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Abdalla MMI. Insulin resistance as the molecular link between diabetes and Alzheimer's disease. World J Diabetes 2024; 15:1430-1447. [DOI: 10.4239/wjd.v15.i7.1430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 04/08/2024] [Accepted: 05/06/2024] [Indexed: 07/08/2024] Open
Abstract
Diabetes mellitus (DM) and Alzheimer's disease (AD) are two major health concerns that have seen a rising prevalence worldwide. Recent studies have indicated a possible link between DM and an increased risk of developing AD. Insulin, while primarily known for its role in regulating blood sugar, also plays a vital role in protecting brain functions. Insulin resistance (IR), especially prevalent in type 2 diabetes, is believed to play a significant role in AD's development. When insulin signalling becomes dysfunctional, it can negatively affect various brain functions, making individuals more susceptible to AD's defining features, such as the buildup of beta-amyloid plaques and tau protein tangles. Emerging research suggests that addressing insulin-related issues might help reduce or even reverse the brain changes linked to AD. This review aims to explore the rela-tionship between DM and AD, with a focus on the role of IR. It also explores the molecular mechanisms by which IR might lead to brain changes and assesses current treatments that target IR. Understanding IR's role in the connection between DM and AD offers new possibilities for treatments and highlights the importance of continued research in this interdisciplinary field.
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Affiliation(s)
- Mona Mohamed Ibrahim Abdalla
- Department of Human Biology, School of Medicine, International Medical University, Bukit Jalil 57000, Kuala Lumpur, Malaysia
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2
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Tzavellas NP, Tsamis KI, Katsenos AP, Davri AS, Simos YV, Nikas IP, Bellos S, Lekkas P, Kanellos FS, Konitsiotis S, Labrakakis C, Vezyraki P, Peschos D. Firing Alterations of Neurons in Alzheimer's Disease: Are They Merely a Consequence of Pathogenesis or a Pivotal Component of Disease Progression? Cells 2024; 13:434. [PMID: 38474398 DOI: 10.3390/cells13050434] [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: 01/14/2024] [Revised: 02/26/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder, yet its underlying causes remain elusive. The conventional perspective on disease pathogenesis attributes alterations in neuronal excitability to molecular changes resulting in synaptic dysfunction. Early hyperexcitability is succeeded by a progressive cessation of electrical activity in neurons, with amyloid beta (Aβ) oligomers and tau protein hyperphosphorylation identified as the initial events leading to hyperactivity. In addition to these key proteins, voltage-gated sodium and potassium channels play a decisive role in the altered electrical properties of neurons in AD. Impaired synaptic function and reduced neuronal plasticity contribute to a vicious cycle, resulting in a reduction in the number of synapses and synaptic proteins, impacting their transportation inside the neuron. An understanding of these neurophysiological alterations, combined with abnormalities in the morphology of brain cells, emerges as a crucial avenue for new treatment investigations. This review aims to delve into the detailed exploration of electrical neuronal alterations observed in different AD models affecting single neurons and neuronal networks.
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Affiliation(s)
- Nikolaos P Tzavellas
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
| | - Konstantinos I Tsamis
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
- Department of Neurology, Faculty of Medicine, School of Health Sciences, University Hospital of Ioannina, 455 00 Ioannina, Greece
| | - Andreas P Katsenos
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
| | - Athena S Davri
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
| | - Yannis V Simos
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
| | - Ilias P Nikas
- Medical School, University of Cyprus, 2029 Nicosia, Cyprus
| | - Stefanos Bellos
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
| | - Panagiotis Lekkas
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
| | - Foivos S Kanellos
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
| | - Spyridon Konitsiotis
- Department of Neurology, Faculty of Medicine, School of Health Sciences, University Hospital of Ioannina, 455 00 Ioannina, Greece
| | - Charalampos Labrakakis
- Department of Biological Applications and Technology, University of Ioannina, 451 10 Ioannina, Greece
| | - Patra Vezyraki
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
| | - Dimitrios Peschos
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 451 10 Ioannina, Greece
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Guo Y, Zhang L. Ghrelin inhibits NLRP3 inflammasome activation by upregulating autophagy to improve Alzheimer's disease. In Vitro Cell Dev Biol Anim 2023; 59:665-673. [PMID: 37989934 DOI: 10.1007/s11626-023-00818-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/21/2023] [Indexed: 11/23/2023]
Abstract
Nod-like receptor protein 3 (NLRP3) inflammasome, autophagy, and the aggregation of β-amyloid (Aβ) are key factors in Alzheimer's disease (AD) development. Ghrelin has shown promise in providing neuroprotection for AD. However, the mechanism underlying ghrelin's ability to improve AD by modulating autophagy and the NLRP3 inflammasome requires further clarification. Primary hippocampus neurons and mice were stimulated with Aβ1-42 to create an in vitro and in vivo AD model, followed by ghrelin administration for intervention. Additionally, we subjected the cells to 3-methyladenine (3-MA) treatment. Neuron morphology, microtubule-associated protein 2 (MAP-2) expression, apoptosis, cytokine levels, and protein expression were measured using various techniques. The escape latency of mice was assessed using the Morris water maze (MWM) test, and histopathology of the hippocampus was determined using hematoxylin-eosin staining. At 1-100 nM, ghrelin increased neuron/synapse numbers and MAP-2 expression dose-dependently while blocking apoptosis in Aβ1-42-treated cells. Moreover, ghrelin reduced the expression of Aβ1-42, p-Tau/Tau, p62, NLRP3, ASC, and cleaved Caspase-1, while increasing the expression of LC3II/LC3I and Beclin1 in AD cells. Furthermore, ghrelin treatment also decreased the levels of Aβ1-42, IL-1β, and IL-18 in the cells. The effects of ghrelin were reversed by 3-MA. Our in vivo experiments provided further confirmation of the above effect of ghrelin on AD. Additionally, the injection of Aβ1-42 induced increased escape latency in mice and histopathological changes in hippocampal neurons. All of these abnormalities were significantly improved following administration of ghrelin. Ghrelin mitigated Aβ1-42-induced neurotoxicity and relieved neuronal damage by upregulating autophagy to inactivate NLRP3, thus showing promising potential in treating AD.
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Affiliation(s)
- Yaoxue Guo
- Department of Clinical Pharmacy, Donghe District, Baotou Central Hospital, 61 Huancheng Road, Baotou, 014040, Inner Mongolia, China
| | - Lixiang Zhang
- Department of Clinical Pharmacy, Donghe District, Baotou Central Hospital, 61 Huancheng Road, Baotou, 014040, Inner Mongolia, China.
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Ghrelin/GHS-R1A antagonism in memory test and its effects on central molecular signaling involved in addiction in rats. Pharmacol Biochem Behav 2023; 224:173528. [PMID: 36870422 DOI: 10.1016/j.pbb.2023.173528] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 12/23/2022] [Accepted: 02/12/2023] [Indexed: 03/06/2023]
Abstract
Central ghrelin signaling seems to play important role in addiction as well as memory processing. Antagonism of the growth hormone secretagogue receptor (GHS-R1A) has been recently proposed as a promising tool for the unsatisfactory drug addiction therapy. However, molecular aspects of GHS-R1A involvement in specific brain regions remain unclear. The present study demonstrated for the first time that acute as well as subchronic (4 days) administration of the experimental GHS-R1A antagonist JMV2959 in usual intraperitoneal doses including 3 mg/kg, had no influence on memory functions tested in the Morris Water Maze in rats as well as no significant effects on the molecular markers linked with memory processing in selected brain areas in rats, specifically on the β-actin, c-Fos, two forms of the calcium/calmodulin-dependent protein kinase II (CaMKII, p-CaMKII) and the cAMP-response element binding protein (CREB, p-CREB), within the medial prefrontal cortex (mPFC), nucleus accumbens (NAc), dorsal striatum, and hippocampus (HIPP). Furthermore, following the methamphetamine intravenous self-administration in rats, the 3 mg/kg JMV2959 pretreatment significantly reduced or prevented the methamphetamine-induced significant decrease of hippocampal β-actin and c-Fos as well as it prevented the significant decrease of CREB in the NAC and mPFC. These results imply, that the GHS-R1A antagonist/JMV2959 might reduce/prevent some of the memory-linked molecular changes elicited by methamphetamine addiction within brain structures associated with memory (HIPP), reward (NAc), and motivation (mPFC), which may contribute to the previously observed significant JMV2959-induced reduction of the methamphetamine self-administration and drug-seeking behavior in the same animals. Further research is necessary to corroborate these results.
