1
|
Liu DQ, Mei W, Zhou YQ, Xi H. Targeting TRPM channels for cerebral ischemia-reperfusion injury. Trends Pharmacol Sci 2024; 45:862-867. [PMID: 39019763 DOI: 10.1016/j.tips.2024.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 06/06/2024] [Accepted: 06/24/2024] [Indexed: 07/19/2024]
Abstract
Transient receptor potential melastatin (TRPM) channels have emerged as potential therapeutic targets for cerebral ischemia-reperfusion (I/R) injury. We highlight recent findings on the involvement of TRPM channels in oxidative stress, mitochondrial dysfunction, inflammation, and calcium overload. We also discuss the challenges and future directions in targeting TRPM channels for cerebral I/R injury.
Collapse
Affiliation(s)
- Dai-Qiang Liu
- Department of Anesthesiology and Pain Medicine, Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, and Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wei Mei
- Department of Anesthesiology and Pain Medicine, Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, and Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Ya-Qun Zhou
- Department of Anesthesiology and Pain Medicine, Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, and Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Hong Xi
- Department of Anesthesiology, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, 030032, China.
| |
Collapse
|
2
|
Zong P, Li CX, Feng J, Cicchetti M, Yue L. TRP Channels in Stroke. Neurosci Bull 2024; 40:1141-1159. [PMID: 37995056 PMCID: PMC11306852 DOI: 10.1007/s12264-023-01151-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/11/2023] [Indexed: 11/24/2023] Open
Abstract
Ischemic stroke is a devastating disease that affects millions of patients worldwide. Unfortunately, there are no effective medications for mitigating brain injury after ischemic stroke. TRP channels are evolutionally ancient biosensors that detect external stimuli as well as tissue or cellular injury. To date, many members of the TRP superfamily have been reported to contribute to ischemic brain injury, including the TRPC subfamily (1, 3, 4, 5, 6, 7), TRPV subfamily (1, 2, 3, 4) and TRPM subfamily (2, 4, 7). These TRP channels share structural similarities but have distinct channel functions and properties. Their activation during ischemic stroke can be beneficial, detrimental, or even both. In this review, we focus on discussing the interesting features of stroke-related TRP channels and summarizing the underlying cellular and molecular mechanisms responsible for their involvement in ischemic brain injury.
Collapse
Affiliation(s)
- Pengyu Zong
- Department of Cell Biology, Calhoun Cardiology Center, School of Medicine (UConn Health), University of Connecticut, Farmington, CT, 06030, USA.
- Institute for the Brain and Cognitive Sciences, University of Connecticut, 337 Mansfield Road, Unit 1272, Storrs, CT, 06269, USA.
| | - Cindy X Li
- Department of Cell Biology, Calhoun Cardiology Center, School of Medicine (UConn Health), University of Connecticut, Farmington, CT, 06030, USA
| | - Jianlin Feng
- Department of Cell Biology, Calhoun Cardiology Center, School of Medicine (UConn Health), University of Connecticut, Farmington, CT, 06030, USA
| | - Mara Cicchetti
- Department of Cell Biology, Calhoun Cardiology Center, School of Medicine (UConn Health), University of Connecticut, Farmington, CT, 06030, USA
- Department of Neuroscience, University of Pittsburgh, 4200 Fifth Ave, Pittsburgh, PA, 15260, USA
| | - Lixia Yue
- Department of Cell Biology, Calhoun Cardiology Center, School of Medicine (UConn Health), University of Connecticut, Farmington, CT, 06030, USA.
