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Xu H, Wang X, Zhu F, Guo S, Chao Z, Cao C, Lu Z, Zhu H, Wang M, Zhu F, Yang J, Zeng R, Yao Y. Comprehensive Pan-Cancer Analysis of Connexin 43 as a Potential Biomarker and Therapeutic Target in Human Kidney Renal Clear Cell Carcinoma (KIRC). MEDICINA (KAUNAS, LITHUANIA) 2024; 60:780. [PMID: 38792963 PMCID: PMC11123162 DOI: 10.3390/medicina60050780] [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: 03/06/2024] [Revised: 04/22/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024]
Abstract
Background and Objectives: Connexin 43 (Cx43) is involved in the transfer of small signaling molecules between neighboring cells, thereby exerting a major influence on the initiation and progression of tumorigenesis. However, there is a lack of systematic research on Cx43 expression and its predictive role in clinical diagnosis and prognosis in pan-cancer. Materials and Methods: Several biological databases were used to evaluate the expression levels of GJA1 (encoding Cx43) and its diagnostic and prognostic significance in pan-cancer. We targeted kidney renal clear cell carcinoma (KIRC) and investigated the relationship between GJA1 expression and different clinical features of KIRC patients. Then, we performed cell-based experiments to partially confirm our results and predicted several proteins that were functionally related to Cx43. Results: The expression of GJA1 has a high level of accuracy in predicting KIRC. High GJA1 expression was remarkably correlated with a favorable prognosis, and this expression was reduced in groups with poor clinical features in KIRC. Cell experiments confirmed the inhibitory effects of increased GJA1 expression on the migratory capacity of human renal cancer (RCC) cell lines, and protein-protein interaction (PPI) analysis predicted that CDH1 and CTNNB1 were closely related to Cx43. Conclusions: GJA1 could be a promising independent favorable prognostic factor for KIRC, and upregulation of GJA1 expression could inhibit the migratory capacity of renal cancer cells.
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Affiliation(s)
- Huzi Xu
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
| | - Xiuru Wang
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
| | - Fan Zhu
- Wuhan Central Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China;
| | - Shuiming Guo
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
| | - Zheng Chao
- Division of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China;
| | - Chujin Cao
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
| | - Zhihui Lu
- Division of Nursing, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China;
| | - Han Zhu
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
| | - Meng Wang
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
| | - Fengming Zhu
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
| | - Juan Yang
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
| | - Rui Zeng
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
| | - Ying Yao
- Division of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; (H.X.); (X.W.); (S.G.); (C.C.); (H.Z.); (M.W.); (F.Z.); (J.Y.)
- Division of Nutrition, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China
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Genet N, Genet G, Chavkin NW, Paila U, Fang JS, Vasavada HH, Goldberg JS, Acharya BR, Bhatt NS, Baker K, McDonnell SP, Huba M, Sankaranarayanan D, Ma GZM, Eichmann A, Thomas JL, Ffrench-Constant C, Hirschi KK. Connexin 43-mediated neurovascular interactions regulate neurogenesis in the adult brain subventricular zone. Cell Rep 2023; 42:112371. [PMID: 37043357 PMCID: PMC10564973 DOI: 10.1016/j.celrep.2023.112371] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 02/20/2023] [Accepted: 03/22/2023] [Indexed: 04/13/2023] Open
Abstract
The subventricular zone (SVZ) is the largest neural stem cell (NSC) niche in the adult brain; herein, the blood-brain barrier is leaky, allowing direct interactions between NSCs and endothelial cells (ECs). Mechanisms by which direct NSC-EC interactions in the adult SVZ control NSC behavior are unclear. We found that Cx43 is highly expressed by SVZ NSCs and ECs, and its deletion in either leads to increased NSC proliferation and neuroblast generation, suggesting that Cx43-mediated NSC-EC interactions maintain NSC quiescence. This is further supported by single-cell RNA sequencing and in vitro studies showing that ECs control NSC proliferation by regulating expression of genes associated with NSC quiescence and/or activation in a Cx43-dependent manner. Cx43 mediates these effects in a channel-independent manner involving its cytoplasmic tail and ERK activation. Such insights inform adult NSC regulation and maintenance aimed at stem cell therapies for neurodegenerative disorders.
