1
|
Baidoo N, Sanger GJ. The human colon: Evidence for degenerative changes during aging and the physiological consequences. Neurogastroenterol Motil 2024:e14848. [PMID: 38887160 DOI: 10.1111/nmo.14848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 04/16/2024] [Accepted: 06/05/2024] [Indexed: 06/20/2024]
Abstract
BACKGROUND The incidence of constipation increases among the elderly (>65 years), while abdominal pain decreases. Causes include changes in lifestyle (e.g., diet and reduced exercise), disease and medications affecting gastrointestinal functions. Degenerative changes may also occur within the colo-rectum. However, most evidence is from rodents, animals with relatively high rates of metabolism and accelerated aging, with considerable variation in time course. In humans, cellular and non-cellular changes in the aging intestine are poorly investigated. PURPOSE To examine all available studies which reported the effects of aging on cellular and tissue functions of human isolated colon, noting the region studied, sex and age of tissue donors and study size. The focus on human colon reflects the ability to access full-thickness tissue over a wide age range, compared with other gastrointestinal regions. Details are important because of natural human variability. We found age-related changes within the muscle, in the enteric and nociceptor innervation, and in the submucosa. Some involve all regions of colon, but the ascending colon appears more vulnerable. Changes can be cell- and sublayer-dependent. Mechanisms are unclear but may include development of "senescent-like" and associated inflammaging, perhaps associated with increased mucosal permeability to harmful luminal contents. In summary, reduced nociceptor innervation can explain diminished abdominal pain among the elderly. Degenerative changes within the colon wall may have little impact on symptoms and colonic functions, because of high "functional reserve," but are likely to facilitate the development of constipation during age-related challenges (e.g., lifestyle, disease, and medications), now operating against a reduced functional reserve.
Collapse
Affiliation(s)
- Nicholas Baidoo
- School of Life Sciences, University of Westminster, London, UK
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Gareth J Sanger
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| |
Collapse
|
2
|
Chang DS, Soni KG, Preidis GA. Smooth muscle contractile responses to bile acids in mouse ileum require TGR5 but not ASBT. Front Neurol 2024; 15:1334319. [PMID: 38721114 PMCID: PMC11076673 DOI: 10.3389/fneur.2024.1334319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 03/08/2024] [Indexed: 05/12/2024] Open
Abstract
Background Many disorders of gut-brain interaction (DGBIs) are more prevalent in women than men and feature alterations in gastrointestinal motility and bile acid homeostasis. Mechanisms by which bile acids regulate gastrointestinal motility are poorly characterized. We recently validated an adapted tissue bath technique using everted mouse ileum, which revealed differential contractile responses to ursodeoxycholic acid (UDCA) and deoxycholic acid (DCA). Here, we aimed to determine whether these responses are dependent on host sex, the plasma membrane bile acid receptor TGR5, or the apical sodium-dependent bile acid transporter ASBT. Methods Ileal segments from male and female mice were everted and suspended in tissue baths. Contractile responses to physiologic concentrations of UDCA and DCA were quantified with or without TGR5 or ASBT inhibitors. Phosphorylation of extracellular signal-regulated kinase (ERK) and myosin light chain (MLC), markers of TGR5 activation and smooth muscle contraction, respectively, were assessed with western blot. Results There were no sex differences in the dose-dependent contractile responses to bile acids. At 100 μmol/L, UDCA but not DCA increased MLC phosphorylation and increased contractility. TGR5 inhibition decreased ERK phosphorylation and led to decreases in contractility, phosphorylated MLC, and surprisingly, total MLC. ASBT inhibition did not affect contractile responses. Conclusion Differential effects of UDCA and DCA on ileal smooth muscle contractility are not dependent on host sex or ASBT-mediated transport. Bile acids signal through mucosal TGR5, which regulates smooth muscle contractility by complex mechanisms. Understanding how bile acids differentially regulate gastrointestinal motility could facilitate new therapeutic options for specific DGBIs.
Collapse
Affiliation(s)
| | | | - Geoffrey A. Preidis
- Division of Gastroenterology, Hepatology & Nutrition, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, TX, United States
| |
Collapse
|
3
|
Gałęcka I, Szyryńska N, Całka J. Influence of polyethylene terephthalate (PET) microplastic on selected active substances in the intramural neurons of the porcine duodenum. Part Fibre Toxicol 2024; 21:5. [PMID: 38321545 PMCID: PMC10845528 DOI: 10.1186/s12989-024-00566-w] [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: 06/18/2023] [Accepted: 01/29/2024] [Indexed: 02/08/2024] Open
Abstract
BACKGROUND Currently, society and industry generate huge amounts of plastics worldwide. The ubiquity of microplastics is obvious, but its impact on the animal and human organism remains not fully understood. The digestive tract is one of the first barriers between pathogens and xenobiotics and a living organism. Its proper functioning is extremely important in order to maintain homeostasis. The aim of this study was to determine the effect of microplastic on enteric nervous system and histological structure of swine duodenum. The experiment was carried out on 15 sexually immature gilts, approximately 8 weeks old. The animals were randomly divided into 3 study groups (n = 5/group). The control group received empty gelatin capsules once a day for 28 days, the first research group received daily gelatin capsules with polyethylene terephthalate (PET) particles as a mixture of particles of various sizes (maximum particle size 300 µm) at a dose of 0.1 g/animal/day. The second study group received a dose ten times higher-1 g/animal/day. RESULTS A dose of 1 g/day/animal causes more changes in the enteric nervous system and in the histological structure of duodenum. Statistically significant differences in the expression of cocaine and amphetamine regulated transcript, galanin, neuronal nitric oxide synthase, substance P, vesicular acetylcholine transporter and vasoactive intestinal peptide between control and high dose group was noted. The histopathological changes were more frequently observed in the pigs receiving higher dose of PET. CONCLUSION Based on this study it may be assumed, that oral intake of microplastic might have potential negative influence on digestive tract, but it is dose-dependent.
Collapse
Affiliation(s)
- Ismena Gałęcka
- Department of Epizootiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719, Olsztyn, Poland.
- Deparment of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719, Olsztyn, Poland.
| | - Natalia Szyryńska
- Department of Histology and Embryology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719, Olsztyn, Poland
| | - Jarosław Całka
- Deparment of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719, Olsztyn, Poland
| |
Collapse
|
4
|
McVey Neufeld KA, Mao YK, West CL, Ahn M, Hameed H, Iwashita E, Stanisz AM, Forsythe P, Barbut D, Zasloff M, Kunze WA. Squalamine reverses age-associated changes of firing patterns of myenteric sensory neurons and vagal fibres. Commun Biol 2024; 7:80. [PMID: 38200107 PMCID: PMC10781697 DOI: 10.1038/s42003-023-05623-2] [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: 05/01/2023] [Accepted: 11/21/2023] [Indexed: 01/12/2024] Open
Abstract
Vagus nerve signaling is a key component of the gut-brain axis and regulates diverse physiological processes that decline with age. Gut to brain vagus firing patterns are regulated by myenteric intrinsic primary afferent neuron (IPAN) to vagus neurotransmission. It remains unclear how IPANs or the afferent vagus age functionally. Here we identified a distinct ageing code in gut to brain neurotransmission defined by consistent differences in firing rates, burst durations, interburst and intraburst firing intervals of IPANs and the vagus, when comparing young and aged neurons. The aminosterol squalamine changed aged neurons firing patterns to a young phenotype. In contrast to young neurons, sertraline failed to increase firing rates in the aged vagus whereas squalamine was effective. These results may have implications for improved treatments involving pharmacological and electrical stimulation of the vagus for age-related mood and other disorders. For example, oral squalamine might be substituted for or added to sertraline for the aged.
Collapse
Affiliation(s)
| | - Yu-Kang Mao
- Brain-Body Institute, McMaster University, Hamilton, ON, Canada
| | - Christine L West
- Brain-Body Institute, McMaster University, Hamilton, ON, Canada
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Matthew Ahn
- Brain-Body Institute, McMaster University, Hamilton, ON, Canada
| | - Hashim Hameed
- Brain-Body Institute, McMaster University, Hamilton, ON, Canada
| | - Eiko Iwashita
- Brain-Body Institute, McMaster University, Hamilton, ON, Canada
| | | | - Paul Forsythe
- Department of Medicine, 569 Heritage Medical Research Center, University of Alberta, Edmonton, AB, Canada
| | | | - Michael Zasloff
- Enterin, Inc., Philadelphia, PA, USA.
- MedStar-Georgetown Transplant Institute, Georgetown University School of Medicine, Washington, DC, USA.
| | - Wolfgang A Kunze
- Brain-Body Institute, McMaster University, Hamilton, ON, Canada.
- Department of Biology, McMaster University, Hamilton, ON, Canada.
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada.
| |
Collapse
|
5
|
López-Tofiño Y, Barragán del Caz LF, Benítez-Álvarez D, Molero-Mateo P, Nurgali K, Vera G, Bagües A, Abalo R. Contractility of isolated colonic smooth muscle strips from rats treated with cancer chemotherapy: differential effects of cisplatin and vincristine. Front Neurosci 2023; 17:1304609. [PMID: 38192512 PMCID: PMC10773793 DOI: 10.3389/fnins.2023.1304609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/27/2023] [Indexed: 01/10/2024] Open
Abstract
Background Certain antineoplastic drugs cause gastrointestinal disorders even after the end of treatment. Enteric neuropathy has been associated with some of these alterations. Our goal was to assess the impact of repeated treatment with cisplatin and vincristine on the contractility of circular and longitudinal muscle strips isolated from the rat colon. Methods Two cohorts of male rats were used: in cohort 1, rats received one intraperitoneal (ip) injection of saline or cisplatin (2 mg kg-1 week-1) on the first day of weeks 1-5; in cohort 2, rats received two cycles of five daily ip injections (Monday to Friday, weeks 1-2) of saline or vincristine (0.1 mg kg-1 day-1). Body weight and food and water intake were monitored throughout the study. One week after treatment, responses of colonic smooth muscle strips to acetylcholine (10-9-10-5 M) and electrical field stimulation (EFS, 0.1-20 Hz), before and after atropine (10-6 M), were evaluated in an organ bath. Results Both drugs decreased body weight gain. Compared to saline, cisplatin significantly decreased responses of both longitudinal and circular smooth muscle strips to EFS, whereas vincristine tended to increase them, although in a non-significant manner. No differences were observed in the muscle response to acetylcholine. Atropine abolished the contractile responses induced by acetylcholine, although those induced by EFS were only partially reduced in the presence of atropine. Conclusion The findings suggest that although both drugs cause the development of enteric neuropathy, this seems to have a functional impact only in cisplatin-treated animals. Understanding the effects of chemotherapy on gastrointestinal motor function is vital for enhancing the quality of life of cancer patients.
