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Suryavanshi P, Langton R, Fairhead K, Glykys J. Brief and diverse excitotoxic insults cause an increase in neuronal nuclear membrane permeability in the neonatal brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.22.554167. [PMID: 37662276 PMCID: PMC10473591 DOI: 10.1101/2023.08.22.554167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Neuronal swelling after excitotoxic insults is implicated in neuronal injury and death in the developing brain, yet mitigating brain edema with osmotic and surgical interventions yields poor clinical outcomes. Importantly, neuronal swelling and its downstream consequences during early brain development remain poorly investigated. Using multiphoton Ca2+ imaging in vivo (P12-17) and in acute brain slices (P8-12), we explored Ca2+-dependent downstream effects after neuronal cytotoxic edema. We observed the translocation of cytosolic GCaMP6s into the nucleus of a subpopulation of neurons minutes after various excitotoxic insults. We used automated morphology-detection algorithms for neuronal segmentation and quantified the nuclear translocation of GCaMP6s as the ratio of nuclear and cytosolic intensity (N/C ratio). Elevated neuronal N/C ratios were correlated to higher Ca2+ loads and could occur independently of neuronal swelling. Electron microscopy revealed that the nuclear translocation was associated with increased nuclear pore size. Inhibiting calpains prevented elevated N/C ratios and neuronal swelling. Thus, our results indicate altered nuclear transport in a subpopulation of neurons shortly after injury in the developing brain, which can be used as an early biomarker of acute neuronal injury.
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Affiliation(s)
- P Suryavanshi
- Department of Pediatrics, University of Iowa, Iowa City, IA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA
| | - R Langton
- Department of Pediatrics, University of Iowa, Iowa City, IA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA
| | - K Fairhead
- Biomedical Sciences, College of Liberal Arts and Sciences, University of Iowa, Iowa City, IA
| | - J Glykys
- Department of Pediatrics, University of Iowa, Iowa City, IA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA
- Department of Neurology, University of Iowa, Iowa City, IA
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2
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Halász H, Szatmári Z, Kovács K, Koppán M, Papp S, Szabó-Meleg E, Szatmári D. Changes of Ex Vivo Cervical Epithelial Cells Due to Electroporation with JMY. Int J Mol Sci 2023; 24:16863. [PMID: 38069185 PMCID: PMC10706833 DOI: 10.3390/ijms242316863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/20/2023] [Accepted: 11/25/2023] [Indexed: 12/18/2023] Open
Abstract
The ionic environment within the nucleoplasm might diverge from the conditions found in the cytoplasm, potentially playing a role in the cellular stress response. As a result, it is conceivable that interactions of nuclear actin and actin-binding proteins (ABPs) with apoptosis factors may differ in the nucleoplasm and cytoplasm. The primary intracellular stress response is Ca2+ influx. The junctional mediating and regulating Y protein (JMY) is an actin-binding protein and has the capability to interact with the apoptosis factor p53 in a Ca2+-dependent manner, forming complexes that play a regulatory role in cytoskeletal remodelling and motility. JMY's presence is observed in both the cytoplasm and nucleoplasm. Here, we show that ex vivo ectocervical squamous cells subjected to electroporation with JMY protein exhibited varying morphological alterations. Specifically, the highly differentiated superficial and intermediate cells displayed reduced nuclear size. In inflamed samples, nuclear enlargement and simultaneous cytoplasmic reduction were observable and showed signs of apoptotic processes. In contrast, the less differentiated parabasal and metaplastic cells showed increased cytoplasmic activity and the formation of membrane protrusions. Surprisingly, in severe inflammation, vaginosis or ASC-US (Atypical Squamous Cells of Undetermined Significance), JMY appears to influence only the nuclear and perinuclear irregularities of differentiated cells, and cytoplasmic abnormalities still existed after the electroporation. Our observations can provide an appropriate basis for the exploration of the relationship between cytopathologically relevant morphological changes of epithelial cells and the function of ABPs. This is particularly important since ABPs are considered potential diagnostic and therapeutic biomarkers for both cancers and chronic inflammation.
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Affiliation(s)
- Henriett Halász
- Department of Biophysics, Medical School, University of Pécs, 7624 Pécs, Hungary; (H.H.); (E.S.-M.)
| | | | - Krisztina Kovács
- Department of Pathology, Medical School, University of Pécs, 7624 Pécs, Hungary;
| | | | - Szilárd Papp
- DaVinci Clinics, 7635 Pécs, Hungary; (M.K.); (S.P.)
| | - Edina Szabó-Meleg
- Department of Biophysics, Medical School, University of Pécs, 7624 Pécs, Hungary; (H.H.); (E.S.-M.)
| | - Dávid Szatmári
- Department of Biophysics, Medical School, University of Pécs, 7624 Pécs, Hungary; (H.H.); (E.S.-M.)
