1
|
Del Gaudio I, Nitzsche A, Boyé K, Bonnin P, Poulet M, Nguyen TQ, Couty L, Ha HTT, Nguyen DT, Cazenave-Gassiot A, Ben Alaya K, Thérond P, Chun J, Wenk MR, Proia RL, Henrion D, Nguyen LN, Eichmann A, Camerer E. Zonation, ligand and dose dependence of S1PR1 signalling in blood and lymphatic vasculature. Cardiovasc Res 2024:cvae168. [PMID: 39086170 DOI: 10.1093/cvr/cvae168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 06/03/2024] [Accepted: 06/12/2024] [Indexed: 08/02/2024] Open
Abstract
AIMS Circulating levels of sphingosine 1-phosphate (S1P), an HDL-associated ligand for endothelial cell (EC) protective S1P receptor-1 (S1PR1), are reduced in disease states associated with endothelial dysfunction. Yet as S1PR1 has high affinity for S1P and can be activated by ligand-independent mechanisms and EC-autonomous S1P production, it is unclear if relative reductions in circulating S1P impact endothelial function. It is also unclear how EC S1PR1 insufficiency, whether induced by ligand deficiency or by S1PR1-directed immunosuppressive therapy, affects different vascular subsets. METHODS AND RESULTS We here fine-map the zonation of S1PR1 signalling in the murine blood and lymphatic vasculature, superimpose cell type-specific and relative deficiencies in S1P production to define ligand source- and dose-dependence, and correlate receptor engagement to essential functions. In naïve blood vessels, despite broad expression, EC S1PR1 engagement was restricted to resistance-size arteries, lung capillaries and high-endothelial venules (HEV). Similar zonation was observed for albumin extravasation in EC S1PR1 deficient mice, and brain extravasation was reproduced with arterial EC-selective S1pr1 deletion. In lymphatic EC, S1PR1 engagement was high in collecting vessels and lymph nodes and low in terminal capillaries that drain tissue fluids. While EC S1P production sustained S1PR1 signaling in lymphatics and HEV, hematopoietic cells provided ∼90% of plasma S1P and sustained signaling in resistance arteries and lung capillaries. S1PR1 signaling and endothelial function were both surprisingly sensitive to reductions in plasma S1P with apparent saturation around 50% of normal levels. S1PR1 engagement did not depend on sex or age, but modestly increased in arteries in hypertension and diabetes. Sphingosine kinase (Sphk)-2 deficiency also increased S1PR1 engagement selectively in arteries, which could be attributed to Sphk1-dependent S1P release from perivascular macrophages. CONCLUSIONS This study highlights vessel subtype-specific S1PR1 functions and mechanisms of engagement and supports the relevance of S1P as circulating biomarker for endothelial function.
Collapse
Affiliation(s)
- Ilaria Del Gaudio
- Université de Paris, Paris Cardiovascular Research Centre, INSERM U970, Paris, France
| | - Anja Nitzsche
- Université de Paris, Paris Cardiovascular Research Centre, INSERM U970, Paris, France
| | - Kevin Boyé
- Université de Paris, Paris Cardiovascular Research Centre, INSERM U970, Paris, France
| | - Philippe Bonnin
- Assistance Publique-Hôpitaux de Paris (AP-HP), Physiologie Clinique, Hôpital Lariboisière, Paris France
- Université Paris Cité, INSERM U1144, UFR de Pharmacie, Paris, France
| | - Mathilde Poulet
- Université de Paris, Paris Cardiovascular Research Centre, INSERM U970, Paris, France
| | - Toan Quoc Nguyen
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Ludovic Couty
- Université de Paris, Paris Cardiovascular Research Centre, INSERM U970, Paris, France
| | - Hoa T T Ha
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Dat T Nguyen
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Amaury Cazenave-Gassiot
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Khaoula Ben Alaya
- Université de Paris, Paris Cardiovascular Research Centre, INSERM U970, Paris, France
| | - Patrice Thérond
- Assistance Publique-Hôpitaux de Paris (AP-HP), Service de Biochimie, Hôpital de Bicêtre, Le Kremlin Bicêtre, France
- UFR de Pharmacie, EA 4529, Châtenay-Malabry, France
| | - Jerold Chun
- Neuroscience Drug Discovery, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Markus R Wenk
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Richard L Proia
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Institutes of Health, Bethesda, MD, USA
| | - Daniel Henrion
- Angers University, MitoVasc Department, Team 2 (CarMe), Angers University Hospital (CHU of Angers), CNRS, INSERM U1083, Angers, France
| | - Long N Nguyen
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Anne Eichmann
- Université de Paris, Paris Cardiovascular Research Centre, INSERM U970, Paris, France
- Yale University School of Medicine, Department of Internal Medicine and Cellular and Molecular Physiology, New Haven, USA
| | - Eric Camerer
- Université de Paris, Paris Cardiovascular Research Centre, INSERM U970, Paris, France
| |
Collapse
|
2
|
Li YY, Qin ZH, Sheng R. The Multiple Roles of Autophagy in Neural Function and Diseases. Neurosci Bull 2024; 40:363-382. [PMID: 37856037 PMCID: PMC10912456 DOI: 10.1007/s12264-023-01120-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/11/2023] [Indexed: 10/20/2023] Open
Abstract
Autophagy involves the sequestration and delivery of cytoplasmic materials to lysosomes, where proteins, lipids, and organelles are degraded and recycled. According to the way the cytoplasmic components are engulfed, autophagy can be divided into macroautophagy, microautophagy, and chaperone-mediated autophagy. Recently, many studies have found that autophagy plays an important role in neurological diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, neuronal excitotoxicity, and cerebral ischemia. Autophagy maintains cell homeostasis in the nervous system via degradation of misfolded proteins, elimination of damaged organelles, and regulation of apoptosis and inflammation. AMPK-mTOR, Beclin 1, TP53, endoplasmic reticulum stress, and other signal pathways are involved in the regulation of autophagy and can be used as potential therapeutic targets for neurological diseases. Here, we discuss the role, functions, and signal pathways of autophagy in neurological diseases, which will shed light on the pathogenic mechanisms of neurological diseases and suggest novel targets for therapies.
Collapse
Affiliation(s)
- Yan-Yan Li
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, 215123, China
| | - Zheng-Hong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, 215123, China.
| | - Rui Sheng
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, 215123, China.
| |
Collapse
|
3
|
Yuan R, Wu C. YTHDF1-mediated sphingosine kinase 2 upregulation alleviates bupivacaine-induced neurotoxicity via the PI3K/AKT axis. Hum Exp Toxicol 2024; 43:9603271231218707. [PMID: 38487884 DOI: 10.1177/09603271231218707] [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] [Indexed: 03/19/2024]
Abstract
BACKGROUND Bupivacaine (BUP), a long-acting local anesthetic, has been widely used in analgesia and anesthesia. However, evidence strongly suggests that excessive application of BUP may lead to neurotoxicity in neurons. Sphingosine kinase 2 (SPHK2) has been reported to exert neuroprotective effects. In this study, we intended to investigate the potential role and mechanism of SPHK2 in BUP-induced neurotoxicity in dorsal root ganglion (DRG) neurons. METHODS DRG neurons were cultured with BUP to simulate BUP-induced neurotoxicity in vitro. CCK-8, LDH, and flow cytometry assays were performed to detect the viability, LDH activity, and apoptosis of DRG neurons. RT-qPCR and western blotting was applied to measure gene and protein expression. Levels. MeRIP-qPCR was applied for quantification of m6A modification. RIP-qPCR was used to analyze the interaction between SPHK2 and YTHDF1. RESULTS SPHK2 expression significantly declined in DRG neurons upon exposure to BUP. BUP challenge substantially reduced the cell viability and increased the apoptosis rate in DRG neurons, which was partly abolished by SPHK2 upregulation. YTHDF1, an N6-methyladenosine (m6A) reader, promoted SPHK2 expression in BUP-treated DRG neurons in an m6A-dependent manner. YTHDF1 knockdown partly eliminated the increase in SPHK2 protein level and the protection against BUP-triggered neurotoxicity in DRG neurons mediated by SPHK2 overexpression. Moreover, SPHK2 activated the PI3K/AKT signaling to protect against BUP-induced cytotoxic effects on DRG neurons. CONCLUSIONS In sum, YTHDF1-mediated SPHK2 upregulation ameliorated BUP-induced neurotoxicity in DRG neurons via promoting activation of the PI3K/AKT signaling pathway.
Collapse
Affiliation(s)
- Ru Yuan
- Department of Anesthesiology, Wujin Hospital Affiliated with Jiangsu University, Changzhou, China
- The Wujin Clinical College of Xuzhou Medical University, Changzhou, China
| | - Chunxia Wu
- Department of Anesthesiology, Wujin Hospital Affiliated with Jiangsu University, Changzhou, China
- The Wujin Clinical College of Xuzhou Medical University, Changzhou, China
| |
Collapse
|
4
|
Gao L, Sun X, Pan M, Zhang W, Zhu D, Lu Z, Wang K, Dong Y, Guan Y. Ischemic Preconditioning Provides Neuroprotection by Inhibiting NLRP3 Inflammasome Activation and Cell Pyroptosis. Brain Sci 2023; 13:897. [PMID: 37371374 DOI: 10.3390/brainsci13060897] [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: 04/05/2023] [Revised: 05/21/2023] [Accepted: 05/28/2023] [Indexed: 06/29/2023] Open
Abstract
Increasing evidence has demonstrated that ischemic preconditioning (IPC) increases cerebral tolerance to subsequent prolonged ischemic insults. However, the exact mechanisms underlying the process have not been fully explored. In the current study, we aim to investigate whether NLRP3 inflammasome and cell pyroptosis are involved in the neuroprotective mechanism of IPC after ischemic stroke. In vitro, IPC was set up by exposing BV-2 cells to 10 min of oxygen-glucose deprivation (OGD). In vivo, IPC was performed by a transient cerebral ischemia of 10 min occlusion of the middle cerebral artery (MCA) in mice. We found that the NLRP3 inflammasome was activated and cell pyroptosis was induced at 6 h and 24 h post-stroke in an ischemic brain. IPC treatment increased cell viability under OGD state, reduced the infarct size, and attenuated the neurological deficits of mice. However, the effects NLRP3 inflammasome activation and pyroptosis after stroke were attenuated by IPC, which decreased the expression of NLRP3, ASC, cleaved caspase 1, and GSDMD-N and reduced the production of IL-1β and IL-18. In addition, confocal immunofluorescence staining of Annexin V-mCherry and SYTOX green was inhibited by IPC. These findings suggest a more enhanced link between IPC and inflammatory signature and cell death, highlighting that the NLRP3 inflammasome may act as a promising target for the prevention and treatment of ischemic stroke.
Collapse
Affiliation(s)
- Li Gao
- Department of Neurology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Xin Sun
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing 211166, China
| | - Meibo Pan
- Department Pathology and Pathophysiology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Wenrui Zhang
- Department of Neurosurgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Desheng Zhu
- Department of Neurology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Zhongjiao Lu
- Department of Neurology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Kan Wang
- Department of Neurology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Yinfeng Dong
- Department Pathology and Pathophysiology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Yangtai Guan
- Department of Neurology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| |
Collapse
|
5
|
van Echten-Deckert G. The role of sphingosine 1-phosphate metabolism in brain health and disease. Pharmacol Ther 2023; 244:108381. [PMID: 36907249 DOI: 10.1016/j.pharmthera.2023.108381] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/02/2023] [Accepted: 03/06/2023] [Indexed: 03/13/2023]
Abstract
Lipids are essential structural and functional components of the central nervous system (CNS). Sphingolipids are ubiquitous membrane components which were discovered in the brain in the late 19th century. In mammals, the brain contains the highest concentration of sphingolipids in the body. Sphingosine 1-phosphate (S1P) derived from membrane sphingolipids evokes multiple cellular responses which, depending on its concentration and localization, make S1P a double-edged sword in the brain. In the present review we highlight the role of S1P in brain development and focus on the often contrasting findings regarding its contributions to the initiation, progression and potential recovery of different brain pathologies, including neurodegeneration, multiple sclerosis (MS), brain cancers, and psychiatric illnesses. A detailed understanding of the critical implications of S1P in brain health and disease may open the door for new therapeutic options. Thus, targeting S1P-metabolizing enzymes and/or signaling pathways might help overcome, or at least ameliorate, several brain illnesses.
