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Li X, Fu YH, Tong XW, Zhang YT, Shan YY, Xu YX, Pu SD, Gao XY. RAAS in diabetic retinopathy: mechanisms and therapies. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2024; 68:e230292. [PMID: 38652701 PMCID: PMC11081058 DOI: 10.20945/2359-4292-2023-0292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 11/23/2023] [Indexed: 04/25/2024]
Abstract
Diabetic retinopathy (DR) is a complication of diabetes with a complex pathophysiology and multiple factors involved. Recently, it has been found that the upregulation of the renin-angiotensin-aldosterone system (RAAS) leads to overexpression of angiotensin II (Ang II), which induces oxidative stress, inflammation, and angiogenesis in the retina. Therefore, RAAS may be a promising therapeutic target in DR. Notably, RAAS inhibitors are often used in the treatment of hypertension. Still, the potential role and mechanism of DR must be further studied. In this review, we discuss and summarize the pathology and potential therapeutic goals of RAAS in DR.
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Affiliation(s)
- Xin Li
- First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Department of Endocrinology, Harbin, China
| | - Yu-Hong Fu
- First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Department of Endocrinology, Harbin, China
| | - Xue-Wei Tong
- First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Department of Endocrinology, Harbin, China
| | - Yi-Tong Zhang
- First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Department of Endocrinology, Harbin, China
| | - Yong-Yan Shan
- First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Department of Endocrinology, Harbin, China
| | - Yu-Xin Xu
- First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Department of Endocrinology, Harbin, China
| | - Sheng-Dan Pu
- First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Department of Endocrinology, Harbin, China
| | - Xin-Yuan Gao
- First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Department of Endocrinology, Harbin, China,
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2
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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.
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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.
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3
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Subramanian A, Han D, Braithwaite T, Thayakaran R, Zemedikun DT, Gokhale KM, Lee WH, Coker J, Keane PA, Denniston AK, Nirantharakumar K, Azoulay L, Adderley NJ. Angiotensin-converting enzyme inhibitors and risk of age-related macular degeneration in individuals with hypertension. Br J Clin Pharmacol 2022; 88:4199-4210. [PMID: 35474585 PMCID: PMC9541840 DOI: 10.1111/bcp.15366] [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: 11/24/2021] [Revised: 03/19/2022] [Accepted: 04/04/2022] [Indexed: 11/27/2022] Open
Abstract
AIMS Several observational studies have examined the potential protective effect of angiotensin-converting enzyme inhibitor (ACE-I) use on the risk of age-related macular degeneration (AMD) and have reported contradictory results owing to confounding and time-related biases. We aimed to assess the risk of AMD in a base cohort of patients aged 40 years and above with hypertension among new users of ACE-I compared to an active comparator cohort of new users of calcium channel blockers (CCB) using data obtained from IQVIA Medical Research Data, a primary care database in the UK. METHODS In this study, 53 832 and 43 106 new users of ACE-I and CCB were included between 1995 and 2019, respectively. In an on-treatment analysis, patients were followed up from the time of index drug initiation to the date of AMD diagnosis, loss to follow-up, discontinuation or switch to the comparator drug. A comprehensive range of covariates were used to estimate propensity scores to weight and match new users of ACE-I and CCB. Standardized mortality ratio weighted Cox proportional hazards model was used to estimate hazard ratios of developing AMD. RESULTS During a median follow-up of 2 years (interquartile range 1-5 years), the incidence rate of AMD was 2.4 (95% confidence interval 2.2-2.6) and 2.2 (2.0-2.4) per 1000 person-years among the weighted new users of ACE-I and CCB, respectively. There was no association of ACE-I use on the risk of AMD compared to CCB use in either the propensity score weighted or matched, on-treatment analysis (adjusted hazard ratio: 1.07 [95% confidence interval 0.90-1.27] and 0.87 [0.71-1.07], respectively). CONCLUSION We found no evidence that the use of ACE-I is associated with risk of AMD in patients with hypertension.
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Affiliation(s)
| | - Diana Han
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Tasanee Braithwaite
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK.,The School of Immunology and Microbial Sciences and The School of Life Course Sciences, Kings College London, London, UK.,The Medical Eye Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Rasiah Thayakaran
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Dawit T Zemedikun
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Krishna M Gokhale
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Wen Hwa Lee
- Action Against Age-Related Macular Degeneration, London, UK
| | - Jesse Coker
- Action Against Age-Related Macular Degeneration, London, UK
| | - Pearse A Keane
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and Institute of Ophthalmology, University College London, London, UK
| | - Alastair K Denniston
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and Institute of Ophthalmology, University College London, London, UK.,University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.,Health Data Research UK (HDRUK), London, UK.,Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - Krishnarajah Nirantharakumar
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK.,Health Data Research UK (HDRUK), London, UK
| | - Laurent Azoulay
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada.,Centre for Clinical Epidemiology, Lady Davis Institute, Montreal, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montreal, Canada
| | - Nicola J Adderley
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
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4
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Lewandowski D, Sander CL, Tworak A, Gao F, Xu Q, Skowronska-Krawczyk D. Dynamic lipid turnover in photoreceptors and retinal pigment epithelium throughout life. Prog Retin Eye Res 2021; 89:101037. [PMID: 34971765 PMCID: PMC10361839 DOI: 10.1016/j.preteyeres.2021.101037] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 12/13/2022]
Abstract
The retinal pigment epithelium-photoreceptor interphase is renewed each day in a stunning display of cellular interdependence. While photoreceptors use photosensitive pigments to convert light into electrical signals, the RPE supports photoreceptors in their function by phagocytizing shed photoreceptor tips, regulating the blood retina barrier, and modulating inflammatory responses, as well as regenerating the 11-cis-retinal chromophore via the classical visual cycle. These processes involve multiple protein complexes, tightly regulated ligand-receptors interactions, and a plethora of lipids and protein-lipids interactions. The role of lipids in maintaining a healthy interplay between the RPE and photoreceptors has not been fully delineated. In recent years, novel technologies have resulted in major advancements in understanding several facets of this interplay, including the involvement of lipids in phagocytosis and phagolysosome function, nutrient recycling, and the metabolic dependence between the two cell types. In this review, we aim to integrate the complex role of lipids in photoreceptor and RPE function, emphasizing the dynamic exchange between the cells as well as discuss how these processes are affected in aging and retinal diseases.
