1
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Christophers B, Leahy SN, Soffar DB, von Saucken VE, Broadie K, Baylies MK. Muscle cofilin alters neuromuscular junction postsynaptic development to strengthen functional neurotransmission. Development 2024; 151:dev202558. [PMID: 38869008 DOI: 10.1242/dev.202558] [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: 11/21/2023] [Accepted: 06/05/2024] [Indexed: 06/14/2024]
Abstract
Cofilin, an actin-severing protein, plays key roles in muscle sarcomere addition and maintenance. Our previous work found that Drosophila cofilin (DmCFL) knockdown in muscle causes progressive deterioration of muscle structure and function and produces features seen in nemaline myopathy caused by cofilin mutations. We hypothesized that disruption of actin cytoskeleton dynamics by DmCFL knockdown would impact other aspects of muscle development, and, thus, conducted an RNA-sequencing analysis that unexpectedly revealed upregulated expression of numerous neuromuscular junction (NMJ) genes. We found that DmCFL is enriched in the muscle postsynaptic compartment and that DmCFL muscle knockdown causes F-actin disorganization in this subcellular domain prior to the sarcomere defects observed later in development. Despite NMJ gene expression changes, we found no significant changes in gross presynaptic Bruchpilot active zones or total postsynaptic glutamate receptor levels. However, DmCFL knockdown resulted in mislocalization of GluRIIA class glutamate receptors in more deteriorated muscles and strongly impaired NMJ transmission strength. These findings expand our understanding of the roles of cofilin in muscle to include NMJ structural development and suggest that NMJ defects may contribute to the pathophysiology of nemaline myopathy.
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Affiliation(s)
- Briana Christophers
- Weill Cornell-Rockefeller-Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Shannon N Leahy
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - David B Soffar
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Victoria E von Saucken
- Weill Cornell-Rockefeller-Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Mary K Baylies
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
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2
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Menzies JAC, Maia Chagas A, Baden T, Alonso CR. A microRNA that controls the emergence of embryonic movement. eLife 2024; 13:RP95209. [PMID: 38869942 PMCID: PMC11175612 DOI: 10.7554/elife.95209] [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] [Indexed: 06/14/2024] Open
Abstract
Movement is a key feature of animal systems, yet its embryonic origins are not fully understood. Here, we investigate the genetic basis underlying the embryonic onset of movement in Drosophila focusing on the role played by small non-coding RNAs (microRNAs, miRNAs). To this end, we first develop a quantitative behavioural pipeline capable of tracking embryonic movement in large populations of fly embryos, and using this system, discover that the Drosophila miRNA miR-2b-1 plays a role in the emergence of movement. Through the combination of spectral analysis of embryonic motor patterns, cell sorting and RNA in situs, genetic reconstitution tests, and neural optical imaging we define that miR-2b-1 influences the emergence of embryonic movement by exerting actions in the developing nervous system. Furthermore, through the combination of bioinformatics coupled to genetic manipulation of miRNA expression and phenocopy tests we identify a previously uncharacterised (but evolutionarily conserved) chloride channel encoding gene - which we term Movement Modulator (Motor) - as a genetic target that mechanistically links miR-2b-1 to the onset of movement. Cell-specific genetic reconstitution of miR-2b-1 expression in a null miRNA mutant background, followed by behavioural assays and target gene analyses, suggest that miR-2b-1 affects the emergence of movement through effects in sensory elements of the embryonic circuitry, rather than in the motor domain. Our work thus reports the first miRNA system capable of regulating embryonic movement, suggesting that other miRNAs are likely to play a role in this key developmental process in Drosophila as well as in other species.
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Affiliation(s)
- Jonathan AC Menzies
- Department of Neuroscience, Sussex Neuroscience, School of Life Sciences, University of SussexBrightonUnited Kingdom
| | - André Maia Chagas
- Department of Neuroscience, Sussex Neuroscience, School of Life Sciences, University of SussexBrightonUnited Kingdom
| | - Tom Baden
- Department of Neuroscience, Sussex Neuroscience, School of Life Sciences, University of SussexBrightonUnited Kingdom
| | - Claudio R Alonso
- Department of Neuroscience, Sussex Neuroscience, School of Life Sciences, University of SussexBrightonUnited Kingdom
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3
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Lu P, Deng S, Liu J, Xiao Q, Zhou Z, Li S, Xin J, Shu G, Yi B, Yin G. Tweety homolog 3 promotes colorectal cancer progression through mutual regulation of histone deacetylase 7. MedComm (Beijing) 2024; 5:e576. [PMID: 38827027 PMCID: PMC11141500 DOI: 10.1002/mco2.576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 03/18/2024] [Accepted: 04/07/2024] [Indexed: 06/04/2024] Open
Abstract
Colorectal cancer (CRC) is one of the leading cancers worldwide, with metastasis being a major cause of high mortality rates among patients. In this study, dysregulated gene Tweety homolog 3 (TTYH3) was identified by Gene Expression Omnibus database. Public databases were used to predict potential competing endogenous RNAs (ceRNAs) for TTYH3. Quantitative real-time polymerase chain reaction, western blot, and immunohistochemistry were utilized to analyze TTYH3 and histone deacetylase 7 (HDAC7) levels. Luciferase assays confirmed miR-1271-5p directly targeting the 3' untranslated regions of TTYH3 and HDAC7. In vitro experiments such as transwell and human umbilical vein endothelial cell tube formation, as well as in vivo mouse models, were conducted to assess the biological functions of TTYH3 and HDAC7. We discovered that upregulation of TTYH3 in CRC promotes cell migration by affecting the Epithelial-mesenchymal transition pathway, which was independent of its ion channel activity. Mechanistically, TTYH3 and HDAC7 functioned as ceRNAs, reciprocally regulating each other's expression. TTYH3 competes for binding miR-1271-5p, increasing HDAC7 expression, facilitating CRC metastasis and angiogenesis. This study reveals the critical role of TTYH3 in promoting CRC metastasis through ceRNA crosstalk, offering new insights into potential therapeutic targets for clinical intervention.
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Affiliation(s)
- Pengyan Lu
- Department of PathologyXiangya Hospital, School of Basic Medical Sciences, Central South UniversityChangshaChina
| | - Shumin Deng
- Department of PathologyXiangya Hospital, School of Basic Medical Sciences, Central South UniversityChangshaChina
| | - Jiaxin Liu
- Department of PathologyXiangya Hospital, School of Basic Medical Sciences, Central South UniversityChangshaChina
| | - Qing Xiao
- Department of PathologyThe Third Xiangya Hospital, Central South UniversityChangshaChina
| | - Zhengwei Zhou
- Department of PathologyXiangya Hospital, School of Basic Medical Sciences, Central South UniversityChangshaChina
| | - Shuojie Li
- Department of PathologyXiangya Hospital, School of Basic Medical Sciences, Central South UniversityChangshaChina
| | - Jiaxuan Xin
- Department of Gastrointestinal SurgeryThe Third Xiangya Hospital, Central South UniversityChangshaChina
| | - Guang Shu
- Department of PathologyXiangya Hospital, School of Basic Medical Sciences, Central South UniversityChangshaChina
| | - Bo Yi
- Department of PathologyThe Third Xiangya Hospital, Central South UniversityChangshaChina
| | - Gang Yin
- Department of PathologyXiangya Hospital, School of Basic Medical Sciences, Central South UniversityChangshaChina
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South UniversityChangshaChina
- China‐Africa Research Center of Infectious Diseases, School of Basic Medical Sciences, Central South UniversityChangshaHunan ProvinceChina
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4
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Pleskač P, Fargeas CA, Veselska R, Corbeil D, Skoda J. Emerging roles of prominin-1 (CD133) in the dynamics of plasma membrane architecture and cell signaling pathways in health and disease. Cell Mol Biol Lett 2024; 29:41. [PMID: 38532366 DOI: 10.1186/s11658-024-00554-0] [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: 10/24/2023] [Accepted: 02/22/2024] [Indexed: 03/28/2024] Open
Abstract
Prominin-1 (CD133) is a cholesterol-binding membrane glycoprotein selectively associated with highly curved and prominent membrane structures. It is widely recognized as an antigenic marker of stem cells and cancer stem cells and is frequently used to isolate them from biological and clinical samples. Recent progress in understanding various aspects of CD133 biology in different cell types has revealed the involvement of CD133 in the architecture and dynamics of plasma membrane protrusions, such as microvilli and cilia, including the release of extracellular vesicles, as well as in various signaling pathways, which may be regulated in part by posttranslational modifications of CD133 and its interactions with a variety of proteins and lipids. Hence, CD133 appears to be a master regulator of cell signaling as its engagement in PI3K/Akt, Src-FAK, Wnt/β-catenin, TGF-β/Smad and MAPK/ERK pathways may explain its broad action in many cellular processes, including cell proliferation, differentiation, and migration or intercellular communication. Here, we summarize early studies on CD133, as they are essential to grasp its novel features, and describe recent evidence demonstrating that this unique molecule is involved in membrane dynamics and molecular signaling that affects various facets of tissue homeostasis and cancer development. We hope this review will provide an informative resource for future efforts to elucidate the details of CD133's molecular function in health and disease.
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Affiliation(s)
- Petr Pleskač
- Laboratory of Tumor Biology, Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic
| | - Christine A Fargeas
- Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, 01307, Dresden, Germany
- Tissue Engineering Laboratories, Medizinische Fakultät der Technischen Universität Dresden, Dresden, Germany
| | - Renata Veselska
- Laboratory of Tumor Biology, Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic
| | - Denis Corbeil
- Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, 01307, Dresden, Germany.
- Tissue Engineering Laboratories, Medizinische Fakultät der Technischen Universität Dresden, Dresden, Germany.
| | - Jan Skoda
- Laboratory of Tumor Biology, Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
- International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic.
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5
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De Fazio E, Pittarello M, Gans A, Ghosh B, Slika H, Alimonti P, Tyler B. Intrinsic and Microenvironmental Drivers of Glioblastoma Invasion. Int J Mol Sci 2024; 25:2563. [PMID: 38473812 DOI: 10.3390/ijms25052563] [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: 01/02/2024] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 03/14/2024] Open
Abstract
Gliomas are diffusely infiltrating brain tumors whose prognosis is strongly influenced by their extent of invasion into the surrounding brain tissue. While lower-grade gliomas present more circumscribed borders, high-grade gliomas are aggressive tumors with widespread brain infiltration and dissemination. Glioblastoma (GBM) is known for its high invasiveness and association with poor prognosis. Its low survival rate is due to the certainty of its recurrence, caused by microscopic brain infiltration which makes surgical eradication unattainable. New insights into GBM biology at the single-cell level have enabled the identification of mechanisms exploited by glioma cells for brain invasion. In this review, we explore the current understanding of several molecular pathways and mechanisms used by tumor cells to invade normal brain tissue. We address the intrinsic biological drivers of tumor cell invasion, by tackling how tumor cells interact with each other and with the tumor microenvironment (TME). We focus on the recently discovered neuronal niche in the TME, including local as well as distant neurons, contributing to glioma growth and invasion. We then address the mechanisms of invasion promoted by astrocytes and immune cells. Finally, we review the current literature on the therapeutic targeting of the molecular mechanisms of invasion.
