1
|
Pérez O, Stanzani A, Huang L, Schipper N, Loftsson T, Bollmark M, Marigo V. New Improved cGMP Analogues to Target Rod Photoreceptor Degeneration. J Med Chem 2024; 67:8396-8405. [PMID: 38688030 PMCID: PMC11129186 DOI: 10.1021/acs.jmedchem.4c00586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 05/02/2024]
Abstract
Retinitis pigmentosa (RP) is a form of retinal degeneration affecting a young population with an unmet medical need. Photoreceptor degeneration has been associated with increased guanosine 3',5'-cyclic monophosphate (cGMP), which reaches toxic levels for photoreceptors. Therefore, inhibitory cGMP analogues attract interest for RP treatments. Here we present the synthesis of dithio-CN03, a phosphorodithioate analogue of cGMP, prepared using the H-phosphonothioate route. Two crystal modifications were identified as a trihydrate and a tetrahydrofuran monosolvates. Dithio-CN03 featured a lower aqueous solubility than its RP-phosphorothioate counterpart CN03, a drug candidate, and this characteristic might be favorable for sustained-release formulations aimed at retinal delivery. Dithio-CN03 was tested in vitro for its neuroprotective effects in photoreceptor models of RP. The comparison of dithio-CN03 to CN03 and its diastereomer SP-CN03, and to their phosphate derivative oxo-CN03 identifies dithio-CN03 as the compound with the highest efficacy in neuroprotection and thus as a promising new candidate for the treatment of RP.
Collapse
Affiliation(s)
- Oswaldo Pérez
- Chemical
Processes and Pharmaceutical Development Research Institutes of Sweden, Forskargatan 20 J, 15136 Södertälje, Sweden
- Faculty
of Pharmaceutical Sciences, University of
Iceland, Hofsvallagata
53, 107 Reykjavik, Iceland
| | - Agnese Stanzani
- Department
of Life Sciences, University of Modena and
Reggio Emilia, via Campi 287, 41125 Modena, Italy
| | - Li Huang
- Department
of Life Sciences, University of Modena and
Reggio Emilia, via Campi 287, 41125 Modena, Italy
| | - Nicolaas Schipper
- Chemical
Processes and Pharmaceutical Development Research Institutes of Sweden, Forskargatan 20 J, 15136 Södertälje, Sweden
| | - Thorsteinn Loftsson
- Faculty
of Pharmaceutical Sciences, University of
Iceland, Hofsvallagata
53, 107 Reykjavik, Iceland
| | - Martin Bollmark
- Chemical
Processes and Pharmaceutical Development Research Institutes of Sweden, Forskargatan 20 J, 15136 Södertälje, Sweden
| | - Valeria Marigo
- Department
of Life Sciences, University of Modena and
Reggio Emilia, via Campi 287, 41125 Modena, Italy
| |
Collapse
|
2
|
Bighinati A, Adani E, Stanzani A, D’Alessandro S, Marigo V. Molecular mechanisms underlying inherited photoreceptor degeneration as targets for therapeutic intervention. Front Cell Neurosci 2024; 18:1343544. [PMID: 38370034 PMCID: PMC10869517 DOI: 10.3389/fncel.2024.1343544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 01/16/2024] [Indexed: 02/20/2024] Open
Abstract
Retinitis pigmentosa (RP) is a form of retinal degeneration characterized by primary degeneration of rod photoreceptors followed by a secondary cone loss that leads to vision impairment and finally blindness. This is a rare disease with mutations in several genes and high genetic heterogeneity. A challenging effort has been the characterization of the molecular mechanisms underlying photoreceptor cell death during the progression of the disease. Some of the cell death pathways have been identified and comprise stress events found in several neurodegenerative diseases such as oxidative stress, inflammation, calcium imbalance and endoplasmic reticulum stress. Other cell death mechanisms appear more relevant to photoreceptor cells, such as high levels of cGMP and metabolic changes. Here we review some of the cell death pathways characterized in the RP mutant retina and discuss preclinical studies of therapeutic approaches targeting the molecular outcomes that lead to photoreceptor cell demise.
Collapse
Affiliation(s)
- Andrea Bighinati
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Elisa Adani
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Agnese Stanzani
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Sara D’Alessandro
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Center for Neuroscience and Neurotechnology, Modena, Italy
| |
Collapse
|
3
|
Yan J, Wang L, Yang QL, Yang QX, He X, Dong Y, Hu Z, Seeliger MW, Jiao K, Paquet-Durand F. T-type voltage-gated channels, Na +/Ca 2+-exchanger, and calpain-2 promote photoreceptor cell death in inherited retinal degeneration. Cell Commun Signal 2024; 22:92. [PMID: 38303059 PMCID: PMC10836022 DOI: 10.1186/s12964-023-01391-y] [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: 09/29/2023] [Accepted: 11/09/2023] [Indexed: 02/03/2024] Open
Abstract
Inherited retinal degenerations (IRDs) are a group of untreatable and commonly blinding diseases characterized by progressive photoreceptor loss. IRD pathology has been linked to an excessive activation of cyclic nucleotide-gated channels (CNGC) leading to Na+- and Ca2+-influx, subsequent activation of voltage-gated Ca2+-channels (VGCC), and further Ca2+ influx. However, a connection between excessive Ca2+ influx and photoreceptor loss has yet to be proven.Here, we used whole-retina and single-cell RNA-sequencing to compare gene expression between the rd1 mouse model for IRD and wild-type (wt) mice. Differentially expressed genes indicated links to several Ca2+-signalling related pathways. To explore these, rd1 and wt organotypic retinal explant cultures were treated with the intracellular Ca2+-chelator BAPTA-AM or inhibitors of different Ca2+-permeable channels, including CNGC, L-type VGCC, T-type VGCC, Ca2+-release-activated channel (CRAC), and Na+/Ca2+ exchanger (NCX). Moreover, we employed the novel compound NA-184 to selectively inhibit the Ca2+-dependent protease calpain-2. Effects on the retinal activity of poly(ADP-ribose) polymerase (PARP), sirtuin-type histone-deacetylase, calpains, as well as on activation of calpain-1, and - 2 were monitored, cell death was assessed via the TUNEL assay.While rd1 photoreceptor cell death was reduced by BAPTA-AM, Ca2+-channel blockers had divergent effects: While inhibition of T-type VGCC and NCX promoted survival, blocking CNGCs and CRACs did not. The treatment-related activity patterns of calpains and PARPs corresponded to the extent of cell death. Remarkably, sirtuin activity and calpain-1 activation were linked to photoreceptor protection, while calpain-2 activity was related to degeneration. In support of this finding, the calpain-2 inhibitor NA-184 protected rd1 photoreceptors.These results suggest that Ca2+ overload in rd1 photoreceptors may be triggered by T-type VGCCs and NCX. High Ca2+-levels likely suppress protective activity of calpain-1 and promote retinal degeneration via activation of calpain-2. Overall, our study details the complexity of Ca2+-signalling in photoreceptors and emphasizes the importance of targeting degenerative processes specifically to achieve a therapeutic benefit for IRDs. Video Abstract.
Collapse
Affiliation(s)
- Jie Yan
- Yunnan Eye Institute & Key Laboratory of Yunnan Province, Yunnan Eye Disease Clinical Medical Center, Affiliated Hospital of Yunnan University, Yunnan University, 176 Qingnian, Kunming, 650021, China
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, 72076, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, 72076, Germany
| | - Lan Wang
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, 72076, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, 72076, Germany
| | - Qian-Lu Yang
- The Third Affiliated Hospital of Kunming Medical University &Yunnan Cancer Hospital, Kunming, Yunnan, 650118, China
| | - Qian-Xi Yang
- The Third Affiliated Hospital of Kunming Medical University &Yunnan Cancer Hospital, Kunming, Yunnan, 650118, China
| | - Xinyi He
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, 72076, Germany
- High-resolution Functional Imaging and Test Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, 72076, Germany
| | - Yujie Dong
- Yunnan Eye Institute & Key Laboratory of Yunnan Province, Yunnan Eye Disease Clinical Medical Center, Affiliated Hospital of Yunnan University, Yunnan University, 176 Qingnian, Kunming, 650021, China
| | - Zhulin Hu
- Yunnan Eye Institute & Key Laboratory of Yunnan Province, Yunnan Eye Disease Clinical Medical Center, Affiliated Hospital of Yunnan University, Yunnan University, 176 Qingnian, Kunming, 650021, China
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, 72076, Germany
| | - Kangwei Jiao
- Yunnan Eye Institute & Key Laboratory of Yunnan Province, Yunnan Eye Disease Clinical Medical Center, Affiliated Hospital of Yunnan University, Yunnan University, 176 Qingnian, Kunming, 650021, China
| | - François Paquet-Durand
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, 72076, Germany.
| |
Collapse
|
4
|
Tolone A, Haq W, Fachinger A, Roy A, Kesh S, Rentsch A, Wucherpfennig S, Zhu Y, Groten J, Schwede F, Tomar T, Herberg FW, Nache V, Paquet-Durand F. The PKG Inhibitor CN238 Affords Functional Protection of Photoreceptors and Ganglion Cells against Retinal Degeneration. Int J Mol Sci 2023; 24:15277. [PMID: 37894958 PMCID: PMC10607377 DOI: 10.3390/ijms242015277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/27/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
Hereditary retinal degeneration (RD) is often associated with excessive cGMP signalling in photoreceptors. Previous research has shown that inhibition of cGMP-dependent protein kinase G (PKG) can reduce photoreceptor loss in two different RD animal models. In this study, we identified a PKG inhibitor, the cGMP analogue CN238, which preserved photoreceptor viability and functionality in rd1 and rd10 mutant mice. Surprisingly, in explanted retinae, CN238 also protected retinal ganglion cells from axotomy-induced retrograde degeneration and preserved their functionality. Furthermore, kinase activity-dependent protein phosphorylation of the PKG target Kv1.6 was reduced in CN238-treated rd10 retinal explants. Ca2+-imaging on rd10 acute retinal explants revealed delayed retinal ganglion cell repolarization with CN238 treatment, suggesting a PKG-dependent modulation of Kv1-channels. Together, these results highlight the strong neuroprotective capacity of PKG inhibitors for both photoreceptors and retinal ganglion cells, illustrating their broad potential for the treatment of retinal diseases and possibly neurodegenerative diseases in general.
Collapse
Affiliation(s)
- Arianna Tolone
- Cell Death Mechanism Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany; (A.T.); (Y.Z.)
| | - Wadood Haq
- Neuroretinal Electrophysiology and Imaging, Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany;
| | - Alexandra Fachinger
- Biochemistry Department, University of Kassel, 34132 Kassel, Germany; (A.F.); (F.W.H.)
| | - Akanksha Roy
- PamGene International B.V., 5211 ‘s-Hertogenbosch, The Netherlands; (A.R.); (J.G.); (T.T.)
| | - Sandeep Kesh
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University Jena, 07743 Jena, Germany; (S.K.); (S.W.); (V.N.)
| | - Andreas Rentsch
- Biolog Life Science Institute GmbH & Co. KG, 28199 Bremen, Germany; (A.R.); (F.S.)
| | - Sophie Wucherpfennig
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University Jena, 07743 Jena, Germany; (S.K.); (S.W.); (V.N.)
| | - Yu Zhu
- Cell Death Mechanism Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany; (A.T.); (Y.Z.)
| | - John Groten
- PamGene International B.V., 5211 ‘s-Hertogenbosch, The Netherlands; (A.R.); (J.G.); (T.T.)
| | - Frank Schwede
- Biolog Life Science Institute GmbH & Co. KG, 28199 Bremen, Germany; (A.R.); (F.S.)
| | - Tushar Tomar
- PamGene International B.V., 5211 ‘s-Hertogenbosch, The Netherlands; (A.R.); (J.G.); (T.T.)
| | - Friedrich W. Herberg
- Biochemistry Department, University of Kassel, 34132 Kassel, Germany; (A.F.); (F.W.H.)
| | - Vasilica Nache
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University Jena, 07743 Jena, Germany; (S.K.); (S.W.); (V.N.)
| | - François Paquet-Durand
- Cell Death Mechanism Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, 72076 Tübingen, Germany; (A.T.); (Y.Z.)
| |
Collapse
|
5
|
Dong Y, Yan J, Xu W, Paquet-Durand F, Hu Z, Jiao K. HDAC inhibition delays photoreceptor loss in Pde6b mutant mice of retinitis pigmentosa: insights from scRNA-seq and CUT&Tag. PeerJ 2023; 11:e15659. [PMID: 37456870 PMCID: PMC10349563 DOI: 10.7717/peerj.15659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/07/2023] [Indexed: 07/18/2023] Open
Abstract
Purpose This research aimed to ascertain the neuroprotective effect of histone deacetylase (HDAC) inhibition on retinal photoreceptors in Pde6brd1 mice, a model of retinitis pigmentosa (RP). Methods Single-cell RNA-sequencing (scRNA-seq) explored HDAC and poly (ADP-ribose) polymerase (PARP)-related gene expression in both Pde6b-mutant rd1 and wild-type (WT) mice. The CUT&Tag method was employed to examine the functions of HDAC in rd1 mice. Organotypic retinal explant cultures from WT and rd1 mice were exposed to the HDAC inhibitor SAHA (suberoylanilide hydroxamic acid) postnatally, from day 5 to day 11. The terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assay was applied to quantify the percentage of photoreceptor loss in the outer nuclear layer (ONL). HDAC activity was confirmed to be inhibited by SAHA through an HDAC activity assay. Moreover, the study evaluated PARP activity, a key driver of the initial response to DNA damage during photoreceptor degeneration, following HDAC inhibition. Results The scRNA-seq revealed that diverse roles of HDAC and PARP isoforms in photoreceptor cell death. HDAC-related genes appeared to regulate cell death and primary immunodeficiency. Alterations in HDAC activity were consistent with the TUNEL-positive cells in the ONL at different time points. Notably, SAHA significantly postponed photoreceptor loss and decreased HDAC and PARP activity, thereby implicating both in the same degenerative pathway. Conclusions This study highlights that the interaction between HDAC inhibition and PARP can delay photoreceptor cell death, proposing a promising therapeutic approach for RP.