| |
Collapse
|
3
|
Huang P, Qu C, Rao Z, Wu D, Zhao J. Bidirectional regulation mechanism of TRPM2 channel: role in oxidative stress, inflammation and ischemia-reperfusion injury. Front Immunol 2024; 15:1391355. [PMID: 39007141 PMCID: PMC11239348 DOI: 10.3389/fimmu.2024.1391355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Accepted: 06/17/2024] [Indexed: 07/16/2024] Open
Abstract
Transient receptor potential melastatin 2 (TRPM2) is a non-selective cation channel that exhibits Ca2+ permeability. The TRPM2 channel is expressed in various tissues and cells and can be activated by multiple factors, including endogenous ligands, Ca2+, reactive oxygen species (ROS) and temperature. This article reviews the multiple roles of the TRPM2 channel in physiological and pathological processes, particularly on oxidative stress, inflammation and ischemia-reperfusion (I/R) injury. In oxidative stress, the excessive influx of Ca2+ caused by the activation of the TRPM2 channel may exacerbate cellular damage. However, under specific conditions, activating the TRPM2 channel can have a protective effect on cells. In inflammation, the activation of the TRPM2 channel may not only promote inflammatory response but also inhibit inflammation by regulating ROS production and bactericidal ability of macrophages and neutrophils. In I/R, the activation of the TRPM2 channel may worsen I/R injury to various organs, including the brain, heart, kidney and liver. However, activating the TRPM2 channel may protect the myocardium from I/R injury by regulating calcium influx and phosphorylating proline-rich tyrosine kinase 2 (Pyk2). A thorough investigation of the bidirectional role and regulatory mechanism of the TRPM2 channel in these physiological and pathological processes will aid in identifying new targets and strategies for treatment of related diseases.
Collapse
Affiliation(s)
- Peng Huang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- Exercise Biological Center, China Institute of Sport Science, Beijing, China
| | - Chaoyi Qu
- Physical Education College, Hebei Normal University, Shijiazhuang, China
| | - Zhijian Rao
- Exercise Biological Center, China Institute of Sport Science, Beijing, China
- College of Physical Education, Shanghai Normal University, Shanghai, China
| | - Dongzhe Wu
- Exercise Biological Center, China Institute of Sport Science, Beijing, China
- Department of Exercise Physiology, Beijing Sport University, Beijing, China
| | - Jiexiu Zhao
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- Exercise Biological Center, China Institute of Sport Science, Beijing, China
| |
Collapse
|
4
|
Sun M, Weng Y, Cheng J, Li G, Xiao Q. Higher baseline serum bilirubin levels are associated with increased risk of early neurological deterioration in women with acute ischemic stroke. Front Neurol 2024; 15:1381055. [PMID: 38651104 PMCID: PMC11033363 DOI: 10.3389/fneur.2024.1381055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/22/2024] [Indexed: 04/25/2024] Open
Abstract
Background and objectives Early neurological deterioration (END) occurs in up to one-third of patients with acute ischemic stroke (AIS) and associated with poor outcome. The role of serum bilirubin in END remains controversial. This study aims to investigate the association of total bilirubin (TBIL), direct bilirubin (DBIL) and indirect bilirubin (IBIL) with END. Methods This study was a cross-sectional retrospective study with 344 AIS patients enrolled. We retrospectively reviewed consecutive AIS patients with END through a medical record retrieval system and enrolled patients as control randomly from the AIS patients without END at the same period. The bilirubin levels were compared between the END group and No END group. The correlations of bilirubin with END were assessed according to the bilirubin tertiles on the cohort of different genders. Results In women, as the bilirubin level increased, the occurrence of END showed an increasing trend. The linear association was significant based on the tertiles of all bilirubin types (TBIL p = 0.003; DBIL p = 0.025; IBIL p = 0.025), while in men no similar trend was observed. After adjustment for confounders, higher TBIL (p for trend 0.009) and DBIL (p for trend 0.033) levels were associated with increased risk of END in women. The adjusted OR for T3 relative to T1 was 5.240 (95% CI 1.496-18.347) in TBIL and 3.549 (95% CI 1.089-11.566) in DBIL. Multivariate logistic regression showed that DBIL was independently associated with END in women (OR 1.717, 95% CI 1.106-2.666). The study also found that DBIL was superior to TBIL and IBIL in prediction of END occurrence in women, with greater predictive value. Discussion There were gender differences in the relationship between bilirubin and END, and DBIL level was positively associated with END occurrence in women, not in men. DBIL had greater incremental predictive value for END than TBIL and IBIL.
