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Zhang W, Wu L, Qu R, Liu T, Wang J, Tong Y, Bei W, Guo J, Hu X. Hesperidin activates the GLP-1R/cAMP-CREB/IRS2/PDX1 pathway to promote transdifferentiation of islet α cells into β cells Across the spectrum. Heliyon 2024; 10:e35424. [PMID: 39220963 PMCID: PMC11365324 DOI: 10.1016/j.heliyon.2024.e35424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/12/2024] [Accepted: 07/29/2024] [Indexed: 09/04/2024] Open
Abstract
Background and aims In all age, FoShou as a Chinese medicinal herb has been active in various kinds of Traditional Chinese medicine formula to treating diabetes. Hesperidin (HES), the main monomeric component of FoShou, has been extensively investigated for interventions with pathogenic mechanism of diabetes as well as subsequent treatment of associated complications. Islet β-cells have an essential effect on dynamically regulating blood sugar. Functional abnormalities in these cells and their death are strongly associated with the onset of diabetes. Therefore, induction of islet endocrine cell lineage re-editing for damaged βcell replenishment would be a promising therapeutic tool. Previously, it has been found that HES can protect islet β-cells in vivo, But, the regenerative function of HES in islet β cells and its role in promoting differential non-β cells transdifferentiation into β cells and cell fate rewriting associated mechanisms remain unclear.This work focused on investigating whether HES can induce islet α cells transdifferentiation into β cells for achieving damaged β cell regeneration and the causes and possible mechanisms involved in the process. Materials and methods In brief, 60 mg/kg/d streptozotocin (STZ) was administered intraperitoneally in each male C57bL/6J mouse raised by the high-sugar and high-fat diet (HFD) to create a diabetic mouse model with severe β-cell damage. After 28 consecutive days of HES treatment (160 mg/kg; 320 mg/kg; once daily, as appropriate). Tracing the dynamics of α as well as β cell transformation, together with β cells growth and apoptosis levels during treatment by cell lineage tracing. The self-enforcing transcriptional network on which the cell lineage is based is used as a clue to explore the underlying mechanisms. Guangdong Pharmaceutical University's Animal Experiment Ethics Committee (GDPulac2019180) approved all animal experiments. Results Localization by cell lineage we find that transdifferentiated newborn β-cells derived from α cells appeared in the islet endocrine cell mass of DM mice under HES'action. Compared to the model group, expressed by Tunel staining and CXCL10 levels the overall apoptosis rate of β-cells of the pancreas were reduced,the inflammatory infiltration feedback from HE staining were lower.Ki-67 positive cells showed enhanced β-cell proliferation. Decreased HbA1c and blood glucose contents, elevated C-Peptide and insulin contents which respond to ability of nascent beta cells. Also upregulated the mRNA levels of MafA, Ngn3, PDX-1, Pax4 and Arx. Moreover, increased the expression of TGR5/cAMP-CREB/GLP-1 in mouse intestinal tissues and GLP-1/GLP-1R and cAMP-CREB/IRS2/PDX-1 in pancreatic tissues. Conclusions HES directly affects β-cells, apart from being anti-apoptotic and reducing inflammatory infiltration. HES promotes GLP-1 release by intestinal L cells by activating the TGR5 receptor in DM mouse and regulating its response element CREB signaling. GLP-1 then uses the GLP-1/GLP-1R system to act on IRS2, IRS2 as a port to influence α precursor cells to express PDX-1, with the mobilization of Pax4 strong expression than Arx so that α cell lineage is finally reversed for achieving β cell endogenous proliferation.
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Affiliation(s)
- Wang Zhang
- Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Lele Wu
- Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Ru Qu
- Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Tianfeng Liu
- Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Jiliang Wang
- Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Ying Tong
- Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Weijian Bei
- Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Jiao Guo
- Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Xuguang Hu
- Guangdong Pharmaceutical University, Guangzhou, 510006, China
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Jamal N, Hollabaugh W, Scott L, Takkouche S. Unravelling the ties that bind: The intersection of obesity, osteoarthritis, and inflammatory pathways with emphasis on glucagon-like peptide-1 agonists. Clin Obes 2024:e12700. [PMID: 39152660 DOI: 10.1111/cob.12700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 07/21/2024] [Indexed: 08/19/2024]
Abstract
This narrative review article explores the complex interplay between obesity, osteoarthritis, and their associated inflammatory cascades, offering a deeper understanding of the underlying of mechanisms of inflammation and potential therapeutic interventions targeting both diseases. Through examination of the shared inflammatory pathway of obesity and osteoarthritis, our objective is to directly elucidate the relationship between these two conditions, highlighting the promising role of glucagon-like peptide-1 agonists in modulating inflammation and its therapeutic implications for patients with obesity and osteoarthritis.
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Affiliation(s)
- Naadir Jamal
- Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - William Hollabaugh
- Department of Orthopaedic Surgery, Division of Sports Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Leon Scott
- Department of Orthopaedic Surgery, Division of Sports Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Sahar Takkouche
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Le R, Nguyen MT, Allahwala MA, Psaltis JP, Marathe CS, Marathe JA, Psaltis PJ. Cardiovascular Protective Properties of GLP-1 Receptor Agonists: More than Just Diabetic and Weight Loss Drugs. J Clin Med 2024; 13:4674. [PMID: 39200816 PMCID: PMC11355214 DOI: 10.3390/jcm13164674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/06/2024] [Accepted: 08/07/2024] [Indexed: 09/02/2024] Open
Abstract
Owing to their potent glucose-lowering efficacy and substantial weight loss effects, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are now considered part of the frontline therapeutic options to treat both type 2 diabetes mellitus and nondiabetic overweight/obesity. Stemming from successful demonstration of their cardiometabolic modulation and reduction of major adverse cardiovascular events in clinical outcome trials, GLP-1 RAs have since been validated as agents with compelling cardiovascular protective properties. Studies spanning from the bench to preclinical and large-scale randomised controlled trials have consistently corroborated the cardiovascular benefits of this pharmacological class. Most notably, there is converging evidence that they exert favourable effects on atherosclerotic ischaemic endpoints, with preclinical data indicating that they may do so by directly modifying the burden and composition of atherosclerotic plaques. This narrative review examines the underlying pharmacology and clinical evidence behind the cardiovascular benefits of GLP-1 RAs, with particular focus on atherosclerotic cardiovascular disease. It also delves into the mechanisms that underpin their putative plaque-modifying actions, addresses existing knowledge gaps and therapeutic challenges and looks to future developments in the field, including the use of combination incretin agents for diabetes and weight loss management.
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Affiliation(s)
- Richard Le
- College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia;
- Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide 5000, Australia; (M.T.N.); (M.A.A.); (J.A.M.)
| | - Mau T. Nguyen
- Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide 5000, Australia; (M.T.N.); (M.A.A.); (J.A.M.)
- Department of Cardiology, Central Adelaide Local Health Network, Adelaide 5000, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (J.P.P.); (C.S.M.)
| | - Momina A. Allahwala
- Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide 5000, Australia; (M.T.N.); (M.A.A.); (J.A.M.)
- Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (J.P.P.); (C.S.M.)
| | - James P. Psaltis
- Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (J.P.P.); (C.S.M.)
| | - Chinmay S. Marathe
- Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (J.P.P.); (C.S.M.)
- Department of Endocrinology, Central Adelaide Local Health Network, Adelaide 5000, Australia
| | - Jessica A. Marathe
- Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide 5000, Australia; (M.T.N.); (M.A.A.); (J.A.M.)
- Department of Cardiology, Central Adelaide Local Health Network, Adelaide 5000, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (J.P.P.); (C.S.M.)
| | - Peter J. Psaltis
- Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide 5000, Australia; (M.T.N.); (M.A.A.); (J.A.M.)
- Department of Cardiology, Central Adelaide Local Health Network, Adelaide 5000, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (J.P.P.); (C.S.M.)
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Chavda VP, Balar PC, Vaghela DA, Dodiya P. Unlocking longevity with GLP-1: A key to turn back the clock? Maturitas 2024; 186:108028. [PMID: 38815535 DOI: 10.1016/j.maturitas.2024.108028] [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: 01/17/2024] [Revised: 05/05/2024] [Accepted: 05/11/2024] [Indexed: 06/01/2024]
Abstract
Traditionally known for managing blood sugar, GLP-1, a gut hormone, is emerging as a potential key to both lengthening lifespan and combating age-related ailments. While widely recognized for its role in blood sugar control, GLP-1 is increasingly recognized for its diverse effects on various biological pathways beyond glucose metabolism. Research across organisms and humans suggests that activating GLP-1 receptors significantly impacts cellular processes linked to aging. Its ability to boost mitochondrial function, enhance cellular stress resistance, and quell inflammation hints at its wider influence on aging mechanisms. This intricate interplay between GLP-1 and longevity appears to act through multiple pathways. One key effect is its ability to modulate insulin sensitivity, potentially curbing age-related metabolic issues like type 2 diabetes. Its neuroprotective properties also make it a promising candidate for addressing age-related cognitive decline and neurodegenerative diseases. Furthermore, preclinical studies using GLP-1 analogs or agonists have shown promising results in extending lifespan and improving healthspan in various model organisms. These findings provide a compelling rationale for exploring GLP-1-based interventions in humans to extend healthy aging. However, despite the exciting therapeutic prospects of GLP-1 in promoting longevity, challenges remain. Determining optimal dosages, establishing long-term safety profiles, and investigating potential adverse effects require comprehensive clinical investigations before we can confidently translate these findings to humans. This article emphasises the wide applicability of GLP-1.
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Affiliation(s)
- Vivek P Chavda
- Department of Pharmaceutics and Pharmaceutical Technology, L M College of Pharmacy, Ahmedabad 380008, Gujarat, India.
| | - Pankti C Balar
- Pharmacy Section, L M College of Pharmacy, Ahmedabad 380008, Gujarat, India
| | - Dixa A Vaghela
- Pharmacy Section, L M College of Pharmacy, Ahmedabad 380008, Gujarat, India
| | - Payal Dodiya
- Pharmacy Section, L M College of Pharmacy, Ahmedabad 380008, Gujarat, India
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Alanteet A, Attia H, Alfayez M, Mahmood A, Alsaleh K, Alsanea S. Liraglutide attenuates obese-associated breast cancer cell proliferation via inhibiting PI3K/Akt/mTOR signaling pathway. Saudi Pharm J 2024; 32:101923. [PMID: 38223522 PMCID: PMC10784703 DOI: 10.1016/j.jsps.2023.101923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 12/13/2023] [Indexed: 01/16/2024] Open
Abstract
This study aims to explore the anti-proliferative, pro-apoptotic, and anti-migration activities of liraglutide (LGT) in MCF-7 breast cancer (BC) cells in subjects with obesity, particularly its effects on the PI3K/Akt/mTOR/AMPK pathway. The role of AMPK/SIRT-1, an essential regulator of adipokine production, in the effect of LGT on the production of adipose-derived adipokine was also assessed. MCF-7 cells were incubated in conditioned medium (CM) generated from adipose-derived stem cells (ADSCs) of obese subjects. MCF-7 cells were then treated with LGT for 72 h. Anti-proliferative, pro-apoptotic, and anti-migration activities were investigated using alamarBlue, annexin V stain, and scratch assay, respectively. Protein levels of phosphorylated PI3K, p-Akt, p-mTOR, and p-AMPK were investigated using immunoblotting. Levels of adipokines in ADSCs were determined using RT-PCR before and after transfection of ADSCs using the specific small interference RNA sequences for AMPK and SIRT-1. LGT evoked anti-proliferative, apoptotic, and potential anti-migratory properties on MCF-7 cells incubated in CM from obese ADSCs and significantly mitigated the activity of the PI3K/Akt/mTOR survival pathway-but not AMPK-in MCF-7 cells. Furthermore, the anti-proliferative effects afforded by LGT were similar to those mediated by LY294002 (PI3K inhibitor) and rapamycin (mTOR inhibitor). Our results reveal that transfection of AMPK/SIRT-1 genes did not affect the beneficial role of LGT in the expression of adipokines in ADSCs. In conclusion, LGT elicits anti-proliferative, apoptotic, and anti-migratory effects on BC cells in obese conditions by suppressing the activity of survival pathways; however, this effect is independent of the AMPK/SIRT1 pathway in ADSCs or AMPK in BC cells.
