1
|
Scudese E, Vue Z, Katti P, Marshall AG, Demirci M, Vang L, López EG, Neikirk K, Shao B, Le H, Stephens D, Hall DD, Rostami R, Rodman T, Kabugi K, Harris C, Shao J, Mungai M, AshShareef ST, Hicsasmaz I, Manus S, Wanjalla C, Whiteside A, Dasari R, Williams C, Damo SM, Gaddy JA, Glancy B, Dantas EHM, Kinder A, Kadam A, Tomar D, Scartoni F, Baffi M, McReynolds MR, Phillips MA, Cooper A, Murray SA, Quintana AM, Exil V, Kirabo A, Mobley BC, Hinton A. 3D Mitochondrial Structure in Aging Human Skeletal Muscle: Insights into MFN-2 Mediated Changes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.13.566502. [PMID: 38168206 PMCID: PMC10760012 DOI: 10.1101/2023.11.13.566502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Age-related atrophy of skeletal muscle, is characterized by loss of mass, strength, endurance, and oxidative capacity during aging. Notably, bioenergetics and protein turnover studies have shown that mitochondria mediate this decline in function. Although exercise has been the only therapy to mitigate sarcopenia, the mechanisms that govern how exercise serves to promote healthy muscle aging are unclear. Mitochondrial aging is associated with decreased mitochondrial capacity, so we sought to investigate how aging affects mitochondrial structure and potential age-related regulators. Specifically, the three-dimensional (3D) mitochondrial structure associated with morphological changes in skeletal muscle during aging requires further elucidation. We hypothesized that aging causes structural remodeling of mitochondrial 3D architecture representative of dysfunction, and this effect is mitigated by exercise. We used serial block-face scanning electron microscopy to image human skeletal tissue samples, followed by manual contour tracing using Amira software for 3D reconstruction and subsequent analysis of mitochondria. We then applied a rigorous in vitro and in vivo exercise regimen during aging. Across 5 human cohorts, we correlate differences in magnetic resonance imaging, mitochondria 3D structure, exercise parameters, and plasma immune markers between young (under 50 years) and old (over 50 years) individuals. We found that mitochondria we less spherical and more complex, indicating age-related declines in contact site capacity. Additionally, aged samples showed a larger volume phenotype in both female and male humans, indicating potential mitochondrial swelling. Concomitantly, muscle area, exercise capacity, and mitochondrial dynamic proteins showed age-related losses. Exercise stimulation restored mitofusin 2 (MFN2), one such of these mitochondrial dynamic proteins, which we show is required for the integrity of mitochondrial structure. Furthermore, we show that this pathway is evolutionarily conserved as Marf, the MFN2 ortholog in Drosophila, knockdown alters mitochondrial morphology and leads to the downregulation of genes regulating mitochondrial processes. Our results define age-related structural changes in mitochondria and further suggest that exercise may mitigate age-related structural decline through modulation of mitofusin 2.
Collapse
Affiliation(s)
- Estevão Scudese
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
- Laboratory of Biosciences of Human Motricity (LABIMH) of the Federal University of State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Sport Sciences and Exercise Laboratory (LaCEE), Catholic University of Petrópolis (UCP), Brazil
| | - Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Prassana Katti
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, AP, 517619, India
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Andrea G. Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Mert Demirci
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Edgar Garza López
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Bryanna Shao
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Han Le
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Dominique Stephens
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Duane D. Hall
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Rahmati Rostami
- Department of Genetic Medicine, Joan & Sanford I. Weill Medical College of Cornell University, New York, NY, 10065, USA
| | - Taylor Rodman
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Kinuthia Kabugi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Chanel Harris
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Jianqiang Shao
- Central Microscopy Research Facility, Iowa City, IA 52242, USA
| | - Margaret Mungai
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Salma T. AshShareef
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Innes Hicsasmaz
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Sasha Manus
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Celestine Wanjalla
