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de la Cruz L, Bui D, Moreno CM, Vivas O. Sympathetic Motor Neuron Dysfunction is a Missing Link in Age-Associated Sympathetic Overactivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.27.559800. [PMID: 37808870 PMCID: PMC10557755 DOI: 10.1101/2023.09.27.559800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Overactivity of the sympathetic nervous system is a hallmark of aging. The cellular mechanisms behind this overactivity remain poorly understood, with most attention paid to likely central nervous system components. In this work, we hypothesized that aging also affects the function of motor neurons in the peripheral sympathetic ganglia. To test this hypothesis, we compared the electrophysiological responses and ion-channel activity of neurons isolated from the superior cervical ganglia of young (12 weeks), middle-aged (64 weeks), and old (115 weeks) mice. These approaches showed that aging does impact the intrinsic properties of sympathetic motor neurons, increasing spontaneous and evoked firing responses. A reduction of M current emerged as a major contributor to age-related hyperexcitability. Thus, it is essential to consider the effect of aging on motor components of the sympathetic reflex as a crucial part of the mechanism involved in sympathetic overactivity.
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Affiliation(s)
- Lizbeth de la Cruz
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Derek Bui
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Claudia M. Moreno
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
- Howard Hughes Medical Institute
| | - Oscar Vivas
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
- Department of Pharmacology, University of Washington, Seattle, WA
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Leenders F, Koole L, Slaets H, Tiane A, Hove DVD, Vanmierlo T. Navigating oligodendrocyte precursor cell aging in brain health. Mech Ageing Dev 2024; 220:111959. [PMID: 38950628 DOI: 10.1016/j.mad.2024.111959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/17/2024] [Accepted: 06/24/2024] [Indexed: 07/03/2024]
Abstract
Oligodendrocyte precursor cells (OPCs) comprise 5-8 % of the adult glial cell population and stand out as the most proliferative cell type in the central nervous system (CNS). OPCs are responsible for generating oligodendrocytes (OLs), the myelinating cells of the CNS. However, OPC functions decline as we age, resulting in impaired differentiation and inadequate remyelination. This review explores the cellular and molecular changes associated with OPC aging, and their impact on OPC differentiation and functionality. Furthermore, it examines the impact of OPC aging within the context of multiple sclerosis and Alzheimer's disease, both neurodegenerative conditions wherein aged OPCs exacerbate disease progression by impeding remyelination. Moreover, various pharmacological interventions targeting pathways related to senescence and differentiation are discussed as potential strategies to rejuvenate aged OPCs. Enhancing our understanding of OPC aging mechanisms holds promise for developing new therapies to improve remyelination and repair in age-related neurodegenerative disorders.
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Affiliation(s)
- Freddy Leenders
- Department Psychiatry and Neuropsychology, Division Translational Neuroscience, Mental Health and Neuroscience Research Institute, Maastricht University, Maastricht, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Lisa Koole
- Department Psychiatry and Neuropsychology, Division Translational Neuroscience, Mental Health and Neuroscience Research Institute, Maastricht University, Maastricht, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Helena Slaets
- University MS Centre (UMSC) Hasselt, Pelt, Belgium; Neuro-Immune Connections and Repair Lab, Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Assia Tiane
- Department Psychiatry and Neuropsychology, Division Translational Neuroscience, Mental Health and Neuroscience Research Institute, Maastricht University, Maastricht, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; University MS Centre (UMSC) Hasselt, Pelt, Belgium
| | - Daniel van den Hove
- Department Psychiatry and Neuropsychology, Division Translational Neuroscience, Mental Health and Neuroscience Research Institute, Maastricht University, Maastricht, the Netherlands
| | - Tim Vanmierlo
- Department Psychiatry and Neuropsychology, Division Translational Neuroscience, Mental Health and Neuroscience Research Institute, Maastricht University, Maastricht, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; University MS Centre (UMSC) Hasselt, Pelt, Belgium.
