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Pierson SR, Fiock KL, Wang R, Balasubramanian N, Reinhardt J, Khan KM, James TD, Hunter ML, Cooper BJ, Williamsen HR, Betters R, Deniz K, Lee G, Aldridge G, Hefti MM, Marcinkiewcz CA. Tau pathology in the dorsal raphe may be a prodromal indicator of Alzheimer's disease. Mol Psychiatry 2024:10.1038/s41380-024-02664-9. [PMID: 39143322 DOI: 10.1038/s41380-024-02664-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 06/22/2024] [Accepted: 07/04/2024] [Indexed: 08/16/2024]
Abstract
Protein aggregation in brainstem nuclei is thought to occur in the early stages of Alzheimer's disease (AD), but its specific role in driving prodromal symptoms and disease progression is largely unknown. The dorsal raphe nucleus (DRN) contains a large population of serotonin (5-hydroxytryptamine; 5-HT) neurons that regulate mood, reward-related behavior, and sleep, which are all disrupted in AD. We report here that tau pathology is present in the DRN of individuals 25-80 years old without a known history of dementia, and its prevalence was comparable to the locus coeruleus (LC). By comparison, fewer cases were positive for other pathological proteins including α-synuclein, β-amyloid, and TDP-43. To evaluate how early tau pathology impacts behavior, we overexpressed human P301L-tau in the DRN of mice and observed depressive-like behaviors and hyperactivity without deficits in spatial memory. Tau pathology was predominantly found in neurons relative to glia and colocalized with a significant proportion of Tph2-expressing neurons in the DRN. 5-HT neurons were also hyperexcitable in P301L-tauDRN mice, and there was an increase in the amplitude of excitatory post-synaptic currents (EPSCs). Moreover, astrocytic density was elevated in the DRN and accompanied by an increase in IL-1α and Frk expression, which suggests increased inflammatory signaling. Additionally, tau pathology was detected in axonal processes in the thalamus, hypothalamus, amygdala, and caudate putamen. A significant proportion of this tau pathology colocalized with the serotonin reuptake transporter (SERT), suggesting that tau may spread in an anterograde manner to regions outside the DRN. Together these results indicate that tau pathology accumulates in the DRN in a subset of individuals over 50 years and may lead to behavioral dysregulation, 5-HT neuronal dysfunction, and activation of local astrocytes which may be prodromal indicators of AD.
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Affiliation(s)
- Samantha R Pierson
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, 52242, USA
| | - Kimberly L Fiock
- Department of Pathology, University of Iowa, Iowa City, IA, 52242, USA
| | - Ruixiang Wang
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, 52242, USA
| | | | - Jessica Reinhardt
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, 52242, USA
| | - Kanza M Khan
- Psychological Sciences Department, Daemen University, Amherst, NY, 14226, USA
| | - Thomas D James
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, 52242, USA
| | - Mikayla L Hunter
- Department of Pathology, University of Iowa, Iowa City, IA, 52242, USA
| | - Benjamin J Cooper
- Department of Pathology, University of Iowa, Iowa City, IA, 52242, USA
| | | | - Ryan Betters
- Department of Pathology, University of Iowa, Iowa City, IA, 52242, USA
| | - Kaancan Deniz
- Department of Neurology, University of Iowa, Iowa City, IA, 52242, USA
| | - Gloria Lee
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52242, USA
| | - Georgina Aldridge
- Department of Neurology, University of Iowa, Iowa City, IA, 52242, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52242, USA
| | - Marco M Hefti
- Department of Pathology, University of Iowa, Iowa City, IA, 52242, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52242, USA
| | - Catherine A Marcinkiewcz
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, 52242, USA.
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52242, USA.