Collapse
Affiliation(s)
- Yolanda López-Tofiño
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
- International Doctoral School, URJC, Móstoles, Spain
| | | | - David Benítez-Álvarez
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
| | - Paula Molero-Mateo
- International Doctoral School, URJC, Móstoles, Spain
- Lescer Center (Neurological Rehabilitation), Madrid, Spain
- Department of Physiotherapy, Occupational Therapy, Rehabilitation and Physical Medicine, URJC, Alcorcón, Spain
| | - Kulmira Nurgali
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
- Department of Medicine Western Health, The University of Melbourne, Melbourne, VIC, Australia
- Regenerative Medicine and Stem Cell Program, Australian Institute for Musculoskeletal Science (AIMSS), Melbourne, VIC, Australia
| | - Gema Vera
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
- Associated I+D+i Unit to the Institute of Medicinal Chemistry (IQM), Scientific Research Superior Council (CSIC), Madrid, Spain
| | - Ana Bagües
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
- Associated I+D+i Unit to the Institute of Medicinal Chemistry (IQM), Scientific Research Superior Council (CSIC), Madrid, Spain
- High Performance Research Group in Experimental Pharmacology (PHARMAKOM-URJC), URJC, Alcorcón, Spain
| | - Raquel Abalo
- Department of Basic Health Sciences, University Rey Juan Carlos (URJC), Alcorcón, Spain
- High Performance Research Group in Physiopathology and Pharmacology of the Digestive System (NeuGut), University Rey Juan Carlos (URJC), Alcorcón, Spain
- Associated I+D+i Unit to the Institute of Medicinal Chemistry (IQM), Scientific Research Superior Council (CSIC), Madrid, Spain
- Working Group of Basic Sciences on Pain and Analgesia of the Spanish Pain Society, Madrid, Spain
- Working Group of Basic Sciences on Cannabinoids of the Spanish Pain Society, Madrid, Spain
| |
Collapse
|
6
|
Pezzoli A, Guarino M, Fusetti N, Pizzo E, Simoni M, Simone L, Cifalà V, Solimando R, Perna B, Testino G, Pellicano R, Caio G, Lungaro L, Caputo F, Zoli G, Merighi A, DE Giorgio R. Efficacy and safety of capsule endoscopy in octogenarian patients: a retrospective study. Minerva Gastroenterol (Torino) 2023; 69:388-395. [PMID: 35708039 DOI: 10.23736/s2724-5985.22.03220-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
BACKGROUND Life expectancy and the number of ultra-octogenarians increased significantly, thus making crucial the appropriateness of several endoscopic procedures in elderly patients. The aim of our study was to provide a retrospective analysis of the efficacy and safety of capsule endoscopy (CE) in patients aged over 80 years. METHODS In this single-centre study, 900 patients underwent capsule endoscopy between 2002 and 2015 for different indications; of these 106 patients aged ≥80 years (group A) and 99 patients aged 40-60 years (control group B) were retrospectively selected. RESULTS Occult gastrointestinal bleeding accounted for 62.1% of all indications for capsule endoscopy in group B, compared to 95.2% in group A (P<0.001). Although not statistically significant, the diagnostic yield was higher in group A (71%) vs. group B (62%). The percentages of reaching the cecum and the median gastric transit time were uniform within the two groups. In contrast, small bowel transit time was longer in group A vs. B. Small bowel preparation was similar in the two groups. The exam was generally well tolerated in both groups, with capsule aspiration being one of the main adverse events, which occurred in two elderly patients. CONCLUSIONS Our data expand previous findings confirming that capsule endoscopy can be performed safely even in very old patients and show that the diagnostic yield is similar to that of younger patients.
Collapse
Affiliation(s)
- Alessandro Pezzoli
- Department of Gastroenterology and Gastrointestinal Endoscopy, University Hospital of Ferrara, Ferrara, Italy
| | - Matteo Guarino
- Department of Translational Medicine, University Hospital of Ferrara, Ferrara, Italy
| | - Nadia Fusetti
- Department of Gastroenterology and Gastrointestinal Endoscopy, University Hospital of Ferrara, Ferrara, Italy
| | - Elena Pizzo
- Department of Applied Health Research, University College of London, London, UK
| | - Marzia Simoni
- Epidemiological Unit of CNR Institute of Clinical Physiology, Pisa, Italy
| | - Loredana Simone
- Department of Gastroenterology and Gastrointestinal Endoscopy, University Hospital of Ferrara, Ferrara, Italy
| | - Viviana Cifalà
- Department of Gastroenterology and Gastrointestinal Endoscopy, University Hospital of Ferrara, Ferrara, Italy
| | - Riccardo Solimando
- Department of Gastroenterology and Gastrointestinal Endoscopy, University Hospital of Ferrara, Ferrara, Italy
| | - Benedetta Perna
- Department of Translational Medicine, University Hospital of Ferrara, Ferrara, Italy
| | - Gianni Testino
- Unit of Addiction and Hepatology, Regional Centre on Alcohol, ASL3 San Martino Hospital, Genoa, Italy
| | | | - Giacomo Caio
- Department of Translational Medicine, University Hospital of Ferrara, Ferrara, Italy
| | - Lisa Lungaro
- Department of Translational Medicine, University Hospital of Ferrara, Ferrara, Italy
| | - Fabio Caputo
- Department of Translational Medicine, University Hospital of Ferrara, Ferrara, Italy
| | - Giorgio Zoli
- Department of Translational Medicine, University Hospital of Ferrara, Ferrara, Italy
| | - Alberto Merighi
- Department of Gastroenterology and Gastrointestinal Endoscopy, University Hospital of Ferrara, Ferrara, Italy
| | - Roberto DE Giorgio
- Department of Translational Medicine, University Hospital of Ferrara, Ferrara, Italy
| |
Collapse
|
7
|
Takla M, Saadeh K, Tse G, Huang CLH, Jeevaratnam K. Ageing and the Autonomic Nervous System. Subcell Biochem 2023; 103:201-252. [PMID: 37120470 DOI: 10.1007/978-3-031-26576-1_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
The vertebrate nervous system is divided into central (CNS) and peripheral (PNS) components. In turn, the PNS is divided into the autonomic (ANS) and enteric (ENS) nervous systems. Ageing implicates time-related changes to anatomy and physiology in reducing organismal fitness. In the case of the CNS, there exists substantial experimental evidence of the effects of age on individual neuronal and glial function. Although many such changes have yet to be experimentally observed in the PNS, there is considerable evidence of the role of ageing in the decline of ANS function over time. As such, this chapter will argue that the ANS constitutes a paradigm for the physiological consequences of ageing, as well as for their clinical implications.
Collapse
Affiliation(s)
| | | | - Gary Tse
- Kent and Medway Medical School, Canterbury, UK
- University of Surrey, Guildford, UK
| | | | | |
Collapse
|
8
|
Zizzo MG, Cicio A, Raimondo S, Alessandro R, Serio R. Age-related differences of γ-aminobutyric acid (GABA)ergic transmission in human colonic smooth muscle. Neurogastroenterol Motil 2022; 34:e14248. [PMID: 34432349 PMCID: PMC9285353 DOI: 10.1111/nmo.14248] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/10/2021] [Accepted: 08/10/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND Enteric neurons undergo to functional changes during aging. We investigated the possible age-associated differences in enteric γ-aminobutyric acid (GABA)ergic transmission evaluating function and distribution of GABAergic receptors in human colon. METHODS Mechanical responses to GABA and GABA receptor agonists on slow phasic contractions were examined in vitro as changes in isometric tension in colonic muscle strips from young (<65 years old) and aged patients (>65 years old). GABAergic receptor expression was assessed by quantitative RT-PCR. KEY RESULTS In both preparations GABA induced an excitatory effect, consisting in an increase in the basal tone, antagonized by the GABAA receptor antagonist, bicuculline, and potentiated by phaclofen, GABAB receptor antagonist.Tetrodotoxin (TTX) and atropine-sensitive contractile responses to GABA and GABAA receptor agonist, muscimol, were more pronounced in old compared to young subjects. Baclofen, GABAB receptor agonist, induced a TTX-sensitive reduction of the amplitude of the spontaneous. Nω-nitro-l-arginine methyl ester (L-NAME), nitric oxide (NO) synthase inhibitor abolished the inhibitory responses in old preparations, but a residual responses persisted in young preparations, which in turn was abolished by suramin, purinergic receptor antagonist. α3-GABAA receptor subunit expression tends to change in an age-dependent manner. CONCLUSIONS AND INFERENCES Our results reveal age-related differences in GABAergic transmission in human colon. At all the age tested GABA regulates muscular contractility modulating the activity of the intrinsic neurons. Activation of GABAA receptor, through acetylcholine release, induces contraction, which increases in amplitude with age. GABAB receptor activation leads to neural release of NO and purines, being a loss of purinergic-component in aged group.
Collapse
Affiliation(s)
- Maria Grazia Zizzo
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF)University of PalermoViale delle Scienze,ed 16Palermo90128Italy,ATeN (Advanced Technologies Network) CenterUniversity of PalermoViale delle Scienze, ed 18Palermo90128Italy
| | - Adele Cicio
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF)University of PalermoViale delle Scienze,ed 16Palermo90128Italy
| | - Stefania Raimondo
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Bi.N.D)University of PalermoSection of Biology and GeneticsPalermo90133Italy
| | - Riccardo Alessandro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Bi.N.D)University of PalermoSection of Biology and GeneticsPalermo90133Italy
| | - Rosa Serio
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF)University of PalermoViale delle Scienze,ed 16Palermo90128Italy
| |
Collapse
|
9
|
Immunisation with UB-312 in the Thy1SNCA mouse prevents motor performance deficits and oligomeric α-synuclein accumulation in the brain and gut. Acta Neuropathol 2022; 143:55-73. [PMID: 34741635 PMCID: PMC8732825 DOI: 10.1007/s00401-021-02381-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/20/2021] [Accepted: 10/29/2021] [Indexed: 01/13/2023]
Abstract
Alpha synuclein has a key role in the pathogenesis of Parkinson's disease (PD), Dementia with Lewy Bodies (LBD) and Multiple System Atrophy (MSA). Immunotherapies aiming at neutralising toxic αSyn species are being investigated in the clinic as potential disease modifying therapies for PD and other synucleinopathies. In this study, the effects of active immunisation against αSyn with the UB-312 vaccine were investigated in the Thy1SNCA/15 mouse model of PD. Young transgenic and wild-type mice received an immunisation regimen over a period of 6 weeks, then observed for an additional 9 weeks. Behavioural assessment was conducted before immunisation and at 15 weeks after the first dose. UB-312 immunisation prevented the development of motor impairment in the wire test and challenging beam test, which was associated with reduced levels of αSyn oligomers in the cerebral cortex, hippocampus and striatum of Thy1SNCA/15 mice. UB-312 immunotherapy resulted in a significant reduction of theαSyn load in the colon, accompanied by a reduction in enteric glial cell reactivity in the colonic ganglia. Our results demonstrate that immunisation with UB-312 prevents functional deficits and both central and peripheral pathology in Thy1SNCA/15 mice.
