1
|
Lalo U, Pankratov Y. Astrocyte ryanodine receptors facilitate gliotransmission and astroglial modulation of synaptic plasticity. Front Cell Neurosci 2024; 18:1382010. [PMID: 38812795 PMCID: PMC11135129 DOI: 10.3389/fncel.2024.1382010] [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: 02/04/2024] [Accepted: 04/29/2024] [Indexed: 05/31/2024] Open
Abstract
Intracellular Ca2+-signaling in astrocytes is instrumental for their brain "housekeeping" role and astroglial control of synaptic plasticity. An important source for elevating the cytosolic Ca2+ level in astrocytes is a release from endoplasmic reticulum which can be triggered via two fundamental pathways: IP3 receptors and calcium-induced calcium release (CICR) mediated by Ca2+-sensitive ryanodine receptors (RyRs). While the physiological role for glial IP3 became a focus of intensive research and debate, ryanodine receptors received much less attention. We explored the role for ryanodine receptors in the modulation of cytosolic Ca2+-signaling in the cortical and hippocampal astrocytes, astrocyte-neuron communication and astroglia modulation of synaptic plasticity. Our data show that RyR-mediated Ca2+-induced Ca2+-release from ER brings substantial contribution into signaling in the functional microdomains hippocampal and neocortical astrocytes. Furthermore, RyR-mediated CICR activated the release of ATP and glutamate from hippocampal and neocortical astrocytes which, in turn, elicited transient purinergic and tonic glutamatergic currents in the neighboring pyramidal neurons. The CICR-facilitated release of ATP and glutamate was inhibited after intracellular perfusion of astrocytes with ryanodine and BAPTA and in the transgenic dnSNARE mice with impaired astroglial exocytosis. We also found out that RyR-mediated amplification of astrocytic Ca2+-signaling enhanced the long-term synaptic potentiation in the hippocampus and neocortex of aged mice. Combined, our data demonstrate that ryanodine receptors are essential for astrocytic Ca2+-signaling and efficient astrocyte-neuron communications. The RyR-mediated CICR contributes to astrocytic control of synaptic plasticity and can underlie, at least partially, neuroprotective and cognitive effects of caffein.
Collapse
Affiliation(s)
| | - Yuriy Pankratov
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| |
Collapse
|
2
|
Impact of Autophagy Impairment on Experience- and Diet-Related Synaptic Plasticity. Int J Mol Sci 2022; 23:ijms23169228. [PMID: 36012495 PMCID: PMC9408861 DOI: 10.3390/ijms23169228] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/09/2022] [Accepted: 08/13/2022] [Indexed: 11/16/2022] Open
Abstract
The beneficial effects of diet and exercise on brain function are traditionally attributed to the enhancement of autophagy, which plays a key role in neuroprotection via the degradation of potentially harmful intracellular structures. The molecular machinery of autophagy has also been suggested to influence synaptic signaling via interaction with trafficking and endocytosis of synaptic vesicles and proteins. Still, the role of autophagy in the regulation of synaptic plasticity remains elusive, especially in the mammalian brain. We explored the impact of autophagy on synaptic transmission and homeostatic and acute synaptic plasticity using transgenic mice with induced deletion of the Beclin1 protein. We observed down-regulation of glutamatergic and up-regulation of GABAergic synaptic currents and impairment of long-term plasticity in the neocortex and hippocampus of Beclin1-deficient mice. Beclin1 deficiency also significantly reduced the effects of environmental enrichment, caloric restriction and its pharmacological mimetics (metformin and resveratrol) on synaptic transmission and plasticity. Taken together, our data strongly support the importance of autophagy in the regulation of excitatory and inhibitory synaptic transmission and synaptic plasticity in the neocortex and hippocampus. Our results also strongly suggest that the positive modulatory actions of metformin and resveratrol in acute and homeostatic synaptic plasticity, and therefore their beneficial effects on brain function, occur via the modulation of autophagy.
Collapse
|
3
|
Actions of Metformin in the Brain: A New Perspective of Metformin Treatments in Related Neurological Disorders. Int J Mol Sci 2022; 23:ijms23158281. [PMID: 35955427 PMCID: PMC9368983 DOI: 10.3390/ijms23158281] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 11/17/2022] Open
Abstract
Metformin is a first-line drug for treating type 2 diabetes mellitus (T2DM) and one of the most commonly prescribed drugs in the world. Besides its hypoglycemic effects, metformin also can improve cognitive or mood functions in some T2DM patients; moreover, it has been reported that metformin exerts beneficial effects on many neurological disorders, including major depressive disorder (MDD), Alzheimer’s disease (AD) and Fragile X syndrome (FXS); however, the mechanism underlying metformin in the brain is not fully understood. Neurotransmission between neurons is fundamental for brain functions, and its defects have been implicated in many neurological disorders. Recent studies suggest that metformin appears not only to regulate synaptic transmission or plasticity in pathological conditions but also to regulate the balance of excitation and inhibition (E/I balance) in neural networks. In this review, we focused on and reviewed the roles of metformin in brain functions and related neurological disorders, which would give us a deeper understanding of the actions of metformin in the brain.
