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Lima FGDM, Silva MPAD, Sestak SS, Guarnier FA, de Oliveira AP, Kuller JV, Gulbransen BD, Perles JVCM, Zanoni JN. Cancer-induced morphological changes in enteric glial cells in the jejunum of Walker-256 tumor-bearing rats. Acta Histochem 2024; 126:152146. [PMID: 38422841 PMCID: PMC11039380 DOI: 10.1016/j.acthis.2024.152146] [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: 07/26/2023] [Revised: 01/29/2024] [Accepted: 02/14/2024] [Indexed: 03/02/2024]
Abstract
Cancer-induced cachexia is associated with systemic inflammation and gastrointestinal dysfunction. How changes to cells of the enteric nervous system contribute to gut dysfunction in tumor development and cancer cachexia is unknown. Here, we tested the hypothesis that changes to enteric glia, a type of peripheral glia that surround enteric neurons and regulate gut homeostasis, are associated with tumor development and that supplementing with the antioxidant L-glutathione is protective against the changes induced. Immunohistochemistry for neurons, enteric glial cells and immune cells was performed in whole-mount preparations and frozen histological sections of the jejunum from 20 Wistar rats, distributed in 4 groups: control, tumor of Walker-256, control administered with 1 % L-glutathione, and tumor of Walker-256 administered with 1 % L-glutathione. Morphoquantitative analyses were made using Image-Pro® Plus 4.5 and ImageJ® 1.43° software. Tumor development significantly reduced neuronal and glial cell populations in the myenteric and submucosal plexuses and enlarged glial cell body area in the submucosal plexus. In contrast, tumors increased glia in the jejunal mucosa and this effect was accompanied by B-lymphocyte recruitment. GSH-supplemented diet was not sufficient to protect against changes to neurons and glia in the submucosal plexus but was partially protective in the myenteric plexus. L-glutathione had no effect on physiological parameters of cachexia but was sufficient to preserve enteric glial cell density in the myenteric plexus. These results suggest that changes to both enteric neurons and glia likely contribute to the gastrointestinal effects of tumor development and that oxidative stress contributes to these effects in the enteric nervous system.
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Affiliation(s)
| | | | - Sabrina Silva Sestak
- Laboratory of Enteric Neural Plasticity, State University of Maringá, Maringá, PR, Brazil
| | | | | | - João Victor Kuller
- Laboratory of Enteric Neural Plasticity, State University of Maringá, Maringá, PR, Brazil
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Protective effects of quercetin-loaded microcapsules on the enteric nervous system of diabetic rats. Auton Neurosci 2021; 230:102759. [DOI: 10.1016/j.autneu.2020.102759] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/27/2020] [Accepted: 12/02/2020] [Indexed: 02/06/2023]
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de Souza SRG, de Miranda Neto MH, Martins Perles JVC, Vieira Frez FC, Zignani I, Ramalho FV, Hermes-Uliana C, Bossolani GDP, Zanoni JN. Antioxidant Effects of the Quercetin in the Jejunal Myenteric Innervation of Diabetic Rats. Front Med (Lausanne) 2017; 4:8. [PMID: 28224126 PMCID: PMC5293826 DOI: 10.3389/fmed.2017.00008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 01/19/2017] [Indexed: 12/31/2022] Open
Abstract
Purpose Enteric glial cells (EGCs) exert a critical role in the structural integrity, defense, and metabolic function of enteric neurons. Diabetes mellitus is a chronic disease characterized by metabolic disorders and chronic autonomic neuropathy. Quercetin supplementation, which is a potent antioxidant, has been used in order to reduce the effects of diabetes-induced oxidative stress. The purpose of this research was to investigate the effects of quercetin supplementation in the drinking water at a daily dose of 40 mg on the glial cells and neurons in the jejunum of diabetic rats. Materials and methods Twenty 90-day-old male adult Wistar rats were split into four groups: normoglycemic control (C), normoglycemic control supplemented with quercetin (Q), diabetic (D), and diabetic supplemented with quercetin (DQ). After 120 days, the jejunums were collected, and immunohistochemical technique was performed to label S-100-immunoreactive glial cells and HuC/D-immunoreactive neurons. Results An intense neuronal and glial reduction was observed in the jejunum of diabetic rats. Quercetin displayed neuroprotective effects due to reduced cell body areas of neurons and glial cells in Q and DQ groups compared to their controls (C and D groups). Interestingly, quercetin prevented the glial and neuronal loss with a higher density for the HuC/D-immunoreactive neurons (23.06%) and for the S100-immunoreactive glial cells (14.55%) in DQ group compared to D group. Conclusion Quercetin supplementation promoted neuroprotective effects through the reduction of neuronal and glial body areas and a slight prevention of neuronal and glial density reduction.
