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Héja L, Simon Á, Kardos J. Simulation of gap junction formation reveals critical role of Cys disulfide redox state in connexin hemichannel docking. Cell Commun Signal 2024; 22:185. [PMID: 38500186 PMCID: PMC10949817 DOI: 10.1186/s12964-023-01439-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 12/12/2023] [Indexed: 03/20/2024] Open
Abstract
Video Abstract.
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Affiliation(s)
- László Héja
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, 1117, Budapest, Hungary.
| | - Ágnes Simon
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, 1117, Budapest, Hungary
| | - Julianna Kardos
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, 1117, Budapest, Hungary
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Wu Y, Du B, Lin M, Ji X, Lv C, Lai J. The identification of genes associated T-cell exhaustion and construction of prognostic signature to predict immunotherapy response in lung adenocarcinoma. Sci Rep 2023; 13:13415. [PMID: 37592010 PMCID: PMC10435542 DOI: 10.1038/s41598-023-40662-z] [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: 01/13/2023] [Accepted: 08/16/2023] [Indexed: 08/19/2023] Open
Abstract
T-cell exhaustion (Tex) is considered to be a reason for immunotherapy resistance and poor prognosis in lung adenocarcinoma. Therefore, we used weighted correlation network analysis to identify Tex-related genes in the cancer genome atlas (TCGA). Unsupervised clustering approach based on Tex-related genes divided patients into cluster 1 and cluster 2. Then, we utilized random forest and the least absolute shrinkage and selection operator to identify nine key genes to construct a riskscore. Patients were classified as low or high-risk groups. The multivariate cox analysis showed the riskscore was an independent prognostic factor in TCGA and GSE72094 cohorts. Moreover, patients in cluster 2 with high riskscore had the worst prognosis. The immune response prediction analysis showed the low-risk group had higher immune, stromal, estimate scores, higher immunophenscore (IPS), and lower tumor immune dysfunction and exclusion score which suggested a better response to immune checkpoint inhibitors (ICIs) therapy in the low-risk group. In the meantime, we included two independent immunotherapy cohorts that also confirmed a better response to ICIs treatment in the low-risk group. Besides, we discovered differences in chemotherapy and targeted drug sensitivity between two groups. Finally, a nomogram was built to facilitate clinical decision making.
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Affiliation(s)
- Yahua Wu
- Department of Medical Oncology, Fujian Medical University Union Hospital, No. 29 Xinquan Street, Fuzhou, 350000, Fujian, China
| | - Bin Du
- Department of Medical Oncology, Fujian Medical University Union Hospital, No. 29 Xinquan Street, Fuzhou, 350000, Fujian, China
| | - Mingqiang Lin
- Department of Radiation Oncology, Fujian Medical University Cancer Hospital, Jin'an District, Fuzhou, 350000, Fujian, China
| | - Xiaohui Ji
- Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China
| | - Chengliu Lv
- Department of Medical Oncology, Fujian Medical University Union Hospital, No. 29 Xinquan Street, Fuzhou, 350000, Fujian, China
| | - Jinhuo Lai
- Department of Medical Oncology, Fujian Medical University Union Hospital, No. 29 Xinquan Street, Fuzhou, 350000, Fujian, China.
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Güiza J, Solís F, Valenzuela B, Arancibia D, Zamorano P, González J, Saavedra J, Neely A, Salgado M, Martínez AD, Sáez JC, Vega JL. Unnexin is a protein subunit of a large-pore channel expressed by unicellular organisms. Proc Natl Acad Sci U S A 2023; 120:e2307898120. [PMID: 37487087 PMCID: PMC10400985 DOI: 10.1073/pnas.2307898120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 06/23/2023] [Indexed: 07/26/2023] Open
Abstract
Cells of vertebrate and invertebrate organisms express proteins specialized in membrane channel-based cell-cell communication that are absent in unicellular organisms. We recently described the prediction of some members of the large-pore channel family in kinetoplastids, consisting of proteins called unnexins, which share several structural features with innexin and pannexin proteins. Here, we demonstrated that the unnexin1 protein (Unx1) is delivered to the cell membrane, displaying a topology consisting of four transmembrane domains with C and N termini on the cytoplasmic side and form large-pore channels that are permeable to small molecules. Low extracellular Ca2+/Mg2+ levels or extracellular alkalinization, but not mechanical stretching, increases channel activity. The Unx1 channel mediates the influx of Ca2+ and does not form intercellular dye coupling between HeLa Unx1 transfected cells. Unx1 channel function was further evidenced by its ability to mediate ionic currents when expressed in Xenopus oocytes. Downregulation of Unx1 mRNA with morpholine contains Trypanosoma cruzi invasion. Phylogenetic analysis revealed the presence of Unx1 homologs in other protozoan parasites, suggesting a conserved function for these channel parasites in other protists. Our data demonstrate that Unx1 forms large-pore membrane channels, which may serve as a diffusional pathway for ions and small molecules that are likely to be metabolic substrates or waste products, and signaling autocrine and paracrine molecules that could be involved in cell invasion. As morpholinos-induced downregulation of Unx1 reduces the infectivity of trypomastigotes, the Unx1 channels might be an attractive target for developing trypanocide drugs.