- Division of Infection Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Aaron Whiteside
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, 45435, USA
| | - Revathi Dasari
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, AP, 517619, India
| | - Clintoria Williams
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, 45435, USA
| | - Steven M. Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, TN, 37208, USA
| | - Jennifer A. Gaddy
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Tennessee Valley Healthcare Systems, U.S. Department of Veterans Affairs, Nashville, TN, 37212, USA
| | - Brian Glancy
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
- NIAMS, NIH, Bethesda, MD, 20892, USA
| | - Estélio Henrique Martin Dantas
- Laboratory of Biosciences of Human Motricity (LABIMH) of the Federal University of State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Doctor’s Degree Program in Nursing and Biosciences - PpgEnfBio, Federal University of the State of Rio de Janeiro - UNIRIO, Rio de Janeiro, RJ, Brazil
- Laboratory of Human Motricity Biosciences - LABIMH, Federal University of the State of Rio de Janeiro - UNIRIO, RJ, Brazil
- Brazilian Paralympic Academy – APB
- Doctor’s Degree Program in Health and Environment - PSA, Tiradentes University - UNIT, Aracaju, SE, Brazil
| | - André Kinder
- Artur Sá Earp Neto University Center - UNIFASE-FMP, Petrópolis Medical School, Brazil
| | - Ashlesha Kadam
- Department of Internal Medicine, Section of Cardiovascular Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157 USA
| | - Dhanendra Tomar
- Department of Internal Medicine, Section of Cardiovascular Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157 USA
| | - Fabiana Scartoni
- Laboratory of Biosciences of Human Motricity (LABIMH) of the Federal University of State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
| | - Matheus Baffi
- Sport Sciences and Exercise Laboratory (LaCEE), Catholic University of Petrópolis (UCP), Brazil
| | - Melanie R. McReynolds
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA, 16801, USA
| | - Mark A. Phillips
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA
| | - Anthonya Cooper
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Sandra A. Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Anita M. Quintana
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, USA
| | - Vernat Exil
- Department of Pediatrics, Div. of Cardiology, St. Louis University School of Medicine, St. Louis, MO, 63104, USA
| | - Annet Kirabo
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Bret C. Mobley
- Department of Pathology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| |
Collapse
|
2
|
Hinton A, Katti P, Mungai M, Hall DD, Koval O, Shao J, Vue Z, Lopez EG, Rostami R, Neikirk K, Ponce J, Streeter J, Schickling B, Bacevac S, Grueter C, Marshall A, Beasley HK, Do Koo Y, Bodine SC, Nava NGR, Quintana AM, Song LS, Grumbach I, Pereira RO, Glancy B, Abel ED. ATF4-dependent increase in mitochondrial-endoplasmic reticulum tethering following OPA1 deletion in skeletal muscle. J Cell Physiol 2024; 239:e31204. [PMID: 38419397 PMCID: PMC11144302 DOI: 10.1002/jcp.31204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/15/2023] [Accepted: 01/16/2024] [Indexed: 03/02/2024]
Abstract
Mitochondria and endoplasmic reticulum (ER) contact sites (MERCs) are protein- and lipid-enriched hubs that mediate interorganellar communication by contributing to the dynamic transfer of Ca2+, lipid, and other metabolites between these organelles. Defective MERCs are associated with cellular oxidative stress, neurodegenerative disease, and cardiac and skeletal muscle pathology via mechanisms that are poorly understood. We previously demonstrated that skeletal muscle-specific knockdown (KD) of the mitochondrial fusion mediator optic atrophy 1 (OPA1) induced ER stress and correlated with an induction of Mitofusin-2, a known MERC protein. In the present study, we tested the hypothesis that Opa1 downregulation in skeletal muscle cells alters MERC formation by evaluating multiple myocyte systems, including from mice and Drosophila, and in primary myotubes. Our results revealed that OPA1 deficiency induced tighter and more frequent MERCs in concert with a greater abundance of MERC proteins involved in calcium exchange. Additionally, loss of OPA1 increased the expression of activating transcription factor 4 (ATF4), an integrated stress response (ISR) pathway effector. Reducing Atf4 expression prevented the OPA1-loss-induced tightening of MERC structures. OPA1 reduction was associated with decreased mitochondrial and sarcoplasmic reticulum, a specialized form of ER, calcium, which was reversed following ATF4 repression. These data suggest that mitochondrial stress, induced by OPA1 deficiency, regulates skeletal muscle MERC formation in an ATF4-dependent manner.
