1
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Jain A, Jung HJ, Aubee J, O’Neil JN, Muhammad LA, Khan S, Thompson K, Fluitt MB, Lee DL, Klinge CM, Khundmiri SJ. Role of NHERF1 in MicroRNA Landscape Changes in Aging Mouse Kidneys. Biomolecules 2024; 14:1048. [PMID: 39334814 PMCID: PMC11430241 DOI: 10.3390/biom14091048] [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: 07/29/2024] [Revised: 08/19/2024] [Accepted: 08/20/2024] [Indexed: 09/30/2024] Open
Abstract
MicroRNAs (miRNAs) play important roles in the regulation of cellular function and fate via post-transcriptional regulation of gene expression. Although several miRNAs are associated with physiological processes and kidney diseases, not much is known about changes in miRNAs in aging kidneys. We previously demonstrated that sodium hydrogen exchanger 1 (NHERF1) expression regulates cellular responses to cisplatin, age-dependent salt-sensitive hypertension, and sodium-phosphate cotransporter trafficking. However, the mechanisms driving these regulatory effects of NHERF1 on cellular processes are unknown. Here, we hypothesize that dysregulation of miRNA-mediated gene regulatory networks that induce fibrosis and cytokines may depend on NHERF1 expression. To address this hypothesis, we compared miRNA expression in kidneys from both male and female old (12-18-month-old) and young (4-7-month-old) wild-type (WT) and NHERF1 knockout (NHERF1-/-) mice. Our results identified that miRNAs significantly decreased in NHERF1-/- mice included miR-669m, miR-590-3p, miR-153, miR-673-3p, and miR-127. Only miR-702 significantly decreased in aged WT mice, while miR-678 decreased in both WT and NHERF1-/- old versus young mice. miR-153 was shown to downregulate transcription factors NFATc2 and NFATc3 which regulate the transcription of several cytokines. Immunohistochemistry and western blotting revealed a significant increase in nuclear NFATc2 and NFATc3 in old NHERF1-/- mice compared to old WT mice. Our data further show that expression of the cytokines IL-1β, IL-6, IL-17A, MCP1, and TNF-α significantly increased in the old NHERF1-/- mice compared to the WT mice. We conclude that loss of NHERF1 expression induces cytokine expression in the kidney through interactive regulation between miR-153 and NFATc2/NFATc3 expression.
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Affiliation(s)
- Anish Jain
- Department of Physiology, Howard University College of Medicine, Washington, DC 20059, USA; (A.J.); (J.N.O.); (L.A.M.); (S.K.); (D.L.L.)
| | - Hyun Jun Jung
- Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
| | - Joseph Aubee
- Department of Microbiology, Howard University College of Medicine, Washington, DC 20059, USA; (J.A.); (K.T.)
| | - Jahn N. O’Neil
- Department of Physiology, Howard University College of Medicine, Washington, DC 20059, USA; (A.J.); (J.N.O.); (L.A.M.); (S.K.); (D.L.L.)
| | - Laila A. Muhammad
- Department of Physiology, Howard University College of Medicine, Washington, DC 20059, USA; (A.J.); (J.N.O.); (L.A.M.); (S.K.); (D.L.L.)
| | - Shaza Khan
- Department of Physiology, Howard University College of Medicine, Washington, DC 20059, USA; (A.J.); (J.N.O.); (L.A.M.); (S.K.); (D.L.L.)
| | - Karl Thompson
- Department of Microbiology, Howard University College of Medicine, Washington, DC 20059, USA; (J.A.); (K.T.)
| | - Maurice B. Fluitt
- Department of Medicine, Howard University College of Medicine, Washington, DC 20059, USA;
| | - Dexter L. Lee
- Department of Physiology, Howard University College of Medicine, Washington, DC 20059, USA; (A.J.); (J.N.O.); (L.A.M.); (S.K.); (D.L.L.)
| | - Carolyn M. Klinge
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY 40202, USA;
| | - Syed J. Khundmiri
- Department of Physiology, Howard University College of Medicine, Washington, DC 20059, USA; (A.J.); (J.N.O.); (L.A.M.); (S.K.); (D.L.L.)
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2
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Cao R, Chen P, Wang H, Jing H, Zhang H, Xing G, Luo B, Pan J, Yu Z, Xiong WC, Mei L. Intrafusal-fiber LRP4 for muscle spindle formation and maintenance in adult and aged animals. Nat Commun 2023; 14:744. [PMID: 36765071 PMCID: PMC9918736 DOI: 10.1038/s41467-023-36454-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 01/30/2023] [Indexed: 02/12/2023] Open
Abstract
Proprioception is sensed by muscle spindles for precise locomotion and body posture. Unlike the neuromuscular junction (NMJ) for muscle contraction which has been well studied, mechanisms of spindle formation are not well understood. Here we show that sensory nerve terminals are disrupted by the mutation of Lrp4, a gene required for NMJ formation; inducible knockout of Lrp4 in adult mice impairs sensory synapses and movement coordination, suggesting that LRP4 is required for spindle formation and maintenance. LRP4 is critical to the expression of Egr3 during development; in adult mice, it interacts in trans with APP and APLP2 on sensory terminals. Finally, spindle sensory endings and function are impaired in aged mice, deficits that could be diminished by LRP4 expression. These observations uncovered LRP4 as an unexpected regulator of muscle spindle formation and maintenance in adult and aged animals and shed light on potential pathological mechanisms of abnormal muscle proprioception.
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Affiliation(s)
- Rangjuan Cao
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.,Department of Hand and Foot Surgery, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Peng Chen
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Hongsheng Wang
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Hongyang Jing
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Hongsheng Zhang
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Guanglin Xing
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Bin Luo
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Jinxiu Pan
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Zheng Yu
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Wen-Cheng Xiong
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA. .,Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, 44106, USA.
| | - Lin Mei
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA. .,Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, 44106, USA.
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3
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Jennings EM, Sullivan LC, Jamshidi RJ, LoCoco PM, Smith HR, Chavera TS, Berg KA, Clarke WP. Age-related changes in peripheral nociceptor function. Neuropharmacology 2022; 216:109187. [PMID: 35835212 DOI: 10.1016/j.neuropharm.2022.109187] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 06/21/2022] [Accepted: 07/03/2022] [Indexed: 01/05/2023]
Abstract
Pain and pain management in the elderly population is a significant social and medical problem. Pain sensation is a complex phenomenon that typically involves activation of peripheral pain-sensing neurons (nociceptors) which send signals to the spinal cord and brain that are interpreted as pain, an unpleasant sensory experience. In this work, young (4-5 months) and aged (26-27 months) Fischer 344 x Brown Norway (F344xBN) rats were examined for nociceptor sensitivity to activation by thermal (cold and heat) and mechanical stimulation following treatment with inflammatory mediators and activators of transient receptor potential (TRP) channels. Unlike other senses that decrease in sensitivity with age, sensitivity of hindpaw nociceptors to thermal and mechanical stimulation was not different between young and aged F344xBN rats. Intraplantar injection of bradykinin (BK) produced greater thermal and mechanical allodynia in aged versus young rats, whereas only mechanical allodynia was greater in aged rats following injection of prostaglandin E2 (PGE2). Intraplantar injection of TRP channel activators, capsaicin (TRPV1), mustard oil (TRPA1) and menthol (TRPM8) each resulted in greater mechanical allodynia in aged versus young rats and capsaicin-induced heat allodynia was also greater in aged rats. A treatment-induced allodynia that was greater in young rats was never observed. The anti-allodynic effects of intraplantar injection of kappa and delta opioid receptor agonists, salvinorin-A and D-Pen2,D-Pen5]enkephalin (DPDPE), respectively, were greater in aged than young rats, whereas mu opioid receptor agonists, [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO) and morphine, were not effective in aged rats. Consistent with these observations, in primary cultures of peripheral sensory neurons, inhibition of cAMP signaling in response to delta and kappa receptor agonists was greater in cultures derived from aged rats. By contrast, mu receptor agonists did not inhibit cAMP signaling in aged rats. Thus, age-related changes in nociceptors generally favor increased pain signaling in aged versus young rats, suggesting that changes in nociceptor sensitivity may play a role in the increased incidence of pain in the elderly population. These results also suggest that development of peripherally-restricted kappa or delta opioid receptor agonists may provide safer and effective pain relief for the elderly.
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Affiliation(s)
- Elaine M Jennings
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Laura C Sullivan
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Raehannah J Jamshidi
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Peter M LoCoco
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Hudson R Smith
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Teresa S Chavera
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - Kelly A Berg
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA
| | - William P Clarke
- Department of Pharmacology, The University of Texas Health San Antonio, 7703 Floyd Curl Dr, San Antonio, TX, 78229-3900, USA.
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Finesso GE, McDevitt RA, Roy R, Brinster LR, Di Francesco A, Meade T, de Cabo R, Ferrucci L, Perdue KA. Impact of large granular lymphocyte leukemia on blood DNA methylation and epigenetic clock modeling in Fischer 344 rats. J Gerontol A Biol Sci Med Sci 2021; 77:956-963. [PMID: 34718551 DOI: 10.1093/gerona/glab328] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Indexed: 11/14/2022] Open
Abstract
Age-dependent differences in methylation at specific cytosine-guanosine sites (CpGs) have been used in "epigenetic clock" formulas to predict age. Deviations of epigenetic age from chronological age are informative of health status and are associated with adverse health outcomes, including mortality. In most cases, epigenetic clocks are performed on methylation from DNA extracted from circulating blood cells. However, the effect of neoplastic cells in the circulation on estimation and interpretation of epigenetic clocks is not well understood. Here, we explored this using Fischer 344 (F344) rats, a strain that often develops large granular lymphocyte leukemia (LGL). We found clear histological markers of LGL pathology in the spleens and livers of 27 out of 61 rats aged 17-27 months. We assessed DNA methylation by reduced representation bisulfite sequencing with coverage of 3 million cytosine residues. Although LGL broadly increased DNA methylation variability, it did not change epigenetic aging. Despite this, inclusion of rats with LGL in clock training sets significantly altered predictor selection probability at 83 of 121 commonly utilized CpGs. Furthermore, models trained on rat samples that included individuals with LGL had greater absolute age error than those trained exclusively on LGL-free rats (39% increase; p<0.0001). We conclude that the epigenetic signals for aging and LGL are distinct, such that LGL assessment is not necessary for valid measures of epigenetic age in F344 rats. The precision and architecture of constructed epigenetic clock formulas, however, can be influenced by the presence of neoplastic hematopoietic cells in training set populations.
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Affiliation(s)
- Giovanni E Finesso
- Comparative Medicine Section, National Institute on Aging - Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Ross A McDevitt
- Comparative Medicine Section, National Institute on Aging - Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Roshni Roy
- Laboratory of Molecular Biology and Immunology, National Institute on Aging - Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Lauren R Brinster
- Office of Research Services, Division of Veterinary Resources, National Institutes of Health, Bethesda, MD
| | - Andrea Di Francesco
- Translational Gerontology Branch, National Institute on Aging - Intramural Research Program, National Institutes of Health, Baltimore, MD.,Calico Life Sciences, South San Francisco, CA
| | - Theresa Meade
- Comparative Medicine Section, National Institute on Aging - Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging - Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Luigi Ferrucci
- Translational Gerontology Branch, National Institute on Aging - Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Kathy A Perdue
- Comparative Medicine Section, National Institute on Aging - Intramural Research Program, National Institutes of Health, Baltimore, MD
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5
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Carter CS, Richardson A, Huffman DM, Austad S. Bring Back the Rat! J Gerontol A Biol Sci Med Sci 2020; 75:405-415. [PMID: 31894235 DOI: 10.1093/gerona/glz298] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Indexed: 12/12/2022] Open
Abstract
As 2020 is "The Year of the Rat" in the Chinese astrological calendar, it seems an appropriate time to consider whether we should bring back the laboratory rat to front-and-center in research on the basic biology of mammalian aging. Beginning in the 1970s, aging research with rats became common, peaking in 1992 but then declined dramatically by 2018 as the mouse became preeminent. The purpose of this review is to highlight some of the historical contributions as well as current advantages of the rat as a mammalian model of human aging, because we suspect at least a generation of researchers is no longer aware of this history or these advantages. Herein, we compare and contrast the mouse and rat in the context of several biological domains relevant to their use as appropriate models of aging: phylogeny/domestication, longevity interventions, pathology/physiology, and behavior/cognition. It is not the goal of this review to give a complete characterization of the differences between mice and rats, but to provide important examples of why using rats as well as mice is important to advance our understanding of the biology of aging.