Collapse
|
10
|
Dietz N, Sarpong K, Ugiliweneza B, Wang D, Aslan SS, Castillo C, Boakye M, Herrity AN. Longitudinal Trends and Prevalence of Bowel Management in Individuals With Spinal Cord Injury. Top Spinal Cord Inj Rehabil 2021; 27:53-67. [PMID: 34866888 DOI: 10.46292/sci21-00008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Background: Neurogenic bowel dysfunction (NBD) following spinal cord injury (SCI) represents a major source of morbidity, negatively impacting quality of life and overall independence. The long-term changes in bowel care needs are not well-reported, preventing consensus on the natural course and optimal management of NBD following injury. Objectives: To understand the changes in bowel management needs over time following SCI. Methods: A retrospective observational study using the National Spinal Cord Injury Model Systems database evaluated the degree of independence with bowel management at discharge from inpatient rehabilitation across time (1988-2016). The prevalence and consecutive trajectory of bowel management was also evaluated at discharge and at each 5-year follow-up period, for 25 years. Results: The majority of individuals discharged from inpatient rehabilitation (n = 17,492) required total assistance with bowel management, a trend that significantly increased over time. However, by 5-years post injury, there was a significant shift in bowel management needs from total assistance to modified independence. In those with consecutive 25-year follow-up data (n = 11,131), a similar shift in bowel management to a less dependent strategy occurred even at chronic time points post injury, primarily in individuals with paraplegia and classified as motor and sensory complete. Conclusion: The findings of this study highlight the need for providing continued multipronged interventions (e.g., rehabilitative, educational, psycho-social) at the different stages of SCI to support individuals not only in the immediate years after discharge but also well into the chronic stages after injury.
Collapse
Affiliation(s)
- Nicholas Dietz
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky
| | - Kwadwo Sarpong
- School of Medicine, Georgetown University, Washington, DC
| | - Beatrice Ugiliweneza
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky.,Department of Health Management and Systems Science, University of Louisville, Louisville, Kentucky
| | - Dengzhi Wang
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky
| | - Sevda S Aslan
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky
| | - Camilo Castillo
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Division of Physical Medicine and Rehabilitation, University of Louisville, Louisville, Kentucky
| | - Maxwell Boakye
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky
| | - April N Herrity
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky.,Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky.,Department of Physiology, University of Louisville, Louisville, Kentucky
| |
Collapse
|
11
|
Jutras G, Wahba G, Ayuso E, Neshkova E, Bouin M. Do Age and Sex Influence Anorectal Manometry Parameters? J Can Assoc Gastroenterol 2021; 4:235-241. [PMID: 34617005 PMCID: PMC8489528 DOI: 10.1093/jcag/gwaa045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 01/05/2021] [Indexed: 12/17/2022] Open
Abstract
Background High-resolution anorectal manometry (HRM) is widely used in the evaluation of anal incontinence and constipation, which become increasingly prevalent with age. However, the impact of age and comorbidities on physiological digestive parameters remains poorly understood. In this study, we aimed to evaluate the effect of age on anorectal function. Methods We conducted a retrospective study on patients at our digestive motility clinic between January 2016 and May 2019. All patients with a normal HRM were included. Clinical data and HRM parameters were collected in a database. Multivariate regression analyses were performed to evaluate the effects of age, sex, medical comorbidities and obstetric history on anorectal HRM parameters. Key Results One hundred and forty-four patients were included (mean age: 53 ± 16 years, 72% females). The main indications for anorectal HRM were incontinence (44%), constipation (37%) and anorectal pain (9%). Age was significantly associated with higher maximum tolerable volume (β = +0.48 mL year-1, P = 0.04) and higher rectal compliance (β = +0.04 mL year-1, P = 0.01). Independently from age and medical comorbidities, female demonstrated significantly lower mean endurance squeeze pressure (β = −44.4 mmHg, P < 0.001), maximal squeeze pressure (β = −62.3 mmHg; P < 0.001), volume at first urge (β = −16.7 mL, P = 0.02) and maximum tolerable volume (β = −16.1 mL, P = 0.046). Vaginal birth was associated with lower tolerable maximum pressure (β = −39.4 mmHg, P = 0.046). Conclusion Age and sex are independent factors which influence anorectal HRM parameters. These findings should be taken into consideration when interpreting anorectal HRM.
Collapse
Affiliation(s)
- Gabrielle Jutras
- Centre Hospitalier Universitaire de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| | - George Wahba
- Centre Hospitalier Universitaire de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| | - Eloise Ayuso
- Centre Hospitalier Universitaire de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| | - Elissaveta Neshkova
- Centre Hospitalier Universitaire de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| | - Mickael Bouin
- Centre Hospitalier Universitaire de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| |
Collapse
|
12
|
Sun T, Li D, Hu S, Huang L, Sun H, Yang S, Wu B, Ji F, Zhou D. Aging-dependent decrease in the numbers of enteric neurons, interstitial cells of Cajal and expression of connexin43 in various regions of gastrointestinal tract. Aging (Albany NY) 2019; 10:3851-3865. [PMID: 30530917 PMCID: PMC6326649 DOI: 10.18632/aging.101677] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 11/18/2018] [Indexed: 12/20/2022]
Abstract
Aging is a significant risk factor for gastrointestinal dysmotility, but aging-associated differences between different organs and the exact time to start degenerating have remained obscure. Here we evaluated alterations of interstitial cells of Cajal, enteric neurons and connexin43 expression in the stomach, jejunum and colon in 2-, 12-, 16-, 20- and 24-month-old mice, as well as in aged human colon. Interstitial cells of Cajal, cholinergic and nitrergic neurons within the whole digestive tract were reduced over time, but their loss first appeared in stomach, then in intestine, helping to understand that gastric function was first impaired during aging. The decrease of connexin43 expression occurred before interstitial cells of Cajal and neurons loss, suggesting that connexin43 might be the major target influenced during senescence. Furthermore, changes in expressions of pro-inflammatory cytokines (tumour necrosis factor-α, interleukin-1β, interleukin-6) and apoptosis-related proteins (B-cell lymphoma-2, caspase-3) which indicated “inflammaging”, might contribute to the loss of enteric neurons and interstitial cells of Cajal in aged gastrointestinal tract. Our results provide possible therapeutic time window for beneficial intervention for geriatric patients with gastrointestinal motility disorders.
Collapse
Affiliation(s)
- Tingyi Sun
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.,Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, 100069, China.,Cancer Institute of Capital Medical University, Beijing, 100069, China
| | - Dandan Li
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Shilong Hu
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Li Huang
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Haimei Sun
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.,Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, 100069, China.,Cancer Institute of Capital Medical University, Beijing, 100069, China
| | - Shu Yang
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.,Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, 100069, China.,Cancer Institute of Capital Medical University, Beijing, 100069, China
| | - Bo Wu
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.,Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, 100069, China.,Cancer Institute of Capital Medical University, Beijing, 100069, China
| | - Fengqing Ji
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.,Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, 100069, China.,Cancer Institute of Capital Medical University, Beijing, 100069, China
| | - Deshan Zhou
- Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.,Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, 100069, China.,Cancer Institute of Capital Medical University, Beijing, 100069, China
| |
Collapse
|
13
|
West CL, Amin JY, Farhin S, Stanisz AM, Mao YK, Kunze WA. Colonic Motility and Jejunal Vagal Afferent Firing Rates Are Decreased in Aged Adult Male Mice and Can Be Restored by an Aminosterol. Front Neurosci 2019; 13:955. [PMID: 31551703 PMCID: PMC6746984 DOI: 10.3389/fnins.2019.00955] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 08/23/2019] [Indexed: 12/19/2022] Open
Abstract
There is a general decline in gastrointestinal function in old age including decreased intestinal motility, sensory signaling, and afferent sensitivity. There is also increased prevalence of significant constipation in aged populations. We hypothesized this may be linked to reduced colonic motility and alterations in vagal-gut-brain sensory signaling. Using in vitro preparations from young (3 months) and old (18–24 months) male CD1 mice we report functional age-related differences in colonic motility and jejunal mesenteric afferent firing. Furthermore, we tested the effect of the aminosterol squalamine on colonic motility and jejunal vagal firing rate. Old mice had significantly reduced velocity of colonic migrating motor complexes (MMC) by 27% compared to young mice (p = 0.0161). Intraluminal squalamine increased colonic MMC velocity by 31% in old mice (p = 0.0150), which also had significantly reduced mesenteric afferent single-unit firing rates from the jejunum by 51% (p < 0.0001). The jejunal vagal afferent firing rate was reduced in aged mice by 62% (p = 0.0004). While the time to peak response to squalamine was longer in old mice compared to young mice (18.82 ± 1.37 min vs. 12.95 ± 0.99 min; p = 0.0182), it significantly increased vagal afferent firing rate by 36 and 56% in young and old mice, respectively (p = 0.0006, p = 0.0013). Our results show for the first time that the jejunal vagal afferent firing rate is reduced in aged-mice. They also suggest that there is translational potential for the therapeutic use of squalamine in the treatment of age-related constipation and dysmotility.
Collapse
Affiliation(s)
- Christine L West
- St. Joseph's Healthcare, The Brain-Body Institute, McMaster University, Hamilton, ON, Canada.,Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Jessica Y Amin
- St. Joseph's Healthcare, The Brain-Body Institute, McMaster University, Hamilton, ON, Canada
| | - Sohana Farhin
- St. Joseph's Healthcare, The Brain-Body Institute, McMaster University, Hamilton, ON, Canada
| | - Andrew M Stanisz
- St. Joseph's Healthcare, The Brain-Body Institute, McMaster University, Hamilton, ON, Canada
| | - Yu-Kang Mao
- St. Joseph's Healthcare, The Brain-Body Institute, McMaster University, Hamilton, ON, Canada
| | - Wolfgang A Kunze
- St. Joseph's Healthcare, The Brain-Body Institute, McMaster University, Hamilton, ON, Canada.,Department of Biology, McMaster University, Hamilton, ON, Canada.,Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
| |
Collapse
|
14
|
Broad J, Kung VWS, Palmer A, Elahi S, Karami A, Darreh-Shori T, Ahmed S, Thaha MA, Carroll R, Chin-Aleong J, Martin JE, Saffrey MJ, Knowles CH, Sanger GJ. Changes in neuromuscular structure and functions of human colon during ageing are region-dependent. Gut 2019; 68:1210-1223. [PMID: 30228216 PMCID: PMC6594449 DOI: 10.1136/gutjnl-2018-316279] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 08/17/2018] [Accepted: 08/20/2018] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To determine if human colonic neuromuscular functions decline with increasing age. DESIGN Looking for non-specific changes in neuromuscular function, a standard burst of electrical field stimulation (EFS) was used to evoke neuronally mediated (cholinergic/nitrergic) contractions/relaxations in ex vivomuscle strips of human ascending and descending colon, aged 35-91 years (macroscopically normal tissue; 239 patients undergoing cancer resection). Then, to understand mechanisms of change, numbers and phenotype of myenteric neurons (30 306 neurons stained with different markers), densities of intramuscular nerve fibres (51 patients in total) and pathways involved in functional changes were systematically investigated (by immunohistochemistry and use of pharmacological tools) in elderly (≥70 years) and adult (35-60 years) groups. RESULTS With increasing age, EFS was more likely to evoke muscle relaxation in ascending colon instead of contraction (linear regression: n=109, slope 0.49%±0.21%/year, 95% CI), generally uninfluenced by comorbidity or use of medications. Similar changes were absent in descending colon. In the elderly, overall numbers of myenteric and neuronal nitric oxide synthase-immunoreactive neurons and intramuscular nerve densities were unchanged in ascending and descending colon, compared with adults. In elderly ascending, not descending, colon numbers of cell bodies exhibiting choline acetyltransferase immunoreactivity increased compared with adults (5.0±0.6 vs 2.4±0.3 neurons/mm myenteric plexus, p=0.04). Cholinergically mediated contractions were smaller in elderly ascending colon compared with adults (2.1±0.4 and 4.1±1.1 g-tension/g-tissue during EFS; n=25/14; p=0.04); there were no changes in nitrergic function or in ability of the muscle to contract/relax. Similar changes were absent in descending colon. CONCLUSION In ascending not descending colon, ageing impairs cholinergic function.
