1
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Cheng Y, Kou Y, Wang J, Wang Y, Rong W, Han H, Zhang G. 5-Hydroxytryptamine 4 Receptor Agonist Attenuates Diabetic Enteric Neuropathy through Inhibition of the Receptor-Interacting Protein Kinase 3 Pathway. THE AMERICAN JOURNAL OF PATHOLOGY 2024; 194:785-795. [PMID: 38311118 DOI: 10.1016/j.ajpath.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 01/09/2024] [Accepted: 01/19/2024] [Indexed: 02/06/2024]
Abstract
Necroptosis, considered as a form of programmed cell death, contributes to neural loss. The 5-hydroxytryptamine 4 receptor (5-HT4R) is involved in neurogenesis in the enteric nervous system. However, whether the activation of 5-HT4R can alleviate diabetic enteric neuropathy by inhibiting receptor-interacting protein kinase 3 (RIPK3)-mediated necroptosis is unclear. This study aimed to explore the beneficial effects of 5-HT4R agonist on enteric neuropathy in a mouse model of diabetes and the mechanisms underlying these effects. Diabetes developed neural loss in the colon of mice. 5-HT4Rs localized in submucosal and myenteric plexuses were confirmed. Administration of 5-HT4R agonist attenuated diabetes-induced colonic hypomotility and neural loss of the colon in mice. Remarkably, RIPK3, phosphorylated RIPK3, and its downstream target mixed lineage kinase domain-like protein (MLKL), two key proteins regulating necroptosis, were significantly up-regulated in the colon of diabetic mice. Treatment with 5-HT4R agonist appeared to inhibit diabetes-induced elevation of RIPK3, phosphorylated RIPK3, and MLKL in the colon of mice. Diabetes-induced up-regulation of MLKL in both the mucosa and the muscularis of the colon was prevented by Ripk3 deletion. Moreover, diabetes-evoked neural loss and delayed colonic transit were significantly inhibited by Ripk3 removal. These findings suggest that activation of 5-HT4Rs could potentially provide a protective effect against diabetic enteric neuropathy by suppressing RIPK3-mediated necroptosis.
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Affiliation(s)
- Yingying Cheng
- Songjiang Research Institute, Shanghai Songjing District Central Hospital, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yueting Kou
- Songjiang Research Institute, Shanghai Songjing District Central Hospital, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Juan Wang
- Songjiang Research Institute, Shanghai Songjing District Central Hospital, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yue Wang
- Songjiang Research Institute, Shanghai Songjing District Central Hospital, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weifang Rong
- Songjiang Research Institute, Shanghai Songjing District Central Hospital, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hongxiu Han
- Department of Pathology, Tongji Hospital, Tongji University, Shanghai, China.
| | - Guohua Zhang
- Songjiang Research Institute, Shanghai Songjing District Central Hospital, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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2
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Zahid SA, Tated R, Mathew M, Rajkumar D, Karnik SB, Pramod Roy A, Jacob FP, Baskara Salian R, Razzaq W, Shivakumar D, Khawaja UA. Diabetic Gastroparesis and its Emerging Therapeutic Options: A Narrative Review of the Literature. Cureus 2023; 15:e44870. [PMID: 37814758 PMCID: PMC10560130 DOI: 10.7759/cureus.44870] [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: 07/15/2023] [Accepted: 09/06/2023] [Indexed: 10/11/2023] Open
Abstract
Diabetic gastroparesis (DG) is one of the many complications of diabetes mellitus (DM). Even though this condition surfaces years after uncontrolled disease, it affects the quality of life in several ways and causes significant morbidity. Common symptoms experienced by the patients include postprandial nausea, vomiting, abdominal fullness, and pain. Strict glycemic control is essential to evade the effects of DG. The purpose of this review article is to briefly study the pathophysiology, clinical features, diagnostic modalities, and the effects of DG on different aspects of life. Furthermore, it also focuses on the emerging treatment modalities for DG. Tradipitant and relamorelin are two such treatment options that are gaining noteworthy recognition and are discussed in detail in this review article. As observed through various clinical trials, these drugs help alleviate symptoms like nausea, vomiting, abdominal pain, and bloating in patients suffering from DG, thereby targeting the most common and bothersome symptoms of the disease. This leads to an improvement in the quality of life, making it a reliable treatment option for this disease. But while pharmacological intervention is vital, psychological support and lifestyle changes are equally important and are the reason why a multidisciplinary approach is required for the treatment of DG.
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Affiliation(s)
- Shiza A Zahid
- Department of Internal Medicine, Jinnah Sindh Medical University, Karachi, PAK
| | - Ritu Tated
- Department of Internal Medicine, Mahatma Gandhi Mission Institute of Medical Sciences, Navi Mumbai, IND
| | - Midhun Mathew
- Department of Internal Medicine, Pennsylvania Hospital, Philadelphia, USA
| | - Daniel Rajkumar
- Department of Internal Medicine, Hospital Alor Gajah, Alor Gajah, MYS
| | - Siddhant B Karnik
- Department of Internal Medicine, Lokmanya Tilak Municipal Medical College and General Hospital, Mumbai, IND
| | | | - Fredy P Jacob
- Department of Internal Medicine, Jonelta Foundation School of Medicine, University of Perpetual Help System DALTA, Las Piñas, PHL
| | | | - Waleed Razzaq
- Department of Internal Medicine, Services Hospital Lahore, Lahore, PAK
| | - Divya Shivakumar
- Department of Internal Medicine, Kamineni Academy of Medical Sciences and Research Center, Hyderabad, IND
| | - Uzzam Ahmed Khawaja
- Department of Paediatrics and Child Health, Aga Khan University Hospital, Karachi, PAK
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3
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Wei L, Ji L, Miao Y, Han X, Li Y, Wang Z, Fu J, Guo L, Su Y, Zhang Y. Constipation in DM are associated with both poor glycemic control and diabetic complications: Current status and future directions. Biomed Pharmacother 2023; 165:115202. [PMID: 37506579 DOI: 10.1016/j.biopha.2023.115202] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/15/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Constipation is a major complications of diabetes mellitus. With the accelerating prevalence of diabetes worldwide and an aging population, there is considerable research interest regarding the altered function and structure of the gastrointestinal tract in diabetic patients. Despite current advances in hyperglycemic treatment strategies, the specific pathogenesis of diabetic constipation remains unknown. Patients with constipation, may be reluctant to eat regularly, which may worsen glycemic control and thus worsen symptoms associated with underlying diabetic bowel disease. This paper presents a review of the complex relationship between diabetes and constipation, exploring the morphological alterations and biomechanical remodeling associated with intestinal motility dysfunction, as well as alterations in intestinal neurons, cellular signaling pathways, and oxidative stress. Further studies focusing on new targets that may play a role in the pathogenesis of diabetic constipation may, provide new ideas for the development of novel therapies to treat or even prevent diabetic constipation.
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Affiliation(s)
- Luge Wei
- Tianjin University of Traditional Chinese Medicine, China.
| | - Lanqi Ji
- Tianjin University of Traditional Chinese Medicine, China
| | - Yulu Miao
- Tianjin University of Traditional Chinese Medicine, China
| | - Xu Han
- Tianjin University of Traditional Chinese Medicine, China
| | - Ying Li
- Tianjin University of Traditional Chinese Medicine, China
| | - Zhe Wang
- Tianjin University of Traditional Chinese Medicine, China
| | - Jiafeng Fu
- Tianjin University of Traditional Chinese Medicine, China
| | - Liuli Guo
- Tianjin University of Traditional Chinese Medicine, China
| | - Yuanyuan Su
- Tianjin University of Traditional Chinese Medicine, China
| | - Yanjun Zhang
- Tianjin University of Traditional Chinese Medicine, China; First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, China
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4
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Sprouse J, Sampath C, Gangula P. 17β-Estradiol Suppresses Gastric Inflammatory and Apoptotic Stress Responses and Restores nNOS-Mediated Gastric Emptying in Streptozotocin (STZ)-Induced Diabetic Female Mice. Antioxidants (Basel) 2023; 12:758. [PMID: 36979006 PMCID: PMC10045314 DOI: 10.3390/antiox12030758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/09/2023] [Accepted: 03/12/2023] [Indexed: 03/30/2023] Open
Abstract
Gastroparesis (Gp) is a severe complication of diabetes mellitus (DM) observed predominantly in women. It is characterized by abnormal gastric emptying (GE) without mechanical obstruction in the stomach. Nitric oxide (NO) is an inhibitory neurotransmitter produced by neuronal nitric oxide synthase (nNOS). It plays a critical role in gastrointestinal (GI) motility and stomach emptying. Here, we wanted to demonstrate the protective effects of supplemental 17β-estradiol (E2) on NO-mediated gastric function. We showed E2 supplementation to alleviate oxidative and inflammatory stress in streptozotocin (STZ)-induced diabetic female mice. Our findings suggest that daily administration of E2 at therapeutic doses is beneficial for metabolic homeostasis. This restoration occurs via regulating and modulating the expression/function of glycogen synthase kinase-3β (GSK-3β), nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), Phase II enzymes, MAPK- and nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB)-mediated inflammatory cytokines (IL-1β, IL-6, TNFα, IGF-1), and gastric apoptotic regulators. We also showed E2 supplementation to elevate GCH-1 protein levels in female diabetic mice. Since GCH-1 facilitates the production of tetrahydrobiopterin (BH4, cofactor for nNOS), an increase in GCH-1 protein levels in diabetic mice may improve their GE and nitrergic function. Our findings provide new insights into the impact of estrogen on gastric oxidative stress and intracellular inflammatory cascades in the context of Gp.
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Affiliation(s)
- Jeremy Sprouse
- Department of Oral Diagnostic Sciences and Research, School of Dentistry, Meharry Medical College, Nashville, TN 37208, USA
- Department of Endodontics, School of Dentistry, Meharry Medical College, Nashville, TN 37208, USA
| | - Chethan Sampath
- Department of Oral Diagnostic Sciences and Research, School of Dentistry, Meharry Medical College, Nashville, TN 37208, USA
| | - Pandu Gangula
- Department of Oral Diagnostic Sciences and Research, School of Dentistry, Meharry Medical College, Nashville, TN 37208, USA
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5
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Fahimi S, Oryan S, Ahmadi R, Eidi A. Downregulation of Bax/Bcl-2 Expression During Apoptosis in the Hippocampus of Diabetic Male Wistar Rats: Ameliorative Effects of Peganum harmala Seed Extract. IRANIAN JOURNAL OF PHARMACEUTICAL RESEARCH : IJPR 2022; 21:e132071. [PMID: 36915407 PMCID: PMC10007996 DOI: 10.5812/ijpr-132071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/10/2022] [Accepted: 01/11/2023] [Indexed: 02/04/2023]
Abstract
Background Apoptosis is proposed as a possible mechanism for diabetes-induced hippocampal neuronal cell death. Numerous studies have suggested that the therapeutic properties of plants, such as antioxidant and anti-apoptotic, are effective in improving the complications of diabetes in the hippocampus. Objectives This study aimed to evaluate the anti-apoptotic properties of Peganum harmala (P. harmala) in the brain hippocampal cells of diabetic rats. Methods In this experimental study, 48 male Wistar rats were divided into six groups (n = 8) as follows: Control (C), diabetic (D), harmine (H), diabetic plus harmine (DH), seed extract (S), and diabetic plus seed extract (DS). A single dose of streptozotocin (STZ) (60 mg/kg) was enough to cause diabetes. Seed extract and harmine were given at 150 mg/kg and 6.5 mg/kg, respectively (daily by oral gavage for 28 days). The glucose levels in the blood were measured, and the histological staining of the hippocampus was examined. Percentages of apoptotic hippocampal cells were identified with flow cytometry. Bax and Bcl-2 expression was assayed via Real time- polymerase chain reaction (PCR) and Western blot. Results In DH (P = 0.001) and DS (P = 0.01) rats, the mean fasting blood glucose level significantly reduced compared with the D group. Bax and Bcl-2 expression at both mRNA and protein levels significantly differed between the D group and other groups (P = 0.01). Harmine and the seed extract considerably reduced the Bax/Bcl-2 ratio in the hippocampal cells compared to the D group (P = 0.001). Conclusions Streptozotocin-induced apoptosis in the hippocampus of diabetic rats was reduced by administering the seed extract of Peganum harmala. The P. harmala seed extract and its active ingredient, harmine, could be used as anti-apoptotic drugs.