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Affiliation(s)
- Juan Güiza
- Laboratory of Gap Junction Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta1240000, Chile
| | - Francisco Solís
- Laboratorio de Microorganismos Extremófilos, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta1240000, Chile
| | - Bernardita Valenzuela
- Laboratorio de Microorganismos Extremófilos, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta1240000, Chile
| | - Duxan Arancibia
- Laboratorio de Microorganismos Extremófilos, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta1240000, Chile
| | - Pedro Zamorano
- Laboratorio de Microorganismos Extremófilos, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta1240000, Chile
| | - Jorge González
- Departamento de Tecnología Médica, Unidad de Parasitología Molecular, Facultad Ciencias de la Salud, Universidad de Antofagasta, Antofagasta1240000, Chile
| | - Jonathan Saavedra
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso2381850, Chile
| | - Alan Neely
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso2381850, Chile
| | - Magdiel Salgado
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso2381850, Chile
| | - Agustín D. Martínez
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso2381850, Chile
| | - Juan C. Sáez
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso2381850, Chile
| | - José L. Vega
- Laboratory of Gap Junction Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta1240000, Chile
- Departamento Biomédico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta1240000, Chile
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Wang Q, Ma Y, Li Y, He Z, Feng B. Lead-induced cardiomyocytes apoptosis by inhibiting gap junction intercellular communication via modulating the PKCα/Cx43 signaling pathway. Chem Biol Interact 2023; 376:110451. [PMID: 36925031 DOI: 10.1016/j.cbi.2023.110451] [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: 12/17/2022] [Revised: 02/28/2023] [Accepted: 03/11/2023] [Indexed: 03/17/2023]
Abstract
OBJECTIVE The aim of this study was to investigate the regulatory mechanism of Pb regulates gap junction intercellular communication to induced apoptosis in H9c2 cells. METHODS H9c2 cell line is used as the research object in this study, and treated with different concentrations of Pb acetate. Subsequently, Cell viability was measured by the Cell Counting Kit-8 (CCK-8) assay. The levels of lactate dehydrogenase (LDH), aspartate transaminase (AST) and creatine kinase-MB (CK-MB) in the supernatants were measured using respective commercial enzyme-linked immune sorbent assay (ELISA) kits. Western blot was used to detect the expression of apoptosis-related protein in H9c2 cells in each group. Quantitative RT-PCR Analysis Total RNA was extracted from frozen H9c2 cells using Trizol reagent, the PKCα and Cx43 in the supernatant of H9c2 cells was determined by the BCA protein detection kit. RESULTS H9c2 cells increased release of cardiac enzymes (LDH, AST, and CK-MB) and decreased cell survival rate, and the Cx43, p-Cx43, PKCα and p-PKCα protein levels showed a dose-dependent decrease after Pb treatment. PKCα was activated with PMA, the relative expression level of Cx43 protein increased significantly, the expression of Bcl-2 increased and Bax and Cyt-c decreased compared with Pb exposure group, and the myocardial enzymes (LDH, AST, and CK-MB) in cell culture supernatant decreased compared with Pb exposure group, indicating that the degree of cell damage was alleviated. Results showed that Pb inhibited PKCα activity, decreased the expression of total Cx43 and P-Cx43 protein, and aggravated myocardial injury. CONCLUSIONS Pb decrease gap junction intercellular communication, which induce apoptosis in H9c2 cells by inhibiting the PKCα/Cx43 signaling pathway.