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Huang M, Tallon C, Zhu X, Huizar KDJ, Picciolini S, Thomas AG, Tenora L, Liyanage W, Rodà F, Gualerzi A, Kannan RM, Bedoni M, Rais R, Slusher BS. Microglial-Targeted nSMase2 Inhibitor Fails to Reduce Tau Propagation in PS19 Mice. Pharmaceutics 2023; 15:2364. [PMID: 37765332 PMCID: PMC10536502 DOI: 10.3390/pharmaceutics15092364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/06/2023] [Accepted: 09/16/2023] [Indexed: 09/29/2023] Open
Abstract
The progression of Alzheimer's disease (AD) correlates with the propagation of hyperphosphorylated tau (pTau) from the entorhinal cortex to the hippocampus and neocortex. Neutral sphingomyelinase2 (nSMase2) is critical in the biosynthesis of extracellular vesicles (EVs), which play a role in pTau propagation. We recently conjugated DPTIP, a potent nSMase2 inhibitor, to hydroxyl-PAMAM-dendrimer nanoparticles that can improve brain delivery. We showed that dendrimer-conjugated DPTIP (D-DPTIP) robustly inhibited the spread of pTau in an AAV-pTau propagation model. To further evaluate its efficacy, we tested D-DPTIP in the PS19 transgenic mouse model. Unexpectantly, D-DPTIP showed no beneficial effect. To understand this discrepancy, we assessed D-DPTIP's brain localization. Using immunofluorescence and fluorescence-activated cell-sorting, D-DPTIP was found to be primarily internalized by microglia, where it selectively inhibited microglial nSMase2 activity with no effect on other cell types. Furthermore, D-DPTIP inhibited microglia-derived EV release into plasma without affecting other brain-derived EVs. We hypothesize that microglial targeting allowed D-DPTIP to inhibit tau propagation in the AAV-hTau model, where microglial EVs play a central role in propagation. However, in PS19 mice, where tau propagation is independent of microglial EVs, it had a limited effect. Our findings confirm microglial targeting with hydroxyl-PAMAM dendrimers and highlight the importance of understanding cell-specific mechanisms when designing targeted AD therapies.
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Affiliation(s)
- Meixiang Huang
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (M.H.); (C.T.); (X.Z.); (K.D.J.H.); (A.G.T.); (L.T.); (R.R.)
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Carolyn Tallon
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (M.H.); (C.T.); (X.Z.); (K.D.J.H.); (A.G.T.); (L.T.); (R.R.)
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xiaolei Zhu
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (M.H.); (C.T.); (X.Z.); (K.D.J.H.); (A.G.T.); (L.T.); (R.R.)
- Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kaitlyn D. J. Huizar
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (M.H.); (C.T.); (X.Z.); (K.D.J.H.); (A.G.T.); (L.T.); (R.R.)
| | - Silvia Picciolini
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, Laboratory of Nanomedicine and Clinical Biophotonics (LABION), 20148 Milan, Italy; (S.P.); (F.R.); (A.G.); (M.B.)
| | - Ajit G. Thomas
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (M.H.); (C.T.); (X.Z.); (K.D.J.H.); (A.G.T.); (L.T.); (R.R.)
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Lukas Tenora
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (M.H.); (C.T.); (X.Z.); (K.D.J.H.); (A.G.T.); (L.T.); (R.R.)
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Wathsala Liyanage
- Center for Nanomedicine, Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; (W.L.); (R.M.K.)
| | - Francesca Rodà
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, Laboratory of Nanomedicine and Clinical Biophotonics (LABION), 20148 Milan, Italy; (S.P.); (F.R.); (A.G.); (M.B.)
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, 42100 Modena, Italy
| | - Alice Gualerzi
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, Laboratory of Nanomedicine and Clinical Biophotonics (LABION), 20148 Milan, Italy; (S.P.); (F.R.); (A.G.); (M.B.)
| | - Rangaramanujam M. Kannan
- Center for Nanomedicine, Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; (W.L.); (R.M.K.)
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Marzia Bedoni
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, Laboratory of Nanomedicine and Clinical Biophotonics (LABION), 20148 Milan, Italy; (S.P.); (F.R.); (A.G.); (M.B.)
| | - Rana Rais
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (M.H.); (C.T.); (X.Z.); (K.D.J.H.); (A.G.T.); (L.T.); (R.R.)
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Barbara S. Slusher
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (M.H.); (C.T.); (X.Z.); (K.D.J.H.); (A.G.T.); (L.T.); (R.R.)
