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Musa M, Chukwuyem E, Ojo OM, Topah EK, Spadea L, Salati C, Gagliano C, Zeppieri M. Unveiling Ocular Manifestations in Systemic Lupus Erythematosus. J Clin Med 2024; 13:1047. [PMID: 38398361 PMCID: PMC10889738 DOI: 10.3390/jcm13041047] [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: 12/04/2023] [Revised: 01/29/2024] [Accepted: 02/09/2024] [Indexed: 02/25/2024] Open
Abstract
Systemic Lupus Erythematosus (SLE) is a complex autoimmune disorder characterized by immune dysregulation and multi-organ involvement. In this concise brief review, we highlight key insights into Ocular Systemic Lupus Erythematosus (SLE), an intricate autoimmune disorder with diverse organ involvement. Emphasizing the formation of autoantibodies and immune complex deposition, we delve into the inflammation and damage affecting ocular structures. Clinical presentations, ranging from mild dry eye syndrome to severe conditions like retinal vasculitis, necessitate a comprehensive diagnostic approach, including clinical exams, serological testing, and imaging studies. Differential diagnosis involves distinguishing SLE-related ocular manifestations from other autoimmune and non-inflammatory ocular conditions. The multidisciplinary management approach, involving rheumatologists, ophthalmologists, and immunologists, tailors treatment based on ocular involvement severity, encompassing corticosteroids, immunosuppressive agents, and biologics. Follow-up is crucial for monitoring disease progression and treatment response. Future perspectives revolve around advancing molecular understanding, refining diagnostic tools, and exploring targeted therapies. Novel research areas include genetic factors, microbiome composition, and biotechnology for tailored and effective SLE ocular treatments.
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Affiliation(s)
- Mutali Musa
- Department of Optometry, University of Benin, Benin City 300238, Nigeria;
- Centre for Sight Africa, Onitsha 434112, Nigeria
| | | | - Oluwasola Michael Ojo
- School of Optometry and Vision Sciences, College of Health Sciences, University of Ilorin, Ilorin 240003, Nigeria
| | - Efioshiomoshi Kings Topah
- Department of Optometry, Faculty of Allied Health Sciences, College of Health Sciences, Bayero University, Kano 700006, Nigeria
| | - Leopoldo Spadea
- Eye Clinic, Policlinico Umberto I, “Sapienza” University of Rome, 00142 Rome, Italy
| | - Carlo Salati
- Department of Ophthalmology, University Hospital of Udine, 33100 Udine, Italy
| | - Caterina Gagliano
- Faculty of Medicine and Surgery, University of Enna “Kore”, Piazza Dell’Università, 94100 Enna, Italy
- Eye Clinic, Catania University San Marco Hospital, Viale Carlo Azeglio Ciampi, 95121 Catania, Italy
| | - Marco Zeppieri
- Department of Ophthalmology, University Hospital of Udine, 33100 Udine, Italy
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Su JW, Li SF, Tao JJ, Xu YY, Wang K, Qian XW, Deng G, Peng XQ, Chen FH. Estrogen protects against acidosis-mediated articular chondrocyte injury by promoting ASIC1a protein degradation. Eur J Pharmacol 2021; 908:174381. [PMID: 34310912 DOI: 10.1016/j.ejphar.2021.174381] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 11/25/2022]
Abstract
Epidemiological data suggest that the incidence of rheumatoid arthritis (RA) increases in postmenopausal women, which may be related to estrogen deficiency. Tissue acidosis is a common symptom of RA. Acid-sensitive ion channel 1a (ASIC1a), a member of the extracellular H+-activated cation channel family, could be activated by changes in extracellular pH and plays a crucial role in the pathogenesis of RA. As the only cellular component in cartilage tissue, chondrocytes play an extremely important role in maintaining cartilage tissue homeostasis. The aim of this study was to investigate whether estrogen could protect acid-stimulated chondrocytes by regulating the expression of ASIC1a and explore the possible mechanism. The results showed that estrogen could protect against acid-induced chondrocyte injury by reducing ASIC1a protein expression. Moreover, lysosome inhibitor chloroquine (CQ) and autophagy inhibitor 3-methyladeniine (3-MA) could reverse the reduction of ASIC1a protein caused by estrogen, indicating that autophagy-lysosome pathway contributes to estrogen-induced degradation of ASIC1a protein. Furthermore, the down-regulation of ASIC1a expression by estrogen was attenuated by MPP, a specific inhibitor of estrogen-related receptor-alpha (Esrra), indicating that Esrra is involved in the process of estrogen regulating the expression of ASIC1a. Additionally, adenosine 5'-monophosphate (AMP)-activated protein kinase/unc-51-like kinase 1 (AMPK-ULK1) signaling pathway was activated by estrogen treatment, which was abrogated by Esrra-silencing, and AMPK-specific inhibitor Compound C pretreatment could reduce estrogen-induced downregulation of ASIC1a protein. Taken together, these results indicate that estrogen could promote autophagy-lysosome pathway-dependent ASIC1a protein degradation and protect against acidosis-induced cytotoxicity, the mechanisms of which might relate to Esrra-AMPK-ULK1 signaling pathway.
