1
|
See LP, Sripinun P, Lu W, Li J, Alboloushi N, Alvarez-Periel E, Lee SM, Karabucak B, Wang S, Jordan Sciutto KL, Theken KN, Mitchell CH. Increased Purinergic Signaling in Human Dental Pulps With Inflammatory Pain is Sex-Dependent. THE JOURNAL OF PAIN 2024; 25:1039-1058. [PMID: 37956743 PMCID: PMC11129867 DOI: 10.1016/j.jpain.2023.10.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/22/2023] [Accepted: 10/28/2023] [Indexed: 11/15/2023]
Abstract
An enhanced understanding of neurotransmitter systems contributing to pain transmission aids in drug development, while the identification of biological variables like age and sex helps in the development of personalized pain management and effective clinical trial design. This study identified enhanced expression of purinergic signaling components specifically in painful inflammation, with levels increased more in women as compared to men. Inflammatory dental pain is common and potentially debilitating; as inflammation of the dental pulp can occur with or without pain, it provides a powerful model to examine distinct pain pathways in humans. In control tissues, P2X3 and P2X2 receptors colocalized with PGP9.5-positive nerves. Expression of the ecto-nucleotidase NTPDase1 (CD39) increased with exposure to extracellular adenosine triphosphate (ATP), implying CD39 acted as a marker for sustained elevation of extracellular ATP. Both immunohistochemistry and immunoblots showed P2X2, P2X3, and CD39 increased in symptomatic pulpitis, suggesting receptors and the ATP agonist were elevated in patients with increased pain. The increased expression of P2X3 and CD39 was more frequently observed in women than men. In summary, this study identifies CD39 as a marker for chronic elevation of extracellular ATP in fixed human tissue. It supports a role for increased purinergic signaling in humans with inflammatory dental pain and suggests the contribution of purines shows sexual dimorphism. This highlights the potential for P2X antagonists to treat pain in humans and stresses the need to consider sex in clinical trials that target pain and purinergic pathways. PERSPECTIVE: This article demonstrates an elevation of ATP-marker CD39 and of ATP receptors P2X2 and P2X3 with inflammatory pain and suggests the rise is greater in women. This highlights the potential for P2X antagonists to treat pain and stresses the consideration of sexual dimorphism in studies of purines and pain.
Collapse
Affiliation(s)
- Lily P. See
- Departments of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA 19104
- Department of Endodontics, University of Pennsylvania, Philadelphia, PA 19104
| | - Puttipong Sripinun
- Departments of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA 19104
- Department of Orthodontics, University of Pennsylvania, Philadelphia, PA 19104
| | - Wennan Lu
- Departments of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA 19104
| | - Jiaqi Li
- Departments of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA 19104
| | - Naela Alboloushi
- Department of Endodontics, University of Pennsylvania, Philadelphia, PA 19104
- Department of Oral Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | | | - Su-Min Lee
- Department of Endodontics, University of Pennsylvania, Philadelphia, PA 19104
| | - Bekir Karabucak
- Department of Endodontics, University of Pennsylvania, Philadelphia, PA 19104
| | - Steven Wang
- Department of Oral Surgery, University of Pennsylvania, Philadelphia, PA 19104
| | | | - Katherine N. Theken
- Department of Oral Surgery, University of Pennsylvania, Philadelphia, PA 19104
| | - Claire H. Mitchell
- Departments of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA 19104
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104
| |
Collapse
|
2
|
Olivier E, Rat P. Role of Oxysterols in Ocular Degeneration Mechanisms and Involvement of P2X7 Receptor. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1440:277-292. [PMID: 38036885 DOI: 10.1007/978-3-031-43883-7_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Ocular degeneration, including cataracts, glaucoma, macular degeneration, and diabetic retinopathy, is a major public health challenge, as it affects the quality of life of millions of people worldwide and, in its advanced stages, leads to blindness. Ocular degeneration, although it can affect different parts of the eye, shares common characteristics such as oxysterols and the P2X7 receptor. Indeed, oxysterols, which are cholesterol derivatives, are associated with ocular degeneration pathogenesis and trigger inflammation and cell death pathways. Activation of the P2X7 receptor is also linked to ocular degeneration and triggers the same pathways. In age-related macular degeneration, these two key players have been associated, but further studies are needed to extrapolate this interrelationship to other ocular degenerations.
Collapse
Affiliation(s)
| | - Patrice Rat
- Université Paris Cité, CNRS, CiTCoM, Paris, France
| |
Collapse
|
3
|
Spurlock M, An W, Reshetnikova G, Wen R, Wang H, Braha M, Solis G, Kurtenbach S, Galindez OJ, de Rivero Vaccari JP, Chou TH, Porciatti V, Shestopalov VI. The Inflammasome-Dependent Dysfunction and Death of Retinal Ganglion Cells after Repetitive Intraocular Pressure Spikes. Cells 2023; 12:2626. [PMID: 37998361 PMCID: PMC10670000 DOI: 10.3390/cells12222626] [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: 09/27/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/25/2023] Open
Abstract
The dysfunction and selective loss of retinal ganglion cells (RGCs) is a known cause of vision loss in glaucoma and other neuropathies, where ocular hypertension (OHT) is the major risk factor. We investigated the impact of transient non-ischemic OHT spikes (spOHT) on RGC function and viability in vivo to identify cellular pathways linking low-grade repetitive mechanical stress to RGC pathology. We found that repetitive spOHT had an unexpectedly high impact on intraocular homeostasis and RGC viability, while exposure to steady OHT (stOHT) of a similar intensity and duration failed to induce pathology. The repetitive spOHT induced the rapid activation of the inflammasome, marked by the upregulation of NLRP1, NLRP3, AIM2, caspases -1, -3/7, -8, and Gasdermin D (GSDMD), and the release of interleukin-1β (IL-1β) and other cytokines into the vitreous. Similar effects were also detected after 5 weeks of exposure to chronic OHT in an induced glaucoma model. The onset of these immune responses in both spOHT and glaucoma models preceded a 50% deficit in pattern electroretinogram (PERG) amplitude and a significant loss of RGCs 7 days post-injury. The inactivation of inflammasome complexes in Nlrp1-/-, Casp1-/-, and GsdmD-/- knockout animals significantly suppressed the spOHT-induced inflammatory response and protected RGCs. Our results demonstrate that mechanical stress produced by acute repetitive spOHT or chronic OHT is mechanistically linked to inflammasome activation, which leads to RGC dysfunction and death.
Collapse
Affiliation(s)
- Markus Spurlock
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Weijun An
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
| | - Galina Reshetnikova
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
| | - Rong Wen
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
| | - Hua Wang
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
| | - Michelle Braha
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
| | - Gabriela Solis
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
| | - Stefan Kurtenbach
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
| | - Orlando J. Galindez
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Juan Pablo de Rivero Vaccari
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Tsung-Han Chou
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
| | - Valery I. Shestopalov
- Bascom Palmer Eye Institute Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (M.S.); (W.A.); (G.R.); (R.W.); (H.W.); (M.B.); (G.S.); (S.K.); (V.P.)
- Department of Cell Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| |
Collapse
|
4
|
Alarcon-Martinez L, Shiga Y, Villafranca-Baughman D, Cueva Vargas JL, Vidal Paredes IA, Quintero H, Fortune B, Danesh-Meyer H, Di Polo A. Neurovascular dysfunction in glaucoma. Prog Retin Eye Res 2023; 97:101217. [PMID: 37778617 DOI: 10.1016/j.preteyeres.2023.101217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Retinal ganglion cells, the neurons that die in glaucoma, are endowed with a high metabolism requiring optimal provision of oxygen and nutrients to sustain their activity. The timely regulation of blood flow is, therefore, essential to supply firing neurons in active areas with the oxygen and glucose they need for energy. Many glaucoma patients suffer from vascular deficits including reduced blood flow, impaired autoregulation, neurovascular coupling dysfunction, and blood-retina/brain-barrier breakdown. These processes are tightly regulated by a community of cells known as the neurovascular unit comprising neurons, endothelial cells, pericytes, Müller cells, astrocytes, and microglia. In this review, the neurovascular unit takes center stage as we examine the ability of its members to regulate neurovascular interactions and how their function might be altered during glaucomatous stress. Pericytes receive special attention based on recent data demonstrating their key role in the regulation of neurovascular coupling in physiological and pathological conditions. Of particular interest is the discovery and characterization of tunneling nanotubes, thin actin-based conduits that connect distal pericytes, which play essential roles in the complex spatial and temporal distribution of blood within the retinal capillary network. We discuss cellular and molecular mechanisms of neurovascular interactions and their pathophysiological implications, while highlighting opportunities to develop strategies for vascular protection and regeneration to improve functional outcomes in glaucoma.
Collapse
Affiliation(s)
- Luis Alarcon-Martinez
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada; Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia
| | - Yukihiro Shiga
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Deborah Villafranca-Baughman
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Jorge L Cueva Vargas
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Isaac A Vidal Paredes
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Heberto Quintero
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Healthy, Portland, OR, USA
| | - Helen Danesh-Meyer
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Adriana Di Polo
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada.
| |
Collapse
|
5
|
Wei M, Zhang G, Huang Z, Ding X, Sun Q, Zhang Y, Zhu R, Guan H, Ji M. ATP-P2X 7R-mediated microglia senescence aggravates retinal ganglion cell injury in chronic ocular hypertension. J Neuroinflammation 2023; 20:180. [PMID: 37525172 PMCID: PMC10392012 DOI: 10.1186/s12974-023-02855-1] [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: 03/15/2023] [Accepted: 07/17/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND Dysfunction of microglia during aging affects normal neuronal function and results in the occurrence of neurodegenerative diseases. Retinal microglial senescence attributes to retinal ganglion cell (RGC) death in glaucoma. This study aims to examine the role of ATP-P2X7R in the mediation of microglia senescence and glaucoma progression. METHODS Forty-eight participants were enrolled, including 24 patients with primary open-angle glaucoma (POAG) and age-related cataract (ARC) and 24 patients with ARC only. We used ARC as the inclusion criteria because of the availability of aqueous humor (AH) before phacoemulsification. AH was collected and the adenosine triphosphate (ATP) concentration was measured by ATP Assay Kit. The chronic ocular hypertension (COH) mouse model was established by microbead occlusion. Microglia were ablated by feeding PLX5622 orally. Mouse bone marrow cells (BMCs) were prepared and infused into mice through the tail vein for the restoration of microglia function. Western blotting, qPCR and ELISA were performed to analyze protein and mRNA expression in the ocular tissue, respectively. Microglial phenotype and RGC survival were assessed by immunofluorescence. The mitochondrial membrane potential was measured using a JC-1 assay kit by flow cytometry. RESULTS ATP concentrations in the AH were increased in older adults and patients with POAG. The expression of P2X7R was upregulated in the retinal tissues of mice with glaucoma, and functional enrichment analysis showed that P2X7R was closely related to cell aging. Through in vivo and in vitro approaches, we showed that pathological activation of ATP-P2X7R induced accelerated microglial senescence through impairing PTEN-induced kinase 1 (PINK1)-mediated mitophagy, which led to RGC damage. Additionally, we found that replacement of senescent microglia in COH model of old mice with BMCs from young mice reversed RGC damage. CONCLUSION ATP-P2X7R induces microglia senescence by inhibiting PINK1-mediated mitophagy pathway. Specific inhibition of ATP-P2X7R may be a fundamental approach for targeted therapy of RGC injury in microglial aging-related glaucoma.
Collapse
Affiliation(s)
- Miao Wei
- Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, China
- Dalian Medical University, Dalian, 116000, China
| | - Guowei Zhang
- Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, China
| | - Zeyu Huang
- Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, China
| | - Xuemeng Ding
- Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, China
| | - Qing Sun
- Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, China
| | - Yujian Zhang
- Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, China
| | - Rongrong Zhu
- Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, China
| | - Huaijin Guan
- Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, China.
| | - Min Ji
- Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, 20 Xisi Road, Nantong, 226001, China.
| |
Collapse
|
6
|
Zhao J, Xiong J, Ning Y, Zhao J, Wang Z, Long L, He H, Gou J, Yin T, Tang X, Zhang Y. A triple crosslinked micelle-hydrogel lacrimal implant for localized and prolonged therapy of glaucoma. Eur J Pharm Biopharm 2023; 185:44-54. [PMID: 36841507 DOI: 10.1016/j.ejpb.2023.02.011] [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: 12/08/2022] [Revised: 02/05/2023] [Accepted: 02/20/2023] [Indexed: 02/27/2023]
Abstract
Glaucoma is a chronic disease that requires lifelong treatment, whereas, discomfort caused by frequent medication may affect the quality of life. Moreover, the therapeutic efficacy of traditional local administration was unsatisfactory due to the rapid ocular clearance mechanism and the ocular barrier. Herein, a triple crosslinked micelle-hydrogel lacrimal implant with low polymer content was fabricated for localized and prolonged therapy of glaucoma. Latanoprost and timolol were simultaneously entrapped in the PEG-PLA micelles with high encapsulation efficiency and further loaded into the triple crosslinked hydrogel, facilitating a double sustained release of drugs. Subsequently, the implant was constructed by a unique molecular orientation fixation technology, which enables the implant to be fixed in the lacrimal duct. The triple crosslinked micelle-hydrogel lacrimal implant manifested a distinguished physicochemical characterization to sustain the release of latanoprost and timolol. In vitro release experiment demonstrated the duration of two drugs was extended for up to 28 days. The in vivo test of elevated intraocular pressure (IOP) in a rabbit model revealed that the IOP-lowering effects were sustained longer than 28 days as expected. The relative pharmacological availability (PA) of lacrimal implants was 5.7 times greater than that of the eye drops. The results of the studies on ocular irritation and histological examination demonstrated the good safety of the lacrimal implant. In conclusion, the triple crosslinked micelle-hydrogel lacrimal implant could effectively lower the IOP with splendid compatibility, demonstrating the promising prospect in the long-term noninvasive treatment of glaucoma.