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Affiliation(s)
- Emerson De Fazio
- Department of Medicine, Vita-Salute San Raffaele University School of Medicine, 20132 Milan, Italy
| | - Matilde Pittarello
- Department of Medicine, Humanitas University School of Medicine, 20089 Rozzano, Italy
| | - Alessandro Gans
- Department of Neurology, University of Milan, 20122 Milan, Italy
| | - Bikona Ghosh
- School of Medicine and Surgery, Dhaka Medical College, Dhaka 1000, Bangladesh
| | - Hasan Slika
- Hunterian Neurosurgical Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Paolo Alimonti
- Department of Medicine, Vita-Salute San Raffaele University School of Medicine, 20132 Milan, Italy
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Betty Tyler
- Hunterian Neurosurgical Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
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6
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Leung HH, Mansour C, Rousseau M, Nakhla A, Kiselyov K, Venkatachalam K, Wong CO. Drosophila tweety facilitates autophagy to regulate mitochondrial homeostasis and bioenergetics in Glia. Glia 2024; 72:433-451. [PMID: 37870193 PMCID: PMC10842981 DOI: 10.1002/glia.24484] [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: 06/02/2023] [Revised: 09/12/2023] [Accepted: 10/08/2023] [Indexed: 10/24/2023]
Abstract
Mitochondria support the energetic demands of the cells. Autophagic turnover of mitochondria serves as a critical pathway for mitochondrial homeostasis. It is unclear how bioenergetics and autophagy are functionally connected. Here, we identify an endolysosomal membrane protein that facilitates autophagy to regulate ATP production in glia. We determined that Drosophila tweety (tty) is highly expressed in glia and localized to endolysosomes. Diminished fusion between autophagosomes and endolysosomes in tty-deficient glia was rescued by expressing the human Tweety Homolog 1 (TTYH1). Loss of tty in glia attenuated mitochondrial turnover, elevated mitochondrial oxidative stress, and impaired locomotor functions. The cellular and organismal defects were partially reversed by antioxidant treatment. We performed live-cell imaging of genetically encoded metabolite sensors to determine the impact of tty and autophagy deficiencies on glial bioenergetics. We found that tty-deficient glia exhibited reduced mitochondrial pyruvate consumption accompanied by a shift toward glycolysis for ATP production. Likewise, genetic inhibition of autophagy in glia resulted in a similar glycolytic shift in bioenergetics. Furthermore, the survival of mutant flies became more sensitive to starvation, underlining the significance of tty in the crosstalk between autophagy and bioenergetics. Together, our findings uncover the role for tty in mitochondrial homeostasis via facilitating autophagy, which determines bioenergetic balance in glia.
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Affiliation(s)
- Ho Hang Leung
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
- Present address: South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA 5000, Australia
| | - Christina Mansour
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Morgan Rousseau
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center (UTHealth), Houston, TX 77030, USA
| | - Anwar Nakhla
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Kirill Kiselyov
- Department of Biological Sciences, University of Pittsburgh, PA 15260, USA
| | - Kartik Venkatachalam
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center (UTHealth), Houston, TX 77030, USA
| | - Ching-On Wong
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
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7
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Okada Y. Physiology of the volume-sensitive/regulatory anion channel VSOR/VRAC. Part 1: from its discovery and phenotype characterization to the molecular entity identification. J Physiol Sci 2024; 74:3. [PMID: 38238667 PMCID: PMC10795261 DOI: 10.1186/s12576-023-00897-x] [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: 11/24/2023] [Accepted: 12/27/2023] [Indexed: 01/22/2024]
Abstract
The volume-sensitive outwardly rectifying or volume-regulated anion channel, VSOR/VRAC, which was discovered in 1988, is expressed in most vertebrate cell types and is essentially involved in cell volume regulation after swelling and in the induction of cell death. This series of review articles describes what is already known and what remains to be uncovered about the functional and molecular properties as well as the physiological and pathophysiological roles of VSOR/VRAC. This Part 1 review article describes, from the physiological standpoint, first its discovery and significance in cell volume regulation, second its phenotypical properties, and third its molecular identification. Although the pore-forming core molecules and the volume-sensing subcomponent of VSOR/VRAC were identified as LRRC8 members and TRPM7 in 2014 and 2021, respectively, it is stressed that the identification of the molecular entity of VSOR/VRAC is still not complete enough to explain the full set of phenotypical properties.
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Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
- Department of Integrative Physiology, Graduate School of Medicine, Akita University, Akita, Japan.
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, Japan.
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
- Cardiovascular Research Institute, Yokohama City University, Yokohama, Japan.
- Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan.
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8
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Jimenez C, Hawn MB, Akin E, Leblanc N. Translational potential of targeting Anoctamin-1-Encoded Calcium-Activated chloride channels in hypertension. Biochem Pharmacol 2022; 206:115320. [PMID: 36279919 DOI: 10.1016/j.bcp.2022.115320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 12/14/2022]
Abstract
Calcium-activated chloride channels (CaCC) provide a depolarizing stimulus to a variety of tissues through chloride efflux in response to a rise in internal Ca2+ and voltage. One of these channels, Anoctamin-1 (ANO1 or TMEM16A) is now recognized to play a central role in promoting smooth muscle tone in various types of blood vessels. Its role in hypertension, and thus the therapeutic promise of targeting ANO1, is less straightforward. This review gives an overview of our current knowledge about the potential role ANO1 may play in hypertension within the systemic, portal, and pulmonary vascular systems and the importance of this information when pursuing potential treatment strategies. While the role of ANO1 is well-established in several forms of pulmonary hypertension, its contributions to both the generation of vascular tone and its role in hypertension within the systemic and portal systems are much less clear. This, combined with ANO1's various roles throughout a multitude of tissues throughout the body, command caution when targeting ANO1 as a therapeutic target and may require tissue-selective strategies.
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Affiliation(s)
- Connor Jimenez
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Matthew B Hawn
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Elizabeth Akin
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Normand Leblanc
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, 1664 North Virginia Street, Reno, Nevada 89557, USA.
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9
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TTYH3 Modulates Bladder Cancer Proliferation and Metastasis via FGFR1/H-Ras/A-Raf/MEK/ERK Pathway. Int J Mol Sci 2022; 23:ijms231810496. [PMID: 36142409 PMCID: PMC9501546 DOI: 10.3390/ijms231810496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 08/31/2022] [Accepted: 09/07/2022] [Indexed: 12/09/2022] Open
Abstract
Tweety family member 3 (TTYH3) is a calcium-activated chloride channel with a non-pore-forming structure that controls cell volume and signal transduction. We investigated the role of TTYH3 as a cancer-promoting factor in bladder cancer. The mRNA expression of TTYH3 in bladder cancer patients was investigated using various bioinformatics databases. The results demonstrated that the increasingly greater expression of TTYH3 increasingly worsened the prognosis of patients with bladder cancer. TTYH3 knockdown bladder cancer cell lines were constructed by their various cancer properties measured. TTYH3 knockdown significantly reduced cell proliferation and sphere formation. Cell migration and invasion were also significantly reduced in knockdown bladder cancer cells, compared to normal bladder cancer cells. The knockdown of TTYH3 led to the downregulation of H-Ras/A-Raf/MEK/ERK signaling by inhibiting fibroblast growth factor receptor 1 (FGFR1) phosphorylation. This signaling pathway also attenuated the expression of c-Jun and c-Fos. The findings implicate TTYH3 as a potential factor regulating the properties of bladder cancer and as a therapeutic target.
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10
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TTYH family members form tetrameric complexes at the cell membrane. Commun Biol 2022; 5:886. [PMID: 36042377 PMCID: PMC9427776 DOI: 10.1038/s42003-022-03862-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 08/18/2022] [Indexed: 11/08/2022] Open
Abstract
The conserved Tweety homolog (TTYH) family consists of three paralogs in vertebrates, displaying a ubiquitous expression pattern. Although considered as ion channels for almost two decades, recent structural and functional analyses refuted this role. Intriguingly, while all paralogs shared a dimeric stoichiometry following detergent solubilization, their structures revealed divergence in their relative subunit orientation. Here, we determined the stoichiometry of intact mouse TTYH (mTTYH) complexes in cells. Using cross-linking and single-molecule fluorescence microscopy, we demonstrate that mTTYH1 and mTTYH3 form tetramers at the plasma membrane, stabilized by interactions between their extracellular domains. Using blue-native PAGE, fluorescence-detection size-exclusion chromatography, and hydrogen/deuterium exchange mass spectrometry (HDX-MS), we reveal that detergent solubilization results in tetramers destabilization, leading to their dissolution into dimers. Moreover, HDX-MS demonstrates that the extracellular domains are stabilized in the context of the tetrameric mTTYH complex. Together, our results expose the innate tetrameric organization of TTYH complexes at the cell membrane. Future structural analyses of these assemblies in native membranes are required to illuminate their long-sought cellular function.
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11
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Venkataramani V, Schneider M, Giordano FA, Kuner T, Wick W, Herrlinger U, Winkler F. Disconnecting multicellular networks in brain tumours. Nat Rev Cancer 2022; 22:481-491. [PMID: 35488036 DOI: 10.1038/s41568-022-00475-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/24/2022] [Indexed: 12/13/2022]
Abstract
Cancer cells can organize and communicate in functional networks. Similarly to other networks in biology and sociology, these can be highly relevant for growth and resilience. In this Perspective, we demonstrate by the example of glioblastomas and other incurable brain tumours how versatile multicellular tumour networks are formed by two classes of long intercellular membrane protrusions: tumour microtubes and tunnelling nanotubes. The resulting networks drive tumour growth and resistance to standard therapies. This raises the question of how to disconnect brain tumour networks to halt tumour growth and whether this can make established therapies more effective. Emerging principles of tumour networks, their potential relevance for tumour types outside the brain and translational implications, including clinical trials that are already based on these discoveries, are discussed.
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Affiliation(s)
- Varun Venkataramani
- Neurology Clinic, University Hospital Heidelberg, Heidelberg, Germany.
- National Center for Tumour Diseases, University Hospital Heidelberg, Heidelberg, Germany.
- Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany.
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany.
| | | | - Frank Anton Giordano
- Department of Radiation Oncology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Thomas Kuner
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Wolfgang Wick
- Neurology Clinic, University Hospital Heidelberg, Heidelberg, Germany
- National Center for Tumour Diseases, University Hospital Heidelberg, Heidelberg, Germany
- Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ulrich Herrlinger
- Division of Clinical Neurooncology, Department of Neurology, University Hospital Bonn, University of Bonn, Bonn, Germany.
| | - Frank Winkler
- Neurology Clinic, University Hospital Heidelberg, Heidelberg, Germany.
- National Center for Tumour Diseases, University Hospital Heidelberg, Heidelberg, Germany.
- Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany.
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12
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Wang Y, Xie Y, Dong B, Xue W, Chen S, Mitsuo S, Zou H, Feng Y, Ma K, Dong Q, Cao J, Zhu C. The TTYH3/MK5 Positive Feedback Loop regulates Tumor Progression via GSK3-β/β-catenin signaling in HCC. Int J Biol Sci 2022; 18:4053-4070. [PMID: 35844789 PMCID: PMC9274494 DOI: 10.7150/ijbs.73009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/05/2022] [Indexed: 12/28/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide, and identification of novel targets is necessary for its diagnosis and treatment. This study aimed to investigate the biological function and clinical significance of tweety homolog 3 (TTYH3) in HCC. TTYH3 overexpression promoted cell proliferation, migration, and invasion and inhibited HCCM3 and Hep3B cell apoptosis. TTYH3 promoted tumor formation and metastasis in vivo. TTYH3 upregulated calcium influx and intracellular chloride concentration, thereby promoting cellular migration and regulating epithelial-mesenchymal transition-related protein expression. The interaction between TTYH3 and MK5 was identified through co-immunoprecipitation assays and protein docking. TTYH3 promoted the expression of MK5, which then activated the GSK3β/β-catenin signaling pathway. MK5 knockdown attenuated the activation of GSK3β/β-catenin signaling by TTYH3. TTYH3 expression was regulated in a positive feedback manner. In clinical HCC samples, TTYH3 was upregulated in the HCC tissues compared to nontumor tissues. Furthermore, high TTYH3 expression was significantly correlated with poor patient survival. The CpG islands were hypomethylated in the promoter region of TTYH3 in HCC tissues. In conclusion, we identified TTYH3 regulates tumor development and progression via MK5/GSK3-β/β-catenin signaling in HCC and promotes itself expression in a positive feedback loop.
