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Guo B, Qi M, Luo X, Guo L, Xu M, Zhang Y, Li Z, Li M, Wu R, Guan T, Liu M, Liu Y. GIP attenuates neuronal oxidative stress by regulating glucose uptake in spinal cord injury of rat. CNS Neurosci Ther 2024; 30:e14806. [PMID: 38887182 PMCID: PMC11183929 DOI: 10.1111/cns.14806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 05/01/2024] [Accepted: 05/18/2024] [Indexed: 06/20/2024] Open
Abstract
AIM Glucose-dependent insulinotropic polypeptide (GIP) is a ligand of glucose-dependent insulinotropic polypeptide receptor (GIPR) that plays an important role in the digestive system. In recent years, GIP has been regarded as a hormone-like peptide to regulate the local metabolic environment. In this study, we investigated the antioxidant role of GIP on the neuron and explored the possible mechanism. METHODS Cell counting Kit-8 (CCK-8) was used to measure cell survival. TdT-mediated dUTP Nick-End Labeling (TUNEL) was used to detect apoptosis in vitro and in vivo. Reactive oxygen species (ROS) levels were probed with 2', 7'-Dichloro dihydrofluorescein diacetate (DCFH-DA), and glucose intake was detected with 2-NBDG. Immunofluorescence staining and western blot were used to evaluate the protein level in cells and tissues. Hematoxylin-eosin (HE) staining, immunofluorescence staining and tract-tracing were used to observe the morphology of the injured spinal cord. Basso-Beattie-Bresnahan (BBB) assay was used to evaluate functional recovery after spinal cord injury. RESULTS GIP reduced the ROS level and protected cells from apoptosis in cultured neurons and injured spinal cord. GIP facilitated wound healing and functional recovery of the injured spinal cord. GIP significantly improved the glucose uptake of cultured neurons. Meanwhile, inhibition of glucose uptake significantly attenuated the antioxidant effect of GIP. GIP increased glucose transporter 3 (GLUT3) expression via up-regulating the level of hypoxia-inducible factor 1α (HIF-1α) in an Akt-dependent manner. CONCLUSION GIP increases GLUT3 expression and promotes glucose intake in neurons, which exerts an antioxidant effect and protects neuronal cells from oxidative stress both in vitro and in vivo.
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Affiliation(s)
- Beibei Guo
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, Medical SchoolNantong UniversityNantongChina
| | - Mengwei Qi
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
| | - Xiaoqian Luo
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
| | - Longyu Guo
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
| | - Man Xu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
| | - Yufang Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, Medical SchoolNantong UniversityNantongChina
| | - Zhen Li
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
| | - Mingxuan Li
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
| | - Ronghua Wu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
| | - Tuchen Guan
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
| | - Mei Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
| | - Yan Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co‐innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsNantong UniversityNantongChina
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Guan T, Guo B, Zhang W, Qi M, Luo X, Li Z, Zhang Y, Bao T, Xu M, Liu M, Liu Y. The activation of gastric inhibitory peptide/gastric inhibitory peptide receptor axis via sonic hedgehog signaling promotes the bridging of gapped nerves in sciatic nerve injury. J Neurochem 2023; 165:842-859. [PMID: 36971732 DOI: 10.1111/jnc.15816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 03/16/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023]
Abstract
Schwann cells play an essential role in peripheral nerve regeneration by generating a favorable microenvironment. Gastric inhibitory peptide/gastric inhibitory peptide receptor (GIP/GIPR) axis deficiency leads to failure of sciatic nerve repair. However, the underlying mechanism remains elusive. In this study, we surprisingly found that GIP treatment significantly enhances the migration of Schwann cells and the formation of Schwann cell cords during recovery from sciatic nerve injury in rats. We further revealed that GIP and GIPR levels in Schwann cells were low under normal conditions, and significantly increased after injury demonstrated by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Wound healing and Transwell assays showed that GIP stimulation and GIPR silencing could affect Schwann cell migration. In vitro and in vivo mechanistic studies based on interference experiment revealed that GIP/GIPR might promote mechanistic target of rapamycin complex 2 (mTORC2) activity, thus facilitating cell migration; Rap1 activation might be involved in this process. Finally, we retrieved the stimulatory factors responsible for GIPR induction after injury. The results indicate that sonic hedgehog (SHH) is a potential candidate whose expression increased upon injury. Luciferase and chromatin immunoprecipitation (ChIP) assays showed that Gli3, the target transcription factor of the SHH pathway, dramatically augmented GIPR expression. Additionally, in vivo inhibition of SHH could effectively reduce GIPR expression after sciatic nerve injury. Collectively, our study reveals the importance of GIP/GIPR signaling in Schwann cell migration, providing a therapeutic avenue toward peripheral nerve injury.
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Affiliation(s)
- Tuchen Guan
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Beibei Guo
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
- Medical School of Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Wenxue Zhang
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Mengwei Qi
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Xiaoqian Luo
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Zhen Li
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Yufang Zhang
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Tiancheng Bao
- Medical School of Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Man Xu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Mei Liu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
| | - Yan Liu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, 226001, China
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Yang G, Liang X, Jiang Y, Li C, Zhang Y, Zhang X, Chang X, Shen Y, Meng X. Molecular Characterization of Grass Carp GIPR and Effect of Nutrition States, Insulin, and Glucagon on Its Expression. AQUACULTURE NUTRITION 2022; 2022:4330251. [PMID: 36860432 PMCID: PMC9973162 DOI: 10.1155/2022/4330251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 10/08/2022] [Accepted: 10/25/2022] [Indexed: 06/18/2023]
Abstract
GIP plays an important regulatory role in glucose and lipid metabolism. As the specific receptor, GIPR is involved in this physiological process. To assess the roles of GIPR in teleost, the GIPR gene was cloned from grass carp. The ORF of cloned GIPR gene was 1560 bp, encoding 519 amino acids. The grass carp GIPR was the G-protein-coupled receptor which contains seven predicted transmembrane domains. In addition, two predicted glycosylation sites were contained in the grass carp GIPR. The grass carp GIPR expression is in multiple tissues and is highly expressed in the kidney, brain regions, and visceral fat tissue. In the OGTT experiment, the GIPR expression is markedly decreased in the kidney, visceral fat, and brain by treatment with glucose for 1 and 3 h. In the fast and refeeding experiment, the GIPR expression in the kidney and visceral fat tissue was significantly induced in the fast groups. In addition, the GIPR expression levels were markedly decreased in the refeeding groups. In the present study, the visceral fat accumulation of grass carp was induced by overfed. The GIPR expression was significantly decreased in the brain, kidney, and visceral fat tissue of overfed grass carp. In primary hepatocytes, the GIPR expression was promoted by treatment with oleic acid and insulin. The GIPR mRNA levels were significantly reduced by treatment with glucose and glucagon in the grass carp primary hepatocytes. To our knowledge, this is the first time the biological role of GIPR is unveiled in teleost.
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Affiliation(s)
- Guokun Yang
- College of Fisheries, Henan Normal University, Xinxiang 453007, China
- Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, China
| | - Xiaomin Liang
- College of Fisheries, Henan Normal University, Xinxiang 453007, China
| | - Yanle Jiang
- College of Fisheries, Henan Normal University, Xinxiang 453007, China
| | - Chengquan Li
- College of Fisheries, Henan Normal University, Xinxiang 453007, China
| | - Yanmin Zhang
- College of Fisheries, Henan Normal University, Xinxiang 453007, China
- Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, China
| | - Xindang Zhang
- College of Fisheries, Henan Normal University, Xinxiang 453007, China
- Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, China
| | - Xulu Chang
- College of Fisheries, Henan Normal University, Xinxiang 453007, China
- Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, China
| | - Yawei Shen
- College of Fisheries, Henan Normal University, Xinxiang 453007, China
- Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, China
| | - Xiaolin Meng
- College of Fisheries, Henan Normal University, Xinxiang 453007, China
- Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, Henan Normal University, Xinxiang 453007, China
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Signaling profiles in HEK 293T cells co-expressing GLP-1 and GIP receptors. Acta Pharmacol Sin 2022; 43:1453-1460. [PMID: 34446852 PMCID: PMC9159978 DOI: 10.1038/s41401-021-00758-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 08/04/2021] [Indexed: 02/07/2023] Open
Abstract
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are regarded as 'incretins' working closely to regulate glucose homeostasis. Unimolecular dual and triple agonists of GLP-1R and GIPR have shown remarkable clinical benefits in treating type 2 diabetes. However, their pharmacological characterization is usually carried out in a single receptor-expressing system. In the present study we constructed a co-expression system of both GLP-1R and GIPR to study the signaling profiles elicited by mono, dual and triple agonists. We show that when the two receptors were co-expressed in HEK 293T cells with comparable receptor ratio to pancreatic cancer cells, GIP predominately induced cAMP accumulation while GLP-1 was biased towards β-arrestin 2 recruitment. The presence of GIPR negatively impacted GLP-1R-mediated cAMP and β-arrestin 2 responses. While sharing some common modulating features, dual agonists (peptide 19 and LY3298176) and a triple agonist displayed differentiated signaling profiles as well as negative impact on the heteromerization that may help interpret their superior clinical efficacies.