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Affiliation(s)
- Sara R Garcia de Souza
- Department of Morphological Sciences, Universidade Estadual de Maringá , Maringá, Paraná , Brazil
| | | | | | | | - Isabela Zignani
- Department of Morphological Sciences, Universidade Estadual de Maringá , Maringá, Paraná , Brazil
| | - Francielle Veiga Ramalho
- Department of Morphological Sciences, Universidade Estadual de Maringá , Maringá, Paraná , Brazil
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Vicentini GE, Fracaro L, de Souza SRG, Martins HA, Guarnier FA, Zanoni JN. Experimental Cancer Cachexia Changes Neuron Numbers and Peptide Levels in the Intestine: Partial Protective Effects after Dietary Supplementation with L-Glutamine. PLoS One 2016; 11:e0162998. [PMID: 27635657 PMCID: PMC5026352 DOI: 10.1371/journal.pone.0162998] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/31/2016] [Indexed: 12/22/2022] Open
Abstract
Gastrointestinal dysmotility frequently occurs in cancer cachexia and may result from damage to enteric innervation caused by oxidative stress, especially due to glutathione depletion. We assessed the effect of dietary supplementation with 20 g/kg l-glutamine (a glutathione precursor) on the intrinsic innervation of the enteric nervous system in healthy and Walker 256 tumor-bearing Wistar rats during the development of experimental cachexia (14 days), in comparison with non-supplemented rats, by using immunohistochemical methods and Western blotting. The total neural population and cholinergic subpopulation densities in the myenteric plexus, as well as the total population and VIPergic subpopulation in the submucosal plexus of the jejunum and ileum, were reduced in cachectic rats, resulting in adaptive morphometric alterations and an increase in vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) expression, suggesting a neuroplastic response. l-glutamine supplementation prevented decrease in myenteric neuronal density in the ileum, morphometric alterations in the neurons and nerve fibers (in both the plexuses of the jejunum and ileum), and the overexpression of VIP and CGRP. Cancer cachexia severely affected the intrinsic innervation of the jejunum and ileum to various degrees and this injury seems to be associated with adaptive neural plasticity. l-glutamine supplementation presented partial protective effects on the enteric innervation against cancer cachexia, possibly by attenuating oxidative stress.