Collapse
Affiliation(s)
- Jingyi Zhao
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Jian Xiong
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Yun Ning
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Jiansong Zhao
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Zhipeng Wang
- School of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Linhui Long
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Haibing He
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Jingxing Gou
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Tian Yin
- School of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Xing Tang
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China
| | - Yu Zhang
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China.
| |
Collapse
|
7
|
Miao Y, Zhao GL, Cheng S, Wang Z, Yang XL. Activation of retinal glial cells contributes to the degeneration of ganglion cells in experimental glaucoma. Prog Retin Eye Res 2023; 93:101169. [PMID: 36736070 DOI: 10.1016/j.preteyeres.2023.101169] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/12/2023] [Accepted: 01/24/2023] [Indexed: 02/04/2023]
Abstract
Elevation of intraocular pressure (IOP) is a major risk factor for neurodegeneration in glaucoma. Glial cells, which play an important role in normal functioning of retinal neurons, are well involved into retinal ganglion cell (RGC) degeneration in experimental glaucoma animal models generated by elevated IOP. In response to elevated IOP, mGluR I is first activated and Kir4.1 channels are subsequently inhibited, which leads to the activation of Müller cells. Müller cell activation is followed by a complex process, including proliferation, release of inflammatory and growth factors (gliosis). Gliosis is further regulated by several factors. Activated Müller cells contribute to RGC degeneration through generating glutamate receptor-mediated excitotoxicity, releasing cytotoxic factors and inducing microglia activation. Elevated IOP activates microglia, and following morphological and functional changes, these cells, as resident immune cells in the retina, show adaptive immune responses, including an enhanced release of pro-inflammatory factors (tumor neurosis factor-α, interleukins, etc.). These ATP and Toll-like receptor-mediated responses are further regulated by heat shock proteins, CD200R, chemokine receptors, and metabotropic purinergic receptors, may aggravate RGC loss. In the optic nerve head, astrogliosis is initiated and regulated by a complex reaction process, including purines, transmitters, chemokines, growth factors and cytokines, which contributes to RGC axon injury through releasing pro-inflammatory factors and changing extracellular matrix in glaucoma. The effects of activated glial cells on RGCs are further modified by the interplay among different types of glial cells. This review is concluded by presenting an in-depth discussion of possible research directions in this field in the future.
Collapse
Affiliation(s)
- Yanying Miao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Guo-Li Zhao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Shuo Cheng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Zhongfeng Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
| | - Xiong-Li Yang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
| |
Collapse
|
8
|
Fu X, Feng S, Qin H, Yan L, Zheng C, Yao K. Microglia: The breakthrough to treat neovascularization and repair blood-retinal barrier in retinopathy. Front Mol Neurosci 2023; 16:1100254. [PMID: 36756614 PMCID: PMC9899825 DOI: 10.3389/fnmol.2023.1100254] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 01/03/2023] [Indexed: 01/24/2023] Open
Abstract
Microglia are the primary resident retinal macrophages that monitor neuronal activity in real-time and facilitate angiogenesis during retinal development. In certain retinal diseases, the activated microglia promote retinal angiogenesis in hypoxia stress through neurovascular coupling and guide neovascularization to avascular areas (e.g., the outer nuclear layer and macula lutea). Furthermore, continuously activated microglia secrete inflammatory factors and expedite the loss of the blood-retinal barrier which causes irreversible damage to the secondary death of neurons. In this review, we support microglia can be a potential cellular therapeutic target in retinopathy. We briefly describe the relevance of microglia to the retinal vasculature and blood-retinal barrier. Then we discuss the signaling pathway related to how microglia move to their destinations and regulate vascular regeneration. We summarize the properties of microglia in different retinal disease models and propose that reducing the number of pro-inflammatory microglial death and conversing microglial phenotypes from pro-inflammatory to anti-inflammatory are feasible for treating retinal neovascularization and the damaged blood-retinal barrier (BRB). Finally, we suppose that the unique properties of microglia may aid in the vascularization of retinal organoids.
Collapse
Affiliation(s)
- Xuefei Fu
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Shuyu Feng
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Huan Qin
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Lin Yan
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Caiyan Zheng
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Kai Yao
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China,College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China,*Correspondence: Kai Yao,
| |
Collapse
|
9
|
Ley-Ngardigal S, Bertolin G. Approaches to monitor ATP levels in living cells: where do we stand? FEBS J 2022; 289:7940-7969. [PMID: 34437768 DOI: 10.1111/febs.16169] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/30/2021] [Accepted: 08/25/2021] [Indexed: 01/14/2023]
Abstract
ATP is the most universal and essential energy molecule in cells. This is due to its ability to store cellular energy in form of high-energy phosphate bonds, which are extremely stable and readily usable by the cell. This energy is key for a variety of biological functions such as cell growth and division, metabolism, and signaling, and for the turnover of biomolecules. Understanding how ATP is produced and hydrolyzed with a spatiotemporal resolution is necessary to understand its functions both in physiological and in pathological contexts. In this review, first we will describe the organization of the electron transport chain and ATP synthase, the main molecular motor for ATP production in mitochondria. Second, we will review the biochemical assays currently available to estimate ATP quantities in cells, and we will compare their readouts, strengths, and weaknesses. Finally, we will explore the palette of genetically encoded biosensors designed for microscopy-based approaches, and show how their spatiotemporal resolution opened up the possibility to follow ATP levels in living cells.
Collapse
Affiliation(s)
- Seyta Ley-Ngardigal
- CNRS, Univ Rennes, IGDR (Genetics and Development Institute of Rennes), Rennes, France.,LVMH Research Perfumes and Cosmetics, Saint-Jean-de-Braye, France
| | - Giulia Bertolin
- CNRS, Univ Rennes, IGDR (Genetics and Development Institute of Rennes), Rennes, France
| |
Collapse
|
10
|
Wang Q, He R, Chen L, Zhang Q, Shan J, Wang P, Wang X, Zhao Y. MIG-23 is involved in sperm migration by modulating extracellular ATP levels in Ascaris suum. Development 2022; 149:275964. [DOI: 10.1242/dev.200478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 05/24/2022] [Indexed: 11/20/2022]
Abstract
ABSTRACT
In nematodes, spermiogenesis is a process of sperm activation in which nonmotile spermatids are transformed into crawling spermatozoa. Sperm motility acquisition during this process is essential for successful fertilization, but the underlying mechanisms remain to be clarified. Herein, we have found that extracellular adenosine-5′-triphosphate (ATP) level regulation by MIG-23, which is a homolog of human ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), was required for major sperm protein (MSP) filament dynamics and sperm motility in the nematode Ascaris suum. During sperm activation, a large amount of ATP was produced in mitochondria and was stored in refringent granules (RGs). Some of the produced ATP was released to the extracellular space through innexin channels. MIG-23 was localized in the sperm plasma membrane and contributed to the ecto-ATPase activity of spermatozoa. Blocking MIG-23 activity resulted in a decrease in the ATP hydrolysis activity of spermatozoa and an increase in the depolymerization rate of MSP filaments in pseudopodia, which eventually affected sperm migration. Overall, our data suggest that MIG-23, which contributes to the ecto-ATPase activity of spermatozoa, regulates sperm migration by modulating extracellular ATP levels.
Collapse
Affiliation(s)
- Qiushi Wang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences 1 , Beijing 100101 , China
| | - Ruijun He
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences 1 , Beijing 100101 , China
| | - Lianwan Chen
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences 1 , Beijing 100101 , China
| | - Qi Zhang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences 1 , Beijing 100101 , China
- University of Chinese Academy of Sciences 2 , Beijing 100049 , China
| | - Jin Shan
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences 1 , Beijing 100101 , China
- University of Chinese Academy of Sciences 2 , Beijing 100049 , China
| | - Peng Wang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences 1 , Beijing 100101 , China
- University of Chinese Academy of Sciences 2 , Beijing 100049 , China
| | - Xia Wang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences 1 , Beijing 100101 , China
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences 3 , Beijing 100101 , China
| | - Yanmei Zhao
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences 1 , Beijing 100101 , China
| |
Collapse
|
11
|
Molecular regulation of neuroinflammation in glaucoma: Current knowledge and the ongoing search for new treatment targets. Prog Retin Eye Res 2022; 87:100998. [PMID: 34348167 PMCID: PMC8803988 DOI: 10.1016/j.preteyeres.2021.100998] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 12/11/2022]
Abstract
Neuroinflammation relying on the inflammatory responses of glial cells has emerged as an impactful component of the multifactorial etiology of neurodegeneration in glaucoma. It has become increasingly evident that despite early adaptive and reparative features of glial responses, prolonged reactivity of the resident glia, along with the peripheral immune cells, create widespread toxicity to retinal ganglion cell (RGC) axons, somas, and synapses. As much as the synchronized responses of astrocytes and microglia to glaucoma-related stress or neuron injury, their bi-directional interactions are critical to build and amplify neuroinflammation and to dictate the neurodegenerative outcome. Although distinct molecular programs regulate somatic and axonal degeneration in glaucoma, inhibition of neurodegenerative inflammation can provide a broadly beneficial treatment strategy to rescue RGC integrity and function. Since inflammatory toxicity and mitochondrial dysfunction are converging etiological paths that can boost each other and feed into a vicious cycle, anti-inflammatory treatments may also offer a multi-target potential. This review presents an overview of the current knowledge on neuroinflammation in glaucoma with particular emphasis on the cell-intrinsic and cell-extrinsic factors involved in the reciprocal regulation of glial responses, the interdependence between inflammatory and mitochondrial routes of neurodegeneration, and the research aspects inspiring for prospective immunomodulatory treatments. With the advent of powerful technologies, ongoing research on molecular and functional characteristics of glial responses is expected to accumulate more comprehensive and complementary information and to rapidly move the field forward to safe and effective modulation of the glial pro-inflammatory activities, while restoring or augmenting the glial immune-regulatory and neurosupport functions.
Collapse
|
12
|
Losenkova K, Takeda A, Ragauskas S, Cerrada-Gimenez M, Vähätupa M, Kaja S, Paul ML, Schmies CC, Rolshoven G, Müller CE, Sandholm J, Jalkanen S, Kalesnykas G, Yegutkin GG. CD73 controls ocular adenosine levels and protects retina from light-induced phototoxicity. Cell Mol Life Sci 2022; 79:152. [PMID: 35212809 PMCID: PMC8881442 DOI: 10.1007/s00018-022-04187-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 01/28/2022] [Accepted: 02/04/2022] [Indexed: 01/03/2023]
Abstract
ATP and adenosine have emerged as important signaling molecules involved in vascular remodeling, retinal functioning and neurovascular coupling in the mammalian eye. However, little is known about the regulatory mechanisms of purinergic signaling in the eye. Here, we used three-dimensional multiplexed imaging, in situ enzyme histochemistry, flow cytometric analysis, and single cell transcriptomics to characterize the whole pattern of purine metabolism in mouse and human eyes. This study identified ecto-nucleoside triphosphate diphosphohydrolase-1 (NTPDase1/CD39), NTPDase2, and ecto-5′-nucleotidase/CD73 as major ocular ecto-nucleotidases, which are selectively expressed in the photoreceptor layer (CD73), optic nerve head, retinal vasculature and microglia (CD39), as well as in neuronal processes and cornea (CD39, NTPDase2). Specifically, microglial cells can create a spatially arranged network in the retinal parenchyma by extending and retracting their branched CD39high/CD73low processes and forming local “purinergic junctions” with CD39low/CD73− neuronal cell bodies and CD39high/CD73− retinal blood vessels. The relevance of the CD73–adenosine pathway was confirmed by flash electroretinography showing that pharmacological inhibition of adenosine production by injection of highly selective CD73 inhibitor PSB-12489 in the vitreous cavity of dark-adapted mouse eyes rendered the animals hypersensitive to prolonged bright light, manifested as decreased a-wave and b-wave amplitudes. The impaired electrical responses of retinal cells in PSB-12489-treated mice were not accompanied by decrease in total thickness of the retina or death of photoreceptors and retinal ganglion cells. Our study thus defines ocular adenosine metabolism as a complex and spatially integrated network and further characterizes the critical role of CD73 in maintaining the functional activity of retinal cells.
