1
|
Zhu DY, Lu J, Xu R, Yang JZ, Meng XR, Ou-Yang XN, Yan QY, Nie RF, Zhao T, Chen YD, Lu Y, Zhang YN, Li WJ, Shen X. FX5, a non-steroidal glucocorticoid receptor antagonist, ameliorates diabetic cognitive impairment in mice. Acta Pharmacol Sin 2022; 43:2495-2510. [PMID: 35260821 PMCID: PMC9525278 DOI: 10.1038/s41401-022-00884-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 02/06/2022] [Indexed: 12/15/2022] Open
Abstract
Diabetic cognitive impairment (DCI) is a common diabetic complication characterized by learning and memory deficits. In diabetic patients, hyperactivated hypothalamic-pituitary-adrenal (HPA) axis leads to abnormal increase of glucocorticoids (GCs), which causes the damage of hippocampal neurons and cognitive impairment. In this study we investigated the cognition-improving effects of a non-steroidal glucocorticoid receptor (GR) antagonist 5-chloro-N-[4-chloro-3-(trifluoromethyl) phenyl]thiophene-2-sulfonamide (FX5) in diabetic mice. Four weeks after T1DM or T2DM was induced, the mice were administered FX5 (20, 40 mg·kg-1·d-1, i.g.) for 8 weeks. Cognitive impairment was assessed in open field test, novel object recognition test, Y-maze test, and Morris water maze test. We showed that FX5 administration significantly ameliorated the cognitive impairments in both type 1 and 2 diabetic mice. Similar cognitive improvement was observed in diabetic mice following brain GR-specific knockdown by injecting AAV-si-GR. Moreover, AAV-si-GR injection occluded the cognition-improving effects of FX5, suggesting that FX5 functioning as a non-steroidal GR antagonist. In PA-treated primary neurons (as DCI model in vitro), we demonstrated that FX5 (2, 5, 10 μM) dose-dependently ameliorated synaptic impairment via upregulating GR/BDNF/TrkB/CREB pathway, protected against neuronal apoptosis through repressing GR/PI3K/AKT/GSK3β-mediated tauopathy and subsequent endoplasmic reticulum stress. In LPS-treated primary microglia, FX5 dose-dependently inhibited inflammation through GR/NF-κB/NLRP3/ASC/Caspase-1 pathway. These beneficial effects were also observed in the hippocampus of diabetic mice following FX5 administration. Collectively, we have elucidated the mechanisms underlying the beneficial effects of non-steroidal GR antagonist FX5 on DCI and highlighted the potential of FX5 in the treatment of the disease.
Collapse
Affiliation(s)
- Dan-Yang Zhu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Jian Lu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Rui Xu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Juan-Zhen Yang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Xiang-Rui Meng
- Faculty of Art and Science, Queens University, Kingston, ON, K7L 3N6, Canada
| | - Xing-Nan Ou-Yang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Qiu-Ying Yan
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Rui-Fang Nie
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Tong Zhao
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Yi-di Chen
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Yin Lu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Yi-Nan Zhang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
| | - Wen-Jun Li
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
| | - Xu Shen
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica and State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
| |
Collapse
|
2
|
Sun DS, Zhong G, Cao HX, Hu Y, Hong XY, Li T, Li X, Liu Q, Wang Q, Ke D, Liu GP, Ma RH, Luo DJ. Repeated Restraint Stress Led to Cognitive Dysfunction by NMDA Receptor-Mediated Hippocampal CA3 Dendritic Spine Impairments in Juvenile Sprague-Dawley Rats. Front Mol Neurosci 2020; 13:552787. [PMID: 33192290 PMCID: PMC7604534 DOI: 10.3389/fnmol.2020.552787] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 08/19/2020] [Indexed: 11/13/2022] Open
Abstract
Although numerous studies have indicated that chronic stress causes cognitive dysfunction with the impairment of synaptic structures and functions, the relationship between cognitive deficits induced by repeated restraint stress and the level of NMDA receptors in the subregion of the hippocampus has been relatively unknown until now. In this study, 3-week-old male Sprague-Dawley rats were exposed to repeated restraint stress for seven consecutive days, their cognitive functions were evaluated through behavioral tests, and then they were sacrificed for electrophysiological, morphological, and biochemical assays. Chronic repeated restraint stress led to cognitive and electrophysiological impairments, with a reduced density of dendritic spines. We also found that the protein level of NMDA receptors only increased in the hippocampal CA3 region. Nevertheless, repeated restraint stress-induced cognitive and synaptic dysfunction were effectively reversed by Ro25-6981, an inhibitor of the GluN2B receptor. These findings suggest that repeated restraint stress-induced synaptic and cognitive deficits are probably mediated through NMDA receptors.