Collapse
Affiliation(s)
- John Broad
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Victor W S Kung
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Alexandra Palmer
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Shezan Elahi
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Azadeh Karami
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, NEO, Stockholm, Sweden
| | - Taher Darreh-Shori
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, NEO, Stockholm, Sweden
| | - Shafi Ahmed
- Department of Surgery, Barts Health NHS Trust, The Royal London Hospital, London, UK,Department of Pathology, Barts Health NHS Trust, The Royal London Hospital, London, UK
| | - Mohamed Adhnan Thaha
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK,Department of Surgery, Barts Health NHS Trust, The Royal London Hospital, London, UK,Department of Pathology, Barts Health NHS Trust, The Royal London Hospital, London, UK
| | - Rebecca Carroll
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Joanne Chin-Aleong
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Joanne E Martin
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - M Jill Saffrey
- School of Life, Health and Chemical Sciences, Open University, Milton Keynes, UK
| | - Charles H Knowles
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK,Department of Surgery, Barts Health NHS Trust, The Royal London Hospital, London, UK,Department of Pathology, Barts Health NHS Trust, The Royal London Hospital, London, UK
| | - Gareth John Sanger
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| |
Collapse
|
15
|
Merchant HA, Liu F, Orlu Gul M, Basit AW. Age-mediated changes in the gastrointestinal tract. Int J Pharm 2016; 512:382-395. [DOI: 10.1016/j.ijpharm.2016.04.024] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 03/22/2016] [Accepted: 04/12/2016] [Indexed: 12/21/2022]
|
16
|
Xuan Q, Zhang YX, Liu DG, Chan P, Xu SL, Cui YQ. Post-translational modifications of α-synuclein contribute to neurodegeneration in the colon of elderly individuals. Mol Med Rep 2016; 13:5077-83. [PMID: 27109489 PMCID: PMC4878562 DOI: 10.3892/mmr.2016.5166] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 02/23/2016] [Indexed: 01/24/2023] Open
Abstract
Synucleinopathies and abnormalities in the nerves of the enteric nervous system are hypothesized to be involved in age-associated motility disorders. The aim of the present study was to investigate the expression of various antigens, including α‑synuclein (Syn) and its post‑translational modified forms, in the human colon at various ages. In addition, the study aimed to correlate the expression of Syn with neurodegeneration. Immunohistochemistry was used to detect the expression of neurofilament (NF), Syn, as well as its nitrated (N) form in the healthy colonic tissue of 12 young (34.08±5.12 years), 10 middle‑aged (51.80±3.52 years), and 11 elderly (75.82±7.70 years) individuals. To the best of our knowledge, the current study is the first to demonstrate the presence of N‑Syn in the colonic tissue. N‑Syn was identified in the upper layer of the mucosa and submucosa layer. Furthermore, Syn (wild‑type) was present in the mucosa and submucosa. The number of NF‑positive neurons in the submucosal layer declined significantly with age (P<0.01). In addition, Syn and N‑Syn significantly increased during aging (P<0.01). Furthermore, a negative correlation was identified between neuron number and synucleinopathies, indicating the abnormal accumulation of both wild-type Syn and N‑Syn in the mucosa, submucosa, muscle layer and myenteric plexus. The present study demonstrates that the Syn pathology may be linked to colic neuronal degeneration during normal aging, and this link may cause functional deficits.
Collapse
Affiliation(s)
- Qi Xuan
- Department of Nutrition, Xuanwu Hospital, Capital Medical University, Beijing 100053, P.R. China
| | - Yu-Xian Zhang
- Department of Internal Medicine, Beijing Moslem Hospital, Beijing 100054, P.R. China
| | - Dian-Gang Liu
- Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, P.R. China
| | - Piu Chan
- Department of Neurobiology, Institute of Geriatrics of Beijing, Xuanwu Hospital, Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Beijing 100053, P.R. China
| | - Sheng-Li Xu
- Department of Neurobiology, Institute of Geriatrics of Beijing, Xuanwu Hospital, Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Beijing 100053, P.R. China
| | - Ye-Qing Cui
- Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, P.R. China
| |
Collapse
|
17
|
Bubenheimer RK, Brown IAM, Fried DE, McClain JL, Gulbransen BD. Sirtuin-3 Is Expressed by Enteric Neurons but It Does not Play a Major Role in Their Regulation of Oxidative Stress. Front Cell Neurosci 2016; 10:73. [PMID: 27047337 PMCID: PMC4801875 DOI: 10.3389/fncel.2016.00073] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/08/2016] [Indexed: 12/30/2022] Open
Abstract
Gut inflammation contributes to the development of gut motility disorders in part by disrupting the function and survival of enteric neurons through mechanisms that involve oxidative stress. How enteric neurons regulate oxidative stress is still poorly understood. Importantly, how neuron autonomous antioxidant mechanisms contribute to the susceptibility of enteric neurons to oxidative stress in disease is not known. Here, we discover that sirtuin-3 (Sirt3), a key regulator of oxidative stress and mitochondrial metabolism, is expressed by neurons in the enteric nervous system (ENS) of the mouse colon. Given the important role of Sirt3 in the regulation of neuronal oxidative stress in the central nervous system (CNS), we hypothesized that Sirt3 plays an important role in the cell autonomous regulation of oxidative stress by enteric neurons and that a loss of Sirt3 increases neuronal vulnerability during intestinal inflammation. We tested our hypothesis using a combination of traditional immunohistochemistry, oxidative stress measurements and in vivo and ex vivo measures of GI motility in healthy and inflamed wild-type (wt) and Sirt3 null (Sirt3−/−) mice. Our results show that Sirt3 is widely expressed by neurons throughout the myenteric plexus of the mouse colon. However, the deletion of Sirt3 had surprisingly little effect on gut function and susceptibility to inflammation. Likewise, neither the genetic ablation of Sirt3 nor the inhibition of Sirt3 with antagonists had a significant effect on neuronal oxidative stress. Therefore, we conclude that Sirt3 contributes very little to the overall regulation of neuronal oxidative stress in the ENS. The functional relevance of Sirt3 in enteric neurons is still unclear but our data show that it is an unlikely candidate to explain neuronal vulnerability to oxidative stress during inflammation.
Collapse
Affiliation(s)
- Rebecca K Bubenheimer
- Neuroscience Program, Michigan State UniversityEast Lansing, MI, USA; Department of Physiology, Michigan State UniversityEast Lansing, MI, USA
| | - Isola A M Brown
- Department of Physiology, Michigan State UniversityEast Lansing, MI, USA; Pharmacology and Toxicology Program, Michigan State UniversityEast Lansing, MI, USA
| | - David E Fried
- Department of Physiology, Michigan State University East Lansing, MI, USA
| | - Jonathon L McClain
- Department of Physiology, Michigan State University East Lansing, MI, USA
| | - Brian D Gulbransen
- Neuroscience Program, Michigan State UniversityEast Lansing, MI, USA; Department of Physiology, Michigan State UniversityEast Lansing, MI, USA
| |
Collapse
|
18
|
Abstract
Aging is characterized by a diminished homeostatic regulation of physiologic functions, including slowing of gastric emptying. Gastric and small intestinal motor and humoral mechanisms in humans are complex and highly variable: ingested food is stored, mixed with digestive enzymes, ground into small particles, and delivered as a liquefied form into the duodenum at a rate allowing efficient digestion and absorption. In healthy aging, motor function is well preserved whereas deficits in sensory function are more apparent. The effects of aging on gastric emptying are relevant to the absorption of oral medications and the regulation of appetite, postprandial glycemia, and blood pressure.
Collapse
Affiliation(s)
- Stijn Soenen
- Discipline of Medicine, National Health and Medical Research Council of Australia (NHMRC) Centre of Research Excellence in Translating Nutritional Science to Good Health, Royal Adelaide Hospital, The University of Adelaide, Frome Road, Adelaide, South Australia 5000, Australia.
| | - Chris K Rayner
- Discipline of Medicine, National Health and Medical Research Council of Australia (NHMRC) Centre of Research Excellence in Translating Nutritional Science to Good Health, Royal Adelaide Hospital, The University of Adelaide, Frome Road, Adelaide, South Australia 5000, Australia
| | - Michael Horowitz
- Discipline of Medicine, National Health and Medical Research Council of Australia (NHMRC) Centre of Research Excellence in Translating Nutritional Science to Good Health, Royal Adelaide Hospital, The University of Adelaide, Frome Road, Adelaide, South Australia 5000, Australia
| | - Karen L Jones
- Discipline of Medicine, National Health and Medical Research Council of Australia (NHMRC) Centre of Research Excellence in Translating Nutritional Science to Good Health, Royal Adelaide Hospital, The University of Adelaide, Frome Road, Adelaide, South Australia 5000, Australia
| |
Collapse
|
19
|
Aqueous Extract of Agaricus blazei Murrill Prevents Age-Related Changes in the Myenteric Plexus of the Jejunum in Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:287153. [PMID: 25960748 PMCID: PMC4415631 DOI: 10.1155/2015/287153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/15/2014] [Accepted: 12/16/2014] [Indexed: 01/27/2023]
Abstract
This study evaluated the effects of the supplementation with aqueous extract of Agaricus blazei Murrill (ABM) on biometric and blood parameters and quantitative morphology of the myenteric plexus and jejunal wall in aging Wistar rats. The animals were euthanized at 7 (C7), 12 (C12 and CA12), and 23 months of age (C23 and CA23). The CA12 and CA23 groups received a daily dose of ABM extract (26 mg/animal) via gavage, beginning at 7 months of age. A reduction in food intake was observed with aging, with increases in the Lee index, retroperitoneal fat, intestinal length, and levels of total cholesterol and total proteins. Aging led to a reduction of the total wall thickness, mucosa tunic, villus height, crypt depth, and number of goblet cells. In the myenteric plexus, aging quantitatively decreased the population of HuC/D(+) neuronal and S100(+) glial cells, with maintenance of the nNOS(+) nitrergic subpopulation and increase in the cell body area of these populations. Supplementation with the ABM extract preserved the myenteric plexus in old animals, in which no differences were detected in the density and cell body profile of neurons and glial cells in the CA12 and CA23 groups, compared with C7 group. The supplementation with the aqueous extract of ABM efficiently maintained myenteric plexus homeostasis, which positively influenced the physiology and prevented the death of the neurons and glial cells.