Collapse
|
4
|
Gorbatenko VO, Goriainov SV, Babenko VA, Plotnikov EY, Sergeeva MG, Chistyakov DV. Anti-Inflammatory Properties of Metformin During Cultivation of Primary Rat Astrocytes in a Medium with High Glucose Concentration. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:577-589. [PMID: 36154879 DOI: 10.1134/s000629792207001x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/10/2022] [Accepted: 05/10/2022] [Indexed: 06/16/2023]
Abstract
Investigation of the relationship between inflammation and energy metabolism is important for understanding biology of chronic noncommunicable diseases. Use of metformin, a drug for treatment of diabetes, is considered as a promising direction for treatment of neurodegenerative diseases and other neuropathologies with an inflammatory component. Astrocytes play an important role in the regulation of energy metabolism and neuroinflammation; therefore, we studied the effect of metformin on the cellular responses of primary rat astrocytes cultured in a medium with high glucose concentration (22.5 mM, 48-h incubation). Lipopolysaccharide (LPS) was used to stimulate inflammation. The effects of metformin were assessed by monitoring changes in the expression of proinflammatory cytokines and synthesis of oxylipins, assayed with ultra-high-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). Changes at the intracellular level were assessed by analyzing phosphorylation of ERK kinase and transcription factor STAT3, as well as enzymes mediating oxylipin synthesis, cyclooxygenase 1 and 2 (COX). It was found that, independent on glucose concentration, metformin reduced the LPS-stimulated release of cytokines IL-1β and IL-6, decreased activity of the transcription factor STAT3, ERK kinase, synthesis of the derivatives of the cyclooxygenase branch of metabolism of oxylipins and anandamide, and did not affect formation of ROS. The study of energy phenotype of the cells showed that metformin activated glycolysis and inhibited mitochondrial respiration and oxidative phosphorylation, independent on LPS stimulation and cell cultivation at high glucose concentration. Thus, it has been shown that metformin exhibits anti-inflammatory effects, and its effect on the synthesis of cytokines, prostaglandins, and other lipid mediators could determine beneficial effects of metformin in models of neuropathology.
Collapse
Affiliation(s)
- Vladislav O Gorbatenko
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Sergey V Goriainov
- Peoples' Friendship University of Russia (RUDN University), Moscow, 117198, Russia
| | - Valentina A Babenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
| | - Egor Y Plotnikov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
| | - Marina G Sergeeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
| | - Dmitry V Chistyakov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.
| |
Collapse
|
5
|
Cao W, Lin J, Xiang W, Liu J, Wang B, Liao W, Jiang T. Physical Exercise-Induced Astrocytic Neuroprotection and Cognitive Improvement Through Primary Cilia and Mitogen-Activated Protein Kinases Pathway in Rats With Chronic Cerebral Hypoperfusion. Front Aging Neurosci 2022; 14:866336. [PMID: 35721009 PMCID: PMC9198634 DOI: 10.3389/fnagi.2022.866336] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/03/2022] [Indexed: 01/02/2023] Open
Abstract
Chronic cerebral hypoperfusion (CCH) is closely related to vascular cognitive impairment and dementia (VCID) and Alzheimer’s disease (AD). The neuroinflammation involving astrocytes is an important pathogenic mechanism. Along with the advancement of the concept and technology of astrocytic biology, the astrocytes have been increasingly regarded as the key contributors to neurological diseases. It is well known that physical exercise can improve cognitive function. As a safe and effective non-drug treatment, physical exercise has attracted continuous interests in neurological research. In this study, we explored the effects of physical exercise on the response of reactive astrocytes, and its role and mechanism in CCH-induced cognitive impairment. A rat CCH model was established by 2 vessel occlusion (2VO) and the wheel running exercise was used as the intervention. The cognitive function of rats was evaluated by morris water maze and novel object recognition test. The phenotypic polarization and the primary cilia expression of astrocytes were detected by immunofluorescence staining. The activation of MAPKs cascades, including ERK, JNK, and P38 signaling pathways, were detected by western blot. The results showed that physical exercise improved cognitive function of rats 2 months after 2VO, reduced the number of C3/GFAP-positive neurotoxic astrocytes, promoted the expression of S100A10/GFAP-positive neuroprotective astrocytes, and enhanced primary ciliogenesis. Additionally, physical exercise also alleviated the phosphorylation of ERK and JNK proteins induced by CCH. These results indicate that physical exercise can improve the cognitive function of rats with CCH possible by promoting primary ciliogenesis and neuroprotective function of astrocytes. The MAPKs signaling cascade, especially ERK and JNK signaling pathways may be involved in this process.