Collapse
Affiliation(s)
- Dong-Sheng Sun
- Institute of Anesthesiology & Pain (IAP), Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Gang Zhong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hong-Xia Cao
- Department of Pathology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Hu
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Yue Hong
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ting Li
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao Li
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qian Liu
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qun Wang
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dan Ke
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gong-Ping Liu
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Rong-Hong Ma
- Department of Clinical Laboratory, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dan-Ju Luo
- Department of Pathology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
3
|
Yang C, Li T, Xue H, Wang L, Deng L, Xie Y, Bai X, Xin D, Yuan H, Qiu J, Wang Z, Li G. Inhibition of Necroptosis Rescues SAH-Induced Synaptic Impairments in Hippocampus via CREB-BDNF Pathway. Front Neurosci 2019; 12:990. [PMID: 30666179 PMCID: PMC6330293 DOI: 10.3389/fnins.2018.00990] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 12/10/2018] [Indexed: 12/13/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) is a devastating form of stroke that leads to incurable outcomes. Increasing evidence has proved that early brain injury (EBI) contributes mostly to unfavorable outcomes after SAH. A previously unknown mechanism of regulated cell death known as necroptosis has recently been reported. Necrostatin-1 (nec-1), a specific and potent inhibitor of necroptosis, can attenuate brain impairments after SAH. However, the effect of nec-1 on the hippocampus and its neuroprotective impact on synapses after SAH is not well understood. Our present study was designed to investigate the potential effects of nec-1 administration on synapses and its relevant signal pathway in EBI after SAH. Nec-1 was administrated in a rat model via intracerebroventricular injection after SAH. Neurobehavior scores and brain edema were detected at 24 h after SAH occurred. The expression of the receptor-interacting proteins 1 and 3 (RIP1and3) was examined as a marker of necroptosis. We used hematoxylin and eosin staining, Nissl staining, silver staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) to observe the morphological changes in hippocampus. The protective effect of nec-1 on synapses was evaluated using western blotting and electron microscopy and Western blotting was used to detect the cAMP responsive element binding (CREB) protein and brain-derived neurotrophic factor (BDNF), and we used transmission electron microscopy and TUNEL to detect the protective effects of nec-1 when a specific inhibitor of CREB, known as 666-15, was used. Our results showed that in the SAH group, RIP1, and RIP3 significantly increased in the hippocampus. Additionally, injection of nec-1 alleviated brain edema and improved neurobehavior scores, compared with those in the SAH group. The damage to neurons was attenuated, and synaptic structure also improved in the Sham+nec-1 group. Furthermore, nec-1 treatment significantly enhanced the levels of phospho-CREB and BDNF compared with those in the SAH group. The protective effect of nec-1 could hindered by 666-15. Thus, nec-1 mitigated SAH-induced synaptic impairments in the hippocampus through the inhibition of necroptosis in connection with the CREB-BDNF pathway. This study may provide a new strategy for SAH patients in clinical practice.
