Published
- 2024
- Full Text
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14. The glycosylation landscape of prostate cancer tissues and biofluids.
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Hartig J, Young LEA, Grimsley G, Mehta AS, Ippolito JE, Leach RJ, Angel PM, and Drake RR
- Subjects
- Glycosylation, Humans, Male, Glycomics methods, Glycoproteins metabolism, Biomarkers, Tumor metabolism, Body Fluids metabolism, Body Fluids chemistry, Protein Processing, Post-Translational, Animals, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods, Prostatic Neoplasms metabolism, Prostatic Neoplasms pathology, Polysaccharides metabolism
- Abstract
An overview of the role of glycosylation in prostate cancer (PCa) development and progression is presented, focusing on recent advancements in defining the N-glycome through glycomic profiling and glycoproteomic methodologies. Glycosylation is a common post-translational modification typified by oligosaccharides attached N-linked to asparagine or O-linked to serine or threonine on carrier proteins. These attached sugars have crucial roles in protein folding and cellular recognition processes, such that altered glycosylation is a hallmark of cancer pathogenesis and progression. In the past decade, advancements in N-glycan profiling workflows using Matrix Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI-MSI) technology have been applied to define the spatial distribution of glycans in PCa tissues. Multiple studies applying N-glycan MALDI-MSI to pathology-defined PCa tissues have identified significant alterations in N-glycan profiles associated with PCa progression. N-glycan compositions progressively increase in number, and structural complexity due to increased fucosylation and sialylation. Additionally, significant progress has been made in defining the glycan and glycopeptide compositions of prostatic-derived glycoproteins like prostate-specific antigen in tissues and biofluids. The glycosyltransferases involved in these changes are potential drug targets for PCa, and new approaches in this area are summarized. These advancements will be discussed in the context of the further development of clinical diagnostics and therapeutics targeting glycans and glycoproteins associated with PCa progression. Integration of large scale spatial glycomic data for PCa with other spatial-omic methodologies is now feasible at the tissue and single-cell levels., (Copyright © 2024. Published by Elsevier Inc.)
- Published
- 2024
- Full Text
- View/download PDF
15. Inhibition of mitochondrial fission activates glycogen synthesis to support cell survival in colon cancer.
- Author
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Hasani S, Young LEA, Van Nort W, Banerjee M, Rivas DR, Kim J, Xiong X, Sun RC, Gentry MS, Sesaki H, and Gao T
- Subjects
- Humans, Cell Survival, Mitochondrial Dynamics, Cell Transformation, Neoplastic, Glycogen metabolism, Dynamins metabolism, Glycogenolysis, Colonic Neoplasms genetics
- Abstract
Metabolic reprogramming has been recognized as one of the major mechanisms that fuel tumor initiation and progression. Our previous studies demonstrate that activation of Drp1 promotes fatty acid oxidation and downstream Wnt signaling. Here we investigate the role of Drp1 in regulating glycogen metabolism in colon cancer. Knockdown of Drp1 decreases mitochondrial respiration without increasing glycolysis. Analysis of cellular metabolites reveals that the levels of glucose-6-phosphate, a precursor for glycogenesis, are significantly elevated whereas pyruvate and other TCA cycle metabolites remain unchanged in Drp1 knockdown cells. Additionally, silencing Drp1 activates AMPK to stimulate the expression glycogen synthase 1 (GYS1) mRNA and promote glycogen storage. Using 3D organoids from Apc
f/f /Villin-CreERT2 models, we show that glycogen levels are elevated in tumor organoids upon genetic deletion of Drp1. Similarly, increased GYS1 expression and glycogen accumulation are detected in xenograft tumors derived from Drp1 knockdown colon cancer cells. Functionally, increased glycogen storage provides survival advantage to Drp1 knockdown cells. Co-targeting glycogen phosphorylase-mediated glycogenolysis sensitizes Drp1 knockdown cells to chemotherapy drug treatment. Taken together, our results suggest that Drp1-loss activates glucose uptake and glycogenesis as compensative metabolic pathways to promote cell survival. Combined inhibition of glycogen metabolism may enhance the efficacy of chemotherapeutic agents for colon cancer treatment., (© 2023. The Author(s).)- Published
- 2023
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16. Gys1 Antisense Therapy Prevents Disease-Driving Aggregates and Epileptiform Discharges in a Lafora Disease Mouse Model.
- Author
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Donohue KJ, Fitzsimmons B, Bruntz RC, Markussen KH, Young LEA, Clarke HA, Coburn PT, Griffith LE, Sanders W, Klier J, Burke SN, Maurer AP, Minassian BA, Sun RC, Kordasiewisz HB, and Gentry MS
- Subjects
- Humans, Mice, Animals, Glycogen Synthase genetics, Disease Models, Animal, Mutation, Oligonucleotides, Antisense therapeutic use, Glycogen metabolism, Ubiquitin-Protein Ligases genetics, Lafora Disease genetics, Lafora Disease metabolism
- Abstract
Patients with Lafora disease have a mutation in EPM2A or EPM2B, resulting in dysregulation of glycogen metabolism throughout the body and aberrant glycogen molecules that aggregate into Lafora bodies. Lafora bodies are particularly damaging in the brain, where the aggregation drives seizures with increasing severity and frequency, coupled with neurodegeneration. Previous work employed mouse genetic models to reduce glycogen synthesis by approximately 50%, and this strategy significantly reduced Lafora body formation and disease phenotypes. Therefore, an antisense oligonucleotide (ASO) was developed to reduce glycogen synthesis in the brain by targeting glycogen synthase 1 (Gys1). To test the distribution and efficacy of this drug, the Gys1-ASO was administered to Epm2b-/- mice via intracerebroventricular administration at 4, 7, and 10 months. The mice were then sacrificed at 13 months and their brains analyzed for Gys1 expression, glycogen aggregation, and neuronal excitability. The mice treated with Gys1-ASO exhibited decreased Gys1 protein levels, decreased glycogen aggregation, and reduced epileptiform discharges compared to untreated Epm2b-/- mice. This work provides proof of concept that a Gys1-ASO halts disease progression of EPM2B mutations of Lafora disease., (© 2023. The Author(s).)
- Published
- 2023
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17. RIT1 regulation of CNS lipids RIT1 deficiency Alters cerebral lipid metabolism and reduces white matter tract oligodendrocytes and conduction velocities.