Collapse
Affiliation(s)
- Yujie Dong
- Kunming Medical University, Kunming, Yunnan, China
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Affiliated Hospital of Yunnan University, Yunnan University, Kunming, Yunnan, China
| | - Jie Yan
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Affiliated Hospital of Yunnan University, Yunnan University, Kunming, Yunnan, China
- Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
| | - Wenrong Xu
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Affiliated Hospital of Yunnan University, Yunnan University, Kunming, Yunnan, China
| | - François Paquet-Durand
- Institute for Ophthalmic Research, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
| | - Zhulin Hu
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Affiliated Hospital of Yunnan University, Yunnan University, Kunming, Yunnan, China
| | - Kangwei Jiao
- Key Laboratory of Yunnan Province, Yunnan Eye Institute, Affiliated Hospital of Yunnan University, Yunnan University, Kunming, Yunnan, China
| |
Collapse
|
6
|
Li S, Ma H, Yang F, Ding X. cGMP Signaling in Photoreceptor Degeneration. Int J Mol Sci 2023; 24:11200. [PMID: 37446378 PMCID: PMC10342299 DOI: 10.3390/ijms241311200] [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: 05/23/2023] [Revised: 07/04/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Photoreceptors in the retina are highly specialized neurons with photosensitive molecules in the outer segment that transform light into chemical and electrical signals, and these signals are ultimately relayed to the visual cortex in the brain to form vision. Photoreceptors are composed of rods and cones. Rods are responsible for dim light vision, whereas cones are responsible for bright light, color vision, and visual acuity. Photoreceptors undergo progressive degeneration over time in many hereditary and age-related retinal diseases. Despite the remarkable heterogeneity of disease-causing genes, environmental factors, and pathogenesis, the progressive death of rod and cone photoreceptors ultimately leads to loss of vision/blindness. There are currently no treatments available for retinal degeneration. Cyclic guanosine 3', 5'-monophosphate (cGMP) plays a pivotal role in phototransduction. cGMP governs the cyclic nucleotide-gated (CNG) channels on the plasma membrane of the photoreceptor outer segments, thereby regulating membrane potential and signal transmission. By gating the CNG channels, cGMP regulates cellular Ca2+ homeostasis and signal transduction. As a second messenger, cGMP activates the cGMP-dependent protein kinase G (PKG), which regulates numerous targets/cellular events. The dysregulation of cGMP signaling is observed in varieties of photoreceptor/retinal degenerative diseases. Abnormally elevated cGMP signaling interferes with various cellular events, which ultimately leads to photoreceptor degeneration. In line with this, strategies to reduce cellular cGMP signaling result in photoreceptor protection in mouse models of retinal degeneration. The potential mechanisms underlying cGMP signaling-induced photoreceptor degeneration involve the activation of PKG and impaired Ca2+ homeostasis/Ca2+ overload, resulting from overactivation of the CNG channels, as well as the subsequent activation of the downstream cellular stress/death pathways. Thus, targeting the cellular cGMP/PKG signaling and the Ca2+-regulating pathways represents a significant strategy for photoreceptor protection in retinal degenerative diseases.
Collapse
Affiliation(s)
| | | | | | - Xiqin Ding
- Department of Cell Biology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.L.); (H.M.); (F.Y.)
| |
Collapse
|
7
|
Christensen G, Chen Y, Urimi D, Zizmare L, Trautwein C, Schipper N, Paquet-Durand F. Pyruvate-conjugation of PEGylated liposomes for targeted drug delivery to retinal photoreceptors. Biomed Pharmacother 2023; 163:114717. [PMID: 37435722 DOI: 10.1016/j.biopha.2023.114717] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/13/2023] [Accepted: 04/14/2023] [Indexed: 07/13/2023] Open
Abstract
Despite several promising candidates, there is a paucity of drug treatments available for patients suffering from retinal diseases. An important reason for this is the lack of suitable delivery systems that can achieve sufficiently high drug uptake in the retina and its photoreceptors. A promising and versatile method for drug delivery to specific cell types involves transporter-targeted liposomes, i.e., liposomes surface-coated with substrates for transporter proteins highly expressed on the target cell. We identified strong lactate transporter (monocarboxylate transporter, MCT) expression on photoreceptors as a potential target for drug delivery vehicles. To evaluate MCT suitability for drug targeting, we used PEG-coated liposomes and conjugated these with different monocarboxylates, including lactate, pyruvate, and cysteine. Monocarboxylate-conjugated and dye-loaded liposomes were tested on both human-derived cell-lines and murine retinal explant cultures. We found that liposomes conjugated with pyruvate consistently displayed higher cell uptake than unconjugated liposomes or liposomes conjugated with lactate or cysteine. Pharmacological inhibition of MCT1 and MCT2 reduced internalization, suggesting an MCT-dependent uptake mechanism. Notably, pyruvate-conjugated liposomes loaded with the drug candidate CN04 reduced photoreceptor cell death in the murine rd1 retinal degeneration model while free drug solutions could not achieve the same therapeutic effect. Our study thus highlights pyruvate-conjugated liposomes as a promising system for drug delivery to retinal photoreceptors, as well as other neuronal cell types displaying high expression of MCT-type proteins.
Collapse
Affiliation(s)
- Gustav Christensen
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn Straße 5-7, Tübingen 72076, Germany
| | - Yiyi Chen
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn Straße 5-7, Tübingen 72076, Germany
| | - Dileep Urimi
- Division Bioeconomy and Health, Chemical Process and Pharmaceutical Development, RISE Research Institutes of Sweden, Forskargatan 18, Södertälje 15136, Sweden
| | - Laimdota Zizmare
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, University Hospital Tübingen, Röntgenweg 13, Tübingen 72076, Germany
| | - Christoph Trautwein
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, University Hospital Tübingen, Röntgenweg 13, Tübingen 72076, Germany
| | - Nicolaas Schipper
- Division Bioeconomy and Health, Chemical Process and Pharmaceutical Development, RISE Research Institutes of Sweden, Forskargatan 18, Södertälje 15136, Sweden
| | - François Paquet-Durand
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn Straße 5-7, Tübingen 72076, Germany.
| |
Collapse
|
8
|
Zhou J, Welinder C, Ekström P. The Phosphoproteome of the Rd1 Mouse Retina, a Model of Inherited Photoreceptor Degeneration, Changes after Protein Kinase G Inhibition. Int J Mol Sci 2023; 24:9836. [PMID: 37372984 DOI: 10.3390/ijms24129836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 05/31/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Retinitis pigmentosa (RP) is a frequent cause of blindness among the working population in industrial countries due to the inheritable death of photoreceptors. Though gene therapy was recently approved for mutations in the RPE65 gene, there is in general no effective treatment presently. Previously, abnormally high levels of cGMP and overactivation of its dependent protein kinase (PKG) have been suggested as causative for the fatal effects on photoreceptors, making it meaningful to explore the cGMP-PKG downstream signaling for more pathological insights and novel therapeutic target development purposes. Here, we manipulated the cGMP-PKG system in degenerating retinas from the rd1 mouse model pharmacologically via adding a PKG inhibitory cGMP-analogue to organotypic retinal explant cultures. A combination of phosphorylated peptide enrichment and mass spectrometry was then applied to study the cGMP-PKG-dependent phosphoproteome. We identified a host of novel potential cGMP-PKG downstream substrates and related kinases using this approach and selected the RAF1 protein, which may act as both a substrate and a kinase, for further validation. This showed that the RAS/RAF1/MAPK/ERK pathway may be involved in retinal degeneration in a yet unclarified mechanism, thus deserving further investigation in the future.
Collapse
Affiliation(s)
- Jiaming Zhou
- Ophthalmology, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 221 00 Lund, Sweden
| | - Charlotte Welinder
- Mass Spectrometry, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 221 00 Lund, Sweden
| | - Per Ekström
- Ophthalmology, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 221 00 Lund, Sweden
| |
Collapse
|
9
|
Christensen G, Urimi D, Lorenzo-Soler L, Schipper N, Paquet-Durand F. Ocular permeability, intraocular biodistribution of lipid nanocapsule formulation intended for retinal drug delivery. Eur J Pharm Biopharm 2023; 187:175-183. [PMID: 37088247 DOI: 10.1016/j.ejpb.2023.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/05/2023] [Accepted: 04/17/2023] [Indexed: 04/25/2023]
Abstract
Recently, cGMP analogues have been investigated for the treatment of inherited retinal degenerations (IRD) using intravitreal injections. However, higher vitreous elimination rates limit the possibility to treat the retina with small molecule drugs. Here, we investigated the potential of lipid nanocapsules (LNCs) as vehicles to reduce clearance and prolong the delivery of cGMP analogue, CN03 to the retinal photoreceptors. Initially LNCs were investigated for both topical/periocular and intravitreal administration routes. While LNC-mediated drug permeation through the cornea proved to be too low for clinical applications, intravitreal application showed significant promise. Intravitreally administered LNCs containing fluorescent tracer in ex vivo porcine eyes showed complete intravitreal dispersal within 24 h. Ocular bio-distribution on histological sections showed that around 10 % of the LNCs had reached the retina, and 40 % accumulated in the ciliary body. For comparison, we used fluorescently labeled liposomes and these showed a different intraocular distribution with 48 % accumulated in the retina, and almost none were in the ciliary body. LNCs were then tested in retinal explants prepared from wild-type (WT) and rd1 mouse. In WT retina LNCs showed no significant toxic effects up to a concentration of 5 mg/mL. In rd1 retina, the LNC/CN03 formulation protected rd1 photoreceptors with similar efficacy to that of free CN03, demonstrating the usefulness of LNC/CN03 formulation in the treatment of IRD. Overall, our results indicate the suitability of LNCs for intraocular administration and drug delivery to both the retina and the ciliary body.
Collapse
Affiliation(s)
- Gustav Christensen
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn Straße 5-7, 72076 Tübingen, Germany
| | - Dileep Urimi
- Division Bioeconomy and Health, Chemical Process and Pharmaceutical Development, RISE Research Institutes of Sweden, Forskargatan 18, Södertälje 151 36, Sweden; Faculty of Pharmaceutical Sciences, School of Health Sciences, University of Iceland, Hofsvallagata 53, Reykjavík IS-107, Iceland
| | - Laura Lorenzo-Soler
- Faculty of Pharmaceutical Sciences, School of Health Sciences, University of Iceland, Hofsvallagata 53, Reykjavík IS-107, Iceland
| | - Nicolaas Schipper
- Division Bioeconomy and Health, Chemical Process and Pharmaceutical Development, RISE Research Institutes of Sweden, Forskargatan 18, Södertälje 151 36, Sweden
| | - François Paquet-Durand
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn Straße 5-7, 72076 Tübingen, Germany.
| |
Collapse
|
10
|
Dong Y, Yan J, Yang M, Xu W, Hu Z, Paquet-Durand F, Jiao K. Inherited Retinal Degeneration: Towards the Development of a Combination Therapy Targeting Histone Deacetylase, Poly (ADP-Ribose) Polymerase, and Calpain. Biomolecules 2023; 13:biom13040581. [PMID: 37189329 DOI: 10.3390/biom13040581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/05/2023] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Inherited retinal degeneration (IRD) represents a diverse group of gene mutation-induced blinding diseases. In IRD, the loss of photoreceptors is often connected to excessive activation of histone-deacetylase (HDAC), poly-ADP-ribose-polymerase (PARP), and calpain-type proteases (calpain). Moreover, the inhibition of either HDACs, PARPs, or calpains has previously shown promise in preventing photoreceptor cell death, although the relationship between these enzyme groups remains unclear. To explore this further, organotypic retinal explant cultures derived from wild-type mice and rd1 mice as a model for IRD were treated with different combinations of inhibitors specific for HDAC, PARP, and calpain. The outcomes were assessed using in situ activity assays for HDAC, PARP, and calpain, immunostaining for activated calpain-2, and the TUNEL assay for cell death detection. We confirmed that inhibition of either HDAC, PARP, or calpain reduced rd1 mouse photoreceptor degeneration, with the HDAC inhibitor Vorinostat (SAHA) being most effective. Calpain activity was reduced by inhibition of both HDAC and PARP whereas PARP activity was only reduced by HDAC inhibition. Unexpectedly, combined treatment with either PARP and calpain inhibitors or HDAC and calpain inhibitors did not produce synergistic rescue of photoreceptors. Together, these results indicate that in rd1 photoreceptors, HDAC, PARP, and calpain are part of the same degenerative pathway and are activated in a sequence that begins with HDAC and ends with calpain.