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Affiliation(s)
- Geraldo E. Vicentini
- Department of Morphological Sciences, Universidade Estadual de Maringa, Maringa, Parana, Brazil
| | - Luciane Fracaro
- Department of Morphological Sciences, Universidade Estadual de Maringa, Maringa, Parana, Brazil
| | - Sara R. G. de Souza
- Department of Morphological Sciences, Universidade Estadual de Maringa, Maringa, Parana, Brazil
| | - Heber A. Martins
- Department of Morphological Sciences, Universidade Estadual de Maringa, Maringa, Parana, Brazil
| | - Flávia A. Guarnier
- Department of General Pathology, Universidade Estadual de Londrina, Londrina, Parana, Brazil
| | - Jacqueline N. Zanoni
- Department of Morphological Sciences, Universidade Estadual de Maringa, Maringa, Parana, Brazil
- * E-mail:
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Supplementation with l-glutamine prevents tumor growth and cancer-induced cachexia as well as restores cell proliferation of intestinal mucosa of Walker-256 tumor-bearing rats. Amino Acids 2016; 48:2773-2784. [DOI: 10.1007/s00726-016-2313-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 08/09/2016] [Indexed: 12/15/2022]
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Panizzon CPDNB, Zanoni JN, Hermes-Uliana C, Trevizan AR, Sehaber CC, Pereira RVF, Linden DR, Neto MHDM. Desired and side effects of the supplementation with l-glutamine and l-glutathione in enteric glia of diabetic rats. Acta Histochem 2016; 118:625-631. [PMID: 27470531 DOI: 10.1016/j.acthis.2016.07.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/07/2016] [Accepted: 07/07/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND/AIMS Enteric neuropathy associated with Diabetes Mellitus causes dysfunction in the digestive system, such as: nausea, diarrhea, constipation, vomiting, among others. The aim of this study was to compare the effects of supplementation with 2% l-glutamine and 1% l-glutathione on neurons and enteric glial cells of ileum of diabetic rats. METHODS Thirty male Wistar rats have been used according to these group distributions: Normoglycemic (N), Normoglycemic supplemented with l-glutamine (NG), Normoglycemic supplemented with l-glutathione (NGO), Diabetic (D), Diabetic supplemented with l-glutamine (DG) and Diabetic supplemented with l-glutathione (DGO). After 120days, the ileum was processed for immunohistochemistry of HuC/D and S100β. Quantitative and morphometric analysis have been performed. RESULTS Diabetic rats presented a decrease in the number of neurons when compared to normoglycemic animals. However, diabetes was not associated with a change in glial density. l-Glutathione prevented the neuronal death in diabetic rats. l-Glutathione increased a glial proliferation in diabetic rats. The neuronal area in diabetic rats increased in relation to the normoglycemics. The diabetic rats supplemented with l-glutamine and l-glutathione showed a smaller neuronal area in comparison to diabetic group. The glial cell area was a decreased in the diabetics. The diabetic rats supplemented with l-glutamine and l-glutathione did not have significant difference in the glial cell body area when compared to diabetic rats. CONCLUSION It is concluded that the usage of l-glutamine and l-glutathione as supplements presents both desired and side effects that are different for the same substance in considering normoglycemic or diabetic animals.
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Yu XY, Zhang L, Yang XY, Li XT, Du GH. Salvianolic acid A improves intestinal motility in diabetic rats through antioxidant capacity and upregulation of nNOS. J Dig Dis 2016; 17:441-7. [PMID: 27273366 DOI: 10.1111/1751-2980.12363] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 05/08/2016] [Accepted: 05/23/2016] [Indexed: 12/11/2022]
Abstract
OBJECTIVE This study aimed to detect the effect of a new herbal extract salvianolic acid A (SalA) on gastrointestinal complications in diabetic rats. METHODS Altogether 80 rats were divided randomly into five groups, including normal control (NC) group, high-fat (HF) diet group, diabetes mellitus (DM) control group, and DM treated with SalA (0.1 mg/kg and 0.3 mg/kg) groups, respectively. DM was induced by feeding the rats with HF diet and the administration of streptozotocin (30 mg/kg). Four weeks after the establishment of the DM model, the rats received SalA or double distilled water for 8 weeks. After the evaluation of intestinal motility, the animals were sacrificed and their intestines were isolated and collected. The levels of advanced glycation end-products (AGE) and malondialdehyde (MDA) were detected. Protein gene product 9.5 (PGP9.5) and neuronal nitric oxide synthase (nNOS) expressions in the intestine were also detected. RESULTS Compared with the NC and HF rats, the DM control rats showed significantly increased blood glucose level and decreased weight. Compared with the DM control group, SalA did not influence their weight and blood glucose level, but significantly reduced the levels of AGE and MDA. Intestinal transit was promoted by SalA in diabetic rats, and the expressions of PGP9.5 and nNOS in the intestine were both upregulated. CONCLUSION The effect of SalA on the intestinal motility of diabetic rats might be due to its antioxidant capacity and restoring nNOS expression.
