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Jiao B, Jiang H, Liu S, Wang Y, Chen Y, Duan H, Niu Y, Shen M, Wang H, Dai Y. Unveiling the mechanisms of trichloroethylene hypersensitivity syndrome: Exploring the role of connexin 43 gap junctions in severe skin damage. Food Chem Toxicol 2024; 187:114594. [PMID: 38485042 DOI: 10.1016/j.fct.2024.114594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/04/2024] [Accepted: 03/11/2024] [Indexed: 03/23/2024]
Abstract
Trichloroethylene (TCE), extensively used as an organic solvent in various industrial applications, has been identified as a causative factor in inducing hypersensitivity syndrome (THS). Currently, there is no specific treatment for THS, and most patients experience serious adverse outcomes due to extensive skin damage leading to severe infection. However, the pathogenesis of THS-associated skin damage remains unclear. This study aims to elucidate the mechanism underlying skin damage from the perspective of intercellular communication and gap junctions in THS. Our results verified that hyperactivation of connexin43 gap junctions, caused by the aberrantly elevated expression of connexin43, triggers a bystander effect that promotes apoptosis and inflammation in THS via the TNF-TNFRSF1B and mitochondria-associated pathways. Additionally, we identified the gap junction inhibitor Carbenoxolone disodium (CBX) as a promising agent for the treatment of skin damage in THS. CBX protects against inflammatory cell infiltration in the skin and decreases immune cell imbalance in the peripheral blood of THS mice. Furthermore, CBX reduces connexin43 expression, apoptosis and inflammation in THS mice. The study reveals new insights into the mechanisms underlying TCE-induced skin damage, offering a potential treatment strategy for the development of effective therapies targeting severe dermatitis induced by chemical exposure.
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Affiliation(s)
- Bo Jiao
- National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, 100050, China
| | - Haiqin Jiang
- Institute of Dermatology, Chinese Academy of Medical Sciences, National Center for STD and Leprosy Control, China CDC, Nanjing, China
| | - Shuai Liu
- National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, 100050, China
| | - Yican Wang
- National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, 100050, China
| | - Yuanyuan Chen
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Huawei Duan
- National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, 100050, China
| | - Yong Niu
- National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, 100050, China
| | - Meili Shen
- National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, 100050, China
| | - Hongsheng Wang
- Institute of Dermatology, Chinese Academy of Medical Sciences, National Center for STD and Leprosy Control, China CDC, Nanjing, China
| | - Yufei Dai
- National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, 100050, China; China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China.
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2
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Wanjari UR, Gopalakrishnan AV. Blood-testis barrier: a review on regulators in maintaining cell junction integrity between Sertoli cells. Cell Tissue Res 2024; 396:157-175. [PMID: 38564020 DOI: 10.1007/s00441-024-03894-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 03/20/2024] [Indexed: 04/04/2024]
Abstract
The blood-testis barrier (BTB) is formed adjacent to the seminiferous basement membrane. It is a distinct ultrastructure, partitioning testicular seminiferous epithelium into apical (adluminal) and basal compartments. It plays a vital role in developing and maturing spermatocytes into spermatozoa via reorganizing its structure. This enables the transportation of preleptotene spermatocytes across the BTB, from basal to adluminal compartments in the seminiferous tubules. Several bioactive peptides and biomolecules secreted by testicular cells regulate the BTB function and support spermatogenesis. These peptides activate various downstream signaling proteins and can also be the target themself, which could improve the diffusion of drugs across the BTB. The gap junction (GJ) and its coexisting junctions at the BTB maintain the immunological barrier integrity and can be the "gateway" during spermatocyte transition. These junctions are the possible route for toxicant entry, causing male reproductive dysfunction. Herein, we summarize the detailed mechanism of all the regulators playing an essential role in the maintenance of the BTB, which will help researchers to understand and find targets for drug delivery inside the testis.
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Affiliation(s)
- Uddesh Ramesh Wanjari
- Department of Biomedical Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology, Tamil Nadu, Vellore, PIN 632014, India
| | - Abilash Valsala Gopalakrishnan
- Department of Biomedical Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology, Tamil Nadu, Vellore, PIN 632014, India.
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3
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Zhang Z, Luo Y, Ma Y, Zhou Y, Zhu D, Shen W, Liu J. Photocatalytic manipulation of Ca 2+ signaling for regulating cellular and animal behaviors via MOF-enabled H 2O 2 generation. Sci Adv 2024; 10:eadl0263. [PMID: 38640246 PMCID: PMC11029810 DOI: 10.1126/sciadv.adl0263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 03/18/2024] [Indexed: 04/21/2024]
Abstract
The in situ generation of H2O2 in cells in response to external stimulation has exceptional advantages in modulating intracellular Ca2+ dynamics, including high controllability and biological safety, but has been rarely explored. Here, we develop photocatalyst-based metal-organic frameworks (DCSA-MOFs) to modulate Ca2+ responses in cells, multicellular spheroids, and organs. By virtue of the efficient photocatalytic oxygen reduction to H2O2 without sacrificial agents, photoexcited DCSA-MOFs can rapidly trigger Ca2+ outflow from the endoplasmic reticulum with single-cell precision in a repeatable and controllable manner, enabling the propagation of intercellular Ca2+ waves (ICW) over long distances in two-dimensional and three-dimensional cell cultures. After photoexcitation, ICWs induced by DCSA-MOFs can activate neural activities in the optical tectum of tadpoles and thighs of spinal frogs, eliciting the corresponding motor behaviors. Our study offers a versatile optical nongenetic modulation technique that enables remote, repeatable, and controlled manipulation of cellular and animal behaviors.
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Affiliation(s)
- Zherui Zhang
- College of Material, Chemistry, and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou 311121, China
| | - Yuhao Luo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 310036, China
| | - Yuanhong Ma
- College of Material, Chemistry, and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou 311121, China
| | - Yaofeng Zhou
- Westlake University, Shilongshan Rd. Cloud Town, Xihu District, Hangzhou, Zhejiang, China
| | - Dingcheng Zhu
- College of Material, Chemistry, and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou 311121, China
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 310036, China
| | - Junqiu Liu
- College of Material, Chemistry, and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou 311121, China
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Mao W, Chen S. Assembly mechanisms of the neuronal gap junction channel connexin 36 elucidated by Cryo-EM. Arch Biochem Biophys 2024; 754:109959. [PMID: 38490311 DOI: 10.1016/j.abb.2024.109959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/20/2024] [Accepted: 03/12/2024] [Indexed: 03/17/2024]
Abstract
Electrical synapses are essential components of neural circuits. Neuronal signal transduction across electrical synapses is primarily mediated by gap junction channels composed of Connexin36 (Cx36), the lack of which causes impaired electrical coupling between certain neurons including cortical interneurons and thalamic reticular nucleus (TRN) neurons. However, the structural basis underlying Cx36 function and assembly remains elusive. Recently, Lee et al. reported cryo-EM structures of Cx36, thus provided first insights of its gating mechanism. Here, we report a consistent cryo-EM structure of Cx36 determined in parallel, and describe unique interactions underpinning its assembly mechanism in complementary to the competing work. In particular, we found non-canonical electrostatic interactions between protomers from opposing hemichannels and a steric complementary site between adjacent protomers within a hemichannel, which together provide a structural explanation for the assembly specificity in homomeric and heteromeric gap junction channels.
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Affiliation(s)
- Wenxuan Mao
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China; Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shanshuang Chen
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China; Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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5
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Schlaeger L, Olejniczak I, Lehmann M, Schmidt CX, Astiz M, Oster H, Pilorz V. Estrogen-mediated coupling via gap junctions in the suprachiasmatic nucleus. Eur J Neurosci 2024; 59:1723-1742. [PMID: 38326974 DOI: 10.1111/ejn.16270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 01/11/2024] [Accepted: 01/22/2024] [Indexed: 02/09/2024]
Abstract
The circadian clock orchestrates many physiological and behavioural rhythms in mammals with 24-h periodicity, through a hierarchical organisation, with the central clock located in the suprachiasmatic nucleus (SCN) in the hypothalamus. The circuits of the SCN generate circadian rhythms with precision, relying on intrinsic coupling mechanisms, for example, neurotransmitters like arginine vasopressin (AVP), vasoactive intestinal peptide (VIP), neuronal gamma-aminobutyric acid (GABA) signalling and astrocytes connected by gap junctions composed of connexins (Cx). In female rodents, the presence of estrogen receptors (ERs) in the dorsal SCN suggests an influence of estrogen (E2) on the circuit timekeeping that could regulate circadian rhythm and coupling. To investigate this, we used SCN explants together with hypothalamic neurons and astrocytes. First, we showed that E2 stabilised the circadian amplitude in the SCN when rAVPs (receptor-associated vasopressin peptides) were inhibited. However, the phase delay induced by VIPAC2 (VIP receptors) inhibition remained unaffected by E2. We then showed that E2 exerted its effects in the SCN via ERβ (estrogen receptor beta), resulting in increased expression of Cx36 and Cx43. Notably, specific inhibition of both connexins resulted in a significant reduction in circadian amplitude within the SCN. Remarkably, E2 restored the period with inhibited Cx36 but not with Cx43 inhibition. This implies that the network between astrocytes and neurons, responsible for coupling in the SCN, can be reinforced through E2. In conclusion, these findings provide new insights into how E2 regulates circadian rhythms ex vivo in an ERβ-dependent manner, underscoring its crucial role in fortifying the SCN's rhythm.
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Affiliation(s)
- Lina Schlaeger
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Iwona Olejniczak
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Marianne Lehmann
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Cosima Xenia Schmidt
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Mariana Astiz
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Henrik Oster
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Violetta Pilorz
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
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Leighton SE, Wong RS, Lucaciu SA, Hauser A, Johnston D, Stathopulos PB, Bai D, Penuela S, Laird DW. Cx31.1 can selectively intermix with co-expressed connexins to facilitate its assembly into gap junctions. J Cell Sci 2024; 137:jcs261631. [PMID: 38533727 DOI: 10.1242/jcs.261631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/05/2024] [Indexed: 03/28/2024] Open
Abstract
Connexins are channel-forming proteins that function to facilitate gap junctional intercellular communication. Here, we use dual cell voltage clamp and dye transfer studies to corroborate past findings showing that Cx31.1 (encoded by GJB5) is defective in gap junction channel formation, illustrating that Cx31.1 alone does not form functional gap junction channels in connexin-deficient mammalian cells. Rather Cx31.1 transiently localizes to the secretory pathway with a subpopulation reaching the cell surface, which is rarely seen in puncta reminiscent of gap junctions. Intracellular retained Cx31.1 was subject to degradation as Cx31.1 accumulated in the presence of proteasomal inhibition, had a faster turnover when Cx43 was present and ultimately reached lysosomes. Although intracellularly retained Cx31.1 was found to interact with Cx43, this interaction did not rescue its delivery to the cell surface. Conversely, the co-expression of Cx31 dramatically rescued the assembly of Cx31.1 into gap junctions where gap junction-mediated dye transfer was enhanced. Collectively, our results indicate that the localization and functional status of Cx31.1 is altered through selective interplay with co-expressed connexins, perhaps suggesting Cx31.1 is a key regulator of intercellular signaling in keratinocytes.