Collapse
|
11
|
Perdigão PRL, Ollington B, Sai H, Leung A, Sacristan-Reviriego A, van der Spuy J. Retinal Organoids from an AIPL1 CRISPR/Cas9 Knockout Cell Line Successfully Recapitulate the Molecular Features of LCA4 Disease. Int J Mol Sci 2023; 24:ijms24065912. [PMID: 36982987 PMCID: PMC10057647 DOI: 10.3390/ijms24065912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/27/2023] [Accepted: 03/07/2023] [Indexed: 03/30/2023] Open
Abstract
Aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1) is expressed in photoreceptors where it facilitates the assembly of phosphodiesterase 6 (PDE6) which hydrolyses cGMP within the phototransduction cascade. Genetic variations in AIPL1 cause type 4 Leber congenital amaurosis (LCA4), which presents as rapid loss of vision in early childhood. Limited in vitro LCA4 models are available, and these rely on patient-derived cells harbouring patient-specific AIPL1 mutations. While valuable, the use and scalability of individual patient-derived LCA4 models may be limited by ethical considerations, access to patient samples and prohibitive costs. To model the functional consequences of patient-independent AIPL1 mutations, CRISPR/Cas9 was implemented to produce an isogenic induced pluripotent stem cell line harbouring a frameshift mutation in the first exon of AIPL1. Retinal organoids were generated using these cells, which retained AIPL1 gene transcription, but AIPL1 protein was undetectable. AIPL1 knockout resulted in a decrease in rod photoreceptor-specific PDE6α and β, and increased cGMP levels, suggesting downstream dysregulation of the phototransduction cascade. The retinal model described here provides a novel platform to assess functional consequences of AIPL1 silencing and measure the rescue of molecular features by potential therapeutic approaches targeting mutation-independent pathogenesis.
Collapse
Affiliation(s)
- Pedro R L Perdigão
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Bethany Ollington
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Hali Sai
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Amy Leung
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | | | | |
Collapse
|
12
|
Zhou J, Ekström P. Pyruvate Kinase 2, an Energy Metabolism Related Enzyme, May Have a Neuroprotective Function in Retinal Degeneration. ASN Neuro 2023; 15:17590914231151534. [PMID: 36799552 PMCID: PMC9940218 DOI: 10.1177/17590914231151534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Retinitis pigmentosa (RP) is an inherited disorder that results in vision impairment but general and mutation-independent therapeutic strategies are not available. However, it is widely regarded that the cGMP system, including cGMP and its interactor cGMP-dependent protein kinase (PKG), acts as a crucial effector during retinal degeneration. We have previously identified a list of cGMP-PKG-dependent genes in the context of RP, and in this study, we further validated one of these, namely pyruvate kinase 2 (PKM2), and investigated the potential role of PKM2 for the photoreceptors' well-being during RP. With the aid of organotypic retinal explant cultures, we pharmacologically manipulated the PKM2 activities in two different RP mouse models (rd2 and rd10) via the addition of TEPP-46 (a PKM2 activator) and found that activation of PKM2 alleviates the progress of photoreceptor death in the rd10 mouse model. We also noted that the expression of both PKM2 and one of its targets, glucose transporter-1 (Glut1), showed alterations depending on the degeneration state. The observations provide supportive evidence that PKM2 may serve as a novel potential molecular target in RP.
Collapse
Affiliation(s)
- Jiaming Zhou
- Ophthalmology, Department of Clinical Sciences, Lund University, Lund, Sweden,Jiaming Zhou, Biomedical Center (BMC-B11), Sölvegatan 19, SE-22362 Lund, Sweden.
| | - Per Ekström
- Ophthalmology, Department of Clinical Sciences, Lund University, Lund, Sweden
| |
Collapse
|
13
|
Zhou J, Rasmussen M, Ekström P. A Potential Neuroprotective Role for Pyruvate Kinase 2 in Retinal Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:479-483. [PMID: 37440075 DOI: 10.1007/978-3-031-27681-1_70] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Retinitis pigmentosa (RP) is an inherited disorder that results in vision impairment that specific therapeutic strategies are not available. However, it is widely regarded that the cGMP system, including cGMP and its interactor cGMP-dependent protein kinase (PKG), acts as a crucial effector during retinal degeneration. We have previously identified a list of cGMP-PKG-dependent genes in the context of RP, and in this study, we further validated one of the targets, namely, pyruvate kinase 2 (PKM2), and investigated the potential role of PKM2 for the photoreceptors' well-being during RP. With the aid of organotypic retinal explant cultures, we pharmacologically manipulated the PKM2 activities in different RP mouse models via the addition of TEPP-46 (a PKM2 activator) and found that activation of PKM2 alleviates the progress of photoreceptor death in the rd10 mouse model. This observation provides supportive evidence that PKM2 may serve as a novel potential molecular target in RP.
Collapse
Affiliation(s)
- Jiaming Zhou
- Ophthalmology, Department of Clinical Sciences, Lund University, Lund, Sweden.
| | - Michel Rasmussen
- Ophthalmology, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Per Ekström
- Ophthalmology, Department of Clinical Sciences, Lund University, Lund, Sweden
| |
Collapse
|
14
|
Inhibition of the MAPK/c-Jun-EGR1 Pathway Decreases Photoreceptor Cell Death in the rd1 Mouse Model for Inherited Retinal Degeneration. Int J Mol Sci 2022; 23:ijms232314600. [PMID: 36498926 PMCID: PMC9740268 DOI: 10.3390/ijms232314600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/17/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies that typically results in photoreceptor cell death and vision loss. Here, we explored the effect of early growth response-1 (EGR1) expression on photoreceptor cell death in Pde6brd1 (rd1) mice and its mechanism of action. To this end, single-cell RNA-seq (scRNA-seq) was used to identify differentially expressed genes in rd1 and congenic wild-type (WT) mice. Chromatin immunoprecipitation (ChIP), the dual-luciferase reporter gene assay, and western blotting were used to verify the relationship between EGR1 and poly (ADP-ribose) polymerase-1 (PARP1). Immunofluorescence staining was used to assess PARP1 expression after silencing or overexpression of EGR1. Photoreceptor cell death was assessed using the TUNEL assay following silencing/overexpression of EGR1 or administration of MAPK/c-Jun pathway inhibitors tanzisertib and PD98059. Our results showed differential expression of ERG1 in rd1 and WT mice via scRNA-seq analysis. The ChIP assay demonstrated EGR1 binding to the PARP1 promoter region. The dual-luciferase reporter gene assay and western blotting results revealed that EGR1 upregulated PARP1 expression. Additionally, the TUNEL assay showed that silencing EGR1 effectively reduced photoreceptor cell death. Similarly, the addition of tanzisertib and PD98059 reduced the expression of c-Jun and EGR1 and decreased photoreceptor cell death. Our study revealed that inhibition of the MAPK/c-Jun pathway reduced the expression of EGR1 and PARP1 and prevented photoreceptor cell death. These results highlight the importance of EGR1 for photoreceptor cell death and identify a new avenue for therapeutic interventions in RP.
Collapse
|
15
|
Depleted Calcium Stores and Increased Calcium Entry in Rod Photoreceptors of the Cacna2d4 Mouse Model of Cone-Rod Dystrophy RCD4. Int J Mol Sci 2022; 23:ijms232113080. [DOI: 10.3390/ijms232113080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/17/2022] [Accepted: 10/21/2022] [Indexed: 11/16/2022] Open
Abstract
Unidentified pathogenetic mechanisms and genetic and clinical heterogeneity represent critical factors hindering the development of treatments for inherited retinal dystrophies. Frameshift mutations in Cacna2d4, which codes for an accessory subunit of voltage-gated calcium channels (VGCC), cause cone-rod dystrophy RCD4 in patients, but the underlying mechanisms remain unknown. To define its pathogenetic mechanisms, we investigated the impact of a Cacna2d4 frameshift mutation on the electrophysiological profile and calcium handling of mouse rod photoreceptors by patch-clamp recordings and calcium imaging, respectively. In mutant (MUT) rods, the dysregulation of calcium handling extends beyond the reduction in calcium entry through VGCC and surprisingly involves internal calcium stores’ depletion and upregulation of calcium entry via non-selective cationic channels (CSC). The similar dependence of CSC on basal calcium levels in WT and MUT rods suggests that the primary defect in MUT rods lies in defective calcium stores. Calcium stores’ depletion, leading to upregulated calcium and sodium influx via CSC, represents a novel and, so far, unsuspected consequence of the Cacna2d4 mutation. Blocking CSC may provide a novel strategy to counteract the well-known pathogenetic mechanisms involved in rod demise, such as the reticulum stress response and calcium and sodium overload due to store depletion.
Collapse
|
16
|
Chen Y, Dong Y, Yan J, Wang L, Yu S, Jiao K, Paquet-Durand F. Single-Cell Transcriptomic Profiling in Inherited Retinal Degeneration Reveals Distinct Metabolic Pathways in Rod and Cone Photoreceptors. Int J Mol Sci 2022; 23:12170. [PMID: 36293024 PMCID: PMC9603353 DOI: 10.3390/ijms232012170] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/28/2022] [Accepted: 10/08/2022] [Indexed: 08/31/2023] Open
Abstract
The cellular mechanisms underlying hereditary photoreceptor degeneration are still poorly understood. The aim of this study was to systematically map the transcriptional changes that occur in the degenerating mouse retina at the single cell level. To this end, we employed single-cell RNA-sequencing (scRNA-seq) and retinal degeneration-1 (rd1) mice to profile the impact of the disease mutation on the diverse retinal cell types during early post-natal development. The transcriptome data allowed to annotate 43,979 individual cells grouped into 20 distinct clusters. We further characterized cluster-specific metabolic and biological changes in individual cell types. Our results highlight Ca2+-signaling as relevant to hereditary photoreceptor degeneration. Although metabolic reprogramming in retina, known as the 'Warburg effect', has been documented, further metabolic changes were noticed in rd1 mice. Such metabolic changes in rd1 mutation was likely regulated through mitogen-activated protein kinase (MAPK) pathway. By combining single-cell transcriptomes and immunofluorescence staining, our study revealed cell type-specific changes in gene expression, as well as interplay between Ca2+-induced cell death and metabolic pathways.
Collapse
Affiliation(s)
- Yiyi Chen
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, 72076 Tübingen, Germany
| | - Yujie Dong
- Yunnan Eye Institute & Key Laboratory of Yunnan Province, 650021 Kunming, China
| | - Jie Yan
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, 72076 Tübingen, Germany
| | - Lan Wang
- Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, 72076 Tübingen, Germany
| | - Shirley Yu
- Graduate Training Centre of Neuroscience, University of Tübingen, 72076 Tübingen, Germany
| | - Kangwei Jiao
- Yunnan Eye Institute & Key Laboratory of Yunnan Province, 650021 Kunming, China
| | | |
Collapse
|
17
|
cGMP Analogues with Opposing Actions on CNG Channels Selectively Modulate Rod or Cone Photoreceptor Function. Pharmaceutics 2022; 14:pharmaceutics14102102. [PMID: 36297537 PMCID: PMC9612005 DOI: 10.3390/pharmaceutics14102102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/23/2022] [Accepted: 09/28/2022] [Indexed: 11/09/2022] Open
Abstract
The vertebrate retina harbors rod and cone photoreceptors. Human vision critically depends on cone photoreceptor function. In the phototransduction cascade, cGMP activates distinct rod and cone isoforms of the cyclic nucleotide-gated (CNG) channel. Excessive cGMP levels initiate a pathophysiological rollercoaster, which starts with CNG channel over-activation, typically in rod photoreceptors. This triggers cell death of rods first, and then cones, and is the root cause of many blinding retinal diseases, including Retinitis pigmentosa. While targeting of CNG channels has been proposed for therapeutic purposes, thus far, it has not been possible to inhibit rod CNG channels without compromising cone function. Here, we present a novel strategy, based on cGMP analogues with opposing actions on CNG channels, which enables the selective modulation of either rod or cone photoreceptor activity. The combined treatment with the weak rod-selective CNG-channel inhibitor (Rp-8-Br-PET-cGMPS) and the cone-selective CNG-channel activator (8-pCPT-cGMP) essentially normalized rod CNG-channel function while preserving cone functionality at physiological and pathological cGMP levels. Hence, combinations of cGMP analogues with desired properties may elegantly address the isoform-specificity problem in future pharmacological therapies. Moreover, this strategy may allow for improvements in visual performance in certain light environments.