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Affiliation(s)
- Yixiu Wang
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, No.16 Jiangsu Road, Qingdao 266003, China
| | - Yuwei Xie
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, No.16 Jiangsu Road, Qingdao 266003, China
| | - Bingzi Dong
- Shandong Key Laboratory of Digital Medicine and Computer Assisted Surgery, The Affiliated Hospital of Qingdao University, No. 16 Jiangsu Road, Qingdao 266003, China.,Department of Endocrinology and Metabolism, The Affiliated Hospital of Qingdao University, No.16 Jiangsu Road, Qingdao 266003, China
| | - Weijie Xue
- Department of Gastrointestinal Surgery, The Affiliated Hospital of Qingdao University, No.16 Jiangsu Road, Qingdao 266003, China
| | - Shuhai Chen
- Department of Surgery, Institute of Biomedical Sciences, Tokushima University, Tokushima 770‑8503, Japan
| | - Shimada Mitsuo
- Department of Surgery, Institute of Biomedical Sciences, Tokushima University, Tokushima 770‑8503, Japan
| | - Hao Zou
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, No.16 Jiangsu Road, Qingdao 266003, China
| | - Yujie Feng
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, No.16 Jiangsu Road, Qingdao 266003, China
| | - Kai Ma
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, No.16 Jiangsu Road, Qingdao 266003, China
| | - Qian Dong
- Shandong Key Laboratory of Digital Medicine and Computer Assisted Surgery, The Affiliated Hospital of Qingdao University, No. 16 Jiangsu Road, Qingdao 266003, China.,Department of Pediatric Surgery, The Affiliated Hospital of Qingdao University, No. 16 Jiangsu Road, Qingdao 266003, China
| | - Jingyu Cao
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, No.16 Jiangsu Road, Qingdao 266003, China
| | - Chengzhan Zhu
- Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University, No.16 Jiangsu Road, Qingdao 266003, China.,Shandong Key Laboratory of Digital Medicine and Computer Assisted Surgery, The Affiliated Hospital of Qingdao University, No. 16 Jiangsu Road, Qingdao 266003, China
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13
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Hawn MB, Akin E, Hartzell H, Greenwood IA, Leblanc N. Molecular mechanisms of activation and regulation of ANO1-Encoded Ca 2+-Activated Cl - channels. Channels (Austin) 2021; 15:569-603. [PMID: 34488544 PMCID: PMC8480199 DOI: 10.1080/19336950.2021.1975411] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 08/29/2021] [Indexed: 01/13/2023] Open
Abstract
Ca2+-activated Cl- channels (CaCCs) perform a multitude of functions including the control of cell excitability, regulation of cell volume and ionic homeostasis, exocrine and endocrine secretion, fertilization, amplification of olfactory sensory function, and control of smooth muscle cell contractility. CaCCs are the translated products of two members (ANO1 and ANO2, also known as TMEM16A and TMEM16B) of the Anoctamin family of genes comprising ten paralogs. This review focuses on recent progress in understanding the molecular mechanisms involved in the regulation of ANO1 by cytoplasmic Ca2+, post-translational modifications, and how the channel protein interacts with membrane lipids and protein partners. After first reviewing the basic properties of native CaCCs, we then present a brief historical perspective highlighting controversies about their molecular identity in native cells. This is followed by a summary of the fundamental biophysical and structural properties of ANO1. We specifically address whether the channel is directly activated by internal Ca2+ or indirectly through the intervention of the Ca2+-binding protein Calmodulin (CaM), and the structural domains responsible for Ca2+- and voltage-dependent gating. We then review the regulation of ANO1 by internal ATP, Calmodulin-dependent protein kinase II-(CaMKII)-mediated phosphorylation and phosphatase activity, membrane lipids such as the phospholipid phosphatidyl-(4,5)-bisphosphate (PIP2), free fatty acids and cholesterol, and the cytoskeleton. The article ends with a survey of physical and functional interactions of ANO1 with other membrane proteins such as CLCA1/2, inositol trisphosphate and ryanodine receptors in the endoplasmic reticulum, several members of the TRP channel family, and the ancillary Κ+ channel β subunits KCNE1/5.
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Affiliation(s)
- M. B. Hawn
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - E. Akin
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - H.C. Hartzell
- Department of Cell Biology, Emory University School of Medicine, USA
| | - I. A. Greenwood
- Department of Vascular Pharmacology, St. George’s University of London, UK
| | - N. Leblanc
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
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14
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Structures of tweety homolog proteins TTYH2 and TTYH3 reveal a Ca 2+-dependent switch from intra- to intermembrane dimerization. Nat Commun 2021; 12:6913. [PMID: 34824283 PMCID: PMC8617170 DOI: 10.1038/s41467-021-27283-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/05/2021] [Indexed: 01/07/2023] Open
Abstract
Tweety homologs (TTYHs) comprise a conserved family of transmembrane proteins found in eukaryotes with three members (TTYH1-3) in vertebrates. They are widely expressed in mammals including at high levels in the nervous system and have been implicated in cancers and other diseases including epilepsy, chronic pain, and viral infections. TTYHs have been reported to form Ca2+- and cell volume-regulated anion channels structurally distinct from any characterized protein family with potential roles in cell adhesion, migration, and developmental signaling. To provide insight into TTYH family structure and function, we determined cryo-EM structures of Mus musculus TTYH2 and TTYH3 in lipid nanodiscs. TTYH2 and TTYH3 adopt a previously unobserved fold which includes an extended extracellular domain with a partially solvent exposed pocket that may be an interaction site for hydrophobic molecules. In the presence of Ca2+, TTYH2 and TTYH3 form homomeric cis-dimers bridged by extracellularly coordinated Ca2+. Strikingly, in the absence of Ca2+, TTYH2 forms trans-dimers that span opposing membranes across a ~130 Å intermembrane space as well as a monomeric state. All TTYH structures lack ion conducting pathways and we do not observe TTYH2-dependent channel activity in cells. We conclude TTYHs are not pore forming subunits of anion channels and their function may involve Ca2+-dependent changes in quaternary structure, interactions with hydrophobic molecules near the extracellular membrane surface, and/or association with additional protein partners.
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15
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Cao Y, Wu HN, Cao XL, Yue KY, Han WJ, Cao ZP, Zhang YF, Gao XY, Luo C, Jiang XF, Han H, Zheng MH. Transmembrane Protein Ttyh1 Maintains the Quiescence of Neural Stem Cells Through Ca 2+/NFATc3 Signaling. Front Cell Dev Biol 2021; 9:779373. [PMID: 34869383 PMCID: PMC8635056 DOI: 10.3389/fcell.2021.779373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 10/28/2021] [Indexed: 11/22/2022] Open
Abstract
The quiescence, activation, and subsequent neurogenesis of neural stem cells (NSCs) play essential roles in the physiological homeostasis and pathological repair of the central nervous system. Previous studies indicate that transmembrane protein Ttyh1 is required for the stemness of NSCs, whereas the exact functions in vivo and precise mechanisms are still waiting to be elucidated. By constructing Ttyh1-promoter driven reporter mice, we determined the specific expression of Ttyh1 in quiescent NSCs and niche astrocytes. Further evaluations on Ttyh1 knockout mice revealed that Ttyh1 ablation leads to activated neurogenesis and enhanced spatial learning and memory in adult mice (6-8 weeks). Correspondingly, Ttyh1 deficiency results in accelerated exhaustion of NSC pool and impaired neurogenesis in aged mice (12 months). By RNA-sequencing, bioinformatics and molecular biological analysis, we found that Ttyh1 is involved in the regulation of calcium signaling in NSCs, and transcription factor NFATc3 is a critical effector in quiescence versus cell cycle entry regulated by Ttyh1. Our research uncovered new endogenous mechanisms that regulate quiescence versus activation of NSCs, therefore provide novel targets for the intervention to activate quiescent NSCs to participate in injury repair during pathology and aging.
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Affiliation(s)
- Yuan Cao
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Hai-ning Wu
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi’an, China
| | - Xiu-li Cao
- Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi’an, China
| | - Kang-yi Yue
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Wen-juan Han
- Department of Neurobiology, Fourth Military Medical University, Xi’an, China
| | - Zi-peng Cao
- Department of Occupational and Environmental Health, Fourth Military Medical University, Xi’an, China
| | - Yu-fei Zhang
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi’an, China
| | - Xiang-yu Gao
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Ceng Luo
- Department of Neurobiology, Fourth Military Medical University, Xi’an, China
| | - Xiao-fan Jiang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Hua Han
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi’an, China
| | - Min-hua Zheng
- Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi’an, China
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16
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Gorniak-Walas M, Nizinska K, Lukasiuk K. Cloning and Functional Analysis of Rat Tweety-Homolog 1 Gene Promoter. Neurochem Res 2021; 46:2463-2472. [PMID: 34173119 PMCID: PMC8302521 DOI: 10.1007/s11064-021-03374-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 06/06/2021] [Accepted: 06/08/2021] [Indexed: 11/06/2022]
Abstract
Tweety-homolog 1 protein (Ttyh1) is abundantly expressed in neurons in the healthy brain, and its expression is induced under pathological conditions. In hippocampal neurons in vitro, Ttyh1 was implicated in the regulation of primary neuron morphology. However, the mechanisms that underlie transcriptional regulation of the Ttyh1 gene in neurons remain elusive. The present study sought to identify the promoter of the Ttyh1 gene and functionally characterize cis-regulatory elements that are potentially involved in the transcriptional regulation of Ttyh1 expression in rat dissociated hippocampal neurons in vitro. We cloned a 592 bp rat Ttyh1 promoter sequence and designed deletion constructs of the transcription factors specificity protein 1 (Sp1), E2F transcription factor 3 (E2f3), and achaete-scute homolog 1 (Ascl1) that were fused upstream of a luciferase reporter gene in pGL4.10[luc2]. The luciferase reporter gene assay showed the possible involvement of Ascl1, Sp1, and responsive cis-regulatory elements in Ttyh1 expression. These findings provide novel information about Ttyh1 gene regulation in neurons.
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Affiliation(s)
- Malgorzata Gorniak-Walas
- Laboratory of Epileptogenesis, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warsaw, Poland
| | - Karolina Nizinska
- Laboratory of Epileptogenesis, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warsaw, Poland
| | - Katarzyna Lukasiuk
- Laboratory of Epileptogenesis, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warsaw, Poland.
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17
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Sukalskaia A, Straub MS, Deneka D, Sawicka M, Dutzler R. Cryo-EM structures of the TTYH family reveal a novel architecture for lipid interactions. Nat Commun 2021; 12:4893. [PMID: 34385445 PMCID: PMC8361169 DOI: 10.1038/s41467-021-25106-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/20/2021] [Indexed: 12/30/2022] Open
Abstract
The Tweety homologs (TTYHs) are members of a conserved family of eukaryotic membrane proteins that are abundant in the brain. The three human paralogs were assigned to function as anion channels that are either activated by Ca2+ or cell swelling. To uncover their unknown architecture and its relationship to function, we have determined the structures of human TTYH1–3 by cryo-electron microscopy. All structures display equivalent features of a dimeric membrane protein that contains five transmembrane segments and an extended extracellular domain. As none of the proteins shows attributes reminiscent of an anion channel, we revisited functional experiments and did not find any indication of ion conduction. Instead, we find density in an extended hydrophobic pocket contained in the extracellular domain that emerges from the lipid bilayer, which suggests a role of TTYH proteins in the interaction with lipid-like compounds residing in the membrane. The human Tweety homologue (TTYH) family of transmembrane proteins have been suggested to act as chloride channels. Here the authors present cryo-EM structures of the 3 human TTYH paralogs that do not display the expected features of an anion channel, and instead appear to interact with lipid-like compounds residing in the membrane; suggesting an involvement in lipid-associated processes.