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Affiliation(s)
- Stephanie E Leighton
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Robert S Wong
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Sergiu A Lucaciu
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON N6A 5C1, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Alexandra Hauser
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Danielle Johnston
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Donglin Bai
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON N6A 5C1, Canada
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, ON N6A 5B9, Canada
- Division of Experimental Oncology, Department of Oncology, University of Western Ontario, London, ON N6A 5W9, Canada
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON N6A 5C1, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5C1, Canada
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7
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Yu S, Ren H, Liu T, Han X, Guo H, Ning Q, Li Y, Zhou H, Chen M, Hu T. Metformin suppresses NFE2L1 pathway activation to inhibit gap junction beta protein expression in NSCLC. Cancer Med 2024; 13:e7021. [PMID: 38562019 PMCID: PMC10985411 DOI: 10.1002/cam4.7021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 01/05/2024] [Accepted: 01/31/2024] [Indexed: 04/04/2024] Open
Abstract
OBJECTIVE Non-small-cell lung cancer (NSCLC) is a deadly form of cancer that exhibits extensive intercellular communication which contributed to chemoradiotherapy resistance. Recent evidence suggests that arrange of key proteins are involved in lung cancer progression, including gap junction proteins (GJPs). METHODS AND RESULTS In this study, we examined the expression patterns of GJPs in NSCLC, uncovering that both gap junction protein, beta 2 (GJB2) and gap junction protein, beta 2 (GJB3) are increased in LUAD and LUSC. We observed a correlation between the upregulation of GJB2, GJB3 in clinical samples and a worse prognosis in patients with NSCLC. By examining the mechanics, we additionally discovered that nuclear factor erythroid-2-related factor 1 (NFE2L1) had the capability to enhance the expression of connexin26 and connexin 31 in the NSCLC cell line A549. In addition, the use of metformin was discovered to cause significant downregulation of gap junction protein, betas (GJBs) by limiting the presence of NFE2L1 in the cytoplasm. CONCLUSION This emphasizes the potential of targeting GJBs as a viable treatment approach for NSCLC patients receiving metformin.
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Affiliation(s)
- Shuo Yu
- Department of Respiratory and Critical Care MedicineThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
- Department of General SurgeryThe Second Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
| | - Hui Ren
- Department of Respiratory and Critical Care MedicineThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
| | - Tingting Liu
- Department of Respiratory and Critical Care MedicineThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
| | - Xiaoyan Han
- Department of General SurgeryWeifang People's HospitalWeifangShandongChina
| | - Hui Guo
- Department of OncologyThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
| | - Qian Ning
- Department of Respiratory and Critical Care MedicineThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
| | - Yang Li
- Department of Respiratory and Critical Care MedicineThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
| | - Hong Zhou
- Department of Respiratory and Critical Care MedicineThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
| | - Mingwei Chen
- Department of Respiratory and Critical Care MedicineThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
| | - Tinghua Hu
- Department of Respiratory and Critical Care MedicineThe First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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9
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Pineros J, Zhu X, Ding B, Frisina RD. Connexins 30 and 43 expression changes in relation to age-related hearing loss. Hear Res 2024; 444:108971. [PMID: 38359484 PMCID: PMC10939722 DOI: 10.1016/j.heares.2024.108971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/27/2024] [Accepted: 02/10/2024] [Indexed: 02/17/2024]
Abstract
Age-related hearing loss (ARHL), also known as presbycusis, is the number one communication disorder for aging adults. Connexin proteins are essential for intercellular communication throughout the human body, including the cochlea. Mutations in connexin genes have been linked to human syndromic and nonsyndromic deafness; thus, we hypothesize that changes in connexin gene and protein expression with age are involved in the etiology of ARHL. Here, connexin gene and protein expression changes for CBA/CaJ mice at different ages were examined, and correlations were analyzed between the changes in expression levels and functional hearing measures, such as ABRs and DPOAEs. Moreover, we investigated potential treatment options for ARHL. Results showed significant downregulation of Cx30 and Cx43 gene expression and significant correlations between the degree of hearing loss and the changes in gene expression for both genes. Moreover, dose-dependent treatments utilizing cochlear cell lines showed that aldosterone hormone therapy significantly increased Cx expression. In vivo mouse treatments with aldosterone also showed protective effects on connexin expression in aging mice. Based on these functionally relevant findings, next steps can include more investigations of the mechanisms related to connexin family gap junction protein expression changes during ARHL; and expand knowledge of clinically-relevant treatment options by knowing what specific members of the Cx family and related inter-cellular proteins should be targeted therapeutically.
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Affiliation(s)
- Jennifer Pineros
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Xiaoxia Zhu
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Bo Ding
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Robert D Frisina
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA; Department of Communication Sciences and Disorders, College of Behavioral & Community Sciences, University of South Florida, Tampa, FL 33620, USA; Morsani College of Medicine, University of South Florida, Tampa, FL 33620, USA.
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10
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Xiong X, Chen W, Chen C, Wu Q, He C. Analysis of the function and therapeutic strategy of connexin 43 from its subcellular localization. Biochimie 2024; 218:1-7. [PMID: 37611889 DOI: 10.1016/j.biochi.2023.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 08/07/2023] [Accepted: 08/18/2023] [Indexed: 08/25/2023]
Abstract
Connexins (Cxs) are a family of transmembrane proteins located in the plasma membrane of human cells, among which connexin 43 (Cx43) is abundantly expressed in various types of human cells. Cx43, encoded by the gap junction protein alpha 1 (GJA1) gene, assembles into a hexameric structure in the Golgi apparatus and translocates to the plasma membrane to form hemichannels (Hcs), which pair with those of the cells in contact with each other and form gap junction intercellular communication (GJIC). The role of Cx43 as a connexin localized at the plasma membrane to perform channel functions is well recognized in previous studies, but recent studies have found that it can also be localized in the nucleus, mitochondria, or present in extracellular vesicles (EVs) and tunneling nanotubes (TNTs). Cx43 in the nucleus is involved in gene transcription regulation, cytoskeleton formation, cell migration and adhesion. Cx43 in mitochondria is involved in mitochondrial respiration-related functions, and Cx43 in extracellular vesicles and tunneling nanotubes is involved in distant cellular information exchange. It is because of the diverse distribution of subcellular localization of Cx43 that it is possible to explore the corresponding functions by analyzing its localization. In this review, we summarize the important roles of Cx43 in disease development from the perspective of subcellular localization, and provide new ideas for Cx43 as a therapeutic target and the search for related pathological mechanisms.
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Affiliation(s)
- Xinhai Xiong
- The Second Affiliated Hospital of Hunan Normal University, Changsha, Hunan, 410003, China
| | - Wenjie Chen
- The Second Affiliated Hospital of Hunan Normal University, Changsha, Hunan, 410003, China
| | - Cheng Chen
- The Second Affiliated Hospital of Hunan Normal University, Changsha, Hunan, 410003, China; 926 Hospital of the People's Liberation Army, Kaiyuan, Yunnan, 661600, China.
| | - Qi Wu
- The Second Affiliated Hospital of Hunan Normal University, Changsha, Hunan, 410003, China
| | - Chaopeng He
- The Second Xiangya Hospital, Changsha, Hunan, 410011, China
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11
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Yao J, Chen C, Sun Y, Lin Y, Tian Z, Liu X, Wang H, Long J, Yan Q, Lin M, Ai Q, Gao Y, Chen N, Yang Y, Yang S. Higenamine exerts antidepressant effect by improving the astrocytic gap junctions and inflammatory response. J Affect Disord 2024; 348:107-115. [PMID: 38101523 DOI: 10.1016/j.jad.2023.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 11/01/2023] [Accepted: 12/02/2023] [Indexed: 12/17/2023]
Abstract
BACKGROUND Depression is a refractory psychiatric disorder closely associated with dysfunction of the gap junctions (GJs) between astrocytes as well as neuroinflammation. Higenamine (Hig) is a potent cardiotonic ingredient in Fuzi (i.e., Aconitum carmichaeli Debx.) with anti-inflammatory and antioxidant effects, which has a significant protective effect on damaged nerve cells and has great potential for the treatment of neuropsychiatric diseases. METHODS Rats were stimulated by chronic unpredictable stress (CUS) for 28 days while given Hig (5, 10, 20 mg/kg) and then analyzed behaviorally by the open field test, sucrose preference test, and forced swimming test. Changes in astrocyte GJs function and morphology were observed by dye transfer and transmission electron microscopy, respectively. Expression and phosphorylation of connexin 43 (Cx43) were analyzed by Western blot. Also, considering the close relationship between depression and neuroinflammation, we determined the inflammatory response in serum with ELISA kits and analyzed the expression of inflammation-related proteins with Western blot. RESULTS Hig ameliorated CUS-induced depression-like behavior in rats. Hig administration improved gap junctional dysfunction in astrocytes, reduced gap junctional gaps and elevated the expression of Cx43 and decreased the phosphorylation of Cx43. Meanwhile, Hig administration was also able to attenuate the inflammatory response that occurs after CUS in rats. LIMITATIONS For the role of Cx43 in depression, we did not validate it more deeply in animal models with knockout Cx43. In addition, GJs dysfunction might be associated with the inflammatory response seen in depression, but this needs to be further investigated. CONCLUSIONS Hig ameliorates depression and exerts its antidepressant effect possibly by improving the dysfunctional GJs between astrocytes and the inflammatory response.
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Affiliation(s)
- Jiao Yao
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Cong Chen
- School of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
| | - Yang Sun
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Yuting Lin
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Zhifeng Tian
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Xinya Liu
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Huiqin Wang
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Junpeng Long
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Qian Yan
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Meiyu Lin
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Qidi Ai
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China
| | - Yan Gao
- Biomedical Innovation Center, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038, China
| | - Naihong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100050, China.
| | - Yantao Yang
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China.
| | - Songwei Yang
- Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha 410208, China.
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12
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Sridhar S, Clayton RH. Fibroblast mediated dynamics in diffusively uncoupled myocytes: a simulation study using 2-cell motifs. Sci Rep 2024; 14:4493. [PMID: 38396245 PMCID: PMC10891142 DOI: 10.1038/s41598-024-54564-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 02/14/2024] [Indexed: 02/25/2024] Open
Abstract
In healthy hearts myocytes are typically coupled to nearest neighbours through gap junctions. Under pathological conditions such as fibrosis, or in scar tissue, or across ablation lines myocytes can uncouple from their neighbours. Electrical conduction may still occur via fibroblasts that not only couple proximal myocytes but can also couple otherwise unconnected regions. We hypothesise that such coupling can alter conduction between myocytes via introduction of delays or by initiation of premature stimuli that can potentially result in reentry or conduction blocks. To test this hypothesis we have developed several 2-cell motifs and investigated the effect of fibroblast mediated electrical coupling between uncoupled myocytes. We have identified various regimes of myocyte behaviour that depend on the strength of gap-junctional conductance, connection topology, and parameters of the myocyte and fibroblast models. These motifs are useful in developing a mechanistic understanding of long-distance coupling on myocyte dynamics and enable the characterisation of interaction between different features such as myocyte and fibroblast properties, coupling strengths and pacing period. They are computationally inexpensive and allow for incorporation of spatial effects such as conduction velocity. They provide a framework for constructing scar tissue boundaries and enable linking of cellular level interactions with scar induced arrhythmia.
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Affiliation(s)
- S Sridhar
- Department of Computer Science, University of Sheffield, Sheffield, UK.
| | - Richard H Clayton
- Department of Computer Science, University of Sheffield, Sheffield, UK
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13
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Kowalewska PM, Milkovich SL, Goldman D, Sandow SL, Ellis CG, Welsh DG. Capillary oxygen regulates demand-supply coupling by triggering connexin40-mediated conduction: Rethinking the metabolic hypothesis. Proc Natl Acad Sci U S A 2024; 121:e2303119121. [PMID: 38349880 PMCID: PMC10895355 DOI: 10.1073/pnas.2303119121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 12/21/2023] [Indexed: 02/15/2024] Open
Abstract
Coupling red blood cell (RBC) supply to O2 demand is an intricate process requiring O2 sensing, generation of a stimulus, and signal transduction that alters upstream arteriolar tone. Although actively debated, this process has been theorized to be induced by hypoxia and to involve activation of endothelial inwardly rectifying K+ channels (KIR) 2.1 by elevated extracellular K+ to trigger conducted hyperpolarization via connexin40 (Cx40) gap junctions to upstream resistors. This concept was tested in resting healthy skeletal muscle of Cx40-/- and endothelial KIR2.1-/- mice using state-of-the-art live animal imaging where the local tissue O2 environment was manipulated using a custom gas chamber. Second-by-second capillary RBC flow responses were recorded as O2 was altered. A stepwise drop in PO2 at the muscle surface increased RBC supply in capillaries of control animals while elevated O2 elicited the opposite response; capillaries were confirmed to express Cx40. The RBC flow responses were rapid and tightly coupled to O2; computer simulations did not support hypoxia as a driving factor. In contrast, RBC flow responses were significantly diminished in Cx40-/- mice. Endothelial KIR2.1-/- mice, on the other hand, reacted normally to O2 changes, even when the O2 challenge was targeted to a smaller area of tissue with fewer capillaries. Conclusively, microvascular O2 responses depend on coordinated electrical signaling via Cx40 gap junctions, and endothelial KIR2.1 channels do not initiate the event. These findings reconceptualize the paradigm of blood flow regulation in skeletal muscle and how O2 triggers this process in capillaries independent of extracellular K+.
