1
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Zhang X, Zhou H, Liu H, Xu P. Role of Oxidative Stress in the Occurrence and Development of Cognitive Dysfunction in Patients with Obstructive Sleep Apnea Syndrome. Mol Neurobiol 2024; 61:5083-5101. [PMID: 38159196 DOI: 10.1007/s12035-023-03899-3] [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: 03/15/2023] [Accepted: 12/14/2023] [Indexed: 01/03/2024]
Abstract
Obstructive sleep apnea syndrome (OSAS) causes recurrent apnea and intermittent hypoxia at night, leading to several complications such as cognitive dysfunction. However, the molecular mechanisms underlying cognitive dysfunction in OSAS are unclear, and oxidative stress mediated by intermittent hypoxia is an important mechanism. In addition, the improvement of cognitive dysfunction in patients with OSAS varies by different treatment regimens; among them, continuous positive airway pressure therapy (CPAP) is mostly recognized for improving cognitive dysfunction. In this review, we discuss the potential mechanisms of oxidative stress in OSAS, the common factors of affecting oxidative stress and the Links between oxidative stress and inflammation in OSAS, focusing on the potential links between oxidative stress and cognitive dysfunction in OSAS and the potential therapies for neurocognitive dysfunction in patients with OSAS mediated by oxidative stress. Therefore, further analysis on the relationship between oxidative stress and cognitive dysfunction in patients with OSAS will help to clarify the etiology and discover new treatment options, which will be of great significance for early clinical intervention.
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Affiliation(s)
- XiaoPing Zhang
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Hongyan Zhou
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - HaiJun Liu
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Ping Xu
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.
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2
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Khalilpour J, Soltani Zangbar H, Alipour MR, Shahabi P. The hypoxic respiratory response of the pre-Bötzinger complex. Heliyon 2024; 10:e34491. [PMID: 39114066 PMCID: PMC11305331 DOI: 10.1016/j.heliyon.2024.e34491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 06/18/2024] [Accepted: 07/10/2024] [Indexed: 08/10/2024] Open
Abstract
Since the discovery of the pre-Bötzinger Complex (preBötC) as a crucial region for generating the main respiratory rhythm, our understanding of its cellular and molecular aspects has rapidly increased within the last few decades. It is now apparent that preBötC is a highly flexible neuronal network that reconfigures state-dependently to produce the most appropriate respiratory output in response to various metabolic challenges, such as hypoxia. However, the responses of the preBötC to hypoxic conditions can be varied based on the intensity, pattern, and duration of the hypoxic challenge. This review discusses the preBötC response to hypoxic challenges at the cellular and network level. Particularly, the involvement of preBötC in the classical biphasic response of the respiratory network to acute hypoxia is illuminated. Furthermore, the article discusses the functional and structural changes of preBötC neurons following intermittent and sustained hypoxic challenges. Accumulating evidence shows that the preBötC neural circuits undergo substantial changes following hypoxia and contribute to several types of the respiratory system's hypoxic ventilatory responses.
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Affiliation(s)
- Jamal Khalilpour
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hamid Soltani Zangbar
- Department of Neuroscience, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Parviz Shahabi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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3
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Pietrucha A, Serdar M, Bendix I, Endesfelder S, Brinke EAD, Urkola A, Bührer C, Schmitz T, Scheuer T. Oxygen and HIF1α-dependent SDF1 expression in primary astrocytes. Dev Neurobiol 2024; 84:113-127. [PMID: 38544386 DOI: 10.1002/dneu.22938] [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: 10/11/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 07/17/2024]
Abstract
In the naturally hypoxic in utero fetal environment of preterm infants, oxygen and oxygen-sensitive signaling pathways play an important role in brain development, with hypoxia-inducible factor-1α (HIF1α) being an important regulator. Early exposure to nonphysiological high oxygen concentrations by birth in room can induce HIF1α degradation and may affect neuronal and glial development. This involves the dysregulation of astroglial maturation and function, which in turn might contribute to oxygen-induced brain injury. In this study, we investigated the effects of early high oxygen exposure on astroglial maturation and, specifically, on astroglial stromal cell-derived factor 1 (SDF1) expression in vivo and in vitro. In our neonatal mouse model of hyperoxia preterm birth brain injury in vivo, high oxygen exposure affected astroglial development and cortical SDF1 expression. These results were further supported by reduced Sdf1 expression, impaired proliferation, decreased total cell number, and altered expression of astroglial markers in astrocytes in primary cultures grown under high oxygen conditions. Moreover, to mimic the naturally hypoxic in utero fetal environment, astroglial Sdf1 expression was increased after low oxygen exposure in vitro, which appears to be regulated by HIF1α activity. Additionally, the knockdown of Hif1α revealed HIF1α-dependent Sdf1 expression in vitro. Our results indicate HIF1α and oxygen-dependent chemokine expression in primary astrocytes and highlight the importance of oxygen conditions for brain development.
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Affiliation(s)
- Andreas Pietrucha
- Department of Neonatology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
| | - Meray Serdar
- Department of Pediatrics I, Neonatology and Experimental perinatal Neurosciences, Centre for Translational and Behavioral Sciences (C-TNBS), University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Ivo Bendix
- Department of Pediatrics I, Neonatology and Experimental perinatal Neurosciences, Centre for Translational and Behavioral Sciences (C-TNBS), University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Stefanie Endesfelder
- Department of Neonatology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
| | - Elena Auf dem Brinke
- Department of Neonatology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
| | - Ane Urkola
- Department of Neonatology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
| | - Christoph Bührer
- Department of Neonatology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
| | - Thomas Schmitz
- Department of Neonatology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
| | - Till Scheuer
- Department of Neonatology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
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4
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Moretti EH, Lino CA, Steiner AA. INTERPLAY BETWEEN BRAIN OXYGENATION AND THE DEVELOPMENT OF HYPOTHERMIA IN ENDOTOXIC SHOCK. Shock 2024; 61:861-868. [PMID: 38662598 DOI: 10.1097/shk.0000000000002350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
ABSTRACT There is evidence to suggest that the hypothermia observed in the most severe cases of systemic inflammation or sepsis is a regulated response with potential adaptive value, but the mechanisms involved are poorly understood. Here, we investigated the interplay between brain oxygenation (assessed by tissue P o2 ) and the development of hypothermia in unanesthetized rats challenged with a hypotension-inducing dose of bacterial LPS (1 mg/kg i.v.). At an ambient temperature of 22°C, oxygen consumption (V̇O 2 ) began to fall only a few minutes after the LPS injection, and this suppression in metabolic rate preceded the decrease in core temperature. No reduction in brain P o2 was observed prior to the development of the hypometabolic, hypothermic response, ruling out the possibility that brain hypoxia served as a trigger for hypothermia in this model. Brain P o2 was even increased. Such an improvement in brain oxygenation could reflect either an increased O 2 delivery or a decreased O 2 consumption. The former explanation seems unlikely because blood flow (cardiac output) was being progressively decreased during the recording period. On the other hand, the decrease in V̇O 2 usually preceded the rise in P o2 , and an inverse correlation between V̇O 2 and brain P o2 was consistently observed. These findings do not support the existence of a closed-loop feedback relationship between brain oxygenation and hypothermia in systemic inflammation. The data are consistent with a feedforward mechanism in which hypothermia is triggered (possibly by cryogenic inflammatory mediators) in anticipation of changes in brain oxygenation to prevent the development of tissue hypoxia.
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Affiliation(s)
- Eduardo H Moretti
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
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5
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Zoccal DB, Vieira BN, Mendes LR, Evangelista AB, Leirão IP. Hypoxia sensing in the body: An update on the peripheral and central mechanisms. Exp Physiol 2024; 109:461-469. [PMID: 38031809 PMCID: PMC10988761 DOI: 10.1113/ep091206] [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: 09/29/2023] [Accepted: 11/15/2023] [Indexed: 12/01/2023]
Abstract
An adequate supply of O2 is essential for the maintenance of cellular activity. Systemic or local hypoxia can be experienced during decreased O2 availability or associated with diseases, or a combination of both. Exposure to hypoxia triggers adjustments in multiple physiological systems in the body to generate appropriate homeostatic responses. However, with significant reductions in the arterial partial pressure of O2, hypoxia can be life-threatening and cause maladaptive changes or cell damage and death. To mitigate the impact of limited O2 availability on cellular activity, O2 chemoreceptors rapidly detect and respond to reductions in the arterial partial pressure of O2, triggering orchestrated responses of increased ventilation and cardiac output, blood flow redistribution and metabolic adjustments. In mammals, the peripheral chemoreceptors of the carotid body are considered to be the main hypoxic sensors and the primary source of excitatory feedback driving respiratory, cardiovascular and autonomic responses. However, current evidence indicates that the CNS contains specialized brainstem and spinal cord regions that can also sense hypoxia and stimulate brain networks independently of the carotid body inputs. In this manuscript, we review the discoveries about the functioning of the O2 chemoreceptors and their contribution to the monitoring of O2 levels in the blood and brain parenchyma and mounting cardiorespiratory responses to maintain O2 homeostasis. We also discuss the implications of the chemoreflex-related mechanisms in paediatric and adult pathologies.
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Affiliation(s)
- Daniel B. Zoccal
- Department of Physiology and Pathology, School of Dentistry of AraraquaraSão Paulo State University (UNESP)AraraquaraSão PauloBrazil
| | - Beatriz N. Vieira
- Department of Physiology and Pathology, School of Dentistry of AraraquaraSão Paulo State University (UNESP)AraraquaraSão PauloBrazil
| | - Letícia R. Mendes
- Department of Physiology and Pathology, School of Dentistry of AraraquaraSão Paulo State University (UNESP)AraraquaraSão PauloBrazil
| | - Andressa B. Evangelista
- Department of Physiology and Pathology, School of Dentistry of AraraquaraSão Paulo State University (UNESP)AraraquaraSão PauloBrazil
| | - Isabela P. Leirão
- Department of Physiology and Pathology, School of Dentistry of AraraquaraSão Paulo State University (UNESP)AraraquaraSão PauloBrazil
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6
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Simpson LL, Stembridge M, Siebenmann C, Moore JP, Lawley JS. Mechanisms underpinning sympathoexcitation in hypoxia. J Physiol 2024. [PMID: 38533641 DOI: 10.1113/jp284579] [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: 11/06/2023] [Accepted: 02/28/2024] [Indexed: 03/28/2024] Open
Abstract
Sympathoexcitation is a hallmark of hypoxic exposure, occurring acutely, as well as persisting in acclimatised lowland populations and with generational exposure in highland native populations of the Andean and Tibetan plateaus. The mechanisms mediating altitude sympathoexcitation are multifactorial, involving alterations in both peripheral autonomic reflexes and central neural pathways, and are dependent on the duration of exposure. Initially, hypoxia-induced sympathoexcitation appears to be an adaptive response, primarily mediated by regulatory reflex mechanisms concerned with preserving systemic and cerebral tissue O2 delivery and maintaining arterial blood pressure. However, as exposure continues, sympathoexcitation is further augmented above that observed with acute exposure, despite acclimatisation processes that restore arterial oxygen content (C a O 2 ${C_{{\mathrm{a}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ). Under these conditions, sympathoexcitation may become maladaptive, giving rise to reduced vascular reactivity and mildly elevated blood pressure. Importantly, current evidence indicates the peripheral chemoreflex does not play a significant role in the augmentation of sympathoexcitation during altitude acclimatisation, although methodological limitations may underestimate its true contribution. Instead, processes that provide no obvious survival benefit in hypoxia appear to contribute, including elevated pulmonary arterial pressure. Nocturnal periodic breathing is also a potential mechanism contributing to altitude sympathoexcitation, although experimental studies are required. Despite recent advancements within the field, several areas remain unexplored, including the mechanisms responsible for the apparent normalisation of muscle sympathetic nerve activity during intermediate hypoxic exposures, the mechanisms accounting for persistent sympathoexcitation following descent from altitude and consideration of whether there are sex-based differences in sympathetic regulation at altitude.
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Affiliation(s)
- Lydia L Simpson
- Department of Sport Science, Performance Physiology and Prevention, Universität Innsbruck, Innsbruck, Austria
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | | | - Jonathan P Moore
- School of Psychology and Sport Science, Institute of Applied Human Physiology, Bangor University, Bangor, UK
| | - Justin S Lawley
- Department of Sport Science, Performance Physiology and Prevention, Universität Innsbruck, Innsbruck, Austria
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
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Bishop M, SheikhBahei S. Brainstem astrocytes regulate breathing and may affect arousal state in rats. Physiol Behav 2024; 275:114457. [PMID: 38184289 PMCID: PMC10853942 DOI: 10.1016/j.physbeh.2024.114457] [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: 09/26/2023] [Revised: 12/29/2023] [Accepted: 01/03/2024] [Indexed: 01/08/2024]
Abstract
Variations in arousal levels can impact respiratory patterns. The mechanisms by which breathing behaviors can influence arousal state is not fully understood. In this study, we investigated the role of astrocytes in the preBötzinger complex (preBötC) in modulating arousal states via breathing in adult conscious rats. Using viral vector tools, we selectively interfered with astrocytic signaling in the preBötC. Rats with inhibited astrocytic signaling exhibited slower breathing rates and behaviors indicative of a calmer state, whereas enhanced purinergic signaling in preBötC astrocytes led to faster breathing and heightened arousal. Our findings reveal a key role for an astrocyte-mediated mechanism in the preBötC that influences both respiratory behaviors and higher-order brain functions like arousal, suggesting a bidirectional link between breathing behaviors and mental states.