Collapse
Affiliation(s)
| | | | | | - Guoyi Li
- Department of Neurology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Qian Xiao
- Department of Neurology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| |
Collapse
|
5
|
Yang Y, Wuren T, Wu B, Cheng S, Fan H. The expression of CTLA-4 in hepatic alveolar echinococcosis patients and blocking CTLA-4 to reverse T cell exhaustion in Echinococcus multilocularis-infected mice. Front Immunol 2024; 15:1358361. [PMID: 38605966 PMCID: PMC11007148 DOI: 10.3389/fimmu.2024.1358361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 03/11/2024] [Indexed: 04/13/2024] Open
Abstract
Alveolar echinococcosis (AE) is a zoonotic parasitic disease caused by the infection of Echinococcus multilocularis (E. multilocularis) larvae. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) produces inhibitory signals and induces T cell exhaustion, thereby inhibiting the parasiticidal efficacy of the liver immune system. Therefore, the purpose of this study is to explore how T-cell exhaustion contributes to AE and whether blocking CTLA-4 could reverse T cell exhaustion. Here we discovered that the expression of CTLA-4 was increased in the infiltrating margin around the lesion of the liver from AE patients by using western blot and immunohistochemistry assay. Multiple fluorescence immunohistochemistry identified that CTLA-4 and CD4/CD8 molecules were co-localized. For in vitro experiments, it was found that the sustained stimulation of E. multilocularis antigen could induce T cell exhaustion, blocking CTLA-4-reversed T cell exhaustion. For in vivo experiments, the expression of CTLA-4 was increased in the liver of E. multilocularis-infected mice, and the CTLA-4 and CD4/CD8 molecules were co-localized. Flow cytometry analysis demonstrated that the percentages of both CD4+ T cells and CD8+ T cells in the liver and peripheral blood were significantly increased and induced T exhaustion. When the mice were treated with anti-CTLA-4 antibodies, the number and weight of the lesions decreased significantly. Meanwhile, the flow cytometry results suggested that blocking CTLA-4 could effectively reverse T cell exhaustion and reactivate immune function. Our work reveals that blocking CTLA-4 could effectively reverse the T cell exhaustion caused by E. multilocularis and could be used as a novel target for the treatment of AE.
Collapse
Affiliation(s)
- Yuxuan Yang
- Research Center for High Altitude Medicine, Qinghai University, Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Laboratory for High Altitude Medicine of Qinghai Province, Xining, Qinghai, China
- Qinghai Research Key Laboratory for Echinococcosis, Qinghai University, Xining, Qinghai, China
| | - Tana Wuren
- Research Center for High Altitude Medicine, Qinghai University, Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Laboratory for High Altitude Medicine of Qinghai Province, Xining, Qinghai, China
| | - Binjie Wu
- Research Center for High Altitude Medicine, Qinghai University, Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Laboratory for High Altitude Medicine of Qinghai Province, Xining, Qinghai, China
- Qinghai Research Key Laboratory for Echinococcosis, Qinghai University, Xining, Qinghai, China
| | - Shilei Cheng
- Research Center for High Altitude Medicine, Qinghai University, Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Laboratory for High Altitude Medicine of Qinghai Province, Xining, Qinghai, China
- Qinghai Research Key Laboratory for Echinococcosis, Qinghai University, Xining, Qinghai, China
| | - Haining Fan
- Qinghai Research Key Laboratory for Echinococcosis, Qinghai University, Xining, Qinghai, China
- Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Qinghai University, Xining, Qinghai, China
| |
Collapse
|
6
|
Jiayi C, Jinying W, Yanhan Y, Tianyu L, Juanjuan C, Feng Z, Xiaohui F, Jinping Z. Probiotics' effects on gut microbiota in jaundiced neonates: a randomized controlled trial protocol. Front Pediatr 2024; 12:1296517. [PMID: 38523836 PMCID: PMC10957549 DOI: 10.3389/fped.2024.1296517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 01/16/2024] [Indexed: 03/26/2024] Open
Abstract