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Affiliation(s)
- Jing-Wen Su
- The Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, 230032, China
| | - Shu-Fang Li
- The Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, 230032, China
| | - Jing-Jing Tao
- The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, 230032, China; Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, 230032, China
| | - Ya-Yun Xu
- The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, 230032, China; Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, 230032, China
| | - Ke Wang
- The Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, 230032, China
| | - Xue-Wen Qian
- The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, 230032, China; Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, 230032, China
| | - Ge Deng
- The Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, 230032, China
| | - Xiao-Qing Peng
- The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, 230032, China; Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, 230032, China
| | - Fei-Hu Chen
- The Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, 230032, China.
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Wang G, Zhuo N, Liao Z, Qi W, Tian F, Wen Z, Li J. Retinal toxicity caused by hydroxychloroquine in patients with systemic lupus erythematosus: A case report. Medicine (Baltimore) 2021; 100:e25688. [PMID: 34087822 PMCID: PMC8183791 DOI: 10.1097/md.0000000000025688] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 04/08/2021] [Indexed: 01/04/2023] Open
Abstract
RATIONALE Hydroxychloroquine has excellent anti-inflammatory and immunomodulatory effects as one of the antimalarial drugs. In particular, hydroxychloroquine was once widely used as a treatment for the new coronavirus pneumonia epidemic in 2020. Retinopathy caused by hydroxychloroquine is normally irreversible, but little attention has been paid to it. PATIENT CONCERNS A 38-year-old young Chinese woman was taking oral hydroxychloroquine 400 mg daily to control lupus disease activity for six years after the diagnosis of systemic lupus erythematosus (SLE). She did not have any history of eye disease and was admitted to the hospital with a sudden blurring of both eyes. DIAGNOSES The diagnosis of retinal macular degeneration caused by hydroxychloroquine was made after excluding other interfering diseases based on the patient's long-term use of hydroxychloroquine and the results of the eye examination. INTERVENTIONS The patient was discontinued from hydroxychloroquine. To control the recurrence of SLE, she was given intravenous methylprednisolone, oral tacrolimus and mycophenolate. Meanwhile, she was asked to take extra care of her eyes and to come to the hospital every three months to have her vision checked. OUTCOMES The patient's blurred vision improved one week later. Three months later, her vision examination showed no further decline (0.4 in the right eye and 0.6 in the left eye). Meanwhile, the SLE disease activity index (SLEDAI) decreased from six points to five points currently. LESSONS Retinopathy caused by hydroxychloroquine is irreversible and there is no particularly effective treatment. Discontinuation of hydroxychloroquine, better daily eye protection, and regular vision checks are the keys to preventing retinopathy. Although hydroxychloroquine causing retinal toxicity was mentioned several years ago, the rate and severity of retinal toxicity require further research. How to get more patients to take care of their eyes requires continuous and increased education by doctors.