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Affiliation(s)
| | - Monique S Straub
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Dawid Deneka
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Marta Sawicka
- Department of Biochemistry, University of Zurich, Zurich, Switzerland.
| | - Raimund Dutzler
- Department of Biochemistry, University of Zurich, Zurich, Switzerland.
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18
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Nalamalapu RR, Yue M, Stone AR, Murphy S, Saha MS. The tweety Gene Family: From Embryo to Disease. Front Mol Neurosci 2021; 14:672511. [PMID: 34262434 PMCID: PMC8273234 DOI: 10.3389/fnmol.2021.672511] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/18/2021] [Indexed: 12/31/2022] Open
Abstract
The tweety genes encode gated chloride channels that are found in animals, plants, and even simple eukaryotes, signifying their deep evolutionary origin. In vertebrates, the tweety gene family is highly conserved and consists of three members—ttyh1, ttyh2, and ttyh3—that are important for the regulation of cell volume. While research has elucidated potential physiological functions of ttyh1 in neural stem cell maintenance, proliferation, and filopodia formation during neural development, the roles of ttyh2 and ttyh3 are less characterized, though their expression patterns during embryonic and fetal development suggest potential roles in the development of a wide range of tissues including a role in the immune system in response to pathogen-associated molecules. Additionally, members of the tweety gene family have been implicated in various pathologies including cancers, particularly pediatric brain tumors, and neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. Here, we review the current state of research using information from published articles and open-source databases on the tweety gene family with regard to its structure, evolution, expression during development and adulthood, biochemical and cellular functions, and role in human disease. We also identify promising areas for further research to advance our understanding of this important, yet still understudied, family of genes.
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Affiliation(s)
- Rithvik R Nalamalapu
- Department of Biology, College of William and Mary, Williamsburg, VA, United States
| | - Michelle Yue
- Department of Biology, College of William and Mary, Williamsburg, VA, United States
| | - Aaron R Stone
- Department of Biology, College of William and Mary, Williamsburg, VA, United States
| | - Samantha Murphy
- Department of Biology, College of William and Mary, Williamsburg, VA, United States
| | - Margaret S Saha
- Department of Biology, College of William and Mary, Williamsburg, VA, United States
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19
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Sabirov RZ, Islam MR, Okada T, Merzlyak PG, Kurbannazarova RS, Tsiferova NA, Okada Y. The ATP-Releasing Maxi-Cl Channel: Its Identity, Molecular Partners and Physiological/Pathophysiological Implications. Life (Basel) 2021; 11:life11060509. [PMID: 34073084 PMCID: PMC8229958 DOI: 10.3390/life11060509] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 05/27/2021] [Indexed: 12/18/2022] Open
Abstract
The Maxi-Cl phenotype accounts for the majority (app. 60%) of reports on the large-conductance maxi-anion channels (MACs) and has been detected in almost every type of cell, including placenta, endothelium, lymphocyte, cardiac myocyte, neuron, and glial cells, and in cells originating from humans to frogs. A unitary conductance of 300-400 pS, linear current-to-voltage relationship, relatively high anion-to-cation selectivity, bell-shaped voltage dependency, and sensitivity to extracellular gadolinium are biophysical and pharmacological hallmarks of the Maxi-Cl channel. Its identification as a complex with SLCO2A1 as a core pore-forming component and two auxiliary regulatory proteins, annexin A2 and S100A10 (p11), explains the activation mechanism as Tyr23 dephosphorylation at ANXA2 in parallel with calcium binding at S100A10. In the resting state, SLCO2A1 functions as a prostaglandin transporter whereas upon activation it turns to an anion channel. As an efficient pathway for chloride, Maxi-Cl is implicated in a number of physiologically and pathophysiologically important processes, such as cell volume regulation, fluid secretion, apoptosis, and charge transfer. Maxi-Cl is permeable for ATP and other small signaling molecules serving as an electrogenic pathway in cell-to-cell signal transduction. Mutations at the SLCO2A1 gene cause inherited bone and gut pathologies and malignancies, signifying the Maxi-Cl channel as a perspective pharmacological target.
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Affiliation(s)
- Ravshan Z. Sabirov
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent 100174, Uzbekistan
- Correspondence: (R.Z.S.); (Y.O.); Tel.: +81-46-858-1501 (Y.O.); Fax: +81-46-858-1542 (Y.O.)
| | - Md. Rafiqul Islam
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Department of Biochemistry and Molecular Biology, Jagannath University, Dhaka 1100, Bangladesh
| | - Toshiaki Okada
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Veneno Technologies Co. Ltd., Tsukuba 305-0031, Japan
| | - Petr G. Merzlyak
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent 100174, Uzbekistan
| | - Ranokhon S. Kurbannazarova
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent 100174, Uzbekistan
| | - Nargiza A. Tsiferova
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent 100174, Uzbekistan
| | - Yasunobu Okada
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute 480-1195, Japan
- Correspondence: (R.Z.S.); (Y.O.); Tel.: +81-46-858-1501 (Y.O.); Fax: +81-46-858-1542 (Y.O.)
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20
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Tweety-Homolog 1 Facilitates Pain via Enhancement of Nociceptor Excitability and Spinal Synaptic Transmission. Neurosci Bull 2020; 37:478-496. [PMID: 33355899 DOI: 10.1007/s12264-020-00617-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 06/09/2020] [Indexed: 12/21/2022] Open
Abstract
Tweety-homolog 1 (Ttyh1) is expressed in neural tissue and has been implicated in the generation of several brain diseases. However, its functional significance in pain processing is not understood. By disrupting the gene encoding Ttyh1, we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice, along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey (PAG) in the basal state. More importantly, the peripheral inflammation-evoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice. Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release. Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief. Thus, in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.
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21
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Xing Y, Chen J, Hilley H, Steele H, Yang J, Han L. Molecular Signature of Pruriceptive MrgprA3 + Neurons. J Invest Dermatol 2020; 140:2041-2050. [PMID: 32234460 DOI: 10.1016/j.jid.2020.03.935] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 03/12/2020] [Accepted: 03/13/2020] [Indexed: 02/07/2023]
Abstract
Itch, initiated by the activation of sensory neurons, is associated frequently with dermatological diseases. MrgprA3+ sensory neurons have been identified as one of the major itch-sensing neuronal populations. Mounting evidence has demonstrated that peripheral pathological conditions induce physiological regulation of sensory neurons, which is critical for the maintenance of chronic itch sensation. However, the underlying molecular mechanisms are not clear. Here, we performed RNA sequencing of genetically labeled MrgprA3+ neurons under both naïve and allergic contact dermatitis conditions. Our results revealed the unique molecular signature of itch-sensing neurons and the distinct transcriptional profile changes that result in response to dermatitis. We found enrichment of nine Mrgpr family members and two histamine receptors in MrgprA3+ neurons, suggesting that MrgprA3+ neurons are a direct neuronal target for histamine and Mrgpr agonists. In addition, PTPN6 and PCDH12 were identified as highly selective markers of MrgprA3+ neurons. We also discovered that MrgprA3+ neurons respond to skin dermatitis in a way that is unique from other sensory neurons by regulating a combination of transcriptional factors, ion channels, and key molecules involved in synaptic transmission. These results significantly increase our knowledge of itch transmission and uncover potential targets for combating itch.
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Affiliation(s)
- Yanyan Xing
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Junyu Chen
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Henry Hilley
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Haley Steele
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Jingjing Yang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Liang Han
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA.
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22
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Barabas P, Augustine J, Fernández JA, McGeown JG, McGahon MK, Curtis TM. Ion channels and myogenic activity in retinal arterioles. CURRENT TOPICS IN MEMBRANES 2020; 85:187-226. [PMID: 32402639 DOI: 10.1016/bs.ctm.2020.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Retinal pressure autoregulation is an important mechanism that protects the retina by stabilizing retinal blood flow during changes in arterial or intraocular pressure. Similar to other vascular beds, retinal pressure autoregulation is thought to be mediated largely through the myogenic response of small arteries and arterioles which constrict when transmural pressure increases or dilate when it decreases. Over recent years, we and others have investigated the signaling pathways underlying the myogenic response in retinal arterioles, with particular emphasis on the involvement of different ion channels expressed in the smooth muscle layer of these vessels. Here, we review and extend previous work on the expression and spatial distribution of the plasma membrane and sarcoplasmic reticulum ion channels present in retinal vascular smooth muscle cells (VSMCs) and discuss their contribution to pressure-induced myogenic tone in retinal arterioles. This includes new data demonstrating that several key players and modulators of the myogenic response show distinctively heterogeneous expression along the length of the retinal arteriolar network, suggesting differences in myogenic signaling between larger and smaller pre-capillary arterioles. Our immunohistochemical investigations have also highlighted the presence of actin-containing microstructures called myobridges that connect the retinal VSMCs to one another. Although further work is still needed, studies to date investigating myogenic mechanisms in the retina have contributed to a better understanding of how blood flow is regulated in this tissue. They also provide a basis to direct future research into retinal diseases where blood flow changes contribute to the pathology.
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Affiliation(s)
- Peter Barabas
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University of Belfast, Belfast, United Kingdom
| | - Josy Augustine
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University of Belfast, Belfast, United Kingdom
| | - José A Fernández
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University of Belfast, Belfast, United Kingdom
| | - J Graham McGeown
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University of Belfast, Belfast, United Kingdom
| | - Mary K McGahon
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University of Belfast, Belfast, United Kingdom
| | - Tim M Curtis
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University of Belfast, Belfast, United Kingdom.
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23
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Jung E, Alfonso J, Osswald M, Monyer H, Wick W, Winkler F. Emerging intersections between neuroscience and glioma biology. Nat Neurosci 2019; 22:1951-1960. [PMID: 31719671 DOI: 10.1038/s41593-019-0540-y] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 10/17/2019] [Indexed: 12/22/2022]
Abstract
The establishment of neuronal and glial networks in the brain depends on the activities of neural progenitors, which are influenced by cell-intrinsic mechanisms, interactions with the local microenvironment and long-range signaling. Progress in neuroscience has helped identify key factors in CNS development. In parallel, studies in recent years have increased our understanding of molecular and cellular factors in the development and growth of primary brain tumors. To thrive, glioma cells exploit pathways that are active in normal CNS progenitor cells, as well as in normal neurotransmitter signaling. Furthermore, tumor cells of incurable gliomas integrate into communicating multicellular networks, where they are interconnected through neurite-like cellular protrusions. In this Review, we discuss evidence that CNS development, organization and function share a number of common features with glioma progression and malignancy. These include mechanisms used by cells to proliferate and migrate, interact with their microenvironment and integrate into multicellular networks. The emerging intersections between the fields of neuroscience and neuro-oncology considered in this review point to new research directions and novel therapeutic opportunities.