- Author
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Wu L, Wang F, Moncman CL, Pandey M, Clarke HA, Frazier HN, Young LEA, Gentry MS, Cai W, Thibault O, Sun RC, and Andres DA
- Abstract
Oligodendrocytes (OLs) generate lipid-rich myelin membranes that wrap axons to enable efficient transmission of electrical impulses. Using a RIT1 knockout mouse model and in situ high-resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) coupled with MS-based lipidomic analysis to determine the contribution of RIT1 to lipid homeostasis. Here, we report that RIT1 loss is associated with altered lipid levels in the central nervous system (CNS), including myelin-associated lipids within the corpus callosum (CC). Perturbed lipid metabolism was correlated with reduced numbers of OLs, but increased numbers of GFAP
+ glia, in the CC, but not in grey matter. This was accompanied by reduced myelin protein expression and axonal conduction deficits. Behavioral analyses revealed significant changes in voluntary locomotor activity and anxiety-like behavior in RIT1KO mice. Together, these data reveal an unexpected role for RIT1 in the regulation of cerebral lipid metabolism, which coincide with altered white matter tract oligodendrocyte levels, reduced axonal conduction velocity, and behavioral abnormalities in the CNS., Competing Interests: Ramon C. Sun has received research support and has received a consultancy fee from Maze Therapeutics. Matthew S. Gentry has received research support and research compounds from Maze Therapeutics, Valerion Therapeutics, and Ionis Pharmaceuticals. Matthew S. Gentry also received a consultancy fee from Maze Therapeutics, PTC Therapeutics, and the Glut1-Deficiency Syndrome Foundation. Fang Wang, Lei Wu, Mritunjay Pandey, Harrison A. Clarke, Hilaree N. Frazier, Carole L. Moncman, Weikang Cai, Lyndsay E.A. Young, Olivier Thibault, and Douglas A. Andres report no disclosures. The content is the responsibility of the authors and does not necessarily represent the official views of the NIH. The paper is subject to the NIH Public Access Policy. This study was carried out in accordance with the Uniform Requirements for Manuscripts Submitted to Biomedical Journals., (© 2023 The Authors. Published by Elsevier Ltd.)- Published
- 2023
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18. Spatial metabolomics reveals glycogen as an actionable target for pulmonary fibrosis.
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Conroy LR, Clarke HA, Allison DB, Valenca SS, Sun Q, Hawkinson TR, Young LEA, Ferreira JE, Hammonds AV, Dunne JB, McDonald RJ, Absher KJ, Dong BE, Bruntz RC, Markussen KH, Juras JA, Alilain WJ, Liu J, Gentry MS, Angel PM, Waters CM, and Sun RC
- Subjects
- Mice, Animals, Humans, Glycogen, Metabolomics methods, Polysaccharides, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods, Pulmonary Fibrosis
- Abstract
Matrix assisted laser desorption/ionization imaging has greatly improved our understanding of spatial biology, however a robust bioinformatic pipeline for data analysis is lacking. Here, we demonstrate the application of high-dimensionality reduction/spatial clustering and histopathological annotation of matrix assisted laser desorption/ionization imaging datasets to assess tissue metabolic heterogeneity in human lung diseases. Using metabolic features identified from this pipeline, we hypothesize that metabolic channeling between glycogen and N-linked glycans is a critical metabolic process favoring pulmonary fibrosis progression. To test our hypothesis, we induced pulmonary fibrosis in two different mouse models with lysosomal glycogen utilization deficiency. Both mouse models displayed blunted N-linked glycan levels and nearly 90% reduction in endpoint fibrosis when compared to WT animals. Collectively, we provide conclusive evidence that lysosomal utilization of glycogen is required for pulmonary fibrosis progression. In summary, our study provides a roadmap to leverage spatial metabolomics to understand foundational biology in pulmonary diseases., (© 2023. The Author(s).)
- Published
- 2023
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19. In situ microwave fixation provides an instantaneous snapshot of the brain metabolome.
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Juras JA, Webb MB, Young LEA, Markussen KH, Hawkinson TR, Buoncristiani MD, Bolton KE, Coburn PT, Williams MI, Sun LPY, Sanders WC, Bruntz RC, Conroy LR, Wang C, Gentry MS, Smith BN, and Sun RC
- Subjects
- Animals, Mice, Metabolome, Glucose, Glycogen, Microwaves, Brain diagnostic imaging
- Abstract
Brain glucose metabolism is highly heterogeneous among brain regions and continues postmortem. In particular, we demonstrate exhaustion of glycogen and glucose and an increase in lactate production during conventional rapid brain resection and preservation by liquid nitrogen. In contrast, we show that these postmortem changes are not observed with simultaneous animal sacrifice and in situ fixation with focused, high-power microwave. We further employ microwave fixation to define brain glucose metabolism in the mouse model of streptozotocin-induced type 1 diabetes. Using both total pool and isotope tracing analyses, we identified global glucose hypometabolism in multiple brain regions, evidenced by reduced
13 C enrichment into glycogen, glycolysis, and the tricarboxylic acid (TCA) cycle. Reduced glucose metabolism correlated with a marked decrease in GLUT2 expression and several metabolic enzymes in unique brain regions. In conclusion, our study supports the incorporation of microwave fixation for more accurate studies of brain metabolism in rodent models., Competing Interests: R.C.S. has research support and received consultancy fees from Maze Therapeutics. R.C.S. is a cofounder of Attrogen, LLC. R.C.S. is a member of the Medical Advisory Board for Little Warrior Foundation. M.S.G. has research support and research compounds from Maze Therapeutics, Valerion Therapeutics, and Ionis Pharmaceuticals. M.S.G. also received consultancy fees from Maze Therapeutics, PTC Therapeutics, Aro Biotherapeutics, and the Glut1-Deficiency Syndrome Foundation. M.S.G. and R.C.B. are cofounders of Attrogen, LLC., (© 2023 The Author(s).)- Published
- 2023
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20. PASK links cellular energy metabolism with a mitotic self-renewal network to establish differentiation competence.
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Xiao M, Wu CH, Meek G, Kelly B, Castillo DB, Young LEA, Martire S, Dhungel S, McCauley E, Saha P, Dube AL, Gentry MS, Banaszynski LA, Sun RC, and Kikani CK
- Subjects
- Animals, Mice, Cell Differentiation physiology, Cells, Cultured, Energy Metabolism, Glutamine, Stem Cells physiology
- Abstract
Quiescent stem cells are activated in response to a mechanical or chemical injury to their tissue niche. Activated cells rapidly generate a heterogeneous progenitor population that regenerates the damaged tissues. While the transcriptional cadence that generates heterogeneity is known, the metabolic pathways influencing the transcriptional machinery to establish a heterogeneous progenitor population remains unclear. Here, we describe a novel pathway downstream of mitochondrial glutamine metabolism that confers stem cell heterogeneity and establishes differentiation competence by countering post-mitotic self-renewal machinery. We discovered that mitochondrial glutamine metabolism induces CBP/EP300-dependent acetylation of stem cell-specific kinase, PAS domain-containing kinase (PASK), resulting in its release from cytoplasmic granules and subsequent nuclear migration. In the nucleus, PASK catalytically outcompetes mitotic WDR5-anaphase-promoting complex/cyclosome (APC/C) interaction resulting in the loss of post-mitotic Pax7 expression and exit from self-renewal. In concordance with these findings, genetic or pharmacological inhibition of PASK or glutamine metabolism upregulated Pax7 expression, reduced stem cell heterogeneity , and blocked myogenesis in vitro and muscle regeneration in mice. These results explain a mechanism whereby stem cells co-opt the proliferative functions of glutamine metabolism to generate transcriptional heterogeneity and establish differentiation competence by countering the mitotic self-renewal network via nuclear PASK., Competing Interests: MX, CW, GM, BK, DC, LY, SM, SD, EM, PS, AD, MG, LB, RS, CK No competing interests declared, (© 2023, Xiao, Wu, Meek et al.)