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Affiliation(s)
- Gang Wang
- Department of Rheumatology and Immunology, Zhuzhou Hospital Affiliated to Xiangya Medical College, Central South University, Zhuzhou
| | - Ning Zhuo
- Department of Nephrology, Xiangya Second Hospital, Central South University, Changsha
| | - Zheng Liao
- Department of Rheumatology and Immunology, Zhuzhou Hospital Affiliated to Xiangya Medical College, Central South University, Zhuzhou
| | - Wei Qi
- Department of Ophthalmology, Zhuzhou Hospital Affiliated to Xiangya Medical College, Central South University, Zhuzhou, Hunan, China
| | - Feng Tian
- Department of Rheumatology and Immunology, Zhuzhou Hospital Affiliated to Xiangya Medical College, Central South University, Zhuzhou
| | - Zhenhua Wen
- Department of Rheumatology and Immunology, Zhuzhou Hospital Affiliated to Xiangya Medical College, Central South University, Zhuzhou
| | - Jingyang Li
- Department of Rheumatology and Immunology, Zhuzhou Hospital Affiliated to Xiangya Medical College, Central South University, Zhuzhou
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ASIC1 and ASIC3 mediate cellular senescence of human nucleus pulposus mesenchymal stem cells during intervertebral disc degeneration. Aging (Albany NY) 2021; 13:10703-10723. [PMID: 33824228 PMCID: PMC8064223 DOI: 10.18632/aging.202850] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 02/16/2021] [Indexed: 12/22/2022]
Abstract
Stem cell approaches have become an attractive therapeutic option for intervertebral disc degeneration (IVDD). Nucleus pulposus mesenchymal stem cells (NP-MSCs) participate in the regeneration and homeostasis of the intervertebral disc (IVD), but the molecular mechanisms governing these processes remain to be elucidated. Acid-sensing ion channels (ASICs) which act as key receptors for extracellular protons in central and peripheral neurons, have been implicated in IVDD where degeneration is associated with reduced microenvironmental pH. Here we show that ASIC1 and ASIC3, but not ASIC2 and ASIC4 are upregulated in human IVDs according to the degree of clinical degeneration. Subjecting IVD-derived NP-MSCs to pH 6.6 culture conditions to mimic pathological IVD changes resulted in decreased cell proliferation that was associated with cell cycle arrest and induction of senescence. Key molecular changes observed were increased expression of p53, p21, p27, p16 and Rb1. Instructively, premature senescence in NP-MSCs could be largely alleviated using ASIC inhibitors, suggesting both ASIC1 and ASIC3 act decisively upstream to activate senescence programming pathways including p53-p21/p27 and p16-Rb1 signaling. These results highlight the potential of ASIC inhibitors as a therapeutic approach for IVDD and broadly define an in vitro system that can be used to evaluate other IVDD therapies.
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Zu SQ, Feng YB, Zhu CJ, Wu XS, Zhou RP, Li G, Dai BB, Wang ZS, Xie YY, Li Y, Ge JF, Chen FH. Acid-sensing ion channel 1a mediates acid-induced pyroptosis through calpain-2/calcineurin pathway in rat articular chondrocytes. Cell Biol Int 2020; 44:2140-2152. [PMID: 32678496 DOI: 10.1002/cbin.11422] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/02/2020] [Accepted: 07/12/2020] [Indexed: 12/19/2022]
Abstract
The pyroptosis is a causative agent of rheumatoid arthritis, a systemic autoimmune disease merged with degenerative articular cartilage. Nevertheless, the precise mechanism of extracellular acidosis on chondrocyte pyroptosis is largely unclear. Acid-sensing ion channels (ASICs) belong to an extracellular H+ -activated cation channel family. Accumulating evidence has highlighted activation of ASICs induced by extracellular acidosis upregulate calpain and calcineurin expression in arthritis. In the present study, to investigate the expression and the role of acid-sensing ion channel 1a (ASIC1a), calpain, calcineurin, and NLRP3 inflammasome proteins in regulating acid-induced articular chondrocyte pyroptosis, primary rat articular chondrocytes were subjected to different pH, different time, and different treatments with or without ASIC1a, calpain-2, and calcineurin, respectively. Initially, the research results showed that extracellular acidosis-induced the protein expression of ASIC1a in a pH- and time-dependent manner, and the messenger RNA and protein expressions of calpain, calcineurin, NLRP3, apoptosis-associated speck-like protein, and caspase-1 were significantly increased in a time-dependent manner. Furthermore, the inhibition of ASIC1a, calpain-2, or calcineurin, respectively, could decrease the cell death accompanied with the decreased interleukin-1β level, and the decreased expression of ASIC1a, calpain-2, calcineurin, and NLRP3 inflammasome proteins. Taken together, these results indicated the activation of ASIC1a induced by extracellular acidosis could trigger pyroptosis of rat articular chondrocytes, the mechanism of which might partly be involved with the activation of calpain-2/calcineurin pathway.