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Affiliation(s)
- Christy S Carter
- Department of Medicine, Division of Gerontology, Geriatrics and Palliative Care, School of Medicine, University of Alabama at Birmingham
| | - Arlan Richardson
- Department of Biochemistry and Molecular Biology, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Science Center, and the Oklahoma City VA Medical Center
| | - Derek M Huffman
- Department of Molecular Pharmacology, Department of Medicine, and Institute for Aging Research, Albert Einstein College of Medicine, Bronx, New York
| | - Steven Austad
- Department of Biology, College of Arts and Sciences, University of Alabama at Birmingham
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6
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Pushpakumar S, Ahmad A, Ketchem CJ, Jose PA, Weinman EJ, Sen U, Lederer ED, Khundmiri SJ. Sodium-hydrogen exchanger regulatory factor-1 (NHERF1) confers salt sensitivity in both male and female models of hypertension in aging. Life Sci 2020; 243:117226. [PMID: 31904366 PMCID: PMC7015806 DOI: 10.1016/j.lfs.2019.117226] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/16/2019] [Accepted: 12/23/2019] [Indexed: 01/11/2023]
Abstract
Hypertension is a risk factor for premature death and roughly 50% of hypertensive patients are salt-sensitive. The incidence of salt-sensitive hypertension increases with age. However, the mechanisms of salt-sensitive hypertension are not well understood. We had demonstrated decreased renal sodium‑hydrogen exchanger regulatory factor 1 (NHERF1) expression in old salt-resistant F344 rats. Based on those studies we hypothesized that NHERF1 expression is required for the development of some forms of salt-sensitive hypertension. To address this hypothesis, we measured blood pressure in NHERF1 expressing salt-sensitive 4-mo and 24-mo-old male and female Fischer Brown Norway (FBN) rats male and female 18-mo-old NHERF1 knock-out (NHERF1-/-) mice and wild-type (WT) littermates on C57BL/6J background after feeding high salt (8% NaCl) diet for 7 days. Our data demonstrate that 8% salt diet increased blood pressure in both male and female 24-mo-old FBN rats but not in 4-mo-old FBN rats and in 18-mo-old male and female WT mice but not in NHERF1-/- mice. Renal dopamine 1 receptor (D1R) expression was decreased in 24-mo-old rats, compared with 4-mo-old FBN rats. However, sodium chloride cotransporter (NCC) expression increased in 24-mo-old FBN rats. In FBN rats, age had no effect on NaK ATPase α1 and NKCC2 expression. By contrast, high salt diet increased the renal expressions of NKCC2, and NCC in 24-mo-old FBN rats. High salt diet also increased NKCC2 and NCC expression in WT mice but not NHERF1-/- mice. Our data suggest that renal NHERF1 expression confers salt sensitivity with aging, associated with increased expression of sodium transporters.
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Affiliation(s)
- Sathnur Pushpakumar
- Department of Physiology, University of Louisville, Louisville, KY, United States of America
| | - Asrar Ahmad
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC, United States of America
| | - Corey J Ketchem
- Department of Medicine, Nephrology and Hypertension, University of Louisville, Louisville, KY, United States of America
| | - Pedro A Jose
- Department of Medicine, Division of Renal Diseases and Hypertension, The George Washington University, Washington, DC, United States of America
| | - Edward J Weinman
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Utpal Sen
- Department of Physiology, University of Louisville, Louisville, KY, United States of America
| | - Eleanor D Lederer
- Department of Physiology, University of Louisville, Louisville, KY, United States of America; Department of Medicine, Nephrology and Hypertension, University of Louisville, Louisville, KY, United States of America; Robley Rex VA Medical Center, Louisville, KY, United States of America
| | - Syed J Khundmiri
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC, United States of America.
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7
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Zhu W, Kim BC, Wang M, Huang J, Isak A, Bexiga NM, Monticone R, Ha T, Lakatta EG, An SS. TGFβ1 reinforces arterial aging in the vascular smooth muscle cell through a long-range regulation of the cytoskeletal stiffness. Sci Rep 2018; 8:2668. [PMID: 29422510 PMCID: PMC5805716 DOI: 10.1038/s41598-018-20763-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 01/24/2018] [Indexed: 02/07/2023] Open
Abstract
Here we report exquisitely distinct material properties of primary vascular smooth muscle (VSM) cells isolated from the thoracic aorta of adult (8 months) vs. aged (30 months) F344XBN rats. Individual VSM cells derived from the aged animals showed a tense internal network of the actin cytoskeleton (CSK), exhibiting increased stiffness (elastic) and frictional (loss) moduli than those derived from the adult animals over a wide frequency range of the imposed oscillatory deformation. This discrete mechanical response was long-lived in culture and persistent across a physiological range of matrix rigidity. Strikingly, the pro-fibrotic transforming growth factor β1 (TGFβ1) emerged as a specific modifier of age-associated VSM stiffening in vitro. TGFβ1 reinforced the mechanical phenotype of arterial aging in VSM cells on multiple time and length scales through clustering of mechanosensitive α5β1 and αvβ3 integrins. Taken together, these studies identify a novel nodal point for the long-range regulation of VSM stiffness and serve as a proof-of-concept that the broad-based inhibition of TGFβ1 expression, or TGFβ1 signal transduction in VSM, may be a useful therapeutic approach to mitigate the pathologic progression of central arterial wall stiffening associated with aging.
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Affiliation(s)
- Wanqu Zhu
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Byoung Choul Kim
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, 21205, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.,Howard Hughes Medical Institute, Baltimore, Maryland, 21218, USA.,Division of Nano-Bioengineering, Incheon National University, Incheon, Republic of Korea
| | - Mingyi Wang
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Jessie Huang
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Abraham Isak
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Natalia M Bexiga
- Immunobiological and Biopharmaceutical Laboratory, Department of Pharmaceutical Biochemistry Technology, University of Sao Paulo, Sao Paulo, Brazil
| | - Robert Monticone
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, 21205, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.,Howard Hughes Medical Institute, Baltimore, Maryland, 21218, USA
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA.
| | - Steven S An
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA. .,Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA. .,Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea.
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8
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Ross CN, Austad S, Brasky K, Brown CJ, Forney LJ, Gelfond JA, Lanford R, Richardson A, Tardif SD. The development of a specific pathogen free (SPF) barrier colony of marmosets ( Callithrix jacchus) for aging research. Aging (Albany NY) 2017; 9:2544-2558. [PMID: 29227963 PMCID: PMC5764392 DOI: 10.18632/aging.101340] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/01/2017] [Indexed: 11/25/2022]
Abstract
A specific pathogen free (SPF) barrier colony of breeding marmosets (Callithrix jacchus) was established at the Barshop Institute for Longevity and Aging Studies. Rodent and other animal models maintained as SPF barrier colonies have demonstrated improved health and lengthened lifespans enhancing the quality and repeatability of aging research. The marmosets were screened for two viruses and several bacterial pathogens prior to establishing the new SPF colony. Twelve founding animals successfully established a breeding colony with increased reproductive success, improved health parameters, and increased median lifespan when compared to a conventionally housed, open colony. The improved health and longevity of marmosets from the SPF barrier colony suggests that such management can be used to produce a unique resource for future studies of aging processes in a nonhuman primate model.
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Affiliation(s)
- Corinna N. Ross
- Department of Science and Mathematics, Texas A&M University San Antonio, San Antonio, TX 78224, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, TX 78245, USA
| | - Steven Austad
- Nathan Shock Center of Excellence in the Basic Biology of Aging, Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Kathy Brasky
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX 78227, USA
| | - Celeste J. Brown
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA
| | - Larry J. Forney
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA
| | - Jonathan A. Gelfond
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, TX 78245, USA
| | - Robert Lanford
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX 78227, USA
| | - Arlan Richardson
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Suzette D. Tardif
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, TX 78245, USA
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX 78227, USA
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9
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Gano A, Doremus-Fitzwater TL, Deak T. A cross-sectional comparison of ethanol-related cytokine expression in the hippocampus of young and aged Fischer 344 rats. Neurobiol Aging 2017; 54:40-53. [PMID: 28319836 PMCID: PMC5401774 DOI: 10.1016/j.neurobiolaging.2017.01.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 01/02/2017] [Accepted: 01/23/2017] [Indexed: 12/22/2022]
Abstract
Our work in Sprague Dawley rats has shown rapid alterations in neuroimmune gene expression (RANGE) in the hippocampus and paraventricular nucleus of the hypothalamus (PVN). These manifest as increased interleukin (IL)-6 and IκBα, and suppressed IL-1β and tumor necrosis factor alpha during acute ethanol intoxication. The present studies tested these effects across the lifespan (young adulthood at 2-3 months; senescence at 18 and 24 months), as well as across strain (Fischer 344) and sex. The hippocampus revealed age-dependent shifts in cytokine expression (IL-6, IL-1β, and monocyte chemoattractant protein 1), but no changes were observed in the PVN at baseline or following ethanol. RANGE in adults was similar across sex and comparable with effects seen in Sprague Dawley rats. Plasma corticosterone levels increased with age, whereas the blood ethanol concentrations and loss of righting reflex were similar in all groups older than 2 months. These findings indicate that the RANGE effect is largely conserved across strain and is durable across age, even in the face of a shifting neuroimmune profile that emerges during immunosenescence.
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Affiliation(s)
- Anny Gano
- Behavioral Neuroscience Program, Department of Psychology, Binghamton University, Binghamton, NY, USA
| | | | - Terrence Deak
- Behavioral Neuroscience Program, Department of Psychology, Binghamton University, Binghamton, NY, USA.
