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Santiago JA, Quinn JP, Potashkin JA. Sex-specific transcriptional rewiring in the brain of Alzheimer’s disease patients. Front Aging Neurosci 2022; 14:1009368. [PMID: 36389068 PMCID: PMC9659968 DOI: 10.3389/fnagi.2022.1009368] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/11/2022] [Indexed: 11/28/2022] Open
Abstract
Sex-specific differences may contribute to Alzheimer’s disease (AD) development. AD is more prevalent in women worldwide, and female sex has been suggested as a disease risk factor. Nevertheless, the molecular mechanisms underlying sex-biased differences in AD remain poorly characterized. To this end, we analyzed the transcriptional changes in the entorhinal cortex of symptomatic and asymptomatic AD patients stratified by sex. Co-expression network analysis implemented by SWItchMiner software identified sex-specific signatures of switch genes responsible for drastic transcriptional changes in the brain of AD and asymptomatic AD individuals. Pathway analysis of the switch genes revealed that morphine addiction, retrograde endocannabinoid signaling, and autophagy are associated with both females with AD (F-AD) and males with (M-AD). In contrast, nicotine addiction, cell adhesion molecules, oxytocin signaling, adipocytokine signaling, prolactin signaling, and alcoholism are uniquely associated with M-AD. Similarly, some of the unique pathways associated with F-AD switch genes are viral myocarditis, Hippo signaling pathway, endometrial cancer, insulin signaling, and PI3K-AKT signaling. Together these results reveal that there are many sex-specific pathways that may lead to AD. Approximately 20–30% of the elderly have an accumulation of amyloid beta in the brain, but show no cognitive deficit. Asymptomatic females (F-asymAD) and males (M-asymAD) both shared dysregulation of endocytosis. In contrast, pathways uniquely associated with F-asymAD switch genes are insulin secretion, progesterone-mediated oocyte maturation, axon guidance, renal cell carcinoma, and ErbB signaling pathway. Similarly, pathways uniquely associated with M-asymAD switch genes are fluid shear stress and atherosclerosis, FcγR mediated phagocytosis, and proteoglycans in cancer. These results reveal for the first time unique pathways associated with either disease progression or cognitive resilience in asymptomatic individuals. Additionally, we identified numerous sex-specific transcription factors and potential neurotoxic chemicals that may be involved in the pathogenesis of AD. Together these results reveal likely molecular drivers of sex differences in the brain of AD patients. Future molecular studies dissecting the functional role of these switch genes in driving sex differences in AD are warranted.
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Affiliation(s)
| | | | - Judith A. Potashkin
- Cellular and Molecular Pharmacology Department, Center for Neurodegenerative Diseases and Therapeutics, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
- *Correspondence: Judith A. Potashkin,
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2
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Anandakrishnan R, Tobey H, Nguyen S, Sandoval O, Klein BG, Costa BM. Cranial manipulation affects cholinergic pathway gene expression in aged rats. J Osteopath Med 2022; 122:95-103. [PMID: 34995434 DOI: 10.1515/jom-2021-0183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/01/2021] [Indexed: 11/15/2022]
Abstract
CONTEXT Age-dependent dementia is a devastating disorder afflicting a growing older population. Although pharmacological agents improve symptoms of dementia, age-related comorbidities combined with adverse effects often outweigh their clinical benefits. Therefore, nonpharmacological therapies are being investigated as an alternative. In a previous pilot study, aged rats demonstrated improved spatial memory after osteopathic cranial manipulative medicine (OCMM) treatment. OBJECTIVES In this continuation of the pilot study, we examine the effect of OCMM on gene expression to elicit possible explanations for the improvement in spatial memory. METHODS OCMM was performed on six of 12 elderly rats every day for 7 days. Rats were then euthanized to obtain the brain tissue, from which RNA samples were extracted. RNA from three treated and three controls were of sufficient quality for sequencing. These samples were sequenced utilizing next-generation sequencing from Illumina NextSeq. The Cufflinks software suite was utilized to assemble transcriptomes and quantify the RNA expression level for each sample. RESULTS Transcriptome analysis revealed that OCMM significantly affected the expression of 36 genes in the neuronal pathway (false discovery rate [FDR] <0.004). The top five neuronal genes with the largest-fold change were part of the cholinergic neurotransmission mechanism, which is known to affect cognitive function. In addition, 39.9% of 426 significant differentially expressed (SDE) genes (FDR<0.004) have been previously implicated in neurological disorders. Overall, changes in SDE genes combined with their role in central nervous system signaling pathways suggest a connection to previously reported OCMM-induced behavioral and biochemical changes in aged rats. CONCLUSIONS Results from this pilot study provide sufficient evidence to support a more extensive study with a larger sample size. Further investigation in this direction will provide a better understanding of the molecular mechanisms of OCMM and its potential in clinical applications. With clinical validation, OCMM could represent a much-needed low-risk adjunct treatment for age-related dementia including Alzheimer's disease.