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Affiliation(s)
- Alaa Alanteet
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Hala Attia
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Musaed Alfayez
- Anatomy Department, Stem Cell Unit, College of Medicine, King Saud University, Riyadh 11451, Saudi Arabia
| | - Amer Mahmood
- Anatomy Department, Stem Cell Unit, College of Medicine, King Saud University, Riyadh 11451, Saudi Arabia
| | - Khalid Alsaleh
- College of Medicine, King Saud University, Riyadh 11451, Saudi Arabia
| | - Sary Alsanea
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
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Tseng YT, Lai R, Oieni F, Standke A, Smyth G, Yang C, Chen M, St John J, Ekberg J. Liraglutide modulates adhesion molecules and enhances cell properties in three-dimensional cultures of olfactory ensheathing cells. Biomed Pharmacother 2023; 165:115084. [PMID: 37399717 DOI: 10.1016/j.biopha.2023.115084] [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: 05/10/2023] [Revised: 06/15/2023] [Accepted: 06/26/2023] [Indexed: 07/05/2023] Open
Abstract
Cell transplantation using olfactory ensheathing cells (OECs) is a promising approach for nerve repair but there are numerous limitations with their delivery method. Three-dimensional (3D) cell culture systems potentially offer a powerful approach for cell production and delivery options. To further optimise the use of OECs, strategies to promote cell viability and maintain cell behaviours in 3D cultures become important. We previously demonstrated an anti-diabetic drug, liraglutide, could modulate OEC migration and re-model extracellular matrix in two-dimensional (2D) cultures. In the present study, we further investigated its beneficial effects in our 3D culture system using primary OECs. OECs treated with liraglutide at 100 nM showed improved cell viability and had modulated expression of N-cadherin and β1-integrin (two important cell adhesion molecules). When formed into 3D spheroids, the pre-treated OECs generated spheroids with an increased volume and a decreased cell density compared to control spheroids. OECs that subsequently migrated out of the liraglutide pre-treated spheroids had higher capacity for migration with increased duration and length, which was attributed to a reduction in the pauses during the migration. Moreover, OECs that migrated out from liraglutide spheroids had a more bipolar morphology consistent with higher migratory capacity. In summary, liraglutide improved the viability of OECs, modulated cell adhesion molecules, and resulted in stable 3D cell constructs which conferred enhanced migratory capacity on the OECs. Overall, liraglutide may potentially improve the therapeutic use of OECs for neural repair by enhancing the generation of stable 3D constructs and increasing the migratory behaviour of OECs.
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Affiliation(s)
- Yu-Ting Tseng
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD 4111, Australia; Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia; Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111, Australia
| | - Richard Lai
- Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia
| | - Francesca Oieni
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD 4111, Australia; Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia
| | - Andrea Standke
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD 4111, Australia; Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia
| | - Graham Smyth
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD 4111, Australia; Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia
| | - Chenying Yang
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD 4111, Australia; Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia
| | - Mo Chen
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD 4111, Australia; Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia; Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111, Australia.
| | - James St John
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD 4111, Australia; Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia; Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111, Australia.
| | - Jenny Ekberg
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD 4111, Australia; Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia; Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111, Australia.
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Maiese K. Cellular Metabolism: A Fundamental Component of Degeneration in the Nervous System. Biomolecules 2023; 13:816. [PMID: 37238686 PMCID: PMC10216724 DOI: 10.3390/biom13050816] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/05/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
It is estimated that, at minimum, 500 million individuals suffer from cellular metabolic dysfunction, such as diabetes mellitus (DM), throughout the world. Even more concerning is the knowledge that metabolic disease is intimately tied to neurodegenerative disorders, affecting both the central and peripheral nervous systems as well as leading to dementia, the seventh leading cause of death. New and innovative therapeutic strategies that address cellular metabolism, apoptosis, autophagy, and pyroptosis, the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), growth factor signaling with erythropoietin (EPO), and risk factors such as the apolipoprotein E (APOE-ε4) gene and coronavirus disease 2019 (COVID-19) can offer valuable insights for the clinical care and treatment of neurodegenerative disorders impacted by cellular metabolic disease. Critical insight into and modulation of these complex pathways are required since mTOR signaling pathways, such as AMPK activation, can improve memory retention in Alzheimer's disease (AD) and DM, promote healthy aging, facilitate clearance of β-amyloid (Aß) and tau in the brain, and control inflammation, but also may lead to cognitive loss and long-COVID syndrome through mechanisms that can include oxidative stress, mitochondrial dysfunction, cytokine release, and APOE-ε4 if pathways such as autophagy and other mechanisms of programmed cell death are left unchecked.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, New York, NY 10022, USA
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Wang LH, Wang YY, Liu L, Gong Q. From Diabetes to Diabetic Complications: Role of Autophagy. Curr Med Sci 2023:10.1007/s11596-023-2727-4. [PMID: 37115396 DOI: 10.1007/s11596-023-2727-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 12/29/2022] [Indexed: 04/29/2023]
Abstract
Diabetes and its complications reduce quality of life and are life-limiting. At present, diabetes treatment consists of hypoglycemic agents to control blood glucose and the use of insulin-sensitizing drugs to overcome insulin resistance. In diabetes, autophagy is impaired and thus there is poor intracellular environment homeostasis. Pancreatic β-cells and insulin target tissues are protected by enhancing autophagy. Autophagy decreases β-cell apoptosis, promotes β-cell proliferation, and alleviates insulin resistance. Autophagy in diabetes is regulated by the mammalian target of rapamycin (mTOR)/adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway and others. Autophagy enhancers can likely be used as a treatment for diabetes and its complications. This review examines the evidence linking autophagy to diabetes.
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Affiliation(s)
- Lin-Hua Wang
- Clinical Molecular Immunology Center, Yangtze University, Jingzhou, 434023, China
| | - Yang-Yang Wang
- Clinical Molecular Immunology Center, Yangtze University, Jingzhou, 434023, China
| | - Lian Liu
- Department of Pharmacology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, 434023, China.
| | - Quan Gong
- Clinical Molecular Immunology Center, Yangtze University, Jingzhou, 434023, China.
- Department of Immunology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, 434023, China.
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Song S, Guo R, Mehmood A, Zhang L, Yin B, Yuan C, Zhang H, Guo L, Li B. Liraglutide attenuate central nervous inflammation and demyelination through AMPK and pyroptosis-related NLRP3 pathway. CNS Neurosci Ther 2022; 28:422-434. [PMID: 34985189 PMCID: PMC8841291 DOI: 10.1111/cns.13791] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/08/2021] [Accepted: 12/15/2021] [Indexed: 12/22/2022] Open
Abstract
Aims Multiple sclerosis (MS) still maintains increasing prevalence and poor prognosis, while glucagon‐like peptide‐1 receptor (GLP‐1R) agonists show excellent neuroprotective capacities recently. Thus, we aim to evaluate whether the GLP‐1R agonist liraglutide (Lira) could ameliorate central nervous system demyelination and inflammation. Methods The therapeutic effect of Lira was tested on experimental autoimmune encephalitis (EAE) in vivo and a microglia cell line BV2 in vitro. Results Lira administration could ameliorate the disease score of EAE mice, delay the disease onset, ameliorate pathological demyelination and inflammation score in lumbar spinal cord, reduce pathogenic T helper cell transcription in spleen, restore phosphorylated adenosine monophosphate‐activated protein kinase (pAMPK) level, autophagy level, and inhibit pyroptosis‐related NLR family, pyrin domain‐containing protein 3 (NLRP3) pathway in lumbar spinal cord. Additionally, cell viability test, lactate dehydrogenase release test, and dead/live cell staining test for BV2 cells showed Lira could not salvage BV2 from nigericin‐induced pyroptosis significantly. Conclusion Lira has anti‐inflammation and anti‐demyelination effect on EAE mice, and the protective effect of Lira in the EAE model may be related to regulation of pAMPK pathway, autophagy, and NLRP3 pathway. However, Lira treatment cannot significantly inhibit pyroptosis of BV2 cells in vitro. Our study provides Lira as a potential candidate for Multiple Sclerosis treatment.
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Affiliation(s)
- Shuang Song
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Key Laboratory of Neurology of Hebei Province, Shijiazhuang, China
| | - Ruoyi Guo
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Key Laboratory of Neurology of Hebei Province, Shijiazhuang, China
| | - Arshad Mehmood
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Key Laboratory of Neurology of Hebei Province, Shijiazhuang, China
| | - Lu Zhang
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Key Laboratory of Neurology of Hebei Province, Shijiazhuang, China
| | - Bowen Yin
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Key Laboratory of Neurology of Hebei Province, Shijiazhuang, China.,Department of Neurology, The First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Congcong Yuan
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Key Laboratory of Neurology of Hebei Province, Shijiazhuang, China.,Department of Neurology, Baoding First Central Hospital, Baoding, China
| | - Huining Zhang
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Key Laboratory of Neurology of Hebei Province, Shijiazhuang, China
| | - Li Guo
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Key Laboratory of Neurology of Hebei Province, Shijiazhuang, China
| | - Bin Li
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Key Laboratory of Neurology of Hebei Province, Shijiazhuang, China
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Holter MM, Saikia M, Cummings BP. Alpha-cell paracrine signaling in the regulation of beta-cell insulin secretion. Front Endocrinol (Lausanne) 2022; 13:934775. [PMID: 35957816 PMCID: PMC9360487 DOI: 10.3389/fendo.2022.934775] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/28/2022] [Indexed: 01/14/2023] Open
Abstract
As an incretin hormone, glucagon-like peptide 1 (GLP-1) lowers blood glucose levels by enhancing glucose-stimulated insulin secretion from pancreatic beta-cells. Therapies targeting the GLP-1 receptor (GLP-1R) use the classical incretin model as a physiological framework in which GLP-1 secreted from enteroendocrine L-cells acts on the beta-cell GLP-1R. However, this model has come into question, as evidence demonstrating local, intra-islet GLP-1 production has advanced the competing hypothesis that the incretin activity of GLP-1 may reflect paracrine signaling of GLP-1 from alpha-cells on GLP-1Rs on beta-cells. Additionally, recent studies suggest that alpha-cell-derived glucagon can serve as an additional, albeit less potent, ligand for the beta-cell GLP-1R, thereby expanding the role of alpha-cells beyond that of a counterregulatory cell type. Efforts to understand the role of the alpha-cell in the regulation of islet function have revealed both transcriptional and functional heterogeneity within the alpha-cell population. Further analysis of this heterogeneity suggests that functionally distinct alpha-cell subpopulations display alterations in islet hormone profile. Thus, the role of the alpha-cell in glucose homeostasis has evolved in recent years, such that alpha-cell to beta-cell communication now presents a critical axis regulating the functional capacity of beta-cells. Herein, we describe and integrate recent advances in our understanding of the impact of alpha-cell paracrine signaling on insulin secretory dynamics and how this intra-islet crosstalk more broadly contributes to whole-body glucose regulation in health and under metabolic stress. Moreover, we explore how these conceptual changes in our understanding of intra-islet GLP-1 biology may impact our understanding of the mechanisms of incretin-based therapeutics.
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Affiliation(s)
- Marlena M. Holter
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
- *Correspondence: Marlena M. Holter,
| | - Mridusmita Saikia
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States
| | - Bethany P. Cummings
- School of Medicine, Department of Surgery, Center for Alimentary and Metabolic Sciences, University of California, Davis, Sacramento, CA, United States
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11
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Wang J, Fan S, Xiong Q, Niu Y, Zhang X, Qin J, Shi Y, Zhang L. Glucagon-like peptide-1 attenuates cardiac hypertrophy via the AngII/AT1R/ACE2 and AMPK/mTOR/p70S6K pathways. Acta Biochim Biophys Sin (Shanghai) 2021; 53:1189-1197. [PMID: 34357376 DOI: 10.1093/abbs/gmab099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Indexed: 12/15/2022] Open
Abstract
Glucagon-like peptide-1 (GLP-1), a novel type of glucose-lowering agent, has been reported to exert cardioprotective effects. However, the cardioprotective mechanism of GLP-1 on spontaneous hypertension-induced cardiac hypertrophy has not been fully elucidated. In this study, we revealed that liraglutide or alogliptin treatment ameliorated spontaneous hypertension-induced cardiac hypertrophy, as evidenced by decreased levels of cardiac hypertrophic markers (atrial natriuretic peptide, brain natriuretic peptide, and β-myosin heavy chain), as well as systolic blood pressure, diastolic blood pressure, mean arterial pressure, and histological changes. Both drugs significantly reduced the levels of angiotensin II (AngII) and AngII type 1 receptor (AT1R) and upregulated the levels of AngII type 2 receptor (AT2R) and angiotensin-converting enzyme 2 (ACE2), as indicated by a reduced AT1R/AT2R ratio. Simultaneously, treatment with liraglutide or alogliptin significantly increased GLP-1 receptor expression and adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and downregulated the phosphorylation of mammalian target of rapamycin (mTOR), p70 ribosomal S6 protein kinase, and eukaryotic translation initiation factor 4E binding protein 1 in spontaneous hypertension rats. Furthermore, our data demonstrated that the AMPK inhibitor compound C or mTOR activator MHY1485 inhibited the anti-hypertrophic effect of GLP-1. In summary, our study suggests that liraglutide or alogliptin protects the heart against cardiac hypertrophy by regulating the expression of AngII/AT1R/ACE2 and activating the AMPK/mTOR pathway, and GLP-1 agonist can be used in the treatment of patients with cardiac hypertrophy.
