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Peng Y, Zhao H, Hu S, Ma Y, Han T, Meng C, Tong X, Zou H, Liu Z, Song R. Exploring the impact of osteoprotegerin on osteoclast and precursor fusion: Mechanisms and modulation by ATP. Differentiation 2024; 138:100789. [PMID: 38896972 DOI: 10.1016/j.diff.2024.100789] [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: 01/19/2024] [Revised: 05/21/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024]
Abstract
Osteoclast (OC) differentiation, vital for bone resorption, depends on osteoclast and precursor fusion. Osteoprotegerin (OPG) inhibits osteoclast differentiation. OPG's influence on fusion and mechanisms is unclear. Osteoclasts and precursors were treated with OPG alone or with ATP. OPG significantly reduced OC number, area and motility and ATP mitigated OPG's inhibition. However, OPG hardly affected the motility of precusors. OPG downregulated fusion-related molecules (CD44, CD47, DC-STAMP, ATP6V0D2) in osteoclasts, reducing only CD47 in precursors. OPG reduced Connexin43 phosphorylated forms (P1 and P2) in osteoclasts, affecting only P2 in precursors. OPG disrupted subcellular localization of CD44, CD47, DC-STAMP, ATP6V0D2, and Connexin43 in both cell types. Findings underscore OPG's multifaceted impact, inhibiting multinucleated osteoclast and mononuclear precursor fusion through distinct molecular mechanisms. Notably, ATP mitigates OPG's inhibitory effect, suggesting a potential regulatory role for the ATP signaling pathway. This study enhances understanding of intricate processes in osteoclast differentiation and fusion, offering insights into potential therapeutic targets for abnormal bone metabolism.
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Affiliation(s)
- Yunwen Peng
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Hongyan Zhao
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Sinan Hu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Yonggang Ma
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Tao Han
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Chuang Meng
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China; Jiangsu Key Lab of Zoonosis, Yangzhou University, Yangzhou, China
| | - Xishuai Tong
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Hui Zou
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Zongping Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China; Jiangsu Key Lab of Zoonosis, Yangzhou University, Yangzhou, China
| | - Ruilong Song
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China; Jiangsu Key Lab of Zoonosis, Yangzhou University, Yangzhou, China.
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2
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Weiss BE, Kraner SD, Artiushin IA, Norris CM. Elevated calcineurin activity in primary astrocytes leads to the dephosphorylation of connexin 43 in conjunction with increased membrane permeability. Neuroreport 2024; 35:673-678. [PMID: 38813906 DOI: 10.1097/wnr.0000000000002051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Hyperactivation of the Ca2+/calmodulin-dependent phosphatase calcineurin (CN) is observed in reactive astrocytes associated with neuroinflammation and progressive degenerative diseases, like Alzheimer's disease. Apart from key transcription factors (e.g. nuclear factor of activated t cells and nuclear factor-κB) very few other CN-dependent pathways have been studied in astrocytes. The hemichannel protein, connexin 43 (Cx43) is found at high levels in astrocytes and contains a CN-sensitive Ser residue near its carboxy terminus. CN-dependent dephosphorylation of Cx43 has been reported in primary astrocytes treated with injurious stimuli, but much remains unknown about CN/Cx43 interactions in the context of neuroinflammation and disease. Western blots were used to assess total Cx43 and dephosphorylated Cx43 subtypes in rat embryonic primary astrocytes treated with a hyperactive CN fragment (ΔCN, via adenovirus), or with a proinflammatory cytokine cocktail. Under similar treatment conditions, an ethidium bromide (EtBr) uptake assay was used to assess membrane permeability. Effects of ΔCN and cytokines were tested in the presence or absence of the CN inhibitor, cyclosporin A. A connexin inhibitor, carbenoxolone was also used in EtBr assays to assess the involvement of connexins in membrane permeability. Treatment with ΔCN or cytokines increased dephosphorylated Cx43 levels in conjunction with increased membrane permeability (elevated EtBr uptake). Effects of ΔCN or cytokine treatment were blocked by cyclosporine A. Treatment-induced changes in EtBr uptake were also inhibited by carbenoxolone. The results suggest that Cx43 hemichannels could be an important mechanism through which astrocytic CN disrupts neurologic function associated with neurodegenerative disease.
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Affiliation(s)
- Blaine E Weiss
- Sanders-Brown Center on Aging
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | | | | | - Christopher M Norris
- Sanders-Brown Center on Aging
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
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3
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Dai B, Liu H, Juan D, Wu K, Cao R. The role of miRNA-29b1 on the hypoxia-induced apoptosis in mammalian cardiomyocytes. Eur J Histochem 2024; 68:4021. [PMID: 38934067 PMCID: PMC11228570 DOI: 10.4081/ejh.2024.4021] [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: 03/12/2024] [Accepted: 05/06/2024] [Indexed: 06/28/2024] Open
Abstract
Cardiomyocyte apoptosis is a complex biological process involving the interaction of many factors and signaling pathways. In hypoxic environment, cardiomyocytes may trigger apoptosis due to insufficient energy supply, increased production of oxygen free radicals, and disturbance of intracellular calcium ion balance. The present research aimed to investigate the role of microRNA-29b1 (miR-29b1) in hypoxia-treated cardiomyocytes and its potential mechanism involved. We established an in vitro ischemia model using AC16 and H9C2 cardiomyocytes through hypoxia treatment (1% O2, 48 h). Cell apoptosis was evaluated by flow cytometry using Annexin V FITC-PI staining assay. Moreover, we used Western blot and immunofluorescence analysis to determine the expression of Bcl-2, Bax caspase-3 and Cx43 proteins. We found that miR-29b1 protected AC16 and H9C2 cells from hypoxia-induced injury as evidence that miR-29b1 attenuated the effects of hypoxia treatment on AC16 and H9C2 cell apoptosis after hypoxia treatment. In conclusion, our findings suggest that miR-29b1 may have potential cardiovascular protective effects during ischemia-related myocardial injury.
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Affiliation(s)
- Bo Dai
- Department of Cardiology, The Sixth Affiliated Hospital, School of Medicine, South China University of Technology, Foshan.
| | - Hailin Liu
- Department of Cardiology, The Sixth Affiliated Hospital, School of Medicine, South China University of Technology, Foshan.
| | - Dingmin Juan
- Department of Cardiology, The Sixth Affiliated Hospital, School of Medicine, South China University of Technology, Foshan.
| | - Kaize Wu
- Department of Cardiology, The Sixth Affiliated Hospital, School of Medicine, South China University of Technology, Foshan.
| | - Ruhao Cao
- Department of Cardiology, The Sixth Affiliated Hospital, School of Medicine, South China University of Technology, Foshan.
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4
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Fu Q, Wu X, Lu Z, Chang Y, Jin Q, Jin T, Zhang M. TMEM205 induces TAM/M2 polarization to promote cisplatin resistance in gastric cancer. Gastric Cancer 2024:10.1007/s10120-024-01517-2. [PMID: 38850316 DOI: 10.1007/s10120-024-01517-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 05/26/2024] [Indexed: 06/10/2024]
Abstract
Cisplatin (DDP) is a basic chemotherapy drug for gastric cancer (GC). With the increase of DDP drug concentration in clinical treatment, cancer cells gradually became resistant. Therefore, it is necessary to find effective therapeutic targets to enhance the sensitivity of GC to DDP. Studies have shown that Transmembrane protein 205 (TMEM205) is overexpressed in DDP-resistant human epidermoid carcinoma cells and correlates with drug resistance, and database analyses show that TMEM 205 is also overexpressed in GC, but its role in cisplatin-resistant gastric cancer remains unclear. In this study, we chose a variety of experiments in vivo and vitro, aiming to investigate the role of TMEM 205 in cisplatin resistance in gastric cancer. The results showed that TMEM 205 promoted proliferation, stemness, epithelial-mesenchymal transition (EMT), migration and angiogenesis of gastric cancer cells through activation of the Wnt/β-catenin signaling pathway. In addition, TMEM205 promotes GC progression by inducing M2 polarization of tumor-associated macrophages (TAMs). These results suggest that TMEM205 may be an effective target to regulate the sensitivity of GC to DDP, providing a new therapeutic direction for clinical treatment.
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Affiliation(s)
- Qiang Fu
- Department of Ultrasound Medicine, Affiliated Hospital of Yanbian University, Yanji, 133000, Jilin, China
- Department of Pathology and Cancer Research Center, Yanbian University Medical College, Yanji, 133002, China
- Key Laboratory of the Science and Technology Department of Jilin Province, Yanji, China
| | - Xuwei Wu
- Department of Pathology and Cancer Research Center, Yanbian University Medical College, Yanji, 133002, China
- Key Laboratory of the Science and Technology Department of Jilin Province, Yanji, China
- Department of Pathology, Chifeng Municipal Hospital, Chifeng, 024000, China
| | - Zhongqi Lu
- Department of Ultrasound Medicine, Affiliated Hospital of Yanbian University, Yanji, 133000, Jilin, China
- Department of Pathology and Cancer Research Center, Yanbian University Medical College, Yanji, 133002, China
- Key Laboratory of the Science and Technology Department of Jilin Province, Yanji, China
| | - Ying Chang
- Department of Ultrasound Medicine, Affiliated Hospital of Yanbian University, Yanji, 133000, Jilin, China
- Department of Pathology and Cancer Research Center, Yanbian University Medical College, Yanji, 133002, China
- Key Laboratory of the Science and Technology Department of Jilin Province, Yanji, China
| | - Quanxin Jin
- Department of Immunology and Pathogenic Biology, Yanbian University Medical College, Yanji, China
| | - Tiefeng Jin
- Department of Pathology and Cancer Research Center, Yanbian University Medical College, Yanji, 133002, China
- Key Laboratory of the Science and Technology Department of Jilin Province, Yanji, China
| | - Meihua Zhang
- Department of Health Examination Centre, Yanbian University Hospital, Yanji, 133002, China.
- Department of Ultrasound Medicine, Affiliated Hospital of Yanbian University, Yanji, 133000, Jilin, China.
- Department of Pathology and Cancer Research Center, Yanbian University Medical College, Yanji, 133002, China.
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5
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Totland MZ, Knudsen LM, Rasmussen NL, Omori Y, Sørensen V, Elster VCW, Stenersen JM, Larsen M, Jensen CL, Zickfeldt Lade AA, Bruusgaard E, Basing S, Kryeziu K, Brech A, Aasen T, Lothe RA, Leithe E. The E3 ubiquitin ligase ITCH negatively regulates intercellular communication via gap junctions by targeting connexin43 for lysosomal degradation. Cell Mol Life Sci 2024; 81:171. [PMID: 38597989 PMCID: PMC11006747 DOI: 10.1007/s00018-024-05165-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 01/27/2024] [Accepted: 02/05/2024] [Indexed: 04/11/2024]
Abstract
Intercellular communication via gap junctions has a fundamental role in regulating cell growth and tissue homeostasis, and its dysregulation may be involved in cancer development and radio- and chemotherapy resistance. Connexin43 (Cx43) is the most ubiquitously expressed gap junction channel protein in human tissues. Emerging evidence indicates that dysregulation of the sorting of Cx43 to lysosomes is important in mediating the loss of Cx43-based gap junctions in cancer cells. However, the molecular basis underlying this process is currently poorly understood. Here, we identified the E3 ubiquitin ligase ITCH as a novel regulator of intercellular communication via gap junctions. We demonstrate that ITCH promotes loss of gap junctions in cervical cancer cells, which is associated with increased degradation of Cx43 in lysosomes. The data further indicate that ITCH interacts with and regulates Cx43 ubiquitination and that the ITCH-induced loss of Cx43-based gap junctions requires its catalytic HECT (homologous to E6-AP C-terminus) domain. The data also suggest that the ability of ITCH to efficiently promote loss of Cx43-based gap junctions and degradation of Cx43 depends on a functional PY (PPXY) motif in the C-terminal tail of Cx43. Together, these data provide new insights into the molecular basis underlying the degradation of Cx43 and have implications for the understanding of how intercellular communication via gap junctions is lost during cancer development.
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Affiliation(s)
- Max Zachrisson Totland
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Lars Mørland Knudsen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Nikoline Lander Rasmussen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
- Centre for Molecular Medicine Norway, Faculty of Medicine, Oslo, Norway
| | - Yasufumi Omori
- Department of Molecular and Tumour Pathology, Akita University Graduate School of Medicine, Akita, 010-8543, Japan
| | - Vigdis Sørensen
- Department of Core Facilities, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
- Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, Oslo, 0379, Norway
| | - Vilde C Wivestad Elster
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Jakob Mørkved Stenersen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Mathias Larsen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Caroline Lunder Jensen
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Anna A Zickfeldt Lade
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Emilie Bruusgaard
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Sebastian Basing
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Kushtrim Kryeziu
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
| | - Andreas Brech
- Department of Core Facilities, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, 0379, Norway
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, Oslo, 0316, Norway
| | - Trond Aasen
- Patologia Molecular Translacional, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron 119-129, Barcelona, 08035, Spain
| | - Ragnhild A Lothe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, Oslo, 0316, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, 0317, Norway
| | - Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, Oslo, NO-0424, Norway
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6
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Anders S, Breithausen B, Unichenko P, Herde MK, Minge D, Abramian A, Behringer C, Deshpande T, Boehlen A, Domingos C, Henning L, Pitsch J, Kim YB, Bedner P, Steinhäuser C, Henneberger C. Epileptic activity triggers rapid ROCK1-dependent astrocyte morphology changes. Glia 2024; 72:643-659. [PMID: 38031824 PMCID: PMC10842783 DOI: 10.1002/glia.24495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 11/16/2023] [Accepted: 11/20/2023] [Indexed: 12/01/2023]
Abstract
Long-term modifications of astrocyte function and morphology are well known to occur in epilepsy. They are implicated in the development and manifestation of the disease, but the relevant mechanisms and their pathophysiological role are not firmly established. For instance, it is unclear how quickly the onset of epileptic activity triggers astrocyte morphology changes and what the relevant molecular signals are. We therefore used two-photon excitation fluorescence microscopy to monitor astrocyte morphology in parallel to the induction of epileptiform activity. We uncovered astrocyte morphology changes within 10-20 min under various experimental conditions in acute hippocampal slices. In vivo, induction of status epilepticus resulted in similarly altered astrocyte morphology within 30 min. Further analysis in vitro revealed a persistent volume reduction of peripheral astrocyte processes triggered by induction of epileptiform activity. In addition, an impaired diffusion within astrocytes and within the astrocyte network was observed, which most likely is a direct consequence of the astrocyte remodeling. These astrocyte morphology changes were prevented by inhibition of the Rho GTPase RhoA and of the Rho-associated kinase (ROCK). Selective deletion of ROCK1 but not ROCK2 from astrocytes also prevented the morphology change after induction of epileptiform activity and reduced epileptiform activity. Together these observations reveal that epileptic activity triggers a rapid ROCK1-dependent astrocyte morphology change, which is mechanistically linked to the strength of epileptiform activity. This suggests that astrocytic ROCK1 signaling is a maladaptive response of astrocytes to the onset of epileptic activity.