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Affiliation(s)
- Dominik Lewandowski
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Christopher L Sander
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Aleksander Tworak
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Fangyuan Gao
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Qianlan Xu
- Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Dorota Skowronska-Krawczyk
- Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA.
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5
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Pang JJ, Gao F, Wu SM. Generators of Pressure-Evoked Currents in Vertebrate Outer Retinal Neurons. Cells 2021; 10:cells10061288. [PMID: 34067375 PMCID: PMC8224636 DOI: 10.3390/cells10061288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 12/19/2022] Open
Abstract
(1) Background: High-tension glaucoma damages the peripheral vision dominated by rods. How mechanosensitive channels (MSCs) in the outer retina mediate pressure responses is unclear. (2) Methods: Immunocytochemistry, patch clamp, and channel fluorescence were used to study MSCs in salamander photoreceptors. (3) Results: Immunoreactivity of transient receptor potential channel vanilloid 4 (TRPV4) was revealed in the outer plexiform layer, K+ channel TRAAK in the photoreceptor outer segment (OS), and TRPV2 in some rod OS disks. Pressure on the rod inner segment evoked sustained currents of three components: (A) the inward current at <-50 mV (Ipi), sensitive to Co2+; (B) leak outward current at ≥-80 mV (Ipo), sensitive to intracellular Cs+ and ruthenium red; and (C) cation current reversed at ~10 mV (Ipc). Hypotonicity induced slow currents like Ipc. Environmental pressure and light increased the FM 1-43-identified open MSCs in the OS membrane, while pressure on the OS with internal Cs+ closed a Ca2+-dependent current reversed at ~0 mV. Rod photocurrents were thermosensitive and affected by MSC blockers. (4) Conclusions: Rods possess depolarizing (TRPV) and hyperpolarizing (K+) MSCs, which mediate mutually compensating currents between -50 mV and 10 mV, serve as an electrical cushion to minimize the impact of ocular mechanical stress.
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6
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Aebersold A, Duff M, Sloan L, Song ZH. Cannabidiol Signaling in the Eye and Its Potential as an Ocular Therapeutic Agent. Cell Physiol Biochem 2021; 55:1-14. [PMID: 33984199 PMCID: PMC8807061 DOI: 10.33594/000000371] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2021] [Indexed: 12/01/2022] Open
Abstract
Cannabidiol (CBD), the major non-intoxicating constituent of Cannabis sativa, has gained recent attention due to its putative therapeutic uses for a wide variety of diseases. CBD was discovered in the 1940s and its structure fully characterized in the 1960s. However, for many years most research efforts related to cannabis derived chemicals have focused on D9-tetrahydrocannabinol (THC). In contrast to THC, the lack of intoxicating psychoactivity associated with CBD highlights the potential of this cannabinoid for clinical drug development. This review details in vitro and in vivo studies of CBD related to the eye, the therapeutic potential of cannabidiol for various ocular conditions, and molecular targets and mechanisms for CBD-induced ocular effects. In addition, challenges of CBD applications for clinical ocular therapeutics and future directions are discussed.
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Affiliation(s)
- Alyssa Aebersold
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Max Duff
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Lucy Sloan
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Zhao-Hui Song
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, USA,
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7
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Polidoro JZ, Rebouças NA, Girardi ACC. The Angiotensin II Type 1 Receptor-Associated Protein Attenuates Angiotensin II-Mediated Inhibition of the Renal Outer Medullary Potassium Channel in Collecting Duct Cells. Front Physiol 2021; 12:642409. [PMID: 34054566 PMCID: PMC8160308 DOI: 10.3389/fphys.2021.642409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/16/2021] [Indexed: 11/13/2022] Open
Abstract
Adjustments in renal K+ excretion constitute a central mechanism for K+ homeostasis. The renal outer medullary potassium (ROMK) channel accounts for the major K+ secretory route in collecting ducts during basal conditions. Activation of the angiotensin II (Ang II) type 1 receptor (AT1R) by Ang II is known to inhibit ROMK activity under the setting of K+ dietary restriction, underscoring the role of the AT1R in K+ conservation. The present study aimed to investigate whether an AT1R binding partner, the AT1R-associated protein (ATRAP), impacts Ang II-mediated ROMK regulation in collecting duct cells and, if so, to gain insight into the potential underlying mechanisms. To this end, we overexpressed either ATRAP or β-galactosidase (LacZ; used as a control), in M-1 cells, a model line of cortical collecting duct cells. We then assessed ROMK channel activity by employing a novel fluorescence-based microplate assay. Experiments were performed in the presence of 10−10 M Ang II or vehicle for 40 min. We observed that Ang II-induced a significant inhibition of ROMK in LacZ, but not in ATRAP-overexpressed M-1 cells. Inhibition of ROMK-mediated K+ secretion by Ang II was accompanied by lower ROMK cell surface expression. Conversely, Ang II did not affect the ROMK-cell surface abundance in M-1 cells transfected with ATRAP. Additionally, diminished response to Ang II in M-1 cells overexpressing ATRAP was accompanied by decreased c-Src phosphorylation at the tyrosine 416. Unexpectedly, reduced phospho-c-Src levels were also found in M-1 cells, overexpressing ATRAP treated with vehicle, suggesting that ATRAP can also downregulate this kinase independently of Ang II-AT1R activation. Collectively, our data support that ATRAP attenuates inhibition of ROMK by Ang II in collecting duct cells, presumably by reducing c-Src activation and blocking ROMK internalization. The potential role of ATRAP in K+ homeostasis and/or disorders awaits further investigation.
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Affiliation(s)
| | - Nancy Amaral Rebouças
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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8
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Angiotensin-Receptor-Associated Protein Modulates Ca 2+ Signals in Photoreceptor and Mossy Fiber cells. Sci Rep 2019; 9:19622. [PMID: 31873081 PMCID: PMC6928155 DOI: 10.1038/s41598-019-55380-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 11/22/2019] [Indexed: 11/29/2022] Open
Abstract
Fast, precise and sustained neurotransmission requires graded Ca2+ signals at the presynaptic terminal. Neurotransmitter release depends on a complex interplay of Ca2+ fluxes and Ca2+ buffering in the presynaptic terminal that is not fully understood. Here, we show that the angiotensin-receptor-associated protein (ATRAP) localizes to synaptic terminals throughout the central nervous system. In the retinal photoreceptor synapse and the cerebellar mossy fiber-granule cell synapse, we find that ATRAP is involved in the generation of depolarization-evoked synaptic Ca2+ transients. Compared to wild type, Ca2+ imaging in acutely isolated preparations of the retina and the cerebellum from ATRAP knockout mice reveals a significant reduction of the sarcoendoplasmic reticulum (SR) Ca2+-ATPase (SERCA) activity. Thus, in addition to its conventional role in angiotensin signaling, ATRAP also modulates presynaptic Ca2+ signaling within the central nervous system.