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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3
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Chen Z, Chang F, Yao L, Yuan F, Hong J, Wu D, Wei Y. Clinical significance of the cognition-related pathogenic proteins in plasma neuronal-derived exosomes among normal cognitive adults over 45 years old with olfactory dysfunction. Eur Arch Otorhinolaryngol 2021; 279:3467-3476. [PMID: 34693486 DOI: 10.1007/s00405-021-07143-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/15/2021] [Indexed: 01/25/2023]
Abstract
OBJECTIVES Exosomal Phospho-Tau-181(P-T181-tau), Total tau (T-tau), and amyloid-β peptide 42 (Aβ42) have been proved the capacity for the amnestic mild cognitive impairment (MCI) and the diagnosis of Alzheimer's disease (AD). This study aimed to explore the cognitive function and the levels of P-T181-tau, T-tau, and Aβ42 in neuronal-derived exosomes (NDEs) extracted from plasma in normal cognitive adults over 45 years old with olfactory dysfunction. METHODS A cross-sectional survey of 29 participants aged over 45 was conducted. Plasma exosomes were isolated, precipitated, and enriched by immuno-absorption with anti- L1 cell adhesion molecule (L1CAM) antibody. NDEs were characterized by CD81, and extracted NDE protein (P-T181-tau, T-tau, and Aβ42) biomarkers were quantified by enzyme-linked immunosorbent assay (ELISAs). Olfactory performance was assessed by Sniffin' Sticks and cognitive performance was assessed by Montreal Cognitive Assessment (MoCA). RESULTS There was no significant difference between adults with olfactory dysfunction and without olfactory dysfunction regarding the cognitive function as measured by MoCA and all the participants showed normal cognition. Adults with olfactory dysfunction showed a higher concentration of P-T181-tau in plasma NDEs than did adults without olfactory dysfunction (P = 0.034). Both the levels of P-T181-tau (r = - 0.553, P = 0.003) and T-tau (r = - 0.417, P = 0.034) negatively correlated with the odor identification scores. In addition, the level of T-tau negatively correlated with MoCA scores (r = - 0.597, P = 0.002). The levels of P-T181-tau (r = - 0.464, P = 0.022) and T-tau (r = - 0.438, P = 0.032) negatively correlated with the delayed recall scores. CONCLUSIONS This study demonstrated that cognition-related pathogenic proteins including P-T181-tau in plasma NDEs were significantly increased in adults over 45 years old with olfactory dysfunction before the occurrence of cognitive impairment. The impaired odor identification and the delayed recall function were highly associated with the increased levels of P-T181-tau and T-tau in plasma NDEs.
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Affiliation(s)
- Zirong Chen
- Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
| | - FeiFan Chang
- Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
| | - Linyin Yao
- Department of Otolaryngology, Smell and Taste Center, Beijing Anzhen Hospital, Capital Medical University, YaBao Road 2, Beijing, 100029, Chaoyang District, China
| | - Fan Yuan
- Department of Otolaryngology, Smell and Taste Center, Beijing Anzhen Hospital, Capital Medical University, YaBao Road 2, Beijing, 100029, Chaoyang District, China
| | - Junsheng Hong
- Department of Otolaryngology, Smell and Taste Center, Beijing Anzhen Hospital, Capital Medical University, YaBao Road 2, Beijing, 100029, Chaoyang District, China
| | - Dawei Wu
- Department of Otolaryngology, Smell and Taste Center, Beijing Anzhen Hospital, Capital Medical University, YaBao Road 2, Beijing, 100029, Chaoyang District, China.
| | - Yongxiang Wei
- Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China. .,Department of Otolaryngology, Smell and Taste Center, Beijing Anzhen Hospital, Capital Medical University, YaBao Road 2, Beijing, 100029, Chaoyang District, China. .,Department of Otolaryngology, Capital Institute of Pediatrics, Beijing, China.
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Wang X, Liu Q, Li XG, Zhou QZ, Wu DQ, Li SH, Liu YC, Wang JZ. T217-Phosphorylation Exacerbates Tau Pathologies and Tau-Induced Cognitive Impairment. J Alzheimers Dis 2021; 81:1403-1418. [PMID: 33935099 DOI: 10.3233/jad-210297] [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] [Indexed: 02/04/2023]
Abstract
BACKGROUND Recent studies show that an increased T217-phosphorylation of tau in plasma could diagnose AD at an early stage with high accuracy and high specificity, while the potential toxic role of tau T217-phosphorylation is not known. OBJECTIVE To study the potential toxic role of tau T217-phosphorylation. METHODS We performed stereotactic brain injection, behavioral testing, immunohistochemistry and immunofluorescence, western blotting, Golgi staining, in vitro recombinant tau polymerization, and other measurements. RESULTS We first constructed tau T217-wild-type (T217), T217-phospho-mimic (T217E), and T217-non-phospho-mimic (T217A) plasmids or their virus vectors on the basis of wild-type tau. We found that expressing tau-T217E induced a significantly increased tau phosphorylation at multiple AD-associated sites with inhibited proteolysis and increased cleavage/fibrillization of tau, while expressing tau-T217A abolished the above changes of tau both in vitro and in vivo. By mutating T217E on tau-P301L, a dominant mutation identified in patients with frontotemporal dementia, we did not observe significant exacerbation of tau-P301L phosphorylation and cognitive impairment although the increased tau cleavage and propagation were shown. CONCLUSION T217-phosphorylation exacerbates wild-type tau hyperphosphorylation with aggravated tau cleavage/fibrillization and cognitive impairments, while overexpressing T217E on the basis P301L does not exacerbate tau phosphorylation or the P301L-induced cognitive deficits, although it aggravates tau cleavage and propagation.