- Published
- 2023
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21. Cervical spinal cord injury leads to injury and altered metabolism in the lungs.
- Author
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Huffman EE, Dong BE, Clarke HA, Young LEA, Gentry MS, Allison DB, Sun RC, Waters CM, and Alilain WJ
- Abstract
High-cervical spinal cord injury often disrupts respiratory motor pathways and disables breathing in the affected population. Moreover, cervically injured individuals are at risk for developing acute lung injury, which predicts substantial mortality rates. While the correlation between acute lung injury and spinal cord injury has been found in the clinical setting, the field lacks an animal model to interrogate the fundamental biology of this relationship. To begin to address this gap in knowledge, we performed an experimental cervical spinal cord injury (N = 18 ) alongside sham injury ( N = 3) and naïve animals ( N = 15) to assess lung injury in adult rats. We demonstrate that animals display some early signs of lung injury two weeks post-spinal cord injury. While no obvious histological signs of injury were observed, the spinal cord injured cohort displayed significant signs of metabolic dysregulation in multiple pathways that include amino acid metabolism, lipid metabolism, and N-linked glycosylation. Collectively, we establish for the first time a model of lung injury after spinal cord injury at an acute time point that can be used to monitor the progression of lung damage, as well as identify potential targets to ameliorate acute lung injury., Competing Interests: The authors report no competing interests., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain.)
- Published
- 2023
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22. In situ mass spectrometry imaging reveals heterogeneous glycogen stores in human normal and cancerous tissues.
- Author
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Young LEA, Conroy LR, Clarke HA, Hawkinson TR, Bolton KE, Sanders WC, Chang JE, Webb MB, Alilain WJ, Vander Kooi CW, Drake RR, Andres DA, Badgett TC, Wagner LM, Allison DB, Sun RC, and Gentry MS
- Subjects
- Male, Humans, Animals, Mice, Child, Glycogen, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods, Sarcoma, Ewing pathology, Osteosarcoma, Bone Neoplasms
- Abstract
Glycogen dysregulation is a hallmark of aging, and aberrant glycogen drives metabolic reprogramming and pathogenesis in multiple diseases. However, glycogen heterogeneity in healthy and diseased tissues remains largely unknown. Herein, we describe a method to define spatial glycogen architecture in mouse and human tissues using matrix-assisted laser desorption/ionization mass spectrometry imaging. This assay provides robust and sensitive spatial glycogen quantification and architecture characterization in the brain, liver, kidney, testis, lung, bladder, and even the bone. Armed with this tool, we interrogated glycogen spatial distribution and architecture in different types of human cancers. We demonstrate that glycogen stores and architecture are heterogeneous among diseases. Additionally, we observe unique hyperphosphorylated glycogen accumulation in Ewing sarcoma, a pediatric bone cancer. Using preclinical models, we correct glycogen hyperphosphorylation in Ewing sarcoma through genetic and pharmacological interventions that ablate in vivo tumor growth, demonstrating the clinical therapeutic potential of targeting glycogen in Ewing sarcoma., (© 2022 The Authors. Published under the terms of the CC BY 4.0 license.)
- Published
- 2022
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23. In situ spatial glycomic imaging of mouse and human Alzheimer's disease brains.
- Author
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Hawkinson TR, Clarke HA, Young LEA, Conroy LR, Markussen KH, Kerch KM, Johnson LA, Nelson PT, Wang C, Allison DB, Gentry MS, and Sun RC
- Subjects
- Humans, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods, Brain metabolism, Polysaccharides analysis, Polysaccharides chemistry, Polysaccharides metabolism, Glucose metabolism, Glycomics methods, Alzheimer Disease diagnostic imaging, Alzheimer Disease metabolism
- Abstract
N-linked protein glycosylation in the brain is an understudied facet of glucose utilization that impacts a myriad of cellular processes including resting membrane potential, axon firing, and synaptic vesicle trafficking. Currently, a spatial map of N-linked glycans within the normal and Alzheimer's disease (AD) human brain does not exist. A comprehensive analysis of the spatial N-linked glycome would improve our understanding of brain energy metabolism, linking metabolism to signaling events perturbed during AD progression, and could illuminate new therapeutic strategies. Herein we report an optimized in situ workflow for enzyme-assisted, matrix-assisted laser desorption and ionization (MALDI) mass spectrometry imaging (MSI) of brain N-linked glycans. Using this workflow, we spatially interrogated N-linked glycan heterogeneity in both mouse and human AD brains and their respective age-matched controls. We identified robust regional-specific N-linked glycan changes associated with AD in mice and humans. These data suggest that N-linked glycan dysregulation could be an underpinning of AD pathologies., (© 2021 the Alzheimer's Association.)
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- 2022
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24. Activation of Drp1 promotes fatty acids-induced metabolic reprograming to potentiate Wnt signaling in colon cancer.
- Author
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Xiong X, Hasani S, Young LEA, Rivas DR, Skaggs AT, Martinez R, Wang C, Weiss HL, Gentry MS, Sun RC, and Gao T
- Subjects
- Fatty Acids, Humans, Mitochondrial Dynamics physiology, Mitochondrial Proteins genetics, Mitochondrial Proteins metabolism, Phosphorylation, Wnt Signaling Pathway, beta Catenin metabolism, Colonic Neoplasms genetics, Dynamins genetics, Dynamins metabolism
- Abstract
Cancer cells are known for their ability to adapt variable metabolic programs depending on the availability of specific nutrients. Our previous studies have shown that uptake of fatty acids alters cellular metabolic pathways in colon cancer cells to favor fatty acid oxidation. Here, we show that fatty acids activate Drp1 to promote metabolic plasticity in cancer cells. Uptake of fatty acids (FAs) induces mitochondrial fragmentation by promoting ERK-dependent phosphorylation of Drp1 at the S616 site. This increased phosphorylation of Drp1 enhances its dimerization and interaction with Mitochondrial Fission Factor (MFF) at the mitochondria. Consequently, knockdown of Drp1 or MFF attenuates fatty acid-induced mitochondrial fission. In addition, uptake of fatty acids triggers mitophagy via a Drp1- and p62-dependent mechanism to protect mitochondrial integrity. Moreover, results from metabolic profiling analysis reveal that silencing Drp1 disrupts cellular metabolism and blocks fatty acid-induced metabolic reprograming by inhibiting fatty acid utilization. Functionally, knockdown of Drp1 decreases Wnt/β-catenin signaling by preventing fatty acid oxidation-dependent acetylation of β-catenin. As a result, Drp1 depletion inhibits the formation of tumor organoids in vitro and xenograft tumor growth in vivo. Taken together, our study identifies Drp1 as a key mediator that connects mitochondrial dynamics with fatty acid metabolism and cancer cell signaling., (© 2022. The Author(s), under exclusive licence to ADMC Associazione Differenziamento e Morte Cellulare.)