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Affiliation(s)
- Mitchell Bishop
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA
| | - Shahriar SheikhBahei
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA.
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8
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Borrus DS, Stettler MK, Grover CJ, Kalajian EJ, Gu J, Conradi Smith GD, Del Negro CA. Inspiratory and sigh breathing rhythms depend on distinct cellular signalling mechanisms in the preBötzinger complex. J Physiol 2024; 602:809-834. [PMID: 38353596 PMCID: PMC10940220 DOI: 10.1113/jp285582] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 12/21/2023] [Indexed: 02/21/2024] Open
Abstract
Breathing behaviour involves the generation of normal breaths (eupnoea) on a timescale of seconds and sigh breaths on the order of minutes. Both rhythms emerge in tandem from a single brainstem site, but whether and how a single cell population can generate two disparate rhythms remains unclear. We posit that recurrent synaptic excitation in concert with synaptic depression and cellular refractoriness gives rise to the eupnoea rhythm, whereas an intracellular calcium oscillation that is slower by orders of magnitude gives rise to the sigh rhythm. A mathematical model capturing these dynamics simultaneously generates eupnoea and sigh rhythms with disparate frequencies, which can be separately regulated by physiological parameters. We experimentally validated key model predictions regarding intracellular calcium signalling. All vertebrate brains feature a network oscillator that drives the breathing pump for regular respiration. However, in air-breathing mammals with compliant lungs susceptible to collapse, the breathing rhythmogenic network may have refashioned ubiquitous intracellular signalling systems to produce a second slower rhythm (for sighs) that prevents atelectasis without impeding eupnoea. KEY POINTS: A simplified activity-based model of the preBötC generates inspiratory and sigh rhythms from a single neuron population. Inspiration is attributable to a canonical excitatory network oscillator mechanism. Sigh emerges from intracellular calcium signalling. The model predicts that perturbations of calcium uptake and release across the endoplasmic reticulum counterintuitively accelerate and decelerate sigh rhythmicity, respectively, which was experimentally validated. Vertebrate evolution may have adapted existing intracellular signalling mechanisms to produce slow oscillations needed to optimize pulmonary function in mammals.
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Affiliation(s)
- Daniel S. Borrus
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Marco K. Stettler
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Cameron J. Grover
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Eva J. Kalajian
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Jeffrey Gu
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Gregory D. Conradi Smith
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
- Conradi Smith and Del Negro contributed equally
| | - Christopher A. Del Negro
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
- Conradi Smith and Del Negro contributed equally
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9
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Gargas J, Janowska J, Gebala P, Maksymiuk W, Sypecka J. Reactive Gliosis in Neonatal Disorders: Friend or Foe for Neuroregeneration? Cells 2024; 13:131. [PMID: 38247822 PMCID: PMC10813898 DOI: 10.3390/cells13020131] [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: 11/17/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/23/2024] Open
Abstract
A developing nervous system is particularly vulnerable to the influence of pathophysiological clues and injuries in the perinatal period. Astrocytes are among the first cells that react to insults against the nervous tissue, the presence of pathogens, misbalance of local tissue homeostasis, and a lack of oxygen and trophic support. Under this background, it remains uncertain if induced astrocyte activation, recognized as astrogliosis, is a friend or foe for progressing neonatal neurodevelopment. Likewise, the state of astrocyte reactivity is considered one of the key factors discriminating between either the initiation of endogenous reparative mechanisms compensating for aberrations in the structures and functions of nervous tissue or the triggering of neurodegeneration. The responses of activated cells are modulated by neighboring neural cells, which exhibit broad immunomodulatory and pro-regenerative properties by secreting a plethora of active compounds (including interleukins and chemokines, neurotrophins, reactive oxygen species, nitric oxide synthase and complement components), which are engaged in cell crosstalk in a paracrine manner. As the developing nervous system is extremely sensitive to the influence of signaling molecules, even subtle changes in the composition or concentration of the cellular secretome can have significant effects on the developing neonatal brain. Thus, modulating the activity of other types of cells and their interactions with overreactive astrocytes might be a promising strategy for controlling neonatal astrogliosis.
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Affiliation(s)
| | | | | | | | - Joanna Sypecka
- NeuroRepair Department, Mossakowski Medical Research Institute, Polish Academy of Sciences, A. Pawinskiego 5, 02-106 Warsaw, Poland; (J.G.); (J.J.)
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10
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SheikhBahaei S, Marina N, Rajani V, Kasparov S, Funk GD, Smith JC, Gourine AV. Contributions of carotid bodies, retrotrapezoid nucleus neurons and preBötzinger complex astrocytes to the CO 2 -sensitive drive for breathing. J Physiol 2024; 602:223-240. [PMID: 37742121 PMCID: PMC10841148 DOI: 10.1113/jp283534] [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: 07/04/2022] [Accepted: 09/06/2023] [Indexed: 09/25/2023] Open
Abstract
Current models of respiratory CO2 chemosensitivity are centred around the function of a specific population of neurons residing in the medullary retrotrapezoid nucleus (RTN). However, there is significant evidence suggesting that chemosensitive neurons exist in other brainstem areas, including the rhythm-generating region of the medulla oblongata - the preBötzinger complex (preBötC). There is also evidence that astrocytes, non-neuronal brain cells, contribute to central CO2 chemosensitivity. In this study, we reevaluated the relative contributions of the RTN neurons, the preBötC astrocytes, and the carotid body chemoreceptors in mediating the respiratory responses to CO2 in experimental animals (adult laboratory rats). To block astroglial signalling via exocytotic release of transmitters, preBötC astrocytes were targeted to express the tetanus toxin light chain (TeLC). Bilateral expression of TeLC in preBötC astrocytes was associated with ∼20% and ∼30% reduction of the respiratory response to CO2 in conscious and anaesthetized animals, respectively. Carotid body denervation reduced the CO2 respiratory response by ∼25%. Bilateral inhibition of RTN neurons transduced to express Gi-coupled designer receptors exclusively activated by designer drug (DREADDGi ) by application of clozapine-N-oxide reduced the CO2 response by ∼20% and ∼40% in conscious and anaesthetized rats, respectively. Combined blockade of astroglial signalling in the preBötC, inhibition of RTN neurons and carotid body denervation reduced the CO2 -induced respiratory response by ∼70%. These data further support the hypothesis that the CO2 -sensitive drive to breathe requires inputs from the peripheral chemoreceptors and several central chemoreceptor sites. At the preBötC level, astrocytes modulate the activity of the respiratory network in response to CO2 , either by relaying chemosensory information (i.e. they act as CO2 sensors) or by enhancing the preBötC network excitability to chemosensory inputs. KEY POINTS: This study reevaluated the roles played by the carotid bodies, neurons of the retrotrapezoid nucleus (RTN) and astrocytes of the preBötC in mediating the CO2 -sensitive drive to breathe. The data obtained show that disruption of preBötC astroglial signalling, blockade of inputs from the peripheral chemoreceptors or inhibition of RTN neurons similarly reduce the respiratory response to hypercapnia. These data provide further support for the hypothesis that the CO2 -sensitive drive to breathe is mediated by the inputs from the peripheral chemoreceptors and several central chemoreceptor sites.
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Affiliation(s)
- Shahriar SheikhBahaei
- Centre for Cardiovascular and Metabolic Neuroscience, Research Department of Neuroscience Physiology and Pharmacology, University College London, London WC1E 6BT, UK
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA
- present address: Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA
| | - Nephtali Marina
- Centre for Cardiovascular and Metabolic Neuroscience, Research Department of Neuroscience Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Vishaal Rajani
- Department of Physiology, Neuroscience & Mental Health Institute, Women and Children’s Health Research Institute, University of Alberta, T6G 2E1, Canada
- present address: Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL A1B 3V6, Canada
| | - Sergey Kasparov
- Department of Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - Gregory D. Funk
- Department of Physiology, Neuroscience & Mental Health Institute, Women and Children’s Health Research Institute, University of Alberta, T6G 2E1, Canada
| | - Jeffrey C. Smith
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA
| | - Alexander V. Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Research Department of Neuroscience Physiology and Pharmacology, University College London, London WC1E 6BT, UK
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11
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Nakao A, Liu K, Takahashi N, Mori Y. [Universal roles of the TRPA1 channel in oxygen-sensing]. Nihon Yakurigaku Zasshi 2024; 159:165-168. [PMID: 38692881 DOI: 10.1254/fpj.23086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Molecular oxygen suffices the ATP production required for the survival of us aerobic organisms. But it is also true that oxygen acts as a source of reactive oxygen species that elicit a spectrum of damages in living organisms. To cope with such intrinsic ambiguity of biological activity oxygen exerts, aerobic mechanisms are equipped with an exquisite adaptive system, which sensitively detects partial pressure of oxygen within the body and controls appropriate oxygen supply to the tissues. Physiological responses to hypoxia are comprised of the acute and chronic phases, in the former of which the oxygen-sensing remains controversial particularly from mechanistic points of view. Recently, we have revealed that the prominently redox-sensitive cation channel TRPA1 plays key roles in oxygen-sensing mechanisms identified in the peripheral tissues and the central nervous system. In this review, we summarize recent development of researches on oxygen-sensing mechanisms including that in the carotid body, which has been recognized as the oxygen receptor organ central to acute oxygen-sensing. We also discuss how ubiquitously the TRPA1 contributes to the mechanisms underlying the acute phase of adaptation to hypoxia.
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Affiliation(s)
- Akito Nakao
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University
| | - Ke Liu
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University
| | - Nobuaki Takahashi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University
| | - Yasuo Mori
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University
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12
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Christie IN, Theparambil SM, Braga A, Doronin M, Hosford PS, Brazhe A, Mascarenhas A, Nizari S, Hadjihambi A, Wells JA, Hobbs A, Semyanov A, Abramov AY, Angelova PR, Gourine AV. Astrocytes produce nitric oxide via nitrite reduction in mitochondria to regulate cerebral blood flow during brain hypoxia. Cell Rep 2023; 42:113514. [PMID: 38041814 PMCID: PMC7615749 DOI: 10.1016/j.celrep.2023.113514] [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: 01/04/2022] [Revised: 10/17/2023] [Accepted: 11/14/2023] [Indexed: 12/04/2023] Open
Abstract
During hypoxia, increases in cerebral blood flow maintain brain oxygen delivery. Here, we describe a mechanism of brain oxygen sensing that mediates the dilation of intraparenchymal cerebral blood vessels in response to reductions in oxygen supply. In vitro and in vivo experiments conducted in rodent models show that during hypoxia, cortical astrocytes produce the potent vasodilator nitric oxide (NO) via nitrite reduction in mitochondria. Inhibition of mitochondrial respiration mimics, but also occludes, the effect of hypoxia on NO production in astrocytes. Astrocytes display high expression of the molybdenum-cofactor-containing mitochondrial enzyme sulfite oxidase, which can catalyze nitrite reduction in hypoxia. Replacement of molybdenum with tungsten or knockdown of sulfite oxidase expression in astrocytes blocks hypoxia-induced NO production by these glial cells and reduces the cerebrovascular response to hypoxia. These data identify astrocyte mitochondria as brain oxygen sensors that regulate cerebral blood flow during hypoxia via release of nitric oxide.
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Affiliation(s)
- Isabel N Christie
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E 6BT, UK
| | - Shefeeq M Theparambil
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E 6BT, UK.
| | - Alice Braga
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E 6BT, UK
| | - Maxim Doronin
- College of Medicine, Jiaxing University, Jiaxing 314001, China
| | - Patrick S Hosford
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E 6BT, UK
| | - Alexey Brazhe
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Moscow 117997, Russian Federation; Faculty of Biology, Lomonosov Moscow State University, Moscow 119234, Russian Federation
| | - Alexander Mascarenhas
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E 6BT, UK
| | - Shereen Nizari
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E 6BT, UK; Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London WC1E 6BT, UK
| | - Anna Hadjihambi
- The Roger Williams Institute of Hepatology, Foundation for Liver Research, and Faculty of Life Sciences and Medicine, King's College London, London SE5 9NT, UK
| | - Jack A Wells
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London WC1E 6BT, UK
| | - Adrian Hobbs
- William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University of London, London EC1M 6BQ, UK
| | - Alexey Semyanov
- College of Medicine, Jiaxing University, Jiaxing 314001, China; Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Moscow 117997, Russian Federation
| | - Andrey Y Abramov
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Plamena R Angelova
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, University College London, London WC1E 6BT, UK.