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Affiliation(s)
- Sheng-Qin Zu
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Yu-Bin Feng
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Chuan-Jun Zhu
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Xiao-Shan Wu
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Ren-Peng Zhou
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Ge Li
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Bei-Bei Dai
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Zhi-Sen Wang
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Ya-Ya Xie
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Yue Li
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Jin-Fang Ge
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Fei-Hu Chen
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
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Osmakov DI, Khasanov TA, Andreev YA, Lyukmanova EN, Kozlov SA. Animal, Herb, and Microbial Toxins for Structural and Pharmacological Study of Acid-Sensing Ion Channels. Front Pharmacol 2020; 11:991. [PMID: 32733241 PMCID: PMC7360831 DOI: 10.3389/fphar.2020.00991] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/19/2020] [Indexed: 12/22/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are of the most sensitive molecular sensors of extracellular pH change in mammals. Six isoforms of these channels are widely represented in membranes of neuronal and non-neuronal cells, where these molecules are involved in different important regulatory functions, such as synaptic plasticity, learning, memory, and nociception, as well as in various pathological states. Structural and functional studies of both wild-type and mutant ASICs are essential for human care and medicine for the efficient treatment of socially significant diseases and ensure a comfortable standard of life. Ligands of ASICs serve as indispensable tools for these studies. Such bioactive compounds can be synthesized artificially. However, to date, the search for such molecules has been most effective amongst natural sources, such as animal venoms or plants and microbial extracts. In this review, we provide a detailed and comprehensive structural and functional description of natural compounds acting on ASICs, as well as the latest information on structural aspects of their interaction with the channels. Many of the examples provided in the review demonstrate the undoubted fundamental and practical successes of using natural toxins. Without toxins, it would not be possible to obtain data on the mechanisms of ASICs' functioning, provide detailed study of their pharmacological properties, or assess the contribution of the channels to development of different pathologies. The selectivity to different isoforms and variety in the channel modulation mode allow for the appraisal of prospective candidates for the development of new drugs.
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Affiliation(s)
- Dmitry I. Osmakov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Timur A. Khasanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
| | - Yaroslav A. Andreev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Ekaterina N. Lyukmanova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
| | - Sergey A. Kozlov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Science, Moscow, Russia
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Wei X, Sun C, Zhou RP, Ma GG, Yang Y, Lu C, Hu W. Nerve growth factor promotes ASIC1a expression via the NF-κB pathway and enhances acid-induced chondrocyte apoptosis. Int Immunopharmacol 2020; 82:106340. [PMID: 32146316 DOI: 10.1016/j.intimp.2020.106340] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/02/2020] [Accepted: 02/21/2020] [Indexed: 12/15/2022]
Abstract
Nerve growth factor (NGF) is a neurotrophic factor that is thought to have a broad role in the nervous system and tumors, and has recently been described as a mediator of inflammation. It is not clear whether or not NGF participates in apoptosis of articular chondrocytes. In this study, we determined if NGF affects ASIC1a expression and NF-κB P65 activation in rat chondrocytes, and measured the effectiveness of NGF on apoptotic protein expression in acid-induced chondrocytes. NGF was shown to up-regulate the level of ASIC1a in a dose- and time-dependent fashion. Simultaneously, NGF activated NF-κB P65 in chondrocytes. Additionally, the elevated ASIC1a expression induced by NGF was eliminated by the NF-κB inhibitor (PDTC) in chondrocytes. Moreover, NGF reduced cell viability and induced LDH release under the premise of acid-induced articular chondrocytes. Furthermore, NGF could enhance cleaved-caspase 9 and cleaved-PARP expression in acid-pretreated chondrocytes, and which could be inhibited by using psalmotoxin 1(PcTX1) or PDTC. Together, these results indicated that NGF may up-regulate ASIC1a expression through the NF-κB signaling pathway, and further promote acid-induced apoptosis of chondrocytes.
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Affiliation(s)
- Xin Wei
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei 230601, China
| | - Cheng Sun
- Department of Pharmacology, Zhongda Hospital Southeast University, Nanjing 210009, China
| | - Ren-Peng Zhou
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei 230601, China
| | - Gang-Gang Ma
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei 230601, China
| | - Yang Yang
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei 230601, China
| | - Chao Lu
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei 230601, China
| | - Wei Hu
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei 230601, China.
