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Gad H, Mohammed I, Dauleh H, Pasha M, Al-Barazenji T, Hussain K, Malik RA. Case report: Nerve fiber regeneration in children with melanocortin 4 receptor gene mutation related obesity treated with semaglutide. Front Endocrinol (Lausanne) 2024; 15:1385463. [PMID: 38974580 PMCID: PMC11227249 DOI: 10.3389/fendo.2024.1385463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 06/07/2024] [Indexed: 07/09/2024] Open
Abstract
Melanocortin 4 receptor (MC4R) mutations are the commonest cause of monogenic obesity through dysregulation of neuronal pathways in the hypothalamus and prefrontal cortex that regulate hunger and satiety. MC4R also regulates neuropathic pain pathways via JNK signaling after nerve injury. We show evidence of corneal small fiber degeneration in 2 siblings carrying a heterozygous missense variant c.508A>G, p.Ille170Val in the MC4R gene. Both children were treated with once weekly semaglutide for 6 months with no change in weight, and only a minor improvement in HbA1c and lipid profile. However, there was evidence of nerve regeneration with an increase in corneal nerve fiber density (CNFD) [child A (13.9%), child B (14.7%)], corneal nerve branch density (CNBD) [child A (110.2%), child B (58.7%)] and corneal nerve fiber length (CNFL) [child A (21.5%), child B (44.0%)].
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Affiliation(s)
- Hoda Gad
- Research Department, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Idris Mohammed
- Endocrinology Department, Sidra Medicine, Doha, Qatar
- College of Health & Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Hajar Dauleh
- Endocrinology Department, Sidra Medicine, Doha, Qatar
| | - Maheen Pasha
- Endocrinology Department, Sidra Medicine, Doha, Qatar
| | | | | | - Rayaz A. Malik
- Research Department, Weill Cornell Medicine-Qatar, Doha, Qatar
- Institute of Cardiovascular Medicine, University of Manchester, Manchester, United Kingdom
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2
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Liu C, Wu T, Ren N. Glucagon-like peptide-1 receptor agonists for the management of diabetic peripheral neuropathy. Front Endocrinol (Lausanne) 2024; 14:1268619. [PMID: 38313844 PMCID: PMC10836428 DOI: 10.3389/fendo.2023.1268619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/27/2023] [Indexed: 02/06/2024] Open
Abstract
Diabetes mellitus is a prevalent chronic disease characterized by hyperglycemia. Diabetic peripheral neuropathy (DPN) is one of the complications of diabetes mellitus and is caused by neuron injury induced by hyperglycemic circumstances. The incidence of DPN varies among different countries and regions, ranging from nearly 20% to over 70%. Patients with DPN may encounter symmetric pain or discomfort of the extremes, leading to reduced quality of life and even amputation. The pharmacological management for painful DPN mainly includes antidepressants due to their analgesic effects. Nevertheless, effective therapies to impact the pathogenesis and progression of DPN are lacking. Glucagon-like peptide-1 receptor (GLP-1R) agonists show efficacy in controlling blood glucose and serve as a treatment modality for diabetes mellitus. In recent years, evidence has been proposed that GLP-1R agonists exert neuroprotective effects through modulating inflammation, oxidative stress, and mitochondrial dysfunction. On the other hand, clinical evidence on the potential of GLP-1R agonists for treating DPN is still controversial and limited. This narrative review summarizes the preclinical and clinical studies investigating the capacity of GLP-1R agonists as therapeutic agents for DPN.
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Affiliation(s)
- Chunyan Liu
- Department of Endocrinology, First Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Tianqiang Wu
- Department of Integrated Traditional Chinese and Western Medicine, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Na Ren
- Department of Endocrinology, First Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin, China
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3
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Goldney J, Sargeant JA, Davies MJ. Incretins and microvascular complications of diabetes: neuropathy, nephropathy, retinopathy and microangiopathy. Diabetologia 2023; 66:1832-1845. [PMID: 37597048 PMCID: PMC10474214 DOI: 10.1007/s00125-023-05988-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 07/17/2023] [Indexed: 08/21/2023]
Abstract
Glucagon-like peptide-1 receptor agonists (GLP-1RAs, incretin mimetics) and dipeptidyl peptidase-4 inhibitors (DPP-4is, incretin enhancers) are glucose-lowering therapies with proven cardiovascular safety, but their effect on microvascular disease is not fully understood. Both therapies increase GLP-1 receptor agonism, which is associated with attenuation of numerous pathological processes that may lead to microvascular benefits, including decreased reactive oxygen species (ROS) production, decreased inflammation and improved vascular function. DPP-4is also increase stromal cell-derived factor-1 (SDF-1), which is associated with neovascularisation and tissue repair. Rodent studies demonstrate several benefits of these agents in the prevention or reversal of nephropathy, retinopathy and neuropathy, but evidence from human populations is less clear. For nephropathy risk in human clinical trials, meta-analyses demonstrate that GLP-1RAs reduce the risk of a composite renal outcome (doubling of serum creatinine, eGFR reduction of 30%, end-stage renal disease or renal death), whereas the benefits of DPP-4is appear to be limited to reductions in the risk of albuminuria. The relationship between GLP-1RAs and retinopathy is less clear. Many large trials and meta-analyses show no effect, but an observed increase in the risk of retinopathy complications with semaglutide therapy (a GLP-1RA) in the SUSTAIN-6 trial warrants caution, particularly in individuals with baseline retinopathy. Similarly, DPP-4is are associated with increased retinopathy risk in both trials and meta-analysis. The association between GLP-1RAs and peripheral neuropathy is unclear due to little trial evidence. For DPP-4is, one trial and several observational studies show a reduced risk of peripheral neuropathy, with others reporting no effect. Evidence in other less-established microvascular outcomes, such as microvascular angina, cerebral small vessel disease, skeletal muscle microvascular disease and autonomic neuropathies (e.g. cardiac autonomic neuropathy, gastroparesis, erectile dysfunction), is sparse. In conclusion, GLP-1RAs are protective against nephropathy, whereas DPP-4is are protective against albuminuria and potentially peripheral neuropathy. Caution is advised with DPP-4is and semaglutide, particularly for patients with background retinopathy, due to increased risk of retinopathy. Well-designed trials powered for microvascular outcomes are needed to clarify associations of incretin therapies and microvascular diseases.
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Affiliation(s)
- Jonathan Goldney
- Diabetes Research Centre, College of Life Sciences, University of Leicester, Leicester, UK.
- NIHR Leicester Biomedical Research Centre, University Hospitals of Leicester NHS Trust and University of Leicester, Leicester, UK.
| | - Jack A Sargeant
- NIHR Leicester Biomedical Research Centre, University Hospitals of Leicester NHS Trust and University of Leicester, Leicester, UK
- Leicester Diabetes Centre, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Melanie J Davies
- Diabetes Research Centre, College of Life Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, University Hospitals of Leicester NHS Trust and University of Leicester, Leicester, UK
- Leicester Diabetes Centre, University Hospitals of Leicester NHS Trust, Leicester, UK
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4
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Wang W, Zhang C, Zhang H, Li L, Fan T, Jin Z. The alleviating effect and mechanism of GLP-1 on ulcerative colitis. Aging (Albany NY) 2023; 15:8044-8060. [PMID: 37595257 PMCID: PMC10496996 DOI: 10.18632/aging.204953] [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: 12/04/2022] [Accepted: 07/17/2023] [Indexed: 08/20/2023]
Abstract
Ulcerative Colitis (UC) is a major type of chronic inflammatory bowel disease of the colonic mucosa and exhibits progressive morbidity. The incidence and prevalence of UC is increasing worldwide. The global burden of UC, which can substantially reduce quality of life, is clearly increasing. These data highlight the need for research into prevention of UC and innovations in health-care systems to manage this complex and costly disease. Glucagon-like peptide-1 (GLP-1), a new antidiabetic drug, is used to treat Type 2 Diabetes Mellitus (T2DM). Accumulating evidence suggests that GLP-1 has additional roles other than glucose-lowering effects. Despite the abundance of GLP-1 research, studies in UC have been less consistent, especially body weight; for example, body weight, colon length, colon injury score, intestinal microbiota, remain to be studied further. To date, the molecular mechanism of the protective effect of GLP-1 on UC remains obscure. The effect of GLP-1 was studied by using a dextran sulfate sodium (DSS)-induced colitic mice and lipopolysaccharide (LPS) treated RAW264.7 cells (macrophage cell line) under in vivo and in vitro conditions, respectively. Our results indicate that GLP-1 significantly relieves ulcerative colitis as it represses the production of proinflammatory mediators. In addition, GLP-1 blocks the activation of the protein kinase B (AKT)/nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways. GLP-1 also alleviates DSS-induced injury to the intestinal mucosa and dysbiosis of gut microbiota. Altogether, GLP-1 has protection effect on ulcerative colitis. Thus, GLP-1 can be considered as a potential therapeutic candidate for the treatment of UC.
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Affiliation(s)
- Wenrui Wang
- Department of Hepatopancreatobiliary Medicine, Digestive Diseases Center, The Second Hospital, Jilin University, Changchun 130000, PR China
| | - Chuan Zhang
- Department of Endocrinology, The Second Hospital of Jilin University, Changchun 130000, PR China
| | - Haolong Zhang
- Department of Gastrointestinal and Colorectal Surgery, China-Japan Union, Hospital of Jilin University, Changchun 130000, PR China
| | - Luyao Li
- Department of Endocrinology, The Second Hospital of Jilin University, Changchun 130000, PR China
| | - Tingting Fan
- Department of Endocrinology, The Second Hospital of Jilin University, Changchun 130000, PR China
| | - Zhenjing Jin
- Department of Hepatopancreatobiliary Medicine, Digestive Diseases Center, The Second Hospital, Jilin University, Changchun 130000, PR China
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Enders J, Elliott D, Wright DE. Emerging Nonpharmacologic Interventions to Treat Diabetic Peripheral Neuropathy. Antioxid Redox Signal 2023; 38:989-1000. [PMID: 36503268 PMCID: PMC10402707 DOI: 10.1089/ars.2022.0158] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/17/2022] [Accepted: 11/19/2022] [Indexed: 12/14/2022]
Abstract
Significance: Diabetic peripheral neuropathy (DPN), a complication of metabolic syndrome, type I and type II diabetes, leads to sensory changes that include slow nerve conduction, nerve degeneration, loss of sensation, pain, and gate disturbances. These complications remain largely untreatable, although tight glycemic control can prevent neuropathy progression. Nonpharmacologic approaches remain the most impactful to date, but additional advances in treatment approaches are needed. Recent Advances: This review highlights several emerging interventions, including a focus on dietary interventions and physical activity, that continue to show promise for treating DPN. We provide an overview of our current understanding of how exercise can improve aspects of DPN. We also highlight new studies in which a ketogenic diet has been used as an intervention to prevent and reverse DPN. Critical Issues: Both exercise and consuming a ketogenic diet induce systemic and cellular changes that collectively improve complications associated with DPN. Both interventions may involve similar signaling pathways and benefits but also impact DPN through unique mechanisms. Future Directions: These lifestyle interventions are critically important as personalized medicine approaches will likely be needed to identify specific subsets of neuropathy symptoms and deficits in patients, and determine the most impactful treatment. Overall, these two interventions have the potential to provide meaningful relief for patients with DPN and provide new avenues to identify new therapeutic targets.
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Affiliation(s)
- Jonathan Enders
- Department of Anesthesiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Daniel Elliott
- Department of Anesthesiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Douglas E. Wright
- Department of Anesthesiology, University of Kansas Medical Center, Kansas City, Kansas, USA
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6
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Miyashita A, Kobayashi M, Yokota T, Zochodne DW. Diabetic Polyneuropathy: New Strategies to Target Sensory Neurons in Dorsal Root Ganglia. Int J Mol Sci 2023; 24:ijms24065977. [PMID: 36983051 PMCID: PMC10051459 DOI: 10.3390/ijms24065977] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/10/2023] [Accepted: 03/11/2023] [Indexed: 03/29/2023] Open
Abstract
Diabetic polyneuropathy (DPN) is the most common type of diabetic neuropathy, rendering a slowly progressive, symmetrical, and length-dependent dying-back axonopathy with preferential sensory involvement. Although the pathogenesis of DPN is complex, this review emphasizes the concept that hyperglycemia and metabolic stressors directly target sensory neurons in the dorsal root ganglia (DRG), leading to distal axonal degeneration. In this context, we discuss the role for DRG-targeting gene delivery, specifically oligonucleotide therapeutics for DPN. Molecules including insulin, GLP-1, PTEN, HSP27, RAGE, CWC22, and DUSP1 that impact neurotrophic signal transduction (for example, phosphatidylinositol-3 kinase/phosphorylated protein kinase B [PI3/pAkt] signaling) and other cellular networks may promote regeneration. Regenerative strategies may be essential in maintaining axon integrity during ongoing degeneration in diabetes mellitus (DM). We discuss specific new findings that relate to sensory neuron function in DM associated with abnormal dynamics of nuclear bodies such as Cajal bodies and nuclear speckles in which mRNA transcription and post-transcriptional processing occur. Manipulating noncoding RNAs such as microRNA and long-noncoding RNA (specifically MALAT1) that regulate gene expression through post-transcriptional modification are interesting avenues to consider in supporting neurons during DM. Finally, we present therapeutic possibilities around the use of a novel DNA/RNA heteroduplex oligonucleotide that provides more efficient gene knockdown in DRG than the single-stranded antisense oligonucleotide.