- Published
- 2022
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25. Tissue-Specific Downregulation of Fatty Acid Synthase Suppresses Intestinal Adenoma Formation via Coordinated Reprograming of Transcriptome and Metabolism in the Mouse Model of Apc-Driven Colorectal Cancer.
- Author
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Drury J, Young LEA, Scott TL, Kelson CO, He D, Liu J, Wu Y, Wang C, Weiss HL, Fan T, Gentry MS, Sun R, and Zaytseva YY
- Subjects
- Animals, Cell Line, Tumor, Disease Models, Animal, Down-Regulation genetics, Fatty Acid Synthase, Type I genetics, Fatty Acid Synthase, Type I metabolism, Fatty Acid Synthases genetics, Fatty Acid Synthases metabolism, Mice, Mice, Inbred C57BL, Transcriptome, Adenoma genetics, Colorectal Neoplasms genetics, Colorectal Neoplasms metabolism
- Abstract
Altered lipid metabolism is a potential target for therapeutic intervention in cancer. Overexpression of Fatty Acid Synthase (FASN) correlates with poor prognosis in colorectal cancer (CRC). While multiple studies show that upregulation of lipogenesis is critically important for CRC progression, the contribution of FASN to CRC initiation is poorly understood. We utilize a C57BL/6-Apc/Villin-Cre mouse model with knockout of FASN in intestinal epithelial cells to show that the heterozygous deletion of FASN increases mouse survival and decreases the number of intestinal adenomas. Using RNA-Seq and gene set enrichment analysis, we demonstrate that a decrease in FASN expression is associated with inhibition of pathways involved in cellular proliferation, energy production, and CRC progression. Metabolic and reverse phase protein array analyses demonstrate consistent changes in alteration of metabolic pathways involved in both anabolism and energy production. Downregulation of FASN expression reduces the levels of metabolites within glycolysis and tricarboxylic acid cycle with the most significant reduction in the level of citrate, a master metabolite, which enhances ATP production and fuels anabolic pathways. In summary, we demonstrate the critical importance of FASN during CRC initiation. These findings suggest that targeting FASN is a potential therapeutic approach for early stages of CRC or as a preventive strategy for this disease.
- Published
- 2022
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26. High-dimensionality reduction clustering of complex carbohydrates to study lung cancer metabolic heterogeneity.
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Conroy LR, Chang JE, Sun Q, Clarke HA, Buoncristiani MD, Young LEA, McDonald RJ, Liu J, Gentry MS, Allison DB, and Sun RC
- Subjects
- Cluster Analysis, Humans, Polysaccharides, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods, Tumor Microenvironment, Lung Neoplasms
- Abstract
The tumor microenvironment contains a heterogeneous population of stromal and cancer cells that engage in metabolic crosstalk to ultimately promote tumor growth and contribute to progression. Due to heterogeneity within solid tumors, pooled mass spectrometry workflows are less sensitive at delineating unique metabolic perturbations between stromal and immune cell populations. Two critical, but understudied, facets of glucose metabolism are anabolic pathways for glycogen and N-linked glycan biosynthesis. Together, these complex carbohydrates modulate bioenergetics and protein-structure function, and create functional microanatomy in distinct cell populations within the tumor heterogeneity. Herein, we combine high-dimensionality reduction and clustering (HDRC) analysis with matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) and demonstrate its ability for the comprehensive assessment of tissue histopathology and metabolic heterogeneity in human FFPE sections. In human lung adenocarcinoma (LUAD) tumor tissues, HDRC accurately clusters distinct regions and cell populations within the tumor microenvironment, including tumor cells, tumor-infiltrating lymphocytes, cancer-associated fibroblasts, and necrotic regions. In-depth pathway enrichment analyses revealed unique metabolic pathways are associated with each distinct pathological region. Further, we highlight the potential of HDRC analysis to study complex carbohydrate metabolism in a case study of lung cancer disparity. Collectively, our results demonstrate the promising potentials of HDRC of pixel-based carbohydrate analysis to study cell-type and regional-specific stromal signaling within the tumor microenvironment., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
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27. Emerging roles of N-linked glycosylation in brain physiology and disorders.
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Conroy LR, Hawkinson TR, Young LEA, Gentry MS, and Sun RC
- Subjects
- Brain metabolism, Glycosylation, Humans, Signal Transduction, Polysaccharides metabolism, Protein Processing, Post-Translational
- Abstract
N-linked glycosylation is a complex, co- and post-translational series of events that connects metabolism to signaling in almost all cells. Metabolic assembly of N-linked glycans spans multiple cellular compartments, and early N-linked glycan biosynthesis is a central mediator of protein folding and the unfolded protein response (UPR). In the brain, N-linked glycosylated proteins participate in a myriad of processes, from electrical gradients to neurotransmission. However, it is less clear how perturbations in N-linked glycosylation impact and even potentially drive aspects of neurological disorders. In this review, we discuss our current understanding of the metabolic origins of N-linked glycans in the brain, their role in modulating neuronal function, and how aberrant N-linked glycosylation can drive neurological disorders., Competing Interests: Declaration of interests R.C.S. and M.S.G. are consultants for Maze Therapeutics, M.S.G. is a consultant for Enable Therapeutics, Glut1-Deficiency Syndrome Foundation, and Chelsea's Hope. M.S.G. and R.C.S. are founders of Atterogen, LLC., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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28. Lactate supports a metabolic-epigenetic link in macrophage polarization.
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Noe JT, Rendon BE, Geller AE, Conroy LR, Morrissey SM, Young LEA, Bruntz RC, Kim EJ, Wise-Mitchell A, Barbosa de Souza Rizzo M, Relich ER, Baby BV, Johnson LA, Affronti HC, McMasters KM, Clem BF, Gentry MS, Yan J, Wellen KE, Sun RC, and Mitchell RA
- Abstract
Lactate accumulation is a hallmark of solid cancers and is linked to the immune suppressive phenotypes of tumor-infiltrating immune cells. We report herein that interleukin-4 (IL-4)–induced M0 → M2 macrophage polarization is accompanied by interchangeable glucose- or lactate-dependent tricarboxylic acid (TCA) cycle metabolism that directly drives histone acetylation, M2 gene transcription, and functional immune suppression. Lactate-dependent M0 → M2 polarization requires both mitochondrial pyruvate uptake and adenosine triphosphate–citrate lyase (ACLY) enzymatic activity. Notably, exogenous acetate rescues defective M2 polarization and histone acetylation following mitochondrial pyruvate carrier 1 (MPC1) inhibition or ACLY deficiency. Lastly, M2 macrophage–dependent tumor progression is impaired by conditional macrophage ACLY deficiency, further supporting a dominant role for glucose/lactate mitochondrial metabolism and histone acetylation in driving immune evasion. This work adds to our understanding of how mitochondrial metabolism affects macrophage functional phenotypes and identifies a unique tumor microenvironment (TME)–driven metabolic-epigenetic link in M2 macrophages.