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9
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Reichhart N, Figura A, Skosyrski S, Strauß O. Control of the retinal local RAS by the RPE: An interface to systemic RAS activity. Exp Eye Res 2019; 189:107838. [PMID: 31622617 DOI: 10.1016/j.exer.2019.107838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/19/2019] [Accepted: 10/11/2019] [Indexed: 01/07/2023]
Abstract
As many other organs, the retina has a local renin-angiotensin-system (RAS). All main elements of the RAS are active in the retina: renin, angiotensinogen, angiotensin-converting enzymes. The functional role of the intraretinal RAS is not fully understood. So far, histological and functional analysis point to a regulation of ganglion cell activity and maybe also of bipolar cell activity, but it is not clear how RAS contributes to retinal signal processing. In contrast to local RAS in other organs, the retinal RAS is clearly separated from the systemic RAS. The angiotensin-2 (AngII)/AngI ratio in the retina is different to that in the plasma. However, it appears that the retinal pigment epithelium (RPE), that forms the outer blood/retina barrier, is a major regulator of the retinal RAS by producing renin. Interestingly, comparable to the kidney, the renin production in the RPE is under control of the angiotensin-2 receptor type-1 (AT1). AT1 localizes to the basolateral membrane of the RPE and faces the blood side of the blood/retina barrier. Increases in systemic AngII reduce renin production in the RPE and therefore decrease the intraretinal RAS activity. The relevance of the local RAS for retinal function remains unclear. Nevertheless, it is of fundamental significance to understand the pathology of systemically induced retinal diseases such as hypertension or diabetes.
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Affiliation(s)
- Nadine Reichhart
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, A Corporate Member of Freie Universität, Humboldt-University, The Berlin Institute of Health, Berlin, Germany
| | - Aleksandar Figura
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, A Corporate Member of Freie Universität, Humboldt-University, The Berlin Institute of Health, Berlin, Germany
| | - Sergej Skosyrski
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, A Corporate Member of Freie Universität, Humboldt-University, The Berlin Institute of Health, Berlin, 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.
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10
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Martins JR, Reichhart N, Kociok N, Stindl J, Foeckler R, Lachmann P, Todorov V, Castrop H, Strauß O. Systemic ß adrenergic stimulation/ sympathetic nerve system stimulation influences intraocular RAS through cAMP in the RPE. Exp Eye Res 2019; 189:107828. [PMID: 31589840 DOI: 10.1016/j.exer.2019.107828] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 10/02/2019] [Accepted: 10/03/2019] [Indexed: 10/25/2022]
Abstract
Several lines of evidence support the existence of a renin-angiotensin system (RAS) in the retina that is separated from the blood stream by the retinal pigment epithelium (RPE). Under physiological conditions, increased activity of intraretinal RAS regulates neuronal activity of the retina but patho-physiologically participates in retinal degeneration such as hypertensive or diabetic retinopathy. Interestingly, the RPE appears to be a modulator of intraretinal RAS in response to changes in systemic RAS. As increased systemic RAS activity is associated with increased sympathetic tonus, we investigated whether systemic β-adrenergic stimulation of the RPE also modulates renin expression in the RPE. In vivo, the mouse RPE expresses the β-adrenergic receptor subtypes 1 and 2. Staining of retina sagittal sections showed tyrosine hydroxylase positive nerve endings in the choroid indicating adrenaline/noradrenaline production sites in close proximity to the RPE. Systemic infusion of isoproterenol increased renin expression in the RPE but not in the retina. This increase was sensitive to concomitant systemic application of the angiotensin-2 receptor-type-1 blocker losartan. In vitro analysis of renin gene expression using polarized porcine RPE showed that the activity of the renin promoter can be increased by cAMP stimulation (IBMX/forskolin) but was not influenced by angiotensin-2. Thus, with the identification of the β-adrenergic system we added a new regulator of the retinal RAS with relevance for retinal function and pathology. Furthermore, it appears that the RPE is not only a close interaction partner of the photoreceptors but also a regulator or retinal activity in general.
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Affiliation(s)
- Joana Raquel Martins
- Experimental Ophthalmology, Eye Hospital, University Medical Center Regensburg, Regensburg, Germany
| | - Nadine Reichhart
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, a Corporate Member of Freie Universität, Humboldt-University, The Berlin Institute of Health, Berlin, Germany
| | - Nobert Kociok
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, a Corporate Member of Freie Universität, Humboldt-University, The Berlin Institute of Health, Berlin, Germany
| | - Julia Stindl
- Experimental Ophthalmology, Eye Hospital, University Medical Center Regensburg, Regensburg, Germany
| | - Renate Foeckler
- Experimental Ophthalmology, Eye Hospital, University Medical Center Regensburg, Regensburg, Germany
| | - Peter Lachmann
- Laboratory for Experimental Nephrology, Dresden University of Technology, Dresden, Germany
| | - Vladimir Todorov
- Laboratory for Experimental Nephrology, Dresden University of Technology, Dresden, Germany
| | - Hayo Castrop
- Institute of Physiology, University of Regensburg, Regensburg, 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.