Collapse
|
6
|
Borodzicz-Jażdżyk S, Jażdżyk P, Łysik W, Cudnoch-Jȩdrzejewska A, Czarzasta K. Sphingolipid metabolism and signaling in cardiovascular diseases. Front Cardiovasc Med 2022; 9:915961. [PMID: 36119733 PMCID: PMC9471951 DOI: 10.3389/fcvm.2022.915961] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/05/2022] [Indexed: 01/10/2023] Open
Abstract
Sphingolipids are a structural component of the cell membrane, derived from sphingosine, an amino alcohol. Its sphingoid base undergoes various types of enzymatic transformations that lead to the formation of biologically active compounds, which play a crucial role in the essential pathways of cellular signaling, proliferation, maturation, and death. The constantly growing number of experimental and clinical studies emphasizes the pivotal role of sphingolipids in the pathophysiology of cardiovascular diseases, including, in particular, ischemic heart disease, hypertension, heart failure, and stroke. It has also been proven that altering the sphingolipid metabolism has cardioprotective properties in cardiac pathologies, including myocardial infarction. Recent studies suggest that selected sphingolipids may serve as valuable biomarkers useful in the prognosis of cardiovascular disorders in clinical practice. This review aims to provide an overview of the current knowledge of sphingolipid metabolism and signaling in cardiovascular diseases.
Collapse
Affiliation(s)
- Sonia Borodzicz-Jażdżyk
- Chair and Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Piotr Jażdżyk
- Chair and Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
- Second Department of Psychiatry, Institute of Psychiatry and Neurology in Warsaw, Warsaw, Poland
| | - Wojciech Łysik
- Chair and Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Agnieszka Cudnoch-Jȩdrzejewska
- Chair and Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Katarzyna Czarzasta
- Chair and Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| |
Collapse
|
7
|
Diao X, Cui Q, Tian N, Zhou Z, Xiang W, Jiang Y, Deng J, Liao H, Lin X, Li Q, Liao R. Hemorrhage-Induced Sphingosine Kinase 1 Contributes to Ferroptosis-Mediated Secondary Brain Injury in Intracerebral Hemorrhage. Mol Neurobiol 2022; 59:1381-1397. [PMID: 34993846 DOI: 10.1007/s12035-021-02605-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/15/2021] [Indexed: 12/18/2022]
Abstract
The pathogenic processes of brain injury after intracerebral hemorrhage (ICH) have not yet been fully elucidated. Increasing evidence suggests that ferroptosis activation aggravates injury after ICH, but the underlying mechanism remains unclear. Sphingosine kinase 1 (Sphk1) is a key enzyme in the regulation of sphingosine metabolism involved in the ferroptosis pathway, but its role in ICH needs clarification. In this study, transcriptional changes in ICH patients were assessed by microarray data, exposing Sphk1 as a highly upregulated gene during ICH. Furthermore, Sphk1 chemical inhibitors and siRNA were used to inhibit ICH-induced Sphk1 upregulation in in vivo and in vitro models, showing that Sphk1 inhibition after protects against ferroptosis and attenuates secondary brain injury and cell death. Mechanistically, this study unveiled that sphingosine kinase 1/sphingosine 1-phosphate/extracellular-regulated protein kinases/phosphorylated extracellular-regulated protein kinases (Sphk1/S1p/ERK/p-ERK) pathway is responsible for regulation of ferroptosis leading to secondary brain injury and cell death following ICH. Collectively, this study demonstrates that ferroptosis is closely associated with ICH, and that Sphk1 has a critical role in this lethal process. These results suggest a novel unique and effective therapeutic approach for ICH prevention and treatment.
Collapse
Affiliation(s)
- Xiaojun Diao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410000, China
- Guangxi Clinical Research Center for Neurological Diseases, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
| | - Qi Cui
- Laboratory of Neuroscience, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
| | - Ning Tian
- Guangxi Clinical Research Center for Neurological Diseases, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
- Laboratory of Neuroscience, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
| | - Zixian Zhou
- Guangxi Clinical Research Center for Neurological Diseases, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
- Laboratory of Neuroscience, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin, 541004, China
| | - Wenjing Xiang
- Guangxi Clinical Research Center for Neurological Diseases, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
- Laboratory of Neuroscience, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin, 541004, China
| | - Yanlin Jiang
- Department of Pharmacology, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
| | - Jungang Deng
- Department of Pharmacology, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
| | - Hongzhan Liao
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
| | - Xiaohui Lin
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China
| | - Qinghua Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410000, China.
- Guangxi Clinical Research Center for Neurological Diseases, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China.
- Laboratory of Neuroscience, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China.
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin, 541004, China.
| | - Rujia Liao
- Guangxi Clinical Research Center for Neurological Diseases, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China.
- Laboratory of Neuroscience, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, 541004, China.
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin, 541004, China.
| |
Collapse
|
8
|
Jiménez-Altayó F, Marzi J, Galan M, Dantas AP, Ortega M, Rojas S, Egea G, Schenke-Layland K, Jiménez-Xarrié E, Planas AM. Arachnoid membrane as a source of sphingosine-1-phosphate that regulates mouse middle cerebral artery tone. J Cereb Blood Flow Metab 2022; 42:162-174. [PMID: 34474613 PMCID: PMC8721773 DOI: 10.1177/0271678x211033362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Growing evidence indicates that perivascular tissue is critical to modulate vessel function. We hypothesized that the arachnoid membrane surrounding middle cerebral artery (MCA) regulates its function via sphingosine-1-phosphate (S1P)-induced vasoconstriction. The MCA from 3- to 9-month-old male and female wild-type (Oncine France 1 and C57BL/6) mice and sphingosine kinase 2 knockout (SphK2-/-) mice in the C57BL/6 background was mounted in pressure myographs with and without arachnoid membrane. Raman microspectroscopy and imaging were used for in situ detection of S1P. The presence of arachnoid tissue was associated with reduced external and lumen MCA diameters, and with an increase in basal tone regardless of sex and strain background. Strong S1P-positive signals were detected in the arachnoid surrounding the MCA wall in both mice models, as well as in a human post-mortem specimen. Selective S1P receptor 3 antagonist TY 52156 markedly reduced both MCA vasoconstriction induced by exogenous S1P and arachnoid-dependent basal tone increase. Compared to 3-month-old mice, the arachnoid-mediated contractile influence persisted in 9-month-old mice despite a decline in arachnoid S1P deposits. Genetic deletion of SphK2 decreased arachnoid S1P content and vasoconstriction. This is the first experimental evidence that arachnoid membrane regulates the MCA tone mediated by S1P.
Collapse
Affiliation(s)
- Francesc Jiménez-Altayó
- Departament de Farmacologia, de Terapèutica i de Toxicologia, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Julia Marzi
- Department of Biomedical Engineering, Eberhard Karls University Tübingen, Tübingen, Germany.,NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany.,Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University of Tübingen, Tübingen, Germany
| | - María Galan
- Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau, 16689Hospital de la Santa Creu i Sant Pau, IIB Sant Pau, Barcelona, Spain
| | - Ana Paula Dantas
- Institut Clínic Del Tòrax, Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Marisa Ortega
- Unit of Human Anatomy and Embriology, Department of Morphological Sciences, Faculty of Medicine, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.,Institute of Legal Medicine and Forensic Sciences of Catalonia, Hospitalet de Llobregat, Catalonia, Spain
| | - Santiago Rojas
- Unit of Human Anatomy and Embriology, Department of Morphological Sciences, Faculty of Medicine, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Gustavo Egea
- Department of Biomedical Sciences, University of Barcelona School of Medicine and Health Sciences, Barcelona, Spain; IDIBAPS-University of Barcelona, Barcelona, Spain
| | - Katja Schenke-Layland
- Department of Biomedical Engineering, Eberhard Karls University Tübingen, Tübingen, Germany.,NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany.,Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", Eberhard Karls University of Tübingen, Tübingen, Germany.,Department of Medicine/Cardiology, Cardiovascular Research Laboratories, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Elena Jiménez-Xarrié
- Stroke Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau (IIB-Sant Pau), Barcelona, Spain
| | - Anna M Planas
- Department of Brain Ischemia and Neurodegeneration, Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain; Area of Neurosciences, IDIBAPS, Barcelona, Spain
| |
Collapse
|
9
|
Hutami IR, Izawa T, Khurel-Ochir T, Sakamaki T, Iwasa A, Tanaka E. Macrophage Motility in Wound Healing Is Regulated by HIF-1α via S1P Signaling. Int J Mol Sci 2021; 22:ijms22168992. [PMID: 34445695 PMCID: PMC8396560 DOI: 10.3390/ijms22168992] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/14/2021] [Accepted: 08/18/2021] [Indexed: 12/20/2022] Open
Abstract
Accumulating evidence indicates that the molecular pathways mediating wound healing induce cell migration and localization of cytokines to sites of injury. Macrophages are immune cells that sense and actively respond to disturbances in tissue homeostasis by initiating, and subsequently resolving, inflammation. Hypoxic conditions generated at a wound site also strongly recruit macrophages and affect their function. Hypoxia inducible factor (HIF)-1α is a transcription factor that contributes to both glycolysis and the induction of inflammatory genes, while also being critical for macrophage activation. For the latter, HIF-1α regulates sphingosine 1-phosphate (S1P) to affect the migration, activation, differentiation, and polarization of macrophages. Recently, S1P and HIF-1α have received much attention, and various studies have been performed to investigate their roles in initiating and resolving inflammation via macrophages. It is hypothesized that the HIF-1α/S1P/S1P receptor axis is an important determinant of macrophage function under inflammatory conditions and during disease pathogenesis. Therefore, in this review, biological regulation of monocytes/macrophages in response to circulating HIF-1α is summarized, including signaling by S1P/S1P receptors, which have essential roles in wound healing.
Collapse
Affiliation(s)
- Islamy Rahma Hutami
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
- Department of Orthodontics, Faculty of Dentistry, Sultan Agung Islamic University, Semarang 50112, Indonesia
| | - Takashi Izawa
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
- Correspondence: ; Tel.: +81-86-235-6691; Fax: +81-88-235-6694
| | - Tsendsuren Khurel-Ochir
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
| | - Takuma Sakamaki
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
| | - Akihiko Iwasa
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
| | - Eiji Tanaka
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
| |
Collapse
|
10
|
Liu J, Gu Y, Guo M, Ji X. Neuroprotective effects and mechanisms of ischemic/hypoxic preconditioning on neurological diseases. CNS Neurosci Ther 2021; 27:869-882. [PMID: 34237192 PMCID: PMC8265941 DOI: 10.1111/cns.13642] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/20/2022] Open
Abstract
As the organ with the highest demand for oxygen, the brain has a poor tolerance to ischemia and hypoxia. Despite severe ischemia/hypoxia induces the occurrence and development of various central nervous system (CNS) diseases, sublethal insult may induce strong protection against subsequent fatal injuries by improving tolerance. Searching for potential measures to improve brain ischemic/hypoxic is of great significance for treatment of ischemia/hypoxia related CNS diseases. Ischemic/hypoxic preconditioning (I/HPC) refers to the approach to give the body a short period of mild ischemic/hypoxic stimulus which can significantly improve the body's tolerance to subsequent more severe ischemia/hypoxia event. It has been extensively studied and been considered as an effective therapeutic strategy in CNS diseases. Its protective mechanisms involved multiple processes, such as activation of hypoxia signaling pathways, anti-inflammation, antioxidant stress, and autophagy induction, etc. As a strategy to induce endogenous neuroprotection, I/HPC has attracted extensive attention and become one of the research frontiers and hotspots in the field of neurotherapy. In this review, we discuss the basic and clinical research progress of I/HPC on CNS diseases, and summarize its mechanisms. Furthermore, we highlight the limitations and challenges of their translation from basic research to clinical application.