Collapse
|
20
|
Stenkamp-Strahm CM, Nyavor YEA, Kappmeyer AJ, Horton S, Gericke M, Balemba OB. Prolonged high fat diet ingestion, obesity, and type 2 diabetes symptoms correlate with phenotypic plasticity in myenteric neurons and nerve damage in the mouse duodenum. Cell Tissue Res 2015; 361:411-26. [PMID: 25722087 DOI: 10.1007/s00441-015-2132-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 01/20/2015] [Indexed: 12/18/2022]
Abstract
Symptoms of diabetic gastrointestinal dysmotility indicate neuropathy of the enteric nervous system. Long-standing diabetic enteric neuropathy has not been fully characterized, however. We used prolonged high fat diet ingestion (20 weeks) in a mouse model to mimic human obese and type 2 diabetic conditions, and analyzed changes seen in neurons of the duodenal myenteric plexus. Ganglionic and neuronal size, number of neurons per ganglionic area, density indices of neuronal phenotypes (immunoreactive nerve cell bodies and varicosities per ganglion or tissue area) and nerve injury were measured. Findings were compared with results previously seen in mice fed the same diet for 8 weeks. Compared to mice fed standard chow, those on a prolonged high fat diet had smaller ganglionic and cell soma areas. Myenteric VIP- and ChAT-immunoreactive density indices were also reduced. Myenteric nerve fibers were markedly swollen and cytoskeletal protein networks were disrupted. The number of nNOS nerve cell bodies per ganglia was increased, contrary to the reduction previously seen after 8 weeks, but the density index of nNOS varicosities was reduced. Mice fed high fat and standard chow diets experienced an age-related reduction in total neurons, with bias towards neurons of sensory phenotype. Meanwhile, ageing was associated with an increase in excitatory neuronal markers. Collectively, these results support a notion that nerve damage underlies diabetic symptoms of dysmotility, and reveals adaptive ENS responses to the prolonged ingestion of a high fat diet. This highlights a need to mechanistically study long-term diet-induced nerve damage and age-related impacts on the ENS.
Collapse
Affiliation(s)
- Chloe M Stenkamp-Strahm
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive 3051, LSS 252, Moscow, ID, 83844-3051, USA
| | | | | | | | | | | |
Collapse
|
21
|
Hetz S, Acikgoez A, Moll C, Jahnke HG, Robitzki AA, Metzger R, Metzger M. Age-related gene expression analysis in enteric ganglia of human colon after laser microdissection. Front Aging Neurosci 2014; 6:276. [PMID: 25360110 PMCID: PMC4197768 DOI: 10.3389/fnagi.2014.00276] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 09/24/2014] [Indexed: 01/16/2023] Open
Abstract
The enteric nervous system (ENS) poses the intrinsic innervation of the gastrointestinal tract and plays a critical role for all stages of postnatal life. There is increasing scientific and clinical interest in acquired or age-related gastrointestinal dysfunctions that can be manifested in diseases such as gut constipation or fecal incontinence. In this study, we sought to analyze age-dependent changes in the gene expression profile of the human ENS, particularly in the myenteric plexus. Therefore, we used the laser microdissection technique which has been proven as a feasible tool to analyze distinct cell populations within heterogeneously composed tissues. Full biopsy gut samples were prepared from children (4-12 months), middle aged (48-58 years) and aged donors (70-95 years). Cryosections were histologically stained with H&E, the ganglia of the myenteric plexus identified and RNA isolated using laser microdissection technique. Quantitative PCR was performed for selected neural genes, neurotransmitters and receptors. Data were confirmed on protein level using NADPH-diaphorase staining and immunohistochemistry. As result, we demonstrate age-associated alterations in site-specific gene expression pattern of the ENS. Thus, in the adult and aged distal parts of the colon a marked decrease in relative gene expression of neural key genes like NGFR, RET, NOS1 and a concurrent increase of CHAT were observed. Further, we detected notable regional differences of RET, CHAT, TH, and S100B comparing gene expression in aged proximal and distal colon. Interestingly, markers indicating cellular senescence or oxidative stress (SNCA, CASP3, CAT, SOD2, and TERT) were largely unchanged within the ENS. For the first time, our study also describes the age-dependent expression pattern of all major sodium channels within the ENS. Our results are in line with previous studies showing spatio-temporal differences within the mammalian ENS.
Collapse
Affiliation(s)
- Susan Hetz
- CELLT Research Group, Translational Centre for Regenerative Medicine, University of Leipzig Leipzig, Germany
| | - Ali Acikgoez
- Department of General and Visceral Surgery, St. George's Hospital Leipzig, Germany
| | - Corinna Moll
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg Wuerzburg, Germany
| | - Heinz-Georg Jahnke
- Division of Molecular biological-biochemical Processing Technology, Center for Biotechnology and Biomedicine (BBZ), University of Leipzig Leipzig, Germany
| | - Andrea A Robitzki
- Division of Molecular biological-biochemical Processing Technology, Center for Biotechnology and Biomedicine (BBZ), University of Leipzig Leipzig, Germany
| | - Roman Metzger
- Department of Pediatric Surgery, University of Leipzig Leipzig, Germany
| | - Marco Metzger
- CELLT Research Group, Translational Centre for Regenerative Medicine, University of Leipzig Leipzig, Germany ; Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg Wuerzburg, Germany
| |
Collapse
|
22
|
Singh J, Kumar S, Krishna CV, Rattan S. Aging-associated oxidative stress leads to decrease in IAS tone via RhoA/ROCK downregulation. Am J Physiol Gastrointest Liver Physiol 2014; 306:G983-91. [PMID: 24742984 PMCID: PMC4042111 DOI: 10.1152/ajpgi.00087.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Internal anal sphincter (IAS) tone plays an important role in rectoanal incontinence (RI). IAS tone may be compromised during aging, leading to RI in certain patients. We examined the influence of oxidative stress in the aging-associated decrease in IAS tone (AADI). Using adult (4-6 mo old) and aging (24-30 mo old) rats, we determined the effect of oxidative stress on IAS tone and the regulatory RhoA/ROCK signal transduction cascade. We determined the effect of the oxidative stress inducer LY83583, which produces superoxide anions (O2 (·-)), on basal and stimulated IAS tone before and after treatment of intact smooth muscle strips and smooth muscle cells with the O2 (·-) scavenger SOD. Our data showed that AADI was associated with a decrease in RhoA/ROCK expression at the transcriptional and translational levels. Oxidative stress with a LY83583-mediated decrease in IAS tone and relaxation of IAS smooth muscle cells was associated with a decrease in RhoA/ROCK signal transduction, which was reversible by SOD. In addition, LY83583 caused a significant decrease in IAS contraction produced by the RhoA activator and a known RhoA/ROCK agonist, U46619, that was also reversible by SOD. The inhibitory effects of LY83583 and the ROCK inhibitor Y27632 on the U46619-induced increase in IAS tone were similar. We conclude that an increase in oxidative stress plays an important role in AADI in the elderly and may be one of the underlying mechanisms of RI in certain aging patients.
Collapse
Affiliation(s)
| | | | | | - Satish Rattan
- Division of Gastroenterology and Hepatology, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| |
Collapse
|
23
|
Schoffen JPF, Santi Rampazzo AP, Cirilo CP, Zapater MCU, Vicentini FA, Comar JF, Bracht A, Natali MRM. Food restriction enhances oxidative status in aging rats with neuroprotective effects on myenteric neuron populations in the proximal colon. Exp Gerontol 2014; 51:54-64. [DOI: 10.1016/j.exger.2014.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 01/03/2014] [Accepted: 01/07/2014] [Indexed: 01/26/2023]
|
24
|
Abstract
Anorectal medical disorders facing the elderly include fecal incontinence, fecal impaction with overflow fecal incontinence, chronic constipation, dyssynergic defecation, hemorrhoids, anal fissure, and pelvic floor disorders. This article discusses the latest advances in age-related changes in morphology and function of anal sphincter, changes in cellular and molecular biology, alterations in neurotransmitters and reflexes, and their impact on functional changes of the anorectum in the elderly. These biophysiologic changes have implications for the pathophysiology of anorectal disorders. A clear understanding and working knowledge of the functional anatomy and pathophysiology will enable appropriate diagnosis and treatment of these disorders.
Collapse
Affiliation(s)
- Siegfried W B Yu
- Division of Gastroenterology and Hepatology, Medical College of Georgia, Georgia Regents University, 1120 15th Street, Augusta, GA 30912, USA
| | | |
Collapse
|
25
|
Anby MU, Williams HD, Feeney O, Edwards GA, Benameur H, Pouton CW, Porter CJH. Non-linear Increases in Danazol Exposure with Dose in Older vs. Younger Beagle Dogs: The Potential Role of Differences in Bile Salt Concentration, Thermodynamic Activity, and Formulation Digestion. Pharm Res 2014; 31:1536-52. [DOI: 10.1007/s11095-013-1260-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 12/05/2013] [Indexed: 01/15/2023]
|
26
|
Serra-Prat M, Mans E, Palomera E, Clavé P. Gastrointestinal peptides, gastrointestinal motility, and anorexia of aging in frail elderly persons. Neurogastroenterol Motil 2013; 25:291-e245. [PMID: 23240772 DOI: 10.1111/nmo.12055] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The mechanisms involved in anorexia in frail elderly people remain unclear. The objective of this study was to establish whether fasting and postprandial levels of gastrointestinal peptides, gastrointestinal motility, and hunger are modified by age and frailty. METHODS Three groups of subjects were studied: (a) frail elderly (>70 years) persons, (b) non-frail elderly (>70 years) persons, and (c) healthy adults (aged 25-65 years). After an overnight fast, participants ingested a 400 Kcal liquid meal and appetite, hormonal, and gastrointestinal responses were monitored during early (0-60 min) and late (60-240 min) postprandial periods. KEY RESULTS Frail persons showed poor nutritional status, sarcopenia, and almost absence of hunger during fasting and postprandial periods. Older persons presented higher levels of glucose and insulin during fasting, enhanced postprandial CCK release in early postprandial period and postprandial hyperglycemia and hyperinsulinemia, but similar ghrelin levels than younger adults. Ultrasound scan showed that the fasting antral area was higher and antral compliance lower in old persons. The paracetamol absorption test showed enhanced postprandial gastric emptying in the frail. Non-gallbladder contractors showed no CCK peak in younger and non-frail groups, but the same high CCK peak as contractors in the frail. CONCLUSIONS & INFERENCES Frailty was associated with anorexia, risk of malnutrition, and sarcopenia. Frail persons showed impaired gastric motility (larger antral area at rest, impaired antral compliance, and enhanced postprandial emptying), impaired gallbladder motility, and fasting and/or postprandial alterations in CCK, glucose, and insulin release. Further studies are needed to determine if these factors may contribute to anorexia of aging in frail persons.