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Affiliation(s)
- Qiong Wang
- Jinan Center for Disease Control and Prevention, Ji'nan, 250021, Shandong, China
| | - Yinghua Ma
- Shandong Academy of Occupational Health and Occupational Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, 250062, Shandong, China
| | - Yi Li
- Shandong Academy of Occupational Health and Occupational Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, 250062, Shandong, China
| | - Zhen He
- Shandong Academy of Occupational Health and Occupational Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, 250062, Shandong, China; Shandong Province Hospital of Occupational Diseases, Ji'nan, 250002, Shandong, China.
| | - Bin Feng
- Shandong Academy of Occupational Health and Occupational Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, 250062, Shandong, China.
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Hendi A, Niu LG, Snow AW, Ikegami R, Wang ZW, Mizumoto K. Channel-independent function of UNC-9/Innexin in spatial arrangement of GABAergic synapses in C. elegans. eLife 2022; 11:80555. [PMID: 36378164 PMCID: PMC9665852 DOI: 10.7554/elife.80555] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 11/03/2022] [Indexed: 11/16/2022] Open
Abstract
Precise synaptic connection of neurons with their targets is essential for the proper functioning of the nervous system. A plethora of signaling pathways act in concert to mediate the precise spatial arrangement of synaptic connections. Here we show a novel role for a gap junction protein in controlling tiled synaptic arrangement in the GABAergic motor neurons in Caenorhabditis elegans, in which their axons and synapses overlap minimally with their neighboring neurons within the same class. We found that while EGL-20/Wnt controls axonal tiling, their presynaptic tiling is mediated by a gap junction protein UNC-9/Innexin, that is localized at the presynaptic tiling border between neighboring dorsal D-type GABAergic motor neurons. Strikingly, the gap junction channel activity of UNC-9 is dispensable for its function in controlling tiled presynaptic patterning. While gap junctions are crucial for the proper functioning of the nervous system as channels, our finding uncovered the novel channel-independent role of UNC-9 in synapse patterning.
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Affiliation(s)
- Ardalan Hendi
- Department of Zoology, University of British Columbia
- Life Sciences Institute, University of British Columbia
| | - Long-Gang Niu
- Department of Neuroscience, University of Connecticut Health Center
| | - Andrew William Snow
- Graduate Program in Cell and Developmental Biology, University of British Columbia
| | | | - Zhao-Wen Wang
- Department of Neuroscience, University of Connecticut Health Center
| | - Kota Mizumoto
- Department of Zoology, University of British Columbia
- Life Sciences Institute, University of British Columbia
- Graduate Program in Cell and Developmental Biology, University of British Columbia
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia
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Bioelectric regulation of intestinal stem cells. Trends Cell Biol 2022:S0962-8924(22)00234-3. [PMID: 36396487 PMCID: PMC10183058 DOI: 10.1016/j.tcb.2022.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022]
Abstract
Proper regulation of ion balance across the intestinal epithelium is essential for physiological functions, while ion imbalance causes intestinal disorders with dire health consequences. Ion channels, pumps, and exchangers are vital for regulating ion movements (i.e., bioelectric currents) that control epithelial absorption and secretion. Recent in vivo studies used the Drosophila gut to identify conserved pathways that link regulators of Ca2+, Na+ and Cl- with intestinal stem cell (ISC) proliferation. These studies laid a foundation for using the Drosophila gut to identify conserved proliferative responses triggered by bioelectric regulators. Here, we review these studies, discuss their significance, as well as the advantages of using Drosophila to unravel conserved bioelectrically induced molecular pathways in the intestinal epithelium under physiological, pathophysiological, and regenerative conditions.
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Huo Y, Zhou Y, Zheng J, Jin G, Tao L, Yao H, Zhang J, Sun Y, Liu Y, Hu LP. GJB3 promotes pancreatic cancer liver metastasis by enhancing the polarization and survival of neutrophil. Front Immunol 2022; 13:983116. [PMID: 36341459 PMCID: PMC9627207 DOI: 10.3389/fimmu.2022.983116] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/28/2022] [Indexed: 07/26/2023] Open
Abstract
Connexins are membrane expressed proteins, which could assemble into hexamers to transfer metabolites and secondary messengers. However, its roles in pancreatic cancer metastasis remains unknown. In this study, by comparing the gene expression patterns in primary pancreatic cancer patients primary and liver metastasis specimens, we found that Gap Junction Protein Beta 3 (GJB3) significantly increased in Pancreatic ductal adenocarcinoma (PDAC) liver metastasis. Animal experiments verified that GJB3 depletion suppressed the hepatic metastasis of PDAC cancer cells. Further, GJB3 over expression increased the neutrophil infiltration. Mechanistic study revealed that GJB3 form channels between PDAC tumor cells and accumulated neutrophil, which transfer cyclic adenosine monophosphate (cAMP) from cancer to neutrophil cells, which supports the survival and polarization. Taken together, our data suggesting that GJB3 could act as a potential therapeutic target of PDAC liver metastasis.