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3
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Kumosa LS. Commonly Overlooked Factors in Biocompatibility Studies of Neural Implants. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205095. [PMID: 36596702 PMCID: PMC9951391 DOI: 10.1002/advs.202205095] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Biocompatibility of cutting-edge neural implants, surgical tools and techniques, and therapeutic technologies is a challenging concept that can be easily misjudged. For example, neural interfaces are routinely gauged on how effectively they determine active neurons near their recording sites. Tissue integration and toxicity of neural interfaces are frequently assessed histologically in animal models to determine tissue morphological and cellular changes in response to surgical implantation and chronic presence. A disconnect between histological and efficacious biocompatibility exists, however, as neuronal numbers frequently observed near electrodes do not match recorded neuronal spiking activity. The downstream effects of the myriad surgical and experimental factors involved in such studies are rarely examined when deciding whether a technology or surgical process is biocompatible. Such surgical factors as anesthesia, temperature excursions, bleed incidence, mechanical forces generated, and metabolic conditions are known to have strong systemic and thus local cellular and extracellular consequences. Many tissue markers are extremely sensitive to the physiological state of cells and tissues, thus significantly impacting histological accuracy. This review aims to shed light on commonly overlooked factors that can have a strong impact on the assessment of neural biocompatibility and to address the mismatch between results stemming from functional and histological methods.
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Affiliation(s)
- Lucas S. Kumosa
- Neuronano Research CenterDepartment of Experimental Medical ScienceMedical FacultyLund UniversityMedicon Village, Byggnad 404 A2, Scheelevägen 8Lund223 81Sweden
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4
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Piezo1 Channel as a Potential Target for Hindering Cardiac Fibrotic Remodeling. Int J Mol Sci 2022; 23:ijms23158065. [PMID: 35897650 PMCID: PMC9330509 DOI: 10.3390/ijms23158065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 02/01/2023] Open
Abstract
Fibrotic tissues share many common features with neoplasms where there is an increased stiffness of the extracellular matrix (ECM). In this review, we present recent discoveries related to the role of the mechanosensitive ion channel Piezo1 in several diseases, especially in regulating tumor progression, and how this can be compared with cardiac mechanobiology. Based on recent findings, Piezo1 could be upregulated in cardiac fibroblasts as a consequence of the mechanical stress and pro-inflammatory stimuli that occurs after myocardial injury, and its increased activity could be responsible for a positive feedback loop that leads to fibrosis progression. The increased Piezo1-mediated calcium flow may play an important role in cytoskeleton reorganization since it induces actin stress fibers formation, a well-known characteristic of fibroblast transdifferentiation into the activated myofibroblast. Moreover, Piezo1 activity stimulates ECM and cytokines production, which in turn promotes the phenoconversion of adjacent fibroblasts into new myofibroblasts, enhancing the invasive character. Thus, by assuming the Piezo1 involvement in the activation of intrinsic fibroblasts, recruitment of new myofibroblasts, and uncontrolled excessive ECM production, a new approach to blocking the fibrotic progression can be predicted. Therefore, targeted therapies against Piezo1 could also be beneficial for cardiac fibrosis.
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5
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Selezneva A, Gibb AJ, Willis D. The Nuclear Envelope as a Regulator of Immune Cell Function. Front Immunol 2022; 13:840069. [PMID: 35757775 PMCID: PMC9226455 DOI: 10.3389/fimmu.2022.840069] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 05/10/2022] [Indexed: 01/07/2023] Open
Abstract
The traditional view of the nuclear envelope (NE) was that it represented a relatively inert physical barrier within the cell, whose main purpose was to separate the nucleoplasm from the cytoplasm. However, recent research suggests that this is far from the case, with new and important cellular functions being attributed to this organelle. In this review we describe research suggesting an important contribution of the NE and its constituents in regulating the functions of cells of the innate and adaptive immune system. One of the standout properties of immune cells is their ability to migrate around the body, allowing them to carry out their physiological/pathophysiology cellular role at the appropriate location. This together with the physiological role of the tissue, changes in tissue matrix composition due to disease and aging, and the activation status of the immune cell, all result in immune cells being subjected to different mechanical forces. We report research which suggests that the NE may be an important sensor/transducer of these mechanical signals and propose that the NE is an integrator of both mechanical and chemical signals, allowing the cells of the innate immune system to precisely regulate gene transcription and functionality. By presenting this overview we hope to stimulate the interests of researchers into this often-overlooked organelle and propose it should join the ranks of mitochondria and phagosome, which are important organelles contributing to immune cell function.