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Affiliation(s)
- Jing Wang
- Department of Cardiology, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Shanxi Medical University, Tongji Shanxi Hospital, Tongji Medical College, Huazhong University of Science and Technology, Taiyuan 030032, China
| | - Shaohua Fan
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Qianfeng Xiong
- Department of Cardiology, Fengcheng People’s Hospital, Fengcheng 331100, China
| | - Yu Niu
- Department of Cardiology, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Shanxi Medical University, Tongji Shanxi Hospital, Tongji Medical College, Huazhong University of Science and Technology, Taiyuan 030032, China
| | - Xin Zhang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Junnan Qin
- Department of Cardiology, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Shanxi Medical University, Tongji Shanxi Hospital, Tongji Medical College, Huazhong University of Science and Technology, Taiyuan 030032, China
| | - Yawei Shi
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Lihui Zhang
- Department of General Medical, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Shanxi Medical University, Tongji Shanxi Hospital, Tongji Medical College, Huazhong University of Science and Technology, Taiyuan 030032, China
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12
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Zummo FP, Krishnanda SI, Georgiou M, O'Harte FP, Parthsarathy V, Cullen KS, Honkanen-Scott M, Shaw JA, Lovat PE, Arden C. Exendin-4 stimulates autophagy in pancreatic β-cells via the RAPGEF/EPAC-Ca 2+-PPP3/calcineurin-TFEB axis. Autophagy 2021; 18:799-815. [PMID: 34338148 PMCID: PMC9037459 DOI: 10.1080/15548627.2021.1956123] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Macroautophagy/autophagy is critical for the regulation of pancreatic β-cell mass and its deregulation has been implicated in the pathogenesis of type 2 diabetes (T2D). We have previously shown that treatment of pancreatic β-cells with the GLP1R (glucagon like peptide 1 receptor) agonist exendin-4 stimulates autophagic flux in a setting of chronic nutrient excess. The aim of this study was to identify the underlying pathways contributing to enhanced autophagic flux. Pancreatic β-cells (INS-1E),mouse and human islets were treated with glucolipotoxic stress (0.5 mM palmitate and 25 mM glucose) in the presence of exendin-4. Consistent with our previous work, exendin-4 stimulated autophagic flux. Using chemical inhibitors and siRNA knockdown, we identified RAPGEF4/EPAC2 (Rap guanine nucleotide exchange factor 4) and downstream calcium signaling to be essential for regulation of autophagic flux by exendin-4. This pathway was independent of AMPK and MTOR signaling. Further analysis identified PPP3/calcineurin and its downstream regulator TFEB (transcription factor EB) as key proteins mediating exendin-4 induced autophagy. Importantly, inhibition of this pathway prevented exendin-4-mediated cell survival and overexpression of TFEB mimicked the cell protective effects of exendin-4 in INS-1E and human islets. Moreover, treatment of db/db mice with exendin-4 for 21 days increased the expression of lysosomal markers within the pancreatic islets. Collectively our data identify the RAPGEF4/EPAC2-calcium-PPP3/calcineurin-TFEB axis as a key mediator of autophagic flux, lysosomal function and cell survival in pancreatic β-cells. Pharmacological modulation of this axis may offer a novel therapeutic target for the treatment of T2D. Abbreviations: AKT1/protein kinase B: AKT serine/threonine kinase 1; AMPK: 5’ AMP-activated protein kinase; CAMKK: calcium/calmodulin-dependent protein kinase kinase; cAMP: cyclic adenosine monophosphate; CASP3: caspase 3; CREB: cAMP response element-binding protein; CTSD: cathepsin D; Ex4: exendin-4(1-39); GLP-1: glucagon like peptide 1; GLP1R: glucagon like peptide 1 receptor; GLT: glucolipotoxicity; INS: insulin; MTOR: mechanistic target of rapamycin kinase; NFAT: nuclear factor of activated T-cells; PPP3/calcineurin: protein phosphatase 3; PRKA/PKA: protein kinase cAMP activated; RAPGEF3/EPAC1: Rap guanine nucleotide exchange factor 3; RAPGEF4/EPAC2: Rap guanine nucleotide exchange factor 4; SQSTM1/p62: sequestosome 1; T2D: type 2 diabetes; TFEB: transcription factor EB
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Affiliation(s)
- Francesco P Zummo
- Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - Stanislaus I Krishnanda
- Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK.,Department of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Merilin Georgiou
- Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - Finbarr Pm O'Harte
- The SAAD Centre for Pharmacy & Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Vadivel Parthsarathy
- The SAAD Centre for Pharmacy & Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Kirsty S Cullen
- Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - Minna Honkanen-Scott
- Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - James Am Shaw
- Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - Penny E Lovat
- Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - Catherine Arden
- Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
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13
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Tong MQ, Luo LZ, Xue PP, Han YH, Wang LF, Zhuge DL, Yao Q, Chen B, Zhao YZ, Xu HL. Glucose-responsive hydrogel enhances the preventive effect of insulin and liraglutide on diabetic nephropathy of rats. Acta Biomater 2021; 122:111-132. [PMID: 33444802 DOI: 10.1016/j.actbio.2021.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/01/2021] [Accepted: 01/05/2021] [Indexed: 01/17/2023]
Abstract
Diabetic nephropathy (DN) is one of the most serious complications of diabetes mellitus. The combination of insulin (Ins) with liraglutide (Lir) has a greater potential for preventing DN than monotherapy. However, the renal protective effect of the combined Ins/Lir therapy is largely compromised due to their short half-lives after subcutaneous injection. Herein, a glucose-responsive hydrogel was designed in situ forming the dynamic boronic esters bonds between phenylboronic acid-grafted γ-Polyglutamic acid (PBA-PGA) and konjac glucomannan (KGM). It was hypothesized that the KGM/PBA-PGA hydrogel as the delivery vehicle of Ins/Lir would enhance the combinational effect of the latter on preventing the DN progress. Scan electronic microscopy and rheological studies showed that KGM/PBA-PGA hydrogel displayed good glucose-responsive property. Besides, the glucose-sensitive release profile of either Ins or Lir from KGM/PBA-PGA hydrogel was uniformly displayed at hyperglycemic level. Furthermore, the preventive efficacy of KGM/PBA-PGA hydrogel incorporating insulin and liraglutide (Ins/Lir-H) on DN progress was evaluated on streptozotocin-induced rats with diabetic mellitus (DM). At 6 weeks after subcutaneous injection of Ins/Lir-H, not only the morphology of kidneys was obviously recovered as shown by ultrasonography, but also the renal hemodynamics was significantly improved. Meanwhile, the 24-h urinary protein and albumin/creatinine ratio were well modulated. Inflammation and fibrosis were also largely inhibited. Besides, the glomerular NPHS-2 was obviously elevated after treatment with Ins/Lir-H. The therapeutic mechanism of Ins/Lir-H was highly associated with the alleviation of oxidative stress and activation of autophagy. Conclusively, the better preventive effect of the combined Ins/Lir via KGM/PBA-PGA hydrogel on DN progress was demonstrated as compared with their mixed solution, suggesting KGM/PBA-PGA hydrogel might be a potential vehicle of Ins/Lir to combat the progression of DN.
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14
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Liu J, Li X, Lu S, Zheng X, Zhang X, Zhao W. Glucagon-like peptide-1 (GLP-1) improved diabetic lung fibrosis via AMPK and microRNA-27a (miR-27a). ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:492. [PMID: 33850889 PMCID: PMC8039657 DOI: 10.21037/atm-21-869] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Background Extracellular matrix proliferation is an issue which leads to lung tissue damage in diabetes mellitus. Glucagon-like peptide-1 (GLP-1) analogues can improve the proliferation of extracellular matrix in diabetic pulmonary disease. In this study, we investigated the effect of GLP-1 on pulmonary fibrosis through the AMPK/microRNA-27a (miR-27a) pathway. Methods Human embryonic lung fibroblast (MRC-5) cells were cultured with a high-glucose medium, and were treated with miR-27a inhibitor, GLP-1 analogues, and AMPK inhibitor. Cell Counting Kit-8 (CCK-8) detected the proliferation of MRC-5 cells. The fibrosis-related genes were analyzed, including Col-IV, fibronectin, NF-κB p65, α-SMA, and TGF-β1. Bioinformatics and dual-luciferase reporter assays were used to identify the targets for miR-27a. Results Compared with the control group, the expression of miR-27a in the hyperglycemic group was significantly up-regulated (P<0.01) and the expression of peroxisome proliferator-activated receptor γ (PPARγ) significantly down-regulated (P<0.01). The expression of Col-IV, fibronectin, NF-κB p65, α-SMA and TGF-β1 increased significantly (P<0.01). The expression level of apoptosis factor caspase-3 decreased significantly (P<0.01). MiR-27a inhibitor could reverse the expression of these proteins. The effect of GLP-1 on miR-27a was time- and concentration-dependent. After pretreating MRC-5 cells via GLP-1, with or without compound C (AMPK inhibitor), the expression of miR-27a in the GLP-1 treated group was significantly lower than that in Vehicle group. The expression of miR-27a was increased after inhibition of the AMPK pathway. A predictive TargetScan algorithm showed that the PPARγ gene was a potential target of miR-27a. MiR-27a was also shown to target 3'-UTR of PPARγ. Conclusions MiR-27a plays an important regulatory role in diabetic pulmonary fibrosis. GLP-1 could down-regulate the expression level of miR-27a by activating AMPK. Furthermore, the target gene PPARγ was up-regulated, consequently improving extracellular matrix proliferation in MRC-5 cells.
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Affiliation(s)
- Jia Liu
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, China
| | - Xiaoyu Li
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, China
| | - Shan Lu
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, China
| | - Xiao Zheng
- Wuhan Puren Hospital Affiliated Medical College of Wuhan University of Science and Technology, Clinical of Endocrinology and Metabolism, Wuhan, China
| | - Xiaohui Zhang
- Department of Nutrition, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Wei Zhao
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, China
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15
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Yao M, Zhang J, Li Z, Bai X, Ma J, Li Y. Liraglutide Protects Nucleus Pulposus Cells Against High-Glucose Induced Apoptosis by Activating PI3K/Akt/ mTOR/Caspase-3 and PI3K/Akt/GSK3β/Caspase-3 Signaling Pathways. Front Med (Lausanne) 2021; 8:630962. [PMID: 33681258 PMCID: PMC7933515 DOI: 10.3389/fmed.2021.630962] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/25/2021] [Indexed: 12/11/2022] Open
Abstract
Background and Objective: Diabetes mellitus (DM) is reportedly a significant risk factor for intervertebral disc degeneration (IDD). Incretin system and particularly glucagon-like peptide 1 (GLP-1) because of its glucose-lowering effects has become an important target in therapeutic strategies of type 2 diabetes (T2D). Liraglutide is a GLP-1 receptor (GLP-1R) agonist with glucoregulatory and insulinotropic functions as well as regulatory functions on cell proliferation, differentiation, and apoptosis. However, little is known on the roles and signaling pathways of apoptosis protecting effects of liraglutide in IDD. This study aimed to investigate the potential protective effects of liraglutide against high glucose-induced apoptosis of nucleus pulposus cells (NPCs) and the possible involved signaling pathways. Methods: The human NPCs were incubated with 100 nM liraglutide alone or in combination with LY294002 (PI3K inhibitor), rapamycin (mTOR inhibitor), and SB216763 (GSK3β inhibitor) in a high glucose culture for 48 h. The four groups were assessed further for apoptosis and genes expressions. The apoptotic effect was evaluated by flow cytometry and further confirmed by cell death detection enzyme-linked immunoassay plus (ELISAPLUS). The gene and protein expression levels were assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting techniques. The results were comparatively assessed between the four groups. Results: The results confirmed the presence of GLP-1R in the NPCs indicating that liraglutide inhibited the high glucose-induced apoptosis, which was blocked by silencing GLP-1R with siRNA. Moreover, liraglutide stimulated the phosphorylation of Akt, mTOR and GSK3β. Treatment with LY294002 significantly increased the apoptosis of NPCs and reduced the levels of their downstream substrates (p-AKT, p-mTOR, and p-GSK3β). Further assessments revealed that activation of mTOR and GSK3β was almost completely inhibited by rapamycin and SB216763, respectively, which significantly increased the caspase-3 levels. Conclusion: Liraglutide could protect NPCs against high glucose-induced apoptosis by activating the PI3K/AKT/mTOR/caspase-3 and PI3K/AKT/GSK3β/caspase-3 signaling pathways.