- Published
- 2021
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29. In Situ Analysis of N-Linked Glycans as Potential Biomarkers of Clinical Course in Human Prostate Cancer.
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Conroy LR, Stanback AE, Young LEA, Clarke HA, Austin GL, Liu J, Allison DB, and Sun RC
- Subjects
- Glycosylation, Humans, Male, Neoplasm Recurrence, Local metabolism, Neoplasm Recurrence, Local pathology, Prostate pathology, Prostatic Neoplasms pathology, Tissue Fixation methods, Biomarkers, Tumor metabolism, Polysaccharides metabolism, Prostatic Neoplasms metabolism
- Abstract
Prostate cancer is the most common cancer in men worldwide. Despite its prevalence, there is a critical knowledge gap in understanding factors driving disparities in survival among different cohorts of patients with prostate cancer. Identifying molecular features separating disparate populations is an important first step in prostate cancer research that could lead to fundamental hypotheses in prostate biology, predictive biomarker discovery, and personalized therapy. N-linked glycosylation is a cotranslational event during protein folding that modulates a myriad of cellular processes. Recently, aberrant N-linked glycosylation has been reported in prostate cancers. However, the full clinical implications of dysregulated glycosylation in prostate cancer has yet to be explored. Herein, we performed direct on-tissue analysis of N-linked glycans using matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) from tissue microarrays of over 100 patient tumors with over 10 years of follow-up metadata. We successfully identified a panel of N-glycans that are unique between benign and prostate tumor tissue. Specifically, high-mannose as well as tri-and tetra-antennary N-glycans were more abundant in tumor tissue and increase proportionally with tumor grade. Further, we expanded our analyses to examine the N-glycan profiles of Black and Appalachian patients and have identified unique glycan signatures that correlate with recurrence in each population. Our study highlights the potential applications of MALDI-MSI for digital pathology and biomarker discovery for prostate cancer. IMPLICATIONS: MALDI-MSI identifies N-glycan perturbations in prostate tumors compared with benign tissue. This method can be utilized to predict prostate cancer recurrence and study prostate cancer disparities., (©2021 American Association for Cancer Research.)
- Published
- 2021
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30. APOΕ4 lowers energy expenditure in females and impairs glucose oxidation by increasing flux through aerobic glycolysis.
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Farmer BC, Williams HC, Devanney NA, Piron MA, Nation GK, Carter DJ, Walsh AE, Khanal R, Young LEA, Kluemper JC, Hernandez G, Allenger EJ, Mooney R, Golden LR, Smith CT, Brandon JA, Gupta VA, Kern PA, Gentry MS, Morganti JM, Sun RC, and Johnson LA
- Subjects
- Adolescent, Adult, Aged, Alzheimer Disease diagnosis, Alzheimer Disease genetics, Alzheimer Disease metabolism, Animals, Apolipoprotein E4 genetics, Astrocytes metabolism, Base Sequence, Brain Chemistry, Cells, Cultured, Early Diagnosis, Energy Metabolism, Female, Gas Chromatography-Mass Spectrometry, Gene Knock-In Techniques, Humans, Metabolomics, Mice, Mice, Transgenic, Middle Aged, Nerve Tissue Proteins genetics, Nerve Tissue Proteins metabolism, Oxidation-Reduction, Oxidative Phosphorylation, Oxygen Consumption genetics, Sex Characteristics, Single-Cell Analysis, Young Adult, Aerobiosis, Apolipoprotein E4 physiology, Glucose metabolism, Glycolysis, Prodromal Symptoms
- Abstract
Background: Cerebral glucose hypometabolism is consistently observed in individuals with Alzheimer's disease (AD), as well as in young cognitively normal carriers of the Ε4 allele of Apolipoprotein E (APOE), the strongest genetic predictor of late-onset AD. While this clinical feature has been described for over two decades, the mechanism underlying these changes in cerebral glucose metabolism remains a critical knowledge gap in the field., Methods: Here, we undertook a multi-omic approach by combining single-cell RNA sequencing (scRNAseq) and stable isotope resolved metabolomics (SIRM) to define a metabolic rewiring across astrocytes, brain tissue, mice, and human subjects expressing APOE4., Results: Single-cell analysis of brain tissue from mice expressing human APOE revealed E4-associated decreases in genes related to oxidative phosphorylation, particularly in astrocytes. This shift was confirmed on a metabolic level with isotopic tracing of
13 C-glucose in E4 mice and astrocytes, which showed decreased pyruvate entry into the TCA cycle and increased lactate synthesis. Metabolic phenotyping of E4 astrocytes showed elevated glycolytic activity, decreased oxygen consumption, blunted oxidative flexibility, and a lower rate of glucose oxidation in the presence of lactate. Together, these cellular findings suggest an E4-associated increase in aerobic glycolysis (i.e. the Warburg effect). To test whether this phenomenon translated to APOE4 humans, we analyzed the plasma metabolome of young and middle-aged human participants with and without the Ε4 allele, and used indirect calorimetry to measure whole body oxygen consumption and energy expenditure. In line with data from E4-expressing female mice, a subgroup analysis revealed that young female E4 carriers showed a striking decrease in energy expenditure compared to non-carriers. This decrease in energy expenditure was primarily driven by a lower rate of oxygen consumption, and was exaggerated following a dietary glucose challenge. Further, the stunted oxygen consumption was accompanied by markedly increased lactate in the plasma of E4 carriers, and a pathway analysis of the plasma metabolome suggested an increase in aerobic glycolysis., Conclusions: Together, these results suggest astrocyte, brain and system-level metabolic reprogramming in the presence of APOE4, a 'Warburg like' endophenotype that is observable in young females decades prior to clinically manifest AD., (© 2021. The Author(s).)- Published
- 2021
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31. Brain glycogen serves as a critical glucosamine cache required for protein glycosylation.
