1
|
Löhn M, Wirth KJ. Potential pathophysiological role of the ion channel TRPM3 in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and the therapeutic effect of low-dose naltrexone. J Transl Med 2024; 22:630. [PMID: 38970055 PMCID: PMC11227206 DOI: 10.1186/s12967-024-05412-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 06/17/2024] [Indexed: 07/07/2024] Open
Abstract
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating disease with a broad overlap of symptomatology with Post-COVID Syndrome (PCS). Despite the severity of symptoms and various neurological, cardiovascular, microvascular, and skeletal muscular findings, no biomarkers have been identified. The Transient receptor potential melastatin 3 (TRPM3) channel, involved in pain transduction, thermosensation, transmitter and neuropeptide release, mechanoregulation, vasorelaxation, and immune defense, shows altered function in ME/CFS. Dysfunction of TRPM3 in natural killer (NK) cells, characterized by reduced calcium flux, has been observed in ME/CFS and PCS patients, suggesting a role in ineffective pathogen clearance and potential virus persistence and autoimmunity development. TRPM3 dysfunction in NK cells can be improved by naltrexone in vitro and ex vivo, which may explain the moderate clinical efficacy of low-dose naltrexone (LDN) treatment. We propose that TRPM3 dysfunction may have a broader involvement in ME/CFS pathophysiology, affecting other organs. This paper discusses TRPM3's expression in various organs and its potential impact on ME/CFS symptoms, with a focus on small nerve fibers and the brain, where TRPM3 is involved in presynaptic GABA release.
Collapse
Affiliation(s)
- Matthias Löhn
- Institute for General Pharmacology and Toxicology, University Hospital, Goethe University, Frankfurt am Main, Germany.
| | - Klaus Josef Wirth
- Institute for General Pharmacology and Toxicology, University Hospital, Goethe University, Frankfurt am Main, Germany.
- Mitodicure GmbH, D-65830, Kriftel, Germany.
| |
Collapse
|
2
|
Shiels A. Through the Cat-Map Gateway: A Brief History of Cataract Genetics. Genes (Basel) 2024; 15:785. [PMID: 38927721 PMCID: PMC11202810 DOI: 10.3390/genes15060785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/06/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
Clouding of the transparent eye lens, or cataract(s), is a leading cause of visual impairment that requires surgical replacement with a synthetic intraocular lens to effectively restore clear vision. Most frequently, cataract is acquired with aging as a multifactorial or complex trait. Cataract may also be inherited as a classic Mendelian trait-often with an early or pediatric onset-with or without other ocular and/or systemic features. Since the early 1990s, over 85 genes and loci have been genetically associated with inherited and/or age-related forms of cataract. While many of these underlying genes-including those for lens crystallins, connexins, and transcription factors-recapitulate signature features of lens development and differentiation, an increasing cohort of unpredicted genes, including those involved in cell-signaling, membrane remodeling, and autophagy, has emerged-providing new insights regarding lens homeostasis and aging. This review provides a brief history of gene discovery for inherited and age-related forms of cataract compiled in the Cat-Map database and highlights potential gene-based therapeutic approaches to delay, reverse, or even prevent cataract formation that may help to reduce the increasing demand for cataract surgery.
Collapse
Affiliation(s)
- Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| |
Collapse
|
3
|
Zhou Y, Bennett TM, Ruzycki PA, Guo Z, Cao YQ, Shahidullah M, Delamere NA, Shiels A. A Cataract-Causing Mutation in the TRPM3 Cation Channel Disrupts Calcium Dynamics in the Lens. Cells 2024; 13:257. [PMID: 38334649 PMCID: PMC10854584 DOI: 10.3390/cells13030257] [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: 01/04/2024] [Revised: 01/23/2024] [Accepted: 01/26/2024] [Indexed: 02/10/2024] Open
Abstract
TRPM3 belongs to the melastatin sub-family of transient receptor potential (TRPM) cation channels and has been shown to function as a steroid-activated, heat-sensitive calcium ion (Ca2+) channel. A missense substitution (p.I65M) in the TRPM3 gene of humans (TRPM3) and mice (Trpm3) has been shown to underlie an inherited form of early-onset, progressive cataract. Here, we model the pathogenetic effects of this cataract-causing mutation using 'knock-in' mutant mice and human cell lines. Trpm3 and its intron-hosted micro-RNA gene (Mir204) were strongly co-expressed in the lens epithelium and other non-pigmented and pigmented ocular epithelia. Homozygous Trpm3-mutant lenses displayed elevated cytosolic Ca2+ levels and an imbalance of sodium (Na+) and potassium (K+) ions coupled with increased water content. Homozygous TRPM3-mutant human lens epithelial (HLE-B3) cell lines and Trpm3-mutant lenses exhibited increased levels of phosphorylated mitogen-activated protein kinase 1/extracellular signal-regulated kinase 2 (MAPK1/ERK2/p42) and MAPK3/ERK1/p44. Mutant TRPM3-M65 channels displayed an increased sensitivity to external Ca2+ concentration and an altered dose response to pregnenolone sulfate (PS) activation. Trpm3-mutant lenses shared the downregulation of genes involved in insulin/peptide secretion and the upregulation of genes involved in Ca2+ dynamics. By contrast, Trpm3-deficient lenses did not replicate the pathophysiological changes observed in Trpm3-mutant lenses. Collectively, our data suggest that a cataract-causing substitution in the TRPM3 cation channel elicits a deleterious gain-of-function rather than a loss-of-function mechanism in the lens.
Collapse
Affiliation(s)
- Yuefang Zhou
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Thomas M. Bennett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Philip A. Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zhaohua Guo
- Department of Anesthesiology and Washington University Pain Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Yu-Qing Cao
- Department of Anesthesiology and Washington University Pain Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Mohammad Shahidullah
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ 85724, USA
| | - Nicholas A. Delamere
- Department of Physiology, University of Arizona College of Medicine, Tucson, AZ 85724, USA
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| |
Collapse
|
4
|
Liu WW, Kinzy TG, Cooke Bailey JN, Xu Z, Hysi P, Wiggs JL. Mechanosensitive ion channel gene survey suggests potential roles in primary open angle glaucoma. Sci Rep 2023; 13:15871. [PMID: 37741866 PMCID: PMC10517927 DOI: 10.1038/s41598-023-43072-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 09/18/2023] [Indexed: 09/25/2023] Open
Abstract
Although glaucoma is a disease modulated by eye pressure, the mechanisms of pressure sensing in the eye are not well understood. Here, we investigated associations between mechanosensitive ion channel gene variants and primary open-angle glaucoma (POAG). Common (minor allele frequency > 5%) single nucleotide polymorphisms located within the genomic regions of 20 mechanosensitive ion channel genes in the K2P, TMEM63, PIEZO and TRP channel families were assessed using genotype data from the NEIGHBORHOOD consortium of 3853 cases and 33,480 controls. Rare (minor allele frequency < 1%) coding variants were assessed using exome array genotyping data for 2606 cases and 2606 controls. Association with POAG was analyzed using logistic regression adjusting for age and sex. Two rare PIEZO1 coding variants with protective effects were identified in the NEIGHBOR dataset: R1527H, (OR 0.17, P = 0.0018) and a variant that alters a canonical splice donor site, g.16-88737727-C-G Hg38 (OR 0.38, P = 0.02). Both variants showed similar effects in the UK Biobank and the R1527H also in the FinnGen database. Several common variants also reached study-specific thresholds for association in the NEIGHBORHOOD dataset. These results identify novel variants in several mechanosensitive channel genes that show associations with POAG, suggesting that these channels may be potential therapeutic targets.
Collapse
Affiliation(s)
- Wendy W Liu
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, 2370 Watson Court, Palo Alto, CA, 94303, USA.
| | - Tyler G Kinzy
- Department of Population and Quantitative Health Sciences, Cleveland Institute for Computational Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Jessica N Cooke Bailey
- Department of Population and Quantitative Health Sciences, Cleveland Institute for Computational Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Zihe Xu
- Department of Ophthalmology, King's College London, St. Thomas' Hospital, London, UK
| | - Pirro Hysi
- Department of Ophthalmology, King's College London, St. Thomas' Hospital, London, UK
- Department of Twin Research and Genetic Epidemiology, King's College London, St. Thomas' Hospital, London, UK
| | - Janey L Wiggs
- Massachusetts Eye and Ear, Harvard Medical School Boston, Boston, MA, USA
| |
Collapse
|
5
|
Szallasi A. "ThermoTRP" Channel Expression in Cancers: Implications for Diagnosis and Prognosis (Practical Approach by a Pathologist). Int J Mol Sci 2023; 24:9098. [PMID: 37240443 PMCID: PMC10219044 DOI: 10.3390/ijms24109098] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/16/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
Temperature-sensitive transient receptor potential (TRP) channels (so-called "thermoTRPs") are multifunctional signaling molecules with important roles in cell growth and differentiation. Several "thermoTRP" channels show altered expression in cancers, though it is unclear if this is a cause or consequence of the disease. Regardless of the underlying pathology, this altered expression may potentially be used for cancer diagnosis and prognostication. "ThermoTRP" expression may distinguish between benign and malignant lesions. For example, TRPV1 is expressed in benign gastric mucosa, but is absent in gastric adenocarcinoma. TRPV1 is also expressed both in normal urothelia and non-invasive papillary urothelial carcinoma, but no TRPV1 expression has been seen in invasive urothelial carcinoma. "ThermoTRP" expression can also be used to predict clinical outcomes. For instance, in prostate cancer, TRPM8 expression predicts aggressive behavior with early metastatic disease. Furthermore, TRPV1 expression can dissect a subset of pulmonary adenocarcinoma patients with bad prognosis and resistance to a number of commonly used chemotherapeutic agents. This review will explore the current state of this rapidly evolving field with special emphasis on immunostains that can already be added to the armoire of diagnostic pathologists.