Collapse
Affiliation(s)
- Wenyue Cao
- Department of Neurorehabilitation, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Junbin Lin
- Department of Neurorehabilitation, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Wei Xiang
- Department of Orthopedics, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Jingying Liu
- Department of Neurorehabilitation, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Biru Wang
- Department of Neurorehabilitation, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Weijing Liao
- Department of Neurorehabilitation, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- Weijing Liao,
| | - Ting Jiang
- Department of Neurorehabilitation, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- *Correspondence: Ting Jiang,
| |
Collapse
|
6
|
Bobermin LD, de Souza Almeida RR, Weber FB, Medeiros LS, Medeiros L, Wyse ATS, Gonçalves CA, Quincozes-Santos A. Lipopolysaccharide Induces Gliotoxicity in Hippocampal Astrocytes from Aged Rats: Insights About the Glioprotective Roles of Resveratrol. Mol Neurobiol 2022; 59:1419-1439. [PMID: 34993844 DOI: 10.1007/s12035-021-02664-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/23/2021] [Indexed: 12/13/2022]
Abstract
Astrocytes may undergo a functional remodeling with aging, acquiring a pro-inflammatory state. In line with this, resveratrol represents an interesting strategy for a healthier brain aging since it can improve glial functions. In the present study, we investigated the glioprotective role of resveratrol against lipopolysaccharide (LPS)-induced gliotoxicity in hippocampal aged astrocytes. Astrocyte cultures were obtained from aged rats (365 days old) and challenged in vitro with LPS in the presence of resveratrol. Cultured astrocytes from newborn rats were used as an age comparative for evaluating LPS gliotoxicity. In addition, aged rats were submitted to an acute systemic inflammation with LPS. Hippocampal astrocyte cultures were also obtained from these LPS-stimulated aged animals to further investigate the glioprotective effects of resveratrol in vitro. Overall, our results show that LPS induced a higher inflammatory response in aged astrocytes, compared to newborn astrocytes. Several inflammatory and gene expression alterations promoted by LPS in aged astrocyte cultures were similar in hippocampal tissue from aged animals submitted to in vivo LPS injection, corroborating our in vitro findings. Resveratrol, in turn, presented anti-inflammatory effects in aged astrocyte cultures, which were associated with downregulation of p21 and pro-inflammatory cytokines, Toll-like receptors (TLRs), and nuclear factor κB (NFκB). Resveratrol also improved astroglial functions. Upregulation of sirtuin 1 (SIRT1), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1) represent potential molecular mechanisms associated with resveratrol-mediated glioprotection. In summary, our data show that resveratrol can prime aged astrocytes against gliotoxic stimuli, contributing to a healthier brain aging.
Collapse
Affiliation(s)
- Larissa Daniele Bobermin
- Programa de Pós-Graduação Em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Rômulo Rodrigo de Souza Almeida
- Programa de Pós-Graduação Em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Fernanda Becker Weber
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul- UFRGS, Rua Ramiro Barcelos, 2600 - Anexo Bairro Santa Cecília, Porto Alegre, RS, Brazil
| | - Lara Scopel Medeiros
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul- UFRGS, Rua Ramiro Barcelos, 2600 - Anexo Bairro Santa Cecília, Porto Alegre, RS, Brazil
| | - Lívia Medeiros
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul- UFRGS, Rua Ramiro Barcelos, 2600 - Anexo Bairro Santa Cecília, Porto Alegre, RS, Brazil
| | - Angela T S Wyse
- Programa de Pós-Graduação Em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil.,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul- UFRGS, Rua Ramiro Barcelos, 2600 - Anexo Bairro Santa Cecília, Porto Alegre, RS, Brazil
| | - Carlos-Alberto Gonçalves
- Programa de Pós-Graduação Em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil.,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul- UFRGS, Rua Ramiro Barcelos, 2600 - Anexo Bairro Santa Cecília, Porto Alegre, RS, Brazil
| | - André Quincozes-Santos
- Programa de Pós-Graduação Em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil. .,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul- UFRGS, Rua Ramiro Barcelos, 2600 - Anexo Bairro Santa Cecília, Porto Alegre, RS, Brazil.
| |
Collapse
|