Collapse
|
18
|
Das A, Imanishi Y. Drug Discovery Strategies for Inherited Retinal Degenerations. BIOLOGY 2022; 11:1338. [PMID: 36138817 PMCID: PMC9495580 DOI: 10.3390/biology11091338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/31/2022] [Accepted: 09/07/2022] [Indexed: 12/03/2022]
Abstract
Inherited retinal degeneration is a group of blinding disorders afflicting more than 1 in 4000 worldwide. These disorders frequently cause the death of photoreceptor cells or retinal ganglion cells. In a subset of these disorders, photoreceptor cell death is a secondary consequence of retinal pigment epithelial cell dysfunction or degeneration. This manuscript reviews current efforts in identifying targets and developing small molecule-based therapies for these devastating neuronal degenerations, for which no cures exist. Photoreceptors and retinal ganglion cells are metabolically demanding owing to their unique structures and functional properties. Modulations of metabolic pathways, which are disrupted in most inherited retinal degenerations, serve as promising therapeutic strategies. In monogenic disorders, great insights were previously obtained regarding targets associated with the defective pathways, including phototransduction, visual cycle, and mitophagy. In addition to these target-based drug discoveries, we will discuss how phenotypic screening can be harnessed to discover beneficial molecules without prior knowledge of their mechanisms of action. Because of major anatomical and biological differences, it has frequently been challenging to model human inherited retinal degeneration conditions using small animals such as rodents. Recent advances in stem cell-based techniques are opening new avenues to obtain pure populations of human retinal ganglion cells and retinal organoids with photoreceptor cells. We will discuss concurrent ideas of utilizing stem-cell-based disease models for drug discovery and preclinical development.
Collapse
Affiliation(s)
- Arupratan Das
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Yoshikazu Imanishi
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| |
Collapse
|
19
|
Miller AL, Fuller-Carter PI, Masarini K, Samardzija M, Carter KW, Rashwan R, Lim XR, Brunet AA, Chopra A, Ram R, Grimm C, Ueffing M, Carvalho LS, Trifunović D. Increased H3K27 trimethylation contributes to cone survival in a mouse model of cone dystrophy. Cell Mol Life Sci 2022; 79:409. [PMID: 35810394 PMCID: PMC9271452 DOI: 10.1007/s00018-022-04436-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 11/30/2022]
Abstract
Inherited retinal diseases (IRDs) are a heterogeneous group of blinding disorders, which result in dysfunction or death of the light-sensing cone and rod photoreceptors. Despite individual IRDs (Inherited retinal disease) being rare, collectively, they affect up to 1:2000 people worldwide, causing a significant socioeconomic burden, especially when cone-mediated central vision is affected. This study uses the Pde6ccpfl1 mouse model of achromatopsia, a cone-specific vision loss IRD (Inherited retinal disease), to investigate the potential gene-independent therapeutic benefits of a histone demethylase inhibitor GSK-J4 on cone cell survival. We investigated the effects of GSK-J4 treatment on cone cell survival in vivo and ex vivo and changes in cone-specific gene expression via single-cell RNA sequencing. A single intravitreal GSK-J4 injection led to transcriptional changes in pathways involved in mitochondrial dysfunction, endoplasmic reticulum stress, among other key epigenetic pathways, highlighting the complex interplay between methylation and acetylation in healthy and diseased cones. Furthermore, continuous administration of GSK-J4 in retinal explants increased cone survival. Our results suggest that IRD (Inherited retinal disease)-affected cones respond positively to epigenetic modulation of histones, indicating the potential of this approach in developing a broad class of novel therapies to slow cone degeneration.
Collapse
Affiliation(s)
- Annie L Miller
- Retinal Genomics and Therapy Group, Lions Eye Institute Ltd, 2 Verdun Street, Nedlands, WA, 6009, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009, Australia
| | - Paula I Fuller-Carter
- Retinal Genomics and Therapy Group, Lions Eye Institute Ltd, 2 Verdun Street, Nedlands, WA, 6009, Australia
| | - Klaudija Masarini
- Institute for Ophthalmic Research, Tübingen University, Elfriede-Aulhorn-Straße 7, 72076, Tübingen, Germany
| | - Marijana Samardzija
- Lab for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zürich, University of Zürich, Zurich, Switzerland
| | - Kim W Carter
- Analytical Computing Solutions, Willetton, WA, 6155, Australia
| | - Rabab Rashwan
- Retinal Genomics and Therapy Group, Lions Eye Institute Ltd, 2 Verdun Street, Nedlands, WA, 6009, Australia
- Department of Microbiology and Immunology, Faculty of Medicine, Minia University, Minia, Egypt
| | - Xin Ru Lim
- Retinal Genomics and Therapy Group, Lions Eye Institute Ltd, 2 Verdun Street, Nedlands, WA, 6009, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009, Australia
| | - Alicia A Brunet
- Retinal Genomics and Therapy Group, Lions Eye Institute Ltd, 2 Verdun Street, Nedlands, WA, 6009, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009, Australia
| | - Abha Chopra
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
- Department of Medicine, Vanderbilt University Medical Centre, Nashville, TN, USA
| | - Ramesh Ram
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Christian Grimm
- Lab for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zürich, University of Zürich, Zurich, Switzerland
| | - Marius Ueffing
- Institute for Ophthalmic Research, Tübingen University, Elfriede-Aulhorn-Straße 7, 72076, Tübingen, Germany
| | - Livia S Carvalho
- Retinal Genomics and Therapy Group, Lions Eye Institute Ltd, 2 Verdun Street, Nedlands, WA, 6009, Australia.
- Centre for Ophthalmology and Visual Science, The University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009, Australia.
| | - Dragana Trifunović
- Institute for Ophthalmic Research, Tübingen University, Elfriede-Aulhorn-Straße 7, 72076, Tübingen, Germany.
| |
Collapse
|
20
|
Zhu Y, Cao B, Tolone A, Yan J, Christensen G, Arango-Gonzalez B, Ueffing M, Paquet-Durand F. In vitro Model Systems for Studies Into Retinal Neuroprotection. Front Neurosci 2022; 16:938089. [PMID: 35873807 PMCID: PMC9301112 DOI: 10.3389/fnins.2022.938089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Therapy development for neurodegenerative diseases of the retina constitutes a major unmet medical need, and this may be particularly relevant for inherited diseases of the retina, which are largely untreatable to this day. Therapy development necessitates appropriate models to improve the understanding of the underlying degenerative mechanisms, as well as for the testing and evaluation of novel treatment approaches. This review provides an overview of various in vitro model systems used to study retinal neuroprotection. The in vitro methods and technologies discussed range from primary retinal cell cultures and cell lines, to retinal organoids and organotypic retinal explants, to the cultivation of whole eyeballs. The advantages and disadvantages of these methods are compared and evaluated, also in view of the 3R principles (i.e., the refinement, reduction, and replacement of live animal testing), to identify suitable in vitro alternatives for in vivo experimentation. The article further expands on the use of in vitro models to test and evaluate neuroprotective treatments and to aid the development of retinal drug delivery systems. Among the pharmacological agents tested and characterized in vitro are such that interfere with aberrant cyclic guanosine monophosphate (cGMP) -signaling or such that inhibit the activities of poly (ADP-ribose) polymerase (PARP), histone deacetylases (HDAC), calpain-type proteases, as well as unfolded protein response-related stress. We then introduce nanoparticle-based drug delivery systems and discuss how different in vitro systems may be used to assess their efficacy in the treatment of retinal diseases. The summary provides a brief comparison of available in vitro models and relates their advantages and limitations to the various experimental requirements, for instance, for studies into disease mechanisms, novel treatments, or retinal toxicity. In many cases, combinations of different in vitro models may be required to obtain a comprehensive view of the efficacy of a given retinal neuroprotection approach.
Collapse
Affiliation(s)
- Yu Zhu
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Bowen Cao
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
- Molecular Biology of Retinal Degenerations, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Arianna Tolone
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Jie Yan
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Gustav Christensen
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Blanca Arango-Gonzalez
- Molecular Biology of Retinal Degenerations, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Marius Ueffing
- Molecular Biology of Retinal Degenerations, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- *Correspondence: Marius Ueffing,
| | - François Paquet-Durand
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- François Paquet-Durand,
| |
Collapse
|
21
|
Rasmussen M, Zhou J, Schwede F, Ekström P. Enhanced cGMP Interactor Rap Guanine Exchange Factor 4 (EPAC2) Expression and Activity in Degenerating Photoreceptors: A Neuroprotective Response? Int J Mol Sci 2022; 23:ijms23094619. [PMID: 35563009 PMCID: PMC9103912 DOI: 10.3390/ijms23094619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/17/2022] [Accepted: 04/19/2022] [Indexed: 11/25/2022] Open
Abstract
The disease retinitis pigmentosa (RP) leads to photoreceptor degeneration by a yet undefined mechanism(s). In several RP mouse models (i.e., rd mice), a high cyclic GMP (cGMP) level within photoreceptors is detected, suggesting that cGMP plays a role in degeneration. The rap guanine exchange factor 4 (EPAC2) is activated by cyclic AMP (cAMP) and is an accepted cGMP-interacting protein. It is unclear whether and how cGMP interacts with EPAC2 in degenerating photoreceptors; we therefore investigated EPAC2 expression and interactions with cGMP and cAMP in retinas of the rd1 and rd10 models for retinal degeneration. EPAC2 expression in the photoreceptor layer increased significantly during rd1 and rd10 degeneration, and an increase in EPAC2 interactions with cGMP but not cAMP in the rd1 was also seen via a proximity ligation assay on histological sections. Retinal explant cultures revealed that pharmacological inhibition of the EPAC2 activity reduced the photoreceptor layer thickness in the rd10 retina, suggesting that EPAC2 inhibition promotes degeneration. Taken together, our results support the hypothesis that high degeneration-related cGMP leads to increased EPAC2 and cGMP interactions, inhibiting EPAC2. By inference, EPAC2 could have neuroprotective capacities that may be exploited in the future.
Collapse
Affiliation(s)
- Michel Rasmussen
- Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 22184 Lund, Sweden; (J.Z.); (P.E.)
- Correspondence:
| | - Jiaming Zhou
- Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 22184 Lund, Sweden; (J.Z.); (P.E.)
| | - Frank Schwede
- BIOLOG Life Science Institute GmbH & Co. KG, 28199 Bremen, Germany;
| | - Per Ekström
- Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, 22184 Lund, Sweden; (J.Z.); (P.E.)
| |
Collapse
|
22
|
Yan J, Günter A, Das S, Mühlfriedel R, Michalakis S, Jiao K, Seeliger MW, Paquet-Durand F. Inherited Retinal Degeneration: PARP-Dependent Activation of Calpain Requires CNG Channel Activity. Biomolecules 2022; 12:biom12030455. [PMID: 35327647 PMCID: PMC8946186 DOI: 10.3390/biom12030455] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/08/2022] [Accepted: 03/10/2022] [Indexed: 01/27/2023] Open
Abstract
Inherited retinal degenerations (IRDs) are a group of blinding diseases, typically involving a progressive loss of photoreceptors. The IRD pathology is often based on an accumulation of cGMP in photoreceptors and associated with the excessive activation of calpain and poly (ADP-ribose) polymerase (PARP). Inhibitors of calpain or PARP have shown promise in preventing photoreceptor cell death, yet the relationship between these enzymes remains unclear. To explore this further, organotypic retinal explant cultures derived from wild-type and IRD-mutant mice were treated with inhibitors specific for calpain, PARP, and voltage-gated Ca2+ channels (VGCCs). The outcomes were assessed using in situ activity assays for calpain and PARP and immunostaining for activated calpain-2, poly (ADP-ribose), and cGMP, as well as the TUNEL assay for cell death detection. The IRD models included the Pde6b-mutant rd1 mouse and rd1*Cngb1−/− double-mutant mice, which lack the beta subunit of the rod cyclic nucleotide-gated (CNG) channel and are partially protected from rd1 degeneration. We confirmed that an inhibition of either calpain or PARP reduces photoreceptor cell death in rd1 retina. However, while the activity of calpain was decreased by the inhibition of PARP, calpain inhibition did not alter the PARP activity. A combination treatment with calpain and PARP inhibitors did not synergistically reduce cell death. In the slow degeneration of rd1*Cngb1−/− double mutant, VGCC inhibition delayed photoreceptor cell death, while PARP inhibition did not. Our results indicate that PARP acts upstream of calpain and that both are part of the same degenerative pathway in Pde6b-dependent photoreceptor degeneration. While PARP activation may be associated with CNG channel activity, calpain activation is linked to VGCC opening. Overall, our data highlights PARP as a target for therapeutic interventions in IRD-type diseases.
Collapse
Affiliation(s)
- Jie Yan
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; (J.Y.); (S.D.)
- Graduate Training Centre of Neuroscience, University of Tübingen, 72076 Tübingen, Germany
| | - Alexander Günter
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; (A.G.); (R.M.)
| | - Soumyaparna Das
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; (J.Y.); (S.D.)
| | - Regine Mühlfriedel
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; (A.G.); (R.M.)
| | - Stylianos Michalakis
- Department of Ophthalmology, University Hospital, LMU Munich, 80539 München, Germany;
| | - Kangwei Jiao
- Key Laboratory of Yunnan Province, Affiliated Hospital of Yunnan University, Kunming 650051, China;
| | - Mathias W. Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; (A.G.); (R.M.)
- Correspondence: (M.W.S.); (F.P.-D.)
| | - François Paquet-Durand
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; (J.Y.); (S.D.)