Collapse
Affiliation(s)
- Jia Liu
- Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Capital Medical University, Beijing, China
| | - Yakun Gu
- Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Capital Medical University, Beijing, China
| | - Mengyuan Guo
- Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Capital Medical University, Beijing, China
| | - Xunming Ji
- Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Capital Medical University, Beijing, China.,Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| |
Collapse
|
11
|
Chua XY, Ho LTY, Xiang P, Chew WS, Lam BWS, Chen CP, Ong WY, Lai MKP, Herr DR. Preclinical and Clinical Evidence for the Involvement of Sphingosine 1-Phosphate Signaling in the Pathophysiology of Vascular Cognitive Impairment. Neuromolecular Med 2020; 23:47-67. [PMID: 33180310 DOI: 10.1007/s12017-020-08632-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 11/03/2020] [Indexed: 02/07/2023]
Abstract
Sphingosine 1-phosphates (S1Ps) are bioactive lipids that mediate a diverse range of effects through the activation of cognate receptors, S1P1-S1P5. Scrutiny of S1P-regulated pathways over the past three decades has identified important and occasionally counteracting functions in the brain and cerebrovascular system. For example, while S1P1 and S1P3 mediate proinflammatory effects on glial cells and directly promote endothelial cell barrier integrity, S1P2 is anti-inflammatory but disrupts barrier integrity. Cumulatively, there is significant preclinical evidence implicating critical roles for this pathway in regulating processes that drive cerebrovascular disease and vascular dementia, both being part of the continuum of vascular cognitive impairment (VCI). This is supported by clinical studies that have identified correlations between alterations of S1P and cognitive deficits. We review studies which proposed and evaluated potential mechanisms by which such alterations contribute to pathological S1P signaling that leads to VCI-associated chronic neuroinflammation and neurodegeneration. Notably, S1P receptors have divergent but overlapping expression patterns and demonstrate complex interactions. Therefore, the net effect produced by S1P represents the cumulative contributions of S1P receptors acting additively, synergistically, or antagonistically on the neural, vascular, and immune cells of the brain. Ultimately, an optimized therapeutic strategy that targets S1P signaling will have to consider these complex interactions.
Collapse
Affiliation(s)
- Xin Ying Chua
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Leona T Y Ho
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119260, Singapore
| | - Ping Xiang
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Wee Siong Chew
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Brenda Wan Shing Lam
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Memory Aging and Cognition Centre, National University Health System, Kent Ridge, Singapore
| | - Wei-Yi Ong
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119260, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, 119260, Singapore
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- Memory Aging and Cognition Centre, National University Health System, Kent Ridge, Singapore.
| | - Deron R Herr
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- Department of Biology, San Diego State University, San Diego, CA, USA.
- American University of Health Sciences, Long Beach, CA, USA.
| |
Collapse
|
12
|
Chen JL, Wang XX, Chen L, Tang J, Xia YF, Qian K, Qin ZH, Waeber C, Sheng R. A sphingosine kinase 2-mimicking TAT-peptide protects neurons against ischemia-reperfusion injury by activating BNIP3-mediated mitophagy. Neuropharmacology 2020; 181:108326. [PMID: 32966847 DOI: 10.1016/j.neuropharm.2020.108326] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/31/2020] [Accepted: 09/16/2020] [Indexed: 12/30/2022]
Abstract
We have previously shown that sphingosine kinase 2 (SPK2) interacts with Bcl-2 via its BH3 domain, activating autophagy by inducing the dissociation of Beclin-1/Bcl-2 complexes, and that a TAT-SPK2 peptide containing the BH3 domain of SPK2 protects neurons against ischemic injury. The goals of the present study were to establish the functional significance of these findings, by testing whether TAT-SPK2 was effective in a mouse model of ischemic stroke, and to explore potential underlying mechanisms. Mice were administered with TAT-SPK2 by intraperitoneal injection before or after transient middle cerebral artery occlusion (tMCAO). Infarct volume, neurological deficit and brain water content were assessed 24 h after reperfusion. Mitophagy inhibitor Mdivi-1 and BNIP3 siRNAs were used to examine the involvement of BNIP3-dependent mitophagy in the neuroprotection of TAT-SPK2. Mitophagy was quantified by immunoblotting, immunofluorescence and electron microscopy. The interaction between TAT-SPK2 and Bcl-2, Bcl-2 and BNIP3 was detected by co-immunoprecipitation. In the tMCAO model, pre-treatment with TAT-SPK2 significantly reduced infarct volume, improved neurological function and decreased brain edema. Neuroprotection by TAT-SPK2 was still seen when the peptide was administered 3 h after reperfusion. TAT-SPK2 also significantly improved functional recovery and reduced long-term brain atrophy of the ischemic hemisphere 30 days after administration. Our studies further showed that TAT-SPK2 directly binds to Bcl-2 and disrupts Bcl-2/Beclin-1 or Bcl-2/BNIP3 complexes to induce mitophagy. These results suggest that TAT-SPK2 protects neurons against ischemia reperfusion injury by activating BNIP3-mediated mitophagy. Agents exploiting this molecular mechanism are potential candidates for the treatment of ischemic stroke.
Collapse
Affiliation(s)
- Jia-Li Chen
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, China
| | - Xin-Xin Wang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, China
| | - Lei Chen
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, China
| | - Jie Tang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, China
| | - Yun-Fei Xia
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, China
| | - Ke Qian
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, China
| | - Zheng-Hong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, China
| | - Christian Waeber
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland; School of Pharmacy, University College Cork, Cork, Ireland
| | - Rui Sheng
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, China.
| |
Collapse
|
13
|
Hao Y, Xin M, Feng L, Wang X, Wang X, Ma D, Feng J. Review Cerebral Ischemic Tolerance and Preconditioning: Methods, Mechanisms, Clinical Applications, and Challenges. Front Neurol 2020; 11:812. [PMID: 33071923 PMCID: PMC7530891 DOI: 10.3389/fneur.2020.00812] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 06/29/2020] [Indexed: 12/13/2022] Open
Abstract
Stroke is one of the leading causes of morbidity and mortality worldwide, and it is increasing in prevalence. The limited therapeutic window and potential severe side effects prevent the widespread clinical application of the venous injection of thrombolytic tissue plasminogen activator and thrombectomy, which are regarded as the only approved treatments for acute ischemic stroke. Triggered by various types of mild stressors or stimuli, ischemic preconditioning (IPreC) induces adaptive endogenous tolerance to ischemia/reperfusion (I/R) injury by activating a multitude cascade of biomolecules, for example, proteins, enzymes, receptors, transcription factors, and others, which eventually lead to transcriptional regulation and epigenetic and genomic reprogramming. During the past 30 years, IPreC has been widely studied to confirm its neuroprotection against subsequent I/R injury, mainly including local ischemic preconditioning (LIPreC), remote ischemic preconditioning (RIPreC), and cross preconditioning. Although LIPreC has a strong neuroprotective effect, the clinical application of IPreC for subsequent cerebral ischemia is difficult. There are two main reasons for the above result: Cerebral ischemia is unpredictable, and LIPreC is also capable of inducing unexpected injury with only minor differences to durations or intensity. RIPreC and pharmacological preconditioning, an easy-to-use and non-invasive therapy, can be performed in a variety of clinical settings and appear to be more suitable for the clinical management of ischemic stroke. Hoping to advance our understanding of IPreC, this review mainly focuses on recent advances in IPreC in stroke management, its challenges, and the potential study directions.
Collapse
Affiliation(s)
| | | | | | | | | | - Di Ma
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Jiachun Feng
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| |
Collapse
|
14
|
Gaire BP, Choi JW. Sphingosine 1-Phosphate Receptors in Cerebral Ischemia. Neuromolecular Med 2020; 23:211-223. [PMID: 32914259 DOI: 10.1007/s12017-020-08614-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 09/02/2020] [Indexed: 01/09/2023]
Abstract
Sphingosine 1-phosphate (S1P) is an important lipid biomolecule that exerts pleiotropic cellular actions as it binds to and activates its five G-protein-coupled receptors, S1P1-5. Through these receptors, S1P can mediate diverse biological activities in both healthy and diseased conditions. S1P is produced by S1P-producing enzymes, sphingosine kinases (SphK1 and SphK2), and is abundantly present in different organs, including the brain. The medically important roles of receptor-mediated S1P signaling are well characterized in multiple sclerosis because FTY720 (Gilenya™, Novartis), a non-selective S1P receptor modulator, is currently used as a treatment for this disease. In cerebral ischemia, its role is also notable because of FTY720's efficacy in both rodent models and human patients with cerebral ischemia. In particular, some of the S1P receptors, including S1P1, S1P2, and S1P3, have been identified as pathogenic players in cerebral ischemia. Other than these receptors, S1P itself and S1P-producing enzymes have been shown to play certain roles in cerebral ischemia. This review aims to compile the current updates and overviews about the roles of S1P signaling, along with a focus on S1P receptors in cerebral ischemia, based on recent studies that used in vivo rodent models of cerebral ischemia.
Collapse
Affiliation(s)
- Bhakta Prasad Gaire
- College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Inchon, 21936, Republic of Korea
| | - Ji Woong Choi
- College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Inchon, 21936, Republic of Korea.
| |
Collapse
|
15
|
Belov Kirdajova D, Kriska J, Tureckova J, Anderova M. Ischemia-Triggered Glutamate Excitotoxicity From the Perspective of Glial Cells. Front Cell Neurosci 2020; 14:51. [PMID: 32265656 PMCID: PMC7098326 DOI: 10.3389/fncel.2020.00051] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/21/2020] [Indexed: 12/21/2022] Open
Abstract
A plethora of neurological disorders shares a final common deadly pathway known as excitotoxicity. Among these disorders, ischemic injury is a prominent cause of death and disability worldwide. Brain ischemia stems from cardiac arrest or stroke, both responsible for insufficient blood supply to the brain parenchyma. Glucose and oxygen deficiency disrupts oxidative phosphorylation, which results in energy depletion and ionic imbalance, followed by cell membrane depolarization, calcium (Ca2+) overload, and extracellular accumulation of excitatory amino acid glutamate. If tight physiological regulation fails to clear the surplus of this neurotransmitter, subsequent prolonged activation of glutamate receptors forms a vicious circle between elevated concentrations of intracellular Ca2+ ions and aberrant glutamate release, aggravating the effect of this ischemic pathway. The activation of downstream Ca2+-dependent enzymes has a catastrophic impact on nervous tissue leading to cell death, accompanied by the formation of free radicals, edema, and inflammation. After decades of “neuron-centric” approaches, recent research has also finally shed some light on the role of glial cells in neurological diseases. It is becoming more and more evident that neurons and glia depend on each other. Neuronal cells, astrocytes, microglia, NG2 glia, and oligodendrocytes all have their roles in what is known as glutamate excitotoxicity. However, who is the main contributor to the ischemic pathway, and who is the unsuspecting victim? In this review article, we summarize the so-far-revealed roles of cells in the central nervous system, with particular attention to glial cells in ischemia-induced glutamate excitotoxicity, its origins, and consequences.