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Affiliation(s)
- Stefanie Anders
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Björn Breithausen
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Petr Unichenko
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Michel K. Herde
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Daniel Minge
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Adlin Abramian
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Charlotte Behringer
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Tushar Deshpande
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Anne Boehlen
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Cátia Domingos
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Lukas Henning
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Julika Pitsch
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Young-Bum Kim
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston, MA, USA
| | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
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7
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Sidell N, Rajakumar A. Retinoic Acid Action in Cumulus Cells: Implications for Oocyte Development and In Vitro Fertilization. Int J Mol Sci 2024; 25:1709. [PMID: 38338985 PMCID: PMC10855907 DOI: 10.3390/ijms25031709] [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: 12/14/2023] [Revised: 01/15/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
In the field of human in vitro fertilization (IVF), selecting the best oocyte for freezing or embryo for transfer remains an important focus of clinical practice. Although several techniques are and have been used for this goal, results have generally not been favorable and/or are invasive such that damage to some embryos occurs, resulting in a reduced number of healthy births. Therefore, the search continues for non-invasive oocyte and embryo quality markers that signal the development of high-quality embryos. Multiple studies indicate the important positive effects of retinoic acid (RA) on oocyte maturation and function. We previously showed that a high follicular fluid (FF) RA concentration at the time of oocyte retrieval in IVF protocols was associated with oocytes, giving rise to the highest quality embryos, and that cumulus granulosa cells (CGCs) are the primary source of follicle RA synthesis. Data also demonstrated that connexin-43 (Cx43), the main connexin that forms gap junctions in CGCs, is regulated by RA and that RA induces a rapid increase in gap junction communication. Here, we hypothesize that CGC RA plays a causal role in oocyte competency through its action on Cx43 and, as such, may serve as a biomarker of oocyte competence. Multiple studies have demonstrated the requirement for Cx43 in CGCs for the normal progression of folliculogenesis, and that the increased expression of this connexin is linked to the improved developmental competence of the oocyte. The data have shown that RA can up-regulate gap junction intercellular communication (GJIC) in the cumulus-oocyte complex via a non-genomic mechanism that results in the dephosphorylation of Cx43 and enhanced GJIC. Recognizing the positive role played by gap junctions in CGCs in oocyte development and the regulation of Cx43 by RA, the findings have highlighted the possibility that CGC RA levels may serve as a non-invasive indicator for selecting high-quality oocytes for IVF procedures. In addition, the data suggest that the manipulation of Cx43 with retinoid compounds could provide new pharmacological approaches to improve IVF outcomes in cases of failed implantation, recurrent miscarriage, or in certain diseases that are characterized by reduced fecundity, such as endometriosis.
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Affiliation(s)
- Neil Sidell
- Department of Gynecology & Obstetrics, Emory University School of Medicine, Atlanta, GA 30322, USA;
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8
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Hanafy MS, Cui Z. Connexin-Containing Vesicles for Drug Delivery. AAPS J 2024; 26:20. [PMID: 38267725 DOI: 10.1208/s12248-024-00889-8] [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: 09/30/2023] [Accepted: 12/20/2023] [Indexed: 01/26/2024] Open
Abstract
Connexin is a transmembrane protein present on the cell membrane of most cell types. Connexins assemble into a hexameric hemichannel known as connexon that pairs with another hemichannel present on a neighboring cell to form gap junction that acts as a channel or pore for the transport of ions and small molecules between the cytoplasm of the two cells. Extracellular vesicles released from connexin-expressing cells could carry connexin hemichannels on their surface and couple with another connexin hemichannel on a distant recipient cell to allow the transfer of the intravesicular content directly into the cytoplasm. Connexin-containing vesicles can be potentially utilized for intracellular drug delivery. In this review, we introduced cell-derived, connexin-containing extracellular vesicles and cell-free connexin-containing liposomes, methods of preparing them, procedures to load cargos in them, factors regulating the connexin hemichannel activity, (potential) applications of connexin-containing vesicles in drug delivery, and finally the challenges and future directions in realizing the promises of this platform delivery system for (intracellular) drug delivery.
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Affiliation(s)
- Mahmoud S Hanafy
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, Texas, USA
| | - Zhengrong Cui
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, Texas, USA.
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9
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Al-attar R, Jargstorf J, Romagnuolo R, Jouni M, Alibhai FJ, Lampe PD, Solan JL, Laflamme MA. Casein Kinase 1 Phosphomimetic Mutations Negatively Impact Connexin-43 Gap Junctions in Human Pluripotent Stem Cell-Derived Cardiomyocytes. Biomolecules 2024; 14:61. [PMID: 38254663 PMCID: PMC10813327 DOI: 10.3390/biom14010061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/14/2023] [Accepted: 12/25/2023] [Indexed: 01/24/2024] Open
Abstract
The transplantation of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) has shown promise in preclinical models of myocardial infarction, but graft myocardium exhibits incomplete host-graft electromechanical integration and a propensity for pro-arrhythmic behavior. Perhaps contributing to this situation, hPSC-CM grafts show low expression of connexin 43 (Cx43), the major gap junction (GJ) protein, in ventricular myocardia. We hypothesized that Cx43 expression and function could be rescued by engineering Cx43 in hPSC-CMs with a series of phosphatase-resistant mutations at three casein kinase 1 phosphorylation sites (Cx43-S3E) that have been previously reported to stabilize Cx43 GJs and reduce arrhythmias in transgenic mice. However, contrary to our predictions, transgenic Cx43-S3E hPSC-CMs exhibited reduced Cx43 expression relative to wild-type cells, both at baseline and following ischemic challenge. Cx43-S3E hPSC-CMs showed correspondingly slower conduction velocities, increased automaticity, and differential expression of other connexin isoforms and various genes involved in cardiac excitation-contraction coupling. Cx43-S3E hPSC-CMs also had phosphorylation marks associated with Cx43 GJ internalization, a finding that may account for their impaired GJ localization. Taken collectively, our data indicate that the Cx43-S3E mutation behaves differently in hPSC-CMs than in adult mouse ventricular myocytes and that multiple biological factors likely need to be addressed synchronously to ensure proper Cx43 expression, localization, and function.
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Affiliation(s)
- Rasha Al-attar
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Joseph Jargstorf
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Rocco Romagnuolo
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Mariam Jouni
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Faisal J. Alibhai
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
| | - Paul D. Lampe
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; (P.D.L.); (J.L.S.)
| | - Joell L. Solan
- Translational Research Program, Public Health Sciences and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; (P.D.L.); (J.L.S.)
| | - Michael A. Laflamme
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; (R.A.-a.); (J.J.); (R.R.); (M.J.); (F.J.A.)
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON M5G 1L7, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5G 1L7, Canada
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10
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Kwek MSY, Thangaveloo M, Madden LE, Phillips ARJ, Becker DL. Targeting Cx43 to Reduce the Severity of Pressure Ulcer Progression. Cells 2023; 12:2856. [PMID: 38132176 PMCID: PMC10741864 DOI: 10.3390/cells12242856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/07/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023] Open
Abstract
In the skin, repeated incidents of ischemia followed by reperfusion can result in the breakdown of the skin and the formation of a pressure ulcer. Here we gently applied paired magnets to the backs of mice to cause ischemia for 1.5 h and then removed them to allow reperfusion. The sterile inflammatory response generated within 4 h causes a stage 1 pressure ulcer with an elevation of the gap junction protein Cx43 in the epidermis. If this process is repeated the insult will result in a more severe stage 2 pressure ulcer with a breakdown of the epidermis 2-3 days later. After a single pinch, the elevation of Cx43 in the epidermis is associated with the inflammatory response with an increased number of neutrophils, HMGB1 (marker of necrosis) and RIP3 (responsible for necroptosis). Delivering Cx43 specific antisense oligonucleotides sub-dermally after a single insult, was able to significantly reduce the elevation of epidermal Cx43 protein expression and reduce the number of neutrophils and prevent the elevation of HMGB1 and RIP3. In a double pinch model, the Cx43 antisense treatment was able to reduce the level of inflammation, necroptosis, and the extent of tissue damage and progression to an open wound. This approach may be useful in reducing the progression of stage 1 pressure ulcers to stage 2.
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Affiliation(s)
- Milton Sheng Yi Kwek
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, 11, Mandalay Road, Singapore 308232, Singapore (M.T.); (L.E.M.)
- Skin Research Institute Singapore, Clinical Sciences Building, 11, Mandalay Road, Singapore 308232, Singapore
| | - Moogaambikai Thangaveloo
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, 11, Mandalay Road, Singapore 308232, Singapore (M.T.); (L.E.M.)
- Skin Research Institute Singapore, Clinical Sciences Building, 11, Mandalay Road, Singapore 308232, Singapore
| | - Leigh E. Madden
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, 11, Mandalay Road, Singapore 308232, Singapore (M.T.); (L.E.M.)
- Skin Research Institute Singapore, Clinical Sciences Building, 11, Mandalay Road, Singapore 308232, Singapore
| | | | - David L. Becker
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, 11, Mandalay Road, Singapore 308232, Singapore (M.T.); (L.E.M.)
- Skin Research Institute Singapore, Clinical Sciences Building, 11, Mandalay Road, Singapore 308232, Singapore
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11
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Billur D, Olgar Y, Durak A, Yozgat AH, Unay S, Tuncay E, Turan B. An increase in intercellular crosstalk and electrotonic coupling between cardiomyocytes and nonmyocytes reshapes the electrical conduction in the metabolic heart characterized by short QT intervals in ECGs. Cell Biochem Funct 2023; 41:1526-1542. [PMID: 38014767 DOI: 10.1002/cbf.3893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/07/2023] [Accepted: 11/17/2023] [Indexed: 11/29/2023]
Abstract
Cardiac conduction abnormalities are disorders in metabolic syndrome (MetS), however, their mechanisms are unknown. Although ventricular arrhythmia reflects the changes in QT-interval of electrocardiograms associated with the changes in cardiomyocyte action potential durations (APDs), recent studies emphasize role of intercellular crosstalk between cardiomyocytes and nonmyocytes via passive (electrotonic)-conduction. Therefore, considering the possible increase in intercellular interactions of nonmyocytes with cardiomyocytes, we hypothesized an early-cardiac-remodeling characterized by short QT-interval via contributions and modulations of changes by nonmyocytes to the ventricular APs in an early-stage MetS hearts. Following the feeding of 8-week-old rats with a high-sucrose diet (32%; MetS rats) and validation of insulin resistance, there was a significant increase in heart rate and changes in the electrical characteristics of the hearts, especially a shortening in action potential (AP) duration of the papillary muscles. The patch-clamp analysis of ventricular cardiomyocytes showed an increase in the Na+ -channel currents while there were decreases in l-type Ca2+ -channel (LTCC) currents with unchanged K+ -channel currents. There was an increase in the phosphorylated form of connexin 43 (pCx43), mostly with lateral localization on sarcolemma, while its unphosphorylated form (Cx43) exhibited a high degree of localization within intercalated discs. A high-level positively-stained α-SMA and CD68 cells were prominently localized and distributed in interfibrillar spaces of the heart, implying the possible contributions of myofibroblasts and macrophages to both shortened APDs and abnormal electrical conduction in MetS hearts. Our data propose a previously unrecognized pathway for SQT induction in the heart. This pathway includes not only the contribution of short ventricular-APDs via ionic mechanisms but also increasing contributions of the electrotonic-cardiomyocyte depolarization, spontaneous electrical activity-associated fast heterogeneous impulse conduction in the heart via increased interactions and relocations between cardiomyocytes and nonmyocytes, which may be an explanation for the development of an SQT in early-cardiac-remodeling.
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Affiliation(s)
- Deniz Billur
- Departments of Histology-Embryology, Faculty of Medicine, Ankara University, Ankara, Türkiye
| | - Yusuf Olgar
- Departments of Biophysics, Faculty of Medicine, Ankara University, Ankara, Türkiye
| | - Aysegul Durak
- Departments of Biophysics, Faculty of Medicine, Ankara University, Ankara, Türkiye
| | - Ayse Hande Yozgat
- Departments of Histology-Embryology, Faculty of Medicine, Ankara University, Ankara, Türkiye
| | - Simge Unay
- Departments of Biophysics, Lokman Hekim University Faculty of Medicine, Ankara, Türkiye
| | - Erkan Tuncay
- Departments of Biophysics, Faculty of Medicine, Ankara University, Ankara, Türkiye
| | - Belma Turan
- Departments of Biophysics, Lokman Hekim University Faculty of Medicine, Ankara, Türkiye
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12
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Fernandez-Flores A, Varela-Vazquez A, Mayan MD, Fonseca E. Connexin 43 in Dermatofibroma and Dermatofibrosarcoma Protuberans: Diagnostic, Pathogenic, and Therapeutic Implications. Am J Dermatopathol 2023; 45:812-815. [PMID: 37982464 DOI: 10.1097/dad.0000000000002562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
ABSTRACT Connexins play a crucial role in the formation of gap junctions that connect cells to each other, as well as cells to the surrounding environment. In recent years, connexin 43 has been extensively studied in various human tumors. In this study, we conducted an immunohistochemical analysis to evaluate the expression of connexin in 16 dermatofibromas (DFs) and 13 dermatofibrosarcoma protuberans (DFSP). Connexin was diffusely expressed in the cytoplasm of all DFs with moderate or strong intensity, whereas all DFSPs showed negative staining. In addition to its diagnostic implications, the loss of Cx43 may elucidate the invasive capacity of DFSP and offer a potential avenue for future therapeutic interventions.