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Affiliation(s)
- Paulina M Kowalewska
- Robarts Research Institute, University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5B7, Canada
| | - Stephanie L Milkovich
- Robarts Research Institute, University of Western Ontario, London, ON N6A 5B7, Canada
| | - Daniel Goldman
- Department of Medical Biophysics, University of Western Ontario, London, ON N6A 5B7, Canada
| | - Shaun L Sandow
- School of Health, University of the Sunshine Coast, Maroochydore, QLD 4556, Australia
- School of Clinical Medicine, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Christopher G Ellis
- Robarts Research Institute, University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Medical Biophysics, University of Western Ontario, London, ON N6A 5B7, Canada
| | - Donald G Welsh
- Robarts Research Institute, University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5B7, Canada
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14
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Chen L, Fang H, Li X, Yu P, Guan Y, Xiao C, Deng Z, Hei Z, Chen C, Luo C. Connexin32 gap junction channels deliver miR155-3p to mediate pyroptosis in renal ischemia-reperfusion injury. Cell Commun Signal 2024; 22:121. [PMID: 38347637 PMCID: PMC10863161 DOI: 10.1186/s12964-023-01443-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 12/13/2023] [Indexed: 02/15/2024] Open
Abstract
OBJECTIVES To explore whether the gap junction (GJ) composed by connexin32(Cx32) mediated pyroptosis in renal ischemia-reperfusion(I/R) injury via transmitting miR155-3p, with aim to provide new strategies for the prevention and treatment of acute kidney injury (AKI) after renal I/R. METHODS 8-10 weeks of male C57BL/ 6 wild-type mice and Cx32 knockdown mice were divided into two groups respectively: control group and renal I/R group. MCC950 (50 mg/kg. ip.) was used to inhibit NLRP3 in vivo. Human kidney tubular epithelial cells (HK - 2) and rat kidney tubular epithelial cells (NRK-52E) were divided into high-density group and low-density group, and treated with hypoxia reoxygenation (H/R) to mimic I/R. The siRNA and plasmid of Cx32, mimic and inhibitor of miR155-3p were transfected into HK - 2 cells respectively. Kidney pathological and functional injuries were measured. Western Blot and immunofluorescent staining were used to observe the expression of NLRP3, GSDMD, GSDMD-N, IL - 18, and mature IL-18. The secretion of IL-18 and IL-1β in serum, kidney tissue and cells supernatant were detected by enzyme-linked immuno sorbent assay (ELISA) kit, and the expression of NLPR3 and miR155-3p were detected by RT-qPCR and fluorescence in situ hybridization (FISH). RESULTS Tubular pyroptosis were found to promote AKI after I/R in vivo and Cx32-GJ regulated pyroptosis by affecting the expression of miR155-3p after renal I/R injury. In vitro, H/R could lead to pyroptosis in HK-2 and NRK-52E cells. When the GJ channels were not formed, and Cx32 was inhibited or knockdown, the expression of miR155-3p was significantly reduced and the pyroptosis was obviously inhibited, leading to the reduction of injury and the increase of survival rate. Moreover, regulating the level of miR155-3p could affect survival rate and pyroptosis in vitro after H/R. CONCLUSIONS The GJ channels composed of Cx32 regulated tubular pyroptosis in renal I/R injury by transmitting miR155-3p. Inhibition of Cx32 could reduce the level of miR155-3p further to inhibit pyroptosis, leading to alleviation of renal I/R injury which provided a new strategy for preventing the occurrence of AKI. Video Abstract.
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Affiliation(s)
- Liubing Chen
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China
| | - Hongyi Fang
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China
| | - Xiaoyun Li
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China
| | - Peiling Yu
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China
| | - Yu Guan
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China
| | - Cuicui Xiao
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China
| | - Zhizhao Deng
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China
| | - Ziqing Hei
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China
| | - Chaojin Chen
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China.
| | - Chenfang Luo
- Department of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, 510630, Guangdong Province, China.
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Wong RS, Chen H, Li YX, Esseltine JL, Stathopulos PB, Bai D. Human Cx50 Isoleucine177 prevents heterotypic docking and formation of functional gap junction channels with Cx43. Am J Physiol Cell Physiol 2024; 326:C414-C428. [PMID: 38145302 DOI: 10.1152/ajpcell.00634.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 12/18/2023] [Accepted: 12/18/2023] [Indexed: 12/26/2023]
Abstract
The human lens is an avascular organ, and its transparency is dependent on gap junction (GJ)-mediated microcirculation. Lens GJs are composed of three connexins with Cx46 and Cx50 being expressed in lens fiber cells and Cx43 and Cx50 in the epithelial cells. Impairment of GJ communication by either Cx46 or Cx50 mutations has been shown to be one of the main molecular mechanisms of congenital cataracts in mutant carrier families. The docking compatibility and formation of functional heterotypic GJs for human lens connexins have not been studied. Previous study on rodent lens connexins revealed that Cx46 can form functional heterotypic GJs with Cx50 and Cx43, but Cx50 cannot form heterotypic GJ with Cx43 due to its second extracellular (EL2) domain. To study human lens connexin docking and formation of functional heterotypic GJs, we developed a genetically engineered HEK293 cell line with endogenously expressed Cx43 and Cx45 ablated. The human lens connexins showed docking compatibility identical to those found in the rodent connexins. To reveal the structural mechanisms of the docking incompatibility between Cx50 and Cx43, we designed eight variants based on the differences between the EL2 of Cx50 and Cx46. We found that Cx50I177L is sufficient to establish heterotypic docking with Cx43 with some interesting gating properties. Our structure models indicate this residue is important for interdomain interactions within a single connexin, Cx50 I177L showed an increased interdomain interaction which might alter the docking interface structure to be compatible with Cx43.NEW & NOTEWORTHY The human lens is an avascular organ, and its transparency is partially dependent on gap junction (GJ) network composed of Cx46, Cx50, and Cx43. We found that human Cx46 can dock and form functional heterotypic GJs with Cx50 and Cx43, but Cx50 is unable to form functional heterotypic GJs with Cx43. Through mutagenesis and patch-clamp study of several designed variants, we found that Cx50 I177L was sufficient to form functional heterotypic GJs with Cx43.
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Affiliation(s)
- Robert S Wong
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Honghong Chen
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Yi X Li
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Jessica L Esseltine
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Donglin Bai
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
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Zheng L, Shi W, Liu B, Duan B, Sorgen PL. Evaluation of Tyrosine Kinase Inhibitors Loaded Injectable Hydrogels for Improving Connexin43 Gap Junction Intercellular Communication. ACS Appl Mater Interfaces 2024; 16:1985-1998. [PMID: 38175743 DOI: 10.1021/acsami.3c10923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Myocardial infarction (MI) is one of the leading causes of death in the developed world, and the loss of cardiomyocytes plays a critical role in the pathogenesis of heart failure. Implicated in this process is a decrease in gap junction intercellular communication due to remodeling of Connexin43 (Cx43). We previously identified that intraperitoneal injection of the Pyk2 inhibitor PF4618433 reduced infarct size, maintained Cx43 at the intercalated disc in left ventricle hypertrophic myocytes, and improved cardiac function in an MI animal model of heart failure. With the emergence of injectable hydrogels as a therapeutic toward the regeneration of cardiac tissue after MI, here, we provide proof of concept that the release of tyrosine kinase inhibitors from hydrogels could have beneficial effects on cardiomyocytes. We developed an injectable hydrogel consisting of thiolated hyaluronic acid and P123-maleimide micelles that can incorporate PF4618433 as well as the Src inhibitor Saracatinib and achieved sustained release (of note, Src activates Pyk2). Using neonatal rat ventricular myocytes in the presence of a phorbol ester, endothelin-1, or phenylephrine to stimulate cardiac hypertrophy, the release of PF4618433 from the hydrogel had the same ability to decrease Cx43 tyrosine phosphorylation and maintain Cx43 localization at the plasma membrane as when directly added to the growth media. Additional beneficial effects included decreases in apoptosis, the hypertrophic marker atrial natriuretic peptide (ANP), and serine kinases upregulated in hypertrophy. Finally, the presence of both PF4618433 and Saracatinib further decreased the level of ANP and apoptosis than each inhibitor alone, suggesting that a combinatorial approach may be most beneficial. These findings provide the groundwork to test if tyrosine kinase inhibitor release from hydrogels will have a beneficial effect in an animal model of MI-induced heart failure.
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Affiliation(s)
- Li Zheng
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Wen Shi
- Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
- Division of Cardiology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Bo Liu
- Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
- Division of Cardiology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Bin Duan
- Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
- Division of Cardiology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
- Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Paul L Sorgen
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
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Paciello F, Pisani A, Rolesi R, Montuoro R, Mohamed-Hizam V, Boni G, Ripoli C, Galli J, Sisto R, Fetoni AR, Grassi C. Oxidative stress and inflammation cause auditory system damage via glial cell activation and dysregulated expression of gap junction proteins in an experimental model of styrene-induced oto/neurotoxicity. J Neuroinflammation 2024; 21:4. [PMID: 38178142 PMCID: PMC10765700 DOI: 10.1186/s12974-023-02996-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 12/13/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Redox imbalance and inflammation have been proposed as the principal mechanisms of damage in the auditory system, resulting in functional alterations and hearing loss. Microglia and astrocytes play a crucial role in mediating oxidative/inflammatory injury in the central nervous system; however, the role of glial cells in the auditory damage is still elusive. OBJECTIVES Here we investigated glial-mediated responses to toxic injury in peripheral and central structures of the auditory pathway, i.e., the cochlea and the auditory cortex (ACx), in rats exposed to styrene, a volatile compound with well-known oto/neurotoxic properties. METHODS Male adult Wistar rats were treated with styrene (400 mg/kg daily for 3 weeks, 5/days a week). Electrophysiological, morphological, immunofluorescence and molecular analyses were performed in both the cochlea and the ACx to evaluate the mechanisms underlying styrene-induced oto/neurotoxicity in the auditory system. RESULTS We showed that the oto/neurotoxic insult induced by styrene increases oxidative stress in both cochlea and ACx. This was associated with macrophages and glial cell activation, increased expression of inflammatory markers (i.e., pro-inflammatory cytokines and chemokine receptors) and alterations in connexin (Cxs) and pannexin (Panx) expression, likely responsible for dysregulation of the microglia/astrocyte network. Specifically, we found downregulation of Cx26 and Cx30 in the cochlea, and high level of Cx43 and Panx1 in the ACx. CONCLUSIONS Collectively, our results provide novel evidence on the role of immune and glial cell activation in the oxidative/inflammatory damage induced by styrene in the auditory system at both peripheral and central levels, also involving alterations of gap junction networks. Our data suggest that targeting glial cells and connexin/pannexin expression might be useful to attenuate oxidative/inflammatory damage in the auditory system.
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Affiliation(s)
- Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
| | - Anna Pisani
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Rolando Rolesi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Raffaele Montuoro
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | - Giammarco Boni
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
| | - Jacopo Galli
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Renata Sisto
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers' Compensation Authority (INAIL), Monte Porzio Catone, Rome, Italy
| | - Anna Rita Fetoni
- Department of Neuroscience, Unit of Audiology, Università Degli Studi di Napoli Federico II, Naples, Italy.
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
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Van Campenhout R, Sanz-Serrano J, Cooreman A, De Vlaeminck Y, Breckpot K, Kadam P, Tabernilla A, Vinken M. Assessment of Connexin43 Hemichannel Functionality Based on Cytosolic Uptake of Yo-Pro1. Methods Mol Biol 2024; 2801:75-85. [PMID: 38578414 DOI: 10.1007/978-1-0716-3842-2_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Connexin proteins are the building blocks of gap junctions and connexin hemichannels. Both provide a pathway for cellular communication. Gap junctions support intercellular communication mechanisms and regulate homeostasis. In contrast, open connexin hemichannels connect the intracellular compartment and the extracellular environment, and their activation fuels inflammation and cell death. The development of clinically applicable connexin hemichannel blockers for therapeutic purposes is therefore gaining momentum. This chapter describes a well-established protocol optimized for assessing connexin hemichannel activity by using the reporter dye Yo-Pro1.