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Affiliation(s)
- Xiao Yan Yu
- Beijing Key Laboratory of Drug Target Identification and Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Science and Peking Union Medical College.,School of Life Sciences, Tsinghua University, Beijing.,Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiaotong University School of Medicine, Shanghai
| | - Li Zhang
- Beijing Key Laboratory of Drug Target Identification and Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Science and Peking Union Medical College
| | - Xiu Ying Yang
- Beijing Key Laboratory of Drug Target Identification and Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Science and Peking Union Medical College
| | - Xiao Ting Li
- Pharmaceutical College of Henan University, Kaifeng, Henan Province, China
| | - Guan Hua Du
- Beijing Key Laboratory of Drug Target Identification and Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Science and Peking Union Medical College.
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PEREIRA RENATAV, LINDEN DAVIDR, MIRANDA-NETO MARCÍLIOH, ZANONI JACQUELINEN. Differential effects in CGRPergic, nitrergic, and VIPergic myenteric innervation in diabetic rats supplemented with 2% L-glutamine. ACTA ACUST UNITED AC 2016; 88 Suppl 1:609-22. [DOI: 10.1590/0001-3765201620150228] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/03/2015] [Indexed: 12/29/2022]
Abstract
ABSTRACT The objective of this study was to investigate the effects of 2% L-glutamine supplementation on myenteric innervation in the ileum of diabetic rats, grouped as follows: normoglycemic (N); normoglycemic supplemented with L-glutamine (NG); diabetic (D); and diabetic supplemented with L-glutamine (DG). The ileums were subjected to immunohistochemical techniques to localize neurons immunoreactive to HuC/D protein (HuC/D-IR) and neuronal nitric oxide synthase enzyme (nNOS-IR) and to analyze varicosities immunoreactive to vasoactive intestinal polypeptide (VIP-IR) and calcitonin gene-related peptide (CGRP-IR). L-Glutamine in the DG group (i) prevented the increase in the cell body area of nNOS-IR neurons, (ii) prevented the increase in the area of VIP-IR varicosities, (iii) did not prevent the loss of HuC/D-IR and nNOS-IR neurons per ganglion, and (iv) reduced the size of CGRP-IR varicosities. L-Glutamine in the NG group reduced (i) the number of HuC/D-IR and nNOS-IR neurons per ganglion, (ii) the cell body area of nNOS-IR neurons, and (iii) the size of VIP-IR and CGRP-IR varicosities. 2% L-glutamine supplementation exerted differential neuroprotective effects in experimental diabetes neuropathy that depended on the type of neurotransmitter analyzed. However, the effects of this dose of L-glutamine on normoglycemic animals suggests there are additional actions of this beyond its antioxidant capacity.
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Tashima CM, Hermes-Uliana C, Perles JVCM, de Miranda Neto MH, Zanoni JN. Vitamins C and E (ascorbate/α-tocopherol) provide synergistic neuroprotection in the jejunum in experimental diabetes. ACTA ACUST UNITED AC 2015; 22:241-8. [PMID: 26433445 DOI: 10.1016/j.pathophys.2015.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 09/21/2015] [Accepted: 09/22/2015] [Indexed: 12/24/2022]
Abstract
The present study evaluated the synergistic effects of the association of ascorbic acid and α-tocopherol on myenteric in the jejunum of diabetic rats. The rats were randomly divided into four equal groups: untreated normoglycemic (UC), untreated diabetic (UD), ascorbic acid and α-tocopherol-treated normoglycemic (CAE) and ascorbic acid and α-tocopherol-treated diabetic (DAE). The rats from the CAE and DAE group received supplementation with ascorbic acid (1g/L in water) and α-tocopherol (1% in chow). At 210-days-old, the animals were sacrified and their jejunum was collected and submitted to immunohistochemistry. Quantitative and/or morphometric analysis were performed. Supplementation with ascorbic acid and α-tocopherol prevented the cell loss of myenteric neurons expressing HuC/D and TrkA in an equivalent proportion. We also observed a reduction of the CGRP nerve fiber varicosities and the prevention of the increased cell body size of submucosal VIP neurons (p<0.05). The association of ascorbic acid and α-tocopherol reduced the deleterious effects of diabetes promoting protection on the enteric neurons.
