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Zago AM, Carvalho FB, Rahmeier FL, Santin M, Guimarães GR, Gutierres JM, da C Fernandes M. Exendin-4 Prevents Memory Loss and Neuronal Death in Rats with Sporadic Alzheimer-Like Disease. Mol Neurobiol 2024; 61:2631-2652. [PMID: 37919602 DOI: 10.1007/s12035-023-03698-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 10/06/2023] [Indexed: 11/04/2023]
Abstract
This study investigated the neuroprotective effects of exendin-4 (EXE-4), an analog of the glucagon-like peptide 1 receptor (GLP-1R) on memory and on the neuronal populations that constitute the hippocampus of rats submitted to a sporadic dementia of Alzheimer's type (SDAT). Male Wistar rats received streptozotocin (STZ icv, 3 mg/kg diluted in aCFS, 5 µl/ventricle) and were treated for 21 days with EXE-4 (10 µg/kg, ip; saline as the vehicle). Four groups were formed: vehicle, EXE-4, STZ, and STZ + EXE-4. The groups were submitted to Y-Maze (YM), object recognition (ORT), and object displacement tasks (ODT) to assess learning and memory. The brains were used for immunohistochemical and immunofluorescent techniques with antibodies to NeuN, cleaved caspase-3 (CC3), PCNA, doublecortin (DCX), synaptophysin (SYP), and insulin receptor (IR). STZ worsened spatial memory in the YMT, as well as short-term (STM) and long-term (LTM) memories in the ORT and ODT, respectively. EXE-4 protected against memory impairment in STZ animals. STZ reduced mature neuron density (NeuN) and increased cell apoptosis (CC3) in the DG, CA1, and CA3. EXE-4 protected against neuronal death in all regions. EXE-4 increased PCNA+ cells in all regions of the hippocampus, and STZ attenuated this effect. STZ reduced neurogenesis in DG per se as well as synaptogenesis induced by EXE-4. EXE-4 increased immunoreactivity to IR in the CA1. From these findings, EXE-4 showed a beneficial effect on hippocampal pyramidal and granular neurons in the SDAT showing anti-apoptotic properties and promoting cell proliferation. In parallel, EXE-4 preserved the memory of SDAT rats. EXE-4 appears to enhance synapses at CA3 and DG. In conclusion, these data indicate that agonists to GLP-1R have a beneficial effect on hippocampal neurons in AD.
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Affiliation(s)
- Adriana M Zago
- Graduate Program in Pathology, Pathology Research Laboratory, Federal University of Health Sciences of Porto Alegre, Sarmento Leite, 245, Room 514, Building 3. CEP 90050-170, Porto Alegre, RS, Brazil
| | - Fabiano B Carvalho
- Graduate Program in Pathology, Pathology Research Laboratory, Federal University of Health Sciences of Porto Alegre, Sarmento Leite, 245, Room 514, Building 3. CEP 90050-170, Porto Alegre, RS, Brazil.
| | - Francine L Rahmeier
- Graduate Program in Pathology, Pathology Research Laboratory, Federal University of Health Sciences of Porto Alegre, Sarmento Leite, 245, Room 514, Building 3. CEP 90050-170, Porto Alegre, RS, Brazil
| | - Marta Santin
- Graduate Program in Pathology, Pathology Research Laboratory, Federal University of Health Sciences of Porto Alegre, Sarmento Leite, 245, Room 514, Building 3. CEP 90050-170, Porto Alegre, RS, Brazil
| | - Giuliano R Guimarães
- Graduate Program in Pathology, Pathology Research Laboratory, Federal University of Health Sciences of Porto Alegre, Sarmento Leite, 245, Room 514, Building 3. CEP 90050-170, Porto Alegre, RS, Brazil
| | - Jessié M Gutierres
- Graduate Program in Pathology, Pathology Research Laboratory, Federal University of Health Sciences of Porto Alegre, Sarmento Leite, 245, Room 514, Building 3. CEP 90050-170, Porto Alegre, RS, Brazil
| | - Marilda da C Fernandes
- Graduate Program in Pathology, Pathology Research Laboratory, Federal University of Health Sciences of Porto Alegre, Sarmento Leite, 245, Room 514, Building 3. CEP 90050-170, Porto Alegre, RS, Brazil.