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Affiliation(s)
- Erik Jung
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Julieta Alfonso
- Department of Clinical Neurobiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Matthias Osswald
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Hannah Monyer
- Department of Clinical Neurobiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Clinical Neurobiology, Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Wolfgang Wick
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, Heidelberg, Germany.,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Frank Winkler
- Neurology Clinic and National Center for Tumor Diseases, University Hospital Heidelberg, INF 400, Heidelberg, Germany. .,Clinical Cooperation Unit Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany.
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Prominin-1 Modulates Rho/ROCK-Mediated Membrane Morphology and Calcium-Dependent Intracellular Chloride Flux. Sci Rep 2019; 9:15911. [PMID: 31685837 PMCID: PMC6828804 DOI: 10.1038/s41598-019-52040-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/12/2019] [Indexed: 01/18/2023] Open
Abstract
Membrane morphology is an important structural determinant as it reflects cellular functions. The pentaspan membrane protein Prominin-1 (Prom1/CD133) is known to be localised to protrusions and plays a pivotal role in migration and the determination of cellular morphology; however, the underlying mechanism of its action have been elusive. Here, we performed molecular characterisation of Prom1, focussing primarily on its effects on cell morphology. Overexpression of Prom1 in RPE-1 cells triggers multiple, long, cholesterol-enriched fibres, independently of actin and microtubule polymerisation. A five amino acid stretch located at the carboxyl cytosolic region is essential for fibre formation. The small GTPase Rho and its downstream Rho-associated coiled-coil-containing protein kinase (ROCK) are also essential for this process, and active Rho colocalises with Prom1 at the site of initialisation of fibre formation. In mouse embryonic fibroblast (MEF) cells we show that Prom1 is required for chloride ion efflux induced by calcium ion uptake, and demonstrate that fibre formation is closely associated with chloride efflux activity. Collectively, these findings suggest that Prom1 affects cell morphology and contributes to chloride conductance.
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25
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High Expression of TTYH3 is Related to Poor Clinical Outcomes in Human Gastric Cancer. J Clin Med 2019; 8:jcm8111762. [PMID: 31652813 PMCID: PMC6912211 DOI: 10.3390/jcm8111762] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/21/2019] [Accepted: 10/22/2019] [Indexed: 12/13/2022] Open
Abstract
Ion channels play important roles in regulating various cellular processes and malignant transformation. Expressions of some chloride channels have been suggested to be associated with patient survival in gastric cancer (GC). However, little is known about the expression and function of TTYH3, a gene encoding a chloride ion channel, in cancer progression. Here, we comprehensively analyzed the expression of TTYH3 and its clinical outcome in GC using publicly available cancer gene expression and patient survival data through various databases. We examined the differences of TTYH3 expression between cancers and their normal tissues using the Oncomine, UALCAN, and GEO (Gene Expression Omnibus) databases. TTYH3 expression was investigated from immunohistochemistry images using the Human Protein Atlas database. Copy number alterations and mutations of TTYH3 were analyzed using cBioPortal. The co-expression profile of TTYH3 in GC was revealed using Oncomine. The gene ontology and pathway analyses were done using those co-expressed genes via the Enrichr tool to explore the predicted signaling pathways in GC. TTYH3 mRNA and protein levels in GC were significantly greater than those in normal tissue. Kaplan–Meier analysis revealed the upregulation of TTYH3 expression, which was significantly correlated with worse patient survival. Collectively, our data suggest that TTYH3 might be a potential prognostic marker for GC patients.
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26
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Wu HN, Cao XL, Fang Z, Zhang YF, Han WJ, Yue KY, Cao Y, Zheng MH, Wang LL, Han H. Deficiency of Ttyh1 downstream to Notch signaling results in precocious differentiation of neural stem cells. Biochem Biophys Res Commun 2019; 514:842-847. [PMID: 31079925 DOI: 10.1016/j.bbrc.2019.04.181] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 04/27/2019] [Indexed: 12/18/2022]
Abstract
Mammalian neural stem cells (NSCs) are not only responsible for normal development of the central nervous system (CNS), but also participate in brain homeostasis and repair, thus hold promising clinical potentials in the treatment of neurodegenerative diseases and trauma. However the molecular networks regulating the stemness and differentiation of NSCs have not been fully understood. In this study, we show that Tweety-homolog 1 (Ttyh1), a five-pass transmembrane protein specifically expressed in mouse brain, is involved in maintaining stemness of murine NSCs. Blocking or activating Notch signal led to downregulation and upregulation of Ttyh1 in cultured NSCs, respectively, suggesting that Ttyh1 is under the control of Notch signaling. Knockdown of Ttyh1 in cultured NSCs resulted in a transient increase in the number and size of neurospheres, followed by a decrease of stemness as manifested by compromised neurosphere formation, downregulated stem cell markers, and increased neuronal differentiation. We generated Ttyh1 knockout mice by deleting its exon 4 using the CRISPR-Cas9 technology. Surprisingly, in contrast to a previous report, Ttyh1 knockout did not result in embryonic lethality. NSCs derived from Ttyh1 knockout mice phenocopied NSCs transfected with Ttyh1 siRNA. Immunofluorescence showed that loss of Ttyh1 leads to the increase of neurogenesis in adult mice. Taken together, these findings indicate that Ttyh1, which is likely downstream to Notch signaling, plays an important role in regulating NSCs.
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Affiliation(s)
- Hai-Ning Wu
- State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, 710032, China; Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Xiu-Li Cao
- State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, 710032, China; Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Zheng Fang
- State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, 710032, China; Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Yu-Fei Zhang
- State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, 710032, China; Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Wen-Juan Han
- State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, 710032, China; Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Kang-Yi Yue
- State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, 710032, China; Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Yuan Cao
- State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, 710032, China; Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Min-Hua Zheng
- State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, 710032, China; Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, 710032, China.
| | - Li-Li Wang
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, Institute of Modern Separation Science, Northwest University, Shaanxi Key Laboratory of Modern Separation Science, Xi'an, 710069, China
| | - Hua Han
- State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, 710032, China; Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China.
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Han YE, Kwon J, Won J, An H, Jang MW, Woo J, Lee JS, Park MG, Yoon BE, Lee SE, Hwang EM, Jung JY, Park H, Oh SJ, Lee CJ. Tweety-homolog ( Ttyh) Family Encodes the Pore-forming Subunits of the Swelling-dependent Volume-regulated Anion Channel (VRAC swell) in the Brain. Exp Neurobiol 2019; 28:183-215. [PMID: 31138989 PMCID: PMC6526117 DOI: 10.5607/en.2019.28.2.183] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 11/19/2022] Open
Abstract
In the brain, a reduction in extracellular osmolality causes water-influx and swelling, which subsequently triggers Cl-- and osmolytes-efflux via volume-regulated anion channel (VRAC). Although LRRC8 family has been recently proposed as the pore-forming VRAC which is activated by low cytoplasmic ionic strength but not by swelling, the molecular identity of the pore-forming swelling-dependent VRAC (VRACswell) remains unclear. Here we identify and characterize Tweety-homologs (TTYH1, TTYH2, TTYH3) as the major VRACswell in astrocytes. Gene-silencing of all Ttyh1/2/3 eliminated hypo-osmotic-solution-induced Cl- conductance (ICl,swell) in cultured and hippocampal astrocytes. When heterologously expressed in HEK293T or CHO-K1 cells, each TTYH isoform showed a significant ICl,swell with similar aquaporin-4 dependency, pharmacological properties and glutamate permeability as ICl,swell observed in native astrocytes. Mutagenesis-based structure-activity analysis revealed that positively charged arginine residue at 165 in TTYH1 and 164 in TTYH2 is critical for the formation of the channel-pore. Our results demonstrate that TTYH family confers the bona fide VRACswell in the brain.
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Affiliation(s)
- Young-Eun Han
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea.,Department of Neuroscience, Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - Jea Kwon
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.,KU-KIST, Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, Korea
| | - Joungha Won
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.,Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Heeyoung An
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.,KU-KIST, Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, Korea
| | - Minwoo Wendy Jang
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.,KU-KIST, Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, Korea
| | - Junsung Woo
- Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - Je Sun Lee
- Molecular Neurobiology Laboratory, Dept. of Structure and Function of Neural Network, Korea Brain Research Institute, Daegu 41068, Korea
| | - Min Gu Park
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.,KU-KIST, Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, Korea
| | - Bo-Eun Yoon
- Department of molecular biology, Dankook University, Cheonan 31116, Korea
| | - Seung Eun Lee
- Virus Facility, Research Animal Resource Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - Eun Mi Hwang
- Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - Jae-Young Jung
- Department of Neuroscience, Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - Hyungju Park
- Molecular Neurobiology Laboratory, Dept. of Structure and Function of Neural Network, Korea Brain Research Institute, Daegu 41068, Korea
| | - Soo-Jin Oh
- Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.,Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea.,Department of Neuroscience, Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea.,Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
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28
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Molecular Identities and ATP Release Activities of Two Types of Volume-Regulatory Anion Channels, VSOR and Maxi-Cl. CURRENT TOPICS IN MEMBRANES 2018; 81:125-176. [PMID: 30243431 DOI: 10.1016/bs.ctm.2018.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An elaborate volume regulation system based on interplay of ion channels and transporters was evolved to cope with constant osmotic challenges caused by intensive metabolism, transport and other physiological/pathophysiological events. In animal cells, two types of anion channels are directly activated by cell swelling and involved in the regulatory volume decrease (RVD): volume-sensitive outwardly rectifying anion channel (VSOR), also called volume-regulated anion channel (VRAC), and Maxi-Cl which is the most major type of maxi-anion channel (MAC). These two channels have very different biophysical profiles and exhibit opposite dependence on intracellular ATP. After several decades of verifying many false-positive candidates for VSOR and Maxi-Cl, LRRC8 family proteins emerged as major VSOR components, and SLCO2A1 protein as a core of Maxi-Cl. Still, neither of these proteins alone can fully reproduce the native channel phenotypes suggesting existence of missing components. Although both VSOR and Maxi-Cl have pores wide enough to accommodate bulky ATP4- and MgATP2- anions, evidence accumulated hitherto, based on pharmacological and gene silencing experiments, suggests that Maxi-Cl, but not VSOR, serves as one of the major pathways for the release of ATP from swollen and ischemic/hypoxic cells. Relations of VSOR and Maxi-Cl with diseases and their selective pharmacology are the topics promoted by recent advance in molecular identification of the two volume-activated, volume-regulatory anion channels.
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29
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Tweety-Homolog 1 Drives Brain Colonization of Gliomas. J Neurosci 2017; 37:6837-6850. [PMID: 28607172 DOI: 10.1523/jneurosci.3532-16.2017] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 03/16/2017] [Accepted: 04/19/2017] [Indexed: 01/25/2023] Open
Abstract
Early and progressive colonization of the healthy brain is one hallmark of diffuse gliomas, including glioblastomas. We recently discovered ultralong (>10 to hundreds of microns) membrane protrusions [tumor microtubes (TMs)] extended by glioma cells. TMs have been associated with the capacity of glioma cells to effectively invade the brain and proliferate. Moreover, TMs are also used by some tumor cells to interconnect to one large, resistant multicellular network. Here, we performed a correlative gene-expression microarray and in vivo imaging analysis, and identified novel molecular candidates for TM formation and function. Interestingly, these genes were previously linked to normal CNS development. One of the genes scoring highest in tests related to the outgrowth of TMs was tweety-homolog 1 (TTYH1), which was highly expressed in a fraction of TMs in mice and patients. Ttyh1 was confirmed to be a potent regulator of normal TM morphology and of TM-mediated tumor-cell invasion and proliferation. Glioma cells with one or two TMs were mainly responsible for effective brain colonization, and Ttyh1 downregulation particularly affected this cellular subtype, resulting in reduced tumor progression and prolonged survival of mice. The remaining Ttyh1-deficient tumor cells, however, had more interconnecting TMs, which were associated with increased radioresistance in those small tumors. These findings imply a cellular and molecular heterogeneity in gliomas regarding formation and function of distinct TM subtypes, with multiple parallels to neuronal development, and suggest that Ttyh1 might be a promising target to specifically reduce TM-associated brain colonization by glioma cells in patients.SIGNIFICANCE STATEMENT In this report, we identify tweety-homolog 1 (Ttyh1), a membrane protein linked to neuronal development, as a potent driver of tumor microtube (TM)-mediated brain colonization by glioma cells. Targeting of Ttyh1 effectively inhibited the formation of invasive TMs and glioma growth, but increased network formation by intercellular TMs, suggesting a functional and molecular heterogeneity of the recently discovered TMs with potential implications for future TM-targeting strategies.