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11
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Xu X, Ritz B, Coleman A, Liew Z, Deapen D, Lee E, Bernstein L, Pinder R, Marshall S, Heck JE. Hypertension, antihypertensive medications use and risk of age-related macular degeneration in California Teachers Cohort. J Hum Hypertens 2019; 34:568-576. [PMID: 31595025 DOI: 10.1038/s41371-019-0269-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/19/2019] [Accepted: 09/25/2019] [Indexed: 01/02/2023]
Abstract
Sustained and inadequately controlled hypertension can promote the development of age-related macular degeneration (AMD) through multiple biologic pathways. Epidemiologic studies of high blood pressure, antihypertensive therapies, and the risk of AMD thus far have been inconclusive. However, few studies evaluated risks according to the use of different classes of antihypertensive drugs or took combinations of use into account. We performed a prospective cohort study by linking the California Teachers Study (CTS) cohort (N = 88 481) to statewide hospital discharge records up to December 31, 2012. History of high blood pressure, regular use of antihypertensive medications, and comprehensive risk factor information was collected via self-administered questionnaires at baseline in 1995-1996, and information on specific classes of antihypertensive drugs was provided by a subsample of CTS participants who completed a follow-up questionnaire in 2000. We identified 1762 female teachers with AMD during 14.8 years of follow-up on average. Applying Cox proportional hazard regression, we estimated increased risks of AMD among women treated for hypertension at baseline (HR = 1.15, 95% CI: 1.03, 1.30); the magnitude of the association increased with longer duration of antihypertensive treatment. In the subsample with more specific information on type of medication use, we estimated a 45% increased risk of AMD among women receiving diuretics as monotherapy compared to women with medications more potent than diuretics (HR = 1.45, 95% CI 1.10, 1.90). In women treated with a combination of antihypertensive drugs, we observed no increased risk of AMD for any individual class of drugs.
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Affiliation(s)
- Xiaoqing Xu
- Department of Epidemiology, Fielding School of Public Health, UCLA, Los Angeles, CA, USA
| | - Beate Ritz
- Department of Epidemiology, Fielding School of Public Health, UCLA, Los Angeles, CA, USA
| | - Anne Coleman
- Department of Epidemiology, Fielding School of Public Health, UCLA, Los Angeles, CA, USA.,Jules Stein Eye Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Zeyan Liew
- Department of Epidemiology, Fielding School of Public Health, UCLA, Los Angeles, CA, USA
| | - Dennis Deapen
- Department of Preventative Medicine, Keck School of Medicine, University of Southern California (USC), Los Angeles, CA, USA
| | - Eunjung Lee
- Department of Preventative Medicine, Keck School of Medicine, University of Southern California (USC), Los Angeles, CA, USA
| | - Leslie Bernstein
- Division of Cancer Etiology, Department of Population Sciences, City of Hope National Medical Center and Comprehensive Cancer Center, Duarte, CA, USA
| | - Rich Pinder
- Department of Preventative Medicine, Keck School of Medicine, University of Southern California (USC), Los Angeles, CA, USA
| | - Sarah Marshall
- Department of Preventative Medicine, Keck School of Medicine, University of Southern California (USC), Los Angeles, CA, USA
| | - Julia E Heck
- Department of Epidemiology, Fielding School of Public Health, UCLA, Los Angeles, CA, USA.
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12
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Jones S, Mann A, Worley MC, Fulford L, Hall D, Karani R, Jiang M, Robbins N, Rubinstein J, Koch SE. The role of transient receptor potential vanilloid 2 channel in cardiac aging. Aging Clin Exp Res 2017; 29:863-873. [PMID: 27804106 DOI: 10.1007/s40520-016-0663-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/18/2016] [Indexed: 12/14/2022]
Abstract
BACKGROUND The aging heart is characterized by cellular and molecular changes leading to a decline in physiologic function and cardiac remodeling, specifically the development of myocyte hypertrophy and fibrosis. Transient receptor potential vanilloid 2 (TRPV2), a stretch-mediated channel and regulator of calcium homeostasis, plays a key role in the function and structure of the heart. TRPV2 also plays an important role in the adaptive and maladaptive compensatory mechanisms of the heart in response to pathologic and exercise-induced stress. Our current study seeks to elucidate the potential role of TRPV2 channels in the regulation of cardiac function in aging. METHODS Wild-type (WT) and TRPV2 functional knockout (FKO) mice were aged out to various time points, and their cardiac function was measured using advanced echocardiography. Furthermore, we histologically analyzed the heart morphology to determine myocyte hypertrophy, the development of fibrosis and the relative expression of TRPV2. RESULTS Our results demonstrate that even though TRPV2-FKO mice have impaired function at baseline, their cardiac function as measured via standard and advanced echocardiographic parameters (ejection fraction, cardiac output and circumferential strain) decreased less with aging in comparison with the WT group. Furthermore, there was less fibrosis and hypertrophy in the TRPV2-FKO group with aging in comparison with the WT. The expression of TRPV2 in the WT group did not significantly change with aging. CONCLUSIONS TRPV2 functional deletion is compatible with aging and associated with a decreased development of myocyte hypertrophy and fibrosis. It may be an important target for prevention of age-induced cardiac remodeling.
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Affiliation(s)
- Shannon Jones
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, ML0542, Cincinnati, OH, 45267, USA
| | - Adrien Mann
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, ML0542, Cincinnati, OH, 45267, USA
| | - Mariah C Worley
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, ML0542, Cincinnati, OH, 45267, USA
| | - Logan Fulford
- Department of Pathobiology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - David Hall
- Department of Nutritional Sciences College of Allied Health, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Rajiv Karani
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, ML0542, Cincinnati, OH, 45267, USA
| | - Min Jiang
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, ML0542, Cincinnati, OH, 45267, USA
| | - Nathan Robbins
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, ML0542, Cincinnati, OH, 45267, USA
| | - Jack Rubinstein
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, ML0542, Cincinnati, OH, 45267, USA
| | - Sheryl E Koch
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, ML0542, Cincinnati, OH, 45267, USA.
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Transient receptor potential vanilloid 2 function regulates cardiac hypertrophy via stretch-induced activation. J Hypertens 2017; 35:602-611. [PMID: 28009703 DOI: 10.1097/hjh.0000000000001213] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Hypertension (increased afterload) results in cardiomyocyte hypertrophy leading to left ventricular hypertrophy and subsequently, heart failure with preserved ejection fraction. This study was performed to test the hypothesis that transient receptor potential vanilloid 2 subtype (TRPV2) function regulates hypertrophy under increased afterload conditions. METHODS We used functional (pore specific) TRPV2 knockout mice to evaluate the effects of increased afterload-induced stretch on cardiac size and function via transverse aortic constriction (TAC) as well as hypertrophic stimuli including adrenergic and angiotensin stimulation via subcutaneous pumps. Wild-type animals served as control for all experiments. Expression and localization of TRPV2 was investigated in wild-type cardiac samples. Changes in cardiac function were measured in vivo via echocardiography and invasive catheterization. Molecular changes, including protein and real-time PCR markers of hypertrophy, were measured in addition to myocyte size. RESULTS TRPV2 is significantly upregulated in wild-type mice after TAC, though not in response to beta-adrenergic or angiotensin stimulation. TAC-induced stretch stimulus caused an upregulation of TRPV2 in the sarcolemmal membrane. The absence of functional TRPV2 resulted in significantly reduced left ventricular hypertrophy after TAC, though not in response to beta-adrenergic or angiotensin stimulation. The decreased development of hypertrophy was not associated with significant deterioration of cardiac function. CONCLUSION We conclude that TRPV2 function, as a stretch-activated channel, regulates the development of cardiomyocyte hypertrophy in response to increased afterload.