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Choi GY, Kim HB, Hwang ES, Park HS, Cho JM, Ham YK, Kim JH, Mun MK, Maeng S, Park JH. Naringin enhances long-term potentiation and recovers learning and memory deficits of amyloid-beta induced Alzheimer's disease-like behavioral rat model. Neurotoxicology 2023; 95:35-45. [PMID: 36549596 DOI: 10.1016/j.neuro.2022.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/15/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Alzheimer's disease (AD), as the most typical type of dementia, is a chronic neurodegenerative disorder characterized by progressive learning and memory impairment. It is known that the main causes of AD are the accumulation of β-amyloid (Aβ) plaques and neurofibrillary tangles (NFT) containing hyperphosphorylated tau protein. Naringin is a flavonoid from citrus fruits, especially in grapefruit, which has anti-inflammatory, antioxidant, anti-apoptotic, and neuroprotective activities. However, the effect of naringin in AD caused by Aβ has not been clearly studied, and there are few studies on the electrophysiological aspect. Thus, we investigated the ex vivo neuroprotective effect of naringin through the long-term potentiation (LTP) on organotypic hippocampal slice cultures. We evaluated the in vivo effects of naringin (100 mg/kg/day) orally treated for 20 days on learning, memory, and cognition which was impaired by bilateral CA1 subregion injection of Aβ. Cognitive behaviors were measured 2 weeks after Aβ injection using behavioral tests and the hippocampal expression of apoptotic and neurotrophic regulators were measured by immunoblotting. In hippocampal tissue slices, naringin dose-dependently increased the field excitatory postsynaptic potential (fEPSP) after theta burst stimulation and attenuated Aβ-induced blockade of fEPSP in the hippocampal CA1 area. In Aβ injected rats, naringin improved object recognition memory in the novel object test, avoidance memory in the passive avoidance test and spatial recognition memory in the Morris water maze test. In the hippocampus, naringin attenuated the Aβ-induced cyclooxygenase-2, Bax activation and Bcl-2, CREB, BDNF and TrkB inhibition. These results suggest that naringin has therapeutic potential to reduce neuronal inflammation and apoptosis induced by Aβ related with the BDNF/TrkB/CREB signaling.
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Affiliation(s)
- Ga-Young Choi
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Hyun-Bum Kim
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eun-Sang Hwang
- Department of Gerontology, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Ho-Sub Park
- Department of Gerontology, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Jae-Min Cho
- Graduate School of Biotechnology, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Young-Ki Ham
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Jin-Hee Kim
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Mi-Kyung Mun
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Sungho Maeng
- Department of Gerontology, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea.
| | - Ji-Ho Park
- Department of Gerontology, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea.
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Liang YW, Lai ML, Chiu FM, Tseng HY, Lo YC, Li SJ, Chang CW, Chen PC, Chen YY. Experimental Verification for Numerical Simulation of Thalamic Stimulation-Evoked Calcium-Sensitive Fluorescence and Electrophysiology with Self-Assembled Multifunctional Optrode. BIOSENSORS 2023; 13:265. [PMID: 36832031 PMCID: PMC9953878 DOI: 10.3390/bios13020265] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
Owing to its capacity to eliminate a long-standing methodological limitation, fiber photometry can assist research gaining novel insight into neural systems. Fiber photometry can reveal artifact-free neural activity under deep brain stimulation (DBS). Although evoking neural potential with DBS is an effective method for mediating neural activity and neural function, the relationship between DBS-evoked neural Ca2+ change and DBS-evoked neural electrophysiology remains unknown. Therefore, in this study, a self-assembled optrode was demonstrated as a DBS stimulator and an optical biosensor capable of concurrently recording Ca2+ fluorescence and electrophysiological signals. Before the in vivo experiment, the volume of tissue activated (VTA) was estimated, and the simulated Ca2+ signals were presented using Monte Carlo (MC) simulation to approach the realistic in vivo environment. When VTA and the simulated Ca2+ signals were combined, the distribution of simulated Ca2+ fluorescence signals matched the VTA region. In addition, the in vivo experiment revealed a correlation between the local field potential (LFP) and the Ca2+ fluorescence signal in the evoked region, revealing the relationship between electrophysiology and the performance of neural Ca2+ concentration behavior. Concurrent with the VTA volume, simulated Ca2+ intensity, and the in vivo experiment, these data suggested that the behavior of neural electrophysiology was consistent with the phenomenon of Ca2+ influx to neurons.
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Affiliation(s)
- Yao-Wen Liang
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Ming-Liang Lai
- Graduate Institute of Intellectual Property, National Taipei University of Technology, Taipei 10608, Taiwan
| | - Feng-Mao Chiu
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Hsin-Yi Tseng
- The Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei 11031, Taiwan
| | - Yu-Chun Lo
- The Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
| | - Ssu-Ju Li
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Ching-Wen Chang
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Po-Chuan Chen
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - You-Yin Chen
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- The Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
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Shalaby AM, Alnasser SM, Ahmed Khairy D, Alabiad MA, Alorini M, Jaber FA, Tawfeek SE. The neuroprotective effect of ginsenoside Rb1 on the cerebral cortex changes induced by aluminium chloride in a mouse model of Alzheimer's disease: A histological, immunohistochemical, and biochemical study. J Chem Neuroanat 2023; 129:102248. [PMID: 36764334 DOI: 10.1016/j.jchemneu.2023.102248] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/18/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023]
Abstract
Alzheimer's disease (AD) is one of the most common types of dementia among neurodegenerative disorders characterized by attention deficits and memory loss. Panax ginseng is a traditional Chinese herbal remedy that has been employed for millennia to manage dementia linked with aging and memory impairment. Ginsenoside Rb1 is one of Panax ginseng's most abundant components. The present work evaluated the neuroprotective effects of ginsenoside Rb1 on the cerebral cortex of AlCl3-induced AD in adult male albino mice. Forty male mice were alienated arbitrarily into; control group, ginsenoside Rb1 group (70 mg/kg/day), AlCl3 group (50 mg/kg/day), and ginsenoside Rb1-AlCl3 group that received ginsenoside Rb1 one hour before AlCl3. Oxidative stress parameters, Amyloid β (Aβ) and phosphorylated tau protein, and acetylcholine esterase (AChE) activity were measured. Cerebral cortex sections were evaluated histologically by light microscopic examination and immunohistochemistry. AlCl3-induced memory impairment, Aβ and phosphorylated tau protein accumulation, and AChE elevation. Moreover, histopathological alterations in the cerebral cortex were reported in the form of irregular shrunken neurons and the surrounding neuropil showed vacuolation. Some neurons appeared with darkly stained nuclei, others had faintly stained ones. The synaptophysin expression was significantly decreased, while the expression of cleaved caspase-3, glial fibrillary acidic protein (GFAP), and ionized calcium-binding adaptor molecule 1 (Iba-1) were significantly elevated. It's interesting to note that these changes were attenuated in mice pretreated with ginsenoside Rb1. Collected data indicated that ginsenoside Rb1 showed a potential neuroprotective effect against cerebral cortex changes caused by AlCl3 via suppression of Amyloid β and phosphorylated tau protein formation, oxidative stress correction, anti-apoptotic effect, and by minimizing gliosis.
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Affiliation(s)
- Amany Mohamed Shalaby
- Histology and Cell Biology Department, Faculty of Medicine, Tanta University, Tanta 31527, Egypt.
| | - Sulaiman Mohammed Alnasser
- Department of Pharmacology and Toxicology, Unaizah College of Pharmacy, Qassim University, Buraydah 52571, Saudi Arabia
| | - Dina Ahmed Khairy
- Pathology Department, Faculty of Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Mohamed Ali Alabiad
- Pathology Department, Faculty of Medicine, Zagazig University, Zagazig 44519, Egypt
| | - Mohammed Alorini
- Department of Basic Medical Sciences, Unaizah College of Medicine and Medical Sciences, Qassim University, Unaizah, Saudi Arabia
| | - Fatima A Jaber
- Department of Biology, College of Science, University of Jeddah, Jeddah 21589, Saudi Arabia
| | - Shereen Elsayed Tawfeek
- Anatomy Department, College of Medicine, Jouf University, Sakaka, Saudi Arabia; Human Anatomy and Embryology Department, Faculty of Medicine, Zagazig University, Zagazig 44519, Egypt
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Tian J, Du E, Jia K, Wang T, Guo L, Zigman JM, Du H. Elevated Ghrelin Promotes Hippocampal Ghrelin Receptor Defects in Humanized Amyloid-β Knockin Mice During Aging. J Alzheimers Dis 2023; 96:1579-1592. [PMID: 38007666 PMCID: PMC10841720 DOI: 10.3233/jad-231002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
BACKGROUND Emerging evidence has revealed that dysregulation of the hormone ghrelin and its receptor, growth hormone secretagogue receptor (GHSR), contributes to the pathogenesis of Alzheimer's disease (AD). Specifically, defective GHSR function and resultant hippocampal ghrelin resistance are linked to hippocampal synaptic injury in AD paradigms. Also, AD patients exhibit elevated ghrelin activation. However, the detailed molecular mechanisms of hippocampal GHSR dysfunction and the relevance of ghrelin elevation to hippocampal ghrelin resistance in AD-relevant pathological settings are not fully understood. OBJECTIVE In the current study, we employed a recently established mouse line of AD risk [humanized amyloid beta knockin (hAβ KI mice), also referred to as a mouse model of late-onset AD in previous literature] to further define the role of ghrelin system dysregulation in the development of AD. METHODS We employed multidisciplinary techniques to determine the change of plasma ghrelin and the functional status of GHSR in hAβ KI mice as well as primary neuron cultures. RESULTS We observed concurrent plasma ghrelin elevation and hippocampal GHSR desensitization with disease progression. Further examination excluded the possibility that ghrelin elevation is a compensatory change in response to GHSR dysfunction. In contrast, further in vitro and in vivo results show that agonist-mediated overstimulation potentiates GHSR desensitization through enhanced GHSR internalization. CONCLUSIONS These findings suggest that circulating ghrelin elevation is a pathological event underlying hippocampal GHSR dysfunction, culminating in hippocampal ghrelin resistance and resultant synaptic injury in late-onset AD-related settings.