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Affiliation(s)
- Cristiano Massao Tashima
- Department of Health and Education, Universidade Estadual do Norte do Paraná, 86360-000 Paraná, Brazil
| | - Catchia Hermes-Uliana
- Universidade Federal de Mato Grosso do Sul, 79400-000 Coxim, Mato Grosso do Sul, Brazil
| | | | | | - Jacqueline Nelisis Zanoni
- Department of Morphological Sciences, Universidade Estadual de Maringá, 87020-900 Maringá, Paraná, Brazil.
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Is L-glutathione more effective than L-glutamine in preventing enteric diabetic neuropathy? Dig Dis Sci 2014; 59:937-48. [PMID: 24370785 DOI: 10.1007/s10620-013-2993-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 12/10/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND Diabetes and its complications appear to be multifactorial. Substances with antioxidant potential have been used to protect enteric neurons in experimental diabetes. AIM This study evaluated the effects of supplementation with L-glutamine and L-glutathione on enteric neurons in the jejunum in diabetic rats. METHODS Rats at 90 days of age were distributed into six groups: normoglycemic, normoglycemic supplemented with 2 % L-glutamine, normoglycemic supplemented with 1 % L-glutathione, diabetic (D), diabetic supplemented with 2 % L-glutamine (DG), and diabetic supplemented with 1 % L-glutathione (DGT). After 120 days, the jejunums were immunohistochemically stained for HuC/D+ neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP). Western blot was performed to evaluate nNOS and VIP. Submucosal and myenteric neurons were quantitatively and morphometrically analyzed. RESULTS Diabetic neuropathy was observed in myenteric HuC/D, nNOS, and VIP neurons (p < 0.05). In the submucosal plexus, diabetes did not change nitrergic innervation but increased VIPergic neuronal density and body size (p < 0.05). Supplementation with L-glutathione prevented changes in HuC/D neurons in the enteric plexus (p < 0.05), showing that supplementation with L-glutathione was more effective than with L-glutamine. Myenteric nNOS neurons in the DGT group exhibited a reduced density (34.5 %) and reduced area (p < 0.05). Submucosal neurons did not exhibit changes. The increase in VIP-expressing neurons was prevented in the submucosal plexus in the DG and DGT groups (p < 0.05). CONCLUSION Supplementation with L-glutathione exerted a better neuroprotective effect than L-glutamine and may prevent the development of enteric diabetic neuropathy.
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Tronchini EA, Trevizan AR, Tashima CM, Pereira RVF, Zanoni JN. Supplementation with 0.1% and 2% vitamin E in diabetic rats: analysis of myenteric neurons immunostained for myosin-V and nNOS in the jejunum. ARQUIVOS DE GASTROENTEROLOGIA 2013; 49:284-90. [PMID: 23329224 DOI: 10.1590/s0004-28032012000400010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Accepted: 06/26/2012] [Indexed: 02/06/2023]
Abstract
CONTEXT Diabetes mellitus is a disease characterized by hyperglycemia that, when allowed to progress long-term untreated, develops vascular and neurological complications, which are responsible for the development of alterations in the enteric nervous system in diabetic patients. In the gastrointestinal tract, diabetes mellitus promotes motor and sensory changes, and in the reflex function of this system, causing gastroparesis, diarrhea, constipation, megacolon, slow gastrointestinal transit, gastric stasis and dilation with decreased or increased peristaltic contractions. Several studies have shown that oxidative stress is the main responsible for the vascular and neurological complications affecting the enteric nervous system of diabetics. OBJECTIVE The effects of 0.1% and 2% vitamin E on myosin-V- and nNOS-immunoreactive neurons in the jejunum of diabetic rats were investigated. METHODS Thirty rats were divided into the groups: normoglycemic, normoglycemic treated with 0.1% vitamin E, normoglycemic treated with 2% vitamin E, diabetic, diabetic treated with 0.1% vitamin E, and diabetic treated with 2% vitamin E. The neuronal density and areas of neuron cell bodies were determined. RESULTS Diabetes (diabetic group) significantly reduced the number of myosin-V-immunoreactive neurons compared with the normoglycemic group. The diabetic treated with 0.1% vitamin E and diabetic treated with 2% vitamin E groups did not exhibit a greater density than the D group (P>0.05). Nitrergic density did not change with diabetes (P>0.05). The areas of myosin-V- and nNOS-immunoreactive neurons significantly increased in the normoglycemic treated with 2% vitamin E and diabetic groups compared with the normoglycemic group. CONCLUSION Supplementation with 2% vitamin E had a neurotrophic effect only in the area of myosin-V-immunoreactive neurons compared with the diabetic group.