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Wu C, Tu T, Xie M, Wang Y, Yan B, Gong Y, Zhang J, Zhou X, Xie Z. Spatially resolved transcriptome of the aging mouse brain. Aging Cell 2024; 23:e14109. [PMID: 38372175 PMCID: PMC11113349 DOI: 10.1111/acel.14109] [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] [Received: 09/28/2023] [Revised: 01/22/2024] [Accepted: 01/29/2024] [Indexed: 02/20/2024] Open
Abstract
Brain aging is associated with cognitive decline, memory loss and many neurodegenerative disorders. The mammalian brain has distinct structural regions that perform specific functions. However, our understanding in gene expression and cell types within the context of the spatial organization of the mammalian aging brain is limited. Here we generated spatial transcriptomic maps of young and old mouse brains. We identified 27 distinguished brain spatial domains, including layer-specific subregions that are difficult to dissect individually. We comprehensively characterized spatial-specific changes in gene expression in the aging brain, particularly for isocortex, the hippocampal formation, brainstem and fiber tracts, and validated some gene expression differences by qPCR and immunohistochemistry. We identified aging-related genes and pathways that vary in a coordinated manner across spatial regions and parsed the spatial features of aging-related signals, providing important clues to understand genes with specific functions in different brain regions during aging. Combined with single-cell transcriptomics data, we characterized the spatial distribution of brain cell types. The proportion of immature neurons decreased in the DG region with aging, indicating that the formation of new neurons is blocked. Finally, we detected changes in information interactions between regions and found specific pathways were deregulated with aging, including classic signaling WNT and layer-specific signaling COLLAGEN. In summary, we established a spatial molecular atlas of the aging mouse brain (http://sysbio.gzzoc.com/Mouse-Brain-Aging/), which provides important resources and novel insights into the molecular mechanism of brain aging.
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Affiliation(s)
- Cheng Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic CenterSun Yat‐sen UniversityGuangzhouChina
| | - Tianxiang Tu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic CenterSun Yat‐sen UniversityGuangzhouChina
| | - Mingzhe Xie
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic CenterSun Yat‐sen UniversityGuangzhouChina
| | - Yiting Wang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, MOE Innovative Center for New Drug Development of Immune Inflammatory DiseasesInstitutes of Brain Science, Institute for Medical and Engineering Innovation, Department of Ophthalmology, Eye & ENT Hospital, Fudan UniversityShanghaiChina
| | - Biao Yan
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, MOE Innovative Center for New Drug Development of Immune Inflammatory DiseasesInstitutes of Brain Science, Institute for Medical and Engineering Innovation, Department of Ophthalmology, Eye & ENT Hospital, Fudan UniversityShanghaiChina
| | - Yajun Gong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic CenterSun Yat‐sen UniversityGuangzhouChina
| | - Jiayi Zhang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, MOE Innovative Center for New Drug Development of Immune Inflammatory DiseasesInstitutes of Brain Science, Institute for Medical and Engineering Innovation, Department of Ophthalmology, Eye & ENT Hospital, Fudan UniversityShanghaiChina
| | - Xiaolai Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic CenterSun Yat‐sen UniversityGuangzhouChina
| | - Zhi Xie
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic CenterSun Yat‐sen UniversityGuangzhouChina
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Wang P, Mi Y, Yu H, Teng X, Jin S, Xiao L, Xue H, Tian D, Guo Q, Wu Y. Trimethylamine-N-oxide aggravated the sympathetic excitation in D-galactose induced aging rats by down-regulating P2Y12 receptor in microglia. Biomed Pharmacother 2024; 174:116549. [PMID: 38593701 DOI: 10.1016/j.biopha.2024.116549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/11/2024] Open
Abstract
This study aimed to determine whether trimethylamine N-oxide (TMAO) was involved in sympathetic activation in aging and the underlying mechanisms. Our hypothesis is TMAO reduces P2Y12 receptor (P2Y12R) and induces microglia-mediated inflammation in the paraventricular nucleus (PVN), then leading to sympathetic activation in aging. This study involved 18 young adults and 16 old adults. Aging rats were established by injecting D-galactose (D-gal, 200 mg/kg/d) subcutaneously for 12 weeks. TMAO (120 mg/kg/d) or 1% 3, 3-dimethyl-l-butanol (DMB) was administrated via drinking water for 12 weeks to investigate their effects on neuroinflammation and sympathetic activation in aging rats. Plasma TMAO, NE and IL-1β levels were higher in old adults than in young adults. In addition, standard deviation of all normal to normal intervals (SDNN) and standard deviation of the average of normal to normal intervals (SDANN) were lower in old adults and negatively correlated with TMAO, indicating sympathetic activation in old adults, which is associated with an increase in TMAO levels. Treatment of rats with D-gal showed increased senescence-associated protein levels and microglia-mediated inflammation, as well as decreased P2Y12R protein levels in PVN. Plasma TMAO, NE and IL-1β levels were increased, accompanied by enhanced renal sympathetic nerve activity (RSNA). While TMAO treatment exacerbated the above phenomenon, DMB mitigated it. These findings suggest that TMAO contributes to sympathetic hyperactivity in aging by downregulating P2Y12R in microglia and increasing inflammation in the PVN. These results may provide promising new target for the prevention and treatment of aging and aging-related diseases.