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Affiliation(s)
- Jing Tian
- Department of Pharmacology and Toxicology, The University of Kansas, Lawrence, KS, USA
| | - Eric Du
- Department of Pharmacology and Toxicology, The University of Kansas, Lawrence, KS, USA
- Blue Valley West High School, Overland Park, KS, USA
| | - Kun Jia
- Department of Pharmacology and Toxicology, The University of Kansas, Lawrence, KS, USA
| | - Tienju Wang
- Department of Pharmacology and Toxicology, The University of Kansas, Lawrence, KS, USA
| | - Lan Guo
- Department of Pharmacology and Toxicology, The University of Kansas, Lawrence, KS, USA
| | - Jeffrey M. Zigman
- Department of Internal Medicine, Center for Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Heng Du
- Department of Pharmacology and Toxicology, The University of Kansas, Lawrence, KS, USA
- Alzheimer’s disease Research Center (ADRC), Department of Neurology, The University of Kansas Medical Center, Kansas City, KS, USA
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Reich N, Hölscher C. Beyond Appetite: Acylated Ghrelin As A Learning, Memory and Fear Behavior-modulating Hormone. Neurosci Biobehav Rev 2022; 143:104952. [DOI: 10.1016/j.neubiorev.2022.104952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 04/27/2022] [Accepted: 11/05/2022] [Indexed: 11/10/2022]
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10
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The Effect of Ghrelin on Apoptosis, Necroptosis and Autophagy Programmed Cell Death Pathways in the Hippocampal Neurons of Amyloid-β 1–42-Induced Rat Model of Alzheimer’s Disease. Int J Pept Res Ther 2022. [DOI: 10.1007/s10989-022-10457-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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11
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Huang Y, Yang Y, Zhao Y, Guo D, Chen L, Shi L, Xu G. DOCK4 regulates ghrelin production in gastric X/A-like cells. J Endocrinol Invest 2022; 45:1447-1454. [PMID: 35302184 DOI: 10.1007/s40618-022-01785-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 03/08/2022] [Indexed: 10/18/2022]
Abstract
PURPOSE Ghrelin, a gastric hormone, provides a hunger signal to the central nervous system to stimulate food intake. Ghrelin also modulates neuroinflammatory and apoptotic processes. Dedicator of cytokinesis 4 (DOCK4), a guanine nucleotide exchange factor (GEF), is involved in the regulation of neuronal polarization and axon regeneration. However, the effect of DOCK4 on ghrelin production has not been explored. METHODS The expression of DOCK4 in human and mouse stomach was examined by immunohistochemical staining. The synthesis and secretion of ghrelin in Dock4 null mice were evaluated by real-time quantitative PCR, Western blot and ELISA. The effects of DOCK4 on ghrelin production in mHypoE-42 cells were measured by real-time quantitative PCR and Western blot. RESULTS We showed that DOCK4 was expressed in both human and mouse gastric ghrelin cells. The mRNA and protein levels of gastric ghrelin, as well as ghrelin secretion, were remarkably diminished in Dock4 null mice. Furthermore, we showed that overexpression of Dock4 significantly stimulated ghrelin expression, while siRNA knockdown of endogenous Dock4 resulted in a marked decrease of ghrelin in mHypoE-N42 cells. CONCLUSIONS Our results identify DOCK4 as a critical regulator for ghrelin production in gastric X/A-like cells.
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Affiliation(s)
- Y Huang
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, 510632, Guangdong, China
| | - Y Yang
- JNU-HKUST Joint Laboratory for Neuroscience and Innovative Drug Research, College of Pharmacy, Jinan University, Guangzhou, Guangdong, China
| | - Y Zhao
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, 510632, Guangdong, China
| | - D Guo
- JNU-HKUST Joint Laboratory for Neuroscience and Innovative Drug Research, College of Pharmacy, Jinan University, Guangzhou, Guangdong, China
- The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong, China
| | - L Chen
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, 510632, Guangdong, China
| | - L Shi
- JNU-HKUST Joint Laboratory for Neuroscience and Innovative Drug Research, College of Pharmacy, Jinan University, Guangzhou, Guangdong, China.
| | - G Xu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, 510632, Guangdong, China.
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Ghosh-Swaby OR, Reichelt AC, Sheppard PAS, Davies J, Bussey TJ, Saksida LM. Metabolic hormones mediate cognition. Front Neuroendocrinol 2022; 66:101009. [PMID: 35679900 DOI: 10.1016/j.yfrne.2022.101009] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 05/18/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022]
Abstract
Recent biochemical and behavioural evidence indicates that metabolic hormones not only regulate energy intake and nutrient content, but also modulate plasticity and cognition in the central nervous system. Disruptions in metabolic hormone signalling may provide a link between metabolic syndromes like obesity and diabetes, and cognitive impairment. For example, altered metabolic homeostasis in obesity is a strong determinant of the severity of age-related cognitive decline and neurodegenerative disease. Here we review the evidence that eating behaviours and metabolic hormones-particularly ghrelin, leptin, and insulin-are key players in the delicate regulation of neural plasticity and cognition. Caloric restriction and antidiabetic therapies, both of which affect metabolic hormone levels can restore metabolic homeostasis and enhance cognitive function. Thus, metabolic hormone pathways provide a promising target for the treatment of cognitive decline.
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Affiliation(s)
- Olivia R Ghosh-Swaby
- Schulich School of Medicine and Dentistry, Neuroscience Program, Western University, London, ON, Canada
| | - Amy C Reichelt
- Faculty of Health and Medical Sciences, Adelaide Medical School, Adelaide, Australia
| | - Paul A S Sheppard
- Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Jeffrey Davies
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Timothy J Bussey
- Schulich School of Medicine and Dentistry, Neuroscience Program, Western University, London, ON, Canada; Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Lisa M Saksida
- Schulich School of Medicine and Dentistry, Neuroscience Program, Western University, London, ON, Canada; Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, Western University, London, ON, Canada.
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13
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Wang Q, Duan L, Li X, Wang Y, Guo W, Guan F, Ma S. Glucose Metabolism, Neural Cell Senescence and Alzheimer’s Disease. Int J Mol Sci 2022; 23:ijms23084351. [PMID: 35457168 PMCID: PMC9030802 DOI: 10.3390/ijms23084351] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/05/2022] [Accepted: 04/12/2022] [Indexed: 12/20/2022] Open
Abstract
Alzheimer’s disease (AD), an elderly neurodegenerative disorder with a high incidence and progressive memory decline, is one of the most expensive, lethal, and burdening diseases. To date, the pathogenesis of AD has not been fully illustrated. Emerging studies have revealed that cellular senescence and abnormal glucose metabolism in the brain are the early hallmarks of AD. Moreover, cellular senescence and glucose metabolism disturbance in the brain of AD patients may precede amyloid-β deposition or Tau protein phosphorylation. Thus, metabolic reprogramming targeting senescent microglia and astrocytes may be a novel strategy for AD intervention and treatment. Here, we recapitulate the relationships between neural cell senescence and abnormal glucose metabolism (e.g., insulin signaling, glucose and lactate metabolism) in AD. We then discuss the potential perspective of metabolic reprogramming towards an AD intervention, providing a theoretical basis for the further exploration of the pathogenesis of and therapeutic approach toward AD.
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Affiliation(s)
- Qianqian Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.W.); (L.D.); (X.L.); (Y.W.); (W.G.)
| | - Linyan Duan
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.W.); (L.D.); (X.L.); (Y.W.); (W.G.)
| | - Xingfan Li
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.W.); (L.D.); (X.L.); (Y.W.); (W.G.)
| | - Yifu Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.W.); (L.D.); (X.L.); (Y.W.); (W.G.)
| | - Wenna Guo
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.W.); (L.D.); (X.L.); (Y.W.); (W.G.)
| | - Fangxia Guan
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.W.); (L.D.); (X.L.); (Y.W.); (W.G.)
- Institute of Neuroscience, Zhengzhou University, Zhengzhou 450052, China
- NHC Key Laboratory of Birth Defects Prevention, Henan Institute of Reproduction Health Science and Technology, Zhengzhou 450002, China
- Correspondence: (F.G.); (S.M.)
| | - Shanshan Ma
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.W.); (L.D.); (X.L.); (Y.W.); (W.G.)
- Institute of Neuroscience, Zhengzhou University, Zhengzhou 450052, China
- NHC Key Laboratory of Birth Defects Prevention, Henan Institute of Reproduction Health Science and Technology, Zhengzhou 450002, China
- Correspondence: (F.G.); (S.M.)
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14
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A review of glucoregulatory hormones potentially applicable to the treatment of Alzheimer’s disease: mechanism and brain delivery. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2022. [DOI: 10.1007/s40005-022-00566-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Can dietary patterns prevent cognitive impairment and reduce Alzheimer's disease risk: exploring the underlying mechanisms of effects. Neurosci Biobehav Rev 2022; 135:104556. [PMID: 35122783 DOI: 10.1016/j.neubiorev.2022.104556] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 01/29/2022] [Accepted: 01/30/2022] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is one of the fastest growing cognitive decline-related neurological diseases. To date, effective curative strategies have remained elusive. A growing body of evidence indicates that dietary patterns have significant effects on cognitive function and the risk of developing AD. Previous studies on the association between diet and AD risk have mainly focused on individual food components and specific nutrients, and the mechanisms responsible for the beneficial effects of dietary patterns on AD are not well understood. This article provides a comprehensive overview of the effects of dietary patterns, including the Mediterranean diet (MedDiet), dietary approaches to stop hypertension (DASH) diet, Mediterranean-DASH diet intervention for neurological delay (MIND), ketogenic diet, caloric restriction, intermittent fasting, methionine restriction, and low-protein and high-carbohydrate diet, on cognitive impairment and summarizes the underlying mechanisms by which dietary patterns attenuate cognitive impairment, especially highlighting the modulation of dietary patterns on cognitive impairment through gut microbiota. Furthermore, considering the variability in individual metabolic responses to dietary intake, we put forward a framework to develop personalized dietary patterns for people with cognitive disorders or AD based on individual gut microbiome compositions.