- Correspondence: (M.W.S.); (F.P.-D.)
| |
Collapse
|
23
|
Roy A, Tolone A, Hilhorst R, Groten J, Tomar T, Paquet-Durand F. Kinase activity profiling identifies putative downstream targets of cGMP/PKG signaling in inherited retinal neurodegeneration. Cell Death Dis 2022; 8:93. [PMID: 35241647 PMCID: PMC8894370 DOI: 10.1038/s41420-022-00897-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/16/2021] [Accepted: 02/08/2022] [Indexed: 11/15/2022]
Abstract
Inherited retinal diseases (IRDs) are a group of neurodegenerative disorders that lead to photoreceptor cell death and eventually blindness. IRDs are characterised by a high genetic heterogeneity, making it imperative to design mutation-independent therapies. Mutations in a number of IRD disease genes have been associated with a rise of cyclic 3’,5’-guanosine monophosphate (cGMP) levels in photoreceptors. Accordingly, the cGMP-dependent protein kinase (PKG) has emerged as a new potential target for the mutation-independent treatment of IRDs. However, the substrates of PKG and the downstream degenerative pathways triggered by its activity have yet to be determined. Here, we performed kinome activity profiling of different murine organotypic retinal explant cultures (diseased rd1 and wild-type controls) using multiplex peptide microarrays to identify proteins whose phosphorylation was significantly altered by PKG activity. In addition, we tested the downstream effect of a known PKG inhibitor CN03 in these organotypic retina cultures. Among the PKG substrates were potassium channels belonging to the Kv1 family (KCNA3, KCNA6), cyclic AMP-responsive element-binding protein 1 (CREB1), DNA topoisomerase 2-α (TOP2A), 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (F263), and the glutamate ionotropic receptor kainate 2 (GRIK2). The retinal expression of these PKG targets was further confirmed by immunofluorescence and could be assigned to various neuronal cell types, including photoreceptors, horizontal cells, and ganglion cells. Taken together, this study confirmed the key role of PKG in photoreceptor cell death and identified new downstream targets of cGMP/PKG signalling that will improve the understanding of the degenerative mechanisms underlying IRDs.
Collapse
Affiliation(s)
- Akanksha Roy
- Division of Toxicology, Wageningen University and Research, 96708 WE, Wageningen, The Netherlands.,PamGene International B.V, 5200 BJ, s-Hertogenbosch, The Netherlands
| | - Arianna Tolone
- Cell Death Mechanism Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität, Tübingen, 72072, Germany
| | - Riet Hilhorst
- PamGene International B.V, 5200 BJ, s-Hertogenbosch, The Netherlands
| | - John Groten
- Division of Toxicology, Wageningen University and Research, 96708 WE, Wageningen, The Netherlands.,PamGene International B.V, 5200 BJ, s-Hertogenbosch, The Netherlands
| | - Tushar Tomar
- PamGene International B.V, 5200 BJ, s-Hertogenbosch, The Netherlands.
| | - François Paquet-Durand
- Cell Death Mechanism Group, Institute for Ophthalmic Research, Eberhard-Karls-Universität, Tübingen, 72072, Germany.
| |
Collapse
|
24
|
Das S, Popp V, Power M, Groeneveld K, Yan J, Melle C, Rogerson L, Achury M, Schwede F, Strasser T, Euler T, Paquet-Durand F, Nache V. Redefining the role of Ca 2+-permeable channels in photoreceptor degeneration using diltiazem. Cell Death Dis 2022; 13:47. [PMID: 35013127 PMCID: PMC8748460 DOI: 10.1038/s41419-021-04482-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 10/07/2021] [Accepted: 11/23/2021] [Indexed: 12/18/2022]
Abstract
Hereditary degeneration of photoreceptors has been linked to over-activation of Ca2+-permeable channels, excessive Ca2+-influx, and downstream activation of Ca2+-dependent calpain-type proteases. Unfortunately, after more than 20 years of pertinent research, unequivocal evidence proving significant and reproducible photoreceptor protection with Ca2+-channel blockers is still lacking. Here, we show that both D- and L-cis enantiomers of the anti-hypertensive drug diltiazem were very effective at blocking photoreceptor Ca2+-influx, most probably by blocking the pore of Ca2+-permeable channels. Yet, unexpectedly, this block neither reduced the activity of calpain-type proteases, nor did it result in photoreceptor protection. Remarkably, application of the L-cis enantiomer of diltiazem even led to a strong increase in photoreceptor cell death. These findings shed doubt on the previously proposed links between Ca2+ and retinal degeneration and are highly relevant for future therapy development as they may serve to refocus research efforts towards alternative, Ca2+-independent degenerative mechanisms.
Collapse
Affiliation(s)
- Soumyaparna Das
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Valerie Popp
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Michael Power
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076, Tübingen, Germany
| | - Kathrin Groeneveld
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany.,Biomolecular Photonics Group, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Jie Yan
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Christian Melle
- Biomolecular Photonics Group, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Luke Rogerson
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076, Tübingen, Germany
| | - Marlly Achury
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Frank Schwede
- BIOLOG Life Science Institute GmbH & Co KG, 28199, Bremen, Germany
| | - Torsten Strasser
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Thomas Euler
- Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany.,Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076, Tübingen, Germany
| | | | - Vasilica Nache
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University Jena, 07743, Jena, Germany.
| |
Collapse
|
25
|
Brunet AA, Harvey AR, Carvalho LS. Primary and Secondary Cone Cell Death Mechanisms in Inherited Retinal Diseases and Potential Treatment Options. Int J Mol Sci 2022; 23:ijms23020726. [PMID: 35054919 PMCID: PMC8775779 DOI: 10.3390/ijms23020726] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/05/2022] [Accepted: 01/05/2022] [Indexed: 12/13/2022] Open
Abstract
Inherited retinal diseases (IRDs) are a leading cause of blindness. To date, 260 disease-causing genes have been identified, but there is currently a lack of available and effective treatment options. Cone photoreceptors are responsible for daylight vision but are highly susceptible to disease progression, the loss of cone-mediated vision having the highest impact on the quality of life of IRD patients. Cone degeneration can occur either directly via mutations in cone-specific genes (primary cone death), or indirectly via the primary degeneration of rods followed by subsequent degeneration of cones (secondary cone death). How cones degenerate as a result of pathological mutations remains unclear, hindering the development of effective therapies for IRDs. This review aims to highlight similarities and differences between primary and secondary cone cell death in inherited retinal diseases in order to better define cone death mechanisms and further identify potential treatment options.
Collapse
Affiliation(s)
- Alicia A. Brunet
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia;
- Lions Eye Institute Ltd., 2 Verdun St, Nedlands, WA 6009, Australia
- Correspondence: ; Tel.: +61-423-359-714
| | - Alan R. Harvey
- School of Human Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia;
- Perron Institute for Neurological and Translational Science, 8 Verdun St, Nedlands, WA 6009, Australia
| | - Livia S. Carvalho
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia;
- Lions Eye Institute Ltd., 2 Verdun St, Nedlands, WA 6009, Australia
| |
Collapse
|
26
|
Yan J, Chen Y, Zhu Y, Paquet-Durand F. Programmed Non-Apoptotic Cell Death in Hereditary Retinal Degeneration: Crosstalk between cGMP-Dependent Pathways and PARthanatos? Int J Mol Sci 2021; 22:10567. [PMID: 34638907 PMCID: PMC8508647 DOI: 10.3390/ijms221910567] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 12/20/2022] Open
Abstract
Programmed cell death (PCD) is a highly regulated process that results in the orderly destruction of a cell. Many different forms of PCD may be distinguished, including apoptosis, PARthanatos, and cGMP-dependent cell death. Misregulation of PCD mechanisms may be the underlying cause of neurodegenerative diseases of the retina, including hereditary retinal degeneration (RD). RD relates to a group of diseases that affect photoreceptors and that are triggered by gene mutations that are often well known nowadays. Nevertheless, the cellular mechanisms of PCD triggered by disease-causing mutations are still poorly understood, and RD is mostly still untreatable. While investigations into the neurodegenerative mechanisms of RD have focused on apoptosis in the past two decades, recent evidence suggests a predominance of non-apoptotic processes as causative mechanisms. Research into these mechanisms carries the hope that the knowledge created can eventually be used to design targeted treatments to prevent photoreceptor loss. Hence, in this review, we summarize studies on PCD in RD, including on apoptosis, PARthanatos, and cGMP-dependent cell death. Then, we focus on a possible interplay between these mechanisms, covering cGMP-signaling targets, overactivation of poly(ADP-ribose)polymerase (PARP), energy depletion, Ca2+-permeable channels, and Ca2+-dependent proteases. Finally, an outlook is given into how specific features of cGMP-signaling and PARthanatos may be targeted by therapeutic interventions.
Collapse
Affiliation(s)
| | | | | | - François Paquet-Durand
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076 Tübingen, Germany; (J.Y.); (Y.C.); (Y.Z.)
| |
Collapse
|
27
|
Andreazzoli M, Barravecchia I, De Cesari C, Angeloni D, Demontis GC. Inducible Pluripotent Stem Cells to Model and Treat Inherited Degenerative Diseases of the Outer Retina: 3D-Organoids Limitations and Bioengineering Solutions. Cells 2021; 10:cells10092489. [PMID: 34572137 PMCID: PMC8471616 DOI: 10.3390/cells10092489] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/12/2021] [Accepted: 09/15/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal degenerations (IRD) affecting either photoreceptors or pigment epithelial cells cause progressive visual loss and severe disability, up to complete blindness. Retinal organoids (ROs) technologies opened up the development of human inducible pluripotent stem cells (hiPSC) for disease modeling and replacement therapies. However, hiPSC-derived ROs applications to IRD presently display limited maturation and functionality, with most photoreceptors lacking well-developed outer segments (OS) and light responsiveness comparable to their adult retinal counterparts. In this review, we address for the first time the microenvironment where OS mature, i.e., the subretinal space (SRS), and discuss SRS role in photoreceptors metabolic reprogramming required for OS generation. We also address bioengineering issues to improve culture systems proficiency to promote OS maturation in hiPSC-derived ROs. This issue is crucial, as satisfying the demanding metabolic needs of photoreceptors may unleash hiPSC-derived ROs full potential for disease modeling, drug development, and replacement therapies.
Collapse
Affiliation(s)
| | - Ivana Barravecchia
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy;
- Institute of Life Sciences, Scuola Superiore Sant’Anna, 56124 Pisa, Italy;
| | | | - Debora Angeloni
- Institute of Life Sciences, Scuola Superiore Sant’Anna, 56124 Pisa, Italy;
| | - Gian Carlo Demontis
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy;
- Correspondence: (M.A.); (G.C.D.)
| |
Collapse
|
28
|
cGMP-PKG dependent transcriptome in normal and degenerating retinas: Novel insights into the retinitis pigmentosa pathology. Exp Eye Res 2021; 212:108752. [PMID: 34478738 DOI: 10.1016/j.exer.2021.108752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 06/25/2021] [Accepted: 08/25/2021] [Indexed: 12/26/2022]
Abstract
Retinitis Pigmentosa represents a group of genetic disorders that cause progressive vision loss via degeneration of photoreceptors, but there is in principle no treatment available. For any therapy development, a deeper comprehension of the disease-leading mechanism(s) at the molecular level is needed. Here we focused on the cGMP-PKG system, which has been suggested to be a driver in several models of the disease. To gain insights in its downstream signaling we manipulated the cGMP-PKG system with the aid of organotypic retinal explant cultures from either a mouse-based disease model, i.e. the rd1 mouse, or its healthy wild-type counterpart (wt), by adding different types of cGMP analogues to either inhibit or activate PKG in retinal explants from rd1 and wt, respectively. An RNA sequencing was then performed to study the cGMP-PKG dependent transcriptome. Expression changes of gene sets related to specific pathways or functions, that fulfilled criteria involving that the changes should match PKG activation and inhibition, were determined via bioinformatics. The analyses highlighted that several gene sets linked to oxidative phosphorylation and mitochondrial pathways were regulated by this enzyme system. Specifically, the expression of such pathway components was upregulated in the rd1 treated with PKG inhibitor and downregulated in the wt with PKG activator treatment, suggesting that cGMP-PKG act as a negative regulator in this context. Downregulation of energy production pathways may thus play an integral part in the mechanism behind the degeneration for at least several RP mutations.
Collapse
|
29
|
Technological advancements to study cellular signaling pathways in inherited retinal degenerative diseases. Curr Opin Pharmacol 2021; 60:102-110. [PMID: 34388439 DOI: 10.1016/j.coph.2021.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/02/2021] [Indexed: 01/01/2023]
Abstract
Inherited retinal degenerative diseases (IRDs) are rare neurodegenerative disorders with mutations in hundreds of genes leading to vision loss, primarily owing to photoreceptor cell death. This genetic diversity is impeding development of effective treatment options. Gene-based therapies have resulted in the first FDA-approved drug (Luxturna) for RPE65-specific IRD. Although currently explored in clinical trials, genomic medicines are mutation-dependent, hence suitable only for patients harboring a specific mutation. Better understanding of the pathways leading to photoreceptor degeneration may help to determine common targets and develop mutation-independent therapies for larger groups of patients with IRDs. In this review, we discuss the key pathways involved in photoreceptor cell death studied by transcriptomics, proteomics, and metabolomics techniques to identify potential therapeutic targets in IRDs.