Collapse
Affiliation(s)
- Chunlei Yang
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China.,Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
| | - Tong Li
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China.,Shandong Key Laboratory of Brain Function Remodeling, Jinan, China.,Department of Neurosurgery, Qingdao Municipal Hospital, Qingdao, China
| | - Hao Xue
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China.,Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
| | - Lingxiao Wang
- Department of Physiology, Shandong University School of Basic Medical Sciences, Jinan, China
| | - Lin Deng
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China.,Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
| | - Yunkai Xie
- Department of Physiology, Shandong University School of Basic Medical Sciences, Jinan, China
| | - Xuemei Bai
- Department of Physiology, Shandong University School of Basic Medical Sciences, Jinan, China
| | - Danqing Xin
- Department of Physiology, Shandong University School of Basic Medical Sciences, Jinan, China
| | - Hongtao Yuan
- Department of Physiology, Shandong University School of Basic Medical Sciences, Jinan, China
| | - Jie Qiu
- Department of Physiology, Shandong University School of Basic Medical Sciences, Jinan, China
| | - Zhen Wang
- Department of Physiology, Shandong University School of Basic Medical Sciences, Jinan, China
| | - Gang Li
- Department of Neurosurgery, Qilu Hospital of Shandong University and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, China.,Shandong Key Laboratory of Brain Function Remodeling, Jinan, China
| |
Collapse
|
4
|
Baglietto-Vargas D, Prieto GA, Limon A, Forner S, Rodriguez-Ortiz CJ, Ikemura K, Ager RR, Medeiros R, Trujillo-Estrada L, Martini AC, Kitazawa M, Davila JC, Cotman CW, Gutierrez A, LaFerla FM. Impaired AMPA signaling and cytoskeletal alterations induce early synaptic dysfunction in a mouse model of Alzheimer's disease. Aging Cell 2018; 17:e12791. [PMID: 29877034 PMCID: PMC6052400 DOI: 10.1111/acel.12791] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2018] [Indexed: 12/30/2022] Open
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder that impairs memory and causes cognitive and psychiatric deficits. New evidences indicate that AD is conceptualized as a disease of synaptic failure, although the molecular and cellular mechanisms underlying these defects remain to be elucidated. Determining the timing and nature of the early synaptic deficits is critical for understanding the progression of the disease and for identifying effective targets for therapeutic intervention. Using single-synapse functional and morphological analyses, we find that AMPA signaling, which mediates fast glutamatergic synaptic transmission in the central nervous system (CNS), is compromised early in the disease course in an AD mouse model. The decline in AMPA signaling is associated with changes in actin cytoskeleton integrity, which alters the number and the structure of dendritic spines. AMPA dysfunction and spine alteration correlate with the presence of soluble but not insoluble Aβ and tau species. In particular, we demonstrate that these synaptic impairments can be mitigated by Aβ immunotherapy. Together, our data suggest that alterations in AMPA signaling and cytoskeletal processes occur early in AD. Most important, these deficits are prevented by Aβ immunotherapy, suggesting that existing therapies, if administered earlier, could confer functional benefits.
Collapse
Affiliation(s)
- David Baglietto-Vargas
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
- Department of Neurobiology and Behavior; University of California; Irvine California
- Department of Cell Biology, Genetic and Physiology; Faculty of Sciences; Biomedical Research Institute of Malaga (IBIMA); Networking Research Center on Neurodegenerative Diseases (CIBERNED); University of Malaga; Malaga Spain
| | - Gilberto Aleph Prieto
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
| | - Agenor Limon
- Department of Psychiatry and Human Behavior; University of California; Irvine California
| | - Stefania Forner
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
| | - Carlos J. Rodriguez-Ortiz
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
- Division of Occupational and Environmental Medicine; Department of Medicine; Center for Occupational and Environmental Health (COEH); University of California; Irvine California
| | - Kenji Ikemura
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
| | - Rahasson R. Ager
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
| | - Rodrigo Medeiros
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
- Clem Jones Centre for Ageing Dementia Research; Queensland Brain Institute; The University of Queensland; Brisbane Qld Australia
| | - Laura Trujillo-Estrada
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
- Department of Cell Biology, Genetic and Physiology; Faculty of Sciences; Biomedical Research Institute of Malaga (IBIMA); Networking Research Center on Neurodegenerative Diseases (CIBERNED); University of Malaga; Malaga Spain
| | - Alessandra C. Martini
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
| | - Masashi Kitazawa
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
- Division of Occupational and Environmental Medicine; Department of Medicine; Center for Occupational and Environmental Health (COEH); University of California; Irvine California
| | - Jose C. Davila
- Department of Cell Biology, Genetic and Physiology; Faculty of Sciences; Biomedical Research Institute of Malaga (IBIMA); Networking Research Center on Neurodegenerative Diseases (CIBERNED); University of Malaga; Malaga Spain
| | - Carl W. Cotman
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
- Department of Neurobiology and Behavior; University of California; Irvine California
- Department of Neurology; University of California; Irvine California
| | - Antonia Gutierrez
