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Hüneke H, Langeheine M, Rode K, Jung K, Pilatz A, Fietz D, Kliesch S, Brehm R. Effects of a Sertoli cell-specific knockout of Connexin43 on maturation and proliferation of postnatal Sertoli cells. Differentiation 2023; 134:31-51. [PMID: 37839230 DOI: 10.1016/j.diff.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 10/17/2023]
Abstract
Adult male Sertoli cell-specific Connexin43 knockout mice (SCCx43KO) exhibit higher Sertoli cell (SC) numbers per seminiferous tubule compared to their wild type (WT) littermates. Thus, deletion of this testicular gap junction protein seems to affect the proliferative potential and differentiation of "younger" SC. Although SC have so far mostly been characterised as postmitotic cells that cease to divide and become an adult, terminally differentiated cell population at around puberty, there is rising evidence that there exist exceptions from this for a very long time accepted paradigm. Aim of this study was to investigate postnatal SC development and to figure out underlying causes for observed higher SC numbers in adult KO mice. Therefore, the amount of SC mitotic figures was compared, resulting in slightly more and prolonged detection of SC mitotic figures in KO mice compared to WT. SC counting per tubular cross section revealed significantly different time curves, and comparing proliferation rates using Bromodesoxyuridine and Sox9 showed higher proliferation rates in 8-day old KO mice. SC proliferation was further investigated by Ki67 immunohistochemistry. SC in KO mice displayed a delayed initiation of cell-cycle-inhibitor p27Kip1 synthesis and prolonged synthesis of the phosphorylated tumour suppressor pRb and proliferation marker Ki67. Thus, the higher SC numbers in adult male SCCx43KO mice may arise due to two different reasons: Firstly, in prepubertal KO mice, the proliferation rate of SC was higher. Secondly, there were differences in their ability to cease proliferation as shown by the delayed initiation of p27Kip1 synthesis and the prolonged production of phosphorylated pRb and Ki67. Immunohistochemical results indicating a prolonged period of SC proliferation in SCCx43KO were confirmed by detection of proliferating SC in 17-days-old KO mice. In conclusion, deletion of the testicular gap junction protein Cx43 might prevent normal SC maturation and might even alter also the proliferation potential of adult SC.
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Affiliation(s)
- Hanna Hüneke
- Institute of Anatomy, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Marion Langeheine
- Institute of Anatomy, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Kristina Rode
- Institute of Anatomy, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Klaus Jung
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Adrian Pilatz
- Department of Urology, Pediatric Urology and Andrology, Justus Liebig University Giessen, Giessen, Germany
| | - Daniela Fietz
- Department of Veterinary Anatomy, Histology and Embryology, Justus Liebig University Giessen, Giessen, Germany
| | - Sabine Kliesch
- Centre of Andrology and Reproductive Medicine, University of Muenster, Muenster, Germany
| | - Ralph Brehm
- Institute of Anatomy, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany.
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2
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Jones JC, Bodenstine TM. Connexins and Glucose Metabolism in Cancer. Int J Mol Sci 2022; 23:ijms231710172. [PMID: 36077565 PMCID: PMC9455984 DOI: 10.3390/ijms231710172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Connexins are a family of transmembrane proteins that regulate diverse cellular functions. Originally characterized for their ability to mediate direct intercellular communication through the formation of highly regulated membrane channels, their functions have been extended to the exchange of molecules with the extracellular environment, and the ability to modulate numerous channel-independent effects on processes such as motility and survival. Notably, connexins have been implicated in cancer biology for their context-dependent roles that can both promote or suppress cancer cell function. Moreover, connexins are able to mediate many aspects of cellular metabolism including the intercellular coupling of nutrients and signaling molecules. During cancer progression, changes to substrate utilization occur to support energy production and biomass accumulation. This results in metabolic plasticity that promotes cell survival and proliferation, and can impact therapeutic resistance. Significant progress has been made in our understanding of connexin and cancer biology, however, delineating the roles these multi-faceted proteins play in metabolic adaptation of cancer cells is just beginning. Glucose represents a major carbon substrate for energy production, nucleotide synthesis, carbohydrate modifications and generation of biosynthetic intermediates. While cancer cells often exhibit a dependence on glycolytic metabolism for survival, cellular reprogramming of metabolic pathways is common when blood perfusion is limited in growing tumors. These metabolic changes drive aggressive phenotypes through the acquisition of functional traits. Connections between glucose metabolism and connexin function in cancer cells and the surrounding stroma are now apparent, however much remains to be discovered regarding these relationships. This review discusses the existing evidence in this area and highlights directions for continued investigation.
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Min JK, Park HS, Lee YB, Kim JG, Kim JI, Park JB. Cross-Talk between Wnt Signaling and Src Tyrosine Kinase. Biomedicines 2022; 10:biomedicines10051112. [PMID: 35625853 PMCID: PMC9138253 DOI: 10.3390/biomedicines10051112] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/09/2022] [Accepted: 05/09/2022] [Indexed: 12/17/2022] Open
Abstract
Src, a non-receptor tyrosine kinase, was first discovered as a prototype oncogene and has been shown to critical for cancer progression for a variety of tissues. Src activity is regulated by a number of post-translational modifications in response to various stimuli. Phosphorylations of Src Tyr419 (human; 416 in chicken) and Src Tyr530 (human; 527 in chicken) have been known to be critical for activation and inactivation of Src, respectively. Wnt signaling regulates a variety of cellular functions including for development and cell proliferation, and has a role in certain diseases such as cancer. Wnt signaling is carried out through two pathways: β-catenin-dependent canonical and β-catenin-independent non-canonical pathways as Wnt ligands bind to their receptors, Frizzled, LRP5/6, and ROR1/2. In addition, many signaling components including Axin, APC, Damm, Dishevelled, JNK kinase and Rho GTPases contribute to these canonical and non-canonical Wnt pathways. However, the communication between Wnt signaling and Src tyrosine kinase has not been well reviewed as Src regulates Wnt signaling through LRP6 tyrosine phosphorylation. GSK-3β phosphorylated by Wnt also regulates Src activity. As Wnt signaling and Src mutually regulate each other, it is noted that aberrant regulation of these components give rise to various diseases including typically cancer, and as such, merit a closer look.
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Affiliation(s)
- Jung Ki Min
- Department of Biochemistry, Hallym University College of Medicine, Chuncheon 25242, Korea; (J.K.M.); (Y.-B.L.); (J.-G.K.)
- Institute of Cell Differentiation and Aging, Hallym University College of Medicine, Chuncheon 24252, Korea
| | - Hwee-Seon Park
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea; (H.-S.P.); (J.-I.K.)
- Genomic Medicine Institute, Medical Research Center, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Yoon-Beom Lee
- Department of Biochemistry, Hallym University College of Medicine, Chuncheon 25242, Korea; (J.K.M.); (Y.-B.L.); (J.-G.K.)
- Institute of Cell Differentiation and Aging, Hallym University College of Medicine, Chuncheon 24252, Korea
| | - Jae-Gyu Kim
- Department of Biochemistry, Hallym University College of Medicine, Chuncheon 25242, Korea; (J.K.M.); (Y.-B.L.); (J.-G.K.)
- Institute of Cell Differentiation and Aging, Hallym University College of Medicine, Chuncheon 24252, Korea
| | - Jong-Il Kim
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea; (H.-S.P.); (J.-I.K.)
- Genomic Medicine Institute, Medical Research Center, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jae-Bong Park
- Department of Biochemistry, Hallym University College of Medicine, Chuncheon 25242, Korea; (J.K.M.); (Y.-B.L.); (J.-G.K.)
- Institute of Cell Differentiation and Aging, Hallym University College of Medicine, Chuncheon 24252, Korea
- Correspondence: ; Tel.: +82-33-248-2542; Fax: +82-33-244-8425
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Logvinov AK, Kirichenko EY, Sehweil SMM, Bragin DE, Logvinova IK, Ermakov AM. Confocal Laser and Electron Microscopic Investigation of Gap Junctions in Anaplastic Astrocytomas. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1395:309-313. [PMID: 36527654 PMCID: PMC10029833 DOI: 10.1007/978-3-031-14190-4_50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Connexin 43 (Cx43) is a multifunction protein that forms gap junction channels and hemichannels and is suggested to play an essential role in oxygen-glucose deprivation, induced via neuroinflammation during astrocytoma expansion into healthy tissue. To prove this assumption we studied connexin 43 localisation and ultrastructure of gap junctions in samples of malignant brain tumour (anaplastic astrocytomas grade III). For confocal laser microscopy, vibratome sections of tumour fragments were incubated in a mixture of primary antibodies to connexin 43 and glial fibrillary acidic protein (GFAP), then in a mixture of secondary antibodies conjugated with a fluorescent label. After the immunofluorescence study, sections were washed in phosphate buffer, additionally postfixed with 1% OsO4 solution, dehydrated and embedded in epoxy resin by a plane-parallel method. Ultra-thin sections obtained from these samples were contrasted with uranyl acetate and lead citrate and viewed under a Jem 1011 electron microscope. Confocal laser examination detected a positive reaction to Cx43 in the form of point fluorescence. These points were of various sizes. Most of them were localised around or at the intersection of small processes containing GFAP. Electron microscopy of the tumour samples containing the most significant number of Cx43 revealed single and closely spaced gap junctions with a typical ultrastructure on the processes and bodies of tumour cells. Sequential analysis in the fields of view revealed 62 gap junctions in the area of 100 μm2. Numerous gap junctions in anaplastic astrocytomas revealed in our study may indicate electrotonic and metabolic transmission between glioma cells, possibly promoting its progression.
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Affiliation(s)
- Alexander K Logvinov
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | | | - Salah M M Sehweil
- Department of Neurology and Nervous Diseases, Rostov State Medical University, Rostov-on-Don, Russia
| | - Denis E Bragin
- Lovelace Biomedical Research Institute, Albuquerque, NM, USA
- Department of Neurology, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | | | - Alexey M Ermakov
- Department of Bioengineering, Rostov State Technical University, Rostov-on-Don, Russia
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Han XJ, Zhang WF, Wang Q, Li M, Zhang CB, Yang ZJ, Tan RJ, Gan LJ, Zhang LL, Lan XM, Zhang FL, Hong T, Jiang LP. HIF-1α promotes the proliferation and migration of pulmonary arterial smooth muscle cells via activation of Cx43. J Cell Mol Med 2021; 25:10663-10673. [PMID: 34698450 PMCID: PMC8581339 DOI: 10.1111/jcmm.17003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 09/14/2021] [Accepted: 10/04/2021] [Indexed: 12/17/2022] Open
Abstract
The proliferation of pulmonary artery smooth muscle cells (PASMCs) is an important cause of pulmonary vascular remodelling in hypoxia-induced pulmonary hypertension (HPH). However, its underlying mechanism has not been well elucidated. Connexin 43 (Cx43) plays crucial roles in vascular smooth muscle cell proliferation in various cardiovascular diseases. Here, the male Sprague-Dawley (SD) rats were exposed to hypoxia (10% O2 ) for 21 days to induce rat HPH model. PASMCs were treated with CoCl2 (200 µM) for 24 h to establish the HPH cell model. It was found that hypoxia up-regulated the expression of Cx43 and phosphorylation of Cx43 at Ser 368 in rat pulmonary arteries and PASMCs, and stimulated the proliferation and migration of PASMCs. HIF-1α inhibitor echinomycin attenuated the CoCl2 -induced Cx43 expression and phosphorylation of Cx43 at Ser 368 in PASMCs. The interaction between HIF-1α and Cx43 promotor was also identified using chromatin immunoprecipitation assay. Moreover, Cx43 specific blocker (37,43 Gap27) or knockdown of Cx43 efficiently alleviated the proliferation and migration of PASMCs under chemically induced hypoxia. Therefore, the results above suggest that HIF-1α, as an upstream regulator, promotes the expression of Cx43, and the HIF-1α/Cx43 axis regulates the proliferation and migration of PASMCs in HPH.