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10
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Elliott JE, Omar TS, Mantilla CB, Sieck GC. Diaphragm muscle sarcopenia in Fischer 344 and Brown Norway rats. Exp Physiol 2016; 101:883-94. [PMID: 27126607 PMCID: PMC4930373 DOI: 10.1113/ep085703] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 04/26/2016] [Indexed: 01/06/2023]
Abstract
NEW FINDINGS What is the central question of this study? Several rat models are commonly used to study the physiology of ageing (e.g. Fischer 344 and Brown Norway rats are recommended by the USA National Institute of Ageing). Diaphragm muscle sarcopenia (ageing-related muscle weakness and atrophy) remains incompletely described in these rat models. What is the main finding and its importance? Diaphragm muscle sarcopenia is present in both the Fischer 344 and Brown Norway rat strains, but appears more pronounced in Fischer 344 rats. The risk for respiratory diseases increases in adults >65 years of age, which may be attributable in part to ageing-related weakening and atrophy (i.e. sarcopenia) of the diaphragm muscle (DIAm). The mechanisms underlying DIAm sarcopenia remain unknown. Based on existing evidence, we hypothesized that sarcopenia is most evident in type IIx and/or IIb DIAm fibres, i.e. more fatigable motor units. Currently, the USA National Institute on Aging supports Fischer 344 (F344) and Brown Norway (BN) rat strains for ageing-related research, yet DIAm sarcopenia has not been evaluated comprehensively in either strain. Thus, the present study examined DIAm sarcopenia in older adult F344 (24 months old, 50% survival) and BN rats (32 months old, 50% survival), compared with young adult (6-month-old) F344 and BN rats. Measurements of contractility, contractile protein concentration, fibre type distribution and fibre cross-sectional area were obtained from midcostal DIAm strips. Maximal specific force was reduced by ∼24 and ∼13% in older F344 and BN rats, respectively. Additionally, although the cross-sectional area of type I and IIa DIAm fibres was unchanged in both F344 and BN rats, the cross-sectional area of type IIx and/or IIb DIAm fibres was reduced by ∼20 and ∼15% in F344 and BN rats, respectively. Thus, although there was ageing-related DIAm weakness and atrophy, selective to type IIx and/or IIb DIAm fibres, in both F344 and BN rats, the sarcopenic phenotype was more pronounced in F344 rats.
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Affiliation(s)
- Jonathan E. Elliott
- Mayo Clinic, Department of Physiology and Biomedical Engineering, Rochester, MN, USA
| | - Tanya S. Omar
- Mayo Clinic, Department of Physiology and Biomedical Engineering, Rochester, MN, USA
| | - Carlos B. Mantilla
- Mayo Clinic, Department of Physiology and Biomedical Engineering, Rochester, MN, USA
- Mayo Clinic,Department of Anesthesiology, Rochester, MN, USA
| | - Gary C. Sieck
- Mayo Clinic, Department of Physiology and Biomedical Engineering, Rochester, MN, USA
- Mayo Clinic,Department of Anesthesiology, Rochester, MN, USA
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Conley MN, Wong CP, Duyck KM, Hord N, Ho E, Sharpton TJ. Aging and serum MCP-1 are associated with gut microbiome composition in a murine model. PeerJ 2016; 4:e1854. [PMID: 27069796 PMCID: PMC4824877 DOI: 10.7717/peerj.1854] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/07/2016] [Indexed: 12/24/2022] Open
Abstract
Introduction. Age is the primary risk factor for major human chronic diseases, including cardiovascular disorders, cancer, type 2 diabetes, and neurodegenerative diseases. Chronic, low-grade, systemic inflammation is associated with aging and the progression of immunosenescence. Immunosenescence may play an important role in the development of age-related chronic disease and the widely observed phenomenon of increased production of inflammatory mediators that accompany this process, referred to as “inflammaging.” While it has been demonstrated that the gut microbiome and immune system interact, the relationship between the gut microbiome and age remains to be clearly defined, particularly in the context of inflammation. The aim of our study was to clarify the associations between age, the gut microbiome, and pro-inflammatory marker serum MCP-1 in a C57BL/6 murine model. Results. We used 16S rRNA gene sequencing to profile the composition of fecal microbiota associated with young and aged mice. Our analysis identified an association between microbiome structure and mouse age and revealed specific groups of taxa whose abundances stratify young and aged mice. This includes the Ruminococcaceae, Clostridiaceae, and Enterobacteriaceae. We also profiled pro-inflammatory serum MCP-1 levels of each mouse and found that aged mice exhibited elevated serum MCP-1, a phenotype consistent with inflammaging. Robust correlation tests identified several taxa whose abundance in the microbiome associates with serum MCP-1 status, indicating that they may interact with the mouse immune system. We find that taxonomically similar organisms can exhibit differing, even opposite, patterns of association with the host immune system. We also find that many of the OTUs that associate with serum MCP-1 stratify individuals by age. Discussion. Our results demonstrate that gut microbiome composition is associated with age and the pro-inflammatory marker, serum MCP-1. The correlation between age, relative abundance of specific taxa in the gut microbiome, and serum MCP-1 status in mice indicates that the gut microbiome may play a modulating role in age-related inflammatory processes. These findings warrant further investigation of taxa associated with the inflammaging phenotype and the role of gut microbiome in the health status and immune function of aged individuals.
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Affiliation(s)
- Melissa N Conley
- School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States; Center for Health Aging Research, Oregon State University, Corvallis, OR, United States
| | - Carmen P Wong
- School of Biological and Population Health Sciences, Oregon State University , Corvallis, OR , United States
| | - Kyle M Duyck
- Department of Microbiology, Oregon State University , Corvallis, OR , United States
| | - Norman Hord
- School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States; Center for Health Aging Research, Oregon State University, Corvallis, OR, United States
| | - Emily Ho
- School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States; Center for Health Aging Research, Oregon State University, Corvallis, OR, United States; Linus Pauling Institute, Oregon State University, Corvallis, OR, United States; Moore Family Center for Whole Grain Foods, Nutrition and Preventive Health, Oregon State University, Corvallis, OR, United States
| | - Thomas J Sharpton
- Center for Health Aging Research, Oregon State University, Corvallis, OR, United States; Department of Microbiology, Oregon State University, Corvallis, OR, United States; Department of Statistics, Oregon State University, Corvallis, OR, United States
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Sohal RS, Forster MJ. Caloric restriction and the aging process: a critique. Free Radic Biol Med 2014; 73:366-82. [PMID: 24941891 PMCID: PMC4111977 DOI: 10.1016/j.freeradbiomed.2014.05.015] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/16/2014] [Accepted: 05/17/2014] [Indexed: 01/06/2023]
Abstract
The main objective of this review is to provide an appraisal of the current status of the relationship between energy intake and the life span of animals. The concept that a reduction in food intake, or caloric restriction (CR), retards the aging process, delays the age-associated decline in physiological fitness, and extends the life span of organisms of diverse phylogenetic groups is one of the leading paradigms in gerontology. However, emerging evidence disputes some of the primary tenets of this conception. One disparity is that the CR-related increase in longevity is not universal and may not even be shared among different strains of the same species. A further misgiving is that the control animals, fed ad libitum (AL), become overweight and prone to early onset of diseases and death, and thus may not be the ideal control animals for studies concerned with comparisons of longevity. Reexamination of body weight and longevity data from a study involving over 60,000 mice and rats, conducted by a National Institute on Aging-sponsored project, suggests that CR-related increase in life span of specific genotypes is directly related to the gain in body weight under the AL feeding regimen. Additionally, CR in mammals and "dietary restriction" in organisms such as Drosophila are dissimilar phenomena, albeit they are often presented to be the very same. The latter involves a reduction in yeast rather than caloric intake, which is inconsistent with the notion of a common, conserved mechanism of CR action in different species. Although specific mechanisms by which CR affects longevity are not well understood, existing evidence supports the view that CR increases the life span of those particular genotypes that develop energy imbalance owing to AL feeding. In such groups, CR lowers body temperature, rate of metabolism, and oxidant production and retards the age-related pro-oxidizing shift in the redox state.
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Affiliation(s)
- Rajindar S Sohal
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA.
| | - Michael J Forster
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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Spatial reference memory in normal aging Fischer 344 × Brown Norway F1 hybrid rats. Neurobiol Aging 2014; 36:323-33. [PMID: 25086838 DOI: 10.1016/j.neurobiolaging.2014.06.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 06/24/2014] [Accepted: 06/28/2014] [Indexed: 01/01/2023]
Abstract
Fischer 344 × Brown Norway F1 (F344 × BN-F1) hybrid rats express greater longevity with improved health relative to aging rodents of other strains; however, few behavioral reports have thoroughly evaluated cognition across the F344 × BN-F1 lifespan. Consequently, this study evaluated spatial reference memory in F344 × BN-F1 rats at 6, 18, 24, or 28 months of age in the Morris water maze. Reference memory decrements were observed between 6 and 18 months and 18 and 24 months. At 28 months, spatial learning was not worse than 24 months, but swim speed was significantly slower. Reliable individual differences revealed that ∼50% of 24- to 28-month-old rats performed similarly to 6 months, whereas others were spatial learning impaired. Aged rats were impaired at learning within daily training sessions but not impaired at retaining information between days of training. Aged rats were also slower to learn to escape onto the platform, regardless of strategy. In summary, these data clarify the trajectory of cognitive decline in aging F344 × BN-F1 rats and elucidate relevant behavioral parameters.
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Thunhorst RL, Beltz T, Johnson AK. Age-related declines in thirst and salt appetite responses in male Fischer 344×Brown Norway rats. Physiol Behav 2014; 135:180-8. [PMID: 24952266 DOI: 10.1016/j.physbeh.2014.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/28/2014] [Accepted: 06/11/2014] [Indexed: 12/14/2022]
Abstract
The F344×BN strain is the first generational cross between Fischer 344 (F344) and Brown Norway (BN) rats. The F344×BN strain is widely used in aging studies as it is regarded as a model of "healthy" aging (Sprott, 1991). In the present work, male F344×BN rats aged 4mo (young, n=6) and 20mo (old, n=9) received a series of experimental challenges to body fluid homeostasis to determine their thirst and salt appetite responses. Corresponding urinary responses were measured in some of the studies. Following sodium depletion, old rats ingested less saline solution (0.3M NaCl) than young rats on a body weight basis, but both ages drank enough saline solution to completely repair the accrued sodium deficits. Following intracellular dehydration, old rats drank less water than young rats, again on a body weight basis, and were less able than young rats to drink amounts of water proportionate to the osmotic challenge. Compared with young rats, old rats drank less of both water and saline solution after combined food and fluid restriction, and also were refractory to the stimulatory effects of low doses of captopril on water drinking and sodium ingestion. Age differences in urinary water and sodium excretion could not account for the age differences in accumulated water and sodium balances. These results extend observations of diminished behavioral responses of aging animals to the F344×BN rat strain and support the idea that impairments in behavior contribute more to the waning ability of aging animals to respond to body fluid challenges than do declines in kidney function. In addition, the results suggest that behavioral defense of sodium homeostasis is less diminished with age in the F344×BN strain compared to other strains so far studied.