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16
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Abstract
The stomach hormone, ghrelin, which is released during food restriction, provides a link between circulating energy state and adaptive brain function. The maintenance of such homeostatic systems is essential for an organism to survive and thrive, and accumulating evidence points to ghrelin being a key regulator of adult hippocampal neurogenesis and memory function. Aberrant neurogenesis is linked to cognitive decline in aging and neurodegeneration. Therefore, identifying endogenous metabolic factors that regulate new adult-born neuron formation is an important objective in understanding the link between nutritional status and CNS function. Here, we review current developments in our understanding of ghrelin's role in regulating neurogenesis and memory function.
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Affiliation(s)
- Jeffrey S Davies
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, Swansea, United Kingdom.
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17
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He X, Yuan W, Yang CQ, Zhu L, Liu F, Feng J, Xue YX. Ghrelin alleviates 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y cells. Neural Regen Res 2022; 17:170-177. [PMID: 34100453 PMCID: PMC8451583 DOI: 10.4103/1673-5374.314314] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ghrelin is a neuropeptide that has various physiological functions and has been demonstrated to be neuroprotective in a number of neurological disease models. However, the underlying mechanisms of ghrelin in Parkinson’s disease remain largely unexplored. The current study aimed to study the effects of ghrelin in a 6-hydroxydopamine (6-OHDA)-induced Parkinson’s disease model and evaluate the potential underlying mechanisms. In the present study, we treated an SH-SY5Y cell model with 6-OHDA, and observed that pretreatment with different concentrations of ghrelin (1, 10, and 100 nM) for 30 minutes relieved the neurotoxic effects of 6-OHDA, as revealed by Cell Counting Kit-8 and Annexin V/propidium iodide (PI) apoptosis assays. Reverse transcription quantitative polymerase chain reaction and western blot assay results demonstrated that 6-OHDA treatment upregulated α-synuclein and lincRNA-p21 and downregulated TG-interacting factor 1 (TGIF1), which was predicted as a potential transcription regulator of the gene encoding α-synuclein (SNCA). Ghrelin pretreatment was able to reverse the trends caused by 6-OHDA. The Annexin V/PI apoptosis assay results revealed that inhibiting either α-synuclein or lincRNA-p21 expression with small interfering RNA (siRNA) relieved 6-OHDA-induced cell apoptosis. Furthermore, inhibiting lincRNA-p21 also partially upregulated TGIF1. By retrieving information from a bioinformatics database and performing both double luciferase and RNA immunoprecipitation assays, we found that lincRNA-p21 and TGIF1 were able to form a double-stranded RNA-binding protein Staufen homolog 1 (STAU1) binding site and further activate the STAU1-mediated mRNA decay pathway. In addition, TGIF1 was able to transcriptionally regulate α-synuclein expression by binding to the promoter of SNCA. The Annexin V/PI apoptosis assay results showed that either knockdown of TGIF1 or overexpression of lincRNA-p21 notably abolished the neuroprotective effects of ghrelin against 6-OHDA-induced neurotoxicity. Collectively, these findings suggest that ghrelin exerts neuroprotective effects against 6-OHDA-induced neurotoxicity via the lincRNA-p21/TGIF1/α-synuclein pathway.
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Affiliation(s)
- Xin He
- Department of Neurobiology, School of Life Sciences, China Medical University; Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Wei Yuan
- Department of Orthopedics, First Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Chun-Qing Yang
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Lu Zhu
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, Liaoning Province, China
| | - Fei Liu
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Juan Feng
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
| | - Yi-Xue Xue
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, Liaoning Province, China
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18
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Beheshti S, Dehestani H. Differential expression levels of the hippocampal ghrelin and its receptor mRNA during memory consolidation. Behav Brain Res 2021; 408:113270. [PMID: 33811951 DOI: 10.1016/j.bbr.2021.113270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 03/23/2021] [Accepted: 03/28/2021] [Indexed: 12/30/2022]
Abstract
Ghrelin is a peptide, secreted mainly from the stomach. But, it is also produced in the brain. Studies have confirmed the positive impact of ghrelin on memory formation. However, the expression levels of ghrelin or its receptors were not measured in the brain during the process of memory formation. The probable alteration in the expression levels of ghrelin or its receptors in the brain during memory formation can be a reason for the contribution of its signaling in this process. We quantified the gene expression levels of ghrelin and its receptors in the hippocampus during fear and spatial memory consolidation. Thirty- nine adult male Wistar rats weighing 180-220 g were utilized. Memory consolidation was evaluated using the inhibitory avoidance task and Morris water maze. Rats were euthanized at different times (1, 3, and 24 h) post-training and their hippocampi were removed and freezed directly in liquid nitrogen. Quantitative real-time polymerize chain reaction (PCR) was used to quantify the messenger ribonucleic acid (mRNA) expression levels of the hippocampal ghrelin and its receptors. The mRNA levels of ghrelin exhibited a significant increase, 24 h post-training in the inhibitory avoidance task, while its receptor levels were down-regulated. Also, the mRNA expression levels of the hippocampal ghrelin were not changed significantly during memory consolidation in the Morris water maze, while its receptor showed a significant increase, 24 h post-training. The results show a differential profile of the expression levels of the hippocampal ghrelin or its receptor mRNA during fear or spatial memory consolidation. This proposes that a local increase in the hippocampal ghrelin or its receptor levels might be crucial for fear, and spatial memory consolidation. However, due to the small sample sizes, it is worth noting the preliminary nature of the conclusions in the present study.
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Affiliation(s)
- Siamak Beheshti
- Department of Plant and Animal Biology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran.
| | - Hadi Dehestani
- Department of Plant and Animal Biology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
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19
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Rojas M, Chávez-Castillo M, Bautista J, Ortega Á, Nava M, Salazar J, Díaz-Camargo E, Medina O, Rojas-Quintero J, Bermúdez V. Alzheimer’s disease and type 2 diabetes mellitus: Pathophysiologic and pharmacotherapeutics links. World J Diabetes 2021; 12:745-766. [PMID: 34168725 PMCID: PMC8192246 DOI: 10.4239/wjd.v12.i6.745] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 03/20/2021] [Accepted: 05/21/2021] [Indexed: 02/06/2023] Open
Abstract
At present, Alzheimer’s disease (AD) and type 2 diabetes mellitus (T2DM) are two highly prevalent disorders worldwide, especially among elderly individuals. T2DM appears to be associated with cognitive dysfunction, with a higher risk of developing neurocognitive disorders, including AD. These diseases have been observed to share various pathophysiological mechanisms, including alterations in insulin signaling, defects in glucose transporters (GLUTs), and mitochondrial dysfunctions in the brain. Therefore, the aim of this review is to summarize the current knowledge regarding the molecular mechanisms implicated in the association of these pathologies as well as recent therapeutic alternatives. In this context, the hyperphosphorylation of tau and the formation of neurofibrillary tangles have been associated with the dysfunction of the phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathways in the nervous tissues as well as the decrease in the expression of GLUT-1 and GLUT-3 in the different areas of the brain, increase in reactive oxygen species, and production of mitochondrial alterations that occur in T2DM. These findings have contributed to the implementation of overlapping pharmacological interventions based on the use of insulin and antidiabetic drugs, or, more recently, azeliragon, amylin, among others, which have shown possible beneficial effects in diabetic patients diagnosed with AD.
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Affiliation(s)
- Milagros Rojas
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela
| | - Mervin Chávez-Castillo
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela
| | - Jordan Bautista
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela
| | - Ángel Ortega
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela
| | - Manuel Nava
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela
| | - Juan Salazar
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela
| | - Edgar Díaz-Camargo
- Universidad Simón Bolívar, Facultad de Ciencias Jurídicas y Sociales, Cúcuta 540006, Colombia
| | - Oscar Medina
- Universidad Simón Bolívar, Facultad de Ciencias Jurídicas y Sociales, Cúcuta 540006, Colombia
| | - Joselyn Rojas-Quintero
- Pulmonary and Critical Care Medicine Department, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02155, United States
| | - Valmore Bermúdez
- Universidad Simón Bolívar, Facultad de Ciencias de la Salud, Barranquilla 080001, Colombia
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20
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Noda M, Liu J, Long J. Neuroprotective and Preventative Effects of Molecular Hydrogen. Curr Pharm Des 2021; 27:585-591. [PMID: 33076798 DOI: 10.2174/1381612826666201019103020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 08/12/2020] [Indexed: 11/22/2022]
Abstract
One of the beneficial effects of molecular hydrogen (H2, hydrogen gas) is neuroprotection and prevention of neurological disorders. It is important and useful if taking H2 every day can prevent or ameliorate the progression of neurodegenerative disorders, such as Parkinson's disease or Alzheimer's disease, both lacking specific therapeutic drugs. There are several mechanisms of how H2 protects neuronal damage. Anti-oxidative, anti-inflammatory, and the regulation of the endocrine system via stomach-brain connection seem to play an important role. At the cellular and tissue level, H2 appears to prevent the production of reactive oxygen species (ROS), and not only hydroxy radical (•OH) but also superoxide. In Parkinson's disease model mice, chronic intake of H2 causes the release of ghrelin from the stomach. In Alzheimer's disease model mice, sex-different neuroprotection is observed by chronic intake of H2. In female mice, declines of estrogen and estrogen receptor-β (ERβ) are prevented by H2, upregulating brain-derived neurotrophic factor (BDNF) and its receptor, tyrosine kinase receptor B (TrkB). The question of how drinking H2 upregulates the release of ghrelin or attenuates the decline of estrogen remains to be investigated and the mechanism of how H2 modulates endocrine systems and the fundamental question of what or where is the target of H2 needs to be elucidated for a better understanding of the effects of H2.