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Affiliation(s)
- Ramu Anandakrishnan
- Biomedical Sciences, Edward Via College of Osteopathic Medicine, Blacksburg, VA, USA.,Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA.,Gibbs Cancer Center and Research Institute, Spartanburg, SC, USA
| | - Hope Tobey
- Sports and Osteopathic Medicine, Edward Via College of Osteopathic Medicine, Blacksburg, VA, USA
| | - Steven Nguyen
- Edward Via College of Osteopathic Medicine, Blacksburg, VA, USA
| | - Osscar Sandoval
- Edward Via College of Osteopathic Medicine, Blacksburg, VA, USA
| | - Bradley G Klein
- Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA.,School of Neuroscience, Virginia Tech, Blacksburg, VA, USA
| | - Blaise M Costa
- Biomedical Sciences, Edward Via College of Osteopathic Medicine, Blacksburg, VA, USA.,Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
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3
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Qiu T, Zeng Q, Luo X, Xu T, Shen Z, Xu X, Wang C, Li K, Huang P, Li X, Xie F, Dai S, Zhang M. Effects of Cigarette Smoking on Resting-State Functional Connectivity of the Nucleus Basalis of Meynert in Mild Cognitive Impairment. Front Aging Neurosci 2021; 13:755630. [PMID: 34867281 PMCID: PMC8638702 DOI: 10.3389/fnagi.2021.755630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/13/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Mild cognitive impairment (MCI) is the prodromal phase of Alzheimer’s disease (AD) and has a high risk of progression to AD. Cigarette smoking is one of the important modifiable risk factors in AD progression. Cholinergic dysfunction, especially the nucleus basalis of Meynert (NBM), is the converging target connecting smoking and AD. However, how cigarette smoking affects NBM connectivity in MCI remains unclear. Objective: This study aimed to evaluate the interaction effects of condition (non-smoking vs. smoking) and diagnosis [cognitively normal (CN) vs. MCI] based on the resting-state functional connectivity (rsFC) of the NBM. Methods: After propensity score matching, we included 86 non-smoking CN, 44 smoking CN, 62 non-smoking MCI, and 32 smoking MCI. All subjects underwent structural and functional magnetic resonance imaging scans and neuropsychological tests. The seed-based rsFC of the NBM with the whole-brain voxel was calculated. Furthermore, the mixed effect analysis was performed to explore the interaction effects between condition and diagnosis on rsFC of the NBM. Results: The interaction effects of condition × diagnosis on rsFC of the NBM were observed in the bilateral prefrontal cortex (PFC), bilateral supplementary motor area (SMA), and right precuneus/middle occipital gyrus (MOG). Specifically, the smoking CN showed decreased rsFC between left NBM and PFC and increased rsFC between left NBM and SMA compared with non-smoking CN and smoking MCI. The smoking MCI showed reduced rsFC between right NBM and precuneus/MOG compared with non-smoking MCI. Additionally, rsFC between the NBM and SMA showed a significant negative correlation with Wechsler Memory Scale-Logical Memory (WMS-LM) immediate recall in smoking CN (r = −0.321, p = 0.041). Conclusion: Our findings indicate that chronic nicotine exposure through smoking may lead to functional connectivity disruption between the NBM and precuneus in MCI patients. The distinct alteration patterns on NBM connectivity in CN smokers and MCI smokers suggest that cigarette smoking has different influences on normal and impaired cognition.