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Affiliation(s)
- Nafiisha Genet
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA.
| | - Gael Genet
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Nicholas W Chavkin
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Umadevi Paila
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Jennifer S Fang
- Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Hema H Vasavada
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Joshua S Goldberg
- Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Bipul R Acharya
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Neha S Bhatt
- Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Kasey Baker
- Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06511, USA; Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Neurology, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Stephanie P McDonnell
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Mahalia Huba
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Danya Sankaranarayanan
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Gerry Z M Ma
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK; Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK
| | - Anne Eichmann
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Jean-Leon Thomas
- Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Neurology, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Charles Ffrench-Constant
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK; Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK
| | - Karen K Hirschi
- Department of Cell Biology, Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Departments of Medicine and Genetics, Yale University School of Medicine, New Haven, CT 06511, USA; Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT 06511, USA.
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Zhang J, Wang X, Hou Z, Neng L, Cai J, Zhang Y, Shi X. Suppression of Connexin 43 Leads to Strial Vascular Hyper-Permeability, Decrease in Endocochlear Potential, and Mild Hearing Loss. Front Physiol 2020; 11:974. [PMID: 32922309 PMCID: PMC7457066 DOI: 10.3389/fphys.2020.00974] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/16/2020] [Indexed: 12/20/2022] Open
Abstract
Objective: Connexin 43 (Cx43) is a protein constituent of gap junctions (GJs) in various barrier cells, especially astrocytes and microglia of the blood-brain-barrier (BBB), where it plays an important role in intercellular communication and regulation of the barrier. Despite the importance of Cx43 in other blood barriers, not much attention has been paid to expression and function of Cx43 in the blood-labyrinth-barrier (BLB) of the stria vascularis in the cochlea. Methods: We used multiple research approaches, including immunocytochemical staining, patch-clamp dye loading technique, real-time quantitative reverse transcription (RT)-PCR, western blot, measurement of endocochlear potential (EP) with an electrode through the scala media, and auditory brainstem response to test hearing function. Results: We found Cx43 expressed in vascular endothelial cells (ECs) and perivascular resident macrophages (PVMs) in the stria vascularis of adult C57BL/6 mouse cochleae. In particular, we found Cx43 expressed in foot processes of PVMs at points of contact with the endothelium. Consistent with Cx43 expression in vivo, we also found Cx43 expressed in EC-EC and EC-PVM interfaces in a co-cultured cell line model. Using a patch-clamp dye loading technique, we demonstrated that Alexa Fluor® 568 dye injected into PVMs diffuses to connected neighboring ECs. The functional coupling between the ECs and PVMs is blocked by 18α-Glycyrrhetinic acid (18α-GA), a GJ blocker. Suppression of Cx43 with small interfering RNA (siRNA) in vivo significantly elevated hearing threshold and caused the EP to drop and the blood barrier to become more permeable. In further study, using in vitro primary EC cell line models, we demonstrated that suppression of Cx43 disrupts intercellular tight junctions (TJs) in the EC monolayer and increases endothelial monolayer permeability. Conculsion: Taken together, these findings underscore the importance of Cx43 expression in the normal ear for maintaining BLB integrity, normal EP, and hearing function.