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Affiliation(s)
- Mami Noda
- Laboratory of Pathophysiology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Jiankang Liu
- Center for Mitochondrial Biology and Medicine and Center for Translational Medicine, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jiangang Long
- Center for Mitochondrial Biology and Medicine and Center for Translational Medicine, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
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21
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Sun N, Mei Y, Hu Z, Xing W, Lv K, Hu N, Zhang T, Wang D. Ghrelin attenuates depressive-like behavior, heart failure, and neuroinflammation in postmyocardial infarction rat model. Eur J Pharmacol 2021; 901:174096. [PMID: 33848542 DOI: 10.1016/j.ejphar.2021.174096] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/26/2021] [Accepted: 04/07/2021] [Indexed: 11/27/2022]
Abstract
Depression after myocardial infarction (MI) and chronic heart failure (CHF) is a common condition that is resistant to anti-depressive drugs. Ghrelin (a peptide hormone) shows dual protective effects on heart and brain. Whether ghrelin treatment attenuated depression after MI was investigated. Coronary artery occlusion was performed to induce MI and subsequent CHF in rats. Ghrelin (100 μg/kg in 0.5 ml of saline) or vehicle (0.5 ml of saline) was injected subcutaneously twice a day for 4 weeks. At week 5, all the animals underwent behavioral assessments including sucrose preference test (SPT), elevated plus maze test (EPM), and open field test (OFT). After cardiac function analysis, brain tissues were processed to determine inflammatory cytokines and microglial activations in hippocampus. Results showed that ghrelin substantially improved cardiac dysfunction, infarction size, and cardiac remodeling and modulated the release of inflammatory cytokines and the increase of Iba-1 positive microglia and glial fibrillary acidic protein-positive astrocytes in the CA1 area of hippocampus. Behavioral tests revealed that this treatment remarkably increased sucrose preference and mobile times and numbers. These findings provided evidence that peripheral ghrelin administration inhibits depression-like behavior and neuroinflammation and thus could be a new approach for the treatment of CHF-associated depression.
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Affiliation(s)
- Nan Sun
- Department of Gerontology, First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, 241001, PR China; Key Laboratory of Non-coding RNA Transformation Research of Anhui Higher Education Institution (First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, 241001, PR China
| | - Yong Mei
- Department of Gerontology, First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, 241001, PR China; Key Laboratory of Non-coding RNA Transformation Research of Anhui Higher Education Institution (First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, 241001, PR China
| | - Zhengtao Hu
- Department of Gerontology, First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, 241001, PR China
| | - Wen Xing
- Department of Gerontology, First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, 241001, PR China
| | - Kun Lv
- Key Laboratory of Non-coding RNA Transformation Research of Anhui Higher Education Institution (First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, 241001, PR China
| | - Nengwei Hu
- Department of Gerontology, First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, 241001, PR China; Department of Physiology and Neurobiology, Zhengzhou University School of Medicine, Zhengzhou, 450001, China; Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Ting Zhang
- Department of Psychology, Wannan Medical College, Wuhu, 241001, PR China.
| | - Deguo Wang
- Department of Gerontology, First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, 241001, PR China; Key Laboratory of Non-coding RNA Transformation Research of Anhui Higher Education Institution (First Affiliated Hospital of Wannan Medical College (Yijishan Hospital), Wuhu, Anhui, 241001, PR China.
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22
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Zhao L, Liu JW, Kan BH, Shi HY, Yang LP, Liu XY. Acupuncture accelerates neural regeneration and synaptophysin production after neural stem cells transplantation in mice. World J Stem Cells 2020; 12:1576-1590. [PMID: 33505601 PMCID: PMC7789117 DOI: 10.4252/wjsc.v12.i12.1576] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 09/23/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Synaptophysin plays a key role in synaptic development and plasticity of neurons and is closely related to the cognitive process of Alzheimer’s disease (AD) patients. Exogenous neural stem cells (NSCs) improve the damaged nerve function. The effects of Sanjiao acupuncture on cognitive impairment may be related to the regulation of the NSC microenvironment.
AIM To explore the anti-dementia mechanism of acupuncture by regulating the NSC microenvironment.
METHODS NSCs were isolated from pregnant senescence-accelerated mouse resistant 1 (SAMR1) mice, labeled with BrdU, and injected into the hippocampus of senescence-accelerated mouse prone 8 (SAMP8) mice. Eight-month-old senescence-accelerated mice (SAM) were randomly divided into six groups: SAMR1 (RC), SAMP8 (PC), sham transplantation (PS), NSC transplantation (PT), NSC transplantation with acupuncture (PTA), and NSC transplantation with non-acupoint acupuncture (PTN). Morris water maze test was used to study the learning and memory ability of mice after NSC transplantation. Hematoxylin-eosin staining and immunofluorescence were used to observe the his-topathological changes and NSC proliferation in mice. A co-culture model of hippocampal slices and NSCs was established in vitro, and the synaptophysin expression in the hippocampal microenvironment of mice was observed by flow cytometry after acupuncture treatment.
RESULTS Morris water maze test showed significant cognitive impairment of learning and memory in 8-mo-old SAMP8, which improved in all the NSC transplantation groups. The behavioral change in the PTA group was stronger than those in the other two groups (P < 0.05). Histopathologically, the hippocampal structure was clear, the cell arrangement was dense and orderly, and the necrosis of cells in CA1 and CA3 areas was significantly reduced in the PTA group when compared with the PC group. The BrdU-positive proliferating cells were found in NSC hippocampal transplantation groups, and the number increased significantly in the PTA group than in the PT and PTN groups (P < 0.05). Flow cytometry showed that after co-culture of NSCs with hippocampal slices in vitro, the synaptophysin expression in the PC group decreased in comparison to the RC group, that in PT, PTA, and PTN groups increased as compared to the PC group, and that in the PTA group increased significantly as compared to the PTN group with acupoint-related specificity (P < 0.05).
CONCLUSION Acupuncture may promote nerve regeneration and synaptogenesis in SAMP8 mice by regulating the microenvironment of NSC transplantation to improve the nerve activity and promote the recovery of AD-damaged cells.
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Affiliation(s)
- Lan Zhao
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300381, China
- Tianjin Key Laboratory of Acupuncture and Moxibustion, Tianjin 300381, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300381, China
| | - Jian-Wei Liu
- Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Bo-Hong Kan
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300381, China
- Tianjin Key Laboratory of Acupuncture and Moxibustion, Tianjin 300381, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300381, China
| | - Hui-Yan Shi
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300381, China
- Tianjin Key Laboratory of Acupuncture and Moxibustion, Tianjin 300381, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300381, China
| | - Lin-Po Yang
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300381, China
| | - Xin-Yu Liu
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300381, China
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Reich N, Hölscher C. Acylated Ghrelin as a Multi-Targeted Therapy for Alzheimer's and Parkinson's Disease. Front Neurosci 2020; 14:614828. [PMID: 33381011 PMCID: PMC7767977 DOI: 10.3389/fnins.2020.614828] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/27/2020] [Indexed: 12/13/2022] Open
Abstract
Much thought has been given to the impact of Amyloid Beta, Tau and Alpha-Synuclein in the development of Alzheimer's disease (AD) and Parkinson's disease (PD), yet the clinical failures of the recent decades indicate that there are further pathological mechanisms at work. Indeed, besides amyloids, AD and PD are characterized by the culminative interplay of oxidative stress, mitochondrial dysfunction and hyperfission, defective autophagy and mitophagy, systemic inflammation, BBB and vascular damage, demyelination, cerebral insulin resistance, the loss of dopamine production in PD, impaired neurogenesis and, of course, widespread axonal, synaptic and neuronal degeneration that leads to cognitive and motor impediments. Interestingly, the acylated form of the hormone ghrelin has shown the potential to ameliorate the latter pathologic changes, although some studies indicate a few complications that need to be considered in the long-term administration of the hormone. As such, this review will illustrate the wide-ranging neuroprotective properties of acylated ghrelin and critically evaluate the hormone's therapeutic benefits for the treatment of AD and PD.