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Affiliation(s)
- Tiantian Qiu
- Department of Radiology, Linyi People's Hospital, Linyi, China
| | - Qingze Zeng
- Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Xiao Luo
- Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Tongcheng Xu
- Department of Radiology, Linyi People's Hospital, Linyi, China
| | - Zhujing Shen
- Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaopei Xu
- Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Chao Wang
- Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Kaicheng Li
- Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Peiyu Huang
- Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaodong Li
- Department of Radiology, Linyi People's Hospital, Linyi, China
| | - Fei Xie
- Department of Equipment and Medical Engineering, Linyi People's Hospital, Linyi, China
| | - Shouping Dai
- Department of Radiology, Linyi People's Hospital, Linyi, China
| | - Minming Zhang
- Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
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Maynard S, Hejl AM, Dinh TST, Keijzers G, Hansen ÅM, Desler C, Moreno-Villanueva M, Bürkle A, Rasmussen LJ, Waldemar G, Bohr VA. Defective mitochondrial respiration, altered dNTP pools and reduced AP endonuclease 1 activity in peripheral blood mononuclear cells of Alzheimer's disease patients. Aging (Albany NY) 2016; 7:793-815. [PMID: 26539816 PMCID: PMC4637207 DOI: 10.18632/aging.100810] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
AIMS Accurate biomarkers for early diagnosis of Alzheimer's disease (AD) are badly needed. Recent reports suggest that dysfunctional mitochondria and DNA damage are associated with AD development. In this report, we measured various cellular parameters, related to mitochondrial bioenergetics and DNA damage, in peripheral blood mononuclear cells (PBMCs) of AD and control participants, for biomarker discovery. METHODS PBMCs were isolated from 53 patients with AD of mild to moderate degree and 30 age-matched healthy controls. Tests were performed on the PBMCs from as many of these participants as possible. We measured glycolysis and mitochondrial respiration fluxes using the Seahorse Bioscience flux analyzer, mitochondrial ROS production using flow cytometry, dNTP levels by way of a DNA polymerization assay, DNA strand breaks using the Fluorometric detection of Alkaline DNA Unwinding (FADU) assay, and APE1 incision activity (in cell lysates) on a DNA substrate containing an AP site (to estimate DNA repair efficiency). RESULTS In the PBMCs of AD patients, we found reduced basal mitochondrial oxygen consumption, reduced proton leak, higher dATP level, and lower AP endonuclease 1 activity, depending on adjustments for gender and/or age. CONCLUSIONS This study reveals impaired mitochondrial respiration, altered dNTP pools and reduced DNA repair activity in PBMCs of AD patients, thus suggesting that these biochemical activities may be useful as biomarkers for AD.
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Affiliation(s)
- Scott Maynard
- Department of Cellular and Molecular Medicine, Center for Healthy Aging, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Anne-Mette Hejl
- Department of Neurology, Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Thuan-Son T Dinh
- Department of Cellular and Molecular Medicine, Center for Healthy Aging, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Guido Keijzers
- Department of Cellular and Molecular Medicine, Center for Healthy Aging, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Åse M Hansen
- Department of Public Health, University of Copenhagen, 1014 Copenhagen, Denmark.,The National Research Centre for the Working Environment, 2100 Copenhagen, Denmark
| | - Claus Desler
- Department of Cellular and Molecular Medicine, Center for Healthy Aging, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | - Alexander Bürkle
- Molecular Toxicology Group, University of Konstanz, D-78457 Konstanz, Germany
| | - Lene J Rasmussen
- Department of Cellular and Molecular Medicine, Center for Healthy Aging, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Gunhild Waldemar
- Department of Neurology, Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Vilhelm A Bohr
- Department of Cellular and Molecular Medicine, Center for Healthy Aging, University of Copenhagen, 2200 Copenhagen, Denmark.,Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224-6825, USA
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Wu ZS, Cheng H, Jiang Y, Melcher K, Xu HE. Ion channels gated by acetylcholine and serotonin: structures, biology, and drug discovery. Acta Pharmacol Sin 2015; 36:895-907. [PMID: 26238288 PMCID: PMC4564887 DOI: 10.1038/aps.2015.66] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 06/24/2015] [Indexed: 12/17/2022] Open
Abstract
The nicotinic acetylcholine receptors (nAChRs) and the 5-HT3 receptors (5-HT3Rs) are cation-selective members of the pentameric ligand-gated ion channels (pLGICs), which are oligomeric protein assemblies that convert a chemical signal into an ion flux through postsynaptic membrane. They are critical components for synaptic transmission in the nervous system, and their dysfunction contributes to many neurological disorders. The diverse subunit compositions of pLGICs give rise to complex mechanisms of ligand recognition, channel gating, and ion-selective permeability, which have been demonstrated in numerous electrophysiological and molecular biological studies, and unraveled by progress in studying the structural biology of this protein family. In this review, we discuss recent insights into the structural and functional basis of two cation-selective pLGICs, the nAChR and the 5-HT3R, including their subunit compositions, ligand binding, and channel gating mechanisms. We also discuss their relevant pharmacology and drug discovery for treating various neurological disorders. Finally, we review a model of two alternative ion conducting pathways based on the latest 5-HT3A crystal structure.