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Affiliation(s)
- Jinhui Zhang
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Xiaohan Wang
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
- Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Zhiqiang Hou
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Lingling Neng
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Jing Cai
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Yunpei Zhang
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Xiaorui Shi
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
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Jain M, Nevin RL, Ahmed I. Mefloquine-associated dizziness, diplopia, and central serous chorioretinopathy: a case report. J Med Case Rep 2016; 10:305. [PMID: 27799060 PMCID: PMC5088661 DOI: 10.1186/s13256-016-1091-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 10/06/2016] [Indexed: 12/02/2022] Open
Abstract
Background Many acute and chronic neurological sequelae from the quinoline derivative antimalarial drug mefloquine, including dizziness and effects on the visual system such as diplopia and blurred vision, may be attributable to focal central nervous system toxicity. Maculopathy has also been reported with use of mefloquine, although the mechanism of this effect has remained unclear. Identification of a common mechanism of toxicity plausibly underlying these visual and non-visual effects may provide broader insights into the acute and chronic neuropsychiatric effects of this and other quinoline antimalarial drugs. Case presentation This case report describes a 30-year-old man of Pakistani descent with sudden onset of dizziness and diplopia following the administration of mefloquine who developed macular changes diagnosed as acute central serous chorioretinopathy by angiography and optical coherence tomography. Similarities between the visual conditions observed in this case and those observed following administration of related quinoline derivative antimalarial drugs including quinine are considered, and plausible mechanisms for the observed drug-induced toxicity are discussed. Conclusions It is proposed that central serous chorioretinopathy be considered a potential ophthalmological sign of mefloquine central nervous system toxicity, and for this effect to potentially indicate susceptibility to other neuropsychiatric effects of mefloquine intoxication. Treating physicians should be aware of the potential for acute and chronic ocular effects resulting from administration of mefloquine and other quinoline antimalarial drugs.
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Affiliation(s)
- Manish Jain
- Department of Ophthalmology, NMC Specialty Hospital, Al Ain, United Arab Emirates
| | - Remington L Nevin
- Department of Environmental Health & Engineering, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD, 21205, USA.
| | - Iajaz Ahmed
- Department of Medicine, NMC Specialty Hospital, Al Ain, United Arab Emirates
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Soares ES, Mendonça MCP, Rocha T, Kalapothakis E, da Cruz-Höfling MA. Are Synchronized Changes in Connexin-43 and Caveolin-3 a Bystander Effect in a Phoneutria nigriventer Venom Model of Blood-Brain Barrier Breakdown? J Mol Neurosci 2016; 59:452-63. [PMID: 27067308 DOI: 10.1007/s12031-016-0749-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 03/23/2016] [Indexed: 12/17/2022]
Abstract
Upregulation of caveolin-3 (Cav-3) or connexin-43 (Cx43) in astrocytes has been associated with important brain pathologies. We used Phoneutria nigriventer spider venom (PNV), which induces blood-brain barrier breakdown in rats, in order to investigate Cav-3 and Cx43 expression in the cerebellum over critical periods of rat envenomation. By immunofluorescence, western blotting (WB), and transmission electron microscopy (TEM), we assessed changes at 1, 2, 5, 24, and 72 h post-venom. WB showed immediate increases in Cav-3 and Cx43 at 1 h (interval of greatest manifestations of envenomation) that persisted at 5 h (when there were signs of recovery) and peaked at 24 h when no signs of envenomation were detectable. At 2 and 72 h, Cav-3 was downregulated and Cx43 had returned to baseline. PNV markedly intensified Cx43 in molecular, Purkinje and granular layers and Cav-3 in astrocytes whose colocalization to increased GFAP suggests interaction between reactive astrogliosis and Cav-3 upregulation. TEM showed swollen perivascular astrocytic end-feet and synaptic contact alterations that had generally resolved by 72 h. It is uncertain whether such PNV-induced synchronized changes are an interactive effect between Cav-3 and Cx43, or a bystander effect. Evidences indicate that Cav-3 downregulation coupled to Cx43 return to baseline at 72 h when no signs of envenomation were visible, suggesting homeostasis reestablishment. This experimental model is relevant to studying mechanisms involved in neurological disorders associated with Cav-3 overexpression.