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Affiliation(s)
- Anna Selezneva
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Alasdair J Gibb
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Dean Willis
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
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6
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Wang D, Huang F, Yan P, Nie Y, Chen L, Luo J, Zhao H, Wang Y, Han S. Cytosolic and Nucleosolic Calcium-Regulated Molecular Networks in Response to Long-Term Treatment with Abscisic Acid and Methyl Jasmonate in Arabidopsis thaliana. Genes (Basel) 2022; 13:genes13030524. [PMID: 35328077 PMCID: PMC8950999 DOI: 10.3390/genes13030524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 12/02/2022] Open
Abstract
Calcium acts as a universal secondary messenger that transfers developmental cues and stress signals for gene expression and adaptive growth. A prior study showed that abiotic stresses induce mutually independent cytosolic Ca2+ ([Ca2+]cyt) and nucleosolic Ca2+ ([Ca2+]nuc) increases in Arabidopsis thaliana root cells. However, gene expression networks deciphering [Ca2+]cyt and [Ca2+]nuc signalling pathways remain elusive. Here, using transgenic A. thaliana to selectively impair abscisic acid (ABA)- or methyl jasmonate (MeJA)-induced [Ca2+]cyt and [Ca2+]nuc increases, we identified [Ca2+]cyt- and [Ca2+]nuc-regulated ABA- or MeJA-responsive genes with a genome oligo-array. Gene co-expression network analysis revealed four Ca2+ signal-decoding genes, CAM1, CIPK8, GAD1, and CPN20, as hub genes co-expressed with Ca2+-regulated hormone-responsive genes and hormone signalling genes. Luciferase complementation imaging assays showed interactions among CAM1, CIPK8, and GAD1; they also showed interactions with several proteins encoded by Ca2+-regulated hormone-responsive genes. Furthermore, CAM1 and CIPK8 were required for MeJA-induced stomatal closure; they were associated with ABA-inhibited seed germination. Quantitative reverse transcription polymerase chain reaction analysis showed the unique expression pattern of [Ca2+]-regulated hormone-responsive genes in cam1, cipk8, and gad1. This comprehensive understanding of distinct Ca2+ and hormonal signalling will allow the application of approaches to uncover novel molecular foundations for responses to developmental and stress signals in plants.
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Affiliation(s)
- Doudou Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (D.W.); (F.H.); (Y.N.); (L.C.); (J.L.); (H.Z.); (Y.W.)
| | - Feifei Huang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (D.W.); (F.H.); (Y.N.); (L.C.); (J.L.); (H.Z.); (Y.W.)
| | - Pengcheng Yan
- Department of Computational Biology, Beijing Computing Center, Beijing 100094, China;
| | - Yanli Nie
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (D.W.); (F.H.); (Y.N.); (L.C.); (J.L.); (H.Z.); (Y.W.)
| | - Lvli Chen
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (D.W.); (F.H.); (Y.N.); (L.C.); (J.L.); (H.Z.); (Y.W.)
| | - Jin Luo
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (D.W.); (F.H.); (Y.N.); (L.C.); (J.L.); (H.Z.); (Y.W.)
| | - Heping Zhao
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (D.W.); (F.H.); (Y.N.); (L.C.); (J.L.); (H.Z.); (Y.W.)
| | - Yingdian Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (D.W.); (F.H.); (Y.N.); (L.C.); (J.L.); (H.Z.); (Y.W.)
| | - Shengcheng Han
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China; (D.W.); (F.H.); (Y.N.); (L.C.); (J.L.); (H.Z.); (Y.W.)
- Correspondence:
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7
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The S100A7 nuclear interactors in autoimmune diseases: a coevolutionary study in mammals. Immunogenetics 2022; 74:271-284. [PMID: 35174412 DOI: 10.1007/s00251-022-01256-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 02/10/2022] [Indexed: 11/05/2022]
Abstract
S100A7, a member of the S100A family of Ca2+-binding proteins, is considered a key effector in immune response. In particular, S100A7 dysregulation has been associated with several diseases, including autoimmune disorders. At the nuclear level, S100A7 interacts with several protein-binding partners which are involved in transcriptional regulation and DNA repair. By using the BioGRID and GAAD databases, S100A7 nuclear interactors with a putative involvement in autoimmune diseases were retrieved. We selected fatty acid-binding protein 5 (FABP5), autoimmune regulator (AIRE), cystic fibrosis transmembrane conductance regulator (CFTR), chromodomain helicase DNA-binding protein 4 (CHD4), epidermal growth factor receptor (EGFR), estrogen receptor 1 (ESR1), histone deacetylase 2 (HDAC2), v-myc avian myelocytomatosis viral oncogene homolog (MYC), protection of telomeres protein 1 (POT1), telomeric repeat-binding factor (NIMA-interacting) 1 (TERF1), telomeric repeat-binding factor 2 (TERF2), and Zic family member 1 (ZIC1). Linear correlation coefficients between interprotein distances were calculated with MirrorTree. Coevolution clusters were also identified with the use of a recent version of the Blocks in Sequences (BIS2) algorithm implemented in the BIS2Analyzer web server. Analysis of pair positions identified interprotein coevolving clusters between S100A7 and the binding partners CFTR and TERF1. Such findings could guide further analysis to better elucidate the function of S100A7 and its binding partners and to design drugs targeting for these molecules in autoimmune diseases.