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15
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Stretch-activated TRPV2 channels: Role in mediating cardiopathies. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 130:273-280. [PMID: 28546113 DOI: 10.1016/j.pbiomolbio.2017.05.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 05/17/2017] [Accepted: 05/19/2017] [Indexed: 02/06/2023]
Abstract
Transient receptor potential vanilloid type 2, TRPV2, is a calcium-permeable cation channel belonging to the TRPV channel family. Although this channel has been first characterized as a noxious heat sensor, its mechanosensor property recently gained importance in various physiological functions. TRPV2 has been described as a stretch-mediated channel and a regulator of calcium homeostasis in several cell types and has been shown to be involved in the stretch-dependent responses in cardiomyocytes. Hence, several studies in the last years support the idea that TRPV2 play a key role in the function and structure of the heart, being involved in the cardiac compensatory mechanisms in response to pathologic or exercise-induced stress. We present here an overview of the current literature and concepts of TRPV2 channels involvement (i) in the mechanical coupling mechanisms in heart and (ii) in the mechanisms that lead to cardiomyopathies. All these studies lead us to think that TRPV2 may also be an important cardiac drug target based on its major physiological roles in heart.
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Choudhary R, Kapoor MS, Singh A, Bodakhe SH. Therapeutic targets of renin-angiotensin system in ocular disorders. J Curr Ophthalmol 2016; 29:7-16. [PMID: 28367520 PMCID: PMC5362395 DOI: 10.1016/j.joco.2016.09.009] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/27/2016] [Accepted: 09/30/2016] [Indexed: 12/16/2022] Open
Abstract
Purpose To review current literature on the renin-angiotensin system (RAS)-mediated pathogenic mechanisms and therapeutic targets in ocular diseases. Methods A comprehensive literature survey was performed on PubMed, Scopus, and Google Scholar databases published from 1977 to 2016. The search terms were a RAS, angiotensin, angiotensin receptor, prorenin, pro (renin) receptor, angiotensin converting enzyme inhibitor, angiotensin receptor blocker associated with ocular disorders like cataract, glaucoma, diabetic retinopathy (DR), macular degeneration, and uveitis. Articles were reviewed on the basis of the association between ocular disorders and RAS and relevant articles were discussed. Results The literature revealed that the individual RAS components including renin, angiotensins, angiotensin converting enzymes, and RAS receptors have been expressed in the specific ocular tissues like retina, choroid, and ciliary body. The activation of both circulatory and local RAS potentiate the various inflammatory and angiogenic signaling molecules, including vascular endothelial growth factor (VEGF), extracellular signal-regulated kinase, and advanced glycation end products (AGE) in the ocular tissues and leads to several blinding disorders like DR, glaucoma, and macular degeneration. The classical and newer RAS inhibitors have illustrated protective effects on blinding disorders, including DR, glaucoma, macular degeneration, uveitis, and cataract. Conclusions The RAS components are present in the extrarenal tissues including ocular tissue and have an imperative role in the ocular pathophysiology. The clinical studies are needed to show the role of therapeutic modalities targeting RAS in the treatment of different ocular disorders.
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Comparison of In Vivo Gene Expression Profiling of RPE/Choroid following Intravitreal Injection of Dexamethasone and Triamcinolone Acetonide. J Ophthalmol 2016; 2016:9856736. [PMID: 27429799 PMCID: PMC4939337 DOI: 10.1155/2016/9856736] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/29/2016] [Accepted: 05/03/2016] [Indexed: 11/17/2022] Open
Abstract
Purpose. To identify retinal pigment epithelium (RPE)/choroid genes and their relevant expression pathways affected by intravitreal injections of dexamethasone and triamcinolone acetonide in mice at clinically relevant time points for patient care. Methods. Differential gene expression of over 34,000 well-characterized mouse genes in the RPE/choroid of 6-week-old C57BL/6J mice was analyzed after intravitreal steroid injections at 1 week and 1 month postinjection, using Affymetrix Mouse Genome 430 2.0 microarrays. The data were analyzed using GeneSpring GX 12.5 and Ingenuity Pathway Analysis (IPA) microarray analysis software for biologically relevant changes. Results. Both triamcinolone and dexamethasone caused differential activation of genes involved in “Circadian Rhythm Signaling” pathway at both time points tested. Triamcinolone (TAA) uniquely induced significant changes in gene expression in “Calcium Signaling” (1 week) and “Glutamate Receptor Signaling” pathways (1 month). In contrast, dexamethasone (Dex) affected the “GABA Receptor Signaling” (1 week) and “Serotonin Receptor Signaling” (1 month) pathways. Understanding how intraocular steroids affect the gene expression of RPE/choroid is clinically relevant. Conclusions. This in vivo study has elucidated several genes and pathways that are potentially altering the circadian rhythms and several other neurotransmitter pathways in RPE/choroid during intravitreal steroid injections, which likely has consequences in the dysregulation of RPE function and neurodegeneration of the retina.