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Teng L, Guan T, Guo B, Ma C, Lin G, Wu R, Xu M, Liu M, Liu Y. GIP-GIPR promotes neurite outgrowth of cortical neurons in Akt dependent manner. Biochem Biophys Res Commun 2021; 534:121-127. [PMID: 33321289 DOI: 10.1016/j.bbrc.2020.11.120] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 11/30/2020] [Accepted: 11/30/2020] [Indexed: 01/01/2023]
Abstract
The intrinsic capacity of axonal growth is varied among the neurons form different tissues or different developmental stages. In this study, we established an in vitro model to compare the axonal growth of neurons from embryonic 18 days, post-natal 1 day and post-natal 3 days rat. The E18 neurons showed powerful ability of neuritogenensis and axon outgrowth and the ability decreased rapidly along with development. The transcriptome profile of these neurons revealed a set of genes positively correlated with the capacity of neurite outgrowth. Glucose-dependent insulinotropic polypeptide receptor (GIPR) is identified as a gene to promote neurite outgrowth, which was approved by siRNA knock down assay in E18 neuron. Glucose-dependent insulinotropic polypeptide (GIP), a ligand of GIPR secreted from enteroendocrine K cells, is well-known for its role in nutrient sensing and intake. To verify the effect of GIP-GIPR signal on neurite outgrowth, we administrated GIP to stimulate the E18 neurons, the results showed that GIP significantly improved extension of axon. We further revealed that GIP increased Rac1/Cdc42 phosphorylation in Akt dependent manner. In summary, our study established an in vitro model to screen the genes involved in neurite outgrowth, and we provided mechanical insight on the GIP-GIPR axis to promote axonal outgrowth.
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Affiliation(s)
- Long Teng
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Tuchen Guan
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Beibei Guo
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Chao Ma
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Ge Lin
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Ronghua Wu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Man Xu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Mei Liu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, China.
| | - Yan Liu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, China.
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Salameh TS, Rhea EM, Talbot K, Banks WA. Brain uptake pharmacokinetics of incretin receptor agonists showing promise as Alzheimer's and Parkinson's disease therapeutics. Biochem Pharmacol 2020; 180:114187. [PMID: 32755557 PMCID: PMC7606641 DOI: 10.1016/j.bcp.2020.114187] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 12/15/2022]
Abstract
Among the more promising treatments proposed for Alzheimer's disease (AD) and Parkinson's disease (PD) are those reducing brain insulin resistance. The antidiabetics in the class of incretin receptor agonists (IRAs) reduce symptoms and brain pathology in animal models of AD and PD, as well as glucose utilization in AD cases and clinical symptoms in PD cases after their systemic administration. At least 9 different IRAs are showing promise as AD and PD therapeutics, but we still lack quantitative data on their relative ability to cross the blood-brain barrier (BBB) reaching the brain parenchyma. We consequently compared brain uptake pharmacokinetics of intravenous 125I-labeled IRAs in adult CD-1 mice over the course of 60 min. We tested single IRAs (exendin-4, liraglutide, lixisenatide, and semaglutide), which bind receptors for one incretin (glucagon-like peptide-1 [GLP-1]), and dual IRAs, which bind receptors for two incretins (GLP-1 and glucose-dependent insulinotropic polypeptide [GIP]), including unbranched, acylated, PEGylated, or C-terminally modified forms (Finan/Ma Peptides 17, 18, and 20 and Hölscher peptides DA3-CH and DA-JC4). The non-acylated and non-PEGylated IRAs (exendin-4, lixisenatide, Peptide 17, DA3-CH and DA-JC4) had significant rates of blood-to-brain influx (Ki), but the acylated IRAs (liraglutide, semaglutide, and Peptide 18) did not measurably cross the BBB. The brain influx of the non-acylated, non-PEGylated IRAs were not saturable up to 1 μg of these drugs and was most likely mediated by adsorptive transcytosis across brain endothelial cells, as observed for exendin-4. Of the non-acylated, non-PEGylated IRAs tested, exendin-4 and DA-JC4 were best able to cross the BBB based on their rate of brain influx, percentage reaching the brain that accumulated in brain parenchyma, and percentage of the systemic dose taken up per gram of brain tissue. Exendin-4 and DA-JC4 thus merit special attention as IRAs well-suited to enter the central nervous system (CNS), thus reaching areas pathologic in AD and PD.
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Affiliation(s)
- Therese S Salameh
- Veterans Affairs Puget Sound Health Care System, Geriatrics Research Education and Clinical Center, Seattle, WA 98108, USA; University of Washington School of Medicine, Division of Gerontology and Geriatric Medicine, Department of Medicine, Seattle, WA 98498, USA
| | - Elizabeth M Rhea
- Veterans Affairs Puget Sound Health Care System, Geriatrics Research Education and Clinical Center, Seattle, WA 98108, USA; University of Washington School of Medicine, Division of Gerontology and Geriatric Medicine, Department of Medicine, Seattle, WA 98498, USA
| | - Konrad Talbot
- Loma Linda University School of Medicine, Departments of Neurosurgery, Basic Sciences, and Pathology and Human Anatomy, Loma Linda, CA 92354, USA
| | - William A Banks
- Veterans Affairs Puget Sound Health Care System, Geriatrics Research Education and Clinical Center, Seattle, WA 98108, USA; University of Washington School of Medicine, Division of Gerontology and Geriatric Medicine, Department of Medicine, Seattle, WA 98498, USA.
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Zhang ZQ, Hölscher C. GIP has neuroprotective effects in Alzheimer and Parkinson's disease models. Peptides 2020; 125:170184. [PMID: 31705913 DOI: 10.1016/j.peptides.2019.170184] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 12/17/2022]
Abstract
Glucose-dependent Insulinotropic polypeptide (GIP) is a peptide hormone of the incretin family. It has growth factor properties and can re-activate energy utilization. In progressive neurodegenerative disorders such as Alzheimer's and Parkinson's disease, energy utilization is much reduced, and GIP has the potential to reverse this. Furthermore, GIP can reduce the inflammation response in the brain and reduce levels of pro-inflammatory cytokines. Tests in animal models of Alzheimer's and Parkinson's disease show good neuroprotective effects. In Parkinson's disease models, motor activity is normalized, dopaminergic neurons are protected, synapse numbers and dopamine levels are maintained. Levels of growth factors that are essential for neuronal and synaptic function are increased and alpha-synuclein levels are reduced. The chronic inflammation response and mitochondrial damage is reduced. In Alzheimer's disease models, memory is rescued, synapse numbers and synaptic plasticity in the hippocampus is normalized, amyloid plaque load and the chronic inflammation is reduced. Similar protective effects have been previously reported with analogues of glucagon-like peptide 1 (GLP-1), the sister incretin hormone. First clinical trials show good protective effects in both diseases. Recently, novel dual GLP-1/GIP receptor agonists have been developed. The ability to cross the blood-brain barrier (BBB) is key to their neuroprotective effects. We have developed two dual GLP-1/GIP receptor agonist that have cell penetrating sequences added for better BBB penetration. In direct comparisons, these dual agonists show improved neuroprotection in a mouse model of Parkinson's disease. Therefore, such novel multiple receptor agonists hold great promise as potential treatments for Alzheimer's and Parkinson's disease.
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Affiliation(s)
- Zhen Qiang Zhang
- Research and Experimental Center, Henan University of Chinese Medicine, Zhengzhou, Henan Province, China
| | - Christian Hölscher
- Research and Experimental Center, Henan University of Chinese Medicine, Zhengzhou, Henan Province, China.