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Sun RC, Young LEA, Bruntz RC, Markussen KH, Zhou Z, Conroy LR, Hawkinson TR, Clarke HA, Stanback AE, Macedo JKA, Emanuelle S, Brewer MK, Rondon AL, Mestas A, Sanders WC, Mahalingan KK, Tang B, Chikwana VM, Segvich DM, Contreras CJ, Allenger EJ, Brainson CF, Johnson LA, Taylor RE, Armstrong DD, Shaffer R, Waechter CJ, Vander Kooi CW, DePaoli-Roach AA, Roach PJ, Hurley TD, Drake RR, and Gentry MS
- Subjects
- Animals, Cells, Cultured, Disease Models, Animal, Female, Glycogen metabolism, Glycogen Synthase genetics, Glycogen Synthase metabolism, Glycogenolysis genetics, Glycosylation, Lafora Disease genetics, Lafora Disease metabolism, Lafora Disease pathology, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Brain metabolism, Glucosamine metabolism, Glycogen physiology, Protein Processing, Post-Translational genetics
- Abstract
Glycosylation defects are a hallmark of many nervous system diseases. However, the molecular and metabolic basis for this pathology is not fully understood. In this study, we found that N-linked protein glycosylation in the brain is metabolically channeled to glucosamine metabolism through glycogenolysis. We discovered that glucosamine is an abundant constituent of brain glycogen, which functions as a glucosamine reservoir for multiple glycoconjugates. We demonstrated the enzymatic incorporation of glucosamine into glycogen by glycogen synthase, and the release by glycogen phosphorylase by biochemical and structural methodologies, in primary astrocytes, and in vivo by isotopic tracing and mass spectrometry. Using two mouse models of glycogen storage diseases, we showed that disruption of brain glycogen metabolism causes global decreases in free pools of UDP-N-acetylglucosamine and N-linked protein glycosylation. These findings revealed fundamental biological roles of brain glycogen in protein glycosylation with direct relevance to multiple human diseases of the central nervous system., Competing Interests: Declaration of interests M.S.G. is a consultant for Maze Therapeutics, Enable Therapeutics, Glut1-Deficiency Syndrome Foundation, and Chelsea's Hope. M.S.G., R.C.S., C.W.V.K., and R.C.B. are founders of Atterogen, LLC., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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32. Enhancing lifespan of budding yeast by pharmacological lowering of amino acid pools.
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Hepowit NL, Macedo JKA, Young LEA, Liu K, Sun RC, MacGurn JA, and Dickson RC
- Subjects
- Dose-Response Relationship, Drug, Saccharomyces cerevisiae drug effects, Signal Transduction drug effects, Sphingosine analogs & derivatives, Sphingosine pharmacology, Amino Acids metabolism, Longevity drug effects, Proteins metabolism, Saccharomyces cerevisiae physiology
- Abstract
The increasing prevalence of age-related diseases and resulting healthcare insecurity and emotional burden require novel treatment approaches. Several promising strategies seek to limit nutrients and promote healthy aging. Unfortunately, the human desire to consume food means this strategy is not practical for most people but pharmacological approaches might be a viable alternative. We previously showed that myriocin, which impairs sphingolipid synthesis, increases lifespan in Saccharomyces cerevisiae by modulating signaling pathways including the target of rapamycin complex 1 (TORC1). Since TORC1 senses cellular amino acids, we analyzed amino acid pools and identified 17 that are lowered by myriocin treatment. Studying the methionine transporter, Mup1, we found that newly synthesized Mup1 traffics to the plasma membrane and is stable for several hours but is inactive in drug-treated cells. Activity can be restored by adding phytosphingosine to culture medium thereby bypassing drug inhibition, thus confirming a sphingolipid requirement for Mup1 activity. Importantly, genetic analysis of myriocin-induced longevity revealed a requirement for the Gtr1/2 (mammalian Rags) and Vps34-Pib2 amino acid sensing pathways upstream of TORC1, consistent with a mechanism of action involving decreased amino acid availability. These studies demonstrate the feasibility of pharmacologically inducing a state resembling amino acid restriction to promote healthy aging.
- Published
- 2021
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33. Regional N-glycan and lipid analysis from tissues using MALDI-mass spectrometry imaging.
- Author
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Stanback AE, Conroy LR, Young LEA, Hawkinson TR, Markussen KH, Clarke HA, Allison DB, and Sun RC
- Subjects
- Animals, Diagnostic Imaging methods, Humans, Lipids chemistry, Polysaccharides chemistry, Spatial Analysis, Specimen Handling methods, Lipids analysis, Polysaccharides analysis, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
- Abstract
N-glycans and lipids are structural metabolites that play important roles in cellular processes. Both show unique regional distribution in tissues; therefore, spatial analyses of these metabolites are crucial to our understanding of cellular physiology. Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) is an innovative technique that enables in situ detection of analytes with spatial distribution. This workflow details a MALDI-MSI protocol for the spatial profiling of N-glycans and lipids from tissues following application of enzyme and MALDI matrix. For complete details on the use and execution of this protocol, please refer to Drake et al. (2018) and Andres et al. (2020)., Competing Interests: The authors declare no competing interests., (© 2021 The Author(s).)
- Published
- 2021
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34. Oral Gavage Delivery of Stable Isotope Tracer for In Vivo Metabolomics.
- Author
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Williams HC, Piron MA, Nation GK, Walsh AE, Young LEA, Sun RC, and Johnson LA
- Abstract
Stable isotope-resolved metabolomics (SIRM) is a powerful tool for understanding disease. Advances in SIRM techniques have improved isotopic delivery and expanded the workflow from exclusively in vitro applications to in vivo methodologies to study systemic metabolism. Here, we report a simple, minimally-invasive and cost-effective method of tracer delivery to study SIRM in vivo in laboratory mice. Following a brief fasting period, we orally administered a solution of [U-
13 C] glucose through a blunt gavage needle without anesthesia, at a physiological dose commonly used for glucose tolerance tests (2 g/kg bodyweight). We defined isotopic enrichment in plasma and tissue at 15, 30, 120, and 240 min post-gavage.13 C-labeled glucose peaked in plasma around 15 min post-gavage, followed by period of metabolic decay and clearance until 4 h. We demonstrate robust enrichment of a variety of central carbon metabolites in the plasma, brain and liver of C57/BL6 mice, including amino acids, neurotransmitters, and glycolytic and tricarboxylic acid (TCA) cycle intermediates. We then applied this method to study in vivo metabolism in two distinct mouse models of diseases known to involve dysregulation of glucose metabolism: Alzheimer's disease and type II diabetes. By delivering [U-13 C] glucose via oral gavage to the 5XFAD Alzheimer's disease model and the Lepob/ob type II diabetes model, we were able to resolve significant differences in multiple central carbon pathways in both model systems, thus providing evidence of the utility of this method to study diseases with metabolic components. Together, these data clearly demonstrate the efficacy and efficiency of an oral gavage delivery method, and present a clear time course for13 C enrichment in plasma, liver and brain of mice following oral gavage of [U-13 C] glucose-data we hope will aid other researchers in their own13 C-glucose metabolomics study design.- Published
- 2020
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35. Spatial profiling of gangliosides in mouse brain by mass spectrometry imaging.