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30
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Cao XL, Zhang X, Zhang YF, Zhang YZ, Song CG, Liu F, Hu YY, Zheng MH, Han H. Expression and purification of mouse Ttyh1 fragments as antigens to generate Ttyh1-specific monoclonal antibodies. Protein Expr Purif 2016; 130:81-89. [PMID: 27678288 DOI: 10.1016/j.pep.2016.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/19/2016] [Accepted: 09/23/2016] [Indexed: 02/03/2023]
Abstract
Ttyh1 is a murine homolog of the Drosophila Tweety and is predicted as a five-pass transmembrane protein. The Ttyh1 mRNA is expressed in mouse brain tissues with a restricted pattern and in human glioma cells. Ttyh1 protein may function as a large-conductance chloride channel, however, the role of Ttyh1 in normal neural development and tumorigenesis has been largely unknown, at least partially due to the lack of effective antibodies. Here we report the expression in E. coli and purification of two recombinant Ttyh1 protein fragments corresponding to one of the predicted extracellular domains and the carboxyl terminus of the mouse Ttyh1. With these Ttyh1 protein products, a set of monoclonal antibodies (mAbs) against the mouse Ttyh1 protein was established by using conventional hybridoma techniques. The specificity of the anti-Ttyh1 mAbs was determined based on their activities in Western blotting and immunofluorescent analysis using embryonic brain tissues and cultured mouse neural stem cells (NSCs). We also show that the mouse Ttyh1 protein was expressed in cultured NSCs, most likely in membrane and cytoplasm. In mouse embryonic brains, it appeared that the Ttyh1 protein was specifically expressed in the apical edge of the ventricular zone as puncta-like structures, as determined by using immunofluorescence. Taken together, our study provided a useful tool for further exploration of the biological functions and pathological significance of Ttyh1 in mice.
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Affiliation(s)
- Xiu-Li Cao
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, The Fourth Military Medical University, Xi'an, 710032, China
| | - Xing Zhang
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, The Fourth Military Medical University, Xi'an, 710032, China
| | - Yu-Fei Zhang
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, The Fourth Military Medical University, Xi'an, 710032, China
| | - Yi-Zhe Zhang
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, The Fourth Military Medical University, Xi'an, 710032, China
| | - Chang-Geng Song
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, The Fourth Military Medical University, Xi'an, 710032, China
| | - Fan Liu
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, The Fourth Military Medical University, Xi'an, 710032, China
| | - Yi-Yang Hu
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, The Fourth Military Medical University, Xi'an, 710032, China
| | - Min-Hua Zheng
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, The Fourth Military Medical University, Xi'an, 710032, China.
| | - Hua Han
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, The Fourth Military Medical University, Xi'an, 710032, China; Department of Biochemistry and Molecular Biology, The Fourth Military Medical University, Xi'an, 710032, China.
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31
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Taylor JY, Schwander K, Kardia SLR, Arnett D, Liang J, Hunt SC, Rao DC, Sun YV. A Genome-wide study of blood pressure in African Americans accounting for gene-smoking interaction. Sci Rep 2016; 6:18812. [PMID: 26752167 PMCID: PMC4707536 DOI: 10.1038/srep18812] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 11/09/2015] [Indexed: 12/28/2022] Open
Abstract
Cigarette smoking has been shown to be a health hazard. In addition to being considered a negative lifestyle behavior, studies have shown that cigarette smoking has been linked to genetic underpinnings of hypertension. Because African Americans have the highest incidence and prevalence of hypertension, we examined the joint effect of genetics and cigarette smoking on health among this understudied population. The sample included African Americans from the genome wide association studies of HyperGEN (N = 1083, discovery sample) and GENOA (N = 1427, replication sample), both part of the FBPP. Results suggested that 2 SNPs located on chromosomes 14 (NEDD8; rs11158609; raw p = 9.80 × 10−9, genomic control-adjusted p = 2.09 × 10−7) and 17 (TTYH2; rs8078051; raw p = 6.28 × 10−8, genomic control-adjusted p = 9.65 × 10−7) were associated with SBP including the genetic interaction with cigarette smoking. These two SNPs were not associated with SBP in a main genetic effect only model. This study advances knowledge in the area of main and joint effects of genetics and cigarette smoking on hypertension among African Americans and offers a model to the reader for assessing these risks. More research is required to determine how these genes play a role in expression of hypertension.
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Affiliation(s)
| | - Karen Schwander
- Division of Biostatistics, School of Medicine, Washington University in St. Louis, St. Louis
| | - Sharon L R Kardia
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor
| | - Donna Arnett
- Department of Epidemiology, School of Public Health, University of Alabama, Birmingham
| | - Jingjing Liang
- Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, Cleveland
| | - Steven C Hunt
- Cardiovascular Genetics Division, School of Medicine, University of Utah, Salt Lake City
| | - D C Rao
- Division of Biostatistics, School of Medicine, Washington University in St. Louis, St. Louis
| | - Yan V Sun
- Department of Epidemiology, Rollins School of Public Health, Emory University.,Department of Biomedical Informatics, School of Medicine, Emory University, Atlanta
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32
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Sabirov RZ, Merzlyak PG, Islam MR, Okada T, Okada Y. The properties, functions, and pathophysiology of maxi-anion channels. Pflugers Arch 2016; 468:405-20. [DOI: 10.1007/s00424-015-1774-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/11/2015] [Accepted: 12/15/2015] [Indexed: 01/19/2023]
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33
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Leblanc N, Forrest AS, Ayon RJ, Wiwchar M, Angermann JE, Pritchard HAT, Singer CA, Valencik ML, Britton F, Greenwood IA. Molecular and functional significance of Ca(2+)-activated Cl(-) channels in pulmonary arterial smooth muscle. Pulm Circ 2015; 5:244-68. [PMID: 26064450 DOI: 10.1086/680189] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 07/22/2014] [Indexed: 12/31/2022] Open
Abstract
Increased peripheral resistance of small distal pulmonary arteries is a hallmark signature of pulmonary hypertension (PH) and is believed to be the consequence of enhanced vasoconstriction to agonists, thickening of the arterial wall due to remodeling, and increased thrombosis. The elevation in arterial tone in PH is attributable, at least in part, to smooth muscle cells of PH patients being more depolarized and displaying higher intracellular Ca(2+) levels than cells from normal subjects. It is now clear that downregulation of voltage-dependent K(+) channels (e.g., Kv1.5) and increased expression and activity of voltage-dependent (Cav1.2) and voltage-independent (e.g., canonical and vanilloid transient receptor potential [TRPC and TRPV]) Ca(2+) channels play an important role in the functional remodeling of pulmonary arteries in PH. This review focuses on an anion-permeable channel that is now considered a novel excitatory mechanism in the systemic and pulmonary circulations. It is permeable to Cl(-) and is activated by a rise in intracellular Ca(2+) concentration (Ca(2+)-activated Cl(-) channel, or CaCC). The first section outlines the biophysical and pharmacological properties of the channel and ends with a description of the molecular candidate genes postulated to encode for CaCCs, with particular emphasis on the bestrophin and the newly discovered TMEM16 and anoctamin families of genes. The second section provides a review of the various sources of Ca(2+) activating CaCCs, which include stimulation by mobilization from intracellular Ca(2+) stores and Ca(2+) entry through voltage-dependent and voltage-independent Ca(2+) channels. The third and final section summarizes recent findings that suggest a potentially important role for CaCCs and the gene TMEM16A in PH.
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Affiliation(s)
- Normand Leblanc
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Abigail S Forrest
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Ramon J Ayon
- Department of Medicine, University of Illinois, Chicago, Illinois, USA
| | - Michael Wiwchar
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Jeff E Angermann
- School of Community Health Sciences, University of Nevada, Reno, Nevada, USA
| | - Harry A T Pritchard
- Vascular Biology Research Centre, Institute of Cardiovascular and Cell Sciences, St. George's University of London, London, United Kingdom
| | - Cherie A Singer
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Maria L Valencik
- Department of Biochemistry and Molecular Biology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Fiona Britton
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Iain A Greenwood
- Vascular Biology Research Centre, Institute of Cardiovascular and Cell Sciences, St. George's University of London, London, United Kingdom
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34
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Characterization of tweety gene (ttyh1-3) expression in Xenopus laevis during embryonic development. Gene Expr Patterns 2014; 17:38-44. [PMID: 25541457 DOI: 10.1016/j.gep.2014.12.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 11/08/2014] [Accepted: 12/02/2014] [Indexed: 02/08/2023]
Abstract
The tweety family of genes encodes large-conductance chloride channels and has been implicated in a wide array of cellular processes including cell division, cell adhesion, regulation of calcium activity, and tumorigenesis, particularly in neuronal cells. However, their expression patterns during early development remain largely unknown. Here, we describe the spatial and temporal patterning of ttyh1, ttyh2, and ttyh3 in Xenopus laevis during early embryonic development. Ttyh1 and ttyh3 are initially expressed at the late neurula stage are and primarily localized to the developing nervous system; however ttyh1 and ttyh3 both show transient expression in the somites. By swimming tadpole stages, all three genes are expressed in the brain, spinal cord, eye, and cranial ganglia. While ttyh1 is restricted to proliferative, ventricular zones, ttyh3 is primarily localized to postmitotic regions of the developing nervous system. Ttyh2, however, is strongly expressed in cranial ganglia V, VII, IX and X. The differing temporal and spatial expression patterns of ttyh1, ttyh2, and ttyh3 suggest that they may play distinct roles throughout embryonic development.
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Ttyh1 protein is expressed in glia in vitro and shows elevated expression in activated astrocytes following status epilepticus. Neurochem Res 2014; 39:2516-26. [PMID: 25316497 PMCID: PMC4246129 DOI: 10.1007/s11064-014-1455-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 09/26/2014] [Accepted: 10/08/2014] [Indexed: 11/29/2022]
Abstract
In a previous study, we showed that Ttyh1 protein is expressed in neurons in vitro and in vivo in the form of punctuate structures, which are localized to neuropil and neuronal somata. Herein, we provide the first description of Ttyh1 protein expression in astrocytes, oligodendrocytes and microglia in vitro. Moreover, using double immunofluorescence, we show Ttyh1 protein expression in activated astrocytes in the hippocampus following amygdala stimulation-induced status epilepticus. We demonstrate that in migrating astrocytes in in vitro wound model Ttyh1 concentrates at the edges of extending processes. These data suggest that Ttyh1 not only participates in shaping neuronal morphology, as previously described, but may also play a role in the function of activated glia in brain pathology. To localize Ttyh1 expression in the cellular compartments of neurons and astrocytes, we performed in vitro double immunofluorescent staining using markers for the following subcellular structures: endoplasmic reticulum (GRP78), Golgi apparatus (GM130), clathrin-coated vehicles (clathrin), early endosomes (Rab5 and APPL2), recycling endosomes (Rab11), trans-Golgi network (TGN46), endoplasmic reticulum membrane (calnexin), late endosomes and lysosomes (LAMP1) and synaptic vesicles (synaptoporin and synaptotagmin 1). We found that Ttyh1 is present in the endoplasmic reticulum, Golgi apparatus and clathrin-coated vesicles (clathrin) in both neurons and astrocytes and also in late endosomes or lysosomes in astrocytes. The presence of Ttyh1 was negligible in early endosomes, recycling endosomes, trans-Golgi network, endoplasmic reticulum membrane and synaptic vesicles.