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13
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Rocher A, Aaronson PI. 'Inflammation, nitro-oxidative stress and altered autonomic outflow in obstructive sleep apnoea: an assault on homeostasis'. J Physiol 2023; 601:5465-5466. [PMID: 37548049 DOI: 10.1113/jp284946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/24/2023] [Indexed: 08/08/2023] Open
Affiliation(s)
- Asuncion Rocher
- Unidad de Excelencia Instituto de Biomedicina y Genética Molecular (IBGM), Consejo Superior de Investigaciones Científicas, Universidad de Valladolid, Valladolid, Spain
- Departamento de Bioquímica, Biologia Molecular y Fisiologia, Facultad de Medicina, Universidad de Valladolid, Valladolid, Spain
| | - Philip I Aaronson
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College, London, UK
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14
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Tooley KB, Chucair-Elliott AJ, Ocañas SR, Machalinski AH, Pham KD, Hoolehan W, Kulpa AM, Stanford DR, Freeman WM. Differential usage of DNA modifications in neurons, astrocytes, and microglia. Epigenetics Chromatin 2023; 16:45. [PMID: 37953264 PMCID: PMC10642035 DOI: 10.1186/s13072-023-00522-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 11/06/2023] [Indexed: 11/14/2023] Open
Abstract
BACKGROUND Cellular identity is determined partly by cell type-specific epigenomic profiles that regulate gene expression. In neuroscience, there is a pressing need to isolate and characterize the epigenomes of specific CNS cell types in health and disease. In this study, we developed an in vivo tagging mouse model (Camk2a-NuTRAP) for paired isolation of neuronal DNA and RNA without cell sorting and then used this model to assess epigenomic regulation, DNA modifications in particular, of gene expression between neurons and glia. RESULTS After validating the cell-specificity of the Camk2a-NuTRAP model, we performed TRAP-RNA-Seq and INTACT-whole genome oxidative bisulfite sequencing (WGoxBS) to assess the neuronal translatome and epigenome in the hippocampus of young mice (4 months old). WGoxBS findings were validated with enzymatic methyl-Seq (EM-Seq) and nanopore sequencing. Comparing neuronal data to microglial and astrocytic data from NuTRAP models, microglia had the highest global mCG levels followed by astrocytes and then neurons, with the opposite pattern observed for hmCG and mCH. Differentially modified regions between cell types were predominantly found within gene bodies and distal intergenic regions, rather than proximal promoters. Across cell types there was a negative correlation between DNA modifications (mCG, mCH, hmCG) and gene expression at proximal promoters. In contrast, a negative correlation of gene body mCG and a positive relationship between distal promoter and gene body hmCG with gene expression was observed. Furthermore, we identified a neuron-specific inverse relationship between mCH and gene expression across promoter and gene body regions. CONCLUSIONS Neurons, astrocytes, and microglia demonstrate different genome-wide levels of mCG, hmCG, and mCH that are reproducible across analytical methods. However, modification-gene expression relationships are conserved across cell types. Enrichment of differential modifications across cell types in gene bodies and distal regulatory elements, but not proximal promoters, highlights epigenomic patterning in these regions as potentially greater determinants of cell identity. These findings also demonstrate the importance of differentiating between mC and hmC in neuroepigenomic analyses, as up to 30% of what is conventionally interpreted as mCG can be hmCG, which often has a different relationship to gene expression than mCG.
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Affiliation(s)
- Kyla B Tooley
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Ana J Chucair-Elliott
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Sarah R Ocañas
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Adeline H Machalinski
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Kevin D Pham
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Walker Hoolehan
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - Adam M Kulpa
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
| | - David R Stanford
- Center for Biomedical Data Sciences, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Willard M Freeman
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Department of Biochemistry, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK, USA.
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15
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Okoye CN, Koren SA, Wojtovich AP. Mitochondrial complex I ROS production and redox signaling in hypoxia. Redox Biol 2023; 67:102926. [PMID: 37871533 PMCID: PMC10598411 DOI: 10.1016/j.redox.2023.102926] [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: 08/31/2023] [Revised: 09/29/2023] [Accepted: 10/06/2023] [Indexed: 10/25/2023] Open
Abstract
Mitochondria are a main source of cellular energy. Oxidative phosphorylation (OXPHOS) is the major process of aerobic respiration. Enzyme complexes of the electron transport chain (ETC) pump protons to generate a protonmotive force (Δp) that drives OXPHOS. Complex I is an electron entry point into the ETC. Complex I oxidizes nicotinamide adenine dinucleotide (NADH) and transfers electrons to ubiquinone in a reaction coupled with proton pumping. Complex I also produces reactive oxygen species (ROS) under various conditions. The enzymatic activities of complex I can be regulated by metabolic conditions and serves as a regulatory node of the ETC. Complex I ROS plays diverse roles in cell metabolism ranging from physiologic to pathologic conditions. Progress in our understanding indicates that ROS release from complex I serves important signaling functions. Increasing evidence suggests that complex I ROS is important in signaling a mismatch in energy production and demand. In this article, we review the role of ROS from complex I in sensing acute hypoxia.
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Affiliation(s)
- Chidozie N Okoye
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Shon A Koren
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Andrew P Wojtovich
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA; Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, 14642, USA.
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16
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Ahmadzadeh E, Polglase GR, Stojanovska V, Herlenius E, Walker DW, Miller SL, Allison BJ. Does fetal growth restriction induce neuropathology within the developing brainstem? J Physiol 2023; 601:4667-4689. [PMID: 37589339 PMCID: PMC10953350 DOI: 10.1113/jp284191] [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: 01/29/2023] [Accepted: 08/04/2023] [Indexed: 08/18/2023] Open
Abstract
Fetal growth restriction (FGR) is a complex obstetric issue describing a fetus that does not reach its genetic growth potential. The primary cause of FGR is placental dysfunction resulting in chronic fetal hypoxaemia, which in turn causes altered neurological, cardiovascular and respiratory development, some of which may be pathophysiological, particularly for neonatal life. The brainstem is the critical site of cardiovascular, respiratory and autonomic control, but there is little information describing how chronic hypoxaemia and the resulting FGR may affect brainstem neurodevelopment. This review provides an overview of the brainstem-specific consequences of acute and chronic hypoxia, and what is known in FGR. In addition, we discuss how brainstem structural alterations may impair functional control of the cardiovascular and respiratory systems. Finally, we highlight the clinical and translational findings of the potential roles of the brainstem in maintaining cardiorespiratory adaptation in the transition from fetal to neonatal life under normal conditions and in response to the pathological environment that arises during development in growth-restricted infants. This review emphasises the crucial role that the brainstem plays in mediating cardiovascular and respiratory responses during fetal and neonatal life. We assess whether chronic fetal hypoxaemia might alter structure and function of the brainstem, but this also serves to highlight knowledge gaps regarding FGR and brainstem development.
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Affiliation(s)
- Elham Ahmadzadeh
- The Ritchie CentreHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Department of Obstetrics and GynaecologyMonash UniversityClaytonVictoriaAustralia
| | - Graeme R. Polglase
- The Ritchie CentreHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Department of Obstetrics and GynaecologyMonash UniversityClaytonVictoriaAustralia
| | - Vanesa Stojanovska
- The Ritchie CentreHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Department of Obstetrics and GynaecologyMonash UniversityClaytonVictoriaAustralia
| | - Eric Herlenius
- Department of Women's and Children's HealthKarolinska InstitutetSolnaSweden
- Astrid Lindgren Children´s HospitalKarolinska University Hospital StockholmSolnaSweden
| | - David W. Walker
- The Ritchie CentreHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Neurodevelopment in Health and Disease Research Program, School of Health and Biomedical SciencesRoyal Melbourne Institute of Technology (RMIT)MelbourneVictoriaAustralia
| | - Suzanne L. Miller
- The Ritchie CentreHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Department of Obstetrics and GynaecologyMonash UniversityClaytonVictoriaAustralia
| | - Beth J. Allison
- The Ritchie CentreHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Department of Obstetrics and GynaecologyMonash UniversityClaytonVictoriaAustralia
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17
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Bishop M, SheikhBahei S. Brainstem astrocytes regulate breathing and may affect arousal state in rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.28.559604. [PMID: 37841850 PMCID: PMC10576258 DOI: 10.1101/2023.09.28.559604] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Variations in arousal levels can impact respiratory patterns. However, whether changes in breathing behaviors can influence arousal state is not fully understood. In this study, we investigated the role of astrocytes in the preBötzinger complex (preBötC) in modulating arousal states via breathing in adult conscious rats. Using viral vector tools, we selectively interfered with astrocytic signaling in the preBötC. Rats with inhibited astrocytic signaling exhibited slower breathing rates and behaviors indicative of a calmer state, whereas enhanced purinergic signaling in preBötC astrocytes led to faster breathing and heightened arousal. Our findings reveal a key role for astrocyte-mediated mechanism in the preBötC that influences both respiratory behaviors and higher-order brain functions like arousal, suggesting a bidirectional link between breathing behaviors and mental states.
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Affiliation(s)
- Mitchell Bishop
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA
| | - Shahriar SheikhBahei
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA
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18
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Ghosh P, Fontanella RA, Scisciola L, Pesapane A, Taktaz F, Franzese M, Puocci A, Ceriello A, Prattichizzo F, Rizzo MR, Paolisso G, Barbieri M. Targeting redox imbalance in neurodegeneration: characterizing the role of GLP-1 receptor agonists. Theranostics 2023; 13:4872-4884. [PMID: 37771773 PMCID: PMC10526673 DOI: 10.7150/thno.86831] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/06/2023] [Indexed: 09/30/2023] Open
Abstract
Reactive oxygen species (ROS) have emerged as essential signaling molecules regulating cell survival, death, inflammation, differentiation, growth, and immune response. Environmental factors, genetic factors, or many pathological condition such as diabetes increase the level of ROS generation by elevating the production of advanced glycation end products, reducing free radical scavengers, increasing mitochondrial oxidative stress, and by interfering with DAG-PKC-NADPH oxidase and xanthine oxidase pathways. Oxidative stress, and therefore the accumulation of intracellular ROS, determines the deregulation of several proteins and caspases, damages DNA and RNA, and interferes with normal neuronal function. Furthermore, ROS play an essential role in the polymerization, phosphorylation, and aggregation of tau and amyloid-beta, key mediators of cognitive function decline. At the neuronal level, ROS interfere with the DNA methylation pattern and various apoptotic factors related to cell death, promoting neurodegeneration. Only few drugs are able to quench ROS production in neurons. The cross-linking pathways between diabetes and dementia suggest that antidiabetic medications can potentially treat dementia. Among antidiabetic drugs, glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been found to reduce ROS generation and ameliorate mitochondrial function, protein aggregation, neuroinflammation, synaptic plasticity, learning, and memory. The incretin hormone glucagon-like peptide-1 (GLP-1) is produced by the enteroendocrine L cells in the distal intestine after food ingestion. Upon interacting with its receptor (GLP-1R), it regulates blood glucose levels by inducing insulin secretion, inhibiting glucagon production, and slowing gastric emptying. No study has evidenced a specific GLP-1RA pathway that quenches ROS production. Here we summarize the effects of GLP-1RAs against ROS overproduction and discuss the putative efficacy of Exendin-4, Lixisenatide, and Liraglutide in treating dementia by decreasing ROS.
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Affiliation(s)
- Puja Ghosh
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Rosaria Anna Fontanella
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Lucia Scisciola
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Ada Pesapane
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Fatemeh Taktaz
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Martina Franzese
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Armando Puocci
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | | | | | - Maria Rosaria Rizzo
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Giuseppe Paolisso
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
- UniCamillus, International Medical University, Rome Italy
| | - Michelangela Barbieri
- Department of Advanced Medical and Surgical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
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19
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Severs LJ, Bush NE, Quina LA, Hidalgo-Andrade S, Burgraff NJ, Dashevskiy T, Shih AY, Baertsch NA, Ramirez JM. Purinergic signaling mediates neuroglial interactions to modulate sighs. Nat Commun 2023; 14:5300. [PMID: 37652903 PMCID: PMC10471608 DOI: 10.1038/s41467-023-40812-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 08/10/2023] [Indexed: 09/02/2023] Open
Abstract
Sighs prevent the collapse of alveoli in the lungs, initiate arousal under hypoxic conditions, and are an expression of sadness and relief. Sighs are periodically superimposed on normal breaths, known as eupnea. Implicated in the generation of these rhythmic behaviors is the preBötzinger complex (preBötC). Our experimental evidence suggests that purinergic signaling is necessary to generate spontaneous and hypoxia-induced sighs in a mouse model. Our results demonstrate that driving calcium increases in astrocytes through pharmacological methods robustly increases sigh, but not eupnea, frequency. Calcium imaging of preBötC slices corroborates this finding with an increase in astrocytic calcium upon application of sigh modulators, increasing intracellular calcium through g-protein signaling. Moreover, photo-activation of preBötC astrocytes is sufficient to elicit sigh activity, and this response is blocked with purinergic antagonists. We conclude that sighs are modulated through neuron-glia coupling in the preBötC network, where the distinct modulatory responses of neurons and glia allow for both rhythms to be independently regulated.
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Affiliation(s)
- Liza J Severs
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA.
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, 98195, USA.
| | - Nicholas E Bush
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Lely A Quina
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Skyler Hidalgo-Andrade
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Nicholas J Burgraff
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Tatiana Dashevskiy
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, 98101, USA
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, 98195, USA
- Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA
| | - Nathan A Baertsch
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA.