Introduction Recent evidence suggests that blue-light phototherapy impacts gut microbiota composition in jaundiced newborns, leading to disturbances closely related to the therapy's side effects. As a result, gut microbiota may serve as a potential intervention target to mitigate these side effects. In this study, we aim to examine the effects of AB-GG (Lactobacillus rhamnosus LGG), Bb-12 (Bifidobacterium animalis Bb-12) and M-16V (Bifidobacterium breve M-16V) and their combination on the intestinal microbiota, metabolomics and phototherapy-related side effects in neonates with jaundice. Methods and analysis A total of 100 jaundiced newborns aged two weeks or younger will be included in this randomized, single-blind (the parents knew, but the neonatologists did not know), single-center controlled trial to receive either 109 colony-forming units of AB-GG, Bb-12, M-16V, a combination of the three probiotics with blue-light phototherapy, or blue-light phototherapy alone. The experimental group will be treated with oral probiotics once daily for 30 days, while the control group will receive only blue-light phototherapy. The follow-up duration will last 30 days. The primary outcomes include changes in gut microbiota, metabolomics, and the incidence of phototherapy side effects, assessed after each phototherapy session, as well as on days 10, 20, and 30. Ethics and dissemination The study protocol has been approved by the Ethics Committee of our institution. The findings of this trial will be submitted to a peer-reviewed pediatric journal. Its abstracts will be submitted to relevant national and international conferences. Clinical Trial Registration http://www.chictr.org.cn/index.aspx, identifer (ChiCTR2000036013).
Collapse
Affiliation(s)
- Chen Jiayi
- Pediatrics, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Jinying
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Yuan Yanhan
- Pediatrics, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Liu Tianyu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Chen Juanjuan
- Pediatrics, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhang Feng
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Fang Xiaohui
- Pediatrics, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhang Jinping
- Pediatrics, Shanghai Sixth People’s Hospital, Shanghai, China
| |
Collapse
|
7
|
He M, Xu C, Yang R, Liu L, Zhou D, Yan S. Causal relationship between human blood metabolites and risk of ischemic stroke: a Mendelian randomization study. Front Genet 2024; 15:1333454. [PMID: 38313676 PMCID: PMC10834680 DOI: 10.3389/fgene.2024.1333454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 01/08/2024] [Indexed: 02/06/2024] Open
Abstract
Background: Ischemic stroke (IS) is a major cause of death and disability worldwide. Previous studies have reported associations between metabolic disorders and IS. However, evidence regarding the causal relationship between blood metabolites and IS lacking. Methods: A two-sample Mendelian randomization analysis (MR) was used to assess the causal relationship between 1,400 serum metabolites and IS. The inverse variance-weighted (IVW) method was employed to estimate the causal effect between exposure and outcome. Additionally, MR-Egger regression, weighted median, simple mode, and weighted mode approaches were employed as supplementary comprehensive evaluations of the causal effects between blood metabolites and IS. Tests for pleiotropy and heterogeneity were conducted. Results: After rigorous selection, 23 known and 5 unknown metabolites were identified to be associated with IS. Among the 23 known metabolites, 13 showed significant causal effects with IS based on 2 MR methods, including 5-acetylamino-6-formylamino-3-methyluracil, 1-ribosyl-imidazoleacetate, Behenoylcarnitine (C22), N-acetyltyrosine, and N-acetylputrescine to (N (1) + N (8))-acetate,these five metabolites were positively associated with increased IS risk. Xanthurenate, Glycosyl-N-tricosanoyl-sphingadienine, Orotate, Bilirubin (E,E), Bilirubin degradation product, C17H18N2O, Bilirubin (Z,Z) to androsterone glucuronide, Bilirubin (Z,Z) to etiocholanolone glucuronide, Biliverdin, and Uridine to pseudouridine ratio were associated with decreased IS risk. Conclusion: Among 1,400 blood metabolites, this study identified 23 known metabolites that are significantly associated with IS risk, with 13 being more prominent. The integration of genomics and metabolomics provides important insights for the screening and prevention of IS.