- Department of Cell Biology, Genetic and Physiology; Faculty of Sciences; Biomedical Research Institute of Malaga (IBIMA); Networking Research Center on Neurodegenerative Diseases (CIBERNED); University of Malaga; Malaga Spain
| | - Frank M. LaFerla
- Institute for Memory Impairments and Neurological Disorders; University of California; Irvine California
- Department of Neurobiology and Behavior; University of California; Irvine California
| |
Collapse
|
5
|
Lerdkrai C, Asavapanumas N, Brawek B, Kovalchuk Y, Mojtahedi N, Olmedillas Del Moral M, Garaschuk O. Intracellular Ca 2+ stores control in vivo neuronal hyperactivity in a mouse model of Alzheimer's disease. Proc Natl Acad Sci U S A 2018; 115:E1279-88. [PMID: 29358403 DOI: 10.1073/pnas.1714409115] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neuronal hyperactivity is the emerging functional hallmark of Alzheimer's disease (AD) in both humans and different mouse models, mediating an impairment of memory and cognition. The mechanisms underlying neuronal hyperactivity remain, however, elusive. In vivo Ca2+ imaging of somatic, dendritic, and axonal activity patterns of cortical neurons revealed that both healthy aging and AD-related mutations augment neuronal hyperactivity. The AD-related enhancement occurred even without amyloid deposition and neuroinflammation, mainly due to presenilin-mediated dysfunction of intracellular Ca2+ stores in presynaptic boutons, likely causing more frequent activation of synaptic NMDA receptors. In mutant but not wild-type mice, store emptying reduced both the frequency and amplitude of presynaptic Ca2+ transients and, most importantly, normalized neuronal network activity. Postsynaptically, the store dysfunction was minor and largely restricted to hyperactive cells. These findings identify presynaptic Ca2+ stores as a key element controlling AD-related neuronal hyperactivity and as a target for disease-modifying treatments.
Collapse
|
6
|
Mirzakhalili E, Gourgou E, Booth V, Epureanu B. Synaptic Impairment and Robustness of Excitatory Neuronal Networks with Different Topologies. Front Neural Circuits 2017; 11:38. [PMID: 28659765 PMCID: PMC5468411 DOI: 10.3389/fncir.2017.00038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 05/22/2017] [Indexed: 11/13/2022] Open
Abstract
Synaptic deficiencies are a known hallmark of neurodegenerative diseases, but the diagnosis of impaired synapses on the cellular level is not an easy task. Nonetheless, changes in the system-level dynamics of neuronal networks with damaged synapses can be detected using techniques that do not require high spatial resolution. This paper investigates how the structure/topology of neuronal networks influences their dynamics when they suffer from synaptic loss. We study different neuronal network structures/topologies by specifying their degree distributions. The modes of the degree distribution can be used to construct networks that consist of rich clubs and resemble small world networks, as well. We define two dynamical metrics to compare the activity of networks with different structures: persistent activity (namely, the self-sustained activity of the network upon removal of the initial stimulus) and quality of activity (namely, percentage of neurons that participate in the persistent activity of the network). Our results show that synaptic loss affects the persistent activity of networks with bimodal degree distributions less than it affects random networks. The robustness of neuronal networks enhances when the distance between the modes of the degree distribution increases, suggesting that the rich clubs of networks with distinct modes keep the whole network active. In addition, a tradeoff is observed between the quality of activity and the persistent activity. For a range of distributions, both of these dynamical metrics are considerably high for networks with bimodal degree distribution compared to random networks. We also propose three different scenarios of synaptic impairment, which may correspond to different pathological or biological conditions. Regardless of the network structure/topology, results demonstrate that synaptic loss has more severe effects on the activity of the network when impairments are correlated with the activity of the neurons.
Collapse
Affiliation(s)
- Ehsan Mirzakhalili
- Department of Mechanical Engineering, University of MichiganAnn Arbor, MI, United States
| | - Eleni Gourgou
- Department of Mechanical Engineering, University of MichiganAnn Arbor, MI, United States.,Division of Geriatrics, Department of Internal Medicine, Medical School, University of MichiganAnn Arbor, MI, United States
| | - Victoria Booth
- Department of Mathematics, University of MichiganAnn Arbor, MI, United States.,Department of Anesthesiology, Medical School, University of MichiganAnn Arbor, MI, United States
| | - Bogdan Epureanu
- Department of Mechanical Engineering, University of MichiganAnn Arbor, MI, United States
| |
Collapse
|
7
|
Forner S, Baglietto-Vargas D, Martini AC, Trujillo-Estrada L, LaFerla FM. Synaptic Impairment in Alzheimer's Disease: A Dysregulated Symphony. Trends Neurosci 2017; 40:347-357. [PMID: 28494972 DOI: 10.1016/j.tins.2017.04.002] [Citation(s) in RCA: 278] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is characterized by memory loss, cognitive decline, and devastating neurodegeneration, not only as a result of the extracellular accumulation of beta-amyloid peptide (Aβ) and intracellular accumulation of tau, but also as a consequence of the dysfunction and loss of synapses. Although significant advances have been made in our understanding of the relationship of the pathological role of Aβ and tau in synapse dysfunction, several questions remain as to how Aβ and tau interdependently cause impairments in synaptic function in AD. Overall, more insight into these questions should enable researchers in this field to develop novel therapeutic targets to mitigate or delay the cognitive deficits associated with this devastating disease.