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Affiliation(s)
- Angel Fernandez-Flores
- Department of Cellular Pathology, Hospital El Bierzo, Ponferrada, Spain
- Department of Cellular Pathology, Hospital de la Reina, Ponferrada, Spain
| | - Adrian Varela-Vazquez
- Department of Research, Institute for Biomedical Research of A Coruña (INIBIC), University of A Coruña (UDC), A Coruña, Spain; and
| | - Maria D Mayan
- Department of Research, Institute for Biomedical Research of A Coruña (INIBIC), University of A Coruña (UDC), A Coruña, Spain; and
| | - Eduardo Fonseca
- Department of Research, Institute for Biomedical Research of A Coruña (INIBIC), University of A Coruña (UDC), A Coruña, Spain; and
- Department of Dermatology, Universitary Hospital of A Coruña, A Coruña, Spain
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13
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Zhao Y, Namei E, Yang B, Bao X, Sun W, Subudeng G, Cao G, Li H, Wang G. Cyclic AMP mediates ovine cumulus-oocyte gap junctional function via balancing connexin 43 expression and phosphorylation. Endocr Connect 2023; 12:e230337. [PMID: 37855365 PMCID: PMC10620458 DOI: 10.1530/ec-23-0337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 09/18/2023] [Indexed: 09/19/2023]
Abstract
Gap junction channels in cumulus-oocyte complexes (COCs) enable the transmission and communication of small molecular signals between adjacent cells, such as cAMP. However, the regulation of gap junction function (GJF) by cAMP and the underlying mechanisms involved are not fully clarified. This study investigated the effect of cAMP on connexin 43 (CX43) expression and GJF in ovine COCs using immunofluorescence, quantitative real-time PCR (qRT-PCR), western blotting, and GJF detection. The CX43 was only found in the cumulus cells (CCs) side of ovine COC. The intra-oocyte cAMP showed a significant increase at 30 min, while the intra-CC cAMP exhibited two peaks at 10 min and 1 h during in vitro maturation (IVM). Phosphorylated CX43 protein exhibited an immediate increase at 10 min, and CX43 protein displayed two peaks at 10 min and 1 h during IVM. The duration of pre-IVM exposure to forskolin and IBMX significantly enhanced phosphorylated and total CX43, as well as Gja1 and Creb genes, for 10 min; these effects were counteracted by Rp-cAMP. Both pre-IVM with forskolin and IBMX for 1 h and the GJF and CX43/p-CX43 ratio were elevated. The closure of gap junction channels caused by phosphorylated CX43 to prevent cAMP outflow from oocytes in early IVM of COC. Cyclic AMP upregulated phosphorylated and total CX43 via genomic and non-genomic pathways, but its functional regulation was dependent on the balance of the two proteins. This study provides a new insight into the regulatory mechanism between cAMP and GJF, which would improve IVM in animal and clinical research.
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Affiliation(s)
- Yufen Zhao
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Animal Embryo and Development Engineering of Autonomous Region Universities, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Erge Namei
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Animal Embryo and Development Engineering of Autonomous Region Universities, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Bingxue Yang
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Animal Embryo and Development Engineering of Autonomous Region Universities, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Xiangnan Bao
- Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Hohhot, PR China
- National Center of Technology Innovation for Dairy Industry, Hohhot, PR China
| | - Wei Sun
- Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Hohhot, PR China
| | - Gerile Subudeng
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Animal Embryo and Development Engineering of Autonomous Region Universities, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Guifang Cao
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Animal Embryo and Development Engineering of Autonomous Region Universities, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Haijun Li
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, PR China
- Key Laboratory of Animal Embryo and Development Engineering of Autonomous Region Universities, Inner Mongolia Agricultural University, Hohhot, PR China
| | - Gui Wang
- Animal Genetic Breeding and Reproduction Research Center, Hetao College, Bayannur, PR China
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14
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Lucaciu SA, Leighton SE, Hauser A, Yee R, Laird DW. Diversity in connexin biology. J Biol Chem 2023; 299:105263. [PMID: 37734551 PMCID: PMC10598745 DOI: 10.1016/j.jbc.2023.105263] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023] Open
Abstract
Over 35 years ago the cell biology community was introduced to connexins as the subunit employed to assemble semicrystalline clusters of intercellular channels that had been well described morphologically as gap junctions. The decade that followed would see knowledge of the unexpectedly large 21-member human connexin family grow to reflect unique and overlapping expression patterns in all organ systems. While connexin biology initially focused on their role in constructing highly regulated intercellular channels, this was destined to change as discoveries revealed that connexin hemichannels at the cell surface had novel roles in many cell types, especially when considering connexin pathologies. Acceptance of connexins as having bifunctional channel properties was initially met with some resistance, which has given way in recent years to the premise that connexins have multifunctional properties. Depending on the connexin isoform and cell of origin, connexins have wide-ranging half-lives that vary from a couple of hours to the life expectancy of the cell. Diversity in connexin channel characteristics and molecular properties were further revealed by X-ray crystallography and single-particle cryo-EM. New avenues have seen connexins or connexin fragments playing roles in cell adhesion, tunneling nanotubes, extracellular vesicles, mitochondrial membranes, transcription regulation, and in other emerging cellular functions. These discoveries were largely linked to Cx43, which is prominent in most human organs. Here, we will review the evolution of knowledge on connexin expression in human adults and more recent evidence linking connexins to a highly diverse array of cellular functions.
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Affiliation(s)
- Sergiu A Lucaciu
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Stephanie E Leighton
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Alexandra Hauser
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Ryan Yee
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada.
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15
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Liu G, Feng L, Liu X, Gao P, Wang F. O-GlcNAcylation Inhibition Upregulates Connexin43 Expression in the Endothelium to Protect the Tight Junction Barrier in Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2023; 64:30. [PMID: 37982762 PMCID: PMC10668625 DOI: 10.1167/iovs.64.14.30] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/28/2023] [Indexed: 11/21/2023] Open
Abstract
Purpose This study aimed to investigate the effects of O-linked N-acetylglucosamine modification (O-GlcNAcylation) on connexin43 (Cx43) expression and its subsequent effects on tight junction properties in diabetic retinopathy (DR). Methods O-GlcNAcylation levels in primary human retinal vascular endothelial cells (HRVECs) and retinas from rats with diabetes were regulated by treatment with Thiamet G or alloxan. Immunoprecipitation was used to examine the relationship between O-GlcNAcylation and Cx43 expression. Stable overexpression and knockdown of Cx43 in HRVECs were achieved using lentivirus constructs; further, their effects on occludin and zonula occluden-1 (ZO-1) expression and tight junction barrier function were determined. Results O-GlcNAcylation level increased significantly, whereas Cx43 expression decreased in retinas from rats with diabetes and HRVECs cultured under high-glucose conditions. Immunoprecipitation revealed that Cx43 was modified by O-GlcNAcylation and phosphorylation simultaneously. O-GlcNAcylation inhibition negatively regulated both total Cx43 and phosphorylated Cx43 expression, subsequently disrupting tight junction properties. Conversely, Cx43 overexpression reversed the disruption of tight junction properties and downregulated vascular endothelial growth factor expression. Consistently, Cx43 overexpression increased transendothelial electrical resistance values in HRVEC layers. Conclusions O-GlcNAcylation negatively regulated Cx43 expression, contributing to the disruption of the blood retinal barrier. However, O-GlcNAcylation inhibition and Cx43 overexpression could reverse the tight junction disruption. Therefore, O-GlcNAcylation inhibition is a potential target for avoiding tight junction disruption through the Cx43 pathway in DR.
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Affiliation(s)
- Guodong Liu
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P.R. China
- Tongji Eye Institute, Tongji University School of Medicine, Shanghai, China
| | - Le Feng
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P.R. China
- Tongji Eye Institute, Tongji University School of Medicine, Shanghai, China
| | - Xiaoqiang Liu
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P.R. China
- Tongji Eye Institute, Tongji University School of Medicine, Shanghai, China
| | - Peng Gao
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P.R. China
| | - Fang Wang
- Tongji Eye Institute, Tongji University School of Medicine, Shanghai, China
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16
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Huang Y, Wei C, Li P, Shao Y, Wang M, Wang F, Niu G, Sun K, Zhang Q, Gou Z, Yan X. FGF21 protects against doxorubicin-induced cardiotoxicity by inhibiting connexin 43 ubiquitination. Free Radic Biol Med 2023; 208:748-758. [PMID: 37774805 DOI: 10.1016/j.freeradbiomed.2023.09.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 09/26/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023]
Abstract
BACKGROUND Fibroblast growth factor 21 (FGF21) regulates glycolipid metabolism and insulin homeostasis and acts as a cardioprotective factor by protecting against myocardial ischemia/reperfusion injury, hypertension, and vascular dysfunction. FGF21 has been reported to prevent Doxorubicin (Dox)-induced cardiotoxicity, and the related signaling pathway is worthy of further study. Connexin43 (Cx43) protein was reduced by Dox treatment, especially low phosphorylated form of Cx43. Thus the aim of study is to explore the protection effect of FGF21 on Dox induced cardiotoxicity by improving the expression of Cx43 and the involved signaling pathway. METHODS AND RESULTS FGF21 inhibited apoptosis in Dox-treated mice and cardiomyocytes. FGF21 increased the levels of connexin43 phosphorylated at serine (S) 282 (p-Cx43 S282) and total Cx43 to inhibit Dox-induced apoptosis. By RNA sequencing, we found that deubiquitinase monocyte chemoattractant protein-induced protein 1 (MCPIP1) expression was increased by FGF21. We further found that FGF21 induced the phosphorylation of fibroblast growth factor receptor 1 (FGFR1), extracellular signal-regulated kinase 1 and 2 (Erk1/2), and Elk. Phosphorylated Elk translocated to the nucleus and increased the expression of MCPIP1. Then, MCPIP1 bound neural precursor cell expressed developmentally downregulated protein 4 (Nedd4), an E3 ubiquitination ligase, as shown by co-immunoprecipitation (Co-IP), and suppressed Cx43 ubiquitination and degradation, competitively inhibiting the binding of Cx43 with Nedd4. Thus Nedd4 could not bind and ubiquitinate Cx43, leading to the up-regulation of Cx43 and phosphorylation of Cx43 at S282. CONCLUSIONS FGF21 inhibited the effects of Dox on cardiomyocytes by elevating the phosphorylation of Cx43 at S282 and total Cx43 expression. This study suggests a previously unknown mechanism for the FGF21-mediated enhancement of cardiomyocyte survival and provides an effective approach to protect against the adverse cardiac effects of Dox.
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Affiliation(s)
- Ying Huang
- Center for Cardiovascular Disease, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China
| | - Chenchen Wei
- Center for Cardiovascular Disease, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China
| | - Ping Li
- Center for Cardiovascular Disease, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China
| | - Yaqing Shao
- Center for Cardiovascular Disease, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China
| | - Min Wang
- Center for Cardiovascular Disease, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China
| | - Feng Wang
- Center for Cardiovascular Disease, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China; Department of Pharmacology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China
| | - Guanghao Niu
- Department of Cardiovascular Surgery of the First Affiliated Hospital & Institute for Cardiovascular Science, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Medical College, Soochow University, Suzhou, Jiangsu, 215000, PR China
| | - Kangyun Sun
- Center for Cardiovascular Disease, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China
| | - Qian Zhang
- Department of Pharmacology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China.
| | - Zhongshan Gou
- Center for Cardiovascular Disease, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China.
| | - Xinxin Yan
- Center for Cardiovascular Disease, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China; Department of Pharmacology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, 215008, PR China.
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17
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Hastings N, Yu Y, Huang B, Middya S, Inaoka M, Erkamp NA, Mason RJ, Carnicer‐Lombarte A, Rahman S, Knowles TPJ, Bance M, Malliaras GG, Kotter MRN. Electrophysiological In Vitro Study of Long-Range Signal Transmission by Astrocytic Networks. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301756. [PMID: 37485646 PMCID: PMC10582426 DOI: 10.1002/advs.202301756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/09/2023] [Indexed: 07/25/2023]
Abstract
Astrocytes are diverse brain cells that form large networks communicating via gap junctions and chemical transmitters. Despite recent advances, the functions of astrocytic networks in information processing in the brain are not fully understood. In culture, brain slices, and in vivo, astrocytes, and neurons grow in tight association, making it challenging to establish whether signals that spread within astrocytic networks communicate with neuronal groups at distant sites, or whether astrocytes solely respond to their local environments. A multi-electrode array (MEA)-based device called AstroMEA is designed to separate neuronal and astrocytic networks, thus allowing to study the transfer of chemical and/or electrical signals transmitted via astrocytic networks capable of changing neuronal electrical behavior. AstroMEA demonstrates that cortical astrocytic networks can induce a significant upregulation in the firing frequency of neurons in response to a theta-burst charge-balanced biphasic current stimulation (5 pulses of 100 Hz × 10 with 200 ms intervals, 2 s total duration) of a separate neuronal-astrocytic group in the absence of direct neuronal contact. This result corroborates the view of astrocytic networks as a parallel mechanism of signal transmission in the brain that is separate from the neuronal connectome. Translationally, it highlights the importance of astrocytic network protection as a treatment target.
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Affiliation(s)
- Nataly Hastings
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Yi‐Lin Yu
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Department of Neurological SurgeryTri‐Service General HospitalNational Defence Medical CentreTaipei, Neihu District11490Taiwan
| | - Botian Huang
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | - Sagnik Middya
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Misaki Inaoka
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Nadia A. Erkamp
- Yusuf Hamied Department of ChemistryCentre for Misfolding DiseasesUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Roger J. Mason
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | | | - Saifur Rahman
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
| | - Tuomas P. J. Knowles
- Yusuf Hamied Department of ChemistryCentre for Misfolding DiseasesUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
- Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AveCambridgeCB3 0HEUK
| | - Manohar Bance
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | - George G. Malliaras
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Mark R. N. Kotter
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
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18
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Adams WP, Raisch TB, Zhao Y, Davalos R, Barrett S, King DR, Bain CB, Colucci-Chang K, Blair GA, Hanlon A, Lozano A, Veeraraghavan R, Wan X, Deschenes I, Smyth JW, Hoeker GS, Gourdie RG, Poelzing S. Extracellular Perinexal Separation Is a Principal Determinant of Cardiac Conduction. Circ Res 2023; 133:658-673. [PMID: 37681314 PMCID: PMC10561697 DOI: 10.1161/circresaha.123.322567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 08/29/2023] [Indexed: 09/09/2023]
Abstract
BACKGROUND Cardiac conduction is understood to occur through gap junctions. Recent evidence supports ephaptic coupling as another mechanism of electrical communication in the heart. Conduction via gap junctions predicts a direct relationship between conduction velocity (CV) and bulk extracellular resistance. By contrast, ephaptic theory is premised on the existence of a biphasic relationship between CV and the volume of specialized extracellular clefts within intercalated discs such as the perinexus. Our objective was to determine the relationship between ventricular CV and structural changes to micro- and nanoscale extracellular spaces. METHODS Conduction and Cx43 (connexin43) protein expression were quantified from optically mapped guinea pig whole-heart preparations perfused with the osmotic agents albumin, mannitol, dextran 70 kDa, or dextran 2 MDa. Peak sodium current was quantified in isolated guinea pig ventricular myocytes. Extracellular resistance was quantified by impedance spectroscopy. Intercellular communication was assessed in a heterologous expression system with fluorescence recovery after photobleaching. Perinexal width was quantified from transmission electron micrographs. RESULTS CV primarily in the transverse direction of propagation was significantly reduced by mannitol and increased by albumin and both dextrans. The combination of albumin and dextran 70 kDa decreased CV relative to albumin alone. Extracellular resistance was reduced by mannitol, unchanged by albumin, and increased by both dextrans. Cx43 expression and conductance and peak sodium currents were not significantly altered by the osmotic agents. In response to osmotic agents, perinexal width, in order of narrowest to widest, was albumin with dextran 70 kDa; albumin or dextran 2 MDa; dextran 70 kDa or no osmotic agent, and mannitol. When compared in the same order, CV was biphasically related to perinexal width. CONCLUSIONS Cardiac conduction does not correlate with extracellular resistance but is biphasically related to perinexal separation, providing evidence that the relationship between CV and extracellular volume is determined by ephaptic mechanisms under conditions of normal gap junctional coupling.