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Affiliation(s)
- Akiko Miyashita
- Department of Neurology, Neurological Science, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
- Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Masaki Kobayashi
- Department of Neurology, Neurological Science, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
- Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
- Department of Neurology, Nissan Tamagawa Hospital, Tokyo 158-0095, Japan
| | - Takanori Yokota
- Department of Neurology, Neurological Science, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
- Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Douglas W. Zochodne
- Division of Neurology and Department of Medicine, Faculty of Medicine and Dentistry, The Neuroscience and Mental Health Institute and The Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G 2G3, Canada
- Correspondence: ; Tel.: +1-780-248-1928; Fax: +1-780-248-1807
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7
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Zochodne DW. Growth factors and molecular-driven plasticity in neurological systems. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:569-598. [PMID: 37620091 DOI: 10.1016/b978-0-323-98817-9.00017-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
It has been almost 70 years since the discovery of nerve growth factor (NGF), a period of a dramatic evolution in our understanding of dynamic growth, regeneration, and rewiring of the nervous system. In 1953, the extraordinary finding that a protein found in mouse submandibular glands generated a halo of outgrowing axons has now redefined our concept of the nervous system connectome. Central and peripheral neurons and their axons or dendrites are no longer considered fixed or static "wiring." Exploiting this molecular-driven plasticity as a therapeutic approach has arrived in the clinic with a slate of new trials and ideas. Neural growth factors (GFs), soluble proteins that alter the behavior of neurons, have expanded in numbers and our understanding of the complexity of their signaling and interactions with other proteins has intensified. However, beyond these "extrinsic" determinants of neuron growth and function are the downstream pathways that impact neurons, ripe for translational development and potentially more important than individual growth factors that may trigger them. Persistent and ongoing nuances in clinical trial design in some of the most intractable and irreversible neurological conditions give hope for connecting new biological ideas with clinical benefits. This review is a targeted update on neural GFs, their signals, and new therapeutic ideas, selected from an expansive literature.
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Affiliation(s)
- Douglas W Zochodne
- Division of Neurology, Department of Medicine and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.
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8
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Kopp KO, Glotfelty EJ, Li Y, Greig NH. Glucagon-like peptide-1 (GLP-1) receptor agonists and neuroinflammation: Implications for neurodegenerative disease treatment. Pharmacol Res 2022; 186:106550. [PMID: 36372278 PMCID: PMC9712272 DOI: 10.1016/j.phrs.2022.106550] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/03/2022] [Accepted: 11/06/2022] [Indexed: 11/13/2022]
Abstract
Chronic, excessive neuroinflammation is a key feature of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). However, neuroinflammatory pathways have yet to be effectively targeted in clinical treatments for such diseases. Interestingly, increased inflammation and neurodegenerative disease risk have been associated with type 2 diabetes mellitus (T2DM) and insulin resistance (IR), suggesting that treatments that mitigate T2DM pathology may be successful in treating neuroinflammatory and neurodegenerative pathology as well. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that promotes healthy insulin signaling, regulates blood sugar levels, and suppresses appetite. Consequently, numerous GLP-1 receptor (GLP-1R) stimulating drugs have been developed and approved by the US Food and Drug Administration (FDA) and related global regulatory authorities for the treatment of T2DM. Furthermore, GLP-1R stimulating drugs have been associated with anti-inflammatory, neurotrophic, and neuroprotective properties in neurodegenerative disorder preclinical models, and hence hold promise for repurposing as a treatment for neurodegenerative diseases. In this review, we discuss incretin signaling, neuroinflammatory pathways, and the intersections between neuroinflammation, brain IR, and neurodegenerative diseases, with a focus on AD and PD. We additionally overview current FDA-approved incretin receptor stimulating drugs and agents in development, including unimolecular single, dual, and triple receptor agonists, and highlight those in clinical trials for neurodegenerative disease treatment. We propose that repurposing already-approved GLP-1R agonists for the treatment of neurodegenerative diseases may be a safe, efficacious, and cost-effective strategy for ameliorating AD and PD pathology by quelling neuroinflammation.
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Affiliation(s)
- Katherine O Kopp
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, NIH, Baltimore, MD 21224, United States.
| | - Elliot J Glotfelty
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, NIH, Baltimore, MD 21224, United States; Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Yazhou Li
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, NIH, Baltimore, MD 21224, United States
| | - Nigel H Greig
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program National Institute on Aging, NIH, Baltimore, MD 21224, United States.
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9
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Markova L, Cvetko E, Ugwoke CK, Horvat S, Umek N, Stopar Pintarič T. The Influence of Diabetic Peripheral Neuropathy on the Duration of Sciatic Nerve Block with 1.3% Liposomal Bupivacaine and 0.25% Bupivacaine Hydrochloride in a Mouse Model. Pharmaceutics 2022; 14:pharmaceutics14091824. [PMID: 36145571 PMCID: PMC9502724 DOI: 10.3390/pharmaceutics14091824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/05/2022] [Accepted: 08/24/2022] [Indexed: 11/18/2022] Open
Abstract
Little is known regarding the pharmacological properties of extended-release local anesthetics in the setting of diabetic peripheral neuropathy. We investigated and compared the duration of sciatic nerve block following administration of clinically relevant concentrations of liposomal bupivacaine (LB) and bupivacaine hydrochloride (BH) in diabetic mice with peripheral neuropathy. In this prospective, randomized, and double-blind study, twenty-four female C57BL/6J-OlaHsd mice were assigned to a streptozotocin-induced type 1 diabetes group and a control group without diabetes. The presence of peripheral neuropathy was established by assessing the duration of thermal latency of the plantar and tail-flick tests, following which both groups were subdivided into two subgroups in which 35 mg/kg of 1.31% LB and 7 mg/kg of 0.25% BH were respectively administered for sciatic nerve block. The average sensory block duration with BH was 106 min and 117.1 min in the control and diabetic groups, respectively. With LB, the average sensory block duration was 118 min in the control mice, while in mice with diabetic peripheral neuropathy, the average block duration was significantly longer and above the 270 min limit set in our study. Accordingly, sensory block duration was longer with LB compared to BH, and diabetic peripheral neuropathy significantly increased sciatic nerve block duration with LB.
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Affiliation(s)
- Liljana Markova
- Department of Anaesthesiology and Surgical Intensive Therapy, University Medical Centre Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Korytkova Ulica 2, 1000 Ljubljana, Slovenia
| | - Erika Cvetko
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Korytkova Ulica 2, 1000 Ljubljana, Slovenia
| | - Chiedozie Kenneth Ugwoke
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Korytkova Ulica 2, 1000 Ljubljana, Slovenia
| | - Simon Horvat
- Department of Animal Science, Biotechnology and Immunology, Biotechnical Faculty, University of Ljubljana, Groblje 3, 1230 Domžale, Slovenia
| | - Nejc Umek
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Korytkova Ulica 2, 1000 Ljubljana, Slovenia
- Correspondence:
| | - Tatjana Stopar Pintarič
- Department of Anaesthesiology and Surgical Intensive Therapy, University Medical Centre Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Korytkova Ulica 2, 1000 Ljubljana, Slovenia
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10
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Piper NBC, Whitfield EA, Stewart GD, Xu X, Furness SGB. Targeting appetite and satiety in diabetes and obesity, via G protein-coupled receptors. Biochem Pharmacol 2022; 202:115115. [PMID: 35671790 DOI: 10.1016/j.bcp.2022.115115] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 11/17/2022]
Abstract
Type 2 diabetes and obesity have reached pandemic proportions throughout the world, so much so that the World Health Organisation coined the term "Globesity" to help encapsulate the magnitude of the problem. G protein-coupled receptors (GPCRs) are highly tractable drug targets due to their wide involvement in all aspects of physiology and pathophysiology, indeed, GPCRs are the targets of approximately 30% of the currently approved drugs. GPCRs are also broadly involved in key physiologies that underlie type 2 diabetes and obesity including feeding reward, appetite and satiety, regulation of blood glucose levels, energy homeostasis and adipose function. Despite this, only two GPCRs are the target of approved pharmaceuticals for treatment of type 2 diabetes and obesity. In this review we discuss the role of these, and select other candidate GPCRs, involved in various facets of type 2 diabetic or obese pathophysiology, how they might be targeted and the potential reasons why pharmaceuticals against these targets have not progressed to clinical use. Finally, we provide a perspective on the current development pipeline of anti-obesity drugs that target GPCRs.
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Affiliation(s)
- Noah B C Piper
- Receptor Transducer Coupling Laboratory, School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Emily A Whitfield
- Receptor Transducer Coupling Laboratory, School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Gregory D Stewart
- Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology Monash University, Parkville, VIC 3052, Australia
| | - Xiaomeng Xu
- Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology Monash University, Parkville, VIC 3052, Australia
| | - Sebastian G B Furness
- Receptor Transducer Coupling Laboratory, School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD 4072, Australia; Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology Monash University, Parkville, VIC 3052, Australia.
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11
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Nasser AH, Gendy AM, El-Yamany MF, El-Tanbouly DM. Upregulation of neuronal progranulin mediates the antinociceptive effect of trimetazidine in paclitaxel-induced peripheral neuropathy: Role of ERK1/2 signaling. Toxicol Appl Pharmacol 2022; 448:116096. [PMID: 35662665 DOI: 10.1016/j.taap.2022.116096] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 05/23/2022] [Accepted: 05/28/2022] [Indexed: 10/18/2022]
Abstract
Neuronal progranulin (PGRN) overexpression is an endogenous adaptive pain defense following nerve injury. It allows the survival of injured neurons to block enhanced nociceptive responses. Trimetazidine (TMZ) is widely used by cardiac patients as an anti-anginal drug, reflecting its anti-ischemic property. TMZ promotes axonal regeneration of sciatic nerves after crush injury. This study explored the interplay between PGRN and extracellular signal-regulated kinases (ERK1/2) to address mechanisms underlying neuropathic pain alleviation following paclitaxel (PTX) administration. Rats were given four injections of PTX (2 mg/kg, i.p.) every other day. Two days after the last dose, rats received TMZ (25 mg/kg) with or without the ERK inhibitor, PD98059, daily for 21 days. TMZ preserved the integrity of myelinated nerve fibers, as evidenced by an obvious reduction in axonal damage biomarkers. Accordingly, it alleviated PTX-evoked thermal, cold, and mechanical hyperalgesia/allodynia. TMZ also promoted ERK1/2 phosphorylation with a profound upsurge in PGRN content. These effects were associated with a substantial increase in Notch1 receptor gene expression and a prominent anti-inflammatory effect with a marked increase in mRNA expression of secretory leukocyte protease inhibitor. Further, TMZ decreased oxidative stress and caspase-3 activity in the sciatic nerve. Conversely, co-administration of PD98059 completely abolished these beneficial effects. Thus, the robust antinociceptive effect of TMZ is largely attributed to upregulating PGRN and Notch1 receptors via ERK1/2 activation.
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Affiliation(s)
- Asmaa H Nasser
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, October 6 University, Giza, Egypt
| | - Abdallah M Gendy
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, October 6 University, Giza, Egypt
| | - Mohammed F El-Yamany
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Dalia M El-Tanbouly
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
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12
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Current and Emerging Pharmacotherapeutic Interventions for the Treatment of Peripheral Nerve Disorders. Pharmaceuticals (Basel) 2022; 15:ph15050607. [PMID: 35631433 PMCID: PMC9144529 DOI: 10.3390/ph15050607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/26/2022] [Accepted: 05/11/2022] [Indexed: 11/16/2022] Open
Abstract
Peripheral nerve disorders are caused by a range of different aetiologies. The range of causes include metabolic conditions such as diabetes, obesity and chronic kidney disease. Diabetic neuropathy may be associated with severe weakness and the loss of sensation, leading to gangrene and amputation in advanced cases. Recent studies have indicated a high prevalence of neuropathy in patients with chronic kidney disease, also known as uraemic neuropathy. Immune-mediated neuropathies including Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy may cause significant physical disability. As survival rates continue to improve in cancer, the prevalence of treatment complications, such as chemotherapy-induced peripheral neuropathy, has also increased in treated patients and survivors. Notably, peripheral neuropathy associated with these conditions may be chronic and long-lasting, drastically affecting the quality of life of affected individuals, and leading to a large socioeconomic burden. This review article explores some of the major emerging clinical and experimental therapeutic agents that have been investigated for the treatment of peripheral neuropathy due to metabolic, toxic and immune aetiologies.