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Affiliation(s)
- Xiao-Jian Han
- Key Laboratory of Drug Targets and Drug Screening of Jiangxi Province, Nanchang, China.,Institute of Geriatrics, Jiangxi Provincial People's Hospital Affiliated to Nanchang University, Nanchang, China.,Department of Neurology, Jiangxi Provincial People's Hospital Affiliated to Nanchang University, Nanchang, China
| | - Wei-Fang Zhang
- Department of Pharmacy, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qin Wang
- Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Min Li
- Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Chun-Bo Zhang
- Key Laboratory of Drug Targets and Drug Screening of Jiangxi Province, Nanchang, China.,Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Zhang-Jian Yang
- Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Ren-Jie Tan
- Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Li-Jun Gan
- Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Le-Ling Zhang
- Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Xue-Mei Lan
- Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Fang-Lin Zhang
- Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Tao Hong
- Department of Neurosurgery, First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Li-Ping Jiang
- Key Laboratory of Drug Targets and Drug Screening of Jiangxi Province, Nanchang, China.,Department of Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, China
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Pelaz SG, Ollauri-Ibáñez C, Lillo C, Tabernero A. Impairment of Autophagic Flux Participates in the Antitumor Effects of TAT-Cx43 266-283 in Glioblastoma Stem Cells. Cancers (Basel) 2021; 13:cancers13174262. [PMID: 34503072 PMCID: PMC8428230 DOI: 10.3390/cancers13174262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/13/2021] [Accepted: 08/21/2021] [Indexed: 11/20/2022] Open
Abstract
Simple Summary Autophagy is a process in which the cell recycles components that are not needed at that moment and uses the resulting elements to satisfy more urgent needs. Depending on the specific context, this can be beneficial or detrimental for tumor development. We found that in glioblastoma, the most lethal brain tumor, autophagy is upregulated and contributes to glioblastoma stem cell survival under starvation. Importantly, the antitumor peptide TAT-Cx43266-283 blocks autophagy flux, contributing to the death of glioblastoma stem cells. This peptide induces glioblastoma stem cell death in nutrient-deprived and complete environments, while the effect of other unsuccessful drugs for glioblastoma depends on nutrient context, supporting the potential of TAT-Cx43266-283 as a treatment to improve the lives of glioblastoma patients. Abstract Autophagy is a physiological process by which various damaged or non-essential cytosolic components are recycled, contributing to cell survival under stress conditions. In cancer, autophagy can have antitumor or protumor effects depending on the developmental stage. Here, we use Western blotting, immunochemistry, and transmission electron microscopy to demonstrate that the antitumor peptide TAT-Cx43266-283, a c-Src inhibitor, blocks autophagic flux in glioblastoma stem cells (GSCs) under basal and nutrient-deprived conditions. Upon nutrient deprivation, GSCs acquired a dormant-like phenotype that was disrupted by inhibition of autophagy with TAT-Cx43266-283 or chloroquine (a classic autophagy inhibitor), leading to GSC death. Remarkably, dasatinib, a clinically available c-Src inhibitor, could not replicate TAT-Cx43266-283 effect on dormant GSCs, revealing for the first time the possible involvement of pathways other than c-Src in TAT-Cx43266-283 effect. TAT-Cx43266-283 exerts an antitumor effect both in nutrient-complete and nutrient-deprived environments, which constitutes an advantage over chloroquine and dasatinib, whose effects depend on nutrient environment. Finally, our analysis of the levels of autophagy-related proteins in healthy and glioma donors suggests that autophagy is upregulated in glioblastoma, further supporting the interest in inhibiting this process in the most aggressive brain tumor and the potential use of TAT-Cx43266-283 as a therapy for this type of cancer.
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Affiliation(s)
- Sara G. Pelaz
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, 37007 Salamanca, Spain; (S.G.P.); (C.O.-I.); (C.L.)
- Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª Planta, Paseo de San Vicente 58-182, 37007 Salamanca, Spain
| | - Claudia Ollauri-Ibáñez
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, 37007 Salamanca, Spain; (S.G.P.); (C.O.-I.); (C.L.)
- Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª Planta, Paseo de San Vicente 58-182, 37007 Salamanca, Spain
| | - Concepción Lillo
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, 37007 Salamanca, Spain; (S.G.P.); (C.O.-I.); (C.L.)
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª Planta, Paseo de San Vicente 58-182, 37007 Salamanca, Spain
- Departamento de Biología Celular y Patología, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Arantxa Tabernero
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, 37007 Salamanca, Spain; (S.G.P.); (C.O.-I.); (C.L.)
- Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª Planta, Paseo de San Vicente 58-182, 37007 Salamanca, Spain
- Correspondence:
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Song HE, Lee Y, Kim E, Cho CY, Jung O, Lee D, Lee EG, Nam SH, Kang M, Macalino SJY, Kim JE, Jung JW, Kwon SW, Choi S, Lee JW. N-terminus-independent activation of c-Src via binding to a tetraspan(in) TM4SF5 in hepatocellular carcinoma is abolished by the TM4SF5 C-terminal peptide application. Am J Cancer Res 2021; 11:8092-8111. [PMID: 34335982 PMCID: PMC8315060 DOI: 10.7150/thno.58739] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 06/25/2021] [Indexed: 12/24/2022] Open
Abstract
Active c-Src non-receptor tyrosine kinase localizes to the plasma membrane via N-terminal lipid modification. Membranous c-Src causes cancer initiation and progression. Even though transmembrane 4 L six family member 5 (TM4SF5), a tetraspan(in), can be involved in this mechanism, the molecular and structural influence of TM4SF5 on c-Src remains unknown. Methods: Here, we investigated molecular and structural details by which TM4SF5 regulated c-Src devoid of its N-terminus and how cell-penetrating peptides were able to interrupt c-Src activation via interference of c-Src-TM4SF5 interaction in hepatocellular carcinoma models. Results: The TM4SF5 C-terminus efficiently bound the c-Src SH1 kinase domain, efficiently to the inactively-closed form. The complex involved protein tyrosine phosphatase 1B able to dephosphorylate Tyr530. The c-Src SH1 domain alone, even in a closed form, bound TM4SF5 to cause c-Src Tyr419 and FAK Y861 phosphorylation. Homology modeling and molecular dynamics simulation studies predicted the directly interfacing residues, which were further validated by mutational studies. Cell penetration of TM4SF5 C-terminal peptides blocked the interaction of TM4SF5 with c-Src and prevented c-Src-dependent tumor initiation and progression in vivo. Conclusions: Collectively, these data demonstrate that binding of the TM4SF5 C-terminus to the kinase domain of inactive c-Src leads to its activation. Because this binding can be abolished by cell-penetrating peptides containing the TM4SF5 C-terminus, targeting this direct interaction may be an effective strategy for developing therapeutics that block the development and progression of hepatocellular carcinoma.
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Jaraíz-Rodríguez M, Talaverón R, García-Vicente L, Pelaz SG, Domínguez-Prieto M, Álvarez-Vázquez A, Flores-Hernández R, Sin WC, Bechberger J, Medina JM, Naus CC, Tabernero A. Connexin43 peptide, TAT-Cx43266-283, selectively targets glioma cells, impairs malignant growth, and enhances survival in mouse models in vivo. Neuro Oncol 2021; 22:493-504. [PMID: 31883012 PMCID: PMC7158688 DOI: 10.1093/neuonc/noz243] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background Malignant gliomas are the most frequent primary brain tumors and remain among the most incurable cancers. Although the role of the gap junction protein, connexin43 (Cx43), has been deeply investigated in malignant gliomas, no compounds have been reported with the ability to recapitulate the tumor suppressor properties of this protein in in vivo glioma models. Methods TAT-Cx43266–283 a cell-penetrating peptide which mimics the effect of Cx43 on c-Src inhibition, was studied in orthotopic immunocompetent and immunosuppressed models of glioma. The effects of this peptide in brain cells were also analyzed. Results While glioma stem cell malignant features were strongly affected by TAT-Cx43266–283, these properties were not significantly modified in neurons and astrocytes. Intraperitoneally administered TAT-Cx43266–283 decreased the invasion of intracranial tumors generated by GL261 mouse glioma cells in immunocompetent mice. When human glioma stem cells were intracranially injected with TAT-Cx43266–283 into immunodeficient mice, there was reduced expression of the stemness markers nestin and Sox2 in human glioma cells at 7 days post-implantation. Consistent with the role of Sox2 as a transcription factor required for tumorigenicity, TAT-Cx43266–283 reduced the number and stemness of human glioma cells at 30 days post-implantation. Furthermore, TAT-Cx43266–283 enhanced the survival of immunocompetent mice bearing gliomas derived from murine glioma stem cells. Conclusion TAT-Cx43266–283 reduces the growth, invasion, and progression of malignant gliomas and enhances the survival of glioma-bearing mice without exerting toxicity in endogenous brain cells, which suggests that this peptide could be considered as a new clinical therapy for high-grade gliomas.
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Affiliation(s)
- Myriam Jaraíz-Rodríguez
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Rocío Talaverón
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Laura García-Vicente
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Sara G Pelaz
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Marta Domínguez-Prieto
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Andrea Álvarez-Vázquez
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Raquel Flores-Hernández
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Wun Chey Sin
- Department of Cellular and Physiological Sciences, The Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - John Bechberger
- Department of Cellular and Physiological Sciences, The Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - José M Medina
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Christian C Naus
- Department of Cellular and Physiological Sciences, The Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Arantxa Tabernero
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
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Mesnil M, Defamie N, Naus C, Sarrouilhe D. Brain Disorders and Chemical Pollutants: A Gap Junction Link? Biomolecules 2020; 11:biom11010051. [PMID: 33396565 PMCID: PMC7824109 DOI: 10.3390/biom11010051] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/07/2023] Open
Abstract
The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.
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Affiliation(s)
- Marc Mesnil
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Norah Defamie
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Christian Naus
- Faculty of Medicine, Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T1Z3, Canada;
| | - Denis Sarrouilhe
- Laboratoire de Physiologie Humaine, Faculté de Médecine et Pharmacie, 6 rue de La Milétrie, bât D1, TSA 51115, 86073 Poitiers, France
- Correspondence: ; Tel.: +33-5-49-45-43-58
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Mulkearns-Hubert EE, Reizes O, Lathia JD. Connexins in Cancer: Jekyll or Hyde? Biomolecules 2020; 10:E1654. [PMID: 33321749 PMCID: PMC7764653 DOI: 10.3390/biom10121654] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 12/16/2022] Open
Abstract
The expression, localization, and function of connexins, the protein subunits that comprise gap junctions, are often altered in cancer. In addition to cell-cell coupling through gap junction channels, connexins also form hemichannels that allow communication between the cell and the extracellular space and perform non-junctional intracellular activities. Historically, connexins have been considered tumor suppressors; however, they can also serve tumor-promoting functions in some contexts. Here, we review the literature surrounding connexins in cancer cells in terms of specific connexin functions and propose that connexins function upstream of most, if not all, of the hallmarks of cancer. The development of advanced connexin targeting approaches remains an opportunity for the field to further interrogate the role of connexins in cancer phenotypes, particularly through the use of in vivo models. More specific modulators of connexin function will both help elucidate the functions of connexins in cancer and advance connexin-specific therapies in the clinic.