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, 98195, USA.
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, 98195, USA.
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, WA, 98195, USA.
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20
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Li K, Gonye EC, Stornetta RL, Bayliss CB, Yi G, Stornetta DS, Baca SM, Abbott SB, Guyenet PG, Bayliss DA. The astrocytic Na + -HCO 3 - cotransporter, NBCe1, is dispensable for respiratory chemosensitivity. J Physiol 2023; 601:3667-3686. [PMID: 37384821 PMCID: PMC10528273 DOI: 10.1113/jp284960] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/02/2023] [Indexed: 07/01/2023] Open
Abstract
The interoceptive homeostatic mechanism that controls breathing, blood gases and acid-base balance in response to changes in CO2 /H+ is exquisitely sensitive, with convergent roles proposed for chemosensory brainstem neurons in the retrotrapezoid nucleus (RTN) and their supporting glial cells. For astrocytes, a central role for NBCe1, a Na+ -HCO3 - cotransporter encoded by Slc4a4, has been envisaged in multiple mechanistic models (i.e. underlying enhanced CO2 -induced local extracellular acidification or purinergic signalling). We tested these NBCe1-centric models by using conditional knockout mice in which Slc4a4 was deleted from astrocytes. In GFAP-Cre;Slc4a4fl/fl mice we found diminished expression of Slc4a4 in RTN astrocytes by comparison to control littermates, and a concomitant reduction in NBCe1-mediated current. Despite disrupted NBCe1 function in RTN-adjacent astrocytes from these conditional knockout mice, CO2 -induced activation of RTN neurons or astrocytes in vitro and in vivo, and CO2 -stimulated breathing, were indistinguishable from NBCe1-intact littermates; hypoxia-stimulated breathing and sighs were likewise unaffected. We obtained a more widespread deletion of NBCe1 in brainstem astrocytes by using tamoxifen-treated Aldh1l1-Cre/ERT2;Slc4a4fl/fl mice. Again, there was no difference in effects of CO2 or hypoxia on breathing or on neuron/astrocyte activation in NBCe1-deleted mice. These data indicate that astrocytic NBCe1 is not required for the respiratory responses to these chemoreceptor stimuli in mice, and that any physiologically relevant astrocytic contributions must involve NBCe1-independent mechanisms. KEY POINTS: The electrogenic NBCe1 transporter is proposed to mediate local astrocytic CO2 /H+ sensing that enables excitatory modulation of nearby retrotrapezoid nucleus (RTN) neurons to support chemosensory control of breathing. We used two different Cre mouse lines for cell-specific and/or temporally regulated deletion of the NBCe1 gene (Slc4a4) in astrocytes to test this hypothesis. In both mouse lines, Slc4a4 was depleted from RTN-associated astrocytes but CO2 -induced Fos expression (i.e. cell activation) in RTN neurons and local astrocytes was intact. Likewise, respiratory chemoreflexes evoked by changes in CO2 or O2 were unaffected by loss of astrocytic Slc4a4. These data do not support the previously proposed role for NBCe1 in respiratory chemosensitivity mediated by astrocytes.
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Affiliation(s)
- Keyong Li
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA, 22908
| | - Elizabeth C. Gonye
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA, 22908
| | - Ruth L. Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA, 22908
| | | | - Grace Yi
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA, 22908
| | - Daniel S. Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA, 22908
| | - Serapio M. Baca
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA, 22908
| | - Stephen B.G. Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA, 22908
| | - Patrice G. Guyenet
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA, 22908
| | - Douglas A. Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA, 22908
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21
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Souza GMPR, Stornetta DS, Shi Y, Lim E, Berry FE, Bayliss DA, Abbott SBG. Neuromedin B-Expressing Neurons in the Retrotrapezoid Nucleus Regulate Respiratory Homeostasis and Promote Stable Breathing in Adult Mice. J Neurosci 2023; 43:5501-5520. [PMID: 37290937 PMCID: PMC10376939 DOI: 10.1523/jneurosci.0386-23.2023] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/10/2023] Open
Abstract
Respiratory chemoreceptor activity encoding arterial Pco2 and Po2 is a critical determinant of ventilation. Currently, the relative importance of several putative chemoreceptor mechanisms for maintaining eupneic breathing and respiratory homeostasis is debated. Transcriptomic and anatomic evidence suggests that bombesin-related peptide Neuromedin-B (Nmb) expression identifies chemoreceptor neurons in the retrotrapezoid nucleus (RTN) that mediate the hypercapnic ventilatory response, but functional support is missing. In this study, we generated a transgenic Nmb-Cre mouse and used Cre-dependent cell ablation and optogenetics to test the hypothesis that RTN Nmb neurons are necessary for the CO2-dependent drive to breathe in adult male and female mice. Selective ablation of ∼95% of RTN Nmb neurons causes compensated respiratory acidosis because of alveolar hypoventilation, as well as profound breathing instability and respiratory-related sleep disruption. Following RTN Nmb lesion, mice were hypoxemic at rest and were prone to severe apneas during hyperoxia, suggesting that oxygen-sensitive mechanisms, presumably the peripheral chemoreceptors, compensate for the loss of RTN Nmb neurons. Interestingly, ventilation following RTN Nmb -lesion was unresponsive to hypercapnia, but behavioral responses to CO2 (freezing and avoidance) and the hypoxia ventilatory response were preserved. Neuroanatomical mapping shows that RTN Nmb neurons are highly collateralized and innervate the respiratory-related centers in the pons and medulla with a strong ipsilateral preference. Together, this evidence suggests that RTN Nmb neurons are dedicated to the respiratory effects of arterial Pco2/pH and maintain respiratory homeostasis in intact conditions and suggest that malfunction of these neurons could underlie the etiology of certain forms of sleep-disordered breathing in humans.SIGNIFICANCE STATEMENT Respiratory chemoreceptors stimulate neural respiratory motor output to regulate arterial Pco2 and Po2, thereby maintaining optimal gas exchange. Neurons in the retrotrapezoid nucleus (RTN) that express the bombesin-related peptide Neuromedin-B are proposed to be important in this process, but functional evidence has not been established. Here, we developed a transgenic mouse model and demonstrated that RTN neurons are fundamental for respiratory homeostasis and mediate the stimulatory effects of CO2 on breathing. Our functional and anatomic data indicate that Nmb-expressing RTN neurons are an integral component of the neural mechanisms that mediate CO2-dependent drive to breathe and maintain alveolar ventilation. This work highlights the importance of the interdependent and dynamic integration of CO2- and O2-sensing mechanisms in respiratory homeostasis of mammals.
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Affiliation(s)
- George M P R Souza
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Daniel S Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Yingtang Shi
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Eunu Lim
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Faye E Berry
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
| | - Stephen B G Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908
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22
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Jimenez-Blasco D, Almeida A, Bolaños JP. Brightness and shadows of mitochondrial ROS in the brain. Neurobiol Dis 2023:106199. [PMID: 37321421 DOI: 10.1016/j.nbd.2023.106199] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 06/10/2023] [Accepted: 06/12/2023] [Indexed: 06/17/2023] Open
Abstract
Mitochondrial reactive oxygen species (mROS) have been generally considered harmful byproducts wanted to clear when elevated to avoid brain damage. However, the abundance of mROS in astrocytes is very high -about one order of magnitude above that in neurons-, despite they are essential to preserve cell metabolism and animal behavior. Here, we have focused on this apparent ambiguity by discussing (i) the intrinsic mechanisms accounting for the higher production of mROS by the mitochondrial respiratory chain in astrocytes than in neurons, (ii) the specific molecular targets of astrocytic beneficial mROS, and (iii) how decreased astrocytic mROS causes excess neuronal mROS leading to cellular and organismal damage. We hope that this mini-review serves to clarifying the apparent controversy on the beneficial versus deleterious faces of ROS in the brain from molecular to higher-order organismal levels.
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Affiliation(s)
- Daniel Jimenez-Blasco
- Instituto de Biología Funcional y Genómica (IBFG), Universidad de Salamanca, CSIC, Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Universidad de Salamanca, CSIC, Salamanca, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Madrid, Spain.
| | - Angeles Almeida
- Instituto de Biología Funcional y Genómica (IBFG), Universidad de Salamanca, CSIC, Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Universidad de Salamanca, CSIC, Salamanca, Spain.
| | - Juan P Bolaños
- Instituto de Biología Funcional y Genómica (IBFG), Universidad de Salamanca, CSIC, Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Universidad de Salamanca, CSIC, Salamanca, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Madrid, Spain.
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23
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Tooley KB, Chucair-Elliott AJ, Ocañas SR, Machalinski AH, Pham KD, Stanford DR, Freeman WM. Differential usage of DNA modifications in neurons, astrocytes, and microglia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543497. [PMID: 37333391 PMCID: PMC10274634 DOI: 10.1101/2023.06.05.543497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Cellular identity is determined partly by cell type-specific epigenomic profiles that regulate gene expression. In neuroscience, there is a pressing need to isolate and characterize the epigenomes of specific CNS cell types in health and disease. This is especially true as for DNA modifications where most data are derived from bisulfite sequencing that cannot differentiate between DNA methylation and hydroxymethylation. In this study, we developed an in vivo tagging mouse model (Camk2a-NuTRAP) for paired isolation of neuronal DNA and RNA without cell sorting and then used this model to assess epigenomic regulation of gene expression between neurons and glia. Results After validating the cell-specificity of the Camk2a-NuTRAP model, we performed TRAP-RNA-Seq and INTACT whole genome oxidative bisulfite sequencing to assess the neuronal translatome and epigenome in the hippocampus of young mice (3 months old). These data were then compared to microglial and astrocytic data from NuTRAP models. When comparing the different cell types, microglia had the highest global mCG levels followed by astrocytes and then neurons, with the opposite pattern observed for hmCG and mCH. Differentially modified regions between cell types were predominantly found within gene bodies and distal intergenic regions, with limited differences occurring within proximal promoters. Across cell types there was a negative correlation between DNA modifications (mCG, mCH, hmCG) and gene expression at proximal promoters. In contrast, a negative correlation of mCG with gene expression within the gene body while a positive relationship between distal promoter and gene body hmCG and gene expression was observed. Furthermore, we identified a neuron-specific inverse relationship between mCH and gene expression across promoter and gene body regions. Conclusions In this study, we identified differential usage of DNA modifications across CNS cell types, and assessed the relationship between DNA modifications and gene expression in neurons and glia. Despite having different global levels, the general modification-gene expression relationship was conserved across cell types. The enrichment of differential modifications in gene bodies and distal regulatory elements, but not proximal promoters, across cell types highlights epigenomic patterning in these regions as potentially greater determinants of cell identity.
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Affiliation(s)
- Kyla B. Tooley
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Ana J. Chucair-Elliott
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Sarah R. Ocañas
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Adeline H. Machalinski
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Kevin D. Pham
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - David R. Stanford
- Center for Biomedical Data Sciences, Oklahoma Medical Research Foundation, Oklahoma City, OK USA
| | - Willard M. Freeman
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
- Department of Biochemistry, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK USA
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24
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Torrens JN, Hetzer SM, Evanson NK. Brief Oxygen Exposure after Traumatic Brain Injury Hastens Recovery and Promotes Adaptive Chronic Endoplasmic Reticulum Stress Responses. Int J Mol Sci 2023; 24:9831. [PMID: 37372978 PMCID: PMC10298247 DOI: 10.3390/ijms24129831] [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: 05/17/2023] [Revised: 06/02/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Traumatic brain injury (TBI) is a major public health concern, particularly in adolescents who have a higher mortality and incidence of visual pathway injury compared to adult patients. Likewise, we have found disparities between adult and adolescent TBI outcomes in rodents. Most interestingly, adolescents suffer a prolonged apneic period immediately post-injury, leading to higher mortality; therefore, we implemented a brief oxygen exposure paradigm to circumvent this increased mortality. Adolescent male mice experienced a closed-head weight-drop TBI and were then exposed to 100% O2 until normal breathing returned or recovered in room air. We followed mice for 7 and 30 days and assessed their optokinetic response; retinal ganglion cell loss; axonal degeneration; glial reactivity; and retinal ER stress protein levels. O2 reduced adolescent mortality by 40%, improved post-injury visual acuity, and reduced axonal degeneration and gliosis in optical projection regions. ER stress protein expression was altered in injured mice, and mice given O2 utilized different ER stress pathways in a time-dependent manner. Finally, O2 exposure may be mediating these ER stress responses through regulation of the redox-sensitive ER folding protein ERO1α, which has been linked to a reduction in the toxic effects of free radicals in other animal models of ER stress.
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Affiliation(s)
- Jordyn N. Torrens
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
| | - Shelby M. Hetzer
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Nathan K. Evanson
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
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25
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Lalo U, Pankratov Y. ATP-mediated signalling in the central synapses. Neuropharmacology 2023; 229:109477. [PMID: 36841527 DOI: 10.1016/j.neuropharm.2023.109477] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 02/13/2023] [Accepted: 02/23/2023] [Indexed: 02/27/2023]
Abstract
ATP released from the synaptic terminals and astrocytes can activate neuronal P2 receptors at a variety of locations across the CNS. Although the postsynaptic ATP-mediated signalling does not bring a major contribution into the excitatory transmission, it is instrumental for slow and diffuse modulation of synaptic dynamics and neuronal firing in many CNS areas. Neuronal P2X and P2Y receptors can be activated by ATP released from the synaptic terminals, astrocytes and microglia and thereby can participate in the regulation of synaptic homeostasis and plasticity. There is growing evidence of importance of purinergic regulation of synaptic transmission in different physiological and pathological contexts. Here, we review the main mechanisms underlying the complexity and diversity of purinergic signalling and purinergic modulation in central neurons.