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Jolivalt CG, Han MM, Nguyen A, Desmond F, Alves Jesus CH, Vasconselos DC, Pedneault A, Sandlin N, Dunne-Cerami S, Frizzi KE, Calcutt NA. Using Corneal Confocal Microscopy to Identify Therapeutic Agents for Diabetic Neuropathy. J Clin Med 2022; 11:jcm11092307. [PMID: 35566433 PMCID: PMC9104226 DOI: 10.3390/jcm11092307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/19/2022] [Accepted: 04/19/2022] [Indexed: 02/04/2023] Open
Abstract
Corneal confocal microscopy (CCM) is emerging as a tool for identifying small fiber neuropathy in both peripheral neuropathies and neurodegenerative disease of the central nervous system (CNS). The value of corneal nerves as biomarkers for efficacy of clinical interventions against small fiber neuropathy and neurodegenerative disease is less clear but may be supported by preclinical studies of investigational agents. We, therefore, used diverse investigational agents to assess concordance of efficacy against corneal nerve loss and peripheral neuropathy in a mouse model of diabetes. Ocular delivery of the peptides ciliary neurotrophic factor (CNTF) or the glucagon-like peptide (GLP) analog exendin-4, both of which prevent diabetic neuropathy when given systemically, restored corneal nerve density within 2 weeks. Similarly, ocular delivery of the muscarinic receptor antagonist cyclopentolate protected corneal nerve density while concurrently reversing indices of systemic peripheral neuropathy. Conversely, systemic delivery of the muscarinic antagonist glycopyrrolate, but not gallamine, prevented multiple indices of systemic peripheral neuropathy and concurrently protected against corneal nerve loss. These data highlight the potential for use of corneal nerve quantification by confocal microscopy as a bridging assay between in vitro and whole animal assays in drug development programs for neuroprotectants and support its use as a biomarker of efficacy against peripheral neuropathy.
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Mandour DA, Shalaby SM, Bendary MA. Spinal cord-wide structural disruption in type 2 diabetes rescued by exenatide "a glucagon-like peptide-1 analogue" via down-regulating inflammatory, oxidative stress and apoptotic signaling pathways. J Chem Neuroanat 2022; 121:102079. [PMID: 35143896 DOI: 10.1016/j.jchemneu.2022.102079] [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: 10/08/2021] [Revised: 12/28/2021] [Accepted: 02/03/2022] [Indexed: 11/16/2022]
Abstract
The mechanisms of spinal cord-wide structural and functional disruption in diabetic patients remain elusive. This study evaluated histopathological alterations of the spinal cord cytoarchitecture in T2DM model of rats and assessed the potential ameliorating effect of exenatide "a potent GLP-1 analogue". Thirty male rats were allocated into three groups; I (control), II (Diabetic): T2DM was induced by high fat diet for 8 weeks followed by a single I.P injection of STZ (25 mg/kg BW) and III (Diabetic/Exenatide): T2DM rats injected with exenatide (10 μg/Kg, S.C. twice daily for 2 weeks). Neurobehavioral sensory and motor tests were carried out and glycemic control biomarkers and indices of insulin resistance and sensitivity were measured. In addition, the spinal cord was processed for histological and immunohistochemical studies besides assessing its tissue homogenate levels of pro-inflammatory/anti-inflamatory cytokines and oxidant/antioxidant biomarkers. Moreover, RT-qPCR was performed to measure the expression of proapoptotic/antiapoptotic and neurotrophic genes. The diabetic rats exhibited thermal hyperalgesia, mechanical allodynia and decreased locomotor activity along with increased serum glucose, insulin, HbA1c, HOMA-IR while, quantitative insulin sensitivity check index (QUICKI) was decreased. Also, IL-1β NF-kB, MDA increased while IL-10, SOD activity and β-endorphin decreased in the spinal tissue. Up regulation of caspase-3 and down regulation of Bcl-2, nerve growth factor (NGF) and glial cell-derived neurotrophic (GDNF) in diabetic rats. Also, they exhibited histopathological changes and increased CD68 positive microglia and Bax immunoreactivity in the spinal cord. Subsequent to exenatide treatment, most biomolecular, structural and functional impairments of the spinal cord were restored in the diabetic rats. In conclusion, the neuro-modulating effect of exenatide against diabetic-induced spinal cord affection warrants the concern about its therapeutic relevance in confronting the devastating diabetic neuropathic complications.
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Affiliation(s)
- Dalia A Mandour
- Department of Human Anatomy and Embryology, Faculty of Medicine, Zagazig University, Egypt.
| | - Sally M Shalaby
- Department of Medical Biochemistry, Faculty of Medicine, Zagazig University, Egypt
| | - M A Bendary
- Department of Physiology, Faculty of Medicine, Menoufia University, Egypt
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Meurot C, Jacques C, Martin C, Sudre L, Breton J, Rattenbach R, Bismuth K, Berenbaum F. Targeting the GLP-1/GLP-1R axis to treat osteoarthritis: A new opportunity? J Orthop Translat 2022; 32:121-129. [PMID: 35280931 PMCID: PMC8888891 DOI: 10.1016/j.jot.2022.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 01/15/2023] Open
Abstract
Osteoarthritis (OA) is a degenerative joint disease affecting millions of people worldwide. In OA, chondrocytes, synovial cells and other joint cells become activated when exposed to an abnormal environment, including mechanical stress, inflammatory cytokines or disorganization of matrix proteins. Several analogues of the hormones called incretins have been developed and are used notably for treating type 2 diabetes mellitus. Data has accumulated to suggest that incretinomimetics, which bind to the glucagon-like peptide-1 receptor (GLP-1R), have beneficial pleiotropic effects such as immunomodulation, anti-inflammation and neuronal protection. Thus, because of their anti-inflammatory properties, GLP-1-based therapies could benefit OA patients. This review focuses on the GLP-1R pathway, molecular mechanisms and phenotypes related to OA pathogenesis. The translational potential of this article The search for new therapeutic targets to treat people suffering from OA remains urgent as there is currently no disease-modifyingtherapy available for this disease. This review discusses how GLP-1 analogues could be potential DMOADs for treating OA thanks to their anti-inflammatory, immunoregulatory and differentiation properties.
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Affiliation(s)
| | - C. Jacques
- Sorbonne University, INSERM UMRS_938 and Labex Transimmunom, CDR St-Antoine Paris, Paris, France
| | | | | | | | - R. Rattenbach
- 4P-Pharma, Lille, France
- 4Moving Biotech, Lille, France
| | | | - F. Berenbaum
- 4Moving Biotech, Lille, France
- APHP, Sorbonne University, Rheumatology Department, INSERM UMRS_938, CDR St-Antoine Paris, Paris, France
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Effect of exenatide on peripheral nerve excitability in type 2 diabetes. Clin Neurophysiol 2021; 132:2532-2539. [PMID: 34455311 DOI: 10.1016/j.clinph.2021.05.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/26/2021] [Accepted: 05/25/2021] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To assess the effect of exenatide (a GLP-1 receptor agonist), dipeptidyl peptidase-IV (DPP-IV) inhibitors, and sodium-glucose co-transporter 2 (SGLT-2) inhibitors on measures of peripheral nerve excitability in patients with type 2 diabetes. METHODS Patients receiving either exenatide (n = 32), a DPP-IV inhibitor (n = 31), or a SGLT-2 inhibitor (n = 27) underwent motor nerve excitability assessments. Groups were similar in age, sex, HbA1c, diabetes duration, lipids, and neuropathy severity. An additional 10 subjects were assessed prospectively over 3 months while oral anti-hyperglycaemic therapy was kept constant. A cohort of healthy controls (n = 32) were recruited for comparison. RESULTS Patients receiving a DPP-IV or SGLT-2 inhibitor demonstrated abnormalities in peak threshold reduction, S2 accommodation, superexcitability, and subexcitability. In contrast, patients treated with exenatide were observed to have normal nerve excitability. In the prospective arm, exenatide therapy was associated with an improvement in nerve function as patients demonstrated corrections in S2 accommodation, superexcitability, and subexcitability at follow-up. These changes were independent of the reductions in HbA1c following exenatide treatment. CONCLUSIONS Exenatide was associated with an improvement in measures of nerve excitability in patients with type 2 diabetes. SIGNIFICANCE Exenatide may improve peripheral nerve function in type 2 diabetes.
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Kobayashi M, Zochodne DW. Diabetic polyneuropathy: Bridging the translational gap. J Peripher Nerv Syst 2021; 25:66-75. [PMID: 32573914 DOI: 10.1111/jns.12392] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 12/22/2022]
Abstract
Clinical trials for diabetic polyneuropathy (DPN) have failed to identify therapeutic impacts that have arrested or reversed the disorder, despite a long history. This review considers DPN in the context of a unique neurodegenerative disorder that targets peripheral neurons and their companion glial cells. The approach is to examine what cells, cell substructures, and pathways are implicated in causing DPN and how they might be addressed therapeutically. These include axonopathy, neuronopathy, hyperglycemia, polyol flux, advanced glycation endproduct (AGE)-receptor AGE signaling, growth factor disruption, abnormal insulin signaling, and abnormalities of other intrinsic neuron pathways. Mitochondrial dysfunction and lipid toxicity are largely delegated to the companion review in this issue by Stino and Feldman. Finally, the linkage between axon plasticity of cutaneous nerves, peripheral neuroregenerative pathways, and diabetes are discussed.
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Affiliation(s)
- Masaki Kobayashi
- Department of Neurology, Nissan Tamagawa Hospital, Tokyo, Japan.,Department of Neurology and Neurological Science, Tokyo Medical and Dental University, Tokyo, Japan
| | - Douglas W Zochodne
- Division of Neurology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
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Mehta K, Behl T, Kumar A, Uddin MS, Zengin G, Arora S. Deciphering the Neuroprotective Role of Glucagon-like Peptide-1 Agonists in Diabetic Neuropathy: Current Perspective and Future Directions. Curr Protein Pept Sci 2021; 22:4-18. [PMID: 33292149 DOI: 10.2174/1389203721999201208195901] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 09/15/2020] [Accepted: 11/25/2020] [Indexed: 11/22/2022]
Abstract
Diabetic neuropathy is referred to as a subsequential and debilitating complication belonging to type 1 and type 2 diabetes mellitus. It is a heterogeneous group of disorders with a particularly complex pathophysiology and also includes multiple forms, ranging from normal discomfort to death. The evaluation of diabetic neuropathy is associated with hyperglycemic responses, resulting in an alteration in various metabolic pathways, including protein kinase C pathway, polyol pathway and hexosamine pathway in Schwann and glial cells of neurons. The essential source of neuronal destruction is analogous to these respective metabolic pathways, thus identified as potential therapeutic targets. These pathways regulating therapeutic medications may be used for diabetic neuropathy, however, only target specific drugs could have partial therapeutic activity. Various antidiabetic medications have been approved and marketed, which possess the therapeutic ability to control hyperglycemia and ameliorate the prevalence of diabetic neuropathy. Among all antidiabetic medications, incretin therapy, including Glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, are the most favorable medications for the management of diabetes mellitus and associated peripheral neuropathic complications. Besides enhancing glucose-evoked insulin release from pancreatic β-cells, these therapeutic agents also play a vital role to facilitate neurite outgrowth and nerve conduction velocity in dorsal root ganglion. Furthermore, incretin therapy also activates cAMP and ERK signalling pathways, resulting in nerve regeneration and repairing. These effects are evidently supported by a series of preclinical data and investigations associated with these medications. However, the literature lacks adequate clinical trial outcomes related to these novel antidiabetic medications. The manuscript emphasizes the pathogenesis, current pharmacological approaches and vivid description of preclinical and clinical data for the effective management of diabetic neuropathy.