Collapse
Affiliation(s)
- Karolina Losenkova
- MediCity Research Laboratory and InFLAMES Flagship, University of Turku, Tykistökatu 6A, 20520, Turku, Finland
| | - Akira Takeda
- MediCity Research Laboratory and InFLAMES Flagship, University of Turku, Tykistökatu 6A, 20520, Turku, Finland
| | | | | | | | - Simon Kaja
- Experimentica Ltd., Kuopio, Finland.,Department of Ophthalmology, Loyola University Chicago, Stritch School of Medicine, Maywood, IL, USA
| | - Marius L Paul
- MediCity Research Laboratory and InFLAMES Flagship, University of Turku, Tykistökatu 6A, 20520, Turku, Finland.,Pharma Center Bonn, Pharmaceutical Institute, Pharmaceutical and Medicinal Chemistry, University of Bonn, Bonn, Germany
| | - Constanze C Schmies
- Pharma Center Bonn, Pharmaceutical Institute, Pharmaceutical and Medicinal Chemistry, University of Bonn, Bonn, Germany
| | - Georg Rolshoven
- Pharma Center Bonn, Pharmaceutical Institute, Pharmaceutical and Medicinal Chemistry, University of Bonn, Bonn, Germany
| | - Christa E Müller
- Pharma Center Bonn, Pharmaceutical Institute, Pharmaceutical and Medicinal Chemistry, University of Bonn, Bonn, Germany
| | - Jouko Sandholm
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Sirpa Jalkanen
- MediCity Research Laboratory and InFLAMES Flagship, University of Turku, Tykistökatu 6A, 20520, Turku, Finland
| | | | - Gennady G Yegutkin
- MediCity Research Laboratory and InFLAMES Flagship, University of Turku, Tykistökatu 6A, 20520, Turku, Finland.
| |
Collapse
|
13
|
McDowell CM, Kizhatil K, Elliott MH, Overby DR, van Batenburg-Sherwood J, Millar JC, Kuehn MH, Zode G, Acott TS, Anderson MG, Bhattacharya SK, Bertrand JA, Borras T, Bovenkamp DE, Cheng L, Danias J, De Ieso ML, Du Y, Faralli JA, Fuchshofer R, Ganapathy PS, Gong H, Herberg S, Hernandez H, Humphries P, John SWM, Kaufman PL, Keller KE, Kelley MJ, Kelly RA, Krizaj D, Kumar A, Leonard BC, Lieberman RL, Liton P, Liu Y, Liu KC, Lopez NN, Mao W, Mavlyutov T, McDonnell F, McLellan GJ, Mzyk P, Nartey A, Pasquale LR, Patel GC, Pattabiraman PP, Peters DM, Raghunathan V, Rao PV, Rayana N, Raychaudhuri U, Reina-Torres E, Ren R, Rhee D, Chowdhury UR, Samples JR, Samples EG, Sharif N, Schuman JS, Sheffield VC, Stevenson CH, Soundararajan A, Subramanian P, Sugali CK, Sun Y, Toris CB, Torrejon KY, Vahabikashi A, Vranka JA, Wang T, Willoughby CE, Xin C, Yun H, Zhang HF, Fautsch MP, Tamm ER, Clark AF, Ethier CR, Stamer WD. Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms. Invest Ophthalmol Vis Sci 2022; 63:12. [PMID: 35129590 PMCID: PMC8842499 DOI: 10.1167/iovs.63.2.12] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/08/2021] [Indexed: 01/07/2023] Open
Abstract
Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings.
Collapse
Affiliation(s)
- Colleen M. McDowell
- Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | | | - Michael H. Elliott
- University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Darryl R. Overby
- Department of Bioengineering, Imperial College London, United Kingdom
| | | | - J. Cameron Millar
- Department of Pharmacology & Neuroscience, and North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Markus H. Kuehn
- Department of Ophthalmology and Visual Sciences and Institute for Vision Research, The University of Iowa; Center for the Prevention and Treatment of Visual Loss, Veterans Affairs Medical Center, Iowa City, Iowa, United States
| | - Gulab Zode
- Department of Pharmacology & Neuroscience, and North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Ted S. Acott
- Ophthalmology and Biochemistry and Molecular Biology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Michael G. Anderson
- Department of Molecular Physiology and Biophysics and Department of Ophthalmology and Visual Sciences, The University of Iowa; Center for the Prevention and Treatment of Visual Loss, Veterans Affairs Medical Center, Iowa City, Iowa, United States
| | | | - Jacques A. Bertrand
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Terete Borras
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | | | - Lin Cheng
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - John Danias
- SUNY Downstate Health Sciences University, Brooklyn, New York, United States
| | - Michael Lucio De Ieso
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, North Carolina, United States
| | - Yiqin Du
- Department of Ophthalmology, University of Pittsburgh, Pennsylvania, United States
| | - Jennifer A. Faralli
- Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Rudolf Fuchshofer
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Preethi S. Ganapathy
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, New York, United States
| | - Haiyan Gong
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Samuel Herberg
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, New York, United States
| | | | - Peter Humphries
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Simon W. M. John
- Department of Ophthalmology, Columbia University, New York, New York, United States
| | - Paul L. Kaufman
- Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Kate E. Keller
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Mary J. Kelley
- Department of Ophthalmology and Department of Integrative Biosciences, Oregon Health & Science University, Portland, Oregon, United States
| | - Ruth A. Kelly
- Ocular Genetics Unit, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - David Krizaj
- Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City, Utah, United States
| | - Ajay Kumar
- Department of Ophthalmology, University of Pittsburgh, Pennsylvania, United States
| | - Brian C. Leonard
- Department of Surgical and Radiological Sciences, University of California, Davis, Davis, California, United States
| | - Raquel L. Lieberman
- Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Paloma Liton
- Department of Ophthalmology and Department of Pathology, Duke University, Durham, North Carolina, United States
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, James & Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
| | - Katy C. Liu
- Duke Eye Center, Duke Health, Durham, North Carolina, United States
| | - Navita N. Lopez
- Department of Neurobiology, University of Utah, Salt Lake City, Utah, United States
| | - Weiming Mao
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Timur Mavlyutov
- Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Fiona McDonnell
- Duke Eye Center, Duke Health, Durham, North Carolina, United States
| | - Gillian J. McLellan
- Department of Surgical Sciences and Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Philip Mzyk
- Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Andrews Nartey
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Louis R. Pasquale
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Gaurang C. Patel
- Ophthalmology Research, Regeneron Pharmaceuticals, Tarreytown, New York, United States
| | | | - Donna M. Peters
- Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | | | - Ponugoti Vasantha Rao
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, United States
| | - Naga Rayana
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Urmimala Raychaudhuri
- Department of Neurobiology, University of California, Irvine, Irvine, California, United States
| | - Ester Reina-Torres
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Ruiyi Ren
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Douglas Rhee
- Case Western Reserve University School of Medicine, Cleveland, Ohio, United States
| | - Uttio Roy Chowdhury
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - John R. Samples
- Washington State University, Floyd Elson College of Medicine, Spokane, Washington, United States
| | | | - Najam Sharif
- Santen Inc., Emeryville, California, United States
| | - Joel S. Schuman
- Department of Ophthalmology and Department of Physiology and Neuroscience, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, New York, United States; Departments of Biomedical Engineering and Electrical and Computer Engineering, New York University Tandon School of Engineering, Brooklyn, New York, United States; Center for Neural Science, College of Arts and Science, New York University, New York, New York, United States
| | - Val C. Sheffield
- Department of Pediatrics and Department of Ophthalmology and Visual Sciences, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
| | - Cooper H. Stevenson
- Department of Pharmacology & Neuroscience, and North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Avinash Soundararajan
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | | | - Chenna Kesavulu Sugali
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Yang Sun
- Veterans Affairs Palo Alto Health Care System, Stanford University, Palo Alto, California, United States
| | - Carol B. Toris
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States; Department of Ophthalmology and Vision Sciences, The Ohio State University, Columbus, Ohio, United States
| | | | - Amir Vahabikashi
- Cell and Developmental Biology Department, Northwestern University, Chicago, Illinois, United States
| | - Janice A. Vranka
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Ting Wang
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Colin E. Willoughby
- Genomic Medicine, Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland, United Kingdom
| | - Chen Xin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Hongmin Yun
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Hao F. Zhang
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois, United States
| | - Michael P. Fautsch
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois, United States
| | | | - Abbot F. Clark
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - C. Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology; Emory University School of Medicine, Emory University, Atlanta, Georgia, United States
| | - W. Daniel Stamer
- Duke Ophthalmology, Duke University, Durham, North Carolina, United States
| |
Collapse
|
14
|
Markitantova YV, Simirskii VN. The Role of the Purinergic Signaling System in the Control of Histogenesis, Homeostasis, and Pathogenesis of the Vertebrate Retina. Russ J Dev Biol 2021. [DOI: 10.1134/s1062360421060084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
15
|
Campagno KE, Lu W, Jassim AH, Albalawi F, Cenaj A, Tso HY, Clark SP, Sripinun P, Gómez NM, Mitchell CH. Rapid morphologic changes to microglial cells and upregulation of mixed microglial activation state markers induced by P2X7 receptor stimulation and increased intraocular pressure. J Neuroinflammation 2021; 18:217. [PMID: 34544431 PMCID: PMC8454080 DOI: 10.1186/s12974-021-02251-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/25/2021] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The identification of endogenous signals that lead to microglial activation is a key step in understanding neuroinflammatory cascades. As ATP release accompanies mechanical strain to neural tissue, and as the P2X7 receptor for ATP is expressed on microglial cells, we examined the morphological and molecular consequences of P2X7 receptor stimulation in vivo and in vitro and investigated the contribution of the P2X7 receptor in a model of increased intraocular pressure (IOP). METHODS In vivo experiments involved intravitreal injections and both transient and sustained elevation of IOP. In vitro experiments were performed on isolated mouse retinal and brain microglial cells. Morphological changes were quantified in vivo using Sholl analysis. Expression of mRNA for M1- and M2-like genes was determined with qPCR. The luciferin/luciferase assay quantified retinal ATP release while fura-2 indicated cytoplasmic calcium. Microglial migration was monitored with a Boyden chamber. RESULTS Sholl analysis of Iba1-stained cells showed retraction of microglial ramifications 1 day after injection of P2X7 receptor agonist BzATP into mouse retinae. Mean branch length of ramifications also decreased, while cell body size and expression of Nos2, Tnfa, Arg1, and Chil3 mRNA increased. BzATP induced similar morphological changes in ex vivo tissue isolated from Cx3CR1+/GFP mice, suggesting recruitment of external cells was unnecessary. Immunohistochemistry suggested primary microglial cultures expressed the P2X7 receptor, while functional expression was demonstrated with Ca2+ elevation by BzATP and block by specific antagonist A839977. BzATP induced process retraction and cell body enlargement within minutes in isolated microglial cells and increased Nos2 and Arg1. While ATP increased microglial migration, this required the P2Y12 receptor and not P2X7 receptor. Transient elevation of IOP led to microglial process retraction, cell body enlargement, and gene upregulation paralleling changes observed with BzATP injection, in addition to retinal ATP release. Pressure-dependent changes were reduced in P2X7-/- mice. Death of retinal ganglion cells accompanied increased IOP in C57Bl/6J, but not P2X7-/- mice, and neuronal loss showed some association with microglial activation. CONCLUSIONS P2X7 receptor stimulation induced rapid morphological activation of microglial cells, including process retraction and cell body enlargement, and upregulation of markers linked to both M1- and M2-type activation. Parallel responses accompanied IOP elevation, suggesting ATP release and P2X7 receptor stimulation influence the early microglial response to increased pressure.
Collapse
Affiliation(s)
- Keith E Campagno
- Department of Basic and Translational Science, University of Pennsylvania, 240 S. 40th St, Philadelphia, PA, 19104, USA
| | - Wennan Lu
- Department of Basic and Translational Science, University of Pennsylvania, 240 S. 40th St, Philadelphia, PA, 19104, USA
| | - Assraa Hassan Jassim
- Department of Basic and Translational Science, University of Pennsylvania, 240 S. 40th St, Philadelphia, PA, 19104, USA
| | - Farraj Albalawi
- Department of Orthodontics, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Preventive Dental Sciences, College of Dentistry, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
- King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Aurora Cenaj
- Department of Basic and Translational Science, University of Pennsylvania, 240 S. 40th St, Philadelphia, PA, 19104, USA
| | - Huen-Yee Tso
- Department of Basic and Translational Science, University of Pennsylvania, 240 S. 40th St, Philadelphia, PA, 19104, USA
| | - Sophia P Clark
- Department of Basic and Translational Science, University of Pennsylvania, 240 S. 40th St, Philadelphia, PA, 19104, USA
| | - Puttipong Sripinun
- Department of Orthodontics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Néstor Más Gómez
- Department of Basic and Translational Science, University of Pennsylvania, 240 S. 40th St, Philadelphia, PA, 19104, USA
| | - Claire H Mitchell
- Department of Basic and Translational Science, University of Pennsylvania, 240 S. 40th St, Philadelphia, PA, 19104, USA.
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| |
Collapse
|
16
|
Physalin pool from Physalis angulata L. leaves and physalin D inhibit P2X7 receptor function in vitro and acute lung injury in vivo. Biomed Pharmacother 2021; 142:112006. [PMID: 34392085 DOI: 10.1016/j.biopha.2021.112006] [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: 02/26/2021] [Revised: 07/14/2021] [Accepted: 08/01/2021] [Indexed: 11/23/2022] Open
Abstract
P2X7 receptor promotes inflammatory response and neuropathic pain. New drugs capable of impairing inflammation and pain-reducing adverse effects extracted from plant extracts have been studied. Physalis angulate L. possesses traditional uses and exhibits antiparasitic, anti-inflammatory, antimicrobial, antinociceptive, antimalarial, antileishmanial, immunosuppressive, antiasthmatic. diuretic, and antitumor activities. The most representative phytochemical constituents identified with medicinal importance are the physalins and withanolides. However, the mechanism of anti-inflammatory action is scarce. Although some physalins and withanolides subtypes have anti-inflammatory activity, only four physalins subtypes (B, D, F, and G) have further studies. Therefore, we evaluated the crude ethanolic extract enriched with physalins B, D, F, and G from P. angulata leaves, a pool containing the physalins B, D, F, G, and the physalins individually, as P2X7 receptor antagonists. For this purpose, we evaluated ATP-induced dye uptake, macroscopic currents, and interleukin 1-β (IL-1β) in vitro. The crude extract and pool dose-dependently inhibited P2X7 receptor function. Thus, physalin B, D, F, and G individually evaluated for 5'-triphosphate (ATP)-induced dye uptake assay, whole-cell patch-clamp, and cytokine release showed distinct antagonist levels. Physalin D displayed higher potency and efficacy than physalin B, F, and G for all these parameters. In vivo mice model as ATP-induced paw edema was potently inhibited for physalin D, in contrast to physalin B, F, and G. ATP and lipopolysaccharide (LPS)-induced pleurisy in mice were reversed for physalin D treatment. Molecular modeling and computational simulation predicted the intermolecular interactions between the P2X7 receptor and physalin derivatives. In silico results indicated physalin D and F as a potent allosteric P2X7 receptor antagonist. These data confirm physalin D as a promisor source for developing a new P2X7 receptor antagonist with anti-inflammatory action.