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Ahrén B, Yamada Y, Seino Y. Islet adaptation in GIP receptor knockout mice. Peptides 2020; 125:170152. [PMID: 31522751 DOI: 10.1016/j.peptides.2019.170152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/01/2019] [Accepted: 09/02/2019] [Indexed: 12/27/2022]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) receptor knockout (KO) mice are tools for studying GIP physiology. Previous results have demonstrated that these mice have impaired insulin response to oral glucose. In this study, we examined the insulin response to intravenous glucose by measuring glucose, insulin and C-peptide after intravenous glucose (0.35 g/kg) in 5-h fasted female GIP receptor KO mice and their wild-type (WT) littermates. The 1 min insulin and C-peptide responses to intravenous glucose were significantly enhanced in GIP receptor KO mice (n = 26) compared to WT mice (n = 30) as was beta cell function (area under the 50 min C-peptide curve divided by area under the 50 min curve for glucose) (P = 0.001). Beta cell function after intravenous glucose was also enhanced in GIP receptor KO mice in the presence of the glucagon-like peptide-1 receptor antagonist exendin 9 (30 nmol/kg; P = 0.007), the muscarinic antagonist atropine (5 mg/kg; P = 0.007) and the combination of the alpha-adrenoceptor antagonist yohimbine (1.4 mg/kg) and the beta-adrenoceptor antagonist propranolol (2.5 mg/kg; P = 0.042). Analysis of the regression between fasting glucose (6.8 ± 0.1 mmol/l in GIP receptor KO mice and 7.5 ± 0.2 mmol/l in WT mice, P = 0.003) and the 1 min C-peptide response to intravenous glucose showed a negative linear regression between these variables in both WT (n = 60; r = -0.425, P = 0.001) and GIP receptor KO mice (n = 56; r = -0.474, P < 0.001). We conclude that there is a beta cell adaptation in GIP receptor KO mice resulting in enhanced insulin secretion after intravenous glucose to which slight long-term reduction in circulating glucose in these mice may contribute.
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Affiliation(s)
- Bo Ahrén
- Department of Clinical Sciences Lund, Lund university, Lund, Sweden.
| | - Yuchiro Yamada
- Department of Endocrinology, Diabetes and Geriatric Medicine, Graduate School of Medicine, Akita University, Akita, Japan
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Killion EA, Lu SC, Fort M, Yamada Y, Véniant MM, Lloyd DJ. Glucose-Dependent Insulinotropic Polypeptide Receptor Therapies for the Treatment of Obesity, Do Agonists = Antagonists? Endocr Rev 2020; 41:5568102. [PMID: 31511854 DOI: 10.1210/endrev/bnz002] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/03/2019] [Indexed: 12/19/2022]
Abstract
Glucose-dependent insulinotropic polypeptide receptor (GIPR) is associated with obesity in human genome-wide association studies. Similarly, mouse genetic studies indicate that loss of function alleles and glucose-dependent insulinotropic polypeptide overexpression both protect from high-fat diet-induced weight gain. Together, these data provide compelling evidence to develop therapies targeting GIPR for the treatment of obesity. Further, both antagonists and agonists alone prevent weight gain, but result in remarkable weight loss when codosed or molecularly combined with glucagon-like peptide-1 analogs preclinically. Here, we review the current literature on GIPR, including biology, human and mouse genetics, and pharmacology of both agonists and antagonists, discussing the similarities and differences between the 2 approaches. Despite opposite approaches being investigated preclinically and clinically, there may be viability of both agonists and antagonists for the treatment of obesity, and we expect this area to continue to evolve with new clinical data and molecular and pharmacological analyses of GIPR function.
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Affiliation(s)
- Elizabeth A Killion
- Department of Cardiometabolic Disorders, Amgen Research, Thousand Oaks, California
| | - Shu-Chen Lu
- Department of Cardiometabolic Disorders, Amgen Research, Thousand Oaks, California
| | - Madeline Fort
- Department of Comparative Biology and Safety Sciences, Amgen Research, Thousand Oaks, California
| | - Yuichiro Yamada
- Department of Endocrinology, Diabetes and Geriatric Medicine, Akita University Graduate School of Medicine, Akita, Japan
| | - Murielle M Véniant
- Department of Cardiometabolic Disorders, Amgen Research, Thousand Oaks, California
| | - David J Lloyd
- Department of Cardiometabolic Disorders, Amgen Research, Thousand Oaks, California
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Guo R, Sun Y, Li H, Ma D, Wang Y. Upregulation of spinal glucose-dependent insulinotropic polypeptide receptor induces membrane translocation of PKCγ and synaptic target of AMPA receptor GluR1 subunits in dorsal horns in a rat model of incisional pain. Neurochem Int 2019; 134:104651. [PMID: 31870892 DOI: 10.1016/j.neuint.2019.104651] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 12/16/2019] [Accepted: 12/19/2019] [Indexed: 01/28/2023]
Abstract
It is unclear whether glucose-dependent insulinotropic polypeptide receptor (GIPR) signaling plays an important role in spinal nociception. We hypothesized that the spinal GIPR is implicated in central sensitization of postoperative pain. Our data showed that the cumulative pain scores peaked at 3 h, kept at a high level at 1 d after incision, gradually decreased afterwards and returned to the baseline values at 5 d after incision. Correspondingly, the expression of GIPR in spinal cord dorsal horn peaked at 1 d after incision, and returned to the baseline value at 5 d after incision. The double-labeling immunofluorescence demonstrated that spinal GIPR was expressed in dorsal horn neurons, but not in astrocyte or microglial cells. At 1 d after incision, the effects of intrathecal saline, GIPR antagonist (Pro3)GIP on pain behaviors were investigated. Our data showed that at 30 min and 60 min following intrathecal treatments of 300 ng (Pro3)GIP, the cumulative pain scores were decreased and paw withdrawal thresholds to mechanical stimuli were increased when compared to those immediately before intrathecal treatments. Accordingly, at 30 min after intrathecal injections, the membrane translocation levels of PKCγ and the GluR1 expression in postsynaptic membrane in ipsilateral dorsal horns to the incision were significantly upregulated in rats with intrathecal saline injections, as compared to normal control group. At 30 min after intrathecal treatment, (Pro3)GIP inhibited the membrane translocation levels of PKCγ and the GluR1 expression in postsynaptic membrane in ipsilateral dorsal horns. Our study indicates that upregulation of spinal GIPR may contribute to pain hypersensitivity through inducing membrane translocation level of PKCγ and synaptic target of AMPA receptor GluR1 subunits in ipsilateral dorsal horns of rats with plantar incision.
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Affiliation(s)
- Ruijuan Guo
- Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Yuqing Sun
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Huili Li
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Danxu Ma
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Yun Wang
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China.
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11
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Li Y, Glotfelty EJ, Namdar I, Tweedie D, Olson L, Hoffer BJ, DiMarchi RD, Pick CG, Greig NH. Neurotrophic and neuroprotective effects of a monomeric GLP-1/GIP/Gcg receptor triagonist in cellular and rodent models of mild traumatic brain injury. Exp Neurol 2019; 324:113113. [PMID: 31730763 DOI: 10.1016/j.expneurol.2019.113113] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 02/08/2023]
Abstract
A synthetic monomeric peptide triple receptor agonist, termed "Triagonist" that incorporates glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon (Gcg) actions, was previously developed to improve upon metabolic and glucose regulatory benefits of single and dual receptor agonists in rodent models of diet-induced obesity and type 2 diabetes. In the current study, the neurotrophic and neuroprotective actions of this Triagonist were probed in cellular and mouse models of mild traumatic brain injury (mTBI), a prevalent cause of neurodegeneration in both the young and elderly. Triagonist dose- and time-dependently elevated cyclic AMP levels in cultured human SH-SY5Y neuronal cells, and induced neurotrophic and neuroprotective actions, mitigating oxidative stress and glutamate excitotoxicity. These actions were inhibited only by the co-administration of antagonists for all three receptor types, indicating the balanced co-involvement of GLP-1, GIP and Gcg receptors. To evaluate physiological relevance, a clinically translatable dose of Triagonist was administered subcutaneously, once daily for 7 days, to mice following a 30 g weight drop close head injury. Triagonist fully mitigated mTBI-induced visual and spatial memory deficits, evaluated at 7 and 30 days post injury. These results establish Triagonist as a novel neurotrophic/protective agent worthy of further evaluation as a TBI treatment strategy.