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Verma A, Chaudhary S, Solanki K, Goyal A, Yadav HN. Exendin-4: A potential therapeutic strategy for Alzheimer's disease and Parkinson's disease. Chem Biol Drug Des 2024; 103:e14426. [PMID: 38230775 DOI: 10.1111/cbdd.14426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/16/2023] [Accepted: 12/05/2023] [Indexed: 01/18/2024]
Abstract
Neurodegenerative disorders, which affect millions worldwide, are marked by a steady decline of neurons that are selectively susceptible. Due to the complex pathological processes underlying neurodegeneration, at present, there is no viable therapy available for neurodegenerative disorders. Consequently, the establishment of a novel therapeutic approach for such conditions is a clinical void that remains. The potential significance of various peptides as neuroprotective interventions for neurodegenerative disorders is gaining increasing attention. In the past few years, there has been growing scientific interest in glucagon-like peptide-1 receptor agonists due to their claimed neuroprotective effects. Exendin-4 is a glucagon-like peptide-1 receptor agonist that is known to possess anti-diabetic effects and does not degrade for hours, making it a superior candidate for such disorders. Moreover, exendin-4's neuroprotective effects have been reported in several preclinical studies. Exendin-4's diverse therapeutic targets suggest its potential therapeutic uses in neurodegenerative ailments like Alzheimer's disease and Parkinson's disease and have garnered an increasing amount of attention. Given the substantial body of evidence supporting the neuroprotective potential of exendin-4 in various research models, this article is dedicated to exploring the promising role of exendin-4 as a therapeutic agent for the treatment and management of Alzheimer's disease and Parkinson's disease. This review draws insights from the findings of numerous preclinical and clinical studies to highlight the collective neuroprotective advantages of exendin-4 and the potential mechanisms that underlie its neuroprotective effects.
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Affiliation(s)
- Aanchal Verma
- Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India
| | - Shobhit Chaudhary
- Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India
| | - Kunal Solanki
- Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India
| | - Ahsas Goyal
- Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India
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Kang X, Wang D, Zhang L, Huang T, Liu S, Feng X, Guo Y, Zhang Z, Wang Z, Ren H, Yuan G. Exendin-4 ameliorates tau hyperphosphorylation and cognitive impairment in type 2 diabetes through acting on Wnt/β-catenin/NeuroD1 pathway. Mol Med 2023; 29:118. [PMID: 37667187 PMCID: PMC10478475 DOI: 10.1186/s10020-023-00718-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 08/21/2023] [Indexed: 09/06/2023] Open
Abstract
BACKGROUND Type 2 diabetes (T2D) is an independent risk factor for Alzheimer's disease (AD). Exendin-4 (Ex-4), a widely used glucagon-like peptide-1 receptor agonist drug in the treatment of T2D, has been demonstrated the therapeutic effects on diabetic encephalopathy (DE). Especially, the Ex-4 ameliorates the tau hyperphosphorylation and cognitive impairment in DE. And these crucial alterations are also important bridge between T2D and AD. However, its unique mechanism is unclear. METHODS The db/db mice, high-fat-diet (HFD) / streptozotocin (STZ)-induced diabetic (HF-diabetic) mice, and high-glucose-damaged (HGD) HT-22 hippocampal cells were enrolled to examine the effects of Ex-4 on AD-like changes in T2D. The Novel object recognition test (NORT) and Morris water maze test (MWMT) were conducted to evaluate the cognitive impairment. The Dickkopf-1 (DKK1) was employed to weaken the activation of the Wnt/β-catenin pathway to explore the mechanism of Ex-4 in protecting the brain functions. The JASPAR was based to predict the interaction between NeuroD1 and the promoter region of Ins2. Moreover, the chromatin immunoprecipitation coupled with quantitative polymerase chain reaction (ChIP-qPCR) and luciferase reporter assays were performed. RESULTS Ex-4 alleviated the tau hyperphosphorylation, increased the brain-derived insulin, and improved the PI3K/AKT/GSK3-β signalling in db/db mice, HF-diabetic mice, and HGD HT-22 hippocampal neuronal cells. The NORT and MWMT indicated that Ex-4 alleviated the learning and memory deficits in HF-diabetic mice. The inhibitor Dickkopf-1 (DKK1) of the Wnt/β-catenin pathway significantly blocked the protective effects of Ex-4. Regarding further molecular mechanisms, NeuroD1 was affected by Ex-4 in vivo and in vitro, and the knockdown or overexpression of NeuroD1 suggested its crucial role in promoting the brain insulin by Ex-4. Meanwhile, the ChIP‒qPCR and luciferase reporter assays confirmed the combination between NeuroD1 and the promoter region of the insulin-encoding gene Ins2. And this interaction could be promoted by Ex-4. CONCLUSIONS Our study proposes that Ex-4 alleviates tau hyperphosphorylation and cognitive dysfunction by increasing Ins2-derived brain insulin through the Wnt/β-catenin/NeuroD1 signaling in T2D. And its also show new lights on part of the progress and mechanism on treatment targets for the DE in T2D.