Collapse
|
17
|
Immune Responses in the Glaucomatous Retina: Regulation and Dynamics. Cells 2021; 10:cells10081973. [PMID: 34440742 PMCID: PMC8391899 DOI: 10.3390/cells10081973] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 12/27/2022] Open
Abstract
Glaucoma is a multifactorial disease resulting in progressive vision loss due to retinal ganglion cell (RGC) dysfunction and death. Early events in the pathobiology of the disease include oxidative, metabolic, or mechanical stress that acts upon RGC, causing these to rapidly release danger signals, including extracellular ATP, resulting in micro- and macroglial activation and neuroinflammation. Danger signaling also leads to the formation of inflammasomes in the retina that enable maturation of proinflammatory cytokines such IL-1β and IL-18. Chronic neuroinflammation can have directly damaging effects on RGC, but it also creates a proinflammatory environment and compromises the immune privilege of the retina. In particular, continuous synthesis of proinflammatory mediators such as TNFα, IL-1β, and anaphylatoxins weakens the blood–retina barrier and recruits or activates T-cells. Recent data have demonstrated that adaptive immune responses strongly exacerbate RGC loss in animal models of the disease as T-cells appear to target heat shock proteins displayed on the surface of stressed RGC to cause their apoptotic death. It is possible that dysregulation of these immune responses contributes to the continued loss of RGC in some patients.
Collapse
|
18
|
Jassim AH, Inman DM, Mitchell CH. Crosstalk Between Dysfunctional Mitochondria and Inflammation in Glaucomatous Neurodegeneration. Front Pharmacol 2021; 12:699623. [PMID: 34366851 PMCID: PMC8334009 DOI: 10.3389/fphar.2021.699623] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/22/2021] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial dysfunction and excessive inflammatory responses are both sufficient to induce pathology in age-dependent neurodegenerations. However, emerging evidence indicates crosstalk between damaged mitochondrial and inflammatory signaling can exacerbate issues in chronic neurodegenerations. This review discusses evidence for the interaction between mitochondrial damage and inflammation, with a focus on glaucomatous neurodegeneration, and proposes that positive feedback resulting from this crosstalk drives pathology. Mitochondrial dysfunction exacerbates inflammatory signaling in multiple ways. Damaged mitochondrial DNA is a damage-associated molecular pattern, which activates the NLRP3 inflammasome; priming and activation of the NLRP3 inflammasome, and the resulting liberation of IL-1β and IL-18 via the gasdermin D pore, is a major pathway to enhance inflammatory responses. The rise in reactive oxygen species induced by mitochondrial damage also activates inflammatory pathways, while blockage of Complex enzymes is sufficient to increase inflammatory signaling. Impaired mitophagy contributes to inflammation as the inability to turnover mitochondria in a timely manner increases levels of ROS and damaged mtDNA, with the latter likely to stimulate the cGAS-STING pathway to increase interferon signaling. Mitochondrial associated ER membrane contacts and the mitochondria-associated adaptor molecule MAVS can activate NLRP3 inflammasome signaling. In addition to dysfunctional mitochondria increasing inflammation, the corollary also occurs, with inflammation reducing mitochondrial function and ATP production; the resulting downward spiral accelerates degeneration. Evidence from several preclinical models including the DBA/2J mouse, microbead injection and transient elevation of IOP, in addition to patient data, implicates both mitochondrial damage and inflammation in glaucomatous neurodegeneration. The pressure-dependent hypoxia and the resulting metabolic vulnerability is associated with mitochondrial damage and IL-1β release. Links between mitochondrial dysfunction and inflammation can occur in retinal ganglion cells, microglia cells and astrocytes. In summary, crosstalk between damaged mitochondria and increased inflammatory signaling enhances pathology in glaucomatous neurodegeneration, with implications for other complex age-dependent neurodegenerations like Alzheimer's and Parkinson's disease.
Collapse
Affiliation(s)
- Assraa Hassan Jassim
- Department of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA, United States
| | - Denise M. Inman
- Department of Pharmaceutical Sciences, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Claire H. Mitchell
- Department of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA, United States
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, United States
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, United States
| |
Collapse
|
19
|
Multifactorial Pathogenic Processes of Retinal Ganglion Cell Degeneration in Glaucoma towards Multi-Target Strategies for Broader Treatment Effects. Cells 2021; 10:cells10061372. [PMID: 34199494 PMCID: PMC8228726 DOI: 10.3390/cells10061372] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/14/2021] [Accepted: 05/29/2021] [Indexed: 02/06/2023] Open
Abstract
Glaucoma is a chronic neurodegenerative disease characterized by apoptosis of retinal ganglion cell (RGC) somas, degeneration of axons, and loss of synapses at dendrites and axon terminals. Glaucomatous neurodegeneration encompasses multiple triggers, multiple cell types, and multiple molecular pathways through the etiological paths with biomechanical, vascular, metabolic, oxidative, and inflammatory components. As much as intrinsic responses of RGCs themselves, divergent responses and intricate interactions of the surrounding glia also play decisive roles for the cell fate. Seen from a broad perspective, multitarget treatment strategies have a compelling pathophysiological basis to more efficiently manipulate multiple pathogenic processes at multiple injury sites in such a multifactorial neurodegenerative disease. Despite distinct molecular programs for somatic and axonal degeneration, mitochondrial dysfunction and glia-driven neuroinflammation present interdependent processes with widespread impacts in the glaucomatous retina and optic nerve. Since dysfunctional mitochondria stimulate inflammatory responses and proinflammatory mediators impair mitochondria, mitochondrial restoration may be immunomodulatory, while anti-inflammatory treatments protect mitochondria. Manipulation of these converging routes may thus allow a unified treatment strategy to protect RGC axons, somas, and synapses. This review presents an overview of recent research advancements with emphasis on potential treatment targets to achieve the best treatment efficacy to preserve visual function in glaucoma.
Collapse
|
20
|
Retinal ganglion cell dysfunction in mice following acute intraocular pressure is exacerbated by P2X7 receptor knockout. Sci Rep 2021; 11:4184. [PMID: 33603067 PMCID: PMC7893065 DOI: 10.1038/s41598-021-83669-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/22/2020] [Indexed: 12/21/2022] Open
Abstract
There is increasing evidence for the vulnerability of specific retinal ganglion cell (RGC) types in those with glaucoma and in animal models. In addition, the P2X7-receptor (P2X7-R) has been suggested to contribute to RGC death following stimulation and elevated IOP, though its role in RGC dysfunction prior to death has not been examined. Therefore, we examined the effect of an acute, non-ischemic intraocular pressure (IOP) insult (50 mmHg for 30 min) on RGC function in wildtype mice and P2X7-R knockout (P2X7-KO) mice. We examined retinal function using electroretinogram recordings and individual RGC responses using multielectrode arrays, 3 days following acute IOP elevation. Immunohistochemistry was used to examine RGC cell death and P2X7-R expression in several RGC types. Acute intraocular pressure elevation produced pronounced dysfunction in RGCs; whilst other retinal neuronal responses showed lesser changes. Dysfunction at 3 days post-injury was not associated with RGC loss or changes in receptive field size. However, in wildtype animals, OFF-RGCs showed reduced spontaneous and light-elicited activity. In the P2X7-KO, both ON- and OFF-RGC light-elicited responses were reduced. Expression of P2X7-R in wildtype ON-RGC dendrites was higher than in other RGC types. In conclusion, OFF-RGCs were vulnerable to acute IOP elevation and their dysfunction was not rescued by genetic ablation of P2X7-R. Indeed, knockout of P2X7-R also caused ON-RGC dysfunction. These findings aid our understanding of how pressure affects RGC function and suggest treatments targeting the P2X7-R need to be carefully considered.
Collapse
|
21
|
Spinozzi E, Baldassarri C, Acquaticci L, Del Bello F, Grifantini M, Cappellacci L, Riccardo P. Adenosine receptors as promising targets for the management of ocular diseases. Med Chem Res 2021; 30:353-370. [PMID: 33519168 PMCID: PMC7829661 DOI: 10.1007/s00044-021-02704-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/01/2020] [Indexed: 12/15/2022]
Abstract
The ocular drug discovery arena has undergone a significant improvement in the last few years culminating in the FDA approvals of 8 new drugs. However, despite a large number of drugs, generics, and combination products available, it remains an urgent need to find breakthrough strategies and therapies for tackling ocular diseases. Targeting the adenosinergic system may represent an innovative strategy for discovering new ocular therapeutics. This review focused on the recent advance in the field and described the numerous nucleoside and non-nucleoside modulators of the four adenosine receptors (ARs) used as potential tools or clinical drug candidates.
Collapse
Affiliation(s)
- Eleonora Spinozzi
- School of Pharmacy Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Cecilia Baldassarri
- School of Pharmacy Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Laura Acquaticci
- School of Pharmacy Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Fabio Del Bello
- School of Pharmacy Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Mario Grifantini
- School of Pharmacy Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Loredana Cappellacci
- School of Pharmacy Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Petrelli Riccardo
- School of Pharmacy Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| |
Collapse
|
22
|
Santiago AR, Madeira MH, Boia R, Aires ID, Rodrigues-Neves AC, Santos PF, Ambrósio AF. Keep an eye on adenosine: Its role in retinal inflammation. Pharmacol Ther 2020; 210:107513. [PMID: 32109489 DOI: 10.1016/j.pharmthera.2020.107513] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adenosine is an endogenous purine nucleoside ubiquitously distributed throughout the body that interacts with G protein-coupled receptors, classified in four subtypes: A1R, A2AR, A2BR and A3R. Among the plethora of functions of adenosine, it has been increasingly recognized as a key mediator of the immune response. Neuroinflammation is a feature of chronic neurodegenerative diseases and contributes to the pathophysiology of several retinal degenerative diseases. Animal models of retinal diseases are helping to elucidate the regulatory roles of adenosine receptors in the development and progression of those diseases. Mounting evidence demonstrates that the adenosinergic system is altered in the retina during pathological conditions, compromising retinal physiology. This review focuses on the roles played by adenosine and the elements of the adenosinergic system (receptors, enzymes, transporters) in the neuroinflammatory processes occurring in the retina. An improved understanding of the molecular and cellular mechanisms of the signalling pathways mediated by adenosine underlying the onset and progression of retinal diseases will pave the way towards the identification of new therapeutic approaches.
Collapse
Affiliation(s)
- Ana Raquel Santiago
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal.
| | - Maria H Madeira
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal
| | - Raquel Boia
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Inês Dinis Aires
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Ana Catarina Rodrigues-Neves
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Paulo Fernando Santos
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - António Francisco Ambrósio
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal.
| |
Collapse
|
23
|
Transplantation of iPSC-TM stimulates division of trabecular meshwork cells in human eyes. Sci Rep 2020; 10:2905. [PMID: 32076077 PMCID: PMC7031365 DOI: 10.1038/s41598-020-59941-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 02/03/2020] [Indexed: 12/14/2022] Open
Abstract
The trabecular meshwork’s (TM) physiological role is to maintain normal intraocular pressure by regulating aqueous humor outflow. With age, and particularly in eyes with primary open angle glaucoma, the number of cells residing within the TM is markedly decreased and the function of the tissue is compromised. Here we evaluate if transplantation of induced pluripotent stem cell derived TM like cells (iPSC-TM) restores TM cellularity and function in human eyes obtained from older human donors. Human iPSC were differentiated into iPSC-TM and compared to primary TM cells by RNAseq. iPSC-TM were then injected into the anterior segments of human eyes maintained in perfusion culture. Seven and 14 days eyes after injection eyes that received iPSC-TM contained significantly more cells in the TM. Fewer than 1% of all cells appeared to be iPSC-TM, but significantly more cells in these eyes were immunopositive for Ki 67 and incorporated BrdU. Our study demonstrates that transplantation iPSC-TM stimulates proliferation of endogenous TM cells in perfusion cultured human eyes from aged donors. These data, in concert with our previous findings in animal models, suggest that functional regeneration of the TM may be possible in human eyes with primary open angle glaucoma.