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Affiliation(s)
- Raf Van Campenhout
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Julen Sanz-Serrano
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Axelle Cooreman
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Yannick De Vlaeminck
- Laboratory for Molecular and Cellular Therapy, Department of Biomedical Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Karine Breckpot
- Laboratory for Molecular and Cellular Therapy, Department of Biomedical Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Prashant Kadam
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Andrés Tabernilla
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Mathieu Vinken
- Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium.
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Lucaciu SA, Leighton SE, Laird DW. Spatial and Temporal Localization of Connexins in Cells Using Confocal Microscopy. Methods Mol Biol 2024; 2801:57-74. [PMID: 38578413 DOI: 10.1007/978-1-0716-3842-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
The 21-member connexin family found in humans is the building block of both single-membrane spanning channels (hemichannels) and double-membrane spanning intercellular channels. These large-pore channels are dynamic and typically have a short life span of only a few hours. Imaging connexins from the time of synthesis in the endoplasmic reticulum through to their degradation can be challenging given their distinct assembly states and transient residences in many subcellular compartments. Here, we describe how connexins can be effectively imaged on a confocal microscope in living cells when tagged with fluorescent proteins and when immunolabeled with high affinity anti-connexin antibodies in fixed cells. Temporal and spatial localization of multiple connexins and disease-linked connexin mutants at the subcellular level extensively informs on the mechanisms governing connexin regulation in health and disease.
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Affiliation(s)
- Sergiu A Lucaciu
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
| | - Stephanie E Leighton
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, Canada
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, Canada.
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada.
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20
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Lavriha P, Qi C, Korkhov VM. Expression, Purification, and Nanodisc Reconstitution of Connexin-43 Hemichannels for Structural Characterization by Cryo-Electron Microscopy. Methods Mol Biol 2024; 2801:29-43. [PMID: 38578411 DOI: 10.1007/978-1-0716-3842-2_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Connexins are polytopic domain membrane proteins that form hexameric hemichannels (HCs) which can assemble into gap junction channels (GJCs) at the interface of two neighboring cells. The HCs may be involved in ion and small-molecule transport across the cellular plasma membrane in response to various stimuli. Despite their importance, relatively few structures of connexin HCs are available to date, compared to the structures of the GJCs. Here, we describe a protocol for expression, purification, and nanodisc reconstitution of connexin-43 (Cx43) HCs, which we have recently structurally characterized using cryo-EM analysis. Application of similar protocols to other connexin family members will lead to breakthroughs in the understanding of the structure and function of connexin HCs.
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Affiliation(s)
- Pia Lavriha
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
| | - Chao Qi
- Institute of Molecular Biology and Biophysics, ETH, Zurich, Switzerland
| | - Volodymyr M Korkhov
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.
- Institute of Molecular Biology and Biophysics, ETH, Zurich, Switzerland.
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21
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Jin Q, Lee KY, Selimi Z, Shimura D, Wang E, Zimmerman JF, Shaw RM, Kucera JP, Parker KK, Saffitz JE, Kleber AG. Determinants of electrical propagation and propagation block in Arrhythmogenic Cardiomyopathy. J Mol Cell Cardiol 2024; 186:71-80. [PMID: 37956903 PMCID: PMC10872523 DOI: 10.1016/j.yjmcc.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/27/2023] [Accepted: 11/06/2023] [Indexed: 11/21/2023]
Abstract
Gap junction and ion channel remodeling occur early in Arrhythmogenic Cardiomyopathy (ACM), but their pathogenic consequences have not been elucidated. Here, we identified the arrhythmogenic substrate, consisting of propagation slowing and conduction block, in ACM models expressing two different desmosomal gene variants. Neonatal rat ventricular myocytes were transduced to express variants in genes encoding desmosomal proteins plakoglobin or plakophilin-2. Studies were performed in engineered cells and anisotropic tissues to quantify changes in conduction velocity, formation of unidirectional propagation, cell-cell electrical coupling, and ion currents. Conduction velocity decreased by 71% and 63% in the two ACM models. SB216763, an inhibitor of glycogen synthase kinase-3 beta, restored conduction velocity to near normal levels. Compared to control, both ACM models showed greater propensity for unidirectional conduction block, which increased further at greater stimulation frequencies. Cell-cell electrical conductance measured in cell pairs was reduced by 86% and 87% in the two ACM models. Computer modeling showed close correspondence between simulated and experimentally determined changes in conduction velocity. The simulation identified that reduced cell-cell electrical coupling was the dominant factor leading to slow conduction, while the combination of reduced cell-cell electrical coupling, reduced sodium current and inward rectifier potassium current explained the development of unidirectional block. Expression of two different ACM variants markedly reduced cell-cell electrical coupling and conduction velocity, and greatly increased the likelihood of developing unidirectional block - both key features of arrhythmogenesis. This study provides the first quantitative analysis of cellular electrophysiological changes leading to the substrate of reentrant arrhythmias in early stage ACM.
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Affiliation(s)
- Qianru Jin
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - Keel Yong Lee
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - Zoja Selimi
- Department of Physiology, University of Bern, Bern, Switzerland
| | - Daisuke Shimura
- Nora Eccles Harrison Cardiovascular Research and Training Institute, Salt Lake City, UT, USA; Department of Surgery, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Ethan Wang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - John F Zimmerman
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, Salt Lake City, UT, USA
| | - Jan P Kucera
- Department of Physiology, University of Bern, Bern, Switzerland
| | - Kevin Kit Parker
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - Jeffrey E Saffitz
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Andre G Kleber
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA; Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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22
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Fiori MC, Altenberg GA. Purification, Reconstitution, and Functional Analysis of Connexin Hemichannels. Methods Mol Biol 2024; 2801:1-16. [PMID: 38578409 DOI: 10.1007/978-1-0716-3842-2_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Connexins are the proteins that form the gap junction channels that are essential for cell-to-cell communication. These channels are formed by head-to-head docking of hemichannels (each from one of two adjacent cells). Free "undocked" hemichannels at the plasma membrane are mostly closed, although they are still important under physiological conditions. However, abnormal and sustained increase in hemichannel activity due to connexin mutations or acquired conditions can produce or contribute to cell damage. For example, mutations of Cx26, a connexin isoform, can increase hemichannel activity and cause deafness. Studies using purified isolated systems under well-controlled conditions are essential for a full understanding of molecular mechanisms of hemichannel function under normal conditions and in disease, and here, we present methodology for the expression, purification, and functional analysis of hemichannels formed by Cx26.
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Affiliation(s)
- Mariana C Fiori
- Clinical Research Institute, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Guillermo A Altenberg
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
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23
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Fernandez-Olivares A, Retamal MA. Protocol for the Study of Connexin and DNA Interactions. Methods Mol Biol 2024; 2801:125-134. [PMID: 38578418 DOI: 10.1007/978-1-0716-3842-2_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Connexins (Cxs) are transmembrane proteins which form hemichannels and gap junction channels at the plasma membrane. These channels allow the exchange of ions and molecules between the intra- and extracellular space and between cytoplasm of adjacent cells, respectively. The channel function of Cx assemblies has been extensively studied; however, "noncanonical" functions have emerged in the last few decades and have capture the attentions of many researchers, including the role of some Cxs as gene modulators or transcription factors. In this chapter, we describe a protocol to study the interaction of Cx46 with DNA in HeLa cells. These methods can facilitate understanding the role of Cxs in physiological processes and pathological mechanisms, including, for example, the contribution of Cx46 in maintaining stemness of glioma cancer stem cells.
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Affiliation(s)
- Ainoa Fernandez-Olivares
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Mauricio A Retamal
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile.
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile.
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24
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Yan Q, Feng Z, Jiang B, Yao J. Biological functions of connexins in the development of inflammatory bowel disease. Scand J Gastroenterol 2024; 59:142-149. [PMID: 37837320 DOI: 10.1080/00365521.2023.2267713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 10/01/2023] [Indexed: 10/16/2023]
Abstract
Inflammatory bowel disease (IBD) is a group of chronic intestinal inflammatory diseases with unknown etiology. Gap junctions composed of connexins (Cxs) have been recently validated as an important factor in the development of IBD. Under IBD-induced inflammatory response in the gut, gap junctions connect multiple signaling pathways involved in the interaction between inflammatory cells with other intestinal cells, which altogether mediate the development of IBD. This paper is a narrative review aiming to comprehensively elucidate the biological function of connexins, especially the ubiquitously and predominantly expressed Cx43, in the pathogenesis of IBD.
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Affiliation(s)
- Qiaojing Yan
- Colorectal Surgery Center, Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, China
- Jiangsu Province Traditional Chinese Medicine Innovation Center for Anorectal Disease, Nanjing, China
| | - Zhiling Feng
- Colorectal Surgery Center, Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, China
| | - Bin Jiang
- Colorectal Surgery Center, Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, China
- Jiangsu Province Traditional Chinese Medicine Innovation Center for Anorectal Disease, Nanjing, China
| | - Jian Yao
- Division of Molecular Signaling, Department of the Advanced Biomedical Research, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, Japan
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25
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Rajagopalan NR, Vista WR, Fujimori M, Vroomen LGPH, Jiménez JM, Khadka N, Bikson M, Srimathveeravalli G. Cytoskeletal Remodeling and Gap Junction Translocation Mediates Blood-Brain Barrier Disruption by Non-invasive Low-Voltage Pulsed Electric Fields. Ann Biomed Eng 2024; 52:89-102. [PMID: 37115366 DOI: 10.1007/s10439-023-03211-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 04/14/2023] [Indexed: 04/29/2023]
Abstract
High-voltage pulsed electric fields (HV-PEF) delivered with invasive needle electrodes for electroporation applications is known to induce off-target blood-brain barrier (BBB) disruption. In this study, we sought to determine the feasibility of minimally invasive PEF application to produce BBB disruption in rat brain and identify the putative mechanisms mediating the effect. We observed dose-dependent presence of Evans Blue (EB) dye in rat brain when PEF were delivered with a skull mounted electrode used for neurostimulation application. Maximum region of dye uptake was observed while using 1500 V, 100 pulses, 100 µs and 10 Hz. Results of computational models suggested that the region of BBB disruption was occurring at thresholds of 63 V/cm or higher; well below intensity levels for electroporation. In vitro experiments recapitulating this effect with human umbilical vein endothelial cells (HUVEC) demonstrated cellular alterations that underlie BBB manifests at low-voltage high-pulse conditions without affecting cell viability or proliferation. Morphological changes in HUVECs due to PEF were accompanied by disruption of actin cytoskeleton, loss of tight junction protein-ZO-1 and VE-Cadherin at cell junctions and partial translocation into the cytoplasm. Uptake of propidium iodide (PI) in PEF treated conditions is less than 1% and 2.5% of total number of cells in high voltage (HV) and low-voltage (LV) groups, respectively, implying that BBB disruption to be independent of electroporation under these conditions. 3-D microfabricated blood vessel permeability was found to increase significantly following PEF treatment and confirmed with correlative cytoskeletal changes and loss of tight junction proteins. Finally, we show that the rat brain model can be scaled to human brains with a similar effect on BBB disruption characterized by electric field strength (EFS) threshold and using a combination of two bilateral HD electrode configurations.
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Affiliation(s)
| | - William-Ray Vista
- Department of Radiology, Interventional Radiology Service, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Masashi Fujimori
- Department of Radiology, Interventional Radiology Service, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
- Department of Radiology, Mie University, Tsu, Mie, Japan
| | | | - Juan M Jiménez
- Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, MA, USA
| | - Niranjan Khadka
- Division of Neuromodulation, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Synchron Inc, Brooklyn, NY, USA
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Govindarajan Srimathveeravalli
- Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, MA, USA.
- Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, MA, USA.