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Affiliation(s)
- Ping Wang
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China
| | - Yuan Mi
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China; Department of Emergency, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China
| | - Hao Yu
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China
| | - Xu Teng
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China
| | - Sheng Jin
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China
| | - Lin Xiao
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China
| | - Hongmei Xue
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China
| | - Danyang Tian
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China
| | - Qi Guo
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China; Experimental Center for Teaching, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Cardiovascular Homeostasis and Aging, China.
| | - Yuming Wu
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang 050017, China; Hebei Collaborative Innovation Center for Cardio-Cerebrovascular Disease, Shijiazhuang 050017, China; The Key Laboratory of Neural and Vascular Biology, Ministry of Education, China; Hebei Key Laboratory of Cardiovascular Homeostasis and Aging, China.
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Hua R, Liu B, He W, Zhang H, Liu Y, Xie Q, Zhou L, Pei F. Calcitriol reverses age-related hypertension via downregulating renal AP1/AT 1R pathway through regulating mitochondrial function. Clin Exp Hypertens 2023; 45:2277653. [PMID: 37939250 DOI: 10.1080/10641963.2023.2277653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/26/2023] [Indexed: 11/10/2023]
Abstract
BACKGROUND The vitamin D level in the blood is associated with the incidence of hypertension. The present study investigated whether or not calcitriol, an active form of vitamin D, reverses age-related hypertension. METHODS Young (3-month-old) and aged (12-month-old) C57BL/6 male mice were administered with or without calcitriol at 150 ng/kg per day by oral gavage for 8 weeks. Blood pressure was measured by tail-cuff plethysmography and telemetry, and superoxide production in renal tissue was assessed by fluorescence imaging, and the protein expression of AP1/AT1R signaling pathway was examined by Western blot. RESULTS We showed that 24-hour renal sodium excretion was impaired and blood pressure was increased in aged mice, which was related to the enhancement of renal AT1R expression and function. In addition, the expression of transcription factor AP1 (a dimer of c-Fos and c-Jun) and the binding of AP1 to the AT1R promoter region was significantly enhanced, accompanied by decreased nuclear translocation of Nrf2, abnormal mitochondrial function including decreased ATP production, NAD+/NADH ratio and mtDNA copy numbers, and increased reactive oxygen species. Calcitriol increased 24-hour urinary sodium excretion and reduced blood pressure in aged mice. Mechanically, calcitriol increased the nuclear translocation of Nrf2, improved mitochondrial function, reduced AP1 binding ability to AT1R promoter, which reversed enhanced AT1R expression and function, and lowered blood pressure in aged mice. CONCLUSIONS Our findings indicated that calcitriol reversed age-related hypertension via downregulating renal AP1/AT1R pathway through regulating mitochondrial function. Thus, calcitriol may be a valuable therapeutic strategy for age-related hypertension.