Collapse
Affiliation(s)
- Arpad Szallasi
- Department of Pathology and Experimental Cancer Research, Semmelweis University, 1085 Budapest, Hungary
| |
Collapse
|
6
|
Mirbod SM, Khanahmad H, Amerizadeh A, Amirpour A, Mirbod SM, Zaker E. Viewpoints on the Role of Transient Receptor Potential Melastatin Channels in Cardiovascular System and Disease: A Systematic Review. Curr Probl Cardiol 2023; 48:101012. [PMID: 34644560 DOI: 10.1016/j.cpcardiol.2021.101012] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 08/08/2021] [Indexed: 01/04/2023]
Abstract
Transient receptor potential (TRP) family play critical roles in cardiovascular system. TRPM family as largest TRP subfamily is non-voltage Ca2+-activated selective channels which has 8 members. This study aimed to discuss the role of TRPM family in cardiovascular system and diseases. Systematic search was performed covering PubMed, ISI Web of Science, and Google Scholar from inception until June 2021 using related keywords and Mesh terms for English studies with human, animal and in-vitro subjects. Finally 10 studies were selected for data extraction. Reviewing the articles showed that TRPM2, TRPM4, TRPM5, TRPM6 and TRPM7 play important roles in cardiovascular system and diseases. TRPM2 could be activated by reactive oxygen species (ROS) and effects on cardiac injury and cardiac fibrosis. TRPM7 and TRPM6 also have been reported to be associated with cardiac fibrosis and atrial fibrosis development respectively. TRPM4 channels contributed to resting membrane potential of cerebral artery smooth muscle cells and atrial contraction. TRPM5 channels are bitter taste sensors and prevent high salt intake and consequently high blood pressure due to the high salt intake. In conclusion based on the proof of the effectiveness of some members of TRPM family in the cardiovascular system, research on other members of this channel group seems to be useful and necessary to find their possible connection to the cardiovascular system.
Collapse
Affiliation(s)
| | - Hossein Khanahmad
- Department of Genetics and Molecular biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Atefeh Amerizadeh
- Department of Cardiology, Isfahan University of Medical Sciences, Isfahan, Iran; Applied Physiology Research Center, Department of Physiology, Cardiovascular Research Institute, Isfahan University of Medical sciences, Isfahan, Iran
| | - Afshin Amirpour
- Cardiac Rehabilitation Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Seyedeh Mojgan Mirbod
- Heart Failure Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Erfan Zaker
- Department of Genetics and Molecular biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
7
|
Križaj D, Cordeiro S, Strauß O. Retinal TRP channels: Cell-type-specific regulators of retinal homeostasis and multimodal integration. Prog Retin Eye Res 2023; 92:101114. [PMID: 36163161 PMCID: PMC9897210 DOI: 10.1016/j.preteyeres.2022.101114] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/03/2022] [Accepted: 08/08/2022] [Indexed: 02/05/2023]
Abstract
Transient receptor potential (TRP) channels are a widely expressed family of 28 evolutionarily conserved cationic ion channels that operate as primary detectors of chemical and physical stimuli and secondary effectors of metabotropic and ionotropic receptors. In vertebrates, the channels are grouped into six related families: TRPC, TRPV, TRPM, TRPA, TRPML, and TRPP. As sensory transducers, TRP channels are ubiquitously expressed across the body and the CNS, mediating critical functions in mechanosensation, nociception, chemosensing, thermosensing, and phototransduction. This article surveys current knowledge about the expression and function of the TRP family in vertebrate retinas, which, while dedicated to transduction and transmission of visual information, are highly susceptible to non-visual stimuli. Every retinal cell expresses multiple TRP subunits, with recent evidence establishing their critical roles in paradigmatic aspects of vertebrate vision that include TRPM1-dependent transduction of ON bipolar signaling, TRPC6/7-mediated ganglion cell phototransduction, TRP/TRPL phototransduction in Drosophila and TRPV4-dependent osmoregulation, mechanotransduction, and regulation of inner and outer blood-retina barriers. TRP channels tune light-dependent and independent functions of retinal circuits by modulating the intracellular concentration of the 2nd messenger calcium, with emerging evidence implicating specific subunits in the pathogenesis of debilitating diseases such as glaucoma, ocular trauma, diabetic retinopathy, and ischemia. Elucidation of TRP channel involvement in retinal biology will yield rewards in terms of fundamental understanding of vertebrate vision and therapeutic targeting to treat diseases caused by channel dysfunction or over-activation.
Collapse
Affiliation(s)
- David Križaj
- Departments of Ophthalmology, Neurobiology, and Bioengineering, University of Utah, Salt Lake City, USA
| | - Soenke Cordeiro
- Institute of Physiology, Faculty of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Olaf Strauß
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, a Corporate Member of Freie Universität, Humboldt-University, The Berlin Institute of Health, Berlin, Germany.
| |
Collapse
|
8
|
London S, Levine MA, Li D, Spiegel R, Lebel A, Halevy R, Tenenbaum-Rakover Y. Hypocalcemia as the Initial Presentation of Type 2 Bartter Syndrome: A Family Report. J Clin Endocrinol Metab 2022; 107:e1679-e1688. [PMID: 34751387 DOI: 10.1210/clinem/dgab821] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Bartter syndrome (BS) is a group of rare autosomal-recessive tubulopathies characterized by hypokalemic, hypochloremic metabolic alkalosis in which the primary defect is a deficiency of transporters involved in sodium chloride reabsorption. Type 2 BS results from a defect in the renal outer medullary potassium channel encoded by the KCNJ1 gene. Type 2 BS presents with polyhydramnios, intrauterine growth retardation, prematurity, failure to thrive, polyuria, hypercalciuria, and life-threatening episodes of dehydration. Hypocalcemia is a very rare presenting symptom of BS, with only a few published cases reporting it as the initial manifestation of type 2 BS. OBJECTIVE To describe a child who presented with hypocalcemic seizure at the age of 2.3 years that was first related to vitamin D deficiency and high-phosphate soft drink consumption. METHODS Whole exome sequencing (WES) was used to evaluate the biochemical abnormalities of the proband. RESULTS We identified a previously described homozygous missense mutation c.212C>T, p.T71M in the KCNJ1 gene associated with type 2 BS. Six additional family members with the same mutation and diagnosed clinically with BS are also reported, 2 presenting with hypocalcemia associated with vitamin D deficiency. CONCLUSION This report expands the clinical spectrum associated with KCNJ1 mutations and emphasizes the role of WES in unsolved cases of hypocalcemia when genetic disease is suspected. It also highlights the hazardous effects of phosphate-containing soft drinks on calcium metabolism.
Collapse
Affiliation(s)
- Shira London
- Pediatric Endocrine Institute, Ha'Emek Medical Center, Afula, Israel
- Armon Child Health Center, Clalit Health Services, Haifa, Israel
| | - Michael A Levine
- Division of Endocrinology and Diabetes, Center for Bone Health, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Dong Li
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Ronen Spiegel
- Pediatric Ward B, Ha'Emek Medical Center, Afula, Israel
- The Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel
| | - Asaf Lebel
- The Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel
- Pediatric Nephrology Unit, Ha'Emek Medical Center, Afula, Israel
| | - Rephael Halevy
- Pediatric Nephrology Unit, Ha'Emek Medical Center, Afula, Israel
| | - Yardena Tenenbaum-Rakover
- Pediatric Endocrine Institute, Ha'Emek Medical Center, Afula, Israel
- The Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel
| |
Collapse
|
9
|
Behrendt M. TRPM3 in the eye and in the nervous system - from new findings to novel mechanisms. Biol Chem 2022; 403:859-868. [PMID: 35240732 DOI: 10.1515/hsz-2021-0403] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 02/10/2022] [Indexed: 01/13/2023]
Abstract
The calcium-permeable cation channel TRPM3 can be activated by heat and the endogenous steroid pregnenolone sulfate. TRPM3's best understood function is its role as a peripheral noxious heat sensor in mice. However, the channel is expressed in various tissues and cell types including neurons as well as glial and epithelial cells. TRPM3 expression patterns differ between species and change during development. Furthermore, a plethora of TRPM3 variants that result from alternative splicing have been identified and the majority of these isoforms are yet to be characterized. Moreover, the mechanisms underlying regulation of TRPM3 are largely unexplored. In addition, a micro-RNA gene (miR-204) is located within the TRPM3 gene. This complexity makes it difficult to obtain a clear picture of TRPM3 characteristics. However, a clear picture is needed to unravel TRPM3's full potential as experimental tool, diagnostic marker and therapeutic target. Therefore, the newest data related to TRPM3 have to be discussed and to be put in context as soon as possible to be up-to-date and to accelerate the translation from bench to bedside. The aim of this review is to highlight recent results and developments with particular focus on findings from studies involving ocular tissues and cells or peripheral neurons of rodents and humans.