Collapse
Affiliation(s)
- Antentor Hinton
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
| | - Prasanna Katti
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA, 20892
| | - Margaret Mungai
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Duane D. Hall
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
| | - Olha Koval
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Jianqiang Shao
- Central Microscopy Research Facility, Iowa City, IA USA 52242
| | - Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
| | - Edgar Garza Lopez
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
| | - Rahmati Rostami
- Department of Genetic Medicine, Joan & Sanford I. Weill Medical College of Cornell University, New York, NY, USA, 10065
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
| | - Jessica Ponce
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Jennifer Streeter
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Brandon Schickling
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Department of Medicine, Duke University, Durham, NC, USA 27708
| | - Serif Bacevac
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Chad Grueter
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Andrea Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
| | - Heather K. Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
| | - Young Do Koo
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Sue C. Bodine
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
- Oklahoma Medical Research Foundation, Oklahoma City, OK, USA 73104
| | - Nayeli G. Reyes Nava
- Department of Biological Sciences and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA 79968
| | - Anita M. Quintana
- Department of Biological Sciences and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, TX, USA 79968
| | - Long-Sheng Song
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Isabella Grumbach
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Renata O. Pereira
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
| | - Brian Glancy
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA, 20892
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA 20892
| | - E. Dale Abel
- Department of Internal Medicine, University of Iowa - Carver College of Medicine, Iowa City, IA, USA 52242
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA, USA 52242
- Department of Medicine, UCLA School of Medicine, Los Angeles, CA, USA 90095
| |
Collapse
|
3
|
Robertson GL, Riffle S, Patel M, Bodnya C, Marshall A, Beasley HK, Garza-Lopez E, Shao J, Vue Z, Hinton A, Stoll MS, de Wet S, Theart RP, Chakrabarty RP, Loos B, Chandel NS, Mears JA, Gama V. DRP1 mutations associated with EMPF1 encephalopathy alter mitochondrial membrane potential and metabolic programs. J Cell Sci 2023; 136:jcs260370. [PMID: 36763487 PMCID: PMC10657212 DOI: 10.1242/jcs.260370] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 12/22/2022] [Indexed: 02/11/2023] Open
Abstract
Mitochondria and peroxisomes are dynamic signaling organelles that constantly undergo fission, driven by the large GTPase dynamin-related protein 1 (DRP1; encoded by DNM1L). Patients with de novo heterozygous missense mutations in DNM1L present with encephalopathy due to defective mitochondrial and peroxisomal fission (EMPF1) - a devastating neurodevelopmental disease with no effective treatment. To interrogate the mechanisms by which DRP1 mutations cause cellular dysfunction, we used human-derived fibroblasts from patients who present with EMPF1. In addition to elongated mitochondrial morphology and lack of fission, patient cells display lower coupling efficiency, increased proton leak and upregulation of glycolysis. Mitochondrial hyperfusion also results in aberrant cristae structure and hyperpolarized mitochondrial membrane potential. Peroxisomes show a severely elongated morphology in patient cells, which is associated with reduced respiration when cells are reliant on fatty acid oxidation. Metabolomic analyses revealed impaired methionine cycle and synthesis of pyrimidine nucleotides. Our study provides insight into the role of mitochondrial dynamics in cristae maintenance and the metabolic capacity of the cell, as well as the disease mechanism underlying EMPF1.