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Affiliation(s)
- Robert L Thunhorst
- Department of Psychology, University of Iowa, Iowa City, IA 52242-1407, United States; The Cardiovascular Center, University of Iowa, Iowa City, IA 52242-1407, United States.
| | - Terry Beltz
- Department of Psychology, University of Iowa, Iowa City, IA 52242-1407, United States
| | - Alan Kim Johnson
- Department of Psychology, University of Iowa, Iowa City, IA 52242-1407, United States; Department of Health and Human Physiology, University of Iowa, Iowa City, IA 52242-1407, United States; Department of Pharmacology, University of Iowa, Iowa City, IA 52242-1407, United States; The Cardiovascular Center, University of Iowa, Iowa City, IA 52242-1407, United States
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Plate JF, Brown PJ, Walters J, Clark JA, Smith TL, Freehill MT, Tuohy CJ, Stitzel JD, Mannava S. Advanced age diminishes tendon-to-bone healing in a rat model of rotator cuff repair. Am J Sports Med 2014; 42:859-68. [PMID: 24500915 DOI: 10.1177/0363546513518418] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Advanced patient age is associated with recurrent tearing and failure of rotator cuff repairs clinically; however, basic science studies have not evaluated the influence of aging on tendon-to-bone healing after rotator cuff repair in an animal model. Hypothesis/ PURPOSE This study examined the effect of aging on tendon-to-bone healing in an established rat model of rotator cuff repair using the aged animal colony from the National Institute on Aging of the National Institutes of Health. The authors hypothesized that normal aging decreases biomechanical strength and histologic organization at the tendon-to-bone junction after acute repair. STUDY DESIGN Controlled laboratory study. METHODS In 56 F344xBN rats, 28 old and 28 young (24 and 8 months of age, respectively), the supraspinatus tendon was transected and repaired. At 2 or 8 weeks after surgery, shoulder specimens underwent biomechanical testing to compare load-to-failure and load-relaxation response between age groups. Histologic sections of the tendon-to-bone interface were assessed with hematoxylin and eosin staining, and collagen fiber organization was assessed by semiquantitative analysis of picrosirius red birefringence under polarized light. RESULTS Peak failure load was similar between young and old animals at 2 weeks after repair (31% vs 26% of age-matched uninjured controls, respectively; P > .05) but significantly higher in young animals compared with old animals 8 weeks after repair (86% vs 65% of age-matched uninjured controls, respectively; P < .01). Eight weeks after repair, fibroblasts appeared more organized and uniformly aligned in young animals on hematoxylin and eosin slides compared with old animals. Collagen birefringence analysis of the tendon-to-bone junction demonstrated that young animals had increased collagen fiber organization and similar histologic structure compared with age-matched controls (53.7 ± 2.4 gray scales; P > .05). In contrast, old animals had decreased collagen fiber organization and altered structure compared with age-matched controls (49.8 ± 3.1 gray scales; P < .01). DISCUSSION In a rat model of aging, old animals demonstrated diminished tendon-to-bone healing after rotator cuff injury and repair. Old animals had significantly decreased failure strength and collagen fiber organization at the tendon-to-bone junction compared with young animals. This study implies that animal age may need to be considered in future studies of rotator cuff repair in animal models. CLINICAL RELEVANCE With increasing age and activity level of the population, the incidence of rotator cuff tears is predicted to rise. Despite advances in rotator cuff repair technique, the retear rate remains specifically high in elderly patients. The findings of this research suggest that aging negatively influences tendon-to-bone healing after rotator cuff repair in a validated animal model.
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Affiliation(s)
- Johannes F Plate
- Johannes F. Plate, Department of Orthopaedic Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA. )
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Ballak SB, Degens H, de Haan A, Jaspers RT. Aging related changes in determinants of muscle force generating capacity: a comparison of muscle aging in men and male rodents. Ageing Res Rev 2014; 14:43-55. [PMID: 24495393 DOI: 10.1016/j.arr.2014.01.005] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 01/20/2014] [Accepted: 01/24/2014] [Indexed: 12/25/2022]
Abstract
Human aging is associated with a progressive decline in skeletal muscle mass and force generating capacity, however the exact mechanisms underlying these changes are not fully understood. Rodents models have often been used to enhance our understanding of mechanisms of age-related changes in human skeletal muscle. However, to what extent age-related alterations in determinants of muscle force generating capacity observed in rodents resemble those in humans has not been considered thoroughly. This review compares the effect of aging on muscle force generating determinants (muscle mass, fiber size, fiber number, fiber type distribution and muscle specific tension), in men and male rodents at similar relative age. It appears that muscle aging in male F344*BN rat resembles that in men most; 32-35-month-old rats exhibit similar signs of muscle weakness to those of 70-80-yr-old men, and the decline in 36-38-month-old rats is similar to that in men aged over 80 yrs. For male C57BL/6 mice, age-related decline in muscle force generating capacity seems to occur only at higher relative age than in men. We conclude that the effects on determinants of muscle force differ between species as well as within species, but qualitatively show the same pattern as that observed in men.
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Affiliation(s)
- Sam B Ballak
- School of Healthcare Science, Cognitive Motor Function Research Group, Manchester Metropolitan University, Manchester M1 5GD, United Kingdom; Laboratory for Myology, Move Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam 1081 BT, The Netherlands.
| | - Hans Degens
- School of Healthcare Science, Cognitive Motor Function Research Group, Manchester Metropolitan University, Manchester M1 5GD, United Kingdom
| | - Arnold de Haan
- School of Healthcare Science, Cognitive Motor Function Research Group, Manchester Metropolitan University, Manchester M1 5GD, United Kingdom; Laboratory for Myology, Move Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam 1081 BT, The Netherlands
| | - Richard T Jaspers
- Laboratory for Myology, Move Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam 1081 BT, The Netherlands
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Plate JF, Wiggins WF, Haubruck P, Scott AT, Smith TL, Saul KR, Mannava S. Normal aging alters in vivo passive biomechanical response of the rat gastrocnemius-Achilles muscle-tendon unit. J Biomech 2012; 46:450-5. [PMID: 23245562 DOI: 10.1016/j.jbiomech.2012.11.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 10/29/2012] [Accepted: 11/01/2012] [Indexed: 10/27/2022]
Abstract
Predisposition to Achilles tendon (AT) ruptures in middle-aged individuals may be associated with age-related changes to inherent passive biomechanical properties of the gastrocnemius-Achilles (GC-AT) muscle-tendon unit, due to known muscle-tendon structural changes in normal aging. The goal of this study was to determine whether the passive biomechanical response of the GC-AT muscle-tendon unit was altered with age in 6 young (8 months) and 6 middle-aged (24 months) F344xBN hybrid rats from the National Institute on Aging colony. Fung's quasilinear viscoelastic (QLV) model was used to determine in vivo history and time-dependent load-relaxation response of the GC-AT. Effective stiffness and modulus were also estimated using linear regression analysis. Fung's QLV revealed a significantly decreased magnitude of the relaxation response (parameter C, p=0.026) in middle-aged animals compared to young animals (0.108±0.007 vs. 0.144±0.015), with similar time-dependent viscous GC-AT properties (τ(1), τ(2)). The product of elastic parameters (A*B), which represents the initial slope of the elastic response, was significantly increased by 50% in middle-aged rats (p=0.014). Estimated GC-AT stiffness increased 28% at peak tensions in middle-aged rats (2.7±0.2 N/mm) compared to young rats (1.9±0.2 N/mm; p=0.036). While the limitations of this animal model must be considered, the changes we describe could be associated with the observation that GC-AT pathology and injury is more common in middle-aged individuals. Further studies are necessary to characterize the load-to-failure behavior of AT in middle-aged compared to young animals.
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Affiliation(s)
- Johannes F Plate
- Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC 27157-1070, USA.
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Gallagher M, Stocker AM, Koh MT. Mindspan: lessons from rat models of neurocognitive aging. ILAR J 2011; 52:32-40. [PMID: 21411856 DOI: 10.1093/ilar.52.1.32] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Research on the biology of aging seeks to enhance understanding of basic mechanisms and thus support improvements in outcomes throughout the lifespan, including longevity itself, susceptibility to disease, and life-long adaptive capacities. The focus of this review is the use of rats as an animal model of cognitive change during aging, and specifically lessons learned from aging rats in behavioral studies of cognitive processes mediated by specialized neural circuitry. An advantage of this approach is the ability to compare brain aging across species where functional homology exists for specific neural systems; in this article we focus on behavioral assessments that target the functions of the medial temporal lobe and prefrontal cortex. We also take a critical look at studies using calorie restriction (CR) as a well-defined experimental approach to manipulating biological aging. We conclude that the effects of CR on cognitive aging in rats are less well established than commonly assumed, with much less supportive evidence relative to its benefits on longevity and susceptibility to disease, and that more research in this area is necessary.
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Affiliation(s)
- Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Ames Hall, 3400 North Charles Street, Baltimore, MD 21218, USA.
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Arvapalli RK, Paturi S, Laurino JP, Katta A, Kakarla SK, Gadde MK, Wu M, Rice KM, Walker EM, Wehner P, Blough ER. Deferasirox decreases age-associated iron accumulation in the aging F344XBN rat heart and liver. Cardiovasc Toxicol 2010; 10:108-16. [PMID: 20229123 DOI: 10.1007/s12012-010-9068-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
It is thought that aging in rats and humans is associated with increases in iron accumulation and cell apoptosis. Here, we examine the relationship between cardiac iron levels and apoptosis in aged F344XBN rats that had been treated with an oral iron chelator (Deferasirox; 100 mg/kg body weight) on alternate days for 6 months. Compared to adult animals (6 month), cardiac iron (+72%), liver iron (+87%), ferritin light chain (+59%), divalent metal transporter-1 (+56%) and the number of TdT-mediated dUTP nick end labeling (TUNEL) positive cells (4.3 fold increase) were higher in 33-month-old animals (P < 0.05). Deferasirox treatment decreased cardiac iron levels by 37% (P < 0.05), and this was associated with decreases in the number of TUNEL-positive cells. Age-associated increases in cell death were coupled with increases in Bax to Bcl-2 ratio, and the amount of Bad, full-length caspase-3, and cleaved caspase-3. Deferasirox treatment decreased the Bax to Bcl-2 ratio by 17% (P < 0.05) and the amount of Bad, full-length caspase-3, cleaved caspase-3 (19 kDa), and cleaved caspase-3 (17 kDa) by 41, 16, 22, and 37%, respectively (P < 0.05). Taken together, these data suggest that deferasirox may be effective in diminishing age-associated iron accumulation and cardiac apoptosis in the F344XBN rat model.
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Affiliation(s)
- Ravi Kumar Arvapalli
- Department of Biological Sciences, Marshall University, Huntington, WV 25755, USA
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Krug AW, Allenhöfer L, Monticone R, Spinetti G, Gekle M, Wang M, Lakatta EG. Elevated mineralocorticoid receptor activity in aged rat vascular smooth muscle cells promotes a proinflammatory phenotype via extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase and epidermal growth factor receptor-dependent pathways. Hypertension 2010; 55:1476-83. [PMID: 20421514 DOI: 10.1161/hypertensionaha.109.148783] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Arterial aging is a predominant risk factor for the onset of cardiovascular diseases, such as hypertension, myocardial infarction, or stroke. Aging is associated with intravascular renin-angiotensin system activation, increased vascular stiffness, intima-media thickening, and a proinflammatory phenotype. Little is known about the influence of aldosterone on arterial aging. Hence, we hypothesized that aldosterone and mineralocorticoid receptor (MR) activation might contribute to and possibly accelerate the arterial aging process. We demonstrate increased MR expression in whole aortae and early passage aortic vascular smooth muscle cells from aged (30 months) compared with adult (8 months) F344XBN rats. Sensitivity to aldosterone-induced extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase activity is increased in aged cells. MR blockade and extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase inhibition prevent age-associated increases of transforming growth factor-beta, intercellular adhesion molecule 1, and procollagen 1. Aldosterone increases expression of proinflammatory marker proteins, shifting the phenotype of adult vascular smooth muscle cells toward the proinflammatory phenotype of aged rats. Epidermal growth factor receptor expression is increased with age and by aldosterone, and inhibition of epidermal growth factor receptor tyrosine kinase decreases age-associated proinflammatory marker expression. Our data support the hypothesis that increased constitutive MR signaling may promote and amplify age-associated inflammation that accompanies arterial aging through increased angiotensin II-stimulated expression of MR and enhanced sensitivity to aldosterone-mediated extracellular signal-regulated kinase 1/2 activation, likely related to increased epidermal growth factor receptor expression.
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Affiliation(s)
- Alexander W Krug
- National Institutes of Health, National Institute on Aging, Laboratory of Cardiovascular Science, Baltimore, MD 21224, USA.