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Affiliation(s)
- Saeedeh Fahimi
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Shahrbanoo Oryan
- Department of Animal Sciences, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Ramesh Ahmadi
- Department of Animal Sciences, Faculty of Basic Sciences, Islamic Azad University of Qom, Qom, Iran
- Corresponding Author: Department of Animal Sciences, Faculty of Basic Sciences, Islamic Azad University of Qom, Qom, Iran.
| | - Akram Eidi
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
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6
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Spinal cord injury-mediated changes in electrophysiological properties of rat gastric nodose ganglion neurons. Exp Neurol 2022; 348:113927. [PMID: 34798136 PMCID: PMC8727501 DOI: 10.1016/j.expneurol.2021.113927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 10/30/2021] [Accepted: 11/11/2021] [Indexed: 02/03/2023]
Abstract
In preclinical rodent models, spinal cord injury (SCI) manifests as gastric vagal afferent dysfunction both acutely and chronically. However, the mechanism that underlies this dysfunction remains unknown. In the current study, we examined the effect of SCI on gastric nodose ganglia (NG) neuron excitability and on voltage-gated Na+ (NaV) channels expression and function in rats after an acute (i.e. 3-days) and chronic (i.e. 3-weeks) period. Rats randomly received either T3-SCI or sham control surgery 3-days or 3-weeks prior to experimentation as well as injections of 3% DiI solution into the stomach to identify gastric NG neurons. Single cell qRT-PCR was performed on acutely dissociated DiI-labeled NG neurons to measure NaV1.7, NaV1.8 and NaV1.9 expression levels. The results indicate that all 3 channel subtypes decreased. Current- and voltage-clamp whole-cell patch-clamp recordings were performed on acutely dissociated DiI-labeled NG neurons to measure active and passive properties of C- and A-fibers as well as the biophysical characteristics of NaV1.8 channels in gastric NG neurons. Acute and chronic SCI did not demonstrate deleterious effects on either passive properties of dissociated gastric NG neurons or biophysical properties of NaV1.8. These findings suggest that although NaV gene expression levels change following SCI, NaV1.8 function is not altered. The disruption throughout the entirety of the vagal afferent neuron has yet to be investigated.
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7
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Meling S, Bertoli D, Sangnes DA, Brock C, Drewes A, Ejskjaer N, Dimcevski G, Søfteland E. Diabetic Gastroenteropathy: Soothe the Symptoms or Unravel a Cure? Curr Diabetes Rev 2022; 18:e220321192412. [PMID: 34225633 DOI: 10.2174/1573399817666210322154618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/19/2021] [Accepted: 02/13/2021] [Indexed: 11/22/2022]
Abstract
Autonomic neuropathy in patients with diabetes mellitus, and especially complications related to gastrointestinal neuropathy, are often overlooked in the clinic. Diabetic gastroenteropathy affects every segment of the gastrointestinal tract and generates symptoms that may include nausea, early satiety, vomiting, abdominal pain, constipation, and diarrhea. Severe cases can be complicated by weight loss, dehydration, and electrolyte disturbances. The pathophysiology is complex, the diagnostics and treatment options are multidisciplinary, and there is generally a lack of evidence for the treatment options. The aims for this review are first to summarize the pathophysiology and describe possible and expected symptoms and complications.Further, we will try to supply the clinician with a straightforward tool for diagnostics, and then, we shall summarize established treatment options, including diet recommendations, pharmacological and non-pharmacological options. Finally, we will explore the multiple possibilities of novel treatment, looking at medications related to the pathophysiology of neuropathy, other manifestations of autonomic neuropathies, and symptomatic treatment for other gastrointestinal disorders, also including new knowledge of endosurgical and neuromodulatory treatment. The overall goal is to increase awareness and knowledge on this frequent diabetic complication and to provide better tools for diagnosis and treatment. Ultimately, we hope to encourage further research in this field, as there are clear shortcomings in terms of biomarkers, pathophysiology, as well as treatment possibilities. In conclusion, diagnosis and management of diabetic gastroenteropathy are challenging and often require multidisciplinary teams and multimodal therapies. Treatment options are sparse, but new pharmacological, endoscopic, and neuromodulatory techniques have shown promising results in initial studies.
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Affiliation(s)
- Sondre Meling
- Department of Medicine, Stavanger University Hospital, Stavanger, Norway
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Davide Bertoli
- Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Dag A Sangnes
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Christina Brock
- Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
- Steno Diabetes Center North Jutland, Aalborg, Denmark
| | - Asbjørn Drewes
- Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
- Steno Diabetes Center North Jutland, Aalborg, Denmark
| | - Niels Ejskjaer
- Steno Diabetes Center North Jutland, Aalborg, Denmark
- Department of Clinical Medicine and Endocrinology, Aalborg University Hospital, Aalborg, Denmark
| | - Georg Dimcevski
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Eirik Søfteland
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
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8
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Klinge MW, Sutter N, Mark EB, Haase AM, Borghammer P, Schlageter V, Lund S, Fleischer J, Knudsen K, Drewes AM, Krogh K. Gastric Emptying Time and Volume of the Small Intestine as Objective Markers in Patients With Symptoms of Diabetic Enteropathy. J Neurogastroenterol Motil 2021; 27:390-399. [PMID: 34210904 PMCID: PMC8266501 DOI: 10.5056/jnm19195] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 03/13/2020] [Accepted: 12/19/2020] [Indexed: 12/15/2022] Open
Abstract
Background/Aims Patients with diabetes mellitus (DM) often suffer from gastrointestinal (GI) symptoms, but these correlate poorly to established objective GI motility measures. Our aim is to perform a detailed evaluation of potential measures of gastric and small intestinal motility in patients with DM type 1 and severe GI symptoms. Methods Twenty patients with DM and 20 healthy controls (HCs) were included. GI motility was examined with a 3-dimensional-Transit capsule, while organ volumes were determined by CT scans. Results Patients with DM and HCs did not differ with regard to median gastric contraction frequency (DM 3.0 contractions/minute [interquartile range {IQR}, 2.9-3.0]; HCs 2.9 [IQR, 2.8-3.1]; P = 0.725), amplitude of gastric contractions (DM 9 mm [IQR, 8-11]; HCs 11 mm (IQR, 9-12); P = 0.151) or fasting volume of the stomach wall (DM 149 cm3 [IQR, 112-187]; HCs 132 cm3 [IQR, 107-154]; P = 0.121). Median gastric emptying time was prolonged in patients (DM 3.3 hours [IQR, 2.6-4.6]; HCs 2.4 hours [IQR, 1.8-2.7]; P = 0.002). No difference was found in small intestinal transit time (DM 5 hours [IQR, 3.7-5.6]; HCs 4.8 hours [IQR, 3.9-6.0]; P = 0.883). However, patients with DM had significantly larger volume of the small intestinal wall (DM 623 cm3 [IQR, 487-766]; HCs 478 cm3 [IQR, 393-589]; P = 0.003). Among patients, 13 (68%) had small intestinal wall volume and 9 (50%) had gastric emptying time above the upper 95% percentile of HCs. Conclusion In our study, gastric emptying time and volume of the small intestinal wall appeared to be the best objective measures in patients with DM type 1 and symptoms and gastroenteropathy.
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Affiliation(s)
- Mette W Klinge
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Denmark
| | - Nanna Sutter
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Denmark
| | - Esben B Mark
- Mech-Sense, Department of Hepatology and Gastroenterology, and Department of Clinical Medicine, Aalborg University Hospital, Denmark
| | - Anne-Mette Haase
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Denmark
| | - Per Borghammer
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Denmark.,Department of Clinical Medicine, Aarhus University, Denmark
| | | | - Sten Lund
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Denmark.,Steno Diabetes Center Aarhus, Denmark
| | - Jesper Fleischer
- Steno Diabetes Center Aarhus, Denmark.,Steno Diabetes Center Copenhagen, Denmark
| | - Karoline Knudsen
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Denmark
| | - Asbjørn M Drewes
- Mech-Sense, Department of Hepatology and Gastroenterology, and Department of Clinical Medicine, Aalborg University Hospital, Denmark
| | - Klaus Krogh
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Denmark.,Steno Diabetes Center Aarhus, Denmark
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Cheng X, Zhao L, Ke T, Wang X, Cao L, Liu S, He J, Rong W. Celecoxib ameliorates diabetic neuropathy by decreasing apoptosis and oxidative stress in dorsal root ganglion neurons via the miR-155/COX-2 axis. Exp Ther Med 2021; 22:825. [PMID: 34149871 DOI: 10.3892/etm.2021.10257] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 03/29/2021] [Indexed: 12/12/2022] Open
Abstract
Celecoxib (CXB) is the only clinical cyclooxygenase-2 (COX-2) inhibitor. Oral administration of CXB in experimental diabetic mice effectively relieved the symptoms of diabetic neuropathy (DN); however, the molecular mechanism remains unclear. The present study aimed to investigate the potential molecular mechanisms of CXB in the treatment of DN. An in vitro cellular model of DN was produced by stimulating dorsal root ganglion (DRG) neurons with high glucose. Cell viability and apoptosis were assessed by Cell Counting Kit-8 assays and flow cytometry, respectively. Reactive oxygen species (ROS) kits, ELISA kits and western blotting were used to determine oxidative cellular damage. The expression level of microRNA (miR)-155 was analyzed by reverse transcription-quantitative PCR. The starBase database and dual-luciferase assays were performed to predict and determine the interaction between miR-155 and COX-2. Protein expression of neurotrophic factors, oxidative stress-related proteins and COX-2 were analyzed by western blotting. Incubation with high glucose led to a decrease in DRG neuron cell viability, facilitated apoptosis, downregulated NGF and BDNF expression, increased ROS and MDA generation and decreased SOD activity. Treatment with CXB significantly protected DRG neurons against high glucose-evoked damage. CXB promoted the expression of miR-155 and COX-2 was revealed to be a direct target of miR-155. Inhibition of COX-2 enhanced the protective effect of CXB on DRG neurons and that treatment with an miR-155 inhibitor partially rescued this effect. The present study demonstrated the involvement of the miR-155/COX-2 axis in the protective effect of CXB against high glucose-induced DN.