Collapse
Affiliation(s)
| | - Stellan Riffle
- Vanderbilt University, Cell and Developmental Biology, Nashville, TN 37232, USA
| | - Mira Patel
- Vanderbilt University, Cell and Developmental Biology, Nashville, TN 37232, USA
| | - Caroline Bodnya
- Vanderbilt University, Cell and Developmental Biology, Nashville, TN 37232, USA
| | - Andrea Marshall
- Vanderbilt University, Molecular Physiology and Biophysics, Nashville, TN 37232, USA
| | - Heather K. Beasley
- Vanderbilt University, Molecular Physiology and Biophysics, Nashville, TN 37232, USA
| | - Edgar Garza-Lopez
- Vanderbilt University, Molecular Physiology and Biophysics, Nashville, TN 37232, USA
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA 52246, USA
| | - Zer Vue
- Vanderbilt University, Molecular Physiology and Biophysics, Nashville, TN 37232, USA
| | - Antentor Hinton
- Vanderbilt University, Molecular Physiology and Biophysics, Nashville, TN 37232, USA
| | - Maria S. Stoll
- Case Western Reserve University, Department of Pharmacology and Center for Mitochondrial Diseases, Cleveland, OH 44106, USA
| | - Sholto de Wet
- Stellenbosch University, Department of Physiological Sciences, Matieland, 7602, Stellenbosch, South Africa
| | - Rensu P. Theart
- Stellenbosch University, Department of Electrical and Electronic Engineering, Matieland, 7602, Stellenbosch, South Africa
| | - Ram Prosad Chakrabarty
- Northwestern University, Feinberg School of Medicine Department of Medicine Division of Pulmonary and Critical Care Medicine, Chicago, IL 60611, USA
| | - Ben Loos
- Stellenbosch University, Department of Electrical and Electronic Engineering, Matieland, 7602, Stellenbosch, South Africa
| | - Navdeep S. Chandel
- Northwestern University, Feinberg School of Medicine Department of Medicine Division of Pulmonary and Critical Care Medicine, Chicago, IL 60611, USA
- Northwestern University, Feinberg School of Medicine Department of Biochemistry and Molecular Genetics, Chicago, IL 60611, USA
| | - Jason A. Mears
- Case Western Reserve University, Department of Pharmacology and Center for Mitochondrial Diseases, Cleveland, OH 44106, USA
| | - Vivian Gama
- Vanderbilt University, Cell and Developmental Biology, Nashville, TN 37232, USA
- Vanderbilt University, Vanderbilt Center for Stem Cell Biology, Nashville, TN 37232, USA
- Vanderbilt University, Vanderbilt Brain Institute, Nashville, TN 37232, USA
| |
Collapse
|
4
|
Garza-Lopez E, Vue Z, Katti P, Neikirk K, Biete M, Lam J, Beasley HK, Marshall AG, Rodman TA, Christensen TA, Salisbury JL, Vang L, Mungai M, AshShareef S, Murray SA, Shao J, Streeter J, Glancy B, Pereira RO, Abel ED, Hinton A. Protocols for Generating Surfaces and Measuring 3D Organelle Morphology Using Amira. Cells 2021; 11:65. [PMID: 35011629 PMCID: PMC8750564 DOI: 10.3390/cells11010065] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 12/18/2021] [Accepted: 12/22/2021] [Indexed: 12/14/2022] Open
Abstract
High-resolution 3D images of organelles are of paramount importance in cellular biology. Although light microscopy and transmission electron microscopy (TEM) have provided the standard for imaging cellular structures, they cannot provide 3D images. However, recent technological advances such as serial block-face scanning electron microscopy (SBF-SEM) and focused ion beam scanning electron microscopy (FIB-SEM) provide the tools to create 3D images for the ultrastructural analysis of organelles. Here, we describe a standardized protocol using the visualization software, Amira, to quantify organelle morphologies in 3D, thereby providing accurate and reproducible measurements of these cellular substructures. We demonstrate applications of SBF-SEM and Amira to quantify mitochondria and endoplasmic reticulum (ER) structures.
Collapse
Affiliation(s)
- Edgar Garza-Lopez
- Hinton and Garza Lopez Family Consulting Company, Iowa City, IA 52246, USA;
| | - Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; (Z.V.); (H.K.B.); (A.G.M.); (T.A.R.); (L.V.)
| | - Prasanna Katti
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA; (P.K.); (B.G.)
| | - Kit Neikirk
- Department of Biology, University of Hawaii at Hilo, Hilo, HI 96720, USA; (K.N.); (M.B.)
| | - Michelle Biete
- Department of Biology, University of Hawaii at Hilo, Hilo, HI 96720, USA; (K.N.); (M.B.)
| | - Jacob Lam
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; (J.L.); (M.M.); (S.A.); (J.S.)
| | - Heather K. Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; (Z.V.); (H.K.B.); (A.G.M.); (T.A.R.); (L.V.)
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, School of Graduate Studies and Research, Meharry Medical College, Nashville, TN 37208, USA
| | - Andrea G. Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; (Z.V.); (H.K.B.); (A.G.M.); (T.A.R.); (L.V.)
| | - Taylor A. Rodman
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; (Z.V.); (H.K.B.); (A.G.M.); (T.A.R.); (L.V.)
| | - Trace A. Christensen
- Microscopy and Cell Analysis Core Facility, Mayo Clinic, Rochester, MN 55905, USA; (T.A.C.); (J.L.S.)
| | - Jeffrey L. Salisbury
- Microscopy and Cell Analysis Core Facility, Mayo Clinic, Rochester, MN 55905, USA; (T.A.C.); (J.L.S.)