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van der Staay FJ, Schuurman T, van Reenen CG, Korte SM. Emotional reactivity and cognitive performance in aversively motivated tasks: a comparison between four rat strains. BEHAVIORAL AND BRAIN FUNCTIONS : BBF 2009; 5:50. [PMID: 20003525 PMCID: PMC2805679 DOI: 10.1186/1744-9081-5-50] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 12/15/2009] [Indexed: 11/10/2022]
Abstract
BACKGROUND Cognitive function might be affected by the subjects' emotional reactivity. We assessed whether behavior in different tests of emotional reactivity is correlated with performance in aversively motivated learning tasks, using four strains of rats generally considered to have a different emotional reactivity. METHODS The performance of male Brown Norway, Lewis, Fischer 344, and Wistar Kyoto rats in open field (OF), elevated plus-maze (EPM), and circular light-dark preference box (cLDB) tasks, which are believed to provide measures of emotional reactivity, was evaluated. Spatial working and reference memory were assessed in two aversively motivated learning and memory tasks: the standard and the "repeated acquisition" versions of the Morris water maze escape task, respectively. All rats were also tested in a passive avoidance task. At the end of the study, levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid, and 5-HT turnover in the hippocampus and frontal cortex were determined. RESULTS Strain differences showed a complex pattern across behavioral tests and serotonergic measures. Fischer 344 rats had the poorest performance in both versions of the Morris water escape task, whereas Brown Norway rats performed these tasks very well but the passive avoidance task poorly. Neither correlation analysis nor principal component analysis provided convincing support for the notion that OF, EPM, and cLDB tasks measure the same underlying trait. CONCLUSIONS Our findings do not support the hypothesis that the level of emotional reactivity modulates cognitive performance in aversively motivated tasks. Concepts such as "emotional reactivity" and "learning and memory" cannot adequately be tapped with only one behavioral test. Our results emphasize the need for multiple testing.
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Affiliation(s)
- F Josef van der Staay
- Programme Emotion & Cognition, Department of Farm Animal Health, Faculty of Veterinary Medicine, University Utrecht, PO Box 80151, 3508 TD Utrecht, the Netherlands
- BioMedical Research, Wageningen University and Research Center, Lelystad, the Netherlands
- Rudolf Magnus Institute of Neuroscience, Utrecht University, Utrecht, the Netherlands
| | - Teun Schuurman
- BioMedical Research, Wageningen University and Research Center, Lelystad, the Netherlands
| | - Cornelis G van Reenen
- Livestock Research, Wageningen University and Research Center, Lelystad, the Netherlands
| | - S Mechiel Korte
- Programme Emotion & Cognition, Department of Farm Animal Health, Faculty of Veterinary Medicine, University Utrecht, PO Box 80151, 3508 TD Utrecht, the Netherlands
- Department of Psychopharmacology, Utrecht Institute of Pharmaceutical Sciences (UIPS), Utrecht University, Utrecht, the Netherlands
- Rudolf Magnus Institute of Neuroscience, Utrecht University, Utrecht, the Netherlands
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Kasckow J, Xiao C, Herman JP. Glial glucocorticoid receptors in aged Fisher 344 (F344) and F344/Brown Norway rats. Exp Gerontol 2009; 44:335-43. [PMID: 19249343 DOI: 10.1016/j.exger.2009.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 02/04/2009] [Accepted: 02/16/2009] [Indexed: 01/15/2023]
Abstract
Glucocorticoid receptors (GR) regulate glial function, and changes in astrocyte gene expression are implicated in age-related pathology. We evaluated changes in astroglial GR expression in two strains of rats--Fisher 344 (F344; 4, 12 and 24 months) and F344/Brown Norway strain (F344/BN; 4, 12 and 30 months). In both strains basal levels of corticosterone were higher in the oldest groups of rats. Age-related increases in GR (+) astrocytes but not the percent of astrocytes expressing GR were observed in the hippocampus CA1 region in F344 rats. Age-related decreases in CA1 GR (+) astrocytes and the percentage of GR (+) astrocytes were observed in the F344/BN strain only. Similar strain-specific changes were observed in the dentate gyrus. In the hypothalamic paraventricular nucleus: (1) F344 rats exhibited significant decreases in the overall number of glial profiles with age, (2) F344/BN rats exhibited decreases in the numbers of GR (+) astrocytes with aging and (3) the proportion of GR (+) astrocytes decreased in older F344/BN, but not F344 rats. Overall, the data demonstrate age- and strain-related alterations in GR astrocytic expression that may explain unique phenotypic differences in brain function observed in both strains.
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Affiliation(s)
- J Kasckow
- VA Pittsburgh Health Care System (116A), Behavioral Health, 7180 Highland Dr. Pittsburgh, PA 15206, USA.
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Rice KM, Wu M, Blough ER. Aortic aging in the Fischer 344 / NNiaHSd x Brown Norway / BiNia Rat. J Pharmacol Sci 2009; 108:393-8. [PMID: 19098384 DOI: 10.1254/jphs.08r02cp] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Aging is now recognized as one of major risk factors for cardiovascular disease (CVD). It is well documented that elderly populations show increased incidence of CVD symptomology but whether these changes are directly related to aging is not well understood since the possibility exists that other age-associated pathologies in different organ systems could impact on cardiovascular function. Hence, the development of an aging model with reduced systemic illness could invigorate efforts to understand the direct role of aging in CVD progression. The Fischer 344 / NNIaHSD x Brown Norway / BiNia rat (F344BN) has been proposed as a potential model for aging that exhibits reduced systemic pathology and increased longevity compared to other models. Here we examine the current literature regarding the F344BN, focusing on age-associated changes in aortic structure and function.
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Affiliation(s)
- Kevin M Rice
- Department of Biological Sciences, College of Science, Marshall University, USA
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25
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Rönicke R, Schröder UH, Böhm K, Reymann KG. The Na+/H+ exchanger modulates long-term potentiation in rat hippocampal slices. Naunyn Schmiedebergs Arch Pharmacol 2008; 379:233-9. [PMID: 18972102 DOI: 10.1007/s00210-008-0364-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 10/07/2008] [Indexed: 11/30/2022]
Abstract
Although present in great variety in the brain, the role of Na(+)/H(+) exchangers (NHEs) in hippocampal plasticity is still unknown and the effect of NHE inhibition on long-term potentiation (LTP) has not been studied yet. As it is conceivable that NHE inhibitors may severely affect mechanisms that are considered to underlie learning and memory we investigated whether the broad-spectrum NHE inhibitor 5'-(N-ethyl-N-isopropyl)-amiloride (EIPA, 10 microM) influences LTP induced by different stimuli based on a theta burst in interface hippocampus slices from 7-8-week-old Wistar and 30-month-old Fischer 344/Brown-Norway F1 hybrid (F344/BN) rats. EIPA did not affect basal synaptic transmission, paired pulse inhibition, or LTP induced by a weak stimulus, but improved the maintenance of the LTP of the population spike induced by a strong tetanus. Our data suggest that NHE activity serves as a negative feedback mechanism to control neuronal excitability and plasticity in both young and senescent animals.
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Affiliation(s)
- Raik Rönicke
- Project Group Neuropharmacology, Leibniz Institute for Neurobiology, Brenneckestrasse 6., 39118, Magdeburg, Germany.
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26
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Effects of chronic adult dietary restriction on spatial learning in the aged F344 x BN hybrid F1 rat. Physiol Behav 2007; 93:560-9. [PMID: 18035382 DOI: 10.1016/j.physbeh.2007.10.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Revised: 09/09/2007] [Accepted: 10/23/2007] [Indexed: 11/29/2022]
Abstract
Dietary restriction (DR) has been shown to increase life span and reduce disease incidence across a variety of species. Recent research suggests that chronic adult DR may also alter age-related cognitive decline. The purpose of this study was twofold: (1) to examine the potential deficits in spatial learning ability in the aged F344 x BN hybrid F1 rat with specific attention to the contributory effects of motoric impairments and (2) to determine the influence of chronic adult DR on any such impairments. The Morris water maze (MWM) task was employed with a 1.8 m diameter tank, 10 cm2 escape platform, 28 degrees C water, and an automated collapsing central starting platform. Spatial learning impairments in the aged rats were evident on all dependent measures during training and the probe test. Motoric function, as reflected in measures of strength and locomotion demonstrated profound age-related performance impairments that were attenuated by chronic adult DR. The present data also replicate previous reports, indicating that DR attenuates the age-related impairments of performance in the MWM as indexed by the latency measure in acquisition, but critically was dissociated from any DR effect on measures of preference and, more critically, accuracy in the probe test. Collectively, the most parsimonious interpretation of DR effects on MWM performance would appear to be the preservation of motoric, and not cognitive, function.
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27
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Phillips RJ, Powley TL. Innervation of the gastrointestinal tract: patterns of aging. Auton Neurosci 2007; 136:1-19. [PMID: 17537681 PMCID: PMC2045700 DOI: 10.1016/j.autneu.2007.04.005] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Revised: 04/10/2007] [Accepted: 04/24/2007] [Indexed: 12/12/2022]
Abstract
The gastrointestinal (GI) tract is innervated by intrinsic enteric neurons and by extrinsic projections, including sympathetic and parasympathetic efferents as well as visceral afferents, all of which are compromised by age to different degrees. In the present review, we summarize and illustrate key structural changes in the aging innervation of the gut, and suggest a provisional list of the general patterns of aging of the GI innervation. For example, age-related neuronal losses occur in both the myenteric plexus and submucosal plexus of the intestines. These losses start in adulthood, increase over the rest of the life span, and are specific to cholinergic neurons. Parallel losses of enteric glia also occur. The extent of neuronal and glial loss varies along an oral-to-anal gradient, with the more distal GI tract being more severely affected. Additionally, with aging, dystrophic axonal swellings and markedly dilated varicosities progressively accumulate in the sympathetic, vagal, dorsal root, and enteric nitrergic innervation of the gut. These dramatic and consistent patterns of neuropathy that characterize the aging autonomic nervous system of the GI tract are candidate mechanisms for some of the age-related declines in function evidenced in the elderly.
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Affiliation(s)
- Robert J Phillips
- Purdue University, Department of Psychological Sciences, 703 Third Street, West Lafayette, IN 47907-2081, USA.
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28
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Kasckow JW, Segar TM, Xiao C, Furay AR, Evanson NK, Ostrander MM, Herman JP. Stability of neuroendocrine and behavioral responsiveness in aging Fischer 344/Brown-Norway hybrid rats. Endocrinology 2005; 146:3105-12. [PMID: 15831572 DOI: 10.1210/en.2004-1648] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aging in rodents and primates is accompanied by changes in hypothalamic-pituitary-adrenal (HPA) activity. We examined behavioral and neuroendocrine responses in 3, 15-, and 30-month-old F344/Brown-Norway rats. Basal corticosterone and ACTH levels did not differ with age, although ACTH responses, but not corticosterone responses to restraint stress, were significantly lower in the 30-month-old group relative to 3- and 15-month-old rats. Induction of c-fos mRNA in the paraventricular nucleus from restraint was not affected by age. Furthermore, there was an enhanced sensitivity to dexamethasone suppression in aged animals as evidenced by lesser ACTH and corticosterone release after dexamethasone administration. Evaluation of emotional behaviors in the forced swim test revealed no differences between the age groups. With fear conditioning, aged rats had decreased freeze times relative to middle-aged or young rats. Regression analysis revealed no significant correlations between the behavioral and HPA axis data in any group. Overall, the data suggest that an apparent decrease in pituitary drive is compensated for at the level of the adrenal, resulting in stable patterns of glucocorticoid secretion. The lack of a correlation between HPA axis measures and emotional as well as fear conditioning-related behaviors indicates that corticosteroid dysfunction may not predict age-related behavioral deficits in this aging model.