Collapse
Affiliation(s)
- Denisa Belov Kirdajova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jan Kriska
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jana Tureckova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Miroslava Anderova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
| |
Collapse
|
16
|
Raza Z, Saleem U, Naureen Z. Sphingosine 1-phosphate signaling in ischemia and reperfusion injury. Prostaglandins Other Lipid Mediat 2020; 149:106436. [PMID: 32173486 DOI: 10.1016/j.prostaglandins.2020.106436] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 02/07/2023]
Abstract
Ischemia and reperfusion injury is a complex hemodynamic pathological phenomenon that engages the metabolic to inflammatory machinery in development of disease conditions like heart failure, stroke and acute kidney failure. Target specific therapeutic approaches for ischemia reperfusion injury remains critical despite the extensive studies contributing to the understanding of its pathogenesis. Ischemic or pharmacological conditionings have been long established manipulations to harness the endogenous protective mechanisms against ischemia reperfusion injury that fostered the development of potential therapeutic targets such as sphingolipids signaling. Sphingosine 1-phosphate has been emerged as a crucial metabolite of sphingolipids to regulate the cell survival, vascular integrity and inflammatory cascades in ischemia reperfusion injury. Sphingosine 1-phosphate signaling process has been implicated to downgrade the mitochondrial dysfunction, apoptotic assembly along with upregulation of RISK and SAFE pro-survival pathways. It also regulates the endothelial dysfunction and immune cells behavior to control the vascular permeability and immune cells infiltration at ischemia reperfusion injury site. Targeting the signaling of this single moiety holds the vast potential to extensively influence the detrimental signaling of ischemia reperfusion injury. This review highlights the role and significance of S1P signaling that can be therapeutically exploit to treat ischemia reperfusion injury mediated pathological conditions in different organs.
Collapse
Affiliation(s)
- Zohaib Raza
- Government College University, Faisalabad, Pakistan.
| | - Uzma Saleem
- Government College University, Faisalabad, Pakistan
| | | |
Collapse
|
17
|
Potential sphingosine-1-phosphate-related therapeutic targets in the treatment of cerebral ischemia reperfusion injury. Life Sci 2020; 249:117542. [PMID: 32169519 DOI: 10.1016/j.lfs.2020.117542] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/29/2020] [Accepted: 03/09/2020] [Indexed: 12/17/2022]
Abstract
Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid that regulates lymphocyte trafficking, glial cell activation, vasoconstriction, endothelial barrier function, and neuronal death pathways in the brain. Research has increasingly implicated S1P in the pathology of cerebral ischemia reperfusion (IR) injury. As a high-affinity agonist of S1P receptor, fingolimod exhibits excellent neuroprotective effects against ischemic challenge both in vivo and in vitro. By summarizing recent progress on how S1P participates in the development of brain IR injury, this review identifies potential therapeutic targets for the treatment of brain IR injury.
Collapse
|
18
|
Grassi S, Mauri L, Prioni S, Cabitta L, Sonnino S, Prinetti A, Giussani P. Sphingosine 1-Phosphate Receptors and Metabolic Enzymes as Druggable Targets for Brain Diseases. Front Pharmacol 2019; 10:807. [PMID: 31427962 PMCID: PMC6689979 DOI: 10.3389/fphar.2019.00807] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/21/2019] [Indexed: 12/12/2022] Open
Abstract
The central nervous system is characterized by a high content of sphingolipids and by a high diversity in terms of different structures. Stage- and cell-specific sphingolipid metabolism and expression are crucial for brain development and maintenance toward adult age. On the other hand, deep dysregulation of sphingolipid metabolism, leading to altered sphingolipid pattern, is associated with the majority of neurological and neurodegenerative diseases, even those totally lacking a common etiological background. Thus, sphingolipid metabolism has always been regarded as a promising pharmacological target for the treatment of brain disorders. However, any therapeutic hypothesis applied to complex amphipathic sphingolipids, components of cellular membranes, has so far failed probably because of the high regional complexity and specificity of the different biological roles of these structures. Simpler sphingosine-based lipids, including ceramide and sphingosine 1-phosphate, are important regulators of brain homeostasis, and, thanks to the relative simplicity of their metabolic network, they seem a feasible druggable target for the treatment of brain diseases. The enzymes involved in the control of the levels of bioactive sphingoids, as well as the receptors engaged by these molecules, have increasingly allured pharmacologists and clinicians, and eventually fingolimod, a functional antagonist of sphingosine 1-phosphate receptors with immunomodulatory properties, was approved for the therapy of relapsing-remitting multiple sclerosis. Considering the importance of neuroinflammation in many other brain diseases, we would expect an extension of the use of such analogs for the treatment of other ailments in the future. Nevertheless, many aspects other than neuroinflammation are regulated by bioactive sphingoids in healthy brain and dysregulated in brain disease. In this review, we are addressing the multifaceted possibility to address the metabolism and biology of bioactive sphingosine 1-phosphate as novel targets for the development of therapeutic paradigms and the discovery of new drugs.
Collapse
Affiliation(s)
- Sara Grassi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Laura Mauri
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Simona Prioni
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Livia Cabitta
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Sandro Sonnino
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Alessandro Prinetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Paola Giussani
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| |
Collapse
|
19
|
Intracellular S1P Levels Dictate Fate of Different Regions of the Hippocampus following Transient Global Cerebral Ischemia. Neuroscience 2018; 384:188-202. [PMID: 29782904 DOI: 10.1016/j.neuroscience.2018.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 05/08/2018] [Accepted: 05/10/2018] [Indexed: 11/21/2022]
Abstract
Sphingosine-1-phosphate (S1P) is a sphingolipid molecule produced by the action of sphingosine kinases (SphK) on sphingosine. It possesses various intracellular functions through its interactions with intracellular proteins or via its action on five G-protein-coupled cell membrane receptors. Following transient global cerebral ischemia (tGCI), only the CA1 subregion of the hippocampus undergoes apoptosis. In this study, we evaluated S1P levels and S1P-processing enzyme expression in different hippocampal areas following tGCI in rats. We found that S1P was upregulated earlier in CA3 than in CA1. This was associated with upregulation of SphK1 in both regions; however, SphK2 was downregulated quickly in CA3. S1P lyase was also downregulated in CA3, but not in CA1. Spinster 2, the S1P exporter, was upregulated early in both regions, but was quickly downregulated in CA3. Together, these effects explain the variable levels of S1P in the CA1 and CA3 areas and indicate that S1P levels play a role in the preferential resistance of the CA3 subregion to tGCI-induced ischemia. FTY720 did not improve neuronal survival in the CA1 subregion, indicating that these effects were due to intracellular S1P accumulation. In conclusion, the findings suggest that intracellular S1P levels affect neuronal cell fate following tGCI.
Collapse
|
20
|
The role of sphingolipids in psychoactive drug use and addiction. J Neural Transm (Vienna) 2018; 125:651-672. [DOI: 10.1007/s00702-018-1840-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/03/2018] [Indexed: 12/14/2022]
|
21
|
Vutukuri R, Brunkhorst R, Kestner RI, Hansen L, Bouzas NF, Pfeilschifter J, Devraj K, Pfeilschifter W. Alteration of sphingolipid metabolism as a putative mechanism underlying LPS-induced BBB disruption. J Neurochem 2017; 144:172-185. [PMID: 29023711 DOI: 10.1111/jnc.14236] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 09/24/2017] [Accepted: 09/25/2017] [Indexed: 12/31/2022]
Abstract
Septic encephalopathy with confusion and agitation occurs early during sepsis and contributes to the severity of the disease. A decrease in the sphingosine-1-phosphate (S1P) blood levels has been shown in patients and in animal models of sepsis. The lipid mediator S1P is known to be involved in endothelial barrier function in a context-dependent manner. We utilized lipopolysaccharide (LPS)-injected mice as a model for septic encephalopathy and first performed tracer permeability assays to assess the blood-brain barrier (BBB) breakdown in vivo. At time points corresponding to the BBB breakdown post LPS injection, we aimed to characterize the regulation of the sphingolipid signaling pathway at the BBB during sepsis. We measured sphingolipid concentrations in blood, in mouse brain microvessels (MBMVs), and brain tissue. We also analyzed the expression of S1P receptors, transporters, and metabolizing enzymes in MBMVs and brain tissue. Primary mouse brain microvascular endothelial cells (MBMECs) were isolated to evaluate the effects of LPS on transendothelial electrical resistance (TEER) as a measure of permeability in vitro. We observed a relevant decrease in S1P levels after LPS injection in all three compartments (blood, MBMVs, brain tissue) that was accompanied by an increased expression of the S1P receptor type 1 and of sphingosine kinase 1 on one hand and of the S1P degrading enzymes lipid phosphate phosphatase 1 (LPP1) and S1P phosphatase 1 on the other hand, as well as a down-regulation of sphingosine kinase 2. Application of LPS to a monolayer of primary MBMECs did not alter TEER, but serum from LPS-treated mice lead to a breakdown of the barrier compared to serum from vehicle-treated mice. We observed profound alterations of the sphingolipid metabolism at the BBB after LPS injection that point toward a therapeutic potential of drugs interfering with this pathway as novel approach for the detrimental overwhelming immune response in sepsis. Read the Editorial Highlight for this article on page 115. Cover Image for this Issue: doi. 10.1111/jnc.14161.
Collapse
Affiliation(s)
- Rajkumar Vutukuri
- Pharmazentrum Frankfurt, Institute for General Pharmacology and Toxicology, Goethe University, Frankfurt, Germany
| | - Robert Brunkhorst
- Department of Neurology, University Hospital Frankfurt and Goethe University, Frankfurt, Germany
| | - Roxane-Isabelle Kestner
- Department of Neurology, University Hospital Frankfurt and Goethe University, Frankfurt, Germany
| | - Lena Hansen
- Pharmazentrum Frankfurt, Institute for General Pharmacology and Toxicology, Goethe University, Frankfurt, Germany
| | - Nerea Ferreiros Bouzas
- Pharmazentrum Frankfurt, Institute for Clinical Pharmacology, Goethe University, Frankfurt, Germany
| | - Josef Pfeilschifter
- Pharmazentrum Frankfurt, Institute for General Pharmacology and Toxicology, Goethe University, Frankfurt, Germany
| | - Kavi Devraj
- Pharmazentrum Frankfurt, Institute for General Pharmacology and Toxicology, Goethe University, Frankfurt, Germany.,Edinger Institute of Neurology, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - Waltraud Pfeilschifter
- Department of Neurology, University Hospital Frankfurt and Goethe University, Frankfurt, Germany
| |
Collapse
|
22
|
Ganta VC, Annex BH. LMO2 (LIM Domain Only 2) and Endothelial Cell Migration in Developmental and Postnatal Angiogenesis. Arterioscler Thromb Vasc Biol 2017; 37:1806-1808. [PMID: 28954807 DOI: 10.1161/atvbaha.117.309953] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Vijay Chaitanya Ganta
- From the Robert M. Berne Cardiovascular Research Center (V.C.G., B.H.A.) and Division of Cardiovascular Medicine, Department of Medicine (B.H.A.), University of Virginia School of Medicine, Charlottesville
| | - Brian H Annex
- From the Robert M. Berne Cardiovascular Research Center (V.C.G., B.H.A.) and Division of Cardiovascular Medicine, Department of Medicine (B.H.A.), University of Virginia School of Medicine, Charlottesville.
| |
Collapse
|
23
|
AntagomiR-613 protects neuronal cells from oxygen glucose deprivation/re-oxygenation via increasing SphK2 expression. Biochem Biophys Res Commun 2017; 493:188-194. [PMID: 28916166 DOI: 10.1016/j.bbrc.2017.09.049] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 09/10/2017] [Indexed: 01/06/2023]
Abstract
Oxygen glucose deprivation (OGD)/re-oxygenation (OGDR) causes damages to neuronal cells. Sphingosine kinase 2 (SphK2) expression could exert neuroprotective functions. Here, we aim to induce SphK2 expression via inhibiting the anti-SphK2 microRNA: microRNA-613 ("miR-613"). In both SH-SY5Y neuronal cells and primary murine hippocampal neurons, transfection of the miR-613's specific inhibitor, antagomiR-613 ("antamiR-613"), induced miR-613 depletion and SphK2 expression. Reversely, forced over-expression of miR-613 caused SphK2 downregulation in SH-SY5Y cells. OGDR-induced cytotoxicity in neuronal cells was largely attenuated by antamiR-613. SphK2 is required for antamiR-613-induced actions in neuronal cells. SphK2 knockdown (by targeted-shRNAs) or inhibition (by its inhibitor ABC294640) almost completely abolished antamiR-613-mediated neuroprotection against OGDR. Further studies showed that OGDR-induced reactive oxygen species (ROS) production, lipid peroxidation, and DNA damages in SH-SY5Y cells were largely attenuated by antamiR-613, but were intensified by miR-613 expression. Taken together, we conclude that antamiR-613 protects neuronal cells from OGDR probably via inducing SphK2 expression.