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; (Z.V.); (H.K.B.); (A.G.M.); (T.A.R.); (L.V.)
| | - Margaret Mungai
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; (J.L.); (M.M.); (S.A.); (J.S.)
| | - Salma AshShareef
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; (J.L.); (M.M.); (S.A.); (J.S.)
| | - Sandra A. Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 52013, USA;
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA 52242, USA;
| | - Jennifer Streeter
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; (J.L.); (M.M.); (S.A.); (J.S.)
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA 52242, USA
| | - Brian Glancy
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA; (P.K.); (B.G.)
| | - Renata O. Pereira
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; (J.L.); (M.M.); (S.A.); (J.S.)
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA 52242, USA
| | - E. Dale Abel
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; (J.L.); (M.M.); (S.A.); (J.S.)
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, IA 52242, USA
| | - Antentor Hinton
- Hinton and Garza Lopez Family Consulting Company, Iowa City, IA 52246, USA;
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; (Z.V.); (H.K.B.); (A.G.M.); (T.A.R.); (L.V.)
| |
Collapse
|
5
|
Inflammation-induced behavioral changes is driven by alterations in Nrf2-dependent apoptosis and autophagy in mouse hippocampus: Role of fluoxetine. Cell Signal 2019; 68:109521. [PMID: 31881324 DOI: 10.1016/j.cellsig.2019.109521] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 12/21/2019] [Accepted: 12/21/2019] [Indexed: 12/13/2022]
Abstract
Inflammation has been associated with the progression of many neurological diseases. Peripheral inflammation has also been vaguely linked to depression-like symptoms in animal models, but the underlying pathways that orchestrate inflammation-induced behavioral or molecular changes in the brain are still elusive. We have recently shown that intraperitoneal injections of lipopolysaccharide (LPS) to Swiss albino mice triggers systemic inflammation, leading to an activated immune response along with changes in monoamine levels in the brain. Herein we pinpoint the fundamental pathways linking peripheral inflammation and depression-like behavior in a mouse model, thereby identifying suitable targets of intervention to combat the situation. We show that LPS-induced peripheral inflammation provoked a depression-like behavior in mice and a distinct pro-inflammatory bias in the hippocampus, as evident from increased microglial activation and elevated levels of pro-inflammatory cytokines IL-6 and TNF-α, and activation of NFκB-p65 pathway. Significant alterations in Nrf2-dependent cellular redox status, coupled with altered autophagy and increased apoptosis were noticed in the hippocampus of LPS-exposed mice. We and others have previously shown that, fluoxetine (an anti-depressant) has effective anti-inflammatory and antioxidant properties by virtue of its abilities to regulate NFκB and Nrf2 signaling. We observed that treatment with fluoxetine or the Nrf2 activator tBHQ (tert-butyl hydroquinone), could reverse depression-like-symptoms and mitigate alterations in autophagy and cell death pathways in the hippocampus by activating Nrf2-dependent gene expressions. Taken together, the data suggests that systemic inflammation potentiates Nrf2-dependent changes in cell death and autophagy pathway in the hippocampus, eventually leading to major pathologic sequelae associated with depression. Therefore, targeting Nrf2 could be a novel approach in combatting depression and ameliorating its associated pathogenesis.