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MESH Headings
- Adrenocorticotropic Hormone/metabolism
- Aging/metabolism
- Aging/psychology
- Animals
- Behavior, Animal
- Conditioning, Psychological
- Corticosterone/metabolism
- Dexamethasone/pharmacology
- Fear
- Glucocorticoids/pharmacology
- Hybridization, Genetic
- Male
- Models, Animal
- Neurosecretory Systems/metabolism
- Paraventricular Hypothalamic Nucleus/metabolism
- Proto-Oncogene Proteins c-fos/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred BN
- Rats, Inbred F344
- Regression Analysis
- Restraint, Physical
- Stress, Physiological/etiology
- Stress, Physiological/metabolism
- Swimming
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Affiliation(s)
- John W Kasckow
- Psychiatry Service, Cincinnati Veterans Affairs Medical Center, Ohio 45220, USA
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29
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Blokland A, Sik A, van der Staay FJ. Delayed non-matching to position performance in aged hybrid Fischer 344 x brown Norway rats: a longitudinal study. Brain Res Bull 2004; 64:39-46. [PMID: 15275955 DOI: 10.1016/j.brainresbull.2004.04.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2004] [Revised: 04/27/2004] [Accepted: 04/28/2004] [Indexed: 11/29/2022]
Abstract
In this study, the effects of aging on the performance in a delayed non-matching to position (DNMTP) task were investigated longitudinally in hybrid Fischer 344 x Brown Norway rats. The rats were first trained to perform the task. Subsequently, their performance was assessed monthly from 28 to 34 months of age. The measures of responding on the DNMTP schedule did not decrease in the course of the study. After the last DNMTP test, choline acetyltransferase (ChAT) activity and glial fibrillary acidic protein (GFAP) content were measured in frontal cortex and hippocampus. We found that higher levels of GFAP in the frontal cortex, but not hippocampus, were associated with a poorer performance in the DNMTP task. Our findings support the notion that repeated testing prevents the age-related decline in cognitive functions that has been reported in cross-sectional studies. Pathology of the frontal cortex seems to predict a faster rate of forgetting in aging rats.
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Affiliation(s)
- Arjan Blokland
- Section of Neurocognition, Faculty of Psychology, Brain and Behavior Institute, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
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Tian Y, Serino R, Verbalis JG. Downregulation of renal vasopressin V2 receptor and aquaporin-2 expression parallels age-associated defects in urine concentration. Am J Physiol Renal Physiol 2004; 287:F797-805. [PMID: 15213068 DOI: 10.1152/ajprenal.00403.2003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Renal concentrating ability is known to be impaired with aging. The antidiuretic hormone AVP plays an important role in renal water excretion by regulating the membrane insertion and abundance of the water channel aquaporin-2 (AQP2); this effect is primarily mediated via the V2 subtype of the AVP receptor (V2R). This study evaluated the hypothesis that decreased renal sensitivity to AVP, with subsequent altered renal AQP2 expression, contributes to the reduced urinary concentrating ability with aging. Our results show that under baseline conditions, urine osmolality is significantly lower in aged Fischer 344 and Brown-Norway F1 hybrid (F344BN) rats despite equivalent plasma AVP concentrations as in young rats. Levels of kidney V2R mRNA expression and AQP2 abundances were also significantly decreased in aged F344BN rats, as was AQP2 immunostaining in collecting duct cells. In response to moderate water restriction, urine osmolality increased by significantly lesser amounts in aged F344BN rats compared with young rats despite similar increases in plasma AVP levels. Moderate water restriction induced equivalent relative increases in renal AQP2 abundances in all age groups but resulted in significantly lower abundances in total kidney AQP2 protein in aged compared with young F344BN rats. These results therefore demonstrate a functional impairment of renal concentrating ability in aged F344BN rats that is not due to impaired secretion of AVP but rather appears to be related to impaired responsiveness of the kidney to AVP that is secondary, at least in part, to a downregulation of renal V2R expression and AQP2 abundance.
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Affiliation(s)
- Ying Tian
- Division of Endocrinology and Metabolism, Department of Medicine, Georgetown University, Washington, DC 20007, USA.
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31
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Abstract
Every living organism is affected by changes as a consequence of aging. Perhaps the most appropriate concept to describe age-related changes is that of 'functional age'. Laboratory rodents are especially suited as models of cognitive aging in humans, because they have a relatively short life-span and because many tests have been developed to investigate their cognitive performance. Examples from studies using the Morris water escape task were chosen to describe and discuss factors which must be considered before drawing conclusions about age-related cognitive deficits. In particular, the roles of rearing and housing conditions, of sensorimotor impairments, and of motivational differences between young and old rats are discussed. Conclusions are drawn about how aging studies should be conceived and performed.
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Affiliation(s)
- F Josef van der Staay
- Cognitive Neurobiology, Institute for Anatomy II, University of Köln, Joseph Stelzmann Str 9, 50931, Cologne, Germany
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32
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Linderman JK, Blough ER. Aging does not attenuate plantaris muscle hypertrophy in male Fischer 344 rats. Med Sci Sports Exerc 2002; 34:1115-9. [PMID: 12131250 DOI: 10.1097/00005768-200207000-00010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The present study examined the effect of extreme old age on the plasticity of the rat plantaris muscle in response to an increase in mechanical load. METHODS Male Fischer 344 rats, aged 7 months (adult) and 25 months (old) underwent bilateral surgical ablation of the gastrocnemius muscle to functionally overload (OV) the fast-twitch plantaris muscle for 8 wk RESULTS At 27 months of age, plantaris wet weight and cross-sectional area (CSA) were unaffected by age, but aging decreased peak isometric tension (Po) 27% (P < 0.05). Plantaris muscle myosin heavy chain composition indicated a loss of faster myosin heavy chains (MHC) isoforms with concomitant increases in slower MHC in old rats (P < 0.05). In adult rats, OV increased muscle CSA and Po 72% and 83%, respectively (P < 0.05). Similarly, OV increased CSA and Po 69% and 73%, respectively, in old rats (P < 0.05). Average fiber CSA increased 57% and 68% in adult-OV and old-OV rats, respectively (P < 0.05). CONCLUSION Collectively, our data indicate that plantaris muscle mass and plasticity in response to increased mechanical load are well conserved in very aged male Fischer 344 rats.
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Affiliation(s)
- Jon K Linderman
- The Laboratory of Basic and Applied Myology, Department of Physical Activity and Educational Services, The Ohio State University, Columbus, OH, USA.
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33
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Hamilton ML, Guo Z, Fuller CD, Van Remmen H, Ward WF, Austad SN, Troyer DA, Thompson I, Richardson A. A reliable assessment of 8-oxo-2-deoxyguanosine levels in nuclear and mitochondrial DNA using the sodium iodide method to isolate DNA. Nucleic Acids Res 2001; 29:2117-26. [PMID: 11353081 PMCID: PMC55450 DOI: 10.1093/nar/29.10.2117] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A major controversy in the area of DNA biochemistry concerns the actual in vivo levels of oxidative damage in DNA. We show here that 8-oxo-2-deoxyguanosine (oxo8dG) generation during DNA isolation is eliminated using the sodium iodide (NaI) isolation method and that the level of oxo8dG in nuclear DNA (nDNA) is almost one-hundredth of the level obtained using the classical phenol method. We found using NaI that the ratio of oxo8dG/10(5 )deoxyguanosine (dG) in nDNA isolated from mouse tissues ranged from 0.032 +/- 0.002 for liver to 0.015 +/- 0.003 for brain. We observed a significant increase (10-fold) in oxo8dG in nDNA isolated from liver tissue after 2 Gy of gamma-irradiation when NaI was used to isolate DNA. The turnover of oxo8dG in nDNA was rapid, e.g. disappearance of oxo8dG in the mouse liver in vivo after gamma-irradiation had a half-life of 11 min. The levels of oxo8dG in mitochondrial DNA isolated from liver, heart and brain were 6-, 16- and 23-fold higher than nDNA from these tissues. Thus, our results showed that the steady-state levels of oxo8dG in mouse tissues range from 180 to 360 lesions in the nuclear genome and from one to two lesions in 100 mitochondrial genomes.
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Affiliation(s)
- M L Hamilton
- Department of Physiology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
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34
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Herman JP, Larson BR, Speert DB, Seasholtz AF. Hypothalamo-pituitary-adrenocortical dysregulation in aging F344/Brown-Norway F1 hybrid rats. Neurobiol Aging 2001; 22:323-32. [PMID: 11182482 DOI: 10.1016/s0197-4580(00)00242-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Hypothalamo-pituitary-adrenocortical (HPA) axis aging was studied in young (3 mo), middle aged (15 mo) and aged (30 mo) F344/Brown Norway hybrid rats. This strain was selected to obviate HPA-relevant pathologies found in other aging models. Aged, unstressed rats showed enhanced central HPA drive, marked by elevated ACTH release and decreased pituitary proopiomelanocortin and corticotropin-releasing factor receptor 1 (CRH-R1) mRNAs. Acute corticosterone responses to spatial novelty were exacerbated in aged rats; however, responses to restraint or hypoxia were not affected. Chronic stress exposure also differentially increased HPA drive in aged animals, marked by elevated paraventricular nucleus CRH peptide levels and pituitary proopiomelanocortin mRNA. Plasma ACTH and pituitary POMC and CRH-R1 mRNA expression in middle-aged rats were intermediate those of young and aged animals. Middle-aged animals responded to chronic stress with disproportionate increases in CRH mRNA levels, and increased corticosterone secretion following hypoxia but not novelty. The results suggest a gradual increase in HPA tone across the aging process, culminating in marked hyperresponsivity to both acute and chronic stress in senescence.
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Affiliation(s)
- J P Herman
- Department of Psychiatry, University of Cincinnati Medical Center, Cincinnati, OH 45267-0559, USA.
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35
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Matsumoto AM, Marck BT, Gruenewald DA, Wolden-Hanson T, Naai MA. Aging and the neuroendocrine regulation of reproduction and body weight. Exp Gerontol 2000; 35:1251-65. [PMID: 11113606 DOI: 10.1016/s0531-5565(00)00158-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Aging in men is associated with a decline in trophic factors such as testosterone (T), alterations in body composition and impaired energy and body weight regulation. We performed studies to investigate the mechanisms underlying age-related changes in the neuroendocrine control of testis function, body composition, food intake and body weight in the Brown Norway (BN) rat. We found that similar to aging men, male BN rats demonstrate both primary and secondary testicular failure with aging without confounding age-related tumors, hormonal changes and systemic illnesses. With aging, these animals have blunted circadian variations in luteinizing hormone (LH) and T, and decreased hypothalamic gonadotropin-releasing hormone (GnRH) synthetic capacity with preserved pituitary gonadotropin responses to GnRH. We found that aging male BN rats have increased peripheral and visceral adiposity associated with increased insulin and leptin levels, and decreased relative lean body mass and muscle mass. We found that these rats exhibit reduced food intake and body weight gain associated with decreased hypothalamic neuropeptide Y (NPY) gene expression in the arcuate nucleus (ARC), both during ad-libitum feeding and after a 72-h fast. Recently, we found that old male BN rats treated chronically with troglitazone, an insulin sensitizer, lowered high insulin and leptin levels, decreased body fat, and corrected the blunted food intake and body weight gain response to fasting without affecting basal ARC NPY gene expression. These findings suggested that hyperinsulinemia and/or hyperleptinemia associated with aging may contribute to the age-related impairment in energy and weight regulation. Our studies suggest that the aging male BN rat is an excellent model to investigate the mechanisms underlying the age-associated changes in the neuroendocrine control of body composition, energy intake and body weight.