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Trigeminal ganglion neurons of mice show intracellular chloride accumulation and chloride-dependent amplification of capsaicin-induced responses. PLoS One 2012; 7:e48005. [PMID: 23144843 PMCID: PMC3493563 DOI: 10.1371/journal.pone.0048005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 09/19/2012] [Indexed: 12/21/2022] Open
Abstract
Intracellular Cl− concentrations ([Cl−]i) of sensory neurons regulate signal transmission and signal amplification. In dorsal root ganglion (DRG) and olfactory sensory neurons (OSNs), Cl− is accumulated by the Na+-K+-2Cl− cotransporter 1 (NKCC1), resulting in a [Cl−]i above electrochemical equilibrium and a depolarizing Cl− efflux upon Cl− channel opening. Here, we investigate the [Cl−]i and function of Cl− in primary sensory neurons of trigeminal ganglia (TG) of wild type (WT) and NKCC1−/− mice using pharmacological and imaging approaches, patch-clamping, as well as behavioral testing. The [Cl−]i of WT TG neurons indicated active NKCC1-dependent Cl− accumulation. Gamma-aminobutyric acid (GABA)A receptor activation induced a reduction of [Cl−]i as well as Ca2+ transients in a corresponding fraction of TG neurons. Ca2+ transients were sensitive to inhibition of NKCC1 and voltage-gated Ca2+ channels (VGCCs). Ca2+ responses induced by capsaicin, a prototypical stimulus of transient receptor potential vanilloid subfamily member-1 (TRPV1) were diminished in NKCC1−/− TG neurons, but elevated under conditions of a lowered [Cl−]o suggesting a Cl−-dependent amplification of capsaicin-induced responses. Using next generation sequencing (NGS), we found expression of different Ca2+-activated Cl− channels (CaCCs) in TGs of mice. Pharmacological inhibition of CaCCs reduced the amplitude of capsaicin-induced responses of TG neurons in Ca2+ imaging and electrophysiological recordings. In a behavioral paradigm, NKCC1−/− mice showed less avoidance of the aversive stimulus capsaicin. In summary, our results strongly argue for a Ca2+-activated Cl−-dependent signal amplification mechanism in TG neurons that requires intracellular Cl− accumulation by NKCC1 and the activation of CaCCs.
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Islam MR, Uramoto H, Okada T, Sabirov RZ, Okada Y. Maxi-anion channel and pannexin 1 hemichannel constitute separate pathways for swelling-induced ATP release in murine L929 fibrosarcoma cells. Am J Physiol Cell Physiol 2012; 303:C924-35. [PMID: 22785119 DOI: 10.1152/ajpcell.00459.2011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The maxi-anion channel plays a classically recognized role in controlling the membrane potential through the chloride conductance. It also has novel functions as a regulated pathway for the release of the anionic signaling molecules ATP and excitatory amino acids from cells subjected to osmotic perturbation, ischemia, or hypoxia. Because hemichannels formed by pannexins and connexins have been reported to mediate ATP release from a number of cell types, these hemichannels may represent the molecular correlate of the maxi-anion channel. Here, we found that L929 fibrosarcoma cells express functional maxi-anion channels which mediate a major portion of swelling-induced ATP release, and that ATP released via maxi-anion channels facilitates the regulatory volume decrease after osmotic swelling. Also, it was found that the cells express the mRNA for pannexin 1, pannexin 2, and connexin 43. Hypotonicity-induced ATP release was partially suppressed not only by known blockers of the maxi-anion channel but also by several blockers of pannexins including the pannexin 1-specific blocking peptide (10)Panx1 and small interfering (si)RNA against pannexin 1 but not pannexin 2. The inhibitory effects of maxi-anion channel blockers and pannexin 1 antagonists were additive. In contrast, maxi-anion channel activity was not affected by pannexin 1 antagonists and siRNAs against pannexins 1 and 2. Although a connexin 43-specific blocking peptide, Gap27, slightly suppressed hypotonicity-induced ATP release, maxi-anion channel activity was not affected by Gap27 or connexin 43-specific siRNA. Thus, it is concluded that the maxi-anion channel is a molecular entity distinct from pannexin 1, pannexin 2, and connexin 43, and that the maxi-anion channel and the hemichannels constitute separate pathways for swelling-induced ATP release in L929 cells.
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Affiliation(s)
- Md Rafiqul Islam
- Dept. of Cell Physiology, National Institute for Physiological Sciences, Myodaiji-cho, Okazaki 444-8585, Japan
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Templin JS, Bang SJ, Soiza-Reilly M, Berde CB, Commons KG. Patterned expression of ion channel genes in mouse dorsal raphe nucleus determined with the Allen Mouse Brain Atlas. Brain Res 2012; 1457:1-12. [PMID: 22534482 DOI: 10.1016/j.brainres.2012.03.066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 03/06/2012] [Accepted: 03/28/2012] [Indexed: 12/29/2022]
Abstract
The dorsal raphe nucleus (DR) is the major source of serotonin (5-hydroxytryptamine, 5-HT) in the forebrain and dysfunction of this midbrain structure is implicated in affective disorders. The DR is composed of several types of 5-HT and non-5-HT neurons and their excitable-membrane properties are heterogeneous and overlapping. In order to understand how these properties may be generated, we examined the mRNA expression patterns of voltage- and ligand-gated ion channels in the DR using the Allen Mouse Brain Atlas. Since DR cytoarchitecture is organized with respect to the midline, we sought to identify genes that were expressed in a pattern with respect to the midline, either enriched or depleted, rather than those that were homogenously expressed throughout the DR. Less than 10% of the screened genes for voltage-gated ion channels showed patterned expression within the DR. Identified genes included voltage-gated sodium channel beta subunits, potassium channels, P/Q-, N-type calcium channels, as well as the alpha2/delta-1 calcium channel. Several voltage-gated chloride channels were also identified, although these may function within intracellular compartments. Of the ligand-gated ion channels examined, 20% showed patterned expression. These consisted primarily of glutamate and GABA-A receptor subunits. The identified genes likely contribute to unique excitable properties of different groups of neurons in the DR and may include novel pharmacologic targets for affective disorders.
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Affiliation(s)
- J Scott Templin
- Department of Anesthesiology, Perioperative, and Pain Medicine, Children's Hospital, Boston, 300 Longwood Ave., Boston, MA 02115, USA
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Mundhenk L, Johannesson B, Anagnostopoulou P, Braun J, Bothe MK, Schultz C, Mall MA, Gruber AD. mCLCA3 does not contribute to calcium-activated chloride conductance in murine airways. Am J Respir Cell Mol Biol 2012; 47:87-93. [PMID: 22362387 DOI: 10.1165/rcmb.2010-0508oc] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Ca(2+)-activated Cl(-) channels (CaCCs) contribute to airway Cl(-) and fluid secretion, and were implicated in the modulation of disease severity and as a therapeutic target in cystic fibrosis (CF). Previous in vitro studies suggested that members of the CLCA gene family, including the murine mCLCA3, contribute to CaCCs. However, the role of mCLCA3 in ion transport in native airway epithelia has not been studied, to the best of our knowledge. In this study, we used mCLCA3-deficient mice and determined bioelectric properties in freshly excised tracheal tissue, airway morphology, and gene expression studies, to determine the role of mCLCA3 in airway ion transport and airway structure. Bioelectric measurements did not detect any differences in basal short-circuit current, amiloride-sensitive Na(+) absorption, cyclic adenosine monophosphate-dependent Cl(-) secretion, and activation of Ca(2+)-activated (uridine-5'-triphosphate-mediated) Cl(-) secretion in mCLCA3-deficient mice compared with wild-type mice. Moreover, no histological changes were observed in the respiratory tract or any other tissues of mCLCA3-deficient mice when compared with wild-type control mice. The intratracheal instillation of IL-13 produced an approximately 30-fold up-regulation of mCLCA3 transcripts without inducing CaCC activity in wild-type airways, and induced goblet-cell hyperplasia and mucin gene expression to similar levels in both genotypes. Further, multiple specific reverse-transcriptase quantitative PCR assays for other CaCC candidates, including mCLCA1, mCLCA2, mCLCA4, mCLCA5, mCLCA6, mCLCA7, mBEST1, mBEST2, mCLC4, mTTYH3, and mTMEM16A, failed to identify the differential expression of genes in the respiratory tract that may compensate for a lack of mCLCA3 function. Together, these findings argue against a role of mCLCA3 in CaCC-mediated Cl(-) secretion in murine respiratory epithelia.
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Affiliation(s)
- Lars Mundhenk
- Department of Veterinary Pathology, College of Veterinary Medicine, Freie Universität Berlin, Germany.
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Volknandt W, Karas M. Proteomic analysis of the presynaptic active zone. Exp Brain Res 2012; 217:449-61. [DOI: 10.1007/s00221-012-3031-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 02/04/2012] [Indexed: 02/06/2023]
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Parsons SP, Kunze WA, Huizinga JD. Maxi-channels recorded in situ from ICC and pericytes associated with the mouse myenteric plexus. Am J Physiol Cell Physiol 2011; 302:C1055-69. [PMID: 22159087 DOI: 10.1152/ajpcell.00334.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Ion channels are fundamental to gastrointestinal pacemaking by interstitial cells of Cajal (ICC). Previously, we have recorded a high-conductance chloride channel (HCCC) from ICC, both in culture and in situ, associated with the myenteric plexus. The biophysical properties of the HCCC (conductance, subconductances, voltage- and time-dependent inactivation) suggest it is a member of a class called the maxi-anion channels. In this study we further investigated the properties of the HCCC in situ. Our main finding was that the HCCC is not strictly a chloride channel but has a relative sodium-chloride permeability (P(Na/Cl)) of 0.76 to 1.64 (depending on the method of measurement). Therefore, we have renamed the HCCC the "maxi-channel." A maxi-channel was also expressed by pericytes associated with the vasculature near the myenteric plexus. This had a lower P(Na/Cl) (0.33 to 0.49, depending on the method of measurement) but similar conductance (326 ± 7 vs. 316 ± 24 pS for ICC). This is the first report of cation permeability equaling anion permeability in a maxi-anion channel. As such, the properties of the maxi-channels described in this article may have implications for the maxi-anion channel field, as well as for studies of their role in ICC and pericytes.