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Affiliation(s)
- Ulyana Lalo
- School of Life Sciences, University of Warwick, United Kingdom
| | - Yuriy Pankratov
- School of Life Sciences, University of Warwick, United Kingdom.
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26
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Torrens JN, Hetzer SM, Evanson NK. Brief oxygen exposure after traumatic brain injury speeds recovery and promotes adaptive chronic endoplasmic reticulum stress responses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.09.540060. [PMID: 37214818 PMCID: PMC10197672 DOI: 10.1101/2023.05.09.540060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Traumatic brain injury (TBI) is a major public health concern particularly in adolescents who have a higher mortality and incidence of visual pathway injury compared to adult patients. Likewise, we have found disparities between adult and adolescent TBI outcomes in rodents. Most interestingly, adolescents suffer a prolonged apneic period immediately post injury leading to higher mortality; so, we implemented a brief oxygen exposure paradigm to circumvent this increased mortality. Adolescent male mice experienced a closed-head weight-drop TBI then were exposed to 100% O 2 until normal breathing returned or recovered in room air. We followed mice for 7- and 30-days and assessed their optokinetic response; retinal ganglion cell loss; axonal degeneration; glial reactivity; and retinal ER stress protein levels. O 2 reduced adolescent mortality by 40%, improved post-injury visual acuity, and reduced axonal degeneration and gliosis in optic projection regions. ER stress protein expression was altered in injured mice, and mice given O 2 utilized different ER-stress pathways in a time dependent manner. Finally, O 2 exposure may be mediating these ER stress responses through regulation of the redox-sensitive ER folding protein ERO1α, which has been linked to a reduction in the toxic effects of free radicals in other animal models of ER stress.
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27
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Felipe Souza E Silva L, Siena Dos Santos A, Mayumi Yuzawa J, Luiz de Barros Torresi J, Ziroldo A, Rosado Rosenstock T. SIRTUINS MODULATORS COUNTERACT MITOCHONDRIAL DYSFUNCTION IN CELLULAR MODELS OF HYPOXIA: RELEVANCE TO SCHIZOPHRENIA. Neuroscience 2023:S0306-4522(23)00200-2. [PMID: 37169164 DOI: 10.1016/j.neuroscience.2023.04.027] [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: 10/24/2022] [Revised: 04/16/2023] [Accepted: 04/27/2023] [Indexed: 05/13/2023]
Abstract
Schizophrenia (SZ) is a neurodevelopmental-associated disorder strongly related to environmental factors, such as hypoxia. Because there is no cure for SZ or any pharmacological approach that could revert hypoxia-induced cellular damages, we evaluated whether modulators of sirtuins could abrogate hypoxia-induced mitochondrial deregulation as a neuroprotective strategy. Firstly, astrocytes from control (Wistar) and Spontaneously Hypertensive Rats (SHR), a model of both SZ and neonatal hypoxia, were submitted to chemical hypoxia. Then, cells were exposed to different concentrations of Nicotinamide (NAM), Resveratrol (Resv), and Sirtinol (Sir) for 48hrs. Our data indicate that sirtuins modulation reduces cell death increasing the acetylation of histone 3. This outcome is related to the rescue of loss of mitochondrial membrane potential, changes in mitochondrial calcium buffering capacity, decreased O2-• levels and increased expression of metabolic regulators (Nrf-1 and Nfe2l2) and mitochondrial content. Such findings are relevant not only for hypoxia-associated conditions, named pre-eclampsia but also for SZ since prenatal hypoxia is a relevant environmental factor related to this burdensome neuropsychiatric disorder.
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Affiliation(s)
- Luiz Felipe Souza E Silva
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Amanda Siena Dos Santos
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Jessica Mayumi Yuzawa
- Department of Physiological Science, Santa Casa de São Paulo School of Medical Science, São Paulo, Brazil
| | | | - Alan Ziroldo
- Department of Physiological Science, Santa Casa de São Paulo School of Medical Science, São Paulo, Brazil
| | - Tatiana Rosado Rosenstock
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil; Dept. of Bioscience, In-vitro Neuroscience, Sygnature Discovery, Nottingham, United Kingdom.
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28
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Rosiewicz KS, Muinjonov B, Kunz S, Radbruch H, Chen J, Jüttner R, Kerkering J, Ucar J, Crowley T, Wielockx B, Paul F, Alisch M, Siffrin V. HIF prolyl hydroxylase 2/3 deletion disrupts astrocytic integrity and exacerbates neuroinflammation. Glia 2023. [PMID: 37140003 DOI: 10.1002/glia.24380] [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: 10/10/2022] [Revised: 04/06/2023] [Accepted: 04/17/2023] [Indexed: 05/05/2023]
Abstract
Astrocytes constitute the parenchymal border of the blood-brain barrier (BBB), modulate the exchange of soluble and cellular elements, and are essential for neuronal metabolic support. Thus, astrocytes critically influence neuronal network integrity. In hypoxia, astrocytes upregulate a transcriptional program that has been shown to boost neuroprotection in several models of neurological diseases. We investigated transgenic mice with astrocyte-specific activation of the hypoxia-response program by deleting the oxygen sensors, HIF prolyl-hydroxylase domains 2 and 3 (Phd2/3). We induced astrocytic Phd2/3 deletion after onset of clinical signs in experimental autoimmune encephalomyelitis (EAE) that led to an exacerbation of the disease mediated by massive immune cell infiltration. We found that Phd2/3-ko astrocytes, though expressing a neuroprotective signature, exhibited a gradual loss of gap-junctional Connexin-43 (Cx43), which was induced by vascular endothelial growth factor-alpha (Vegf-a) expression. These results provide mechanistic insights into astrocyte biology, their critical role in hypoxic states, and in chronic inflammatory CNS diseases.
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Affiliation(s)
- Kamil Sebastian Rosiewicz
- Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin und Max Delbrück Center or Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Bakhrom Muinjonov
- Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin und Max Delbrück Center or Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Séverine Kunz
- Technology Platform for Electron Microscopy, Max Delbrück Centre for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Helena Radbruch
- Department of Neuropathology, Charité-Universitätsmedizin Berlin., Berlin, Germany
| | - Jessy Chen
- Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin und Max Delbrück Center or Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Department of Neurology, Charité Universitätsmedizin Berlin., Berlin, Germany
| | - René Jüttner
- Neuromuscular and Cardiovascular Cell Biology Group, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Janis Kerkering
- Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin und Max Delbrück Center or Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Julia Ucar
- Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin und Max Delbrück Center or Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Tadhg Crowley
- Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin und Max Delbrück Center or Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Ben Wielockx
- Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden., Dresden, Germany
| | - Friedemann Paul
- Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin und Max Delbrück Center or Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Marlen Alisch
- Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin und Max Delbrück Center or Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Volker Siffrin
- Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin und Max Delbrück Center or Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Department of Neurology, Charité Universitätsmedizin Berlin., Berlin, Germany
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29
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Lear CA, Westgate JA, Bennet L, Ugwumadu A, Stone PR, Tournier A, Gunn AJ. Fetal defenses against intrapartum head compression-implications for intrapartum decelerations and hypoxic-ischemic injury. Am J Obstet Gynecol 2023; 228:S1117-S1128. [PMID: 34801443 DOI: 10.1016/j.ajog.2021.11.1352] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/05/2021] [Accepted: 11/14/2021] [Indexed: 01/27/2023]
Abstract
Uterine contractions during labor and engagement of the fetus in the birth canal can compress the fetal head. Its impact on the fetus is unclear and still controversial. In this integrative physiological review, we highlight evidence that decelerations are uncommonly associated with fetal head compression. Next, the fetus has an impressive ability to adapt to increased intracranial pressure through activation of the intracranial baroreflex, such that fetal cerebral perfusion is well-maintained during labor, except in the setting of prolonged systemic hypoxemia leading to secondary cardiovascular compromise. Thus, when it occurs, fetal head compression is not necessarily benign but does not seem to be a common contributor to intrapartum decelerations. Finally, the intracranial baroreflex and the peripheral chemoreflex (the response to acute hypoxemia) have overlapping efferent effects. We propose the hypothesis that these reflexes may work synergistically to promote fetal adaptation to labor.
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Affiliation(s)
- Christopher A Lear
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Jenny A Westgate
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand; Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Austin Ugwumadu
- Department of Obstetrics and Gynaecology, St. George's University of London, London, United Kingdom
| | - Peter R Stone
- Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Alexane Tournier
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand; Department of Paediatrics, Starship Children's Hospital, Auckland, New Zealand.
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30
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Hosford PS, Jalan R, Hadjihambi A. Reply to: "Does ammonia really disrupt brain oxygen homeostasis?". JHEP Rep 2023; 5:100666. [PMID: 37096141 PMCID: PMC10121447 DOI: 10.1016/j.jhepr.2022.100666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 12/16/2022] [Indexed: 01/01/2023] Open
Affiliation(s)
| | - Rajiv Jalan
- Liver Failure Group, Institute for Liver and Digestive Health, University College London, Royal Free Campus, London, United Kingdom
- European Foundation for the Study of Chronic Liver Failure (EF Clif), Spain
| | - Anna Hadjihambi
- The Roger Williams Institute of Hepatology London, Foundation for Liver Research, London, United Kingdom
- Faculty of Life Sciences and Medicine, King’s College London, United Kingdom
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31
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Zhang W, Han B, Zhang H, Fu R, Lu Y, Zhang G. Integrated transcriptomic and metabolomic analysis of cortical neurons reveals dysregulated lipid metabolism, enhanced glycolysis and activated HIF-1 signaling pathways in acute hypoxia. Heliyon 2023; 9:e14949. [PMID: 37025787 PMCID: PMC10070144 DOI: 10.1016/j.heliyon.2023.e14949] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 03/09/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
The brain is the main oxygen-consuming organ and is vulnerable to ischemic shock or insufficient blood perfusion. Brain hypoxia has a persistent and detrimental effect on resident neurons. Previous studies have identified alterations in genes and metabolites in ischemic brain shock by single omics, but the adaptive systems that neurons use to cope with hypoxia remain uncovered. In the present study, we constructed an acute hypoxia model and performed a multi-omics analysis from RNA-sequencing and liquid chromatography-mass spectrometry (LC-MS)-based metabolomics on exploring potentially differentially expressed genes (DEGs) and metabolites (DEMs) in primary cortical neurons under severe acute hypoxic conditions. The TUNEL assay showed acute hypoxia-induced apoptosis in cortical neurons. Omics analysis identified 564 DEGs and 46 DEMs categorized in the Kyoto encyclopedia of genes and genomes (KEGG) database. Integrative pathway analysis highlighted that dysregulated lipid metabolism, enhanced glycolysis, and activated HIF-1 signaling pathways could regulate neuron physiology and pathophysiology under hypoxia. These findings may help us understand the transcriptional and metabolic mechanisms by which cortical neurons respond to hypoxia and identify potential targets for neuron protection.
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Affiliation(s)
- Wenyi Zhang
- Department of Anesthesiology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Bo Han
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Huijun Zhang
- Department of Neurology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Rao Fu
- Department of Neurology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Yinzhong Lu
- Department of Anesthesiology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
- Corresponding author. Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Xianxia Rd 720, Shanghai 200336, China.
| | - Guangming Zhang
- Department of Anesthesiology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
- Corresponding author. Department of Anesthesiology, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Xianxia Rd 1111, Shanghai 200336, China.
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32
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Kawabata R, Shimoyama S, Ueno S, Yao I, Arata A, Koga K. TRPA1 as a O 2 sensor detects microenvironmental hypoxia in the mice anterior cingulate cortex. Sci Rep 2023; 13:2960. [PMID: 36807332 PMCID: PMC9941080 DOI: 10.1038/s41598-023-29140-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 01/31/2023] [Indexed: 02/22/2023] Open
Abstract
Transient receptor potential ankyrin 1 (TRPA1) is a member of the TRP channel family and is expressed in peripheral and central nervous systems. In the periphery, TRPA1 senses cold and pain. However, the functions of TRPA1 in the CNS are unclear. Here, we examined the roles of TRPA1 on neural activity and synaptic transmission in layer II/III pyramidal neurons from mice anterior cingulate cortex (ACC) by whole-cell patch-clamp recordings. The activation of Cinnamaldehyde (CA), which is TRPA1 agonist produced inward currents and these were blocked by the TRPA1 antagonists. Furthermore, activating TRPA1 changed the properties of action potentials such as the firing rate, rise time and decay time. In contrast, stimulating TRPA1 did not alter the spontaneous synaptic transmission. Finally, we examined the functional role of TRPA1 on neurons in a hypoxic environment. We induced an acute hypoxia by substituting nitrogen (N2) gas for oxygen (O2) in the external solution. N2 produced biphasic effects that consisting of inward currents in the early phase and outward currents in the late phase. Importantly, blocking TRPA1 reduced inward currents, but not outward currents. In contrast, a KATP channel blocker completely inhibited outward currents. These results suggest that TRPA1 acts on postsynaptic neurons in the ACC as an acute O2 sensor.