Collapse
Affiliation(s)
- Marc Behrendt
- Department of Experimental Pain Research, Medical Faculty Mannheim, University of Heidelberg, Ludolf-Krehl-Str. 13-17, D-68167 Mannheim, Germany
| |
Collapse
|
10
|
Ma L, Liu X, Liu Q, Jin S, Chang H, Liu H. The Roles of Transient Receptor Potential Ion Channels in Pathologies of Glaucoma. Front Physiol 2022; 13:806786. [PMID: 35185615 PMCID: PMC8850928 DOI: 10.3389/fphys.2022.806786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/03/2022] [Indexed: 11/13/2022] Open
Abstract
Transient receptor ion potential (TRP) channels are a cluster of non-selective cation channels present on cell membranes. They are important mediators of sensory signals to regulate cellular functions and signaling pathways. Alterations and dysfunction of these channels could disrupt physiological processes, thus leading to a broad array of disorders, such as cardiovascular, renal and nervous system diseases. These effects position them as potential targets for drug design and treatment. Because TRP channels can mediate processes such as mechanical conduction, osmotic pressure, and oxidative stress, they have been studied in the context of glaucoma. Glaucoma is an irreversible blinding eye disease caused by an intermittent or sustained increase in intraocular pressure (IOP), which results in the apoptosis of retinal ganglion cells (RGCs), optic nerve atrophy and eventually visual field defects. An increasing number of studies have documented that various TRP subfamilies are abundantly expressed in ocular structures, including the cornea, lens, ciliary body (CB), trabecular meshwork (TM) and retina. In alignment with these findings, there is also mounting evidence supporting the potential role of the TRP family in glaucoma progression. Therefore, it is of great interest and clinical significance to gain an increased understanding of these channels, which in turn could shed more light on the identification of new therapeutic targets for glaucoma. Moreover, this role is not understood completely to date, and whether the activation of TRP channels contributes to glaucoma, or instead aggravates progression, needs to be explored. In this manuscript, we aim to provide a comprehensive overview of recent research on TRP channels in glaucoma and to suggest novel targets for future therapeutic interventions in glaucoma.
Collapse
Affiliation(s)
- Lin Ma
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xin Liu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qing Liu
- Shenzhen Key Laboratory of Viral Vectors for Biomedicine, Chinese Academy of Sciences, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, The Brain Cognition and Brain Disease Institute, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Sen Jin
- Shenzhen Key Laboratory of Viral Vectors for Biomedicine, Chinese Academy of Sciences, Shenzhen Institute of Advanced Technology, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, The Brain Cognition and Brain Disease Institute, Shenzhen, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Heng Chang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Haixia Liu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Haixia Liu,
| |
Collapse
|
11
|
Zhao S, Rohacs T. The newest TRP channelopathy: Gain of function TRPM3 mutations cause epilepsy and intellectual disability. Channels (Austin) 2021; 15:386-397. [PMID: 33853504 PMCID: PMC8057083 DOI: 10.1080/19336950.2021.1908781] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/25/2021] [Accepted: 02/25/2021] [Indexed: 12/13/2022] Open
Abstract
Transient Receptor Potential Melastatin 3 (TRPM3) is a Ca2+ permeable nonselective cation channel, activated by heat and chemical agonists, such as the endogenous neuro-steroid Pregnenolone Sulfate (PregS) and the chemical compound CIM0216. TRPM3 is expressed in peripheral sensory neurons of the dorsal root ganglia (DRG), and its role in noxious heat sensation in mice is well established. TRPM3 is also expressed in a number of other tissues, including the brain, but its role there has been largely unexplored. Recent reports showed that two mutations in TRPM3 are associated with a developmental and epileptic encephalopathy, pointing to an important role of TRPM3 in the human brain. Subsequent reports found that the two disease-associated mutations increased basal channel activity, and sensitivity of the channel to activation by heat and chemical agonists. This review will discuss these mutations in the context of human diseases caused by mutations in other TRP channels, and in the context of the biophysical properties and physiological functions of TRPM3.
Collapse
Affiliation(s)
- Siyuan Zhao
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, Newark, NJ, USA
| | - Tibor Rohacs
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, Newark, NJ, USA
| |
Collapse
|
12
|
Hellenthal KEM, Brabenec L, Gross ER, Wagner NM. TRP Channels as Sensors of Aldehyde and Oxidative Stress. Biomolecules 2021; 11:biom11101401. [PMID: 34680034 PMCID: PMC8533644 DOI: 10.3390/biom11101401] [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: 09/04/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 12/15/2022] Open
Abstract
The transient receptor potential (TRP) cation channel superfamily comprises more than 50 channels that play crucial roles in physiological processes. TRP channels are responsive to several exogenous and endogenous biomolecules, with aldehydes emerging as a TRP channel trigger contributing to a cellular cascade that can lead to disease pathophysiology. The body is not only exposed to exogenous aldehydes via tobacco products or alcoholic beverages, but also to endogenous aldehydes triggered by lipid peroxidation. In response to lipid peroxidation from inflammation or organ injury, polyunsaturated fatty acids undergo lipid peroxidation to aldehydes, such as 4-hydroxynonenal. Reactive aldehydes activate TRP channels via aldehyde-induced protein adducts, leading to the release of pro-inflammatory mediators driving the pathophysiology caused by cellular injury, including inflammatory pain and organ reperfusion injury. Recent studies have outlined how aldehyde dehydrogenase 2 protects against aldehyde toxicity through the clearance of toxic aldehydes, indicating that targeting the endogenous aldehyde metabolism may represent a novel treatment strategy. An addition approach can involve targeting specific TRP channel regions to limit the triggering of a cellular cascade induced by aldehydes. In this review, we provide a comprehensive summary of aldehydes, TRP channels, and their interactions, as well as their role in pathological conditions and the different therapeutical treatment options.
Collapse
Affiliation(s)
- Katharina E. M. Hellenthal
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; (K.E.M.H.); (L.B.)
| | - Laura Brabenec
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; (K.E.M.H.); (L.B.)
| | - Eric R. Gross
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA 94305, USA;
| | - Nana-Maria Wagner
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; (K.E.M.H.); (L.B.)
- Correspondence: ; Tel.: +49-251-83-46837
| |
Collapse
|
13
|
Shiels A, Hejtmancik JF. Inherited cataracts: Genetic mechanisms and pathways new and old. Exp Eye Res 2021; 209:108662. [PMID: 34126080 PMCID: PMC8595562 DOI: 10.1016/j.exer.2021.108662] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/13/2021] [Accepted: 06/01/2021] [Indexed: 12/15/2022]
Abstract
Cataract(s) is the clinical equivalent of lens opacity and is caused by light scattering either by high molecular weight protein aggregates in lens cells or disruption of the lens microarchitecture itself. Genetic mutations underlying inherited cataract can provide insight into the biological processes and pathways critical for lens homeostasis and transparency, classically including the lens crystallins, connexins, membrane proteins or components, and intermediate filament proteins. More recently, cataract genes have been expanded to include newly identified biological processes such as chaperone or protein degradation components, transcription or growth factors, channels active in the lens circulation, and collagen and extracellular matrix components. Cataracts can be classified by age, and in general congenital cataracts are caused by severe mutations resulting in major damage to lens proteins, while age related cataracts are associated with variants that merely destabilize proteins thereby increasing susceptibility to environmental insults over time. Thus there might be separate pathways to opacity for congenital and age-related cataracts whereby congenital cataracts induce the unfolded protein response (UPR) and apoptosis to destroy the lens microarchitecture, while in age related cataract high molecular weight (HMW) aggregates formed by denatured crystallins bound by α-crystallin result in light scattering without severe damage to the lens microarchitecture.
Collapse
Affiliation(s)
- Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892-1860, USA.
| |
Collapse
|
14
|
Abstract
The transient receptor potential (TRP) channel superfamily consists of a large group of non-selective cation channels that serve as cellular sensors for a wide spectrum of physical and environmental stimuli. The 28 mammalian TRPs, categorized into six subfamilies, including TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPA (ankyrin), TRPML (mucolipin) and TRPP (polycystin), are widely expressed in different cells and tissues. TRPs exhibit a variety of unique features that not only distinguish them from other superfamilies of ion channels, but also confer diverse physiological functions. Located at the plasma membrane or in the membranes of intracellular organelles, TRPs are the cellular safeguards that sense various cell stresses and environmental stimuli and translate this information into responses at the organismal level. Loss- or gain-of-function mutations of TRPs cause inherited diseases and pathologies in different physiological systems, whereas up- or down-regulation of TRPs is associated with acquired human disorders. In this Cell Science at a Glance article and the accompanying poster, we briefly summarize the history of the discovery of TRPs, their unique features, recent advances in the understanding of TRP activation mechanisms, the structural basis of TRP Ca2+ selectivity and ligand binding, as well as potential roles in mammalian physiology and pathology.