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Affiliation(s)
- Xiaoliang Cheng
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650101, P.R. China
| | - Ling Zhao
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650101, P.R. China
| | - Tingyu Ke
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650101, P.R. China
| | - Xi Wang
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650101, P.R. China
| | - Lijun Cao
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650101, P.R. China
| | - Shuyan Liu
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650101, P.R. China
| | - Jie He
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650101, P.R. China
| | - Wei Rong
- Department of Neurology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650101, P.R. China
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10
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Klinge MW, Haase AM, Mark EB, Sutter N, Fynne LV, Drewes AM, Schlageter V, Lund S, Borghammer P, Krogh K. Colonic motility in patients with type 1 diabetes and gastrointestinal symptoms. Neurogastroenterol Motil 2020; 32:e13948. [PMID: 32688448 DOI: 10.1111/nmo.13948] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/22/2020] [Accepted: 06/25/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Gastrointestinal (GI) symptoms are common in patients with diabetes mellitus (DM). The electromagnetic 3D-Transit system allows assessment of regional transit times and motility patterns throughout the GI tract. We aimed to compare GI transit times and detailed motility patterns of the colon in patients with DM and GI symptoms to those of healthy controls (HC). We further aimed to determine whether any abnormalities in motility were reversible by cholinergic stimulation. METHODS We compared 18 patients with DM with 20 HC by means of the 3D-Transit system. Patients were studied before and during oral administration of 60 mg pyridostigmine. KEY RESULTS Compared to HC, patients had prolonged gastric emptying (DM: 3.3 hours (interquartile range (IQR) 2.6-4.6); HC: 2.3 hours (IQR 1.7-2.7) (P < .01)), colonic transit time (DM: 52.6 hours (IQR 23.3-83.0); HC: 22.4 hours (IQR 18.9-43.6) (P = .02)), and whole gut transit time (DM: 69.4 hours (IQR 32.9-103.6); HC: 30.3 hours (IQR 25.2-49.9) (P < .01)). In addition, compared to HC, patients had prolonged transit time in the ascending colon (DM: 20.5 hours (IQR 11.0-44.0); HC: 8.0 hours (IQR 3.8-21.0) (P < .05)) and more slow retrograde movements in the colon (DM: 2 movements (IQR 1-4); HC: 1 movement (IQR 0-1) (P = .01)). In patients, pyridostigmine increased the number of bowel movements (P < .01) and reduced small intestine transit times (P < .05). CONCLUSIONS Patients with DM and GI symptoms have longer than normal GI transit times. This is only partly reversible by pyridostigmine. The increased number of retrograde colonic movements in patients could potentially explain the abnormally long transit time in proximal colon.
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Affiliation(s)
- Mette Winther Klinge
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Anne-Mette Haase
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Esben Bolvig Mark
- Mech-Sense, Department of Gastroenterology and Hepatology and Steno Diabetes Center North, Aalborg University Hospital, Aalborg, Denmark
| | - Nanna Sutter
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Asbjørn Mohr Drewes
- Mech-Sense, Department of Gastroenterology and Hepatology and Steno Diabetes Center North, Aalborg University Hospital, Aalborg, Denmark
| | | | - Sten Lund
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Per Borghammer
- Department of Nuclear Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Klaus Krogh
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark.,Steno Diabetes Center Aarhus, Aarhus, Denmark
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11
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Klinge MW, Borghammer P, Lund S, Fedorova T, Knudsen K, Haase AM, Christiansen JJ, Krogh K. Enteric cholinergic neuropathy in patients with diabetes: Non-invasive assessment with positron emission tomography. Neurogastroenterol Motil 2020; 32:e13731. [PMID: 31595630 DOI: 10.1111/nmo.13731] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/09/2019] [Accepted: 09/12/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND 11 C-Donepezil positron emission tomography (PET) allows non-invasive assessment of cholinergic innervation of visceral organs. We aimed to compare cholinergic innervation in the gut in patients with diabetes mellitus (DM) and in healthy controls (HC). METHODS 11 C-Donepezil PET and computed tomography (CT) were performed in 19 patients with type 1 DM and gastrointestinal symptoms and in 19 age- and sex-matched HC in a cross-sectional design. KEY RESULTS All patients had severe gastrointestinal symptoms when assessed by standard questionnaires. DM patients had significantly increased volume of the small intestinal wall (DM: median 557 cm3 [interquartile range [IQR] 446-697] vs HC median: 448 cm3 [IQR; 341-518; P < .01]), and the 11 C Donepezil PET uptake was reduced in patients (DM: median 7.08 standardized uptake value [SUV] [IQR; 5.94-8.43] vs HC: median 9.18 SUV [IQR; 8.57-10.11; P < .01]). A similar pattern was found in colon (DM: median volume 1064 cm3 [IQR; 882-1312] vs HC: median 939 cm3 [IQR; 785-1081; P = .13] and DM: median 1.22 SUV (IQR; 1.08-1.36) vs HC: median 1.42 SUV (IQR; 1.32-1.53; P = .03). Furthermore, patients had significantly reduced pancreatic volume (DM: median 53 cm3 [IQR; 41-69] vs HC: median 98 cm3 [IQR;82-110; P < .01]) and reduced PET uptake of the pancreas (DM: median 13.14 SUV [IQR;9.58-15.82] vs HC: median 21.46 SUV [IQR;18.97-24.06; P < .01]) as well as the adrenal gland (DM: median 7.62 SUV [IQR;7.61;15.82] vs HC: median 15.51 SUV [IQR;12.22;19.49; P = .03]). CONCLUSION AND INFERENCES Assessed with 11 C-Donepezil PET/CT, patients with DM and severe bowel symptoms have reduced cholinergic innervation of the gut indicative of parasympathetic denervation.
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Affiliation(s)
- Mette W Klinge
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Per Borghammer
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Sten Lund
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark.,Steno Diabetes Center, Aarhus, Denmark
| | - Tatyana Fedorova
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Karoline Knudsen
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Anne-Mette Haase
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Juel Christiansen
- Department of Internal Medicine and Endocrinology, Herning Regional Hospital, Herning, Denmark
| | - Klaus Krogh
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark.,Steno Diabetes Center, Aarhus, Denmark
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12
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Meldgaard T, Keller J, Olesen AE, Olesen SS, Krogh K, Borre M, Farmer A, Brock B, Brock C, Drewes AM. Pathophysiology and management of diabetic gastroenteropathy. Therap Adv Gastroenterol 2019; 12:1756284819852047. [PMID: 31244895 PMCID: PMC6580709 DOI: 10.1177/1756284819852047] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/26/2019] [Indexed: 02/04/2023] Open
Abstract
Polyneuropathy is a common complication to diabetes. Neuropathies within the enteric nervous system are associated with gastroenteropathy and marked symptoms that severely reduce quality of life. Symptoms are pleomorphic but include nausea, vomiting, dysphagia, dyspepsia, pain, bloating, diarrhoea, constipation and faecal incontinence. The aims of this review are fourfold. First, to provide a summary of the pathophysiology underlying diabetic gastroenteropathy. Secondly to give an overview of the diagnostic methods. Thirdly, to provide clinicians with a focussed overview of current and future methods for pharmacological and nonpharmacological treatment modalities. Pharmacological management is categorised according to symptoms arising from the upper or lower gut as well as sensory dysfunctions. Dietary management is central to improvement of symptoms and is discussed in detail, and neuromodulatory treatment modalities and other emerging management strategies for diabetic gastroenteropathy are discussed. Finally, we propose a diagnostic/investigation algorithm that can be used to support multidisciplinary management.
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Affiliation(s)
| | - Jutta Keller
- Israelitic Hospital in Hamburg, Academic
Hospital University of Hamburg, Germany
| | - Anne Estrup Olesen
- Mech-Sense, Department of Gastroenterology and
Hepatology and Department of Clinical Medicine, Aalborg University Hospital,
Denmark,Department of Clinical Medicine, Aalborg
University, Denmark
| | - Søren Schou Olesen
- Mech-Sense, Department of Gastroenterology and
Hepatology and Department of Clinical Medicine, Aalborg University Hospital,
Denmark,Department of Clinical Medicine, Aalborg
University, Denmark
| | - Klaus Krogh
- Department of Hepatology and Gastroenterology,
Aarhus University Hospital, Denmark
| | - Mette Borre
- Department of Hepatology and Gastroenterology,
Aarhus University Hospital, Denmark
| | - Adam Farmer
- Department of Gastroenterology, University
Hospitals of North Midlands, Stoke on Trent, Staffordshire, UK,Centre for Digestive Diseases, Blizard
Institute of Cell and Molecular Science, Wingate Institute of
Neurogastroenterology, Barts and the London School of Medicine and
Dentistry, Queen Mary University of London, UK
| | - Birgitte Brock
- Department of Clinical Research, Steno Diabetes
Center Copenhagen (SDCC), Denmark
| | - Christina Brock
- Mech-Sense, Department of Gastroenterology and
Hepatology and Department of Clinical Medicine, Aalborg University Hospital,
Denmark,Department of Clinical Medicine, Aalborg
University, Denmark
| | - Asbjørn Mohr Drewes
- Mech-Sense, Department of Gastroenterology and
Hepatology and Department of Clinical Medicine, Aalborg University Hospital,
Denmark,Department of Clinical Medicine, Aalborg
University, Denmark
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13
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Chen Y, Liu G, He F, Zhang L, Yang K, Yu H, Zhou J, Gan H. MicroRNA 375 modulates hyperglycemia-induced enteric glial cell apoptosis and Diabetes-induced gastrointestinal dysfunction by targeting Pdk1 and repressing PI3K/Akt pathway. Sci Rep 2018; 8:12681. [PMID: 30140011 PMCID: PMC6107553 DOI: 10.1038/s41598-018-30714-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/02/2018] [Indexed: 02/06/2023] Open
Abstract
Diabetic neuropathy can damage systemic nervous system, including alteration of enteric nervous system and subsequent gastrointestinal dysfunction. The effect of diabetes on enteric glia cell (EGC) is not clear. We investigated the effect of diabetes and hyperglycemia on EGC, and the role of microRNA375 in modulating EGC survival in vivo and in vitro. Streptozotocin-induced diabetic mice were intraperitoneally injected with microRNA375 inhibitor or its negative control. EGC was transfected with microRNA375 inhibitor or its mimic. Diabetes mice with gastrointestinal dysfunction showed increased apoptosis of EGC (no difference in cell numbers) and gene expression of micorRNA375 in the myenteric plexus. Hyperglycemia triggered apoptosis of EGC in vitro with decreased expression of Pdk1 and p-Akt, but increased expression of micorRNA375. MicorRNA375 mimic induced apoptosis of EGC in vitro with repressed Pdk1and p-Akt. MicorRNA375 inhibitor could both prevent hyperglycemia-induced apoptosis of EGC in vitro and diabetes-induced gastrointestinal dysfunction in vivo. Our results suggest that diabetes-induced gastrointestinal dysfunction is related to increased apoptosis of EGC in the myenteric plexus. Hyperglycemia can increase the expression of microRNA375 and damage EGC survival through PI3K/Akt pathway. MicroRNA375 specific inhibition can prevent hyperglycemia induced EGC damage and diabetes-induced gastrointestinal dysfunction.
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Affiliation(s)
- Yan Chen
- The Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Gongxiang Liu
- The Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Fuqian He
- The Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Li Zhang
- Department of elderly digestive, Sichuan Provincial People's Hospital, Chengdu, 610072, China
| | - Kun Yang
- The Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Huan Yu
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Jinqiu Zhou
- The Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Huatian Gan
- The Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, China.
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, 610041, China.
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14
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Namazi Sarvestani N, Saberi Firouzi S, Falak R, Karimi MY, Davoodzadeh Gholami M, Rangbar A, Hosseini A. Phosphodiesterase 4 and 7 inhibitors produce protective effects against high glucose-induced neurotoxicity in PC12 cells via modulation of the oxidative stress, apoptosis and inflammation pathways. Metab Brain Dis 2018; 33:1293-1306. [PMID: 29713919 DOI: 10.1007/s11011-018-0241-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/13/2018] [Indexed: 12/13/2022]
Abstract
Diabetic neuropathy (DN) is the most common diabetic complication. It is estimated diabetic population will increase to 592 million by the year 2035. This is while at least 50-60% of all diabetic patients will suffer from neuropathy in their lifetime. Oxidative stress, mitochondrial dysfunction, apoptosis, and inflammation are crucial pathways in development and progression of DN. Since there is also no selective and effective therapeutic agent to prevent or treat high glucose (HG)-induced neuronal cell injury, it is crucial to explore tools by which one can reduce factors related to these pathways. Phosphodiesterase 4 and 7 (PDE 4 and 7) regulate oxidative damage, neurodegenaration, and inflammatory responses through modulation of cyclic adenosine monophosphate (cAMP) level, and thus can be as important drug targets for regulating DN. The aim of this study was to evaluate the protective effects of inhibitors of PDE 4 and 7, named rolipram and BRL5048, on HG-induced neurotoxicity in PC12 cells as an in vitro cellular model for DN and determine the possible mechanisms for theirs effects. We report that the PC12 cells pre-treatment with rolipram (2 μM) and/or BRL5048 (0.2 μM) for 60 min and then exposing the cells to HG (4.5 g/L for 72 h) or normal glucose (NG) (1 g/L for 72 h) condition show: (1) significant attenuation in ROS, MDA and TNF-a levels, Bax/Bcl-2 ratio, expression of caspase 3 and UCP2 proteins; (2) significant increase in viability, GSH/GSSG ratio, MMP and ATP levels. All these data together led us to propose PDE 4 and 7 inhibitors, and specifically, rolipram and BRL5048, as potential drugs candidate to be further studied for the prevention and treatment of DN.