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Affiliation(s)
- William P. Adams
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Tristan B. Raisch
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Yajun Zhao
- School of Biomedical Engineering and Sciences, Virginia Tech
| | - Rafael Davalos
- School of Biomedical Engineering and Sciences, Virginia Tech
| | | | - D. Ryan King
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Chandra B. Bain
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
| | - Katrina Colucci-Chang
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- School of Biomedical Engineering and Sciences, Virginia Tech
| | - Grace A. Blair
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
| | - Alexandra Hanlon
- Virginia Tech Center for Biostatistics and Health Data Science, Roanoke, Virginia
| | - Alicia Lozano
- Virginia Tech Center for Biostatistics and Health Data Science, Roanoke, Virginia
| | - Rengasayee Veeraraghavan
- Department of Biomedical Engineering, College of Engineering, The Ohio State University
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center
| | - Xiaoping Wan
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center
| | - Isabelle Deschenes
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center
| | - James W. Smyth
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Department of Biological Sciences, College of Science, Virginia Tech
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia
| | - Gregory S. Hoeker
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
| | - Robert G. Gourdie
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- School of Biomedical Engineering and Sciences, Virginia Tech
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia
| | - Steven Poelzing
- Center for Vascular and Heart Research at Fralin Biomedical Research Institute at VTC
- Translational Biology, Medicine and Health Program at Virginia Tech
- School of Biomedical Engineering and Sciences, Virginia Tech
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia
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19
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Totland MZ, Omori Y, Sørensen V, Kryeziu K, Aasen T, Brech A, Leithe E. Endocytic trafficking of connexins in cancer pathogenesis. Biochim Biophys Acta Mol Basis Dis 2023:166812. [PMID: 37454772 DOI: 10.1016/j.bbadis.2023.166812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/26/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Gap junctions are specialized regions of the plasma membrane containing clusters of channels that provide for the diffusion of ions and small molecules between adjacent cells. A fundamental role of gap junctions is to coordinate the functions of cells in tissues. Cancer pathogenesis is usually associated with loss of intercellular communication mediated by gap junctions, which may affect tumor growth and the response to radio- and chemotherapy. Gap junction channels consist of integral membrane proteins termed connexins. In addition to their canonical roles in cell-cell communication, connexins modulate a range of signal transduction pathways via interactions with proteins such as β-catenin, c-Src, and PTEN. Consequently, connexins can regulate cellular processes such as cell growth, migration, and differentiation through both channel-dependent and independent mechanisms. Gap junctions are dynamic plasma membrane entities, and by modulating the rate at which connexins undergo endocytosis and sorting to lysosomes for degradation, cells rapidly adjust the level of gap junctions in response to alterations in the intracellular or extracellular milieu. Current experimental evidence indicates that aberrant trafficking of connexins in the endocytic system is intrinsically involved in mediating the loss of gap junctions during carcinogenesis. This review highlights the role played by the endocytic system in controlling connexin degradation, and consequently gap junction levels, and discusses how dysregulation of these processes contributes to the loss of gap junctions during cancer development. We also discuss the therapeutic implications of aberrant endocytic trafficking of connexins in cancer cells.
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Affiliation(s)
| | - Yasufumi Omori
- Department of Molecular and Tumour Pathology, Akita University Graduate School of Medicine, Akita, Japan
| | | | | | - Trond Aasen
- Patologia Molecular Translacional, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Passeig Vall d'Hebron, Barcelona, Spain
| | - Andreas Brech
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, Oslo, Norway; Section for Physiology and Cell Biology, Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
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20
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Cao X, Cai L, Guo D, Zhang D, Zhou X, Xie J. Fibroblast growth factor 8 facilitates cell-cell communication in chondrocytes via p38-MAPK signaling. Tissue Cell 2023; 83:102155. [PMID: 37451010 DOI: 10.1016/j.tice.2023.102155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/10/2023] [Accepted: 07/03/2023] [Indexed: 07/18/2023]
Abstract
Gap junction intercellular communication (GJIC) is essential for regulating the development of the organism and sustaining the internal environmental homeostasis of multi-cellular tissue. Fibroblast growth factor 8 (FGF8), an indispensable regulator of the skeletal system, is implicated in regulating chondrocyte growth, differentiation, and disease occurrence. However, the influence of FGF8 on GJIC in chondrocytes is not yet known. The study aims to investigate the role of FGF8 on cell-cell communication in chondrocytes and its underlying biomechanism. We found that FGF8 facilitated cell-cell communication in living chondrocytes by the up-regulation of connexin43 (Cx43), the major fundamental component unit of gap junction channels in chondrocytes. FGF8 activated p38-MAPK signaling to increase the expression of Cx43 and promote the cell-cell communication. Inhibition of p38-MAPK signaling impaired the increase of Cx43 expression and cell-cell communication induced by FGF8, indicating the importance of p38-MAPK signaling. These results help to understand the role of FGF8 on cell communication and provide a potential cue for the treatment of cartilage diseases.
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Affiliation(s)
- Xiaoling Cao
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Lang Cai
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Daimo Guo
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Demao Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
| | - Jing Xie
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
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21
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Zhang M, Wang ZZ, Chen NH. Connexin 43 Phosphorylation: Implications in Multiple Diseases. Molecules 2023; 28:4914. [PMID: 37446576 DOI: 10.3390/molecules28134914] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
Connexin 43 (Cx43) is most widely distributed in mammals, especially in the cardiovascular and nervous systems. Its phosphorylation state has been found to be regulated by the action of more than ten kinases and phosphatases, including mitogen-activated protein kinase/extracellular signaling and regulating kinase signaling. In addition, the phosphorylation status of different phosphorylation sites affects its own synthesis and assembly and the function of the gap junctions (GJs) to varying degrees. The phosphorylation of Cx43 can affect the permeability, electrical conductivity, and gating properties of GJs, thereby having various effects on intercellular communication and affecting physiological or pathological processes in vitro and in vivo. Therefore, clarifying the relationship between Cx43 phosphorylation and specific disease processes will help us better understand the disease. Based on the above clinical and preclinical findings, we present in this review the functional significance of Cx43 phosphorylation in multiple diseases and discuss the potential of Cx43 as a drug target in Cx43-related disease pathophysiology, with an emphasis on the importance of connexin 43 as an emerging therapeutic target in cardiac and neuroprotection.
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Affiliation(s)
- Meng Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100050, China
| | - Zhen-Zhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100050, China
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100050, China
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22
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Bedner P, Steinhäuser C. Role of Impaired Astrocyte Gap Junction Coupling in Epileptogenesis. Cells 2023; 12:1669. [PMID: 37371139 DOI: 10.3390/cells12121669] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/25/2023] [Accepted: 06/19/2023] [Indexed: 06/29/2023] Open
Abstract
The gap-junction-coupled astroglial network plays a central role in the regulation of neuronal activity and synchronisation, but its involvement in the pathogenesis of neuronal diseases is not yet understood. Here, we present the current state of knowledge about the impact of impaired glial coupling in the development and progression of epilepsy and discuss whether astrocytes represent alternative therapeutic targets. We focus mainly on temporal lobe epilepsy (TLE), which is the most common form of epilepsy in adults and is characterised by high therapy resistance. Functional data from TLE patients and corresponding experimental models point to a complete loss of astrocytic coupling, but preservation of the gap junction forming proteins connexin43 and connexin30 in hippocampal sclerosis. Several studies further indicate that astrocyte uncoupling is a causal event in the initiation of TLE, as it occurs very early in epileptogenesis, clearly preceding dysfunctional changes in neurons. However, more research is needed to fully understand the role of gap junction channels in epilepsy and to develop safe and effective therapeutic strategies targeting astrocytes.
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Affiliation(s)
- Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
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23
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Buxton ILO, Asif H, Barnett SD. β3 Receptor Signaling in Pregnant Human Myometrium Suggests a Role for β3 Agonists as Tocolytics. Biomolecules 2023; 13:1005. [PMID: 37371585 DOI: 10.3390/biom13061005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/07/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
Preterm labor leading to preterm birth is the leading cause of infant morbidity and mortality. At the present time, nothing can reliably halt labor once it begins. The knowledge that agonists of the β2 adrenergic receptor relax airway smooth muscle and are effective in the treatment of asthma led to the notion that β2 mimetics would prevent preterm birth by relaxing uterine smooth muscle. The activation of cAMP-dependent protein kinase by β2 receptors is unable to provide meaningful tocolysis. The failure of β2 agonists such as ritodrine and terbutaline to prevent preterm birth suggests that the regulation of uterine smooth muscle is disparate from that of airway. Other smooth muscle quiescent-mediating molecules, such as nitric oxide, relax vascular smooth muscle in a cGMP-protein kinase G-dependent manner; however, nitric oxide activation of protein kinase G fails to explain the relaxation of the myometrium to nitric oxide. Moreover, nitric oxide-mediated relaxation is blunted in preterm labor, and thus, for this reason and because of the fall in maternal blood pressure, nitric oxide cannot be employed as a tocolytic. The β3 adrenergic receptor-mediated relaxation of the human myometrium is claimed to be cAMP-dependent protein kinase-dependent. This is scientifically displeasing given the failure of β2 agonists as tocolytics and suggests a non-canonical signaling role for β3AR in myometrium. The addition of the β3 agonist mirabegron to pregnant human myometrial strips in the tissue bath relaxes oxytocin-induced contractions. Mirabegron stimulates nitric oxide production in myometrial microvascular endothelial cells, and the relaxation of uterine tissue in vitro is partially blocked by the addition of the endothelial nitric oxide synthase blocker Nω-Nitro-L-arginine. Recent data suggest that both endothelial and smooth muscle cells respond to β3 stimulation and contribute to relaxation through disparate signaling pathways. The repurposing of approved medications such as mirabegron (Mybetriq™) tested in human myometrium as uterine tocolytics can advance the prevention of preterm birth.
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Affiliation(s)
- Iain L O Buxton
- Myometrial Function Group, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
| | - Hazik Asif
- Myometrial Function Group, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
| | - Scott D Barnett
- Myometrial Function Group, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
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24
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Karatsai O, Lehka L, Wojton D, Grabowska AI, Duda MK, Lenartowski R, Redowicz MJ. Unconventional myosin VI in the heart: Involvement in cardiac dysfunction progressing with age. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166748. [PMID: 37169038 DOI: 10.1016/j.bbadis.2023.166748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/28/2023] [Accepted: 05/03/2023] [Indexed: 05/13/2023]
Abstract
Hypertrophic cardiomyopathy is the most common cardiovascular disease, which is characterized by structural and functional myocardial abnormalities. It is caused predominantly by autosomal dominant mutations, mainly in genes encoding cardiac sarcomeric proteins, resulting in diverse phenotypical patterns and a heterogenic clinical course. Unconventional myosin VI (MVI) is one of the proteins important for heart function, as it was shown that a point mutation within MYO6 is associated with left ventricular hypertrophy. Previously, we showed that MVI is expressed in the cardiac muscle, where it localizes to the sarcoplasmic reticulum and intercalated discs. Here, we addressed the mechanisms of its involvement in cardiac dysfunction in Snell's waltzer mice (natural MVI knockouts) during heart development. We showed that heart enlargement was already seen in the E14.5 embryos and newborn animals (P0), and was maintained throughout the examined lifespan (up to 12 months). The higher levels of MVI were observed in the hearts of E14.5 embryos and P0 of control heterozygous mice. A search for the mechanisms behind the observed phenotype revealed several changes, accumulation of which resulted in age-progressing heart dysfunction. The main changes that mostly contribute to this functional impairment are the increase in cardiomyocyte proliferation in newborns, disorganization of intercalated discs, and overexpression of SERCA2 in hearts isolated from 12-month-old mice, indicative of functional alterations of sarcoplasmic reticulum. Also, possible aberrations in the heart vascularization, observed in 12-month-old animals could be additional factors responsible for MVI-associated heart dysfunction.
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Affiliation(s)
- Olena Karatsai
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland.
| | - Lilya Lehka
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland.
| | - Dominika Wojton
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland.
| | - Anna Izabela Grabowska
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland.
| | - Monika Katarzyna Duda
- Department of Clinical Physiology, Centre of Postgraduate Medical Education, 99/103 Marymoncka St., 01-813 Warsaw, Poland.
| | - Robert Lenartowski
- Faculty of Biological and Veterinary Sciences, The Nicolaus Copernicus University in Torun, 1 Lwowska St., 87-100 Torun, Poland.
| | - Maria Jolanta Redowicz
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland.
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25
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Chang CWT, Poudyal N, Verdugo DA, Peña F, Stehberg J, Retamal MA. KI04 an Aminoglycosides-Derived Molecule Acts as an Inhibitor of Human Connexin46 Hemichannels Expressed in HeLa Cells. Biomolecules 2023; 13:411. [PMID: 36979346 PMCID: PMC10046693 DOI: 10.3390/biom13030411] [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: 01/21/2023] [Revised: 02/12/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Connexins (Cxs) are proteins that help cells to communicate with the extracellular media and with the cytoplasm of neighboring cells. Despite their importance in several human physiological and pathological conditions, their pharmacology is very poor. In the last decade, some molecules derived from aminoglycosides have been developed as inhibitors of Cxs hemichannels. However, these studies have been performed in E. coli, which is a very simple model. Therefore, our main goal is to test whether these molecules have similar effects in mammalian cells. METHODS We transfected HeLa cells with the human Cx46tGFP and characterized the effect of a kanamycin-derived molecule (KI04) on Cx46 hemichannel activity by time-lapse recordings, changes in phosphorylation by Western blot, localization by epifluorescence, and possible binding sites by molecular dynamics (MD). RESULTS We observed that kanamycin and KI04 were the most potent inhibitors of Cx46 hemichannels among several aminoglycosides, presenting an IC50 close to 10 μM. The inhibitory effect was not associated with changes in Cx46 electrophoretic mobility or its intracellular localization. Interestingly, 5 mM DTT did not reverse KI04 inhibition, but the KI04 effect completely disappeared after washing out KI04 from the recording media. MD analysis revealed two putative binding sites of KI04 in the Cx46 hemichannel. RESULTS These results demonstrate that KI04 could be used as a Cx46 inhibitor and could help to develop future selective Cx46 inhibitors.