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Affiliation(s)
- A M Matsumoto
- Geriatric Research, Education and Clinical Center, V.A. Puget Sound Health Care System, 1660 South Columbian Way (S-182-GRECC), Seattle, WA 98108-1597, USA.
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36
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Gaballa MA, Eckhart AD, Koch WJ, Goldman S. Vascular beta-adrenergic receptor adenylyl cyclase system in maturation and aging. J Mol Cell Cardiol 2000; 32:1745-55. [PMID: 10966835 DOI: 10.1006/jmcc.2000.1210] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to determine how maturation and aging affects beta (beta)-adrenergic receptor (AR) control of arterial vasorelaxation. Left ventricular (LV) hemodynamics and arterial vasorelaxation in thoracic artery segments were studied in Brown Norway, Fisher 344 cross rats at 6 weeks, 6 months, and 23 months of age. We defined changes in maturation as occurring between 6 weeks and 6 months of age and changes in aging as occurring between 6 months and 23 months of age. With maturation, isoproterenol resulted in a downward shift in heart rate and an upward shift in both LV dP/dt and peripheral vascular resistance responses. Similar changes were noted with aging except for the downward shift in LV dP/dt isoproterenol response. There was a dose-dependent increase in arterial vasorelaxation in response to isoproterenol in all age groups, but the 6-week-old animals had a 5-fold (P<0.01) increase in vasorelaxation compared to other age groups. The isoproterenol-induced arterial vasorelaxation response was not altered by removal of the endothelium. The vasodilatory responses to nitroglycerin, acetylcholine, and adenosine were diminished (P<0.05) with aging. The vasorelaxation responses to forskolin and IBMX were unchanged with maturation and diminished with aging. Incubation of arterial rings in cholera toxin resulted in a reduction in relaxation only in arteries from 6-week-old rats. Maturation resulted in no change in beta -AR density [20.2+/-0.7 v. 18.5+/-0.5 fmol/mg protein, P=n.s., 6 weeks (n=2, 18 aortas were combined v 6-month-old rats)]. With maturation, there was no change in G alpha(i)level. However, beta ARK1 levels were increased (55. 4+/-2.1 v. 40.8+/-0.4, arbitrary densitometry units) and G alpha(s)levels were decreased (29.5+/-0.8 v. 49.9+/-1.9, arbitrary densitometry units). Aging resulted in no change in beta -AR density (15.3+/-1.7 v. 18.5+/-0.5 fmol/mg membrane protein), but decreases in basal, isoproterenol-, naF-, and forskolin-stimulated AC activities. Compared to 6 week data, 23-month-old rats exhibited no change in either G alpha(i)or beta ARK1, however, G alpha(s) was decreased. In summary, beta -AR-stimulated arterial vasorelaxation is depressed during maturation and aging. Since there is no change in beta -AR density but a decrease in G alpha(s)and in basal/stimulated AC activities, the defect in beta -AR signaling during maturation and aging is probably a post receptor defect, i.e. possibly in the receptor-G protein coupling.
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Affiliation(s)
- M A Gaballa
- Departments of Internal Medicine, Veterans Administration Medical Center and University of Arizona Sarver Heart Center, Tucson, AZ, USA.
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37
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Blough ER, Linderman JK. Lack of skeletal muscle hypertrophy in very aged male Fischer 344 x Brown Norway rats. J Appl Physiol (1985) 2000; 88:1265-70. [PMID: 10749817 DOI: 10.1152/jappl.2000.88.4.1265] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To examine the effect of extreme old age on muscle plasticity, 6- (adult) and 36-mo-old (old) male Fischer 344 x Brown Norway hybrid rats underwent bilateral surgical ablation of the gastrocnemius muscle to functionally overload (OV) the fast-twitch plantaris muscle for 8 wk. Plantaris muscle wet weight, muscle cross-sectional area (CSA), and average fiber CSA decreased by 44, 42, and 40%, respectively, in old compared with adult rats, and peak isometric tetanic tension decreased by 83%. Compared with muscles in age-matched controls, plantaris muscle mass increased by 53% and type I, IIA, and IIX/IIB CSA increased by 91, 76, and 103%, respectively, in adult-OV rats, but neither wet mass nor fiber CSA increased in old-OV rats. OV decreased type I, IIA, and IIX/IIB mean fiber CSA by 31, 35, and 30%, respectively, in old-OV rats. Collectively, our data indicate that in extreme old age the plantaris muscle undergoes significant loss of mass, fiber CSA, and contractile function, as well as its capacity to undergo hypertrophy in response to a chronic increase in mechanical load.
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Affiliation(s)
- E R Blough
- Laboratory of Basic and Applied Myology, School of Physical Activity and Educational Services, Ohio State University, Columbus, Ohio 43210-1284, USA
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38
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Affiliation(s)
- D R Wallace
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tulsa, Oklahoma 74107-1898, USA
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39
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Perron JT, Tyson RL, Sutherland GR. Maintenance of tricarboxylic acid cycle kinetics in Brown-Norway Fischer 344 rats may translate to longevity. Neurosci Lett 2000; 281:91-4. [PMID: 10704750 DOI: 10.1016/s0304-3940(00)00825-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Glucose metabolism and tricarboxylic acid cycle (TCA) kinetics have been shown to decline in brain with age in various animal species. This study examined TCA cycle kinetics and age in Brown-Norway Fischer 344 rats. Using [1-(13)C]glucose infused over 10, 30, 60 or 100 min, and following the label through the TCA cycle using (1)H¿(13)C¿ spin-echo difference magnetic resonance spectroscopy, groups of 2 (n=18), 12 (n=16), and 24 (n=16) month old rats were evaluated. Unexpectedly, TCA cycle kinetics did not change with age. Observed decreases in glutamate, glutamine and N-acetyl aspartate levels are consistent with an age-related decrease in neuronal numbers. The possible link between this observation and increased longevity, together with a decreased incidence of neoplasia in the Brown-Norway Fischer 344 rat is discussed.
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Affiliation(s)
- J T Perron
- Seaman Family MR Research Center and the Department of Clinical Neurosciences, University of Calgary, Foothills Hospital, 1403-29 Street NW, Calgary, Alberta, Canada
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Eijkenboom M, Gerlach I, Jork R, Lowe D, van der Staay FJ. Effects of subdural haematoma on sensorimotor functioning and spatial learning in rats. Neuropharmacology 2000; 39:817-34. [PMID: 10699447 DOI: 10.1016/s0028-3908(00)00002-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Twenty per cent of all strokes are haemorrhagic in character and are associated with severe disturbances in sensorimotor behaviour and cognition. Although spontaneous recovery of pre-stroke functioning occurs in some cases, the process is demanding, slow, and often incomplete. A first step in the preclinical testing of new putative, neuroprotective and recovery-supporting therapeutics is to validate animal models of brain injury. In a series of four experiments we evaluated the behavioural impairments and the time course of recovery of functional deficits in rats with an experimentally induced subdural haematoma. We found that unilateral subdural haematoma resulted in dysfunction in both simple reflexive (experiment 1) and skilled sensorimotor behaviour (experiment 2). Reflexive behaviour did not recover, or recovered only marginally, and neither did the deficits in skilled forepaw use. Bilateral subdural haematoma impaired the learning and memory performance of adult (experiment 3) and old rats (experiment 4) in the Morris water escape task. Considering the diversity of the deficits found in our experiments, we conclude that different models are needed to cover the broad range of deficits seen in stroke patients.
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MESH Headings
- Age Factors
- Animals
- Behavior, Animal/physiology
- Corpus Callosum/pathology
- Crosses, Genetic
- Disease Models, Animal
- Escape Reaction/physiology
- Forelimb/physiology
- Hematoma, Subdural, Acute/pathology
- Hematoma, Subdural, Acute/physiopathology
- Hindlimb/physiology
- Male
- Maze Learning/physiology
- Motor Cortex/pathology
- Motor Cortex/physiopathology
- Psychomotor Performance/physiology
- Rats
- Rats, Inbred BN
- Rats, Inbred F344
- Rats, Wistar
- Reaction Time/physiology
- Reflex/physiology
- Somatosensory Cortex/pathology
- Somatosensory Cortex/physiopathology
- Space Perception
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Affiliation(s)
- M Eijkenboom
- CNS Research, Bayer AG, Pharma Research Center, Building 500, Aprather Weg 18a, D-42096, Wuppertal, Germany
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41
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Abstract
Genetic conceptualizations and procedures have become integral to the conduct of research across the spectrum of life sciences, including gerontology, even when genetics is not the focus of inquiry. Among the research tools thus provided, one of the most basic is that of inbred strains. A close approximation to genetic uniformity is achieved by a sufficient number of successive generations of matings of relatives, and, once this near-uniformity is attained, the members of an inbred strain constitute a reference group relatively stable over time and available to diverse investigators. Different inbred strains possess different genotypes, so that numerous distinctive reference groups are available. The stability of these groups enhances prospects of replication-testing, and makes possible the focused accumulation of pertinent data. Phenotypic differences among strains identify particular groups that can be most appropriate for particular subsequent research objectives (and also provide ipso facto evidence of genetic influence on the phenotype). The very substantial advantages of the uniform genotypes provided by inbred strains (and by their F1 offspring) are purchased at the cost of limited generalizability of results and constraints on assessment of co-variation among variables. Uniform genotypes are, thus, not a tool for all purposes but must be seen as a powerful basic tool within an abundant genetic tool-kit. Particular research purposes will require use of more than one tool from the kit.
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Affiliation(s)
- G E McClearn
- Center for Developmental and Health Genetics, The Pennsylvania State University, University Park 16802, USA
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Yurek DM, Hipkens SB, Hebert MA, Gash DM, Gerhardt GA. Age-related decline in striatal dopamine release and motoric function in brown Norway/Fischer 344 hybrid rats. Brain Res 1998; 791:246-56. [PMID: 9593919 DOI: 10.1016/s0006-8993(98)00110-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Brown Norway/Fischer 344 F1 hybrid rats (F344BNF1) is a newer rat model and is emerging as an important rodent model of aging. In the present study we used motoric performance tests, intracerebral microdialysis, and neurochemical measures of postmortem brain tissue to investigate the effects of aging in young (4-5 months), middle-aged (18-19), and old (24-25 months) F344BNF1 hybrid rats. We observed that old F344BNF1 rats exhibited decreased motoric performance, and lower levels of spontaneous and d-amphetamine-induced locomotor activity than those observed in young F344BNF1 rats. Microdialysis measures of extracellular basal levels of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), and 4-hydroxy-3-methoxyphenylacetic acid (HVA) were significantly diminished in the striata of the middle-aged and old rats as compared to levels in young animals. In addition, d-amphetamine-evoked overflow of DA was significantly decreased in the middle-aged and aged rat striatum as compared to DA overflow in young F344BNF1 rats. Studies of postmortem brain tissue showed that the changes in overflow of DA correlated with significantly lower DA tissue content in ventral striatum and midbrain. Moreover, both dopamine turnover ratios (DOPAC/DA, HVA/DA) and the serotonin turnover ratio (5-HIAA/5-HT) were significantly elevated in the ventral striatum and nucleus accumbens. The results of this study demonstrate a correlation between reductions in striatal DA neurochemistry and diminished motor function in aged F344BNF1 rats.