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Affiliation(s)
- Niklas Reich
- Biomedical & Life Sciences Division, Lancaster University, Lancaster, United Kingdom
| | - Christian Hölscher
- Neurology Department, A Second Hospital, Shanxi Medical University, Taiyuan, China.,Research and Experimental Center, Henan University of Chinese Medicine, Zhengzhou, China
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24
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Tian J, Wang T, Wang Q, Guo L, Du H. MK0677, a Ghrelin Mimetic, Improves Neurogenesis but Fails to Prevent Hippocampal Lesions in a Mouse Model of Alzheimer's Disease Pathology. J Alzheimers Dis 2020; 72:467-478. [PMID: 31594237 DOI: 10.3233/jad-190779] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hippocampal lesions including synaptic injury, neuroinflammation, and impaired neurogenesis are featured pathology closely associated with neuronal stress and cognitive impairment in Alzheimer's disease (AD). Previous studies suggest that ghrelin and its receptor, growth hormone secretagogue receptor 1α (GHSR1α), promote hippocampal synaptic function and neurogenesis. GHSR1α activation thus holds the potential to be a therapeutic avenue for the treatment of hippocampal pathology in AD; however, a comprehensive study on the preventive effect of MK0677 on hippocampal lesions in AD-related conditions is still lacking. In this study, we treated a transgenic mouse model of AD-like amyloidosis (5xFAD mice) at the asymptomatic stage with MK0677, a potent ghrelin mimetic. We found that MK0677 fostered hippocampal neurogenesis in 5xFAD mice but observed little preventive function with regards to the development of hippocampal amyloid-β (Aβ) deposition, synaptic loss, microglial activation, or cognitive impairment. Furthermore, MK0677 at a dose of 3 mg/kg significantly increased 5xFAD mouse mortality. Despite enhanced hippocampal neurogenesis, MK0677 treatment has little beneficial effect to prevent hippocampal lesions or cognitive deficits against Aβ toxicity. This study, together with a failed large-scale clinical trial, suggests the ineffectiveness of MK0677 alone for AD prevention and treatment.
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Affiliation(s)
- Jing Tian
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Tienju Wang
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Qi Wang
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA.,Department of Neurology, Qianfoshan Hospital, Shandong First Medical University, Jinan, China
| | - Lan Guo
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Heng Du
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
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25
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Kim S, Nam Y, Shin SJ, Park YH, Jeon SG, Kim JI, Kim MJ, Moon M. The Potential Roles of Ghrelin in Metabolic Syndrome and Secondary Symptoms of Alzheimer's Disease. Front Neurosci 2020; 14:583097. [PMID: 33071750 PMCID: PMC7543232 DOI: 10.3389/fnins.2020.583097] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 08/26/2020] [Indexed: 12/12/2022] Open
Abstract
Although the major causative factors of Alzheimer's disease (AD) are the accumulation of amyloid β and hyperphosphorylated tau, AD can also be caused by metabolic dysfunction. The major clinical symptom of AD is cognitive dysfunction. However, AD is also accompanied by various secondary symptoms such as depression, sleep-wake disturbances, and abnormal eating behaviors. Interestingly, the orexigenic hormone ghrelin has been suggested to have beneficial effects on AD-related metabolic syndrome and secondary symptoms. Ghrelin improves lipid distribution and alters insulin sensitivity, effects that are hypothesized to delay the progression of AD. Furthermore, ghrelin can relieve depression by enhancing the secretion of hormones such as serotonin, noradrenaline, and orexin. Moreover, ghrelin can upregulate the expression of neurotrophic factors such as brain-derived neurotrophic factor and modulate the release of proinflammatory cytokines such as tumor necrosis factor α and interleukin 1β. Ghrelin alleviates sleep-wake disturbances by increasing the levels of melatonin, melanin-concentrating hormone. Ghrelin reduces the risk of abnormal eating behaviors by increasing neuropeptide Y and γ-aminobutyric acid. In addition, ghrelin increases food intake by inhibiting fatty acid biosynthesis. However, despite the numerous studies on the role of ghrelin in the AD-related pathology and metabolic disorders, there are only a few studies that investigate the effects of ghrelin on secondary symptoms associated with AD. In this mini review, our purpose is to provide the insights of future study by organizing the previous studies for the role of ghrelin in AD-related pathology and metabolic disorders.
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Affiliation(s)
- Sujin Kim
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Yunkwon Nam
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Soo Jung Shin
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Yong Ho Park
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Seong Gak Jeon
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea.,Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu, South Korea
| | - Jin-Il Kim
- Department of Nursing, College of Nursing, Jeju National University, Jeju-si, South Korea
| | - Min-Jeong Kim
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
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26
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Tian J, Guo L, Sui S, Driskill C, Phensy A, Wang Q, Gauba E, Zigman JM, Swerdlow RH, Kroener S, Du H. Disrupted hippocampal growth hormone secretagogue receptor 1α interaction with dopamine receptor D1 plays a role in Alzheimer's disease. Sci Transl Med 2020; 11:11/505/eaav6278. [PMID: 31413143 PMCID: PMC6776822 DOI: 10.1126/scitranslmed.aav6278] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 06/24/2019] [Indexed: 12/12/2022]
Abstract
Hippocampal lesions are a defining pathology of Alzheimer's disease (AD). However, the molecular mechanisms that underlie hippocampal synaptic injury in AD have not been fully elucidated. Current therapeutic efforts for AD treatment are not effective in correcting hippocampal synaptic deficits. Growth hormone secretagogue receptor 1α (GHSR1α) is critical for hippocampal synaptic physiology. Here, we report that GHSR1α interaction with β-amyloid (Aβ) suppresses GHSR1α activation, leading to compromised GHSR1α regulation of dopamine receptor D1 (DRD1) in the hippocampus from patients with AD. The simultaneous application of the selective GHSR1α agonist MK0677 with the selective DRD1 agonist SKF81297 rescued Ghsr1α function from Aβ inhibition, mitigating hippocampal synaptic injury and improving spatial memory in an AD mouse model. Our data reveal a mechanism of hippocampal vulnerability in AD and suggest that a combined activation of GHSR1α and DRD1 may be a promising approach for treating AD.
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Affiliation(s)
- Jing Tian
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Lan Guo
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Shaomei Sui
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA.,Department of Neurology, Qianfoshan Hospital, Shandong First Medical University, Jinan, Shandong 250014, China
| | - Christopher Driskill
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Aarron Phensy
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Qi Wang
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA.,Department of Neurology, Qianfoshan Hospital, Shandong First Medical University, Jinan, Shandong 250014, China
| | - Esha Gauba
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Jeffrey M Zigman
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Russell H Swerdlow
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Sven Kroener
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Heng Du
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA.
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27
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Cognitive enhancing effect of diapocynin in D-galactose-ovariectomy-induced Alzheimer's-like disease in rats: Role of ERK, GSK-3β, and JNK signaling. Toxicol Appl Pharmacol 2020; 398:115028. [DOI: 10.1016/j.taap.2020.115028] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/25/2020] [Accepted: 04/27/2020] [Indexed: 12/20/2022]
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28
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Martínez-Moreno CG, Arámburo C. Growth hormone (GH) and synaptogenesis. VITAMINS AND HORMONES 2020; 114:91-123. [PMID: 32723552 DOI: 10.1016/bs.vh.2020.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Growth hormone (GH) is known to exert several roles during development and function of the nervous system. Initially, GH was exclusively considered a pituitary hormone that regulates body growth and metabolism, but now its alternative extrapituitary production and pleiotropic functions are widely accepted. Through excess and deficit models, the critical role of GH in nervous system development and adult brain function has been extensively demonstrated. Moreover, neurotrophic actions of GH in neural tissues include pro-survival effects, neuroprotection, axonal growth, synaptogenesis, neurogenesis and neuroregeneration. The positive effects of GH upon memory, behavior, mood, sensorimotor function and quality of life, clearly implicate a beneficial action in synaptic physiology. Experimental and clinical evidence about GH actions in synaptic function modulation, protection and restoration are revised in this chapter.
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Affiliation(s)
- Carlos G Martínez-Moreno
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Carlos Arámburo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México.
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29
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Peng FZ, Fan J, Ge TT, Liu QQ, Li BJ. Rapid anti-depressant-like effects of ketamine and other candidates: Molecular and cellular mechanisms. Cell Prolif 2020; 53:e12804. [PMID: 32266752 PMCID: PMC7260066 DOI: 10.1111/cpr.12804] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 12/27/2022] Open
Abstract
Major depressive disorder takes at least 3 weeks for clinical anti‐depressants, such as serotonin selective reuptake inhibitors, to take effect, and only one‐third of patients remit. Ketamine, a kind of anaesthetic, can alleviate symptoms of major depressive disorder patients in a short time and is reported to be effective to treatment‐resistant depression patients. The rapid and strong anti‐depressant‐like effects of ketamine cause wide concern. In addition to ketamine, caloric restriction and sleep deprivation also elicit similar rapid anti‐depressant‐like effects. However, mechanisms about the rapid anti‐depressant‐like effects remain unclear. Elucidating the mechanisms of rapid anti‐depressant effects is the key to finding new therapeutic targets and developing therapeutic patterns. Therefore, in this review we summarize potential molecular and cellular mechanisms of rapid anti‐depressant‐like effects based on the pre‐clinical and clinical evidence, trying to provide new insight into future therapy.