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Affiliation(s)
- Cheng-Wei T. Chang
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA
| | - Naveena Poudyal
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA
| | - Daniel A. Verdugo
- Laboratorio de Neurobiología, Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andres Bello, Santiago 7780272, Chile
| | - Francisca Peña
- Laboratorio de Neurobiología, Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andres Bello, Santiago 7780272, Chile
| | - Jimmy Stehberg
- Laboratorio de Neurobiología, Facultad de Medicina y Facultad de Ciencias de la Vida, Instituto de Ciencias Biomédicas, Universidad Andres Bello, Santiago 7780272, Chile
| | - Mauricio A. Retamal
- Center for Membrane Protein Research, Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6551, USA
- Programa de Comunicación Celular en Cáncer, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7610496, Chile
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26
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Cruz Del Puerto M, Rojas ML, Racca AC, Kourdova LT, Miranda AL, Panzetta-Dutari G, Genti-Raimondi S, Flores-Martín JB. StarD7 deficiency hinders cell motility through p-ERK1/2/Cx43 reduction. PLoS One 2022; 17:e0279912. [PMID: 36584213 PMCID: PMC9803278 DOI: 10.1371/journal.pone.0279912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/18/2022] [Indexed: 01/01/2023] Open
Abstract
StarD7 belongs to START protein family involved in lipid traffic, metabolism, and signaling events. Its precursor, StarD7.I which is important for mitochondrial homeostasis, is processed to the StarD7.II isoform that lacks the mitochondrial targeting sequence and is mainly released to the cytosol. StarD7 knockdown interferes with cell migration by an unknown mechanism. Here, we demonstrate that StarD7 silencing decreased connexin 43 (Cx43), integrin β1, and p-ERK1/2 expression in the non-tumoral migratory HTR-8/SVneo cells. StarD7-deficient cells exhibited Golgi disruption and reduced competence to reorient the microtubule-organizing center. The migratory capacity of StarD7-silenced cells was reestablished when Cx43 level was resettled, while p-ERK1/2 expression remained low. Importantly, ectopic expression of the StarD7.II isoform not only restored cell migration but also ERK1/2, Cx43, and integrin β1 expression. Thus, StarD7 is implicated in cell migration through an ERK1/2/Cx43 dependent mechanism but independent of the StarD7.I function in the mitochondria.
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Affiliation(s)
- Mariano Cruz Del Puerto
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Ciudad Universitaria, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Ciudad Universitaria, Córdoba, Argentina
| | - María Laura Rojas
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Ciudad Universitaria, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Ciudad Universitaria, Córdoba, Argentina
| | - Ana Cristina Racca
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Ciudad Universitaria, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Ciudad Universitaria, Córdoba, Argentina
| | - Lucille Tihomirova Kourdova
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Ciudad Universitaria, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Ciudad Universitaria, Córdoba, Argentina
| | - Andrea Lis Miranda
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Ciudad Universitaria, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Ciudad Universitaria, Córdoba, Argentina
| | - Graciela Panzetta-Dutari
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Ciudad Universitaria, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Ciudad Universitaria, Córdoba, Argentina
| | - Susana Genti-Raimondi
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Ciudad Universitaria, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Ciudad Universitaria, Córdoba, Argentina
| | - Jésica Belén Flores-Martín
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Ciudad Universitaria, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Ciudad Universitaria, Córdoba, Argentina
- * E-mail:
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27
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Zhang N, Jiang H, Wang H, Wang Y, Peng Y, Liu Y, Xia C, Yan X, Chu S, Zhang Y, Wang Z, Chen N. Novel Antidepressant Mechanism of Ginsenoside Rg1 in Regulating the Dysfunction of the Glutamatergic System in Astrocytes. Int J Mol Sci 2022; 24:ijms24010575. [PMID: 36614017 PMCID: PMC9820673 DOI: 10.3390/ijms24010575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/19/2022] [Accepted: 12/23/2022] [Indexed: 12/31/2022] Open
Abstract
Ginsenoside Rg1, a traditional Chinese medicine monomer, has been shown to have antidepressant effects. We previously found that Rg1 exerts antidepressant effects by improving the gap junction channels (GJCs) dysfunction; however, the downstream mechanisms through which Rg1 ameliorates GJC dysfunction remain unclear. Since hemichannels directly release glutamate, GJC dysfunction decreases the expression levels of glutamate transporters in astrocytes, and glutamatergic system dysfunction plays an essential role in the pathogenesis of depression. The glutamatergic system may be a potential downstream target of Rg1 that exerts antidepressant effects. Therefore, in this study, we aimed to determine the downstream mechanisms by which Rg1 ameliorated GJC dysfunction and exerted its antidepressant effects. Corticosterone (CORT) is used to mimic high glucocorticoid levels in patients with depression in vitro. Primary cortical astrocytes were isolated and phosphorylation of connexin43 (Cx43) as well as the functions of hemichannels, GJCs, and the glutamatergic system were evaluated after drug treatment. Rg1 pretreatment reversed the anomalous activation of Cx43 phosphorylation as well as the dysfunction of hemichannels, GJCs, and the glutamatergic system induced by CORT. These results suggest that Rg1 can ameliorate CORT-induced dysfunction of the glutamatergic system in astrocytes by potentially reducing Cx43 phosphorylation and inhibiting opening of hemichannels, thereby improving GJC dysfunction.
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Affiliation(s)
- Ningning Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Hong Jiang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Huiqin Wang
- School of Pharmacy, Hunan University of Traditional Chinese Medicine & Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, Changsha 410208, China
| | - Yating Wang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Ye Peng
- School of Pharmacy, Hunan University of Traditional Chinese Medicine & Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, Changsha 410208, China
| | - Yangbo Liu
- School of Pharmacy, Hunan University of Traditional Chinese Medicine & Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, Changsha 410208, China
| | - Congyuan Xia
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xu Yan
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Shifeng Chu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yi Zhang
- Department of Anatomy, School of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Zhenzhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- Correspondence: (Z.W.); (N.C.); Tel.: +86-10-6316-5182 (Z.W.); +86-10-6316-5177 (N.C.)
| | - Naihong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- School of Pharmacy, Hunan University of Traditional Chinese Medicine & Hunan Engineering Technology Center of Standardization and Function of Chinese Herbal Decoction Pieces, Changsha 410208, China
- Correspondence: (Z.W.); (N.C.); Tel.: +86-10-6316-5182 (Z.W.); +86-10-6316-5177 (N.C.)
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Rexius-Hall ML, Khalil NN, Escopete SS, Li X, Hu J, Yuan H, Parker SJ, McCain ML. A myocardial infarct border-zone-on-a-chip demonstrates distinct regulation of cardiac tissue function by an oxygen gradient. SCIENCE ADVANCES 2022; 8:eabn7097. [PMID: 36475790 PMCID: PMC9728975 DOI: 10.1126/sciadv.abn7097] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
After a myocardial infarction, the boundary between the injured, hypoxic tissue and the adjacent viable, normoxic tissue, known as the border zone, is characterized by an oxygen gradient. Yet, the impact of an oxygen gradient on cardiac tissue function is poorly understood, largely due to limitations of existing experimental models. Here, we engineered a microphysiological system to controllably expose engineered cardiac tissue to an oxygen gradient that mimics the border zone and measured the effects of the gradient on electromechanical function and the transcriptome. The gradient delayed calcium release, reuptake, and propagation; decreased diastolic and peak systolic stress; and increased expression of inflammatory cascades that are hallmarks of myocardial infarction. These changes were distinct from those observed in tissues exposed to uniform normoxia or hypoxia, demonstrating distinct regulation of cardiac tissue phenotypes by an oxygen gradient. Our border-zone-on-a-chip model advances functional and mechanistic insight into oxygen-dependent cardiac tissue pathophysiology.
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Affiliation(s)
- Megan L. Rexius-Hall
- Laboratory for Living Systems Engineering, Department of Biomedical Engineering, USC Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Natalie N. Khalil
- Laboratory for Living Systems Engineering, Department of Biomedical Engineering, USC Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Sean S. Escopete
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Xin Li
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Jiayi Hu
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Hongyan Yuan
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Sarah J. Parker
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Megan L. McCain
- Laboratory for Living Systems Engineering, Department of Biomedical Engineering, USC Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
- Corresponding author.
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Kwek XY, Hall AR, Lim WW, Katwadi K, Soong PL, Grishina E, Lin KH, Crespo-Avilan G, Yap EP, Ismail NI, Chinda K, Chung YY, Wei H, Shim W, Montaigne D, Tinker A, Ong SB, Hausenloy DJ. Role of cardiac mitofusins in cardiac conduction following simulated ischemia-reperfusion. Sci Rep 2022; 12:21049. [PMID: 36473917 PMCID: PMC9727036 DOI: 10.1038/s41598-022-25625-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction induced by acute cardiac ischemia-reperfusion (IR), may increase susceptibility to arrhythmias by perturbing energetics, oxidative stress production and calcium homeostasis. Although changes in mitochondrial morphology are known to impact on mitochondrial function, their role in cardiac arrhythmogenesis is not known. To assess action potential duration (APD) in cardiomyocytes from the Mitofusins-1/2 (Mfn1/Mfn2)-double-knockout (Mfn-DKO) compared to wild-type (WT) mice, optical-electrophysiology was conducted. To measure conduction velocity (CV) in atrial and ventricular tissue from the Mfn-DKO and WT mice, at both baseline and following simulated acute IR, multi-electrode array (MEA) was employed. Intracellular localization of connexin-43 (Cx43) at baseline was evaluated by immunohistochemistry, while Cx-43 phosphorylation was assessed by Western-blotting. Mfn-DKO cardiomyocytes demonstrated an increased APD. At baseline, CV was significantly lower in the left ventricle of the Mfn-DKO mice. CV decreased with simulated-ischemia and returned to baseline levels during simulated-reperfusion in WT but not in atria of Mfn-DKO mice. Mfn-DKO hearts displayed increased Cx43 lateralization, although phosphorylation of Cx43 at Ser-368 did not differ. In summary, Mfn-DKO mice have increased APD and reduced CV at baseline and impaired alterations in CV following cardiac IR. These findings were associated with increased Cx43 lateralization, suggesting that the mitofusins may impact on post-MI cardiac-arrhythmogenesis.
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Affiliation(s)
- Xiu-Yi Kwek
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore
| | - Andrew R. Hall
- grid.83440.3b0000000121901201The Hatter Cardiovascular Institute, Institute of Cardiovascular Science, University College London, London, UK
| | - Wei-Wen Lim
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore ,grid.428397.30000 0004 0385 0924Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Khairunnisa Katwadi
- grid.428397.30000 0004 0385 0924Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Poh Loong Soong
- grid.4280.e0000 0001 2180 6431Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore ,grid.4280.e0000 0001 2180 6431Cardiovascular Translational Program, Cardiovascular Research Institute (CVRI), National University of Singapore, Singapore, Singapore ,grid.412106.00000 0004 0621 9599Department of Medicine, National University Hospital of Singapore (NUHS), Singapore, Singapore ,Ternion Biosciences, Singapore, Singapore
| | | | | | - Gustavo Crespo-Avilan
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore ,grid.428397.30000 0004 0385 0924Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore ,grid.8664.c0000 0001 2165 8627Department of Biochemistry, Medical Faculty, Justus Liebig-University, Giessen, Germany
| | - En Ping Yap
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore
| | - Nur Izzah Ismail
- grid.10784.3a0000 0004 1937 0482Centre for Cardiovascular Genomics and Medicine (CCGM), Lui Che Woo Institute of Innovative Medicine, Chinese University of Hong Kong (CUHK), Hong Kong, SAR China ,grid.10784.3a0000 0004 1937 0482Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong (CUHK), Hong Kong, SAR China ,Hong Kong Hub of Paediatric Excellence (HK HOPE), Hong Kong Children’s Hospital (HKCH), Kowloon Bay, Hong Kong, SAR China
| | - Kroekkiat Chinda
- grid.412029.c0000 0000 9211 2704Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand ,grid.412029.c0000 0000 9211 2704Integrative Cardiovascular Research Unit, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Ying Ying Chung
- grid.428397.30000 0004 0385 0924Centre for Vision Research, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Heming Wei
- grid.414963.d0000 0000 8958 3388Research Laboratory, KK Women’s & Children’s Hospital, Singapore, Singapore
| | - Winston Shim
- grid.486188.b0000 0004 1790 4399Health and Social Sciences Cluster, Singapore Institute of Technology, Singapore, Singapore
| | - David Montaigne
- grid.503422.20000 0001 2242 6780Inserm, CHU Lille, Institut Pasteur Lille, U1011-European Genomic Institute for Diabetes (EGID), University of Lille, 59000 Lille, France
| | - Andrew Tinker
- grid.4868.20000 0001 2171 1133Centre for Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | - Sang-Bing Ong
- grid.10784.3a0000 0004 1937 0482Centre for Cardiovascular Genomics and Medicine (CCGM), Lui Che Woo Institute of Innovative Medicine, Chinese University of Hong Kong (CUHK), Hong Kong, SAR China ,grid.10784.3a0000 0004 1937 0482Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong (CUHK), Hong Kong, SAR China ,Hong Kong Hub of Paediatric Excellence (HK HOPE), Hong Kong Children’s Hospital (HKCH), Kowloon Bay, Hong Kong, SAR China ,grid.9227.e0000000119573309Joint Laboratory of Bioresources and Molecular Research of Common Diseases, Kunming Institute of Zoology-The Chinese University of Hong Kong (KIZ-CUHK), Chinese Academy of Sciences, Kunming, Yunnan China ,grid.10784.3a0000 0004 1937 0482Shenzhen Research Institute (SZRI), Chinese University of Hong Kong (CUHK), Shenzhen, China
| | - Derek J. Hausenloy
- grid.419385.20000 0004 0620 9905National Heart Research Institute Singapore, National Heart Centre, Singapore, Singapore ,grid.83440.3b0000000121901201The Hatter Cardiovascular Institute, Institute of Cardiovascular Science, University College London, London, UK ,grid.428397.30000 0004 0385 0924Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore, Singapore ,grid.4280.e0000 0001 2180 6431Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore
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Ismail FS, Faustmann PM, Kümmel ML, Förster E, Faustmann TJ, Corvace F. Brivaracetam exhibits mild pro-inflammatory features in an in vitro astrocyte-microglia co-culture model of inflammation. Front Cell Neurosci 2022; 16:995861. [DOI: 10.3389/fncel.2022.995861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022] Open
Abstract
Implications of glia in the pathophysiology of epilepsy raise the question of how these cells besides neurons are responsive to antiseizure medications (ASMs). Understanding ASM effects on glia and glia-mediated inflammation may help to explore astrocytes and microglia as potential targets for alternative anti-epileptogenic therapies. The aim of this study was to investigate the effects of the new generation ASM brivaracetam (BRV) in an astrocyte-microglia co-culture model of inflammation. Primary rat astrocytes co-cultures containing 5%–10% (M5, “physiological” conditions) or 30%–40% (M30, “pathological inflammatory” conditions) of microglia were treated with different concentrations of BRV (0.5, 2, 10, and 20 μg/ml) for 24 h. Glial cell viability was measured by MTT assay. Microglial activation states were analyzed by immunocytochemistry and astroglial connexin 43 (Cx43) expression by Western blot analysis and immunocytochemistry. Gap-junctional coupling was studied via Scrape Loading. Incubation with high, overdose concentration (20 μg/ml) of BRV significantly reduced the glial cell viability under physiological conditions (p < 0.01: **). Treatment with BRV in therapeutic concentrations (0.5 and 2 μg/ml) reduced the resting microglia (p < 0.05: *) and increased the microglial activation under inflammatory conditions (p < 0.01: **). Astroglial Cx43 expression was not affected. The gap-junctional coupling significantly increased only by 0.5 μg/ml BRV under physiological conditions (p < 0.05: *). Our findings suggest mild pro-inflammatory, in vitro features of BRV with regard to microglia morphology. BRV showed no effects on Cx43 expression and only limited effects on gap-junctional coupling. Reduction of glial viability by overdose BRV indicates possible toxic effects.