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Yang K, Yan J, Peng L, Zou YP, He FQ, Gan HT, Huang XL. Effect of PLCε gene silencing on inhibiting the cancerous transformation of ulcerative colitis. Exp Ther Med 2016; 12:422-426. [PMID: 27347072 DOI: 10.3892/etm.2016.3257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 07/29/2015] [Indexed: 02/05/2023] Open
Abstract
The aim of the present study was to investigate the effect of phosphoinositide-specific phospholipase Cε (PLCε) gene silencing on the inhibition of cancer development in ulcerative colitis (UC) and to explore the pathogenesis and carcinogenic mechanism of UC, in order to facilitate the establishment of novel strategies for the treatment of UC, prevent the cancerous transformation of UC and discern the association between inflammation and cancer. A pGenesil-PLCε RNA interference vector was constructed and transfected into HEK293 cells (pGenesil-PLCε group). HEK293 cells transfected with pGenesil empty plasmid were set as the negative control (pGenesil-NC group). The expression of PLCε was observed, and molecules associated with the PLC signaling pathway were detected using a reverse transcription-quantitative polymerase chain reaction and western blotting. ELISA was used to determine the expression of serum interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α) of mice in which the PLCε gene had been silenced. Compared with the pGenesil-NC group, the mRNA and protein levels of PLCε were significantly decreased in the pGenesil-PLCε group. In addition, the mRNA levels of K-ras, NF-κB, Fas and Bcl-2 were markedly reduced, while P53 mRNA level was notably enhanced, in the pGenesil-PLCε group, and these changes were accompanied by similar changes in the corresponding protein levels. The serum IL-1 and TNF-α expression in the PLCε gene-silenced mice was significantly reduced compared with that in the control mice. In conclusion, PLCε RNA silencing can effectively inhibit the cancerous transformation of UC by regulating the colorectal cancer-related cell proliferation and cell cycle in vivo. In addition, PLCε RNA silencing can suppress the expression of inflammatory factors in vitro.
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Affiliation(s)
- Kun Yang
- Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Jing Yan
- Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Lan Peng
- Department of Gastroenterology, Mianyang Central Hospital, Mianyang, Sichuan 621000, P.R. China
| | - Yu-Pei Zou
- Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Fu-Qian He
- Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Hua-Tian Gan
- Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Xiao-Li Huang
- Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
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Pharmacology of the retinal pigment epithelium, the interface between retina and body system. Eur J Pharmacol 2016; 787:84-93. [PMID: 27044435 DOI: 10.1016/j.ejphar.2016.03.066] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/14/2016] [Accepted: 03/31/2016] [Indexed: 12/12/2022]
Abstract
The retinal pigment epithelium (RPE) is a close, interactive partner to the photoreceptors as well as an interface with the endothelium of the choroid and thus with the body's circulatory system. To fulfill these roles, the RPE communicates with neighboring tissue by secretion of a large variety of factors and is able to react to secreted factors via a plethora of transmembrane receptors. Clinically relevant local pharmacological effects are caused by anti-VEGF-A treatment in choroidal neovascularization or by carboanhydrase inhibitors reducing fluid accumulation in the macula. Being exposed to the bloodstream, the RPE reacts to systemic disease, such as diabetes or hypertension, but also to systemic pharmacological intervention, for example to hypotensive drugs acting on the renin-angiotensin-system. Sustained pharmacological treatments, in particular, cause side effects at the RPE with consequences for both RPE function and photoreceptor survival. Among these are systemic inhibition of angiotensin-converting enzyme, insulin treatment in diabetes and anti-VEGF-A therapy. Given the special anatomical and functional relationships of the RPE, pharmacological intervention targeting either the eye or the body systemically should take potential alteration of RPE and subsequently photoreceptor function into account.
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20
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Giblin JP, Comes N, Strauss O, Gasull X. Ion Channels in the Eye: Involvement in Ocular Pathologies. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2015; 104:157-231. [PMID: 27038375 DOI: 10.1016/bs.apcsb.2015.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The eye is the sensory organ of vision. There, the retina transforms photons into electrical signals that are sent to higher brain areas to produce visual sensations. In the light path to the retina, different types of cells and tissues are involved in maintaining the transparency of avascular structures like the cornea or lens, while others, like the retinal pigment epithelium, have a critical role in the maintenance of photoreceptor function by regenerating the visual pigment. Here, we have reviewed the roles of different ion channels expressed in ocular tissues (cornea, conjunctiva and neurons innervating the ocular surface, lens, retina, retinal pigment epithelium, and the inflow and outflow systems of the aqueous humor) that are involved in ocular disease pathophysiologies and those whose deletion or pharmacological modulation leads to specific diseases of the eye. These include pathologies such as retinitis pigmentosa, macular degeneration, achromatopsia, glaucoma, cataracts, dry eye, or keratoconjunctivitis among others. Several disease-associated ion channels are potential targets for pharmacological intervention or other therapeutic approaches, thus highlighting the importance of these channels in ocular physiology and pathophysiology.
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Affiliation(s)
- Jonathan P Giblin
- Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Nuria Comes
- Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | | | - Xavier Gasull
- Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
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21
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Naticchioni M, Karani R, Smith MA, Onusko E, Robbins N, Jiang M, Radzyukevich T, Fulford L, Gao X, Apel R, Heiny J, Rubinstein J, Koch SE. Transient Receptor Potential Vanilloid 2 Regulates Myocardial Response to Exercise. PLoS One 2015; 10:e0136901. [PMID: 26356305 PMCID: PMC4565583 DOI: 10.1371/journal.pone.0136901] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 08/10/2015] [Indexed: 01/14/2023] Open
Abstract
The myocardial response to exercise is an adaptive mechanism that permits the heart to maintain cardiac output via improved cardiac function and development of hypertrophy. There are many overlapping mechanisms via which this occurs with calcium handling being a crucial component of this process. Our laboratory has previously found that the stretch sensitive TRPV2 channels are active regulators of calcium handling and cardiac function under baseline conditions based on our observations that TRPV2-KO mice have impaired cardiac function at baseline. The focus of this study was to determine the cardiac function of TRPV2-KO mice under exercise conditions. We measured skeletal muscle at baseline in WT and TRPV2-KO mice and subjected them to various exercise protocols and measured the cardiac response using echocardiography and molecular markers. Our results demonstrate that the TRPV2-KO mouse did not tolerate forced exercise although they became increasingly exercise tolerant with voluntary exercise. This occurs as the cardiac function deteriorates further with exercise. Thus, our conclusion is that TRPV2-KO mice have impaired cardiac functional response to exercise.