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Affiliation(s)
- Erin E. Mulkearns-Hubert
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (O.R.); (J.D.L.)
| | - Ofer Reizes
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (O.R.); (J.D.L.)
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College, Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Justin D. Lathia
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (O.R.); (J.D.L.)
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College, Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
- Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH, 44195, USA
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11
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Pelaz SG, Jaraíz-Rodríguez M, Álvarez-Vázquez A, Talaverón R, García-Vicente L, Flores-Hernández R, Gómez de Cedrón M, Tabernero M, Ramírez de Molina A, Lillo C, Medina JM, Tabernero A. Targeting metabolic plasticity in glioma stem cells in vitro and in vivo through specific inhibition of c-Src by TAT-Cx43 266-283. EBioMedicine 2020; 62:103134. [PMID: 33254027 PMCID: PMC7708820 DOI: 10.1016/j.ebiom.2020.103134] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 10/24/2020] [Accepted: 11/02/2020] [Indexed: 12/22/2022] Open
Abstract
Background Glioblastoma is the most aggressive primary brain tumour and has a very poor prognosis. Inhibition of c-Src activity in glioblastoma stem cells (GSCs, responsible for glioblastoma lethality) and primary glioblastoma cells by the peptide TAT-Cx43266–283 reduces tumorigenicity, and boosts survival in preclinical models. Because c-Src can modulate cell metabolism and several reports revealed poor clinical efficacy of various antitumoral drugs due to metabolic rewiring in cancer cells, here we explored the inhibition of advantageous GSC metabolic plasticity by the c-Src inhibitor TAT-Cx43266-283. Methods Metabolic impairment induced by the c-Src inhibitor TAT-Cx43266-283 in vitro was assessed by fluorometry, western blotting, immunofluorescence, qPCR, enzyme activity assays, electron microscopy, Seahorse analysis, time-lapse imaging, siRNA, and MTT assays. Protein expression in tumours from a xenograft orthotopic glioblastoma mouse model was evaluated by immunofluorescence. Findings TAT-Cx43266–283 decreased glucose uptake in human GSCs and reduced oxidative phosphorylation without a compensatory increase in glycolysis, with no effect on brain cell metabolism, including rat neurons, human and rat astrocytes, and human neural stem cells. TAT-Cx43266-283 impaired metabolic plasticity, reducing GSC growth and survival under different nutrient environments. Finally, GSCs intracranially implanted with TAT-Cx43266–283 showed decreased levels of important metabolic targets for cancer therapy, such as hexokinase-2 and GLUT-3. Interpretation The reduced ability of TAT-Cx43266-283–treated GSCs to survive in metabolically challenging settings, such as those with restricted nutrient availability or the ever-changing in vivo environment, allows us to conclude that the advantageous metabolic plasticity of GSCs can be therapeutically exploited through the specific and cell-selective inhibition of c-Src by TAT-Cx43266-283. Funding Spanish Ministerio de Economía y Competitividad (FEDER BFU2015-70040-R and FEDER RTI2018-099873-B-I00), Fundación Ramón Areces. Fellowships from the Junta de Castilla y León, European Social Fund, Ministerio de Ciencia and Asociación Española Contra el Cáncer (AECC).
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Affiliation(s)
- Sara G Pelaz
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, Salamanca 37007, Spain; Departamento de Bioquímica y Biología Celular, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca 37007, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª planta, Paseo de San Vicente, 58-182, Salamanca 37007, Spain
| | - Myriam Jaraíz-Rodríguez
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, Salamanca 37007, Spain; Departamento de Bioquímica y Biología Celular, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca 37007, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª planta, Paseo de San Vicente, 58-182, Salamanca 37007, Spain
| | - Andrea Álvarez-Vázquez
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, Salamanca 37007, Spain; Departamento de Bioquímica y Biología Celular, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca 37007, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª planta, Paseo de San Vicente, 58-182, Salamanca 37007, Spain
| | - Rocío Talaverón
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, Salamanca 37007, Spain; Departamento de Bioquímica y Biología Celular, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca 37007, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª planta, Paseo de San Vicente, 58-182, Salamanca 37007, Spain
| | - Laura García-Vicente
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, Salamanca 37007, Spain; Departamento de Bioquímica y Biología Celular, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca 37007, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª planta, Paseo de San Vicente, 58-182, Salamanca 37007, Spain
| | - Raquel Flores-Hernández
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, Salamanca 37007, Spain; Departamento de Bioquímica y Biología Celular, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca 37007, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª planta, Paseo de San Vicente, 58-182, Salamanca 37007, Spain
| | - Marta Gómez de Cedrón
- Precision Nutrition and Cancer Program, Molecular Oncology and Nutritional Genomics of Cancer Group, IMDEA Food Institute, CEI UAM + CSIC, Carretera de Canto Blanco 8 E, Madrid 28049, Spain
| | - María Tabernero
- Precision Nutrition and Cancer Program, Molecular Oncology and Nutritional Genomics of Cancer Group, IMDEA Food Institute, CEI UAM + CSIC, Carretera de Canto Blanco 8 E, Madrid 28049, Spain
| | - Ana Ramírez de Molina
- Precision Nutrition and Cancer Program, Molecular Oncology and Nutritional Genomics of Cancer Group, IMDEA Food Institute, CEI UAM + CSIC, Carretera de Canto Blanco 8 E, Madrid 28049, Spain
| | - Concepción Lillo
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, Salamanca 37007, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª planta, Paseo de San Vicente, 58-182, Salamanca 37007, Spain
| | - José M Medina
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, Salamanca 37007, Spain; Departamento de Bioquímica y Biología Celular, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca 37007, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª planta, Paseo de San Vicente, 58-182, Salamanca 37007, Spain
| | - Arantxa Tabernero
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Calle Pintor Fernando Gallego 1, Salamanca 37007, Spain; Departamento de Bioquímica y Biología Celular, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca 37007, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Virgen de la Vega, 10ª planta, Paseo de San Vicente, 58-182, Salamanca 37007, Spain.
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12
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Talaverón R, Matarredona ER, Herrera A, Medina JM, Tabernero A. Connexin43 Region 266-283, via Src Inhibition, Reduces Neural Progenitor Cell Proliferation Promoted by EGF and FGF-2 and Increases Astrocytic Differentiation. Int J Mol Sci 2020; 21:ijms21228852. [PMID: 33238452 PMCID: PMC7700635 DOI: 10.3390/ijms21228852] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/20/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022] Open
Abstract
Neural progenitor cells (NPCs) are self-renewing cells that give rise to the major cells in the nervous system and are considered to be the possible cell of origin of glioblastoma. The gap junction protein connexin43 (Cx43) is expressed by NPCs, exerting channel-dependent and -independent roles. We focused on one property of Cx43—its ability to inhibit Src, a key protein in brain development and oncogenesis. Because Src inhibition is carried out by the sequence 266–283 of the intracellular C terminus in Cx43, we used a cell-penetrating peptide containing this sequence, TAT-Cx43266–283, to explore its effects on postnatal subventricular zone NPCs. Our results show that TAT-Cx43266–283 inhibited Src activity and reduced NPC proliferation and survival promoted by epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2). In differentiation conditions, TAT-Cx43266–283 increased astrocyte differentiation at the expense of neuronal differentiation, which coincided with a reduction in Src activity and β-catenin expression. We propose that Cx43, through the region 266–283, reduces Src activity, leading to disruption of EGF and FGF-2 signaling and to down-regulation of β-catenin with effects on proliferation and differentiation. Our data indicate that the inhibition of Src might contribute to the complex role of Cx43 in NPCs and open new opportunities for further research in gliomagenesis.
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Affiliation(s)
- Rocío Talaverón
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, 37007 Salamanca, Spain; (R.T.); (J.M.M.)
| | | | - Alejandro Herrera
- Departamento de Fisiología, Universidad de Sevilla, 41012 Sevilla, Spain; (E.R.M.); (A.H.)
| | - José M. Medina
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, 37007 Salamanca, Spain; (R.T.); (J.M.M.)
| | - Arantxa Tabernero
- Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, 37007 Salamanca, Spain; (R.T.); (J.M.M.)
- Correspondence: ; Tel.: +34-923-29-45-00 (ext. 5311)
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13
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Loss of Cx43 in Murine Sertoli Cells Leads to Altered Prepubertal Sertoli Cell Maturation and Impairment of the Mitosis-Meiosis Switch. Cells 2020; 9:cells9030676. [PMID: 32164318 PMCID: PMC7140672 DOI: 10.3390/cells9030676] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 12/12/2022] Open
Abstract
Male factor infertility is a problem in today’s society but many underlying causes are still unknown. The generation of a conditional Sertoli cell (SC)-specific connexin 43 (Cx43) knockout mouse line (SCCx43KO) has provided a translational model. Expression of the gap junction protein Cx43 between adjacent SCs as well as between SCs and germ cells (GCs) is known to be essential for the initiation and maintenance of spermatogenesis in different species and men. Adult SCCx43KO males show altered spermatogenesis and are infertile. Thus, the present study aims to identify molecular mechanisms leading to testicular alterations in prepubertal SCCx43KO mice. Transcriptome analysis of 8-, 10- and 12-day-old mice was performed by next-generation sequencing (NGS). Additionally, candidate genes were examined by qRT-PCR and immunohistochemistry. NGS revealed many significantly differentially expressed genes in the SCCx43KO mice. For example, GC-specific genes were mostly downregulated and found to be involved in meiosis and spermatogonial differentiation (e.g., Dmrtb1, Sohlh1). In contrast, SC-specific genes implicated in SC maturation and proliferation were mostly upregulated (e.g., Amh, Fshr). In conclusion, Cx43 in SCs appears to be required for normal progression of the first wave of spermatogenesis, especially for the mitosis-meiosis switch, and also for the regulation of prepubertal SC maturation.
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14
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Wang J, Yang ZY, Guo YF, Kuang JY, Bian XW, Yu SC. Targeting different domains of gap junction protein to control malignant glioma. Neuro Oncol 2019; 20:885-896. [PMID: 29106645 DOI: 10.1093/neuonc/nox207] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A rational treatment strategy for glioma, the most common primary central nervous system tumor, should focus on early invasive growth and resistance to current therapeutics. Connexin 43 (Cx43), a gap junction protein, plays important roles not only in the development of the central nervous system and but also in the progression of glioma. The different structural domains of Cx43, including extracellular loops, transmembrane domains, and an intracellular carboxyl terminal, have distinct functions in the invasion and proliferation of gliomas. Targeting these domains of Cx43, which is expressed in distinct patterns in the heterogeneous glioma cell population, can inhibit tumor cell invasion and new tumor formation. Thus, this review summarizes the structural characteristics of Cx43, the effects of regulating different Cx43 domains on the biological characteristics of glioma cells, intervention strategies targeting different domains of Cx43, and future research directions.