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Affiliation(s)
- Ryo Kawabata
- grid.258777.80000 0001 2295 9421Department of Biomedical Chemistry major, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo Japan ,grid.272264.70000 0000 9142 153XDepartment of Neurophysiology, Hyogo Medical University, Nishinomiya, Hyogo Japan
| | - Shuji Shimoyama
- grid.257016.70000 0001 0673 6172Department of Neurophysiology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori Japan
| | - Shinya Ueno
- grid.257016.70000 0001 0673 6172Department of Neurophysiology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori Japan
| | - Ikuko Yao
- grid.258777.80000 0001 2295 9421Department of Biomedical Chemistry major, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo Japan
| | - Akiko Arata
- Department of Physiology, Hyogo Medical University, Nishinomiya, Hyogo, Japan.
| | - Kohei Koga
- Department of Neurophysiology, Hyogo Medical University, Nishinomiya, Hyogo, Japan.
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33
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Varlamova EG, Khabatova VV, Gudkov SV, Turovsky EA. Ca 2+-Dependent Effects of the Selenium-Sorafenib Nanocomplex on Glioblastoma Cells and Astrocytes of the Cerebral Cortex: Anticancer Agent and Cytoprotector. Int J Mol Sci 2023; 24:ijms24032411. [PMID: 36768736 PMCID: PMC9917080 DOI: 10.3390/ijms24032411] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 01/21/2023] [Accepted: 01/24/2023] [Indexed: 01/28/2023] Open
Abstract
Despite the fact that sorafenib is recommended for the treatment of oncological diseases of the liver, kidneys, and thyroid gland, and recently it has been used for combination therapy of brain cancer of various genesis, there are still significant problems for its widespread and effective use. Among these problems, the presence of the blood-brain barrier of the brain and the need to use high doses of sorafenib, the existence of mechanisms for the redistribution of sorafenib and its release in the brain tissue, as well as the high resistance of gliomas and glioblastomas to therapy should be considered the main ones. Therefore, there is a need to create new methods for delivering sorafenib to brain tumors, enhancing the therapeutic potential of sorafenib and reducing the cytotoxic effects of active compounds on the healthy environment of tumors, and ideally, increasing the survival of healthy cells during therapy. Using vitality tests, fluorescence microscopy, and molecular biology methods, we showed that the selenium-sorafenib (SeSo) nanocomplex, at relatively low concentrations, is able to bypass the mechanisms of glioblastoma cell chemoresistance and to induce apoptosis through Ca2+-dependent induction of endoplasmic reticulum stress, changes in the expression of selenoproteins and selenium-containing proteins, as well as key kinases-regulators of oncogenicity and cell death. Selenium nanoparticles (SeNPs) also have a high anticancer efficacy in glioblastomas, but are less selective, since SeSo in cortical astrocytes causes a more pronounced activation of the cytoprotective pathways.
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Affiliation(s)
- Elena G. Varlamova
- Institute of Cell Biophysics of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 142290 Pushchino, Russia
| | - Venera V. Khabatova
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilove st., 119991 Moscow, Russia
| | - Sergey V. Gudkov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilove st., 119991 Moscow, Russia
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia
| | - Egor A. Turovsky
- Institute of Cell Biophysics of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 142290 Pushchino, Russia
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia
- Correspondence:
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Angelova PR, Myers I, Abramov AY. Carbon monoxide neurotoxicity is triggered by oxidative stress induced by ROS production from three distinct cellular sources. Redox Biol 2023; 60:102598. [PMID: 36640724 PMCID: PMC9852609 DOI: 10.1016/j.redox.2022.102598] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 12/30/2022] [Indexed: 01/09/2023] Open
Abstract
Carbon monoxide (CO) poisoning is one of the leading causes of toxic mortality and morbidity. We have studied the generation of reactive oxygen species in cortical neurons in culture in response to toxic doses of CO exposure. Fluorescence microscopy was used to measure the rate of free radical generation, lipid peroxidation, GSH level and also mitochondrial metabolism. We have found that toxic concentrations of CO released from CORM-401 induced mitochondrial depolarisation and inhibition of NADH dependent respiration to a lesser degree than when compared to ischaemia. Energy collapse was not observed within 40 min of CO exposure. We have found that CO induces the generation of reactive oxygen species resulting in lipid peroxidation and a decrease in GSH via three different mechanisms: from mitochondria during the first minutes of CO exposure, from xanthine oxidase at around 20 min exposure due to energy deprivation, and considerable ROS production from NADPH oxidase in the post CO exposure period (re-oxygenation). Inhibition of these different phases with mitochondrial antioxidants, inhibitors of xanthine oxidase, or NADPH oxidase, protected neurons and astrocytes against CO-induced oxidative stress and cell death. The most profound effect was seen during NADPH oxidase inhibition. Thus, oxidative stress has a remarkably significant role in CO-induced neuronal cell death and preventing its occurrence during reoxygenation is of great importance in the consideration of a positive, neurologically protective therapeutic outcome for CO exposed patients.
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E G, Sun B, Liu B, Xu G, He S, Wang Y, Feng L, Wei H, Zhang J, Chen J, Gao Y, Zhang E. Enhanced BPGM/2,3-DPG pathway activity suppresses glycolysis in hypoxic astrocytes via FIH-1 and TET2. Brain Res Bull 2023; 192:36-46. [PMID: 36334804 DOI: 10.1016/j.brainresbull.2022.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/21/2022] [Accepted: 11/01/2022] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Bisphosphoglycerate mutase (BPGM) is expressed in human erythrocytes and responsible for the production of 2,3-bisphosphoglycerate (2,3-DPG). However, the expression and role of BPGM in other cells have not been reported. In this work, we found that BPGM was significantly upregulated in astrocytes upon acute hypoxia, and the role of this phenomenon will be clarified in the following report. METHODS The mRNA and protein expression levels of BPGM and the content of 2,3-DPG with hypoxia treatment were determined in vitro and in vivo. Furthermore, glycolysis was evaluated upon in hypoxic astrocytes with BPGM knockdown and in normoxic astrocytes with BPGM overexpression or 2,3-DPG treatment. To investigate the mechanism by which BPGM/2,3-DPG regulated glycolysis in hypoxic astrocytes, we detected the expression of HIF-1α, FIH-1 and TET2 with silencing or overexpression of BPGM and 2,3-DPG treatment. RESULTS The expression of glycolytic genes and the capacity of lactate markedly increased with 6 h, 12 h, 24 h, 36 h and 48 h 1 % O2 hypoxic treatment in astrocytes. The expression of BPGM was upregulated, and the production of 2,3-DPG was accelerated upon hypoxia. Moreover, when BPGM expression was knocked down, glycolysis was promoted in HEB cells. However, overexpression of BPGM and addition of 2,3-DPG to the cellular medium in normoxic cells could downregulate glycolytic genes. Furthermore, HIF-1α and TET2 exhibited higher expression levels and FIH-1 showed a lower expression level upon BPGM silencing, while these changes were reversed under BPGM overexpression and 2,3-DPG treatment. CONCLUSIONS Our study revealed that the BPGM/2,3-DPG pathway presented a suppressive effect on glycolysis in hypoxic astrocytes by negatively regulating HIF-1α and TET2.
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Affiliation(s)
- Guoji E
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Binda Sun
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Bao Liu
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Gang Xu
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Shu He
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Yu Wang
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Lan Feng
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Hannan Wei
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Jianyang Zhang
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Jian Chen
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Yuqi Gao
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
| | - Erlong Zhang
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Army Medical University, Chongqing, China; Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, China; Key Laboratory of High Altitude Medicine, People's Liberation Army, Chongqing, China.
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Lei X, Wei M, Qi Y, Wang L, Liu C, Guo Y, Xu Y, Cao X, Liu R, Luo G. The patent foramen ovale may alter migraine brain activity: A pilot study of electroencephalography spectrum and functional connectivity analysis. Front Mol Neurosci 2023; 16:1133303. [PMID: 36959871 PMCID: PMC10029922 DOI: 10.3389/fnmol.2023.1133303] [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: 12/28/2022] [Accepted: 02/21/2023] [Indexed: 03/09/2023] Open
Abstract
Background A link has been shown between patent foramen ovale (PFO) and migraine, particularly migraine with aura. However, it is unknown if PFO might cause migraine by altering cortical excitability and neural network, which may lower the threshold of cortical spreading depression (CSD). This study aims to compare the spectrum power and functional connectivity of the alpha and beta bands of electroencephalography (EEG) across migraine patients with and without PFO. Methods Thirty-five migraine patients with PFO (PFO +), 35 migraine patients without PFO (PFO -) and 20 PFO patients without migraine (control) were enrolled in this cross-sectional analysis. 19-channel EEG was recorded for all patients under resting state and intermittent photic stimulation. Power spectrum density (PSD) and phase lag index (PLI) of alpha and beta bands were then calculated and compared between the three groups. Results During photic stimulation, the beta band PSD at the occipital area was substantially higher in PFO + migraine patients compared to PFO-migraine patients (p < 0.05, Bonferroni corrected). Subgroup analysis showed that both migraine with and without aura patients with PFO had increased PSD in the alpha and beta bands at the occipital region during photic stimulation (p < 0.05, Bonferroni corrected). Meanwhile, the beta band PLI during photic stimulation was significantly elevated (adjusted p = 0.008, utilizing the network-based statistic technique) in PFO + group compared to PFO-group. Furthermore, although failed to pass the correction, the beta band power in the occipital area during photic stimulation at 20 Hz on O1 (R = 0.392, p = 0.024) and O2 channel (R = 0.348, p = 0.047) was prone to positively correlated with MIDAS score, and during photic stimulation at 12 Hz on O2 channel (R = 0.396, p = 0.022) and 20 Hz (R = 0.365, p = 0.037) on O1 channel was prone to positively correlated to HIT-6 score in PFO+ migraineurs, whereas no similar correlation was found in the PFO-group patients. Conclusion The outcomes of this investigation suggested that PFO may change the cortical excitability in the occipital lobe of both migraineurs with and without aura. Meanwhile, the beta band PSD on the occipital area during photic stimulation might be an objective measure of severity in migraineurs with PFO.
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Rey F, Messa L, Maghraby E, Casili G, Ottolenghi S, Barzaghini B, Raimondi MT, Cereda C, Cuzzocrea S, Zuccotti G, Esposito E, Paterniti I, Carelli S. Oxygen Sensing in Neurodegenerative Diseases: Current Mechanisms, Implication of Transcriptional Response, and Pharmacological Modulation. Antioxid Redox Signal 2023; 38:160-182. [PMID: 35793106 DOI: 10.1089/ars.2022.0046] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Significance: Oxygen (O2) sensing is the fundamental process through which organisms respond to changes in O2 levels. Complex networks exist allowing the maintenance of O2 levels through the perception, capture, binding, transport, and delivery of molecular O2. The brain extreme sensitivity to O2 balance makes the dysregulation of related processes crucial players in the pathogenesis of neurodegenerative diseases (NDs). In this study, we wish to review the most relevant advances in O2 sensing in relation to Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Recent Advances: Over the years, it has been clarified that most NDs share common pathways, a great number of which are in relation to O2 imbalance. These include hypoxia, hyperoxia, reactive oxygen species production, metabolism of metals, protein misfolding, and neuroinflammation. Critical Issues: There is still a gap in knowledge concerning how O2 sensing plays a role in the above indicated neurodegenerations. Specifically, O2 concentrations are perceived in body sites that are not limited to the brain, but primarily reside in other organs. Moreover, the mechanisms of O2 sensing, gene expression, and signal transduction seem to correlate with neurodegeneration, but many aspects are mechanistically still unexplained. Future Directions: Future studies should focus on the precise characterization of O2 level disruption and O2 sensing mechanisms in NDs. Moreover, advances need to be made also concerning the techniques used to assess O2 sensing dysfunctions in these diseases. There is also the need to develop innovative therapies targeting this precise mechanism rather than its secondary effects, as early intervention is necessary. Antioxid. Redox Signal. 38, 160-182.