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8
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Lewuillon C, Laguillaumie MO, Quesnel B, Idziorek T, Touil Y, Lemonnier L. Put in a “Ca2+ll” to Acute Myeloid Leukemia. Cells 2022; 11:cells11030543. [PMID: 35159351 PMCID: PMC8834247 DOI: 10.3390/cells11030543] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/28/2022] [Accepted: 02/01/2022] [Indexed: 02/05/2023] Open
Abstract
Acute myeloid leukemia (AML) is a clonal disorder characterized by genetic aberrations in myeloid primitive cells (blasts) which lead to their defective maturation/function and their proliferation in the bone marrow (BM) and blood of affected individuals. Current intensive chemotherapy protocols result in complete remission in 50% to 80% of AML patients depending on their age and the AML type involved. While alterations in calcium signaling have been extensively studied in solid tumors, little is known about the role of calcium in most hematologic malignancies, including AML. Our purpose with this review is to raise awareness about this issue and to present (i) the role of calcium signaling in AML cell proliferation and differentiation and in the quiescence of hematopoietic stem cells; (ii) the interplay between mitochondria, metabolism, and oxidative stress; (iii) the effect of the BM microenvironment on AML cell fate; and finally (iv) the mechanism by which chemotherapeutic treatments modify calcium homeostasis in AML cells.
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Affiliation(s)
- Clara Lewuillon
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277—CANTHER—Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France; (C.L.); (M.-O.L.); (B.Q.); (T.I.); (Y.T.)
| | - Marie-Océane Laguillaumie
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277—CANTHER—Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France; (C.L.); (M.-O.L.); (B.Q.); (T.I.); (Y.T.)
| | - Bruno Quesnel
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277—CANTHER—Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France; (C.L.); (M.-O.L.); (B.Q.); (T.I.); (Y.T.)
| | - Thierry Idziorek
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277—CANTHER—Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France; (C.L.); (M.-O.L.); (B.Q.); (T.I.); (Y.T.)
| | - Yasmine Touil
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277—CANTHER—Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France; (C.L.); (M.-O.L.); (B.Q.); (T.I.); (Y.T.)
| | - Loïc Lemonnier
- Univ. Lille, Inserm, U1003—PHYCEL—Physiologie Cellulaire, F-59000 Lille, France
- Laboratory of Excellence, Ion Channels Science and Therapeutics, F-59655 Villeneuve d’Ascq, France
- Correspondence:
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9
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Pivato M, Ballottari M. Chlamydomonas reinhardtii cellular compartments and their contribution to intracellular calcium signalling. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5312-5335. [PMID: 34077536 PMCID: PMC8318260 DOI: 10.1093/jxb/erab212] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 05/11/2021] [Indexed: 05/12/2023]
Abstract
Calcium (Ca2+)-dependent signalling plays a well-characterized role in the response to different environmental stimuli, in both plant and animal cells. In the model organism for green algae, Chlamydomonas reinhardtii, Ca2+ signals were reported to have a crucial role in different physiological processes, such as stress responses, photosynthesis, and flagella functions. Recent reports identified the underlying components of the Ca2+ signalling machinery at the level of specific subcellular compartments and reported in vivo imaging of cytosolic Ca2+ concentration in response to environmental stimuli. The characterization of these Ca2+-related mechanisms and proteins in C. reinhardtii is providing knowledge on how microalgae can perceive and respond to environmental stimuli, but also on how this Ca2+ signalling machinery has evolved. Here, we review current knowledge on the cellular mechanisms underlying the generation, shaping, and decoding of Ca2+ signals in C. reinhardtii, providing an overview of the known and possible molecular players involved in the Ca2+ signalling of its different subcellular compartments. The advanced toolkits recently developed to measure time-resolved Ca2+ signalling in living C. reinhardtii cells are also discussed, suggesting how they can improve the study of the role of Ca2+ signals in the cellular response of microalgae to environmental stimuli.
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Affiliation(s)
- Matteo Pivato
- Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Matteo Ballottari
- Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134 Verona, Italy
- Correspondence:
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10
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Studying Proton Gradients Across the Nuclear Envelope. Methods Mol Biol 2021; 2175:47-63. [PMID: 32681483 DOI: 10.1007/978-1-0716-0763-3_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The existence of nuclear pore complexes in the nuclear envelope has led to the assumption that ions move freely from the cytosol into the nucleus, and that the molecular mechanisms at the plasma membrane that regulate cytosolic pH also regulate nuclear pH. Furthermore, studies to measure pH in the nucleus have produced contradictory results, since it has been found that the nuclear pH is either similar to the cytosol or more alkaline than the cytosol. However, most studies of nuclear pH have lacked the rigor needed to understand pH regulation in the nucleus. A major problem has been the lack of in situ titrations in the nucleus and cytosol, since the intracellular environment is different in the cytosol and nucleus and the behavior of fluorescent pH probes is different in these environments. Here we present a method that uses the fluorescence of SNARF-1 that labels both cytosol and nucleus. Using ratio imaging microscopy, regions of interest corresponding to the nucleus and cytosol to perform steady-state pH measurements followed by in situ titrations, to correctly assign pH in those cellular domains.