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Affiliation(s)
- Mingyan Yao
- Department of Endocrinology, The Third Hospital of Hebei Medical University, Shijiazhuang, China.,Department of Endocrinology, Baoding No.1 Central Hospital, Baoding, China
| | - Jing Zhang
- Department of Cardiology, Affiliated Hospital of Hebei University, Baoding, China
| | - Zhihong Li
- Department of Endocrinology, Baoding No.1 Central Hospital, Baoding, China
| | - Xiaoliang Bai
- Department of Orthopedics, Baoding No.1 Central Hospital, Baoding, China
| | - Jinhui Ma
- Department of Endocrinology, Affiliated Hospital of Hebei University, Baoding, China
| | - Yukun Li
- Department of Endocrinology, The Third Hospital of Hebei Medical University, Shijiazhuang, China
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16
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Wu H, Xiao C, Zhao Y, Yin H, Yu M. Liraglutide Improves Endothelial Function via the mTOR Signaling Pathway. J Diabetes Res 2021; 2021:2936667. [PMID: 34447854 PMCID: PMC8384515 DOI: 10.1155/2021/2936667] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 07/28/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Mammalian target of rapamycin (mTOR) is crucial for endothelial function. This study is aimed at assessing whether the glucagon-like peptide-1 (GLP-1) analogue liraglutide has a protective effect on endothelial function via the mTOR signaling pathway. METHODS Human umbilical vein endothelial cells (HUVECs) were administered liraglutide (100 nM) for 0, 10, 30, 60, 720, and 1440 minutes, respectively. Then, the expression and phosphorylation levels of mTOR, mTOR-Raptor complex (mTORC1), and mTOR-Rictor complex (mTORC2) were determined by Western blot and immunoprecipitation, while mTORC1 and mTORC2 expression was blocked by siRNA-Raptor and siRNA-Rictor, respectively. Akt phosphorylation was detected by Western blot. HUVECs were then incubated with liraglutide in the absence or presence of Akt inhibitor IV. Nitric oxide (NO) release was assessed by the nitrate reductase method. Phosphorylated endothelial nitric oxide synthase (eNOS), human telomerase reverse transcriptase (hTERT), and apoptosis-related effectors were assessed for protein levels by Western blot. Telomerase activity was evaluated by ELISA. RESULTS Sustained mTOR phosphorylation, mTORC2 formation, and mTORC2-dependent Akt phosphorylation were induced by liraglutide. In addition, eNOS phosphorylation, NO production, nuclear hTERT accumulation, and nuclear telomerase activity were enhanced by mTORC2-mediated Akt activation. Liraglutide also showed an antiapoptotic effect by upregulating antiapoptotic proteins and downregulating proapoptotic proteins in an mTORC2-Akt activation-dependent manner. CONCLUSION Liraglutide significantly improves endothelial function, at least partially via the mTORC2/Akt signaling pathway.
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Affiliation(s)
- Han Wu
- Department of Endocrinology, Key Laboratory of Endocrinology, National Health Commission, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Cheng Xiao
- Department of Endocrinology, Key Laboratory of Endocrinology, National Health Commission, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Yiting Zhao
- Department of PET-CT Center, Cancer Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100021, China
| | - Hongchao Yin
- Department of Pathology, Institute of Basic Medical Sciences, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Miao Yu
- Department of Endocrinology, Key Laboratory of Endocrinology, National Health Commission, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
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17
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Hu R, Yuan Y, Liu C, Zhou J, Ji L, Jiang G. New insights into the links between anti-diabetes drugs and gut microbiota. Endocr Connect 2021; 10:R36-R42. [PMID: 33338029 PMCID: PMC7923145 DOI: 10.1530/ec-20-0431] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 12/17/2020] [Indexed: 12/29/2022]
Abstract
In patients with type 2 diabetes mellitus (T2DM), the intestinal flora is out of balance and accompanied by leaky gut. The flora is characterized by an increase in mucus-degrading bacteria and a decrease in fiber-degrading bacteria. Short-chain fatty acids (SCFAs), as the major fiber-degrading bacteria fermentation, not only ameliorate the leaky gut, but also activate GPR43 to increase the mass of functional pancreatic β-cells and exert anti-inflammation effect. At present, the gut microbiota is considered as the potential target for anti-diabetes drugs, and how to reverse the imbalance of gut microbiota has become a therapeutic strategy for T2DM. This review briefly summarizes the drugs or compounds that have direct or potential therapeutic effects on T2DM by modulating the gut microbiota, including biguanides, isoquinoline alkaloids, stilbene and C7N-aminocyclic alcohols.
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Affiliation(s)
- Ruixin Hu
- School of pharmacy, Qing Dao University, Qingdao, China
| | - Yanting Yuan
- School of pharmacy, Qing Dao University, Qingdao, China
| | - Chaolong Liu
- School of pharmacy, Qing Dao University, Qingdao, China
| | - Ji Zhou
- School of pharmacy, Qing Dao University, Qingdao, China
| | - Lixia Ji
- School of pharmacy, Qing Dao University, Qingdao, China
- Correspondence should be addressed to L Ji or G Jiang : or
| | - Guohui Jiang
- School of pharmacy, Qing Dao University, Qingdao, China
- Correspondence should be addressed to L Ji or G Jiang : or
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18
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Goenka V, Borkar T, Desai A, Das RK. Therapeutic potential of mesenchymal stem cells in treating both types of diabetes mellitus and associated diseases. J Diabetes Metab Disord 2020; 19:1979-1993. [PMID: 33520872 PMCID: PMC7843693 DOI: 10.1007/s40200-020-00647-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 09/24/2020] [Indexed: 10/23/2022]
Abstract
Diabetes mellitus is a common lifestyle disease which can be classified into type 1 diabetes mellitus and type 2 diabetes mellitus. While both result in hyperglycemia due to lack of insulin action and further associated chronic ailments, there is a marked distinction in the cause for each type due to which both require a different prophylaxis. As observed, type 1 diabetes is caused due to the autoimmune action of the body resulting in the destruction of pancreatic islet cells. On the other hand, type 2 diabetes is caused either due to insulin resistance of target cells or lack of insulin production as per physiological requirements. Attempts to cure the disease have been made by bringing drastic changes in the patients' lifestyle; parenteral administration of insulin; prescription of drugs such as biguanides, meglitinides, and amylin; pancreatic transplantation; and immunotherapy. While these attempts cause a certain degree of relief to the patient, none of these can cure diabetes mellitus. However, a new treatment strategy led by the discovery of mesenchymal stem cells and their unique immunomodulatory and multipotent properties has inspired therapies to treat diabetes by essentially reversing the conditions causing the disease. The current review aims to enumerate the role of various mesenchymal stem cells and the different approaches to treat both types of diabetes and its associated diseases as well.
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Affiliation(s)
- Vidul Goenka
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu India
| | - Tanhai Borkar
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu India
| | - Aska Desai
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu India
| | - Raunak Kumar Das
- Centre for Biomaterials, Cellular and Molecular Theranostics, Vellore Institute of Technology, Vellore, Tamil Nadu India
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19
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Maiese K. Dysregulation of metabolic flexibility: The impact of mTOR on autophagy in neurodegenerative disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2020; 155:1-35. [PMID: 32854851 DOI: 10.1016/bs.irn.2020.01.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Non-communicable diseases (NCDs) that involve neurodegenerative disorders and metabolic disease impact over 400 million individuals globally. Interestingly, metabolic disorders, such as diabetes mellitus, are significant risk factors for the development of neurodegenerative diseases. Given that current therapies for these NCDs address symptomatic care, new avenues of discovery are required to offer treatments that affect disease progression. Innovative strategies that fill this void involve the mechanistic target of rapamycin (mTOR) and its associated pathways of mTOR complex 1 (mTORC1), mTOR complex 2 (mTORC2), AMP activated protein kinase (AMPK), trophic factors that include erythropoietin (EPO), and the programmed cell death pathways of autophagy and apoptosis. These pathways are intriguing in their potential to provide effective care for metabolic and neurodegenerative disorders. Yet, future work is necessary to fully comprehend the entire breadth of the mTOR pathways that can effectively and safely translate treatments to clinical medicine without the development of unexpected clinical disabilities.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, New York, NY, United States.
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20
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Daneshjou D, Zadeh Modarres S, Soleimani Mehranjani M, Shariat Zadeh SMA. Comparing the effect of sitagliptin and metformin on the oocyte and embryo quality in classic PCOS patients undergoing ICSI. Ir J Med Sci 2020; 190:685-692. [PMID: 32720198 DOI: 10.1007/s11845-020-02320-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/17/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Insulin resistance plays a major role in the pathogenesis of polycystic ovary syndrome (PCOS). Therefore, there is a growing interest in the use of insulin sensitizer drugs in the treatment of PCOS. Research in recent years has shown that sitagliptin has been reported to improve ovarian cycles and ovulation in PCOS patients. AIMS We aimed to compare the effects of metformin and sitagliptin on PCOS individuals undergoing ICSI. METHODS Sixty PCOS patients were divided into 3 groups: metformin, sitagliptin, and placebo group. Treatment was carried out 2 months before the start of the ovulation cycle and continued until the day of oocyte aspiration. The serum levels of total testosterone, estradiol, and fasting insulin along with the total number of retrieved, normal and abnormal MII, and fertilized oocytes, the number of transferred embryos (grades I, II and III), and biochemical and clinical pregnancy rates as well as the ovarian hyperstimulation syndrome (OHSS) were evaluated. RESULTS There was a significant reduction in the serum levels of Insulin and total testosterone in the treated groups compared with the placebo. The number of mature and normal MII oocytes increased significantly in the treated groups compared with the placebo. Moreover, the number of immature oocytes decreased significantly and the number of grade I embryos increases significantly in the sitagliptin group compared with the placebo group. CONCLUSION We conclude that sitagliptin can improve the maturation of oocytes and embryos' quality more effectively than metformin, in PCOS patients undergoing ICSI. TRIAL REGISTRATION Trial registration is NCT04268563 ( https://clinicaltrials.gov ).
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Affiliation(s)
- Delbar Daneshjou
- Department of Biologyt, Faculty of Science, Arak University, Arak, Iran
| | - Shahrzad Zadeh Modarres
- Men's Health and Reproductive Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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21
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Abstract
Metabolic disorders, such as diabetes mellitus (DM), are increasingly becoming significant risk factors for the health of the global population and consume substantial portions of the gross domestic product of all nations. Although conventional therapies that include early diagnosis, nutritional modification of diet, and pharmacological treatments may limit disease progression, tight serum glucose control cannot prevent the onset of future disease complications. With these concerns, novel strategies for the treatment of metabolic disorders that involve the vitamin nicotinamide, the mechanistic target of rapamycin (mTOR), mTOR Complex 1 (mTORC1), mTOR Complex 2 (mTORC2), AMP activated protein kinase (AMPK), and the cellular pathways of autophagy and apoptosis offer exceptional promise to provide new avenues of treatment. Oversight of these pathways can promote cellular energy homeostasis, maintain mitochondrial function, improve glucose utilization, and preserve pancreatic beta-cell function. Yet, the interplay among mTOR, AMPK, and autophagy pathways can be complex and affect desired clinical outcomes, necessitating further investigations to provide efficacious treatment strategies for metabolic dysfunction and DM.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, New York, New York 10022,
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22
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Wang W, Wu RD, Chen P, Xu XJ, Shi XZ, Huang LH, Shao ZL, Guo W. Liraglutide combined with human umbilical cord mesenchymal stem cell transplantation inhibits beta-cell apoptosis via mediating the ASK1/JNK/BAX pathway in rats with type 2 diabetes. Diabetes Metab Res Rev 2020; 36:e3212. [PMID: 31411368 DOI: 10.1002/dmrr.3212] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 06/15/2019] [Accepted: 08/09/2019] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Accumulating evidence suggests an association between beta-cell apoptosis and the ASK1/JNK/BAX pathway. The aim of this study was to investigate the effects of a combined therapy of liraglutide and human umbilical cord mesenchymal stem cells (hUC-MSCs) on the glucose metabolism and islet beta-cell apoptosis, and further explore its relationship to the ASK1/JNK/BAX pathway. METHOD Type 2 diabetes mellitus (T2DM) rat model was induced by a high-sugar and high-fat diet and intraperitoneal injection of low-dose streptozotocin (STZ) (30 mg/kg). Three days after STZ injection, diabetic rats were randomly treated with subcutaneous injection of liraglutide (200 μg/kg/12 h) for 8 weeks and or hUC-MSCs (1 × 106 /rat) at the first and fifth weeks. Diabetes-related physical and biochemical parameters, pancreatic histopathological changes, immunohistochemical staining, quantitative real-time polymerase chain reaction, and western blot were used to measure the expression of apoptosis signal-regulating kinase 1 (ASK1), Jun N-terminal kinase (JNK), Bcl-2 associated X protein (BAX), and B-cell lymphoma-2 (Bcl-2). RESULTS Eight weeks after liraglutide or human umbilical cord mesenchymal stem cell administration, FPG, HbA1c , glucagon, body weight, and pancreatic ASK1, JNK, and BAX mRNA and proteins were significantly decreased, and the levels of serum C-p, INS and GLP-1, ratio of insulin positive area, and Bcl-2 expression were significantly increased in three treatment groups compared with T2DM group (P<.05). CONCLUSION Liraglutide combined with hUC-MSCs improve glucose metabolism and inhibit islet beta-cell apoptosis in a ASK1/JNK/BAX pathway-dependent manner.