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Affiliation(s)
- Sean P Parsons
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
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Effects of elevated seawater pCO(2) on gene expression patterns in the gills of the green crab, Carcinus maenas. BMC Genomics 2011; 12:488. [PMID: 21978240 PMCID: PMC3206878 DOI: 10.1186/1471-2164-12-488] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 10/06/2011] [Indexed: 11/10/2022] Open
Abstract
Background The green crab Carcinus maenas is known for its high acclimation potential to varying environmental abiotic conditions. A high ability for ion and acid-base regulation is mainly based on an efficient regulation apparatus located in gill epithelia. However, at present it is neither known which ion transport proteins play a key role in the acid-base compensation response nor how gill epithelia respond to elevated seawater pCO2 as predicted for the future. In order to promote our understanding of the responses of green crab acid-base regulatory epithelia to high pCO2, Baltic Sea green crabs were exposed to a pCO2 of 400 Pa. Gills were screened for differentially expressed gene transcripts using a 4,462-feature microarray and quantitative real-time PCR. Results Crabs responded mainly through fine scale adjustment of gene expression to elevated pCO2. However, 2% of all investigated transcripts were significantly regulated 1.3 to 2.2-fold upon one-week exposure to CO2 stress. Most of the genes known to code for proteins involved in osmo- and acid-base regulation, as well as cellular stress response, were were not impacted by elevated pCO2. However, after one week of exposure, significant changes were detected in a calcium-activated chloride channel, a hyperpolarization activated nucleotide-gated potassium channel, a tetraspanin, and an integrin. Furthermore, a putative syntaxin-binding protein, a protein of the transmembrane 9 superfamily, and a Cl-/HCO3- exchanger of the SLC 4 family were differentially regulated. These genes were also affected in a previously published hypoosmotic acclimation response study. Conclusions The moderate, but specific response of C. maenas gill gene expression indicates that (1) seawater acidification does not act as a strong stressor on the cellular level in gill epithelia; (2) the response to hypercapnia is to some degree comparable to a hypoosmotic acclimation response; (3) the specialization of each of the posterior gill arches might go beyond what has been demonstrated up to date; and (4) a re-configuration of gill epithelia might occur in response to hypercapnia.
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Sabirov RZ, Merzlyak PG. Plasmalemmal VDAC controversies and maxi-anion channel puzzle. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:1570-80. [PMID: 21986486 DOI: 10.1016/j.bbamem.2011.09.024] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 09/22/2011] [Accepted: 09/23/2011] [Indexed: 12/14/2022]
Abstract
The maxi-anion channel has been observed in many cell types from the very beginning of the patch-clamp era. The channel is highly conductive for chloride and thus can modulate the resting membrane potential and play a role in fluid secretion/absorption and cell volume regulation. A wide nanoscopic pore of the maxi-anion channel permits passage of excitatory amino acids and nucleotides. The channel-mediated release of these signaling molecules is associated with kidney tubuloglomerular feedback, cardiac ischemia/hypoxia, as well as brain ischemia/hypoxia and excitotoxic neurodegeneration. Despite the ubiquitous expression and physiological/pathophysiological significance, the molecular identity of the maxi-anion channel is still obscure. VDAC is primarily a mitochondrial protein; however several groups detected it on the cellular surface. VDAC in lipid bilayers reproduced the most important biophysical properties of the maxi-anion channel, such as a wide nano-sized pore, closure in response to moderately high voltages, ATP-block and ATP-permeability. However, these similarities turned out to be superficial, and the hypothesis of plasmalemmal VDAC as the maxi-anion channel did not withstand the test by genetic manipulations of VDAC protein expression. VDAC on the cellular surface could also function as a ferricyanide reductase or a receptor for plasminogen kringle 5 and for neuroactive steroids. These ideas, as well as the very presence of VDAC on plasmalemma, remain to be scrutinized by genetic manipulations of the VDAC protein expression. This article is part of a Special Issue entitled: VDAC structure, function, and regulation of mitochondrial metabolism.
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Affiliation(s)
- Ravshan Z Sabirov
- Laboratory of Molecular Physiology, Institute of Pysiology and Biphysics, Academy of Science, RUz, Tashkent, Uzbekistan.
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Yoon H, Lee DJ, Kim MH, Bok J. Identification of genes concordantly expressed with Atoh1 during inner ear development. Anat Cell Biol 2011; 44:69-78. [PMID: 21519551 PMCID: PMC3080010 DOI: 10.5115/acb.2011.44.1.69] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 12/02/2010] [Accepted: 12/15/2010] [Indexed: 01/19/2023] Open
Abstract
The inner ear is composed of a cochlear duct and five vestibular organs in which mechanosensory hair cells play critical roles in receiving and relaying sound and balance signals to the brain. To identify novel genes associated with hair cell differentiation or function, we analyzed an archived gene expression dataset from embryonic mouse inner ear tissues. Since atonal homolog 1a (Atoh1) is a well known factor required for hair cell differentiation, we searched for genes expressed in a similar pattern with Atoh1 during inner ear development. The list from our analysis includes many genes previously reported to be involved in hair cell differentiation such as Myo6, Tecta, Myo7a, Cdh23, Atp6v1b1, and Gfi1. In addition, we identified many other genes that have not been associated with hair cell differentiation, including Tekt2, Spag6, Smpx, Lmod1, Myh7b, Kif9, Ttyh1, Scn11a and Cnga2. We examined expression patterns of some of the newly identified genes using real-time polymerase chain reaction and in situ hybridization. For example, Smpx and Tekt2, which are regulators for cytoskeletal dynamics, were shown specifically expressed in the hair cells, suggesting a possible role in hair cell differentiation or function. Here, by reanalyzing archived genetic profiling data, we identified a list of novel genes possibly involved in hair cell differentiation.
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Affiliation(s)
- Heejei Yoon
- Department of Anatomy, Brain Korea 21 Project for Medical Science, College of Medicine, Yonsei University, Seoul, Korea
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Toxin mediated diarrhea in the 21 century: the pathophysiology of intestinal ion transport in the course of ETEC, V. cholerae and rotavirus infection. Toxins (Basel) 2010; 2:2132-57. [PMID: 22069677 PMCID: PMC3153279 DOI: 10.3390/toxins2082132] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 08/09/2010] [Indexed: 12/31/2022] Open
Abstract
An estimated 4 billion episodes of diarrhea occur each year. As a result, 2–3 million children and 0.5–1 million adults succumb to the consequences of this major healthcare concern. The majority of these deaths can be attributed to toxin mediated diarrhea by infectious agents, such as E. coli, V. cholerae or Rotavirus. Our understanding of the pathophysiological processes underlying these infectious diseases has notably improved over the last years. This review will focus on the cellular mechanism of action of the most common enterotoxins and the latest specific therapeutic approaches that have been developed to contain their lethal effects.
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Sabirov RZ, Okada Y. The maxi-anion channel: a classical channel playing novel roles through an unidentified molecular entity. J Physiol Sci 2009; 59:3-21. [PMID: 19340557 PMCID: PMC10717152 DOI: 10.1007/s12576-008-0008-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 11/05/2008] [Indexed: 10/20/2022]
Abstract
The maxi-anion channel is widely expressed and found in almost every part of the body. The channel is activated in response to osmotic cell swelling, to excision of the membrane patch, and also to some other physiologically and pathophysiologically relevant stimuli, such as salt stress in kidney macula densa as well as ischemia/hypoxia in heart and brain. Biophysically, the maxi-anion channel is characterized by a large single-channel conductance of 300-400 pS, which saturates at 580-640 pS with increasing the Cl(-) concentration. The channel discriminates well between Na(+) and Cl(-), but is poorly selective to other halides exhibiting weak electric-field selectivity with an Eisenman's selectivity sequence I. The maxi-anion channel has a wide pore with an effective radius of approximately 1.3 nm and permits passage not only of Cl(-) but also of some intracellular large organic anions, thereby releasing major extracellular signals and gliotransmitters such as glutamate(-) and ATP(4-). The channel-mediated efflux of these signaling molecules is associated with kidney tubuloglomerular feedback, cardiac ischemia/hypoxia, as well as brain ischemia/hypoxia and excitotoxic neurodegeneration. Despite the ubiquitous expression, well-defined properties and physiological/pathophysiological significance of this classical channel, the molecular entity has not been identified. Molecular identification of the maxi-anion channel is an urgent task that would greatly promote investigation in the fields not only of anion channel but also of physiological/pathophysiological signaling in the brain, heart and kidney.
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Affiliation(s)
- Ravshan Z. Sabirov
- Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki, 444-8585 Japan
- Laboratory of Molecular Physiology, Institute of Physiology and Biophysics, Tashkent, 100095 Uzbekistan
| | - Yasunobu Okada
- Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki, 444-8585 Japan
- Department of Physiological Sciences, School of Life Science, The Graduate University for Advanced Studies (Sokendai), Okazaki, 444-8585 Japan
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Hartzell HC, Yu K, Xiao Q, Chien LT, Qu Z. Anoctamin/TMEM16 family members are Ca2+-activated Cl- channels. J Physiol 2008; 587:2127-39. [PMID: 19015192 DOI: 10.1113/jphysiol.2008.163709] [Citation(s) in RCA: 202] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Ca(2+)-activated Cl- channels (CaCCs) perform many important functions in cell physiology including secretion of fluids from acinar cells of secretory glands, amplification of olfactory transduction, regulation of cardiac and neuronal excitability, mediation of the fast block to polyspermy in amphibian oocytes, and regulation of vascular tone. Although a number of proteins have been proposed to be responsible for CaCC currents, the anoctamin family (ANO, also known as TMEM16) exhibits characteristics most similar to those expected for the classical CaCC. Interestingly, this family of proteins has previously attracted the interest of both developmental and cancer biologists. Some members of this family are up-regulated in a number of tumours and functional deficiency in others is linked to developmental defects.
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Affiliation(s)
- H Criss Hartzell
- Department of Cell Biology, Emory University School of Medicine, 615 Michael Street, 535 Whitehead Bldg, Atlanta, GA 30322, USA.
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De Marchi U, Szabò I, Cereghetti GM, Hoxha P, Craigen WJ, Zoratti M. A maxi-chloride channel in the inner membrane of mammalian mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:1438-48. [DOI: 10.1016/j.bbabio.2008.08.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 08/01/2008] [Accepted: 08/12/2008] [Indexed: 01/09/2023]
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Srivastava A, Romanenko VG, Gonzalez-Begne M, Catalán MA, Melvin JE. A variant of the Ca2+-activated Cl channel Best3 is expressed in mouse exocrine glands. J Membr Biol 2008; 222:43-54. [PMID: 18414923 DOI: 10.1007/s00232-008-9098-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2007] [Accepted: 02/21/2008] [Indexed: 11/27/2022]
Abstract
Fluid secretion by exocrine glands requires the activation of an apical Ca2+-dependent Cl channel, the molecular identity of which is unknown. We found that mouse exocrine glands expressed an alternately spliced variant of Best3, a member of the Bestrophin (Vmd2) Ca2+-activated Cl channel gene family, whereas the heart expressed full-length Best3. The spliced transcript lacked exons 2, 3 and 6 (Best3-Delta2,3,6) and is predicted to generate an in-frame protein missing the entire cytoplasmic N terminus, the initial two transmembrane domains and part of the first intracellular loop. In addition to exocrine glands, the Best3-Delta2,3,6 splice variant transcript was detected in lung, testis and kidney. The parotid gland and heart expressed proteins of the predicted size for Best3-Delta2,3,6 and full-length Best3, respectively, that targeted to the plasma membrane in HEK293 cells. HEK293 cells expressing Best3 displayed Ca2+-dependent Cl(-) currents that were sensitive to the Cl channel blocker DIDS. In contrast, no Ca2+-dependent Cl(-) currents were detected in cells expressing Best3-Delta2,3,6. Cotransfection of Best3-Delta2,3,6 with Best3 or Best2 (also expressed in salivary gland acinar cells) had no significant effects on the currents generated by either of these Ca2+-dependent Cl channels. Our results demonstrate that exocrine glands express a unique splice variant of Best3. Nevertheless, Best3-Delta2,3,6 does not produce Ca2+-dependent Cl(-) currents, nor does it regulate the activity of Best2 or the full-length Best3 channel.
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Affiliation(s)
- Alaka Srivastava
- Center for Oral Biology, Medical Center, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave., Box 611, Rochester, NY 14642, USA
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