Collapse
|
24
|
Lee Y, Kim MT, Rhodes G, Sack K, Son SJ, Rich CB, Kolachalama VB, Gabel CV, Trinkaus-Randall V. Sustained Ca2+ mobilizations: A quantitative approach to predict their importance in cell-cell communication and wound healing. PLoS One 2019; 14:e0213422. [PMID: 31017899 PMCID: PMC6481807 DOI: 10.1371/journal.pone.0213422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/11/2019] [Indexed: 01/12/2023] Open
Abstract
Epithelial wound healing requires the coordination of cells to migrate as a unit over the basement membrane after injury. To understand the process of this coordinated movement, it is critical to study the dynamics of cell-cell communication. We developed a method to characterize the injury-induced sustained Ca2+ mobilizations that travel between cells for periods of time up to several hours. These events of communication are concentrated along the wound edge and are reduced in cells further away from the wound. Our goal was to delineate the role and contribution of these sustained mobilizations and using MATLAB analyses, we determined the probability of cell-cell communication events in both in vitro models and ex vivo organ culture models. We demonstrated that the injury response was complex and represented the activation of a number of receptors. In addition, we found that pannexin channels mediated the cell-cell communication and motility. Furthermore, the sustained Ca2+ mobilizations are associated with changes in cell morphology and motility during wound healing. The results demonstrate that both purinoreceptors and pannexins regulate the sustained Ca2+ mobilization necessary for cell-cell communication in wound healing.
Collapse
Affiliation(s)
- Yoonjoo Lee
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Min Tae Kim
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Garrett Rhodes
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Kelsey Sack
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - Sung Jun Son
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Celeste B. Rich
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Vijaya B. Kolachalama
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Christopher V. Gabel
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Vickery Trinkaus-Randall
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| |
Collapse
|
25
|
Fletcher EL, Wang AY, Jobling AI, Rutar MV, Greferath U, Gu B, Vessey KA. Targeting P2X7 receptors as a means for treating retinal disease. Drug Discov Today 2019; 24:1598-1605. [PMID: 30954685 DOI: 10.1016/j.drudis.2019.03.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/07/2019] [Accepted: 03/29/2019] [Indexed: 12/28/2022]
Abstract
Age-related macular degeneration and glaucoma are the commonest causes of irreversible vision loss in industrialized countries. The purine ATP is known to regulate a range of cellular functions in the retina via its action on P2 receptors, especially the P2X7 receptor. Although agents that attenuate P2X7 receptor function have been in development for many years, no compound is currently approved for the treatment of eye disease. However, newer compounds that cross the blood-brain barrier could have potential to reduce vision loss. This review will outline recent information relating to the role of P2X7 in age-related macular degeneration and glaucoma and, subsequently, we will discuss recent developments for attenuating P2X7 receptor function.
Collapse
Affiliation(s)
- Erica L Fletcher
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville 3010, Victoria, Australia.
| | - Anna Y Wang
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Andrew I Jobling
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Matthew V Rutar
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Ursula Greferath
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Ben Gu
- Florey Institute of Neuroscience and Mental Health, Parkville 3010, Victoria, Australia
| | - Kirstan A Vessey
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville 3010, Victoria, Australia
| |
Collapse
|
26
|
Soluble and membrane-bound adenylate kinase and nucleotidases augment ATP-mediated inflammation in diabetic retinopathy eyes with vitreous hemorrhage. J Mol Med (Berl) 2019; 97:341-354. [PMID: 30617853 PMCID: PMC6394560 DOI: 10.1007/s00109-018-01734-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/23/2018] [Accepted: 12/17/2018] [Indexed: 12/28/2022]
Abstract
Abstract ATP and adenosine are important signaling molecules involved in vascular remodeling, retinal function, and neurovascular coupling in the eye. Current knowledge on enzymatic pathways governing the duration and magnitude of ocular purinergic signaling is incompletely understood. By employing sensitive analytical assays, this study dissected ocular purine homeostasis as a complex and coordinated network. Along with previously characterized ecto-5′-nucleotidase/CD73 and adenylate kinase activities, other enzymes have been identified in vitreous fluids, including nucleoside triphosphate diphosphohydrolase (NTPDase), adenosine deaminase, and alkaline phosphatase. Strikingly, activities of soluble adenylate kinase, adenosine deaminase, ecto-5′-nucleotidase/CD73, and alkaline phosphatase, as well as intravitreal concentrations of ATP and ADP, were concurrently upregulated in patients suffering from diabetic retinopathy (DR) with non-clearing vitreous hemorrhage (VH), when compared to DR eyes without VH and control eyes operated due to macular hole or pucker. Additional histochemical analysis revealed selective distribution of key ecto-nucleotidases (NTPDase1/CD39, NTPDase2, ecto-5′-nucleotidase/CD73, and alkaline phosphatase) in the human sensory neuroretina and optic nerve head, and also in pathological neofibrovascular tissues surgically excised from patients with advanced proliferative DR. Collectively, these data provide evidence for specific hemorrhage-related shifts in purine homeostasis in DR eyes from the generation of anti-inflammatory adenosine towards a pro-inflammatory and pro-angiogenic ATP-regenerating phenotype. In the future, identifying the exact mechanisms by which a broad spectrum of soluble and membrane-bound enzymes coordinately regulates ocular purine levels and the further translation of purine-converting enzymes as potential therapeutic targets in the treatment of proliferative DR and other vitreoretinal diseases will be an area of intense interest. Key messages NTPDase, alkaline phosphatase, and adenosine deaminase circulate in human vitreous. Purinergic enzymes are up-regulated in diabetic eyes with vitreous hemorrhage. Soluble adenylate kinase maintains high ATP levels in diabetic retinopathy eyes. Ecto-nucleotidases are co-expressed in the human retina and optic nerve head. Alkaline phosphatase is expressed on neovascular tissues excised from diabetic eyes.
Electronic supplementary material The online version of this article (10.1007/s00109-018-01734-0) contains supplementary material, which is available to authorized users.
Collapse
|
27
|
Ventura ALM, Dos Santos-Rodrigues A, Mitchell CH, Faillace MP. Purinergic signaling in the retina: From development to disease. Brain Res Bull 2018; 151:92-108. [PMID: 30458250 DOI: 10.1016/j.brainresbull.2018.10.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/14/2018] [Accepted: 10/23/2018] [Indexed: 02/07/2023]
Abstract
Retinal injuries and diseases are major causes of human disability involving vision impairment by the progressive and permanent loss of retinal neurons. During development, assembly of this tissue entails a successive and overlapping, signal-regulated engagement of complex events that include proliferation of progenitors, neurogenesis, cell death, neurochemical differentiation and synaptogenesis. During retinal damage, several of these events are re-activated with both protective and detrimental consequences. Purines and pyrimidines, along with their metabolites are emerging as important molecules regulating both retinal development and the tissue's responses to damage. The present review provides an overview of the purinergic signaling in the developing and injured retina. Recent findings on the presence of vesicular and channel-mediated ATP release by retinal and retinal pigment epithelial cells, adenosine synthesis and release, expression of receptors and intracellular signaling pathways activated by purinergic signaling in retinal cells are reported. The pathways by which purinergic receptors modulate retinal cell proliferation, migration and death of retinal cells during development and injury are summarized. The contribution of nucleotides to the self-repair of the injured zebrafish retina is also discussed.
Collapse
Affiliation(s)
- Ana Lucia Marques Ventura
- Department of Neurobiology, Neuroscience Program, Fluminense Federal University, Niterói, RJ, Brazil.
| | | | - Claire H Mitchell
- Department of Anatomy and Cell Biology, Ophthalmology, and Physiology, University of Pennsylvania, Philadelphia, PA 19104, United States.
| | - Maria Paula Faillace
- Instituto de Fisiología y Biofísica Prof. Bernardo Houssay (IFIBIO-Houssay), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina; Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
| |
Collapse
|
28
|
Zhang W, Zhou S, Liu G, Kong F, Chen S, Yan H. Multiple steps determine CD73 shedding from RPE: lipid raft localization, ARA1 interaction, and MMP-9 up-regulation. Purinergic Signal 2018; 14:443-457. [PMID: 30392016 DOI: 10.1007/s11302-018-9628-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 09/26/2018] [Indexed: 12/14/2022] Open
Abstract
Physiologically, retinal pigment epithelium (RPE) expresses high levels of CD73 in their membrane, converting AMP to immune suppressive adenosine, mediates an anti-inflammatory effect. However, after being exposed to inflammatory factors, RPE rapidly becomes CD73-negative cells, which render RPE's immune suppressive function and accelerate local inflammation. Here, we investigated the mechanism leading to the loss of membrane CD73 in RPE. We found the controversy that when membrane CD73 was significantly diminished in inflammatory RPE, Cd73 mRNA levels were not changed at all. It was further verified that, matrix metalloproteinase-9 (MMP-9) mediated the shedding of CD73 from the cell membrane of inflammatory RPE by catalyzing its K547/F548 site. However, MMP-9 could not catalyze uncomplexed CD73, the interaction of CD73 with adenosine receptor A1 subtype (ARA1) is necessary for being catalyzed by MMP-9. After being treated by LPS and TNF-α, the formation of CD73/ARA1 complex in RPE was verified by co-immunoprecipitation and FRET-based assays. It was also revealed that CD73 need to be localized in lipid rafts to be capable of interacting with ARA1, since CD73/ARA1 interaction and CD73 shedding were completely blocked by the addition of lipid raft synthesis inhibitor. As a conclusion, multiple steps are involved in CD73 shedding in RPE, including up-regulation of MMP-9 activity, localization of CD73 in lipid rafts, and the formation of CD73/ARA1 complex. Lipid rafts committed CD73 with high mobility, shuttled CD73 to ARA1 to form a complex, which was capable of being recognized and catalyzed by MMP-9.
Collapse
Affiliation(s)
- Wei Zhang
- Department of Strabismus, Tianjin Eye Disease Hospital, Tianjin, 300020, China
| | - Shumin Zhou
- Clinical laboratory, The 2nd hospital of Tianjin Medical University, Tianjin, 300211, China
| | - Guoping Liu
- Department of Neurology, Tianjin first central hospital, Tianjin, 300192, China
| | - Fanqiang Kong
- General hospital of Tianjin Medical University, Tianjin, 300052, China
| | - Song Chen
- General hospital of Tianjin Medical University, Tianjin, 300052, China.
| | - Hua Yan
- General hospital of Tianjin Medical University, Tianjin, 300052, China
| |
Collapse
|
29
|
Li T, Li L, Liu Z. Time Course Changes of the Mechanical Properties of the Iris Pigment Epithelium in a Rat Chronic Ocular Hypertension Model. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4862309. [PMID: 30420963 PMCID: PMC6215589 DOI: 10.1155/2018/4862309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/06/2018] [Accepted: 10/01/2018] [Indexed: 01/04/2023]
Abstract
BACKGROUND The flow field of aqueous humor correlates to the stiffness of iris pigment epithelium (IPE) which acts as a wall of posterior chamber. We focus on the variations of IPE stiffness in a rat ocular hypertension (OHT) model, so as to prepare for exploring the mechanism of duration of OHT. METHODS Episcleral venous cauterization (EVC) was applied on one eye of male adult Sprague-Dawley rats to induce chronic high intraocular pressure. According to the duration of OHT (0, 1, 2, 4, and 8 weeks), rats were randomly divided into Gw0, Gw1, Gw2, Gw4, and Gw8. Atomic force microscope (AFM) analysis was applied to test IPE stiffness in three regions: iris root, mid-periphery, and pupillary-margin in each group. Histological changes of IPE were also examined in Gw4 and Gw8. RESULTS There was an overall growing tendency of IPE stiffness in EVC eye. IPE in EVC eye was significantly stiffer than fellow eye in Gw2, Gw4, and Gw8 (in iris root, mid-periphery, and pupillary-margin, p<0.05). IPE in EVC eye in pupillary-margin was significantly stiffer than iris root in Gw4 and Gw8 (p<0.05). In EVC eye, IPE becomes thinner and IPE cell density decreases. CONCLUSION IPE stiffness increases gradually with the duration of chronic high intraocular pressure.
Collapse
Affiliation(s)
- Tan Li
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, China
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing 100069, China
| | - Lin Li
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, China
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing 100069, China
| | - Zhicheng Liu
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, China
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing 100069, China
| |
Collapse
|
30
|
Lakk M, Young D, Baumann JM, Jo AO, Hu H, Križaj D. Polymodal TRPV1 and TRPV4 Sensors Colocalize but Do Not Functionally Interact in a Subpopulation of Mouse Retinal Ganglion Cells. Front Cell Neurosci 2018; 12:353. [PMID: 30386208 PMCID: PMC6198093 DOI: 10.3389/fncel.2018.00353] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/20/2018] [Indexed: 01/23/2023] Open
Abstract
Retinal ganglion cells (RGCs) are projection neurons that transmit the visual signal from the retina to the brain. Their excitability and survival can be strongly influenced by mechanical stressors, temperature, lipid metabolites, and inflammatory mediators but the transduction mechanisms for these non-synaptic sensory inputs are not well characterized. Here, we investigate the distribution, functional expression, and localization of two polymodal transducers of mechanical, lipid, and inflammatory signals, TRPV1 and TRPV4 cation channels, in mouse RGCs. The most abundant vanilloid mRNA species was Trpv4, followed by Trpv2 and residual expression of Trpv3 and Trpv1. Immunohistochemical and functional analyses showed that TRPV1 and TRPV4 channels are expressed as separate molecular entities, with TRPV1-only (∼10%), TRPV4-only (∼40%), and TRPV1 + TRPV4 (∼10%) expressing RGC subpopulations. The TRPV1 + TRPV4 cohort included SMI-32-immunopositive alpha RGCs, suggesting potential roles for polymodal signal transduction in modulation of fast visual signaling. Arguing against obligatory heteromerization, optical imaging showed that activation and desensitization of TRPV1 and TRPV4 responses evoked by capsaicin and GSK1016790A are independent of each other. Overall, these data predict that RGC subpopulations will be differentially sensitive to mechanical and inflammatory stressors.