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Affiliation(s)
- Edilene Siqueira Soares
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Monique Culturato Padilha Mendonça
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil.,Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Thalita Rocha
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil.,Multidisciplinary Research Laboratory, São Francisco University (USF), Bragança Paulista, SP, Brazil
| | - Evanguedes Kalapothakis
- Department of General Biology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Maria Alice da Cruz-Höfling
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil. .,Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
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Kim Y, Davidson JO, Gunn KC, Phillips AR, Green CR, Gunn AJ. Role of Hemichannels in CNS Inflammation and the Inflammasome Pathway. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2016; 104:1-37. [DOI: 10.1016/bs.apcsb.2015.12.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Chen YS, Green CR, Danesh-Meyer HV, Rupenthal ID. Neuroprotection in the treatment of glaucoma--A focus on connexin43 gap junction channel blockers. Eur J Pharm Biopharm 2015; 95:182-93. [PMID: 25676338 DOI: 10.1016/j.ejpb.2015.01.031] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/23/2014] [Accepted: 01/07/2015] [Indexed: 01/01/2023]
Abstract
Glaucoma is a form of optic neuropathy and a common cause of blindness, affecting over 60 million people worldwide with an expected rise to 80 million by 2020. Successful treatment is challenging due to the various causes of glaucoma, undetectable symptoms at an early stage and inefficient delivery of drugs to the back of the eye. Conventional glaucoma treatments focus on the reduction of elevated intraocular pressure (IOP) using topical eye drops. However, their efficacy is limited to patients who suffer from high IOP glaucoma and do not address the underlying susceptibility of retinal ganglion cells (RGC) to degeneration. Glaucoma is known as a neurodegenerative disease which starts with RGC death and eventually results in damage of the optic nerve. Neuroprotective strategies therefore offer a novel treatment option for glaucoma by not only preventing neuronal loss but also disease progression. This review firstly gives an overview of the pathophysiology of glaucoma as well as current treatment options including conventional and novel delivery strategies. It then summarizes the rational for neuroprotection as a novel therapy for glaucomatous neuropathies and reviews current potential neuroprotective strategies to preserve RGC, with a focus on connexin43 (Cx43) gap junction channel blockers.
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Affiliation(s)
- Ying-Shan Chen
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Colin R Green
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Helen V Danesh-Meyer
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Ilva D Rupenthal
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
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Craven CJ. A model to explain specific cellular communications and cellular harmony:- a hypothesis of coupled cells and interactive coupling molecules. Theor Biol Med Model 2014; 11:40. [PMID: 25218581 PMCID: PMC4237941 DOI: 10.1186/1742-4682-11-40] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 09/02/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The various cell types and their relative numbers in multicellular organisms are controlled by growth factors and related extracellular molecules which affect genetic expression pathways. However, these substances may have both/either inhibitory and/or stimulatory effects on cell division and cell differentiation depending on the cellular environment. It is not known how cells respond to these substances in such an ambiguous way. Many cellular effects have been investigated and reported using cell culture from cancer cell lines in an effort to define normal cellular behaviour using these abnormal cells.A model is offered to explain the harmony of cellular life in multicellular organisms involving interacting extracellular substances. METHODS A basic model was proposed based on asymmetric cell division and evidence to support the hypothetical model was accumulated from the literature. In particular, relevant evidence was selected for the Insulin-Like Growth Factor system from the published data, especially from certain cell lines, to support the model. The evidence has been selective in an attempt to provide a picture of normal cellular responses, derived from the cell lines. RESULTS The formation of a pair of coupled cells by asymmetric cell division is an integral part of the model as is the interaction of couplet molecules derived from these cells. Each couplet cell will have a receptor to measure the amount of the couplet molecule produced by the other cell; each cell will be receptor-positive or receptor-negative for the respective receptors. The couplet molecules will form a binary complex whose level is also measured by the cell. The hypothesis is heavily supported by selective collection of circumstantial evidence and by some direct evidence. The basic model can be expanded to other cellular interactions. CONCLUSIONS These couplet cells and interacting couplet molecules can be viewed as a mechanism that provides a controlled and balanced division-of-labour between the two progeny cells, and, in turn, their progeny. The presence or absence of a particular receptor for a couplet molecule will define a cell type and the presence or absence of many such receptors will define the cell types of the progeny within cell lineages.