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Affiliation(s)
- Mindi Naticchioni
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Rajiv Karani
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Margaret A. Smith
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Evan Onusko
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Nathan Robbins
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Min Jiang
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Tatiana Radzyukevich
- Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Logan Fulford
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Xu Gao
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Ryan Apel
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Judith Heiny
- Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Jack Rubinstein
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Sheryl E. Koch
- Department of Internal Medicine, Division of Cardiovascular Health & Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail:
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Reichhart N, Keckeis S, Fried F, Fels G, Strauss O. Regulation of surface expression of TRPV2 channels in the retinal pigment epithelium. Graefes Arch Clin Exp Ophthalmol 2015; 253:865-74. [DOI: 10.1007/s00417-014-2917-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/23/2014] [Accepted: 12/23/2014] [Indexed: 12/31/2022] Open
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Ophthalmological assessment of cannabis-induced persisting perception disorder: is there a direct retinal effect? Doc Ophthalmol 2015; 130:121-30. [PMID: 25612939 DOI: 10.1007/s10633-015-9481-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 01/06/2015] [Indexed: 12/22/2022]
Abstract
PURPOSE Cannabis is a psychotomimetic agent that induces impairment of sensory perception. We present detailed clinical and electrophysiological data of patients with hallucinogen persisting perception disorder (HPPD) after marijuana consumption. METHODS A HPPD patient and four heavy cannabis smokers with no visual disturbances (controls) underwent complete ophthalmological examination including psychophysical tests (visual acuity, color vision, visual field, and dark adaptation) and detailed electrophysiological examinations, including extended Ganzfeld ERG, multifocal ERG, and electrooculography (EOG). Furthermore, electrically evoked phosphene thresholds (EPTs) were measured to further evaluate retinal function. RESULTS Ophthalmological and most electrophysiological examinations were within normal limits for the HPPD patient and for all control subjects. Interestingly, EOG results of the HPPD patient showed a slightly reduced fast oscillation ratio, diminished standing potentials of the slow oscillations, and a light peak within normal range resulting in higher Arden ratios. The EPTs of the patient were reduced, in particular for pulses with long durations (50 ms) causing visual sensations even at lowest possible currents of the neurostimulator. The control subjects did not reveal such alterations. CONCLUSIONS Our findings suggest a direct effect of cannabinoids on the retina and retinal pigment epithelium function, which may be involved in disturbances of the visual function experienced after drug consumption. The observations presented here may contribute to the elucidation of the detailed mechanism. Furthermore, EOG and EPT measurements may be useful tools to demonstrate long-term retinal alterations in cannabis-induced HPPD in patients.
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Cheng ZY, Wang XP, Schmid KL, Han XG. GABAB1 and GABAB2 receptor subunits co-expressed in cultured human RPE cells regulate intracellular Ca2+ via Gi/o-protein and phospholipase C pathways. Neuroscience 2014; 280:254-61. [PMID: 25241062 DOI: 10.1016/j.neuroscience.2014.09.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/10/2014] [Accepted: 09/10/2014] [Indexed: 11/26/2022]
Abstract
GABAB receptors associate with Gi/o-proteins that regulate voltage-gated Ca(2+) channels and thus the intracellular Ca(2+) concentration ([Ca(2+)]i), there is also reported cross-regulation of phospholipase C. These associations have been studied extensively in the brain and also shown to occur in non-neural cells (e.g. human airway smooth muscle). More recently GABAB receptors have been observed in chick retinal pigment epithelium (RPE). The aims were to investigate whether the GABAB receptor subunits, GABAB1 and GABAB2, are co-expressed in cultured human RPE cells, and then determine if the GABAB receptor similarly regulates the [Ca(2+)]i of RPE cells and if phospholipase C is involved. Human RPE cells were cultured from five donor eye cups. Evidence for GABAB1 and GABAB2 mRNAs and proteins in the RPE cell cultures was investigated using real time polymerase chain reaction, western blots and immunofluorescence. The effects of the GABAB receptor agonist baclofen, antagonist CGP46381, a Gi/o-protein inhibitor pertussis toxin, and the phospholipase C inhibitor U73122 on [Ca(2+)]i in cultured human RPE were demonstrated using Fluo-3. Both GABAB1 and GABAB2 mRNA and protein were identified in cell cultures of human RPE; antibody staining was co-localized to the cell membrane and cytoplasm. One-hundred micromolars of baclofen caused a transient increase in the [Ca(2+)]i of RPE cells regardless of whether Ca(2+) was added to the buffer. Baclofen-induced increases in the [Ca(2+)]i were attenuated by pre-treatment with CGP46381, pertussis toxin, and U73122. GABAB1 and GABAB2 are co-expressed in cell cultures of human RPE. GABAB receptors in RPE regulate the [Ca(2+)]i via a Gi/o-protein and phospholipase C pathway.
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Affiliation(s)
- Z-Y Cheng
- Department of Ophthalmology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
| | - X-P Wang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
| | - K L Schmid
- School of Optometry and Vision Science, Faculty of Health, and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4059, Australia
| | - X-G Han
- Department of Ophthalmology, The Second Hospital, Jinan, Shandong 250001, China
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Ion channels and transporters of the retinal pigment epithelium. Exp Eye Res 2014; 126:27-37. [DOI: 10.1016/j.exer.2014.05.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 05/02/2014] [Accepted: 05/12/2014] [Indexed: 12/19/2022]
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Huang R, Zhao J, Wu L, Dou C, Liu H, Weng Z, Lu Y, Shi Y, Wang X, Zhou C, Wu H. Mechanisms underlying the analgesic effect of moxibustion on visceral pain in irritable bowel syndrome: a review. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2014; 2014:895914. [PMID: 25093032 PMCID: PMC4100266 DOI: 10.1155/2014/895914] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/10/2014] [Accepted: 06/12/2014] [Indexed: 01/08/2023]
Abstract
Irritable bowel syndrome (IBS) is a functional bowel disorder that causes recurrent abdominal (visceral) pain. Epidemiological data show that the incidence rate of IBS is as high as 25%. Most of the medications may lead to tolerance, addiction and toxic side effects. Moxibustion is an important component of traditional Chinese medicine and has been used to treat IBS-like abdominal pain for several thousand years in China. As a mild treatment, moxibustion has been widely applied in clinical treatment of visceral pain in IBS. In recent years, it has played an irreplaceable role in alternative medicine. Extensive clinical studies have demonstrated that moxibustion for treatment of visceral pain is simple, convenient, and inexpensive, and it is being accepted by an increasing number of patients. There have not been many studies investigating the analgesic mechanisms of moxibustion. Studies exploring the analgesic mechanisms have mainly focused on visceral hypersensitivity, brain-gut axis neuroendocrine system, and immune system. This paper reviews the latest developments in moxibustion use for treatment of visceral pain in IBS from these perspectives. It also evaluates potential problems in relevant studies on the mechanisms of moxibustion therapy to promote the application of moxibustion in the treatment of IBS.