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Affiliation(s)
- Jun Wang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, The Third Military Medical University, Chongqing, China.,Key Laboratory of Tumor Immunology and Pathology of the Ministry of Education, Chongqing, China
| | - Ze-Yu Yang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, The Third Military Medical University, Chongqing, China.,Key Laboratory of Tumor Immunology and Pathology of the Ministry of Education, Chongqing, China
| | - Yu-Feng Guo
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, The Third Military Medical University, Chongqing, China.,Key Laboratory of Tumor Immunology and Pathology of the Ministry of Education, Chongqing, China
| | - Jing-Ya Kuang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, The Third Military Medical University, Chongqing, China.,Key Laboratory of Tumor Immunology and Pathology of the Ministry of Education, Chongqing, China
| | - Xiu-Wu Bian
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, The Third Military Medical University, Chongqing, China.,Key Laboratory of Tumor Immunology and Pathology of the Ministry of Education, Chongqing, China
| | - Shi-Cang Yu
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, The Third Military Medical University, Chongqing, China.,Key Laboratory of Tumor Immunology and Pathology of the Ministry of Education, Chongqing, China
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15
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Aasen T, Leithe E, Graham SV, Kameritsch P, Mayán MD, Mesnil M, Pogoda K, Tabernero A. Connexins in cancer: bridging the gap to the clinic. Oncogene 2019; 38:4429-4451. [PMID: 30814684 PMCID: PMC6555763 DOI: 10.1038/s41388-019-0741-6] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/26/2019] [Accepted: 01/26/2019] [Indexed: 02/08/2023]
Abstract
Gap junctions comprise arrays of intercellular channels formed by connexin proteins and provide for the direct communication between adjacent cells. This type of intercellular communication permits the coordination of cellular activities and plays key roles in the control of cell growth and differentiation and in the maintenance of tissue homoeostasis. After more than 50 years, deciphering the links among connexins, gap junctions and cancer, researchers are now beginning to translate this knowledge to the clinic. The emergence of new strategies for connexin targeting, combined with an improved understanding of the molecular bases underlying the dysregulation of connexins during cancer development, offers novel opportunities for clinical applications. However, different connexin isoforms have diverse channel-dependent and -independent functions that are tissue and stage specific. This can elicit both pro- and anti-tumorigenic effects that engender significant challenges in the path towards personalised medicine. Here, we review the current understanding of the role of connexins and gap junctions in cancer, with particular focus on the recent progress made in determining their prognostic and therapeutic potential.
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Affiliation(s)
- Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, Barcelona, Spain.
| | - Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital and K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
| | - Sheila V Graham
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Petra Kameritsch
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, München, Germany
| | - María D Mayán
- CellCOM Research Group, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servizo Galego de Saúde (SERGAS), University of A Coruña, A Coruña, Spain
| | - Marc Mesnil
- STIM Laboratory, Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers, France
| | - Kristin Pogoda
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, München, Germany
| | - Arantxa Tabernero
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain.
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16
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Deng W, Shao F, He Q, Wang Q, Shi W, Yu Q, Cao X, Feng C, Bi S, Chen J, Ma P, Li Y, Gong A, Tong S, Yu J, Spector M, Xu X, Zhang Z. EMSCs Build an All-in-One Niche via Cell-Cell Lipid Raft Assembly for Promoted Neuronal but Suppressed Astroglial Differentiation of Neural Stem Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1806861. [PMID: 30633831 DOI: 10.1002/adma.201806861] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/29/2018] [Indexed: 05/11/2023]
Abstract
The therapeutic efficiency of allogenic/intrinsic neural stem cells (NSCs) after spinal cord injury is severely compromised because the hostile niche at the lesion site incurs massive astroglial but not neuronal differentiation of NSCs. Although many attempts are made to reconstruct a permissive niche for nerve regeneration, solely using a living cell material to build an all-in-one, multifunctional, permissive niche for promoting neuronal while inhibiting astroglial differentiation of NSCs is not reported. Here, ectomesenchymal stem cells (EMSCs) are reported to serve as a living, smart material that creates a permissive, all-in-one niche which provides neurotrophic factors, extracellular matrix molecules, cell-cell contact, and favorable substrate stiffness for directing NSC differentiation. Interestingly, in this all-in-one niche, a corresponding all-in-one signal-sensing platform is assembled through recruiting various niche signaling molecules into lipid rafts for promoting neuronal differentiation of NSCs, and meanwhile, inhibiting astrocyte overproliferation through the connexin43/YAP/14-3-3θ pathway. In vivo studies confirm that EMSCs can promote intrinsic NSC neuronal differentiation and domesticating astrocyte behaviors for nerve regeneration. Collectively, this study represents an all-in-one niche created by a single-cell material-EMSCs for directing NSC differentiation.
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Affiliation(s)
- Wenwen Deng
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Fengxia Shao
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Qinghua He
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Qiang Wang
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Wentao Shi
- School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, 212001, P. R. China
| | - Qingtong Yu
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Xia Cao
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Chunlai Feng
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Shiqi Bi
- School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, 212001, P. R. China
| | - Jiaxin Chen
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Ping Ma
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Yang Li
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Aihua Gong
- School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, 212001, P. R. China
| | - Shanshan Tong
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Jiangnan Yu
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Myron Spector
- Department of Orthopedic Surgery, Harvard Medical School, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
| | - Ximing Xu
- School of Pharmacy, Jiangsu University, Laboratory of Drug Delivery and Tissue Regeneration and Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Zhenjiang, 212001, P. R. China
| | - Zhijian Zhang
- School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, 212001, P. R. China
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17
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Li K, Zhou H, Zhan L, Shi Z, Sun W, Liu D, Liu L, Liang D, Tan Y, Xu W, Xu E. Hypoxic Preconditioning Maintains GLT-1 Against Transient Global Cerebral Ischemia Through Upregulating Cx43 and Inhibiting c-Src. Front Mol Neurosci 2018; 11:344. [PMID: 30323740 PMCID: PMC6172853 DOI: 10.3389/fnmol.2018.00344] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 09/03/2018] [Indexed: 01/06/2023] Open
Abstract
Transient global cerebral ischemia (tGCI) causes excessive release of glutamate from neurons. Astrocytic glutamate transporter-1 (GLT-1) and glutamine synthetase (GS) together play a predominant role in maintaining glutamate at normal extracellular concentrations. Though our previous studies reported the alleviation of tGCI-induced neuronal death by hypoxic preconditioning (HPC) in hippocampal Cornu Ammonis 1 (CA1) of adult rats, the underlying mechanism has not yet been fully elaborated. In this study, we aimed to investigate the roles of GLT-1 and GS in the neuroprotection mediated by HPC against tGCI and to ascertain whether these roles can be regulated by connexin 43 (Cx43) and cellular-Src (c-Src) activity. We found that HPC decreased the level of extracellular glutamate in CA1 after tGCI via maintenance of GLT-1 expression and GS activity. Inhibition of GLT-1 expression with dihydrokainate (DHK) or inhibition of GS activity with methionine sulfoximine (MSO) abolished the neuroprotection induced by HPC. Also, HPC markedly upregulated Cx43 and inhibited p-c-Src expression in CA1 after tGCI, whereas inhibition of Cx43 with Gap26 dramatically reversed this effect. Furthermore, inhibition of p-c-Src with 4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo (3, 4-d) pyrimidine (PP2) decreased c-Src activity, increased protein levels of GLT-1 and Cx43, enhanced GS activity, and thus reduced extracellular glutamate level in CA1 after tGCI. Collectively, our data demonstrated that reduced extracellular glutamate induced by HPC against tGCI through preventing the reduction of GLT-1 expression and maintaining GS activity in hippocampal CA1, which was mediated by upregulating Cx43 expression and inhibiting c-Src activity.
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Affiliation(s)
- Kongping Li
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Huarong Zhou
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Lixuan Zhan
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Zhe Shi
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Weiwen Sun
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Dandan Liu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Liu Liu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Donghai Liang
- Department of Environmental Health Sciences, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Yafu Tan
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.,Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Wensheng Xu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - En Xu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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18
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González-Sánchez A, Jaraíz-Rodríguez M, Domínguez-Prieto M, Herrero-González S, Medina JM, Tabernero A. Connexin43 recruits PTEN and Csk to inhibit c-Src activity in glioma cells and astrocytes. Oncotarget 2018; 7:49819-49833. [PMID: 27391443 PMCID: PMC5226550 DOI: 10.18632/oncotarget.10454] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 06/26/2016] [Indexed: 11/30/2022] Open
Abstract
Connexin43 (Cx43), the major protein forming gap junctions in astrocytes, is reduced in high-grade gliomas, where its ectopic expression exerts important effects, including the inhibition of the proto-oncogene tyrosine-protein kinase Src (c-Src). In this work we aimed to investigate the mechanism responsible for this effect. The inhibition of c-Src requires phosphorylation at tyrosine 527 mediated by C-terminal Src kinase (Csk) and dephosphorylation at tyrosine 416 mediated by phosphatases, such as phosphatase and tensin homolog (PTEN). Our results showed that the antiproliferative effect of Cx43 is reduced when Csk and PTEN are silenced in glioma cells, suggesting the involvement of both enzymes. Confocal microscopy and immunoprecipitation assays confirmed that Cx43, in addition to c-Src, binds to PTEN and Csk in glioma cells transfected with Cx43 and in astrocytes. Pull-down assays showed that region 266–283 in Cx43 is sufficient to recruit c-Src, PTEN and Csk and to inhibit the oncogenic activity of c-Src. As a result of c-Src inhibition, PTEN was increased with subsequent inactivation of Akt and reduction of proliferation of human glioblastoma stem cells. We conclude that the recruitment of Csk and PTEN to the region between residues 266 and 283 within the C-terminus of Cx43 leads to c-Src inhibition.
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Affiliation(s)
- Ana González-Sánchez
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Salamanca, Spain
| | - Myriam Jaraíz-Rodríguez
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Salamanca, Spain
| | - Marta Domínguez-Prieto
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Salamanca, Spain
| | - Sandra Herrero-González
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Salamanca, Spain
| | - José M Medina
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Salamanca, Spain
| | - Arantxa Tabernero
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Salamanca, Spain
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19
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The unrecognized role of tumor suppressor genes in atrial fibrillation. Gene 2018; 642:26-31. [DOI: 10.1016/j.gene.2017.11.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 10/25/2017] [Accepted: 11/07/2017] [Indexed: 02/07/2023]
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20
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Jaraíz-Rodríguez M, González-Sánchez A, García-Vicente L, Medina JM, Tabernero A. Biotinylated Cell-penetrating Peptides to Study Intracellular Protein-protein Interactions. J Vis Exp 2017:56457. [PMID: 29286477 PMCID: PMC5755618 DOI: 10.3791/56457] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Here we present a protocol to study intracellular protein-protein interactions that is based on the widely used biotin-avidin pull-down system. The modification presented includes the combination of this technique with cell-penetrating sequences. We propose to design cell-penetrating baits that can be incubated with living cells instead of cell lysates and therefore the interactions found will reflect those that occur within the intracellular context. Connexin43 (Cx43), a protein that forms gap junction channels and hemichannels is down-regulated in high-grade gliomas. The Cx43 region comprising amino acids 266-283 is responsible for the inhibition of the oncogenic activity of c-Src in glioma cells. Here we use TAT as the cell-penetrating sequence, biotin as the pull-down tag and the region of Cx43 comprised between amino acids 266-283 as the target to find intracellular interactions in the hard-to-transfect human glioma stem cells. One of the limitations of the proposed method is that the molecule used as bait could fail to fold properly and, consequently, the interactions found could not be associated with the effect. However, this method can be especially interesting for the interactions involved in signal transduction pathways because they are usually carried out by intrinsically disordered regions and, therefore, they do not require an ordered folding. In addition, one of the advantages of the proposed method is that the relevance of each residue on the interaction can be easily studied. This is a modular system; therefore, other cell-penetrating sequences, other tags, and other intracellular targets can be employed. Finally, the scope of this protocol is far beyond protein-protein interaction because this system can be applied to other bioactive cargoes such as RNA sequences, nanoparticles, viruses or any molecule that can be transduced with cell-penetrating sequences and fused to pull-down tags to study their intracellular mechanism of action.