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Affiliation(s)
- Yanmiao Huo
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yaoqi Zhou
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jiahao Zheng
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Guangxin Jin
- Department of Interventional Oncology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lingye Tao
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hongfei Yao
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Junfeng Zhang
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yongwei Sun
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yingbin Liu
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Li-Peng Hu
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Shi Y, Li X, Yang J. Mutations of CX46/CX50 and Cataract Development. Front Mol Biosci 2022; 9:842399. [PMID: 35223995 PMCID: PMC8874012 DOI: 10.3389/fmolb.2022.842399] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 01/12/2022] [Indexed: 12/24/2022] Open
Abstract
Cataract is a common disease in the aging population. Gap junction has been considered a central component in maintaining homeostasis for preventing cataract formation. Gap junction channels consist of connexin proteins with more than 20 members. Three genes including GJA1, GJA3, and GJA8, that encode protein Cx43 (connexin43), Cx46 (connexin46), and Cx50 (connexin50), respectively, have been identified in human and rodent lens. Cx46 together with Cx50 have been detected in lens fiber cells with high expression, whereas Cx43 is mainly expressed in lens epithelial cells. Disrupted expression of the two connexin proteins Cx46 and Cx50 is directly related to the development of severe cataract in human and mice. In this review article, we describe the main role of Cx46 and Cx50 connexin proteins in the lens and the relationship between mutations of Cx46 or Cx50 and hereditary cataracts. Furthermore, the latest progress in the fundamental research of lens connexin and the mechanism of cataract formation caused by lens connexin dysfunction are summarized. Overall, targeting connexin could be a novel approach for the treatment of cataract.
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Affiliation(s)
- Yumeng Shi
- Key Laboratory of Visual Impairment and Restoration of Shanghai, Department of Ophthalmology and Visual Science, Eye Ear Nose and Throat Hospital of Fudan University, Shanghai, China
| | - Xinbo Li
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, United States
- *Correspondence: Jin Yang, ; Xinbo Li,
| | - Jin Yang
- Key Laboratory of Visual Impairment and Restoration of Shanghai, Department of Ophthalmology and Visual Science, Eye Ear Nose and Throat Hospital of Fudan University, Shanghai, China
- *Correspondence: Jin Yang, ; Xinbo Li,
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Guan L, Yang Y, Liang JJ, Miao Y, Shang AY, Wang B, Wang YC, Ding M. ERGIC2 and ERGIC3 regulate the ER-to-Golgi transport of gap junction proteins in metazoans. Traffic 2022; 23:140-157. [PMID: 34994051 DOI: 10.1111/tra.12830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/16/2021] [Accepted: 01/04/2022] [Indexed: 11/26/2022]
Abstract
The extremely dynamic life cycle of gap junction connections requires highly efficient intracellular trafficking system especially designed for gap junction proteins, but the underlying mechanisms are largely unknown. Here, we identified that the COPII-associated proteins ERGIC2 (ER-Golgi intermediate compartment) and ERGIC3 are specifically required for the efficient intracellular transport of gap junction proteins in both C. elegans and mice. In the absence of Ergic2 or Ergic3, gap junction proteins accumulate in the ER and Golgi apparatus and the size of endogenous gap junction plaques is reduced. Knocking out the Ergic2 or Ergic3 in mice results in heart enlargement and cardiac malfunction accompanied by reduced number and size of connexin 43 (Cx43) gap junctions. Invertebrates' gap junction protein innexins share no sequence similarity with vertebrates' connexins. However, ERGIC2 and ERGIC3 could bind to gap junction proteins in both worms and mice. Characterization of the highly specialized roles of ERGIC2 and ERGIC3 in metazoans reveals how the early secretory pathway could be adapted to facilitate the efficient transport for gap junction proteins in vivo. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Liying Guan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yongzhi Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jing Jing Liang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yue Miao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Ang Yang Shang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Baolei Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Ying Chun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Mei Ding