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Affiliation(s)
- Fan Zhen Peng
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun, China
| | - Jie Fan
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun, China
| | - Tong Tong Ge
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun, China
| | - Qian Qian Liu
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun, China
| | - Bing Jin Li
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun, China
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30
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Meloni BP, Mastaglia FL, Knuckey NW. Cationic Arginine-Rich Peptides (CARPs): A Novel Class of Neuroprotective Agents With a Multimodal Mechanism of Action. Front Neurol 2020; 11:108. [PMID: 32158425 PMCID: PMC7052017 DOI: 10.3389/fneur.2020.00108] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/30/2020] [Indexed: 12/17/2022] Open
Abstract
There are virtually no clinically available neuroprotective drugs for the treatment of acute and chronic neurological disorders, hence there is an urgent need for the development of new neuroprotective molecules. Cationic arginine-rich peptides (CARPs) are an expanding and relatively novel class of compounds, which possess intrinsic neuroprotective properties. Intriguingly, CARPs possess a combination of biological properties unprecedented for a neuroprotective agent including the ability to traverse cell membranes and enter the CNS, antagonize calcium influx, target mitochondria, stabilize proteins, inhibit proteolytic enzymes, induce pro-survival signaling, scavenge toxic molecules, and reduce oxidative stress as well as, having a range of anti-inflammatory, analgesic, anti-microbial, and anti-cancer actions. CARPs have also been used as carrier molecules for the delivery of other putative neuroprotective agents across the blood-brain barrier and blood-spinal cord barrier. However, there is increasing evidence that the neuroprotective efficacy of many, if not all these other agents delivered using a cationic arginine-rich cell-penetrating peptide (CCPPs) carrier (e.g., TAT) may actually be mediated largely by the properties of the carrier molecule, with overall efficacy further enhanced according to the amino acid composition of the cargo peptide, in particular its arginine content. Therefore, in reviewing the neuroprotective mechanisms of action of CARPs we also consider studies using CCPPs fused to a putative neuroprotective peptide. We review the history of CARPs in neuroprotection and discuss in detail the intrinsic biological properties that may contribute to their cytoprotective effects and their usefulness as a broad-acting class of neuroprotective drugs.
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Affiliation(s)
- Bruno P Meloni
- Department of Neurosurgery, QEII Medical Centre, Sir Charles Gairdner Hospital, Nedlands, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA, Australia
| | - Frank L Mastaglia
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA, Australia
| | - Neville W Knuckey
- Department of Neurosurgery, QEII Medical Centre, Sir Charles Gairdner Hospital, Nedlands, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA, Australia
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31
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Insulin signaling pathway and related molecules: Role in neurodegeneration and Alzheimer's disease. Neurochem Int 2020; 135:104707. [PMID: 32092326 DOI: 10.1016/j.neuint.2020.104707] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Its major pathological hallmarks, neurofibrillary tangles (NFT), and amyloid-β plaques can result from dysfunctional insulin signaling. Insulin is an important growth factor that regulates cell growth, energy utilization, mitochondrial function, autophagy, oxidative stress, synaptic plasticity, and cognitive function. Insulin and its downstream signaling molecules are located majorly in the regions of cortex and hippocampus. The major molecules involved in impaired insulin signaling include IRS, PI3K, Akt, and GSK-3β. Activation or inactivation of these major molecules through increased or decreased phosphorylation plays a role in insulin signaling abnormalities or insulin resistance. Insulin resistance, therefore, is considered as a major culprit in generating the hallmarks of AD arising from neuroinflammation and oxidative stress, etc. Moreover, caspases, Nrf2, and NF-κB influence this pathway in an indirect way. Various studies also suggest a strong link between Diabetes Mellitus and AD due to the impairment of insulin signaling pathway. Moreover, studies also depict a strong correlation of other neurodegenerative diseases such as Parkinson's disease and Huntington's disease with insulin resistance. Hence this review will provide an insight into the role of insulin signaling pathway and related molecules as therapeutic targets in AD and other neurodegenerative diseases.
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32
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Sánchez-Rodríguez I, Djebari S, Temprano-Carazo S, Vega-Avelaira D, Jiménez-Herrera R, Iborra-Lázaro G, Yajeya J, Jiménez-Díaz L, Navarro-López JD. Hippocampal long-term synaptic depression and memory deficits induced in early amyloidopathy are prevented by enhancing G-protein-gated inwardly rectifying potassium channel activity. J Neurochem 2020; 153:362-376. [PMID: 31875959 PMCID: PMC7217154 DOI: 10.1111/jnc.14946] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 12/06/2019] [Accepted: 12/20/2019] [Indexed: 12/11/2022]
Abstract
Hippocampal synaptic plasticity disruption by amyloid‐β (Aβ) peptides + thought to be responsible for learning and memory impairments in Alzheimer's disease (AD) early stage. Failures in neuronal excitability maintenance seems to be an underlying mechanism. G‐protein‐gated inwardly rectifying potassium (GirK) channels control neural excitability by hyperpolarization in response to many G‐protein‐coupled receptors activation. Here, in early in vitro and in vivo amyloidosis mouse models, we study whether GirK channels take part of the hippocampal synaptic plasticity impairments generated by Aβ1–42. In vitro electrophysiological recordings from slices showed that Aβ1–42 alters synaptic plasticity by switching high‐frequency stimulation (HFS) induced long‐term potentiation (LTP) to long‐term depression (LTD), which led to in vivo hippocampal‐dependent memory deficits. Remarkably, selective pharmacological activation of GirK channels with ML297 rescued both HFS‐induced LTP and habituation memory from Aβ1–42 action. Moreover, when GirK channels were specifically blocked by Tertiapin‐Q, their activation with ML297 failed to rescue LTP from the HFS‐dependent LTD induced by Aβ1–42. On the other hand, the molecular analysis of the recorded slices by western blot showed that the expression of GIRK1/2 subunits, which form the prototypical GirK channel in the hippocampus, was not significantly regulated by Aβ1–42. However, immunohistochemical examination of our in vivo amyloidosis model showed Aβ1–42 to down‐regulate hippocampal GIRK1 subunit expression. Together, our results describe an Aβ‐mediated deleterious synaptic mechanism that modifies the induction threshold for hippocampal LTP/LTD and underlies memory alterations observed in amyloidosis models. In this scenario, GirK activation assures memory formation by preventing the transformation of HFS‐induced LTP into LTD. ![]()
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Affiliation(s)
- Irene Sánchez-Rodríguez
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Souhail Djebari
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Sara Temprano-Carazo
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - David Vega-Avelaira
- Departamento de Ciencias Biomédicas Básicas, European University of Madrid, Madrid, Spain
| | - Raquel Jiménez-Herrera
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Guillermo Iborra-Lázaro
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Javier Yajeya
- Instituto de Neurociencias de Castilla y León, University of Salamanca, Salamanca, Spain
| | - Lydia Jiménez-Díaz
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Juan D Navarro-López
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
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33
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Fan L, Mao C, Hu X, Zhang S, Yang Z, Hu Z, Sun H, Fan Y, Dong Y, Yang J, Shi C, Xu Y. New Insights Into the Pathogenesis of Alzheimer's Disease. Front Neurol 2020; 10:1312. [PMID: 31998208 PMCID: PMC6965067 DOI: 10.3389/fneur.2019.01312] [Citation(s) in RCA: 167] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 11/27/2019] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD), a common neurodegenerative disease in the elderly and the most prevalent cause of dementia, is characterized by progressive cognitive impairment. The prevalence of AD continues to increase worldwide, becoming a great healthcare challenge of the twenty-first century. In the more than 110 years since AD was discovered, many related pathogenic mechanisms have been proposed, and the most recognized hypotheses are the amyloid and tau hypotheses. However, almost all clinical trials targeting these mechanisms have not identified any effective methods to treat AD. Scientists are gradually moving away from the simple assumption, as proposed in the original amyloid hypothesis, to new theories of pathogenesis, including gamma oscillations, prion transmission, cerebral vasoconstriction, growth hormone secretagogue receptor 1α (GHSR1α)-mediated mechanism, and infection. To place these findings in context, we first reviewed the neuropathology of AD and further discussed new insights in the pathogenesis of AD.
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Affiliation(s)
- Liyuan Fan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China.,Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Chengyuan Mao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Xinchao Hu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Shuo Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China.,Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Zhihua Yang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China.,Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Zhengwei Hu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China.,Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Huifang Sun
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China.,Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Yu Fan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China.,Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Yali Dong
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Jing Yang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Changhe Shi
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Yuming Xu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
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34
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Loprinzi PD. Effects of Exercise on Long-Term Potentiation in Neuropsychiatric Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1228:439-451. [PMID: 32342476 DOI: 10.1007/978-981-15-1792-1_30] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Various neuropsychiatric conditions, such as depression, Alzheimer's disease, and Parkinson's disease, demonstrate evidence of impaired long-term potentiation, a cellular correlate of episodic memory function. This chapter discusses the mechanistic effects of these neuropsychiatric conditions on long-term potentiation and how exercise may help to attenuate these detrimental effects.
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Affiliation(s)
- Paul D Loprinzi
- Department of Health, Exercise Science, and Recreation Management, Exercise and Memory Laboratory, The University of Mississippi, Oxford, MS, USA.
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35
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Jeon SG, Hong SB, Nam Y, Tae J, Yoo A, Song EJ, Kim KI, Lee D, Park J, Lee SM, Kim JI, Moon M. Ghrelin in Alzheimer's disease: Pathologic roles and therapeutic implications. Ageing Res Rev 2019; 55:100945. [PMID: 31434007 DOI: 10.1016/j.arr.2019.100945] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/25/2019] [Accepted: 08/16/2019] [Indexed: 12/11/2022]
Abstract
Ghrelin, which has many important physiological roles, such as stimulating food intake, regulating energy homeostasis, and releasing insulin, has recently been studied for its roles in a diverse range of neurological disorders. Despite the several functions of ghrelin in the central nervous system, whether it works as a therapeutic agent for neurological dysfunction has been unclear. Altered levels and various roles of ghrelin have been reported in Alzheimer's disease (AD), which is characterized by the accumulation of misfolded proteins resulting in synaptic loss and cognitive decline. Interestingly, treatment with ghrelin or with the agonist of ghrelin receptor showed attenuation in several cases of AD-related pathology. These findings suggest the potential therapeutic implications of ghrelin in the pathogenesis of AD. In the present review, we summarized the roles of ghrelin in AD pathogenesis, amyloid beta (Aβ) homeostasis, tau hyperphosphorylation, neuroinflammation, mitochondrial deficit, synaptic dysfunction and cognitive impairment. The findings from this review suggest that ghrelin has a novel therapeutic potential for AD treatment. Thus, rigorously designed studies are needed to establish an effective AD-modifying strategy.