Collapse
|
6
|
Lai J, Su Y, Swain DL, Huang D, Getchevski D, Gong H. The Role of Schlemm's Canal Endothelium Cellular Connectivity in Giant Vacuole Formation: A 3D Electron Microscopy Study. Invest Ophthalmol Vis Sci 2019; 60:1630-1643. [PMID: 30995299 PMCID: PMC6736380 DOI: 10.1167/iovs.18-26011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Purpose We investigated whether cellular connectivity between Schlemm's canal (SC) inner wall (IW) endothelium, and juxtacanalicular connective tissue (JCT), and between IW endothelial cells, plays a role in giant vacuole (GV) and pore formation by comparing perfusion- and immersion-fixed eyes. Methods Normal human donor eyes (n = 4) were either immersion-fixed (0 mm Hg) or perfusion-fixed (15 mm Hg). Trabecular meshwork near SC was imaged using serial block-face scanning electron microscopy. A total of 12 IW cells from each group were 3D-reconstructed from ∼7040 electron micrographs and compared. In each cell, connections between IW cells and JCT cells/matrix were quantified; IW/IW connectivity was measured by cell border overlap length. GV volume, density, shape, and intracellular and paracellular pores were analyzed. Results The mean number of IW/JCT cell-cell connections per cell significantly decreased (P < 0.01) while the summed GV volume per cell significantly increased (P < 0.01) in perfusion-fixed eyes compared to immersion-fixed eyes. Intracellular pores were observed in 14.6% of GVs in perfusion-fixed eyes and not observed in immersion-fixed eyes. The mean IW/IW overlap length per cell decreased (P < 0.01), and paracellular pores were found only in regions where IW/IW connectivity was minimal (overlap length = 0 μm) in perfusion-fixed eyes and not observed in immersion-fixed eyes. Conclusions Our data suggest that changes in IW/JCT connectivity may be an important factor in the formation of larger GVs, and decreased IW/IW connectivity may promote paracellular pore formation. Targeting the IW/JCT and IW/IW connectivity may therefore be a potential strategy to regulate outflow resistance and IOP.
Collapse
Affiliation(s)
- Julia Lai
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Yanfeng Su
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States.,The Affiliated Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - David L Swain
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States.,Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Davy Huang
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Dimitr Getchevski
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Haiyan Gong
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States.,Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, United States
| |
Collapse
|
7
|
Gupta RK, Kaur I, Nag TC, Chhablani J. Diagnostic Electron Microscopy of Retina. Semin Ophthalmol 2018; 33:700-710. [PMID: 29388866 DOI: 10.1080/08820538.2017.1416415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The electron microscopy techniques were used in various fields as an analytical technique under in vitro conditions, which provides the sufficient resolution for better visualization and interpretation. This review gives a brief overview of the analytical application of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques and critical findings in different retinal pathologies. This review article aims to improvise understanding of retinal microstructures for clinicians which will help to improve the interpretation of the current advanced imaging techniques.
Collapse
Affiliation(s)
- Rishikesh Kumar Gupta
- a Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre , L V Prasad Eye Institute (KAR Campus) , Hyderabad , Telangana , India
| | - Inderjeet Kaur
- a Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre , L V Prasad Eye Institute (KAR Campus) , Hyderabad , Telangana , India
| | - Tapas C Nag
- c All India Institute of Medical Sciences , Department of Anatomy , New Delhi , India
| | - Jay Chhablani
- b Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases , L V Prasad Eye Institute (KAR Campus) , Hyderabad , Telangana , India
| |
Collapse
|
8
|
Yadav S, Storrie B. The cellular basis of platelet secretion: Emerging structure/function relationships. Platelets 2017; 28:108-118. [PMID: 28010140 PMCID: PMC5627609 DOI: 10.1080/09537104.2016.1257786] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/12/2016] [Accepted: 10/27/2016] [Indexed: 12/27/2022]
Abstract
Platelet activation has long been known to be accompanied by secretion from at least three types of compartments. These include dense granules, the major source of small molecules; α-granules, the major protein storage organelle; and lysosomes, the site of acid hydrolase storage. Despite ~60 years of research, there are still many unanswered questions about the cell biology of platelet secretion: for example, how are these secretory organelles organized to support cargo release and what are the key routes of cargo release, granule to plasma membrane or granule to canalicular system. Moreover, in recent years, increasing evidence points to the platelet being organized for secretion of the contents from other organelles, namely the dense tubular system (endoplasmic reticulum) and the Golgi apparatus. Conceivably, protein secretion is a widespread property of the platelet and its organelles. In this review, we concentrate on the cell biology of the α-granule and its structure/function relationships. We both review the literature and discuss the wide array of 3-dimensional, high-resolution structural approaches that have emerged in the last few years. These have begun to reveal new and unanticipated outcomes and some of these are discussed. We are hopeful that the next several years will bring rapid advances to this field that will resolve past controversies and be clinically relevant.
Collapse
Affiliation(s)
- Shilpi Yadav
- a Department of Physiology and Biophysics , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Brian Storrie
- a Department of Physiology and Biophysics , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| |
Collapse
|