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Neuroprotective effect of quercetin on the duodenum enteric nervous system of streptozotocin-induced diabetic rats. Dig Dis Sci 2012; 57:3106-15. [PMID: 22878915 DOI: 10.1007/s10620-012-2300-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 06/15/2012] [Indexed: 12/12/2022]
Abstract
BACKGROUND In diabetes mellitus (DM), hyperglycemia promotes changes in biochemical mechanisms that induce oxidative stress. Oxidative stress has been closely linked to adverse consequences that affect the function of the gastrointestinal tract caused by injuries to the enteric nervous system (ENS) that in turn cause neurodegeneration and enteric glial loss. Therapeutic approaches have shown that diet supplementation with antioxidants, such as quercetin, reduce oxidative stress. AIMS This work sought to evaluate neurons and enteric glial cells in the myenteric and submucosal plexuses of the duodenum in diabetic rats supplemented with quercetin. METHODS The duodenum of 24 rats, including a control group (C), control quercetin supplementation group (CQ), diabetic group (D), and diabetic quercetin supplementation group (DQ), were used to investigate whole mounts of muscular and submucosal layers subjected to immunohistochemistry to detect vasoactive intestinal peptide in the myenteric layer and double-staining for HuC-D/neuronal nitric oxide synthase (nNOS) and HuC-D/S100. RESULTS A reduction of the general neuronal population (HuC/D) was found in the myenteric and submucosal plexuses (p < 0.001) in the D and DQ groups. The nitrergic subpopulation (nNOS) decreased only in the myenteric plexus (p < 0.001), and glial cells decreased in both plexuses (p < 0.001) in the D and DQ groups. In diabetic rats, quercetin supplementation reduced neuronal and glial loss. Diabetes promoted an increase in the cell body area of both the general and nitrergic populations. Quercetin supplementation only prevented neuronal hypertrophy in the general population. CONCLUSION Supplementation with quercetin eased the damage caused by diabetes, promoting a neuroprotective effect and reducing enteric glial loss in the duodenum.
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Bagyánszki M, Bódi N. Diabetes-related alterations in the enteric nervous system and its microenvironment. World J Diabetes 2012; 3:80-93. [PMID: 22645637 PMCID: PMC3360223 DOI: 10.4239/wjd.v3.i5.80] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 04/06/2012] [Accepted: 05/11/2012] [Indexed: 02/05/2023] Open
Abstract
Gastric intestinal symptoms common among diabetic patients are often caused by intestinal motility abnormalities related to enteric neuropathy. It has recently been demonstrated that the nitrergic subpopulation of myenteric neurons are especially susceptible to the development of diabetic neuropathy. Additionally, different susceptibility of nitrergic neurons located in different intestinal segments to diabetic damage and their different levels of responsiveness to insulin treatment have been revealed. These findings indicate the importance of the neuronal microenvironment in the pathogenesis of diabetic nitrergic neuropathy. The main focus of this review therefore was to summarize recent advances related to the diabetes-related selective nitrergic neuropathy and associated motility disturbances. Special attention was given to the findings on capillary endothelium and enteric glial cells. Growing evidence indicates that capillary endothelium adjacent to the myenteric ganglia and enteric glial cells surrounding them are determinative in establishing the ganglionic microenvironment. Additionally, recent advances in the development of new strategies to improve glycemic control in type 1 and type 2 diabetes mellitus are also considered in this review. Finally, looking to the future, the recent and promising results of metagenomics for the characterization of the gut microbiome in health and disease such as diabetes are highlighted.