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Affiliation(s)
- Myriam Jaraíz-Rodríguez
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca
| | - Ana González-Sánchez
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca; Centre for Cancer Research & Cell Biology (CCRCB), School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast
| | - Laura García-Vicente
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca
| | - Jose M Medina
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca
| | - Arantxa Tabernero
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca;
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21
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Gangoso E, Talaverón R, Jaraíz-Rodríguez M, Domínguez-Prieto M, Ezan P, Koulakoff A, Medina JM, Giaume C, Tabernero A. A c-Src Inhibitor Peptide Based on Connexin43 Exerts Neuroprotective Effects through the Inhibition of Glial Hemichannel Activity. Front Mol Neurosci 2017; 10:418. [PMID: 29326548 PMCID: PMC5737028 DOI: 10.3389/fnmol.2017.00418] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 12/01/2017] [Indexed: 12/29/2022] Open
Abstract
The non-receptor tyrosine kinase c-Src is an important mediator in several signaling pathways related to neuroinflammation. Our previous study showed that cortical injection of kainic acid (KA) promoted a transient increase in c-Src activity in reactive astrocytes surrounding the neuronal lesion. As a cell-penetrating peptide based on connexin43 (Cx43), specifically TAT-Cx43266–283, inhibits Src activity, we investigated the effect of TAT-Cx43266–283 on neuronal death promoted by cortical KA injections in adult mice. As expected, KA promoted neuronal death, estimated by the reduction in NeuN-positive cells and reactive gliosis, characterized by the increase in glial fibrillary acidic protein (GFAP) expression. Interestingly, TAT-Cx43266–283 injected with KA diminished neuronal death and reactive gliosis compared to KA or KA+TAT injections. In order to gain insight into the neuroprotective mechanism, we used in vitro models. In primary cultured neurons, TAT-Cx43266–283 did not prevent neuronal death promoted by KA, but when neurons were grown on top of astrocytes, TAT-Cx43266–283 prevented neuronal death promoted by KA. These observations demonstrate the participation of astrocytes in the neuroprotective effect of TAT-Cx43266–283. Furthermore, the neuroprotective effect was also present in non-contact co-cultures, suggesting the contribution of soluble factors released by astrocytes. As glial hemichannel activity is associated with the release of several factors, such as ATP and glutamate, that cause neuronal death, we explored the participation of these channels on the neuroprotective effect of TAT-Cx43266–283. Our results confirmed that inhibitors of ATP and NMDA receptors prevented neuronal death in co-cultures treated with KA, suggesting the participation of astrocyte hemichannels in neurotoxicity. Furthermore, TAT-Cx43266–283 reduced hemichannel activity promoted by KA in neuron-astrocyte co-cultures as assessed by ethidium bromide (EtBr) uptake assay. In fact, TAT-Cx43266–283 and dasatinib, a potent c-Src inhibitor, strongly reduced the activation of astrocyte hemichannels. In conclusion, our results suggest that TAT-Cx43266–283 exerts a neuroprotective effect through the reduction of hemichannel activity likely mediated by c-Src in astrocytes. These data unveil a new role of c-Src in the regulation of Cx43-hemichannel activity that could be part of the mechanism by which astroglial c-Src participates in neuroinflammation.
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Affiliation(s)
- Ester Gangoso
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - Rocío Talaverón
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Myriam Jaraíz-Rodríguez
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Marta Domínguez-Prieto
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Pascal Ezan
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - Annette Koulakoff
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - José M Medina
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Christian Giaume
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - Arantxa Tabernero
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
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22
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Dong H, Zhou XW, Wang X, Yang Y, Luo JW, Liu YH, Mao Q. Complex role of connexin 43 in astrocytic tumors and possible promotion of glioma‑associated epileptic discharge (Review). Mol Med Rep 2017; 16:7890-7900. [PMID: 28983585 DOI: 10.3892/mmr.2017.7618] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 06/19/2017] [Indexed: 02/05/2023] Open
Abstract
Connexin (Cx)43 is a multifunction protein which forms gap junction channels and hemi‑channels. It also contains abundant binding domains which possess the ability to interact with certain Cx43‑associated proteins and therefore serve a fundamental role in various physiological and pathological functions. However, the understanding of the association between cancer and Cx43 along with Cx43‑gap junctions (GJ) remains unclear. All available data illustrate that Cx43 and its associated GJ serve important functions in cancers. The expression levels of Cx43 demonstrate a downward trend and an increase in the levels of malignancy, particularly in astrocytomas. The GJ intercellular communication activity in glioma cells can be adjusted via Cx43 phosphorylation and through the combination of Cx43 and its associated protein. Available evidence reveals Cx43 as a tumor‑inhibiting factor that suppresses glioma growth and proliferation. However, its mechanism is also regarded as complicated and ambiguous. Furthermore, it is apparent that Cx43‑GJ and the carboxyl tail may contribute to glioma growth and proliferation too. However, this valuable role could be weakened by its effects on migration and invasiveness. The detailed mechanism remains unclear and full of controversies. Cx43 can enhance the motor ability and invasiveness of astrocytic glioma cells. It is also able to influence glioma cells to detach from the tumor core to the peritumoral neocortex. This peritumoral region has recently been regarded as the basic focus of glioma‑associated seizure. Thus, Cx43 may take part in the onset and development of glioma‑associated epileptic discharge. In addition, change and increase of Cx43 expression in GJs has been observed in seizure perilesional tissue, which is associated with brain tumors. Cx43 or GJ/hemi‑channels exert enduring effects in the promotion of glioma‑associated epileptic release through direct mass effects and change of the tumor microenvironment. However, there are still a number of issues concerning this aspect that require further exploration. Cx43, as a potential treatment target against this incurable disease and its common symptom of epilepsy, requires further investigation.
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Affiliation(s)
- Hui Dong
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Xing-Wang Zhou
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Xiang Wang
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Yuan Yang
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Jie-Wen Luo
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Yan-Hui Liu
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Qing Mao
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
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23
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Jaraíz-Rodríguez M, Tabernero MD, González-Tablas M, Otero A, Orfao A, Medina JM, Tabernero A. A Short Region of Connexin43 Reduces Human Glioma Stem Cell Migration, Invasion, and Survival through Src, PTEN, and FAK. Stem Cell Reports 2017; 9:451-463. [PMID: 28712848 PMCID: PMC5549880 DOI: 10.1016/j.stemcr.2017.06.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 06/13/2017] [Accepted: 06/14/2017] [Indexed: 12/22/2022] Open
Abstract
Connexin43 (CX43), a protein that forms gap junction channels and hemichannels in astrocytes, is downregulated in high-grade gliomas. Its relevance for glioma therapy has been thoroughly explored; however, its positive effects on proliferation are counterbalanced by its effects on migration and invasion. Here, we show that a cell-penetrating peptide based on CX43 (TAT-Cx43266-283) inhibited c-Src and focal adhesion kinase (FAK) and upregulated phosphatase and tensin homolog in glioma stem cells (GSCs) derived from patients. Consequently, TAT-Cx43266-283 reduced GSC motility, as analyzed by time-lapse microscopy, and strongly reduced their invasive ability. Interestingly, we investigated the effects of TAT-Cx43266-283 on freshly removed surgical specimens as undissociated glioblastoma blocks, which revealed a dramatic reduction in the growth, migration, and survival of these cells. In conclusion, a region of CX43 (amino acids 266–283) exerts an important anti-tumor effect in patient-derived glioblastoma models that includes impairment of GSC migration and invasion. TAT-Cx43266-283 exerts anti-tumor effects in patient-derived glioblastoma models TAT-Cx43266-283 targets Src, PTEN, and FAK TAT-Cx43266-283 inhibits glioma stem cell migration and invasion
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Affiliation(s)
- Myriam Jaraíz-Rodríguez
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, C/ Pintor Fernando Gallego 1, 37007 Salamanca, Spain
| | - Ma Dolores Tabernero
- Instituto de Estudios de Ciencias de la Salud de Castilla y León (IECSCYL), Instituto de Investigación Biomédica de Salamanca (IBSAL), 37007 Salamanca, Spain; Centre for Cancer Research (CIC-IBMCC; CSIC/USAL; IBSAL), Departamento de Medicina Universidad de Salamanca, 37007 Salamanca, Spain
| | - María González-Tablas
- Instituto de Estudios de Ciencias de la Salud de Castilla y León (IECSCYL), Instituto de Investigación Biomédica de Salamanca (IBSAL), 37007 Salamanca, Spain; Centre for Cancer Research (CIC-IBMCC; CSIC/USAL; IBSAL), Departamento de Medicina Universidad de Salamanca, 37007 Salamanca, Spain
| | - Alvaro Otero
- Neurosurgery Service, Hospital Universitario de Salamanca and IBSAL, 37007 Salamanca, Spain
| | - Alberto Orfao
- Centre for Cancer Research (CIC-IBMCC; CSIC/USAL; IBSAL), Departamento de Medicina Universidad de Salamanca, 37007 Salamanca, Spain
| | - Jose M Medina
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, C/ Pintor Fernando Gallego 1, 37007 Salamanca, Spain
| | - Arantxa Tabernero
- Instituto de Neurociencias de Castilla y León (INCYL), Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, C/ Pintor Fernando Gallego 1, 37007 Salamanca, Spain.
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24
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Mesnil M, Aasen T, Boucher J, Chépied A, Cronier L, Defamie N, Kameritsch P, Laird DW, Lampe PD, Lathia JD, Leithe E, Mehta PP, Monvoisin A, Pogoda K, Sin WC, Tabernero A, Yamasaki H, Yeh ES, Dagli MLZ, Naus CC. An update on minding the gap in cancer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:237-243. [PMID: 28655619 DOI: 10.1016/j.bbamem.2017.06.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/22/2017] [Accepted: 06/23/2017] [Indexed: 01/08/2023]
Abstract
This article is a report of the "International Colloquium on Gap junctions: 50Years of Impact on Cancer" that was held 8-9 September 2016, at the Amphitheater "Pôle Biologie Santé" of the University of Poitiers (Poitiers, France). The colloquium was organized by M Mesnil (Université de Poitiers, Poitiers, France) and C Naus (University of British Columbia, Vancouver, Canada) to celebrate the 50th anniversary of the seminal work published in 1966 by Loewenstein and Kanno [Intercellular communication and the control of tissue growth: lack of communication between cancer cells, Nature, 116 (1966) 1248-1249] which initiated studies on the involvement of gap junctions in carcinogenesis. During the colloquium, 15 participants presented reviews or research updates in the field which are summarized below.