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26
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Palacios-Prado N, Vergara T, Sáez JC. Enhanced Methodologies for Investigating the Electrophysiological Characteristics of Endogenous Pannexin 1 Intercellular Cell-Cell Channels. Methods Mol Biol 2024; 2801:135-145. [PMID: 38578419 DOI: 10.1007/978-1-0716-3842-2_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Gap junctions, pivotal intercellular conduits, serve as communication channels between adjacent cells, playing a critical role in modulating membrane potential distribution across cellular networks. The family of Pannexin (Panx) proteins, in particular Pannexin1 (Panx1), are widely expressed in vertebrate cells and exhibit sequence homology with innexins, the invertebrate gap junction channel constituents. Despite being ubiquitously expressed, detailed functional and pharmacological properties of Panx1 intercellular cell-cell channels require further investigation. In this chapter, we introduce optimized cell culture methodologies and electrophysiology protocols to expedite the exploration of endogenous Panx1 cell-cell channels in TC620 cells, a human oligodendroglioma cell line that naturally expresses Panx1. We anticipate these refined protocols will significantly contribute to future characterizations of Panx1-based intercellular cell-cell channels across diverse cell types and offer valuable insights into both normal cellular physiology and pathophysiology.
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Affiliation(s)
- Nicolás Palacios-Prado
- Laboratorio de Neurobiología, Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Teresa Vergara
- Laboratorio de Neurobiología, Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan C Sáez
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile
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27
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Li Y, Acosta FM, Jiang JX. Gap Junctions or Hemichannel-Dependent and Independent Roles of Connexins in Fibrosis, Epithelial-Mesenchymal Transitions, and Wound Healing. Biomolecules 2023; 13:1796. [PMID: 38136665 PMCID: PMC10742173 DOI: 10.3390/biom13121796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/09/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Fibrosis initially appears as a normal response to damage, where activated fibroblasts produce large amounts of the extracellular matrix (ECM) during the wound healing process to assist in the repair of injured tissue. However, the excessive accumulation of the ECM, unresolved by remodeling mechanisms, leads to organ dysfunction. Connexins, a family of transmembrane channel proteins, are widely recognized for their major roles in fibrosis, the epithelial-mesenchymal transition (EMT), and wound healing. Efforts have been made in recent years to identify novel mediators and targets for this regulation. Connexins form gap junctions and hemichannels, mediating communications between neighboring cells and inside and outside of cells, respectively. Recent evidence suggests that connexins, beyond forming channels, possess channel-independent functions in fibrosis, the EMT, and wound healing. One crucial channel-independent function is their role as the primary functional component for cell adhesion. Other channel-independent functions of connexins involve their roles in mitochondria and exosomes. This review summarizes the latest advances in the channel-dependent and independent roles of connexins in fibrosis, the EMT, and wound healing, with a particular focus on eye diseases, emphasizing their potential as novel, promising therapeutic targets.
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Affiliation(s)
- Yuting Li
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
- Department of Pathology, Basic Medical School, Ningxia Medical University, Yinchuan 750004, China
| | - Francisca M. Acosta
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
| | - Jean X. Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
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28
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Zhao Z, Wang W, Wang G, Huang Z, Zhou L, Lin L, Ou Y, Huang W, Zhang X, Wu C, Tao L, Wang Q. Dual peptides-modified cationic liposomes for enhanced Lung cancer gene therapy by a gap junction regulating strategy. J Nanobiotechnology 2023; 21:473. [PMID: 38066528 PMCID: PMC10709977 DOI: 10.1186/s12951-023-02242-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 12/03/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Gene therapy for lung cancer has emerged as a novel tumor-combating strategy for its superior tumor specificity, low systematical toxicity and huge clinical translation potential. Especially, the applications of microRNA shed led on effective tumor ablation by directly interfering with the crucial gene expression, making it one of the most promising gene therapy agents. However, for lung cancer therapy, the microRNA treatment confronted three bottlenecks, the poor tumor tissue penetration effect, the insufficient lung drug accumulation and unsatisfied gene transfection efficiency. To address these issues, an inhalable RGD-TAT dual peptides-modified cationic liposomes loaded with microRNA miR-34a and gap junction (GJ) regulation agent all-trans retinoic acid (ATRA) was proposed, which was further engineered into dry powder inhalers (DPIs). RESULTS Equipped with a rough particle surface and appropriate aerodynamic size, the proposed RGD-TAT-CLPs/ARTA@miR-34a DPIs were expected to deposit into the deep lung and reach lung tumor lesions guided by targeting peptide RGD. Assisted by cellular transmembrane peptides TAT, the RGD-TAT-CLPs/ARTA@miR-34a was proven to be effectively internalized by cancer cells, enhancing gene transfection efficiency. Then, the GJ between tumor cells was upregulated by ARTA, facilitating the intercellular transport of miR-34a and boosting the gene expression in the deep tumor. CONCLUSION Overall, the proposed RGD-TAT-CLPs/ARTA@miR-34a DPIs could enhance tumor tissue penetration, elevate lung drug accumulation and boost gene transfection efficiency, breaking the three bottlenecks to enhancing tumor elimination in vitro and in vivo. We believe that the proposed RGD-TAT-CLPs/ARTA@miR-34a DPIs could serve as a promising pulmonary gene delivery platform for multiple lung local disease treatments.
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Affiliation(s)
- Ziyu Zhao
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, PR China
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Jinan University, Guangzhou, Guangdong, 510632, PR China
- College of Pharmacy, Jinan University, Guangzhou, Guangdong, 510632, PR China
| | - Wenhao Wang
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong, 510006, PR China
| | - Guanlin Wang
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong, 510006, PR China
| | - Zhengwei Huang
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Jinan University, Guangzhou, Guangdong, 510632, PR China
- College of Pharmacy, Jinan University, Guangzhou, Guangdong, 510632, PR China
| | - Liping Zhou
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, PR China
| | - Li Lin
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, PR China
| | - Yueling Ou
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, PR China
| | - Wanzhen Huang
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, PR China
| | - Xuejuan Zhang
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Jinan University, Guangzhou, Guangdong, 510632, PR China.
- College of Pharmacy, Jinan University, Guangzhou, Guangdong, 510632, PR China.
| | - Chuanbin Wu
- State Key Laboratory of Bioactive Molecules and Druggability Assessment, Jinan University, Guangzhou, Guangdong, 510632, PR China
- College of Pharmacy, Jinan University, Guangzhou, Guangdong, 510632, PR China
| | - Liang Tao
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, PR China.
- Nanchang Research Institute, Sun Yat-Sen University, Nanchang, Jiangxi, 330096, PR China.
| | - Qin Wang
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, PR China.
- Nanchang Research Institute, Sun Yat-Sen University, Nanchang, Jiangxi, 330096, PR China.
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29
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Yin L, Wang W, Pang W, Yang G, Gao L, Chu G. Insulin regulates gap junction intercellular communication in porcine granulosa cells through modulation of connexin43 protein expression. Theriogenology 2023; 212:172-180. [PMID: 37738821 DOI: 10.1016/j.theriogenology.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 09/24/2023]
Abstract
Gap junction intercellular communication (GJIC) among granulosa cells plays an important role in folliculogenesis, and it is temporal-spatially regulated during follicular development. Connexin (Cx) proteins predominantly form the basal structure of gap junctions in granulosa cells. In our study, immunohistochemical analysis revealed that Cx43 is the most widely expressed connexin in porcine follicles, especially among the large antral follicles. With application of insulin on porcine granulosa cells, we found that insulin significantly facilitated the protein level of Cx43, not mRNA level. This process is dependent on the phosphorylated activities of AKT and Erk since selective AKT and Erk inhibitors, LY294002 and U0126, respectively, hampered the potential of insulin to up-regulate Cx43 protein expression. As a consequence, the insulin-enhanced Cx43-couple GJIC activity in porcine granulosa cells was corresponding attenuated by the administration of LY294002 and U0126. Our findings provide a new insight into the molecular mechanisms by which insulin mediates cell-cell communication in porcine granulosa cells and sheds light on nutrition-reproduction interactions.
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Affiliation(s)
- Lin Yin
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Wusu Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Weijun Pang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Gongshe Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Lei Gao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, PR China.
| | - Guiyan Chu
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, PR China.
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30
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Briggs JK, Gresch A, Marinelli I, Dwulet JM, Albers DJ, Kravets V, Benninger RKP. β-cell intrinsic dynamics rather than gap junction structure dictates subpopulations in the islet functional network. eLife 2023; 12:e83147. [PMID: 38018905 PMCID: PMC10803032 DOI: 10.7554/elife.83147] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/27/2023] [Indexed: 11/30/2023] Open
Abstract
Diabetes is caused by the inability of electrically coupled, functionally heterogeneous β-cells within the pancreatic islet to provide adequate insulin secretion. Functional networks have been used to represent synchronized oscillatory [Ca2+] dynamics and to study β-cell subpopulations, which play an important role in driving islet function. The mechanism by which highly synchronized β-cell subpopulations drive islet function is unclear. We used experimental and computational techniques to investigate the relationship between functional networks, structural (gap junction) networks, and intrinsic β-cell dynamics in slow and fast oscillating islets. Highly synchronized subpopulations in the functional network were differentiated by intrinsic dynamics, including metabolic activity and KATP channel conductance, more than structural coupling. Consistent with this, intrinsic dynamics were more predictive of high synchronization in the islet functional network as compared to high levels of structural coupling. Finally, dysfunction of gap junctions, which can occur in diabetes, caused decreases in the efficiency and clustering of the functional network. These results indicate that intrinsic dynamics rather than structure drive connections in the functional network and highly synchronized subpopulations, but gap junctions are still essential for overall network efficiency. These findings deepen our interpretation of functional networks and the formation of functional subpopulations in dynamic tissues such as the islet.
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Affiliation(s)
- Jennifer K Briggs
- Department of Bioengineering, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Anne Gresch
- Department of Bioengineering, University of Colorado Anschutz Medical CampusAuroraUnited States
- Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Isabella Marinelli
- Centre for Systems Modelling and Quantitative Biomedicine, University of BirminghamBirminghamUnited Kingdom
| | - JaeAnn M Dwulet
- Department of Bioengineering, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - David J Albers
- Department of Bioengineering, University of Colorado Anschutz Medical CampusAuroraUnited States
- Department of Biomedical Informatics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Vira Kravets
- Department of Bioengineering, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Richard KP Benninger
- Department of Bioengineering, University of Colorado Anschutz Medical CampusAuroraUnited States
- Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical CampusAuroraUnited States
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31
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Yamasaki R. Connexins Control Glial Inflammation in Various Neurological Diseases. Int J Mol Sci 2023; 24:16879. [PMID: 38069203 PMCID: PMC10706219 DOI: 10.3390/ijms242316879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/25/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
Connexins (Cxs) form gap junctions through homotypic/heterotypic oligomerization. Cxs are initially synthesized in the endoplasmic reticulum, then assembled as hexamers in the Golgi apparatus before being integrated into the cell membrane as hemichannels. These hemichannels remain closed until they combine to create gap junctions, directly connecting neighboring cells. Changes in the intracellular or extracellular environment are believed to trigger the opening of hemichannels, creating a passage between the inside and outside of the cell. The size of the channel pore depends on the Cx isoform and cellular context-specific effects such as posttranslational modifications. Hemichannels allow various bioactive molecules, under ~1 kDa, to move in and out of the host cell in the direction of the electrochemical gradient. In this review, we explore the fundamental roles of Cxs and their clinical implications in various neurological dysfunctions, including hereditary diseases, ischemic brain disorders, degenerative conditions, demyelinating disorders, and psychiatric illnesses. The influence of Cxs on the pathomechanisms of different neurological disorders varies depending on the circumstances. Hemichannels are hypothesized to contribute to proinflammatory effects by releasing ATP, adenosine, glutamate, and other bioactive molecules, leading to neuroglial inflammation. Modulating Cxs' hemichannels has emerged as a promising therapeutic approach.