Collapse
Affiliation(s)
- Monika Lakk
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States
| | - Derek Young
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States
| | - Jackson M Baumann
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States.,Department of Bioengineering, University of Utah, Salt Lake City, UT, United States
| | - Andrew O Jo
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States
| | - Hongzhen Hu
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, United States
| | - David Križaj
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States.,Department of Bioengineering, University of Utah, Salt Lake City, UT, United States.,Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, United States
| |
Collapse
|
31
|
Makarenkova HP, Shah SB, Shestopalov VI. The two faces of pannexins: new roles in inflammation and repair. J Inflamm Res 2018; 11:273-288. [PMID: 29950881 PMCID: PMC6016592 DOI: 10.2147/jir.s128401] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Pannexins belong to a family of ATP-release channels expressed in almost all cell types. An increasing body of literature on pannexins suggests that these channels play dual and sometimes contradictory roles, contributing to normal cell function, as well as to the pathological progression of disease. In this review, we summarize our understanding of pannexin "protective" and "harmful" functions in inflammation, regeneration and mechanical signaling. We also suggest a possible basis for pannexin's dual roles, related to extracellular ATP and K+ levels and the activation of various types of P2 receptors that are associated with pannexin. Finally, we speculate upon therapeutic strategies related to pannexin using eyes, lacrimal glands, and peripheral nerves as examples of interesting therapeutic targets.
Collapse
Affiliation(s)
| | - Sameer B Shah
- Departments of Orthopaedic Surgery and Bioengineering, University of California.,Research Division, Veterans Affairs San Diego Healthcare System, San Diego, CA
| | - Valery I Shestopalov
- Bascom Eye Institute, Department of Ophthalmology, University of Miami, Miami, FL, USA.,Vavilov Institute for General Genetics, Russian Academy of Sciences.,Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
32
|
Pérez de Lara MJ, Guzmán-Aranguez A, Gómez-Villafuertes R, Gualix J, Miras-Portugal MT, Pintor J. Increased Ap 4A levels and ecto-nucleotidase activity in glaucomatous mice retina. Purinergic Signal 2018; 14:259-270. [PMID: 29948577 DOI: 10.1007/s11302-018-9612-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 05/22/2018] [Indexed: 10/14/2022] Open
Abstract
The pathogenesis of glaucoma involves numerous intracellular mechanisms including the purinergic system contribution. Furthermore, the presence and release of nucleotides and dinucleotides during the glaucomatous damage and the maintenance of degradation machinery through ecto-nucleotidase activity are participating in the modulation of the suitable extracellular complex balance. The aim of this study was to investigate the levels of diadenosine tetraphosphate (Ap4A) and the pattern of ecto-nucleotidase activity expression in glaucomatous retinas during the progress the pathology. Ap4A levels were analyzed by HPLC in glaucomatous retinas from the DBA/2J mice at 3, 9, 15, and 23 months of age. For that, retinas were dissected as flattened whole-mounts and stimulated in Ringer buffer with or without 59 mM KCl. NPP1 expression was analyzed by RT-PCR and western blot and its distribution was assessed by immunohistochemistry studies examined under confocal microscopy. Glaucomatous mice exhibited Ap4A values, which changed in stimulated retinas as long as the pathology progressed varying from 0.73 ± 0.04 (3 months) to 0.170 ± 0.05 pmol/mg retina (23 months). Concomitantly, NPP1 expression was significantly increased (82.15%) in the DBA/2J mice at 15 months. Furthermore, immunohistochemical studies showed that NPP1 labeling was stronger in OPL and IPL labeling tangentially in the vitreal part of the retina and was upregulated at 15 months of age. Our findings demonstrate that Ap4A decreased levels may be related with exacerbated activity of NPP1 protein in glaucomatous degeneration and in this way contributing to elucidate different mechanisms involved in retinal impairment in glaucomatous degeneration.
Collapse
Affiliation(s)
- María J Pérez de Lara
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Complutense University of Madrid, c/Arcos de Jalón 118, 28037, Madrid, Spain
| | - Ana Guzmán-Aranguez
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Complutense University of Madrid, c/Arcos de Jalón 118, 28037, Madrid, Spain
| | - Rosa Gómez-Villafuertes
- Department of Biochemistry and Molecular Biology IV, Faculty of Veterinary, Complutense University of Madrid, Av/ Puerta del Hierro s/n, 28040, Madrid, Spain
| | - Javier Gualix
- Department of Biochemistry and Molecular Biology IV, Faculty of Veterinary, Complutense University of Madrid, Av/ Puerta del Hierro s/n, 28040, Madrid, Spain
| | - María Teresa Miras-Portugal
- Department of Biochemistry and Molecular Biology IV, Faculty of Veterinary, Complutense University of Madrid, Av/ Puerta del Hierro s/n, 28040, Madrid, Spain
| | - Jesús Pintor
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Complutense University of Madrid, c/Arcos de Jalón 118, 28037, Madrid, Spain.
| |
Collapse
|
33
|
Beckel JM, Gómez NM, Lu W, Campagno KE, Nabet B, Albalawi F, Lim JC, Boesze-Battaglia K, Mitchell CH. Stimulation of TLR3 triggers release of lysosomal ATP in astrocytes and epithelial cells that requires TRPML1 channels. Sci Rep 2018; 8:5726. [PMID: 29636491 PMCID: PMC5893592 DOI: 10.1038/s41598-018-23877-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 03/16/2018] [Indexed: 01/25/2023] Open
Abstract
Cross-reactions between innate immunity, lysosomal function, and purinergic pathways may link signaling systems in cellular pathologies. We found activation of toll-like receptor 3 (TLR3) triggers lysosomal ATP release from both astrocytes and retinal pigmented epithelial (RPE) cells. ATP efflux was accompanied by lysosomal acid phosphatase and beta hexosaminidase release. Poly(I:C) alkalinized lysosomes, and lysosomal alkalization with bafilomycin or chloroquine triggered ATP release. Lysosomal rupture with glycyl-L-phenylalanine-2-naphthylamide (GPN) eliminated both ATP and acid phosphatase release. Secretory lysosome marker LAMP3 colocalized with VNUT, while MANT-ATP colocalized with LysoTracker. Unmodified membrane-impermeant 21-nt and "non-targeting" scrambled 21-nt siRNA triggered ATP and acid phosphatase release, while smaller 16-nt RNA was ineffective. Poly(I:C)-dependent ATP release was reduced by TBK-1 block and in TRPML1-/- cells, while TRPML activation with ML-SA1 was sufficient to release both ATP and acid phosphatase. The ability of poly(I:C) to raise cytoplasmic Ca2+ was abolished by removing extracellular ATP with apyrase, suggesting ATP release by poly(I:C) increased cellular signaling. Starvation but not rapamycin prevented lysosomal ATP release. In summary, stimulation of TLR3 triggers lysosomal alkalization and release of lysosomal ATP through activation of TRPML1; this links innate immunity to purinergic signaling via lysosomal physiology, and suggests even scrambled siRNA can influence these pathways.
Collapse
Affiliation(s)
- Jonathan M Beckel
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Néstor Más Gómez
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Wennan Lu
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Keith E Campagno
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Bardia Nabet
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Farraj Albalawi
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Orthodontics, University of Pennsylvania, Philadelphia, PA, USA
| | - Jason C Lim
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Claire H Mitchell
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA.
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA.
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
34
|
Neuroprotective effect of Qinggan Lishui formula on retinal ganglion cell apoptosis in a microbead-induced rat chronic glaucoma model. J TRADIT CHIN MED 2018. [DOI: 10.1016/j.jtcm.2018.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
35
|
Rodrigues-Neves AC, Aires ID, Vindeirinho J, Boia R, Madeira MH, Gonçalves FQ, Cunha RA, Santos PF, Ambrósio AF, Santiago AR. Elevated Pressure Changes the Purinergic System of Microglial Cells. Front Pharmacol 2018; 9:16. [PMID: 29416510 PMCID: PMC5787565 DOI: 10.3389/fphar.2018.00016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/05/2018] [Indexed: 12/20/2022] Open
Abstract
Glaucoma is the second cause of blindness worldwide and is characterized by the degeneration of retinal ganglion cells (RGCs) and optic nerve atrophy. Increased microglia reactivity is an early event in glaucoma that may precede the loss of RGCs, suggesting that microglia and neuroinflammation are involved in the pathophysiology of this disease. Although global changes of the purinergic system have been reported in experimental and human glaucoma, it is not known if this is due to alterations of the purinergic system of microglial cells, the resident immune cells of the central nervous system. We now studied if elevated hydrostatic pressure (EHP), mimicking ocular hypertension, changed the extracellular levels of ATP and adenosine and the expression, density and activity of enzymes, transporters and receptors defining the purinergic system. The exposure of the murine microglial BV-2 cell line to EHP increased the extracellular levels of ATP and adenosine, increased the density of ecto-nucleoside triphosphate diphosphohydrolase 1 (E-NTPDase1, CD39) and decreased the density of the equilibrative nucleotide transporter 2 as well as the activity of adenosine deaminase. The expression of adenosine A1 receptor also decreased, but the adenosine A3 receptor was not affected. Notably, ATP and adenosine selectively control migration rather than phagocytosis, both bolstered by EHP. The results show that the purinergic system is altered in microglia in conditions of elevated pressure. Understanding the impact of elevated pressure on the purinergic system will help to unravel the mechanisms underlying inflammation and neurodegeneration associated with glaucoma.
Collapse
Affiliation(s)
- Ana C Rodrigues-Neves
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Inês D Aires
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Joana Vindeirinho
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Raquel Boia
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Maria H Madeira
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Francisco Q Gonçalves
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Paulo F Santos
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | - António F Ambrósio
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image, Coimbra, Portugal
| | - Ana R Santiago
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image, Coimbra, Portugal
| |
Collapse
|
36
|
Burnstock G. Purinergic Signalling: Therapeutic Developments. Front Pharmacol 2017; 8:661. [PMID: 28993732 PMCID: PMC5622197 DOI: 10.3389/fphar.2017.00661] [Citation(s) in RCA: 263] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/05/2017] [Indexed: 12/15/2022] Open
Abstract
Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990's when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine) receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and biochemistry of purinergic signalling. More recently, the focus has been on the pathophysiology and therapeutic potential. There was early recognition of the use of P1 receptor agonists for the treatment of supraventricular tachycardia and A2A receptor antagonists are promising for the treatment of Parkinson's disease. Clopidogrel, a P2Y12 antagonist, is widely used for the treatment of thrombosis and stroke, blocking P2Y12 receptor-mediated platelet aggregation. Diquafosol, a long acting P2Y2 receptor agonist, is being used for the treatment of dry eye. P2X3 receptor antagonists have been developed that are orally bioavailable and stable in vivo and are currently in clinical trials for the treatment of chronic cough, bladder incontinence, visceral pain and hypertension. Antagonists to P2X7 receptors are being investigated for the treatment of inflammatory disorders, including neurodegenerative diseases. Other investigations are in progress for the use of purinergic agents for the treatment of osteoporosis, myocardial infarction, irritable bowel syndrome, epilepsy, atherosclerosis, depression, autism, diabetes, and cancer.
Collapse
Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical SchoolLondon, United Kingdom
- Department of Pharmacology and Therapeutics, The University of Melbourne, MelbourneVIC, Australia
| |
Collapse
|
37
|
Albalawi F, Lu W, Beckel JM, Lim JC, McCaughey SA, Mitchell CH. The P2X7 Receptor Primes IL-1β and the NLRP3 Inflammasome in Astrocytes Exposed to Mechanical Strain. Front Cell Neurosci 2017; 11:227. [PMID: 28848393 PMCID: PMC5550720 DOI: 10.3389/fncel.2017.00227] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 07/19/2017] [Indexed: 11/13/2022] Open
Abstract
Inflammatory responses play a key role in many neural pathologies, with localized signaling from the non-immune cells making critical contributions. The NLRP3 inflammasome is an important component of innate immune signaling and can link neural insult to chronic inflammation. The NLRP3 inflammasome requires two stages to contribute: priming and activation. The priming stage involves upregulation of inflammasome components while the activation stage results in the assembly and activation of the inflammasome complex. The priming step can be rate limiting and can connect insult to chronic inflammation, but our knowledge of the signals that regulate NLRP3 inflammasome priming in sterile inflammation is limited. This study examined the link between mechanical strain and inflammasome priming in neural systems. Transient non-ischemic elevation of intraocular pressure increased mRNA for inflammasome components IL-1β, NLRP3, ASC, and CASP1 in rat and mouse retinas. The elevation was greater 1 day after the insult, with the rise in IL-1β most pronounced. The P2X7 receptor was implicated in the mechanosensitive priming of IL-1β mRNA in vivo, as the antagonist Brilliant Blue G (BBG) blocked the increased expression, the agonist BzATP mimicked the pressure-dependent rise in IL-1β, and the rise was absent in P2X7 knockout mice. In vitro measurements from optic nerve head astrocytes demonstrated an increased expression of IL-1β following stretch or swelling. This increase in IL-1β was eliminated by degradation of extracellular ATP with apyrase, or by the block of pannexin hemichannels with carbenoxolone, probenecid, or 10panx1 peptide. The rise in IL-1β expression was also blocked by P2X7 receptor antagonists BBG, A839977 or A740003. The rise in IL-1β was prevented by blocking transcription factor NFκB with Bay 11-7082, while the swelling-dependent fall in NFκB inhibitor IκB-α was reduced by A839977 and in P2X7 knockout mice. In summary, mechanical trauma to the retina primed NLRP3 inflammasome components, but only if there was ATP release through pannexin hemichannels, and autostimulation of the P2X7 receptor. As the P2X7 receptor can also trigger stage two of inflammasome assembly and activation, the P2X7 receptor may have a central role in linking mechanical strain to neuroinflammation.