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Affiliation(s)
- Nazanin Namazi Sarvestani
- Department of Animal Biology, School of Biology, Department of Science, University of Tehran, Tehran, Iran
| | - Saeedeh Saberi Firouzi
- Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Falak
- Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | | | | | - Akram Rangbar
- Department of Toxicology and Pharmacology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Asieh Hosseini
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran.
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15
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Hauschildt AT, Corá LA, Volpato GT, Sinzato YK, Damasceno DC, Américo MF. Mild diabetes: long-term effects on gastric motility evaluated in rats. Int J Exp Pathol 2018; 99:29-37. [PMID: 29479759 PMCID: PMC5917388 DOI: 10.1111/iep.12262] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 01/04/2018] [Indexed: 12/22/2022] Open
Abstract
Moderate hyperglycaemic levels seem to be related to abnormal gastric motility in diabetes mellitus. However, experimental models designed to evaluate the relationship between motility and diabetes over time are not yet well established. Our objective was to investigate the long-term effects of mild diabetes on gastric motility in rats. Newborn male rats received streptozotocin (mild diabetes groups - MD) or vehicle (control groups - C), and both groups were evaluated after 3 (C3 and MD3) and 6 months (C6 and MD6) postinduction. Mild diabetic animals (MD3 and MD6) showed moderately elevated blood glucose and decreased insulin levels compared with control (C3 and C6). Insulin secretion was enhanced in MD6 compared with MD3, most likely due to partial β-cell regeneration indicated by HOMA-β. In HOMA-IR, it was noticed that MD6 animals had impaired insulin response compared with MD3. Gastric emptying was faster, amplitude of contraction was stronger in MD6 compared with MD3, and in both groups, the differences were significant when compared with control animals. A significant abnormal rhythmic index was calculated for the mild diabetic groups, despite unchanged mean frequency of contraction. In conclusion, despite increased insulin levels over time, constant levels of moderate hyperglycaemia are also related to abnormal gastric motility and impairment of gastric function.
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Affiliation(s)
| | - Luciana A. Corá
- Alagoas State University of Health Sciences – UNCISALMaceió/ALBrazil
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16
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Xiaogang L, Zhe Z, Rui W, Xinxin X, Yonghui L, Lianqing S. Ginsenoside Rb1 prevents high glucose-induced Schwann cell injury through the mitochondrial apoptosis pathway. J TRADIT CHIN MED 2017. [DOI: 10.1016/s0254-6272(18)30037-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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17
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Soleymaninejad M, Joursaraei SG, Feizi F, Jafari Anarkooli I. The Effects of Lycopene and Insulin on Histological Changes and the Expression Level of Bcl-2 Family Genes in the Hippocampus of Streptozotocin-Induced Diabetic Rats. J Diabetes Res 2017; 2017:4650939. [PMID: 28656152 PMCID: PMC5471551 DOI: 10.1155/2017/4650939] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 04/09/2017] [Accepted: 04/19/2017] [Indexed: 01/11/2023] Open
Abstract
The aim of this study was to evaluate the effects of antioxidants lycopene and insulin on histological changes and expression of Bcl-2 family genes in the hippocampus of streptozotocin-induced type 1 diabetic rats. Forty-eight Wistar rats were divided into six groups of control (C), control treated with lycopene (CL), diabetic (D), diabetic treated with insulin (DI), diabetic treated with lycopene (DL), and diabetic treated with insulin and lycopene (DIL). Diabetes was induced by an injection of streptozotocin (60 mg/kg, IP), lycopene (4 mg/kg/day) was given to the lycopene treated groups as gavages, and insulin (Sc, 1-2 U/kg/day) was injected to the groups treated with insulin. The number of hippocampus neurons undergoing cell death in group D had significant differences with groups C and DIL (p < 0.001). Furthermore, insulin and lycopene alone or together reduced the expression of Bax, but increased Bcl-2 and Bcl-xL levels in DI, DL, and DIL rats, especially when compared to group D (p < 0.001). The ratios of Bax/Bcl-2 and Bax/Bcl-xL in DI, DL, and DIL rats were also reduced (p < 0.001). Our results indicate that treatment with insulin and/or lycopene contribute to the prevention of cell death by reducing the expression of proapoptotic genes and increasing the expression of antiapoptotic genes in the hippocampus.
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Affiliation(s)
- Masoume Soleymaninejad
- Department of Anatomy, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | | | - Farideh Feizi
- Department of Anatomy, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Iraj Jafari Anarkooli
- Department of Anatomy, School of Medicine, Zanjan University of Medical Sciences (ZUMS), Zanjan, Iran
- *Iraj Jafari Anarkooli:
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18
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Sun M, Wang F, Feng P. Insulin-like growth factor-1 inhibits colonic smooth muscle cell apoptosis in diabetic rats with colonic dysmotility. ACTA ACUST UNITED AC 2014; 194-195:41-8. [PMID: 25450576 DOI: 10.1016/j.regpep.2014.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 11/04/2014] [Accepted: 11/11/2014] [Indexed: 02/08/2023]
Abstract
Cellular apoptosis and colonic dysmotility are involved in diabetes mellitus (DM) complications. Insulin-like growth factor-1 (IGF-1) is known to affect apoptosis and proliferation. Here, we demonstrated that the treatment of 1500 ng/kg IGF-1 partly recovers the decrease of the muscle thickness, body weight and gastrointestinal transit rate in DM rats. The gastrointestinal transit rate is positively correlated with the IGF-I level, but negatively correlated with the level of colonic cellular apoptosis. The DM-induced colonic apoptosis is also attenuated by the IGF-1 stimulation. Moreover, IGF-1 inhibits the apoptosis of the isolated colonic SMCs in vitro via the activation of PI3K/Akt and ERK1/2 signaling pathways. Taken together, our data indicated that IGF-1 inhibits the DM-induced colonic SMC apoptosis and might be involved in the alleviation of colonic dysmotility in diabetic rats.
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Affiliation(s)
- Manyi Sun
- Department of Metabolic Diseases, Tianjin Medical University General Hospital, Tianjin 300052, China; Department of Gastroenterology, Tianjin Union Medicine Center, Tianjin 300121, China
| | - Feng Wang
- Department of Gastroenterology and Digestive Endoscopy, Tianjin Union Medicine Center & Tianjin People's Hospital, Tianjin 300121, China
| | - Ping Feng
- Department of Metabolic Diseases, Tianjin Medical University General Hospital, Tianjin 300052, China.
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19
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Wu Y, Xue B, Li X, Liu H. Puerarin prevents high glucose-induced apoptosis of Schwann cells by inhibiting oxidative stress. Neural Regen Res 2014; 7:2583-91. [PMID: 25368634 PMCID: PMC4200725 DOI: 10.3969/j.issn.1673-5374.2012.33.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Accepted: 10/16/2012] [Indexed: 11/18/2022] Open
Abstract
Oxidative stress may be the unifying factor for the injury caused by hyperglycemia in diabetic peripheral neuropathy. Puerarin is the major isoflavonoid derived from Radix puerariae and has been shown to be effective in increasing superoxide dismutase activity. This study sought to investigate the neuroprotective effect of puerarin on high glucose-induced oxidative stress and Schwann cell apoptosis in vitro. Intracellular reactive oxygen radicals and mitochondrial transmembrane potential were detected by flow cytometry analysis. Apoptosis was confirmed by TUNEL and oxidative stress was monitored using an enzyme-linked immunosorbent assay for the DNA marker 8-hydroxy-2-deoxyguanosine. The expression levels of bax and bcl-2 were analyzed by quantitative real-time reverse transcriptase-PCR, while protein expression of cleaved caspase-3 and -9 were analyzed by means of western blotting. Results suggested that puerarin treatment inhibited high glucose-induced oxidative stress, mitochondrial depolarization and apoptosis in a dose-dependent manner. Furthermore, puerarin treatment downregulated Bax expression, upregulated bcl-2 expression and attenuated the activation of caspase-3 and -9. Overall, our results indicated that puerarin antagonized high glucose-induced oxidative stress and apoptosis in Schwann cells.
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Affiliation(s)
- Yingying Wu
- Institute of Stomatology, Chinese PLA General Hospital, Beijing 100853, China
| | - Bing Xue
- Department of Endocrinology, General Hospital of Shenyang Military Region, Shenyang 110016, Liaoning Province, China
| | - Xiaojin Li
- Department of Endocrinology, Chinese PLA General Hospital, Beijing 100853, China
| | - Hongchen Liu
- Institute of Stomatology, Chinese PLA General Hospital, Beijing 100853, China
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20
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Yarandi SS, Srinivasan S. Diabetic gastrointestinal motility disorders and the role of enteric nervous system: current status and future directions. Neurogastroenterol Motil 2014; 26:611-24. [PMID: 24661628 PMCID: PMC4104990 DOI: 10.1111/nmo.12330] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Accepted: 02/18/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND Gastrointestinal manifestations of diabetes are common and a source of significant discomfort and disability. Diabetes affects almost every part of gastrointestinal tract from the esophagus to the rectum and causes a variety of symptoms including heartburn, nausea, vomiting, abdominal pain, diarrhea and constipation. Understanding the underlying mechanisms of diabetic gastroenteropathy is important to guide development of therapies for this common problem. Over recent years, the data regarding the pathophysiology of diabetic gastroenteropathy is expanding. In addition to autonomic neuropathy causing gastrointestinal disturbances the role of enteric nervous system is becoming more evident. PURPOSE In this review, we summarize the reported alterations in enteric nervous system including enteric neurons, interstitial cells of Cajal and neurotransmission in diabetic animal models and patients. We also review the possible underlying mechanisms of these alterations, with focus on oxidative stress, growth factors and diabetes induced changes in gastrointestinal smooth muscle. Finally, we will discuss recent advances and potential areas for future research related to diabetes and the ENS such as gut microbiota, micro-RNAs and changes in the microvasculature and endothelial dysfunction.
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Affiliation(s)
- S. S. Yarandi
- Division of Digestive Diseases; Emory University; Atlanta GA
- Atlanta VA Medical Center; Decatur Georgia USA
| | - S. Srinivasan
- Division of Digestive Diseases; Emory University; Atlanta GA
- Atlanta VA Medical Center; Decatur Georgia USA
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21
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Jafari Anarkooli I, Barzegar Ganji H, Pourheidar M. The protective effects of insulin and natural honey against hippocampal cell death in streptozotocin-induced diabetic rats. J Diabetes Res 2014; 2014:491571. [PMID: 24745031 PMCID: PMC3976855 DOI: 10.1155/2014/491571] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 02/05/2014] [Accepted: 02/09/2014] [Indexed: 11/18/2022] Open
Abstract
We investigated the effects of insulin and honey as antioxidants to prevent the hippocampal cell death in streptozotocin-induced diabetic rats. We selected sixty Wister rats (5 groups of 12 animals each), including the control group (C), and four diabetic groups (control (D) and 3 groups treated with insulin (I), honey (H), and insulin plus honey (I + H)). Diabetes was induced by streptozotocin injection (IP, 60 mg/kg). Six weeks after the induction of diabetes, the group I received insulin (3-4 U/kg/day, SC), group H received honey (5 mg/kg/day, IP), and group I + H received a combination of the above at the same dose. Groups C and D received normal saline. Two weeks after treatment, rats were sacrificed and the hippocampus was extracted. Neuronal cell death in the hippocampal region was examined using trypan blue assay, "H & E" staining, and TUNEL assay. Cell viability assessment showed significantly lower number of living cells in group D than in group C. Besides, the mean number of living cells was significantly higher in group I, H, and I + H compared to group D. Therefore, it can be concluded that the treatment of the diabetic rats with insulin, honey, and a combination of insulin and honey can prevent neuronal cell death in different hippocampal areas of the studied samples.