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Affiliation(s)
- Xiaonan Kang
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Dan Wang
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Lu Zhang
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Teng Huang
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Siyue Liu
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiaohui Feng
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yaoyao Guo
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ziyin Zhang
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhongjing Wang
- Department of Endocrinology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
| | - Huihui Ren
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Branch of National Clinical Research Center for Metabolic Disease, Hubei, People's Republic of China.
| | - Gang Yuan
- Department of Endocrinology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Branch of National Clinical Research Center for Metabolic Disease, Hubei, People's Republic of China.
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Woodfield A, Gonzales T, Helmerhorst E, Laws S, Newsholme P, Porter T, Verdile G. Current Insights on the Use of Insulin and the Potential Use of Insulin Mimetics in Targeting Insulin Signalling in Alzheimer's Disease. Int J Mol Sci 2022; 23:ijms232415811. [PMID: 36555450 PMCID: PMC9779379 DOI: 10.3390/ijms232415811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/10/2022] [Accepted: 12/11/2022] [Indexed: 12/15/2022] Open
Abstract
Alzheimer's disease (AD) and type 2 diabetes (T2D) are chronic diseases that share several pathological mechanisms, including insulin resistance and impaired insulin signalling. Their shared features have prompted the evaluation of the drugs used to manage diabetes for the treatment of AD. Insulin delivery itself has been utilized, with promising effects, in improving cognition and reducing AD related neuropathology. The most recent clinical trial involving intranasal insulin reported no slowing of cognitive decline; however, several factors may have impacted the trial outcomes. Long-acting and rapid-acting insulin analogues have also been evaluated within the context of AD with a lack of consistent outcomes. This narrative review provided insight into how targeting insulin signalling in the brain has potential as a therapeutic target for AD and provided a detailed update on the efficacy of insulin, its analogues and the outcomes of human clinical trials. We also discussed the current evidence that warrants the further investigation of the use of the mimetics of insulin for AD. These small molecules may provide a modifiable alternative to insulin, aiding in developing drugs that selectively target insulin signalling in the brain with the aim to attenuate cognitive dysfunction and AD pathologies.