Collapse
|
24
|
Sphingosine kinase 2 activates autophagy and protects neurons against ischemic injury through interaction with Bcl-2 via its putative BH3 domain. Cell Death Dis 2017; 8:e2912. [PMID: 28682313 PMCID: PMC5550846 DOI: 10.1038/cddis.2017.289] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/26/2017] [Accepted: 05/29/2017] [Indexed: 01/05/2023]
Abstract
Our previous findings suggest that sphingosine kinase 2 (SPK2) mediates ischemic tolerance and autophagy in cerebral preconditioning. The aim of this study was to determine by which mechanism SPK2 activates autophagy in neural cells. In both primary murine cortical neurons and HT22 hippocampal neuronal cells, overexpression of SPK2 increased LC3II and enhanced the autophagy flux. SPK2 overexpression protected cortical neurons against oxygen glucose deprivation (OGD) injury, as evidenced by improvement of neuronal morphology, increased cell viability and reduced lactate dehydrogenase release. The inhibition of autophagy effectively suppressed the neuroprotective effect of SPK2. SPK2 overexpression reduced the co-immunoprecipitation of Beclin-1 and Bcl-2, while Beclin-1 knockdown inhibited SPK2-induced autophagy. Both co-immunoprecipitation and GST pull-down analysis suggest that SPK2 directly interacts with Bcl-2. SPK2 might interact to Bcl-2 in the cytoplasm. Notably, an SPK2 mutant with L219A substitution in its putative BH3 domain was not able to activate autophagy. A Tat peptide fused to an 18-amino acid peptide encompassing the native, but not the L219A mutated BH3 domain of SPK2 activated autophagy in neural cells. The Tat-SPK2 peptide also protected neurons against OGD injury through autophagy activation. These results suggest that SPK2 interacts with Bcl-2 via its BH3 domain, thereby dissociating it from Beclin-1 and activating autophagy. The observation that Tat-SPK2 peptide designed from the BH3 domain of SPK2 activates autophagy and protects neural cells against OGD injury suggest that this structure may provide the basis for a novel class of therapeutic agents against ischemic stroke.
Collapse
|
25
|
Hatoum D, Haddadi N, Lin Y, Nassif NT, McGowan EM. Mammalian sphingosine kinase (SphK) isoenzymes and isoform expression: challenges for SphK as an oncotarget. Oncotarget 2017; 8:36898-36929. [PMID: 28415564 PMCID: PMC5482707 DOI: 10.18632/oncotarget.16370] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/02/2017] [Indexed: 12/16/2022] Open
Abstract
The various sphingosine kinase (SphK) isoenzymes (isozymes) and isoforms, key players in normal cellular physiology, are strongly implicated in cancer and other diseases. Mutations in SphKs, that may justify abnormal physiological function, have not been recorded. Nonetheless, there is a large and growing body of evidence demonstrating the contribution of gain or loss of function and the imbalance in the SphK/S1P rheostat to a plethora of pathological conditions including cancer, diabetes and inflammatory diseases. SphK is expressed as two isozymes SphK1 and SphK2, transcribed from genes located on different chromosomes and both isozymes catalyze the phosphorylation of sphingosine to S1P. Expression of each SphK isozyme produces alternately spliced isoforms. In recent years the importance of the contribution of SpK1 expression to treatment resistance in cancer has been highlighted and, additionally, differences in treatment outcome appear to also be dependent upon SphK isoform expression. This review focuses on an exciting emerging area of research involving SphKs functions, expression and subcellular localization, highlighting the complexity of targeting SphK in cancer and also comorbid diseases. This review also covers the SphK isoenzymes and isoforms from a historical perspective, from their first discovery in murine species and then in humans, their role(s) in normal cellular function and in disease processes, to advancement of SphK as an oncotarget.
Collapse
Affiliation(s)
- Diana Hatoum
- School of Life Sciences, University of Technology Sydney, Ultimo, Sydney, NSW 2007, Australia
| | - Nahal Haddadi
- School of Life Sciences, University of Technology Sydney, Ultimo, Sydney, NSW 2007, Australia
| | - Yiguang Lin
- School of Life Sciences, University of Technology Sydney, Ultimo, Sydney, NSW 2007, Australia
| | - Najah T. Nassif
- School of Life Sciences, University of Technology Sydney, Ultimo, Sydney, NSW 2007, Australia
| | - Eileen M. McGowan
- School of Life Sciences, University of Technology Sydney, Ultimo, Sydney, NSW 2007, Australia
| |
Collapse
|
26
|
Su D, Cheng Y, Li S, Dai D, Zhang W, Lv M. Sphk1 mediates neuroinflammation and neuronal injury via TRAF2/NF-κB pathways in activated microglia in cerebral ischemia reperfusion. J Neuroimmunol 2017; 305:35-41. [DOI: 10.1016/j.jneuroim.2017.01.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 01/22/2017] [Accepted: 01/23/2017] [Indexed: 01/08/2023]
|
27
|
Sphingosine-1-phosphate receptor therapies: Advances in clinical trials for CNS-related diseases. Neuropharmacology 2017; 113:597-607. [DOI: 10.1016/j.neuropharm.2016.11.006] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 10/25/2016] [Accepted: 11/02/2016] [Indexed: 12/31/2022]
|
28
|
Pitman MR, Costabile M, Pitson SM. Recent advances in the development of sphingosine kinase inhibitors. Cell Signal 2016; 28:1349-1363. [DOI: 10.1016/j.cellsig.2016.06.007] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/09/2016] [Accepted: 06/09/2016] [Indexed: 12/11/2022]
|
29
|
Zhang Q, Bian H, Guo L, Zhu H. Berberine Preconditioning Protects Neurons Against Ischemia via Sphingosine-1-Phosphate and Hypoxia-Inducible Factor-1α. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2016; 44:927-41. [DOI: 10.1142/s0192415x16500518] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Berberine exerts neuroprotective and modulates hypoxia inducible factor-1-alpha (HIF-1[Formula: see text]. Based on the role of HIF-1[Formula: see text] in hypoxia preconditioning and association between HIF-1[Formula: see text] and sphingosine-1-phosphate (S1P), we hypothesized that berberine preconditioning (BP) would ameliorate the cerebral injury induced by ischemia through activating the system of HIF-1[Formula: see text] and S1P. Adult male rats with middle cerebral artery occlusion (MCAO) and rat primary cortical neurons treated with oxygen and glucose deprivation (OGD) with BP at 24[Formula: see text]h (40[Formula: see text]mg/kg) and 2[Formula: see text]h (10[Formula: see text][Formula: see text]mol/L), respectively, were used to determine the neuroprotective effects. The HIF-1[Formula: see text] accumulation, and S1P metabolism were assayed in the berberine-preconditioned neurons, and the HIF-1[Formula: see text]-mediated transcriptional modulation of sphingosine kinases (Sphk) 1 and 2 was analyzed using chromatin immunoprecipitation and real-time polymerase chain reaction. BP significantly prevented cerebral ischemic injury in the MCAO rats at 24[Formula: see text]h and 72[Formula: see text]h following ischemia/reperfusion. In OGD-treated neurons, BP enhanced HIF-1[Formula: see text] accumulation with activation of PI3K/Akt, and induced S1P production by activating Sphk2 via the promotion of HIF-1[Formula: see text]-mediated Sphk2 transcription. In conclusion, BP activated endogenous neuroprotective mechanisms associated with the S1P/HIF-1 pathway and helped protect neuronal cells against hypoxia/ischemia.
Collapse
Affiliation(s)
- Qichun Zhang
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China
- Jiangsu Botanical Medicine Refine Engineering Research Center, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China
- Department of Clinic Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China
| | - Huimin Bian
- Department of Clinic Pharmacology, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China
| | - Liwei Guo
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China
- Jiangsu Botanical Medicine Refine Engineering Research Center, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China
| | - Huaxu Zhu
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China
- Jiangsu Botanical Medicine Refine Engineering Research Center, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China
| |
Collapse
|
30
|
Sun N, Keep RF, Hua Y, Xi G. Critical Role of the Sphingolipid Pathway in Stroke: a Review of Current Utility and Potential Therapeutic Targets. Transl Stroke Res 2016; 7:420-38. [PMID: 27339463 DOI: 10.1007/s12975-016-0477-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/12/2016] [Accepted: 06/15/2016] [Indexed: 12/16/2022]
Abstract
Sphingolipids are a series of cell membrane-derived lipids which act as signaling molecules and play a critical role in cell death and survival, proliferation, recognition, and migration. Sphingosine-1-phosphate acts as a key signaling molecule and regulates lymphocyte trafficking, glial cell activation, vasoconstriction, endothelial barrier function, and neuronal death pathways which plays a critical role in numerous neurological conditions. Stroke is a second leading cause of death all over the world and effective therapies are still in great demand, including ischemic stroke and hemorrhagic stroke as well as poststroke repair. Significantly, sphingolipid activities change after stroke and correlate with stroke outcome, which has promoted efforts to testify whether the sphingolipid pathway could be a novel therapeutic target in stroke. The sphingolipid metabolic pathway, the connection between the pathway and stroke, as well as therapeutic interventions to manipulate the pathway to reduce stroke-induced brain injury are discussed in this review.
Collapse
Affiliation(s)
- Na Sun
- Department of Neurosurgery, University of Michigan, 5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, 5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
| | - Ya Hua
- Department of Neurosurgery, University of Michigan, 5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, 5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA.
| |
Collapse
|
31
|
TIGAR contributes to ischemic tolerance induced by cerebral preconditioning through scavenging of reactive oxygen species and inhibition of apoptosis. Sci Rep 2016; 6:27096. [PMID: 27256465 PMCID: PMC4891774 DOI: 10.1038/srep27096] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/13/2016] [Indexed: 12/12/2022] Open
Abstract
Previous study showed that TIGAR (TP53-induced glycolysis and apoptosis regulator) protected ischemic brain injury via enhancing pentose phosphate pathway (PPP) flux and preserving mitochondria function. This study was aimed to study the role of TIGAR in cerebral preconditioning. The ischemic preconditioning (IPC) and isoflurane preconditioning (ISO) models were established in primary cultured cortical neurons and in mice. Both IPC and ISO increased TIGAR expression in cortical neurons. Preconditioning might upregulate TIGAR through SP1 transcription factor. Lentivirus mediated knockdown of TIGAR significantly abolished the ischemic tolerance induced by IPC and ISO. ISO also increased TIGAR in mouse cortex and hippocampus and alleviated subsequent brain ischemia-reperfusion injury, while the ischemic tolerance induced by ISO was eliminated with TIGAR knockdown in mouse brain. ISO increased the production of NADPH and glutathione (GSH), and scavenged reactive oxygen species (ROS), while TIGAR knockdown decreased GSH and NADPH production and increased the level of ROS. Supplementation of ROS scavenger NAC and PPP product NADPH effectively rescue the neuronal injury caused by TIGAR deficiency. Notably, TIGAR knockdown inhibited ISO-induced anti-apoptotic effects in cortical neurons. These results suggest that TIGAR participates in the cerebral preconditioning through reduction of ROS and subsequent cell apoptosis.