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Affiliation(s)
- Ryo Yamasaki
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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Badaoui M, Chanson M. Intercellular Communication in Airway Epithelial Cell Regeneration: Potential Roles of Connexins and Pannexins. Int J Mol Sci 2023; 24:16160. [PMID: 38003349 PMCID: PMC10671439 DOI: 10.3390/ijms242216160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/19/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Connexins and pannexins are transmembrane proteins that can form direct (gap junctions) or indirect (connexons, pannexons) intercellular communication channels. By propagating ions, metabolites, sugars, nucleotides, miRNAs, and/or second messengers, they participate in a variety of physiological functions, such as tissue homeostasis and host defense. There is solid evidence supporting a role for intercellular signaling in various pulmonary inflammatory diseases where alteration of connexin/pannexin channel functional expression occurs, thus leading to abnormal intercellular communication pathways and contributing to pathophysiological aspects, such as innate immune defense and remodeling. The integrity of the airway epithelium, which is the first line of defense against invading microbes, is established and maintained by a repair mechanism that involves processes such as proliferation, migration, and differentiation. Here, we briefly summarize current knowledge on the contribution of connexins and pannexins to necessary processes of tissue repair and speculate on their possible involvement in the shaping of the airway epithelium integrity.
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Affiliation(s)
| | - Marc Chanson
- Department of Cell Physiology & Metabolism, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland;
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Snipas M, Gudaitis L, Kraujaliene L, Kraujalis T, Verselis VK. Modeling and analysis of voltage gating of gap junction channels at a single-channel level. Biophys J 2023; 122:4176-4193. [PMID: 37766427 PMCID: PMC10645554 DOI: 10.1016/j.bpj.2023.09.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/20/2023] [Accepted: 09/25/2023] [Indexed: 09/29/2023] Open
Abstract
The advancement of single-channel-level recording via the patch-clamp technique has provided a powerful means of assessing the detailed behaviors of various types of ion channels in native and exogenously expressed cellular environments. However, such recordings of gap junction (GJ) channels are hampered by unique challenges that are related to their unusual intercellular configuration and natural clustering into densely packed plaques. Thus, the methods for reliable cross-correlation of data recorded at macroscopic and single-channel levels are lacking in studies of GJs. To address this issue, we combined our previously published four-state model (4SM) of GJ channel gating by voltage with maximum likelihood estimation (MLE)-based analyses of electrophysiological recordings of GJ channel currents. First, we consider evaluation of single-channel characteristics and the methods for efficient stochastic simulation of single GJ channels from the kinetic scheme described by 4SM using data obtained from macroscopic recordings. We then present an MLE-based methodology for extraction of information about transition rates for GJ channels and, ultimately, gating parameters defined in 4SM from recordings with visible unitary events. The validity of the proposed methodology is illustrated using stochastic simulations of single GJ channels and is extended to electrophysiological data recorded in cells expressing connexin 43 tagged with enhanced green fluorescent protein.
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Affiliation(s)
- Mindaugas Snipas
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania; Department of Mathematical Modelling, Kaunas University of Technology, Kaunas, Lithuania.
| | - Lukas Gudaitis
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Lina Kraujaliene
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Tadas Kraujalis
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania; Department of Applied Informatics, Kaunas University of Technology, Kaunas, Lithuania
| | - Vytas K Verselis
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, New York
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Ho KYL, An K, Carr RL, Dvoskin AD, Ou AYJ, Vogl W, Tanentzapf G. Maintenance of hematopoietic stem cell niche homeostasis requires gap junction-mediated calcium signaling. Proc Natl Acad Sci U S A 2023; 120:e2303018120. [PMID: 37903259 PMCID: PMC10636368 DOI: 10.1073/pnas.2303018120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 09/11/2023] [Indexed: 11/01/2023] Open
Abstract
Regulation of stem cells requires coordination of the cells that make up the stem cell niche. Here, we describe a mechanism that allows communication between niche cells to coordinate their activity and shape the signaling environment surrounding resident stem cells. Using the Drosophila hematopoietic organ, the lymph gland, we show that cells of the hematopoietic niche, the posterior signaling center (PSC), communicate using gap junctions (GJs) and form a signaling network. This network allows PSC cells to exchange Ca2+ signals repetitively which regulate the hematopoietic niche. Disruption of Ca2+ signaling in the PSC or the GJ-mediated network connecting niche cells causes dysregulation of the PSC and blood progenitor differentiation. Analysis of PSC-derived cell signaling shows that the Hedgehog pathway acts downstream of GJ-mediated Ca2+ signaling to modulate the niche microenvironment. These data show that GJ-mediated communication between hematopoietic niche cells maintains their homeostasis and consequently controls blood progenitor behavior.
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Affiliation(s)
- Kevin Y. L. Ho
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
| | - Kevin An
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
| | - Rosalyn L. Carr
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
- School of Biomedical Engineering, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
- British Columbia Children’s Hospital Research Institute, British Columbia Children’s Hospital, Vancouver, BCV5Z 4H4, Canada
| | - Alexandra D. Dvoskin
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
| | - Annie Y. J. Ou
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
- School of Kinesiology, University of British Columbia, Vancouver, BCV6T 1Z1, Canada
| | - Wayne Vogl
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
| | - Guy Tanentzapf
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
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35
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Lei L, Wang YT, Hu D, Gai C, Zhang Y. Astroglial Connexin 43-Mediated Gap Junctions and Hemichannels: Potential Antidepressant Mechanisms and the Link to Neuroinflammation. Cell Mol Neurobiol 2023; 43:4023-4040. [PMID: 37875763 DOI: 10.1007/s10571-023-01426-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 10/14/2023] [Indexed: 10/26/2023]
Abstract
Major depression disorder (MDD) is a neuropsychiatric disorder associated with a high suicide rate and a higher disability rate than any other disease. Evidence suggests that the pathological mechanism of MDD is related to astrocyte dysfunction. Depression is mainly associated with the expression of connexin 43 (Cx43) and the function of Cx43-mediated gap junctions and hemichannels in astrocytes. Moreover, neuroinflammation has been a hotspot in research on the pathology of depression, and Cx43-mediated functions are thought to be involved in neuroinflammation-related depression. However, the specific mechanism of Cx43-mediated functions in neuroinflammation-related depression pathology remains unclear. Therefore, this review summarizes and discusses Cx43 expression, the role of gap junction intercellular communication, and its relationship with neuroinflammation in depression. This review also focuses on the effects of antidepressant drugs (e.g., monoamine antidepressants, psychotropic drugs, and N-methyl-D-aspartate receptor antagonists) on Cx43-mediated function and provides evidence for Cx43 as a novel target for the treatment of MDD. The pathogenesis of MDD is related to astrocyte dysfunction, with reduced Cx43 expression, GJ dysfunction, decreased GJIC and reduced BDNF expression in the depressed brain. The effect of Cx43 on neuroinflammation-related depression involving inflammatory cytokines, glutamate excitotoxicity, and HPA axis dysregulation. Antidepressant drugs targeting Cx43 can effectively relieve depressive symptoms.
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Affiliation(s)
- Lan Lei
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China
| | - Ya-Ting Wang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China
| | - Die Hu
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China
| | - Cong Gai
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China
| | - Yi Zhang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Sunshine Southern Avenue, Fang-Shan District, Beijing, 102488, China.
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Tetenborg S, Liss V, Breitsprecher L, Timonina K, Kotova A, Acevedo Harnecker AJ, Yuan C, Shihabeddin E, Ariakia F, Qin G, Chengzhi C, Dedek K, Zoidl G, Hensel M, O'Brien J. Intralumenal docking of connexin 36 channels in the ER isolates mistrafficked protein. J Biol Chem 2023; 299:105282. [PMID: 37742923 PMCID: PMC10637963 DOI: 10.1016/j.jbc.2023.105282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 08/30/2023] [Accepted: 09/05/2023] [Indexed: 09/26/2023] Open
Abstract
The intracellular domains of connexins are essential for the assembly of gap junctions. For connexin 36 (Cx36), the major neuronal connexin, it has been shown that a dysfunctional PDZ-binding motif interferes with electrical synapse formation. However, it is still unknown how this motif coordinates the transport of Cx36. In the present study, we characterize a phenotype of Cx36 mutants that lack a functional PDZ-binding motif using HEK293T cells as an expression system. We provide evidence that an intact PDZ-binding motif is critical for proper endoplasmic reticulum (ER) export of Cx36. Removing the PDZ-binding motif of Cx36 results in ER retention and the formation of multimembrane vesicles containing gap junction-like connexin aggregates. Using a combination of site-directed mutagenesis and electron micrographs, we reveal that these vesicles consist of Cx36 channels that docked prematurely in the ER. Our data suggest a model in which ER-retained Cx36 channels reshape the ER membrane into concentric whorls that are released into the cytoplasm.
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Affiliation(s)
| | - Viktoria Liss
- Department of Biology/Chemistry, iBiOs-Integrated Bioimaging Facility, CellNanOs - Center of Cellular Nanoanalytics, Osnabrück, Germany; Department of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Leonhard Breitsprecher
- Department of Biology/Chemistry, iBiOs-Integrated Bioimaging Facility, CellNanOs - Center of Cellular Nanoanalytics, Osnabrück, Germany; Department of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Ksenia Timonina
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Anna Kotova
- Department of Biology, York University, Toronto, Ontario, Canada
| | | | - Chunxu Yuan
- Animal Navigation/Neurosensorics, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Eyad Shihabeddin
- College of Optometry, University of Houston, Houston, Texas, USA; MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Fatemeh Ariakia
- College of Optometry, University of Houston, Houston, Texas, USA
| | - Guoting Qin
- College of Optometry, University of Houston, Houston, Texas, USA
| | - Cai Chengzhi
- Department of Chemistry, University of Houston, Houston, Texas, USA
| | - Karin Dedek
- Animal Navigation/Neurosensorics, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany; Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
| | - Georg Zoidl
- Department of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Michael Hensel
- Department of Biology/Chemistry, iBiOs-Integrated Bioimaging Facility, CellNanOs - Center of Cellular Nanoanalytics, Osnabrück, Germany; Department of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - John O'Brien
- College of Optometry, University of Houston, Houston, Texas, USA.
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37
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Lucaciu SA, Leighton SE, Hauser A, Yee R, Laird DW. Diversity in connexin biology. J Biol Chem 2023; 299:105263. [PMID: 37734551 PMCID: PMC10598745 DOI: 10.1016/j.jbc.2023.105263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023] Open
Abstract
Over 35 years ago the cell biology community was introduced to connexins as the subunit employed to assemble semicrystalline clusters of intercellular channels that had been well described morphologically as gap junctions. The decade that followed would see knowledge of the unexpectedly large 21-member human connexin family grow to reflect unique and overlapping expression patterns in all organ systems. While connexin biology initially focused on their role in constructing highly regulated intercellular channels, this was destined to change as discoveries revealed that connexin hemichannels at the cell surface had novel roles in many cell types, especially when considering connexin pathologies. Acceptance of connexins as having bifunctional channel properties was initially met with some resistance, which has given way in recent years to the premise that connexins have multifunctional properties. Depending on the connexin isoform and cell of origin, connexins have wide-ranging half-lives that vary from a couple of hours to the life expectancy of the cell. Diversity in connexin channel characteristics and molecular properties were further revealed by X-ray crystallography and single-particle cryo-EM. New avenues have seen connexins or connexin fragments playing roles in cell adhesion, tunneling nanotubes, extracellular vesicles, mitochondrial membranes, transcription regulation, and in other emerging cellular functions. These discoveries were largely linked to Cx43, which is prominent in most human organs. Here, we will review the evolution of knowledge on connexin expression in human adults and more recent evidence linking connexins to a highly diverse array of cellular functions.
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Affiliation(s)
- Sergiu A Lucaciu
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Stephanie E Leighton
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Alexandra Hauser
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Ryan Yee
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada.
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Zhang X, Wang Y, Cai Z, Wan Z, Aihemaiti Y, Tu H. A gonadal gap junction INX-14/Notch GLP-1 signaling axis suppresses gut defense through an intestinal lysosome pathway. Front Immunol 2023; 14:1249436. [PMID: 37928537 PMCID: PMC10620905 DOI: 10.3389/fimmu.2023.1249436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/03/2023] [Indexed: 11/07/2023] Open
Abstract
Gap junctions mediate intercellular communications across cellular networks in the nervous and immune systems. Yet their roles in intestinal innate immunity are poorly understood. Here, we show that the gap junction/innexin subunit inx-14 acts in the C. elegans gonad to attenuate intestinal defenses to Pseudomonas aeruginosa PA14 infection through the PMK-1/p38 pathway. RNA-Seq analyses revealed that germline-specific inx-14 RNAi downregulated Notch/GLP-1 signaling, while lysosome and PMK-1/p38 pathways were upregulated. Consistently, disruption of inx-14 or glp-1 in the germline enhanced resistance to PA14 infection and upregulated lysosome and PMK-1/p38 activity. We show that lysosome signaling functions downstream of the INX-14/GLP-1 signaling axis and upstream of PMK-1/p38 pathway to facilitate intestinal defense. Our findings expand the understanding of the links between the reproductive system and intestinal defense, which may be evolutionarily conserved in higher organism.