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Affiliation(s)
- Wei Wang
- Fuzong Clinical Medical College, Fujian Medical University, Fuzhou, China
- Department of Endocrinology, Fuzhou General Hospital, Fuzhou, China
| | - Rong Dan Wu
- Fuzong Clinical Medical College, Fujian Medical University, Fuzhou, China
- Department of Endocrinology, Fuzhou General Hospital, Fuzhou, China
| | - Pin Chen
- Fuzong Clinical Medical College, Fujian Medical University, Fuzhou, China
- Department of Endocrinology, Fuzhou General Hospital, Fuzhou, China
| | - Xiang Jin Xu
- Fuzong Clinical Medical College, Fujian Medical University, Fuzhou, China
- Department of Endocrinology, Fuzhou General Hospital, Fuzhou, China
| | - Xiao Zhi Shi
- Fuzong Clinical Medical College, Fujian Medical University, Fuzhou, China
- Department of Endocrinology, Fuzhou General Hospital, Fuzhou, China
| | - Li Hong Huang
- Fuzong Clinical Medical College, Fujian Medical University, Fuzhou, China
- Department of Endocrinology, Fuzhou General Hospital, Fuzhou, China
| | - Zhu Lin Shao
- Department of Endocrinology, Fuzhou General Hospital, Fuzhou, China
| | - Wen Guo
- Department of Endocrinology, Fuzhou General Hospital, Fuzhou, China
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23
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Nauck MA. The rollercoaster history of using physiological and pharmacological properties of incretin hormones to develop diabetes medications with a convincing benefit-risk relationship. Metabolism 2020; 103:154031. [PMID: 31785258 DOI: 10.1016/j.metabol.2019.154031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 11/15/2019] [Accepted: 11/25/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Michael A Nauck
- Diabetes Division, Katholisches Klinikum Bochum, St. Josef Hospital (Ruhr-University Bochum), Gudrunstr. 56, 44791 Bochum, Germany.
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24
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Maiese K. Cognitive impairment with diabetes mellitus and metabolic disease: innovative insights with the mechanistic target of rapamycin and circadian clock gene pathways. Expert Rev Clin Pharmacol 2020; 13:23-34. [PMID: 31794280 PMCID: PMC6959472 DOI: 10.1080/17512433.2020.1698288] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/25/2019] [Indexed: 12/18/2022]
Abstract
Introduction: Dementia is the 7th leading cause of death that imposes a significant financial and service burden on the global population. Presently, only symptomatic care exists for cognitive loss, such as Alzheimer's disease.Areas covered: Given the advancing age of the global population, it becomes imperative to develop innovative therapeutic strategies for cognitive loss. New studies provide insight to the association of cognitive loss with metabolic disorders, such as diabetes mellitus.Expert opinion: Diabetes mellitus is increasing in incidence throughout the world and affects 350 million individuals. Treatment strategies identifying novel pathways that oversee metabolic and neurodegenerative disorders offer exciting prospects to treat dementia. The mechanistic target of rapamycin (mTOR) and circadian clock gene pathways that include AMP activated protein kinase (AMPK), Wnt1 inducible signaling pathway protein 1 (WISP1), erythropoietin (EPO), and silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1) provide novel strategies to treat cognitive loss that has its basis in metabolic cellular dysfunction. However, these pathways are complex and require precise regulation to maximize treatment efficacy and minimize any potential clinical disability. Further investigations hold great promise to treat both the onset and progression of cognitive loss that is associated with metabolic disease.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, New York, New York 10022
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25
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Maiese K. Nicotinamide: Oversight of Metabolic Dysfunction Through SIRT1, mTOR, and Clock Genes. Curr Neurovasc Res 2020; 17:765-783. [PMID: 33183203 PMCID: PMC7914159 DOI: 10.2174/1567202617999201111195232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/24/2020] [Accepted: 10/27/2020] [Indexed: 12/13/2022]
Abstract
Metabolic disorders that include diabetes mellitus present significant challenges for maintaining the welfare of the global population. Metabolic diseases impact all systems of the body and despite current therapies that offer some protection through tight serum glucose control, ultimately such treatments cannot block the progression of disability and death realized with metabolic disorders. As a result, novel therapeutic avenues are critical for further development to address these concerns. An innovative strategy involves the vitamin nicotinamide and the pathways associated with the silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), the mechanistic target of rapamycin (mTOR), mTOR Complex 1 (mTORC1), mTOR Complex 2 (mTORC2), AMP activated protein kinase (AMPK), and clock genes. Nicotinamide maintains an intimate relationship with these pathways to oversee metabolic disease and improve glucose utilization, limit mitochondrial dysfunction, block oxidative stress, potentially function as antiviral therapy, and foster cellular survival through mechanisms involving autophagy. However, the pathways of nicotinamide, SIRT1, mTOR, AMPK, and clock genes are complex and involve feedback pathways as well as trophic factors such as erythropoietin that require a careful balance to ensure metabolic homeostasis. Future work is warranted to gain additional insight into these vital pathways that can oversee both normal metabolic physiology and metabolic disease.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, New York, New York 10022
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26
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Xue L, Pan Z, Yin Q, Zhang P, Zhang J, Qi W. Liraglutide promotes autophagy by regulating the AMPK/mTOR pathway in a rat remnant kidney model of chronic renal failure. Int Urol Nephrol 2019; 51:2305-2313. [PMID: 31531806 DOI: 10.1007/s11255-019-02274-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 08/29/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND We aimed to determine whether the glucagon-like peptide-1 receptor (GLP-1R) agonist liraglutide (LRG) could ameliorate renal function through promoting autophagy via regulating the AMPK/mTOR pathway in a rat remnant kidney model of chronic renal failure. METHODS Rats were divided into four groups (n = 10 per group) as follows: (1) sham, (2) nephrectomy (NPX), (3) LRG control (LRG control), and (4) LRG treatment (LRG). Except for rats in the sham group, all rats underwent 5/6 nephrectomy surgery to establish a remnant kidney model of chronic renal failure. In addition, rats in LRG group received LRG as a subcutaneous injection at a dose of 10 mg/kg (once daily) for 4 consecutive weeks, whereas rats in the LRG control group received treatment similar to that of rats in the LRG group, except saline was used instead of LRG. After 4 weeks of treatment, serum creatinine (Scr), blood urea nitrogen (BUN), and urinary albumin excretion were determined. Immunofluorescence assay, immunoprecipitation assay, and Western blot analysis were performed to evaluate the AMPK/mTOR pathway expression of proteins. RESULTS Nephrectomized rats (including rats in the NPX, LRG control, and LRG groups) showed higher levels of the Scr, BUN, and urinary albumin excretion, as well as down-regulation of GLP-1R, LC3-II, and AMPK phosphorylation, and up-regulation of mTOR phosphorylation when compared with rats in the sham group. However, those changes were blocked by liraglutide. CONCLUSION Liraglutide may promote autophagy through regulating the AMPK/mTOR pathway to exert renoprotective effects in a rat remnant kidney model of chronic renal failure.
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Affiliation(s)
- Lingyu Xue
- Department of Nephrology, The Second Affiliated Hospital of Shandong First Medical University, No. 706, Taishan Street, Taian, 271000, Shandong, China.
| | - Zhanglei Pan
- Department of Nephrology, The Second Affiliated Hospital of Shandong First Medical University, No. 706, Taishan Street, Taian, 271000, Shandong, China
| | - Qiao Yin
- Department of Nephrology, The Second Affiliated Hospital of Shandong First Medical University, No. 706, Taishan Street, Taian, 271000, Shandong, China
| | - Peng Zhang
- Department of Nephrology, The Second Affiliated Hospital of Shandong First Medical University, No. 706, Taishan Street, Taian, 271000, Shandong, China
| | - Jing Zhang
- Department of Nephrology, The Second Affiliated Hospital of Shandong First Medical University, No. 706, Taishan Street, Taian, 271000, Shandong, China
| | - Wenwen Qi
- Department of Nephrology, The Second Affiliated Hospital of Shandong First Medical University, No. 706, Taishan Street, Taian, 271000, Shandong, China
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Dutta D, Kalra S, Sharma M. Adenosine monophosphate-activated protein kinase-based classification of diabetes pharmacotherapy. J Postgrad Med 2019; 63:114-121. [PMID: 27652986 PMCID: PMC5414421 DOI: 10.4103/0022-3859.191007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The current classification of both diabetes and antidiabetes medication is complex, preventing a treating physician from choosing the most appropriate treatment for an individual patient, sometimes resulting in patient-drug mismatch. We propose a novel, simple systematic classification of drugs, based on their effect on adenosine monophosphate-activated protein kinase (AMPK). AMPK is the master regular of energy metabolism, an energy sensor, activated when cellular energy levels are low, resulting in activation of catabolic process, and inactivation of anabolic process, having a beneficial effect on glycemia in diabetes. This listing of drugs makes it easier for students and practitioners to analyze drug profiles and match them with patient requirements. It also facilitates choice of rational combinations, with complementary modes of action. Drugs are classified as stimulators, inhibitors, mixed action, possible action, and no action on AMPK activity. Metformin and glitazones are pure stimulators of AMPK. Incretin-based therapies have a mixed action on AMPK. Sulfonylureas either inhibit AMPK or have no effect on AMPK. Glycemic efficacy of alpha-glucosidase inhibitors, sodium glucose co-transporter-2 inhibitor, colesevelam, and bromocriptine may also involve AMPK activation, which warrants further evaluation. Berberine, salicylates, and resveratrol are newer promising agents in the management of diabetes, having well-documented evidence of AMPK stimulation medicated glycemic efficacy. Hence, AMPK-based classification of antidiabetes medications provides a holistic unifying understanding of pharmacotherapy in diabetes. This classification is flexible with a scope for inclusion of promising agents of future.
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Affiliation(s)
- D Dutta
- Department of Endocrinology, Post-graduate Institute of Medical Education and Research and Dr. Ram Manohar Lohia Hospital, New Delhi, India
| | - S Kalra
- Department of Endocrinology, Bharti Hospital and BRIDE, Karnal, Haryana, India
| | - M Sharma
- Department of Rheumatology, King George's Medical University, Lucknow, Uttar Pradesh, India
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28
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Tomas A, Jones B, Leech C. New Insights into Beta-Cell GLP-1 Receptor and cAMP Signaling. J Mol Biol 2019; 432:1347-1366. [PMID: 31446075 DOI: 10.1016/j.jmb.2019.08.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 08/06/2019] [Accepted: 08/13/2019] [Indexed: 12/14/2022]
Abstract
Harnessing the translational potential of the GLP-1/GLP-1R system in pancreatic beta cells has led to the development of established GLP-1R-based therapies for the long-term preservation of beta cell function. In this review, we discuss recent advances in the current research on the GLP-1/GLP-1R system in beta cells, including the regulation of signaling by endocytic trafficking as well as the application of concepts such as signal bias, allosteric modulation, dual agonism, polymorphic receptor variants, spatial compartmentalization of cAMP signaling and new downstream signaling targets involved in the control of beta cell function.
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Affiliation(s)
- Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 0NN, UK.
| | - Ben Jones
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 0NN, UK
| | - Colin Leech
- Department of Surgery, State University of New York, Upstate Medical University, Syracuse, NY, 13210, USA
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29
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Wang J, Wang X, Li ZZ, Guo F, Ding CZ, Zhao YY, Liu YL, Ma XJ, Li C, Wu LN, Qin Q, Zhao SY, Zhao D, Hao X, Wang SJ, Qin GJ. The apoptosis and GLP-1 hyposecretion induced by LPS via RIP/ROS/mTOR pathway in GLUTag cells. Biochimie 2019; 162:229-238. [DOI: 10.1016/j.biochi.2019.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 04/01/2019] [Indexed: 01/31/2023]
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30
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Ding M, Fang QH, Cui YT, Shen QL, Liu Q, Wang PH, Yu DM, Li CJ. Liraglutide prevents β-cell apoptosis via inactivation of NOX2 and its related signaling pathway. J Diabetes Complications 2019; 33:267-277. [PMID: 30772113 DOI: 10.1016/j.jdiacomp.2018.12.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 11/20/2018] [Accepted: 12/26/2018] [Indexed: 01/01/2023]
Abstract
AIMS High glucose (HG)-induced pancreatic β-cell apoptosis may be a major contributor to the progression of diabetes mellitus (DM). NADPH oxidase (NOX2) has been considered a crucial regulator in β-cell apoptosis. This study was designed to evaluate the impact of GLP-1 receptor agonist (GLP-1Ra) liraglutide on pancreatic β-cell apoptosis in diabetes and the underlying mechanisms involved. METHODS The diabetic rat models induced by streptozotocin (STZ) and a high fat diet (HFD) received 12 weeks of liraglutide treatment. Hyperglycemic clamp test was carried out to evaluate β-cell function in vivo. Flow cytometry analysis was used to measure apoptosis rates in vitro. DCFH-DA method was used to detected ROS level in vivo and in vitro. RESULTS Liraglutide significantly improved islet function and morphology in diabetic rats and decreased cell apoptosis rates. Thr183/Thr185 p-JNK1/2 and NOX2 levels reduced in diabetic rats and HG-induced INS-1 cell following liraglutide treatment. In addition, liraglutide upregulated the phosphorylation of AMPKα (p-AMPKα), which prevented NOX2 activation and alleviated HG-induced β-cell apoptosis. CONCLUSION The p-AMPKα/NOX2/JNK1/2 pathway is essential for liraglutide to attenuate HG-induced β-cell apoptosis, which further proves that GLP-1Ras may become promising therapeutics for diabetes mellitus.