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Affiliation(s)
- Keshav Mehta
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Arun Kumar
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - M Sahab Uddin
- Department of Pharmacy, Southeast University, Dhaka, Bangladesh
| | - Gokhan Zengin
- Department of Biology, Faculty of Science, Selcuk Uniersity Campus, Konya, Turkey
| | - Sandeep Arora
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
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Lee KA, Park TS, Jin HY. Non-glucose risk factors in the pathogenesis of diabetic peripheral neuropathy. Endocrine 2020; 70:465-478. [PMID: 32895875 DOI: 10.1007/s12020-020-02473-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 08/23/2020] [Indexed: 11/29/2022]
Abstract
In this review, we consider the diverse risk factors in diabetes patients beyond hyperglycemia that are being recognized as contributors to diabetic peripheral neuropathy (DPN). Interest in such alternative mechanisms has been encouraged by the recognition that neuropathy occurs in subjects with metabolic syndrome and pre-diabetes and by the reporting of several large clinical studies that failed to show reduced prevalence of neuropathy after intensive glucose control in patients with type 2 diabetes. Animal models of obesity, dyslipidemia, hypertension, and other disorders common to both pre-diabetes and diabetes have been used to highlight a number of plausible pathogenic mechanisms that may either damage the nerve independent of hyperglycemia or augment the toxic potential of hyperglycemia. While pathogenic mechanisms stemming from hyperglycemia are likely to be significant contributors to DPN, future therapeutic strategies will require a more nuanced approach that considers a range of concurrent insults derived from the complex pathophysiology of diabetes beyond direct hyperglycemia.
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Affiliation(s)
- Kyung Ae Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Research Institute of Clinical Medicine of Jeonbuk National University-Jeonbuk National University Hospital, Jeonbuk National University, Medical School, Jeonju, South Korea
| | - Tae Sun Park
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Research Institute of Clinical Medicine of Jeonbuk National University-Jeonbuk National University Hospital, Jeonbuk National University, Medical School, Jeonju, South Korea
| | - Heung Yong Jin
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Research Institute of Clinical Medicine of Jeonbuk National University-Jeonbuk National University Hospital, Jeonbuk National University, Medical School, Jeonju, South Korea.
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King MR, Anderson NJ, Deciu M, Guernsey LS, Cundiff M, Hajizadeh S, Jolivalt CG. Insulin deficiency, but not resistance, exaggerates cognitive deficits in transgenic mice expressing human amyloid and tau proteins. Reversal by Exendin-4 treatment. J Neurosci Res 2020; 98:2357-2369. [PMID: 32737929 DOI: 10.1002/jnr.24706] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 06/29/2020] [Accepted: 07/12/2020] [Indexed: 12/24/2022]
Abstract
Epidemiological studies have pointed at diabetes as a risk factor for Alzheimer's disease (AD) and this has been supported by several studies in animal models of both type 1 and type 2 diabetes. However, side-by-side comparison of the two types of diabetes is limited. We investigated the role of insulin deficiency and insulin resistance in the development of memory impairments and the effect of Exendin-4 (Ex4) treatment in a mouse model of AD. Three-4-month-old female wild type (WT) mice and mice overexpressing human tau and amyloid precursor protein (TAPP) were injected with streptozotocin (STZ) or fed a high-fat diet (HFD). A second study was performed in TAPP-STZ mice treated with Ex4, a long-lasting analog of GLP-1. Plasma and brain were collected at study termination for ELISA, Western blot, and immunohistochemistry analysis. Learning and memory deficits were impaired in TAPP transgenic mice compared with WT mice at the end of the study. Deficits were exaggerated by insulin deficiency in TAPP mice but 12 weeks of insulin resistance did not affect memory performances in either WT or TAPP mice. Levels of phosphorylated tau were increased in the brain of WT-STZ and TAPP-STZ mice but not in the brain of WT or TAPP mice on HFD. In the TAPP-STZ mice, treatment with Ex4 initiated after established cognitive deficits ameliorated learning, but not memory, impairments. This was accompanied by the reduction of amyloid β and phosphorylated tau expression. Theses studies support the role of Ex4 in AD, independently from its actions on diabetes.
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Affiliation(s)
- Matthew R King
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Nicholas J Anderson
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Mihaela Deciu
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Lucie S Guernsey
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Morgan Cundiff
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Shohreh Hajizadeh
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Corinne G Jolivalt
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
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Abstract
PURPOSE OF REVIEW The current review addresses one of the most common neurological disorders, diabetic polyneuropathy (DPN). DPN is debilitating, irreversible and dwarfs the prevalence of most other chronic disorders of the nervous system. Its complications include foot ulceration, amputation, falling and intractable neuropathic pain. Moreover, tight control of hyperglycemia reduces the incidence of DPN in type 1 diabetes mellitus but its role in type 2 diabetes mellitus is less clear. RECENT FINDINGS New therapeutic options to reverse the development of DPN or its associated pain have been proposed but none have significantly changed the clinical approach. The cause of DPN remains controversial traditionally focused on the impact of metabolic abnormalities, polyol flux, microvascular changes, mitochondria, oxidative stress, lipid biology and others. In particular, there has been less attention toward how this chronic disorder alters peripheral neurobiology. It is now clear that in chronic models of diabetes mellitus there exists a unique form of neurodegeneration with a range of protein, mRNA and microRNA alterations to consider. How to reconcile these molecular and structural alterations with metabolic mechanisms is a challenge. In sensory neurons alone, a primary target of DPN, both central perikaryal cytoplasmic and nuclear changes and altered distal sensory axon terminal plasticity may be involved. SUMMARY In this review, the current therapeutic status of DPN is described with greater emphasis on some new but selected thoughts on its neurobiology. New mechanistic understanding will be essential to developing precision therapeutics for DPN.
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Exendin-4 Promotes Schwann Cell Proliferation and Migration via Activating the Jak-STAT Pathway after Peripheral Nerve Injury. Neuroscience 2020; 437:1-10. [PMID: 32334071 DOI: 10.1016/j.neuroscience.2020.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/12/2020] [Accepted: 04/15/2020] [Indexed: 12/15/2022]
Abstract
Peripheral nerve injury (PNI) is a common clinical disease that causes the partial loss of segmental exercise and sensory and autonomic nervous function, placing a heavy burden on patients and their families. A previous study confirmed that exendin-4 can effectively improve nerve regeneration and functional recovery after PNI. However, the specific mechanisms by which exendin-4-mediates this repair have not been clarified. To explore the mechanism of exendin-4 in the treatment of PNI, we used microarray analysis to detect gene expression in the distal segment of the sciatic nerve after sciatic injury. Bioinformatics analyses were used to predict the roles of differentially expressed genes (DEGs) in nerve damage repair. Schwann cells (SCs) were cultured, and we verified the molecular mechanism of exendin-4 in SCs and the effect of exendin-4 on peripheral nerve regeneration through in vitro molecular biology and cell biology experiments. In vivo, exendin-4 could significantly promote peripheral nerve regeneration. A total of 180 DEGs between the exendin-4 group and the control group were detected. Bioinformatics analysis indicated that these DEGs were mainly enriched in the Jak-STAT signaling pathway. In vitro, exendin-4 could significantly promote the proliferation and migration of SCs by activating the Jak-STAT pathway, which promoted peripheral nerve regeneration. Our results indicate that exendin-4 promotes SC proliferation, migration and nerve regeneration after PNI by activating the Jak-STAT pathway. Our findings provide a basis and direction for further elucidation of the mechanisms of exendin-4 in the repair of PNI and provide a new way to treat PNI.
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Gurjar AA, Kushwaha S, Chattopadhyay S, Das N, Pal S, China SP, Kumar H, Trivedi AK, Guha R, Chattopadhyay N, Sanyal S. Long acting GLP-1 analog liraglutide ameliorates skeletal muscle atrophy in rodents. Metabolism 2020; 103:154044. [PMID: 31812628 DOI: 10.1016/j.metabol.2019.154044] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/28/2019] [Accepted: 12/02/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Skeletal muscle atrophy is characterized by muscle wasting with partial or complete functional loss. Skeletal muscle atrophy severely affects the quality of life and currently, there is no available therapy except for spinal muscular atrophy. OBJECTIVE Drug repositioning is a promising strategy that reduces cost and time due to prior availability of safety and toxicity details. Here we investigated myogenic and anti-atrophy effects of glucagon-like peptide-1 (GLP-1) analog liraglutide. METHODS We used several in vitro atrophy models in C2C12 cells and in vivo models in Sprague Dawley rats to study Liraglutide's efficacy. Western blotting was used to assess cAMP-dependent signaling pathways specifically activated by liraglutide. Therapeutic efficacy of liraglutide was investigated by histological analysis of transverse muscle sections followed by morphometry. Myogenic capacity was investigated by immunoblotting for myogenic factors. RESULTS Liraglutide induced myogenesis in C2C12 myoblasts through GLP-1 receptor via a cAMP-dependent complex network of signaling events involving protein kinase A, phosphoinositide 3-kinase/protein kinase B, p38 mitogen-activated protein kinase and extracellular signal-regulated kinase. Liraglutide imparted protection against freeze injury, denervation, and dexamethasone -induced skeletal muscle atrophy and improved muscular function in all these models. In a therapeutic model, liraglutide restored myofibrillar architecture in ovariectomy-induced atrophy. Anti-atrophy actions of liraglutide involved suppression of atrogene expression and enhancement in expression of myogenic factors. CONCLUSION Liraglutide imparted protection and restored myofibrillar architecture in diverse models of muscle atrophy. Given its potent anti-atrophy, and recently reported osteoanabolic effects, we propose liraglutide's clinical evaluation in skeletal muscle atrophy and musculoskeletal disorders associated with diverse pathologies.
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Affiliation(s)
- Anagha Ashok Gurjar
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Sapana Kushwaha
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Sourav Chattopadhyay
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Nabanita Das
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Subhashis Pal
- Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Shyamsundar Pal China
- Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Harish Kumar
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Arun Kumar Trivedi
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Rajdeep Guha
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India; Laboratory Animals Facility CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Naibedya Chattopadhyay
- Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Sabyasachi Sanyal
- Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India.
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GLP-1 Gene-Modified Human Umbilical Cord Mesenchymal Stem Cell Line Improves Blood Glucose Level in Type 2 Diabetic Mice. Stem Cells Int 2019; 2019:4961865. [PMID: 31949438 PMCID: PMC6948274 DOI: 10.1155/2019/4961865] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 10/09/2019] [Accepted: 10/21/2019] [Indexed: 12/12/2022] Open
Abstract
Type 2 diabetes constitutes a serious threat to the health of patients, but there is currently no ideal treatment in the clinic. Glucagon-like peptide-1 and human umbilical cord mesenchymal stem cells have been confirmed to have antidiabetic effects, but both of them have certain defects in the process of antidiabetes, which cannot meet the need of clinical treatment. We hypothesized that human umbilical cord mesenchymal stem cells can be used as a vector to construct a novel cell line that expresses GLP-1 in vivo for a long time. And this cell strain results in lowering blood glucose in type 2 diabetic mice. The results showed that after 3 weeks of intramuscular injection of the new cell line, the fasting blood glucose of type 2 diabetic mice returned to the normal range, and the hypoglycemic effect was maintained within 3 weeks after putting an end to the drug. At the same time, during the administration, the mice lost weight, the food intake decreased, the half-life of GLP-1 in the body prolonged, the IR reduced, and the pancreatic function recovered. The results of this study indicate that the novel cell line can prolong the half-life of GLP-1 in vivo and effectively lower blood sugar, which is a feasible method to improve type 2 diabetes.
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Abstract
The regulation of glycemia is under a tight neuronal detection of glucose levels performed by the gut-brain axis and an efficient efferent neuronal message sent to the peripheral organs, as the pancreas to induce insulin and inhibit glucagon secretions. The neuronal detection of glucose levels is performed by the autonomic nervous system including the enteric nervous system and the vagus nerve innervating the gastro-intestinal tractus, from the mouth to the anus. A dysregulation of this detection leads to the one of the most important current health issue around the world i.e. diabetes mellitus. Furthemore, the consequences of diabetes mellitus on neuronal homeostasis and activities participate to the aggravation of the disease establishing a viscious circle. Prokaryotic cells as bacteria, reside in our gut. The strong relationship between prokaryotic cells and our eukaryotic cells has been established long ago, and prokaryotic and eukaryotic cells in our body have evolved synbiotically. For the last decades, studies demonstrated the critical role of the gut microbiota on the metabolic control and how its shift can induce diseases such as diabetes. Despite an important increase of knowledge, few is known about 1) how the gut microbiota influences the neuronal detection of glucose and 2) how the diabetes mellitus-induced gut microbiota shift observed participates to the alterations of autonomic nervous system and the gut-brain axis activity.