Collapse
|
30
|
Christensen G, Barut L, Urimi D, Schipper N, Paquet-Durand F. Investigating Ex Vivo Animal Models to Test the Performance of Intravitreal Liposomal Drug Delivery Systems. Pharmaceutics 2021; 13:1013. [PMID: 34371707 PMCID: PMC8309192 DOI: 10.3390/pharmaceutics13071013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 12/31/2022] Open
Abstract
There is a strong need for innovative and efficient drug delivery systems for ocular therapy development. However, testing intravitreal drug delivery systems without using live animals is challenging. Ex vivo animal models offer an interesting alternative. We analyzed the potential of using fresh porcine eyes obtained from the local slaughterhouse as a model for testing the intravitreal biodistribution and retention of liposomes with or without polyethylene glycol (PEG) conjugation and with different surface charges. The histology of the eyes was analyzed to localize the liposomes, and it was found that liposomes with PEG absorbed rapidly on the retina (within 1 h), with positively charged and PEG-coated liposomes being retained for at least 24 h. In parallel, fluorophotometry was employed on intact eyes, to determine the pharmacokinetics of the fluorophore calcein, as a substitute for a small hydrophilic therapeutic compound. We found a 4.5-fold increase in the vitreous half-life of calcein loaded in liposomes, compared with the free solution. Retinal toxicity was addressed using murine-derived retinal explant cultures. Liposomes were non-toxic up to 500 µg/mL. Toxicity was observed at 5 mg/mL for anionic and cationic liposomes, with 2-fold and 2.5-fold increased photoreceptor cell death, respectively. Overall, we could show that important ocular drug delivery considerations such as pharmacokinetics and biodistribution can be estimated in ex vivo porcine eyes, and may guide subsequent in vivo experiments.
Collapse
Affiliation(s)
- Gustav Christensen
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn Straße 5-7, 72076 Tübingen, Germany; (G.C.); (L.B.)
| | - Leon Barut
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn Straße 5-7, 72076 Tübingen, Germany; (G.C.); (L.B.)
| | - Dileep Urimi
- Division Bioeconomy and Health, Chemical Process and Pharmaceutical Development, RISE Research Institutes of Sweden, Forskargatan 18, 151 36 Södertälje, Sweden; (D.U.); (N.S.)
| | - Nicolaas Schipper
- Division Bioeconomy and Health, Chemical Process and Pharmaceutical Development, RISE Research Institutes of Sweden, Forskargatan 18, 151 36 Södertälje, Sweden; (D.U.); (N.S.)
| | - François Paquet-Durand
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn Straße 5-7, 72076 Tübingen, Germany; (G.C.); (L.B.)
| |
Collapse
|
31
|
New In Vitro Cellular Model for Molecular Studies of Retinitis Pigmentosa. Int J Mol Sci 2021; 22:ijms22126440. [PMID: 34208617 PMCID: PMC8235468 DOI: 10.3390/ijms22126440] [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: 05/07/2021] [Revised: 06/04/2021] [Accepted: 06/13/2021] [Indexed: 02/05/2023] Open
Abstract
Retinitis pigmentosa (RP) is an inherited form of retinal degeneration characterized by primary rod photoreceptor cell death followed by cone loss. Mutations in several genes linked to the disease cause increased levels of cyclic guanosine monophosphate (cGMP) and calcium ion influxes. The purpose of this project was to develop a new in vitro photoreceptor degeneration model for molecular studies of RP. 661W cells were genetically modified to stably express the neural retina leucine zipper (NRL) transcription factor. One clone (661W-A11) was selected based on the expression of Nrl target genes. 661W-A11 showed a significant increase in expression of rod-specific genes but not of cone-specific genes, compared with 661W cells. Zaprinast was used to inhibit phosphodiesterase 6 (PDE6) activity to mimic photoreceptor degeneration in vitro. The activation of cell death pathways resulting from PDE6 inhibition was confirmed by detection of decreased viability and increased intracellular cGMP and calcium, as well as activation of protein kinase G (PKG) and calpains. In this new in vitro system, we validated the effects of previously published neuroprotective drugs. The 661W-A11 cells may serve as a new model for molecular studies of RP and for high-throughput drug screening.
Collapse
|
32
|
Lin TY, Chang YC, Hsiao YJ, Chien Y, Jheng YC, Wu JR, Ching LJ, Hwang DK, Hsu CC, Lin TC, Chou YB, Huang YM, Chen SJ, Yang YP, Tsai PH. Identification of Novel Genomic-Variant Patterns of OR56A5, OR52L1, and CTSD in Retinitis Pigmentosa Patients by Whole-Exome Sequencing. Int J Mol Sci 2021; 22:ijms22115594. [PMID: 34070492 PMCID: PMC8198027 DOI: 10.3390/ijms22115594] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 12/24/2022] Open
Abstract
Inherited retinal dystrophies (IRDs) are rare but highly heterogeneous genetic disorders that affect individuals and families worldwide. However, given its wide variability, its analysis of the driver genes for over 50% of the cases remains unexplored. The present study aims to identify novel driver genes, disease-causing variants, and retinitis pigmentosa (RP)-associated pathways. Using family-based whole-exome sequencing (WES) to identify putative RP-causing rare variants, we identified a total of five potentially pathogenic variants located in genes OR56A5, OR52L1, CTSD, PRF1, KBTBD13, and ATP2B4. Of the variants present in all affected individuals, genes OR56A5, OR52L1, CTSD, KBTBD13, and ATP2B4 present as missense mutations, while PRF1 and CTSD present as frameshift variants. Sanger sequencing confirmed the presence of the novel pathogenic variant PRF1 (c.124_128del) that has not been reported previously. More causal-effect or evidence-based studies will be required to elucidate the precise roles of these SNPs in the RP pathogenesis. Taken together, our findings may allow us to explore the risk variants based on the sequencing data and upgrade the existing variant annotation database in Taiwan. It may help detect specific eye diseases such as retinitis pigmentosa in East Asia.
Collapse
Affiliation(s)
- Ting-Yi Lin
- College of Medicine, Kaohsiung Medical University, Kaohsiung 807378, Taiwan;
| | - Yun-Chia Chang
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112304, Taiwan; (Y.-C.C.); (D.-K.H.); (C.-C.H.); (T.-C.L.); (Y.-B.C.); (Y.-M.H.); (S.-J.C.)
| | - Yu-Jer Hsiao
- College of Medicine, National Yang-Ming Chiao-Tung University, Taipei 11217, Taiwan;
| | - Yueh Chien
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (Y.C.); (Y.-C.J.); (J.-R.W.); (L.-J.C.)
- Institute of Pharmacology, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Ying-Chun Jheng
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (Y.C.); (Y.-C.J.); (J.-R.W.); (L.-J.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
- Big Data Center, Taipei Veterans General Hospital, Taipei 112201, Taiwan
| | - Jing-Rong Wu
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (Y.C.); (Y.-C.J.); (J.-R.W.); (L.-J.C.)
| | - Lo-Jei Ching
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (Y.C.); (Y.-C.J.); (J.-R.W.); (L.-J.C.)
| | - De-Kuang Hwang
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112304, Taiwan; (Y.-C.C.); (D.-K.H.); (C.-C.H.); (T.-C.L.); (Y.-B.C.); (Y.-M.H.); (S.-J.C.)
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (Y.C.); (Y.-C.J.); (J.-R.W.); (L.-J.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Chih-Chien Hsu
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112304, Taiwan; (Y.-C.C.); (D.-K.H.); (C.-C.H.); (T.-C.L.); (Y.-B.C.); (Y.-M.H.); (S.-J.C.)
| | - Tai-Chi Lin
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112304, Taiwan; (Y.-C.C.); (D.-K.H.); (C.-C.H.); (T.-C.L.); (Y.-B.C.); (Y.-M.H.); (S.-J.C.)
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (Y.C.); (Y.-C.J.); (J.-R.W.); (L.-J.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Yu-Bai Chou
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112304, Taiwan; (Y.-C.C.); (D.-K.H.); (C.-C.H.); (T.-C.L.); (Y.-B.C.); (Y.-M.H.); (S.-J.C.)
| | - Yi-Ming Huang
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112304, Taiwan; (Y.-C.C.); (D.-K.H.); (C.-C.H.); (T.-C.L.); (Y.-B.C.); (Y.-M.H.); (S.-J.C.)
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112304, Taiwan; (Y.-C.C.); (D.-K.H.); (C.-C.H.); (T.-C.L.); (Y.-B.C.); (Y.-M.H.); (S.-J.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Yi-Ping Yang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (Y.C.); (Y.-C.J.); (J.-R.W.); (L.-J.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Internal Medicine, Taipei Veterans General Hospital, Taipei 112201, Taiwan
- Critical Center, Taipei Veterans General Hospital, Taipei 112201, Taiwan
- Correspondence: (Y.-P.Y.); (P.H.T.); Tel.: +886-2-2875-7394 (Y.-P.Y.); +886-2-2875-7394 (P.H.T.)
| | - Ping-Hsing Tsai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan; (Y.C.); (Y.-C.J.); (J.-R.W.); (L.-J.C.)
- Institute of Pharmacology, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
- Correspondence: (Y.-P.Y.); (P.H.T.); Tel.: +886-2-2875-7394 (Y.-P.Y.); +886-2-2875-7394 (P.H.T.)
| |
Collapse
|
33
|
Das S, Chen Y, Yan J, Christensen G, Belhadj S, Tolone A, Paquet-Durand F. The role of cGMP-signalling and calcium-signalling in photoreceptor cell death: perspectives for therapy development. Pflugers Arch 2021; 473:1411-1421. [PMID: 33864120 PMCID: PMC8370896 DOI: 10.1007/s00424-021-02556-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/04/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022]
Abstract
The second messengers, cGMP and Ca2+, have both been implicated in retinal degeneration; however, it is still unclear which of the two is most relevant for photoreceptor cell death. This problem is exacerbated by the close connections and crosstalk between cGMP-signalling and calcium (Ca2+)-signalling in photoreceptors. In this review, we summarize key aspects of cGMP-signalling and Ca2+-signalling relevant for hereditary photoreceptor degeneration. The topics covered include cGMP-signalling targets, the role of Ca2+ permeable channels, relation to energy metabolism, calpain-type proteases, and how the related metabolic processes may trigger and execute photoreceptor cell death. A focus is then put on cGMP-dependent mechanisms and how exceedingly high photoreceptor cGMP levels set in motion cascades of Ca2+-dependent and independent processes that eventually bring about photoreceptor cell death. Finally, an outlook is given into mutation-independent therapeutic approaches that exploit specific features of cGMP-signalling. Such approaches might be combined with suitable drug delivery systems for translation into clinical applications.
Collapse
Affiliation(s)
- Soumyaparna Das
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Yiyi Chen
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Jie Yan
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Gustav Christensen
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Soumaya Belhadj
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - Arianna Tolone
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany
| | - François Paquet-Durand
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076, Tübingen, Germany.
| |
Collapse
|
34
|
Visual Side Effects Linked to Sildenafil Consumption: An Update. Biomedicines 2021; 9:biomedicines9030291. [PMID: 33809319 PMCID: PMC7998971 DOI: 10.3390/biomedicines9030291] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 12/14/2022] Open
Abstract
Phosphodiesterase type 5 (PDE5) inhibitors such as Viagra® (sildenafil citrate) have demonstrated efficacy in the treatment of erectile dysfunction (ED) by inducing cyclic guanosine monophosphate (cGMP) elevation followed by vasodilation and increased blood flow. It also exerts minor inhibitory action against PDE6, which is present exclusively in rod and cone photoreceptors. The effects of sildenafil on the visual system have been investigated in a wide variety of clinical and preclinical studies due to the fact that a high dose of sildenafil may cause mild and transient visual symptoms in some patients. A literature review was performed using PubMed, Cochrane Library and Clinical Trials databases from 1990 up to 2020, focusing on the pathophysiology of visual disorders induced by sildenafil. The aim of this review was not only to gather and summarize the information available on sildenafil clinical trials (CTs), but also to spot subpopulations with increased risk of developing undesirable visual side effects. This PDE inhibitor has been associated with transient and reversible ocular side effects, including changes in color vision and light perception, blurred vision, photophobia, conjunctival hyperemia and keratitis, and alterations in the electroretinogram (ERG). Sildenafil may induce a reversible increase in intraocular pressure (IOP) and a few case reports suggest it is involved in the development of nonarteritic ischemic optic neuropathy (NAION). Reversible idiopathic serous macular detachment, central serous retinopathy and ERG disturbances have been related to the significant impact of sildenafil on retinal perfusion. So far, sildenafil does not seem to cause permanent toxic effects on chorioretinal tissue and photoreceptors as long as the therapeutic dose is not exceeded and is taken under a physician’s direction to treat a medical condition. However, the recreational use of sildenafil can lead to harmful side effects, including vision changes.
Collapse
|
35
|
Identification of Novel Substrates for cGMP Dependent Protein Kinase (PKG) through Kinase Activity Profiling to Understand Its Putative Role in Inherited Retinal Degeneration. Int J Mol Sci 2021; 22:ijms22031180. [PMID: 33503999 PMCID: PMC7865299 DOI: 10.3390/ijms22031180] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal degenerative diseases (IRDs), which ultimately lead to photoreceptor cell death, are characterized by high genetic heterogeneity. Many IRD-associated genetic defects affect 3′,5′-cyclic guanosine monophosphate (cGMP) levels. cGMP-dependent protein kinases (PKGI and PKGII) have emerged as novel targets, and their inhibition has shown functional protection in IRDs. The development of such novel neuroprotective compounds warrants a better understanding of the pathways downstream of PKGs that lead to photoreceptor degeneration. Here, we used human recombinant PKGs in combination with PKG activity modulators (cGMP, 3′,5′-cyclic adenosine monophosphate (cAMP), PKG activator, and PKG inhibitors) on a multiplex peptide microarray to identify substrates for PKGI and PKGII. In addition, we applied this technology in combination with PKG modulators to monitor kinase activity in a complex cell system, i.e. the retinal cell line 661W, which is used as a model system for IRDs. The high-throughput method allowed quick identification of bona fide substrates for PKGI and PKGII. The response to PKG modulators helped us to identify, in addition to ten known substrates, about 50 novel substrates for PKGI and/or PKGII which are either specific for one enzyme or common to both. Interestingly, both PKGs are able to phosphorylate the regulatory subunit of PKA, whereas only PKGII can phosphorylate the catalytic subunit of PKA. In 661W cells, the results suggest that PKG activators cause minor activation of PKG, but a prominent increase in the activity of cAMP-dependent protein kinase (PKA). However, the literature suggests an important role for PKG in IRDs. This conflicting information could be reconciled by cross-talk between PKG and PKA in the retinal cells. This must be explored further to elucidate the role of PKGs in IRDs.