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Dreffs A, Henderson D, Dmitriev AV, Antonetti DA, Linsenmeier RA. Retinal pH and Acid Regulation During Metabolic Acidosis. Curr Eye Res 2018; 43:902-912. [PMID: 29641914 PMCID: PMC6095710 DOI: 10.1080/02713683.2018.1458882] [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] [Indexed: 12/21/2022]
Abstract
PURPOSE Changes in retinal pH may contribute to a variety of eye diseases. To study the effect of acidosis alone, we induced systemic metabolic acidosis and hypothesized that the retina would respond with altered expression of genes involved in acid/base regulation. METHODS Systemic metabolic acidosis was induced in Long-Evans rats for up to 2 weeks by adding NH4Cl to the drinking water. After 2 weeks, venous pH was 7.25 ± 0.08 (SD) and [HCO3-] was 21.4 ± 4.6 mM in acidotic animals; pH was 7.41 ± 0.03 and [HCO3-] was 30.5 ± 1.0 mM in controls. Retinal mRNAs were quantified by quantitative reverse transcription polymerase chain reaction. Protein was quantified with Western blots and localized by confocal microscopy. Retinal [H+]o was measured in vivo with pH microelectrodes in animals subjected to metabolic acidosis and in controls. RESULTS NH4Cl in drinking water or given intravenous was effective in acidifying the retina. Cariporide, a blocker of Na+/H+ exchange, further acidified the retina. Metabolic acidosis for 2 weeks led to increases of 40-100% in mRNA for carbonic anhydrase isoforms II (CA-II) and XIV (CA-XIV) and acid-sensing ion channels 1 and 4 (ASIC1 and ASIC4) (all p < 0.005). Expression of anion exchange protein 3 (AEP-3) and Na+/H+ exchanger (NHE)-1 also increased by ≥50% (both p < 0.0001). Changes were similar after 1 week of acidosis. Protein for AEP-3 doubled. NHE-1 co-localized with vascular markers, particularly in the outer plexiform layer. CA-II was located in the neural parenchyma of the ganglion cell layer and diffusely in the rest of the inner retina. CONCLUSIONS The retina responds to systemic acidosis with increased expression of proton and bicarbonate exchangers, carbonic anhydrase, and ASICs. While responses to acidosis are usually associated with renal regulation, these studies suggest that the retina responds to changes in local pH presumably to control its acid/base environment in response to systemic acidosis.
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Affiliation(s)
- Alyssa Dreffs
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI
| | - Desmond Henderson
- Department of Biomedical Engineering, Northwestern University, Evanston and Chicago, IL
| | - Andrey V. Dmitriev
- Department of Biomedical Engineering, Northwestern University, Evanston and Chicago, IL
| | - David A. Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI
| | - Robert A. Linsenmeier
- Department of Biomedical Engineering, Northwestern University, Evanston and Chicago, IL
- Department of Neurobiology, Northwestern University, Evanston and Chicago, IL
- Department of Ophthalmology, Northwestern University, Evanston and Chicago, IL
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9
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Effects of autophagy on acid-sensing ion channel 1a-mediated apoptosis in rat articular chondrocytes. Mol Cell Biochem 2017; 443:181-191. [DOI: 10.1007/s11010-017-3223-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 11/23/2017] [Indexed: 11/30/2022]
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Acid-Sensing Ion Channels as Potential Therapeutic Targets in Neurodegeneration and Neuroinflammation. Mediators Inflamm 2017; 2017:3728096. [PMID: 29056828 PMCID: PMC5625748 DOI: 10.1155/2017/3728096] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 07/29/2017] [Accepted: 08/13/2017] [Indexed: 12/21/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are a family of proton-sensing channels that are voltage insensitive, cation selective (mostly permeable to Na+), and nonspecifically blocked by amiloride. Derived from 5 genes (ACCN1-5), 7 subunits have been identified, 1a, 1b, 2a, 2b, 3, 4, and 5, that are widely expressed in the peripheral and central nervous system as well as other tissues. Over the years, different studies have shown that activation of these channels is linked to various physiological and pathological processes, such as memory, learning, fear, anxiety, ischemia, and multiple sclerosis to name a few, so their potential as therapeutic targets is increasing. This review focuses on recent advances that have helped us to better understand the role played by ASICs in different pathologies related to neurodegenerative diseases, inflammatory processes, and pain.