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11
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Repairing plasma membrane damage in regulated necrotic cell death. Mol Biol Rep 2021; 48:2751-2759. [PMID: 33687702 DOI: 10.1007/s11033-021-06252-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/24/2021] [Indexed: 10/22/2022]
Abstract
The plasma membrane performs a central role in maintaining cellular homeostasis and viability by acting as a semi-permeable barrier separating the cell from its surroundings. Under physiological conditions, it is constantly exposed to different kinds of stress, such as from pore-forming proteins/toxins and mechanical activity, that compromises its integrity resulting in cells developing various ways to cope with these dangers to survive. These plasma membrane repair mechanisms are initiated by the rapid influx of extracellular Ca2+ ions and are thus hinged on the activity of various Ca2+-binding proteins. The cell's response to membrane damage also depends on the nature and extent of the stimuli as well as the cell type, and the mechanisms involved are believed to be not mutually exclusive. In regulated necrotic cell death, specifically necroptosis, pyroptosis, and ferroptosis, plasma membrane damage ultimately causes cell lysis and the release of immunomodulating damage-associated molecular patterns. Here, I will discuss how these three cell death pathways are counterbalanced by the action of ESCRT (Endosomal Sorting Complex Required for Transport)-III-dependent plasma membrane repair mechanism, that eventually affects the profile of released cytokines and cell-to-cell communication. These highlight a crucial role that plasma membrane repair play in regulated necrosis, and its potential as a viable target to modulate the immune responses associated with these pathways in the context of the various human pathologies where these cell death modalities are implicated.
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12
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Yang YF, Lee CY, Hsieh JY, Liu YL, Lin CL, Liu GY, Hung HC. Regulation of polyamine homeostasis through an antizyme citrullination pathway. J Cell Physiol 2021; 236:5646-5663. [PMID: 33432662 DOI: 10.1002/jcp.30252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/05/2020] [Accepted: 12/18/2020] [Indexed: 11/12/2022]
Abstract
This study reveals an uncovered mechanism for the regulation of polyamine homeostasis through protein arginyl citrullination of antizyme (AZ), a natural inhibitor of ornithine decarboxylase (ODC). ODC is critical for the cellular production of polyamines. AZ binds to ODC dimers and promotes the degradation of ODC via the 26S proteasome. This study demonstrates the protein citrullination of AZ catalyzed by peptidylarginine deiminase type 4 (PAD4) both in vitro and in cells. Upon PAD4 activation, the AZ protein was citrullinated and accumulated, leading to higher levels of ODC proteins in the cell. In the PAD4-overexpressing and activating cells, the levels of ODC enzyme activity and the product putrescine increased with the level of citrullinated AZ proteins and PAD4 activity. Suppressing cellular PAD4 activity reduces the cellular levels of ODC and downregulates cellular polyamines. Furthermore, citrullination of AZ in the C-terminus attenuates AZ function in the inhibition, binding, and degradation of ODC. This paper provides evidence to illustrate that PAD4-mediated AZ citrullination upregulates cellular ODC and polyamines by retarding ODC degradation, thus interfering with the homeostasis of cellular polyamines, which may be an important pathway regulating AZ functions that is relevant to cancer biology.
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Affiliation(s)
- Yi-Fang Yang
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.,Ph.D. Program in Tissue Engineering and Regenerative Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Chien-Yun Lee
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.,Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan.,Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
| | - Ju-Yi Hsieh
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Liang Liu
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.,Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Chi-Li Lin
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Guang-Yaw Liu
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.,Department of Allergy Immunology and Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Hui-Chih Hung
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.,Institute of Genomics & Bioinformatics, National Chung Hsing University, Taichung, Taiwan.,iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
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13
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Comprehensive Analysis of Differently Expressed and Methylated Genes in Preeclampsia. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2020; 2020:2139270. [PMID: 33204297 PMCID: PMC7652635 DOI: 10.1155/2020/2139270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/18/2020] [Accepted: 09/06/2020] [Indexed: 11/28/2022]
Abstract
Preeclampsia (PE) is one of the mainly caused maternal and infant incidences and mortalities worldwide. However, the mechanisms underlying PE remained largely unclear. The present study identified 1716 high expressions of gene and 2705 low expressions of gene using GSE60438 database, and identified 7087 hypermethylated and 15120 hypomethylated genes in preeclampsia using GSE100197. Finally, 536 upregulated genes with hypomethylation and 322 downregulated genes with hypermethylation were for the first time revealed in PE. Gene Ontology (GO) analysis revealed that these genes were associated with peptidyl-tyrosine phosphorylation, skeletal system development, leukocyte migration, transcription regulation, T cell receptor and IFN-γ-involved pathways, innate immune response, signal transduction, cell adhesion, angiogenesis, and hemopoiesis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that aberrantly methylated differentially expressed genes were involved in regulating adherens junction, pluripotency of stem cell regulation, immune processing, T cell receptor and NF-κB pathways, HTLV-I and HSV infections, leishmaniasis, and NK-induced cytotoxicity. Protein-protein interaction (PPI) network analysis identified several hub networks and key genes, including MAPK8, CCNF, CDC23, ABL1, NF1, UBE2E3, CD44, and PIK3R1. We hope these findings will draw more attention to these hub genes in future PE studies.