- Author
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Andres DA, Young LEA, Gentry MS, and Sun RC
- Subjects
- Animals, Mice, Mass Spectrometry methods, Gangliosides analysis, Gangliosides metabolism, Gangliosides chemistry, Brain metabolism, Brain diagnostic imaging
- Published
- 2020
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36. Improved workflow for mass spectrometry-based metabolomics analysis of the heart.
- Author
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Andres DA, Young LEA, Veeranki S, Hawkinson TR, Levitan BM, He D, Wang C, Satin J, and Sun RC
- Subjects
- Animals, Heart physiology, Mice, Myocardium metabolism, Reference Standards, Gas Chromatography-Mass Spectrometry methods, Metabolomics methods, Workflow
- Abstract
MS-based metabolomics methods are powerful techniques to map the complex and interconnected metabolic pathways of the heart; however, normalization of metabolite abundance to sample input in heart tissues remains a technical challenge. Herein, we describe an improved GC-MS-based metabolomics workflow that uses insoluble protein-derived glutamate for the normalization of metabolites within each sample and includes normalization to protein-derived amino acids to reduce biological variation and detect small metabolic changes. Moreover, glycogen is measured within the metabolomics workflow. We applied this workflow to study heart metabolism by first comparing two different methods of heart removal: the Langendorff heart method (reverse aortic perfusion) and in situ freezing of mouse heart with a modified tissue freeze-clamp approach. We then used the in situ freezing method to study the effects of acute β-adrenergic receptor stimulation (through isoproterenol (ISO) treatment) on heart metabolism. Using our workflow and within minutes, ISO reduced the levels of metabolites involved in glycogen metabolism, glycolysis, and the Krebs cycle, but the levels of pentose phosphate pathway metabolites and of many free amino acids remained unchanged. This observation was coupled to a 6-fold increase in phosphorylated adenosine nucleotide abundance. These results support the notion that ISO acutely accelerates oxidative metabolism of glucose to meet the ATP demand required to support increased heart rate and cardiac output. In summary, our MS-based metabolomics workflow enables improved quantification of cardiac metabolites and may also be compatible with other methods such as LC or capillary electrophoresis., (© 2020 Andres et al.)
- Published
- 2020
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37. Accurate and sensitive quantitation of glucose and glucose phosphates derived from storage carbohydrates by mass spectrometry.
- Author
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Young LEA, Brizzee CO, Macedo JKA, Murphy RD, Contreras CJ, DePaoli-Roach AA, Roach PJ, Gentry MS, and Sun RC
- Abstract
The addition of phosphate groups into glycogen modulates its branching pattern and solubility which all impact its accessibility to glycogen interacting enzymes. As glycogen architecture modulates its metabolism, it is essential to accurately evaluate and quantify its phosphate content. Simultaneous direct quantitation of glucose and its phosphate esters requires an assay with high sensitivity and a robust dynamic range. Herein, we describe a highly-sensitive method for the accurate detection of both glycogen-derived glucose and glucose-phosphate esters utilizing gas-chromatography coupled mass spectrometry. Using this method, we observed higher glycogen levels in the liver compared to skeletal muscle, but skeletal muscle contained many more phosphate esters. Importantly, this method can detect femtomole levels of glucose and glucose phosphate esters within an extremely robust dynamic range with excellent accuracy and reproducibility. The method can also be easily adapted for the quantification of plant starch, amylopectin or other biopolymers., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2020
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38. Loss of Rb1 Enhances Glycolytic Metabolism in Kras -Driven Lung Tumors In Vivo.
- Author
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Conroy LR, Dougherty S, Kruer T, Metcalf S, Lorkiewicz P, He L, Yin X, Zhang X, Arumugam S, Young LEA, Sun RC, and Clem BF
- Abstract
Dysregulated metabolism is a hallmark of cancer cells and is driven in part by specific genetic alterations in various oncogenes or tumor suppressors. The retinoblastoma protein (pRb) is a tumor suppressor that canonically regulates cell cycle progression; however, recent studies have highlighted a functional role for pRb in controlling cellular metabolism. Here, we report that loss of the gene encoding pRb ( Rb1 ) in a transgenic mutant Kras -driven model of lung cancer results in metabolic reprogramming. Our tracer studies using bolus dosing of [U-
13 C]-glucose revealed an increase in glucose carbon incorporation into select glycolytic intermediates. Consistent with this result, Rb1 -depleted tumors exhibited increased expression of key glycolytic enzymes. Interestingly, loss of Rb1 did not alter mitochondrial pyruvate oxidation compared to lung tumors with intact Rb1 . Additional tracer studies using [U-13 C,15 N]-glutamine and [U-13 C]-lactate demonstrated that loss of Rb1 did not alter glutaminolysis or utilization of circulating lactate within the tricarboxylic acid cycle (TCA) in vivo. Taken together, these data suggest that the loss of Rb1 promotes a glycolytic phenotype, while not altering pyruvate oxidative metabolism or glutamine anaplerosis in Kras -driven lung tumors.- Published
- 2020
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39. Nuclear Glycogenolysis Modulates Histone Acetylation in Human Non-Small Cell Lung Cancers.
- Author
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Sun RC, Dukhande VV, Zhou Z, Young LEA, Emanuelle S, Brainson CF, and Gentry MS
- Subjects
- A549 Cells, Acetylation, Animals, Carbon metabolism, Carcinoma, Non-Small-Cell Lung pathology, Glycogen biosynthesis, Glycogen Phosphorylase metabolism, HEK293 Cells, Humans, Lung Neoplasms pathology, Mice, Mice, Knockout, Mice, Nude, Transfection, Ubiquitin-Protein Ligases genetics, Ubiquitin-Protein Ligases metabolism, Carcinoma, Non-Small-Cell Lung metabolism, Cell Nucleus metabolism, Glycogenolysis genetics, Histones metabolism, Lung Neoplasms metabolism
- Abstract
Nuclear glycogen was first documented in the early 1940s, but its role in cellular physiology remained elusive. In this study, we utilized pure nuclei preparations and stable isotope tracers to define the origin and metabolic fate of nuclear glycogen. Herein, we describe a key function for nuclear glycogen in epigenetic regulation through compartmentalized pyruvate production and histone acetylation. This pathway is altered in human non-small cell lung cancers, as surgical specimens accumulate glycogen in the nucleus. We demonstrate that the decreased abundance of malin, an E3 ubiquitin ligase, impaired nuclear glycogenolysis by preventing the nuclear translocation of glycogen phosphorylase and causing nuclear glycogen accumulation. Re-introduction of malin in lung cancer cells restored nuclear glycogenolysis, increased histone acetylation, and decreased growth of cancer cells transplanted into mice. This study uncovers a previously unknown role for glycogen metabolism in the nucleus and elucidates another mechanism by which cellular metabolites control epigenetic regulation., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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40. Targeting Pathogenic Lafora Bodies in Lafora Disease Using an Antibody-Enzyme Fusion.