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Affiliation(s)
- Ruifang Hua
- Department of Nephrology, Ganzhou Hospital of Guangdong Provincial People's Hospital, Ganzhou Municipal Hospital, Ganzhou, China
| | - Baixiong Liu
- Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou, China
| | - Wenxiu He
- Department of Nephrology, Ganzhou Hospital of Guangdong Provincial People's Hospital, Ganzhou Municipal Hospital, Ganzhou, China
| | - Huilin Zhang
- Department of Nephrology, Ganzhou Hospital of Guangdong Provincial People's Hospital, Ganzhou Municipal Hospital, Ganzhou, China
| | - Yong Liu
- Department of Nephrology, Ganzhou Hospital of Guangdong Provincial People's Hospital, Ganzhou Municipal Hospital, Ganzhou, China
| | - Qiang Xie
- Department of Nephrology, Ganzhou Hospital of Guangdong Provincial People's Hospital, Ganzhou Municipal Hospital, Ganzhou, China
| | - Linjun Zhou
- Department of Nephrology, Ganzhou Hospital of Guangdong Provincial People's Hospital, Ganzhou Municipal Hospital, Ganzhou, China
| | - Fang Pei
- Department of Cardiology, Ganzhou Hospital of Guangdong Provincial People's Hospital, Ganzhou Municipal Hospital, Ganzhou, China
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Feng S, Yang M, Liu S, He Y, Deng S, Gong Y. Oxidative stress as a bridge between age and stroke: A narrative review. JOURNAL OF INTENSIVE MEDICINE 2023; 3:313-319. [PMID: 38028635 PMCID: PMC10658045 DOI: 10.1016/j.jointm.2023.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 12/09/2022] [Accepted: 02/07/2023] [Indexed: 12/01/2023]
Abstract
Stroke is the third most common cause of death globally and a leading cause of disability. The cellular and molecular changes following stroke and causes of neuronal death are not fully understood, and there are few effective treatments currently available. A rapid increase in the levels of reactive oxygen species (ROS) post stroke can overwhelm antioxidant defenses and trigger a series of pathophysiologic events including the inflammatory response, blood-brain barrier (BBB) disruption, apoptosis, and autophagy, ultimately leading to neuron degeneration and apoptosis. It is thought that beyond a certain age, the ROS accumulation resulting from stroke increases the risk of morbidity and mortality. In the present review, we summarize the role of oxidative stress (OS) as a link between aging and stroke pathogenesis. We also discuss how antioxidants can play a beneficial role in the prevention and treatment of stroke by eliminating harmful ROS, delaying aging, and alleviating damage to neurons.
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Affiliation(s)
- Shengjie Feng
- Department of Critical Care Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Miaoxian Yang
- Department of Critical Care Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Shengpeng Liu
- Department of Pediatrics, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, Shenzhen, Guangdong, 518020,China
| | - Yu He
- Department of Critical Care Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Shuixiang Deng
- Department of Critical Care Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Ye Gong
- Department of Critical Care Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai 200040, China
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Brandt A, Kromm F, Hernández-Arriaga A, Martínez Sánchez I, Bozkir HÖ, Staltner R, Baumann A, Camarinha-Silva A, Heijtz RD, Bergheim I. Cognitive Alterations in Old Mice Are Associated with Intestinal Barrier Dysfunction and Induced Toll-like Receptor 2 and 4 Signaling in Different Brain Regions. Cells 2023; 12:2153. [PMID: 37681885 PMCID: PMC10486476 DOI: 10.3390/cells12172153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/24/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Emerging evidence implicate the 'microbiota-gut-brain axis' in cognitive aging and neuroinflammation; however, underlying mechanisms still remain to be elucidated. Here, we assessed if potential alterations in intestinal barrier function and microbiota composition as well as levels of two key pattern-recognition receptors namely Toll-like receptor (TLR) 2 and TLR4, in blood and different brain regions, and depending signaling cascades are paralleling aging associated alterations of cognition in healthy aging mice. Cognitive function was assessed in the Y-maze and intestinal and brain tissue and blood were collected in young (4 months old) and old (24 months old) male C57BL/6 mice to determine intestinal microbiota composition by Illumina amplicon sequencing, the concentration of TLR2 and TLR4 ligands in plasma and brain tissue as well as to determine markers of intestinal barrier function, senescence and TLR2 and TLR4 signaling. Cognitive function was significantly impaired in old mice. Also, in old mice, intestinal microbiota composition was significantly altered, while the relative abundance of Gram-negative or Gram-positive bacteria in the small and large intestines at different ages was not altered. Moreover, intestinal barrier function was impaired in small intestine of old mice, and the levels of TLR2 and TLR4 ligands were also significantly higher in both portal and peripheral blood. Furthermore, levels of TLR2 and TLR4 ligands, and downstream markers of TLR signaling were higher in the hippocampal and prefrontal cortex of old mice compared to young animals. Taken together, our results suggest that even in 'healthy' aging, cognitive function is impaired in mice going along with an increased intestinal translocation of TLR ligands and alterations of TLR signaling in several brain regions.