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Affiliation(s)
- Marc Mesnil
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers 86073, cedex 09, France.
| | - Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain
| | - Jonathan Boucher
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers 86073, cedex 09, France
| | - Amandine Chépied
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers 86073, cedex 09, France
| | - Laurent Cronier
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers 86073, cedex 09, France
| | - Norah Defamie
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers 86073, cedex 09, France
| | - Petra Kameritsch
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, München, Germany
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario N6A 5C1, Canada
| | - Paul D Lampe
- Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Justin D Lathia
- Cleveland Clinic, Lerner College of Medicine, Case Western Reserve University, Cleveland, OH 44195, USA
| | - Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, and Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, NO-0424 Oslo, Norway
| | - Parmender P Mehta
- Department of Biochemistry and Molecular Biology, University of Nebraska, Medical Center, Omaha, NE 68198, USA
| | - Arnaud Monvoisin
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers 86073, cedex 09, France
| | - Kristin Pogoda
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München and Munich University Hospital, München, Germany
| | - Wun-Chey Sin
- Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Arantxa Tabernero
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca 37007, Spain
| | | | - Elizabeth S Yeh
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29412, USA
| | - Maria Lucia Zaidan Dagli
- Laboratory of Experimental and Comparative Oncology, School of Veterinary Medicine and Animal Science of the University of São Paulo, São Paulo, SP CEP 05508-900, Brazil
| | - Christian C Naus
- Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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25
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miRNA-mediated expression switch of cell adhesion genes driven by microcirculation in chip. BIOCHIP JOURNAL 2017. [DOI: 10.1007/s13206-017-1305-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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26
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Connexin 43 enhances Bax activation via JNK activation in sunitinib-induced apoptosis in mesothelioma cells. J Pharmacol Sci 2017; 134:101-107. [DOI: 10.1016/j.jphs.2017.05.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 05/11/2017] [Accepted: 05/22/2017] [Indexed: 12/17/2022] Open
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27
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Leithe E, Mesnil M, Aasen T. The connexin 43 C-terminus: A tail of many tales. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:48-64. [PMID: 28526583 DOI: 10.1016/j.bbamem.2017.05.008] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/10/2017] [Accepted: 05/12/2017] [Indexed: 10/19/2022]
Abstract
Connexins are chordate gap junction channel proteins that, by enabling direct communication between the cytosols of adjacent cells, create a unique cell signalling network. Gap junctional intercellular communication (GJIC) has important roles in controlling cell growth and differentiation and in tissue development and homeostasis. Moreover, several non-canonical connexin functions unrelated to GJIC have been discovered. Of the 21 members of the human connexin family, connexin 43 (Cx43) is the most widely expressed and studied. The long cytosolic C-terminus (CT) of Cx43 is subject to extensive post-translational modifications that modulate its intracellular trafficking and gap junction channel gating. Moreover, the Cx43 CT contains multiple domains involved in protein interactions that permit crosstalk between Cx43 and cytoskeletal and regulatory proteins. These domains endow Cx43 with the capacity to affect cell growth and differentiation independently of GJIC. Here, we review the current understanding of the regulation and unique functions of the Cx43 CT, both as an essential component of full-length Cx43 and as an independent signalling hub. We highlight the complex regulatory and signalling networks controlled by the Cx43 CT, including the extensive protein interactome that underlies both gap junction channel-dependent and -independent functions. We discuss these data in relation to the recent discovery of the direct translation of specific truncated forms of Cx43. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, University of Oslo, NO-0424 Oslo, Norway; Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, NO-0424 Oslo, Norway
| | - Marc Mesnil
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers 86073, France
| | - Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain.
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Naus CC, Giaume C. Bridging the gap to therapeutic strategies based on connexin/pannexin biology. J Transl Med 2016; 14:330. [PMID: 27899102 PMCID: PMC5129631 DOI: 10.1186/s12967-016-1089-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/18/2016] [Indexed: 01/02/2023] Open
Abstract
A unique workshop was recently held focusing on enhancing collaborations leading to identify and update the development of therapeutic strategies targeting connexin/pannexin large pore channels. Basic scientists exploring the functions of these channels in various pathologies gathered together with leading pharma companies which are targeting gap junction proteins for specific therapeutic applications. This highlights how paths of discovery research can converge with therapeutic strategies in innovative ways to enhance target identification and validation.
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Affiliation(s)
- Christian C Naus
- Department of Cellular and Physiological Sciences, Faculty of Medicine, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
| | - Christian Giaume
- ICIRB, CNRS UMR7241/INSERM U1050, Collège de France, Paris Cedex 05, France
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Liu X, Xu C. DNA Methylation Analysis of Human Tissue-Specific Connexin Genes. Methods Mol Biol 2016; 1437:21-36. [PMID: 27207284 DOI: 10.1007/978-1-4939-3664-9_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Connexins are the structural proteins of gap junctions and their functioning as tumor suppressors is well known. Epigenetic modifications, such as methylation of connexin genes, play important roles in regulating gene expression. Over the past decade, several methods have been applied to characterize DNA methylation-specific loci of connexin genes. This chapter describes analysis of selective connexin32 and connexin43 gene DNA methylation in human gastric tissues using methylation-specific PCR, bisulfite-specific PCR sequencing as well as MassArray techniques.
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Affiliation(s)
- Xiaoming Liu
- Department of Gastroenterology, Third Xiangya Hospital of Central South University, 138 Tongzipo Road, Changsha, Hunan, 410013, China
| | - Canxia Xu
- Department of Gastroenterology, Third Xiangya Hospital of Central South University, 138 Tongzipo Road, Changsha, Hunan, 410013, China.
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Upregulation of connexin43 contributes to PX-12-induced oxidative cell death. Tumour Biol 2015; 37:7535-46. [PMID: 26684802 DOI: 10.1007/s13277-015-4620-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 12/10/2015] [Indexed: 01/24/2023] Open
Abstract
Thioredoxin (Trx) is a small redox protein that underlies aggressive tumor growth and resistance to chemotherapy. Inhibition of Trx with the chemical inhibitor PX-12 suppresses tumor growth and induces cell apoptosis. Currently, the mechanism underlying the therapeutic actions of PX-12 and the molecules influencing cell susceptibility to PX-12 are incompletely understood. Given that connexin43 (Cx43), a tumor suppressor, regulates tumor cell susceptibility to chemotherapy, we examined the possible involvement of Cx43 in PX-12-induced cell death. Exposure of cells to PX-12 led to a loss of cell viability, which was associated with the activation of oxidative sensitive c-Jun N-terminal kinase (JNK). Inhibition of JNK or supplement of cells with anti-oxidants prevented the cell-killing action of PX-12. The forced expression of Cx43 in normal and tumor cells increased cell sensitivity to PX-12-induced JNK activation and cell death. In contrast, the downregulation of Cx43 with siRNA or the suppression of gap junctions with chemical inhibitors attenuated JNK activation and enhanced cell resistance to PX-12. Further analysis revealed that PX-12 at low concentrations induced a JNK-dependent elevation in the Cx43 protein, which was also preventable by supplementing the cells with anti-oxidants. Our results thus indicate that Cx43 is a determinant in the regulation of cell susceptibility to PX-12 and that the upregulation of Cx43 may be an additional mechanism by which PX-12 exerts its anti-tumor actions.
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Schulz R, Görge PM, Görbe A, Ferdinandy P, Lampe PD, Leybaert L. Connexin 43 is an emerging therapeutic target in ischemia/reperfusion injury, cardioprotection and neuroprotection. Pharmacol Ther 2015; 153:90-106. [PMID: 26073311 DOI: 10.1016/j.pharmthera.2015.06.005] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 05/29/2015] [Indexed: 12/22/2022]
Abstract
Connexins are widely distributed proteins in the body that are crucially important for heart and brain functions. Six connexin subunits form a connexon or hemichannel in the plasma membrane. Interactions between two hemichannels in a head-to-head arrangement result in the formation of a gap junction channel. Gap junctions are necessary to coordinate cell function by passing electrical current flow between heart and nerve cells or by allowing exchange of chemical signals and energy substrates. Apart from its localization at the sarcolemma of cardiomyocytes and brain cells, connexins are also found in the mitochondria where they are involved in the regulation of mitochondrial matrix ion fluxes and respiration. Connexin expression is affected by age and gender as well as several pathophysiological alterations such as hypertension, hypertrophy, diabetes, hypercholesterolemia, ischemia, post-myocardial infarction remodeling or heart failure, and post-translationally connexins are modified by phosphorylation/de-phosphorylation and nitros(yl)ation which can modulate channel activity. Using knockout/knockin technology as well as pharmacological approaches, one of the connexins, namely connexin 43, has been identified to be important for cardiac and brain ischemia/reperfusion injuries as well as protection from it. Therefore, the current review will focus on the importance of connexin 43 for irreversible injury of heart and brain tissues following ischemia/reperfusion and will highlight the importance of connexin 43 as an emerging therapeutic target in cardio- and neuroprotection.
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Affiliation(s)
- Rainer Schulz
- Institut für Physiologie, JustusLiebig Universität Giessen, Gießen, Germany.
| | | | - Anikó Görbe
- Cardiovascular Research Group, Department of Biochemistry, Faculty of Medicine, University of Szeged, Hungary; Pharmahungary Group, Szeged, Hungary
| | - Péter Ferdinandy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary; Pharmahungary Group, Szeged, Hungary
| | - Paul D Lampe
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Luc Leybaert
- Physiology Group, Department Basic Medical Sciences, Ghent University, Belgium
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Uzu M, Sato H, Yamada R, Kashiba T, Shibata Y, Yamaura K, Ueno K. Effect of enhanced expression of connexin 43 on sunitinib-induced cytotoxicity in mesothelioma cells. J Pharmacol Sci 2015; 128:17-26. [PMID: 26003083 DOI: 10.1016/j.jphs.2015.04.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 03/31/2015] [Accepted: 04/02/2015] [Indexed: 12/30/2022] Open
Abstract
Connexin (Cx) makes up a type of intercellular channel called gap junction (GJ). GJ plays a regulatory role in cellular physiology. The Cx expression level is often decreased in cancer cells compared to that in healthy ones, and the restoration of its expression has been shown to exert antiproliferative effects. This work aims to evaluate the effect of the restoration of connexin 43 (Cx43) (the most ubiquitous Cx subtype) expression on sunitinib (SU)-induced cytotoxicity in malignant mesothelioma (MM) cells. Increased Cx43 expression in an MM cell line (H28) improved the ability of SU to inhibit receptor tyrosine kinase (RTK) signaling. Moreover, higher Cx43 expression promoted SU-induced apoptosis. The cell viability test revealed that Cx43 enhanced the cytotoxic effect of SU in a GJ-independent manner. The effect of Cx43 on a proapoptotic factor, Bax, was then investigated. The interaction between Cx43 and Bax was confirmed by immunoprecipitation. Furthermore, higher Cx43 expression increased the production of a cleaved (active) form of Bax during SU-induced apoptosis with no alteration in total Bax expression. These findings indicate that Cx43 most likely increases sensitivity to SU in H28 through direct interaction with Bax. In conclusion, we found that Cx43 overcame the chemoresistance of MM cells.