Collapse
Affiliation(s)
- Stefania Forner
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - David Baglietto-Vargas
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Alessandra C Martini
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Laura Trujillo-Estrada
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Frank M LaFerla
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, USA.
| |
Collapse
|
8
|
Cárdenas-Aguayo MDC, Gómez-Virgilio L, DeRosa S, Meraz-Ríos MA. The role of tau oligomers in the onset of Alzheimer's disease neuropathology. ACS Chem Neurosci 2014; 5:1178-91. [PMID: 25268947 DOI: 10.1021/cn500148z] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Most neurodegenerative diseases are characterized by the presence of protein aggregates. Alzheimer's disease (AD) is the most common cause of dementia in people over age 60. One of the histopathological hallmarks of AD is the presence of tau protein aggregates. Historically, it has been thought that paired helical filaments (PHFs) were the toxic form of tau that assembled to form neurofibrillary tangles (NFTs), but recently there has been evidence that tau oligomers, which form before PHFs and NFTs, could be the structures mediating neurodegeneration even before the fibrillary tau is deposited. Here, we discuss the recent advances in tau oligomer research, their implications on AD and other tauopathies, the mechanisms of tau turnover by the principal protein clearance systems (the proteasome and autophagy), and the potential use of tau oligomers as drug targets for the development of new therapeutic approaches.
Collapse
Affiliation(s)
- María del Carmen Cárdenas-Aguayo
- Molecular
Biomedicine Department, CINVESTAV-IPN, Ave. Politécnico 2508, Colonia
San Pedro Zacatenco, México City, D.F. 07360, México
| | - Laura Gómez-Virgilio
- Molecular
Biomedicine Department, CINVESTAV-IPN, Ave. Politécnico 2508, Colonia
San Pedro Zacatenco, México City, D.F. 07360, México
| | - Steven DeRosa
- Center
for Dementia Research, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, New York 10962, United States
| | - Marco Antonio Meraz-Ríos
- Molecular
Biomedicine Department, CINVESTAV-IPN, Ave. Politécnico 2508, Colonia
San Pedro Zacatenco, México City, D.F. 07360, México
| |
Collapse
|
9
|
Cai Z, Yan LJ. Rapamycin, Autophagy, and Alzheimer's Disease. J Biochem Pharmacol Res 2013; 1:84-90. [PMID: 23826514 PMCID: PMC3697866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive impairment and multiple pathological lesions. At the molecular level, AD is characterized by overt amyloid β (Aβ) production and tau hyper-phosphorylation. Hence, pharmacological agents that can attenuate Aβ accumulation and tau hyper-phosphorylation have potential promise for treatment of AD. Rapamycin, an inhibitor of mammalian target of rapamycin (mTOR), is believed to be one of such pharmacological agents. It is neuroprotective in neurodegenerative diseases and its primary action is thought to be via enhancement of autophagy, a biological process that not only facilitates the clearance of mutant proteins but also significantly reduces the build-up of toxic protein aggregates such as Aβ. Since rapamycin enhancement of autophagy has been associated with abrogation of AD pathological processes such as clearance of Aβ and neurofibrillary tangles (NTFs) as well as reduction of tau hyper-phosphorylation and improvement of cognition, rapamycin is emerging as a potential therapeutic compound for AD.
Collapse
Affiliation(s)
- Zhiyou Cai
- Department of Neurology, Lu'an People's Hospital, the Lu'an Affiliated Hospital of Anhui Medical University, Lu'an, Anhui Province, China, 237005
| | - Liang-Jun Yan
- Department of Pharmacology and Neuroscience and Institute for Aging and Alzheimer's Disease Research, University of North Texas Health Science Center, Fort Worth, Texas, USA
| |
Collapse
|