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Affiliation(s)
- Min Ding
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Qian-Hua Fang
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Yuan-Tao Cui
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Qi-Ling Shen
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Qian Liu
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Peng-Hua Wang
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - De-Min Yu
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China.
| | - Chun-Jun Li
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China.
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31
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Dos Santos JM, Tewari S, Mendes RH. The Role of Oxidative Stress in the Development of Diabetes Mellitus and Its Complications. J Diabetes Res 2019; 2019:4189813. [PMID: 31192263 PMCID: PMC6525877 DOI: 10.1155/2019/4189813] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 04/11/2019] [Indexed: 01/01/2023] Open
Affiliation(s)
- Julia M. Dos Santos
- School of Education, Health and Human Performance, Fairmont State University, West Virginia, USA
- Henry Ford College, Dearborn, Michigan, USA
| | - Shikha Tewari
- Department of Pathology, King George Medical University, Lucknow, India
| | - Roberta H. Mendes
- UCD School of Agriculture and Food Science Institute of Food and Health, University College Dublin, Belfield, Dublin 4, Ireland
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Zhang Z, Hu Y, Xu N, Zhou W, Yang L, Chen R, Yang R, Sun J, Chen H. A New Way for Beta Cell Neogenesis: Transdifferentiation from Alpha Cells Induced by Glucagon-Like Peptide 1. J Diabetes Res 2019; 2019:2583047. [PMID: 31001561 PMCID: PMC6436340 DOI: 10.1155/2019/2583047] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 11/14/2018] [Accepted: 11/21/2018] [Indexed: 12/17/2022] Open
Abstract
Recent studies showed that alpha cells, especially immature cells and proalpha cells, might be the precursors of beta cells. Exposure to glucagon-like peptide 1 (GLP1) can ameliorate hyperglycemia in diabetic mice and restore the beta cell mass. In the present study, we adopted single high-dose (60 mg/kg, i.p.) streptozotocin (STZ) to model diabetes mellitus (DM) and randomly assigned short-tail (SD) rats to a normal group, a diabetic group, GLP1 groups (50 μg/kg, 100 μg/kg, and 200 μg/kg), a GLP1 (200 μg/kg) with exendin (9-39) group, and a GLP1 with LY294002 group. We found that the pancreatic insulin-glucagon-positive cell populations increased according to the increase in GLP1 exposure. By contrast, no insulin-amylase-positive cell populations or insulin/pan-cytokeratin cells were observed in the pancreatic sections. The GLP1 receptor antagonist exendin (9-39) and the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) family inhibitor LY294002 not only suppressed protein kinase B (Akt), pancreatic and duodenal homeobox 1 (Pdx1), forkhead box O 1 (FoxO1), and mast cell function-associated antigen A (MafA) mRNA expression but also increased MAFB expression. We concluded that treatment with GLP1 might result in beta cell neogenesis by promoting the transdifferentiation of alpha cells but not by pancreatic acinar cells, ductal cells, or the self-replication of beta cells. The regulation on the GLP1 receptor and its downstream transcription factor PI3K/AKT/FOXO1 pathway, which causes increased pancreatic and duodenal homeobox 1 (Pdx1) and MafA mRNA expression but causes decreased MAFB expression, may be the mechanism involved in this process.
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Affiliation(s)
- Zhen Zhang
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yinghui Hu
- Department of International Medical Center, The First Affiliated Hospital of Xi'an Jiaotong University, Shangxi, China
| | - Ningning Xu
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Wenjun Zhou
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Lei Yang
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Rongping Chen
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Rui Yang
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jia Sun
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Hong Chen
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
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SAD-A, a downstream mediator of GLP-1 signaling, promotes the phosphorylation of Bad S155 to regulate in vitro β-cell functions. Biochem Biophys Res Commun 2018; 509:76-81. [PMID: 30573363 DOI: 10.1016/j.bbrc.2018.12.063] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 12/07/2018] [Indexed: 12/12/2022]
Abstract
The incretin hormone GLP-1 reduces β-cell failure in patients with type 2 diabetes. Previous studies demonstrated that GLP-1 activates SAD-A, a member of the AMPK family, to regulate glucose-stimulated secretion (GSIS), but the underlying mechanisms of SAD-A regulation of β-cell functions remain poorly understood. Here, we propose that activation of SAD-A by GLP-1 promotes the phosphorylation of Bad S155, which in turn positively affects GSIS and β-cell survival. Bad therefore appears to be a downstream molecule of a SAD-A pathway that mediates the GLP-1-triggered reduction in β-cell failure. Knockdown of endogenous SAD-A expression significantly exacerbated in vitro β-cell dysfunction under lipotoxic conditions and promoted lipotoxicity-induced apoptosis, whereas overexpression of SAD-A inhibited β-cell apoptosis. SAD-A silencing increased ER stress and inhibited the autophagic flux, which contributed to β-cell apoptosis. Thus, SAD-A appears to function as a downstream molecule of GLP-1 signaling that results in Bad S155 phosphorylation. This phosphorylation might therefore be involved in the GLP-1-linked protection against β-cell dysfunction and apoptosis.
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Rowlands J, Heng J, Newsholme P, Carlessi R. Pleiotropic Effects of GLP-1 and Analogs on Cell Signaling, Metabolism, and Function. Front Endocrinol (Lausanne) 2018; 9:672. [PMID: 30532733 PMCID: PMC6266510 DOI: 10.3389/fendo.2018.00672] [Citation(s) in RCA: 159] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/29/2018] [Indexed: 12/22/2022] Open
Abstract
The incretin hormone Glucagon-Like Peptide-1 (GLP-1) is best known for its "incretin effect" in restoring glucose homeostasis in diabetics, however, it is now apparent that it has a broader range of physiological effects in the body. Both in vitro and in vivo studies have demonstrated that GLP-1 mimetics alleviate endoplasmic reticulum stress, regulate autophagy, promote metabolic reprogramming, stimulate anti-inflammatory signaling, alter gene expression, and influence neuroprotective pathways. A substantial body of evidence has accumulated with respect to how GLP-1 and its analogs act to restore and maintain normal cellular functions. These findings have prompted several clinical trials which have reported GLP-1 analogs improve cardiac function, restore lung function and reduce mortality in patients with obstructive lung disease, influence blood pressure and lipid storage, and even prevent synaptic loss and neurodegeneration. Mechanistically, GLP-1 elicits its effects via acute elevation in cAMP levels, and subsequent protein kinase(s) activation, pathways well-defined in pancreatic β-cells which stimulate insulin secretion in conjunction with elevated Ca2+ and ATP. More recently, new studies have shed light on additional downstream pathways stimulated by chronic GLP-1 exposure, findings which have direct relevance to our understanding of the potential therapeutic effects of longer lasting analogs recently developed for clinical use. In this review, we provide a comprehensive description of the diverse roles for GLP-1 across multiple tissues, describe downstream pathways stimulated by acute and chronic exposure, and discuss novel pleiotropic applications of GLP-1 mimetics in the treatment of human disease.
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Affiliation(s)
| | | | - Philip Newsholme
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Perth, WA, Australia
| | - Rodrigo Carlessi
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Perth, WA, Australia
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35
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Park SW, Mansur RB, Lee Y, Lee JH, Seo MK, Choi AJ, McIntyre RS, Lee JG. Liraglutide Activates mTORC1 Signaling and AMPA Receptors in Rat Hippocampal Neurons Under Toxic Conditions. Front Neurosci 2018; 12:756. [PMID: 30405339 PMCID: PMC6205986 DOI: 10.3389/fnins.2018.00756] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 10/01/2018] [Indexed: 12/31/2022] Open
Abstract
The aim of the present study was to determine whether treatment with liraglutide, a glucagon-like peptide 1 (GLP-1) receptor agonist, would alter mammalian target of rapamycin complex 1 (mTORC1) signaling and/or α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor activity under dexamethasone-induced toxic conditions. Western blot analyses were performed to assess changes in mTORC1-mediated proteins, brain-derived neurotrophic factor (BDNF), and various synaptic proteins (PSD-95, synapsin I, and GluA1) in rat hippocampal cultures under toxic conditions induced by dexamethasone, which causes hippocampal cell death. Hippocampal dendritic outgrowth and spine formation were measured using immunostaining procedures. Dexamethasone significantly decreased the phosphorylation levels of mTORC1 as well as its downstream proteins. However, treatment with liraglutide prevented these reductions and significantly increased BDNF expression. The increase in BDNF expression was completely blocked by rapamycin and 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonamide (NBQX). Liraglutide also recovered dexamethasone-induced decreases in the total length of hippocampal dendrites and reductions in spine density in a concentration-dependent manner. However, the positive effects of liraglutide on neural plasticity were abolished by the blockade of mTORC1 signaling and AMPA receptors. Furthermore, liraglutide significantly increased the expression levels of PSD-95, synapsin I, and GluA1, whereas rapamycin and NBQX blocked these effects. The present study demonstrated that liraglutide activated mTORC1 signaling and AMPA receptor activity as well as increased dendritic outgrowth, spine density, and synaptic proteins under toxic conditions in rat primary hippocampal neurons. These findings suggest that GLP-1 receptor (GLP-1R) activation by liraglutide may affect neuroplasticity through mTORC1 and AMPA receptors.
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Affiliation(s)
- Sung Woo Park
- Paik Institute for Clinical Research, Inje University, Busan, South Korea.,Department of Health Science and Technology, Graduate School, Inje University, Busan, South Korea.,Department of Convergence Biomedical Science, College of Medicine, Inje University, Busan, South Korea
| | - Rodrigo B Mansur
- Mood Disorders Psychopharmacology Unit, University Health Network, University of Toronto, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Yena Lee
- Mood Disorders Psychopharmacology Unit, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Jae-Hon Lee
- Department of Psychiatry, National Rehabilitation Center, Seoul, South Korea
| | - Mi Kyoung Seo
- Paik Institute for Clinical Research, Inje University, Busan, South Korea
| | - Ah Jeong Choi
- Paik Institute for Clinical Research, Inje University, Busan, South Korea
| | - Roger S McIntyre
- Mood Disorders Psychopharmacology Unit, University Health Network, University of Toronto, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Department of Pharmacology, University of Toronto, Toronto, ON, Canada
| | - Jung Goo Lee
- Paik Institute for Clinical Research, Inje University, Busan, South Korea.,Department of Health Science and Technology, Graduate School, Inje University, Busan, South Korea.,Department of Psychiatry, College of Medicine, Haeundae Paik Hospital, Inje University, Busan, South Korea
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36
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Abstract
AMP-activated protein kinase (AMPK) is the main cellular energy sensor. Activated following a depletion of cellular energy stores, AMPK will restore the energy homoeostasis by increasing energy production and limiting energy waste. At a central level, the AMPK pathway will integrate peripheral signals (mostly hormones and metabolites) through neuronal networks. Hypothalamic AMPK is directly implicated in feeding behaviour, brown adipose tissue (BAT) thermogenesis and browning of white adipose tissue (WAT). It also participates in other metabolic functions: glucose and muscle metabolisms, as well as hepatic function. Numerous anti-obesity and/or antidiabetic agents, such as nicotine, metformin and liraglutide, are known to induce their effects through a modulation of AMPK pathway, either at central or at peripheral levels. Moreover, the weight-gaining side effects of antipsychotic drugs, such as olanzapine, are also mediated by hypothalamic AMPK. Therefore, considering hypothalamic AMPK as a therapeutic target in metabolic diseases appears as an interesting strategy due to its implication in feeding and energy expenditure, the two sides of the energy balance equation.
