1
|
Smith JA. STING, the Endoplasmic Reticulum, and Mitochondria: Is Three a Crowd or a Conversation? Front Immunol 2021; 11:611347. [PMID: 33552072 PMCID: PMC7858662 DOI: 10.3389/fimmu.2020.611347] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/04/2020] [Indexed: 12/20/2022] Open
Abstract
The anti-viral pattern recognition receptor STING and its partnering cytosolic DNA sensor cGAS have been increasingly recognized to respond to self DNA in multiple pathologic settings including cancer and autoimmune disease. Endogenous DNA sources that trigger STING include damaged nuclear DNA in micronuclei and mitochondrial DNA (mtDNA). STING resides in the endoplasmic reticulum (ER), and particularly in the ER-mitochondria associated membranes. This unique location renders STING well poised to respond to intracellular organelle stress. Whereas the pathways linking mtDNA and STING have been addressed recently, the mechanisms governing ER stress and STING interaction remain more opaque. The ER and mitochondria share a close anatomic and functional relationship, with mutual production of, and inter-organelle communication via calcium and reactive oxygen species (ROS). This interdependent relationship has potential to both generate the essential ligands for STING activation and to regulate its activity. Herein, we review the interactions between STING and mitochondria, STING and ER, ER and mitochondria (vis-à-vis calcium and ROS), and the evidence for 3-way communication.
Collapse
Affiliation(s)
- Judith A Smith
- Department of Pediatrics and Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, United States
| |
Collapse
|
2
|
Xu SY, Hu FY, Ren LJ, Chen L, Zhou ZQ, Zhang XJ, Li WP. Dantrolene enhances the protective effect of hypothermia on cerebral cortex neurons. Neural Regen Res 2015; 10:1279-85. [PMID: 26487856 PMCID: PMC4590241 DOI: 10.4103/1673-5374.162761] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2015] [Indexed: 01/05/2023] Open
Abstract
Therapeutic hypothermia is the most promising non-pharmacological neuroprotective strategy against ischemic injury. However, shivering is the most common adverse reaction. Many studies have shown that dantrolene is neuroprotective in in vitro and in vivo ischemic injury models. In addition to its neuroprotective effect, dantrolene neutralizes the adverse reaction of hypothermia. Dantrolene may be an effective adjunctive therapy to enhance the neuroprotection of hypothermia in treating ischemic stroke. Cortical neurons isolated from rat fetuses were exposed to 90 minutes of oxygen-glucose deprivation followed by reoxygenation. Neurons were treated with 40 μM dantrolene, hypothermia (at 33°C), or the combination of both for 12 hours. Results revealed that the combination of dantrolene and hypothermia increased neuronal survival and the mitochondrial membrane potential, and reduced intracellular active oxygen cytoplasmic histone-associated DNA fragmentation, and apoptosis. Furthermore, improvements in cell morphology were observed. The combined treatment enhanced these responses compared with either treatment alone. These findings indicate that dantrolene may be used as an effective adjunctive therapy to enhance the neuroprotective effects of hypothermia in ischemic stroke.
Collapse
Affiliation(s)
- Sui-yi Xu
- Postdoctoral Workstation, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong Province, China
- Department of Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University First Affiliated Hospital, Shenzhen, Guangdong Province, China
| | - Feng-yun Hu
- Department of Neurology, Shanxi Provincial People's Hospital, Shanxi Medical University, Taiyuan, Shanxi Province, China
| | - Li-jie Ren
- Department of Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University First Affiliated Hospital, Shenzhen, Guangdong Province, China
| | - Lei Chen
- Department of Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University First Affiliated Hospital, Shenzhen, Guangdong Province, China
| | - Zhu-qing Zhou
- Department of Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University First Affiliated Hospital, Shenzhen, Guangdong Province, China
| | - Xie-jun Zhang
- Department of Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University First Affiliated Hospital, Shenzhen, Guangdong Province, China
| | - Wei-ping Li
- Postdoctoral Workstation, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong Province, China
- Department of Brain Center, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University First Affiliated Hospital, Shenzhen, Guangdong Province, China
| |
Collapse
|
3
|
Neuroprotective effect of noscapine on cerebral oxygen–glucose deprivation injury. Pharmacol Rep 2015; 67:281-8. [DOI: 10.1016/j.pharep.2014.10.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 09/17/2014] [Accepted: 10/15/2014] [Indexed: 12/14/2022]
|
4