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Affiliation(s)
- Xin Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qian Liu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Guang Li
- Clinic Center of Human Gene Research, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qiu-Zhi Zhou
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dong-Qin Wu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shi-Hong Li
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan-Chao Liu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
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Peripheral inflammation promotes brain tau transmission via disrupting blood-brain barrier. Biosci Rep 2021; 40:222089. [PMID: 32043530 PMCID: PMC7033313 DOI: 10.1042/bsr20193629] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/03/2020] [Accepted: 02/10/2020] [Indexed: 12/15/2022] Open
Abstract
Abnormal aggregation of pathological tau protein is a neuropathological feature of Alzheimer's disease (AD). In the AD patients, the abnormal tau accumulation first appeared in entorhinal cortex (EC) and then propagated to the hippocampus with microglia activation and inflammation, but the mechanism is elusive. Here, we studied the role and mechanisms underlying periphery inflammation on brain tau transmission. By intraperitoneal injection of lipopolysaccharide (LPS) with brain medial entorhinal cortex (MEC)-specific overexpressing P301L human tau (P301L-hTau), we found that both acute and chronic administration of LPS remarkably promoted P301L-hTau transmission from MEC to the hippocampal subsets. Interestingly, the chronic LPS-induced P301L-hTau transmission was still apparent after blocking microglia activation. Further studies demonstrated that LPS disrupted the integrity of blood-brain barrier (BBB) and simultaneous intraperitoneal administration of glucocorticoid (GC) attenuated LPS-promoted P301L-hTau transmission. These data together suggest that a non-microglia-dependent BBB disruption contributes to peripheral LPS-promoted brain P301L-hTau transmission, therefore, maintaining the integrity of BBB can be a novel strategy for preventing pathological tau propagation in AD and other tauopathies.
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Bell BJ, Malvankar MM, Tallon C, Slusher BS. Sowing the Seeds of Discovery: Tau-Propagation Models of Alzheimer's Disease. ACS Chem Neurosci 2020; 11:3499-3509. [PMID: 33050700 DOI: 10.1021/acschemneuro.0c00531] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The propagation of pathological proteins throughout the brain is the primary physiological hallmark of the progression of Alzheimer's Disease (AD). A growing body of evidence indicates that hyperphosphorylated Tau proteins are spread transcellularly between neurons in a prionlike fashion, inducing misfolding and aggregation into neurofibrillary tangles which accumulate along specific connectivity pathways. Earlier transgenic rodent AD models did not capture this disease-relevant spread, and therefore, seeded Tau-propagation models have been developed. Here, mutant human Tau (as isolated protein or packaged into an adeno-associated virus (AAV) viral vector) is stereotaxically injected into select brain regions and its histopathological propagation to downstream neurons quantified. These models offer a faster and more direct mechanism to evaluate genetic components and therapeutic approaches which attenuate Tau spreading in vivo. Recently, these Tau-seeding models have revealed several new targets for AD drug discovery, including nSMase2, SIRT1, p300/CBP, LRP1, and TYROBP, as well as the potential therapeutics based on melatonin and chondroitinase ABC. Importantly, these Tau-propagation rodent models more closely phenocopy the progression of AD in humans and are therefore likely to improve preclinical studies and derisk future moves into clinical trials.