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Affiliation(s)
- D M Yurek
- Department of Surgery/Neurosurgery, University of Kentucky College of Medicine, Lexington, KY 40536, USA.
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43
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Yu HJ, Levin RM, Longhurst PA, Damaser MS. Effect of age and outlet resistance on rabbit urinary bladder emptying. J Urol 1997; 158:924-30. [PMID: 9258120 DOI: 10.1097/00005392-199709000-00073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To investigate the influence of age and effect of increased outlet resistance on the ability of rabbit bladders to empty in response to various methods of stimulation. MATERIALS AND METHODS Bladders from six-month-old (young) and three-year-old rabbits (aged) were mounted in an in vitro whole organ bath system and filled with 15 ml. saline. The ability of the bladders to empty against low outlet resistance (LOR) and high outlet resistance (HOR) in response to field stimulation, bethanechol, and KCl was measured. The following parameters were measured: intravesical pressure and volume emptied. From these, flow rate, power, and external mechanical work were calculated. RESULTS Maximum isometric pressure did not change with age. All bladders emptied with increased pressure and decreased flow rate at HOR. The young bladders generated a greater maximum power in response to bethanechol and KCl than the aged bladders at both outlet resistances, and maximum power did not change with increased resistance. The aged bladders did less work and emptied significantly less than the young bladders at the HOR. CONCLUSIONS The aged rabbit bladders were unable to maintain the bladder contraction long enough to empty completely through an increased outlet resistance. Because maximum power remained constant when the outlet resistance was increased, it might be useful clinically to determine the emptying ability of the urinary bladder, independent of changes in outlet resistance. In addition, bladder work could be used to evaluate bladder function if the volume emptied is also taken into consideration.
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Affiliation(s)
- H J Yu
- Division of Urology, University of Pennsylvania School of Medicine, Philadelphia, USA
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Yu HJ, Levin RM, Longhurst PA, Damaser MS. Effect of Age and Outlet Resistance on Rabbit Urinary Bladder Emptying. J Urol 1997. [DOI: 10.1016/s0022-5347(01)64365-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Hong-Jeng Yu
- From the Division of Urology, University of Pennsylvania School of Medicine and the Philadelphia Veteran's Administration Medical Center, Philadelphia, Pennsylvania, and the Departments of Physiology and Urology, Medical College of National Taiwan University, Taipei, Taiwan
| | - Robert M. Levin
- From the Division of Urology, University of Pennsylvania School of Medicine and the Philadelphia Veteran's Administration Medical Center, Philadelphia, Pennsylvania, and the Departments of Physiology and Urology, Medical College of National Taiwan University, Taipei, Taiwan
| | - Penelope A. Longhurst
- From the Division of Urology, University of Pennsylvania School of Medicine and the Philadelphia Veteran's Administration Medical Center, Philadelphia, Pennsylvania, and the Departments of Physiology and Urology, Medical College of National Taiwan University, Taipei, Taiwan
| | - Margot S. Damaser
- From the Division of Urology, University of Pennsylvania School of Medicine and the Philadelphia Veteran's Administration Medical Center, Philadelphia, Pennsylvania, and the Departments of Physiology and Urology, Medical College of National Taiwan University, Taipei, Taiwan
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45
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Abstract
In the past, structural changes in the brain with aging have been studied using a variety of animal models, with rats and nonhuman primates being the most popular. With the rapid evolution of mouse genetics, murine models have gained increased attention in the neurobiology of aging. The genetic contribution of age-related traits as well as specific mechanistic hypotheses underlying brain aging and age-related neurodegenerative diseases can now be assessed by using genetically-selected and genetically-manipulated mice. Against this background of increased demand for aging research in mouse models, relatively few studies have examined structural alterations with aging in the normal mouse brain, and the data available are almost exclusively restricted to the C57BL/6 strain. Moreover, many older studies have used quantitative techniques which today can be questioned regarding their accuracy. Here we review the state of knowledge about structural changes with aging in outbred, inbred, genetically-selected, and genetically-engineered murine models. Moreover, we suggest several new opportunities that are emerging to study brain aging and age-related neurodegenerative diseases using genetically-defined mouse models. By reviewing the literature, it has become clear to us that in light of the rapid progress in genetically-engineered and selected mouse models for brain aging and age-related neurodegenerative diseases, there is a great and urgent need to study and define morphological changes in the aging brain of normal inbred mice and to analyze the structural changes in genetically-engineered mice more carefully and completely than accomplished to date. Such investigations will broaden knowledge in the neurobiology of aging, particularly regarding the genetics of aging, and possibly identify the most useful murine models.
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Affiliation(s)
- M Jucker
- Gerontology Research Centre, Nathan W. Shock Laboratories, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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Wallace DR, Booze RM. Dopamine D3 receptor density elevation in aged Fischer-344 x Brown-Norway (F1) rats. Eur J Pharmacol 1996; 308:283-5. [PMID: 8858300 DOI: 10.1016/0014-2999(96)00354-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The density of dopamine D3 receptors was determined in young (4-month-old) and aged (37-month-old) Fischer-344 x Brown-Norway (F1) male rats using the putative D3 receptor-preferring agonist, [3H](+)-7.hydroxy-2-(N,N-di-n-propylamino)tetralin ([3H](+)-7-OH-DPAT). In the presence of the non-hydrolyzable GTP analog, 5'-guanylylimidodiphosphate (Gpp(NH)p), the density of dopamine D3 receptors in the striatum and nucleus accumbens was significantly increased (29-102%, respectively) in aged Fischer-344 x Brown-Norway (F1) rats compared to young adults. These findings suggest that dopaminergic activity in aged rats is compromised by increased D3 receptor density, resulting in altered striatal/nucleus accumbens function via presynaptic or postsynaptic modifications.
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Affiliation(s)
- D R Wallace
- University of Kentucky Medical Center, Department of Pharmacology, Lexington 40536-0084, USA
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47
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Tanhauser SM, Laipis PJ. Multiple deletions are detectable in mitochondrial DNA of aging mice. J Biol Chem 1995; 270:24769-75. [PMID: 7559594 DOI: 10.1074/jbc.270.42.24769] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Mutational damage to human mitochondrial DNA (mtDNA) can cause disorders in oxidative phosphorylation; speculation that such damage is involved in degenerative diseases and aging is common. We have detected deletions in mouse mtDNA which resemble those found in elderly humans or patients with certain mtDNA disorders. Five different mtDNA deletions, predicted from the positions of short, direct DNA repeats, were present in aged, but not young, mice. Deleted regions were surrounded by either exact or inexact repeats and occurred in both the major and minor regions of the mtDNA genome. The abundance of a particular deletion was generally related to the thermodynamic stability of the bounding repeat sequence. Deletions in aged mice were present at low levels (less than 0.01% of total mtDNA). However, in contrast to results from aged humans, deletions were more abundant in liver than in brain, heart, or skeletal muscle. These results make it possible to predict the location and relative abundance of deletions in any sequenced mtDNA, including inbred mouse strains differing in inherent natural lifespan. The inbred mouse model will allow a critical examination of the relationship between the presence and abundance of mtDNA deletions and the aging process.
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Affiliation(s)
- S M Tanhauser
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville 32610, USA
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48
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Spangler EL, Waggie KS, Rea W, Roberts D, Hengemihle J, Danon D, Ingram DK. Relationship of hematological variables to learning performance in aged Fischer-344 rats. Neurobiol Aging 1995; 16:85-9. [PMID: 7723940 DOI: 10.1016/0197-4580(95)80011-f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The relationship between hematological variables and the ability to perform behaviorally in two learning tests was evaluated in male F344 rats aged 22-24 months. Rats were screened for ability to meet criterion for learning one-way active avoidance in a straight runway task. Rats failing to meet criterion were given no further testing and were assigned to Group 1 (G1). Rats meeting criterion were tested in a 14-unit T-maze (2 days, 10 trials/day). Failure to negotiate the T-maze within 600 s on any three trials resulted in assignment to Group 2 (G2) with no further testing. Rats successfully completing both tasks constituted Group 3 (G3). Trunk blood was collected following behavioral testing and was assayed to determine red blood cell count (RBC), hematocrit (HCT), hemoglobin (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white blood cell count (WBC), bands (BND), polymorphs (POLY), lymphocytes (LYM), monocytes (MON), and eosinophils (EOS). The combined G1/G2 group had significantly lower RBC, HCT, HGB, and EOS but significantly higher MCV and MCH than G3 rats. Correlation analysis revealed a positive relationship of group membership (i.e., learning test completion) to RBC, HCT, HGB, and EOS, but a negative correlation of group membership to MCH. No significant correlation emerged between any hematological characteristic and performance in either behavioral task. These results suggest that a simple blood test to determine HCT may be a useful screen for removal of moribund rats from aging studies attempting to control for effects of health on behavioral performance in rodent models.
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Affiliation(s)
- E L Spangler
- Molecular Physiology and Genetics Section, Laboratory of Cellular and Molecular Biology, Gerontology Research Center (NIA, NIH), Baltimore, MD 21224, USA
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49
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Lai CC, Andrus PK, Chiu TH. Hydroxyl radical generation and nitric oxide synthase activity in Fisher 344 x brown-Norway F1 rat brain. Neurosci Lett 1994; 179:37-40. [PMID: 7531314 DOI: 10.1016/0304-3940(94)90929-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Hydroxyl radical production in the cerebral cortex, striatum and hippocampus of young (6 months), middle-aged (15 months) and old (28 months) Fisher 344 x Brown-Norway F1 rats was quantitated by measuring the salicylate hydroxyl radical-trapping product, 2,5-dihydroxybenzoic acid. The levels of hydroxyl radical between different age groups in each region examined were not statistically different. In all regions, with the exception of hippocampus from old rats which had a lower content of hydroxyl radical, the levels of hydroxyl radical were higher for middle-aged and old rats than young ones. There was no regional difference in the production of hydroxyl radicals, except that the level was significantly higher in striatum than in cortex for 15-month-old rats. The cerebral cortical nitric oxide synthase activities were similar in the three age groups studied.
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Affiliation(s)
- C C Lai
- Department of Pharmacology, Medical College of Ohio, Toledo 43699-0008
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50
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DiLoreto D, Cox C, Grover DA, Lazar E, del Cerro C, del Cerro M. The influences of age, retinal topography, and gender on retinal degeneration in the Fischer 344 rat. Brain Res 1994; 647:181-91. [PMID: 7922494 DOI: 10.1016/0006-8993(94)91316-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The Fischer 344 (F344) rat is presently the animal of choice for age-related research. The existence of an age-related retinal degeneration was reported previously in the males of this strain, but a gender comparison has not been performed. In this study, histological and morphometric measurements of the retina related to age, retinal topography, and gender were made on 3- to 24-month-old animals. The thicknesses of the outer nuclear layer (ONL) and the photoreceptor layer (PRL) were measured from sagittal sections at six loci. Retinas of both sexes showed steady decline with age in the thicknesses of the ONL and PRL at all locations. An important finding was the presence, after 12 months of age, of a drastically accelerated rate of peripheral retinal degeneration seen only in male subjects. Females showed a less dramatic rate of peripheral degeneration which did not begin until after 18 months of age. In addition, two other forms of retinal degeneration were found--cystoid degeneration was found earlier and more frequently in the male, while a paving-stone type of degeneration was found in both sexes. These two types of lesions were preferentially, but not exclusively found in the peripheral retina. In conclusion, the F344 rat offers a convenient model to study a pattern of retinal degeneration affected by the combination of gender, regional and age-related factors.
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Affiliation(s)
- D DiLoreto
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine, NY 14642
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