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Affiliation(s)
- Miaki Uzu
- Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ward, Chiba-city, Chiba 260-8675, Japan
| | - Hiromi Sato
- Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ward, Chiba-city, Chiba 260-8675, Japan.
| | - Ryota Yamada
- Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ward, Chiba-city, Chiba 260-8675, Japan
| | - Tatsuro Kashiba
- Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ward, Chiba-city, Chiba 260-8675, Japan
| | - Yukihiro Shibata
- Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ward, Chiba-city, Chiba 260-8675, Japan
| | - Katsunori Yamaura
- Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ward, Chiba-city, Chiba 260-8675, Japan
| | - Koichi Ueno
- Center for Preventive Medical Science, Chiba University, 1-8-1 Inohana, Chuo-ward, Chiba-city, Chiba 260-8675, Japan
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Tabernero A, Gangoso E, Jaraíz-Rodríguez M, Medina JM. The role of connexin43-Src interaction in astrocytomas: A molecular puzzle. Neuroscience 2015; 323:183-94. [PMID: 25711938 DOI: 10.1016/j.neuroscience.2015.02.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 02/10/2015] [Accepted: 02/13/2015] [Indexed: 12/18/2022]
Abstract
Connexin43 (Cx43) as a building block of gap junction channels and hemichannels exerts important functions in astrocytes. When these cells acquire a malignant phenotype Cx43 protein but not mRNA levels are downregulated, being negligible in high-grade astrocytoma or glioblastoma multiforme, the most common and deadliest of malignant primary brain tumors in adults. Some microRNAs associated to glioma target Cx43 and could explain the lack of correlation between mRNA and protein levels of Cx43 found in some high-grade astrocytomas. More importantly, these microRNAs could be a promising therapeutic target. A great number of studies have confirmed the relationship between cancer and connexins that was proposed by Loewenstein more than 40years ago, but these studies have also revealed that this is a very complex relationship. Indeed, restoring Cx43 to glioma cells reduces their rate of proliferation and their tumorigenicity but this tumor suppressor effect could be counterbalanced by its effects on invasiveness, adhesion and migration. The mechanisms underlying these effects suggest the participation of a great variety of proteins that bind to different regions of Cx43. The present review focuses on an intrinsically disordered region of the C-terminal domain of Cx43 in which converges the interaction of several proteins, including the proto-oncogene Src. We summarize data that indicate that Cx43-Src interaction inhibits the oncogenic activity of Src and promotes a conformational change in the structure of Cx43 that allosterically modifies the binding to other important signaling proteins. As a consequence, crucial cell functions, such as proliferation or migration, could be strongly affected. We propose that the knowledge of the structural basis of the antitumorigenic effect of Cx43 on astrocytomas could help to design new therapies against this incurable disease.
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Affiliation(s)
- A Tabernero
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Spain.
| | - E Gangoso
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Spain
| | - M Jaraíz-Rodríguez
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Spain
| | - J M Medina
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Spain
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Aasen T. Connexins: junctional and non-junctional modulators of proliferation. Cell Tissue Res 2014; 360:685-99. [PMID: 25547217 DOI: 10.1007/s00441-014-2078-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Accepted: 11/14/2014] [Indexed: 12/11/2022]
Abstract
Mounting evidence indicates that dysregulation of gap junctions and their structural subunits-connexins-often occurs in, and sometimes causes, a variety of proliferative disorders, including cancer. Connexin-mediated regulation of cell proliferation is complex and may involve modulation of gap junction intercellular communication (GJIC), hemichannel signalling, or gap junction-independent paths. However, the exact mechanisms linking connexins to proliferation remain poorly defined and a number of contradictory studies report both pro- and anti-proliferative effects, effects that often depend on the cell or tissue type or the microenvironment. The present review covers junctional and non-junctional regulation of proliferation by connexins, with a particular emphasis on their association with cancer.
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Affiliation(s)
- Trond Aasen
- Molecular Pathology Group, Vall d'Hebron Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d'Hebron 119-129, Barcelona, 08035, Spain,
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35
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Gangoso E, Thirant C, Chneiweiss H, Medina JM, Tabernero A. A cell-penetrating peptide based on the interaction between c-Src and connexin43 reverses glioma stem cell phenotype. Cell Death Dis 2014; 5:e1023. [PMID: 24457967 PMCID: PMC4040690 DOI: 10.1038/cddis.2013.560] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 12/06/2013] [Accepted: 12/13/2013] [Indexed: 01/09/2023]
Abstract
Connexin43 (Cx43), the main gap junction channel-forming protein in astrocytes, is downregulated in malignant gliomas. These tumors are composed of a heterogeneous population of cells that include many with stem-cell-like properties, called glioma stem cells (GSCs), which are highly tumorigenic and lack Cx43 expression. Interestingly, restoring Cx43 reverses GSC phenotype and consequently reduces their tumorigenicity. In this study, we investigated the mechanism by which Cx43 exerts its antitumorigenic effects on GSCs. We have focused on the tyrosine kinase c-Src, which interacts with the intracellular carboxy tail of Cx43. We found that Cx43 regulates c-Src activity and proliferation in human GSCs expanded in adherent culture. Thus, restoring Cx43 in GSCs inhibited c-Src activity, which in turn promoted the downregulation of the inhibitor of differentiation Id1. Id1 sustains stem cell phenotype as it controls the expression of Sox2, responsible for stem cell self-renewal, and promotes cadherin switching, which has been associated to epithelial–mesenchymal transition. Our results show that both the ectopic expression of Cx43 and the inhibition of c-Src reduced Id1, Sox2 expression and promoted the switch from N- to E-cadherin, suggesting that Cx43, by inhibiting c-Src, downregulates Id1 with the subsequent changes in stem cell phenotype. On the basis of this mechanism, we found that a cell-penetrating peptide, containing the region of Cx43 that interacts with c-Src, mimics the effect of Cx43 on GSC phenotype, confirming the relevance of the interaction between Cx43 and c-Src in the regulation of the malignant phenotype and pinpointing this interaction as a promising therapeutic target.
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Affiliation(s)
- E Gangoso
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - C Thirant
- Laboratoire Plasticité Gliale, Centre de Psychiatrie et de Neuroscience-INSERM U894, Paris 75014, France
| | - H Chneiweiss
- Laboratoire Plasticité Gliale, Centre de Psychiatrie et de Neuroscience-INSERM U894, Paris 75014, France
| | - J M Medina
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - A Tabernero
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
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Zhou JZ, Jiang JX. Gap junction and hemichannel-independent actions of connexins on cell and tissue functions--an update. FEBS Lett 2014; 588:1186-92. [PMID: 24434539 DOI: 10.1016/j.febslet.2014.01.001] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 12/20/2013] [Accepted: 01/02/2014] [Indexed: 10/25/2022]
Abstract
Connexins, a family of transmembrane proteins, are components of both gap junction channels and hemichannels, which mediate the exchange of ions and small molecules between adjacent cells, and between the inside and outside of the cell, respectively. Substantial advancements have been made in the comprehension of the role of gap junctions and hemichannels in coordinating cellular events. In recent years, a plethora of studies demonstrate a role of connexin proteins in the regulation of tissue homeostasis that occurs independently of their channel activities. This is shown in the context of cell growth, adhesion, migration, apoptosis, and signaling. The major mechanisms of these channel-independent activities still remain to be discovered. In this review, we provide an updated overview on the current knowledge of gap junction- and hemichannel-independent functions of connexins, in particular, their effects on tumorigenesis, neurogenesis and disease development.
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Affiliation(s)
- Jade Z Zhou
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA
| | - Jean X Jiang
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
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Jeyaraman MM, Fandrich RR, Kardami E. Together and apart: inhibition of DNA synthesis by connexin-43 and its relationship to transforming growth factor β. Front Pharmacol 2013; 4:90. [PMID: 23882217 PMCID: PMC3715720 DOI: 10.3389/fphar.2013.00090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 06/28/2013] [Indexed: 11/18/2022] Open
Abstract
The membrane and channel protein connexin-43 (Cx43), as well as the cytokine transforming growth factor (TGF) β, suppress proliferative growth in cardiomyocytes and other cell types. Previously we showed that the inhibitory effect of Cx43 is canceled when Cx43 becomes phosphorylated at serine (S) 262 in response to mitogen stimulation. We have now asked if the TGFβ-triggered inhibition of DNA synthesis is associated with changes in Cx43 phosphorylation at S262. Conversely, we investigated if inhibition of DNA synthesis by overexpressed Cx43 is dependent on engaging TGFβ signal transduction. We report that TGFβ acutely prevented mitogen-induced Cx43 phosphorylation at S262, while chronic inhibition of TGFβ signal transduction raised baseline levels of endogenous phospho-S262-Cx43 without affecting total Cx43. Inhibition of baseline TGFβ signal transduction through (a) inhibiting TGFβ receptor I (TGFβRI) with SB431542, (b) inhibiting TGFβ receptor II (TGFβRII) by overexpressing dominant-negative (DN) TGFβRII, (c) inhibiting the downstream signaling mediator Smad2 by overexpressing DN Smad2, each separately increased baseline cardiomyocyte DNA synthesis, but could not reverse DNA synthesis inhibition by overexpressed Cx43. It is suggested that inhibition of cardiomyocyte DNA synthesis by TGFβ/TGFβRI/II/phospho-Smad2 signaling is mediated, at least in part, by reducing endogenous phospho-S262-Cx43 levels.
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Affiliation(s)
- Maya M Jeyaraman
- Institute of Cardiovascular Sciences, St. Boniface Research Centre, University of Manitoba Winnipeg, MB, Canada ; Department of Physiology, University of Manitoba Winnipeg, MB, Canada
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Xie X, Lan T, Chang X, Huang K, Huang J, Wang S, Chen C, Shen X, Liu P, Huang H. Connexin43 mediates NF-κB signalling activation induced by high glucose in GMCs: involvement of c-Src. Cell Commun Signal 2013; 11:38. [PMID: 23718910 PMCID: PMC3699363 DOI: 10.1186/1478-811x-11-38] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 05/10/2013] [Indexed: 12/23/2022] Open
Abstract
Background Nuclear factor kappa-B (NF-κB) signalling plays an important role in diabetic nephropathy. Altered expression of connexin43 (Cx43) has been found in kidneys of diabetic animals. The aim of the current study was to investigate the role of Cx43 in the activation of NF-κB induced by high glucose in glomerular mesangial cells (GMCs) and to determine whether c-Src is involved in this process. Results We found that downregulation of Cx43 expression induced by high glucose activated NF-κB in GMCs. Orverexpression of Cx43 attenuated NF-κB p65 nuclear translocation induced by high glucose. High glucose inhibited the interaction between Cx43 and c-Src, and enhanced the interaction between c-Src and IκB-α. PP2, a c-Src inhibitor, also inhibited the tyrosine phosphorylation of IκB-α and NF-κB p65 nuclear translocation induced by high glucose. Furthermore, overexpression of Cx43 or inhibition of c-Src attenuated the upregulation of intercellular adhesion molecule-1 (ICAM-1), transforming growth factor-beta 1 (TGF-β1) and fibronectin (FN) expression induced by high glucose. Conclusions In conclusion, downregulation of Cx43 in GMCs induced by high glucose activates c-Src, which in turn promotes interaction between c-Src and IκB-α and contributes to NF-κB activation in GMCs, leading to renal inflammation.
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Affiliation(s)
- Xi Xie
- Laboratory of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China.