|
Xu SY, Hu YF, Li WP, Wu YM, Ji Z, Wang SN, Li K, Pan SY. Intermittent hypothermia is neuroprotective in an in vitro model of ischemic stroke. Int J Biol Sci 2014; 10:873-81. [PMID: 25170301 PMCID: PMC4147221 DOI: 10.7150/ijbs.8868] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 07/14/2014] [Indexed: 01/05/2023] Open
Abstract
OBJECTIVE To investigate whether the intermittent hypothermia (IH) protects neurons against ischemic insult and the potential molecular targets using an in vitro ischemic model of oxygen glucose deprivation (OGD). METHODS Fetal rat cortical neurons isolated from Day E18 rat embryos were subjected to 90-min OGD and hypothermia treatments during reoxygenation before examining the changes in microscopic morphology, cell viability, microtubule- associated protein 2 (MAP-2) release, intracellular pH value and calcium, reactive oxygen species (ROS) generation, mitochondrial membrane potential (△Ψm) and neuronal death using cell counting kit (CCK-8), enzyme-linked immunosorbent assay (ELISA), BCECF AM, Fluo-3 AM, DCFH-DA and dihydroethidium (DHE), JC-1 staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), respectively. RESULTS 90-min OGD induced morphologic abnormalities, cell viability decline, MAP-2 release, intracellular acidosis, calcium overload, increased ROS generation, △Ψm decrease and cell death in primary neurons, which was partially inhibited by continuous hypothermia (CH) and intermittent hypothermia (IH). Interestingly, 6-h CH was insufficient to reduce intracellular calcium overload and stabilize mitochondrial membrane potential (△Ψm), while 12-h CH was effective in reversing the above changes. All IH treatments (6×1 h, 4×1.5 h or 3×2 h) effectively attenuated intracellular free calcium overload, inhibited ROS production, stabilized mitochondrial membrane potential (△Ψm) and reduced delayed cell death in OGD-treated cells. However, only IH intervals longer than 1.5 h appeared to be effective in preventing cell viability loss and intracellular pH decline. CONCLUSION Both CH and IH were neuroprotective in an in vitro model of ischemic stroke, and in spite of shorter hypothermia duration, IH could provide a comparable neuroprotection to CH.
Collapse
Affiliation(s)
- Sui-yi Xu
- 1. Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; ; 2. Department of Neurosurgery, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen 518035, China
| | - Ya-fang Hu
- 1. Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Wei-pin Li
- 2. Department of Neurosurgery, Shenzhen Key Laboratory of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University 1st Affiliated Hospital, Shenzhen 518035, China
| | - Yong-ming Wu
- 1. Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Zhong Ji
- 1. Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Sheng-nan Wang
- 1. Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Ke Li
- 3. Research Center of Clinical Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Su-yue Pan
- 1. Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| |
Collapse
|
5
|
Duncan C, Mueller S, Simon E, Renger JJ, Uebele VN, Hogan QH, Wu HE. Painful nerve injury decreases sarco-endoplasmic reticulum Ca²⁺-ATPase activity in axotomized sensory neurons. Neuroscience 2012; 231:247-57. [PMID: 23219911 DOI: 10.1016/j.neuroscience.2012.11.055] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 11/28/2012] [Accepted: 11/29/2012] [Indexed: 12/15/2022]
Abstract
The sarco-endoplasmic reticulum Ca(2+)-ATPase (SERCA) is a critical pathway by which sensory neurons sequester cytosolic Ca(2+) and thereby maintain intracellular Ca(2+) homeostasis. We have previously demonstrated decreased intraluminal endoplasmic reticulum Ca(2+) concentration in traumatized sensory neurons. Here we examine SERCA function in dissociated sensory neurons using Fura-2 fluorometry. Blocking SERCA with thapsigargin (1 μM) increased resting [Ca(2+)](c) and prolonged recovery (τ) from transients induced by neuronal activation (elevated bath K(+)), demonstrating SERCA contributes to control of resting [Ca(2+)](c) and recovery from transient [Ca(2+)](c) elevation. To evaluate SERCA in isolation, plasma membrane Ca(2+) ATPase was blocked with pH 8.8 bath solution and mitochondrial buffering was avoided by keeping transients small (≤ 400 nM). Neurons axotomized by spinal nerve ligation (SNL) showed a slowed rate of transient recovery compared to control neurons, representing diminished SERCA function, whereas neighboring non-axotomized neurons from SNL animals were unaffected. Injury did not affect SERCA function in large neurons. Repeated depolarization prolonged transient recovery, showing that neuronal activation inhibits SERCA function. These findings suggest that injury-induced loss of SERCA function in small sensory neurons may contribute to the generation of pain following peripheral nerve injury.