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Rash LD. Acid-Sensing Ion Channel Pharmacology, Past, Present, and Future …. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 79:35-66. [PMID: 28528673 DOI: 10.1016/bs.apha.2017.02.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
pH is one of the most strictly controlled parameters in mammalian physiology. An extracellular pH of ~7.4 is crucial for normal physiological processes, and perturbations to this have profound effects on cell function. Acidic microenvironments occur in many physiological and pathological conditions, including inflammation, bone remodeling, ischemia, trauma, and intense synaptic activity. Cells exposed to these conditions respond in different ways, from tumor cells that thrive to neurons that are either suppressed or hyperactivated, often fatally. Acid-sensing ion channels (ASICs) are primary pH sensors in mammals and are expressed widely in neuronal and nonneuronal cells. There are six main subtypes of ASICs in rodents that can form homo- or heteromeric channels resulting in many potential combinations. ASICs are present and activated under all of the conditions mentioned earlier, suggesting that they play an important role in how cells respond to acidosis. Compared to many other ion channel families, ASICs were relatively recently discovered-1997-and there is a substantial lack of potent, subtype-selective ligands that can be used to elucidate their structural and functional properties. In this chapter I cover the history of ASIC channel pharmacology, which began before the proteins were even identified, and describe the current arsenal of tools available, their limitations, and take a glance into the future to predict from where new tools are likely to emerge.
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Affiliation(s)
- Lachlan D Rash
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, Australia.
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Zhou RP, Wu XS, Wang ZS, Xie YY, Ge JF, Chen FH. Novel Insights into Acid-Sensing Ion Channels: Implications for Degenerative Diseases. Aging Dis 2015; 7:491-501. [PMID: 27493834 DOI: 10.14336/ad.2015.1213] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 12/13/2015] [Indexed: 12/16/2022] Open
Abstract
Degenerative diseases often strike older adults and are characterized by progressive deterioration of cells, eventually leading to tissue and organ degeneration for which limited effective treatment options are currently available. Acid-sensing ion channels (ASICs), a family of extracellular H(+)-activated ligand-gated ion channels, play critical roles in physiological and pathological conditions. Aberrant activation of ASICs is reported to regulate cell apoptosis, differentiation and autophagy. Accumulating evidence has highlighted a dramatic increase and activation of ASICs in degenerative disorders, including multiple sclerosis, Parkinson's disease, Huntington's disease, intervertebral disc degeneration and arthritis. In this review, we have comprehensively discussed the critical roles of ASICs and their potential utility as therapeutic targets in degenerative diseases.
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Affiliation(s)
- Ren-Peng Zhou
- 1Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; 2The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
| | - Xiao-Shan Wu
- 1Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; 2The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
| | - Zhi-Sen Wang
- 1Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; 2The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
| | - Ya-Ya Xie
- 1Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; 2The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
| | - Jin-Fang Ge
- 1Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; 2The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
| | - Fei-Hu Chen
- 1Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; 2The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
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Radu BM, Banciu A, Banciu DD, Radu M. Acid-Sensing Ion Channels as Potential Pharmacological Targets in Peripheral and Central Nervous System Diseases. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2015; 103:137-67. [PMID: 26920689 DOI: 10.1016/bs.apcsb.2015.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Acid-sensing ion channels (ASICs) are widely expressed in the body and represent good sensors for detecting protons. The pH drop in the nervous system is equivalent to ischemia and acidosis, and ASICs are very good detectors in discriminating slight changes in acidity. ASICs are important pharmacological targets being involved in a variety of pathophysiological processes affecting both the peripheral nervous system (e.g., peripheral pain, diabetic neuropathy) and the central nervous system (e.g., stroke, epilepsy, migraine, anxiety, fear, depression, neurodegenerative diseases, etc.). This review discusses the role played by ASICs in different pathologies and the pharmacological agents acting on ASICs that might represent promising drugs. As the majority of above-mentioned pathologies involve not only neuronal dysfunctions but also microvascular alterations, in the next future, ASICs may be also considered as potential pharmacological targets at the vasculature level. Perspectives and limitations in the use of ASICs antagonists and modulators as pharmaceutical agents are also discussed.