Collapse
Affiliation(s)
- Lixia Yue
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut School of Medicine (UConn Health), Farmington, CT 06030, USA
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|
15
|
Zhou Y, Bennett TM, Shiels A. Mutation of the TRPM3 cation channel underlies progressive cataract development and lens calcification associated with pro-fibrotic and immune cell responses. FASEB J 2021; 35:e21288. [PMID: 33484482 DOI: 10.1096/fj.202002037r] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/23/2020] [Accepted: 12/03/2020] [Indexed: 12/11/2022]
Abstract
Transient-receptor-potential cation channel, subfamily M, member 3 (TRPM3) serves as a polymodal calcium sensor in diverse mammalian cell-types. Mutation of the human TRPM3 gene (TRPM3) has been linked with inherited forms of early-onset cataract with or without other eye abnormalities. Here, we have characterized the ocular phenotypes of germline "knock-in" mice that harbor a human cataract-associated isoleucine-to-methionine mutation (p.I65M) in TRPM3 (Trpm3-mutant) compared with germline "knock-out" mice that functionally lack TRPM3 (Trpm3-null). Despite strong expression of Trpm3 in lens epithelial cells, neither heterozygous (Trpm3+/- ) nor homozygous (Trpm3-/- ) Trpm3-null mice developed cataract; however, the latter exhibited a mild impairment of lens growth. In contrast, homozygous Trpm3-M/M mutants developed severe, progressive, anterior pyramid-like cataract with microphthalmia, whereas heterozygous Trpm3-I/M and hemizygous Trpm3-M/- mutants developed anterior pyramidal cataract with delayed onset and progression-consistent with a semi-dominant lens phenotype. Histochemical staining revealed abnormal accumulation of calcium phosphate-like deposits and collagen fibrils in Trpm3-mutant lenses and immunoblotting detected increased αII-spectrin cleavage products consistent with calpain hyper-activation. Immunofluorescent confocal microscopy of Trpm3-M/M mutant lenses revealed fiber cell membrane degeneration that was accompanied by accumulation of alpha-smooth muscle actin positive (α-SMA+ve) myofibroblast-like cells and macrosialin positive (CD68+ve) macrophage-like cells. Collectively, our mouse model data support an ocular disease association for TRPM3 in humans and suggest that (1) Trpm3 deficiency impaired lens growth but not lens transparency and (2) Trpm3 dysfunction resulted in progressive lens degeneration and calcification coupled with pro-fibrotic (α-SMA+ve) and immune (CD68+ve) cell responses.
Collapse
Affiliation(s)
- Yuefang Zhou
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Thomas M Bennett
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
16
|
Hossain Saad MZ, Xiang L, Liao YS, Reznikov LR, Du J. The Underlying Mechanism of Modulation of Transient Receptor Potential Melastatin 3 by protons. Front Pharmacol 2021; 12:632711. [PMID: 33603674 PMCID: PMC7884864 DOI: 10.3389/fphar.2021.632711] [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: 11/23/2020] [Accepted: 01/04/2021] [Indexed: 12/03/2022] Open
Abstract
Transient receptor potential melastatin 3 channel (TRPM3) is a calcium-permeable nonselective cation channel that plays an important role in modulating glucose homeostasis in the pancreatic beta cells. However, how TRPM3 is regulated under physiological and pathological conditions is poorly understood. In this study, we found that both intracellular and extracellular protons block TRPM3 through its binding sites in the pore region. We demonstrated that external protons block TRPM3 with an inhibitory pH50 of 5.5. whereas internal protons inhibit TRPM3 with an inhibitory pH50 of 6.9. We identified three titratable residues, D1059, D1062, and D1073, at the vestibule of the channel pore that contributes to pH sensitivity. The mutation of D1073Q reduced TRPM3 current by low external pH 5.5 from 62 ± 3% in wildtype to 25 ± 6.0% in D1073Q mutant. These results indicate that D1073 is essential for pH sensitivity. In addition, we found that a single mutation of D1059 or D1062 enhanced pH sensitivity. In summary, our findings identify molecular determinants respionsible for the pH regulation of TRPM3. The inhibition of TRPM3 by protons may indicate an endogenous mechanism governing TRPM3 gating and its physiological/pathological functions.
Collapse
Affiliation(s)
- Md Zubayer Hossain Saad
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Biological Sciences, University of Toledo, Toledo, OH, United States
| | - Liuruimin Xiang
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Biological Sciences, University of Toledo, Toledo, OH, United States.,Program of Neuroscience, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Yan-Shin Liao
- Department of Physiological Sciences, University of Florida, Gainesville, FL, United States
| | - Leah R Reznikov
- Department of Physiological Sciences, University of Florida, Gainesville, FL, United States
| | - Jianyang Du
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.,Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, United States
| |
Collapse
|
17
|
Jimenez I, Prado Y, Marchant F, Otero C, Eltit F, Cabello-Verrugio C, Cerda O, Simon F. TRPM Channels in Human Diseases. Cells 2020; 9:E2604. [PMID: 33291725 PMCID: PMC7761947 DOI: 10.3390/cells9122604] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/11/2022] Open
Abstract
The transient receptor potential melastatin (TRPM) subfamily belongs to the TRP cation channels family. Since the first cloning of TRPM1 in 1989, tremendous progress has been made in identifying novel members of the TRPM subfamily and their functions. The TRPM subfamily is composed of eight members consisting of four six-transmembrane domain subunits, resulting in homomeric or heteromeric channels. From a structural point of view, based on the homology sequence of the coiled-coil in the C-terminus, the eight TRPM members are clustered into four groups: TRPM1/M3, M2/M8, M4/M5 and M6/M7. TRPM subfamily members have been involved in several physiological functions. However, they are also linked to diverse pathophysiological human processes. Alterations in the expression and function of TRPM subfamily ion channels might generate several human diseases including cardiovascular and neurodegenerative alterations, organ dysfunction, cancer and many other channelopathies. These effects position them as remarkable putative targets for novel diagnostic strategies, drug design and therapeutic approaches. Here, we review the current knowledge about the main characteristics of all members of the TRPM family, focusing on their actions in human diseases.
Collapse
Affiliation(s)
- Ivanka Jimenez
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Yolanda Prado
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Felipe Marchant
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Carolina Otero
- Faculty of Medicine, School of Chemistry and Pharmacy, Universidad Andrés Bello, Santiago 8370186, Chile;
| | - Felipe Eltit
- Vancouver Prostate Centre, Vancouver, BC V6Z 1Y6, Canada;
- Department of Urological Sciences, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada
| | - Claudio Cabello-Verrugio
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago 7560484, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
| | - Oscar Cerda
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Felipe Simon
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
| |
Collapse
|
18
|
Guarino BD, Paruchuri S, Thodeti CK. The role of TRPV4 channels in ocular function and pathologies. Exp Eye Res 2020; 201:108257. [PMID: 32979394 DOI: 10.1016/j.exer.2020.108257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/15/2022]
Abstract
Transient potential receptor vanilloid 4 (TRPV4) is an ion channel responsible for sensing osmotic and mechanical signals, which in turn regulates calcium signaling across cell membranes. TRPV4 is widely expressed throughout the body, and plays an important role in normal physiological function, as well as different pathologies, however, its role in the eye is not well known. In the eye, TRPV4 is expressed in various tissues, such as the retina, corneal epithelium, ciliary body, and the lens. In this review, we provide an overview on TRPV4 structure, activation, mutations, and summarize the current knowledge of TRPV4 function and signaling mechanisms in various locations throughout the eye, as well as its role in ocular diseases, such as glaucoma and diabetic retinopathy. Based on the available data, we highlight the therapeutic potential of TRPV4 as well as the shortcomings of current research. Finally, we provide future perspectives on the implications of targeting TRPV4 to treat various ocular pathologies.
Collapse
Affiliation(s)
- Brianna D Guarino
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, 44272, USA
| | | | - Charles K Thodeti
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, 44272, USA.
| |
Collapse
|
19
|
Berthoud VM, Gao J, Minogue PJ, Jara O, Mathias RT, Beyer EC. Connexin Mutants Compromise the Lens Circulation and Cause Cataracts through Biomineralization. Int J Mol Sci 2020; 21:E5822. [PMID: 32823750 PMCID: PMC7461132 DOI: 10.3390/ijms21165822] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 12/18/2022] Open
Abstract
Gap junction-mediated intercellular communication facilitates the circulation of ions, small molecules, and metabolites in the avascular eye lens. Mutants of the lens fiber cell gap junction proteins, connexin46 (Cx46) and connexin50 (Cx50), cause cataracts in people and in mice. Studies in mouse models have begun to elucidate the mechanisms by which these mutants lead to cataracts. The expression of the dominant mutants causes severe decreases in connexin levels, reducing the gap junctional communication between lens fiber cells and compromising the lens circulation. The impairment of the lens circulation results in several changes, including the accumulation of Ca2+ in central lens regions, leading to the formation of precipitates that stain with Alizarin red. The cataract morphology and the distribution of Alizarin red-stained material are similar, suggesting that the cataracts result from biomineralization within the organ. In this review, we suggest that this may be a general process for the formation of cataracts of different etiologies.