Collapse
|
32
|
Galluzzi L, Bravo-San Pedro JM, Blomgren K, Kroemer G. Autophagy in acute brain injury. Nat Rev Neurosci 2016; 17:467-84. [PMID: 27256553 DOI: 10.1038/nrn.2016.51] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autophagy is an evolutionarily ancient mechanism that ensures the lysosomal degradation of old, supernumerary or ectopic cytoplasmic entities. Most eukaryotic cells, including neurons, rely on proficient autophagic responses for the maintenance of homeostasis in response to stress. Accordingly, autophagy mediates neuroprotective effects following some forms of acute brain damage, including methamphetamine intoxication, spinal cord injury and subarachnoid haemorrhage. In some other circumstances, however, the autophagic machinery precipitates a peculiar form of cell death (known as autosis) that contributes to the aetiology of other types of acute brain damage, such as neonatal asphyxia. Here, we dissect the context-specific impact of autophagy on non-infectious acute brain injury, emphasizing the possible therapeutic application of pharmacological activators and inhibitors of this catabolic process for neuroprotection.
Collapse
Affiliation(s)
- Lorenzo Galluzzi
- Equipe 11 Labellisée Ligue Contre le Cancer, Centre de Recherche des Cordeliers, 75006 Paris, France.,INSERM, U1138, 75006 Paris, France.,Université Paris Descartes/Paris V, Sorbonne Paris Cité, 75006 Paris, France.,Université Pierre et Marie Curie/Paris VI, 75006 Paris, France.,Gustave Roussy Comprehensive Cancer Institute, 94805 Villejuif, France
| | - José Manuel Bravo-San Pedro
- Equipe 11 Labellisée Ligue Contre le Cancer, Centre de Recherche des Cordeliers, 75006 Paris, France.,INSERM, U1138, 75006 Paris, France.,Université Paris Descartes/Paris V, Sorbonne Paris Cité, 75006 Paris, France.,Université Pierre et Marie Curie/Paris VI, 75006 Paris, France.,Gustave Roussy Comprehensive Cancer Institute, 94805 Villejuif, France
| | - Klas Blomgren
- Karolinska Institute, Department of Women's and Children's Health, Karolinska University Hospital Q2:07, 17176 Stockholm, Sweden
| | - Guido Kroemer
- Equipe 11 Labellisée Ligue Contre le Cancer, Centre de Recherche des Cordeliers, 75006 Paris, France.,INSERM, U1138, 75006 Paris, France.,Université Paris Descartes/Paris V, Sorbonne Paris Cité, 75006 Paris, France.,Université Pierre et Marie Curie/Paris VI, 75006 Paris, France.,Karolinska Institute, Department of Women's and Children's Health, Karolinska University Hospital Q2:07, 17176 Stockholm, Sweden.,Metabolomics and Cell Biology Platforms, Gustave Roussy Comprehensive Cancer Institute, 94805 Villejuif, France.,Pôle de Biologie, Hopitâl Européen George Pompidou, AP-HP, 75015 Paris, France
| |
Collapse
|
33
|
Sphingosine kinase 1/sphingosine-1-phosphate regulates the expression of interleukin-17A in activated microglia in cerebral ischemia/reperfusion. Inflamm Res 2016; 65:551-62. [PMID: 27002656 DOI: 10.1007/s00011-016-0939-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 02/23/2016] [Accepted: 03/10/2016] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Microglial activation is one of the causative factors of neuroinflammation in cerebral ischemia/reperfusion (IR). Sphingosine kinase 1 (Sphk1), a key enzyme responsible for phosphorylating sphingosine into sphingosine-1-phosphate (S1P), plays an important role in the regulation of proinflammatory cytokines in activated microglia. Recent research demonstrated that S1P increased IL-17A-secretion and then worsened CNS (central nervous system) inflammation. Thus, in the present study, we sought to use microglial cells as the object of study to discuss the molecular mechanisms in Sphk1/S1P-regulated IL-17A-secretion in IR. METHODS We used immunofluorescence and confocal microscopy to detect whether Sphk1 is expressed in microglia after cerebral IR or oxygen-glucose deprivation (OGDR). Western blot analysis was used to estimate the total Sphk1 protein level at different time points after OGDR. To detect cytokine secretion in microglial supernatants in response to OGDR, we measured the concentration of IL-17A in the culture supernatants using an enzyme-linked immunosorbent assay (ELISA). To evaluate whether microglia subjected to OGDR exhibited neuronal injury, we used a commercially available terminal transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) kit to detect apoptotic neurons. RESULTS Sphk1 was expressed in microglia in response to cerebral IR or OGDR at appointed time. Pre-injection with PF-543, an inhibitor of Sphk1, before IR clearly reduced the expression of Sphk1 in microglia relative to brain IR alone. The number of TUNEL-positive neurons was also decreased in the PF-543-pretreated animals before IR compared to the animals with IR alone. When S1P was administered in OGDR microglia, IL-17A expression and neuronal apoptosis were increased compared to OGDR alone and the administration of S1P alone. ELISA further confirmed the above results. Moreover, the inhibition of Sphk1 by siRNA reduced IL-17A production and relieved neuronal apoptosis in OGDR microglia. CONCLUSION These results indicated that Sphk1/S1P regulates the expression of IL-17A in activated microglia, inducing neuronal apoptosis in cerebral ischemia/reperfusion. The microglial Sphk1/S1P pathway may thus be a potential therapeutic target to control neuroinflammation in brain IR.
Collapse
|
34
|
Pyne S, Adams DR, Pyne NJ. Sphingosine 1-phosphate and sphingosine kinases in health and disease: Recent advances. Prog Lipid Res 2016; 62:93-106. [PMID: 26970273 DOI: 10.1016/j.plipres.2016.03.001] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/07/2016] [Accepted: 03/08/2016] [Indexed: 12/24/2022]
Abstract
Sphingosine kinases (isoforms SK1 and SK2) catalyse the formation of a bioactive lipid, sphingosine 1-phosphate (S1P). S1P is a well-established ligand of a family of five S1P-specific G protein coupled receptors but also has intracellular signalling roles. There is substantial evidence to support a role for sphingosine kinases and S1P in health and disease. This review summarises recent advances in the area in relation to receptor-mediated signalling by S1P and novel intracellular targets of this lipid. New evidence for a role of each sphingosine kinase isoform in cancer, the cardiovascular system, central nervous system, inflammation and diabetes is discussed. There is continued research to develop isoform selective SK inhibitors, summarised here. Analysis of the crystal structure of SK1 with the SK1-selective inhibitor, PF-543, is used to identify residues that could be exploited to improve selectivity in SK inhibitor development for future therapeutic application.
Collapse
Affiliation(s)
- Susan Pyne
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral St, Glasgow, G4 0RE, Scotland, UK.
| | - David R Adams
- School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, Scotland, UK.
| | - Nigel J Pyne
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral St, Glasgow, G4 0RE, Scotland, UK.
| |
Collapse
|
35
|
Yang Y, Torta F, Arai K, Wenk MR, Herr DR, Wong PTH, Lai MKP. Sphingosine kinase inhibition ameliorates chronic hypoperfusion-induced white matter lesions. Neurochem Int 2016; 94:90-7. [PMID: 26921668 DOI: 10.1016/j.neuint.2016.02.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 02/18/2016] [Accepted: 02/22/2016] [Indexed: 12/17/2022]
Abstract
White matter lesions (WML) are thought to contribute to vascular cognitive impairment in elderly patients. Growing evidence show that failure of myelin formation arising from the disruption of oligodendrocyte progenitor cell (OPC) differentiation is a cause of chronic vascular white matter damage. The sphingosine kinase (SphK)/sphingosine-1-phosphate (S1P) signaling pathway regulates oligodendroglia differentiation and function, and is known to be altered in hypoxia. In this study, we measured SphK, S1P as well as markers of WML, hypoxia and OPC (NG2) in a mouse bilateral carotid artery stenosis (BCAS) model of chronic cerebral hypoperfusion. Our results indicated that BCAS induced hypoxia inducible factor (HIF)-1α, Sphk2, S1P, and NG2 up-regulation together with accumulation of WML. In contrast, BCAS mice treated with the SphK inhibitor, SKI-II, showed partial reversal of SphK2, S1P and NG2 elevation and amelioration of WML. In an in vitro model of hypoxia, SKI-II reversed the suppression of OPC differentiation. Our study suggests a mechanism for hypoperfusion-associated WML involving HIF-1α-SphK2-S1P-mediated disruption of OPC differentiation, and proposes the SphK signaling pathway as a potential therapeutic target for white matter disease.
Collapse
Affiliation(s)
- Ying Yang
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore
| | - Federico Torta
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore
| | - Ken Arai
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Markus R Wenk
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore; Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore
| | - Deron R Herr
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore
| | - Peter T-H Wong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore.
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore.
| |
Collapse
|
36
|
Ingberg E, Dock H, Theodorsson E, Theodorsson A, Ström JO. Method parameters' impact on mortality and variability in mouse stroke experiments: a meta-analysis. Sci Rep 2016; 6:21086. [PMID: 26876353 PMCID: PMC4753409 DOI: 10.1038/srep21086] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/13/2016] [Indexed: 12/17/2022] Open
Abstract
Although hundreds of promising substances have been tested in clinical trials,
thrombolysis currently remains the only specific pharmacological treatment for
ischemic stroke. Poor quality, e.g. low statistical power, in the preclinical
studies has been suggested to play an important role in these failures. Therefore,
it would be attractive to use animal models optimized to minimize unnecessary
mortality and outcome variability, or at least to be able to power studies more
exactly by predicting variability and mortality given a certain experimental setup.
The possible combinations of methodological parameters are innumerous, and an
experimental comparison of them all is therefore not feasible. As an alternative
approach, we extracted data from 334 experimental mouse stroke articles and, using a
hypothesis-driven meta-analysis, investigated the method parameters’
impact on infarct size variability and mortality. The use of Swiss and C57BL6 mice
as well as permanent occlusion of the middle cerebral artery rendered the lowest
variability of the infarct size while the emboli methods increased variability. The
use of Swiss mice increased mortality. Our study offers guidance for researchers
striving to optimize mouse stroke models.