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Affiliation(s)
- Miguel López
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain.,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
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37
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Zhu J, Chen Y, Ji Y, Yu Y, Jin Y, Zhang X, Zhou J. Gemcitabine induces apoptosis and autophagy via the AMPK/mTOR signaling pathway in pancreatic cancer cells. Biotechnol Appl Biochem 2018; 65:665-671. [PMID: 29575133 DOI: 10.1002/bab.1657] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 03/15/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Jinhui Zhu
- Department of General Surgery and Laparoscopic Center; Second Affiliated Hospital Zhejiang University School of Medicine; Hangzhou People's Republic of China
| | - Yan Chen
- Department of General Surgery and Laparoscopic Center; Second Affiliated Hospital Zhejiang University School of Medicine; Hangzhou People's Republic of China
| | - Yun Ji
- Department of General Surgery; Second Affiliated Hospital Zhejiang University School of Medicine; Hangzhou People's Republic of China
| | - Yuanquan Yu
- Department of General Surgery; Second Affiliated Hospital Zhejiang University School of Medicine; Hangzhou People's Republic of China
| | - Yun Jin
- Department of General Surgery; Second Affiliated Hospital Zhejiang University School of Medicine; Hangzhou People's Republic of China
| | - Xiaoxiao Zhang
- Department of General Surgery; Second Affiliated Hospital Zhejiang University School of Medicine; Hangzhou People's Republic of China
| | - Jiale Zhou
- Department of General Surgery; Second Affiliated Hospital Zhejiang University School of Medicine; Hangzhou People's Republic of China
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38
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Tuo Y, Xiang M. mTOR: A double‐edged sword for diabetes. J Leukoc Biol 2018; 106:385-395. [DOI: 10.1002/jlb.3mr0317-095rr] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 09/05/2017] [Accepted: 09/14/2017] [Indexed: 12/14/2022] Open
Affiliation(s)
- Yali Tuo
- Department of PharmacologySchool of PharmacyTongji Medical CollegeHuazhong University of Science and Technology Wuhan China
| | - Ming Xiang
- Department of PharmacologySchool of PharmacyTongji Medical CollegeHuazhong University of Science and Technology Wuhan China
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39
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Ardestani A, Lupse B, Kido Y, Leibowitz G, Maedler K. mTORC1 Signaling: A Double-Edged Sword in Diabetic β Cells. Cell Metab 2018; 27:314-331. [PMID: 29275961 DOI: 10.1016/j.cmet.2017.11.004] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/11/2017] [Accepted: 11/15/2017] [Indexed: 12/21/2022]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is a central regulator of metabolic and nutrient cues that integrates environmental inputs into downstream signaling pathways to control cellular metabolism, growth, and survival. While numerous in vitro and in vivo studies reported the positive functions of mTORC1 in the regulation of β cell survival and proliferation under physiological conditions, more recent work demonstrates the opposite in the long term; this is exemplified by the constitutive inappropriate hyper-activation of mTORC1 in diabetic islets or β cells under conditions of increased β cell stress and metabolic demands. These recent findings uncover mTORC1's importance as an emerging significant player in the development and progression of β cell failure in type 2 diabetes and suggest that mTORC1 may act as a "double edge sword" in the regulation of β cell mass and function in response to metabolic stress such as nutrient overload and insulin resistance.
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Affiliation(s)
- Amin Ardestani
- University of Bremen, Centre for Biomolecular Interactions Bremen, Bremen 28359, Germany.
| | - Blaz Lupse
- University of Bremen, Centre for Biomolecular Interactions Bremen, Bremen 28359, Germany
| | - Yoshiaki Kido
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan; Division of Metabolism and Disease, Department of Biophysics, Kobe University Graduate School of Health Sciences, Kobe 654-0142, Japan
| | - Gil Leibowitz
- Endocrinology and Metabolism Service and the Hadassah Diabetes Unit, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Kathrin Maedler
- University of Bremen, Centre for Biomolecular Interactions Bremen, Bremen 28359, Germany.
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40
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Arden C. A role for Glucagon-Like Peptide-1 in the regulation of β-cell autophagy. Peptides 2018; 100:85-93. [PMID: 29412836 DOI: 10.1016/j.peptides.2017.12.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 12/11/2022]
Abstract
Autophagy is a highly conserved intracellular recycling pathway that serves to recycle damaged organelles/proteins or superfluous nutrients during times of nutritional stress to provide energy to maintain intracellular homeostasis and sustain core metabolic functions. Under these conditions, autophagy functions as a cell survival mechanism but impairment of this pathway can lead to pro-death stimuli. Due to their role in synthesising and secreting insulin, pancreatic β-cells have a high requirement for robust degradation pathways. Recent research suggests that functional autophagy is required to maintain β-cell survival and function in response to high fat diet suggesting a pro-survival role. However, a role for autophagy has also been implicated in the pathogenesis of type 2 diabetes. Thus, the pro-survival vs pro-death role of autophagy in regulating β-cell mass requires discussion. Emerging evidence suggests that Glucagon-Like Peptide-1 (GLP-1) may exert beneficial effects on glucose homeostasis via autophagy-dependent pathways both in pancreatic β-cells and in other cell types. The aim of the current review is to: i) summarise the literature surrounding β-cell autophagy and its pro-death vs pro-survival role in regulating β-cell mass; ii) review the literature describing the impact of GLP-1 on β-cell autophagy and in other cell types; iii) discuss the potential underlying mechanisms.
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Affiliation(s)
- Catherine Arden
- Institute of Cellular Medicine, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
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41
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Rourke JL, Hu Q, Screaton RA. AMPK and Friends: Central Regulators of β Cell Biology. Trends Endocrinol Metab 2018; 29:111-122. [PMID: 29289437 DOI: 10.1016/j.tem.2017.11.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 11/20/2017] [Accepted: 11/29/2017] [Indexed: 02/08/2023]
Abstract
If left unchecked, prediabetic hyperglycemia can progress to diabetes and often life-threatening attendant secondary complications. Central to the process of glucose homeostasis are pancreatic β cells, which sense elevations in plasma glucose and additional dietary components and respond by releasing the appropriate quantity of insulin, ensuring the arrest of hepatic glucose output and glucose uptake in peripheral tissues. Given that β cell failure is associated with the transition from prediabetes to diabetes, improved β cell function ('compensation') has a central role in preventing type 2 diabetes mellitus (T2DM). Recent data have shown that both insulin secretion and β cell mass dynamics are regulated by the liver kinase B1-AMP-activated kinase (LKB1-AMPK) pathway and related kinases of the AMPK family; thus, an improved understanding of the biological roles of AMPK in the β cell is now of considerable interest.
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Affiliation(s)
- Jillian L Rourke
- Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ONT, M4N 3M5, Canada
| | - Queenie Hu
- Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ONT, M4N 3M5, Canada
| | - Robert A Screaton
- Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ONT, M4N 3M5, Canada; Department of Biochemistry, University of Toronto, Toronto, ONT, M5S 1A8, Canada.
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42
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Miao X, Gu Z, Liu Y, Jin M, Lu Y, Gong Y, Li L, Li C. The glucagon-like peptide-1 analogue liraglutide promotes autophagy through the modulation of 5'-AMP-activated protein kinase in INS-1 β-cells under high glucose conditions. Peptides 2018; 100:127-139. [PMID: 28712893 DOI: 10.1016/j.peptides.2017.07.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/04/2017] [Accepted: 07/07/2017] [Indexed: 01/07/2023]
Abstract
Glucagon-like peptide-1 (GLP-1) is a potent therapeutic agent for the treatment of diabetes and has been proven to protect pancreatic β-cells from glucotoxicity; however, its mechanisms of action are not entirely understood. Autophagy is a dynamic lysosomal degradation process that can protect organisms against metabolic stress. Studies have shown that autophagy plays a protective role in the survival of pancreatic β-cells under high glucose conditions. In the present study, we explored the role of autophagy in GLP-1-induced protection of pancreatic β-cells exposed to high glucose. We demonstrated that the GLP-1 analogue liraglutide increased autophagy in rat INS-1 β-cells, and inhibition of autophagy abated the anti-apoptosis effect of liraglutide under high glucose conditions. Our results also showed that activation of 5'-AMP-activated protein kinase (AMPK) reduced liraglutide-induced autophagy enhancement and inhibited liraglutide-induced protection of INS-1 β-cells from high glucose. These data suggest that GLP-1 may protect β-cells from glucotoxicity through promoting autophagy by the modulation of AMPK. Deeper insight into the molecular mechanisms linking autophagy and GLP-1-induced β-cell protection may reveal novel therapeutic targets to preserve β-cell mass.
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Affiliation(s)
- Xinyu Miao
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Zhaoyan Gu
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Yu Liu
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Mengmeng Jin
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Yanhui Lu
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Yanping Gong
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Lin Li
- Department of Endocrinology, General Hospital of The PLA Rocket Force, Beijing, China
| | - Chunlin Li
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China.
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43
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Zhao W, Zhang X, Zhou Z, Sun B, Gu W, Liu J, Zhang H. Liraglutide inhibits the proliferation and promotes the apoptosis of MCF-7 human breast cancer cells through downregulation of microRNA-27a expression. Mol Med Rep 2018; 17:5202-5212. [PMID: 29393459 PMCID: PMC5865986 DOI: 10.3892/mmr.2018.8475] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 12/11/2017] [Indexed: 12/14/2022] Open
Abstract
The use of glucagon-like peptide-1 analogues, such as liraglutide, as hypoglycemic drugs has been widely employed in clinical practice. Liraglutide is reported to exert potential anti-breast cancer effects, however the specific mechanisms of this action remain unknown. In the present study, MCF-7 human breast cancer cells were cultured in vitro and treated with various concentrations of liraglutide. Cell Counting Kit-8, colony formation and flow cytometry assays were performed to determine the proliferation and apoptosis of cells following treatment. Furthermore, reverse transcription-quantitative polymerase chain reaction was employed to measure the expression level of microRNA (miRNA/miR)-27a. In addition, miR-27a mimics, inhibitors and negative controls were transfected into MCF-7 cells and the proliferation and apoptosis of cells following transfection was subsequently determined. Western blotting was performed to detect alterations in the protein expression of AMP-activated protein kinase catalytic subunit α2 (AMPKα2), proliferating cell nuclear antigen and cleaved-caspase-3 following treatments. The results demonstrated that, following treatment with liraglutide, the proliferation of MCF-7 cells was reduced and the apoptosis was increased, compared with the control group; this effect was increased with increasing concentrations of liraglutide. In addition, liraglutide treatment downregulated miR-27a expression in MCF-7 cells. While the overexpression of miR-27a promoted cell proliferation and inhibited apoptosis, knockdown of endogenous miR-27a inhibited cell proliferation and promoted apoptosis in MCF-7 cells. Furthermore, the expression of AMPKα2 protein in the group transfected with miR-27a mimics was decreased, while it was increased in MCF-7 cells transfected with miR-27a inhibitors. In conclusion, liraglutide may have a role in the inhibition of proliferation and promotion of apoptosis in MCF-7 cells. Concerning the mechanism of these effects, liraglutide may inhibit miR-27a expression, which subsequently increases the expression of AMPKα2 protein. The present study provides an experimental basis for the clinical treatment strategies of T2DM patients with breast cancer.
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Affiliation(s)
- Wei Zhao
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Xiaohui Zhang
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Zhichao Zhou
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Bei Sun
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Wenyuan Gu
- Emergency Department, The Second Affiliated Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300150, P.R. China
| | - Jia Liu
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Hong Zhang
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, P.R. China
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44
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Khan S, Kowluru A. CD36 mediates lipid accumulation in pancreatic beta cells under the duress of glucolipotoxic conditions: Novel roles of lysine deacetylases. Biochem Biophys Res Commun 2017; 495:2221-2226. [PMID: 29274335 DOI: 10.1016/j.bbrc.2017.12.111] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 12/19/2017] [Indexed: 12/13/2022]
Abstract
The cluster of differentiation 36 (CD36) is implicated in the intake of long-chain fatty acids and fat storage in various cell types including the pancreatic beta cell, thus contributing to the pathogenesis of metabolic stress and diabetes. Recent evidence indicates that CD36 undergoes post-translational modifications such as acetylation-deacetylation. However, putative roles of such modifications in its functional activation and onset of beta cell dysregulation under the duress of glucolipotoxicity (GLT) remain largely unknown. Using pharmacological approaches, we validated, herein, the hypothesis that acetylation-deacetylation signaling steps are involved in CD36-mediated lipid accumulation and downstream apoptotic signaling in pancreatic beta (INS-1832/13) cells under GLT. Exposure of these cells to GLT resulted in significant lipid accumulation without affecting the CD36 expression. Sulfo-n-succinimidyl oleate (SSO), an irreversible inhibitor of CD36, significantly attenuated lipid accumulation under GLT conditions, thus implicating CD36 in this metabolic step. Furthermore, trichostatin A (TSA) or valproic acid (VPA), known inhibitors of lysine deacetylases, markedly suppressed GLT-associated lipid accumulation with no discernible effects on CD36 expression. Lastly, SSO or TSA prevented caspase 3 activation in INS-1832/13 cells exposed to GLT conditions. Based on these findings, we conclude that an acetylation-deacetylation signaling step might regulate CD36 functional activity and subsequent lipid accumulation and caspase 3 activation in pancreatic beta cells exposed to GLT conditions. Identification of specific lysine deacetylases that control CD36 function should provide novel clues for the prevention of beta-cell dysfunction under GLT.