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Affiliation(s)
- Iraj Jafari Anarkooli
- Department of Anatomy, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan 4513956111, Iran
| | - Hossein Barzegar Ganji
- Department of Anatomy, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan 4513956111, Iran
| | - Maryam Pourheidar
- Department of Histology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
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22
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Burnstock G. Purinergic signalling in the gastrointestinal tract and related organs in health and disease. Purinergic Signal 2014; 10:3-50. [PMID: 24307520 PMCID: PMC3944042 DOI: 10.1007/s11302-013-9397-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/24/2013] [Indexed: 01/04/2023] Open
Abstract
Purinergic signalling plays major roles in the physiology and pathophysiology of digestive organs. Adenosine 5'-triphosphate (ATP), together with nitric oxide and vasoactive intestinal peptide, is a cotransmitter in non-adrenergic, non-cholinergic inhibitory neuromuscular transmission. P2X and P2Y receptors are widely expressed in myenteric and submucous enteric plexuses and participate in sympathetic transmission and neuromodulation involved in enteric reflex activities, as well as influencing gastric and intestinal epithelial secretion and vascular activities. Involvement of purinergic signalling has been identified in a variety of diseases, including inflammatory bowel disease, ischaemia, diabetes and cancer. Purinergic mechanosensory transduction forms the basis of enteric nociception, where ATP released from mucosal epithelial cells by distension activates nociceptive subepithelial primary afferent sensory fibres expressing P2X3 receptors to send messages to the pain centres in the central nervous system via interneurons in the spinal cord. Purinergic signalling is also involved in salivary gland and bile duct secretion.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK,
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23
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Li YL. Angiotensin II-Superoxide Signaling and Arterial Baroreceptor Function in Type-1 Diabetes Mellitus. JOURNAL OF DIABETES & METABOLISM 2014; Suppl 12:1-6. [PMID: 24567847 DOI: 10.4172/2155-6156.s12-001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Diabetes is a major world health problem. Growing evidence from both clinical trials and animal experiments has clearly confirmed that arterial baroreflex dysfunction is a feature of type 1 diabetes, which links to prognosis and mortality of the type 1 diabetic patients. The arterial baroreflex normally regulates the blood pressure and heart rate through sensing changes of arterial vascular tension by the arterial baroreceptors in the aortic arch and carotid sinus. The aortic baroreceptor neuron located in the nodose ganglia is a primary afferent component of the arterial baroreflex. The functional changes of these neurons are involved in the arterial baroreflex dysfunction in the type 1 diabetes. Type 1 diabetes causes the overexpression and hyperactivation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and further reduces cell excitability of the aortic baroreceptor neurons. The alterations of the HCN channels are regulated by angiotensin II-NADPH oxidase-superoxide signaling in the aortic baroreceptor neurons. From the present review, we can understand the possible mechanisms responsible for the attenuated arterial baroreflex in the type 1 diabetes. These findings are beneficial for improving quality of life and prognosis in patients with the type 1 diabetes mellitus.
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Affiliation(s)
- Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, USA
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24
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Abstract
Autonomic neuropathy complicates diabetes by increasing patient morbidity and mortality. Surprisingly, considering its importance, development and exploitation of animal models has lagged behind the wealth of information collected for somatic symmetrical sensory neuropathy. Nonetheless, animal studies have resulted in a variety of insights into the pathogenesis, neuropathology, and pathophysiology of diabetic autonomic neuropathy (DAN) with significant and, in some cases, remarkable correspondence between rodent models and human disease. Particularly in the study of alimentary dysfunction, findings in intrinsic intramural ganglia, interstitial cells of Cajal and the extrinsic parasympathetic and sympathetic ganglia serving the bowel vie for recognition as the chief mechanism. A body of work focused on neuropathologic findings in experimental animals and human subjects has demonstrated that axonal and dendritic pathology in sympathetic ganglia with relative neuron preservation represents one of the neuropathologic hallmarks of DAN but it is unlikely to represent the entire story. There is a surprising selectivity of the diabetic process for subpopulations of neurons and nerve terminals within intramural, parasympathetic, and sympathetic ganglia and innervation of end organs, afflicting some while sparing others, and differing between vascular and other targets within individual end organs. Rather than resulting from a simple deficit in one limb of an effector pathway, autonomic dysfunction may proceed from the inability to integrate portions of several complex pathways. The selectivity of the diabetic process appears to confound a simple global explanation (e.g., ischemia) of DAN. Although the search for a single unifying pathogenetic hypothesis continues, it is possible that autonomic neuropathy will have multiple pathogenetic mechanisms whose interplay may require therapies consisting of a cocktail of drugs. The role of multiple neurotrophic substances, antioxidants (general or pathway specific), inhibitors of formation of advanced glycosylation end products and drugs affecting the polyol pathway may be complex and therapeutic elements may have both salutary and untoward effects. This review has attempted to present the background and current findings and hypotheses, focusing on autonomic elements including and beyond the typical parasympathetic and sympathetic nervous systems to include visceral sensory and enteric nervous systems.
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Affiliation(s)
- Robert E Schmidt
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, USA.
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25
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Brun P, Giron MC, Qesari M, Porzionato A, Caputi V, Zoppellaro C, Banzato S, Grillo AR, Spagnol L, De Caro R, Pizzuti D, Barbieri V, Rosato A, Sturniolo GC, Martines D, Zaninotto G, Palù G, Castagliuolo I. Toll-like receptor 2 regulates intestinal inflammation by controlling integrity of the enteric nervous system. Gastroenterology 2013; 145:1323-33. [PMID: 23994200 DOI: 10.1053/j.gastro.2013.08.047] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 08/03/2013] [Accepted: 08/15/2013] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS In the intestines, Toll-like receptor 2 (TLR2) mediates immune responses to pathogens and regulates epithelial barrier function; polymorphisms in TLR2 have been associated with inflammatory bowel disease phenotype. We assessed the effects of TLR2 signaling on the enteric nervous system (ENS) in mice. METHODS TLR2 distribution and function in the ileal neuromuscular layer of mice were determined by immunofluorescence, cytofluorimetric analysis, immunoprecipitation, and immunoblot analyses. We assessed morphology and function of the ENS in Tlr2(-/-) mice and in mice with wild-type Tlr2 (wild-type mice) depleted of intestinal microbiota, using immunofluorescence, immunoblot, and gastrointestinal motility assays. Levels and signaling of glial cell line-derived neurotrophic factor (GDNF) were determined using quantitative reverse transcriptase polymerase chain reaction, immunohistochemistry, and immunoprecipitation analyses. Colitis was induced by administration of dextran sulfate sodium or 2,4 dinitrobenzensulfonic acid to Tlr2(-/-) mice after termination of GDNF administration. RESULTS TLR2 was expressed in enteric neurons, glia, and smooth muscle cells of the intestinal wall. Tlr2(-/-) mice had alterations in ENS architecture and neurochemical profile, intestinal dysmotility, abnormal mucosal secretion, reduced levels of GDNF in smooth muscle cells, and impaired signaling via Ret-GFRα1. ENS structural and functional anomalies were completely corrected by administration of GDNF to Tlr2(-/-) mice. Wild-type mice depleted of intestinal microbiota had ENS defects and GDNF deficiency, similar to Tlr2(-/-) mice; these defects were partially restored by administration of a TLR2 agonist. Tlr2(-/-) mice developed more severe colitis than wild-type mice after administration of dextran sulfate sodium or 2,4 dinitrobenzensulfonic acid; colitis was not more severe if Tlr2(-/-) mice were given GDNF before dextran sulfate sodium or 2,4 dinitrobenzensulfonic acid. CONCLUSIONS In mice, TLR2 signaling regulates intestinal inflammation by controlling ENS structure and neurochemical coding, along with intestinal neuromuscular function. These findings provide information as to how defective TLR2 signaling in the ENS affects inflammatory bowel disease phenotype in humans.
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Affiliation(s)
- Paola Brun
- Department of Molecular Medicine, University of Padova, Padova, Italy
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Electroacupuncture regulates apoptosis/proliferation of intramuscular interstitial cells of cajal and restores colonic motility in diabetic constipation rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:584179. [PMID: 24348706 PMCID: PMC3852313 DOI: 10.1155/2013/584179] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 10/21/2013] [Indexed: 11/18/2022]
Abstract
Injury of interstitial cells of Cajal (ICC) is associated with gut dysmotility in diabetic rats. We have shown an acceleration of the colonic contractility by electroacupuncture stimulation (EAS). However, little is known about potential roles of EAS on colonic transit and ICC. In this study, we evaluate the effect of EAS on colonic transit and investigate whether apoptosis/proliferation of ICC was involved in regulative effect of EAS on colonic transit. Rats were randomly assigned to normal, diabetic, diabetic-plus-sham stimulation, diabetic-plus-low-frequency stimulation, and diabetic-plus-high-frequency stimulation groups. Bead expulsion test was used for measuring the distal colonic transit. The Kit (ICC marker) was detected by western blot. Apoptotic ICC was detected by terminal dUTP nucleotide end labeling. Proliferating ICC was identified by Kit/Ki67 double immunofluorescent staining on whole mount preparations. Ultrastructure changes of ICC were studied using electron microscopy. Results showed that high-frequency stimulation significantly promoted colonic transit. Low- and high-frequency stimulation markedly rescued intramuscular ICC from apoptosis. Abundant proliferating intramuscular ICC was found in low- and high-frequency stimulation groups. Our results indicate that high-frequency EAS has stimulatory effect on the distal colonic transit, which may be mediated by downregulation of the apoptosis and upregulation of the proliferation of intramuscular ICC.
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Demedts I, Masaoka T, Kindt S, De Hertogh G, Geboes K, Farré R, Vanden Berghe P, Tack J. Gastrointestinal motility changes and myenteric plexus alterations in spontaneously diabetic biobreeding rats. J Neurogastroenterol Motil 2013; 19:161-70. [PMID: 23667747 PMCID: PMC3644652 DOI: 10.5056/jnm.2013.19.2.161] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 12/17/2012] [Accepted: 01/02/2013] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND/AIMS Type 1 diabetes is often accompanied by gastrointestinal motility disturbances. Vagal neuropathy, hyperglycemia, and alterations in the myenteric plexus have been proposed as underlying mechanism. We therefore studied the relationship between vagal function, gastrointestinal motiliy and characteristics of the enteric nervous system in the biobreeding (BB) rat known as model for spontaneous type 1 diabetes. METHODS Gastric emptying breath test, small intestinal electromyography, relative risk-interval variability, histology and immunohistochemistry on antral and jejunal segments were performed at 1, 8 and 16 weeks after diabetes onset and on age-matched controls. RESULTS We observed no consistent changes in relative risk-interval variability and gastric emptying rate. There was however, a loss of phases 3 with longer duration of diabetes on small intestinal electromyography. We found a progressive decrease of nitrergic neurons in the myenteric plexus of antrum and jejunum, while numbers of cholinergic nerve were not altered. In addition, a transient inflammatory infiltrate in jejunal wall was found in spontaneous diabetic BB rats at 8 weeks of diabetes. CONCLUSIONS In diabetic BB rats, altered small intestinal motor control associated with a loss of myenteric nitric oxide synthase expression occurs, which does not depend on hyperglycemia or vagal dysfunction, and which is preceded by transient intestinal inflammation.