- Author
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Brewer MK, Uittenbogaard A, Austin GL, Segvich DM, DePaoli-Roach A, Roach PJ, McCarthy JJ, Simmons ZR, Brandon JA, Zhou Z, Zeller J, Young LEA, Sun RC, Pauly JR, Aziz NM, Hodges BL, McKnight TR, Armstrong DD, and Gentry MS
- Subjects
- Animals, Brain pathology, Disease Models, Animal, HEK293 Cells, Humans, Immunoglobulin G therapeutic use, Mice, Mice, Inbred C57BL, Pancreatic alpha-Amylases therapeutic use, Rats, Recombinant Fusion Proteins therapeutic use, Brain drug effects, Drug Discovery, Inclusion Bodies drug effects, Lafora Disease therapy, Pancreatic alpha-Amylases pharmacology, Recombinant Fusion Proteins pharmacology
- Abstract
Lafora disease (LD) is a fatal childhood epilepsy caused by recessive mutations in either the EPM2A or EPM2B gene. A hallmark of LD is the intracellular accumulation of insoluble polysaccharide deposits known as Lafora bodies (LBs) in the brain and other tissues. In LD mouse models, genetic reduction of glycogen synthesis eliminates LB formation and rescues the neurological phenotype. Therefore, LBs have become a therapeutic target for ameliorating LD. Herein, we demonstrate that human pancreatic α-amylase degrades LBs. We fused this amylase to a cell-penetrating antibody fragment, and this antibody-enzyme fusion (VAL-0417) degrades LBs in vitro and dramatically reduces LB loads in vivo in Epm2a
-/- mice. Using metabolomics and multivariate analysis, we demonstrate that VAL-0417 treatment of Epm2a-/- mice reverses the metabolic phenotype to a wild-type profile. VAL-0417 is a promising drug for the treatment of LD and a putative precision therapy platform for intractable epilepsy., (Copyright © 2019 Elsevier Inc. All rights reserved.)- Published
- 2019
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41. Caloric Restriction Alters Postprandial Responses of Essential Brain Metabolites in Young Adult Mice.
- Author
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Yanckello LM, Young LEA, Hoffman JD, Mohney RP, Keaton MA, Abner E, and Lin AL
- Abstract
Caloric restriction (CR) has been shown to extend longevity and protect brain function in aging. However, the effects of CR in young adult mice remain largely unexplored. In addition to the fundamental, long-term changes, recent studies demonstrate that CR has a significant impact on transient, postprandial metabolic flexibility and turnover compared to control groups. The goal of this study was to identify the brain metabolic changes at a transient (2 h) and steady (6 h) postprandial state in young mice (5-6 months of age) fed with CR or ad libitum (AL; free eating). Using metabolomics profiling, we show that CR mice had significantly higher levels of neurotransmitters (e.g., glutamate, N-acetylglutamate ) , neuronal integrity markers (e.g., NAA and NAAG), essential fatty acids (e.g., DHA and DPA), and biochemicals associated carnitine metabolism (related to reduced oxidative stress and inflammation) in the cerebral cortex and hippocampus at 2-h. These biochemicals remained at high levels at the 6-h postprandial time-point. The AL mice did not show the similar increases in essential fatty acid and carnitine metabolism until the 6-h time-point, and failed to show increases in neurotransmitters and neuronal integrity markers at any time-point. On the other hand, metabolites related to glucose utilization-glycolysis and pentose phosphate pathway (PPP)-were low in the CR mice throughout the 6-h period and significantly increased at the 6-h time-point in the AL mice. Our findings suggest that CR induces distinct postprandial responses in metabolites that are essential to maintain brain functions. CR mice produced higher levels of essential brain metabolites in a shorter period after a meal and sustained the levels for an extended period, while maintaining a lower level of glucose utilization. These early brain metabolism changes in the CR mice might play a critical role for neuroprotection in aging. Understanding the interplay between dietary intervention and postprandial metabolic responses from an early age may have profound implications for impeding brain aging and reducing risk for neurodegenerative disorders.
- Published
- 2019
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42. Genetic analysis of KillerRed in C. elegans identifies a shared role of calcium genes in ROS-mediated neurodegeneration.
- Author
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Young LEA, Shoben C, Ricci K, and Williams DC
- Subjects
- Animals, Caenorhabditis elegans, Calreticulin genetics, GABAergic Neurons metabolism, GABAergic Neurons pathology, Green Fluorescent Proteins toxicity, Inositol 1,4,5-Trisphosphate Receptors genetics, Nerve Degeneration chemically induced, Nerve Degeneration metabolism, Ryanodine Receptor Calcium Release Channel genetics, Caenorhabditis elegans Proteins genetics, Calcium metabolism, Nerve Degeneration genetics, Reactive Oxygen Species metabolism
- Abstract
In C. elegans, neurodegeneration induced by excitotoxicity or aggregation of misfolded proteins is dependent on genes involved in calcium release from the endoplasmic reticulum. Reactive oxygen species (ROS) can also induce neurodegeneration, but the relationship between ROS-mediated neurodegeneration and calcium has not been established. We activated KillerRed in the GABA neurons of C. elegans to produce ROS that leads to functional loss and structural degeneration of these neurons and demonstrated that the severity of neurodegeneration was dependent on extent of KillerRed activation. To genetically examine the role of calcium in ROS-mediated neurodegeneration, we measured functional neurodegeneration in itr-1 (inositol trisphosphate receptor), crt-1 (caltreticulin), and unc-68 (ryanodine receptor) mutants. Similar to other neurotoxic conditions, neurodegeneration triggered by KillerRed was reduced in itr-1 and crt-1 mutants. Somewhat unexpectedly, genetic or pharmacological disruption of unc-68 had a minimal effect on neurodegeneration. Our results indicate ROS-mediated neurodegeneration occurs through a conserved calcium regulated mechanism and suggest that components of the degeneration process have different sensitivities to ROS.
- Published
- 2019
- Full Text
- View/download PDF
43. Mitochondrial Metabolism in Major Neurological Diseases.
- Author
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Zhou Z, Austin GL, Young LEA, Johnson LA, and Sun R
- Abstract
Mitochondria are bilayer sub-cellular organelles that are an integral part of normal cellular physiology. They are responsible for producing the majority of a cell's ATP, thus supplying energy for a variety of key cellular processes, especially in the brain. Although energy production is a key aspect of mitochondrial metabolism, its role extends far beyond energy production to cell signaling and epigenetic regulation⁻functions that contribute to cellular proliferation, differentiation, apoptosis, migration, and autophagy. Recent research on neurological disorders suggest a major metabolic component in disease pathophysiology, and mitochondria have been shown to be in the center of metabolic dysregulation and possibly disease manifestation. This review will discuss the basic functions of mitochondria and how alterations in mitochondrial activity lead to neurological disease progression.
- Published
- 2018
- Full Text
- View/download PDF
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