Collapse
Affiliation(s)
- M Serra-Prat
- Research Unit, Consorci Sanitari del Maresme, Mataró, Barcelona, Spain.
| | | | | | | |
Collapse
|
27
|
Dietary restriction interferes with oxidative status and intrinsic intestinal innervation in aging rats. Nutrition 2013; 29:673-80. [PMID: 23317927 DOI: 10.1016/j.nut.2012.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/20/2012] [Accepted: 09/24/2012] [Indexed: 02/06/2023]
Abstract
OBJECTIVES To evaluate the effects of dietary restriction on oxidative status, the HuC/D-neuronal nitric oxide synthase (nNOS) myenteric neuron population, HuC/D-S100 glial cells, and the morphometry of the small intestine in rats at various ages. METHODS Fifteen Wistar rats were divided into 7-and 12-mo-old control groups and a 12-mo-old experimental group subjected to dietary restrictions (50% of normal ration) for 5 mo. At 7 and 12 mo of age, the animals were anesthetized, and blood was collected to assess the biochemical components and oxidative status. Ileum samples were subjected to double-marker (HuC/D-nNOS and HuC/D-S100) immunostaining and histologic processing to morphometrically analyze intestinal wall elements and determine the metaphase index and rate of caliciform cells. The data were subjected to analysis of variance and the Tukey post hoc test with a 5% significance level. RESULTS Age affected the oxidative status by increasing lipid peroxidation, with no effect on blood components, intrinsic innervation, and intestinal wall elements. The animals subjected to dietary restriction showed improved levels of total cholesterol, triacylglycerols, and oxidative status, with no changes in the nNOS neuron population. However, the dietary restriction dramatically decreased the glial and HuC/D myenteric populations, led to atrophy of the neuronal cell body, induced glial hypertrophy, and decreased the thickness of the intestinal wall. CONCLUSION The high oxidative status of the aging animals was reversed by dietary restriction, which also lowered cholesterol and triacylglycerol levels. The present dietary restriction elicited morpho-quantitative changes in the myenteric plexus and histology of the ileum, with likely effects on intestinal functions.
Collapse
|
28
|
De Giorgio R, Giancola F, Boschetti E, Abdo H, Lardeux B, Neunlist M. Enteric glia and neuroprotection: basic and clinical aspects. Am J Physiol Gastrointest Liver Physiol 2012; 303:G887-93. [PMID: 22878122 DOI: 10.1152/ajpgi.00096.2012] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The enteric nervous system (ENS), a major regulatory system for gastrointestinal function, is composed of neurons and enteric glial cells (EGCs). Enteric glia have long been thought to provide only structural support to neurons. However, recent evidence indicates enteric glia-neuron cross talk significantly contributes to neuronal maintenance, survival, and function. Thus damage to EGCs may trigger neurodegenerative processes thought to play a role in gastrointestinal dysfunctions and symptoms. The purpose of this review is to provide an update on EGCs, particularly focusing on their possible neuroprotective features and the resultant enteric neuron abnormalities subsequent to EGC damage. These neuroprotective mechanisms may have pathogenetic relevance in a variety of functional and inflammatory gut diseases. Basic and clinical (translational) studies support a neuroprotective role mediated by EGCs. Different models have been developed to test whether selective EGC damage/ablation has an impact on gut functions and the ENS. Preclinical data indicated that selective EGC alterations were associated with changes in gut physiology related to enteric neuron abnormalities. In humans, a substantial loss of EGCs was described in patients with various functional and/or inflammatory gastrointestinal diseases. However, whether EGC changes precede or follow neuronal degeneration and loss and how this damage occurs is not defined. Additional studies on EGC neuroprotective capacity are expected to improve knowledge of gut diseases and pave the way for targeted therapeutic strategies of underlying neuropathies.
Collapse
Affiliation(s)
- Roberto De Giorgio
- Department of Clinical Medicine and Digestive Diseases and Internal Medicine, 40138 Bologna, Italy.
| | | | | | | | | | | |
Collapse
|
29
|
Stehle JR, Leng X, Kitzman DW, Nicklas BJ, Kritchevsky SB, High KP. Lipopolysaccharide-binding protein, a surrogate marker of microbial translocation, is associated with physical function in healthy older adults. J Gerontol A Biol Sci Med Sci 2012; 67:1212-8. [PMID: 22960476 DOI: 10.1093/gerona/gls178] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Physical function declines, and markers of inflammation increase with advancing age, even in healthy persons. Microbial translocation (MT) is the systemic exposure to mucosal surface microbes/microbial products without overt bacteremia and has been described in a number of pathologic conditions. We hypothesized that markers of MT, soluble CD14 (sCD14) and lipopolysaccharide (LPS) binding protein (LBP), may be a source of chronic inflammation in older persons and be associated with poorer physical function. METHODS We assessed cross-sectional relationships among two plasma biomarkers of MT (sCD14 and LBP), physical function (hand grip strength, short physical performance battery [SPPB], gait speed, walking distance, and disability questionnaire), and biomarkers of inflammation (C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), TNF-α soluble receptor 1 [TNFsR1]) in 59 older (60-89 years), healthy (no evidence of acute or chronic illness) men and women. RESULTS LBP was inversely correlated with SPPB score and grip strength (p = .02 and p < .01, respectively) and positively correlated with CRP (p = 0.04) after adjusting for age, gender, and body mass index. sCD14 correlated with IL-6 (p = .01), TNF-α (p = .05), and TNFsR1 (p < .0001). Furthermore, the correlations between LBP and SPPB and grip strength remained significant after adjusting for each inflammatory biomarker. CONCLUSIONS In healthy older individuals, LBP, a surrogate marker of MT, is associated with worse physical function and inflammation. Additional study is needed to determine whether MT is a marker for or a cause of inflammation and the associated functional impairments.
Collapse
Affiliation(s)
- John R Stehle
- Section on Gerontology and Geriatric Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
| | | | | | | | | | | |
Collapse
|
30
|
Abstract
Early postnatal development encounters milk as a key environmental variable and yet the sole nutrient source. One evolutionary conserved constituent of milk is sialic acid, which is generally displayed on glycoconjugates and free glycans. During early postnatal development, high sialic acid need was proposed to be unmet by the endogenous sialic acid synthetic capacity. Hence, milk sialic acid was proposed to serve as a conditional nutrient for the newborn. In the elderly, at the other end of ontogeny, decreased sialylation in the brain, saliva, and immune system is observed. Analogous to the neonatal situation, the endogenous synthetic capacity may be unable to keep up with the need in this age group. The data discussed here propose a functional dietary role of sialic acid as a building block for sialylation and beyond.
Collapse
|
31
|
Tsibouris P, Kalantzis C, Apostolopoulos P, Alexandrakis G, Mavrogianni P, Kalantzis N. Capsule endoscopy findings in patients with occult or overt bleeding older than 80 years. Dig Endosc 2012; 24:154-8. [PMID: 22507088 DOI: 10.1111/j.1443-1661.2011.01197.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND Overt and occult bleeding are the main indications for a wireless capsule endoscopy (WCE) study of the small bowel. Most published studies omit patients aged over 80. AIM To determine whether WCE is feasible in patients with overt or occult bleeding over age 80 and to define the spectrum of small bowel pathologies in this age group. PATIENTS AND METHODS In a retrospective non-randomized tertiary care study, 60 patients at least 80 years or older (aged group) and 120 matched patients aged <80 years (younger group) with overt or occult bleeding (including iron deficiency anaemia) and no significant gastroscopic or colonoscopic findings underwent WCE. RESULTS Of the 180 patients, 46 (77%) patients in the aged group and 97 (81%) in the younger group successfully completed small bowel study (P = 0.51). There was no difference in gastric transit time and small bowel passing time between the two groups. More patients in the aged group (48 cases, 80%) than the younger group (56 cases, 47%) presented with small bowel angiodysplasias (P < 0.0001). Nevertheless, there was no difference between the two groups concerning ulcerative and neoplastic lesions. No patient presented with capsule impaction, but more patients in the aged group (35 cases, 58%) than in the younger group (10 cases, 8%) found the study difficult and tiresome (P < 0.001). Preparation validation was poor in 34% of small bowel lumen in the aged group and 19% in the younger group (P = 0.03). CONCLUSION WCE is feasible, although rather tiresome, in patients over the age of 80. Though the vast majority of patients older than 80 presented with angiodysplasias, there were no differences between the aged and younger groups in the presence of ulcerative lesions and polyps or tumors.
Collapse
Affiliation(s)
- Panagiotis Tsibouris
- Department of Gastroenterology, NIMTS General Hospital, 29 Biskini Str, Zografou, Athens, Greece.
| | | | | | | | | | | |
Collapse
|
32
|
Parmar L, Fidalgo S, Yeoman MS, Patel BA. Chromatographic analysis of age-related changes in mucosal serotonin transmission in the murine distal ileum. Chem Cent J 2012; 6:31. [PMID: 22494644 PMCID: PMC3483693 DOI: 10.1186/1752-153x-6-31] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 02/27/2012] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND In the upper bowel, alterations in motility and absorption of key nutrients have been observed as part of the normal ageing process. Serotonin (5-HT) is a key signalling molecule in the gastrointestinal tract and is known to influence motility, however little is known of how the ageing process alters 5-HT signalling processes in the bowel. RESULTS An isocratic chromatographic method was able to detect all 5-HT precursors and metabolites. Using extracellular and intracellular sampling approaches, we were able to monitor all key parameters associated with the transmission process. There was no alteration in the levels of tryptophan and 5-HTP between 3 and 18 month old animals. There was a significant increase in the ratio of 5-HT:5-HTP and an increase in intracellular 5-HT between 3 and 18 month old animals suggesting an increase in 5-HT synthesis. There was also a significant increase in extracellular 5-HT with age, suggesting increased 5-HT release. There was an age-related decrease in the ratio of intracellular 5-HIAA:extracellular 5-HT, whilst the amount of 5-HIAA did not change with age. In the presence of an increase in extracellular 5-HT, the lack of an age-related change in 5-HIAA is suggestive of a decrease in re-uptake via the serotonin transporter (SERT). CONCLUSIONS We have used intracellular and extracellular sampling to provide more insight into alterations in the neurotransmission process of 5-HT during normal ageing. We observed elevated 5-HT synthesis and release and a possible decrease in the activity of SERT. Taken together these changes lead to increased 5-HT availability and may alter motility function and could lead to the changes in adsorption observed in the elderly.
Collapse
Affiliation(s)
- Leena Parmar
- Centre for Biomedical and Health Sciences Research, University of Brighton, Brighton, BN2 4GJ, UK.
| | | | | | | |
Collapse
|
33
|
Southwell BR, Koh TL, Wong SQ, King SK, Ong SY, Lee M, Farmer PJ, Peck CJ, Sutcliffe JR, Stanton MP, Keck J, Cook DJ, Chow CW, Hutson JM. Decrease in nerve fibre density in human sigmoid colon circular muscle occurs with growth but not aging. Neurogastroenterol Motil 2010; 22:439-45, e106. [PMID: 19840272 DOI: 10.1111/j.1365-2982.2009.01423.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Studies in animals suggest that enteric neurons decrease in density or number with increasing age. Neurons containing nitric oxide (NO), vasoactive intestinal peptide (VIP) and Substance P (SP) have been implicated. In human large intestine, NO-utilizing neurons decrease during childhood or early adulthood but it is not known if the innervation of the muscle changes. This study examined the density of nerve fibres containing these transmitters in sigmoid colon circular muscle from children and adults. METHODS Fluorescence immunohistochemistry using antibodies to neuronal NO synthase (nNOS), VIP and SP was performed on sigmoid colon from 18 adults with colorectal cancer, two children with familial adenomatous polyposis, and normal colon from nine children with Hirschsprung's disease. The percentage area of immunoreactive (IR) nerve fibres containing each transmitter in circular muscle was quantified in confocal images. KEY RESULTS In the adult sigmoid colon circular muscle, the percentage area of nerve fibres containing nNOS>VIP>SP (6 : 2 : 1). Paediatric groups had significantly higher percentage area of nerve fibres containing nNOS, VIP or SP-IR than adults, with the decrease in nerve fibre density occurring from birth to 30 years. Circular muscle thickness increased between 12 and 30 years. Total nerve fibre area remained constant, while the muscle increased in thickness. CONCLUSIONS & INFERENCES In human sigmoid colon circular muscle, there are reductions in nNOS-, VIP- and SP-IR nerve fibre density with growth from newborn to late adolescence but little further change with aging. The reduction in nerve density is due to an increase in circular muscle thickness rather than a loss of nerve fibres.