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Oknińska M, Mączewski M, Mackiewicz U. Ventricular arrhythmias in acute myocardial ischaemia-Focus on the ageing and sex. Ageing Res Rev 2022; 81:101722. [PMID: 36038114 DOI: 10.1016/j.arr.2022.101722] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/17/2022] [Accepted: 08/20/2022] [Indexed: 01/31/2023]
Abstract
Annually, approximately 17 million people die from cardiovascular diseases worldwide, half of them suddenly. The most common direct cause of sudden cardiac death is ventricular arrhythmia triggered by an acute coronary syndrome (ACS). The study summarizes the knowledge of the mechanisms of arrhythmia onset during ACS in humans and in animal models and factors that may influence the susceptibility to life-threatening arrhythmias during ACS with particular focus on the age and sex. The real impact of age and sex on the arrhythmic susceptibility within the setting of acute ischaemia is masked by the fact that ACSs result from coronary artery disease appearing with age much earlier among men than among women. However, results of researches show that in ageing process changes with potential pro-arrhythmic significance, such as increased fibrosis, cardiomyocyte hypertrophy, decrease number of gap junction channels, disturbances of the intracellular Ca2+ signalling or changes in electrophysiological parameters, occur independently of the development of cardiovascular diseases and are more severe in male individuals. A review of the literature also indicates a marked paucity of research in this area in female and elderly individuals. Greater awareness of sex differences in the aging process could help in the development of personalized prevention methods targeting potential pro-arrhythmic factors in patients of both sexes to reduce mortality during the acute phase of myocardial infarction. This is especially important in an era of aging populations in which women will predominate due to their longer lifespan.
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Affiliation(s)
- Marta Oknińska
- Department of Clinical Physiology, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland
| | - Michał Mączewski
- Department of Clinical Physiology, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland
| | - Urszula Mackiewicz
- Department of Clinical Physiology, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland.
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Huang Y, Liu W, Liu Y, Zhang M, Lv X, Hu K, Xu S, Lu M. Glycated serum albumin decreases connexin 43 phosphorylation in the corpus cavernosum. Transl Androl Urol 2022; 11:1486-1494. [PMID: 36507487 PMCID: PMC9732700 DOI: 10.21037/tau-22-317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 10/13/2022] [Indexed: 11/29/2022] Open
Abstract
Background Glycated serum albumin (GSA) is an early glycosylation product that participates in diabetic vascular complications. This study examined the role of GSA in early damage to the corpus cavernosum and the involved mechanisms. Methods Nine 8-week-old male Sprague-Dawley (SD) rats (250-300 g) were divided into the control (saline vehicle, n=3) and GSA (200 µg/kg, n=6) groups. The corpus cavernosum tissues were harvested. Phosphorylated and non-phosphorylated connexin 43 (Cx43), endothelial nitric oxide synthase (eNOS), phosphatidylinositol 3-kinase (PI3K), and serine-threonine kinase (Akt) were tested by immunohistochemistry and western blotting. Human umbilical vein endothelial cells (HUVECs) overexpressing Cx43 were used to analyze the Cx43 phosphorylation sites (S368, S262, Y265, S255, and S279/282) using western blotting. Results The expression of phosphorylated Cx43 in the penis was significantly lower in GSA-treated rats than in controls. The expression levels of p-Cx43, p-eNOS, p-PI3K, and p-Akt were significantly decreased in HUVECs exposed to GSA in dose- and time-dependent manners. The most significant impact on all four proteins was observed with 1 µg/mL of GSA for 12 h. Phosphorylation at the S368, S262, Y265, S255, and S279/282 sites of Cx43 was downregulated by GSA, and S368 was the most significantly suppressed phosphorylation site compared with the other sites. Conclusions GSA decreases the expression of p-Cx43 in the corpus cavernosum of rats. This effect might be also related to the decreased phosphorylation of p-eNOS, p-PI3K, and p-Akt, as well as by the downregulation of phosphorylation at the S368 site.
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Affiliation(s)
- Yanping Huang
- Department of Urology and Andrology, Renji Hospital, Medical School of Shanghai Jiao Tong University, Shanghai Institute of Andrology, Shanghai, China
| | - Wei Liu
- Department of Urology and Andrology, Renji Hospital, Medical School of Shanghai Jiao Tong University, Shanghai Institute of Andrology, Shanghai, China
| | - Yidong Liu
- Department of Urology and Andrology, Renji Hospital, Medical School of Shanghai Jiao Tong University, Shanghai Institute of Andrology, Shanghai, China
| | - Ming Zhang
- Department of Urology and Andrology, Renji Hospital, Medical School of Shanghai Jiao Tong University, Shanghai Institute of Andrology, Shanghai, China
| | - Xiangguo Lv
- Department of Urology and Andrology, Renji Hospital, Medical School of Shanghai Jiao Tong University, Shanghai Institute of Andrology, Shanghai, China
| | - Kai Hu
- Department of Urology and Andrology, Renji Hospital, Medical School of Shanghai Jiao Tong University, Shanghai Institute of Andrology, Shanghai, China
| | - Shiran Xu
- Department of Urology and Andrology, Renji Hospital, Medical School of Shanghai Jiao Tong University, Shanghai Institute of Andrology, Shanghai, China
| | - Mujun Lu
- Department of Urology and Andrology, Renji Hospital, Medical School of Shanghai Jiao Tong University, Shanghai Institute of Andrology, Shanghai, China
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Wen S, Unuma K, Funakoshi T, Aki T, Uemura K. Contraction Band Necrosis with Dephosphorylated Connexin 43 in Rat Myocardium after Daily Cocaine Administration. Int J Mol Sci 2022; 23:ijms231911978. [PMID: 36233284 PMCID: PMC9570416 DOI: 10.3390/ijms231911978] [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: 08/22/2022] [Revised: 09/21/2022] [Accepted: 10/07/2022] [Indexed: 11/12/2022] Open
Abstract
Contraction band necrosis (CBN) is a common abnormality found in the myocardium of cocaine abusers, but is rarely reported in experimental models of cocaine abuse. Connexin 43 (Cx43) is essential for cardiac intercellular communication and the propagation of CBN. Under stress or injury, cardiac Cx43 is dephosphorylated, which is related to cardiomyocyte dysfunction and pathogenesis, whereas adiponectin exerts beneficial effects in the myocardium. In this study, we explore the effects of cocaine on cardiac Cx43 in vivo. Rats were administered cocaine via the tail vein at 20 mg/kg/day for 14 days, and showed widespread CBN, microfocal myocarditis and myocardial fibrosis, corresponding to a dysfunction of cardiac mitochondria under increased oxidative stress. The increase in dephosphorylated cardiac Cx43 and its negative correlation with the myocardial distribution of CBN after cocaine administration were determined. In addition, apoptosis and necroptosis, as well as increased adiponectin levels, were observed in the myocardium after cocaine exposure. Accordingly, we found altered profiles of cardiac Cx43, CBN and its negative correlation with dephosphorylated cardiac Cx43, and the possible involvement of adiponectin in the myocardium after 14 days of cocaine administration. The latter might play a protective role in the cardiotoxicity of cocaine. The current findings would be beneficial for establishing novel therapeutic strategies in cocaine-induced cardiac consequences.
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Paracrine ADP Ribosyl Cyclase-Mediated Regulation of Biological Processes. Cells 2022; 11:cells11172637. [PMID: 36078044 PMCID: PMC9454491 DOI: 10.3390/cells11172637] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/12/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022] Open
Abstract
ADP-ribosyl cyclases (ADPRCs) catalyze the synthesis of the Ca2+-active second messengers Cyclic ADP-ribose (cADPR) and ADP-ribose (ADPR) from NAD+ as well as nicotinic acid adenine dinucleotide phosphate (NAADP+) from NADP+. The best characterized ADPRC in mammals is CD38, a single-pass transmembrane protein with two opposite membrane orientations. The first identified form, type II CD38, is a glycosylated ectoenzyme, while type III CD38 has its active site in the cytosol. The ectoenzymatic nature of type II CD38 raised long ago the question of a topological paradox concerning the access of the intracellular NAD+ substrate to the extracellular active site and of extracellular cADPR product to its intracellular receptors, ryanodine (RyR) channels. Two different transporters, equilibrative connexin 43 (Cx43) hemichannels for NAD+ and concentrative nucleoside transporters (CNTs) for cADPR, proved to mediate cell-autonomous trafficking of both nucleotides. Here, we discussed how type II CD38, Cx43 and CNTs also play a role in mediating several paracrine processes where an ADPRC+ cell supplies a neighboring CNT-and RyR-expressing cell with cADPR. Recently, type II CD38 was shown to start an ectoenzymatic sequence of reactions from NAD+/ADPR to the strong immunosuppressant adenosine; this paracrine effect represents a major mechanism of acquired resistance of several tumors to immune checkpoint therapy.
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Fu ZP, Wu LL, Xue JY, Zhang LE, Li C, You HJ, Luo DL. Connexin 43 hyper-phosphorylation at serine 282 triggers apoptosis in rat cardiomyocytes via activation of mitochondrial apoptotic pathway. Acta Pharmacol Sin 2022; 43:1970-1978. [PMID: 34931018 PMCID: PMC9343349 DOI: 10.1038/s41401-021-00824-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/16/2021] [Indexed: 12/12/2022] Open
Abstract
Cx43 is the major connexin in ventricular gap junctions, and plays a pivotal role in control of electrical and metabolic communication among adjacent cardiomyocytes. We previously found that Cx43 dephosphorylation at serine 282 (pS282) caused cardiomyocyte apoptosis, which is involved in cardiac ischemia/reperfusion injury. In this study we investigated whether Cx43-S282 hyper-phosphorylation could protect cardiomyocytes against apoptosis. Adenovirus carrying rat full length Cx43 gene (Cx43-wt) or a mutant gene at S282 substituted with aspartic acid (S282D) were transfected into neonatal rat ventricular myocytes (NRVMs) or injected into rat ventricular wall. Rat abdominal aorta constriction model (AAC) was used to assess Cx43-S282 phosphorylation status. We showed that Cx43 phosphorylation at S282 was increased over 2-times compared to Cx43-wt cells at 24 h after transfection, while pS262 and pS368 were unaltered. S282D-transfected cells displayed enhanced gap junctional communication, and increased basal intracellular Ca2+ concentration and spontaneous Ca2+ transients compared to Cx43-wt cells. However, spontaneous apoptosis appeared in NRVMs transfected with S282D for 34 h. Rat ventricular myocardium transfected with S282D in vivo also exhibited apoptotic responses, including increased Bax/Bcl-xL ratio, cytochrome c release as well as caspase-3 and caspase-9 activities, while factor-associated suicide (Fas)/Fas-associated death domain expression and caspase-8 activity remained unaltered. In addition, AAC-induced hypertrophic ventricles had apoptotic injury with Cx43-S282 hyper-phosphorylation compared with Sham ventricles. In conclusion, Cx43 hyper-phosphorylation at S282, as dephosphorylation, also triggers cardiomyocyte apoptosis, but through activation of mitochondrial apoptosis pathway, providing a fine-tuned Cx43-S282 phosphorylation range required for the maintenance of cardiomyocyte function and survival.
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Affiliation(s)
- Zhi-ping Fu
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Lu-lin Wu
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Jing-yi Xue
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Lan-e Zhang
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Chen Li
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Hong-jie You
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
| | - Da-li Luo
- grid.24696.3f0000 0004 0369 153XDepartment of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing, 100069 China
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权 会, 徐 卫, 祁 宇, 李 清, 周 辉, 黄 婧. [Inhibition connexin 43 by mimetic peptide Gap27 mediates protective effects on 6-hydroxydopamine induced Parkinson's disease mouse model]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2022; 54:421-426. [PMID: 35701117 PMCID: PMC9197703 DOI: 10.19723/j.issn.1671-167x.2022.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Indexed: 06/15/2023]
Abstract
OBJECTIVE To explore whether the using of mimetic peptide Gap27, a selective inhibitor of connexin 43 (Cx43), could block the death of dopamine neurons and influence the expression of Cx43 in 6-hydroxydopamine (6-OHDA)-induced Parkinson's disease mouse models. METHODS Eighteen C57BL/6 mice were randomly divided into control group, 6-OHDA group and 6-OHDA+Gap27 group, with 6 mice in each group. Bilateral substantia nigra stereotactic injection was performed. The control group was injected with ascorbate solution, 6-OHDA group was injected with 6-OHDA solution, and 6-OHDA+Gap27 group was injected with 6-OHDA and Gap27 mixed solution. Immuno-histochemical staining was used to detect the number of dopamine neurons, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of Cx43 messenger ribonucleic acid (mRNA), immuno-fluorescence staining was used to detect the distribution of Cx43 protein, the contents of Cx43 protein and Cx43 phosphorylation at serine 368 (Cx43-ps368) in mouse midbrain were detected by Western blot. RESULTS After injection of 6-OHDA, numerous dopamine neurons in substantia nigra died as Cx43 content increased, Cx43-ps368 content decreased. Mixing Gap27 while injecting 6-OHDA could reduce the number of death dopamine neurons and weaken the changes of Cx43 and Cx43-ps368 content caused by 6-OHDA. The number of tyrosine hydroxylase (TH) immunoreactive positive neurons in 6-OHDA group decreased to 27.7% ± 0.02% of the control group (P < 0.01); The number of TH immunoreactive positive neurons in 6-OHDA+Gap27 group was (1.64±0.16) times higher than that in 6-OHDA group (P < 0.05); The content of total Cx43 protein in 6-OHDA group was (1.44±0.07) times higher than that in 6-OHDA+Gap27 group (P < 0.05) while (1.68±0.07) times higher than that in control group (P < 0.01). In 6-OHDA group, the content of Cx43-ps368 protein and its proportion in total Cx43 protein were significantly lower than that in 6-OHDA+Gap27 group (P < 0.05). CONCLUSION In 6-OHDA mouse models, mimetic peptide Gap27 played a protective role in reducing the damage to substantia nigra dopamine neurons, which was induced by 6-OHDA. The overexpression of Cx43 protein might have neurotoxicity to dopamine neuron. Meanwhile, decreasing Cx43 protein level and keeping Cx43-ps368 protein level may be the protective mechanisms of Gap27.