Collapse
Affiliation(s)
- Viviana M. Berthoud
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA; (P.J.M.); (O.J.); (E.C.B.)
| | - Junyuan Gao
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, USA; (J.G.); (R.T.M.)
| | - Peter J. Minogue
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA; (P.J.M.); (O.J.); (E.C.B.)
| | - Oscar Jara
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA; (P.J.M.); (O.J.); (E.C.B.)
| | - Richard T. Mathias
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, USA; (J.G.); (R.T.M.)
| | - Eric C. Beyer
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA; (P.J.M.); (O.J.); (E.C.B.)
| |
Collapse
|
20
|
Developmental change in the gene expression of transient receptor potential melastatin channel 3 (TRPM3) in murine lacrimal gland. Ann Anat 2020; 231:151551. [PMID: 32512204 DOI: 10.1016/j.aanat.2020.151551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 05/19/2020] [Indexed: 11/20/2022]
Abstract
Transient receptor potential (TRP) channels are cation channels with ubiquitous expression. Various TRP channels are functionally active at the ocular surface and are involved in tear secretion and multiple inflammatory processes. So far, the impact of TRP channels regarding the development of the lacrimal gland (LG) is unclear. While investigating TRP channels in the LG, the TRPM3 channel presented itself as a promising candidate to play a role in the development and functioning of the LG. Therefore, Trpm3 expression was analyzed in different embryonic and postembryonic LGs. Thus, gene expression of TRPM channels including Trpm2, Trpm3, Trpm4 and Trpm6 was analyzed by quantitative RT-PCR in murine LGs at different developmental stages. Localization of TRPM3 in LGs was examined by immunohistochemistry. Primary LG epithelial cells (LGEC) and mesenchymal cells (MC) from newborn mice were cultured (either separately or collectively) for three days, and Trpm3 expression was analyzed in LGEC and MC. As a result, gene expression of Trpm2, Trpm4 and Trpm6 showed no significant difference in LGs in the different stages of development. However, Trpm3 gene expression was significantly higher in the embryonic stage than in the postnatal stage with the peak at E18. Postnatal, Trpm3 expression significantly decreased up to 28-fold until two years of age. Immunohistochemistry for TRPM3 revealed apical membranous expression in the excretory ducts, as well as in the acini of up to P7 old mice. Trpm3 expression in LGEC were significantly higher than that of MC. Our results indicate that Trpm3 expression in murine LG is age-dependent and peaks at age E18. Its expression is localized in the apical membrane of the glandular epithelium. However, its functional role still requires additional study in the LG.
Collapse
|
21
|
Shiels A. TRPM3_miR-204: a complex locus for eye development and disease. Hum Genomics 2020; 14:7. [PMID: 32070426 PMCID: PMC7027284 DOI: 10.1186/s40246-020-00258-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 02/06/2020] [Indexed: 02/07/2023] Open
Abstract
First discovered in a light-sensitive retinal mutant of Drosophila, the transient receptor potential (TRP) superfamily of non-selective cation channels serve as polymodal cellular sensors that participate in diverse physiological processes across the animal kingdom including the perception of light, temperature, pressure, and pain. TRPM3 belongs to the melastatin sub-family of TRP channels and has been shown to function as a spontaneous calcium channel, with permeability to other cations influenced by alternative splicing and/or non-canonical channel activity. Activators of TRPM3 channels include the neurosteroid pregnenolone sulfate, calmodulin, phosphoinositides, and heat, whereas inhibitors include certain drugs, plant-derived metabolites, and G-protein subunits. Activation of TRPM3 channels at the cell membrane elicits a signal transduction cascade of mitogen-activated kinases and stimulus response transcription factors. The mammalian TRPM3 gene hosts a non-coding microRNA gene specifying miR-204 that serves as both a tumor suppressor and a negative regulator of post-transcriptional gene expression during eye development in vertebrates. Ocular co-expression of TRPM3 and miR-204 is upregulated by the paired box 6 transcription factor (PAX6) and mutations in all three corresponding genes underlie inherited forms of eye disease in humans including early-onset cataract, retinal dystrophy, and coloboma. This review outlines the genomic and functional complexity of the TRPM3_miR-204 locus in mammalian eye development and disease.
Collapse
Affiliation(s)
- Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Ave., Box 8096, St. Louis, MO, 63110, USA.
| |
Collapse
|
22
|
Behrendt M. Transient receptor potential channels in the context of nociception and pain - recent insights into TRPM3 properties and function. Biol Chem 2020; 400:917-926. [PMID: 30844758 DOI: 10.1515/hsz-2018-0455] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 02/25/2019] [Indexed: 01/09/2023]
Abstract
Potential harmful stimuli like heat, mechanical pressure or chemicals are detected by specialized cutaneous nerve fiber endings of nociceptor neurons in a process called nociception. Acute stimulation results in immediate protective reflexes and pain sensation as a normal, physiological behavior. However, ongoing (chronic) pain is a severe pathophysiological condition with diverse pathogeneses that is clinically challenging because of limited therapeutic options. Therefore, an urgent need exists for new potent and specific analgesics without afflicting adverse effects. Recently, TRPM3, a member of the superfamily of transient receptor potential (TRP) ion channels, has been shown to be expressed in nociceptors and to be involved in the detection of noxious heat (acute pain) as well as inflammatory hyperalgesia (acute and chronic pain). Current results in TRPM3 research indicate that this ion channel might not only be part of yet unraveled mechanisms underlying chronic pain but also has the potential to become a clinically relevant pharmacological target of future analgesic strategies. The aim of this review is to summarize and present the basic features of TRPM3 proteins and channels, to highlight recent findings and developments and to provide an outlook on emerging directions of TRPM3 research in the field of chronic pain.
Collapse
Affiliation(s)
- Marc Behrendt
- Experimental Pain Research, Heidelberg University, Medical Faculty Mannheim, CBTM, Tridomus, Building C, Ludolf-Krehl-Straße 13-17, D-68167 Mannheim, Germany
| |
Collapse
|
23
|
Dyment DA, Terhal PA, Rustad CF, Tveten K, Griffith C, Jayakar P, Shinawi M, Ellingwood S, Smith R, van Gassen K, McWalter K, Innes AM, Lines MA. De novo substitutions of TRPM3 cause intellectual disability and epilepsy. Eur J Hum Genet 2019; 27:1611-1618. [PMID: 31278393 PMCID: PMC6777445 DOI: 10.1038/s41431-019-0462-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/26/2019] [Accepted: 06/25/2019] [Indexed: 02/04/2023] Open
Abstract
The developmental and epileptic encephalopathies (DEE) are a heterogeneous group of chronic encephalopathies frequently associated with rare de novo nonsynonymous coding variants in neuronally expressed genes. Here, we describe eight probands with a DEE phenotype comprising intellectual disability, epilepsy, and hypotonia. Exome trio analysis showed de novo variants in TRPM3, encoding a brain-expressed transient receptor potential channel, in each. Seven probands were identically heterozygous for a recurrent substitution, p.(Val837Met), in TRPM3's S4-S5 linker region, a conserved domain proposed to undergo conformational change during gated channel opening. The eighth individual was heterozygous for a proline substitution, p.(Pro937Gln), at the boundary between TRPM3's flexible pore-forming loop and an adjacent alpha-helix. General-population truncating variants and microdeletions occur throughout TRPM3, suggesting a pathomechanism other than simple haploinsufficiency. We conclude that de novo variants in TRPM3 are a cause of intellectual disability and epilepsy.
Collapse
Affiliation(s)
- David A Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada.,Department of Pediatrics, University of Ottawa, Ottawa, ON, Canada
| | - Paulien A Terhal
- Department of Genetics, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Cecilie F Rustad
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Kristian Tveten
- Department of Medical Genetics, Telemark Hospital Trust, Skien, Norway
| | | | | | - Marwan Shinawi
- Department of Pediatrics, Division of Genetics and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Sara Ellingwood
- Department of Pediatrics, Division of Genetics, Maine Medical Center, Portland, ME, USA
| | - Rosemarie Smith
- Department of Pediatrics, Division of Genetics, Maine Medical Center, Portland, ME, USA
| | - Koen van Gassen
- Department of Genetics, University Medical Centre Utrecht, Utrecht, the Netherlands
| | | | - A Micheil Innes
- Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Matthew A Lines
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada. .,Department of Pediatrics, University of Ottawa, Ottawa, ON, Canada.