Collapse
Affiliation(s)
- B R Southwell
- Department of General Surgery, Royal Children's Hospital, Melbourne, Australia.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Phillips RJ, Walter GC, Powley TL. Age-related changes in vagal afferents innervating the gastrointestinal tract. Auton Neurosci 2010; 153:90-8. [PMID: 19665435 PMCID: PMC2818053 DOI: 10.1016/j.autneu.2009.07.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2009] [Revised: 07/11/2009] [Accepted: 07/13/2009] [Indexed: 12/16/2022]
Abstract
Recent progress in understanding visceral afferents, some of it reviewed in the present issue, serves to underscore how little is known about the aging of the visceral afferents in the gastrointestinal (GI) tract. In spite of the clinical importance of the issue-with age, GI function often becomes severely compromised-only a few initial observations on age-related structural changes of visceral afferents are available. Primary afferent cell bodies in both the nodose ganglia and dorsal root ganglia lose Nissl material and accumulate lipofucsin, inclusions, aggregates, and tangles. Additionally, in changes that we focus on in the present review, vagal visceral afferent terminals in both the muscle wall and the mucosa of the GI tract exhibit age-related structural changes. In aged animals, both of the vagal terminal types examined, namely intraganglionic laminar endings and villus afferents, exhibit dystrophic or regressive morphological changes. These neuropathies are associated with age-related changes in the structural integrity of the target organs of the affected afferents, suggesting that local changes in trophic environment may give rise to the aging of GI innervation. Given the clinical relevance of GI tract aging, a more complete understanding both of how aging alters the innervation of the gut and of how such changes might be mitigated should be made research priorities.
Collapse
Affiliation(s)
- Robert J Phillips
- Purdue University, Ingestive Behavior Research Center, Department of Psychological Sciences, West Lafayette, IN 47907-2081, USA.
| | | | | |
Collapse
|
35
|
Abstract
Colonic sensorimotor dysfunction is recognized as the principal pathophysiological mechanism underpinning chronic constipation. This review addresses current understanding derived from both human and animal studies, with particular reference made to methods of investigation.
Collapse
Affiliation(s)
- P. G. Dinning
- Department of Medicine, University of New South Wales, St George Hospital, Sydney, Australia
| | - T. K. Smith
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, USA
| | - S. M. Scott
- Queen Mary University London, Barts and the London School of Medicine & Dentistry, London, UK
| |
Collapse
|
36
|
Abstract
Acute and chronic diarrheal disorders are common problems at all ages. It has been estimated that 5% to 7% of the population has an episode of acute diarrhea each year and that 3% to 5% have chronic diarrhea that lasts more than 4 weeks. It is likely that the prevalence of diarrhea is similar in older individuals. This article reviews the impact of diarrhea in the elderly, many of whom are less fit physiologically to withstand the effect of diarrhea on fluid balance and nutritional balance.
Collapse
Affiliation(s)
- Lawrence R Schiller
- Digestive Health Associates of Texas, 712 North Washington Avenue, #200, Dallas, TX 75246, USA.
| |
Collapse
|
37
|
Sprenger N, Julita M, Donnicola D, Jann A. Sialic acid feeding aged rats rejuvenates stimulated salivation and colon enteric neuron chemotypes. Glycobiology 2009; 19:1492-502. [PMID: 19696237 DOI: 10.1093/glycob/cwp124] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Old age is linked to numerous changes of body functions such as salivation, gastrointestinal motility, and permeability all linked to central and enteric nervous system decline. Thus, gut motility and barrier functions suffer. Sialic acid plays a key role in the nervous system at large and for many receptor functions specifically. Decreased sialylation in the elderly suggests an endogenous sialic acid deficit. We used a rat model of aging, to ask whether sialic acid feeding would affect (i) stimulated salivation, (ii) gut functions, and (iii) sialic acid levels and neuronal markers in brain and gut. We observed reduced levels of pilocarpine-stimulated salivation in old versus young rats and restored this function by sialic acid feeding. Brain ganglioside bound sialic acid levels were found lower in aged versus young rats, and sialic acid feeding partly restored the levels. The hypothalamic expression of cholinergic and panneuronal markers was reduced in aged rats. The expression of the nitrergic marker nNOS was increased upon sialic acid feeding in aged rats. Neither fecal output nor gut permeability was different between young and aged rats studied here, and sialic acid feeding did not alter these parameters. However, the colonic expression of specific nervous system markers nNOS and Uchl1 and the key enzyme for sialic acid synthesis GNE were differentially affected in young and aged rats by sialic acid feeding indicating that regulatory mechanisms change with age. Investigation of sialic acid supplementation as a functional nutrient in the elderly may help those who suffer from disorders of reduced salivation. Further research is needed to understand the differential effects of sialic acid feeding in young and aged rats.
Collapse
Affiliation(s)
- Norbert Sprenger
- Nestlé Research Center, Vers-chez-les-Blanc, Lausanne 26, CH-1000 Switzerland.
| | | | | | | |
Collapse
|
38
|
Freitas PD, Natali MRM, Pereira RVF, Neto MHM, Zanoni JN. Myenteric neurons and intestinal mucosa of diabetic rats after ascorbic acid supplementation. World J Gastroenterol 2008; 14:6518-24. [PMID: 19030205 PMCID: PMC2773339 DOI: 10.3748/wjg.14.6518] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of ascorbic acid (AA) dietary supplementation on myenteric neurons and epithelial cell proliferation of the jejunum of adult rats with chronic diabetes mellitus.
METHODS: Thirty rats at 90 d of age were divided into three groups: Non-diabetic, diabetic and diabetic treated with AA (DA) (1 g/L). After 120 d of treatment with AA the animals were killed. The myenteric neurons were stained for myosin-V and analyzed quantitatively in an area of 11.2 mm2/animal. We further measured the cellular area of 500 neurons per group. We also determined the metaphasic index (MI) of the jejunum mucosa layer of about 2500 cells in the intestinal crypts, as well as the dimensions of 30 villi and 30 crypts/animal. The data area was analyzed using the Olympus BX40 microscope.
RESULTS: There was an increase of 14% in the neuronal density (792.6 ± 46.52 vs 680.6 ± 30.27) and 4.4% in the cellular area (303.4 ± 5.19 vs 291.1 ± 6.0) respectively of the diabetic group treated with AA when compared to control diabetic animals. There were no significant differences in MI parameters, villi height or crypt depths among the groups.
CONCLUSION: Supplementation with AA in the diabetic animal promoted moderate neuroprotection. There was no observation of alteration of the cellular proliferation of the jejunum mucosa layer of rats with chronic diabetes mellitus with or without supplementation with AA.
Collapse
|
39
|
Choi JH, Lee CH, Chung DW, Hwang IK, Won MH, Seong JK, Yoon YS, Lee IS. Age-related changes of calbindin D-28k-immunoreactive neurons in the myenteric plexus of gerbil duodenum. J Vet Med Sci 2008; 70:343-8. [PMID: 18460827 DOI: 10.1292/jvms.70.343] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We examined the age-related changes of calbindin D-28k (CB)-immunoreactive neurons and overall populations of neurons in the myenteric plexus of gerbil duodenum using whole mount preparations and immunohistochemistry. The circumference of duodenum increased age-dependently. CB-immunoreactive neurons were observed in all groups, and most of them had the Dogiel type II morphology. The fully developed cobweb-like structures were observed in the myenteric plexus of duodenum at postnatal month (PM) 3 to 24. Although the highest numbers of CB-immunoreactive neurons and overall population were observed in PM 1.5, it is related with significant increase of the size of circumference between PM 1.5 to PM 3. CB-immunoreactive neurons were slightly decreased with age between PM 3 to PM 24. We have also found that whole numbers of myenteric neurons were also significantly decreased in PM 24 group. These results suggest that loss of overall numbers of myenteric neurons and CB-immunoreactive neurons may be related with age-related neurodegeneration and functional loss of duodenum in the gerbil.
Collapse
Affiliation(s)
- Jung Hoon Choi
- Department of Anatomy and Cell Biology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Abstract
PURPOSE OF REVIEW With the graying of the world's population, there is an increased interest in the physiological effects of aging. This review examines the physiological changes of the gut with aging and their clinical significance. RECENT FINDINGS Changes with aging in the gastrointestinal tract are variable, but in some cases they are responsible for a variety of symptoms. Thus, alterations in taste and smell, gastric motility, intestinal overgrowth and changes in gastrointestinal hormone release are the basis of the physiological anorexia of aging. Alterations in swallowing lead to silent aspiration. Changes in gastric emptying play a role in postprandial hypotension. Changes in gastrointestinal function can lead to constipation and fecal incontinence. Weakening of the colonic muscular wall produces diverticula. Achlorhydria is associated with malabsorption of some forms of iron and calcium. Vitamin D malabsorption aggravates the hypovitaminosis D that is so common in older persons. Changes in probiotics can lead to diarrhea and altered immune system. In the liver, aging is associated with delayed drug metabolism. SUMMARY Changes in the physiology of the gut play a role in the anorexia of aging, aspiration pneumonia, postprandial hypotension, constipation and fecal incontinence.
Collapse
Affiliation(s)
- Asif Bhutto
- Division of Geriatric Medicine, Saint Louis University, USA bGRECC, VA Medical Center, St. Louis, Missouri, USA
| | | |
Collapse
|
41
|
De Britto Mari R, Clebis NK, Gagliardo KM, Guimares JP, Stabille SR, De Mello Germano R, De Souza RR. Effects of Exercise on the Morphology of the Myenteric Neurons of the Duodenum of Wistar Rats during the Ageing Process. Anat Histol Embryol 2008; 37:289-95. [DOI: 10.1111/j.1439-0264.2008.00843.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
42
|
Roberts RR, Bornstein JC, Bergner AJ, Young HM. Disturbances of colonic motility in mouse models of Hirschsprung's disease. Am J Physiol Gastrointest Liver Physiol 2008; 294:G996-G1008. [PMID: 18276829 DOI: 10.1152/ajpgi.00558.2007] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mutations in genes encoding members of the GDNF and endothelin-3 (Et-3) signaling pathways can cause Hirschsprung's disease, a congenital condition associated with an absence of enteric neurons in the distal gut. GDNF signals through Ret, a receptor tyrosine kinase, and Et-3 signals through endothelin receptor B (Ednrb). The effects of Gdnf, Ret, and ET-3 haploinsufficiency and a null mutation in ET-3 on spontaneous motility patterns in adult and developing mice were investigated. Video recordings were used to construct spatiotemporal maps of spontaneous contractile patterns in colon from postnatal and adult mice in vitro. In Ret(+/-) and ET-3(+/-) mice, which have normal numbers of enteric neurons, colonic migrating motor complexes (CMMCs) displayed similar properties under control conditions and following inhibition of nitric oxide synthase (NOS) activity to wild-type mice. In the colon of Gdnf(+/-) mice and in the ganglionic region of ET-3(-/-) mice, there was a 50-60% reduction in myenteric neuron number. In Gdnf(+/-) mice, CMMCs were present, but abnormal, and the proportion of myenteric neurons containing NOS was not different from that of wild-type mice. In the ganglionic region of postnatal ET-3(-/-) mice, CMMCs were absent, and the proportion of myenteric neurons containing NOS was over 100% higher than in wild-type mice. Thus impairments in spontaneous motility patterns in the colon of Gdnf(+/-) mice and in the ganglionic region of ET-3(-/-) mice are correlated with a reduction in myenteric neuron density.