Collapse
Affiliation(s)
- C Duncan
- Medical College of Wisconsin, Department of Anesthesiology, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | | | | | | | | | | | | |
Collapse
|
6
|
Abstract
The stromal interaction molecules STIM1 and STIM2 are Ca2+ sensors, mostly located in the endoplasmic reticulum, that detect changes in the intraluminal Ca2+ concentration and communicate this information to plasma membrane store-operated channels, including members of the Orai family, thus mediating store-operated Ca2+ entry (SOCE). Orai and STIM proteins are almost ubiquitously expressed in human cells, where SOCE has been reported to play a relevant functional role. The phenotype of patients bearing mutations in STIM and Orai proteins, together with models of STIM or Orai deficiency in mice, as well as other organisms such as Drosophila melanogaster, have provided compelling evidence on the relevant role of these proteins in cellular physiology and pathology. Orai1-deficient patients suffer from severe immunodeficiency, congenital myopathy, chronic pulmonary disease, anhydrotic ectodermal dysplasia and defective dental enamel calcification. STIM1-deficient patients showed similar abnormalities, as well as autoimmune disorders. This review summarizes the current evidence that identifies and explains diseases induced by disturbances in SOCE due to deficiencies or mutations in Orai and STIM proteins.
Collapse
Affiliation(s)
- A Berna-Erro
- Department of Physiology, University of Extremadura, Cáceres, Spain
| | | | | |
Collapse
|
7
|
Gniel HM, Martin RL. Changes in membrane potential and the intracellular calcium concentration during CSD and OGD in layer V and layer II/III mouse cortical neurons. J Neurophysiol 2010; 104:3203-12. [PMID: 20810684 DOI: 10.1152/jn.00922.2009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cortical spreading depression (CSD) is an episode of electrical silence following intense neuronal activity that propagates across the cortex at ∼3-6 mm/min and is associated with transient neuronal depolarization. CSD is benign in normally perfused brain tissue, but there is evidence suggesting that repetitive CSD contributes to infarct growth following focal ischemia. Studies to date have assumed that the cellular responses to CSD are uniform across neuronal types because there are no data to the contrary. In this study, we investigated the effect of CSD on membrane potential and the intracellular calcium concentration ([Ca(2+)](i)) of mouse layer V and layer II/III pyramidal neurons in brain slices. To place the data in context, we made similar measurements during anoxic depolarization induced by oxygen and glucose deprivation (OGD). The [Ca(2+)](i) was quantified using the low-affinity ratiometric indicator Fura-4F. During both CSD- and OGD-induced depolarization, the membrane potential approached 0 mV in all neurons. In layer V pyramids OGD resulted in an increase in [Ca(2+)](i) to a maximum of 3.69 ± 0.73 (SD) μM (n = 12), significantly greater than the increase to 1.81 ± 0.70 μM in CSD (n = 34; P < 0.0001). Membrane potential and [Ca(2+)](i) returned to nearly basal levels following CSD but not OGD. Layer II/III neurons responded to CSD with a greater peak increase in [Ca(2+)](i) than layer V neurons (2.88 ± 0.6 μM; n = 9; P < 0.01). We conclude there is a laminar difference in the response of pyramidal neurons to CSD; possible explanations are discussed.
Collapse
Affiliation(s)
- Helen M Gniel
- School of Biochemistry and Molecular Biology, The Australian National Univ., Canberra, Australia.
| | | |
Collapse
|
8
|
ASIC1a channels are activated by endogenous protons during ischemia and contribute to synergistic potentiation of intracellular Ca(2+) overload during ischemia and acidosis. Cell Calcium 2010; 48:70-82. [PMID: 20678793 DOI: 10.1016/j.ceca.2010.07.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 06/30/2010] [Accepted: 07/05/2010] [Indexed: 01/27/2023]
Abstract
Acidosis accompanying cerebral ischemia activates acid-sensing ion channels (ASIC) causing increases in intracellular calcium concentration ([Ca(2+)]i) and enhanced neuronal death. Experiments were undertaken in rat cortical neurons to explore the effects of ASIC1a activation on ischemia-induced [Ca(2+)]i elevations and whole-cell currents. There was a significant contribution of ASIC1a channels to ischemia-evoked [Ca(2+)]i increases at pH 7.4, suggesting that ASIC1a channels are activated by endogenous protons during ischemia. The combination of ischemia and acidosis resulted in synergistic increases in [Ca(2+)]i and plasma membrane currents relative to acidosis or ischemia alone. ASIC1a inhibitors significantly blunted [Ca(2+)]i increases and a transient current activated by ischemia+acidosis, demonstrating that homomeric ASIC1a channels are involved. However, ASIC1a inhibitors failed to diminish a sustained current activated in response to combined ischemia and acidosis, indicating that acidosis can potentiate ischemia effects through mechanisms other than ASIC1a. The [Ca(2+)]i overload produced by acidosis and ischemia was not blocked by tetrodotoxin, 2-amino-5-phosphonopentanoic acid or nifedipine. Thus, acidosis and activation of ASIC1a channels during ischemia can promote [Ca(2+)]i overload in the absence of neurotransmission, independent of NMDA receptor or L-type voltage-gated Ca(2+) channel activation. Postsynaptic ASIC1a channels play a critical role in ischemia-induced [Ca(2+)]i dysregulation and membrane dysfunction.