Collapse
Affiliation(s)
- Edvin Ingberg
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden
| | - Hua Dock
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden
| | - Elvar Theodorsson
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden
| | - Annette Theodorsson
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden.,Division of Neuro and Inflammation Science, Department of Clinical and Experimental Medicine, Linköping University, Department of Neurosurgery, Anaesthetics, Operations and Specialty Surgery Center, Region Östergötland, Sweden
| | - Jakob O Ström
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Linköping University, Department of Clinical Chemistry, Center for Diagnostics, Region Östergötland, Sweden.,Vårdvetenskapligt Forskningscentrum/Centre for Health Sciences, Örebro University Hospital, County Council of Örebro, Örebro, Sweden.,School of Health and Medical Sciences, Örebro University, Örebro, Sweden
| |
Collapse
|
37
|
Affiliation(s)
- Bhakta Prasad Gaire
- Department of Pharmacology, College of Pharmacy, and Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon 406-799, Republic of Korea
| |
Collapse
|
38
|
Lin JJ, Chang T, Cai WK, Zhang Z, Yang YX, Sun C, Li ZY, Li WX. Post-injury administration of allicin attenuates ischemic brain injury through sphingosine kinase 2: In vivo and in vitro studies. Neurochem Int 2015; 89:92-100. [DOI: 10.1016/j.neuint.2015.07.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 07/22/2015] [Accepted: 07/24/2015] [Indexed: 01/24/2023]
|
39
|
Thushara Vijayakumar N, Sangwan A, Sharma B, Majid A, Rajanikant GK. Cerebral Ischemic Preconditioning: the Road So Far…. Mol Neurobiol 2015; 53:2579-93. [PMID: 26081149 DOI: 10.1007/s12035-015-9278-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 06/02/2015] [Indexed: 12/25/2022]
Abstract
Cerebral preconditioning constitutes the brain's adaptation to lethal ischemia when first exposed to mild doses of a subtoxic stressor. The phenomenon of preconditioning has been largely studied in the heart, and data from in vivo and in vitro models from past 2-3 decades have provided sufficient evidence that similar machinery exists in the brain as well. Since preconditioning results in a transient protective phenotype labeled as ischemic tolerance, it can open many doors in the medical warfare against stroke, a debilitating cerebrovascular disorder that kills or cripples thousands of people worldwide every year. Preconditioning can be induced by a variety of stimuli from hypoxia to pharmacological anesthetics, and each, in turn, induces tolerance by activating a multitude of proteins, enzymes, receptors, transcription factors, and other biomolecules eventually leading to genomic reprogramming. The intracellular signaling pathways and molecular cascades behind preconditioning are extensively being investigated, and several first-rate papers have come out in the last few years centered on the topic of cerebral ischemic tolerance. However, translating the experimental knowledge into the clinical scaffold still evades practicality and faces several challenges. Of the various preconditioning strategies, remote ischemic preconditioning and pharmacological preconditioning appears to be more clinically relevant for the management of ischemic stroke. In this review, we discuss current developments in the field of cerebral preconditioning and then examine the potential of various preconditioning agents to confer neuroprotection in the brain.
Collapse
Affiliation(s)
- N Thushara Vijayakumar
- School of Biotechnology, DBT-Centre for Bioinformatics, National Institute of Technology Calicut, Calicut, 673601, India
| | - Amit Sangwan
- School of Biotechnology, DBT-Centre for Bioinformatics, National Institute of Technology Calicut, Calicut, 673601, India
| | - Bhargy Sharma
- School of Biotechnology, DBT-Centre for Bioinformatics, National Institute of Technology Calicut, Calicut, 673601, India
| | - Arshad Majid
- Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - G K Rajanikant
- School of Biotechnology, DBT-Centre for Bioinformatics, National Institute of Technology Calicut, Calicut, 673601, India.
| |
Collapse
|
40
|
The divergent roles of autophagy in ischemia and preconditioning. Acta Pharmacol Sin 2015; 36:411-20. [PMID: 25832421 PMCID: PMC4387298 DOI: 10.1038/aps.2014.151] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 12/20/2014] [Indexed: 12/11/2022] Open
Abstract
Autophagy is an evolutionarily conserved and lysosome-dependent process for degrading and recycling cellular constituents. Autophagy is activated following an ischemic insult or preconditioning, but it may exert dual roles in cell death or survival during these two processes. Preconditioning or lethal ischemia may trigger autophagy via multiple signaling pathways involving endoplasmic reticulum (ER) stress, AMPK/TSC/mTOR, Beclin 1/BNIP3/SPK2, and FoxO/NF-κB transcription factors, etc. Autophagy then interacts with apoptotic and necrotic signaling pathways to regulate cell death. Autophagy may also maintain cell function by removing protein aggregates or damaged mitochondria. To date, the dual roles of autophagy in ischemia and preconditioning have not been fully clarified. The purpose of the present review is to summarize the recent progress in the mechanisms underlying autophagy activation during ischemia and preconditioning. A better understanding of the dual effects of autophagy in ischemia and preconditioning could help to develop new strategies for the preventive treatment of ischemia.
Collapse
|
41
|
Zheng S, Wei S, Wang X, Xu Y, Xiao Y, Liu H, Jia J, Cheng J. Sphingosine kinase 1 mediates neuroinflammation following cerebral ischemia. Exp Neurol 2015; 272:160-9. [PMID: 25797575 DOI: 10.1016/j.expneurol.2015.03.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/10/2015] [Accepted: 03/13/2015] [Indexed: 11/18/2022]
Abstract
Sphingosine kinases (Sphks) are the rate-limiting kinases in the generation of sphingosine-1-phosphate, which is a well-established intracellular pro-survival lipid mediator. Sphk2 has been reported to be protective following experimental stroke. We investigated the role of Sphk1 in cerebral ischemia using a mouse middle cerebral artery occlusion (MCAO) model and an in vitro glucose-oxygen deprivation (OGD) model. Sphk expression and activity were assessed in the ischemic brain with quantitative PCR (qPCR), Western blot, immunohistochemistry and enzyme-linked immunosorbent assay (ELISA). Pharmacological and gene knockdown approaches were utilized to investigate the effects of Sphk1 on stroke outcomes. The expression of Sphk1 but not that of Sphk2 was rapidly induced in the cortical penumbra over 96h after MCAO, and the microglia were one of the major cellular sources of Sphk1 induction. Consistently, Sphk activity was enhanced in the cortical penumbra. In contrast to the protective role of Sphk2, pharmacological inhibition and cortical knockdown of Sphk1 reduced infarction at 24 and 96h after reperfusion. Additionally, the Sphk1 inhibitor improved the neurological deficits at 96h after reperfusion. Mechanistically, Sphk1 inhibition and knockdown significantly attenuated MCAO-induced expression of inflammatory mediators in the cortical penumbra. Moreover, using a conditioned medium transfer approach, we demonstrated that OGD-treated neurons induced the expression of Sphk1 and pro-inflammatory mediators in primary microglia, and the microglial induction of pro-inflammatory mediators by ischemic neurons was blunted by Sphk1 inhibition. Taken together, our results indicate that Sphk1 plays an essential role in mediating post-stroke neuroinflammation.
Collapse
Affiliation(s)
- Shuli Zheng
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, China; Department of Skin & Cosmetic Research, Shanghai Skin Disease Hospital, Shanghai, China
| | - Shanwen Wei
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Xiaoyu Wang
- College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Yingxiu Xu
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Yunqi Xiao
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Hui Liu
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Jia Jia
- College of Pharmaceutical Sciences, Soochow University, Suzhou, China.
| | - Jian Cheng
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, China.
| |
Collapse
|
42
|
Sheng R, Zhang TT, Felice VD, Qin T, Qin ZH, Smith CD, Sapp E, Difiglia M, Waeber C. Preconditioning stimuli induce autophagy via sphingosine kinase 2 in mouse cortical neurons. J Biol Chem 2015; 289:20845-57. [PMID: 24928515 DOI: 10.1074/jbc.m114.578120] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sphingosine kinase 2 (SPK2) and autophagy are both involved in brain preconditioning, but whether preconditioning-induced SPK2 up-regulation and autophagy activation are linked mechanistically remains to be elucidated. In this study, we used in vitro and in vivo models to explore the role of SPK2-mediated autophagy in isoflurane and hypoxic preconditioning. In primary mouse cortical neurons, both isoflurane and hypoxic preconditioning induced autophagy. Isoflurane and hypoxic preconditioning protected against subsequent oxygen glucose deprivation or glutamate injury, whereas pretreatment with autophagy inhibitors (3-methyladenine or KU55933) abolished preconditioning-induced tolerance. Pretreatment with SPK2 inhibitors (ABC294640 and SKI-II) or SPK2 knockdown prevented preconditioning-induced autophagy. Isoflurane also induced autophagy in mouse in vivo as shown by Western blots for LC3 and p62, LC3 immunostaining, and electron microscopy. Isoflurane-induced autophagy in mice lacking the SPK1 isoform (SPK1(-/-)), but not in SPK2(-/-)mice. Sphingosine 1-phosphate and the sphingosine 1-phosphate receptor agonist FTY720 did not protect against oxygen glucose deprivation in cultured neurons and did not alter the expression of LC3 and p62, suggesting that SPK2-mediated autophagy and protections are not S1P-dependent. Beclin 1 knockdown abolished preconditioning-induced autophagy, and SPK2 inhibitors abolished isoflurane-induced disruption of the Beclin 1/Bcl-2 association. These results strongly indicate that autophagy is involved in isoflurane preconditioning both in vivo and in vitro and that SPK2 contributes to preconditioning-induced autophagy, possibly by disrupting the Beclin 1/Bcl-2 interaction.
Collapse
|
43
|
Testai FD, Xu HL, Kilkus J, Suryadevara V, Gorshkova I, Berdyshev E, Pelligrino DA, Dawson G. Changes in the metabolism of sphingolipids after subarachnoid hemorrhage. J Neurosci Res 2015; 93:796-805. [PMID: 25597763 DOI: 10.1002/jnr.23542] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 11/19/2014] [Accepted: 11/20/2014] [Indexed: 12/31/2022]
Abstract
We previously described how ceramide (Cer), a mediator of cell death, increases in the cerebrospinal fluid (CSF) of subarachnoid hemorrhage (SAH) patients. This study investigates the alterations of biochemical pathways involved in Cer homeostasis in SAH. Cer, dihydroceramide (DHC), sphingosine-1-phosphate (S1P), and the activities of acid sphingomyelinase (ASMase), neutral sphingomyelinase (NSMase), sphingomyelinase synthase (SMS), S1P-lyase, and glucosylceramide synthase (GCS) were determined in the CSF of SAH subjects and in brain homogenate of SAH rats. Compared with controls (n = 8), SAH patients (n = 26) had higher ASMase activity (10.0 ± 3.5 IF/µl· min vs. 15.0 ± 4.6 IF/µl • min; P = 0.009) and elevated levels of Cer (11.4 ± 8.8 pmol/ml vs. 33.3 ± 48.3 pmol/ml; P = 0.001) and DHC (1.3 ± 1.1 pmol/ml vs. 3.8 ± 3.4 pmol/ml; P = 0.001) in the CSF. The activities of GCS, NSMase, and SMS in the CSF were undetectable. Brain homogenates from SAH animals had increased ASMase activity (control: 9.7 ± 1.2 IF/µg • min; SAH: 16.8 ± 1.6 IF/µg • min; P < 0.05) and Cer levels (control: 3,422 ± 26 fmol/nmol of total lipid P; SAH: 7,073 ± 2,467 fmol/nmol of total lipid P; P < 0.05) compared with controls. In addition, SAH was associated with a reduction of 60% in S1P levels, a 40% increase in S1P-lyase activity, and a twofold increase in the activity of GCS. In comparison, NSMase and SMS activities were similar to controls and SMS activities similar to controls. In conclusion, our results show an activation of ASMase, S1P-lyase, and GCS resulting in a shift in the production of protective (S1P) in favor of deleterious (Cer) sphingolipids after SAH. Additional studies are needed to determine the effect of modulators of the pathways described here in SAH.
Collapse
Affiliation(s)
- Fernando D Testai
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, Illinois
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Brunkhorst R, Vutukuri R, Pfeilschifter W. Fingolimod for the treatment of neurological diseases-state of play and future perspectives. Front Cell Neurosci 2014; 8:283. [PMID: 25309325 PMCID: PMC4162362 DOI: 10.3389/fncel.2014.00283] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 08/25/2014] [Indexed: 11/25/2022] Open
Abstract
Sphingolipids are a fascinating class of signaling molecules derived from the membrane lipid sphingomyelin. They show abundant expression in the brain. Complex sphingolipids such as glycosphingolipids (gangliosides and cerebrosides) regulate vesicular transport and lysosomal degradation and their dysregulation can lead to storage diseases with a neurological phenotype. More recently, simple sphingolipids such ceramide, sphingosine and sphingosine 1-phosphate (S1P) were discovered to signal in response to many extracellular stimuli. Forming an intricate signaling network, the balance of these readily interchangeable mediators is decisive for cell fate under stressful conditions. The immunomodulator fingolimod is the prodrug of an S1P receptor agonist. Following receptor activation, the drug leads to downregulation of the S1P1 receptor inducing functional antagonism. As the first drug to modulate the sphingolipid signaling pathway, it was marketed in 2010 for the treatment of multiple sclerosis (MS). At that time, immunomodulation was widely accepted as the key mechanism of fingolimod’s efficacy in MS. But given the excellent passage of this lipophilic compound into the brain and its massive brain accumulation as well as the abundant expression of S1P receptors on brain cells, it is conceivable that fingolimod also affects brain cells directly. Indeed, a seminal study showed that the protective effect of fingolimod in experimental autoimmune encephalitis (EAE), a murine MS model, is lost in mice lacking the S1P1 receptor on astrocytes, arguing for a specific role of astrocytic S1P signaling in MS. In this review, we discuss the role of sphingolipid mediators and their metabolizing enzymes in neurologic diseases and putative therapeutic strategies arising thereof.