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Snoeck HW. Calcium regulation of stem cells. EMBO Rep 2020; 21:e50028. [PMID: 32419314 DOI: 10.15252/embr.202050028] [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: 01/14/2020] [Revised: 03/14/2020] [Accepted: 04/03/2020] [Indexed: 12/14/2022] Open
Abstract
Pluripotent and post-natal, tissue-specific stem cells share functional features such as the capacity to differentiate into multiple lineages and to self-renew, and are endowed with specific cell maintenance mechanism as well as transcriptional and epigenetic signatures that determine stem cell identity and distinguish them from their progeny. Calcium is a highly versatile and ubiquitous second messenger that regulates a wide variety of cellular functions. Specific roles of calcium in stem cell niches and stem cell maintenance mechanisms are only beginning to be explored, however. In this review, I discuss stem cell-specific regulation and roles of calcium, focusing on its potential involvement in the intertwined metabolic and epigenetic regulation of stem cells.
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Affiliation(s)
- Hans-Willem Snoeck
- Columbia Center of Human Development, Columbia University Irving Medical Center, New York, NY, USA.,Division of Pulmonary Medicine, Allergy and Critical Care, Columbia University Irving Medical Center, New York, NY, USA.,Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA.,Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
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Lemos FDO, Florentino RM, Lima Filho ACM, Santos MLD, Leite MF. Inositol 1,4,5-trisphosphate receptor in the liver: Expression and function. World J Gastroenterol 2019; 25:6483-6494. [PMID: 31802829 PMCID: PMC6886013 DOI: 10.3748/wjg.v25.i44.6483] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 10/22/2019] [Accepted: 11/13/2019] [Indexed: 02/06/2023] Open
Abstract
The liver is a complex organ that performs several functions to maintain homeostasis. These functions are modulated by calcium, a second messenger that regulates several intracellular events. In hepatocytes and cholangiocytes, which are the epithelial cell types in the liver, inositol 1,4,5-trisphosphate (InsP3) receptors (ITPR) are the only intracellular calcium release channels. Three isoforms of the ITPR have been described, named type 1, type 2 and type 3. These ITPR isoforms are differentially expressed in liver cells where they regulate distinct physiological functions. Changes in the expression level of these receptors correlate with several liver diseases and hepatic dysfunctions. In this review, we highlight how the expression level, modulation, and localization of ITPR isoforms in hepatocytes and cholangiocytes play a role in hepatic homeostasis and liver pathology.
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Affiliation(s)
- Fernanda de Oliveira Lemos
- Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Rodrigo M Florentino
- Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Antônio Carlos Melo Lima Filho
- Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Marcone Loiola dos Santos
- Department of Cell Biology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - M Fatima Leite
- Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
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Nguyen HTH, Bouteau F, Mazars C, Kuse M, Kawano T. The involvement of calmodulin and protein kinases in the upstream of cytosolic and nucleic calcium signaling induced by hypoosmotic shock in tobacco cells. PLANT SIGNALING & BEHAVIOR 2018; 13:e1494467. [PMID: 30067454 PMCID: PMC6149468 DOI: 10.1080/15592324.2018.1494467] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 06/19/2018] [Indexed: 05/21/2023]
Abstract
Changes in Ca2+ concentrations in cytosol ([Ca2+]C) or nucleus ([Ca2+]N) may play some vital roles in plants under hypoosmotic shock (Hypo-OS). Here, we observed that Hypo-OS induces biphasic increases in [Ca2+]C and [Ca2+]N in two tobacco cell lines (BY-2) expressing apoaequorin either in the cytosol or in the nucleus. Both [Ca2+]C and [Ca2+]N were sensitively modulated by the inhibitors of calmodulin and protein kinases, supporting the view that calmodulin suppresses the 1st peaks and and protein kinases enhance 2nd peaks in [Ca2+]C and [Ca2+]N. Data also suggested that the 1st and 2nd events depend on the internal and extracellular Ca2+ sources, respectively.