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36
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Buntwal L, Sassi M, Morgan AH, Andrews ZB, Davies JS. Ghrelin-Mediated Hippocampal Neurogenesis: Implications for Health and Disease. Trends Endocrinol Metab 2019; 30:844-859. [PMID: 31445747 DOI: 10.1016/j.tem.2019.07.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/21/2019] [Accepted: 07/08/2019] [Indexed: 12/13/2022]
Abstract
There is a close relationship between cognition and nutritional status, however, the mechanisms underlying this relationship require elucidation. The stomach hormone, ghrelin, which is released during food restriction, provides a link between circulating energy state and adaptive brain function. The maintenance of such homeostatic systems is essential for an organism to thrive and survive, and accumulating evidence points to ghrelin being key in promoting adult hippocampal neurogenesis and memory. Aberrant neurogenesis is linked to cognitive decline in ageing and neurodegeneration. Therefore, identifying endogenous metabolic factors that regulate new adult-born neurone formation is an important objective in understanding the link between nutritional status and central nervous system (CNS) function. Here, we review current developments in our understanding of ghrelin's role in regulating neurogenesis and memory function.
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Affiliation(s)
- Luke Buntwal
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, SA2 8PP, UK
| | - Martina Sassi
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, SA2 8PP, UK
| | - Alwena H Morgan
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, SA2 8PP, UK
| | - Zane B Andrews
- Department of Physiology, Biomedical Discovery Unit, Monash University, Melbourne, Australia
| | - Jeffrey S Davies
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, SA2 8PP, UK.
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37
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Gut Microbiota in Alzheimer's Disease, Depression, and Type 2 Diabetes Mellitus: The Role of Oxidative Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4730539. [PMID: 31178961 PMCID: PMC6501164 DOI: 10.1155/2019/4730539] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 03/13/2019] [Indexed: 02/07/2023]
Abstract
Gut microbiota consists of over 100 trillion microorganisms including at least 1000 different species of bacteria and is crucially involved in physiological and pathophysiological processes occurring in the host. An imbalanced gastrointestinal ecosystem (dysbiosis) seems to be a contributor to the development and maintenance of several diseases, such as Alzheimer's disease, depression, and type 2 diabetes mellitus. Interestingly, the three disorders are frequently associated as demonstrated by the high comorbidity rates. In this review, we introduce gut microbiota and its role in both normal and pathological processes; then, we discuss the importance of the gut-brain axis as well as the role of oxidative stress and inflammation as mediators of the pathological processes in which dysbiosis is involved. Specific sections pertain the role of the altered gut microbiota in the pathogenesis of Alzheimer's disease, depression, and type 2 diabetes mellitus. The therapeutic implications of microbiota manipulation are briefly discussed. Finally, a conclusion comments on the possible role of dysbiosis as a common pathogenetic contributor (via oxidative stress and inflammation) shared by the three disorders.
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Tripchlorolide May Improve Spatial Cognition Dysfunction and Synaptic Plasticity after Chronic Cerebral Hypoperfusion. Neural Plast 2019; 2019:2158285. [PMID: 30923551 PMCID: PMC6409048 DOI: 10.1155/2019/2158285] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/10/2018] [Accepted: 12/16/2018] [Indexed: 12/11/2022] Open
Abstract
Chronic cerebral hypoperfusion (CCH) is a common pathophysiological mechanism that underlies cognitive decline and degenerative processes in dementia and other neurodegenerative diseases. Low cerebral blood flow (CBF) during CCH leads to disturbances in the homeostasis of hemodynamics and energy metabolism, which in turn results in oxidative stress, astroglia overactivation, and synaptic protein downregulation. These events contribute to synaptic plasticity and cognitive dysfunction after CCH. Tripchlorolide (TRC) is an herbal compound with potent neuroprotective effects. The potential of TRC to improve CCH-induced cognitive impairment has not yet been determined. In the current study, we employed behavioral techniques, electrophysiology, Western blotting, immunofluorescence, and Golgi staining to investigate the effect of TRC on spatial learning and memory impairment and on synaptic plasticity changes in rats after CCH. Our findings showed that TRC could rescue CCH-induced spatial learning and memory dysfunction and improve long-term potentiation (LTP) disorders. We also found that TRC could prevent CCH-induced reductions in N-methyl-D-aspartic acid receptor 2B, synapsin I, and postsynaptic density protein 95 levels. Moreover, TRC upregulated cAMP-response element binding protein, which is an important transcription factor for synaptic proteins. TRC also prevented the reduction in dendritic spine density that is caused by CCH. However, sham rats treated with TRC did not show any improvement in cognition. Because CCH causes disturbances in brain energy homeostasis, TRC therapy may resolve this instability by correcting a variety of cognitive-related signaling pathways. However, for the normal brain, TRC treatment led to neither disturbance nor improvement in neural plasticity. Additionally, this treatment neither impaired nor further improved cognition. In conclusion, we found that TRC can improve spatial learning and memory, enhance synaptic plasticity, upregulate the expression of some synaptic proteins, and increase the density of dendritic spines. Our findings suggest that TRC may be beneficial in the treatment of cognitive impairment induced by CCH.
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Maletínská L, Popelová A, Železná B, Bencze M, Kuneš J. The impact of anorexigenic peptides in experimental models of Alzheimer's disease pathology. J Endocrinol 2019; 240:R47-R72. [PMID: 30475219 DOI: 10.1530/joe-18-0532] [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: 11/12/2018] [Accepted: 11/20/2018] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder in the elderly population. Numerous epidemiological and experimental studies have demonstrated that patients who suffer from obesity or type 2 diabetes mellitus have a higher risk of cognitive dysfunction and AD. Several recent studies demonstrated that food intake-lowering (anorexigenic) peptides have the potential to improve metabolic disorders and that they may also potentially be useful in the treatment of neurodegenerative diseases. In this review, the neuroprotective effects of anorexigenic peptides of both peripheral and central origins are discussed. Moreover, the role of leptin as a key modulator of energy homeostasis is discussed in relation to its interaction with anorexigenic peptides and their analogs in AD-like pathology. Although there is no perfect experimental model of human AD pathology, animal studies have already proven that anorexigenic peptides exhibit neuroprotective properties. This phenomenon is extremely important for the potential development of new drugs in view of the aging of the human population and of the significantly increasing incidence of AD.
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Affiliation(s)
- Lenka Maletínská
- Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic
| | - Andrea Popelová
- Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic
| | - Blanka Železná
- Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic
| | - Michal Bencze
- Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic
- Institute of Physiology AS CR, Prague, Czech Republic
| | - Jaroslav Kuneš
- Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic
- Institute of Physiology AS CR, Prague, Czech Republic
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Seminara RS, Jeet C, Biswas S, Kanwal B, Iftikhar W, Sakibuzzaman M, Rutkofsky IH. The Neurocognitive Effects of Ghrelin-induced Signaling on the Hippocampus: A Promising Approach to Alzheimer's Disease. Cureus 2018; 10:e3285. [PMID: 30443455 PMCID: PMC6235652 DOI: 10.7759/cureus.3285] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 09/11/2018] [Indexed: 12/17/2022] Open
Abstract
The communication between the gastrointestinal tract and the central nervous system (CNS) allows for certain peptide hormones to influence neurocognitive function. Ghrelin, also known as the 'hunger hormone,' has the unique ability to enter the CNS and interact with the growth hormone secretagogue receptor (GHS-R) within the hippocampus. Upon interaction with ghrelin, a conformational change in the receptor causes an increase in transcription factors to foster a wide array of physiologic changes in response to caloric deprivation. With the GHS-R in a relatively high concentration within the hippocampus, ghrelin can promote memory, spatial, learning, and behavioral effects. In fact, ghrelin appears to also have a neuroprotective and neuromodulatory response once active within the hippocampal dentate gyrus. Through the GHS-R, higher levels of ghrelin may alter cognitive circuitry and offer a possible link to the treatment of some pathologies implicated in neurological dysfunction. Alzheimer's disease (AD) is already becoming a significant target for ghrelin neuroreceptor therapy. In such experimental models, ghrelin has been shown to combat this degenerative process by eliciting an ameliorative and regenerative response. Although trials and research are still ongoing, further studies are indicated as early research into this adjuvant therapy is promising. The research team explored the effects of ghrelin by reviewing the downstream signaling modifications of ghrelin's interaction with a specific CNS receptor, the GHS-R. Although the GHS-R is found in multiple locations within the CNS, the team investigated the role of the GHS-R within the hippocampus to focus solely on the neurocognitive implications of ghrelin. The team noted which signaling pathways in particular that ghrelin initiated and used this approach to determine whether ghrelin may have any therapeutic benefits. The team explored the possible therapeutic indications of ghrelin by looking at studies conducted with a specific neurodegenerative disease known to target the hippocampus.
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Affiliation(s)
- Robert S Seminara
- Neuroscience, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Charan Jeet
- Research, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Sharmi Biswas
- Pediatrics, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Bushra Kanwal
- Department of Research, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Waleed Iftikhar
- Internal Medicine, CMH Lahore Medical College and Institute of Dentistry, Lahore, PAK
| | - Md Sakibuzzaman
- Neuroscience, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Ian H Rutkofsky
- Medicine, International American University College of Medicine, Washington, D.C., USA
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