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Affiliation(s)
- Estelle Grasset
- Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345, Gothenburg, Sweden.
| | - Remy Burcelin
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France
- Unité Mixte de Recherche (UMR) 1048, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Team 2 : 'Intestinal Risk Factors, Diabetes, Université Paul Sabatier (UPS), Dyslipidemia', F-31432, Toulouse, Cedex 4, France
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Erbil D, Eren CY, Demirel C, Küçüker MU, Solaroğlu I, Eser HY. GLP-1's role in neuroprotection: a systematic review. Brain Inj 2019; 33:734-819. [PMID: 30938196 DOI: 10.1080/02699052.2019.1587000] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Glucagon-like peptide 1 (GLP-1) is a target for treatment of diabetes; however, its function in the brain is not well studied. In this systematic review, we aimed to analyze the neuroprotective role of GLP-1 and its defined mechanisms. Methods: We searched 'Web of Science' and 'Pubmed' to identify relevant studies using GLP-1 as the keyword. Two hundred and eighty-nine clinical and preclinical studies have been included. Data have been presented by grouping neurodegenerative, neurovascular and specific cell culture models. Results: Recent literature shows that GLP-1 and its agonists, DPP-4 inhibitors and combined GLP-1/GIP molecules are effective in partially or fully reversing the effects of neurotoxic compounds, neurovascular complications of diabetes, neuropathological changes related with Alzheimer's disease, Parkinson's disease or vascular occlusion. Possible mechanisms that provide neuroprotection are enhancing the viability of the neurons and restoring neurite outgrowth by increased neurotrophic factors, increasing subventricular zone progenitor cells, decreasing apoptosis, decreasing the level of pro-inflammatory factors, and strengthening blood-brain barrier. Conclusion: Based on the preclinical studies, GLP-1 modifying agents are promising targets for neuroprotection. On the other hand, the number of clinical studies that investigate GLP-1 as a treatment is low and further clinical trials are needed for a benchside to bedside translation of recent findings.
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Affiliation(s)
- Damla Erbil
- a School of Medicine , Koç University , Istanbul , Turkey
| | - Candan Yasemin Eren
- b Research Center for Translational Medicine , Koç University , Istanbul , Turkey
| | - Cağrı Demirel
- a School of Medicine , Koç University , Istanbul , Turkey
| | | | - Ihsan Solaroğlu
- a School of Medicine , Koç University , Istanbul , Turkey.,b Research Center for Translational Medicine , Koç University , Istanbul , Turkey
| | - Hale Yapıcı Eser
- a School of Medicine , Koç University , Istanbul , Turkey.,b Research Center for Translational Medicine , Koç University , Istanbul , Turkey
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Liu W, Liu J, Huang Z, Cui Z, Li L, Liu W, Qi Z. Possible role of GLP-1 in antidepressant effects of metformin and exercise in CUMS mice. J Affect Disord 2019; 246:486-497. [PMID: 30599373 DOI: 10.1016/j.jad.2018.12.112] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 12/18/2018] [Accepted: 12/24/2018] [Indexed: 12/18/2022]
Abstract
BACKGROUND Both depression itself and antidepressant medication have been reported to be significantly related to the risk of type 2 diabetes mellitus (T2DM). Glucagon-like peptide-1 (GLP-1), a treatment target for T2DM, has a neuroprotective effect. As an enhancer and sensitiser of GLP-1, metformin has been reported to be safe for the neurodevelopment. The present study aimed to determine whether and how GLP-1 mediates antidepressant effects of metformin and exercise in mice. METHODS Male C57BL/6 mice were exposed to chronic unpredictable mild stress (CUMS) for 8 weeks. From the 4th week, CUMS mice were subjected to oral metformin treatment and/or treadmill running. A videocomputerized tracking system was used to record behaviors of mice for a 5-min session. ELISA, western blotting and immunohistochemistry were used to examine serum protein concentrations, protein levels in whole hippocampus, protein distribution and expression in dorsal and ventral hippocampus, respectively. RESULTS Our results supported the validity of metformin as a useful antidepressant; moreover, treadmill running favored metformin effects on exploratory behaviors and serum corticosterone levels. CUMS reduced GLP-1 protein levels and phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), but increased protein levels of B-cell lymphoma 2-associated X-protein (BAX) in mice hippocampus. All these changes were restored by both single and combined treatment with metformin and exercise. LIMITATIONS We did not establish a causal relationship between GLP-1 expression and related signaling, using GLP-1 agonist and antagonist or knockout techniques. CONCLUSIONS Our findings have demonstrated that protein levels of pERK and BAX may be relevant to the role of GLP-1 in antidepressant effects of metformin and exercise, which may provide a novel topic for future clinical research.
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Affiliation(s)
- Weina Liu
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, East China Normal University, Shanghai 200241, China; School of Physical Education & Health Care, East China Normal University, Shanghai 200241, China.
| | - Jiatong Liu
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, East China Normal University, Shanghai 200241, China; School of Physical Education & Health Care, East China Normal University, Shanghai 200241, China
| | - Zhuochun Huang
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, East China Normal University, Shanghai 200241, China; School of Physical Education & Health Care, East China Normal University, Shanghai 200241, China
| | - Zhiming Cui
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, East China Normal University, Shanghai 200241, China; School of Physical Education & Health Care, East China Normal University, Shanghai 200241, China
| | - Lingxia Li
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, East China Normal University, Shanghai 200241, China; School of Physical Education & Health Care, East China Normal University, Shanghai 200241, China
| | - Wenbin Liu
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, East China Normal University, Shanghai 200241, China; School of Physical Education & Health Care, East China Normal University, Shanghai 200241, China
| | - Zhengtang Qi
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, East China Normal University, Shanghai 200241, China; School of Physical Education & Health Care, East China Normal University, Shanghai 200241, China.
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Kobayashi M, Zochodne DW. Diabetic neuropathy and the sensory neuron: New aspects of pathogenesis and their treatment implications. J Diabetes Investig 2018; 9:1239-1254. [PMID: 29533535 PMCID: PMC6215951 DOI: 10.1111/jdi.12833] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/20/2018] [Accepted: 03/03/2018] [Indexed: 12/17/2022] Open
Abstract
Diabetic polyneuropathy (DPN) continues to be generally considered as a "microvascular" complication of diabetes mellitus alongside nephropathy and retinopathy. The microvascular hypothesis, however, might be tempered by the concept that diabetes directly targets dorsal root ganglion sensory neurons. This neuron-specific concept, supported by accumulating evidence, might account for important features of DPN, such as its early sensory neuron degeneration. Diabetic sensory neurons develop neuronal atrophy alongside a series of messenger ribonucleic acid (RNA) changes related to declines in structural proteins, increases in heat shock protein, increases in the receptor for advanced glycation end-products, declines in growth factor signaling and other changes. Insulin is recognized as a potent neurotrophic factor, and insulin ligation enhances neurite outgrowth through activation of the phosphoinositide 3-kinase-protein kinase B pathway within sensory neurons and attenuates phenotypic features of experimental DPN. Several interventions, including glucagon-like peptide-1 agonism, and phosphatase and tensin homolog inhibition to activate growth signals in sensory neurons, or heat shock protein overexpression, prevent or reverse neuropathic abnormalities in experimental DPN. Diabetic sensory neurons show a unique pattern of microRNA alterations, a key element of messenger RNA silencing. For example, let-7i is widely expressed in sensory neurons, supports their growth and is depleted in experimental DPN; its replenishment improves features of DPN models. Finally, impairment of pre-messenger RNA splicing in diabetic sensory neurons including abnormal nuclear RNA metabolism and structure with loss of survival motor neuron protein, a neuron survival molecule, and overexpression of CWC22, a splicing factor, offer further novel insights. The present review addresses these new aspects of DPN sensory neurodegeneration.
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Affiliation(s)
- Masaki Kobayashi
- Department of Neurology and Neurological ScienceGraduate School of MedicineTokyo Medical and Dental UniversityTokyoJapan
- Department of NeurologyYokufukai Geriatric HospitalTokyoJapan
| | - Douglas W Zochodne
- Division of Neurology and Department of MedicineNeuroscience and Mental Health InstituteFaculty of Medicine and DentistryUniversity of AlbertaEdmontonAlbertaCanada
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Candeias E, Sebastião I, Cardoso S, Carvalho C, Santos MS, Oliveira CR, Moreira PI, Duarte AI. Brain GLP-1/IGF-1 Signaling and Autophagy Mediate Exendin-4 Protection Against Apoptosis in Type 2 Diabetic Rats. Mol Neurobiol 2018; 55:4030-4050. [PMID: 28573460 DOI: 10.1007/s12035-017-0622-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/16/2017] [Indexed: 02/08/2023]
Abstract
Type 2 diabetes (T2D) is a modern socioeconomic burden, mostly due to its long-term complications affecting nearly all tissues. One of them is the brain, whose dysfunctional intracellular quality control mechanisms (namely autophagy) may upregulate apoptosis, leading to cognitive dysfunction and Alzheimer disease (AD). Since impaired brain insulin signaling may constitute the crosslink between T2D and AD, its restoration may be potentially therapeutic herein. Accordingly, the insulinotropic anti-T2D drugs from glucagon-like peptide-1 (GLP-1) mimetics, namely, exendin-4 (Ex-4), could be a promising therapy. In line with this, we hypothesized that peripherally administered Ex-4 rescues brain intracellular signaling pathways, promoting autophagy and ultimately protecting against chronic T2D-induced apoptosis. Thus, we aimed to explore the effects of chronic, continuous, subcutaneous (s.c.) exposure to Ex-4 in brain cortical GLP-1/insulin/insulin-like growth factor-1 (IGF-1) signaling, and in autophagic and cell death mechanisms in middle-aged (8 months old), male T2D Goto-Kakizaki (GK) rats. We used brain cortical homogenates obtained from middle-aged (8 months old) male Wistar (control) and T2D GK rats. Ex-4 was continuously administered for 28 days, via s.c. implanted micro-osmotic pumps (5 μg/kg/day; infusion rate 2.5 μL/h). Peripheral characterization of the animal models was given by the standard biochemical analyses of blood or plasma, the intraperitoneal glucose tolerance test, and the heart rate. GLP-1, insulin, and IGF-1, their downstream signaling and autophagic markers were evaluated by specific ELISA kits and Western blotting. Caspase-like activities and other apoptotic markers were given by colorimetric methods and Western blotting. Chronic Ex-4 treatment attenuated peripheral features of T2D in GK rats, including hyperglycemia and insulin resistance. Furthermore, s.c. Ex-4 enhanced their brain cortical GLP-1 and IGF-1 levels, and subsequent signaling pathways. Specifically, Ex-4 stimulated protein kinase A (PKA) and phosphoinositide 3-kinase (PI3K)/Akt signaling, increasing cGMP and AMPK levels, and decreasing GSK3β and JNK activation in T2D rat brains. Moreover, Ex-4 regulated several markers for autophagy in GK rat brains (as mTOR, PI3K class III, LC3 II, Atg7, p62, LAMP-1, and Parkin), ultimately protecting against apoptosis (by decreasing several caspase-like activities and mitochondrial cytochrome c, and increasing Bcl2 levels upon T2D). Altogether, this study demonstrates that peripheral Ex-4 administration may constitute a promising therapy against the chronic complications of T2D affecting the brain.
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Affiliation(s)
- Emanuel Candeias
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão - Pólo II, Rua D. Francisco de Lemos, 3030-789, Coimbra, Portugal
| | - Inês Sebastião
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
| | - Susana Cardoso
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão - Pólo II, Rua D. Francisco de Lemos, 3030-789, Coimbra, Portugal
| | - Cristina Carvalho
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão - Pólo II, Rua D. Francisco de Lemos, 3030-789, Coimbra, Portugal
| | - Maria Sancha Santos
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Life Sciences Department, University of Coimbra, Largo Marquês de Pombal, 3004-517, Coimbra, Portugal
| | - Catarina Resende Oliveira
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal
- Institute of Biochemistry, Faculty of Medicine, University of Coimbra, 3004-504, Coimbra, Portugal
| | - Paula I Moreira
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal.
- Institute of Physiology, Faculty of Medicine, University of Coimbra, 3004-504, Coimbra, Portugal.
| | - Ana I Duarte
- CNC-Center for Neuroscience and Cell Biology, Rua Larga, Faculty of Medicine (Pólo 1, 1st Floor), University of Coimbra, 3004-517, Coimbra, Portugal.
- Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão - Pólo II, Rua D. Francisco de Lemos, 3030-789, Coimbra, Portugal.