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Affiliation(s)
- Federica Rey
- Department of Biomedical and Clinical Sciences, University of Milano, Milano, Italy.,Department of Biomedical and Clinical Sciences, Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milano, Milano, Italy
| | - Letizia Messa
- Department of Biomedical and Clinical Sciences, University of Milano, Milano, Italy.,Department of Biomedical and Clinical Sciences, Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milano, Milano, Italy
| | - Erika Maghraby
- Department of Biomedical and Clinical Sciences, University of Milano, Milano, Italy.,Department of Biomedical and Clinical Sciences, Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milano, Milano, Italy
| | - Giovanna Casili
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Sara Ottolenghi
- Department of Medicine and Surgery, University of Milano Bicocca, Milano, Italy
| | - Bianca Barzaghini
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milano, Italy
| | - Manuela Teresa Raimondi
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milano, Italy
| | - Cristina Cereda
- Department of Women, Mothers and Neonatal Care, Children's Hospital "V. Buzzi," Milano, Italy
| | - Salvatore Cuzzocrea
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Gianvincenzo Zuccotti
- Department of Biomedical and Clinical Sciences, University of Milano, Milano, Italy.,Department of Biomedical and Clinical Sciences, Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milano, Milano, Italy.,Department of Pediatrics, Children's Hospital "V. Buzzi," Milano, Italy
| | - Emanuela Esposito
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Irene Paterniti
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Stephana Carelli
- Department of Biomedical and Clinical Sciences, University of Milano, Milano, Italy.,Department of Biomedical and Clinical Sciences, Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milano, Milano, Italy
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Fukushi I, Ikeda K, Takeda K, Yoshizawa M, Kono Y, Hasebe Y, Pokorski M, Okada Y. Minocycline prevents hypoxia-induced seizures. Front Neural Circuits 2023; 17:1006424. [PMID: 37035503 PMCID: PMC10073501 DOI: 10.3389/fncir.2023.1006424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
Severe hypoxia induces seizures, which reduces ventilation and worsens the ictal state. It is a health threat to patients, particularly those with underlying hypoxic respiratory pathologies, which may be conducive to a sudden unexpected death in epilepsy (SUDEP). Recent studies provide evidence that brain microglia are involved with both respiratory and ictal processes. Here, we investigated the hypothesis that microglia could interact with hypoxia-induced seizures. To this end, we recorded electroencephalogram (EEG) and acute ventilatory responses to hypoxia (5% O2 in N2) in conscious, spontaneously breathing adult mice. We compared control vehicle pre-treated animals with those pre-treated with minocycline, an inhibitory modulator of microglial activation. First, we histologically confirmed that hypoxia activates microglia and that pre-treatment with minocycline blocks hypoxia-induced microglial activation. Then, we analyzed the effects of minocycline pre-treatment on ventilatory responses to hypoxia by plethysmography. Minocycline alone failed to affect respiratory variables in room air or the initial respiratory augmentation in hypoxia. The comparative results showed that hypoxia caused seizures, which were accompanied by the late phase ventilatory suppression in all but one minocycline pre-treated mouse. Compared to the vehicle pre-treated, the minocycline pre-treated mice showed a delayed occurrence of seizures. Further, minocycline pre-treated mice tended to resist post-ictal respiratory arrest. These results suggest that microglia are conducive to seizure activity in severe hypoxia. Thus, inhibition of microglial activation may help suppress or prevent hypoxia-induced ictal episodes.
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Affiliation(s)
- Isato Fukushi
- Faculty of Health Sciences, Aomori University of Health and Welfare, Aomori, Japan
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- *Correspondence: Isato Fukushi
| | - Keiko Ikeda
- Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Toyoake, Japan
| | - Masashi Yoshizawa
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | - Yosuke Kono
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | - Yohei Hasebe
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | | | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
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Zhang Q, Haselden WD, Charpak S, Drew PJ. Could respiration-driven blood oxygen changes modulate neural activity? Pflugers Arch 2023; 475:37-48. [PMID: 35761104 PMCID: PMC9794637 DOI: 10.1007/s00424-022-02721-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/26/2022] [Accepted: 06/16/2022] [Indexed: 01/31/2023]
Abstract
Oxygen is critical for neural metabolism, but under most physiological conditions, oxygen levels in the brain are far more than are required. Oxygen levels can be dynamically increased by increases in respiration rate that are tied to the arousal state of the brain and cognition, and not necessarily linked to exertion by the body. Why these changes in respiration occur when oxygen is already adequate has been a long-standing puzzle. In humans, performance on cognitive tasks can be affected by very high or very low oxygen levels, but whether the physiological changes in blood oxygenation produced by respiration have an appreciable effect is an open question. Oxygen has direct effects on potassium channels, increases the degradation rate of nitric oxide, and is rate limiting for the synthesis of some neuromodulators. We discuss whether oxygenation changes due to respiration contribute to neural dynamics associated with attention and arousal.
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Affiliation(s)
- Qingguang Zhang
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - William D Haselden
- Medical Scientist Training Program, College of Medicine, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Serge Charpak
- Institut de La Vision, INSERM, CNRS, Sorbonne Université, Paris, France
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Patrick J Drew
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA.
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA, 16802, USA.
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Goenaga J, Araque A, Kofuji P, Herrera Moro Chao D. Calcium signaling in astrocytes and gliotransmitter release. Front Synaptic Neurosci 2023; 15:1138577. [PMID: 36937570 PMCID: PMC10017551 DOI: 10.3389/fnsyn.2023.1138577] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
Glia are as numerous in the brain as neurons and widely known to serve supportive roles such as structural scaffolding, extracellular ionic and neurotransmitter homeostasis, and metabolic support. However, over the past two decades, several lines of evidence indicate that astrocytes, which are a type of glia, play active roles in neural information processing. Astrocytes, although not electrically active, can exhibit a form of excitability by dynamic changes in intracellular calcium levels. They sense synaptic activity and release neuroactive substances, named gliotransmitters, that modulate neuronal activity and synaptic transmission in several brain areas, thus impacting animal behavior. This "dialogue" between astrocytes and neurons is embodied in the concept of the tripartite synapse that includes astrocytes as integral elements of synaptic function. Here, we review the recent work and discuss how astrocytes via calcium-mediated excitability modulate synaptic information processing at various spatial and time scales.
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Doufas AG, Tian L, Kutscher S, Finnsson E, Ágústsson JS, Chung BI, Panousis P. The effect of hyperoxia on ventilation during recovery from general anesthesia: A randomized pilot study for a parallel randomized controlled trial. J Clin Anesth 2022; 83:110982. [PMID: 36265267 DOI: 10.1016/j.jclinane.2022.110982] [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: 07/26/2022] [Revised: 09/29/2022] [Accepted: 10/05/2022] [Indexed: 11/06/2022]
Abstract
STUDY OBJECTIVE While supplemental O2 inhalation corrects hypoxemia, its effect on post-anesthesia ventilation remains unknown. This pilot trial tested the hypothesis that hyperoxia increases the time spent with a transcutaneous PCO2 (TcPCO2) > 45 mmHg, compared with standard O2 supplementation. DESIGN Single-blinded, parallel two-arm randomized pilot trial. SETTING University hospital. PATIENTS 20 patients undergoing robotic-assisted laparoscopic nephrectomy. MEASUREMENTS After institutional approval and informed consent, patients were randomized to receive O2 titrated to arterial saturation (SpO2): 90-94% (Conservative O2, N =10), or to SpO2 > 96% (Liberal O2, N = 10) for up to 90 min after anesthesia. Continuous TcPCO2, respiratory inductance plethysmography (RIP), and SpO2, were recorded. We calculated the percentage of time at TcPCO2 > 45 mmHg for each patient and compared the two groups using analysis of covariance, adjusting for sex, age, and body mass index. We also estimated the sample size required to detect the between-group difference observed in this pilot trial. RIP signals were used to calculate apnea/hypopnea index (AHI), which was then compared between two groups. MAIN RESULTS The mean percentage of time with a TcPCO2 > 45 mmHg was 80.6% for the Conservative O2 (N=9) and 61.2% for the Liberal O2 (N=10) group [between-group difference of 19.4% (95% CI: -18.7% to 57.6%), P = 0.140]. With an observed effect size of 0.73, we estimated that 30 participants per group are required, to demonstrate this difference with a power of 80% at a two-sided alpha of 5%. Means SpO2 were 94.5% and 99.9% for the Conservative O2 and the Liberal O2 groups, respectively. AHI was significantly higher in the Conservative O2, compared with the Liberal O2 group (median AHI: 16 vs. 3; P = 0.0014). CONCLUSIONS Hyperoxia in the post-anesthesia period reduced the time spent at TcPCO2 > 45 mmHg and significantly decreased AHI, while mean SpO2 ranged inside the a priori defined limits. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT04723433.
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Affiliation(s)
- Anthony G Doufas
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, United States of America; Center for Sleep and Circadian Sciences, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States of America.
| | - Lu Tian
- Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA, United States of America
| | - Scott Kutscher
- Department of Psychiatry and Behavioral Sciences, and Center for Sleep Sciences and Medicine, Stanford University School of Medicine, Stanford, CA, United States of America
| | | | | | - Benjamin I Chung
- Department of Urology, Stanford University School of Medicine, Stanford, CA, United States of America
| | - Periklis Panousis
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, United States of America
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Zuchegna C, Porcellini A, Messina S. Redox-sensitive small GTPase H-Ras in murine astrocytes, an in vitro study. Redox Rep 2022; 27:150-157. [PMID: 35822835 PMCID: PMC9291712 DOI: 10.1080/13510002.2022.2094109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Although the protooncogenes small GTPases Ras are redox-sensitive proteins, how they are regulated by redox signaling in the central nervous system (CNS) is still poorly understood. Alteration in redox-sensitive targets by redox signaling may have myriad effects on Ras stability, activity and localization. Redox-mediated changes in astrocytic RAS may contribute to the control of redox homeostasis in the CNS that is connected to the pathogenesis of many diseases. RESULTS AND METHODS Here, we investigated the transient physiological induction, at both transcriptional and translational levels, of small GTPases Ras in response to redox stimulation. Cultured astrocytes were treated with hydrogen peroxide as in bolus addition and relative mRNA levels of murine hras and kras genes were detected by qRT-PCR. We found that de novo transcription of hras mRNA in reactive astrocytes is redox-sensitive and mimics the prototypical redox-sensitive gene iNOS. Protein abundance in combination with protein turnover measurements by cycloheximide-chase experiments revealed distinct translation efficiency, GTP-bound enrichment, and protein turnover rates between the two isoforms H-Ras and K-Ras. CONCLUSION Reports from recent years support a significant role of H-Ras in driving redox processes. Beyond its canonical functions, Ras may impact on the core astrocytic cellular machinery that operates during redox stimulation.
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Affiliation(s)
- Candida Zuchegna
- Dipartimento di Biologia, Complesso Universitario di Monte Sant'Angelo, Università degli Studi di Napoli “Federico II”, Napoli, Italia
| | - Antonio Porcellini
- Dipartimento di Biologia, Complesso Universitario di Monte Sant'Angelo, Università degli Studi di Napoli “Federico II”, Napoli, Italia
| | - Samantha Messina
- Dipartimento di Scienze, Università degli Studi Roma Tre, Roma, Italia
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Mikkelsen ACD, Thomsen KL, Mookerjee RP, Hadjihambi A. The role of brain inflammation and abnormal brain oxygen homeostasis in the development of hepatic encephalopathy. Metab Brain Dis 2022; 38:1707-1716. [PMID: 36326976 DOI: 10.1007/s11011-022-01105-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022]
Abstract
Hepatic encephalopathy (HE) is a frequent complication of chronic liver disease (CLD) and has a complex pathogenesis. Several preclinical and clinical studies have reported the presence of both peripheral and brain inflammation in CLD and their potential impact in the development of HE. Altered brain vascular density and tone, as well as compromised cerebral and systemic blood flow contributing to the development of brain hypoxia, have also been reported in animal models of HE, while a decrease in cerebral metabolic rate of oxygen and cerebral blood flow has consistently been observed in patients with HE. Whilst significant strides in our understanding have been made over the years, evaluating all these mechanistic elements in vivo and showing causal association with development of HE, have been limited through the practical constraints of experimentation. Nonetheless, improvements in non-invasive assessments of different neurophysiological parameters, coupled with techniques to assess changes in inflammatory and metabolic pathways, will help provide more granular insights on these mechanisms. In this special issue we discuss some of the emerging evidence supporting the hypothesis that brain inflammation and abnormal oxygen homeostasis occur interdependently during CLD and comprise important contributors to the development of HE. This review aims at furnishing evidence for further research in brain inflammation and oxygen homeostasis as additional therapeutic targets and potentially diagnostic markers for HE.
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Affiliation(s)
| | - Karen Louise Thomsen
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Rajeshwar Prosad Mookerjee
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Anna Hadjihambi
- The Roger Williams Institute of Hepatology London, Foundation for Liver Research, London, SE5 9NT, UK.
- Faculty of Life Sciences and Medicine, King's College London, London, UK.