| |
Collapse
|
24
|
Kleene SJ, Siroky BJ, Landero-Figueroa JA, Dixon BP, Pachciarz NW, Lu L, Kleene NK. The TRPP2-dependent channel of renal primary cilia also requires TRPM3. PLoS One 2019; 14:e0214053. [PMID: 30883612 PMCID: PMC6422334 DOI: 10.1371/journal.pone.0214053] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 03/06/2019] [Indexed: 12/21/2022] Open
Abstract
Primary cilia of renal epithelial cells express several members of the transient receptor potential (TRP) class of cation-conducting channel, including TRPC1, TRPM3, TRPM4, TRPP2, and TRPV4. Some cases of autosomal dominant polycystic kidney disease (ADPKD) are caused by defects in TRPP2 (also called polycystin-2, PC2, or PKD2). A large-conductance, TRPP2-dependent channel in renal cilia has been well described, but it is not known whether this channel includes any other protein subunits. To study this question, we investigated the pharmacology of the TRPP2-dependent channel through electrical recordings from the cilia of mIMCD-3 cells, a murine cell line of renal epithelial origin. The pharmacology was found to match that of TRPM3 channels. The ciliary TRPP2-dependent channel is known to be activated by depolarization and by increasing cytoplasmic Ca2+. This activation was greatly enhanced by external pregnenolone sulfate, an agonist of TRPM3 channels. Pregnenolone sulfate did not change the single-channel current-voltage relation. The channels were effectively blocked by isosakuranetin, a specific inhibitor of TRPM3 channels. Both pregnenolone sulfate and isosakuranetin were effective at concentrations as low as 1 μM. Knocking out TRPM3 by CRISPR/Cas9 genome editing eliminated the ciliary channel. Thus the channel is both TRPM3-dependent and TRPP2-dependent, suggesting that it may include both types of subunit. Knocking out TRPM3 did not change the level of TRPP2 protein in the cilia, so it is unlikely that the absence of functional ciliary channels results from a failure of trafficking.
Collapse
Affiliation(s)
- Steven J. Kleene
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
| | - Brian J. Siroky
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
| | | | - Bradley P. Dixon
- Renal Section, Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Nolan W. Pachciarz
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Lu Lu
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Nancy K. Kleene
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, United States of America
| |
Collapse
|
25
|
Shahidullah M, Mandal A, Delamere NA. Activation of TRPV1 channels leads to stimulation of NKCC1 cotransport in the lens. Am J Physiol Cell Physiol 2018; 315:C793-C802. [PMID: 30207782 DOI: 10.1152/ajpcell.00252.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lens ion homeostasis is crucial in maintaining water content and, in turn, refractive index and transparency of the multicellular syncytium-like structure. New information is emerging on the regulation of ion transport in the lens by mechanisms that rely on transient receptor potential vanilloid (TRPV) ion channels. We found recently that TRPV1 activation leads to Ca2+/PKC-dependent ERK1/2 signaling. Here, we show that the TRPV1 agonist capsaicin (100 nM) and hyperosmotic solution (350 vs. 300 mosM) each caused an increase of bumetanide-inhibitable Rb uptake by intact porcine lenses and Na-K-2Cl cotransporter 1 (NKCC1) phosphorylation in the lens epithelium. The TRPV1 antagonist A889425 (1 µM) abolished the increases of Rb uptake and NKCC1 phosphorylation in response to hyperosmotic solution. Exposing lenses to hyperosmotic solution in the presence of MEK/ERK inhibitor U0126 (10 µM) or the with-no-lysine kinase (WNK) inhibitor WNK463 (1 µM) also prevented NKCC1 phosphorylation and the Rb uptake responses to hyperosmotic solution. WNK463 did not prevent the increase in ERK1/2 phosphorylation that occurs in response to capsaicin or hyperosmotic solution, suggesting that ERK1/2 activation occurs before WNK activation in the sequence of signaling events. Taken together, the evidence indicates that activation of TRPV1 is a critical early step in a signaling mechanism that responds to a hyperosmotic stimulus, possibly lens shrinkage. By activating ERK1/2 and WNK, TRPV1 activation leads to NKCC1 phosphorylation and stimulation of NKCC1-mediated ion transport.
Collapse
Affiliation(s)
- Mohammad Shahidullah
- Department of Physiology, University of Arizona , Tucson, Arizona.,Department of Ophthalmology and Vision Science, University of Arizona , Tucson, Arizona
| | - Amritlal Mandal
- Department of Physiology, University of Arizona , Tucson, Arizona
| | - Nicholas A Delamere
- Department of Physiology, University of Arizona , Tucson, Arizona.,Department of Ophthalmology and Vision Science, University of Arizona , Tucson, Arizona
| |
Collapse
|
26
|
Reis LM, Semina EV. Genetic landscape of isolated pediatric cataracts: extreme heterogeneity and variable inheritance patterns within genes. Hum Genet 2018; 138:847-863. [PMID: 30187164 DOI: 10.1007/s00439-018-1932-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/29/2018] [Indexed: 12/12/2022]
Abstract
Pediatric cataract represents an important cause of pediatric visual impairment. While both genetic and environmental causes for pediatric cataract are known, a large proportion remains idiopathic. The purpose of this review is to discuss genes involved in isolated pediatric cataract, with a focus on variable inheritance patterns within genes. Mutations in over 52 genes are known to cause isolated pediatric cataract, with a major contribution from genes encoding for crystallins, transcription factors, membrane proteins, and cytoskeletal proteins. Interestingly, both dominant and recessive inheritance patterns have been reported for mutations in 13 different cataract genes. For some genes, dominant and recessive alleles represent distinct types of mutations, but for many, especially missense variants, there are no clear patterns to distinguish between dominant and recessive alleles. Further research into the functional effects of these mutations, as well as additional data on the frequency of the identified variants, is needed to clarify variant pathogenicity. Exome sequencing continues to be successful in identifying novel genes associated with congenital cataract but is hindered by the extreme genetic heterogeneity of this condition. The large number of idiopathic cases suggests that more genes and potentially novel mechanisms of gene disruption remain to be identified.
Collapse
Affiliation(s)
- Linda M Reis
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA. .,Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| |
Collapse
|
27
|
Singh M, Tyagi SC. Genes and genetics in eye diseases: a genomic medicine approach for investigating hereditary and inflammatory ocular disorders. Int J Ophthalmol 2018; 11:117-134. [PMID: 29376001 DOI: 10.18240/ijo.2018.01.20] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 10/31/2017] [Indexed: 12/27/2022] Open
Abstract
Past 25y have witnessed an exponential increase in knowledge and understanding of ocular diseases and their respective genetic underpinnings. As a result, scientists have mapped many genes and their variants that can influence vision and health of our eyes. Based on these findings, it is becoming clear that an early diagnosis employing genetic testing can help evaluate patients' conditions for instituting treatment plan(s) and follow-up care to avoid vision complications later. For example, knowing family history becomes crucial for inherited eye diseases as it can benefit members in family who may have similar eye diseases or predispositions. Therefore, gathering information from an elaborate examination along with complete assessment of past medical illness by ophthalmologists followed by consultation with geneticists can help create a roadmap for making diagnosis and treatment precise and beneficial. In this review, we present an update on ocular genomic medicine that we believe has tremendous potential towards unraveling genetic implications in ocular diseases and patients' susceptibilities. We also discuss translational aspects of genetic ophthalmology and genome engineering that may help advance molecular diagnostics and therapeutics.
Collapse
Affiliation(s)
- Mahavir Singh
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA
| | - Suresh C Tyagi
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA
| |
Collapse
|
28
|
Thiel G, Rubil S, Lesch A, Guethlein LA, Rössler OG. Transient receptor potential TRPM3 channels: Pharmacology, signaling, and biological functions. Pharmacol Res 2017; 124:92-99. [DOI: 10.1016/j.phrs.2017.07.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/12/2017] [Accepted: 07/12/2017] [Indexed: 12/13/2022]
|
29
|
Messina-Baas O, Cuevas-Covarrubias SA. Inherited Congenital Cataract: A Guide to Suspect the Genetic Etiology in the Cataract Genesis. Mol Syndromol 2017; 8:58-78. [PMID: 28611546 DOI: 10.1159/000455752] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2016] [Indexed: 01/23/2023] Open
Abstract
Cataracts are the principal cause of treatable blindness worldwide. Inherited congenital cataract (CC) shows all types of inheritance patterns in a syndromic and nonsyndromic form. There are more than 100 genes associated with cataract with a predominance of autosomal dominant inheritance. A cataract is defined as an opacity of the lens producing a variation of the refractive index of the lens. This variation derives from modifications in the lens structure resulting in light scattering, frequently a consequence of a significant concentration of high-molecular-weight protein aggregates. The aim of this review is to introduce a guide to identify the gene involved in inherited CC. Due to the manifold clinical and genetic heterogeneity, we discarded the cataract phenotype as a cardinal sign; a 4-group classification with the genes implicated in inherited CC is proposed. We consider that this classification will assist in identifying the probable gene involved in inherited CC.