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Affiliation(s)
- Mária Bagyánszki
- Mária Bagyánszki, Nikolett Bódi, Department of Physiology, Anatomy and Neuroscience, Faculty of Science, University of Szeged, H-6726 Szeged, Hungary
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Pereira RVF, Tronchini EA, Tashima CM, Alves EPB, Lima MM, Zanoni JN. L-glutamine supplementation prevents myenteric neuron loss and has gliatrophic effects in the ileum of diabetic rats. Dig Dis Sci 2011; 56:3507-16. [PMID: 21710226 DOI: 10.1007/s10620-011-1806-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Accepted: 06/14/2011] [Indexed: 12/16/2022]
Abstract
BACKGROUND Peripheral neuropathy caused chronically by diabetes mellitus is related to exacerbation of oxidative stress and a significant reduction in important endogenous antioxidants. L: -Glutamine is an amino acid involved in defense mechanisms and is a substrate for the formation of glutathione, the major endogenous cellular antioxidant. AIM This study investigated the effects of 2% L: -glutamine supplementation on peripheral diabetic neuropathy and enteric glia in the ileum in rats. METHODS Male Wistar rats were divided into four groups: normoglycemics (N), normoglycemics supplemented with L: -glutamine (NG), diabetics (D), and diabetics supplemented with L: -glutamine (DG). After 120 days, the ileums were processed for HuC/D and S100 immunohistochemistry. Quantitative and morphometric analysis was performed. RESULTS Diabetes significantly reduced the number of HuC/D-immunoreactive myenteric neurons per unit area and per ganglion in group D compared with normoglycemic animals (group N). L: -Glutamine (2%) prevented neuronal death induced by diabetes (group DG) compared with group D. The glial density per unit area did not change with diabetes (group D) but was significantly reduced after L: -glutamine supplementation (groups NG and DG). Ganglionic glial density was similar among the four groups. The neuronal area was not altered in groups D and DG. Glial size was reduced in group D; this was reversed by L: -glutamine supplementation (group DG). CONCLUSIONS We concluded that 2% L: -glutamine had neuroprotective effects directly on myenteric neurons and indirectly through glial cells, which had gliatrophic effects.
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Affiliation(s)
- Renata Virginia Fernandes Pereira
- Department of Morphological Sciences, Universidade Estadual de Maringá, Avenida Colombo, nº 5790 Bloco H-79, Maringá, PR, CEP 87020-900, Brazil.
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Silva GGPD, Zanoni JN, Buttow NC. Neuroprotective action of Ginkgo biloba on the enteric nervous system of diabetic rats. World J Gastroenterol 2011; 17:898-905. [PMID: 21412498 PMCID: PMC3051139 DOI: 10.3748/wjg.v17.i7.898] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 03/24/2010] [Accepted: 03/31/2010] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of Ginkgo biloba extract on the enteric neurons in the small intestine of diabetic rats.
METHODS: Fifteen Wistar rats were divided into three groups: control group (C), diabetic group (D) and diabetic-treated (DT) daily with EGb 761 extract (50 mg/kg body weight) for 120 d. The enteric neurons were identified by the myosin-V immunohistochemical technique. The neuronal density and the cell body area were also analyzed.
RESULTS: There was a significant decrease in the neuronal population (myenteric plexus P = 0.0351; submucous plexus P = 0.0217) in both plexuses of the jejunum in group D when compared to group C. With regard to the ileum, there was a significant decrease (P = 0.0117) only in the myenteric plexus. The DT group showed preservation of the neuronal population in the jejunum submucous plexus and in the myenteric plexus in the ileum. The cell body area in group D increased significantly (P = 0.0001) in the myenteric plexus of both segments studied as well as in the ileum submucosal plexus, when compared to C. The treatment reduced (P = 0.0001) the cell body area of the submucosal neurons of both segments and the jejunum myenteric neurons.