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Affiliation(s)
- Renjia Huang
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jimeng Zhao
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Luyi Wu
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Chuanzi Dou
- Key Laboratory of Acupuncture-Moxibustion and Immunological Effects, Shanghai University of Traditional Chinese Medicine, 650 South Wanping Road, Xuhui District, Shanghai 200030, China
| | - Huirong Liu
- Key Laboratory of Acupuncture-Moxibustion and Immunological Effects, Shanghai University of Traditional Chinese Medicine, 650 South Wanping Road, Xuhui District, Shanghai 200030, China
| | - Zhijun Weng
- Key Laboratory of Acupuncture-Moxibustion and Immunological Effects, Shanghai University of Traditional Chinese Medicine, 650 South Wanping Road, Xuhui District, Shanghai 200030, China
| | - Yuan Lu
- Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yin Shi
- Key Laboratory of Acupuncture-Moxibustion and Immunological Effects, Shanghai University of Traditional Chinese Medicine, 650 South Wanping Road, Xuhui District, Shanghai 200030, China
| | - Xiaomei Wang
- Key Laboratory of Acupuncture-Moxibustion and Immunological Effects, Shanghai University of Traditional Chinese Medicine, 650 South Wanping Road, Xuhui District, Shanghai 200030, China
| | - Cili Zhou
- Key Laboratory of Acupuncture-Moxibustion and Immunological Effects, Shanghai University of Traditional Chinese Medicine, 650 South Wanping Road, Xuhui District, Shanghai 200030, China
| | - Huangan Wu
- Key Laboratory of Acupuncture-Moxibustion and Immunological Effects, Shanghai University of Traditional Chinese Medicine, 650 South Wanping Road, Xuhui District, Shanghai 200030, China
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CaV1.3 L-type channels, maxiK Ca2+-dependent K+ channels and bestrophin-1 regulate rhythmic photoreceptor outer segment phagocytosis by retinal pigment epithelial cells. Cell Signal 2014; 26:968-78. [DOI: 10.1016/j.cellsig.2013.12.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 12/31/2013] [Indexed: 11/20/2022]
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Brailoiu E, Deliu E, Sporici RA, Benamar K, Brailoiu GC. HIV-1-Tat excites cardiac parasympathetic neurons of nucleus ambiguus and triggers prolonged bradycardia in conscious rats. Am J Physiol Regul Integr Comp Physiol 2014; 306:R814-22. [PMID: 24694382 DOI: 10.1152/ajpregu.00529.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The mechanisms of autonomic imbalance and subsequent cardiovascular manifestations in HIV-1-infected patients are poorly understood. We report here that HIV-1 transactivator of transcription (Tat, fragment 1-86) produced a concentration-dependent increase in cytosolic Ca(2+) in cardiac-projecting parasympathetic neurons of nucleus ambiguus retrogradely labeled with rhodamine. Using store-specific pharmacological agents, we identified several mechanisms of the Tat-induced Ca(2+) elevation: 1) lysosomal Ca(2+) mobilization, 2) Ca(2+) release via inositol 1,4,5-trisphosphate-sensitive endoplasmic reticulum pools, and 3) Ca(2+) influx via transient receptor potential vanilloid type 2 (TRPV2) channels. Activation of TRPV2, nonselective cation channels, induced a robust and prolonged neuronal membrane depolarization, thus triggering an additional P/Q-mediated Ca(2+) entry. In vivo microinjection studies indicate a dose-dependent, prolonged bradycardic effect of Tat administration into the nucleus ambiguus of conscious rats, in which neuronal TRPV2 played a major role. Our results support previous studies, indicating that Tat promotes bradycardia and, consequently, may be involved in the QT interval prolongation reported in HIV-infected patients. In the context of an overall HIV-dependent autonomic dysfunction, these Tat-mediated mechanisms may account for the higher prevalence of sudden cardiac death in HIV-1-infected patients compared with general population with similar risk factors. Our results may be particularly relevant in view of the recent findings that significant Tat levels can still be identified in the cerebrospinal fluid of HIV-infected patients with viral load suppression due to efficient antiretroviral therapy.
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Affiliation(s)
- Eugen Brailoiu
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Elena Deliu
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Romeo A Sporici
- Department of Internal Medicine, Brandywine Hospital, Coatesville, Pennsylvania
| | - Khalid Benamar
- Center for Substance Abuse, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - G Cristina Brailoiu
- Department of Pharmaceutical Sciences, Thomas Jefferson University, Jefferson School of Pharmacy, Philadelphia, Pennsylvania
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29
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Cockcroft S, Garner K. Potential role for phosphatidylinositol transfer protein (PITP) family in lipid transfer during phospholipase C signalling. Adv Biol Regul 2013; 53:280-291. [PMID: 23916246 DOI: 10.1016/j.jbior.2013.07.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 07/11/2013] [Accepted: 07/12/2013] [Indexed: 06/02/2023]
Abstract
The hallmark of mammalian phosphatidylinositol transfer proteins (PITPs) is to transfer phosphatidylinositol between membrane compartments. In the mammalian genome, there are three genes that code for soluble PITP proteins, PITPα, PITPβ and RdgBβ and two genes that code for membrane-associated multi-domain proteins (RdgBαI and II) containing a PITP domain. PITPα and PITPβ constitute Class I PITPs whilst the RdgB proteins constitute Class II proteins based on sequence analysis. The PITP domain of both Class I and II can sequester one molecule of phosphatidylinositol (PI) in its hydrophobic cavity. Therefore, in principle, PITPs are therefore ideally poised to couple phosphatidylinositol delivery to the PI kinases for substrate provision for phospholipases C during cell activation. Since phosphatidylinositol (4,5)bisphosphate plays critical roles in cells, particularly at the plasma membrane, where it is a substrate for both phospholipase C and phosphoinositide-3-kinases as well as required as an intact lipid to regulate ion channels and the actin cytoskeleton, homeostatic mechanisms to maintain phosphatidylinositol(4,5)bisphosphate levels are vital. To maintain phosphatidylinositol levels, phospholipase C activation inevitably leads to the resynthesis of PI at the endoplasmic reticulum where the enzymes are located. Phosphatidic acid generated at the plasma membrane during phospholipase C activation needs to move to the ER for conversion to PI and here we provide evidence that Class II PITPs are also able to bind and transport phosphatidic acid. Thus RdgB proteins could couple PA and PI transport bidirectionally during phospholipase C signalling.
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Affiliation(s)
- Shamshad Cockcroft
- Dept. of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, London WC1E 6JJ, UK.
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