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Affiliation(s)
- H. T. H. Nguyen
- Laboratory of Chemical Biology and Bioengineering, Faculty and Graduate School of Environmental Engineering, The University of Kitakyushu, Kitakyushu, Japan
| | - F. Bouteau
- Sorbonne Paris Cité, Laboratoire Interdisciplinaire des Energies de Demain, Université Paris Diderot, Paris, France
- University of Florence LINV Kitakyushu Research Center (LINV@Kitakyushu), Kitakyushu, Japan
- International Photosynthesis Industrialization Research Center, The University of Kitakyushu, Kitakyushu, Japan
| | - C. Mazars
- Laboratoire de Recherches en Sciences Végétales, Université de Toulouse UPS, CNRS UMR, Castanet-Tolosan, France
| | - M. Kuse
- Laboratory of Natural Products Chemistry, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - T. Kawano
- Laboratory of Chemical Biology and Bioengineering, Faculty and Graduate School of Environmental Engineering, The University of Kitakyushu, Kitakyushu, Japan
- University of Florence LINV Kitakyushu Research Center (LINV@Kitakyushu), Kitakyushu, Japan
- International Photosynthesis Industrialization Research Center, The University of Kitakyushu, Kitakyushu, Japan
- Univ. Paris-Diderot, Sorbonne Paris Cité, Paris Interdisciplinary Energy Research Institute (PIERI), Paris, France
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Dhar P, Kaushal P, Kumar P. Antioxidant supplementation upregulates calbindin expression in cerebellar Purkinje cells of rat pups subjected to post natal exposure to sodium arsenite. Brain Res 2018; 1690:23-30. [PMID: 29630858 DOI: 10.1016/j.brainres.2018.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 03/06/2018] [Accepted: 04/03/2018] [Indexed: 12/01/2022]
Abstract
Optimal cytoplasmic calcium (Ca2+) levels have been associated with adequate cell functioning and neuronal survival. Altered intracellular Ca2+ levels following impaired Ca2+ homeostasis could induce neuronal degeneration or even cell death. There are reports of arsenite induced oxidative stress and the associated disturbances in intracellular calcium homeostasis. The present study focused on determining the strategies that would modulate tissue redox status and calcium binding protein (CaBP) (Calbindin D28k-CB) expression affected adversely by sodium arsenite (NaAsO2) exposure (postnatal) of rat pups. NaAsO2 alone or along with antioxidants (AOXs) (alpha lipoic acid or curcumin) was administered by intraperitoneal (i.p.) route from postnatal day (PND) 1-21 (covering rapid brain growth period - RBGP) to experimental groups and animals receiving sterile water by the same route served as the controls. At the end of the experimental period, the animals were subjected to euthanasia and the cerebellar tissue obtained therefrom was processed for immunohistochemical localization and western blot analysis of CB protein. CB was diffusely expressed in cell body as well as dendritic processes of Purkinje cells (PCs) along the PC Layer (PCL) in all cerebellar folia of the control and the experimental animals. The multilayered pattern of CB +ve cells along with their downregulated expression and low packing density was significantly evident in the arsenic (iAs) alone exposed group as against the controls and AOX supplemented groups. The observations are suggestive of AOX induced restoration of CaBP expression in rat cerebellum following early postnatal exposure to NaAsO2.
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Affiliation(s)
- Pushpa Dhar
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India.
| | - Parul Kaushal
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India
| | - Pavan Kumar
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India
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18
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Drozdz MM, Vaux DJ. Shared mechanisms in physiological and pathological nucleoplasmic reticulum formation. Nucleus 2017; 8:34-45. [PMID: 27797635 PMCID: PMC5287099 DOI: 10.1080/19491034.2016.1252893] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/13/2016] [Accepted: 10/19/2016] [Indexed: 12/14/2022] Open
Abstract
The mammalian nuclear envelope (NE) can develop complex dynamic membrane-bounded invaginations in response to both physiological and pathological stimuli. Since the formation of these nucleoplasmic reticulum (NR) structures can occur during interphase, without mitotic NE breakdown and reassembly, some other mechanism must drive their development. Here we consider models for deformation of the interphase NE, together with the evidence for their potential roles in NR formation.
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Affiliation(s)
| | - David John Vaux
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
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19
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Angiotensin Converting Enzyme Regulates Cell Proliferation and Migration. PLoS One 2016; 11:e0165371. [PMID: 27992423 PMCID: PMC5167550 DOI: 10.1371/journal.pone.0165371] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 11/29/2016] [Indexed: 12/31/2022] Open
Abstract
Background The angiotensin-I converting enzyme (ACE) plays a central role in the renin-angiotensin system, acting by converting the hormone angiotensin-I to the active peptide angiotensin-II (Ang-II). More recently, ACE was shown to act as a receptor for Ang-II, and its expression level was demonstrated to be higher in melanoma cells compared to their normal counterparts. However, the function that ACE plays as an Ang-II receptor in melanoma cells has not been defined yet. Aim Therefore, our aim was to examine the role of ACE in tumor cell proliferation and migration. Results We found that upon binding to ACE, Ang-II internalizes with a faster onset compared to the binding of Ang-II to its classical AT1 receptor. We also found that the complex Ang-II/ACE translocates to the nucleus, through a clathrin-mediated process, triggering a transient nuclear Ca2+ signal. In silico studies revealed a possible interaction site between ACE and phospholipase C (PLC), and experimental results in CHO cells, demonstrated that the β3 isoform of PLC is the one involved in the Ca2+ signals induced by Ang-II/ACE interaction. Further studies in melanoma cells (TM-5) showed that Ang-II induced cell proliferation through ACE activation, an event that could be inhibited either by ACE inhibitor (Lisinopril) or by the silencing of ACE. In addition, we found that stimulation of ACE by Ang-II caused the melanoma cells to migrate, at least in part due to decreased vinculin expression, a focal adhesion structural protein. Conclusion ACE activation regulates melanoma cell proliferation and migration.