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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Héja L, Simon Á, Szabó Z, Kardos J. Connexons Coupling to Gap Junction Channel: Potential Role for Extracellular Protein Stabilization Centers. Biomolecules 2021; 12:biom12010049. [PMID: 35053197 PMCID: PMC8773650 DOI: 10.3390/biom12010049] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/21/2021] [Accepted: 12/27/2021] [Indexed: 12/13/2022] Open
Abstract
Connexin (Cx) proteins establish intercellular gap junction channels (Cx GJCs) through coupling of two apposed hexameric Cx hemichannels (Cx HCs, connexons). Pre- and post-GJ interfaces consist of extracellular EL1 and EL2 loops, each with three conserved cysteines. Previously, we reported that known peptide inhibitors, mimicking a variety of Cx43 sequences, appear non-selective when binding to homomeric Cx43 vs. Cx36 GJC homology model subtypes. In pursuit of finding potentially Cx subtype-specific inhibitors of connexon-connexon coupling, we aimed at to understand better how the GJ interface is formed. Here we report on the discovery of Cx GJC subtype-specific protein stabilization centers (SCs) featuring GJ interface architecture. First, the Cx43 GJC homology model, embedded in two opposed membrane bilayers, has been devised. Next, we endorsed the fluctuation dynamics of SCs of the interface domain of Cx43 GJC by applying standard molecular dynamics under open and closed cystine disulfide bond (CS-SC) preconditions. The simulations confirmed the major role of the unique trans-GJ SC pattern comprising conserved (55N, 56T) and non-conserved (57Q) residues of the apposed EL1 loops in the stabilization of the GJC complex. Importantly, clusters of SC patterns residing close to the GJ interface domain appear to orient the interface formation via the numerous SCs between EL1 and EL2. These include central 54CS-S198C or 61CS-S192C contacts with residues 53R, 54C, 55N, 197D, 199F or 64V, 191P, respectively. In addition, we revealed that GJC interface formation is favoured when the psi dihedral angle of the nearby 193P residue is stable around 180° and the interface SCs disappear when this angle moves to the 0° to −45° range. The potential of the association of non-conserved residues with SC motifs in connexon-connexon coupling makes the development of Cx subtype-specific inhibitors viable.
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Xiang Y, Peng F, Guo Y, Ge H, Cai S, Fan L, Peng Y, Wen H, Wang Q, Tao L. Connexin32 activates necroptosis through Src-mediated inhibition of caspase 8 in hepatocellular carcinoma. Cancer Sci 2021; 112:3507-3519. [PMID: 34050696 PMCID: PMC8409421 DOI: 10.1111/cas.14994] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 05/19/2021] [Accepted: 05/25/2021] [Indexed: 12/28/2022] Open
Abstract
Necroptosis is an alternative form of programmed cell death that generally occurs under apoptosis-deficient conditions. Our previous work showed that connexin32 (Cx32) promotes the malignant progress of hepatocellular carcinoma (HCC) by enhancing the ability of resisting apoptosis in vivo and in vitro. Whether triggering necroptosis is a promising strategy to eliminate the apoptosis-resistant HCC cells with high Cx32 expression remains unknown. In this study, we found that Cx32 expression was positively correlated with the expression of necroptosis protein biomarkers in human HCC specimens, cell lines, and a xenograft model. Treatment with shikonin, a well-used necroptosis inducer, markedly caused necroptosis in HCC cells. Interestingly, overexpressed Cx32 exacerbated shikonin-induced necroptosis, but downregulation of Cx32 alleviated necroptosis in vitro and in vivo. Mechanistically, Cx32 was found to bind to Src and promote Src-mediated caspase 8 phosphorylation and inactivation, which ultimately reduced the activated caspase 8-mediated proteolysis of receptor-interacting serine-threonine protein kinase 1/3, the key molecule for necroptosis activation. In conclusion, we showed that Cx32 contributed to the activation of necroptosis in HCC cells through binding to Src and then mediating the inactivation of caspase 8. The present study suggested that necroptosis inducers could be more favorable than apoptosis inducers to eliminate HCC cells with high expression of Cx32.