Collapse
Affiliation(s)
- Menghao He
- The First Hospital of Hunan University of Chinese Medicine, Changsha, Hunan, China
- Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Chun Xu
- Changde College of Science and Technology, Changde, Hunan, China
| | - Renyi Yang
- Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Lijuan Liu
- The First Hospital of Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Desheng Zhou
- The First Hospital of Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Siyang Yan
- The First Hospital of Hunan University of Chinese Medicine, Changsha, Hunan, China
| |
Collapse
|
8
|
Okada Y, Numata T, Sabirov RZ, Kashio M, Merzlyak PG, Sato-Numata K. Cell death induction and protection by activation of ubiquitously expressed anion/cation channels. Part 3: the roles and properties of TRPM2 and TRPM7. Front Cell Dev Biol 2023; 11:1246955. [PMID: 37842082 PMCID: PMC10576435 DOI: 10.3389/fcell.2023.1246955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 09/15/2023] [Indexed: 10/17/2023] Open
Abstract
Cell volume regulation (CVR) is a prerequisite for animal cells to survive and fulfill their functions. CVR dysfunction is essentially involved in the induction of cell death. In fact, sustained normotonic cell swelling and shrinkage are associated with necrosis and apoptosis, and thus called the necrotic volume increase (NVI) and the apoptotic volume decrease (AVD), respectively. Since a number of ubiquitously expressed ion channels are involved in the CVR processes, these volume-regulatory ion channels are also implicated in the NVI and AVD events. In Part 1 and Part 2 of this series of review articles, we described the roles of swelling-activated anion channels called VSOR or VRAC and acid-activated anion channels called ASOR or PAC in CVR and cell death processes. Here, Part 3 focuses on therein roles of Ca2+-permeable non-selective TRPM2 and TRPM7 cation channels activated by stress. First, we summarize their phenotypic properties and molecular structure. Second, we describe their roles in CVR. Since cell death induction is tightly coupled to dysfunction of CVR, third, we focus on their participation in the induction of or protection against cell death under oxidative, acidotoxic, excitotoxic, and ischemic conditions. In this regard, we pay attention to the sensitivity of TRPM2 and TRPM7 to a variety of stress as well as to their capability to physicall and functionally interact with other volume-related channels and membrane enzymes. Also, we summarize a large number of reports hitherto published in which TRPM2 and TRPM7 channels are shown to be involved in cell death associated with a variety of diseases or disorders, in some cases as double-edged swords. Lastly, we attempt to describe how TRPM2 and TRPM7 are organized in the ionic mechanisms leading to cell death induction and protection.