Collapse
Affiliation(s)
- Farraj Albalawi
- Department of Anatomy and Cell Biology, University of Pennsylvania, PhiladelphiaPA, United States.,Department of Orthodontics, University of Pennsylvania, PhiladelphiaPA, United States
| | - Wennan Lu
- Department of Anatomy and Cell Biology, University of Pennsylvania, PhiladelphiaPA, United States
| | - Jonathan M Beckel
- Department of Anatomy and Cell Biology, University of Pennsylvania, PhiladelphiaPA, United States.,Department of Pharmacology and Chemical Biology, Pittsburgh University, PittsburghPA, United States
| | - Jason C Lim
- Department of Anatomy and Cell Biology, University of Pennsylvania, PhiladelphiaPA, United States
| | - Stuart A McCaughey
- Department of Anatomy and Cell Biology, University of Pennsylvania, PhiladelphiaPA, United States
| | - Claire H Mitchell
- Department of Anatomy and Cell Biology, University of Pennsylvania, PhiladelphiaPA, United States.,Department of Ophthalmology, University of Pennsylvania, PhiladelphiaPA, United States.,Department of Physiology, University of Pennsylvania, PhiladelphiaPA, United States
| |
Collapse
|
38
|
Zhu W, Jain A, Gramlich OW, Tucker BA, Sheffield VC, Kuehn MH. Restoration of Aqueous Humor Outflow Following Transplantation of iPSC-Derived Trabecular Meshwork Cells in a Transgenic Mouse Model of Glaucoma. Invest Ophthalmol Vis Sci 2017; 58:2054-2062. [PMID: 28384726 PMCID: PMC6108236 DOI: 10.1167/iovs.16-20672] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Purpose Primary open-angle glaucoma (POAG) is particularly common in older individuals and associated with pathologic degeneration of the trabecular meshwork (TM). We have shown previously that transplantation of induced pluripotent stem cell (iPSC) derived TM cells restores aqueous humor dynamics in young transgenic mice expressing a pathogenic form of human myocilin (Tg-MYOCY437H). This study was designed to determine if this approach is feasible in older mice with more pronounced TM dysfunction. Methods Mouse iPSC were differentiated toward a TM cell phenotype (iPSC-TM) and injected into the anterior chamber of 6-month-old Tg-MYOCY437H or control mice. IOP and aqueous humor outflow facility were recorded for up to 3 months. Transmission electron microscopy, Western blot, and immunohistochemistry were performed to analyze TM morphology, quantify endoplasmic reticulum (ER) stress, and assess TM cellularity. Results A 12 weeks after transplantation, IOP in iPSC-TM recipients was statistically lower and outflow facility was significantly improved compared to untreated controls. The number of endogenous TM cells increased significantly in iPSC-TM recipients along with the appearance of TM cells immmunopositive for a marker of cellular division. Morphologically, transplantation of iPSC-TM preserves ER structure 12 weeks after transplantation. However, myocilin and calnexin expression levels remain elevated in transplanted eyes of these 9-month-old Tg-MYOCY437H mice, indicating that ER stress persists within the TM. Conclusions Transplantation of iPSC-TM can restore IOP and outflow facility in aged Tg-MYOCY437H mice. This type of stem cell–based therapy is a promising possibility for restoration of IOP control in some glaucoma patients.
Collapse
Affiliation(s)
- Wei Zhu
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States 2Center for the Prevention and Treatment of Visual Loss, Iowa City Veterans Affairs Medical Center, Iowa City, Iowa, United States
| | - Ankur Jain
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
| | - Oliver W Gramlich
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Budd A Tucker
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Val C Sheffield
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States 3Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States 4Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City, Iowa, United States
| | - Markus H Kuehn
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States 2Center for the Prevention and Treatment of Visual Loss, Iowa City Veterans Affairs Medical Center, Iowa City, Iowa, United States
| |
Collapse
|
39
|
Whyte-Fagundes P, Siu R, Brown C, Zoidl G. Pannexins in vision, hearing, olfaction and taste. Neurosci Lett 2017; 695:32-39. [PMID: 28495272 DOI: 10.1016/j.neulet.2017.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 04/06/2017] [Accepted: 05/05/2017] [Indexed: 12/25/2022]
Abstract
In mammals, the pannexin gene family consists of three members (Panx1, 2, 3), which represent a class of integral membrane channel proteins sharing some structural features with chordate gap junction proteins, the connexins. Since their discovery in the early 21st century, pannexin expression has been detected throughout the vertebrate body including eye, ear, nose and tongue, making the investigation of the roles of this new class of channel protein in health and disease very appealing. The localization in sensory organs, coupled with unique channel properties and associations with major signaling pathways make Panx1, and its relative's, significant contributors for fundamental functions in sensory perception. Until recently, cell-based studies were at the forefront of pannexin research. Lately, the availability of mice with genetic ablation of pannexins opened new avenues for testing pannexin functions and behavioural phenotyping. Although we are only at the beginning of understanding the roles of pannexins in health and disease, this review summarizes recent advances in elucidating the various emerging roles pannexins play in sensory systems, with an emphasis on unresolved conflicts.
Collapse
Affiliation(s)
- Paige Whyte-Fagundes
- Graduate Program In Biology, Faculty of Science, York University, Toronto, ON, Canada
| | - Ryan Siu
- Graduate Program In Biology, Faculty of Science, York University, Toronto, ON, Canada
| | - Cherie Brown
- Graduate Program In Biology, Faculty of Science, York University, Toronto, ON, Canada
| | - Georg Zoidl
- Department of Biology, Faculty of Science, York University, Toronto, ON, Canada; Center for Vision Research, York University, Toronto, ON, Canada.
| |
Collapse
|
40
|
Lu W, Albalawi F, Beckel JM, Lim JC, Laties AM, Mitchell CH. The P2X7 receptor links mechanical strain to cytokine IL-6 up-regulation and release in neurons and astrocytes. J Neurochem 2017; 141:436-448. [PMID: 28244110 DOI: 10.1111/jnc.13998] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 01/11/2017] [Accepted: 02/09/2017] [Indexed: 12/15/2022]
Abstract
Mechanical strain in neural tissues can lead to the up-regulation and release of multiple cytokines including interleukin 6 (IL-6). In the retina, the mechanosensitive release of ATP can autostimulate P2X7 receptors on both retinal ganglion cell neurons and optic nerve head astrocytes. Here, we asked whether the purinergic signaling contributed to the IL-6 response to increased intraocular pressure (IOP) in vivo, and stretch or swelling in vitro. Rat and mouse eyes were exposed to non-ischemic elevations in IOP to 50-60 mmHg for 4 h. A PCR array was used to screen cytokine changes, with quantitative (q)PCR used to confirm mRNA elevations and immunoblots used for protein levels. P2X7 antagonist Brilliant Blue G (BBG) and agonist (4-benzoyl-benzoyl)-ATP (BzATP) were injected intravitreally. ELISA was used to quantify IL-6 release from optic nerve head astrocytes or retinal ganglion cells. Receptor identity was confirmed pharmacologically and in P2X7-/- mice, acute elevation of IOP altered retinal expression of multiple cytokine genes. Elevation of IL-6 was greatest, with expression of IL1rn, IL24, Tnf, Csf1, and Lif also increased more than twofold, while expression of Tnfsf11, Gdf9, and Tnfsf4 were reduced. qPCR confirmed the rise in IL-6 and extracellular ATP marker ENTPD1, but not pro-apoptotic genes. Intravitreal injection of P2X7 receptor antagonist BBG prevented the pressure-dependent rise in IL-6 mRNA and protein in the rat retina, while injection of P2X7 receptor agonist BzATP was sufficient to elevate IL-6 expression. IOP elevation increased IL-6 in wild-type but not P2X7R knockout mice. Application of mechanical strain to isolated optic nerve head astrocytes increased IL-6 levels. This response was mimicked by agonist BzATP, but blocked by antagonists BBG and A839977. Stretch or BzATP led to IL-6 release from both astrocytes and isolated retinal ganglion cells. The mechanosensitive up-regulation and release of cytokine IL-6 from the retina involves the P2X7 receptor, with both astrocytes and neurons contributing to the response.
Collapse
Affiliation(s)
- Wennan Lu
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Farraj Albalawi
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Orthodontics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jonathan M Beckel
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pennsylvania, USA
| | - Jason C Lim
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Alan M Laties
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Claire H Mitchell
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
41
|
Zhao D, Nguyen CTO, Wong VHY, Lim JKH, He Z, Jobling AI, Fletcher EL, Chinnery HR, Vingrys AJ, Bui BV. Characterization of the Circumlimbal Suture Model of Chronic IOP Elevation in Mice and Assessment of Changes in Gene Expression of Stretch Sensitive Channels. Front Neurosci 2017; 11:41. [PMID: 28239332 PMCID: PMC5301305 DOI: 10.3389/fnins.2017.00041] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 01/19/2017] [Indexed: 12/30/2022] Open
Abstract
To consider whether a circumlimbal suture can be used to chronically elevate intraocular pressure (IOP) in mice and to assess its effect on retinal structure, function and gene expression of stretch sensitive channels. Anesthetized adult C57BL6/J mice had a circumlimbal suture (10/0) applied around the equator of one eye. In treated eyes (n = 23) the suture was left in place for 12 weeks whilst in sham control eyes the suture was removed at day two (n = 17). Contralateral eyes served as untreated controls. IOP was measured after surgery and once a week thereafter. After 12 weeks, electroretinography (ERG) was performed to assess photoreceptor, bipolar cell and retinal ganglion cell (RGC) function. Retinal structure was evaluated using optical coherence tomography. Retinae were processed for counts of ganglion cell density or for quantitative RT-PCR to quantify purinergic (P2x7, Adora3, Entpd1) or stretch sensitive channel (Panx1, Trpv4) gene expression. Immediately after suture application, IOP spiked to 33 ± 3 mmHg. After 1 day, IOP had recovered to 27 ± 3 mmHg. Between weeks 2 and 12, IOP remained elevated above baseline (control 14 ± 1 mmHg, ocular hypertensive 19 ± 1 mmHg). Suture removal at day 2 (Sham) restored IOP to baseline levels, where it remained through to week 12. ERG analysis showed that 12 weeks of IOP elevation reduced photoreceptor (−15 ± 4%), bipolar cell (−15 ± 4%) and ganglion cell responses (−19 ± 6%) compared to sham controls and respective contralateral eyes (untreated). The retinal nerve fiber layer was thinned in the presence of normal total retinal thickness. Ganglion cell density was reduced across all quadrants (superior −12 ± 5%; temporal, −7% ± 2%; inferior −9 ± 4%; nasal −8 ± 5%). Quantitative RT-PCR revealed a significant increase in Entpd1 gene expression (+11 ± 4%), whilst other genes were not significantly altered (P2x7, Adora3, Trpv4, Panx1). Our results show that circumlimbal ligation produces mild chronic ocular hypertension and retinal dysfunction in mice. Consistent with a sustained change to purinergic signaling we found an up-regulation of Entpd1.
Collapse
Affiliation(s)
- Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Jeremiah K H Lim
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Andrew I Jobling
- Department of Anatomy and Neuroscience, University of Melbourne Parkville, VIC, Australia
| | - Erica L Fletcher
- Department of Anatomy and Neuroscience, University of Melbourne Parkville, VIC, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| |
Collapse
|
42
|
Abstract
Glaucoma is both the most common optic neuropathy worldwide and the most common cause of irreversible blindness in the world. The only proven treatment for glaucomatous optic neuropathy is lowering the intraocular pressure, achieved with a variety of pharmacological, laser, and surgical approaches. Over the past 2 decades there has been much basic and clinical research into achieving treatment of the underlying optic nerve damage with neuroprotective approaches. However, none has resulted in regulatory approval based on successful phase 3 studies. This chapter discusses the reasons for this "lost in translation" aspect of glaucoma neuroprotection, and outlines issues at the laboratory and clinical trial level that need to be addressed for successful development of neuroprotective therapies.