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Affiliation(s)
- Amy Woodfield
- Curtin Medical School, Curtin University, Bentley 6102, Australia
- Curtin Health Innovation Research Institute, Curtin University, Bentley 6102, Australia
| | - Tatiana Gonzales
- Curtin Medical School, Curtin University, Bentley 6102, Australia
| | - Erik Helmerhorst
- Curtin Medical School, Curtin University, Bentley 6102, Australia
- Curtin Health Innovation Research Institute, Curtin University, Bentley 6102, Australia
| | - Simon Laws
- Curtin Medical School, Curtin University, Bentley 6102, Australia
- Centre for Precision Health, Edith Cowan University, Joondalup 6027, Australia
- Collaborative Genomics and Translation Group, School of Medical and Health Sciences, Edith Cowan University, Joondalup 6027, Australia
| | - Philip Newsholme
- Curtin Medical School, Curtin University, Bentley 6102, Australia
- Curtin Health Innovation Research Institute, Curtin University, Bentley 6102, Australia
| | - Tenielle Porter
- Curtin Medical School, Curtin University, Bentley 6102, Australia
- Centre for Precision Health, Edith Cowan University, Joondalup 6027, Australia
- Collaborative Genomics and Translation Group, School of Medical and Health Sciences, Edith Cowan University, Joondalup 6027, Australia
| | - Giuseppe Verdile
- Curtin Medical School, Curtin University, Bentley 6102, Australia
- Curtin Health Innovation Research Institute, Curtin University, Bentley 6102, Australia
- School of Medical and Health Sciences, Edith Cowan University, Joondalup 6027, Australia
- Correspondence: ; Tel.: +61-8-9266 5618
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Bailey J, Coucha M, Bolduc DR, Burnett FN, Barrett AC, Ghaly M, Abdelsaid M. GLP-1 receptor nitration contributes to loss of brain pericyte function in a mouse model of diabetes. Diabetologia 2022; 65:1541-1554. [PMID: 35687178 DOI: 10.1007/s00125-022-05730-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/17/2022] [Indexed: 12/21/2022]
Abstract
AIMS/HYPOTHESIS We have previously shown that diabetes causes pericyte dysfunction, leading to loss of vascular integrity and vascular cognitive impairment and dementia (VCID). Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1 RAs), used in managing type 2 diabetes mellitus, improve the cognitive function of diabetic individuals beyond glycaemic control, yet the mechanism is not fully understood. In the present study, we hypothesise that GLP-1 RAs improve VCID by preventing diabetes-induced pericyte dysfunction. METHODS Mice with streptozotocin-induced diabetes and non-diabetic control mice received either saline (NaCl 154 mmol/l) or exendin-4, a GLP-1 RA, through an osmotic pump over 28 days. Vascular integrity was assessed by measuring cerebrovascular neovascularisation indices (vascular density, tortuosity and branching density). Cognitive function was evaluated with Barnes maze and Morris water maze. Human brain microvascular pericytes (HBMPCs), were grown in high glucose (25 mmol/l) and sodium palmitate (200 μmol/l) to mimic diabetic conditions. HBMPCs were treated with/without exendin-4 and assessed for nitrative and oxidative stress, and angiogenic and blood-brain barrier functions. RESULTS Diabetic mice treated with exendin-4 showed a significant reduction in all cerebral pathological neovascularisation indices and an improved blood-brain barrier (p<0.05). The vascular protective effects were accompanied by significant improvement in the learning and memory functions of diabetic mice compared with control mice (p<0.05). Our results showed that HBMPCs expressed the GLP-1 receptor. Diabetes increased GLP-1 receptor expression and receptor nitration in HBMPCs. Stimulation of HBMPCs with exendin-4 under diabetic conditions decreased diabetes-induced vascular inflammation and oxidative stress, and restored pericyte function (p<0.05). CONCLUSIONS/INTERPRETATION This study provides novel evidence that brain pericytes express the GLP-1 receptor, which is nitrated under diabetic conditions. GLP-1 receptor activation improves brain pericyte function resulting in restoration of vascular integrity and BBB functions in diabetes. Furthermore, the GLP-1 RA exendin-4 alleviates diabetes-induced cognitive impairment in mice. Restoration of pericyte function in diabetes represents a novel therapeutic target for diabetes-induced cerebrovascular microangiopathy and VCID.
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Affiliation(s)
- Joseph Bailey
- Department of Biomedical Sciences, School of Medicine, Mercer University, Savannah, GA, USA
| | - Maha Coucha
- Department of Pharmaceutical Sciences, School of Pharmacy, South University, Savannah, GA, USA
| | - Deanna R Bolduc
- Department of Biomedical Sciences, School of Medicine, Mercer University, Savannah, GA, USA
| | - Faith N Burnett
- Department of Biomedical Sciences, School of Medicine, Mercer University, Savannah, GA, USA
| | - Amy C Barrett
- Department of Biomedical Sciences, School of Medicine, Mercer University, Savannah, GA, USA
| | - Mark Ghaly
- Department of Biomedical Sciences, School of Medicine, Mercer University, Savannah, GA, USA
| | - Mohammed Abdelsaid
- Department of Biomedical Sciences, School of Medicine, Mercer University, Savannah, GA, USA.
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