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Crystallization scale purification of α7 nicotinic acetylcholine receptor from mammalian cells using a BacMam expression system. Acta Pharmacol Sin 2015; 36:1013-23. [PMID: 26073323 DOI: 10.1038/aps.2015.34] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 04/07/2015] [Indexed: 12/16/2022] Open
Abstract
AIM To report our methods for expression and purification of α7 nicotinic acetylcholine receptor (α7-nAChR), a ligand-gated pentameric ion channel and an important drug target. METHODS α7-nAChRs of 10 different species were cloned into an inducible BacMam vector with an N-terminal tag of a tandem maltose-binding protein (MBP) and a TEV cleavage site. This α7-nAChR fusion receptor was expressed in mammalian HEK293F cells and detected by Western blot. The expression was scaled up to liters. The receptor was purified using amylose resin and size-exclusion chromatography. The quality of the purified receptor was assessed using SDS-PAGE gels, thermal stability analysis, and negative stain electron microscopy (EM). The expression construct was optimized through terminal truncations and site-directed mutagenesis. RESULTS Expression screening revealed that α7-nAChR from Taeniopygia guttata had the highest expression levels. The fusion receptor was expressed mostly on the cell surface, and it could be efficiently purified using one-step amylose affinity chromatography. One to two milligrams of the optimized α7-nAChR expression construct were purified from one liter of cell culture. The purified α7-nAChR samples displayed high thermal stability with a Tm of 60 °C, which was further enhanced by antagonist binding but decreased in the presence of agonist. EM analysis revealed ring-like structures with a central hydrophilic hole, which was consistent with the pentameric assembly of the α7-nAChR channel. CONCLUSION We have established methods for crystallization scale expression and purification of α7-nAChR, which lays a foundation for high-resolution structural studies using X-ray crystallography or single particle cryo-EM analysis.
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Falcone M, Wileyto EP, Ruparel K, Gerraty RT, LaPrate L, Detre JA, Gur R, Loughead J, Lerman C. Age-related differences in working memory deficits during nicotine withdrawal. Addict Biol 2014; 19:907-17. [PMID: 23496760 DOI: 10.1111/adb.12051] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nicotine withdrawal is associated with subtle working memory deficits that predict subsequent relapse. We examined the neural substrates underlying these processes in treatment-seeking smokers, and explored the moderating influence of age on abstinence-induced alterations in brain activity and performance. Sixty-three smokers participated in two blood oxygen level-dependent (BOLD) functional magnetic resonance imaging scans while performing a visual N-back task on two separate occasions: smoking as usual and after 24 hours of biochemically confirmed abstinence (order counterbalanced). Abstinence (versus smoking) led to reduced accuracy, slower median correct response time and reduced BOLD signal change in the three a priori regions of interest: medial frontal/cingulate gyrus and right and left dorsolateral prefrontal cortex. Significant age × session effects were found for BOLD signal change in all three regions, as well as for withdrawal and craving; for all measures, abstinence effects were attenuated in smokers aged ≥50 years compared with those <50 years old. These results suggest that abstinence effects on neurocognitive function may be more pronounced for younger smokers, and may indicate a new avenue for research exploring mechanisms underlying age differences in smoking cessation success.
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Affiliation(s)
- Mary Falcone
- Department of Pharmacology; University of Pennsylvania; Philadelphia PA USA
- Center for Interdisciplinary Research on Nicotine Addiction; Department of Psychiatry; University of Pennsylvania; Philadelphia PA USA
| | - E. Paul Wileyto
- Center for Interdisciplinary Research on Nicotine Addiction; Department of Psychiatry; University of Pennsylvania; Philadelphia PA USA
- Department of Biostatistics and Epidemiology; University of Pennsylvania; Philadelphia PA USA
| | - Kosha Ruparel
- Brain Behavior Laboratory; Neuropsychiatry Department; Hospital of the University of Pennsylvania; Philadelphia PA USA
| | - Raphael T. Gerraty
- Brain Behavior Laboratory; Neuropsychiatry Department; Hospital of the University of Pennsylvania; Philadelphia PA USA
| | - Leah LaPrate
- Center for Interdisciplinary Research on Nicotine Addiction; Department of Psychiatry; University of Pennsylvania; Philadelphia PA USA
| | - John A. Detre
- Center for Functional Neuroimaging; Department of Neurology; University of Pennsylvania; Philadelphia PA USA
| | - Ruben Gur
- Brain Behavior Laboratory; Neuropsychiatry Department; Hospital of the University of Pennsylvania; Philadelphia PA USA
| | - James Loughead
- Brain Behavior Laboratory; Neuropsychiatry Department; Hospital of the University of Pennsylvania; Philadelphia PA USA
| | - Caryn Lerman
- Center for Interdisciplinary Research on Nicotine Addiction; Department of Psychiatry; University of Pennsylvania; Philadelphia PA USA
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