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Affiliation(s)
- Benjamin J. Bell
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Medhinee M. Malvankar
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Carolyn Tallon
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Barbara S. Slusher
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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7
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Li X, Run X, Wei Z, Zeng K, Liang Z, Huang F, Ke D, Wang Q, Wang JZ, Liu R, Zhang B, Wang X. Intranasal Insulin Prevents Anesthesia-induced Cognitive Impairments in Aged Mice. Curr Alzheimer Res 2020; 16:8-18. [PMID: 30381076 DOI: 10.2174/1567205015666181031145045] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/16/2018] [Accepted: 10/15/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND Preclinical and clinical evidence suggests that elderly individuals are at increased risk of cognitive decline after general anesthesia. General anesthesia is also believed to be a risk factor for Postoperative Cognitive Dysfunction (POCD) and Alzheimer's Disease (AD). Intranasal administration of insulin, which delivers the drug directly into the brain, improves memory and cognition in both animal studies and small clinical trials. However, how insulin treatment improves cognitive function is poorly understood. METHODS Aged mice were pretreated with intranasal insulin or saline before anesthesia. Propofol was added intraperitoneally to the mice from 7th day of insulin/saline treatment, and general anesthesia was induced and maintained for 2 hours/day for 5 consecutive days. Mice were evaluated at 26th day when the mice were continued on insulin or saline administration for another 15 days. RESULTS We found that intranasal insulin treatment prevented anesthesia-induced cognitive impairments, as measured by novel object recognition test and contextual-dependent fear conditioning test. Insulin treatment also increased the expression level of Post-synaptic Density Protein 95 (PSD95), as well as upregulated Microtubule-associated Protein-2 (MAP-2) in the dentate gyrus of the hippocampus. Furthermore, we found that insulin treatment restored insulin signaling disturbed by anesthesia via activating PI3K/PDK1/AKT pathway, and attenuated anesthesia-induced hyperphosphorylation of tau at multiple AD-associated sites. We found the attenuation of tau hyperphosphorylation occurred by increasing the level of GSK3β phosphorylated at Ser9, which leads to inactivation of GSK-3β. CONCLUSION Intranasal insulin administration might be a promising therapy to prevent anesthesiainduced cognitive deficit in elderly individuals.
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Affiliation(s)
- Xing Li
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoqin Run
- Department of Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhen Wei
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Kuan Zeng
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhihou Liang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fang Huang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Dan Ke
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Qun Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
| | - Rong Liu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Xiaochuan Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
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8
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AD-Related N-Terminal Truncated Tau Is Sufficient to Recapitulate In Vivo the Early Perturbations of Human Neuropathology: Implications for Immunotherapy. Mol Neurobiol 2018; 55:8124-8153. [PMID: 29508283 DOI: 10.1007/s12035-018-0974-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/19/2018] [Indexed: 01/08/2023]
Abstract
The NH2tau 26-44 aa (i.e., NH2htau) is the minimal biologically active moiety of longer 20-22-kDa NH2-truncated form of human tau-a neurotoxic fragment mapping between 26 and 230 amino acids of full-length protein (htau40)-which is detectable in presynaptic terminals and peripheral CSF from patients suffering from AD and other non-AD neurodegenerative diseases. Nevertheless, whether its exogenous administration in healthy nontransgenic mice is able to elicit a neuropathological phenotype resembling human tauopathies has not been yet investigated. We explored the in vivo effects evoked by subchronic intracerebroventricular (i.c.v.) infusion of NH2htau or its reverse counterpart into two lines of young (2-month-old) wild-type mice (C57BL/6 and B6SJL). Six days after its accumulation into hippocampal parenchyma, significant impairment in memory/learning performance was detected in NH2htau-treated group in association with reduced synaptic connectivity and neuroinflammatory response. Compromised short-term plasticity in paired-pulse facilitation paradigm (PPF) was detected in the CA3/CA1 synapses from NH2htau-impaired animals along with downregulation in calcineurin (CaN)-stimulated pCREB/c-Fos pathway(s). Importantly, these behavioral, synaptotoxic, and neuropathological effects were independent from the genetic background, occurred prior to frank neuronal loss, and were specific because no alterations were detected in the control group infused with its reverse counterpart. Finally, a 2.0-kDa peptide which biochemically and immunologically resembles the injected NH2htau was endogenously detected in vivo, being present in hippocampal synaptosomal preparations from AD subjects. Given that the identification of the neurotoxic tau species is mandatory to develop a more effective tau-based immunological approach, our evidence can have important translational implications for cure of human tauopathies.
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