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Affiliation(s)
- Beatrice Mihaela Radu
- Department of Neurological and Movement Sciences, Section of Anatomy and Histology, University of Verona, Verona, Italy; Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Adela Banciu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Daniel Dumitru Banciu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Mihai Radu
- Department of Neurological and Movement Sciences, Section of Anatomy and Histology, University of Verona, Verona, Italy; Department of Life and Environmental Physics, 'Horia Hulubei' National Institute for Physics and Nuclear Engineering, Magurele, Romania.
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Wang Y, O’Bryant Z, Wang H, Huang Y. Regulating Factors in Acid-Sensing Ion Channel 1a Function. Neurochem Res 2015; 41:631-45. [DOI: 10.1007/s11064-015-1768-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 11/04/2015] [Accepted: 11/08/2015] [Indexed: 12/11/2022]
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15
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Zhou R, Wu X, Wang Z, Ge J, Chen F. Interleukin-6 enhances acid-induced apoptosis via upregulating acid-sensing ion channel 1a expression and function in rat articular chondrocytes. Int Immunopharmacol 2015; 29:748-760. [PMID: 26359543 DOI: 10.1016/j.intimp.2015.08.044] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 08/14/2015] [Accepted: 08/31/2015] [Indexed: 12/24/2022]
Abstract
The inflammatory cytokine interleukin-6 (IL-6) is a causative agent of rheumatoid arthritis (RA), a chronic inflammatory disease complicated with degenerative arthritic cartilage. However, the precise mechanism of IL-6 on chondrocyte apoptosis is largely unclear. Acid-sensing ion channels (ASICs), a family of extracellular H(+)-activated cation channels, can be transiently activated by extracellular acid and play a pivotal role in acid-induced cell injury. In the present study, to investigate the role of IL-6 in regulating acid-induced articular chondrocyte apoptosis, primary rat articular chondrocytes were subjected to different treatments with or without IL-6 in the presence of acid. The results showed that the mRNA and protein expressions of ASIC1a were significantly increased in articular cartilage and chondrocytes of adjuvant arthritis (AA) rats. IL-6 could dramatically upregulate the level of ASIC1a in a time- and dose-dependent manner, and induce the activation of JAK2, STAT3, ERK, JNK and NF-κB in articular chondrocytes. Moreover, both the respective inhibitors of these signaling pathways and the specific antibody against IL-6 receptor (tocilizumab) could partially abrogate the ASIC1a upregulation induced by IL-6. Furthermore, IL-6 inhibited the cell viability and enhanced LDH release, [Ca(2+)]i elevation, and apoptosis in acid-induced articular chondrocytes, and these changes could be reversed by using psalmotoxin 1(PcTX1), which is the specific antagonist of ASIC1a. In addition, pretreatment with PcTX1 could inhibit the downregulated expression of Bcl-2 and the upregulated expression of Bax induced by IL-6 in acid-induced articular chondrocytes. Taken together, these results indicated that IL-6 could enhance acid-induced articular chondrocyte apoptosis, the mechanism of which might partially be involved with its ability of regulating the activation of ASIC1a-dependent JAK2/STAT3 and MAPK/NF-κB signaling pathways.
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Affiliation(s)
- Renpeng Zhou
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
| | - Xiaoshan Wu
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
| | - Zhisen Wang
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
| | - Jinfang Ge
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China
| | - Feihu Chen
- Anhui Key Laboratory of Bioactivity of Natural Products, School of Pharmacy, Anhui Medical University, Hefei 230032, China; The Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Hefei 230032, China.
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Baron A, Lingueglia E. Pharmacology of acid-sensing ion channels – Physiological and therapeutical perspectives. Neuropharmacology 2015; 94:19-35. [DOI: 10.1016/j.neuropharm.2015.01.005] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 12/15/2014] [Accepted: 01/07/2015] [Indexed: 12/29/2022]
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Liu S, Wang MX, Mao CJ, Cheng XY, Wang CT, Huang J, Zhong ZM, Hu WD, Wang F, Hu LF, Wang H, Liu CF. Expression and functions of ASIC1 in the zebrafish retina. Biochem Biophys Res Commun 2014; 455:353-7. [DOI: 10.1016/j.bbrc.2014.11.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 11/08/2014] [Indexed: 10/24/2022]
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