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44
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Toledo C, Andrade DC, Diaz-Jara E, Ortolani D, Bernal-Santander I, Schwarz KG, Ortiz FC, Marcus NJ, Oliveira LM, Takakura AC, Moreira TS, Del Rio R. Cardiorespiratory alterations following intermittent photostimulation of RVLM C1 neurons: Implications for long-term blood pressure, breathing and sleep regulation in freely moving rats. Acta Physiol (Oxf) 2022; 236:e13864. [PMID: 35959519 DOI: 10.1111/apha.13864] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 08/08/2022] [Accepted: 08/09/2022] [Indexed: 01/29/2023]
Abstract
AIM Sympathoexcitation and sleep-disordered breathing are common contributors for disease progression. Catecholaminergic neurons from the rostral ventrolateral medulla (RVLM-C1) modulate sympathetic outflow and have anatomical projections to respiratory neurons; however, the contribution of highly selective activation of RVLM-C1 neurons on long-term autonomic and breathing (dys)regulation remains to be understood. METHODS To explore this relationship, a lentiviral vector carrying the light-sensitive cation channel channelrhodopsin-2 (LVV-PRSX8-ChR2-YFP) was unilaterally injected into the RVLM of healthy rats. On the contralateral side, LVV-PRSX8-ChR2-YFP was co-injected with a specific immunotoxin (DβH-SAP) targeted to eliminate C1 neurons. RESULTS Intermittent photostimulation of RVLM-C1 in vivo, in unrestrained freely moving rats, elicited long-term facilitation of the sympathetic drive, a rise in blood pressure and sympatho-respiratory coupling. In addition, photoactivation of RVLM-C1 induced long-lasting ventilatory instability, characterized by oscillations in tidal volume and increased breathing variability, but only during non-rapid eye movement sleep. These effects were not observed when photostimulation of the RVLM was performed in the presence of DβH-SAP toxin. CONCLUSIONS The finding that intermittent activation of RVLM-C1 neurons induces autonomic and breathing dysfunction suggest that episodic stimulation of RVLM-C1 may serve as a pathological substrate for the long-term development of cardiorespiratory disorders.
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Affiliation(s)
- Camilo Toledo
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - David C Andrade
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Fisiología y Medicina de Altura, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
| | - Esteban Diaz-Jara
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Domiziana Ortolani
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ignacio Bernal-Santander
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Karla G Schwarz
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Fernando C Ortiz
- Mechanisms of Myelin Formation and Repair Laboratory, Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad, Autónoma de Chile, Santiago, Chile
| | - Noah J Marcus
- Department of Physiology and Pharmacology, Des Moines University, Des Moines, Iowa, USA
| | - Luiz M Oliveira
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo, Sao Paulo, Brazil
| | - Ana C Takakura
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo, Sao Paulo, Brazil
| | - Thiago S Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of Sao Paulo, Sao Paulo, Brazil
| | - Rodrigo Del Rio
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
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45
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Yoshizawa M, Fukushi I, Takeda K, Kono Y, Hasebe Y, Koizumi K, Ikeda K, Pokorski M, Toda T, Okada Y. Role of microglia in blood pressure and respiratory responses to acute hypoxic exposure in rats. J Physiol Sci 2022; 72:26. [PMID: 36229778 DOI: 10.1186/s12576-022-00848-y] [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: 10/21/2021] [Accepted: 09/02/2022] [Indexed: 11/10/2022]
Abstract
Microglia modulate cardiorespiratory activities during chronic hypoxia. It has not been clarified whether microglia are involved in the cardiorespiratory responses to acute hypoxia. Here we investigated this issue by comparing cardiorespiratory responses to two levels of acute hypoxia (13% O2 for 4 min and 7% O2 for 5 min) in conscious unrestrained rats before and after systemic injection of minocycline (MINO), an inhibitor of microglia activation. MINO increased blood pressure but not lung ventilation in the control normoxic condition. Acute hypoxia stimulated cardiorespiratory responses in MINO-untreated rats. MINO failed to significantly affect the magnitude of hypoxia-induced blood pressure elevation. In contrast, MINO tended to suppress the ventilatory responses to hypoxia. We conclude that microglia differentially affect cardiorespiratory regulation depending on the level of blood oxygenation. Microglia suppressively contribute to blood pressure regulation in normoxia but help maintain ventilatory augmentation in hypoxia, which underscores the dichotomy of central regulatory pathways for both systems.
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Affiliation(s)
- Masashi Yoshizawa
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.,Clinical Research Center, Murayama Medical Center, Tokyo, Japan
| | - Isato Fukushi
- Clinical Research Center, Murayama Medical Center, Tokyo, Japan.,Faculty of Health Sciences, Aomori University of Health and Welfare, Aomori, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Tokyo, Japan.,Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Toyoake, Japan
| | - Yosuke Kono
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.,Clinical Research Center, Murayama Medical Center, Tokyo, Japan
| | - Yohei Hasebe
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.,Clinical Research Center, Murayama Medical Center, Tokyo, Japan
| | - Keiichi Koizumi
- Department of Pediatrics, Fujiyoshida Municipal Hospital, Yamanashi, Japan
| | - Keiko Ikeda
- Institute of Innovative Research, Homeostatic Mechanism Research Unit, Tokyo Institute of Technology, Yokohama, Japan
| | | | - Takako Toda
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Tokyo, Japan.
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46
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Brain dysfunction during warming is linked to oxygen limitation in larval zebrafish. Proc Natl Acad Sci U S A 2022; 119:e2207052119. [PMID: 36122217 PMCID: PMC9522358 DOI: 10.1073/pnas.2207052119] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Understanding the physiological mechanisms that limit animal thermal tolerance is crucial in predicting how animals will respond to increasingly severe heat waves. Despite their importance for understanding climate change impacts, these mechanisms underlying the upper thermal tolerance limits of animals are largely unknown. It has been hypothesized that the upper thermal tolerance in fish is limited by the thermal tolerance of the brain and is ultimately caused by a global brain depolarization. In this study, we developed methods for measuring the upper thermal limit (CTmax) in larval zebrafish (Danio rerio) with simultaneous recordings of brain activity using GCaMP6s calcium imaging in both free-swimming and agar-embedded fish. We discovered that during warming, CTmax precedes, and is therefore not caused by, a global brain depolarization. Instead, the CTmax coincides with a decline in spontaneous neural activity and a loss of neural response to visual stimuli. By manipulating water oxygen levels both up and down, we found that oxygen availability during heating affects locomotor-related neural activity, the neural response to visual stimuli, and CTmax. Our results suggest that the mechanism limiting the upper thermal tolerance in zebrafish larvae is insufficient oxygen availability causing impaired brain function.
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47
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Ciumas C, Rheims S, Ryvlin P. fMRI studies evaluating central respiratory control in humans. Front Neural Circuits 2022; 16:982963. [PMID: 36213203 PMCID: PMC9537466 DOI: 10.3389/fncir.2022.982963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/01/2022] [Indexed: 11/13/2022] Open
Abstract
A plethora of neural centers in the central nervous system control the fundamental respiratory pattern. This control is ensured by neurons that act as pacemakers, modulating activity through chemical control driven by changes in the O2/CO2 balance. Most of the respiratory neural centers are located in the brainstem, but difficult to localize on magnetic resonance imaging (MRI) due to their small size, lack of visually-detectable borders with neighboring areas, and significant physiological noise hampering detection of its activity with functional MRI (fMRI). Yet, several approaches make it possible to study the normal response to different abnormal stimuli or conditions such as CO2 inhalation, induced hypercapnia, volitional apnea, induced hypoxia etc. This review provides a comprehensive overview of the majority of available studies on central respiratory control in humans.
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Affiliation(s)
- Carolina Ciumas
- Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Lyon Neuroscience Research Center, Institut National de la Santé et de la Recherche Médicale U1028/CNRS UMR 5292 Lyon 1 University, Bron, France
- IDEE Epilepsy Institute, Lyon, France
| | - Sylvain Rheims
- Lyon Neuroscience Research Center, Institut National de la Santé et de la Recherche Médicale U1028/CNRS UMR 5292 Lyon 1 University, Bron, France
- IDEE Epilepsy Institute, Lyon, France
- Department of Functional Neurology and Epileptology, Hospices Civils de Lyon, Lyon, France
| | - Philippe Ryvlin
- Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
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48
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Düking T, Spieth L, Berghoff SA, Piepkorn L, Schmidke AM, Mitkovski M, Kannaiyan N, Hosang L, Scholz P, Shaib AH, Schneider LV, Hesse D, Ruhwedel T, Sun T, Linhoff L, Trevisiol A, Köhler S, Pastor AM, Misgeld T, Sereda M, Hassouna I, Rossner MJ, Odoardi F, Ischebeck T, de Hoz L, Hirrlinger J, Jahn O, Saher G. Ketogenic diet uncovers differential metabolic plasticity of brain cells. SCIENCE ADVANCES 2022; 8:eabo7639. [PMID: 36112685 PMCID: PMC9481126 DOI: 10.1126/sciadv.abo7639] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
To maintain homeostasis, the body, including the brain, reprograms its metabolism in response to altered nutrition or disease. However, the consequences of these challenges for the energy metabolism of the different brain cell types remain unknown. Here, we generated a proteome atlas of the major central nervous system (CNS) cell types from young and adult mice, after feeding the therapeutically relevant low-carbohydrate, high-fat ketogenic diet (KD) and during neuroinflammation. Under steady-state conditions, CNS cell types prefer distinct modes of energy metabolism. Unexpectedly, the comparison with KD revealed distinct cell type-specific strategies to manage the altered availability of energy metabolites. Astrocytes and neurons but not oligodendrocytes demonstrated metabolic plasticity. Moreover, inflammatory demyelinating disease changed the neuronal metabolic signature in a similar direction as KD. Together, these findings highlight the importance of the metabolic cross-talk between CNS cells and between the periphery and the brain to manage altered nutrition and neurological disease.
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Affiliation(s)
- Tim Düking
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lena Spieth
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Stefan A. Berghoff
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lars Piepkorn
- Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Annika M. Schmidke
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Miso Mitkovski
- City Campus Light Microscopy Facility, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Nirmal Kannaiyan
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Leon Hosang
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Center Göttingen, Göttingen, Germany
| | - Patricia Scholz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Ali H. Shaib
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Institute for Neuro- and Sensory Physiology, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Lennart V. Schneider
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Dörte Hesse
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Electron Microscopy Core Unit, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Ting Sun
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lisa Linhoff
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
- Translational Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Andrea Trevisiol
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Susanne Köhler
- Carl-Ludwig-Institute for Physiology, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Adrian Marti Pastor
- Institute of Neuronal Cell Biology, Technische Universität München, Cluster for Systems Neurology (SyNergy), German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technische Universität München, Cluster for Systems Neurology (SyNergy), German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Michael Sereda
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
- Translational Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Imam Hassouna
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Moritz J. Rossner
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Francesca Odoardi
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Center Göttingen, Göttingen, Germany
| | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
- Institute of Plant Biology and Biotechnology (IBBP), Green Biotechnology, University of Münster, Münster, Germany
| | - Livia de Hoz
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Neurowissenschafliches Forschungszentrum, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Johannes Hirrlinger
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Carl-Ludwig-Institute for Physiology, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Olaf Jahn
- Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Gesine Saher
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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49
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Zhang X, Zhang J. The human brain in a high altitude natural environment: A review. Front Hum Neurosci 2022; 16:915995. [PMID: 36188182 PMCID: PMC9520777 DOI: 10.3389/fnhum.2022.915995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/25/2022] [Indexed: 12/04/2022] Open
Abstract
With the advancement of in vivo magnetic resonance imaging (MRI) technique, more detailed information about the human brain at high altitude (HA) has been revealed. The present review aimed to draw a conclusion regarding changes in the human brain in both unacclimatized and acclimatized states in a natural HA environment. Using multiple advanced analysis methods that based on MRI as well as electroencephalography, the modulations of brain gray and white matter morphology and the electrophysiological mechanisms underlying processing of cognitive activity have been explored in certain extent. The visual, motor and insular cortices are brain regions seen to be consistently affected in both HA immigrants and natives. Current findings regarding cortical electrophysiological and blood dynamic signals may be related to cardiovascular and respiratory regulations, and may clarify the mechanisms underlying some behaviors at HA. In general, in the past 10 years, researches on the brain at HA have gone beyond cognitive tests. Due to the sample size is not large enough, the current findings in HA brain are not very reliable, and thus much more researches are needed. Moreover, the histological and genetic bases of brain structures at HA are also needed to be elucidated.
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Affiliation(s)
- Xinjuan Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, China
- Department of Physiology, School of Medicine, Xiamen University, Xiamen, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, China
- Department of Physiology, School of Medicine, Xiamen University, Xiamen, China
- *Correspondence: Jiaxing Zhang,
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50
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Esteras N, Abramov AY. Nrf2 as a regulator of mitochondrial function: Energy metabolism and beyond. Free Radic Biol Med 2022; 189:136-153. [PMID: 35918014 DOI: 10.1016/j.freeradbiomed.2022.07.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/20/2022] [Accepted: 07/19/2022] [Indexed: 12/14/2022]
Abstract
Mitochondria are unique and essential organelles that mediate many vital cellular processes including energy metabolism and cell death. The transcription factor Nrf2 (NF-E2 p45-related factor 2) has emerged in the last few years as an important modulator of multiple aspects of mitochondrial function. Well-known for controlling cellular redox homeostasis, the cytoprotective effects of Nrf2 extend beyond its ability to regulate a diverse network of antioxidant and detoxification enzymes. Here, we review the role of Nrf2 in the regulation of mitochondrial function and structure. We focus on Nrf2 involvement in promoting mitochondrial quality control and regulation of basic aspects of mitochondrial function, including energy production, reactive oxygen species generation, calcium signalling, and cell death induction. Given the importance of mitochondria in the development of multiple diseases, these findings reinforce the pharmacological activation of Nrf2 as an attractive strategy to counteract mitochondrial dysfunction.
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Affiliation(s)
- Noemí Esteras
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK.
| | - Andrey Y Abramov
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London, UK.
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