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Affiliation(s)
- 会会 权
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 卫星 徐
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 宇泽 祁
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 清如 李
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 辉 周
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
| | - 婧 黄
- />北京大学公共卫生学院劳动卫生与环境卫生学系,北京 100191Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing 100191, China
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Yawer A, Sychrová E, Raška J, Babica P, Sovadinová I. Endocrine-disrupting chemicals affect sertoli TM4 cell functionality through dysregulation of gap junctional intercellular communication in vitro. Food Chem Toxicol 2022; 164:113004. [PMID: 35413382 DOI: 10.1016/j.fct.2022.113004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/20/2022] [Accepted: 04/06/2022] [Indexed: 01/10/2023]
Abstract
The frequencies of adverse outcomes associated with male reproductive health, including infertility and testicular cancer, are increasing. These adverse trends are partially attributed to increased exposure to environmental agents such as endocrine-disrupting chemicals (EDCs). This study addresses effects on EDCs on adjacent prepubertal Sertoli TM4 cells, specifically on 1) testicular gap junctional intercellular communication (GJIC), one of the hallmarks of non-genotoxic carcinogenicity, 2) GJIC building blocks connexins (Cx), and 3) mitogen-activated protein kinases MAPKs. We selected eight representatives of EDCs: bisphenol A and organochlorine chemicals such as pesticides dichlorodiphenyltrichloroethane, lindane, methoxychlor, and vinclozolin, industrial chemical 2,2',4,4',5,5'-hexachlorobiphenyl, and components of personal care products, triclocarban and triclosan. EDCs rapidly dysregulated GJIC in Sertoli TM4 cells mainly via MAPK p38 and/or Erk1/2/pathways by the intermediate hyper- or de-phosphorylation of Cx43 (Ser368, Ser282) and translocalization of Cx43 from the plasma membrane, suggesting disturbed intracellular trafficking of Cx43 protein. Surprisingly, EDCs did not rapidly activate MAPK Erk1/2 or p38; on the contrary, TCC and TCS decreased their activity (phosphorylation). Our results indicate that EDCs might disrupt testicular homeostasis and development via testicular GJIC, junctional and non-junctional functions of Cx43 and MAPK-signalling pathways in Sertoli cells.
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Affiliation(s)
- Affiefa Yawer
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Eliška Sychrová
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Jan Raška
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Pavel Babica
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
| | - Iva Sovadinová
- RECETOX, Faculty of Science, Masaryk University, Kotlarska 2, Brno, Czech Republic.
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Chen SN, Lam CK, Wan YW, Gao S, Malak OA, Zhao SR, Lombardi R, Ambardekar AV, Bristow MR, Cleveland J, Gigli M, Sinagra G, Graw S, Taylor MR, Wu JC, Mestroni L. Activation of PDGFRA signaling contributes to filamin C-related arrhythmogenic cardiomyopathy. SCIENCE ADVANCES 2022; 8:eabk0052. [PMID: 35196083 PMCID: PMC8865769 DOI: 10.1126/sciadv.abk0052] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 12/25/2021] [Indexed: 05/07/2023]
Abstract
FLNC truncating mutations (FLNCtv) are prevalent causes of inherited dilated cardiomyopathy (DCM), with a high risk of developing arrhythmogenic cardiomyopathy. We investigated the molecular mechanisms of mutant FLNC in the pathogenesis of arrhythmogenic DCM (a-DCM) using patient-specific induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). We demonstrated that iPSC-CMs from two patients with different FLNCtv mutations displayed arrhythmias and impaired contraction. FLNC ablation induced a similar phenotype, suggesting that FLNCtv are loss-of-function mutations. Coimmunoprecipitation and proteomic analysis identified β-catenin (CTNNB1) as a downstream target. FLNC deficiency induced nuclear translocation of CTNNB1 and subsequently activated the platelet-derived growth factor receptor alpha (PDGFRA) pathway, which were also observed in human hearts with a-DCM and FLNCtv. Treatment with the PDGFRA inhibitor, crenolanib, improved contractile function of patient iPSC-CMs. Collectively, our findings suggest that PDGFRA signaling is implicated in the pathogenesis, and inhibition of this pathway is a potential therapeutic strategy in FLNC-related cardiomyopathies.
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Affiliation(s)
- Suet Nee Chen
- University of Colorado Cardiovascular Institute, University of Colorado Anschutz Medical Aurora, CO, USA
| | - Chi Keung Lam
- Stanford Cardiovascular Institute, Stanford, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Ying-Wooi Wan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Shanshan Gao
- University of Colorado Cardiovascular Institute, University of Colorado Anschutz Medical Aurora, CO, USA
| | - Olfat A. Malak
- Stanford Cardiovascular Institute, Stanford, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Shane Rui Zhao
- Stanford Cardiovascular Institute, Stanford, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Raffaella Lombardi
- University of Colorado Cardiovascular Institute, University of Colorado Anschutz Medical Aurora, CO, USA
- Department of Advanced Biomedical Sciences University of Naples “Federico II”, Naples, Italy
| | - Amrut V. Ambardekar
- University of Colorado Cardiovascular Institute, University of Colorado Anschutz Medical Aurora, CO, USA
| | - Michael R. Bristow
- University of Colorado Cardiovascular Institute, University of Colorado Anschutz Medical Aurora, CO, USA
| | - Joseph Cleveland
- University of Colorado Cardiovascular Institute, University of Colorado Anschutz Medical Aurora, CO, USA
| | - Marta Gigli
- Cardiovascular Department, Azienda Sanitaria-Universitaria Giuliano Isontina (ASUGI), Trieste, Italy
| | - Gianfranco Sinagra
- Cardiovascular Department, Azienda Sanitaria-Universitaria Giuliano Isontina (ASUGI), Trieste, Italy
| | - Sharon Graw
- University of Colorado Cardiovascular Institute, University of Colorado Anschutz Medical Aurora, CO, USA
| | - Matthew R.G. Taylor
- University of Colorado Cardiovascular Institute, University of Colorado Anschutz Medical Aurora, CO, USA
| | - Joseph C. Wu
- Stanford Cardiovascular Institute, Stanford, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Luisa Mestroni
- University of Colorado Cardiovascular Institute, University of Colorado Anschutz Medical Aurora, CO, USA
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Minogue PJ, Tong JJ, Wichmann K, Mysliwiec H, Ebihara L, Beyer EC, Berthoud VM. Cataract-linked serine mutations in the gap junction protein connexin50 expose a sorting signal that promotes its lysosomal degradation. J Biol Chem 2022; 298:101673. [PMID: 35120923 PMCID: PMC8927986 DOI: 10.1016/j.jbc.2022.101673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 01/24/2023] Open
Abstract
Many human connexin50 (Cx50) mutants have been linked to cataracts including two carboxyl terminus serine mutants that are known phosphorylation sites in the lens (Cx50S258F and Cx50S259Y). To examine the behavior of these mutants and the role of phosphorylation at these positions, we stably transfected HeLa cells with cataract-linked and phosphorylation-mimicking (Cx50S258D and Cx50S259D) Cx50 mutants. We observed that gap junctional plaques were rarely detected in Cx50S258F- and Cx50S259Y-expressing cells compared with wild-type cells. In addition, gap junction abundance and size were greatly increased for Cx50S258D and Cx50S259D mutants. Cx50S258F and Cx50S259Y supported very low levels of gap junctional coupling, whereas Cx50S258D and Cx50S259D supported extensive intercellular communication. Furthermore, Cx50 levels as detected by immunoblotting were lower in Cx50S258F and Cx50S259Y mutants than in the wild type or the aspartate substitution mutants, and chloroquine or ammonium chloride treatment significantly increased Cx50S258F and Cx50S259Y protein levels, implying participation of the lysosome in their increased degradation. Alanine substitution of amino acids within a predicted tyrosine-based sorting signal in Cx50S258F and Cx50S259Y increased levels of gap junctional plaques and intercellular transfer of Neurobiotin. These results suggest that absence of phosphorylatable serines at these positions exposes a sorting signal leading to lysosomal degradation of Cx50, whereas phosphorylation at these sites conceals this signal and allows targeting of Cx50 to the plasma membrane and stabilization of gap junction plaques. We propose that in the lens degradation of Cx50S258F and Cx50S259Y decreases Cx50 levels at the plasma membrane and consequently Cx50 function, leading to cataracts.
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Affiliation(s)
- Peter J Minogue
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
| | - Jun-Jie Tong
- Center of Proteomics and Molecular Therapeutics, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | - Kelly Wichmann
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
| | - Hubert Mysliwiec
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
| | - Lisa Ebihara
- Center of Proteomics and Molecular Therapeutics/Discipline of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USA
| | - Eric C Beyer
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
| | - Viviana M Berthoud
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA.
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Corvace F, Faustmann TJ, Faustmann PM, Ismail FS. Anti-inflammatory properties of lacosamide in an astrocyte-microglia co-culture model of inflammation. Eur J Pharmacol 2022; 915:174696. [PMID: 34902360 DOI: 10.1016/j.ejphar.2021.174696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 11/03/2022]
Abstract
PURPOSE Understanding the effects of antiepileptic drugs on glial cells and glia-mediated inflammation is a new approach to future treatment of epilepsy. Little is known about direct effects of the antiepileptic drug lacosamide (LCM) on glial cells. Therefore, we aimed to study the LCM effects on glial viability, microglial activation, expression of gap-junctional (GJ) protein Cx43 as well as intercellular communication in an in vitro astrocyte-microglia co-culture model of inflammation. METHODS Primary rat astrocytes co-cultures containing 5% (M5, "physiological" conditions) or 30% (M30, "pathological inflammatory" conditions) of microglia were treated with different concentrations of LCM [5, 15, 30, and 90 μg/ml] for 24 h. Glial cell viability was measured by MTT assay. Immunocytochemistry was performed to analyze the microglial activation state. Western blot analysis was used to quantify the astroglial Cx43 expression. The GJ cell communication was studied via Scrape Loading. RESULTS A concentration-dependent incubation with LCM did not affect the glial cell viability both under physiological and pathological conditions. LCM induced a significant concentration-dependent decrease of activated microglia with parallel increase of ramified microglia under pathological inflammatory conditions. This correlated with an increase in astroglial Cx43 expression. Nevertheless, the functional coupling via GJs was significantly reduced after incubation with LCM. CONCLUSION LCM has not shown effects on the glial cell viability. The reduced GJ coupling by LCM could be related to its anti-epileptic activity. The anti-inflammatory glial features of LCM with inhibition of microglial activation under inflammatory conditions support beneficial role in epilepsy associated with neuroinflammation.
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Affiliation(s)
- Franco Corvace
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Bochum, Germany
| | - Timo Jendrik Faustmann
- Department of Psychiatry and Psychotherapy, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Pedro M Faustmann
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Bochum, Germany; International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Fatme Seval Ismail
- Department of Neurology, University Hospital Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Bochum, Germany.
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An S, Zheng S, Cai Z, Chen S, Wang C, Li Y, Deng Z. Connexin43 in Musculoskeletal System: New Targets for Development and Disease Progression. Aging Dis 2022; 13:1715-1732. [DOI: 10.14336/ad.2022.0421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/21/2022] [Indexed: 11/18/2022] Open
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Gong K, Hong Q, Wu H, Wang F, Zhong L, Shen L, Xu P, Zhang W, Cao H, Zhan YY, Hu T, Hong X. Gap junctions mediate glucose transfer to promote colon cancer growth in three-dimensional spheroid culture. Cancer Lett 2022; 531:27-38. [DOI: 10.1016/j.canlet.2022.01.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 01/18/2022] [Accepted: 01/18/2022] [Indexed: 11/02/2022]
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Cx43 Promotes Endothelial Cell Migration and Angiogenesis via the Tyrosine Phosphatase SHP-2. Int J Mol Sci 2021; 23:ijms23010294. [PMID: 35008716 PMCID: PMC8745637 DOI: 10.3390/ijms23010294] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/21/2021] [Accepted: 12/24/2021] [Indexed: 12/16/2022] Open
Abstract
The gap junction protein connexin 43 (Cx43) is associated with increased cell migration and to related changes of the actin cytoskeleton, which is mediated via its C-terminal cytoplasmic tail and is independent of its channel function. Cx43 has been shown to possess an angiogenic potential, however, the role of Cx43 in endothelial cell migration has not yet been investigated. Here, we found that the knock-down of Cx43 by siRNA in human microvascular endothelial cells (HMEC) reduces migration, as assessed by a wound assay in vitro and impaired aortic vessel sprouting ex vivo. Immunoprecipitation of Cx43 revealed an interaction with the tyrosine phosphatase SHP-2, which enhanced its phosphatase activity, as observed in Cx43 expressing HeLa cells compared to cells treated with an empty vector. Interestingly, the expression of a dominant negative substrate trapping mutant SHP-2 (CS) in HMEC, via lentiviral transduction, also impaired endothelial migration to a similar extent as Cx43 siRNA compared to SHP-2 WT. Moreover, the reduction in endothelial migration upon Cx43 siRNA could not be rescued by the introduction of a constitutively active SHP-2 construct (EA). Our data demonstrate that Cx43 and SHP-2 mediate endothelial cell migration, revealing a novel interaction between Cx43 and SHP-2, which is essential for this process.