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Affiliation(s)
- Yazhou Li
- Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
| | - Elliot J Glotfelty
- Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA; Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Inbar Namdar
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv 69978, Israel
| | - David Tweedie
- Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Lars Olson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Barry J Hoffer
- Department of Neurosurgery, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | | | - Chagi G Pick
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv 69978, Israel
| | - Nigel H Greig
- Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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12
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Verma MK, Goel R, Krishnadas N, Nemmani KVS. Targeting glucose-dependent insulinotropic polypeptide receptor for neurodegenerative disorders. Expert Opin Ther Targets 2018; 22:615-628. [PMID: 29911915 DOI: 10.1080/14728222.2018.1487952] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Incretin hormones, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide-1 (GLP-1) exert pleiotropic effects on endocrine pancreas and nervous system. Expression of GIP and GIP receptor (GIPR) in neurons, their roles in neurogenesis, synaptic plasticity, neurotransmission, and neuromodulation uniquely position GIPR for therapeutic applications in neurodegenerative disorders. GIP analogs acting as GIPR agonists attenuate neurobehavioral and neuropathological sequelae of neurodegenerative disorders in preclinical models, e.g. Alzheimer's disease (AD), Parkinson's disease (PD), and cerebrovascular disorders. Modulation of GIPR signaling offers an unprecedented approach for disease modification by arresting neuronal viability decline, enabling neuronal regeneration, and reducing neuroinflammation. Growth-promoting effects of GIP signaling and broad-based neuroprotection highlight the therapeutic potential of GIPR agonists. Areas covered: This review focuses on the role of GIPR-mediated signaling in the central nervous system in neurophysiological and neuropathological conditions. In context of neurodegeneration, the article summarizes potential of targeting GIPR signaling for neurodegenerative conditions such as AD, PD, traumatic brain injury, and cerebrovascular disorders. Expert opinion: GIPR represents a validated therapeutic target for neurodegenerative disorders. GIPR agonists impart symptomatic improvements, slowed neurodegeneration, and enhanced neuronal regenerative capacity in preclinical models. Modulation of GIPR signaling is potentially a viable therapeutic approach for disease modification in neurodegenerative disorders.
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Affiliation(s)
- Mahip K Verma
- a Department of Pharmacology, Novel Drug Discovery and Development , Lupin Limited , Pune , India
| | - Rajan Goel
- a Department of Pharmacology, Novel Drug Discovery and Development , Lupin Limited , Pune , India
| | - Nandakumar Krishnadas
- b Department of Pharmacology , Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education (MAHE) , Manipal , India
| | - Kumar V S Nemmani
- a Department of Pharmacology, Novel Drug Discovery and Development , Lupin Limited , Pune , India
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13
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Li Y, Li L, Hölscher C. Incretin-based therapy for type 2 diabetes mellitus is promising for treating neurodegenerative diseases. Rev Neurosci 2018; 27:689-711. [PMID: 27276528 DOI: 10.1515/revneuro-2016-0018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/02/2016] [Indexed: 12/13/2022]
Abstract
Incretin hormones include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Due to their promising action on insulinotropic secretion and improving insulin resistance (IR), incretin-based therapies have become a new class of antidiabetic agents for the treatment of type 2 diabetes mellitus (T2DM). Recently, the links between neurodegenerative diseases and T2DM have been identified in a number of studies, which suggested that shared mechanisms, such as insulin dysregulation or IR, may underlie these conditions. Therefore, the effects of incretins in neurodegenerative diseases have been extensively investigated. Protease-resistant long-lasting GLP-1 mimetics such as lixisenatide, liraglutide, and exenatide not only have demonstrated promising effects for treating neurodegenerative diseases in preclinical studies but also have shown first positive results in Alzheimer's disease (AD) and Parkinson's disease (PD) patients in clinical trials. Furthermore, the effects of other related incretin-based therapies such as GIP agonists, dipeptidyl peptidase-IV (DPP-IV) inhibitors, oxyntomodulin (OXM), dual GLP-1/GIP, and triple GLP-1/GIP/glucagon receptor agonists on neurodegenerative diseases have been tested in preclinical studies. Incretin-based therapies are a promising approach for treating neurodegenerative diseases.
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14
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Spielman LJ, Gibson DL, Klegeris A. Incretin hormones regulate microglia oxidative stress, survival and expression of trophic factors. Eur J Cell Biol 2017; 96:240-253. [PMID: 28336086 DOI: 10.1016/j.ejcb.2017.03.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 02/11/2017] [Accepted: 03/06/2017] [Indexed: 12/19/2022] Open
Abstract
The incretin hormones glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP) are primarily known for their metabolic function in the periphery. GLP-1 and GIP are secreted by intestinal endocrine cells in response to ingested nutrients. Both GLP-1 and GIP stimulate the production and release of insulin from pancreatic β cells as well as exhibit several growth-regulating effects on peripheral tissues. GLP-1 and GIP are also present in the brain, where they provide modulatory and anti-apoptotic signals to neurons. However, very limited information is available regarding the effects of these hormones on glia, the immune and supporting cells of the brain. Therefore, we set out to resolve whether primary human microglia and astrocytes, two subtypes of glial cells, express the GLP-1 receptor (GLP-1R) and GIP receptor (GIPR), which are necessary to detect and respond to GLP-1 and GIP, respectively. We further tested whether these hormones, similar to their effects on neuronal cells, have growth-regulating, antioxidant and anti-apoptotic effects on microglia. We show for the first time expression of the GLP-1R and the GIPR by primary human microglia and astrocytes. We demonstrate that GLP-1 and GIP reduce apoptotic death of murine BV-2 microglia through the binding and activation of the GLP-1R and GIPR, respectively, with subsequent activation of the protein kinase A (PKA) pathway. Moreover, we reveal that incretins upregulate BV-2 microglia expression of brain derived neurotrophic factor (BDNF), glial cell-line derived neurotrophic factor (GDNF) and nerve growth factor (NGF) in a phosphoinositide 3-kinase (PI3K)- and PKA-dependent manner. We also show that incretins reduce oxidative stress in BV-2 microglia by inhibiting the accumulation of intracellular reactive oxygen species (ROS) and release of nitric oxide (NO), as well as by increasing the expression of the antioxidant glutathione peroxidase 1 (GPx1) and superoxide dismutase 1 (SOD1). We confirm these results by demonstrating that GLP-1 and GIP also inhibit apoptosis of primary murine microglia, and upregulate expression of BDNF by primary murine microglia. These results indicate that GLP-1 and GIP affect several critical homeostatic functions of microglia, and could therefore be tested as a novel therapeutic treatment option for brain disorders that are characterized by increased oxidative stress and microglial degeneration.
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Affiliation(s)
- Lindsay Joy Spielman
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada.
| | - Deanna Lynn Gibson
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada.
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, 3187 University Way, Kelowna, BC V1V 1V7, Canada.
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15
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Yu YW, Hsieh TH, Chen KY, Wu JCC, Hoffer BJ, Greig NH, Li Y, Lai JH, Chang CF, Lin JW, Chen YH, Yang LY, Chiang YH. Glucose-Dependent Insulinotropic Polypeptide Ameliorates Mild Traumatic Brain Injury-Induced Cognitive and Sensorimotor Deficits and Neuroinflammation in Rats. J Neurotrauma 2016; 33:2044-2054. [PMID: 26972789 PMCID: PMC5116684 DOI: 10.1089/neu.2015.4229] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mild traumatic brain injury (mTBI) is a major public health issue, representing 75-90% of all cases of TBI. In clinical settings, mTBI, which is defined as a Glascow Coma Scale (GCS) score of 13-15, can lead to various physical, cognitive, emotional, and psychological-related symptoms. To date, there are no pharmaceutical-based therapies to manage the development of the pathological deficits associated with mTBI. In this study, the neurotrophic and neuroprotective properties of glucose-dependent insulinotropic polypeptide (GIP), an incretin similar to glucagon-like peptide-1 (GLP-1), was investigated after its steady-state subcutaneous administration, focusing on behavior after mTBI in an in vivo animal model. The mTBI rat model was generated by a mild controlled cortical impact (mCCI) and used to evaluate the therapeutic potential of GIP. We used the Morris water maze and novel object recognition tests, which are tasks for spatial and recognition memory, respectively, to identify the putative therapeutic effects of GIP on cognitive function. Further, beam walking and the adhesive removal tests were used to evaluate locomotor activity and somatosensory functions in rats with and without GIP administration after mCCI lesion. Lastly, we used immunohistochemical (IHC) staining and Western blot analyses to evaluate the inflammatory markers, glial fibrillary acidic protein (GFAP), amyloid-β precursor protein (APP), and bone marrow tyrosine kinase gene in chromosome X (BMX) in animals with mTBI. GIP was well tolerated and ameliorated mTBI-induced memory impairments, poor balance, and sensorimotor deficits after initiation in the post-injury period. In addition, GIP mitigated mTBI-induced neuroinflammatory changes on GFAP, APP, and BMX protein levels. These findings suggest GIP has significant benefits in managing mTBI-related symptoms and represents a novel strategy for mTBI treatment.