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Affiliation(s)
- Ingrid Demedts
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Tatsuhiro Masaoka
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Sebastien Kindt
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Gert De Hertogh
- Department of Pathology, University of Leuven, Leuven, Belgium
| | - Karel Geboes
- Department of Pathology, University of Leuven, Leuven, Belgium
| | - Ricard Farré
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Pieter Vanden Berghe
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Jan Tack
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
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LePard KJ, Cellini J. Age-dependent slowing of enteric axonal transport in insulin-resistant mice. World J Gastroenterol 2013; 19:482-91. [PMID: 23382626 PMCID: PMC3558571 DOI: 10.3748/wjg.v19.i4.482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 11/20/2012] [Accepted: 12/15/2012] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate retrograde tracer transport by gastric enteric neurons in insulin resistant mice with low or high glycosylated hemoglobin (Hb).
METHODS: Under anesthesia, the retrograde tracer fluorogold was superficially injected into the fundus or antrum using a microsyringe in KK Cg-Ay/J mice prior to onset of type 2 diabetes mellitus (T2DM; 4 wk of age), at onset of T2DM (8 wk of age), and after 8, 16, or 24 wk of untreated T2DM and in age-matched KK/HIJ mice. Six days later, mice were sacrificed by CO2 narcosis followed by pneumothorax. Stomachs were removed and fixed. Sections from fundus, corpus and antrum were excised and mounted on a glass slide. Tracer-labeled neurons were viewed using a microscope and manually counted. Data were expressed as the number of neurons in short and long descending and ascending pathways and in local fundus and antrum pathways, and the number of neurons in all regions labeled after injection of tracer into either the fundus or the antrum.
RESULTS: By 8 wk of age, body weights of KKAy mice (n = 12, 34 ± 1 g) were heavier than KK mice (n = 17, 29 ± 1 g; F (4, 120) = 4.414, P = 0.002] and glycosylated Hb was higher [KK: (n = 7), 4.97% ± 0.04%; KKAy: (n = 6), 6.57% ± 0.47%; F (1, 26) = 24.748, P < 0.001]. The number of tracer labeled enteric neurons was similar in KK and KKAy mice of all ages in the short descending pathway [F (1, 57) = 2.374, P = 0.129], long descending pathway [F (1, 57) = 0.922, P = 0.341], local fundus pathway [F (1, 53) = 2.464, P = 0.122], local antrum pathway [F (1, 57) = 0.728, P = 0.397], and short ascending pathway [F (1, 53) = 2.940, P = 0.092]. In the long ascending pathway, fewer tracer-labeled neurons were present in KKAy as compared to KK mice [KK: (n = 34), 302 ± 17; KKAy: (n = 29), 230 ± 15; F (1, 53) = 8.136, P = 0.006]. The number of tracer-labeled neurons was decreased in all mice by 16 wk as compared to 8 wk of age in the short descending pathway [8 wk: (n = 15), 305 ± 26; 16 wk: (n = 13), 210 ± 30; F (4, 57) = 9.336, P < 0.001], local antrum pathway [8 wk: (n = 15), 349 ± 20; 16 wk: (n = 13), 220 ± 33; F (4, 57) = 8.920, P < 0.001], short ascending pathway [8 wk: (n = 14), 392 ± 15; 16 wk: (n = 14), 257 ± 33; F (4, 53) = 17.188, P < 0.001], and long ascending pathway [8 wk: (n = 14), 379 ± 39; 16 wk: (n = 14), 235 ± 26; F (4, 53) = 24.936, P < 0.001]. The number of tracer-labeled neurons decreased at 24 wk of age in the local fundus pathway [8 wk: (n = 14), 33 ± 11; 24 wk: (n = 12), 3 ± 2; F (4, 53) = 5.195, P = 0.001] and 32 wk of age in the long descending pathway [8 wk: (n = 15), 16 ± 3; 32 wk: (n = 12), 3 ± 2; F (4, 57) = 2.944, P = 0.028]. The number of tracer-labeled enteric neurons was correlated to final body weight for local fundus and ascending pathways [KK: (n = 34), r = -0.746, P < 0.001; KKAy: (n = 29), r = -0.842, P < 0.001] as well as local antrum and descending pathways [KK (n = 36), r = -0.660, P < 0.001; KKAy (n = 31), r = -0.622, P < 0.001]. In contrast, glycosylated Hb was not significantly correlated to number of tracer-labeled neurons [KK (n = 17), r = -0.164, P = 0.528; KKAy (n = 16), r = -0.078, P = 0.774].
CONCLUSION: Since uncontrolled T2DM did not uniformly impair tracer transport in gastric neurons, long ascending neurons may be more susceptible to persistent hyperglycemia and low effective insulin.
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Chang MJ, Xiao JH, Wang Y, Yan YL, Yang J, Wang JL. 2, 3, 5, 4'-Tetrahydroxystilbene-2-O-beta-D-glucoside improves gastrointestinal motility disorders in STZ-induced diabetic mice. PLoS One 2012; 7:e50291. [PMID: 23226517 PMCID: PMC3513302 DOI: 10.1371/journal.pone.0050291] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 10/22/2012] [Indexed: 01/19/2023] Open
Abstract
Oxidative stress has recently been considered as a pivotal player in the pathogenesis of diabetic gastrointestinal dysfunction. We therefore investigated the role of 2, 3, 5, 4'-tetrahydroxystilbene-2-O-beta-D-glucoside (THSG) that has a strong anti-oxidant property, in diabetic gastrointestinal dysmotility as well as the underlying protective mechanisms. THSG restored the delayed gastric emptying and the increased intestinal transit in streptozotocin (STZ)-induced diabetic mice. Loss of neuronal nitric oxide synthase (nNOS) expression and impaired nonadrenergic, noncholinergic (NANC) relaxations in diabetic mice were relieved by long-term preventive treatment with THSG. Meanwhile, THSG (10(-7)~10(-4) mol/L) enhanced concentration-dependently NANC relaxations of isolated colons in diabetic mice. Diabetic mice displayed a significant increase in Malondialdehyde (MDA) level and decrease in the activity of glutathione peroxidase (GSH-Px), which were ameliorated by THSG. Inhibition of caspase-3 and activation of ERK phosphorylation related MAPK pathway were involved in prevention of enhanced apoptosis in diabetes afforded by THSG. Moreover, THSG prevented the significant decrease in PPAR-γ and SIRT1 expression in diabetic ileum. Our study indicates that THSG improves diabetic gastrointestinal disorders through activation of MAPK pathway and upregulation of PPAR-γ and SIRT1.
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Affiliation(s)
- Mu-Jun Chang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Jun-Hua Xiao
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Yong Wang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Yong-Li Yan
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Jun Yang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Jia-Ling Wang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
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Voss U, Sand E, Hellström PM, Ekblad E. Glucagon-like peptides 1 and 2 and vasoactive intestinal peptide are neuroprotective on cultured and mast cell co-cultured rat myenteric neurons. BMC Gastroenterol 2012; 12:30. [PMID: 22463807 PMCID: PMC3352054 DOI: 10.1186/1471-230x-12-30] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 04/01/2012] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Neuropathy is believed to be a common feature of functional and inflammatory intestinal diseases. Vasoactive intestinal peptide (VIP) is an acknowledged neuroprotective agent in peripheral, including enteric, and central neurons. The proglucagon-like hormones glucagon-like peptide 1 and 2 (GLP1 and GLP2) belong to the secretin/glucagon/VIP superfamily of peptides and GLP1 and GLP2 receptors are expressed in enteric neurons. Possible neuroprotective effects of these peptides were investigated in the present study. METHODS GLP1, GLP2 and VIP were added to cultured myenteric neurons from rat small intestine or to co-cultures of myenteric neurons and rat peritoneal mast cells. Receptor selectivity was tested by the simultaneous presence of a GLP1 receptor antagonist (exendin (9-39) amide) or a VIP receptor antagonist (hybrid of neurotensin 6-11 and VIP 7-28). Neuronal survival was examined using immunocytochemistry and cell counting. RESULTS GLP1, GLP2 and VIP significantly and concentration-dependently enhanced neuronal survival. In addition the peptides efficiently counteracted mast cell-induced neuronal cell death in a concentration-dependent manner. Exendin(9-39)amide reversed GLP1-induced neuroprotection while GLP2- and VIP-induced enhanced neuronal survival were unaffected. The VIP receptor antagonist reversed GLP1- and VIP-induced neuroprotection while the GLP2-induced effect on neuronal survival was unaffected. CONCLUSIONS By activating separate receptors VIP, GLP1 and GLP2 elicit neuroprotective effects on rat myenteric neurons cultured with or without mast cells. This implies a powerful therapeutic potential of these peptides in enteric neuropathies with a broad spectrum of applications from autoimmunity to functional disorders.
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Affiliation(s)
- Ulrikke Voss
- Department of Experimental Medical Science, BMC B11, Lund University, SE-22184 Lund, Sweden
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31
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Sun LQ, Zhao J, Zhang TT, Qu L, Wang X, Xue B, Li XJ, Mu YM, Lu JM. Protective effects of Salvianolic acid B on Schwann cells apoptosis induced by high glucose. Neurochem Res 2012; 37:996-1010. [PMID: 22252725 DOI: 10.1007/s11064-011-0695-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 12/14/2011] [Accepted: 12/29/2011] [Indexed: 02/07/2023]
Abstract
Diabetic peripheral neuropathy (DPN) is one of the most common and debilitating microvascular complications of diabetes, and there is no effective therapy for the prevention or treatment of DPN. Oxidative stress triggers several pathways of injury and may be the unifying factor of hyperglycemia. The aim of this study was to investigate protective effect of Salvianolic acid B (Sal B) on the high glucose (HG)-induced oxidative stress-induced mitochondrial pathway activation and Schwann cells (SCs) apoptosis in vitro. We found that Sal B inhibited the HG-induced oxidative stress by reducing ROS and 8-hydroxy-2-deoxy Guanosine (8-OHdG) production, and mitochondrial depolarization and apoptosis in SCs in a dose-dependent manner. Furthermore, Sal B down-regulated the HG-mediated Bax expression and AIF nuclear translocation and the release of cytochrome c, but up-regulated the HG-induced BcL-2 expression in SCs. In addition, Sal B attenuated the HG-induced activation of caspase 3 and 9 and minimized the cleavage of PARP in SCs. Our results indicated that Sal B antagonized the HG-induced oxidative stress, activation of the mitochondrial pathway and apoptosis in SCs.
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Affiliation(s)
- Lian-Qing Sun
- Department of Endocrinology, Chinese PLA General Hospital, 28 Fu Xing Road, Beijing 100853, China
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Sun LQ, Xue B, Li XJ, Wang X, Qu L, Zhang TT, Zhao J, Wang BA, Zou XM, Mu YM, Lu JM. Inhibitory effects of Salvianolic acid B on apoptosis of Schwann cells and its mechanism induced by intermittent high glucose. Life Sci 2012; 90:99-108. [DOI: 10.1016/j.lfs.2011.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2011] [Revised: 09/12/2011] [Accepted: 10/05/2011] [Indexed: 01/22/2023]
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Lee J, Cummings BP, Martin E, Sharp JW, Graham JL, Stanhope KL, Havel PJ, Raybould HE. Glucose sensing by gut endocrine cells and activation of the vagal afferent pathway is impaired in a rodent model of type 2 diabetes mellitus. Am J Physiol Regul Integr Comp Physiol 2011; 302:R657-66. [PMID: 22160540 DOI: 10.1152/ajpregu.00345.2011] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Glucose in the gut lumen activates gut endocrine cells to release 5-HT, glucagon-like peptide 1/2 (GLP-1/2), and glucose-dependent insulinotropic polypeptide (GIP), which act to change gastrointestinal function and regulate postprandial plasma glucose. There is evidence that both release and action of incretin hormones is reduced in type 2 diabetes (T2D). We measured cellular activation of enteroendocrine and enterochromaffin cells, enteric neurons, and vagal afferent neurons in response to intestinal glucose in a model of type 2 diabetes mellitus, the UCD-T2DM rat. Prediabetic (PD), recent-diabetic (RD, 2 wk postonset), and 3-mo diabetic (3MD) fasted UCD-T2DM rats were given an orogastric gavage of vehicle (water, 0.5 ml /100 g body wt) or glucose (330 μmol/100 g body wt); after 6 min tissue was removed and cellular activation was determined by immunohistochemistry for phosphorylated calcium calmodulin-dependent kinase II (pCaMKII). In PD rats, pCaMKII immunoreactivity was increased in duodenal 5-HT (P < 0.001), K (P < 0.01) and L (P < 0.01) cells in response to glucose; glucose-induced activation of all three cell types was significantly reduced in RD and 3MD compared with PD rats. Immunoreactivity for GLP-1, but not GIP, was significantly reduced in RD and 3MD compared with PD rats (P < 0.01). Administration of glucose significantly increased pCaMKII in enteric and vagal afferent neurons in PD rats; glucose-induced pCaMKII immunoreactivity was attenuated in enteric and vagal afferent neurons (P < 0.01, P < 0.001, respectively) in RD and 3MD. These data suggest that glucose sensing in enteroendocrine and enterochromaffin cells and activation of neural pathways is markedly impaired in UCD-T2DM rats.