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Kan HW, Hsieh JH, Chien HF, Lin YH, Yeh TY, Chao CC, Hsieh ST. CD40-mediated HIF-1α expression underlying microangiopathy in diabetic nerve pathology. Dis Model Mech 2018; 11:dmm033647. [PMID: 29549140 PMCID: PMC5963861 DOI: 10.1242/dmm.033647] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 03/12/2018] [Indexed: 01/31/2023] Open
Abstract
To understand the pathology and molecular signatures of microangiopathy in diabetic neuropathy, we systemically and quantitatively examined the morphometry of microvascular and nerve pathologies of sural nerves. In the endoneurium of diabetic nerves, prominent microangiopathy was observed, as evidenced by reduced capillary luminal area, increased capillary basement membrane thickness and increased proportion of fibrin(+) blood vessels. Furthermore, capillary basement membrane thickness and the proportion of fibrin(+) blood vessels were correlated with small myelinated fiber density in diabetic nerves. In diabetic nerves, there was also significant macrophage and T cell infiltration, and cluster of differentiation 40 (CD40) expression was increased. The molecular alterations observed were upregulation of hypoxia-inducible factor-1α (HIF-1α), mitogen-activated protein kinase-activated protein kinase 2 (MK2; MAPKAPK2) and phosphatase and tensin homolog (PTEN). In addition, HIF-1α was correlated with small myelinated fiber density and capillary luminal area, while both MK2 and PTEN were correlated with capillary basement membrane thickness. The molecular cascades were further demonstrated and replicated in a cell model of microangiopathy on human umbilical vein endothelial cells (HUVECs) exposed to high-glucose medium by silencing of CD40, PTEN and HIF-1α in HUVECs using shRNA. These data clarified the hierarchy of the molecular cascades, i.e. upregulation of CD40 leading to HIF-1α expression in endothelium and nerve fibers. In conclusion, this study revealed the association of microangiopathy, thrombosis and inflammatory infiltrates with nerve degeneration in diabetic nerves, demonstrating that CD40 is a key molecule for the upregulation of HIF-1α and PTEN underlying the severity of microangiopathy.
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Affiliation(s)
- Hung-Wei Kan
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei 10051, Taiwan
| | - Jung-Hsien Hsieh
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei 10051, Taiwan
- Department of Surgery, National Taiwan University Hospital, Taipei 10002, Taiwan
| | - Hsiung-Fei Chien
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei 10051, Taiwan
- Department of Surgery, National Taiwan University Hospital, Taipei 10002, Taiwan
| | - Yea-Huey Lin
- Department of Neurology, National Taiwan University Hospital, Taipei 10002, Taiwan
| | - Ti-Yen Yeh
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei 10051, Taiwan
| | - Chi-Chao Chao
- Department of Neurology, National Taiwan University Hospital, Taipei 10002, Taiwan
| | - Sung-Tsang Hsieh
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei 10051, Taiwan
- Department of Neurology, National Taiwan University Hospital, Taipei 10002, Taiwan
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
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Danhong Injection Alleviates Mechanical Allodynia via Inhibiting ERK1/2 Activation and Elevates BDNF Level in Sciatic Nerve in Diabetic Rat. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 2018:5798453. [PMID: 29552083 PMCID: PMC5820641 DOI: 10.1155/2018/5798453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 12/01/2017] [Accepted: 12/04/2017] [Indexed: 11/22/2022]
Abstract
Danhong injection (DHI) has been widely used in China for cardiocerebrovascular diseases treatments. And in this study, we demonstrated the therapeutic effect of DHI on experimental diabetic neuropathy for the first time. Methods. Streptozotocin- (STZ-) induced SD rats were used. In experiment 1, 4-week treatment with DHI or saline started 4 weeks after STZ injection; mechanical allodynia was measured before and every 2 weeks after STZ injection. In experiment 2, chronic intrathecal infusion of U0126 was conducted during the 8th week of diabetes. Phosphorylated and total ERK1/2 in spinal cord were analyzed by western blot. BDNF level in sciatic nerve was evaluated by ELISA. Results. DHI treatment significantly alleviated mechanical allodynia at the end of the study and downregulated the expression of phosphorylated ERK1/2 in spinal cord. In addition, DHI treatment also elevated brain-derived neurotrophic factor (BDNF) level in sciatic nerve of DPN rat. In experiment 2, inhibition of ERK1/2 activation was confirmed to result in the alleviation of mechanical allodynia. Conclusions. We demonstrated that DHI was able to alleviate mechanical allodynia in diabetic neuropathy rat through inhibiting the activation of ERK1/2. The reduction of BDNF content in sciatic nerve was also partially reversed by DHI treatment.
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Ma J, Shi M, Zhang X, Liu X, Chen J, Zhang R, Wang X, Zhang H. GLP‑1R agonists ameliorate peripheral nerve dysfunction and inflammation via p38 MAPK/NF‑κB signaling pathways in streptozotocin‑induced diabetic rats. Int J Mol Med 2018; 41:2977-2985. [PMID: 29484377 DOI: 10.3892/ijmm.2018.3509] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 01/19/2018] [Indexed: 11/06/2022] Open
Abstract
The present study aimed to investigate the mechanism of glucagon‑like peptide‑1 receptor (GLP‑1R) agonists in the progression of diabetic peripheral neuropathy (DPN) in streptozotocin (STZ)‑induced diabetic rats, through inflammatory signaling pathways. The DPN rat model was generated by intraperitoneal injection of STZ and then treated with the GLP‑1R agonist liraglutide or saline for 8 weeks. These animals were randomly divided into 4 groups (10 rats in each): The normal control + saline group, the normal control + liraglutide group, the diabetic + saline (DM) group and the diabetic + liraglutide (DML) group. The nerve conduction velocity (NCV) in the sciatic nerves of the rats was monitored over a period of 8 weeks. Peripheral serum was obtained for the measurement of blood glucose, tumor necrosis factor‑α (TNF‑α), interleukin‑6 (IL‑6) and IL‑1β level. The protein levels of phosphorylated (p‑) and total extracellular signal‑regulated kinase, c‑Jun NH2‑terminal kinases, p38 mitogen‑activated protein kinases (MAPK), and nuclear and cytoplasmic nuclear factor‑κB (NF‑κB) were measured through western blot analysis. Sciatic nerve mRNA expression levels of proinflammatory chemokines (TNF‑α, IL‑6 and IL‑1β), chemokines [monocyte chemoattractant protein‑1 (MCP‑1)], adhesion molecules [intercellular adhesion molecule 1 (ICAM‑1)], neurotrophic factors [neuritin, nerve growth factor (NGF) and neuron‑specific enolase (NSE)] and NADPH oxidase 4 (NOX4) were evaluated by reverse transcription-quantitative polymerase chain reaction. Subsequent to 8 weeks of treatment with liraglutide, the density of myelin nerve fibers was partially restored in the DML group. The delayed motor NCV and sensory NCV in the DML group were improved. The IOD value of NOX4 staining in the DML group (24.43±9.01) was reduced compared with that in the DM group (56.60±6.91). The levels of TNF‑α, IL‑1β and IL‑6 in the peripheral serum of the DML group were significantly suppressed compared with those of the DM group. It was also observed that the mRNA expression levels of TNF‑α, IL‑6, IL‑1β, MCP‑1, ICAM‑1 and NOX4 in the sciatic nerve were attenuated in the DML group. The mRNA expression of neuritin and NGF was significantly increased in the DML group compared with that of the DM group; NSE was reduced in the sciatic nerves of the DML group compared with that of the DM group. Additionally, the protein expression of p‑p38 MAPK and NF‑κB in the DML group was significantly suppressed. These data demonstrated that GLP‑1R agonists may prevent nerve dysfunction in the sciatic nerves of diabetic rats via p38 MAPK/NF‑κB signaling pathways independent of glycemic control. GLP‑1R agonists may be a useful therapeutic strategy for slowing the progression of DPN.
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Affiliation(s)
- Jingjing Ma
- Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, Jiangsu 223300, P.R. China
| | - Min Shi
- Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, Jiangsu 223300, P.R. China
| | - Xiangcheng Zhang
- Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, Jiangsu 223300, P.R. China
| | - Xiaoning Liu
- Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, Jiangsu 223300, P.R. China
| | - Juan Chen
- Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, Jiangsu 223300, P.R. China
| | - Ridong Zhang
- Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, Jiangsu 223300, P.R. China
| | - Xingzhou Wang
- Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, Jiangsu 223300, P.R. China
| | - Hong Zhang
- Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, Jiangsu 223300, P.R. China
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Salviz EA, Onbasi S, Ozonur A, Orhan-Sungur M, Berkoz O, Tugrul KM. Comparison of Ultrasound-Guided Axillary Brachial Plexus Block Properties in Diabetic and Nondiabetic Patients: A Prospective Observational Study. J Hand Surg Am 2017; 42:190-197. [PMID: 28259276 DOI: 10.1016/j.jhsa.2017.01.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 12/31/2016] [Accepted: 01/11/2017] [Indexed: 02/02/2023]
Abstract
PURPOSE Patients with diabetes mellitus (DM) type 2 may have subclinical peripheral nerve neuropathy. We performed this study to compare the differences in duration of axillary brachial plexus blocks in patients with type 2 DM and without DM (NODM). Our hypothesis was that the sensory block duration would be prolonged in patients with DM. METHODS A total of 71 patients who were scheduled for elective forearm and/or hand surgery were enrolled in this study. Before surgery, they received ultrasound-guided axillary brachial plexus blocks with a mixture of 10 mL lidocaine 2% and 20 mL bupivacaine 0.5%. After surgery, all patients received 1 g paracetamol every 6 hours as needed. The primary end point was sensory block duration. Secondary end points were motor block duration, time until first pain (numeric rating scale [NRS] 4 or greater), highest NRS pain scores, and rescue analgesic consumption (NRS 4 or greater) through the first 2 postoperative days. RESULTS In all, 67 patients completed the study: 22 in the DM group and 45 in the NODM group. Sensory and motor block durations were longer in the DM group than in the NODM group (mean [range], 773.5 [479-1155] vs 375 [113-900] minutes, and 523 [205-955] vs 300 [110-680] minutes). Time until first pain was 855 (590-1,285) minutes in the DM group and 500 (200-990) minutes in the NODM group. The highest NRS scores were also significantly lower in the DM group at 6 and 12 hours. Paracetamol consumption was lower in the DM group through the first 2 postoperative days. CONCLUSIONS The presence of DM was associated with longer duration of the sensory block after axillary brachial plexus block. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic II.
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Affiliation(s)
- Emine Aysu Salviz
- Department of Anesthesiology, Division of Hand, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
| | - Sukru Onbasi
- Department of Anesthesiology, Division of Hand, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Anil Ozonur
- Department of Anesthesiology, Division of Hand, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Mukadder Orhan-Sungur
- Department of Anesthesiology, Division of Hand, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Omer Berkoz
- Department of Plastic and Reconstructive Surgery, Division of Hand, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Kamil Mehmet Tugrul
- Department of Anesthesiology, Division of Hand, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
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VEGF-B promotes recovery of corneal innervations and trophic functions in diabetic mice. Sci Rep 2017; 7:40582. [PMID: 28091556 PMCID: PMC5238415 DOI: 10.1038/srep40582] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 12/08/2016] [Indexed: 12/19/2022] Open
Abstract
Vascular endothelial growth factor (VEGF)-B possesses the capacity of promoting injured peripheral nerve regeneration and restore their sensory and trophic functions. However, the contribution and mechanism of VEGF-B in diabetic peripheral neuropathy remains unclear. In the present study, we investigated the expression and role of VEGF-B in diabetic corneal neuropathy by using type 1 diabetic mice and cultured trigeminal ganglion (TG) neurons. Hyperglycemia attenuated the endogenous expression of VEGF-B in regenerated diabetic corneal epithelium, but not that of VEGF receptors in diabetic TG neurons and axons. Exogenous VEGF-B promoted diabetic corneal nerve fiber regeneration through the reactivation of PI-3K/Akt-GSK3β-mTOR signaling and the attenuation of neuronal mitochondria dysfunction via the VEGF receptor-1 and neuropilin-1. Moreover, VEGF-B improved corneal sensation and epithelial regeneration in both normal and diabetic mice, accompanied with the elevated corneal content of pigment epithelial-derived factor (PEDF). PEDF blockade partially abolished trophic function of VEGF-B in diabetic corneal re-innervation. In conclusion, hyperglycemia suppressed endogenous VEGF-B expression in regenerated corneal epithelium of diabetic mice, while exogenous VEGF-B promoted recovery of corneal innervations and trophic functions through reactivating PI-3K/Akt-GSK-3β-mTOR signaling, attenuating neuronal oxidative stress and elevating PEDF expression.