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Affiliation(s)
- Yu-Wen Yu
- 1 PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes , Taipei, Taiwan
| | - Tsung-Hsun Hsieh
- 1 PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes , Taipei, Taiwan .,2 Center for Neurotrauma and Neuroregeneration, Taipei Medical University , Taipei, Taiwan .,3 Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University , Taoyuan, Taiwan
| | - Kai-Yun Chen
- 1 PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes , Taipei, Taiwan .,2 Center for Neurotrauma and Neuroregeneration, Taipei Medical University , Taipei, Taiwan
| | - John Chung-Che Wu
- 4 Department of Surgery, College of Medicine, Taipei Medical University , Taipei, Taiwan
| | - Barry J Hoffer
- 1 PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes , Taipei, Taiwan .,5 Department of Neurosurgery, Case Western Reserve University , School of Medicine, Cleveland, Ohio
| | - Nigel H Greig
- 6 Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health , Baltimore, Maryland
| | - Yazhou Li
- 6 Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health , Baltimore, Maryland
| | - Jing-Huei Lai
- 2 Center for Neurotrauma and Neuroregeneration, Taipei Medical University , Taipei, Taiwan .,4 Department of Surgery, College of Medicine, Taipei Medical University , Taipei, Taiwan
| | - Cheng-Fu Chang
- 4 Department of Surgery, College of Medicine, Taipei Medical University , Taipei, Taiwan
| | - Jia-Wei Lin
- 4 Department of Surgery, College of Medicine, Taipei Medical University , Taipei, Taiwan
| | - Yu-Hsin Chen
- 7 Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University , Taipei, Taiwan .,8 Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University , Taipei, Taiwan
| | - Liang-Yo Yang
- 7 Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University , Taipei, Taiwan .,9 Research Center for Biomedical Devices and Prototyping Production, Taipei Medical University , Taipei, Taiwan .,11 School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan
| | - Yung-Hsiao Chiang
- 1 PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes , Taipei, Taiwan .,2 Center for Neurotrauma and Neuroregeneration, Taipei Medical University , Taipei, Taiwan .,4 Department of Surgery, College of Medicine, Taipei Medical University , Taipei, Taiwan .,10 Translational Laboratory, Department of Medical Research, Taipei Medical University Hospital, Taipei, Taiwan
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16
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Li Y, Liu W, Li L, Hölscher C. Neuroprotective effects of a GIP analogue in the MPTP Parkinson's disease mouse model. Neuropharmacology 2016; 101:255-63. [DOI: 10.1016/j.neuropharm.2015.10.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 09/06/2015] [Accepted: 10/02/2015] [Indexed: 12/25/2022]
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17
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Marcos ABW, Forner S, Martini AC, Patrício ES, Clarke JR, Costa R, Felix-Alves J, Vieira VJ, de Andrade EL, Mazzuco TL, Calixto JB, Figueiredo CP. Temporal and Regional Expression of Glucose-Dependent Insulinotropic Peptide and Its Receptor in Spinal Cord Injured Rats. J Neurotrauma 2015; 33:261-8. [PMID: 26421658 DOI: 10.1089/neu.2015.3877] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Spinal cord injury (SCI) results in loss of movement, sensibility, and autonomic control at the level of the lesion and at lower parts of the body. Several experimental strategies have been used in attempts to increase endogenous mechanisms of neuroprotection, neuroplasticity, and repair, but with limited success. It is known that glucose-dependent insulinotropic peptide (GIP) and its receptor (GIPR) can enhance synaptic plasticity, neurogenesis, and axonal outgrowth. However, their role in the injury has never been studied. The aim of this study was to evaluate the changes in expression levels of both GIP and GIPR in acute and chronic phases of SCI in rats. Following SCI (2 to 24 h after damage), the rat spinal cord showed a lesion in which the epicenter had a cavity with hemorrhage and necrosis. Furthermore, the lesion cavity also showed ballooned cells 14 and 28 days after injury. We found that SCI induced increases in GIPR expression in areas neighboring the site of injury at 6 h and 28 days after the injury. Moreover, higher GIP expression was observed in these regions on day 28. Neuronal projections from the injury epicenter showed an increase in GIP immunoreactivity 24 h and 14 and 28 days after SCI. Interestingly, GIP was also found in progenitor cells at the spinal cord canal 24 h after injury, whereas both GIP and GIPR were present in progenitor cells at the injury epicenter 14 days after in SCI animals. These results suggest that GIP and its receptor might be implicated with neurogenesis and the repair process after SCI.
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Affiliation(s)
- Ana Beatriz W Marcos
- 1 Programa de Pós-Graduação em Ciências Médicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina (UFSC) , Florianópolis, SC, Brazil
| | - Stefania Forner
- 2 Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC) , Florianópolis, SC, Brazil
| | - Alessandra C Martini
- 2 Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC) , Florianópolis, SC, Brazil
| | - Eliziane S Patrício
- 2 Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC) , Florianópolis, SC, Brazil
| | - Julia R Clarke
- 3 Faculdade de Farmácia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro (UFRJ) , Rio de Janeiro, RJ, Brazil
| | - Robson Costa
- 3 Faculdade de Farmácia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro (UFRJ) , Rio de Janeiro, RJ, Brazil
| | - João Felix-Alves
- 2 Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC) , Florianópolis, SC, Brazil
| | - Vilberto José Vieira
- 1 Programa de Pós-Graduação em Ciências Médicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina (UFSC) , Florianópolis, SC, Brazil
| | - Edinéia Lemos de Andrade
- 2 Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC) , Florianópolis, SC, Brazil
| | - Tânia Longo Mazzuco
- 4 Departamento de Clínica Médica, Centro de Ciências da Saúde, Universidade Estadual de Londrina , PR, Brazil
| | - João Batista Calixto
- 2 Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC) , Florianópolis, SC, Brazil
| | - Claudia Pinto Figueiredo
- 3 Faculdade de Farmácia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro (UFRJ) , Rio de Janeiro, RJ, Brazil
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18
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Seino Y, Yabe D. Glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1: Incretin actions beyond the pancreas. J Diabetes Investig 2014; 4:108-30. [PMID: 24843641 PMCID: PMC4019264 DOI: 10.1111/jdi.12065] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 01/24/2013] [Indexed: 12/14/2022] Open
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are the two primary incretin hormones secreted from the intestine on ingestion of various nutrients to stimulate insulin secretion from pancreatic β-cells glucose-dependently. GIP and GLP-1 undergo degradation by dipeptidyl peptidase-4 (DPP-4), and rapidly lose their biological activities. The actions of GIP and GLP-1 are mediated by their specific receptors, the GIP receptor (GIPR) and the GLP-1 receptor (GLP-1R), which are expressed in pancreatic β-cells, as well as in various tissues and organs. A series of investigations using mice lacking GIPR and/or GLP-1R, as well as mice lacking DPP-4, showed involvement of GIP and GLP-1 in divergent biological activities, some of which could have implications for preventing diabetes-related microvascular complications (e.g., retinopathy, nephropathy and neuropathy) and macrovascular complications (e.g., coronary artery disease, peripheral artery disease and cerebrovascular disease), as well as diabetes-related comorbidity (e.g., obesity, non-alcoholic fatty liver disease, bone fracture and cognitive dysfunction). Furthermore, recent studies using incretin-based drugs, such as GLP-1 receptor agonists, which stably activate GLP-1R signaling, and DPP-4 inhibitors, which enhance both GLP-1R and GIPR signaling, showed that GLP-1 and GIP exert effects possibly linked to prevention or treatment of diabetes-related complications and comorbidities independently of hyperglycemia. We review recent findings on the extrapancreatic effects of GIP and GLP-1 on the heart, brain, kidney, eye and nerves, as well as in the liver, fat and several organs from the perspective of diabetes-related complications and comorbidities.