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Nuclear Lipids in the Nervous System: What they do in Health and Disease. Neurochem Res 2016; 42:321-336. [PMID: 27766461 DOI: 10.1007/s11064-016-2085-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/21/2016] [Accepted: 10/11/2016] [Indexed: 12/18/2022]
Abstract
In the last 20 years it has been widely demonstrated that cell nucleus contains neutral and polar lipids localized in nuclear membranes, nucleoli, nuclear matrix and chromatin. Nuclear lipids may show specific organization forming nuclear lipid microdomains and have both structural and functional roles. Depending on their localization, nuclear lipids play different roles such as the regulation of nuclear membrane and nuclear matrix fluidity but they also can act as platforms for vitamin and hormone function, for active chromatin anchoring, and for the regulation of gene expression, DNA duplication and transcription. Crosstalk among different kinds of lipid signalling pathways influence the physiopathology of numerous cell types. In neural cells the nuclear lipids are involved in cell proliferation, differentiation, inflammation, migration and apoptosis. Abnormal metabolism of nuclear lipids might be closely associated with tumorigenesis and neurodegenerative diseases such as Alzheimer disease and Parkinson disease among others.
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Charpentier M, Sun J, Vaz Martins T, Radhakrishnan GV, Findlay K, Soumpourou E, Thouin J, Véry AA, Sanders D, Morris RJ, Oldroyd GED. Nuclear-localized cyclic nucleotide-gated channels mediate symbiotic calcium oscillations. Science 2016; 352:1102-5. [PMID: 27230377 DOI: 10.1126/science.aae0109] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 04/20/2016] [Indexed: 12/21/2022]
Abstract
Nuclear-associated Ca(2+) oscillations mediate plant responses to beneficial microbial partners--namely, nitrogen-fixing rhizobial bacteria that colonize roots of legumes and arbuscular mycorrhizal fungi that colonize roots of the majority of plant species. A potassium-permeable channel is known to be required for symbiotic Ca(2+) oscillations, but the calcium channels themselves have been unknown until now. We show that three cyclic nucleotide-gated channels in Medicago truncatula are required for nuclear Ca(2+) oscillations and subsequent symbiotic responses. These cyclic nucleotide-gated channels are located at the nuclear envelope and are permeable to Ca(2+) We demonstrate that the cyclic nucleotide-gated channels form a complex with the postassium-permeable channel, which modulates nuclear Ca(2+) release. These channels, like their counterparts in animal cells, might regulate multiple nuclear Ca(2+) responses to developmental and environmental conditions.
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Affiliation(s)
- Myriam Charpentier
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
| | - Jongho Sun
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Teresa Vaz Martins
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Guru V Radhakrishnan
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Kim Findlay
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Eleni Soumpourou
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Julien Thouin
- Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, UMR 5004 CNRS-386 INRA (French National Institute for Agricultural Research)-SupAgro-M-Université Montpellier, Campus SupAgro-INRA, 34060 Montpellier, France
| | - Anne-Aliénor Véry
- Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, UMR 5004 CNRS-386 INRA (French National Institute for Agricultural Research)-SupAgro-M-Université Montpellier, Campus SupAgro-INRA, 34060 Montpellier, France
| | - Dale Sanders
- Metabolic Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Richard J Morris
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Giles E D Oldroyd
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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Kotyk OA, Kotliarova AB, Polishchuk AO, Marchenko SM. SINGLE-CHANNEL ION CURRENTS IN THE NUCLEAR ENVELOPE OF RAT CARDIOMYOCYTES. ACTA ACUST UNITED AC 2016; 62:3-8. [PMID: 29762965 DOI: 10.15407/fz62.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Using the patch clamp technique in nucleus attached configuration we have found that the nuclear membrane of rat cardiomyocytes contains different types of ion channels with conductances in the range from 10 to 400 pS. In particular, we recorded inositol 1,4,5-trisphosphate receptors with conductance of 384 ± 5 pS and 209 ± 13 pS cation channels similar to LCC-channels, previously reported in neurons. In addition, we found at least two types of ion channels with significantly higher conductance than that of LCC-channels and several types of ion channels with lower conductance (10-90 pS).
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Distinct spatial Ca2+ signatures selectively activate different NFAT transcription factor isoforms. Mol Cell 2015; 58:232-43. [PMID: 25818645 PMCID: PMC4405353 DOI: 10.1016/j.molcel.2015.02.027] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/21/2015] [Accepted: 02/19/2015] [Indexed: 11/21/2022]
Abstract
Protein isoforms are widely expressed in biological systems. How isoforms that co-exist within the same sub-cellular domain are differentially activated remains unclear. Here, we compare the regulatory mechanism of two closely related transcription factor isoforms, NFAT1 and NFAT4, that migrate from the cytoplasm to the nucleus following the increase in intracellular Ca(2+) that accompanies the opening of store-operated Orai1/CRAC channels. We demonstrate that NFAT1 has a private line of communication with Orai1, activating in response to Ca(2+) microdomains near the open channels. By contrast, NFAT4 stimulation requires both local Ca(2+) entry and a nuclear Ca(2+) rise. We mapped differences in nuclear location to amino acids within the SP-3 motif of the NFAT regulatory domain. The different Ca(2+) dependencies enable agonists to recruit different isoform combinations as stimulus strength increases. Our study uncovers a mechanism whereby co-existing cytoplasmic transcription factor isoforms are differentially activated by distinct sub-cellular Ca(2+) signals.
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