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Affiliation(s)
- Yu‐ke Xiang
- Department of Pharmacology, Zhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- Key Laboratory of Molecular Target & Clinical Pharmacology, School of Pharmaceutical Sciences & The Fifth Affiliated HospitalGuangzhou Medical UniversityGuangzhouChina
| | - Fu‐hua Peng
- Department of Pharmacology, Zhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Yun‐quan Guo
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central AsiaThe First Affiliated Hospital of Xinjiang Medical UniversityUrumqiPR China
| | - Hui Ge
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central AsiaThe First Affiliated Hospital of Xinjiang Medical UniversityUrumqiPR China
| | - Shao‐yi Cai
- Department of Pharmacology, Zhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Li‐xia Fan
- Department of Pharmacology, Zhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Yue‐xia Peng
- Department of Pharmacology, Zhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Hao Wen
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central AsiaThe First Affiliated Hospital of Xinjiang Medical UniversityUrumqiPR China
| | - Qin Wang
- Department of Pharmacology, Zhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Liang Tao
- Department of Pharmacology, Zhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central AsiaThe First Affiliated Hospital of Xinjiang Medical UniversityUrumqiPR China
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Zheng XS, Zheng H, Xu D, Liu PP, Li B, Cao ZM, Liu Y, Liu Y. Effect of zymosan on the expression and function of the gap-junction protein connexin 43 in human corneal fibroblasts. Int J Ophthalmol 2021; 14:341-348. [PMID: 33747807 DOI: 10.18240/ijo.2021.03.02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 11/17/2020] [Indexed: 12/27/2022] Open
Abstract
AIM To study the effect of zymosan, a ligand found on the surface of fungi, on gap junctional intercellular communication (GJIC) in cultured human corneal fibroblasts (HCFs). METHODS Zymosan was added to the medium of cultured HCFs with or without the administration of mitogen-activated protein kinase (MAPK) inhibitors or the inhibitor kappa B kinase 2 (IKK2) inhibitor IV. The protein and mRNA levels of connexin 43 (Cx43) in HCFs were measured by Western blot, immunofluorescence, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses. The GJIC activity was tested using a dye-coupling assay. RESULTS The reduction of Cx43 protein and mRNA levels as well as a significant decrease in GJIC activity were observed in cultured HCFs when zymosan was added into the culture medium. Compared with controls (no zymosan), the protein level of Cx43 was reduced by 45% and 54% in the presence of zymosan at 200 and 600 µg/mL, respectively (P<0.05); and it was reduced by 45%, 48%, and 75% in the presence of zymosan (600 µg/mL) for 24, 36, and 48h, respectively (P<0.05). The mRNA expression of Cx43 was reduced by 98% in the presence of zymosan (P<0.05). The effects of zymosan on Cx43 expression and GJIC activity were attenuated by the administration of PD98059 [an extracellular signal-regulated kinase (ERK) signaling inhibitor] (P<0.05), c-Jun NH2-terminal kinase (JNK) inhibitor II (P<0.05), and IKK2 inhibitor IV (P<0.05). CONCLUSION Zymosan inhibits the activity of GJIC in cultured HCFs. This effect is likely regulated via the nuclear factor-κB (NF-κB), MAPK/ERK, and JNK signaling pathways. The inhibitory effects of zymosan on Cx43 expression and GJIC activity in HCFs may induce damage of corneal stroma during corneal fungal infection.
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Affiliation(s)
- Xiao-Shuo Zheng
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Hui Zheng
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Dan Xu
- Institute of Environmental Systems Biology, Environmental Science and Engineering College, Dalian Maritime University, Dalian 116027, Liaoning Province, China
| | - Ping-Ping Liu
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Bing Li
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Zi-Mu Cao
- Institute of Environmental Systems Biology, Environmental Science and Engineering College, Dalian Maritime University, Dalian 116027, Liaoning Province, China
| | - Yang Liu
- Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
| | - Ye Liu
- Department of Pathology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangzhou Province, China
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Fernandez-Abascal J, Graziano B, Encalada N, Bianchi L. Glial Chloride Channels in the Function of the Nervous System Across Species. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:195-223. [PMID: 35138616 DOI: 10.1007/978-981-16-4254-8_10] [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] [Indexed: 10/19/2022]
Abstract
In the nervous system, the concentration of Cl- in neurons that express GABA receptors plays a key role in establishing whether these neurons are excitatory, mostly during early development, or inhibitory. Thus, much attention has been dedicated to understanding how neurons regulate their intracellular Cl- concentration. However, regulation of the extracellular Cl- concentration by other cells of the nervous system, including glia and microglia, is as important because it ultimately affects the Cl- equilibrium potential across the neuronal plasma membrane. Moreover, Cl- ions are transported in and out of the cell, via either passive or active transporter systems, as counter ions for K+ whose concentration in the extracellular environment of the nervous system is tightly regulated because it directly affects neuronal excitability. In this book chapter, we report on the Cl- channel types expressed in the various types of glial cells focusing on the role they play in the function of the nervous system in health and disease. Furthermore, we describe the types of stimuli that these channels are activated by, the other solutes that they may transport, and the involvement of these channels in processes such as pH regulation and Regulatory Volume Decrease (RVD). The picture that emerges is one of the glial cells expressing a variety of Cl- channels, encoded by members of different gene families, involved both in short- and long-term regulation of the nervous system function. Finally, we report data on invertebrate model organisms, such as C. elegans and Drosophila, that are revealing important and previously unsuspected functions of some of these channels in the context of living and behaving animals.