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Affiliation(s)
| | - Daisuke Yabe
- Division of Diabetes Clinical Nutrition and Endocrinology Kansai Electric Power Hospital Osaka Japan
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19
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Transcriptional analysis of apoptotic cerebellar granule neurons following rescue by gastric inhibitory polypeptide. Int J Mol Sci 2014; 15:5596-622. [PMID: 24694544 PMCID: PMC4013584 DOI: 10.3390/ijms15045596] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/04/2014] [Accepted: 03/17/2014] [Indexed: 12/31/2022] Open
Abstract
Apoptosis triggered by exogenous or endogenous stimuli is a crucial phenomenon to determine the fate of neurons, both in physiological and in pathological conditions. Our previous study established that gastric inhibitory polypeptide (Gip) is a neurotrophic factor capable of preventing apoptosis of cerebellar granule neurons (CGNs), during its pre-commitment phase. In the present study, we conducted whole-genome expression profiling to obtain a comprehensive view of the transcriptional program underlying the rescue effect of Gip in CGNs. By using DNA microarray technology, we identified 65 genes, we named survival related genes, whose expression is significantly de-regulated following Gip treatment. The expression levels of six transcripts were confirmed by real-time quantitative polymerase chain reaction. The proteins encoded by the survival related genes are functionally grouped in the following categories: signal transduction, transcription, cell cycle, chromatin remodeling, cell death, antioxidant activity, ubiquitination, metabolism and cytoskeletal organization. Our data outline that Gip supports CGNs rescue via a molecular framework, orchestrated by a wide spectrum of gene actors, which propagate survival signals and support neuronal viability.
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20
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Yabe D, Seino Y. Incretin actions beyond the pancreas: lessons from knockout mice. Curr Opin Pharmacol 2013; 13:946-53. [DOI: 10.1016/j.coph.2013.09.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 09/13/2013] [Accepted: 09/13/2013] [Indexed: 02/06/2023]
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21
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Coon SD, Schwartz JH, Rajendran VM, Jepeal L, Singh SK. Glucose-dependent insulinotropic polypeptide regulates dipeptide absorption in mouse jejunum. Am J Physiol Gastrointest Liver Physiol 2013; 305:G678-84. [PMID: 24072682 PMCID: PMC3840233 DOI: 10.1152/ajpgi.00098.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) secreted from jejunal mucosal K cells augments insulin secretion and plays a critical role in the pathogenesis of obesity and Type 2 diabetes mellitus. In recent studies, we have shown GIP directly activates Na-glucose cotransporter-1 (SGLT1) and enhances glucose absorption in mouse jejunum. It is not known whether GIP would also regulate other intestinal nutrient absorptive processes. The present study investigated the effect of GIP on proton-peptide cotransporter-1 (PepT1) that mediates di- and tripeptide absorption as well as peptidomimetic drugs. Immunohistochemistry studies localized both GIP receptor (GIPR) and PepT1 proteins on the basolateral and apical membranes of normal mouse jejunum, respectively. Anti-GIPR antibody detected 50-, 55-, 65-, and 70-kDa proteins, whereas anti-PepT1 detected a 70-kDa proteins in mucosal homogenates of mouse jejunum. RT-PCR analyses established the expression of GIPR- and PepT1-specific mRNA in mucosal cells of mouse jejunum. Absorption of Gly-Sar (a nondigestible dipeptide) measured under voltage-clamp conditions revealed that the imposed mucosal H(+) gradient-enhanced Gly-Sar absorption as an evidence for the presence of PepT1-mediated H(+):Gly-Sar cotransport on the apical membranes of mouse jejunum. H(+):Gly-Sar absorption was completely inhibited by cephalexin (a competitive inhibitor of PepT1) and was activated by GIP. The GIP-activated Gly-Sar absorption was completely inhibited by RP-cAMP (a cAMP antagonist). In contrast to GIP, the ileal L cell secreting glucagon-like peptide-1 (GLP-1) did not affect the H(+):Gly-Sar absorption in mouse jejunum. We conclude from these observations that GIP, but not GLP-1, directly activates PepT1 activity by a cAMP-dependent signaling pathway in jejunum.
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Affiliation(s)
- Steven D. Coon
- 1Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; ,2Veterans Affairs Boston Healthcare System, Boston, Massachusetts; ,3Boston University Clinical and Translational Science Institute, Boston, Massachusetts; and
| | - John H. Schwartz
- 1Department of Medicine, Boston University School of Medicine, Boston, Massachusetts;
| | - Vazhaikkurichi M. Rajendran
- 4Department of Biochemistry and Molecular Biology, West Virginia University School of Medicine, Morgantown, West Virginia
| | - Lisa Jepeal
- 1Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; ,2Veterans Affairs Boston Healthcare System, Boston, Massachusetts;
| | - Satish K. Singh
- 1Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; ,2Veterans Affairs Boston Healthcare System, Boston, Massachusetts;
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22
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Okawa T, Kamiya H, Himeno T, Seino Y, Tsunekawa S, Hayashi Y, Harada N, Yamada Y, Inagaki N, Seino Y, Oiso Y, Nakamura J. Sensory and motor physiological functions are impaired in gastric inhibitory polypeptide receptor-deficient mice. J Diabetes Investig 2013; 5:31-7. [PMID: 24843734 PMCID: PMC4025241 DOI: 10.1111/jdi.12129] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 05/24/2013] [Accepted: 06/18/2013] [Indexed: 12/21/2022] Open
Abstract
AIMS/INTRODUCTION Gastric inhibitory polypeptide (GIP) is an incretin secreted from the gastrointestinal tract after an ingestion of nutrients, and stimulates an insulin secretion from the pancreatic islets. Additionally, GIP has important roles in extrapancreatic tissues: fat accumulation in adipose tissue, neuroprotective effects in the central nervous system and an inhibition of bone resorption. In the current study, we investigated the effects of GIP signaling on the peripheral nervous system (PNS). MATERIALS AND METHODS First, the presence of the GIP receptor (GIPR) in mouse dorsal root ganglion (DRG) was evaluated utilizing immunohistochemical analysis, western blotting and reverse transcription polymerase chain reaction. DRG neurons of male wild-type mice (WT) were cultured with or without GIP, and their neurite lengths were quantified. Functions of the PNS were evaluated in GIPR-deficient mice (gipr-/-) and WT by using current perception thresholds (CPTs), Thermal Plantar Test (TPT), and motor (MNCV) and sensory nerve conduction velocity (SNCV, respectively). Sciatic nerve blood flow (SNBF) and plantar skin blood flow (PSBF) were also evaluated. RESULTS We confirmed the expression of GIPR in DRG neurons. The neurite outgrowths of DRG neurons were promoted by the GIP administrations. The gipr-/- showed impaired perception functions in the examination of CPTs and TPT. Both MNCV and SNCV were delayed in gipr-/- compared with these in WT. There was no difference in SNBF and PSBF between WT and gipr-/-. CONCLUSIONS Our findings show that the GIP signal could exert direct physiological roles in the PNS, which might be directly exerted on the PNS.