Collapse
Affiliation(s)
- Robert Brunkhorst
- Cerebrovascular Research Group, Department of Neurology, Frankfurt University Hospital Frankfurt am Main, Germany
| | - Rajkumar Vutukuri
- Institute of General Pharmacology and Toxicology, pharmazentrum frankfurt, Goethe University Frankfurt Frankfurt am Main, Germany
| | - Waltraud Pfeilschifter
- Cerebrovascular Research Group, Department of Neurology, Frankfurt University Hospital Frankfurt am Main, Germany
| |
Collapse
|
45
|
Abstract
Diverse preconditioning (PC) stimuli protect against a wide variety of neuronal insults in animal models, engendering enthusiasm that PC could be used to protect the brain clinically. Candidate clinical applications include cardiac and vascular surgery, after subarachnoid hemorrhage, and prior to conditions in which acute neuronal injury is anticipated. However, disappointments in clinical validation of multiple neuroprotectants suggest potential problems translating animal data into successful human therapies. Thus, despite strong promise of preclinical PC studies, caution should be maintained in translating these findings into clinical applications. The Stroke Therapy Academic Industry Roundtable (STAIR) working group and the National institute of Neurological Diseases and Stroke (NINDS) proposed working guidelines to improve the utility of preclinical studies that form the foundation of therapies for neurological disease. Here, we review the applicability of these consensus criteria to preconditioning studies and discuss additional considerations for PC studies. We propose that special attention should be paid to several areas, including 1) safety and dosage of PC treatments; 2) meticulously matching preclinical modeling to the human condition to be tested; and 3) timing of both the initiation and discontinuation of the PC stimulus relative to injury ictus.
Collapse
Affiliation(s)
- Michael M Wang
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA ; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA ; Neurology Service, VA Ann Arbor Healthcare System, Ann Arbor, Michigan USA
| | | | | |
Collapse
|
46
|
Bae M, Bandaru VVR, Patel N, Haughey NJ. Ceramide metabolism analysis in a model of binge drinking reveals both neuroprotective and toxic effects of ethanol. J Neurochem 2014; 131:645-54. [PMID: 25060779 DOI: 10.1111/jnc.12834] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 06/25/2014] [Accepted: 06/27/2014] [Indexed: 01/05/2023]
Abstract
Binge drinking is a common form of alcohol abuse that involves repeated rounds of intoxication followed by withdrawal. The episodic effects of binge drinking and withdrawal on brain resident cells are thought to contribute to neural remodeling and neurological damage. However, the molecular mechanisms for these neurodegenerative effects are not understood. Ethanol (EtOH) regulates the metabolism of ceramide, a highly bioactive lipid that is enriched in brain. We used a mouse model of binge drinking to determine the effects of EtOH intoxication and withdrawal on brain ceramide metabolism. Intoxication and acute alcohol withdrawal were each associated with distinct changes in ceramide regulatory genes and metabolic products. EtOH intoxication was accompanied by decreased concentrations of multiple ceramides, coincident with reductions in the expression of enzymes involved in the production of ceramides, and increased expression of ceramide-degrading enzymes. EtOH withdrawal was associated with specific increases in ceramide C16:0, C18:0, and C20:0 and increased expression of enzymes involved with ceramide production. These data suggest that EtOH intoxication may evoke a ceramide phenotype that is neuroprotective, whereas EtOH withdrawal results in a metabolic shift that increases the production of potentially toxic ceramide species.
Collapse
Affiliation(s)
- Mihyun Bae
- Richard T. Johnson Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | | | | |
Collapse
|
47
|
Leitzke AS, Rolland WB, Krafft PR, Lekic T, Klebe D, Flores JJ, Van Allen NR, Applegate RL, Zhang JH. Isoflurane post-treatment ameliorates GMH-induced brain injury in neonatal rats. Stroke 2013; 44:3587-90. [PMID: 24149004 DOI: 10.1161/strokeaha.113.001988] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE This study investigated whether isoflurane ameliorates neurological sequelae after germinal matrix hemorrhage (GMH) through activation of the cytoprotective sphingosine kinase/sphingosine-1-phosphate receptor/Akt pathway. METHODS GMH was induced in P7 rat pups by intraparenchymal infusion of bacterial collagenase (0.3 U) into the right hemispheric germinal matrix. GMH animals received 2% isoflurane either once 1 hour after surgery or every 12 hours for 3 days. Isoflurane treatment was then combined with sphingosine-1-phosphate receptor-1/2 antagonist VPC23019 or sphingosine kinase 1/2 antagonist N,N-dimethylsphingosine. RESULTS Brain protein expression of sphingosine kinase-1 and phosphorylated Akt were significantly increased after isoflurane post-treatment, and cleaved caspase-3 was decreased at 24 hours after surgery, which was reversed by the antagonists. Isoflurane significantly reduced posthemorrhagic ventricular dilation and improved motor, but not cognitive, functions in GMH animals 3 weeks after surgery; no improvements were observed after VPC23019 administration. CONCLUSIONS Isoflurane post-treatment improved the neurological sequelae after GMH possibly by activation of the sphingosine kinase/Akt pathway.
Collapse
Affiliation(s)
- Arthur S Leitzke
- From the Department of Physiology and Pharmacology (A.S.L., W.B.R., P.R.K., T.L., D.K., J.J.F., N.R.V.A., J.H.Z.), and Department of Anesthesiology (A.S.L., R.L.A., J.H.Z.), Loma Linda University School of Medicine, CA
| | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Adada MM, Orr-Gandy KA, Snider AJ, Canals D, Hannun YA, Obeid LM, Clarke CJ. Sphingosine kinase 1 regulates tumor necrosis factor-mediated RANTES induction through p38 mitogen-activated protein kinase but independently of nuclear factor κB activation. J Biol Chem 2013; 288:27667-27679. [PMID: 23935096 DOI: 10.1074/jbc.m113.489443] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sphingosine kinase 1 (SK1) produces the pro-survival sphingolipid sphingosine 1-phosphate and has been implicated in inflammation, proliferation, and angiogenesis. Recent studies identified TRAF2 as a sphingosine 1-phosphate target, implicating SK1 in activation of the NF-κB pathway, but the functional consequences of this connection on gene expression are unknown. Here, we find that loss of SK1 potentiates induction of the chemokine RANTES (regulated on activation, normal T cell expressed and secreted; also known as CCL5) in HeLa cells stimulated with TNF-α despite RANTES induction being highly dependent on the NF-κB pathway. Additionally, we find that SK1 is not required for TNF-induced IKK phosphorylation, IκB degradation, nuclear translocation of NF-κB subunits, and transcriptional NF-κB activity. In contrast, loss of SK1 prevented TNF-induced phosphorylation of p38 MAPK, and inhibition of p38 MAPK, like SK1 knockdown, also potentiates RANTES induction. Finally, in addition to RANTES, loss of SK1 also potentiated the induction of multiple chemokines and cytokines in the TNF response. Taken together, these data identify a potential and novel anti-inflammatory function of SK1 in which chemokine levels are suppressed through SK1-mediated activation of p38 MAPK. Furthermore, in this system, activation of NF-κB is dissociated from SK1, suggesting that the interaction between these pathways may be more complex than currently thought.
Collapse
Affiliation(s)
- Mohamad M Adada
- Department of Medicine, Stony Brook University, Stony Brook, New York 11794
| | - K Alexa Orr-Gandy
- Department of Pathology, Microbiology and Immunology, University of South Carolina, School of Medicine, Columbia, South Carolina 29209
| | - Ashley J Snider
- Department of Medicine, Stony Brook University, Stony Brook, New York 11794; Northport Veterans Affairs Medical Center, Northport, New York 11768
| | - Daniel Canals
- Department of Medicine, Stony Brook University, Stony Brook, New York 11794
| | - Yusuf A Hannun
- Department of Medicine, Stony Brook University, Stony Brook, New York 11794
| | - Lina M Obeid
- Department of Medicine, Stony Brook University, Stony Brook, New York 11794; Northport Veterans Affairs Medical Center, Northport, New York 11768.
| | | |
Collapse
|
49
|
Della-Morte D, Guadagni F, Palmirotta R, Ferroni P, Testa G, Cacciatore F, Abete P, Rengo F, Perez-Pinzon MA, Sacco RL, Rundek T. Genetics and genomics of ischemic tolerance: focus on cardiac and cerebral ischemic preconditioning. Pharmacogenomics 2013; 13:1741-57. [PMID: 23171338 DOI: 10.2217/pgs.12.157] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
A subthreshold ischemic insult applied to an organ such as the heart and/or brain may help to reduce damage caused by subsequent ischemic episodes. This phenomenon is known as ischemic tolerance mediated by ischemic preconditioning (IPC) and represents the most powerful endogenous mechanism against ischemic injury. Various molecular pathways have been implicated in IPC, and several compounds have been proposed as activators or mediators of IPC. Recently, it has been established that the protective phenotype in response to ischemia depends on a coordinated response at the genomic, molecular, cellular and tissue levels by introducing the concept of 'genomic reprogramming' following IPC. In this article, we sought to review the genetic expression profiles found in cardiac and cerebral IPC studies, describe the differences between young and aged organs in IPC-mediated protection, and discuss the potential therapeutic application of IPC and pharmacological preconditioning based on the genomic response.
Collapse
Affiliation(s)
- David Della-Morte
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Neubauer HA, Pitson SM. Roles, regulation and inhibitors of sphingosine kinase 2. FEBS J 2013; 280:5317-36. [PMID: 23638983 DOI: 10.1111/febs.12314] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 04/29/2013] [Accepted: 04/29/2013] [Indexed: 12/19/2022]
Abstract
The bioactive sphingolipids ceramide, sphingosine and sphingosine-1-phosphate (S1P) are important signalling molecules that regulate a diverse array of cellular processes. Most notably, the balance of the levels of these three sphingolipids in cells, termed the 'sphingolipid rheostat', can dictate cell fate, where ceramide and sphingosine enhance apoptosis and S1P promotes cell survival and proliferation. The sphingosine kinases (SKs) catalyse the production of S1P from sphingosine and are therefore central regulators of the sphingolipid rheostat and attractive targets for cancer therapy. Two SKs exist in humans: SK1 and SK2. SK1 has been extensively studied and there is a large body of evidence to demonstrate its role in promoting cell survival, proliferation and neoplastic transformation. SK1 is also elevated in many human cancers which appears to contribute to carcinogenesis, chemotherapeutic resistance and poor patient outcome. SK2, however, has not been as well characterized, and there are contradictions in the key physiological functions that have been proposed for this isoform. Despite this, many studies are now emerging that implicate SK2 in key roles in a variety of diseases, including the development of a range of solid tumours. Here, we review the literature examining SK2, its physiological and pathophysiological functions, the current knowledge of its regulation, and recent developments in targeting this complex enzyme.
Collapse
Affiliation(s)
- Heidi A Neubauer
- Centre for Cancer Biology, SA Pathology, Adelaide, Australia; School of Molecular and Biomedical Science, University of Adelaide, Australia
| | | |
Collapse
|