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Beckmann A, Recktenwald J, Ferdinand A, Grißmer A, Meier C. First Responders to Hyperosmotic Stress in Murine Astrocytes: Connexin 43 Gap Junctions Are Subject to an Immediate Ultrastructural Reorganization. BIOLOGY 2021; 10:biology10121307. [PMID: 34943223 PMCID: PMC8698406 DOI: 10.3390/biology10121307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary Gap junctions are intercellular channels that provide the means for direct transport of small molecules, ions, and water between connected cells. With these functions, gap junctions are essential for the maintenance of astrocytic homeostasis and of particular importance in the context of pathophysiological disbalances. These include the hyperosmolar hyperglycemic syndrome or the pathology after brain trauma. We demonstrate that short-term hyperosmolarity reduces intercellular communication via gap junctions. These functional changes coincide with the transformation of gap junction ultrastructure as evidenced by freeze-fracture replica immunolabeling and transmission electron microscopy. The hyperosmolarity-induced immediate changes in the ultrastructural assembly of connexons, the protein constituents of gap junction channels, have not been described in astrocytes before and are revealing the coherence of structure and function in gap junctions. Phosphorylation of Connexin 43, the main gap junction protein in astrocytes, at amino acid 368 (Serine) might link the two. Abstract In a short-term model of hyperosmotic stress, primary murine astrocytes were stimulated with a hyperosmolar sucrose solution for five minutes. Astrocytic gap junctions, which are mainly composed of Connexin (Cx) 43, displayed immediate ultrastructural changes, demonstrated by freeze–fracture replica immunogold labeling: their area, perimeter, and distance of intramembrane particles increased, whereas particle numbers per area decreased. Ultrastructural changes were, however, not accompanied by changes in Cx43 mRNA expression. In contrast, transcription of the gap junction regulator zonula occludens (ZO) protein 1 significantly increased, whereas its protein expression was unaffected. Phosphorylation of Serine (S) 368 of the Cx43 C–terminus has previously been associated with gap junction disassembly and reduction in gap junction communication. Hyperosmolar sucrose treatment led to enhanced phosphorylation of Cx43S368 and was accompanied by inhibition of gap junctional intercellular communication, demonstrated by a scrape loading-dye transfer assay. Taken together, Cx43 gap junctions are fast reacting elements in response to hyperosmolar challenges and can therefore be considered as one of the first responders to hyperosmolarity. In this process, phosphorylation of Cx43S368 was associated with disassembly of gap junctions and inhibition of their function. Thus, modulation of the gap junction assembly might represent a target in the treatment of brain edema or trauma.
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Palumbos SD, Skelton R, McWhirter R, Mitchell A, Swann I, Heifner S, Von Stetina S, Miller DM. cAMP controls a trafficking mechanism that maintains the neuron specificity and subcellular placement of electrical synapses. Dev Cell 2021; 56:3235-3249.e4. [PMID: 34741804 DOI: 10.1016/j.devcel.2021.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 08/30/2021] [Accepted: 10/08/2021] [Indexed: 11/28/2022]
Abstract
Electrical synapses are established between specific neurons and within distinct subcellular compartments, but the mechanisms that direct gap junction assembly in the nervous system are largely unknown. Here, we show that a developmental program tunes cAMP signaling to direct the neuron-specific assembly and placement of electrical synapses in the C. elegans motor circuit. We use live-cell imaging to visualize electrical synapses in vivo and an optogenetic assay to confirm that they are functional. In ventral A class (VA) motor neurons, the UNC-4 transcription factor blocks expression of cAMP antagonists that promote gap junction miswiring. In unc-4 mutants, VA electrical synapses are established with an alternative synaptic partner and are repositioned from the VA axon to soma. cAMP counters these effects by driving gap junction trafficking into the VA axon for electrical synapse assembly. Thus, our experiments establish that cAMP regulates gap junction trafficking for the biogenesis of functional electrical synapses.
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Affiliation(s)
- Sierra D Palumbos
- Neuroscience Program, Vanderbilt University, Nashville, TN 37212, USA
| | - Rachel Skelton
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37212, USA
| | - Rebecca McWhirter
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37212, USA
| | - Amanda Mitchell
- Vanderbilt Summer Science Academy, Vanderbilt University, Nashville, TN 37212, USA
| | - Isaiah Swann
- Vanderbilt Summer Science Academy, Vanderbilt University, Nashville, TN 37212, USA
| | | | - Stephen Von Stetina
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37212, USA
| | - David M Miller
- Neuroscience Program, Vanderbilt University, Nashville, TN 37212, USA; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37212, USA.
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Faustmann TJ, Corvace F, Faustmann PM, Ismail FS. Effects of Lamotrigine and Topiramate on Glial Properties in an Astrocyte-Microglia Co-Culture Model of Inflammation. Int J Neuropsychopharmacol 2021; 25:185-196. [PMID: 34791253 PMCID: PMC8929754 DOI: 10.1093/ijnp/pyab080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/17/2021] [Accepted: 11/11/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Astrocytes and microglia are involved in the pathophysiology of epilepsy and bipolar disorder with a link to inflammation. We aimed to investigate the effects of the antiepileptic and mood-stabilizing drugs lamotrigine (LTG) and topiramate (TPM) on glial viability, microglial activation, cytokine release, and expression of gap-junctional protein connexin 43 (Cx43) in different set-ups of an in vitro astrocyte-microglia co-culture model of inflammation. METHODS Primary rat co-cultures of astrocytes containing 5% (M5, representing "physiological" conditions) or 30% (M30, representing "pathological, inflammatory" conditions) of microglia were treated with different concentrations of LTG and TPM for 24 hours. An 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to measure the glial cell viability. The microglial activation state was analyzed by immunocytochemistry. The pro-inflammatory tumor necrosis factor-α (TNF-α) and anti-inflammatory transforming growth factor-ß1 (TGF-ß1) cytokine levels were measured by enzyme-linked immunosorbent assay. The astroglial Cx43 expression was quantified by western blot. RESULTS A significant reduction of the glial cell viability after incubation with LTG or TPM was observed in a concentration-dependent manner under all conditions. LTG caused no significant alterations of the microglial phenotypes. Under pathological conditions, TPM led to a significant concentration-dependent reduction of microglial activation. This correlated with increased astroglial Cx43 expression. TNF-α levels were not affected by LTG and TPM. Treatment with higher concentrations of LTG, but not with TPM, led to a significant increase in TGF-ß1 levels in M5 and M30 co-cultures. CONCLUSIONS Despite the possible glial toxicity of LTG and TPM, both drugs reduced inflammatory activity, suggesting potential positive effects on the neuroinflammatory components of the pathogenesis of epilepsy and bipolar disorder.
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Affiliation(s)
- Timo Jendrik Faustmann
- Department of Psychiatry and Psychotherapy, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Franco Corvace
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Bochum, Germany
| | - Pedro M Faustmann
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Bochum, Germany
| | - Fatme Seval Ismail
- Department of Neurology, University Hospital Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Bochum, Germany,Correspondence: Fatme Seval Ismail, MD, Department of Neurology, University Hospital Knappschaftskrankenhaus Bochum, In der Schornau 23–25, 44892 Bochum (; )
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Güiza J, García A, Arriagada J, Gutiérrez C, González J, Márquez-Miranda V, Alegría-Arcos M, Duarte Y, Rojas M, González-Nilo F, Sáez JC, Vega JL. Unnexins: Homologs of innexin proteins in Trypanosomatidae parasites. J Cell Physiol 2021; 237:1547-1560. [PMID: 34779505 DOI: 10.1002/jcp.30626] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/05/2021] [Accepted: 10/26/2021] [Indexed: 11/07/2022]
Abstract
Large-pore channels, including those formed by connexin, pannexin, innexin proteins, are part of a broad family of plasma membrane channels found in vertebrates and invertebrates, which share topology features. Despite their relevance in parasitic diseases such as Chagas and malaria, it was unknown whether these large-pore channels are present in unicellular organisms. We identified 14 putative proteins in Trypanosomatidae parasites as presumptive homologs of innexin proteins. All proteins possess the canonical motif of the innexin family, a pentapeptide YYQWV, and 10 of them share a classical membrane topology of large-pore channels. A sequence similarity network analysis confirmed their closeness to innexin proteins. A bioinformatic model showed that a homolog of Trypanosoma cruzi (T. cruzi) could presumptively form a stable octamer channel with a highly positive electrostatic potential in the internal cavities and extracellular entrance due to the notable predominance of residues such as Arg or Lys. In vitro dye uptake assays showed that divalent cations-free solution increases YO-PRO-1 uptake and hyperosmotic stress increases DAPI uptake in epimastigotes of T. cruzi. Those effects were sensitive to probenecid. Furthermore, probenecid reduced the proliferation and transformation of T. cruzi. Moreover, probenecid or carbenoxolone increased the parasite sensitivity to antiparasitic drugs commonly used in therapy against Chagas. Our study suggests the existence of innexin homologs in unicellular organisms, which could be protein subunits of new large-pore channels in unicellular organisms.
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Affiliation(s)
- Juan Güiza
- Laboratory of Gap Junction Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Aníbal García
- Laboratory of Gap Junction Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Javiera Arriagada
- Laboratory of Gap Junction Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Camila Gutiérrez
- Laboratory of Gap Junction Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Jorge González
- Centro de Investigación en Inmunología y Biotecnología Biomédica de Antofagasta (CIIBBA), Universidad de Antofagasta, Antofagasta, Chile.,Molecular Parasitology Unit, Medical Technology Department, Faculty of Health Sciences, Universidad de Antofagasta, Antofagasta, Chile
| | | | | | - Yorley Duarte
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Maximiliano Rojas
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Fernando González-Nilo
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile.,Instituto de Neurosciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Juan C Sáez
- Instituto de Neurosciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - José L Vega
- Laboratory of Gap Junction Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile.,Centro de Investigación en Inmunología y Biotecnología Biomédica de Antofagasta (CIIBBA), Universidad de Antofagasta, Antofagasta, Chile
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Toychiev AH, Batsuuri K, Srinivas M. Gap Junctional Coupling Between Retinal Astrocytes Exacerbates Neuronal Damage in Ischemia-Reperfusion Injury. Invest Ophthalmol Vis Sci 2021; 62:27. [PMID: 34846518 PMCID: PMC8648063 DOI: 10.1167/iovs.62.14.27] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose Retinal astrocytes abundantly express connexin 43 (Cx43), a transmembrane protein that forms gap junction (GJ) channels and unopposed hemichannels. While it is well established that Cx43 is upregulated in retinal injuries, it is unclear whether astrocytic Cx43 plays a role in retinal ganglion cell (RGC) loss associated with injury. Here, we investigated the effect of astrocyte-specific deletion of Cx43 (Cx43KO) and channel inhibitors on RGC loss in retinal ischemia/reperfusion (I/R) injury and assessed changes in expression and GJ channel and hemichannel function that occur in I/R injury. The effect of Cx43 deletion on neural function in the uninjured retina was also assessed. Methods Cx43 expression, astrocyte density and morphology, and RGC death in wild-type and Cx43KO mice after I/R injury were determined using immunohistochemistry and Western blotting. Visual function was assessed using ERG recordings. GJ coupling and hemichannel activity were evaluated using tracer coupling and uptake studies, respectively. Results Loss of RGCs in I/R injury was accompanied by an increase of Cx43 expression in astrocytes. Functional studies indicated that I/R injury augmented astrocytic GJ coupling but not Cx43 hemichannel activity. Importantly, deletion of astrocytic Cx43 improved neuronal survival in acute ischemia but did not affect RGC function in the absence of injury. In support, pharmacologic inhibition of GJ coupling provided neuroprotection in I/R injury. Conclusions The increase in Cx43 expression and GJ coupling during acute I/R injury exacerbates RGC loss. Inhibition of astrocytic Cx43 channels might represent a useful strategy to promote RGC survival in pathologic conditions.
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Affiliation(s)
- Abduqodir H Toychiev
- Department of Biological and Vision Sciences, SUNY College of Optometry, New York, NY, United States
| | - Khulan Batsuuri
- Department of Biological and Vision Sciences, SUNY College of Optometry, New York, NY, United States
| | - Miduturu Srinivas
- Department of Biological and Vision Sciences, SUNY College of Optometry, New York, NY, United States
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Savio LEB, Leite-Aguiar R, Alves VS, Coutinho-Silva R, Wyse ATS. Purinergic signaling in the modulation of redox biology. Redox Biol 2021; 47:102137. [PMID: 34563872 PMCID: PMC8479832 DOI: 10.1016/j.redox.2021.102137] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 01/07/2023] Open
Abstract
Purinergic signaling is a cell communication pathway mediated by extracellular nucleotides and nucleosides. Tri- and diphosphonucleotides are released in physiological and pathological circumstances activating purinergic type 2 receptors (P2 receptors): P2X ion channels and P2Y G protein-coupled receptors. The activation of these receptors triggers the production of reactive oxygen and nitrogen species and alters antioxidant defenses, modulating the redox biology of cells. The activation of P2 receptors is controlled by ecto-enzymes named ectonucleotidases, E-NTPDase1/CD39 and ecto-5'-nucleotidase/CD73) being the most relevant. The first enzyme hydrolyzes adenosine triphosphate (ATP) and adenosine diphosphate (ADP) into adenosine monophosphate (AMP), and the second catalyzes the hydrolysis of AMP to adenosine. The activity of these enzymes is diminished by oxidative stress. Adenosine actives P1 G-coupled receptors that, in general, promote the maintenance of redox hemostasis by decreasing reactive oxygen species (ROS) production and increase antioxidant enzymes. Intracellular purine metabolism can also contribute to ROS generation via xanthine oxidase activity, which converts hypoxanthine into xanthine, and finally, uric acid. In this review, we describe the mechanisms of redox biology modulated by purinergic signaling and how this signaling may be affected by disturbances in the redox homeostasis of cells.
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Affiliation(s)
- Luiz Eduardo Baggio Savio
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Raíssa Leite-Aguiar
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vinícius Santos Alves
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Robson Coutinho-Silva
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Angela T S Wyse
- Laboratório de Neuroproteção e Doenças Metabólicas, Departamento de Bioquímica, ICBS, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
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King DR, Sedovy MW, Leng X, Xue J, Lamouille S, Koval M, Isakson BE, Johnstone SR. Mechanisms of Connexin Regulating Peptides. Int J Mol Sci 2021; 22:ijms221910186. [PMID: 34638526 PMCID: PMC8507914 DOI: 10.3390/ijms221910186] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 12/22/2022] Open
Abstract
Gap junctions (GJ) and connexins play integral roles in cellular physiology and have been found to be involved in multiple pathophysiological states from cancer to cardiovascular disease. Studies over the last 60 years have demonstrated the utility of altering GJ signaling pathways in experimental models, which has led to them being attractive targets for therapeutic intervention. A number of different mechanisms have been proposed to regulate GJ signaling, including channel blocking, enhancing channel open state, and disrupting protein-protein interactions. The primary mechanism for this has been through the design of numerous peptides as therapeutics, that are either currently in early development or are in various stages of clinical trials. Despite over 25 years of research into connexin targeting peptides, the overall mechanisms of action are still poorly understood. In this overview, we discuss published connexin targeting peptides, their reported mechanisms of action, and the potential for these molecules in the treatment of disease.
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Affiliation(s)
- D. Ryan King
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
| | - Meghan W. Sedovy
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
- Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Blacksburg, VA 24061, USA
| | - Xinyan Leng
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
| | - Jianxiang Xue
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; (J.X.); (B.E.I.)
| | - Samy Lamouille
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
- Center for Vascular and Heart Research, Virginia Tech, Roanoke, VA 24016, USA
| | - Michael Koval
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
| | - Brant E. Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; (J.X.); (B.E.I.)
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Scott R. Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA 24016, USA; (D.R.K.); (M.W.S.); (X.L.); (S.L.)
- Center for Vascular and Heart Research, Virginia Tech, Roanoke, VA 24016, USA
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA
- Correspondence:
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