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Affiliation(s)
- Jesus Fernandez-Abascal
- Department Physiology and Biophysics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Bianca Graziano
- Department Physiology and Biophysics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Nicole Encalada
- Department Physiology and Biophysics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Laura Bianchi
- Department Physiology and Biophysics, University of Miami, Miller School of Medicine, Miami, FL, USA.
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Kordowitzki P, Kranc W, Bryl R, Kempisty B, Skowronska A, Skowronski MT. The Relevance of Aquaporins for the Physiology, Pathology, and Aging of the Female Reproductive System in Mammals. Cells 2020; 9:cells9122570. [PMID: 33271827 PMCID: PMC7760214 DOI: 10.3390/cells9122570] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/23/2020] [Accepted: 11/29/2020] [Indexed: 12/26/2022] Open
Abstract
Aquaporins constitute a group of water channel proteins located in numerous cell types. These are pore-forming transmembrane proteins, which mediate the specific passage of water molecules through membranes. It is well-known that water homeostasis plays a crucial role in different reproductive processes, e.g., oocyte transport, hormonal secretion, completion of successful fertilization, blastocyst formation, pregnancy, and birth. Further, aquaporins are involved in the process of spermatogenesis, and they have been reported to be involved during the storage of spermatozoa. It is noteworthy that aquaporins are relevant for the physiological function of specific parts in the female reproductive system, which will be presented in detail in the first section of this review. Moreover, they are relevant in different pathologies in the female reproductive system. The contribution of aquaporins in selected reproductive disorders and aging will be summarized in the second section of this review, followed by a section dedicated to aquaporin-related proteins. Since the relevance of aquaporins for the male reproductive system has been reviewed several times in the recent past, this review aims to provide an update on the distribution and impact of aquaporins only in the female reproductive system. Therefore, this paper seeks to determine the physiological and patho-physiological relevance of aquaporins on female reproduction, and female reproductive aging.
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Affiliation(s)
- Paweł Kordowitzki
- Department of Basic and Preclinical Sciences, Institute for Veterinary Medicine, Nicolaus Copernicus University, 87-100 Torun, Poland;
- Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, 10-243 Olsztyn, Poland
| | - Wiesława Kranc
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznan, Poland; (W.K.); (R.B.); (B.K.)
| | - Rut Bryl
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznan, Poland; (W.K.); (R.B.); (B.K.)
| | - Bartosz Kempisty
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznan, Poland; (W.K.); (R.B.); (B.K.)
- Department of Histology and Embryology, Poznan University of Medical Sciences, 60-781 Poznan, Poland
- Department of Veterinary Surgery, Institute for Veterinary Medicine, Nicolaus Copernicus University, 87-100 Torun, Poland
| | - Agnieszka Skowronska
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury, Warszawska Street 30, 10-082 Olsztyn, Poland;
| | - Mariusz T. Skowronski
- Department of Basic and Preclinical Sciences, Institute for Veterinary Medicine, Nicolaus Copernicus University, 87-100 Torun, Poland;
- Correspondence: ; Tel.: +48-56-611-2231
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Cell Communications among Microorganisms, Plants, and Animals: Origin, Evolution, and Interplays. Int J Mol Sci 2020; 21:ijms21218052. [PMID: 33126770 PMCID: PMC7663094 DOI: 10.3390/ijms21218052] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/17/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023] Open
Abstract
Cellular communications play pivotal roles in multi-cellular species, but they do so also in uni-cellular species. Moreover, cells communicate with each other not only within the same individual, but also with cells in other individuals belonging to the same or other species. These communications occur between two unicellular species, two multicellular species, or between unicellular and multicellular species. The molecular mechanisms involved exhibit diversity and specificity, but they share common basic features, which allow common pathways of communication between different species, often phylogenetically very distant. These interactions are possible by the high degree of conservation of the basic molecular mechanisms of interaction of many ligand-receptor pairs in evolutionary remote species. These inter-species cellular communications played crucial roles during Evolution and must have been positively selected, particularly when collectively beneficial in hostile environments. It is likely that communications between cells did not arise after their emergence, but were part of the very nature of the first cells. Synchronization of populations of non-living protocells through chemical communications may have been a mandatory step towards their emergence as populations of living cells and explain the large commonality of cell communication mechanisms among microorganisms, plants, and animals.