Collapse
|
30
|
Badheka D, Borbiro I, Rohacs T. Transient receptor potential melastatin 3 is a phosphoinositide-dependent ion channel. ACTA ACUST UNITED AC 2016; 146:65-77. [PMID: 26123195 PMCID: PMC4485020 DOI: 10.1085/jgp.201411336] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
PI(4,5)P2 is required for TRPM3 activity, establishing its role as a crucial cofactor for the entire TRPM channel family. Phosphoinositides are emerging as general regulators of the functionally diverse transient receptor potential (TRP) ion channel family. Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) has been reported to positively regulate many TRP channels, but in several cases phosphoinositide regulation is controversial. TRP melastatin 3 (TRPM3) is a heat-activated ion channel that is also stimulated by chemical agonists, such as pregnenolone sulfate. Here, we used a wide array of approaches to determine the effects of phosphoinositides on TRPM3. We found that channel activity in excised inside-out patches decreased over time (rundown), an attribute of PI(4,5)P2-dependent ion channels. Channel activity could be restored by application of either synthetic dioctanoyl (diC8) or natural arachidonyl stearyl (AASt) PI(4,5)P2. The PI(4,5)P2 precursor phosphatidylinositol 4-phosphate (PI(4)P) was less effective at restoring channel activity. TRPM3 currents were also restored by MgATP, an effect which was inhibited by two different phosphatidylinositol 4-kinase inhibitors, or by pretreatment with a phosphatidylinositol-specific phospholipase C (PI-PLC) enzyme, indicating that MgATP acted by generating phosphoinositides. In intact cells, reduction of PI(4,5)P2 levels by chemically inducible phosphoinositide phosphatases or a voltage-sensitive 5′-phosphatase inhibited channel activity. Activation of PLC via muscarinic receptors also inhibited TRPM3 channel activity. Overall, our data indicate that TRPM3 is a phosphoinositide-dependent ion channel and that decreasing PI(4,5)P2 abundance limits its activity. As all other members of the TRPM family have also been shown to require PI(4,5)P2 for activity, our data establish PI(4,5)P2 as a general positive cofactor of this ion channel subfamily.
Collapse
Affiliation(s)
- Doreen Badheka
- Department of Pharmacology and Physiology, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Istvan Borbiro
- Department of Pharmacology and Physiology, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Tibor Rohacs
- Department of Pharmacology and Physiology, Rutgers New Jersey Medical School, Newark, NJ 07103
| |
Collapse
|
31
|
Rubil S, Rössler OG, Thiel G. CREB, AP-1, ternary complex factors and MAP kinases connect transient receptor potential melastatin-3 (TRPM3) channel stimulation with increased c-Fos expression. Br J Pharmacol 2015; 173:305-18. [PMID: 26493679 DOI: 10.1111/bph.13372] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 10/08/2015] [Accepted: 10/14/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND AND PURPOSE The rise in intracellular Ca(2+) stimulates the expression of the transcription factor c-Fos. Depending on the mode of entry of Ca(2+) into the cytosol, distinct signal transducers and transcription factors are required. Here, we have analysed the signalling pathway connecting a Ca(2+) influx via activation of transient receptor potential melastatin-3 (TRPM3) channels with enhanced c-Fos expression. EXPERIMENTAL APPROACH Transcription of c-Fos promoter/reporter genes that were integrated into the chromatin via lentiviral gene transfer was analysed in HEK293 cells overexpressing TRPM3. The transcriptional activation potential of c-Fos was measured using a GAL4-c-Fos fusion protein. KEY RESULTS The signalling pathway connecting TRPM3 stimulation with enhanced c-Fos expression requires the activation of MAP kinases. On the transcriptional level, three Ca(2+) -responsive elements, the cAMP-response element and the binding sites for the serum response factor (SRF) and AP-1, are essential for the TRPM3-mediated stimulation of the c-Fos promoter. Ternary complex factors are additionally involved in connecting TRPM3 stimulation with the up-regulation of c-Fos expression. Stimulation of TRPM3 channels also increases the transcriptional activation potential of c-Fos. CONCLUSIONS AND IMPLICATIONS Signalling molecules involved in connecting TRPM3 with the c-Fos gene are MAP kinases and the transcription factors CREB, SRF, AP-1 and ternary complex factors. As c-Fos constitutes, together with other basic region leucine zipper transcription factors, the AP-1 transcription factor complex, the results of this study explain TRPM3-induced activation of AP-1 and connects TRPM3 with the biological functions regulated by AP-1.
Collapse
Affiliation(s)
- Sandra Rubil
- Department of Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany
| | - Oliver G Rössler
- Department of Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany
| | - Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany
| |
Collapse
|
32
|
Reinach PS, Mergler S, Okada Y, Saika S. Ocular transient receptor potential channel function in health and disease. BMC Ophthalmol 2015; 15 Suppl 1:153. [PMID: 26818117 PMCID: PMC4895786 DOI: 10.1186/s12886-015-0135-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Transient receptor potential (TRP) channels sense and transduce environmental stimuli into Ca(2+) transients that in turn induce responses essential for cell function and adaptation. These non-selective channels with variable Ca(2+) selectivity are grouped into seven different subfamilies containing 28 subtypes based on differences in amino acid sequence homology. Many of these subtypes are expressed in the eye on both neuronal and non-neuronal cells where they affect a host of stress-induced regulatory responses essential for normal vision maintenance. This article reviews our current knowledge about the expression, function and regulation of TRPs in different eye tissues. We also describe how under certain conditions TRP activation can induce responses that are maladaptive to ocular function. Furthermore, the possibility of an association between TRP mutations and disease is considered. These findings contribute to evidence suggesting that drug targeting TRP channels may be of therapeutic benefit in a clinical setting. We point out issues that must be more extensively addressed before it will be possible to decide with certainty that this is a realistic endeavor. Another possible upshot of future studies is that disease process progression can be better evaluated by profiling changes in tissue specific functional TRP subtype activity as well as their gene and protein expression.
Collapse
Affiliation(s)
- Peter S Reinach
- Department of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xuejuan Road, Wenzhou, Zhejiang, 325027, P. R. China.
| | - Stefan Mergler
- Department of Ophthalmology, Charité-University Medicine Berlin, Campus Virchow-Clinic, Augustenburger Platz 1, 13353, Berlin, Germany.
| | - Yuka Okada
- Department of Ophthalmology, Wakayama Medical University School of Medicine, Wakayama, Japan.
| | - Shizuya Saika
- Department of Ophthalmology, Wakayama Medical University School of Medicine, Wakayama, Japan.
| |
Collapse
|
33
|
Marshall-Gradisnik SM, Smith P, Brenu EW, Nilius B, Ramos SB, Staines DR. Examination of Single Nucleotide Polymorphisms (SNPs) in Transient Receptor Potential (TRP) Ion Channels in Chronic Fatigue Syndrome Patients. ACTA ACUST UNITED AC 2015. [DOI: 10.4137/iii.s25147] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Background The transient receptor potential (TRP) superfamily in humans comprises 27 cation channels with permeability to monovalent and divalent cations. These channels are widely expressed within humans on cells and tissues and have significant sensory and regulatory roles on most physiological functions. Chronic fatigue syndrome (CFS) is an unexplained disorder with multiple physiological impairments. OBJECTIVES The purpose of this study was to determine the role of TRPs in CFS. Methods The study comprised 115 CFS patients (age = 48.68 ± 1.06 years) and 90 nonfatigued controls (age = 46.48 ± 1.22 years). CFS patients were defined according to the 1994 Center for Disease Prevention and Control criteria for CFS. A total of 240 single nucleotide polymorphisms (SNPs) for 21 mammalian TRP ion channel genes ( TRPA1, TRPC1, TRPC2, TRPC3, TRPC4, TRPC6, TRPC7, TRPM1, TRPM2, TRPM3, TRPM4, TRPM5, TRPM6, TRPM7, TRPM8, TRPV1, TRPV2, TRPV3, TRPV4, TRPV5, and TRPV6) were examined via the Agena Biosciences iPLEX Gold assay. Statistical analysis was performed using the PLINK analysis software. Results Thirteen SNPs were significantly associated with CFS patients compared with the controls. Nine of these SNPs were associated with TRPM3 (rs12682832; P < 0.003, rs11142508; P < 0.004, rs1160742; P < 0.08, rs4454352; P < 0.013, rs1328153; P < 0.013, rs3763619; P < 0.014, rs7865858; P ≤ 0.021, rs1504401; P ≤ 0041, rs10115622; P ≤ 0.050), while the remainder were associated with TRPA1 (rs2383844; P ≤ 0.040, rs4738202; P ≤ 0.018) and TRPC4 (rs6650469; P ≤ 0.016, rs655207; P ≤ 0.018). Conclusion The data from this pilot study suggest an association between TRP ion channels, predominantly TRPM3 and CFS. This and other TRPs identified may contribute to the etiology and pathomechanism of CFS.