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Affiliation(s)
- Jennifer Lee
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, California 95616, USA
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35
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Domènech A, Pasquinelli G, De Giorgio R, Gori A, Bosch F, Pumarola M, Jiménez M. Morphofunctional changes underlying intestinal dysmotility in diabetic RIP-I/hIFNβ transgenic mice. Int J Exp Pathol 2011; 92:400-12. [PMID: 22050417 DOI: 10.1111/j.1365-2613.2011.00789.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The pathogenetic mechanisms underlying gastrointestinal dysmotility in diabetic patients remain poorly understood, although enteric neuropathy, damage to interstitial cells of Cajal (ICC) and smooth muscle cell injury are believed to play a role. The aim of this study was to investigate the morphological and functional changes underlying intestinal dysmotility in RIP-I/hIFNβ transgenic mice treated with multiple very low doses of streptozotocin (20 mg/kg, i.p., 5 days). Compared with vehicle-treated mice, streptozotocin-treated animals developed type 1 diabetes mellitus, with sustained hyperglycaemia for 3.5 months, polyphagia, polydipsia and increased faecal output without changes in faecal water content (metabolic cages). Diabetic mice had a longer intestine, longer ileal villi and wider colonic crypts (conventional microscopy) and displayed faster gastric emptying and intestinal transit. Contractility studies showed selective impaired neurotransmission in the ileum and mid-colon of diabetic mice. Compared with controls, the ileal and colonic myenteric plexus of diabetic mice revealed ultrastructural features of neuronal degeneration and HuD immunohistochemistry on whole-mount preparations showed 15% reduction in neuronal numbers. However, no immunohistochemical changes in apoptosis-related markers were noted. Lower absolute numbers of neuronal nitric oxide synthase- and choline acetyltransferase-immunopositive neurons and enhanced vasoactive intestinal polypeptide and substance P immunopositivity were observed. Ultrastructural and immunohistochemical analyses did not reveal changes in the enteric glial or ICC networks. In conclusion, this model of diabetic enteropathy shows enhanced intestinal transit associated with intestinal remodelling, including neuroplastic changes, and overt myenteric neuropathy. Such abnormalities are likely to reflect neuroadaptive and neuropathological changes occurring in this diabetic model.
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Affiliation(s)
- Anna Domènech
- Department of Animal Medicine and Surgery, Universitat Autònoma de Barcelona, Bellaterra, Spain.
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Yamakawa I, Kojima H, Terashima T, Katagi M, Oi J, Urabe H, Sanada M, Kawai H, Chan L, Yasuda H, Maegawa H, Kimura H. Inactivation of TNF-α ameliorates diabetic neuropathy in mice. Am J Physiol Endocrinol Metab 2011; 301:E844-52. [PMID: 21810933 PMCID: PMC3213998 DOI: 10.1152/ajpendo.00029.2011] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tumor necrosis factor (TNF)-α is a potent proinflammatory cytokine involved in the pathogenesis of diabetic neuropathy. We inactivated TNF-α to determine if it is a valid therapeutic target for the treatment of diabetic neuropathy. We effected the inactivation in diabetic neuropathy using two approaches: by genetic inactivation of TNF-α (TNF-α(-/-) mice) or by neutralization of TNF-α protein using the monoclonal antibody infliximab. We induced diabetes using streptozotocin in wild-type and TNF-α(-/-) mice. We measured serum TNF-α concentration and the level of TNF-α mRNA in the dorsal root ganglion (DRG) and evaluated nerve function by a combination of motor (MNCV) and sensory (SNCV) nerve conduction velocities and tail flick test, as well as cytological analysis of intraepidermal nerve fiber density (IENFD) and immunostaining of DRG for NF-κB p65 serine-276 phosphorylated and cleaved caspase-3. Compared with nondiabetic mice, TNF-α(+/+) diabetic mice displayed significant impairments of MNCV, SNCV, tail flick test, and IENFD as well as increased expression of NF-κB p65 and cleaved caspase-3 in their DRG. In contrast, although nondiabetic TNF-α(-/-) mice showed mild abnormalities of IENFD under basal conditions, diabetic TNF-α(-/-) mice showed no evidence of abnormal nerve function tests compared with nondiabetic mice. A single injection of infliximab in diabetic TNF-α(+/+) mice led to suppression of the increased serum TNF-α and amelioration of the electrophysiological and biochemical deficits for at least 4 wk. Moreover, the increased TNF-α mRNA expression in diabetic DRG was also attenuated by infliximab, suggesting infliximab's effects may involve the local suppression of TNF-α. Infliximab, an agent currently in clinical use, is effective in targeting TNF-α action and expression and amelioration of diabetic neuropathy in mice.
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MESH Headings
- Animals
- Anti-Inflammatory Agents/pharmacology
- Anti-Inflammatory Agents/therapeutic use
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal/therapeutic use
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/pathology
- Diabetic Neuropathies/drug therapy
- Diabetic Neuropathies/genetics
- Diabetic Neuropathies/metabolism
- Diabetic Neuropathies/pathology
- Drug Evaluation, Preclinical
- Ganglia, Spinal/metabolism
- Ganglia, Spinal/pathology
- Gene Expression Regulation/drug effects
- Gene Silencing/physiology
- Infliximab
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Molecular Targeted Therapy
- Streptozocin
- Transcription Factor RelA/metabolism
- Tumor Necrosis Factor-alpha/antagonists & inhibitors
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/metabolism
- Tumor Necrosis Factor-alpha/physiology
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Affiliation(s)
- Isamu Yamakawa
- Department of Molecular Genetics in Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
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Zanoni JN, Tronchini EA, Moure SA, Souza IDDS. Effects of L-glutamine supplementation on the myenteric neurons from the duodenum and cecum of diabetic rats. ARQUIVOS DE GASTROENTEROLOGIA 2011; 48:66-71. [PMID: 21537546 DOI: 10.1590/s0004-28032011000100014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Accepted: 08/19/2010] [Indexed: 12/16/2022]
Abstract
CONTEXT Peripheral neuropathy is one of the chronic complications of diabetes mellitus and is directly related to gastrointestinal consequences of the disease. Myenteric neurons are affected in some pathological conditions such as diabetic neuropathy. The imbalance between cellular antioxidants and free radicals, leading to an increase in oxidative stress, is considered one of the main factors responsible for neuronal damages in diabetes. Drugs that reduce the oxidative stress may play a significant role in the treatment of neurological complications of diabetes mellitus. OBJECTIVE To evaluate the effect of L-glutamine supplementation on the myenteric neurons from the cecum and duodenum of Wistar rats with streptozotocin-induced diabetes mellitus. METHODS The animals were divided in four groups (n = 5): non-treated normoglycemics, normoglycemics treated with L-glutamine, non-treated diabetics and diabetics treated with L-glutamine from the 4th day of diabetes induction on. The amino acid L-glutamine was added to their diet at 1%. Giemsa's technique was employed to stain the myenteric neurons. We determined the cell body area of 500 neurons in each group studied. The quantitative analysis was performed by sampling in an area of 16.6 mm² in the cecum and 3.6 mm² in the duodenum of each animal. RESULTS After the supplementation with L-glutamine in the duodenum, we observed a preservation of neuronal density in groups normoglycemic and diabetic (P<0.05). We also observed a preservation of the cell bodies area in diabetic animals (group treated with L-glutamine) (P<0.05). In the cecum, that preservation was not evident. CONCLUSION Supplementation with L-glutamine (1%) promoted a neuroprotective effect on the myenteric neurons from the duodenum of rats, both in terms of natural aging and of diabetes mellitus.
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Voukali E, Shotton HR, Lincoln J. Selective responses of myenteric neurons to oxidative stress and diabetic stimuli. Neurogastroenterol Motil 2011; 23:964-e411. [PMID: 21914042 DOI: 10.1111/j.1365-2982.2011.01778.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Diabetes has a differential effect on different subpopulations of myenteric neurons. Our aim was to investigate an in vitro model to examine the pathways underlying the development of nerve changes in diabetes. METHODS The proportions of neuronal cell bodies containing vasoactive intestinal polypeptide (VIP), neuronal nitric oxide synthase (nNOS) and calbindin relative to the pan-neuronal marker HuC/D were quantified in wholemount preparations of the myenteric plexus of adult rat ileum using double labeling immunohistochemistry. Preparations were maintained in culture for 24 h in the presence and absence of stimuli mimicking the diabetic environment including oxidative stress, carbonyl stress, high glucose and advanced glycation end products (AGEs). Data were compared with the effect of streptozotocin-induced diabetes in vivo. KEY RESULTS Only oxidative stress in vitro produced the same pattern as observed in diabetes with an increase in VIP-, decrease in nNOS-, and no change in calbindin-positive neurons. Carbonyl stress and high glucose caused an increase in VIP-containing neurons without affecting nNOS expression. In contrast, exposure to AGEs only caused a decrease in nNOS-positive neurons. Calbindin expression was unaffected by any of the stimuli. The effects of the stimuli were prevented by the antioxidant, α-lipoic acid, or the carbonyl scavenger, aminoguanidine. CONCLUSIONS & INFERENCES The results provide evidence that oxidative stress is the common factor in the development of neuronal changes in diabetes; however, the mechanism by which oxidative stress occurs depends on the individual subpopulation of myenteric neurons examined. The presence of calbindin appears to protect myenteric neurons against harmful stimuli.
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Affiliation(s)
- E Voukali
- Department of Cell and Developmental Biology, University College London, Gower Street, London, UK
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Cellini J, DiNovo K, Harlow J, LePard KJ. Regional differences in neostigmine-induced contraction and relaxation of stomach from diabetic guinea pig. Auton Neurosci 2010; 160:69-81. [PMID: 21075692 DOI: 10.1016/j.autneu.2010.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 09/27/2010] [Accepted: 10/07/2010] [Indexed: 12/19/2022]
Abstract
Delayed gastric emptying and autonomic neuropathy have been documented in patients with diabetes mellitus. Some medications used to treat delayed gastric emptying enhance release of acetylcholine from autonomic neurons to strengthen gastric contractions. Autonomic coordination among gastric regions may be altered in diabetes resulting in poor outcomes in response to prokinetic drugs. Fundus, antrum, and pylorus from STZ or control guinea pigs were treated with neostigmine to mimic release of acetylcholine from autonomic neurons by prokinetic agents. In diabetic animals, neostigmine-induced contractions were weaker in fundus and pylorus but similar in antrum. The muscarinic receptor antagonist 4-DAMP or the nicotinic receptor antagonist hexamethonium reduced neostigmine-induced contractions. Activation of presynaptic muscarinic receptors on nitrergic neurons was impaired in fundus and antrum from diabetic animals. Nerve-stimulated contractions and relaxations, number of nNOS myenteric neurons, and tissue choline content were reduced in fundus from diabetic animals. Despite reduced number of myenteric neurons, tissue choline content was increased in antrum from diabetic animals. Since cholinergic motility of each gastric region was affected differently by diabetes, prokinetic drugs that nondiscriminately enhance acetylcholine release from autonomic neurons may not effectively normalize delayed gastric emptying in patients with diabetes and more selective medications may be warranted.