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Affiliation(s)
| | | | | | | | | | - Haijun Tu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
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Sharma M, Mukherjee S, Shaw AK, Mondal A, Behera A, Das J, Bose A, Sinha B, Sarma JD. Connexin 43 mediated collective cell migration is independent of Golgi orientation. Biol Open 2023; 12:bio060006. [PMID: 37815438 PMCID: PMC10629497 DOI: 10.1242/bio.060006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 09/28/2023] [Indexed: 10/11/2023] Open
Abstract
Cell migration is vital for multiple physiological functions and is involved in the metastatic dissemination of tumour cells in various cancers. For effective directional migration, cells often reorient their Golgi apparatus and, therefore, the secretory traffic towards the leading edge. However, not much is understood about the regulation of Golgi's reorientation. Herein, we address the role of gap junction protein Connexin 43 (Cx43), which connects cells, allowing the direct exchange of molecules. We utilized HeLa WT cells lacking Cx43 and HeLa 43 cells, stably expressing Cx43, and found that functional Cx43 channels affected Golgi morphology and reduced the reorientation of Golgi during cell migration. Although the migration velocity of the front was reduced in HeLa 43, the front displayed enhanced coherence in movement, implying an augmented collective nature of migration. On BFA treatment, Golgi was dispersed and the high heterogeneity in inter-regional front velocity of HeLa WT cells was reduced to resemble the HeLa 43. HeLa 43 had higher vimentin expression and stronger basal F-actin. Furthermore, non-invasive measurement of basal membrane height fluctuations revealed a lower membrane tension. We, therefore, propose that reorientation of Golgi is not the major determinant of migration in the presence of Cx43, which induces collective-like coherent migration in cells.
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Affiliation(s)
- Madhav Sharma
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, India
| | - Suvam Mukherjee
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, India
| | - Archana Kumari Shaw
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, India
| | - Anushka Mondal
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, India
| | - Amrutamaya Behera
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, India
| | - Jibitesh Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, India
| | - Abhishek Bose
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, India
| | - Bidisha Sinha
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, India
| | - Jayasri Das Sarma
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, India
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Li S, Graham ES, Unsworth CP. Extracellular ATP release predominantly mediates Ca2+ communication locally in highly organised, stellate-Like patterned networks of adult human astrocytes. PLoS One 2023; 18:e0289350. [PMID: 37788259 PMCID: PMC10547170 DOI: 10.1371/journal.pone.0289350] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 07/17/2023] [Indexed: 10/05/2023] Open
Abstract
The 'Astrocyte Network' and the understanding of its communication has been posed as a new grand challenge to be investigated by contemporary science. However, communication studies in astrocyte networks have investigated traditional petri-dish in vitro culture models where cells are closely packed and can deviate from the stellate form observed in the brain. Using novel cell patterning approaches, highly organised, regular grid networks of astrocytes on chip, to single-cell fidelity are constructed, permitting a stellate-like in vitro network model to be realised. By stimulating the central cell with a single UV nanosecond laser pulse, the initiation/propagation pathways of stellate-like networks are re-explored. The authors investigate the mechanisms of intercellular Ca2+ communication and discover that stellate-like networks of adult human astrocytes in vitro actually exploit extracellular ATP release as their dominant propagation pathway to cells in the network locally; being observed even down to the nearest neighbour and next nearest neighbouring cells-contrary to the reported gap junction. This discovery has significant ramifications to many neurological conditions such as epilepsy, stroke and aggressive astrocytomas where gap junctions can be targeted. In cases where such gap junction targeting has failed, this new finding suggests that these conditions should be re-visited and the ATP transmission pathway targeted instead.
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Affiliation(s)
- Si Li
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Auckland, New Zealand
| | - E. Scott Graham
- Department of Molecular Medicine and Pathology & Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Charles P. Unsworth
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Auckland, New Zealand
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41
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Gutiérrez R. Gap Junctions in the Brain: Hardwired but Functionally Versatile. Neuroscientist 2023; 29:554-568. [PMID: 36125001 DOI: 10.1177/10738584221120804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Gap junctions between neurons of the brain are thought to be present in only certain cell types, and they mostly connect dendrites, somata, and axons. Synapses with gap junctions serve bidirectional metabolic and electrical coupling between connected neuronal compartments. Although plasticity of electrical synapses has been described, recent evidence of the presence of silent, but activatable, gap junctions suggests that electrical nodes in a neuronal circuit can be added or suppressed by changes in the synaptic microenvironment. This opens the possibility of reconfiguration of neuronal ensembles in response to activity. Moreover, the coexistence of gap junctions in a glutamatergic synapse may add electric and metabolic coupling to a neuronal aggregate and may serve to constitute primed ensembles within a higher-order neural network. The interaction of chemical with electrical synapses should be further explored to find, especially, emerging properties of neuronal ensembles. It will be worth to reexamine in a new light the "functional" implications of the "anatomic" concepts: "continuity" and "contiguity," which were championed by Golgi and Ramón y Cajal, respectively. In any case, exploring the versatility of the gap junctions will likely enrich the heuristic aspects of the neural and network postulates.
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Affiliation(s)
- Rafael Gutiérrez
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
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42
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Adams WP, Raisch TB, Zhao Y, Davalos R, Barrett S, King DR, Bain CB, Colucci-Chang K, Blair GA, Hanlon A, Lozano A, Veeraraghavan R, Wan X, Deschenes I, Smyth JW, Hoeker GS, Gourdie RG, Poelzing S. Extracellular Perinexal Separation Is a Principal Determinant of Cardiac Conduction. Circ Res 2023; 133:658-673. [PMID: 37681314 PMCID: PMC10561697 DOI: 10.1161/circresaha.123.322567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 08/29/2023] [Indexed: 09/09/2023]
Abstract
BACKGROUND Cardiac conduction is understood to occur through gap junctions. Recent evidence supports ephaptic coupling as another mechanism of electrical communication in the heart. Conduction via gap junctions predicts a direct relationship between conduction velocity (CV) and bulk extracellular resistance. By contrast, ephaptic theory is premised on the existence of a biphasic relationship between CV and the volume of specialized extracellular clefts within intercalated discs such as the perinexus. Our objective was to determine the relationship between ventricular CV and structural changes to micro- and nanoscale extracellular spaces. METHODS Conduction and Cx43 (connexin43) protein expression were quantified from optically mapped guinea pig whole-heart preparations perfused with the osmotic agents albumin, mannitol, dextran 70 kDa, or dextran 2 MDa. Peak sodium current was quantified in isolated guinea pig ventricular myocytes. Extracellular resistance was quantified by impedance spectroscopy. Intercellular communication was assessed in a heterologous expression system with fluorescence recovery after photobleaching. Perinexal width was quantified from transmission electron micrographs. RESULTS CV primarily in the transverse direction of propagation was significantly reduced by mannitol and increased by albumin and both dextrans. The combination of albumin and dextran 70 kDa decreased CV relative to albumin alone. Extracellular resistance was reduced by mannitol, unchanged by albumin, and increased by both dextrans. Cx43 expression and conductance and peak sodium currents were not significantly altered by the osmotic agents. In response to osmotic agents, perinexal width, in order of narrowest to widest, was albumin with dextran 70 kDa; albumin or dextran 2 MDa; dextran 70 kDa or no osmotic agent, and mannitol. When compared in the same order, CV was biphasically related to perinexal width. CONCLUSIONS Cardiac conduction does not correlate with extracellular resistance but is biphasically related to perinexal separation, providing evidence that the relationship between CV and extracellular volume is determined by ephaptic mechanisms under conditions of normal gap junctional coupling.
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Affiliation(s)
- William P. Adams
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Tristan B. Raisch
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Yajun Zhao
- School of Biomedical Engineering and Sciences, Virginia Tech
| | - Rafael Davalos
- School of Biomedical Engineering and Sciences, Virginia Tech
| | | | - D. Ryan King
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Chandra B. Bain
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
| | - Katrina Colucci-Chang
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- School of Biomedical Engineering and Sciences, Virginia Tech
| | - Grace A. Blair
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Alexandra Hanlon
- Virginia Tech Center for Biostatistics and Health Data Science, Roanoke, Virginia
| | - Alicia Lozano
- Virginia Tech Center for Biostatistics and Health Data Science, Roanoke, Virginia
| | - Rengasayee Veeraraghavan
- Department of Biomedical Engineering, College of Engineering, The Ohio State University
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center
| | - Xiaoping Wan
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center
| | - Isabelle Deschenes
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center
| | - James W. Smyth
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Department of Biological Sciences, College of Science, Virginia Tech
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia
| | - Gregory S. Hoeker
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
| | - Robert G. Gourdie
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- School of Biomedical Engineering and Sciences, Virginia Tech
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia
| | - Steven Poelzing
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
- School of Biomedical Engineering and Sciences, Virginia Tech
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia
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León-Fuentes IM, Salgado-Gil MG, Novoa MS, Retamal MA. Connexins in Cancer, the Possible Role of Connexin46 as a Cancer Stem Cell-Determining Protein. Biomolecules 2023; 13:1460. [PMID: 37892142 PMCID: PMC10604234 DOI: 10.3390/biom13101460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/15/2023] [Accepted: 09/22/2023] [Indexed: 10/29/2023] Open
Abstract
Cancer is a widespread and incurable disease caused by genetic mutations, leading to uncontrolled cell proliferation and metastasis. Connexins (Cx) are transmembrane proteins that facilitate intercellular communication via hemichannels and gap junction channels. Among them, Cx46 is found mostly in the eye lens. However, in pathological conditions, Cx46 has been observed in various types of cancers, such as glioblastoma, melanoma, and breast cancer. It has been demonstrated that elevated Cx46 levels in breast cancer contribute to cellular resistance to hypoxia, and it is an enhancer of cancer aggressiveness supporting a pro-tumoral role. Accordingly, Cx46 is associated with an increase in cancer stem cell phenotype. These cells display radio- and chemoresistance, high proliferative abilities, self-renewal, and differentiation capacities. This review aims to consolidate the knowledge of the relationship between Cx46, its role in forming hemichannels and gap junctions, and its connection with cancer and cancer stem cells.
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Affiliation(s)
| | | | | | - Mauricio A. Retamal
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, República de Honduras 12740, Las Condes, Santiago 7610496, Chile; (I.M.L.-F.); (M.G.S.-G.); (M.S.N.)
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Beckham JL, van Venrooy AR, Kim S, Li G, Li B, Duret G, Arnold D, Zhao X, Li JT, Santos AL, Chaudhry G, Liu D, Robinson JT, Tour JM. Molecular machines stimulate intercellular calcium waves and cause muscle contraction. Nat Nanotechnol 2023; 18:1051-1059. [PMID: 37430037 DOI: 10.1038/s41565-023-01436-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 05/03/2023] [Indexed: 07/12/2023]
Abstract
Intercellular calcium waves (ICW) are complex signalling phenomena that control many essential biological activities, including smooth muscle contraction, vesicle secretion, gene expression and changes in neuronal excitability. Accordingly, the remote stimulation of ICW could result in versatile biomodulation and therapeutic strategies. Here we demonstrate that light-activated molecular machines (MM)-molecules that perform mechanical work on the molecular scale-can remotely stimulate ICW. MM consist of a polycyclic rotor and stator that rotate around a central alkene when activated with visible light. Live-cell calcium-tracking and pharmacological experiments reveal that MM-induced ICW are driven by the activation of inositol-triphosphate-mediated signalling pathways by unidirectional, fast-rotating MM. Our data suggest that MM-induced ICW can control muscle contraction in vitro in cardiomyocytes and animal behaviour in vivo in Hydra vulgaris. This work demonstrates a strategy for directly controlling cell signalling and downstream biological function using molecular-scale devices.