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Qiu C, Wang YP, Pan XD, Liu XY, Chen Z, Liu LB. Exendin-4 protects Aβ(1-42) oligomer-induced PC12 cell apoptosis. Am J Transl Res 2016; 8:3540-3548. [PMID: 27648144 PMCID: PMC5009406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 07/15/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Type 2 diabetes mellitus (T2DM) increases the risk of developing Alzheimer's disease. Most recently, GLP-1 analogs have been shown to have a significant neuroprotective role in several neurodegenerative diseases. However, few are known on its potential mechanism. OBJECTIVE In this study, we report the effect of exendin-4 (Ex-4), a GLP-1 receptor agonist, on amyloid-β(1-42) peptide oligomer-induced apoptosis in a PC12 neuronal cell model. METHODS MTT, DAPI and Annexin-V/PI assays revealed that the viability of PC12 cells decreased in a dose- and time-dependent manner after exposure to amyloid-β(1-42) oligomers. This apoptotic effect could be attenuated by Ex-4 (100-300 nM) pre-treatment, compared with the PC12 cells treated with amyloid-β(1-42) oligomers alone. Moreover, treatment with amyloid-β(1-42) oligomers (10 μM) resulted in a decrease in active- and pro-caspase-3 expression, as well as in Bcl-2 protein expression; suggesting that amyloid-β(1-42) oligomers impaired neuronal cells via the apoptosis signaling pathway. A further study of this mechanism revealed that amyloid-β oligomers (AβOs) decreased the phosphorylation of Akt and CREB. As expected, pre-treatment with Ex-4 (300 nM) increased the expression of anti-apoptotic protein Bcl-2 and reduced active caspase-3 expression levels. In addition, Ex-4 upregulated the phosphorylation levels of Akt and CREB. CONCLUSIONS These findings indicate that GLP-1 analogue Ex-4 has a neuroprotective effect against AβO-induced PC12 cell apoptosis through reversing the impairment of the neuronal survival signaling pathway. This strongly suggests that Ex-4 is a potential therapeutic option for ameliorating AβO-induced neurotoxicity in the clinical application of Ex-4 for AD treatment, particularly when associated with diabetes.
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Affiliation(s)
- Chen Qiu
- Fujian Institute of Endocrinology, Fujian Medical University Union HospitalFuzhou 350001, Fujian, China
- Department of Endocrinology, People’s Hospital Affiliated to Fujian University of Traditional Chinese MedicineFuzhou 350004, Fujian, China
| | - Yan-Ping Wang
- Fujian Institute of Endocrinology, Fujian Medical University Union HospitalFuzhou 350001, Fujian, China
- Department of Endocrinology, Fujian Medical University Union HospitalFuzhou 350001, Fujian, China
- Department of Geriatrics, Fujian Medical University Union HospitalFuzhou 350001, Fujian, China
| | - Xiao-Dong Pan
- Department of Neurology, Fujian Medical University Union HospitalFuzhou 350001, Fujian, China
| | - Xiao-Ying Liu
- Fujian Institute of Endocrinology, Fujian Medical University Union HospitalFuzhou 350001, Fujian, China
| | - Zhou Chen
- College of Pharmacy, Fujian Medical UniversityFuzhou 350108, Fujian, China
| | - Li-Bin Liu
- Fujian Institute of Endocrinology, Fujian Medical University Union HospitalFuzhou 350001, Fujian, China
- Institute of Geriatric Health Science, Fujian Medical UniversityFuzhou 350001, Fujian, China
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DPP-4 inhibitors in diabetic complications: role of DPP-4 beyond glucose control. Arch Pharm Res 2016; 39:1114-28. [PMID: 27502601 DOI: 10.1007/s12272-016-0813-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 08/04/2016] [Indexed: 12/12/2022]
Abstract
Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) are an emerging class of antidiabetic drugs that constitutes approximately fifty percent of the market share of the oral hypoglycemic drugs. Its mechanism of action for lowering blood glucose is essentially via inhibition of the rapid degradation of incretin hormones, such as glucagon-like peptide (GLP)-1 and gastric inhibitory polypeptide (GIP), thus the plasma concentration of GLP-1 increases, which promotes insulin secretion from the pancreatic β cells and suppresses glucagon secretion from the α cells. In addition to the direct actions on the pancreas, GLP-1 exhibits diverse actions on different tissues through its action on GLP-1 receptor, which is expressed ubiquitously. Moreover, DPP-4 has multiple substrates besides GLP-1 and GIP, including cytokines, chemokines, neuropeptides, and growth factors, which are involved in many pathophysiological conditions. Recently, it was suggested that DPP-4 is a new adipokine secreted from the adipose tissue, which plays an important role in the regulation of the endocrine function in obesity-associated type 2 diabetes. Consequently, DPP-4 inhibitors have been reported to exhibit cytoprotective functions against various diabetic complications affecting the liver, heart, kidneys, retina, and neurons. This review outlines the current understanding of the effect of DPP-4 inhibitors on the complications associated with type 2 diabetes, such as liver steatosis and inflammation, dysfunction of the adipose tissue and pancreas, cardiovascular diseases, nephropathy, and neuropathy in preclinical and clinical studies.
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Incretin-Based Therapies for Diabetic Complications: Basic Mechanisms and Clinical Evidence. Int J Mol Sci 2016; 17:ijms17081223. [PMID: 27483245 PMCID: PMC5000621 DOI: 10.3390/ijms17081223] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 07/16/2016] [Accepted: 07/25/2016] [Indexed: 02/07/2023] Open
Abstract
An increase in the rates of morbidity and mortality associated with diabetic complications is a global concern. Glycemic control is important to prevent the development and progression of diabetic complications. Various classes of anti-diabetic agents are currently available, and their pleiotropic effects on diabetic complications have been investigated. Incretin-based therapies such as dipeptidyl peptidase (DPP)-4 inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RA) are now widely used in the treatment of patients with type 2 diabetes. A series of experimental studies showed that incretin-based therapies have beneficial effects on diabetic complications, independent of their glucose-lowering abilities, which are mediated by anti-inflammatory and anti-oxidative stress properties. Based on these findings, clinical studies to assess the effects of DPP-4 inhibitors and GLP-1RA on diabetic microvascular and macrovascular complications have been performed. Several but not all studies have provided evidence to support the beneficial effects of incretin-based therapies on diabetic complications in patients with type 2 diabetes. We herein discuss the experimental and clinical evidence of incretin-based therapy for diabetic complications.
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Zochodne DW. Sensory Neurodegeneration in Diabetes: Beyond Glucotoxicity. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 127:151-80. [PMID: 27133149 DOI: 10.1016/bs.irn.2016.03.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Diabetic polyneuropathy in humans is of gradual, sometimes insidious onset, and is more likely to occur if glucose control is poor. Arguments that the disorder arises chiefly from glucose toxicity however ignore the greater complexity of a unique neurodegenerative disorder. For example, sensory neurons regularly thrive in media with levels of glucose at or exceeding those of poorly controlled diabetic persons. Also, all of the linkages between hyperglycemia and neuropathy develop in the setting of altered insulin availability or sensitivity. Insulin itself is recognized as a potent growth, or trophic factor for adult sensory neurons. Low doses of insulin, insufficient to alter blood glucose levels, reverse features of diabetic neurodegeneration in animal models. Insulin resistance, as occurs in diabetic adipose tissue, liver, and muscle, also develops in sensory neurons, offering a mechanism for neurodegeneration in the setting of normal or elevated insulin levels. Other interventions that "shore up" sensory neurons prevent features of diabetic polyneuropathy from developing despite persistent hyperglycemia. More recently evidence has emerged that a series of subtle molecular changes in sensory neurons can be linked to neurodegeneration including epigenetic changes in the control of gene expression. Understanding the new complexity of sensory neuron degeneration may give rise to therapeutic strategies that have a higher chance of success in the clinical trial arena.
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Affiliation(s)
- D W Zochodne
- Neuroscience and Mental Health Institute and Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada.
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Sango K, Utsunomiya K. Efficacy of glucagon-like peptide-1 mimetics for neural regeneration. Neural Regen Res 2016; 10:1723-4. [PMID: 26807090 PMCID: PMC4705767 DOI: 10.4103/1673-5374.169611] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Kazunori Sango
- Diabetic Neuropathy Project (Former ALS/Neuropathy project), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
| | - Kazunori Utsunomiya
- Division of Diabetes, Metabolism & Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
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Tsuboi K, Mizukami H, Inaba W, Baba M, Yagihashi S. The dipeptidyl peptidase IV inhibitor vildagliptin suppresses development of neuropathy in diabetic rodents: effects on peripheral sensory nerve function, structure and molecular changes. J Neurochem 2016; 136:859-870. [PMID: 26603140 DOI: 10.1111/jnc.13439] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 11/03/2015] [Accepted: 11/04/2015] [Indexed: 01/01/2023]
Abstract
Incretin-related therapy was found to be beneficial for experimental diabetic neuropathy, but its mechanism is obscure. The purpose of this study is to explore the mechanism through which dipeptidyl peptidase IV inhibitor, vildagliptin (VG), influences neuropathy in diabetic rodents. To this end, non-obese type 2 diabetic Goto-Kakizaki rats (GK) and streptozotocin (STZ)-induced diabetic mice were treated with VG orally. Neuropathy was evaluated by nerve conduction velocity (NCV) in both GK and STZ-diabetic mice, whereas calcitonin-gene-related peptide expressions, neuronal cell size of dorsal root ganglion (DRG) and intraepidermal nerve fiber density were examined in GK. DRG from GK and STZ-diabetic mice served for the analyses of GLP-1 and insulin signaling. As results, VG treatment improved glucose intolerance and increased serum insulin and GLP-1 in GK accompanied by the amelioration of delayed NCV and neuronal atrophy, reduced calcitonin-gene-related peptide expressions and intraepidermal nerve fiber density. Diet restriction alone did not significantly influence these measures. Impaired GLP-1 signals such as cAMP response element binding protein, protein kinase B/Akt (PKB/Akt) and S6RP in DRG of GK were restored in VG-treated group, but the effect was equivocal in diet-treated GK. Concurrently, decreased phosphorylation of insulin receptor substrate 2 in GK was corrected by VG treatment. Consistent with the effect on GK, VG treatment improved NCV in diabetic mice without influence on hyperglycemia. DRG of VG-treated diabetic mice were characterized by correction of GLP-1 signals and insulin receptor substrate 2 phosphorylation without effects on insulin receptor β expression. The results suggest close association of neuropathy development with impaired signaling of insulin and GLP-1 in diabetic rodents. Diabetic neurons are resistant to insulin and such insulin resistance may contribute to development of neuropathy. DPP-IV inhibitor, vildagliptin, corrected insulin resistance and improved neuropathy irrespective of blood glucose via augmented action of GLP-1.
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Affiliation(s)
- Kentaro Tsuboi
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Hiroki Mizukami
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Wataru Inaba
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Masayuki Baba
- Department of Neurology, Aomori Prefectural Hospital, Aomori, Japan
| | - Soroku Yagihashi
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
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Jaiswal M, Martin CL, Brown MB, Callaghan B, Albers JW, Feldman EL, Pop-Busui R. Effects of exenatide on measures of diabetic neuropathy in subjects with type 2 diabetes: results from an 18-month proof-of-concept open-label randomized study. J Diabetes Complications 2015; 29:1287-94. [PMID: 26264399 PMCID: PMC4656068 DOI: 10.1016/j.jdiacomp.2015.07.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/10/2015] [Accepted: 07/11/2015] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Experimental studies have reported potential benefit of glucagon-like peptide-1(GLP-1) receptor agonists in preventing diabetic peripheral neuropathy (DPN). We therefore performed a proof-of-concept pilot study to evaluate the effect of exenatide, a GLP-1 agonist, on measures of DPN and cardiovascular autonomic neuropathy (CAN) in patients with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS Forty-six T2D subjects (age 54±10years, diabetes duration 8±5years, HbA1c 8.2±1.3%) with mild to moderate DPN at baseline were randomized to receive either twice daily exenatide (n=22) or daily insulin glargine (n=24). The subjects, with similar HbA1c levels, were followed for 18months. The primary end point was the prevalence of confirmed clinical neuropathy (CCN). Changes in measures of CAN, other measures of small fiber neuropathy such as intra-epidermal nerve fiber density (IENFD), and quality of life were also analyzed. RESULTS Glucose control was similar in both groups during the study. There were no statistically significant treatment group differences in the prevalence of CCN, IENFD, measures of CAN, nerve conductions studies, or quality of life indices. CONCLUSIONS In this pilot study of patients with T2D and mild to moderate DPN, 18months of exenatide treatment had no significant effect on measures of neuropathy compared with glargine treatment.
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Affiliation(s)
- Mamta Jaiswal
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - Catherine L Martin
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Morton B Brown
- Department of Biostatistics, University of Michigan, Ann Arbor, MI
| | - Brian Callaghan
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - James W Albers
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - Eva L Feldman
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - Rodica Pop-Busui
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI.