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Affiliation(s)
- Tetsuji Okawa
- Department of Endocrinology and Diabetes Nagoya University Graduate School of Medicine Nagoya Japan
| | - Hideki Kamiya
- Department of Chronic Kidney Disease Initiatives Nagoya University Graduate School of Medicine Nagoya Japan
| | - Tatsuhito Himeno
- Department of Endocrinology and Diabetes Nagoya University Graduate School of Medicine Nagoya Japan
| | - Yusuke Seino
- Department of Metabolic Medicine Nagoya University School of Medicine Nagoya Japan
| | - Shin Tsunekawa
- Department of Endocrinology and Diabetes Nagoya University Graduate School of Medicine Nagoya Japan
| | - Yoshitaka Hayashi
- Department of Genetics Research Institute of Environmental Medicine Nagoya University Nagoya Japan
| | - Norio Harada
- Department of Diabetes and Clinical Nutrition Kyoto University Graduate School of Medicine Kyoto Japan
| | - Yuichiro Yamada
- Department of Endocrinology Diabetes and Geriatric Medicine Akita University Graduate School of Medicine Akita Japan
| | - Nobuya Inagaki
- Department of Diabetes and Clinical Nutrition Kyoto University Graduate School of Medicine Kyoto Japan
| | | | - Yutaka Oiso
- Department of Endocrinology and Diabetes Nagoya University Graduate School of Medicine Nagoya Japan
| | - Jiro Nakamura
- Department of Endocrinology and Diabetes Nagoya University Graduate School of Medicine Nagoya Japan
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23
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Faivre E, Hölscher C. Neuroprotective effects of D-Ala(2)GIP on Alzheimer's disease biomarkers in an APP/PS1 mouse model. ALZHEIMERS RESEARCH & THERAPY 2013; 5:20. [PMID: 23601582 PMCID: PMC3706793 DOI: 10.1186/alzrt174] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 03/09/2013] [Accepted: 04/08/2013] [Indexed: 12/16/2022]
Abstract
Introduction Type 2 diabetes mellitus has been identified as a risk factor for Alzheimer's disease (AD). An impairment of insulin signaling as well as a desensitization of its receptor has been found in AD brains. Glucose-dependent insulinotropic polypeptide (GIP) normalises insulin signaling by facilitating insulin release. GIP directly modulates neurotransmitter release, LTP formation, and protects synapses from the detrimental effects of beta-amyloid fragments on LTP formation, and cell proliferation of progenitor cells in the dentate gyrus. Here we investigate the potential therapeutic property of the new long lasting incretin hormone analogue D-Ala2GIP on key symptoms found in a mouse model of Alzheimer' disease (APPswe/PS1detaE9). Methods D-Ala2GIP was injected for 21 days at 25 nmol/kg ip once daily in APP/PS1 male mice and wild type (WT) littermates aged 6 or 12 months of age. Amyloid plaque load, inflammation biomarkers, synaptic plasticity in the brain (LTP), and memory were measured. Results D-Ala2GIP improved memory in WT mice and rescued the cognitive decline of 12 months old APP/PS1 mice in two different memory tasks. Furthermore, deterioration of synaptic function in the dentate gyrus and cortex was prevented in 12 months old APP/PS1 mice. D-Ala2GIP facilitated synaptic plasticity in APP/PS1 and WT mice and reduced the number of amyloid plaques in the cortex of D-Ala2GIP injected APP/PS1 mice. The inflammatory response in microglia was also reduced. Conclusion The results demonstrate that D-Ala2GIP has neuroprotective properties on key hallmarks found in AD. This finding shows that novel GIP analogues have the potential as a novel therapeutic for AD.
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Affiliation(s)
- Emilie Faivre
- School of Biomedical Sciences, Ulster University, Cromore road, Coleraine, BT52 1SA, UK
| | - Christian Hölscher
- School of Biomedical Sciences, Ulster University, Cromore road, Coleraine, BT52 1SA, UK
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24
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Pedersen J, Ugleholdt RK, Jørgensen SM, Windeløv JA, Grunddal KV, Schwartz TW, Füchtbauer EM, Poulsen SS, Holst PJ, Holst JJ. Glucose metabolism is altered after loss of L cells and α-cells but not influenced by loss of K cells. Am J Physiol Endocrinol Metab 2013; 304:E60-73. [PMID: 23115082 DOI: 10.1152/ajpendo.00547.2011] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The enteroendocrine K and L cells are responsible for secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon like-peptide 1 (GLP-1), whereas pancreatic α-cells are responsible for secretion of glucagon. In rodents and humans, dysregulation of the secretion of GIP, GLP-1, and glucagon is associated with impaired regulation of metabolism. This study evaluates the consequences of acute removal of Gip- or Gcg-expressing cells on glucose metabolism. Generation of the two diphtheria toxin receptor cellular knockout mice, TgN(GIP.DTR) and TgN(GCG.DTR), allowed us to study effects of acute ablation of K and L cells and α-cells. Diphtheria toxin administration reduced the expression of Gip and content of GIP in the proximal jejunum in TgN(GIP.DTR) and expression of Gcg and content of proglucagon-derived peptides in both proximal jejunum and terminal ileum as well as content of glucagon in pancreas in TgN(GCG.DTR) compared with wild-type mice. GIP response to oral glucose was attenuated following K cell loss, but oral and intraperitoneal glucose tolerances were unaffected. Intraperitoneal glucose tolerance was impaired following combined L cell and α-cell loss and normal following α-cell loss. Oral glucose tolerance was improved following L cell and α-cell loss and supernormal following α-cell loss. We present two mouse models that allow studies of the effects of K cell or L cell and α-cell loss as well as isolated α-cell loss. Our findings show that intraperitoneal glucose tolerance is dependent on an intact L cell mass and underscore the diabetogenic effects of α-cell signaling. Furthermore, the results suggest that K cells are less involved in acute regulation of mouse glucose metabolism than L cells and α-cells.
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Affiliation(s)
- J Pedersen
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
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25
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Duffy AM, Hölscher C. The incretin analogue D-Ala2GIP reduces plaque load, astrogliosis and oxidative stress in an APP/PS1 mouse model of Alzheimer's disease. Neuroscience 2012; 228:294-300. [PMID: 23103794 DOI: 10.1016/j.neuroscience.2012.10.045] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 10/19/2012] [Indexed: 12/24/2022]
Abstract
Type 2 diabetes mellitus has been identified as a risk factor for Alzheimer's disease (AD). Insulin is a neuroprotective growth factor, and an impairment of insulin signalling has been found in AD brains. Glucose-dependent insulinotropic polypeptide (GIP), an incretin hormone, normalises insulin signalling and also acts as a neuroprotective growth factor. GIP plays an important role in memory formation, synaptic plasticity and cell proliferation. We have shown previously that the long-lasting incretin hormone analogue D-Ala(2)GIP protects memory formation and synaptic plasticity, reduces plaques, normalises the proliferation of stem cells, reduces the activation of microglia, and prevents the loss of synapses in the cortex of the APPswe/PS1deltaE9 mouse model of Alzheimer's disease. D-Ala(2)GIP was injected for 35 days at 25 nmol/kg i.p. once daily in APP/PS1 male mice and wild-type (WT) littermates aged 6, 12 and 19 months. In a follow-up study, we analysed plaque load, the activation of astrocytes as a means of chronic inflammation in the brain, and oxidative stress in the brains of these mice (8-oxoguanine levels). D-Ala(2)GIP reduced the amyloid plaque load in 12- and 19-month-old mice, and the inflammation response as shown in the reduction of activated astrocytes in 12- and 19-month old APP/PS1 mice. Chronic oxidative stress in the brain was reduced in 12- and 19-month-old mice as shown in the reduction of 8-oxoguanine levels in the cortex of D-Ala(2)GIP-injected APP/PS1 mice. The results demonstrate that D-Ala(2)GIP has neuroprotective properties on key markers found in Alzheimer's disease. This finding shows that novel GIP analogues have the potential to be developed as novel therapeutics for Alzheimer's disease.
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Affiliation(s)
- A M Duffy
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
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26
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Schelshorn D, Joly F, Mutel S, Hampe C, Breton B, Mutel V, Lütjens R. Lateral Allosterism in the Glucagon Receptor Family: Glucagon-Like Peptide 1 Induces G-Protein-Coupled Receptor Heteromer Formation. Mol Pharmacol 2011; 81:309-18. [DOI: 10.1124/mol.111.074757] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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27
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Faivre E, Hamilton A, Hölscher C. Effects of acute and chronic administration of GIP analogues on cognition, synaptic plasticity and neurogenesis in mice. Eur J Pharmacol 2011; 674:294-306. [PMID: 22115896 DOI: 10.1016/j.ejphar.2011.11.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2011] [Revised: 10/27/2011] [Accepted: 11/04/2011] [Indexed: 12/14/2022]
Abstract
Type 2 diabetes is a risk factor for Alzheimer's disease. Insulin receptor desensitisation has been found in Alzheimer brains, which may be the underlying link. Glucose-dependent insulinotropic polypeptide (GIP), an incretin hormone, normalises insulin signalling in diabetes. GIP and the GIP receptors are widely expressed in the brain, and GIP has been shown to have growth factor and neuroprotective properties. Here we investigate the potential therapeutic properties of different doses of the protease resistant long-lasting GIP receptor agonist D-Ala2GIP and the antagonist (Pro3)GIP in C57Bl/6 mice. We found that after acute injection, D-Ala2GIP had few effects on general behaviour in the open field at any dose tested (2.5, 25, 100, or 250 nmol/kg i.p.). In memory tests, no change was observed, whilst (Pro3)GIP at 25 nmol/kg i.p. impaired memory formation. In a chronic study over 4 weeks, mice injected with D-Ala2GIP (2.5 or 25 nmol/kg i.p.) and (Pro3)GIP (25 nmol/kg i.p.) learned a water maze task and object recognition task without impairment. In LTP recording in area CA1, both (Pro3)GIP as well as D-Ala2GIP enhanced LTP formation. In addition, the proliferation of neuronal progenitor cells in the dentate gyrus was increased both by D-Ala2GIP and (Pro3)GIP. The results show that the antagonist (Pro3)GIP has agonistic effects in chronic use, and both (Pro3)GIP and the agonist D-Ala2GIP are safe to use in wt mice and induces no major behavioural side effects nor impairments in learning whilst enhancing LTP and neuronal progenitor cell proliferation, which may be useful in treating neurodegenerative diseases.