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Affiliation(s)
| | | | - Soonyoung Kim
- Department of Electrical Engineering, Rice University, Houston, TX, USA
| | - Gang Li
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Bowen Li
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Guillaume Duret
- Department of Electrical Engineering, Rice University, Houston, TX, USA
| | - Dallin Arnold
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Xuan Zhao
- Department of Electrical Engineering, Rice University, Houston, TX, USA
| | - John T Li
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Ana L Santos
- Department of Chemistry, Rice University, Houston, TX, USA
- IdISBA-Fundación de Investigación Sanitaria de las Islas Baleares, Palma, Spain
| | | | - Dongdong Liu
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Jacob T Robinson
- Department of Bioengineering, Department of Electrical Engineering, Rice University, Houston, TX, USA.
| | - James M Tour
- Department of Chemistry, Smalley-Curl Institute, NanoCarbon Center and Rice Advanced Materials Institute, Department of Materials Science and Nanoengineering, Department of Computer Science, Rice University, Houston, TX, USA.
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45
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Hilgen G. Connexin45 colocalization patterns in the plexiform layers of the developing mouse retina. J Anat 2023; 243:258-264. [PMID: 35315057 PMCID: PMC10335376 DOI: 10.1111/joa.13651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/14/2022] [Accepted: 02/28/2022] [Indexed: 11/29/2022] Open
Abstract
Chemical and electrical synapses (gap junctions) are widely prevalent in the nervous system. Gap junctions emerge long before chemical synapses, allowing communication between developing cells, and are thought to be involved in establishing neural circuits. Mounting evidence indicates that these two modalities of synaptic transmission closely interact during retinal development and that such interactions play a critical role in synaptogenesis and circuit formation during the perinatal period. In vertebrates, gap junctions consist of two connexins which in turn are made up of six connexins (Cx). To what extent Cx45 and Cx36, the most abundant connexins in the retina, are involved in synaptogenesis and retinal circuit formation is not known. The here presented immunohistochemical study used stainings of Cx45, Cx36 and Synaptophysin in the outer and inner (IPL) plexiform layers of postnatal day 8-16 mice retinas to shed light on the role of connexins during critical neuronal developmental processes. Cx45 and Cx36 expressions in both plexiform layers of the mouse retina increased till eye opening and dropped afterwards. The percentage of heterotypic Cx45/Cx36 gap junctions is also higher before the critical event of eye opening. Finally, Cx45 is closely located and/or colocalized with Synaptophysin also shortly before eye opening in the IPL of the mouse retina. All findings point towards a pivotal role for Cx45 during postnatal synaptogenesis in the mouse retina. However, a more functional study is needed to determine the role of Cx45 during synaptogenesis and circuit formation.
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Affiliation(s)
- Gerrit Hilgen
- Health & Life Sciences, Applied SciencesNorthumbria UniversityNewcastle upon TyneUK
- Biosciences InstituteNewcastle UniversityNewcastle upon TyneUK
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46
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Green J, Bruno CA, Traunmüller L, Ding J, Hrvatin S, Wilson DE, Khodadad T, Samuels J, Greenberg ME, Harvey CD. A cell-type-specific error-correction signal in the posterior parietal cortex. Nature 2023; 620:366-373. [PMID: 37468637 PMCID: PMC10412446 DOI: 10.1038/s41586-023-06357-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 06/21/2023] [Indexed: 07/21/2023]
Abstract
Neurons in the posterior parietal cortex contribute to the execution of goal-directed navigation1 and other decision-making tasks2-4. Although molecular studies have catalogued more than 50 cortical cell types5, it remains unclear what distinct functions they have in this area. Here we identified a molecularly defined subset of somatostatin (Sst) inhibitory neurons that, in the mouse posterior parietal cortex, carry a cell-type-specific error-correction signal for navigation. We obtained repeatable experimental access to these cells using an adeno-associated virus in which gene expression is driven by an enhancer that functions specifically in a subset of Sst cells6. We found that during goal-directed navigation in a virtual environment, this subset of Sst neurons activates in a synchronous pattern that is distinct from the activity of surrounding neurons, including other Sst neurons. Using in vivo two-photon photostimulation and ex vivo paired patch-clamp recordings, we show that nearby cells of this Sst subtype excite each other through gap junctions, revealing a self-excitation circuit motif that contributes to the synchronous activity of this cell type. These cells selectively activate as mice execute course corrections for deviations in their virtual heading during navigation towards a reward location, for both self-induced and experimentally induced deviations. We propose that this subtype of Sst neurons provides a self-reinforcing and cell-type-specific error-correction signal in the posterior parietal cortex that may help with the execution and learning of accurate goal-directed navigation trajectories.
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Affiliation(s)
- Jonathan Green
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
| | - Carissa A Bruno
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Lisa Traunmüller
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Jennifer Ding
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Siniša Hrvatin
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Whitehead Institute, MIT, Cambridge, MA, USA
| | - Daniel E Wilson
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Thomas Khodadad
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Jonathan Samuels
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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Lissoni A, Tao S, Allewaert R, Witschas K, Leybaert L. Cx43 Hemichannel and Panx1 Channel Modulation by Gap19 and 10Panx1 Peptides. Int J Mol Sci 2023; 24:11612. [PMID: 37511370 PMCID: PMC10380488 DOI: 10.3390/ijms241411612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/14/2023] [Accepted: 07/16/2023] [Indexed: 07/30/2023] Open
Abstract
Cx43 hemichannels (HCs) and Panx1 channels are two genetically distant protein families. Despite the lack of sequence homology, Cx43 and Panx1 channels have been the subject of debate due to their overlapping expression and the fact that both channels present similarities in terms of their membrane topology and electrical properties. Using the mimetic peptides Gap19 and 10Panx1, this study aimed to investigate the cross-effects of these peptides on Cx43 HCs and Panx1 channels. The single-channel current activity from stably expressing HeLa-Cx43 and C6-Panx1 cells was recorded using patch-clamp experiments in whole-cell voltage-clamp mode, demonstrating 214 pS and 68 pS average unitary conductances for the respective channels. Gap19 was applied intracellularly while 10Panx1 was applied extracellularly at different concentrations (100, 200 and 500 μM) and the average nominal open probability (NPo) was determined for each testing condition. A concentration of 100 µM Gap19 more than halved the NPo of Cx43 HCs, while 200 µM 10Panx1 was necessary to obtain a half-maximal NPo reduction in the Panx1 channels. Gap19 started to significantly inhibit the Panx1 channels at 500 µM, reducing the NPo by 26% while reducing the NPo of the Cx43 HCs by 84%. In contrast 10Panx1 significantly reduced the NPo of the Cx43 HCs by 37% at 100 µM and by 83% at 200 µM, a concentration that caused the half-maximal inhibition of the Panx1 channels. These results demonstrate that 10Panx1 inhibits Cx43 HCs over the 100-500 µM concentration range while 500 µM intracellular Gap19 is necessary to observe some inhibition of Panx1 channels.
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48
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Nielsen MS, van Opbergen CJM, van Veen TAB, Delmar M. The intercalated disc: a unique organelle for electromechanical synchrony in cardiomyocytes. Physiol Rev 2023; 103:2271-2319. [PMID: 36731030 PMCID: PMC10191137 DOI: 10.1152/physrev.00021.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
The intercalated disc (ID) is a highly specialized structure that connects cardiomyocytes via mechanical and electrical junctions. Although described in some detail by light microscopy in the 19th century, it was in 1966 that electron microscopy images showed that the ID represented apposing cell borders and provided detailed insight into the complex ID nanostructure. Since then, much has been learned about the ID and its molecular composition, and it has become evident that a large number of proteins, not all of them involved in direct cell-to-cell coupling via mechanical or gap junctions, reside at the ID. Furthermore, an increasing number of functional interactions between ID components are emerging, leading to the concept that the ID is not the sum of isolated molecular silos but an interacting molecular complex, an "organelle" where components work in concert to bring about electrical and mechanical synchrony. The aim of the present review is to give a short historical account of the ID's discovery and an updated overview of its composition and organization, followed by a discussion of the physiological implications of the ID architecture and the local intermolecular interactions. The latter will focus on both the importance of normal conduction of cardiac action potentials as well as the impact on the pathophysiology of arrhythmias.
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Affiliation(s)
- Morten S Nielsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chantal J M van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
| | - Toon A B van Veen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
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49
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Márquez M, Muñoz M, Córdova A, Puebla M, Figueroa XF. Connexin 40-Mediated Regulation of Systemic Circulation and Arterial Blood Pressure. J Vasc Res 2023; 60:87-100. [PMID: 37331352 DOI: 10.1159/000531035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 05/05/2023] [Indexed: 06/20/2023] Open
Abstract
Vascular system is a complex network in which different cell types and vascular segments must work in concert to regulate blood flow distribution and arterial blood pressure. Although paracrine/autocrine signaling is involved in the regulation of vasomotor tone, direct intercellular communication via gap junctions plays a central role in the control and coordination of vascular function in the microvascular network. Gap junctions are made up by connexin (Cx) proteins, and among the four Cxs expressed in the cardiovascular system (Cx37, Cx40, Cx43, and Cx45), Cx40 has emerged as a critical signaling pathway in the vessel wall. This Cx is predominantly found in the endothelium, but it is involved in the development of the cardiovascular system and in the coordination of endothelial and smooth muscle cell function along the length of the vessels. In addition, Cx40 participates in the control of vasomotor tone through the transmission of electrical signals from the endothelium to the underlying smooth muscle and in the regulation of arterial blood pressure by renin-angiotensin system in afferent arterioles. In this review, we discuss the participation of Cx40-formed channels in the development of cardiovascular system, control and coordination of vascular function, and regulation of arterial blood pressure.
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Affiliation(s)
- Mónica Márquez
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Matías Muñoz
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexandra Córdova
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mariela Puebla
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Xavier F Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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50
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Singhal P, Senecal JMM, Senecal JEM, Silwal P, Lynn BD, Nagy JI. Characteristics of Electrical Synapses, C-terminals and Small-conductance Ca 2+ activated Potassium Channels in the Sexually Dimorphic Cremaster Motor Nucleus in Spinal Cord of Mouse and Rat. Neuroscience 2023; 521:58-76. [PMID: 37100373 DOI: 10.1016/j.neuroscience.2023.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 03/17/2023] [Accepted: 04/18/2023] [Indexed: 04/28/2023]
Abstract
Sexually dimorphic motoneurons (MNs) located in lower lumbar spinal cord are involved in mating and reproductive behaviours and are known to be coupled by electrical synapses. The cremaster motor nucleus in upper lumbar spinal cord has also been suggested to support physiological processes associated with sexual behaviours in addition to its thermoregulatory and protective role in maintaining testes integrity. Using immunofluorescence approaches, we investigated whether cremaster MNs also exhibit features reflecting their potential for electrical synaptic communication and examined some of their other synaptic characteristics. Both mice and rats displayed punctate immunolabelling of Cx36 associated with cremaster MNs, indicative of gap junction formation. Transgenic mice with enhanced green fluorescent protein (eGFP) reporter for connexin36 expression showed that subpopulations of cremaster MNs in both male and female mice express eGFP, with greater proportions of those in male mice. The eGFP+ MNs within the cremaster nucleus vs. eGFP- MNs inside and outside this nucleus displayed a 5-fold greater density of serotonergic innervation and exhibited a paucity of innervation by C-terminals arising from cholinergic V0c interneurons. All MNs within the cremaster motor nucleus displayed prominent patches of immunolabelling for SK3 (K+) channels around their periphery, suggestive of their identity as slow MNs, many though not all of which were in apposition to C-terminals. The results provide evidence for electrical coupling of a large proportion of cremaster MNs and suggest the existence of two populations of these MNs with possibly differential innervation of their peripheral target muscles serving different functions.
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Affiliation(s)
- P Singhal
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg R3E 0J9, Canada
| | - J M M Senecal
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg R3E 0J9, Canada
| | - J E M Senecal
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg R3E 0J9, Canada
| | - P Silwal
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg R3E 0J9, Canada
| | - B D Lynn
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg R3E 0J9, Canada
| | - J I Nagy
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg R3E 0J9, Canada.
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