Collapse
Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Integrative Physiology, Graduate School of Medicine, AkitaUniversity, Akita, Japan
- Department of Physiology, School of Medicine, Aichi Medical Uniersity, Nagakute, Japan
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
- Cardiovascular Research Institute, Yokohama City University, Yokohama, Japan
| | - Tomohiro Numata
- Department of Integrative Physiology, Graduate School of Medicine, AkitaUniversity, Akita, Japan
| | - Ravshan Z. Sabirov
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Makiko Kashio
- National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Physiology, School of Medicine, Aichi Medical Uniersity, Nagakute, Japan
| | - Peter G. Merzlyak
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Kaori Sato-Numata
- Department of Integrative Physiology, Graduate School of Medicine, AkitaUniversity, Akita, Japan
| |
Collapse
|
9
|
Liu HW, Lai K, Gong LN, Shi HB, Yin SK, Wang LY. Measuring endogenous levels of unconjugated bilirubin released from isolated murine brain tissue during oxygen-glucose deprivation. STAR Protoc 2023; 4:102550. [PMID: 37660297 PMCID: PMC10491851 DOI: 10.1016/j.xpro.2023.102550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 06/24/2023] [Accepted: 08/09/2023] [Indexed: 09/05/2023] Open
Abstract
Quantitative assessment of endogenously synthesized and released bilirubin from brain tissue remains a challenge. Here, we present a sensitive and reproducible experimental paradigm to quantify, in real time, unconjugated bilirubin (UCB) from isolated murine brain tissue during oxygen-glucose deprivation (OGD). We describe steps for perfusion, brain dissection, brain slice preparation and incubation, glucose depletion, and OGD processing. We then detail procedures for standard calibration plotting and sample UCB measurement. For complete details on the use and execution of this protocol, please refer to Liu et al.1.
Collapse
Affiliation(s)
- Han-Wei Liu
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China.
| | - Ke Lai
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Program in Neuroscience and Mental Health, SickKids Research Institute, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Li-Na Gong
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Hai-Bo Shi
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Shan-Kai Yin
- Department of Otorhinolaryngology Head & Neck Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Lu-Yang Wang
- Program in Neuroscience and Mental Health, SickKids Research Institute, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.
| |
Collapse
|
10
|
Szollosi A, Almássy J. Functional characterization of the transient receptor potential melastatin 2 (TRPM2) cation channel from Nematostella vectensis reconstituted into lipid bilayer. Sci Rep 2023; 13:11471. [PMID: 37454209 PMCID: PMC10349829 DOI: 10.1038/s41598-023-38640-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023] Open
Abstract
Transient receptor potential melastatin 2 (TRPM2) cation channel activity is required for insulin secretion, immune cell activation and body heat control. Channel activation upon oxidative stress is involved in the pathology of stroke and neurodegenerative disorders. Cytosolic Ca2+, ADP-ribose (ADPR) and phosphatidylinositol-4,5-bisphosphate (PIP2) are the obligate activators of the channel. Several TRPM2 cryo-EM structures have been resolved to date, yet functionality of the purified protein has not been tested. Here we reconstituted overexpressed and purified TRPM2 from Nematostella vectensis (nvTRPM2) into lipid bilayers and found that the protein is fully functional. Consistent with the observations in native membranes, nvTRPM2 in lipid bilayers is co-activated by cytosolic Ca2+ and either ADPR or ADPR-2'-phosphate (ADPRP). The physiological metabolite ADPRP has a higher apparent affinity than ADPR. In lipid bilayers nvTRPM2 displays a large linear unitary conductance, its open probability (Po) shows little voltage dependence and is stable over several minutes. Po is high without addition of exogenous PIP2, but is largely blunted by treatment with poly-L-Lysine, a polycation that masks PIP2 headgroups. These results indicate that PIP2 or some other activating phosphoinositol lipid co-purifies with nvTRPM2, suggesting a high PIP2 binding affinity of nvTRPM2 under physiological conditions.
Collapse
Affiliation(s)
- Andras Szollosi
- Department of Biochemistry, Semmelweis University, Tuzolto u. 37-47, Budapest, 1094, Hungary.
- ELKH-SE Ion Channel Research Group, Semmelweis University, Tuzolto u. 37-47, Budapest, 1094, Hungary.
- HCEMM-SE Molecular Channelopathies Research Group, Semmelweis University, Tuzolto u. 37-47, Budapest, 1094, Hungary.
| | - János Almássy
- Department of Physiology, Semmelweis University, Tuzolto u. 37-47, Budapest, 1094, Hungary
| |
Collapse
|