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Affiliation(s)
- Emilie Faivre
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
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28
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Figueiredo CP, Antunes VLS, Moreira ELG, de Mello N, Medeiros R, Di Giunta G, Lobão-Soares B, Linhares M, Lin K, Mazzuco TL, Prediger RDS, Walz R. Glucose-dependent insulinotropic peptide receptor expression in the hippocampus and neocortex of mesial temporal lobe epilepsy patients and rats undergoing pilocarpine induced status epilepticus. Peptides 2011; 32:781-9. [PMID: 21185343 DOI: 10.1016/j.peptides.2010.12.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 12/07/2010] [Accepted: 12/14/2010] [Indexed: 11/16/2022]
Abstract
The glucose-dependent insulinotropic peptide receptor (GIPR) has been implicated with neuroplasticity and may be related to epilepsy. GIPR expression was analyzed by immunohistochemistry in the hippocampus (HIP) and neocortex (Cx) of rats undergoing pilocarpine induced status epilepticus (Pilo-SE), and in three young male patients with left mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) treated surgically. A combined GIPR immunohistochemistry and Fluoro-Jade staining was carried out to investigate the association between the GIPR expression and neuronal degeneration induced by Pilo-SE. GIPR was expressed in the cytoplasm of neurons from the HIP CA subfields, dentate gyrus (DG) and Cx of animals and human samples. The GIPR expression after the Pilo-SE induction increases significantly in the HIP after 1h and 5 days, but not after 12h or 50 days. In the Cx, the GIPR expression increases after 1h, 12h and 5 days, but not 50 days after the Pilo-SE. The expression of GIPR 12h after Pilo-SE was inversely proportional to the Fluoro-Jade staining intensity. In the human tissue, GIPR expression patterns were similar to those observed in chronic Pilo-SE animals. No Fluoro-Jade stained cells were observed in the human sample. GIPR is expressed in human HIP and Cx. There was a time and region dependent increase of GIPR expression in the HIP and Cx after Pilo-SE that was inversely associated to neuronal degeneration.
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Affiliation(s)
- Cláudia P Figueiredo
- Programa de Pós-graduação em Neurociências, Departamento Ciências Fisiológicas, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
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29
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Faivre E, Gault VA, Thorens B, Hölscher C. Glucose-dependent insulinotropic polypeptide receptor knockout mice are impaired in learning, synaptic plasticity, and neurogenesis. J Neurophysiol 2011; 105:1574-80. [PMID: 21273318 DOI: 10.1152/jn.00866.2010] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is a key incretin hormone, released from intestine after a meal, producing a glucose-dependent insulin secretion. The GIP receptor (GIPR) is expressed on pyramidal neurons in the cortex and hippocampus, and GIP is synthesized in a subset of neurons in the brain. However, the role of the GIPR in neuronal signaling is not clear. In this study, we used a mouse strain with GIPR gene deletion (GIPR KO) to elucidate the role of the GIPR in neuronal communication and brain function. Compared with C57BL/6 control mice, GIPR KO mice displayed higher locomotor activity in an open-field task. Impairment of recognition and spatial learning and memory of GIPR KO mice were found in the object recognition task and a spatial water maze task, respectively. In an object location task, no impairment was found. GIPR KO mice also showed impaired synaptic plasticity in paired-pulse facilitation and a block of long-term potentiation in area CA1 of the hippocampus. Moreover, a large decrease in the number of neuronal progenitor cells was found in the dentate gyrus of transgenic mice, although the numbers of young neurons was not changed. Together the results suggest that GIP receptors play an important role in cognition, neurotransmission, and cell proliferation.
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Affiliation(s)
- Emilie Faivre
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
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30
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Role of the glucose-dependent insulinotropic polypeptide and its receptor in the central nervous system: therapeutic potential in neurological diseases. Behav Pharmacol 2010; 21:394-408. [PMID: 20574409 DOI: 10.1097/fbp.0b013e32833c8544] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is a 42-amino acid hormone, secreted from the enteroendocrine K cells, which has insulin-releasing and extra-pancreatic actions. GIP and its receptor present a widespread distribution in the mammalian brain where they have been implicated with synaptic plasticity, neurogenesis, neuroprotection and behavioral alterations. This review attempts to provide a comprehensive picture of the role of GIP in the central nervous system and to highlight recent findings from our group showing its potential involvement in neurological illnesses including epilepsies, Parkinson's disease and Alzheimer's disease.
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31
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Asmar M, Holst JJ. Glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide: new advances. Curr Opin Endocrinol Diabetes Obes 2010; 17:57-62. [PMID: 19881341 DOI: 10.1097/med.0b013e3283339051] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE OF REVIEW This article highlights recent advances in our understanding of glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) physiology and their various sites of action beyond the incretin effect. RECENT FINDINGS Both GLP-1 and GIP stimulate insulin secretion in a glucose-dependent manner and are thus classified as incretins. Beyond glucose-dependent insulin secretion, the peptides have common actions on islet beta cells, leading beta-cell proliferation and resistance to apoptosis. However, the action of GLP-1 and GIP is not limited to the islet cells; they have regulatory functions in many organs. Recent evidence has suggested that GLP-1 has important beneficial effects in the cardiovascular system and central nervous system. GIP may play a role in promoting energy storage in humans, enhances bone formation via stimulation of osteoblast proliferation and inhibition of apoptosis and may play a role in central nervous system function. SUMMARY These new findings suggest further application of these hormones for the treatment of conditions such as cardiovascular disease and obesity.
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Affiliation(s)
- Meena Asmar
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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32
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McIntosh CHS, Widenmaier S, Kim SJ. Pleiotropic actions of the incretin hormones. VITAMINS AND HORMONES 2010; 84:21-79. [PMID: 21094896 DOI: 10.1016/b978-0-12-381517-0.00002-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The insulin secretory response to a meal results largely from glucose stimulation of the pancreatic islets and both direct and indirect (autonomic) glucose-dependent stimulation by incretin hormones released from the gastrointestinal tract. Two incretins, Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), have so far been identified. Localization of the cognate G protein-coupled receptors for GIP and GLP-1 revealed that they are present in numerous tissues in addition to the endocrine pancreas, including the gastrointestinal, cardiovascular, central nervous and autonomic nervous systems (ANSs), adipose tissue, and bone. At these sites, the incretin hormones exert a range of pleiotropic effects, many of which contribute to the integration of processes involved in the regulation of food intake, and nutrient and mineral processing and storage. From detailed studies at the cellular and molecular level, it is also evident that both incretin hormones act via multiple signal transduction pathways that regulate both acute and long-term cell function. Here, we provide an overview of current knowledge relating to the physiological roles of GIP and GLP-1, with specific emphasis on their modes of action on islet hormone secretion, β-cell proliferation and survival, central and autonomic neuronal function, gastrointestinal motility, and glucose and lipid metabolism. However, it is emphasized that despite intensive research on the various body systems, in many cases there is uncertainty as to the pathways by which the incretins mediate their pleiotropic effects and only a rudimentary understanding of the underlying cellular mechanisms involved, and these are challenges for the future.
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Affiliation(s)
- Christopher H S McIntosh
- Department of Cellular & Physiological Sciences and the Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
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