Collapse
Affiliation(s)
- Rachael R Roberts
- Dept. of Physiology, Univ. of Melbourne, Parkville, Vic 3010, Australia.
| | | | | | | |
Collapse
|
43
|
Burcher E, Shang F, Warner FJ, Du Q, Lubowski DZ, King DW, Liu L. Tachykinin NK2 Receptor and Functional Mechanisms in Human Colon: Changes with Indomethacin and in Diverticular Disease and Ulcerative Colitis. J Pharmacol Exp Ther 2007; 324:170-8. [DOI: 10.1124/jpet.107.130385] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
|
44
|
Abstract
The 5-HT(4) partial agonist tegaserod is effective in the treatment of chronic constipation and constipation predominant irritable bowel syndrome. 5-HT(4) receptors are located on presynaptic terminals in the enteric nervous system. Stimulation of 5-HT(4) receptors enhances the release of acetylcholine and calcitonin gene related peptide from stimulated nerve terminals. This action strengthens neurotransmission in prokinetic pathways, enhancing gastrointestinal motility. The knockout of 5-HT(4) receptors in mice not only slows gastrointestinal activity but also, after 1 month of age, increases the age-related loss of enteric neurons and decreases the size of neurons that survive. 5-HT(4) receptor agonists, tegaserod and RS67506, increase numbers of enteric neurons developing from precursor cells and/or surviving in culture; they also increase neurite outgrowth and decrease apoptosis. The 5-HT(4) receptor antagonist, GR113808, blocks all of these effects, which are thus specific and 5-HT(4)-mediated. 5-HT(4) receptor agonists, therefore, are neuroprotective and neurotrophic for enteric neurons. Because the age-related decline in numbers of enteric neurons may contribute to the dysmotilities of the elderly, the possibility that the neuroprotective actions of 5-HT agonists can be utilized to prevent the occurrence or worsening of these conditions should be investigated.
Collapse
Affiliation(s)
- M D Gershon
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA.
| | | |
Collapse
|
45
|
Abstract
The 5-HT(4) partial agonist tegaserod is effective in the treatment of chronic constipation and constipation predominant irritable bowel syndrome. 5-HT(4) receptors are located on presynaptic terminals in the enteric nervous system. Stimulation of 5-HT(4) receptors enhances the release of acetylcholine and calcitonin gene related peptide from stimulated nerve terminals. This action strengthens neurotransmission in prokinetic pathways, enhancing gastrointestinal motility. The knockout of 5-HT(4) receptors in mice not only slows gastrointestinal activity but also, after 1 month of age, increases the age-related loss of enteric neurons and decreases the size of neurons that survive. 5-HT(4) receptor agonists, tegaserod and RS67506, increase numbers of enteric neurons developing from precursor cells and/or surviving in culture; they also increase neurite outgrowth and decrease apoptosis. The 5-HT(4) receptor antagonist, GR113808, blocks all of these effects, which are thus specific and 5-HT(4)-mediated. 5-HT(4) receptor agonists, therefore, are neuroprotective and neurotrophic for enteric neurons. Because the age-related decline in numbers of enteric neurons may contribute to the dysmotilities of the elderly, the possibility that the neuroprotective actions of 5-HT agonists can be utilized to prevent the occurrence or worsening of these conditions should be investigated.
Collapse
Affiliation(s)
- M D Gershon
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA.
| | | |
Collapse
|
46
|
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.
Collapse
Affiliation(s)
- Robert J Phillips
- Purdue University, Department of Psychological Sciences, 703 Third Street, West Lafayette, IN 47907-2081, USA.
| | | |
Collapse
|
47
|
Wolf M, Schrödl F, Neuhuber W, Brehmer A. Calcitonin Gene-Related Peptide: A Marker for Putative Primary Afferent Neurons in the Pig Small Intestinal Myenteric Plexus? Anat Rec (Hoboken) 2007; 290:1273-9. [PMID: 17763367 DOI: 10.1002/ar.20577] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
For years, calcitonin gene-related peptide (CGRP) has been used as a marker peptide for Dogiel type II neurons, putative intrinsic primary afferent neurons, in the pig enteric nervous system. Recently, some studies showed CGRP-positive neurons displaying distinctly different shapes. The aims of this study were to evaluate (1) the proportion of myenteric type II neurons that contain CGRP and (2) the proportion of myenteric CGRP-positive neurons that display type II vs. non-type II morphologies and to conclude if this peptide could be suited as a marker for type II neurons. For this purpose, nine myenteric whole-mounts (each one from duodenum, jejunum, and ileum, respectively, derived from three pigs) were triple-immunostained for CGRP, neurofilaments (NF), and choline acetyl transferase (ChAT). Each whole-mount was evaluated twice. First, 50 NF-stained type II neurons were selected randomly and their coreactivities for CGRP and ChAT were observed. Second, 50 CGRP-positive neurons were located randomly and their NF morphology and ChAT coreactivity were observed. Altogether, 92% of all type II neurons investigated displayed CGRP immunoreactivity, whereas 94.9% of all CGRP-reactive neurons recorded displayed type II morphology. We observed three further shapes of CGRP-positive neurons: 7 type V neurons (all were ChAT-positive; mainly in the ileal whole-mounts), 6 type I-like neurons (all were ChAT-positive), and 14 type III-like neurons (mostly ChAT-negative; mainly in duodenal and jejunal specimens). We conclude that CGRP-antibodies can be used as markers for type II neurons in the pig small intestinal myenteric plexus in quantitative studies but it should be kept in mind that up to one-tenth of CGRP-reactive neurons may be non-type II neurons. In case of single cell evaluation, CGRP-immunoreactivity alone is not suited as a marker. In such cases additional, morphological analysis is necessary.
Collapse
|
48
|
Li M, Li ZG, Zhu XB, Feng XL, Hu HZ. Mechanism of decreased response of jejunal smooth muscle to isoproterenol in aged rats. Shijie Huaren Xiaohua Zazhi 2005; 13:1852-1855. [DOI: 10.11569/wcjd.v13.i15.1852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the response of jejunal smooth muscles (JSMs) to nonselective b-adrenoceptor agonist (Isoprot-erenol, Iso) in rats with different ages and its possible mechanism.
METHODS: The nonselective b-adrenoceptor agonist Iso and nonselective nitric oxide synthase (NOS) inhibitor Nw-nitro -L-arginine (L-NNA) were perfused into the baths of rat JSMs. Muscle force transducer (MFT) was used to measure the tension of JSMs.
RESULTS: The contractive frequency of JSMs was markedly lower in 20-mo rats than that in 3-mo rats (27.0±2.5 vs30±3.1, P<0.05). After perfusion with Iso (Final concentration: 1×10-9-1×10-6 mol/L), the variation rates of contractive amplitude of JSMs in 20-mo rats were lower than those in 3-mo rats (3×10-8 mol/L: -41.4%, P<0.05; 1×10-7 mol/L: -34.6%, P<0.05; 3×10-7 mol/L: -25.0%, P<0.05; 1×10-6 mol/L: -19.5%, P<0.05). After the administration of L-NNA, the relaxation responses of JSMs decreased in 3-mo rats, while there was no obvious variation in 20-mo rats. Before the administration of L-NNA, the pD2 of b-adrenoceptor decreased in 20-mo rats as compared with that in 3-mo rats (6.52±0.54 vs 6.98±0.30, P<0.05).
CONCLUSION: The response of JSMs to Iso in aged rats decreases, and the mechanism may be related to the decreased effect of NOS or nitric oxide.
Collapse
|
49
|
Abstract
The intrinsic neurones of the enteric nervous system (ENS) play a fundamental role in the regulation of gastrointestinal functions. Although much remains to be learnt about the changes that take place in intestinal nerves during ageing, evidence suggests that selective neurodegeneration may occur in the ageing ENS. Age-associated changes in intestinal innervation may contribute to the gastrointestinal disorders that increase in incidence in the elderly, such as dysphagia, gastrointestinal reflux and constipation. A number of other factors, such as immobility, co-morbidity, and side effects of therapeutic medication for other disorders however, are also likely to contribute to the aetiology of these conditions. An important finding in rodents is that the neuronal losses that take place in the ENS during ageing may be prevented by calorie restriction; an indication that diet may influence gastrointestinal ageing. Thus, it is of importance to understand not only how the ENS changes during 'normal' ageing, but also how external factors contribute to these changes. Here, current knowledge of how intestinal innervation is affected during normal ageing and how these changes may impact upon gastrointestinal physiology are reviewed.
Collapse
Affiliation(s)
- M Jill Saffrey
- Department of Biological Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
| |
Collapse
|
50
|
Phillips RJ, Kieffer EJ, Powley TL. Loss of glia and neurons in the myenteric plexus of the aged Fischer 344 rat. ACTA ACUST UNITED AC 2005; 209:19-30. [PMID: 15480773 DOI: 10.1007/s00429-004-0426-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Over the normal lifespan, a subpopulation of myenteric neurons in the small and large intestines dies. This loss is one possible mechanism for the disruptions of gastrointestinal function seen in the elderly. Little, however, is known about how the glia constituting the supportive cells of the myenteric plexus may change with aging and the losses of the enteric neurons. The goal of the present study, therefore, was to determine what, if any, changes occur in the glia associated with myenteric neurons in the aged gut. Two experimental groups, consisting of adult (5-6 months of age, n = 8) or aged (26 months of age, n = 8) virgin male Fischer 344 rats, fed ad libitum, were examined. The duodenum, jejunum, ileum, colon, and rectum from each rat were prepared as whole mounts, and indirect immunofluorescence was used to visualize the myenteric glia and neurons (antibodies to S-100 and the HuC/D protein, respectively). Separate counts of glia and neurons from the same specimens were determined, and these counts were expressed both as per ganglionic area and as per ganglion to correct for "dilution" effects resulting from age-associated changes in tissue area. Significant reductions in both the numbers of glia as well as neurons occurred in every region of the small and large intestine sampled from aged rats, except for the rectum, where a nonsignificant decrease was observed. Glial loss was proportional to neuronal death, suggesting an interdependency between the two cell types. Thus, an understanding of the nature of the neuron-glia interaction in the enteric nervous system may provide insight into the deterioration of function seen in the aged gut.
Collapse
Affiliation(s)
- Robert J Phillips
- Purdue University, Department of Psychological Sciences, 703 Third Street, West Lafayette, IN 47907-2081, USA.
| | | | | |
Collapse
|