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Affiliation(s)
- Annette Brandt
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | - Franziska Kromm
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | - Angélica Hernández-Arriaga
- Animal Nutrition Department, Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany
| | - Inés Martínez Sánchez
- Department of Neuroscience, Karolinska Institute, Biomedicum, 17177 Stockholm, Sweden
| | - Haktan Övül Bozkir
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | - Raphaela Staltner
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | - Anja Baumann
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | - Amélia Camarinha-Silva
- Animal Nutrition Department, Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany
| | - Rochellys Diaz Heijtz
- Department of Neuroscience, Karolinska Institute, Biomedicum, 17177 Stockholm, Sweden
| | - Ina Bergheim
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
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Plakkot B, Di Agostino A, Subramanian M. Implications of Hypothalamic Neural Stem Cells on Aging and Obesity-Associated Cardiovascular Diseases. Cells 2023; 12:cells12050769. [PMID: 36899905 PMCID: PMC10000584 DOI: 10.3390/cells12050769] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/14/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023] Open
Abstract
The hypothalamus, one of the major regulatory centers in the brain, controls various homeostatic processes, and hypothalamic neural stem cells (htNSCs) have been observed to interfere with hypothalamic mechanisms regulating aging. NSCs play a pivotal role in the repair and regeneration of brain cells during neurodegenerative diseases and rejuvenate the brain tissue microenvironment. The hypothalamus was recently observed to be involved in neuroinflammation mediated by cellular senescence. Cellular senescence, or systemic aging, is characterized by a progressive irreversible state of cell cycle arrest that causes physiological dysregulation in the body and it is evident in many neuroinflammatory conditions, including obesity. Upregulation of neuroinflammation and oxidative stress due to senescence has the potential to alter the functioning of NSCs. Various studies have substantiated the chances of obesity inducing accelerated aging. Therefore, it is essential to explore the potential effects of htNSC dysregulation in obesity and underlying pathways to develop strategies to address obesity-induced comorbidities associated with brain aging. This review will summarize hypothalamic neurogenesis associated with obesity and prospective NSC-based regenerative therapy for the treatment of obesity-induced cardiovascular conditions.
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Herpes Simplex Virus Type 1 Preferentially Enhances Neuro-Inflammation and Senescence in Brainstem of Female Mice. J Virol 2022; 96:e0108122. [PMID: 35975996 PMCID: PMC9472638 DOI: 10.1128/jvi.01081-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Following acute infection, herpes simplex virus 1 (HSV-1) establishes lifelong latency in neurons. The latency associated transcript (LAT) is the only viral gene abundantly expressed during latency. Wild-type (WT) HSV-1 reactivates more efficiently than LAT mutants because LAT promotes establishment and maintenance of latency. While sensory neurons in trigeminal ganglia (TG) are important sites for latency, brainstem is also a site for latency and reactivation from latency. The principal sensory nucleus of the spinal trigeminal tract (Pr5) likely harbors latent HSV-1 because it receives afferent inputs from TG. The locus coeruleus (LC), an adjacent brainstem region, sends axonal projections to cortical structures and is indirectly linked to Pr5. Senescent cells accumulate in the nervous system during aging and accelerate neurodegenerative processes. Generally senescent cells undergo irreversible cell cycle arrest and produce inflammatory cytokines and chemokines. Based on these observations, we hypothesized HSV-1 influences senescence and inflammation in Pr5 and LC of latently infected mice. This hypothesis was tested using a mouse model of infection. Strikingly, female but not age-matched male mice latently infected with a LAT null mutant (dLAT2903) exhibited significantly higher levels of senescence markers and inflammation in LC, including cell cycle inhibitor p16, NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3), IL-1α, and IL-β. Conversely, Pr5 in female but not male mice latently infected with WT HSV-1 or dLAT2903 exhibited enhanced expression of important inflammatory markers. The predilection of HSV-1 to induce senescence and inflammation in key brainstem regions of female mice infers that enhanced neurodegeneration occurs. IMPORTANCE HSV-1 (herpes simplex virus 1), an important human pathogen, establishes lifelong latency in neurons in trigeminal ganglia and the central nervous system. In contrast to productive infection, the only viral transcript abundantly expressed in latently infected neurons is the latency associated transcript (LAT). The brainstem, including principal sensory nucleus of the spinal trigeminal tract (Pr5) and locus coeruleus (LC), may expedite HSV-1 spread from trigeminal ganglia to the brain. Enhanced senescence and expression of key inflammatory markers were detected in LC of female mice latently infected with a LAT null mutant (dLAT2903) relative to age-matched male or female mice latently infected with wild-type HSV-1. Conversely, wild-type HSV-1 and dLAT2903 induced higher levels of senescence and inflammatory markers in Pr5 of latently infected female mice. In summary, enhanced inflammation and senescence in LC and Pr5 of female mice latently infected with HSV-1 are predicted to accelerate neurodegeneration.
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