Collapse
|
36
|
Charish J, Shabanzadeh AP, Chen D, Mehlen P, Sethuramanujam S, Harada H, Bonilha VL, Awatramani G, Bremner R, Monnier PP. Neogenin neutralization prevents photoreceptor loss in inherited retinal degeneration. J Clin Invest 2020; 130:2054-2068. [PMID: 32175920 DOI: 10.1172/jci125898] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/14/2020] [Indexed: 02/05/2023] Open
Abstract
Inherited retinal degenerations (IRDs) are characterized by the progressive loss of photoreceptors and represent one of the most prevalent causes of blindness among working-age populations. Cyclic nucleotide dysregulation is a common pathological feature linked to numerous forms of IRD, yet the precise mechanisms through which this contributes to photoreceptor death remain elusive. Here we demonstrate that cAMP induced upregulation of the dependence receptor neogenin in the retina. Neogenin levels were also elevated in both human and murine degenerating photoreceptors. We found that overexpressing neogenin in mouse photoreceptors was sufficient to induce cell death, whereas silencing neogenin in degenerating murine photoreceptors promoted survival, thus identifying a pro-death signal in IRDs. A possible treatment strategy is modeled whereby peptide neutralization of neogenin in Rd1, Rd10, and Rho P23H-knockin mice promotes rod and cone survival and rescues visual function as measured by light-evoked retinal ganglion cell recordings, scotopic/photopic electroretinogram recordings, and visual acuity tests. These results expose neogenin as a critical link between cAMP and photoreceptor death, and identify a druggable target for the treatment of retinal degeneration.
Collapse
Affiliation(s)
- Jason Charish
- Vision Division, Krembil Research Institute, Toronto, Ontario, Canada.,Department of Physiology and
| | - Alireza P Shabanzadeh
- Vision Division, Krembil Research Institute, Toronto, Ontario, Canada.,Department of Anatomy, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Danian Chen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.,Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy and.,Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Patrick Mehlen
- Apoptosis, Cancer and Development Laboratory, INSERM U1052, CNRS UMR5286, Université de Lyon, Lyon, France
| | | | - Hidekiyo Harada
- Vision Division, Krembil Research Institute, Toronto, Ontario, Canada
| | - Vera L Bonilha
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Gautam Awatramani
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Rod Bremner
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology and.,Department of Ophthalmology and Vision Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Philippe P Monnier
- Vision Division, Krembil Research Institute, Toronto, Ontario, Canada.,Department of Physiology and.,Department of Ophthalmology and Vision Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
37
|
Rasmussen M, Welinder C, Schwede F, Ekström P. The cGMP system in normal and degenerating mouse neuroretina: New proteins with cGMP interaction potential identified by a proteomics approach. J Neurochem 2020; 157:2173-2186. [PMID: 33230839 PMCID: PMC8359485 DOI: 10.1111/jnc.15251] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/17/2022]
Abstract
The hereditary disease Retinitis pigmentosa results in severe vision loss due to photoreceptor degeneration by unclear mechanisms. In several disease models, the second messenger cGMP accumulates in the degenerating photoreceptors, where it may over‐activate specific cGMP‐interacting proteins, like cGMP‐dependent protein kinase. Moreover, interventions that counteract the activity of these proteins lead to reduced photoreceptor cell death. Yet there is little or no information whether other than such regular cGMP‐interactors are present in the retina, which we, therefore, investigated in wild‐type and retinal degeneration (rd1, rd10, and rd2) mouse models. An affinity chromatography based proteomics approach that utilized immobilized cGMP analogs was applied to enrich and select for regular and potentially new cGMP‐interacting proteins as identified by mass spectrometry. This approach revealed 12 regular and 10 potentially new retinal cGMP‐interacting proteins (e.g., EPAC2 and CaMKIIα). Several of the latter were found to be expressed in the photoreceptors and to have proximity to cGMP and may thus be of interest when defining prospective therapeutic targets or biomarkers for retinal degeneration.
Collapse
Affiliation(s)
- Michel Rasmussen
- Faculty of Medicine, Department of Clinical Sciences Lund, Lund University, Ophthalmology, Lund, Sweden
| | - Charlotte Welinder
- Faculty of Medicine, Department of Clinical Sciences Lund, Oncology, Lund University, Lund, Sweden
| | - Frank Schwede
- BIOLOG Life Science Institute GmbH & Co. KG, Bremen, Germany
| | - Per Ekström
- Faculty of Medicine, Department of Clinical Sciences Lund, Lund University, Ophthalmology, Lund, Sweden
| |
Collapse
|
38
|
Sheet S, Krishnamoorthy S, Park W, Lim D, Park JE, Ko M, Choi BH. Mechanistic insight into the progressive retinal atrophy disease in dogs via pathway-based genome-wide association analysis. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2020; 62:765-776. [PMID: 33987558 PMCID: PMC7721568 DOI: 10.5187/jast.2020.62.6.765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/25/2020] [Accepted: 09/06/2020] [Indexed: 01/01/2023]
Abstract
The retinal degenerative disease, progressive retinal atrophy (PRA) is a major
reason of vision impairment in canine population. Canine PRA signifies an
inherently dissimilar category of retinal dystrophies which has solid
resemblances to human retinis pigmentosa. Even though much is known about the
biology of PRA, the knowledge about the intricate connection among genetic loci,
genes and pathways associated to this disease in dogs are still remain unknown.
Therefore, we have performed a genome wide association study (GWAS) to identify
susceptibility single nucleotide polymorphisms (SNPs) of PRA. The GWAS was
performed using a case–control based association analysis method on PRA
dataset of 129 dogs and 135,553 markers. Further, the gene-set and pathway
analysis were conducted in this study. A total of 1,114 markers associations
with PRA trait at p < 0.01 were extracted and mapped to
640 unique genes, and then selected significant (p <
0.05) enriched 35 gene ontology (GO) terms and 5 Kyoto Encyclopedia of Genes and
Genomes (KEGG) pathways contain these genes. In particular, apoptosis process,
homophilic cell adhesion, calcium ion binding, and endoplasmic reticulum GO
terms as well as pathways related to focal adhesion, cyclic guanosine
monophosphate)-protein kinase G signaling, and axon guidance were more likely
associated to the PRA disease in dogs. These data could provide new insight for
further research on identification of potential genes and causative pathways for
PRA in dogs.
Collapse
Affiliation(s)
- Sunirmal Sheet
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Srikanth Krishnamoorthy
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Woncheoul Park
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Dajeong Lim
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Jong-Eun Park
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Minjeong Ko
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Bong-Hwan Choi
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| |
Collapse
|
39
|
Newton F, Megaw R. Mechanisms of Photoreceptor Death in Retinitis Pigmentosa. Genes (Basel) 2020; 11:genes11101120. [PMID: 32987769 PMCID: PMC7598671 DOI: 10.3390/genes11101120] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 02/08/2023] Open
Abstract
Retinitis pigmentosa (RP) is the most common cause of inherited blindness and is characterised by the progressive loss of retinal photoreceptors. However, RP is a highly heterogeneous disease and, while much progress has been made in developing gene replacement and gene editing treatments for RP, it is also necessary to develop treatments that are applicable to all causative mutations. Further understanding of the mechanisms leading to photoreceptor death is essential for the development of these treatments. Recent work has therefore focused on the role of apoptotic and non-apoptotic cell death pathways in RP and the various mechanisms that trigger these pathways in degenerating photoreceptors. In particular, several recent studies have begun to elucidate the role of microglia and innate immune response in the progression of RP. Here, we discuss some of the recent progress in understanding mechanisms of rod and cone photoreceptor death in RP and summarise recent clinical trials targeting these pathways.
Collapse
Affiliation(s)
- Fay Newton
- MRC Human Genetics Unit, University of Edinburgh, South Bridge, Edinburgh EH8 9YL, UK;
- Correspondence:
| | - Roly Megaw
- MRC Human Genetics Unit, University of Edinburgh, South Bridge, Edinburgh EH8 9YL, UK;
- Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh EH3 9HA, UK
| |
Collapse
|
40
|
Karlen SJ, Miller EB, Burns ME. Microglia Activation and Inflammation During the Death of Mammalian Photoreceptors. Annu Rev Vis Sci 2020; 6:149-169. [PMID: 32936734 PMCID: PMC10135402 DOI: 10.1146/annurev-vision-121219-081730] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Photoreceptors are highly specialized sensory neurons with unique metabolic and physiological requirements. These requirements are partially met by Müller glia and cells of the retinal pigment epithelium (RPE), which provide essential metabolites, phagocytose waste, and control the composition of the surrounding microenvironment. A third vital supporting cell type, the retinal microglia, can provide photoreceptors with neurotrophic support or exacerbate neuroinflammation and hasten neuronal cell death. Understanding the physiological requirements for photoreceptor homeostasis and the factors that drive microglia to best promote photoreceptor survival has important implications for the treatment and prevention of blinding degenerative diseases like retinitis pigmentosa and age-related macular degeneration.
Collapse
Affiliation(s)
- Sarah J. Karlen
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, California 95616, USA
| | - Eric B. Miller
- Center for Neuroscience, University of California, Davis, Davis, California 95616, USA
| | - Marie E. Burns
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, California 95616, USA
- Center for Neuroscience, University of California, Davis, Davis, California 95616, USA
- Department of Ophthalmology & Vision Science, University of California, Davis, Davis, California 95616, USA
| |
Collapse
|
41
|
Yang P, Lockard RA, Titus H. Techniques to Quantify cGMP Dysregulation as a Common Pathway Associated with Photoreceptor Cell Death in Retinitis Pigmentosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1185:407-411. [PMID: 31884646 DOI: 10.1007/978-3-030-27378-1_67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The targeted development of neuroprotective therapies for retinitis pigmentosa (RP) depends upon a better understanding of the mechanisms of photoreceptor cell death. Nucleotide metabolite-associated photoreceptor cell death is an emerging area of research that is important in multiple models of RP, yet the exact pathophysiology remains to be elucidated. One common pathway of photoreceptor cell death in RP is cGMP dysregulation, which is underscored by its potential to be relevant in up to 30% of patients with RP. Optimizing tools for detecting and quantifying nucleotide metabolites in the retina is vital to expanding this area of research. Immunohistochemistry is useful for localizing abnormally high levels of cGMP in a cell-specific manner, while enzyme-linked immunosorbent assay and liquid chromatography-mass spectrometry are quantitative and more sensitive. These techniques can form the basis for more sophisticated experiments to elucidate upstream events in photoreceptor cell death, which will hopefully lead to the development of novel therapies for patients with RP.
Collapse
Affiliation(s)
- Paul Yang
- Casey Eye Institute, Orgeon Health and Science University, Portland, OR, USA.
| | - Rachel A Lockard
- Casey Eye Institute, Orgeon Health and Science University, Portland, OR, USA
| | - Hope Titus
- Casey Eye Institute, Orgeon Health and Science University, Portland, OR, USA
| |
Collapse
|
42
|
RD Genes Associated with High Photoreceptor cGMP-Levels (Mini-Review). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1185:245-249. [PMID: 31884619 DOI: 10.1007/978-3-030-27378-1_40] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Many RD-causing mutations lead to a dysregulation of cyclic guanosine monophosphate (cGMP), making cGMP signalling a prime target for the development of new treatment approaches. We showed previously that an analogue of cGMP, which inhibited cGMP signalling targets, increased photoreceptor viability in three rodent RD models carrying different genetic defects, in different RD genes. This raises the question of the possible generality of this approach as a treatment for RD. Here, we review RD genes that can be associated with high cGMP and discuss which RD genes might be amenable to a treatment aimed at inhibiting excessive cGMP signalling.
Collapse
|
43
|
Kutluer M, Huang L, Marigo V. Targeting molecular pathways for the treatment of inherited retinal degeneration. Neural Regen Res 2020; 15:1784-1791. [PMID: 32246618 PMCID: PMC7513962 DOI: 10.4103/1673-5374.280303] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Inherited retinal degeneration is a major cause of incurable blindness characterized by loss of retinal photoreceptor cells. Inherited retinal degeneration is characterized by high genetic and phenotypic heterogeneity with several genes mutated in patients affected by these genetic diseases. The high genetic heterogeneity of these diseases hampers the development of effective therapeutic interventions for the cure of a large cohort of patients. Common cell demise mechanisms can be envisioned as targets to treat patients regardless the specific mutation. One of these targets is the increase of intracellular calcium ions, that has been detected in several murine models of inherited retinal degeneration. Recently, neurotrophic factors that favor the efflux of calcium ions to concentrations below toxic levels have been identified as promising molecules that should be evaluated as new treatments for retinal degeneration. Here, we discuss therapeutic options for inherited retinal degeneration and we will focus on neuroprotective approaches, such as the neuroprotective activity of the Pigment epithelium-derived factor. The characterization of specific targets for neuroprotection opens new perspectives together with many questions that require deep analyses to take advantage of this knowledge and develop new therapeutic approaches. We believe that minimizing cell demise by neuroprotection may represent a promising treatment strategy for retinal degeneration.