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Affiliation(s)
- Cyril J Craven
- Queensland University of Technology (QUT), Brisbane, Australia.
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Kerr NM, Johnson CS, Zhang J, Eady EK, Green CR, Danesh-Meyer HV. High pressure-induced retinal ischaemia reperfusion causes upregulation of gap junction protein connexin43 prior to retinal ganglion cell loss. Exp Neurol 2012; 234:144-52. [DOI: 10.1016/j.expneurol.2011.12.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 11/24/2011] [Accepted: 12/15/2011] [Indexed: 10/14/2022]
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Yang Y, Cao MH, Wang Q, Yuan DD, Li L, Tao L. The effects of 2-aminoethoxydiphenyl borate and diphenylboronic anhydride on gap junctions composed of Connexin43 in TM₄ sertoli cells. Biol Pharm Bull 2011; 34:1390-7. [PMID: 21881223 DOI: 10.1248/bpb.34.1390] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
2-Aminoethoxydiphenyl borate (2-APB) has recently been demonstrated to inhibit gap junction (GJ) channels, whereas the underlying mechanisms are still unknown. Using mouse TM₄ Sertoli cell which expresses connexin43 (Cx43), we explored the effects of 2-APB and its analogues on dye-coupling through junctional channels formed by Cx43 and on expression of Cx43. Exposure of the cells to 2-APB (1-50 µM) and one of its analogues diphenylboronic anhydride (DPBA) (1-30 µM) for 4 h leads to a significant decrease in dye coupling of GJ in a concentration-dependent manner. The inhibitory effects of 2-APB and DPBA are reversible since decreased GJ coupling resumes after the two compounds are washed out. The disfunction of GJ induced by 2-APB and DPBA is associated with a decrease in total amount of Cx43 protein and number of GJs on the cell membrane. 2-APB and DPBA do not alter Cx43 phosphorylation state and the level of Cx43 mRNA expression. The loss of Cx43 protein is prevented by either lysosomal or proteasomal inhibitor, suggesting that the decrease in Cx43 results from a 2-APB or DPBA-enhanced degradation of Cx43. The present results indicate that 2-APB and DPBA inhibit GJ communication through decreasing Cx43 expression in TM₄ cells.
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Affiliation(s)
- Yan Yang
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, China
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11
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Role of connexin43 in central nervous system injury. Exp Neurol 2010; 225:250-61. [DOI: 10.1016/j.expneurol.2010.07.014] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 06/09/2010] [Accepted: 07/15/2010] [Indexed: 01/03/2023]
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12
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D'hondt C, Ponsaerts R, De Smedt H, Bultynck G, Himpens B. Pannexins, distant relatives of the connexin family with specific cellular functions? Bioessays 2009; 31:953-74. [PMID: 19644918 DOI: 10.1002/bies.200800236] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Intercellular communication (IC) is mediated by gap junctions (GJs) and hemichannels, which consist of proteins. This has been particularly well documented for the connexin (Cx) family. Initially, Cxs were thought to be the only proteins capable of GJ formation in vertebrates. About 10 years ago, however, a new GJ-forming protein family related to invertebrate innexins (Inxs) was discovered in vertebrates, and named the pannexin (Panx) family. Panxs, which are structurally similar to Cxs, but evolutionarily distinct, have been shown to be co-expressed with Cxs in vertebrates. Both protein families show distinct properties and have their own particular function. Identification of the mechanisms that control Panx channel gating is a major challenge for future work. In this review, we focus on the specific properties and role of Panxs in normal and pathological conditions.
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Affiliation(s)
- Catheleyne D'hondt
- Laboratory of Molecular and Cellular Signalling, KULeuven, Campus Gasthuisberg O/N, Leuven, Belgium
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