Collapse
Affiliation(s)
- Leonard A Levin
- Department of Ophthalmology, McGill University, Montreal, QC, Canada
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- McGill Academic Eye Centre, 5252 de Maisonneuve West, Suite 400, Montreal, QC, Canada, H4A 3S5
- Department of Ophthalmology, University of Montreal, Montreal, QC, Canada
| |
Collapse
|
43
|
Zhao J, Zhu TH, Chen WC, Peng SM, Huang XS, Cho KS, Chen DF, Liu GS. Optic neuropathy and increased retinal glial fibrillary acidic protein due to microbead-induced ocular hypertension in the rabbit. Int J Ophthalmol 2016; 9:1732-1739. [PMID: 28003971 DOI: 10.18240/ijo.2016.12.05] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 09/19/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To characterize whether a glaucoma model with chronic elevation of the intraocular pressure (IOP) was able to be induced by anterior chamber injection of microbeads in rabbits. METHODS In order to screen the optimal dose of microbead injection, IOP was measured every 3d for 4wk using handheld applanation tonometer after a single intracameral injection of 10 µL, 25 µL, 50 µL or 100 µL microbeads (5×106 beads/mL; n=6/group) in New Zealand White rabbits. To prolong IOP elevation, two intracameral injections of 50 µL microbeads or phosphate buffer saline (PBS) were made respectively at days 0 and 21 (n=24/group). The fellow eye was not treated. At 5wk after the second injection of microbeads or PBS, bright-field microscopy and transmission electron microscopy (TEM) were used to assess the changes in the retina. The expression of glial fibrillary acidic protein (GFAP) in the retina was evaluated by immunofluorescence, quantitative real-time polymerase chain reaction and Western blot at 5wk after the second injection of microbeads. RESULTS Following a single intracameral injection of 10 µL, 25 µL, 50 µL or 100 µL microbead, IOP levels showed a gradual increase and a later decrease over a 4wk period after a single injection of microbead into the anterior chamber of rabbits. A peak IOP was observed at day 15 after injection. No significant difference in peak value of IOP was found between 10 µL and 25 µL groups (17.13±1.25 mm Hg vs 17.63±0.74 mm Hg; P=0.346). The peak value of IOP from 50 µL group (23.25±1.16 mm Hg) was significantly higher than 10 µL and 25 µL groups (all P<0.05). Administration of 100 µL microbead solution (23.00±0.93 mm Hg) did not lead to a significant increase in IOP compared to the 50 µL group (P=0.64). A prolonged elevated IOP duration up to 8wk was achieved by administering two injections of 50 µL microbeads (20.48±1.21 mm Hg vs 13.60±0.90 mm Hg in PBS-injected group; P<0.05). The bright-field and TEM were used to assess the changes of retinal ganglion cells (RGCs). Compared with PBS-injected group, the extended IOP elevation was associated with the degeneration of optic nerve, the reduction of RGC axons (47.16%, P<0.05) and the increased GFAP expression in the retina (4.74±1.10 vs 1.00±0.46, P<0.05). CONCLUSION Two injections of microbeads into the ocular anterior chamber of rabbits lead to a prolonged IOP elevation which results in structural abnormality as well as loss in RGCs and their axons without observable ocular structural damage or inflammatory response. We have therefore established a novel and practical model of experimental glaucoma in rabbits.
Collapse
Affiliation(s)
- Jun Zhao
- School of Ophthalmology & Optometry Affiliated to Shenzhen University, Shenzhen 518040, Guangdong Province, China; Shenzhen Eye Hospital Affiliated to Jinan University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, Guangdong Province, China
| | - Tian-Hui Zhu
- Shenzhen Eye Hospital Affiliated to Jinan University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, Guangdong Province, China
| | - Wen-Chieh Chen
- Shenzhen Eye Hospital Affiliated to Jinan University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, Guangdong Province, China
| | - Shi-Ming Peng
- Shenzhen Eye Hospital Affiliated to Jinan University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, Guangdong Province, China
| | - Xiao-Sheng Huang
- Shenzhen Eye Hospital Affiliated to Jinan University, Shenzhen Key Laboratory of Ophthalmology, Shenzhen 518040, Guangdong Province, China
| | - Kin-Sang Cho
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston 02114, USA
| | - Dong Feng Chen
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston 02114, USA
| | - Guei-Sheung Liu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne 3002, Australia; Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne 3002, Australia
| |
Collapse
|
44
|
Lim JC, Lu W, Beckel JM, Mitchell CH. Neuronal Release of Cytokine IL-3 Triggered by Mechanosensitive Autostimulation of the P2X7 Receptor Is Neuroprotective. Front Cell Neurosci 2016; 10:270. [PMID: 27932954 PMCID: PMC5120082 DOI: 10.3389/fncel.2016.00270] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/07/2016] [Indexed: 12/05/2022] Open
Abstract
Mechanical strain due to increased pressure or swelling activates inflammatory responses in many neural systems. As cytokines and chemokine messengers lead to both pro-inflammatory and neuroprotective actions, understanding the signaling patterns triggered by mechanical stress may help improve overall outcomes. While cytokine signaling in neural systems is often associated with glial cells like astrocytes and microglia, the contribution of neurons themselves to the cytokine response is underappreciated and has bearing on any balanced response. Mechanical stretch of isolated neurons was previously shown to trigger ATP release through pannexin hemichannels and autostimulation of P2X7 receptors (P2X7Rs) on the neural membrane. Given that P2X7Rs are linked to cytokine activation in other cells, this study investigates the link between neuronal stretch and cytokine release through a P2X7-dependent pathway. Cytokine assays showed application of a 4% strain to isolated rat retinal ganglion cells (RGCs) released multiple cytokines. The P2X7R agonist BzATP also released multiple cytokines; Interleukin 3 (IL-3), TNF-α, CXCL9, VEGF, L-selectin, IL-4, GM-CSF, IL-10, IL-1Rα, MIP and CCL20 were released by both stimuli, with the release of IL-3 greatest with either stimuli. Stretch-dependent IL-3 release was confirmed with ELISA and blocked by P2X7R antagonists A438079 and Brilliant Blue G (BBG), implicating autostimulation of the P2X7R in stretch-dependent IL-3 release. Neuronal IL-3 release triggered by BzATP required extracellular calcium. The IL-3Rα receptor was expressed on RGCs but not astrocytes, and both IL-3Rα and IL-3 itself were predominantly expressed in the retinal ganglion cell layer of adult retinal sections, implying autostimulation of receptors by released IL-3. While the number of surviving ganglion cells decreased with time in culture, the addition of IL-3 protected against this loss of neurons. Expression of mRNA for IL-3 and IL-3Rα increased in rat retinas stretched with moderate intraocular pressure (IOP) elevation; BBG blocked the rise in IL-3, implicating a role for the P2X7R in transcriptional regulation in vivo. In summary, mechanical stretch triggers release of cytokines from neurons that can convey neuroprotection. The enhancement of these signals in vivo implicates P2X7R-mediated IL-3 signaling as an endogenous pathway that could minimize damage following neuronal exposure to chronic mechanical strain.
Collapse
Affiliation(s)
- Jason C Lim
- Department of Anatomy and Cell Biology, University of Pennsylvania Philadelphia, PA, USA
| | - Wennan Lu
- Department of Anatomy and Cell Biology, University of Pennsylvania Philadelphia, PA, USA
| | - Jonathan M Beckel
- Department of Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA
| | - Claire H Mitchell
- Department of Anatomy and Cell Biology, University of PennsylvaniaPhiladelphia, PA, USA; Department of Physiology, University of PennsylvaniaPhiladelphia, PA, USA; Department of Ophthalmology, University of PennsylvaniaPhiladelphia, PA, USA
| |
Collapse
|
45
|
Deregulation of ocular nucleotide homeostasis in patients with diabetic retinopathy. J Mol Med (Berl) 2016; 95:193-204. [PMID: 27638339 DOI: 10.1007/s00109-016-1472-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/31/2016] [Accepted: 09/07/2016] [Indexed: 10/21/2022]
Abstract
Clear signaling roles for ATP and adenosine have been established in all tissues, including the eye. The magnitude of signaling responses is governed by networks of enzymes; however, little is known about the regulatory mechanisms of purinergic signaling in the eye. By employing thin-layer chromatographic assays with 3H-labeled substrates, this study aimed to evaluate the role of nucleotide homeostasis in the pathogenesis of vitreoretinal diseases in humans. We have identified soluble enzymes ecto-5'-nucleotidase/CD73, adenylate kinase-1, and nucleoside diphosphate kinase in the vitreous fluid that control active cycling between pro-inflammatory ATP and anti-inflammatory adenosine. Strikingly, patients with proliferative form of diabetic retinopathy (DR) had higher adenylate kinase activity and ATP concentration, when compared to non-proliferative DR eyes and non-diabetic controls operated for rhegmatogenous retinal detachment, macular hole, and pucker. The non-parametric correlation analysis revealed positive correlations between intravitreal adenylate kinase and concentrations of ATP, ADP, and other angiogenic (angiopoietins-1 and -2), profibrotic (transforming growth factor-β1), and proteolytic (matrix metalloproteinase-9) factors but not erythropoietin and VEGF. Immunohistochemical staining of postmortem human retina additionally revealed selective expression of ecto-5'-nucleotidase/CD73 on the rod-and-cone-containing photoreceptor cells. Collectively, these findings provide novel insights into the regulatory mechanisms that influence purinergic signaling in diseased eye and open up new possibilities in the development of enzyme-targeted therapeutic approaches for prevention and treatment of DR. KEY MESSAGE Ecto-5'-nucleotidase/CD73 and adenylate kinase-1 circulate in human vitreous fluid. Adenylate kinase activity is high in diabetic eyes with proliferative retinopathy. Diabetic eyes display higher intravitreal ATP/ADP ratio than non-diabetic controls. Soluble adenylate kinase maintains resynthesis of inflammatory ATP in diabetic eyes.
Collapse
|
46
|
Mac Nair CE, Schlamp CL, Montgomery AD, Shestopalov VI, Nickells RW. Retinal glial responses to optic nerve crush are attenuated in Bax-deficient mice and modulated by purinergic signaling pathways. J Neuroinflammation 2016; 13:93. [PMID: 27126275 PMCID: PMC4850653 DOI: 10.1186/s12974-016-0558-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 04/20/2016] [Indexed: 01/14/2023] Open
Abstract
Background Retinal ganglion cell (RGC) soma death is a consequence of optic nerve damage, including in optic neuropathies like glaucoma. The activation of the innate immune network in the retina after nerve damage has been linked to RGC pathology. Since the eye is immune privileged, innate immune functions are the responsibility of the glia, specifically the microglia, astrocytes, and Müller cells that populate the retina. Glial activation, leading to the production of inflammatory cytokines, is a hallmark feature of retinal injury resulting from optic nerve damage and purported to elicit secondary degeneration of RGC somas. Methods A mouse model of optic nerve crush (ONC) was used to study retinal glial activation responses. RGC apoptosis was blocked using Bax-deficient mice. Glial activation responses were monitored by quantitative PCR and immunofluorescent labeling in retinal sections of activation markers. ATP signaling pathways were interrogated using P2X receptor agonists and antagonists and Pannexin 1 (Panx1)-deficient mice with RGC-specific deletion. Results ONC induced activation of both macroglia and microglia in the retina, and both these responses were dramatically muted if RGC death was blocked by deletion of the Bax gene. Macroglial, but not microglial, activation was modulated by purinergic receptor activation. Release of ATP after optic nerve damage was not mediated by PANX1 channels in RGCs. Conclusions RGC death in response to ONC plays a principal stimulatory role in the retinal glial activation response. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0558-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Caitlin E Mac Nair
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A Medical Sciences-1300 University Ave, Madison, WI, 53706, USA.,Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, 3170-10K/L MFCB, 1685 Highland Avenue, Madison, WI, 53705, USA
| | - Cassandra L Schlamp
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A Medical Sciences-1300 University Ave, Madison, WI, 53706, USA
| | - Angela D Montgomery
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A Medical Sciences-1300 University Ave, Madison, WI, 53706, USA
| | - Valery I Shestopalov
- Department of Ophthalmology, University of Miami Miller School of Medicine, 900 N.W. 17th Street, Miami, FL, 33136, USA.,Department of Cell Biology and Anatomy, University of Miami Miller School of Medicine, 900 N.W. 17th Street, Miami, FL, 33136, USA
| | - Robert W Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, 571A Medical Sciences-1300 University Ave, Madison, WI, 53706, USA.
| |
Collapse
|
47
|
Minns MS, Teicher G, Rich CB, Trinkaus-Randall V. Purinoreceptor P2X7 Regulation of Ca(2+) Mobilization and Cytoskeletal Rearrangement Is Required for Corneal Reepithelialization after Injury. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 186:285-96. [PMID: 26683661 DOI: 10.1016/j.ajpath.2015.10.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 10/05/2015] [Accepted: 10/16/2015] [Indexed: 01/17/2023]
Abstract
The process of wound healing involves a complex network of signaling pathways working to promote rapid cell migration and wound closure. Activation of purinergic receptors by secreted nucleotides plays a major role in calcium mobilization and the subsequent calcium-dependent signaling that is essential for proper healing. The role of the purinergic receptor P2X7 in wound healing is still relatively unknown. We demonstrate that P2X7 expression increases at the leading edge of corneal epithelium after injury in an organ culture model, and that this change occurs despite an overall decrease in P2X7 expression throughout the epithelium. Inhibition of P2X7 prevents this change in localization after injury and impairs wound healing. In cell culture, P2X7 inhibition attenuates the amplitude and duration of injury-induced calcium mobilization in cells at the leading edge. Immunofluorescence analysis of scratch-wounded cells reveals that P2X7 inhibition results in an overall decrease in the number of focal adhesions along with a concentration of focal adhesions at the wound margin. Live cell imaging of green fluorescent protein-labeled actin and talin shows that P2X7 inhibition alters actin cytoskeletal rearrangements and focal adhesion dynamics after injury. Together, these data demonstrate that P2X7 plays a critical role in mediating calcium signaling and coordinating cytoskeletal rearrangement at the leading edge, both of which processes are early signaling events necessary for proper epithelial wound healing.
Collapse
Affiliation(s)
- Martin S Minns
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts
| | - Gregory Teicher
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts
| | - Celeste B Rich
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts
| | - Vickery Trinkaus-Randall
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts.
| |
Collapse
|