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Zochodne DW. Diabetes and the plasticity of sensory neurons. Neurosci Lett 2015; 596:60-5. [DOI: 10.1016/j.neulet.2014.11.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 12/13/2022]
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Tsukamoto M, Niimi N, Sango K, Takaku S, Kanazawa Y, Utsunomiya K. Neurotrophic and neuroprotective properties of exendin-4 in adult rat dorsal root ganglion neurons: involvement of insulin and RhoA. Histochem Cell Biol 2015; 144:249-59. [PMID: 26026990 DOI: 10.1007/s00418-015-1333-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2015] [Indexed: 11/26/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is thought to preserve neurons and glia following axonal injury and neurodegenerative disorders. We investigated the neurotrophic and neuroprotective properties of exendin (Ex)-4, a synthetic GLP-1 receptor (GLP-1R) agonist, on adult rat dorsal root ganglion (DRG) neurons and PC12 cells. GLP-1R was predominantly localized on large and small peptidergic neurons in vivo and in vitro, suggesting the involvement of GLP-1 in both the large and small sensory fiber functions. Ex-4 dose-dependently (1 ≤ 10 ≤ 100 nM) promoted neurite outgrowth and neuronal survival at 2 and 7 days in culture, respectively. Treatment with 100 nM Ex-4 restored the reduced neurite outgrowth and viability of DRG neurons caused by the insulin removal from the medium and suppressed the activity of RhoA, an inhibitory regulator for peripheral nerve regeneration, in PC12 cells. Furthermore, these effects were attenuated by co-treatment with phosphatidylinositol-3'-phosphate kinase (PI3K) inhibitor, LY294002. These findings imply that Ex-4 enhances neurite outgrowth and neuronal survival through the activation of PI3K signaling pathway, which negatively regulates RhoA activity. Ex-4 and other GLP-1R agonists may compensate for the reduced insulin effects on neurons, thereby being beneficial for the treatment of diabetic neuropathy.
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Affiliation(s)
- Masami Tsukamoto
- Diabetic Neuropathy Project (Former Laboratory of Peripheral Nerve Pathophysiology), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
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Barros JIT, Fechine FV, Montenegro Júnior RM, Vale OCD, Fernandes VO, Souza MHLPD, Cunha GHD, Moraes MOD, d'Alva CB, Moraes MEAD. Effect of treatment with sitagliptin on somatosensory-evoked potentials and metabolic control in patients with type 2 diabetes mellitus. ACTA ACUST UNITED AC 2015; 58:369-76. [PMID: 24936731 DOI: 10.1590/0004-2730000002914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 01/24/2014] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To evaluate the effect of sitagliptin on somatosensory-evoked potentials (SEPs) and metabolic control in patients with type 2 diabetes mellitus without clinical diabetic neuropathy. MATERIALS AND METHODS Interventional, prospective, and open study. Patients with less than six months from the diagnosis were included. Examinations of SEPs and laboratory tests at fasting and after food stimulation were performed before and after three months of treatment with sitagliptin (100 mg/day). RESULTS There was a reduction in the mean levels of HbA1c (P < 0.0001), fasting glucose (P = 0.001), total cholesterol (P = 0.019), and ALT (P = 0.022). An increase in active GLP-1 was found at the end of the study (P = 0.0025). Several SEPs showed statistically significant differences when analyzed before and after treatment with sitagliptin. CONCLUSION The results give a glimpse of the possible use of sitagliptin in the treatment of some neurodegenerative conditions of the peripheral nervous system, in addition to its already established role in glycemic control.
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Affiliation(s)
- Joelma Ines Tagliapietra Barros
- Clinical Pharmacology Unit, Department of Physiology and Pharmacology, School of Medicine, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Francisco Vagnaldo Fechine
- Clinical Pharmacology Unit, Department of Physiology and Pharmacology, School of Medicine, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | | | | | | | | | | | - Manoel Odorico de Moraes
- Clinical Pharmacology Unit, Department of Physiology and Pharmacology, School of Medicine, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Catarina Brasil d'Alva
- Clinical Pharmacology Unit, Department of Physiology and Pharmacology, School of Medicine, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Maria Elisabete Amaral de Moraes
- Clinical Pharmacology Unit, Department of Physiology and Pharmacology, School of Medicine, Universidade Federal do Ceará, Fortaleza, CE, Brazil
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Li H, Jia Z, Li G, Zhao X, Sun P, Wang J, Fan Z, Lv G. Neuroprotective effects of exendin-4 in rat model of spinal cord injury via inhibiting mitochondrial apoptotic pathway. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:4837-4843. [PMID: 26191175 PMCID: PMC4503047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 04/15/2015] [Indexed: 06/04/2023]
Abstract
Spinal cord injury (SCI) is a devastating problem of health. Glucagon-like peptide-1 (GLP-1) is glucose-dependent insulinotropic hormone. Exendin-4 is the longacting GLP-1 receptor agonist that used as an anti-diabetic drug. Recent studies demonstrated exendin-4 has a series of beneficial neuroprotective properties. This study was designed to assess the neuroprotective effects of exendin-4 against spinal cord injury. 72 rats were randomly divided into three groups as follows: sham operation group, SCI group, and exendin-4 group (intraperitoneal injection of exendin-4 at 10 μg/rat immediately after SCI). First, a decrease of malodialdehyde (MDA) levels and an increase of glutathione (GSH) levels in the exendin-4 group demonstrated the anti-oxidation effect of exendin-4. Further, the preservation of mitochondrial membrane potential (ΔΨm) and the reduction of cytochrome c release suggested the protection for mitochondria. Moreover, a decline of the expression level of Bax, Bcl-2 and caspase-3 and the results of TUNEL staining indicated its anti-apoptosis role. Finally, behavioral assessment with Basso Beattle Bresnahan locomotor rating scale (BBB) showed that animals in exendin-4 group achieved a significant increase in BBB scores. Our results suggest that exendin-4 prevents against SCI-induced mitochondrial apoptotic pathway and contributes to functional improvement after SCI.
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Affiliation(s)
- Haotian Li
- Department of Orthopaedics, The First Affiliated Hospital, Liaoning Medical University Jinzhou 121000, China
| | - Zhiqiang Jia
- Department of Orthopaedics, The First Affiliated Hospital, Liaoning Medical University Jinzhou 121000, China
| | - Gang Li
- Department of Orthopaedics, The First Affiliated Hospital, Liaoning Medical University Jinzhou 121000, China
| | - Xingzhang Zhao
- Department of Orthopaedics, The First Affiliated Hospital, Liaoning Medical University Jinzhou 121000, China
| | - Ping Sun
- Department of Orthopaedics, The First Affiliated Hospital, Liaoning Medical University Jinzhou 121000, China
| | - Jiquan Wang
- Department of Orthopaedics, The First Affiliated Hospital, Liaoning Medical University Jinzhou 121000, China
| | - Zhongkai Fan
- Department of Orthopaedics, The First Affiliated Hospital, Liaoning Medical University Jinzhou 121000, China
| | - Gang Lv
- Department of Orthopaedics, The First Affiliated Hospital, Liaoning Medical University Jinzhou 121000, China
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Liraglutide Promotes Cortical Neurite Outgrowth via the MEK–ERK Pathway. Cell Mol Neurobiol 2015; 35:987-93. [DOI: 10.1007/s10571-015-0193-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/06/2015] [Indexed: 12/18/2022]
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Thompson A, Kanamarlapudi V. Agonist-induced internalisation of the glucagon-like peptide-1 receptor is mediated by the Gαq pathway. Biochem Pharmacol 2015; 93:72-84. [DOI: 10.1016/j.bcp.2014.10.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 10/27/2014] [Accepted: 10/30/2014] [Indexed: 12/12/2022]
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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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Zhao H, Wei R, Wang L, Tian Q, Tao M, Ke J, Liu Y, Hou W, Zhang L, Yang J, Hong T. Activation of glucagon-like peptide-1 receptor inhibits growth and promotes apoptosis of human pancreatic cancer cells in a cAMP-dependent manner. Am J Physiol Endocrinol Metab 2014; 306:E1431-41. [PMID: 24801389 DOI: 10.1152/ajpendo.00017.2014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) promotes pancreatic β-cell regeneration through GLP-1 receptor (GLP-1R) activation. However, whether it promotes exocrine pancreas growth and thereby increases the risk of pancreatic cancer has been a topic of debate in recent years. Clinical data and animal studies published so far have been controversial. In the present study, we report that GLP-1R activation with liraglutide inhibited growth and promoted apoptosis in human pancreatic cancer cell lines in vitro and attenuated pancreatic tumor growth in a mouse xenograft model in vivo. These effects of liraglutide were mediated through activation of cAMP production and consequent inhibition of Akt and ERK1/2 signaling pathways in a GLP-1R-dependent manner. Moreover, we examined GLP-1R expression in human pancreatic cancer tissues and found that 43.3% of tumor tissues were GLP-1R-null. In the GLP-1R-positive tumor tissues (56.7%), the level of GLP-1R was lower compared with that in tumor-adjacent normal pancreatic tissues. Furthermore, the GLP-1R-positive tumors were significantly smaller than the GLP-1R-null tumors. Our study shows for the first time that GLP-1R activation has a cytoreductive effect on human pancreatic cancer cells in vitro and in vivo, which may help address safety concerns of GLP-1-based therapies in the context of human pancreatic cancer.
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Affiliation(s)
- Hejun Zhao
- Department of Endocrinology and Metabolism and
| | - Rui Wei
- Department of Endocrinology and Metabolism and
| | - Liang Wang
- Department of Endocrinology and Metabolism and
| | - Qing Tian
- Department of Endocrinology and Metabolism and
| | - Ming Tao
- Department of General Surgery, Peking University Third Hospital, Beijing, China
| | - Jing Ke
- Department of Endocrinology and Metabolism and
| | - Ye Liu
- Department of Endocrinology and Metabolism and
| | - Wenfang Hou
- Department of Endocrinology and Metabolism and
| | - Lin Zhang
- Department of Endocrinology and Metabolism and
| | - Jin Yang
- Department of Endocrinology and Metabolism and
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Greig NH, Tweedie D, Rachmany L, Li Y, Rubovitch V, Schreiber S, Chiang YH, Hoffer BJ, Miller J, Lahiri DK, Sambamurti K, Becker RE, Pick CG. Incretin mimetics as pharmacologic tools to elucidate and as a new drug strategy to treat traumatic brain injury. Alzheimers Dement 2014; 10:S62-75. [PMID: 24529527 PMCID: PMC4201593 DOI: 10.1016/j.jalz.2013.12.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 12/05/2013] [Indexed: 01/12/2023]
Abstract
Traumatic brain injury (TBI), either as an isolated injury or in conjunction with other injuries, is an increasingly common event. An estimated 1.7 million injuries occur within the USA each year and 10 million people are affected annually worldwide. Indeed, nearly one third (30.5%) of all injury-related deaths in the USA are associated with TBI, which will soon outpace many common diseases as the major cause of death and disability. Associated with a high morbidity and mortality and no specific therapeutic treatment, TBI has become a pressing public health and medical problem. The highest incidence of TBI occurs in young adults (15-24 years age) and in the elderly (≥75 years of age). Older individuals are particularly vulnerable to these types of injury, often associated with falls, and have shown increased mortality and worse functional outcome after lower initial injury severity. In addition, a new and growing form of TBI, blast injury, associated with the detonation of improvised explosive devices in the war theaters of Iraq and Afghanistan, are inflicting a wave of unique casualties of immediate impact to both military personnel and civilians, for which long-term consequences remain unknown and may potentially be catastrophic. The neuropathology underpinning head injury is becoming increasingly better understood. Depending on severity, TBI induces immediate neuropathologic effects that, for the mildest form, may be transient; however, with increasing severity, these injuries cause cumulative neural damage and degeneration. Even with mild TBI, which represents the majority of cases, a broad spectrum of neurologic deficits, including cognitive impairments, can manifest that may significantly influence quality of life. Further, TBI can act as a conduit to longer term neurodegenerative disorders. Prior studies of glucagon-like peptide-1 (GLP-1) and long-acting GLP-1 receptor agonists have demonstrated neurotrophic/neuroprotective activities across a broad spectrum of cellular and animal models of chronic neurodegenerative (Alzheimer's and Parkinson's diseases) and acute cerebrovascular (stroke) disorders. In view of the mechanisms underpinning these disorders as well as TBI, we review the literature and recent studies assessing GLP-1 receptor agonists as a potential treatment strategy for mild to moderate TBI.
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Affiliation(s)
- Nigel H Greig
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.
| | - David Tweedie
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Lital Rachmany
- Department of Anatomy & Anthropology, Sackler School of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
| | - Yazhou Li
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Vardit Rubovitch
- Department of Anatomy & Anthropology, Sackler School of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
| | - Shaul Schreiber
- Department of Psychiatry, Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Yung-Hsiao Chiang
- Department of Neurosurgery, Taipei Medical University Hospital, Taipei City, Taiwan, ROC; Graduate Institute of Neural Regenerative Medicine, Taipei Medical University, Taipei City, Taiwan, ROC
| | - Barry J Hoffer
- Department of Neurosurgery, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Jonathan Miller
- Department of Neurosurgery, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Debomoy K Lahiri
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kumar Sambamurti
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Robert E Becker
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA; Aristea Translational Medicine, Park City, UT, USA
| | - Chaim G Pick
- Department of Anatomy & Anthropology, Sackler School of Medicine and Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
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