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Affiliation(s)
- Sabbir Khan
- β-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, and Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, 48201, USA
| | - Anjaneyulu Kowluru
- β-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, and Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, 48201, USA.
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45
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Maiese K. Erythropoietin and mTOR: A "One-Two Punch" for Aging-Related Disorders Accompanied by Enhanced Life Expectancy. Curr Neurovasc Res 2017; 13:329-340. [PMID: 27488211 DOI: 10.2174/1567202613666160729164900] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 07/12/2016] [Accepted: 07/14/2016] [Indexed: 12/16/2022]
Abstract
Life expectancy continues to increase throughout the world, but is accompanied by a rise in the incidence of non-communicable diseases. As a result, the benefits of an increased lifespan can be limited by aging-related disorders that necessitate new directives for the development of effective and safe treatment modalities. With this objective, the mechanistic target of rapamycin (mTOR), a 289-kDa serine/threonine protein, and its related pathways of mTOR Complex 1 (mTORC1), mTOR Complex 2 (mTORC2), proline rich Akt substrate 40 kDa (PRAS40), AMP activated protein kinase (AMPK), Wnt signaling, and silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), have generated significant excitement for furthering novel therapies applicable to multiple systems of the body. Yet, the biological and clinical outcome of these pathways can be complex especially with oversight of cell death mechanisms that involve apoptosis and autophagy. Growth factors, and in particular erythropoietin (EPO), are one avenue under consideration to implement control over cell death pathways since EPO can offer potential treatment for multiple disease entities and is intimately dependent upon mTOR signaling. In experimental and clinical studies, EPO appears to have significant efficacy in treating several disorders including those involving the developing brain. However, in mature populations that are affected by aging-related disorders, the direction for the use of EPO to treat clinical disease is less clear that may be dependent upon a number of factors including the understanding of mTOR signaling. Continued focus upon the regulatory elements that control EPO and mTOR signaling could generate critical insights for targeting a broad range of clinical maladies.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey 07101, USA.
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46
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Zhang Y, Fava GE, Wu M, Htun W, Klein T, Fonseca VA, Wu H. Effects of Linagliptin on Pancreatic α Cells of Type 1 Diabetic Mice. J Endocr Soc 2017; 1:1224-1234. [PMID: 29264448 PMCID: PMC5686619 DOI: 10.1210/js.2017-00253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 08/28/2017] [Indexed: 11/19/2022] Open
Abstract
The dipeptidyl peptidase-4 inhibitor linagliptin promotes β-cell survival and insulin secretion by prolonging endogenous glucagon-like peptide 1 (GLP-1) action and therefore helps to maintain normoglycemia in diabetic patients. The effect of linagliptin on glucagon-producing α cells, however, was not clear. In this study, we investigated whether linagliptin had any effects on α cells with regard to their proliferation and hormonal production using type 1 diabetes mouse models, including streptozotocin-induced and nonobese diabetes mice. After diabetes development, the mice were either untreated or treated with linagliptin or insulin for up to 6 weeks. Our results showed that linagliptin significantly increased circulating GLP-1 levels in both type 1 diabetes models, but therapeutic benefit was detected in nonobese diabetes mice only. Circulating C-peptide and glucagon levels (nonfasting) were not significantly altered by linagliptin treatment in either model. In addition, we found that linagliptin did not increase α-cell proliferation compared with the untreated or insulin-treated controls as assessed by in vivo 5-bromo-2'-deoxyuridine labeling assay. Finally, we examined whether linagliptin treatment altered GLP-1 vs glucagon expression in pancreatic α cells. Immunohistochemistry assays showed that linagliptin treatment resulted in detection of GLP-1 in more α cells than in control groups, suggesting linagliptin was able to increase intraislet GLP-1 presence, presumably by inhibiting GLP-1 degradation. In summary, this study indicates that linagliptin would not confer adverse effect on α cells, such as causing α cell hyperplasia, and instead may facilitate a blood glucose-lowering effect by increasing GLP-1 presence in α cells.
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Affiliation(s)
- Yanqing Zhang
- Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana 70112
| | - Genevieve E. Fava
- Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana 70112
| | - Meifen Wu
- Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana 70112
| | - Wynn Htun
- Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana 70112
| | - Thomas Klein
- Boehringer-Ingelheim Pharma GmbH & Co. KG, Biberach 88597, Germany
| | - Vivian A. Fonseca
- Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana 70112
| | - Hongju Wu
- Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana 70112
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47
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Muhammad AB, Xing B, Liu C, Naji A, Ma X, Simmons RA, Hua X. Menin and PRMT5 suppress GLP1 receptor transcript and PKA-mediated phosphorylation of FOXO1 and CREB. Am J Physiol Endocrinol Metab 2017; 313:E148-E166. [PMID: 28270438 PMCID: PMC5582886 DOI: 10.1152/ajpendo.00241.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 01/11/2017] [Accepted: 02/20/2017] [Indexed: 12/23/2022]
Abstract
Menin is a scaffold protein that interacts with several epigenetic mediators to regulate gene transcription, and suppresses pancreatic β-cell proliferation. Tamoxifen-inducible deletion of multiple endocrine neoplasia type 1 (MEN1) gene, which encodes the protein menin, increases β-cell mass in multiple murine models of diabetes and ameliorates diabetes. Glucagon-like-peptide-1 (GLP1) is another key physiological modulator of β-cell mass and glucose homeostasis. However, it is not clearly understood whether menin crosstalks with GLP1 signaling. Here, we show that menin and protein arginine methyltransferase 5 (PRMT5) suppress GLP1 receptor (GLP1R) transcript levels. Notably, a GLP1R agonist induces phosphorylation of forkhead box protein O1 (FOXO1) at S253, and the phosphorylation is mediated by PKA. Interestingly, menin suppresses GLP1-induced and PKA-mediated phosphorylation of both FOXO1 and cAMP response element binding protein (CREB), likely through a protein arginine methyltransferase. Menin-mediated suppression of FOXO1 and CREB phosphorylation increases FOXO1 levels and suppresses CREB target genes, respectively. A small-molecule menin inhibitor reverses menin-mediated suppression of both FOXO1 and CREB phosphorylation. In addition, ex vivo treatment of both mouse and human pancreatic islets with a menin inhibitor increases levels of proliferation marker Ki67. In conclusion, our results suggest that menin and PRMT5 suppress GLP1R transcript levels and PKA-mediated phosphorylation of FOXO1 and CREB, and a menin inhibitor may reverse this suppression to induce β-cell proliferation.
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Affiliation(s)
- Abdul Bari Muhammad
- Abramson Family Cancer Research Institute, Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Institute for Diabetes, Obesity, and Metabolism Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Bowen Xing
- Shenzen University School of Medicine, Institute of Diabetes Research, Shenzhen, Guangdong, China
| | - Chengyang Liu
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ali Naji
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Institute for Diabetes, Obesity, and Metabolism Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Xiaosong Ma
- Shenzen University School of Medicine, Institute of Diabetes Research, Shenzhen, Guangdong, China
| | - Rebecca A Simmons
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; and
- Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Xianxin Hua
- Abramson Family Cancer Research Institute, Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;
- Institute for Diabetes, Obesity, and Metabolism Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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48
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Huang CN, Wang CJ, Lee YJ, Peng CH. Active subfractions of Abelmoschus esculentus substantially prevent free fatty acid-induced β cell apoptosis via inhibiting dipeptidyl peptidase-4. PLoS One 2017; 12:e0180285. [PMID: 28715446 PMCID: PMC5513409 DOI: 10.1371/journal.pone.0180285] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 06/13/2017] [Indexed: 12/24/2022] Open
Abstract
Lipotoxicity plays an important role in exacerbating type 2 diabetes mellitus (T2DM) and leads to apoptosis of β cells. Recently dipeptidyl peptidase-4 (DPP-4) inhibitors have emerged as a useful tool in the treatment of T2DM. DPP-4 degrades type 1 glucagon-like peptide (GLP-1), and GLP-1 receptor (GLP-1R) signaling has been shown to protect β cells by modulating AMPK/mTOR, PI3K, and Bax. The anti-hyperglycemic effect of Abelmoschus esculentus (AE) is well known, however its mucilage makes it difficult to further examine this effect. In our recent report, a sequence of extraction steps was used to obtain a series of subfractions from AE, each with its own composition and property. Among them F1 (rich in quercetin glucosides and pentacyclic triterpene ester) and F2 (containing large amounts of carbohydrates and polysaccharides) were found to be especially effective in attenuating DPP-4 signaling, and to have the potential to counter diabetic nephropathy. Hence, the aim of the present study was to investigate whether AE subfractions can prevent the palmitate-induced apoptosis of β cells, and the putative signals involved. We demonstrated that AE, and especially 1 μg/mL of F2, decreased palmitate-induced apoptosis analyzed by flow cytometry. The result of western blot revealed that palmitate-induced decrease in GLP-1R and increase in DPP-4 were restored by F1 and F2. The DPP-4 inhibitor linagliptin decreased the expression of caspase 3, suggesting that DPP-4 is critically involved in apoptotic signaling. Analysis of enzyme activity revealed that palmitate increased the activity of DPP4 nearly 2 folds, while F2 especially inhibited the activation. In addition, AMPK/mTOR, PI3K and mitochondrial pathways were regulated by AE, and this attenuated the palmitate-induced signaling cascades. In conclusion, AE is useful to prevent the exacerbation of β cell apoptosis, and it could potentially be used as adjuvant or nutraceutical therapy for diabetes.
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Affiliation(s)
- Chien-Ning Huang
- Department of Internal Medicine, Chung-Shan Medical University Hospital, Taichung, Taiwan
- Institute of Medicine, Chung-Shan Medical University, Taichung, Taiwan
| | - Chau-Jong Wang
- Institute of Biochemistry, Microbiology and Immunology, Chung-Shan Medical University, Taichung, Taiwan
| | - Yi-Ju Lee
- Department of Pathology, Chung-Shan Medical University Hospital, Taichung, Taiwan
| | - Chiung-Huei Peng
- Division of Basic Medical Science, Hungkuang University, Shalu District, Taichung, Taiwan
- * E-mail:
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49
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Li L. The Molecular Mechanism of Glucagon-Like Peptide-1 Therapy in Alzheimer's Disease, Based on a Mechanistic Target of Rapamycin Pathway. CNS Drugs 2017; 31:535-549. [PMID: 28540646 DOI: 10.1007/s40263-017-0431-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The mechanistic target of rapamycin (mTOR) is an important molecule that connects aging, lifespan, energy balance, glucose and lipid metabolism, and neurodegeneration. Rapamycin exerts effects in numerous biological activities via its target protein, playing a key role in energy balance, regulation of autophagy, extension of lifespan, immunosuppression, and protection against neurodegeneration. There are many similar pathophysiological processes and molecular pathways between Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM), and pharmacologic agents used to treat T2DM, including glucagon-like peptide-1 (GLP-1) analogs, seem to be beneficial for AD. mTOR mediates the effects of GLP-1 analogs in the treatment of T2DM; hence, I hypothesize that mTOR is a key molecule for mediating the protective effects of GLP-1 for AD.
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Affiliation(s)
- Lin Li
- Key Laboratory of Cellular Physiology, Shanxi Medical University, Taiyuan, Shanxi, China.
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50
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GLP-1 receptor signalling promotes β-cell glucose metabolism via mTOR-dependent HIF-1α activation. Sci Rep 2017; 7:2661. [PMID: 28572610 PMCID: PMC5454020 DOI: 10.1038/s41598-017-02838-2] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/19/2017] [Indexed: 02/05/2023] Open
Abstract
Glucagon-like peptide-1 (GLP-1) promotes insulin secretion from pancreatic β-cells in a glucose dependent manner. Several pathways mediate this action by rapid, kinase phosphorylation-dependent, but gene expression-independent mechanisms. Since GLP-1-induced insulin secretion requires glucose metabolism, we aimed to address the hypothesis that GLP-1 receptor (GLP-1R) signalling can modulate glucose uptake and utilization in β-cells. We have assessed various metabolic parameters after short and long exposure of clonal BRIN-BD11 β-cells and rodent islets to the GLP-1R agonist Exendin-4 (50 nM). Here we report for the first time that prolonged stimulation of the GLP-1R for 18 hours promotes metabolic reprogramming of β-cells. This is evidenced by up-regulation of glycolytic enzyme expression, increased rates of glucose uptake and consumption, as well as augmented ATP content, insulin secretion and glycolytic flux after removal of Exendin-4. In our model, depletion of Hypoxia-Inducible Factor 1 alpha (HIF-1α) impaired the effects of Exendin-4 on glucose metabolism, while pharmacological inhibition of Phosphoinositide 3-kinase (PI3K) or mTOR completely abolished such effects. Considering the central role of glucose catabolism for stimulus-secretion coupling in β-cells, our findings suggest that chronic GLP-1 actions on insulin secretion include elevated β-cell glucose metabolism. Moreover, our data reveal novel aspects of GLP-1 stimulated insulin secretion involving de novo gene expression.
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