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Yulyana Y, Endaya BB, Ng WH, Guo CM, Hui KM, Lam PYP, Ho IAW. Carbenoxolone enhances TRAIL-induced apoptosis through the upregulation of death receptor 5 and inhibition of gap junction intercellular communication in human glioma. Stem Cells Dev 2013; 22:1870-82. [PMID: 23428290 DOI: 10.1089/scd.2012.0529] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been used extensively in cancer therapy. However, more than half of glioblastoma multiforme are insensitive to the apoptotic effect of TRAIL. Improvement in therapeutic modalities that enhances the efficacy of TRAIL in glioma is much sought after. In this study, we combined the tumor selectivity of TRAIL and tumor-homing properties of mesenchymal stem cells (MSC) with gap junction (GJ) inhibitory effect of carbenoxolone (CBX) to target orthotopic glioma. MSC were engineered to express TRAIL (MSC-TRAIL) by incorporating the secretable trimeric form of TRAIL into a Herpes Simplex Virus (HSV) type I amplicon vector. Our results showed that combined treatment of MSC-TRAIL and CBX enhanced glioma cell death, especially in three primary human glioma isolates, of which two of those are marginally sensitive to TRAIL. CBX enhanced TRAIL-induced apoptosis through upregulation of death receptor 5, blockade of GJ intercellular communication, and downregulation of connexin 43. Dual arm therapy using TRAIL and CBX prolonged the survival of treated mice by ~27% when compared with the controls in an intracranial glioma model. The enhanced efficacy of TRAIL in combination with CBX coupled with the minimal cytotoxic nature of CBX suggested a favorable clinical usage of this treatment regimen.
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Affiliation(s)
- Yulyana Yulyana
- Laboratory of Cancer Gene Therapy, Cellular and Molecular Research Division, Humphrey Oei Institute of Cancer Research, National Cancer Centre of Singapore, Singapore, Singapore
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Human articular chondrocytes express multiple gap junction proteins: differential expression of connexins in normal and osteoarthritic cartilage. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 182:1337-46. [PMID: 23416160 DOI: 10.1016/j.ajpath.2012.12.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 11/25/2012] [Accepted: 12/17/2012] [Indexed: 11/24/2022]
Abstract
Osteoarthritis (OA) is the most common joint disease and involves progressive degeneration of articular cartilage. The aim of this study was to investigate if chondrocytes from human articular cartilage express gap junction proteins called connexins (Cxs). We show that human chondrocytes in tissue express Cx43, Cx45, Cx32, and Cx46. We also find that primary chondrocytes from adults retain the capacity to form functional voltage-dependent gap junctions. Immunohistochemistry experiments in cartilage from OA patients revealed significantly elevated levels of Cx43 and Cx45 in the superficial zone and down through the next approximately 1000 μm of tissue. These zones corresponded with regions damaged in OA that also had high levels of proliferative cell nuclear antigen. An increased number of Cxs may help explain the increased proliferation of cells in clusters that finally lead to tissue homeostasis loss. Conversely, high levels of Cxs in OA cartilage reflect the increased number of adjacent cells in clusters that are able to interact directly by gap junctions as compared with hemichannels on single cells in normal cartilage. Our data provide strong evidence that OA patients have a loss of the usual ordered distribution of Cxs in the damaged zones and that the reductions in Cx43 levels are accompanied by the loss of correct Cx localization in the nondamaged areas.
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Gangoso E, Ezan P, Valle-Casuso JC, Herrero-González S, Koulakoff A, Medina JM, Giaume C, Tabernero A. Reduced connexin43 expression correlates with c-Src activation, proliferation, and glucose uptake in reactive astrocytes after an excitotoxic insult. Glia 2012; 60:2040-9. [PMID: 22987484 DOI: 10.1002/glia.22418] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 08/23/2012] [Indexed: 11/06/2022]
Abstract
In diverse brain pathologies, astrocytes become reactive and undergo profound phenotypic changes. Connexin43 (Cx43), the main gap junction channel-forming protein in astrocytes, is one of the proteins modified in reactive astrocytes. Downregulation of Cx43 in cultured astrocytes activates c-Src, promotes proliferation, and increases the rate of glucose uptake; however, so far there have been no studies examining whether this cascade of events takes place in reactive astrocytes. In this work, we analyzed this pathway after a cortical lesion induced by a kainic acid injection. As previously described, astrocytes reacted to the lesion with an increase in glial fibrillary acidic protein and a decrease in Cx43 expression. Some of these reactive astrocytes proliferated, as estimated by bromodeoxyuridine incorporation and cyclins D1 and D3 upregulation. In addition, the expression of the glucose transporter GLUT-3 and the enzyme responsible for glucose phosphorylation, Type II hexokinase (Hx-2), were induced in reactive astrocytes, suggesting an increased glucose uptake. Previous in vitro studies reported that c-Src is the link between Cx43 and glucose uptake and proliferation in astrocytes. Here, we found that c-Src activity increased in the lesioned area. c-Src activation and Cx43 downregulation preceded the peak of Hx-2 and cyclin D3 expression, suggesting that c-Src could mediate the effect of Cx43 on glucose uptake and proliferation in reactive astrocytes after an excitotoxic insult. Interestingly, we identify c-Src, GLUT-3, and Hx-2 in the signaling mechanisms involved in the reaction of astroglia to injury. Altogether these data contribute to identify new therapeutical targets to enhance astrocyte neuroprotective activities.
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Affiliation(s)
- Ester Gangoso
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Spain
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Opposing roles of connexin43 in glioma progression. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2058-67. [DOI: 10.1016/j.bbamem.2011.10.022] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 10/17/2011] [Accepted: 10/24/2011] [Indexed: 12/12/2022]
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SUN YAN, ZHAO XIAOPING, YAO YUTING, QI XINYI, YUAN YAOZONG, HU YU. Connexin 43 interacts with Bax to regulate apoptosis of pancreatic cancer through a gap junction-independent pathway. Int J Oncol 2012; 41:941-8. [DOI: 10.3892/ijo.2012.1524] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Accepted: 04/24/2012] [Indexed: 11/05/2022] Open
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Valle-Casuso JC, González-Sánchez A, Medina JM, Tabernero A. HIF-1 and c-Src mediate increased glucose uptake induced by endothelin-1 and connexin43 in astrocytes. PLoS One 2012; 7:e32448. [PMID: 22384254 PMCID: PMC3285680 DOI: 10.1371/journal.pone.0032448] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 01/31/2012] [Indexed: 11/19/2022] Open
Abstract
In previous work we showed that endothelin-1 (ET-1) increases the rate of glucose uptake in astrocytes, an important aspect of brain function since glucose taken up by astrocytes is used to supply the neurons with metabolic substrates. In the present work we sought to identify the signalling pathway responsible for this process in primary culture of rat astrocytes. Our results show that ET-1 promoted an increase in the transcription factor hypoxia-inducible factor-1α (HIF-1α) in astrocytes, as shown in other cell types. Furthermore, HIF-1α-siRNA experiments revealed that HIF-1α participates in the effects of ET-1 on glucose uptake and on the expression of GLUT-1, GLUT-3, type I and type II hexokinase. We previously reported that these effects of ET-1 are mediated by connexin43 (Cx43), the major gap junction protein in astrocytes. Indeed, our results show that silencing Cx43 increased HIF-1α and reduced the effect of ET-1 on HIF-1α, indicating that the effect of ET-1 on HIF-1α is mediated by Cx43. The activity of oncogenes such as c-Src can up-regulate HIF-1α. Since Cx43 interacts with c-Src, we investigated the participation of c-Src in this pathway. Interestingly, both the treatment with ET-1 and with Cx43-siRNA increased c-Src activity. In addition, when c-Src activity was inhibited neither ET-1 nor silencing Cx43 were able to up-regulate HIF-1α. In conclusion, our results suggest that ET-1 by down-regulating Cx43 activates c-Src, which in turn increases HIF-1α leading to the up-regulation of the machinery required to take up glucose in astrocytes. Cx43 expression can be reduced in response not only to ET-1 but also to various physiological and pathological stimuli. This study contributes to the identification of the signalling pathway evoked after Cx43 down-regulation that results in increased glucose uptake in astrocytes. Interestingly, this is the first evidence linking Cx43 to HIF-1, which is a master regulator of glucose metabolism.
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Affiliation(s)
| | | | | | - Arantxa Tabernero
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
- * E-mail:
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Rooj AK, McNicholas CM, Bartoszewski R, Bebok Z, Benos DJ, Fuller CM. Glioma-specific cation conductance regulates migration and cell cycle progression. J Biol Chem 2011; 287:4053-65. [PMID: 22130665 DOI: 10.1074/jbc.m111.311688] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, we have investigated the role of a glioma-specific cation channel assembled from subunits of the Deg/epithelial sodium channel (ENaC) superfamily, in the regulation of migration and cell cycle progression in glioma cells. Channel inhibition by psalmotoxin-1 (PcTX-1) significantly inhibited migration and proliferation of D54-MG glioma cells. Both PcTX-1 and benzamil, an amiloride analog, caused cell cycle arrest of D54-MG cells in G(0)/G(1) phases (by 30 and 40%, respectively) and reduced cell accumulation in S and G(2)/M phases after 24 h of incubation. Both PcTX-1 and benzamil up-regulated expression of cyclin-dependent kinase inhibitor proteins p21(Cip1) and p27(Kip1). Similar results were obtained in U87MG and primary glioblastoma multiforme cells maintained in primary culture and following knockdown of one of the component subunits, ASIC1. In contrast, knocking down δENaC, which is not a component of the glioma cation channel complex, had no effect on cyclin-dependent kinase inhibitor expression. Phosphorylation of ERK1/2 was also inhibited by PcTX-1, benzamil, and knockdown of ASIC1 but not δENaC in D54MG cells. Our data suggest that a specific cation conductance composed of acid-sensing ion channels and ENaC subunits regulates migration and cell cycle progression in gliomas.
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Affiliation(s)
- Arun K Rooj
- Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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Paíno T, Gangoso E, Medina JM, Tabernero A. Inhibition of ATP-sensitive potassium channels increases HSV-tk/GCV bystander effect in U373 human glioma cells by enhancing gap junctional intercellular communication. Neuropharmacology 2010; 59:480-91. [PMID: 20603136 DOI: 10.1016/j.neuropharm.2010.06.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 06/15/2010] [Accepted: 06/25/2010] [Indexed: 01/16/2023]
Abstract
It is well known that the efficiency of Herpes simplex virus thymidine kinase gene/ganciclovir (HSV-tk/GCV) therapy is improved by the bystander effect, which mainly relies on gap junctional intercellular communication (GJIC). Malignant gliomas communicate poorly through gap junctions, consequently, agents with the ability to increase GJIC are good candidates to improve the efficiency of this therapy. Since we previously showed that the inhibition of ATP-sensitive potassium (KATP) channels promoted by tolbutamide increased GJIC in rat C6 glioma cells, we have investigated whether tolbutamide could increase the bystander effect in HSV-tk/GCV therapy against human glioma cells. We found that tolbutamide increased GJIC in U373 human glioma cells, an effect that was due to the up-regulation of connexin43, a protein that forms gap junctions channels. More interestingly, our results show that tolbutamide increased the efficiency of HSV-tk/GCV in co-cultures containing U373 cells and U373 cells transfected with HSV-tk. This effect was impaired in the presence of carbenoxolone, an inhibitor of GJIC. Furthermore, tolbutamide did not enhance the bystander effect in connexin43-silenced co-cultures. Together our results reveal that the inhibition of KATP channels promoted by tolbutamide enhances the bystander effect in HSV-tk/GCV therapy by increasing connexin43-mediated gap junctional intercellular communication in U373 human glioma cells.
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Affiliation(s)
- Teresa Paíno
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León, INCYL, Universidad de Salamanca, Spain
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