Collapse
Affiliation(s)
- Meltem Kutluer
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Li Huang
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| |
Collapse
|
44
|
Power MJ, Rogerson LE, Schubert T, Berens P, Euler T, Paquet-Durand F. Systematic spatiotemporal mapping reveals divergent cell death pathways in three mouse models of hereditary retinal degeneration. J Comp Neurol 2019; 528:1113-1139. [PMID: 31710697 DOI: 10.1002/cne.24807] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 08/06/2019] [Accepted: 10/20/2019] [Indexed: 12/20/2022]
Abstract
Calcium (Ca2+ ) dysregulation has been linked to neuronal cell death, including in hereditary retinal degeneration. Ca2+ dysregulation is thought to cause rod and cone photoreceptor cell death. Spatial and temporal heterogeneities in retinal disease models have hampered validation of this hypothesis. We examined the role of Ca2+ in photoreceptor degeneration, assessing the activation pattern of Ca2+ -dependent calpain proteases, generating spatiotemporal maps of the entire retina in the cpfl1 mouse model for primary cone degeneration, and in the rd1 and rd10 models for primary rod degeneration. We used Gaussian process models to distinguish the temporal sequences of degenerative molecular processes from other variability sources.In the rd1 and rd10 models, spatiotemporal pattern of increased calpain activity matched the progression of primary rod degeneration. High calpain activity coincided with activation of the calpain-2 isoform but not with calpain-1, suggesting differential roles for both calpain isoforms. Primary rod loss was linked to upregulation of apoptosis-inducing factor, although only a minute fraction of cells showed activity of the apoptotic marker caspase-3. After primary rod degeneration concluded, caspase-3 activation appeared in cones, suggesting apoptosis as the dominant mechanism for secondary cone loss. Gaussian process models highlighted calpain activity as a key event during primary rod photoreceptor cell death. Our data suggest a causal link between Ca2+ dysregulation and primary, nonapoptotic degeneration of photoreceptors and a role for apoptosis in secondary degeneration of cones, highlighting the importance of the spatial and temporal location of key molecular events, which may guide the evaluation of new therapies.
Collapse
Affiliation(s)
- Michael J Power
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.,Centre for Integrative Neuroscience (CIN), University of Tübingen, Tübingen, Germany.,Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Tübingen, Germany
| | - Luke E Rogerson
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.,Centre for Integrative Neuroscience (CIN), University of Tübingen, Tübingen, Germany.,Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Tübingen, Germany.,Bernstein Center for Computational Neuroscience, Tübingen, Germany.,Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, Germany
| | - Timm Schubert
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.,Centre for Integrative Neuroscience (CIN), University of Tübingen, Tübingen, Germany
| | - Philipp Berens
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.,Centre for Integrative Neuroscience (CIN), University of Tübingen, Tübingen, Germany.,Bernstein Center for Computational Neuroscience, Tübingen, Germany.,Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, Germany
| | - Thomas Euler
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.,Centre for Integrative Neuroscience (CIN), University of Tübingen, Tübingen, Germany.,Bernstein Center for Computational Neuroscience, Tübingen, Germany
| | | |
Collapse
|
45
|
Calbiague VM, Vielma AH, Cadiz B, Paquet‐Durand F, Schmachtenberg O. Physiological assessment of high glucose neurotoxicity in mouse and rat retinal explants. J Comp Neurol 2019; 528:989-1002. [DOI: 10.1002/cne.24805] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/09/2019] [Accepted: 10/20/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Víctor M. Calbiague
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
- Programa Doctorado en Ciencias, mención Neurociencias Universidad de Valparaíso Valparaíso Chile
| | - Alex H. Vielma
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
| | - Bárbara Cadiz
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
| | - Francois Paquet‐Durand
- Cell Death Mechanism Group Institute for Ophthalmic Research, University of Tübingen Tübingen Germany
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
| |
Collapse
|
46
|
Power M, Das S, Schütze K, Marigo V, Ekström P, Paquet-Durand F. Cellular mechanisms of hereditary photoreceptor degeneration - Focus on cGMP. Prog Retin Eye Res 2019; 74:100772. [PMID: 31374251 DOI: 10.1016/j.preteyeres.2019.07.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 12/21/2022]
Abstract
The cellular mechanisms underlying hereditary photoreceptor degeneration are still poorly understood, a problem that is exacerbated by the enormous genetic heterogeneity of this disease group. However, the last decade has yielded a wealth of new knowledge on degenerative pathways and their diversity. Notably, a central role of cGMP-signalling has surfaced for photoreceptor cell death triggered by a subset of disease-causing mutations. In this review, we examine key aspects relevant for photoreceptor degeneration of hereditary origin. The topics covered include energy metabolism, epigenetics, protein quality control, as well as cGMP- and Ca2+-signalling, and how the related molecular and metabolic processes may trigger photoreceptor demise. We compare and integrate evidence on different cell death mechanisms that have been associated with photoreceptor degeneration, including apoptosis, necrosis, necroptosis, and PARthanatos. A special focus is then put on the mechanisms of cGMP-dependent cell death and how exceedingly high photoreceptor cGMP levels may cause activation of Ca2+-dependent calpain-type proteases, histone deacetylases and poly-ADP-ribose polymerase. An evaluation of the available literature reveals that a large group of patients suffering from hereditary photoreceptor degeneration carry mutations that are likely to trigger cGMP-dependent cell death, making this pathway a prime target for future therapy development. Finally, an outlook is given into technological and methodological developments that will with time likely contribute to a comprehensive overview over the entire metabolic complexity of photoreceptor cell death. Building on such developments, new imaging technology and novel biomarkers may be used to develop clinical test strategies, that fully consider the genetic heterogeneity of hereditary retinal degenerations, in order to facilitate clinical testing of novel treatment approaches.
Collapse
Affiliation(s)
- Michael Power
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany; Centre for Integrative Neurosciences (CIN), University of Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Germany
| | - Soumyaparna Das
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Germany
| | | | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Italy
| | - Per Ekström
- Ophthalmology, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Sweden
| | - François Paquet-Durand
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany.
| |
Collapse
|
47
|
Tolone A, Belhadj S, Rentsch A, Schwede F, Paquet-Durand F. The cGMP Pathway and Inherited Photoreceptor Degeneration: Targets, Compounds, and Biomarkers. Genes (Basel) 2019; 10:genes10060453. [PMID: 31207907 PMCID: PMC6627777 DOI: 10.3390/genes10060453] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/05/2019] [Accepted: 06/11/2019] [Indexed: 12/17/2022] Open
Abstract
Photoreceptor physiology and pathophysiology is intricately linked to guanosine-3’,5’-cyclic monophosphate (cGMP)-signaling. Here, we discuss the importance of cGMP-signaling for the pathogenesis of hereditary retinal degeneration. Excessive accumulation of cGMP in photoreceptors is a common denominator in cell death caused by a variety of different gene mutations. The cGMP-dependent cell death pathway may be targeted for the treatment of inherited photoreceptor degeneration, using specifically designed and formulated inhibitory cGMP analogues. Moreover, cGMP-signaling and its down-stream targets may be exploited for the development of novel biomarkers that could facilitate monitoring of disease progression and reveal the response to treatment in future clinical trials. We then briefly present the importance of appropriate formulations for delivery to the retina, both for drug and biomarker applications. Finally, the review touches on important aspects of future clinical translation, highlighting the need for interdisciplinary cooperation of researchers from a diverse range of fields.
Collapse
Affiliation(s)
- Arianna Tolone
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 5-7, 72076 Tübingen, Germany.
| | - Soumaya Belhadj
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 5-7, 72076 Tübingen, Germany.
| | | | - Frank Schwede
- Biolog Life Science Institute, 28199 Bremen, Germany.
| | - François Paquet-Durand
- Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Strasse 5-7, 72076 Tübingen, Germany.
| |
Collapse
|
48
|
Mencl S, Trifunović D, Zrenner E, Paquet-Durand F. PKG-Dependent Cell Death in 661W Cone Photoreceptor-like Cell Cultures (Experimental Study). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1074:511-517. [PMID: 29721983 DOI: 10.1007/978-3-319-75402-4_63] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In humans cone photoreceptors are responsible for high-resolution colour vision. A variety of retinal diseases can compromise cone viability, and, at present, no satisfactory treatment options are available. Here, we present data towards establishing a reliable, high-throughput assay system that will facilitate the search for cone neuroprotective compounds using the murine-photoreceptor cell line 661 W. To further characterize 661 W cells, a retinal marker study was performed, followed by the induction of cell death using paradigms over-activating cGMP-dependent protein kinase G (PKG). We found that 661 W cells may be used to mimic specific aspects of cone degeneration and may thus be valuable for future compound screening studies.
Collapse
Affiliation(s)
- Stine Mencl
- University Hospital Essen, Department of Neurology, Essen, Germany
- Department für Augenheilkunde, Forschungsinstitut für Augenheilkunde, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Dragana Trifunović
- Department für Augenheilkunde, Forschungsinstitut für Augenheilkunde, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Eberhart Zrenner
- Department für Augenheilkunde, Forschungsinstitut für Augenheilkunde, Eberhard Karls Universität Tübingen, Tübingen, Germany
- Centre for Integrative Neuroscience (CIN), Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - François Paquet-Durand
- Department für Augenheilkunde, Forschungsinstitut für Augenheilkunde, Eberhard Karls Universität Tübingen, Tübingen, Germany.
| |
Collapse
|
49
|
Do cGMP Levels Drive the Speed of Photoreceptor Degeneration? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1074:327-333. [PMID: 29721960 DOI: 10.1007/978-3-319-75402-4_40] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Humans with mutations in the phototransduction pathway develop forms of retinal degeneration, such as retinitis pigmentosa, cone dystrophy, or Leber congenital amaurosis. Similarly, numerous phototransduction mutant animal models resemble retinal degeneration. In our lab, using a zebrafish model, we study cone-specific phototransduction mutants. cGMP is the second messenger in the phototransduction pathway, and abnormal cGMP levels are associated with photoreceptor death. Rd1, a rod-specific phosphodiesterase 6 (Pde6) subunit mutant in mice, is one of the most widely used animal models for retinal degeneration. Rd1 mutant mice accumulate cGMP, causing rapid photoreceptor degeneration. However, much less is known about photoreceptor mutants producing abnormally low levels of cGMP. Here, focusing on Pde6 mutants in zebrafish and mice, we propose a correlation between cGMP levels and speed of photoreceptor degeneration.
Collapse
|
50
|
A L, Zou T, He J, Chen X, Sun D, Fan X, Xu H. Rescue of Retinal Degeneration in rd1 Mice by Intravitreally Injected Metformin. Front Mol Neurosci 2019; 12:102. [PMID: 31080404 PMCID: PMC6497809 DOI: 10.3389/fnmol.2019.00102] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 04/04/2019] [Indexed: 12/18/2022] Open
Abstract
Retinitis pigmentosa (RP) is a progressive hereditary retinal degenerative disease in which photoreceptor cells undergo degeneration and apoptosis, eventually resulting in irreversible loss of visual function. Currently, no effective treatment exists for this disease. Neuroprotection and inflammation suppression have been reported to delay the development of RP. Metformin is a well-tested drug used to treat type 2 diabetes, and it has been reported to exert beneficial effects in neurodegenerative diseases, such as Parkinson’s disease and Alzheimer’s disease. In the present study, we used immunofluorescence staining, electroretinogram (ERG) recordings and RNA-Seq to explore the effects of metformin on photoreceptor degeneration and its mechanism in rd1 mice. We found that metformin significantly reduced apoptosis in photoreceptors and delayed the degeneration of photoreceptors and rod bipolar cells in rd1 mice, thus markedly improving the visual function of rd1 mice at P14, P18, and P22 when tested with a light/dark transition test and ERG. Microglial activation in the outer nuclear layer (ONL) of the retina of rd1 mice was significantly suppressed by metformin. RNA-Seq showed that metformin markedly downregulated inflammatory genes and upregulated the expression of crystallin proteins, which have been demonstrated to be important neuroprotective molecules in the retina, revealing the therapeutic potential of metformin for RP treatment. αA-crystallin proteins were further confirmed to be involved in the neuroprotective effects of metformin in a Ca2+ ionophore-damaged 661W photoreceptor-like cell line. These data suggest that metformin exerts a protective effect in rd1 mice via both immunoregulatory and new neuroprotective mechanisms.
Collapse
Affiliation(s)
- Luodan A
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Chongqing, China.,Southwest Hospital, Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Ting Zou
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Juncai He
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Xia Chen
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Dayu Sun
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Xiaotang Fan
- Department of Developmental Neuropsychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing, China
| | - Haiwei Xu
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| |
Collapse
|