Collapse
Affiliation(s)
- Sonya M. Marshall-Gradisnik
- School of Medical Science, Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
- The National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Peter Smith
- The National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Ekua W. Brenu
- School of Medical Science, Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
- The National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Bernd Nilius
- Department of Cellular and Molecular Medicine, Laboratory of Ion Channel Research, KU Leuven, Belgium
| | - Sandra B. Ramos
- School of Medical Science, Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
- The National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Donald R. Staines
- The National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| |
Collapse
|
34
|
Held K, Voets T, Vriens J. TRPM3 in temperature sensing and beyond. Temperature (Austin) 2015; 2:201-13. [PMID: 27227024 PMCID: PMC4844244 DOI: 10.4161/23328940.2014.988524] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Revised: 11/06/2014] [Accepted: 11/12/2014] [Indexed: 12/13/2022] Open
Abstract
TRPM3, also known as melastatin 2 (MLSN2), LTRPC3 (long TRPC3) and KIAA1616, is a member of the TRPM subfamily of transient receptor potential (TRP) ion channels. The channel was originally identified as a volume-regulated ion channel that can be activated upon reduction of the extracellular osmolality. Later, the channel was proposed to be involved in the modulation of insulin release in pancreatic islets. However, new evidence has uncovered a role of TRPM3 as a thermosensitive nociceptor channel implicated in the detection of noxious heat. The channel is functionally expressed in a subset of neurons of the somatosensory system and can be activated by heat. The purpose of the present review is to summarize existing knowledge of the expression, biophysics and pharmacology of TRPM3 and to serve as a guide for future studies aimed at improving the understanding of the mechanism of thermosensation and proposed physiological functions of TRPM3.
Collapse
Key Words
- Clt, Clotrimazole
- DHEA, Dehydroepiandrosterone
- DRG, Dorsal root ganglion
- DeSPH, D-erythro-sphingosine
- PCR, Polymerase chain reaction
- PPAR-γ, Peroxisome proliferator-activator receptor - γ
- PS, Pregnenolone sulfate
- Q10, 10-degree temperature coefficient
- RT, Room temperature
- TG, Trigeminal ganglion
- TRP channel
- TRP, Transient receptor potential
- TRPM, Transient receptor potential melastatin
- TRPM3
- TRPV, Transient receptor potential vanilloid
- nociceptor
- sensory system
- temperature sensing
- ΔG, Gibbs free energy
- ΔH, Enthalpy
- ΔS, Entropy
Collapse
Affiliation(s)
- Katharina Held
- Laboratory of Experimental Gynecology; KU Leuven; Leuven, Belgium; Laboratory of Ion Channel Research and TRP Research Platform Leuven (TRPLe); KU Leuven; Leuven, Belgium
| | - Thomas Voets
- Laboratory of Ion Channel Research and TRP Research Platform Leuven (TRPLe); KU Leuven ; Leuven, Belgium
| | - Joris Vriens
- Laboratory of Experimental Gynecology; KU Leuven ; Leuven, Belgium
| |
Collapse
|
35
|
Doucette LP, Rasnitsyn A, Seifi M, Walter MA. The interactions of genes, age, and environment in glaucoma pathogenesis. Surv Ophthalmol 2015; 60:310-26. [PMID: 25907525 DOI: 10.1016/j.survophthal.2015.01.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 12/30/2022]
Abstract
Glaucoma, a progressive degenerative condition that results in the death of retinal ganglion cells, is one of the leading causes of blindness, affecting millions worldwide. The mechanisms underlying glaucoma are not well understood, although years of studies have shown that the largest risk factors are elevated intraocular pressure, age, and genetics. Eleven genes and multiple loci have been identified as contributing factors. These genes act by a number of mechanisms, including mechanical stress, ischemic/oxidative stress, and neurodegeneration. We summarize the recent advances in the understanding of glaucoma and propose a unified hypothesis for glaucoma pathogenesis. Glaucoma does not result from a single pathological mechanism, but rather a combination of pathways that are influenced by genes, age, and environment. In particular, we hypothesize that, in the presence of genetic risk factors, exposure to environment stresses results in an earlier age of onset for glaucoma. This hypothesis is based upon the overlap of the molecular pathways in which glaucoma genes are involved. Because of the interactions between these processes, it is likely that there are common therapies that may be effective for different subtypes of glaucoma.
Collapse
Affiliation(s)
- Lance P Doucette
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada
| | - Alexandra Rasnitsyn
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada
| | - Morteza Seifi
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada
| | - Michael A Walter
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada.
| |
Collapse
|
36
|
Terrell AM, Anand D, Smith SF, Dang CA, Waters SM, Pathania M, Beebe DC, Lachke SA. Molecular characterization of mouse lens epithelial cell lines and their suitability to study RNA granules and cataract associated genes. Exp Eye Res 2014; 131:42-55. [PMID: 25530357 DOI: 10.1016/j.exer.2014.12.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/02/2014] [Accepted: 12/18/2014] [Indexed: 01/10/2023]
Abstract
The discovery of cytosolic RNA granule (RG) component proteins associated with human cataract has initiated investigations on post-transcriptional mechanisms of gene expression control in the lens. Application of established mouse lens epithelial cell lines (LECs) can provide rapid insights on RG function in lens cells, especially because mouse mutants in several RG components are not available. However, although these LECs represent potential reagents for such analyses, they are uncharacterized for lens gene expression or RG formation. Therefore, a detailed molecular and cellular characterization of three permanent mouse LECs 17EM15, 21EM15 and αTN4 is performed in this study. Comparative analysis between microarray gene expression datasets on LEC 21EM15 and iSyTE lens tissue demonstrates that 30% of top 200 iSyTE identified lens-enriched genes are expressed in these cells. Majority of these candidates are independently validated to either have lens expression, function or linkage to cataract. Moreover, analysis of microarray data with genes described in Cat-Map, an online database of cataract associated genes and loci, demonstrates that 131 genes linked to cataract loci are expressed in 21EM15 cells. Furthermore, gene expression in LECs is compared to isolated lens epithelium or fiber cells by qRT-PCR and by comparative analyses with publically available epithelium or fiber-specific microarray and RNA-seq (sequencing) datasets. Expression of select candidate genes was validated by regular and real-time quantitative RT-PCR. Expression of lens epithelium-enriched genes Foxe3, Pax6, Anxa4 and Mcm4 is up-regulated in LEC lines, compared to isolated lens fiber cells. Moreover, similar to isolated lens epithelium, all three LECs exhibit down-regulation of fiber cell-expressed genes Crybb1, Mip and Prox1 when compared to fiber cells. These data indicate that the LEC lines exhibit greater similarity to lens epithelium than to fiber cells. Compared to non-lens cell line NIH3T3, LECs exhibit significantly enriched expression of transcription factors with important function in the lens, namely Pax6, Foxe3 and Prox1. In addition to these genes, all three LECs also express key lens- and cataract-associated genes, namely Dkk3, Epha2, Hsf4, Jag1, Mab21l1, Meis1, Pknox1, Pou2f1, Sfrp1, Sparc, Tdrd7 and Trpm3. Additionally, 21EM15 microarrays indicate expression of Chmp4b, Cryab and Tcfap2a among others important genes. Immunostaining with makers for Processing bodies (P-bodies) and Stress granules (SGs) demonstrates that these classes of RGs are robustly expressed in all three LECs. Moreover, under conditions of stress, 17EM15 and αTN4 exhibit significantly higher numbers of P-bodies and SGs compared to NIH3T3 cells. In sum, these data indicate that mouse LECs 21EM15, 17EM15 and αTN4 express key lens or cataract genes, are similar to lens epithelium than fiber cells, and exhibit high levels of P-bodies and SGs, indicating their suitability for investigating gene expression control and RG function in lens-derived cells.
Collapse
Affiliation(s)
- Anne M Terrell
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Sylvie F Smith
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Christine A Dang
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Stephanie M Waters
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Mallika Pathania
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - David C Beebe
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, USA
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, USA; Center for Bioinformatics & Computational Biology, University of Delaware, Newark, DE, USA.
| |
Collapse
|
37
|
Higuchi H, Macke EL, Lee WH, Miller SA, Xu JC, Ikeda S, Ikeda A. Genetic basis of age-dependent synaptic abnormalities in the retina. Mamm Genome 2014; 26:21-32. [PMID: 25273269 DOI: 10.1007/s00335-014-9546-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 09/01/2014] [Indexed: 12/17/2022]
Abstract
Understanding the normal aging process will help us determine the mechanisms of how age-related diseases are caused and progress. A/J inbred mice have been shown to exhibit accelerated aging phenotypes in the retina including increased inflammation and photoreceptor cell degeneration, which resemble human aging symptoms. C57BL/6J (B6) inbred mice are less susceptible for these abnormalities, indicating the existence of genetic factor(s) that affect their severity. In this study, we determined that another age-dependent phenotype, ectopic synapse formation, is also accelerated in the A/J retina compared to the B6 retina. Through genetic mapping utilizing recombinant inbred strains, we identified quantitative trait loci (QTLs) on chromosome 7 and 19, which contribute to abnormal retinal synapses as well as other age-dependent phenotypes. Using consomic single chromosome substitution lines where a single chromosome is from A/J and the rest of the genome is B6, we investigated the individual effect of each QTL on retinal aging phenotypes. We observed that both QTLs independently contribute to abnormal retinal synapses, reduction in the number of cone cells, and an up-regulation of retinal stress marker, glial fibrillary acidic protein (GFAP). Mice with a single chromosome substitution on chromosome 19 also exhibited an increase in inflammatory cells, which is characteristic of aging and age-related macular degeneration. Thus, we identified QTLs that are independently capable of affecting the severity and progression of age-dependent retinal abnormalities in mice.
Collapse
Affiliation(s)
- Hitoshi Higuchi
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | | | | | | | | | | | | |
Collapse
|