Collapse
|
9
|
A novel method for inducing focal ischemia in vitro. J Neurosci Methods 2010; 190:20-7. [PMID: 20417233 DOI: 10.1016/j.jneumeth.2010.04.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 04/15/2010] [Accepted: 04/15/2010] [Indexed: 11/23/2022]
Abstract
Current in vitro models of stroke involve applying oxygen-glucose deprived (OGD) media over an entire brain slice or plate of cultured neurons. Thus, these models fail to mimic the focal nature of stroke as observed clinically and with in vivo rodent models of stroke. Our aim was to develop a novel in vitro brain slice model of stroke that would mimic focal ischemia and thus allow for the investigation of events occurring in the penumbra. This was accomplished by focally applying OGD medium to a small portion of a brain slice while bathing the remainder of the slice with normal oxygenated media. This technique produced a focal infarct on the brain slice that increased as a function of time. Electrophysiological recordings made within the flow of the OGD solution ("core") revealed that neurons rapidly depolarized (anoxic depolarization; AD) in a manner similar to that observed in other stroke models. Edaravone, a known neuroprotectant, significantly delayed this onset of AD. Electrophysiological recordings made outside the flow of the OGD solution ("penumbra") revealed that neurons within this region progressively depolarized throughout the 75 min of OGD application. Edaravone attenuated this depolarization and doubled neuronal survival. Finally, synaptic transmission in the penumbra was abolished within 50 min of focal OGD application. These results suggest that this in vitro model mimics events that occur during focal ischemia in vivo and can be used to determine the efficacy of therapeutics that target neuronal survival in the core and/or penumbra.
Collapse
|
10
|
Rosa AO, Rapoport SI. Intracellular- and extracellular-derived Ca(2+) influence phospholipase A(2)-mediated fatty acid release from brain phospholipids. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:697-705. [PMID: 19327408 DOI: 10.1016/j.bbalip.2009.03.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 03/01/2009] [Accepted: 03/11/2009] [Indexed: 02/01/2023]
Abstract
Docosahexaenoic acid (DHA) and arachidonic acid (AA) are found in high concentrations in brain cell membranes and are important for brain function and structure. Studies suggest that AA and DHA are hydrolyzed selectively from the sn-2 position of synaptic membrane phospholipids by Ca(2+)-dependent cytosolic phospholipase A(2) (cPLA(2)) and Ca(2+)-independent phospholipase A(2) (iPLA(2)), respectively, resulting in increased levels of the unesterified fatty acids and lysophospholipids. Cell studies also suggest that AA and DHA release depend on increased concentrations of Ca(2+), even though iPLA(2) has been thought to be Ca(2+)-independent. The source of Ca(2+) for activation of cPLA(2) is largely extracellular, whereas Ca(2+) released from the endoplasmic reticulum can activate iPLA(2) by a number of mechanisms. This review focuses on the role of Ca(2+) in modulating cPLA(2) and iPLA(2) activities in different conditions. Furthermore, a model is suggested in which neurotransmitters regulate the activity of these enzymes and thus the balanced and localized release of AA and DHA from phospholipid in the brain, depending on the primary source of the Ca(2+) signal.
Collapse
Affiliation(s)
- Angelo O Rosa
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.
| | | |
Collapse
|
11
|
Larsen GA, Skjellegrind HK, Vinje ML, Berg-Johnsen J. Mitochondria are More Resistant to Hypoxic Depolarization in the Newborn than in the Adult Brain. Neurochem Res 2008; 33:1894-900. [DOI: 10.1007/s11064-008-9664-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Accepted: 03/11/2008] [Indexed: 11/29/2022]
|
12
|
Hwang IK, Yoo KY, Kim DW, Kwon OS, Lim SS, Kang IJ, Choi SY, Won MH. Differential Changes in Pyridoxine 5′-Phosphate Oxidase Immunoreactivity and Protein Levels in the Somatosensory Cortex and Striatum of the Ischemic Gerbil Brain. Neurochem Res 2008; 33:1356-64. [DOI: 10.1007/s11064-008-9591-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Accepted: 01/07/2008] [Indexed: 11/30/2022]
|