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Cocozzelli AG, White TW. Connexin 43 Mutations Lead to Increased Hemichannel Functionality in Skin Disease. Int J Mol Sci 2019; 20:ijms20246186. [PMID: 31817921 PMCID: PMC6940829 DOI: 10.3390/ijms20246186] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/29/2019] [Accepted: 12/04/2019] [Indexed: 12/22/2022] Open
Abstract
Gap junctional channels are specialized components of the cellular membrane that allow the intercellular passage of small metabolites, ions, and second messengers to maintain homeostasis. They are comprised of members of the connexin gene family that encode a wide array of proteins that are expressed in nearly every tissue type. Cx43 is perceived to be the most broadly expressed connexin in humans, with several genetic skin diseases being linked to Cx43 mutations specifically. These mutations, in large, produce a gain of functional hemichannels that contribute to the phenotypes of Erythrokeratoderma Variabilis et Progressiva (EKVP), Palmoplantar Keratodemra Congenital Alopecia-1 (PPKCA1), and others that produce large conductance and increased permselectivity in otherwise quiescent structures. Gaining functional hemichannels can have adverse effects in the skin, inducing apoptosis via Ca2+ overload or increased ATP permeability. Here, we review the link between Cx43 and skin disease. We aim to provide insight into the mechanisms regulating the normal and pathophysiological gating of these essential proteins, as well as address current therapeutic strategies. We also demonstrate that transient transfection of neuro-2a (N2a) cells with mutant Cx43 cDNA resulted in increased hemichannel activity compared to wild-type Cx43 and untransfected cells, which is consistent with other studies in the current literature.
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Yang L, Dong C, Tian L, Ji X, Yang L, Li L. Gadolinium Chloride Restores the Function of the Gap Junctional Intercellular Communication between Hepatocytes in a Liver Injury. Int J Mol Sci 2019; 20:E3748. [PMID: 31370360 PMCID: PMC6695937 DOI: 10.3390/ijms20153748] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Gadolinium chloride (GdCl3) has been reported to attenuate liver injury caused by a variety of toxicants. Gap junctional intercellular communication (GJIC) is thought to be essential in controlling liver homeostasis and pathology. Here we evaluate the effects of GdCl3 on functional GJIC and connexin expression in mouse models and primary hepatocytes. METHODS Mice were administered GdCl3 intraperitoneally the day before a carbon tetrachloride (CCl4) injection or bile duct ligation (BDL) operation. Primary hepatocytes were treated with CCl4 or lipopolysaccharides (LPS), with or without GdCl3. A scrape loading/dye transfer assay was performed to assess the GJIC function. The expression of connexins was examined by real-time reverse transcription polymerase chain reaction (RT-PCR), western blot and immunofluorescent staining. RESULTS CCl4 treatment or the BDL operation led to the dysfunction of GJIC and a down-regulation of Cx32 and Cx26 in injured liver. GdCl3 administration restored GJIC function between hepatocytes by facilitating the transfer of fluorescent dye from one cell into adjacent cells via GJIC, and markedly prevented the decrease of Cx32 and Cx26 in injured liver. In primary hepatocytes, CCl4 or LPS treatment induced an obvious decline of Cx32 and Cx26, whereas GdCl3 pretreatment prevented the down-regulation of connexins. In vivo GdCl3 protected hepatocytes and attenuated the liver inflammation and fibrosis in liver injury mouse models. CONCLUSION GdCl3 administration protects functional GJIC between hepatocytes, and prevents the decrease of connexin proteins at mRNA and protein levels during liver injury, leading to the alleviation of chronic liver injury.
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Affiliation(s)
- Le Yang
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
| | - Chengbin Dong
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
| | - Lei Tian
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
| | - Xiaofang Ji
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
| | - Lin Yang
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
| | - Liying Li
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China.
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