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Affiliation(s)
- Joseph Cellini
- Department of Physiology, Chicago College of Osteopathic Medicine, Midwestern University, USA
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Roldi LP, Pereira RVF, Tronchini EA, Rizo GV, Scoaris CR, Zanoni JN, Natali MRM. Vitamin E (alpha-tocopherol) supplementation in diabetic rats: effects on the proximal colon. BMC Gastroenterol 2009; 9:88. [PMID: 19930636 PMCID: PMC2788574 DOI: 10.1186/1471-230x-9-88] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Accepted: 11/23/2009] [Indexed: 12/17/2022] Open
Abstract
Background Neuropathy is one of the complications caused by diabetes mellitus which is directly related to the gastrointestinal manifestations of the disease. Antioxidant substances, such as vitamin E, may play an important role in the reduction of the neurological damage caused by diabetes mellitus. The aim of the present study was to determine whether vitamin E (α-tocopherol) at different concentrations induces any effects on the morphology of the intestinal wall and intrinsic innervation in the proximal colon of diabetic rats. Methods Thirty rats (90-day-old) were assigned to the following groups: N (normoglycemic), NE1 (normoglycemic supplemented with vitamin E 0.1%), NE2 (normoglycemic supplemented with vitamin E 2%), D (diabetic), DE1 (diabetic supplemented with vitamin E 0.1%), and DE2 (diabetic supplemented with vitamin E 2%). Animals received vitamin E supplementation for 120 days and were sacrificed when they were 210 days old. The proximal colon of each animal was subjected to histology to study the intestinal wall and goblet cells and processed for whole-mount preparations to morphoquantitatively determine the total myenteric population. Results Supplementation with vitamin E significantly reduced glycemia and glycated hemoglobin values and preserved the number of myenteric neurons in group DE2, without affecting intestinal area or thickness of the intestinal wall or muscular tunic. Conclusion Vitamin E (2%) influenced the glycemic parameters and had a neuroprotective effect on the total myenteric population, but the morphometric characteristics of the intestinal wall were unaffected.
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Affiliation(s)
- Luciana P Roldi
- Department of Morphophysiological Sciences, Laboratory of Enteric Neurons, State University of Maringá, Brazil.
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Du F, Wang L, Qian W, Liu S. Loss of enteric neurons accompanied by decreased expression of GDNF and PI3K/Akt pathway in diabetic rats. Neurogastroenterol Motil 2009; 21:1229-e114. [PMID: 19709371 DOI: 10.1111/j.1365-2982.2009.01379.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
To investigate the enteric neuropathy in diabetic rats and the role of glia cell line-derived neurotrophic factor (GDNF) and its signalling pathway PI3K/Akt in regulating enteric neurons survival. Male Sprague-Dawley (SD) rats were randomly divided into normal control group, diabetic groups (rats with diabetes for 4, 8 and 12 weeks respectively). Proximal and distal colon specimens were obtained from each rat. Phosphoinositol-3-kinase signalling pathway was analysed by Akt phosphorylation. Protein gene product 9.5 (PGP9.5) used as a pan-neuronal marker. The expressions of GDNF, phospho-Akt (p-Akt), neuronal nitric oxide synthase (nNOS) neurons, cholinergic [choline acetyltransferase (CHAT) stained] neurons and total neurons were measured by immunohistochemical streptavidin-biotin complex (SABC) methods, Western blot and real-time polymerase chain reaction methods for each specimen. (i) Expression of GDNF was significantly decreased in diabetes 8 and 12 weeks group compared with the control group in both proximal (P < 0.01) and distal (P < 0.01) colon. The change of GDNF expression was greater in the 12 weeks group than that in the 8 weeks group (P < 0.05). There were no significant differences between the 4 weeks group and the control group in expression of GDNF (P > 0.05). (ii) The change trend of Akt phosphorylation was the same with GDNF. (iii) The numbers of nNOS, CHAT neurons and total neurons in proximal and distal colon were decreased significantly during the course of diabetes (P < 0.05). Diabetes can significantly induce enteric neuropathy. This change may be mediated, in partly, via a reduction of GDNF and its main downstream signalling pathway PI3K/Akt, which is a survival signal for enteric neurons.
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Affiliation(s)
- F Du
- Division of Gastroenterology, Union Hospital, Tongji medical college, Huazhong University of Science and Technology, Wuhan, China
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Tu H, Zhang L, Tran TP, Muelleman RL, Li YL. Diabetes alters protein expression of hyperpolarization-activated cyclic nucleotide-gated channel subunits in rat nodose ganglion cells. Neuroscience 2009; 165:39-52. [PMID: 19815055 DOI: 10.1016/j.neuroscience.2009.10.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 10/01/2009] [Accepted: 10/02/2009] [Indexed: 10/20/2022]
Abstract
Vagal afferent neurons, serving as the primary afferent limb of the parasympathetic reflex, could be involved in diabetic autonomic neuropathy. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed in the vagal afferent neurons and play an important role in determining cell membrane excitation. In the present study, the protein expression and the electrophysiological characteristics of HCN channels were investigated in nodose ganglion (NG) afferent neurons (A-fiber and C-fiber neurons) from sham and streptozotocin (STZ)-induced diabetic rats. In the sham NG, HCN1, HCN3, and HCN4 were expressed in the A-fiber neurons; and HCN2, HCN3, and HCN4 were expressed in the C-fiber neurons. Compared to the sham NG neurons, diabetes induced the expression of HCN2 in the A-fiber neurons besides overexpression of HCN1 and HCN3; and enhanced the expression of HCN2 and HCN3 in C-fiber neurons. In addition, whole-cell patch-clamp data revealed diabetes also increased HCN currents in A-fiber and C-fiber neurons. However, we found that diabetes did not alter the total nodose afferent neuron number and the ratio of A-fiber/C-fiber neurons. These results indicate that diabetes induces the overexpression of HCN channels and the electrophysiological changes of HCN currents in the A- and C-fiber nodose neurons, which might contribute to the diabetes-induced alteration of cell excitability in the vagal afferent neurons.
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Affiliation(s)
- H Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, 68198, USA
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Sharifi AM, Eslami H, Larijani B, Davoodi J. Involvement of caspase-8, -9, and -3 in high glucose-induced apoptosis in PC12 cells. Neurosci Lett 2009; 459:47-51. [DOI: 10.1016/j.neulet.2009.03.100] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 03/17/2009] [Accepted: 03/30/2009] [Indexed: 01/06/2023]
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Ikeda Y, Abe A, Ishida C, Takahashi K, Hayasaka K, Yamada M. A clinical phenotype of distal hereditary motor neuronopathy type II with a novel HSPB1 mutation. J Neurol Sci 2009; 277:9-12. [DOI: 10.1016/j.jns.2008.09.031] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 09/19/2008] [Accepted: 09/23/2008] [Indexed: 11/24/2022]
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Aroni K, Grapsa A, Lazaris AC, Kavantzas N, Kordosis T, Patsouris ES. Tissue estimation of protein gene product 9.5 (PGP 9.5) expression and apoptosis in vitiligo. Int J Dermatol 2008; 47:911-7. [DOI: 10.1111/j.1365-4632.2008.03723.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Yang Z, Nassar R, Dolber PC, Fraser MO. Voltage-dependent potassium currents of urethral afferent neurons in diabetes mellitus. Brain Res 2008; 1217:132-8. [DOI: 10.1016/j.brainres.2008.03.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Revised: 03/18/2008] [Accepted: 03/21/2008] [Indexed: 01/06/2023]
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Miller SM, Narasimhan RA, Schmalz PF, Soffer EE, Walsh RM, Krishnamurthi V, Pasricha PJ, Szurszewski JH, Farrugia G. Distribution of interstitial cells of Cajal and nitrergic neurons in normal and diabetic human appendix. Neurogastroenterol Motil 2008; 20:349-57. [PMID: 18069951 DOI: 10.1111/j.1365-2982.2007.01040.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The objective of this study was to determine the distribution of enteric nerves and interstitial cells of Cajal (ICC) in the normal human appendix and in type 1 diabetes. Appendixes were collected from patients with type 1 diabetes and from non-diabetic controls. Volumes of nerves and ICC were determined using 3-D reconstruction and neuronal nitric oxide synthase (nNOS) expressing neurons were counted. Enteric ganglia were found in the myenteric plexus region and within the longitudinal muscle. ICC were found throughout the muscle layers. In diabetes, c-Kit positive ICC volumes were significantly reduced as were nNOS expressing neurons. In conclusion, we describe the distribution of ICC and enteric nerves in health and in diabetes. The data also suggest that the human appendix, a readily available source of human tissue, may be useful model for the study of motility disorders.
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Affiliation(s)
- S M Miller
- Division of Gastroenterology and Hepatology, Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
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Knowles CH, De Giorgio R. Observations on a vestigial organ: a potential surrogate for enteric neuromesenchymal disease. Neurogastroenterol Motil 2008; 20:263-8. [PMID: 18371008 DOI: 10.1111/j.1365-2982.2008.01090.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Abnormalities of enteric nerves, interstitial cells of Cajal (ICC) and smooth muscle are often associated with severe gastrointestinal motility disorders. In this context, full-thickness biopsy of the gut may provide important diagnostic and prognostic clues as well as some possible therapeutic implications. Nonetheless, the unavoidable risk to further worsen prognosis evoked by laparotomy, and the unclear yield of histopathological analysis has hampered full-thickness gut sampling in patients with severe dysmotility. However, recent advances in minimally invasive surgery have refuelled enthusiasm in gastrointestinal neuromuscular pathology. In this issue of Neurogastroenterology and Motility, Miller et al. provide novel and exciting evidence that the appendix might be used as a surrogate tissue to analyse changes to enteric nerves, ICC and smooth muscle cells in patients with diabetic gastroenteropathy. The objective of this short review was to place this very important work in the context of current understanding of enteric neuromuscular dysfunction.
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Affiliation(s)
- C H Knowles
- Centre for Academic Surgery, Barts & The London, Queen Mary's School of Medicine and Dentistry, London, UK
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Ishihara E, Nagahama M, Naruse S, Semba R, Miura T, Usami M, Narita M. Neuropathological alteration of aquaporin 1 immunoreactive enteric neurons in the streptozotocin-induced diabetic rats. Auton Neurosci 2008; 138:31-40. [DOI: 10.1016/j.autneu.2007.09.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2007] [Revised: 08/29/2007] [Accepted: 09/06/2007] [Indexed: 01/15/2023]
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Abstract
Diabetes is associated with several changes in gastrointestinal (GI) motility and associated symptoms such as nausea, bloating, abdominal pain, diarrhoea and constipation. The pathogenesis of altered GI functions in diabetes is multifactorial and the role of the enteric nervous system (ENS) in this respect has gained significant importance. In this review, we summarize the research carried out on diabetes-related changes in the ENS. Changes in the inhibitory and excitatory enteric neurons are described highlighting the role of loss of inhibitory neurons in early diabetic enteric neuropathy. The functional consequences of these neuronal changes result in altered gastric emptying, diarrhoea or constipation. Diabetes can also affect GI motility through changes in intestinal smooth muscle or alterations in extrinsic neuronal control. Hyperglycaemia and oxidative stress play an important role in the pathophysiology of these ENS changes. Antioxidants to prevent or treat diabetic GI motility problems have therapeutic potential. Recent research on the nerve-immune interactions demonstrates inflammation-associated neurodegeneration which can lead to motility related problems in diabetes.
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Affiliation(s)
- B Chandrasekharan
- Division of Digestive Diseases, Emory University, Atlanta, GA 30322, USA
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