CONCLUSION: The purified Ginkgo biloba extract has a neuroprotective effect on the jejunum submucous plexus and the myenteric plexus of the ileum of diabetic rats.
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Alves EPB, Alves AMP, Pereira RVF, de Miranda Neto MH, Zanoni JN. Immunohistochemical study of vasoactive intestinal peptide (VIP) enteric neurons in diabetic rats supplemented with L-glutamine. Nutr Neurosci 2010; 13:43-51. [PMID: 20132654 DOI: 10.1179/147683010x12611460763841] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The purpose of this work was to study the area of the varicosities of nerve fibers of myenteric neurons immunoreactive to vasoactive intestinal peptide (VIP-IR) and of the cell bodies of VIP-IR submucosal neurons of the jejunum of diabetic rats supplemented with 2% L-glutamine. Twenty male rats were divided into the following groups: normoglycemic (N), normoglycemic supplemented with L-glutamine (NG), diabetic (D) and diabetic supplemented with L-glutamine (DG). Whole-mounts of the muscle tunica and the submucosal layer were subjected to the immunohistochemical technique for neurotransmitter VIP identification. Morphometric analyses were carried out in 500 VIP-IR cell bodies of submucosal neurons and 2000 VIP-IR varicosities from each group. L-Glutamine supplementation to the normoglycemic animals caused an increase in the areas of the cell bodies (8.49%) and varicosities (21.3%) relative to the controls (P < 0.05). On the other hand, there was a decrease in the areas of the cell bodies (4.55%) and varicosities (28.9%) of group DG compared to those of group D (P < 0.05). It is concluded that L-glutamine supplementation was positive both to normoglycemic and diabetic animals.
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Affiliation(s)
- Eder Paulo Belato Alves
- Department of Morphophysiological Sciences, Laboratory of Enteric Neurons, State University of Maringa, Avenida Colombo, 5790 Bloco H-79, CEP 87020-900 Maringá, PR, Brazil.
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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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Pereira RVF, de Miranda-Neto MH, da Silva Souza ID, Zanoni JN. Vitamin E supplementation in rats with experimental diabetes mellitus: analysis of myosin-V and nNOS immunoreactive myenteric neurons from terminal ileum. J Mol Histol 2008; 39:595-603. [PMID: 18953659 DOI: 10.1007/s10735-008-9200-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Accepted: 10/09/2008] [Indexed: 12/16/2022]
Abstract
The effect of vitamin E (1 g/kg body weight) supplementation on myosin-V and neuronal nitric oxide synthase (nNOS) immunoreactive myenteric neurons from the ileum of diabetic rats was investigated in the present study. Forty animals were divided into the following groups: normoglycemics (N), normoglycemics treated with vitamin E (NE), diabetics (D), and diabetics treated with vitamin E (DE). Quantitative and morphometric analyses were performed. The area of the tertiary plexus was also determined. Diabetes produced a 24% reduction in the number of myosin-V neurons in group D compared with group N, an effect that was accompanied by an increase in the tertiary plexus area (P < 0.05). Neuronal density was 27% higher in group NE than group N (P < 0.05). Nitrergic neuronal density was not altered as a consequence of either diabetes or vitamin E treatment. Myosin-V and nNOS immunoreactive neuronal cell body area increased significantly in group NE. The area of myosin-V and nNOS myenteric neurons also increased in group D. Vitamin E treatment (group DE) increased only the size of nitrergic neurons. The present results suggest that vitamin E elicited a neuroprotective and neurotrophic effect on the natural aging process, but with regard to diabetes, vitamin E supplementation exerted a neurotrophic effect only on nitrergic neurons.
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Affiliation(s)
- Renata Virginia Fernandes Pereira
- Department of Morphophysiological Sciences, Universidade Estadual de Maringá, Avenida Colombo, no. 5790 Bloco H-79, CEP 87020-900 Maringá, PR, Brazil
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