1
|
Matusevičiūtė R, Ignatavičiūtė E, Mickus R, Bordel S, Skeberdis VA, Raškevičius V. Evaluation of Cx43 Gap Junction Inhibitors Using a Quantitative Structure-Activity Relationship Model. Biomedicines 2023; 11:1972. [PMID: 37509611 PMCID: PMC10377234 DOI: 10.3390/biomedicines11071972] [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: 06/09/2023] [Revised: 07/07/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
Gap junctions (GJs) made of connexin-43 (Cx43) are necessary for the conduction of electrical impulses in the heart. Modulation of Cx43 GJ activity may be beneficial in the treatment of cardiac arrhythmias and other dysfunctions. The search for novel GJ-modulating agents using molecular docking allows for the accurate prediction of binding affinities of ligands, which, unfortunately, often poorly correlate with their potencies. The objective of this study was to demonstrate that a Quantitative Structure-Activity Relationship (QSAR) model could be used for more precise identification of potent Cx43 GJ inhibitors. Using molecular docking, QSAR, and 3D-QSAR, we evaluated 16 known Cx43 GJ inhibitors, suggested the monocyclic monoterpene d-limonene as a putative Cx43 inhibitor, and tested it experimentally in HeLa cells expressing exogenous Cx43. The predicted concentrations required to produce 50% of the maximal effect (IC50) for each of these compounds were compared with those determined experimentally (pIC50 and eIC50, respectively). The pIC50ies of d-limonene and other Cx43 GJ inhibitors examined by our QSAR and 3D-QSAR models showed a good correlation with their eIC50ies (R = 0.88 and 0.90, respectively) in contrast to pIC50ies obtained from molecular docking (R = 0.78). However, molecular docking suggests that inhibitor potency may depend on their docking conformation on Cx43. Searching for new potent, selective, and specific inhibitors of GJ channels, we propose to perform the primary screening of new putative compounds using the QSAR model, followed by the validation of the most suitable candidates by patch-clamp techniques.
Collapse
Affiliation(s)
- Ramona Matusevičiūtė
- Faculty of Medicine, Lithuanian University of Health Sciences, 03101 Kaunas, Lithuania; (R.M.); (E.I.)
| | - Eglė Ignatavičiūtė
- Faculty of Medicine, Lithuanian University of Health Sciences, 03101 Kaunas, Lithuania; (R.M.); (E.I.)
| | - Rokas Mickus
- Institute of Cardiology, Lithuanian University of Health Sciences, 50162 Kaunas, Lithuania; (R.M.); (S.B.); (V.A.S.)
| | - Sergio Bordel
- Institute of Cardiology, Lithuanian University of Health Sciences, 50162 Kaunas, Lithuania; (R.M.); (S.B.); (V.A.S.)
- Institute of Sustainable Processes, University of Valladolid, 47011 Valladolid, Spain
| | - Vytenis Arvydas Skeberdis
- Institute of Cardiology, Lithuanian University of Health Sciences, 50162 Kaunas, Lithuania; (R.M.); (S.B.); (V.A.S.)
| | - Vytautas Raškevičius
- Institute of Cardiology, Lithuanian University of Health Sciences, 50162 Kaunas, Lithuania; (R.M.); (S.B.); (V.A.S.)
| |
Collapse
|
2
|
Dong X, Tse G, Hao G, Du Y. Heterogeneities in Ventricular Conduction Following Treatment with Heptanol: A Multi-Electrode Array Study in Langendorff-Perfused Mouse Hearts. Life (Basel) 2022; 12:life12070996. [PMID: 35888085 PMCID: PMC9321110 DOI: 10.3390/life12070996] [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: 05/30/2022] [Revised: 06/21/2022] [Accepted: 06/30/2022] [Indexed: 11/26/2022] Open
Abstract
Background: Previous studies have associated slowed ventricular conduction with the arrhythmogenesis mediated by the gap junction and sodium channel inhibitor heptanol in mouse hearts. However, they did not study the propagation patterns that might contribute to the arrhythmic substrate. This study used a multi-electrode array mapping technique to further investigate different conduction abnormalities in Langendorff-perfused mouse hearts exposed to 0.1 or 2 mM heptanol. Methods: Recordings were made from the left ventricular epicardium using multi-electrode arrays in spontaneously beating hearts during right ventricular 8 Hz pacing or S1S2 pacing. Results: In spontaneously beating hearts, heptanol at 0.1 and 2 mM significantly reduced the heart rate from 314 ± 25 to 189 ± 24 and 157 ± 7 bpm, respectively (ANOVA, p < 0.05 and p < 0.001). During regular 8 Hz pacing, the mean LATs were increased by 0.1 and 2 mM heptanol from 7.1 ± 2.2 ms to 19.9 ± 5.0 ms (p < 0.05) and 18.4 ± 5.7 ms (p < 0.05). The standard deviation of the mean LATs was increased from 2.5 ± 0.8 ms to 10.3 ± 4.0 ms and 8.0 ± 2.5 ms (p < 0.05), and the median of phase differences was increased from 1.7 ± 1.1 ms to 13.9 ± 7.8 ms and 12.1 ± 5.0 ms by 0.1 and 2 mM heptanol (p < 0.05). P5 took a value of 0.2 ± 0.1 ms and was not significantly altered by heptanol at 0.1 or 2 mM (1.1 ± 0.9 ms and 0.9 ± 0.5 ms, p > 0.05). P50 was increased from 7.3 ± 2.7 ms to 24.0 ± 12.0 ms by 0.1 mM heptanol and then to 22.5 ± 7.5 ms by 2 mM heptanol (p < 0.05). P95 was increased from 1.7 ± 1.1 ms to 13.9 ± 7.8 ms by 0.1 mM heptanol and to 12.1 ± 5.0 ms by 2 mM heptanol (p < 0.05). These changes led to increases in the absolute inhomogeneity in conduction (P5−95) from 7.1 ± 2.6 ms to 31.4 ± 11.3 ms, 2 mM: 21.6 ± 7.2 ms, respectively (p < 0.05). The inhomogeneity index (P5−95/P50) was significantly reduced from 3.7 ± 1.2 to 3.1 ± 0.8 by 0.1 mM and then to 3.3 ± 0.9 by 2 mM heptanol (p < 0.05). Conclusion: Increased activation latencies, reduced CVs, and the increased inhomogeneity index of conduction were associated with both spontaneous and induced ventricular arrhythmias.
Collapse
Affiliation(s)
- Xiuming Dong
- Henan SCOPE Research Institute of Electrophysiology Co., Ltd., Kaifeng 475000, China; (X.D.); (G.H.)
| | - Gary Tse
- Cardiac Electrophysiology Unit, Cardiovascular Analytics Group, Hong Kong, China;
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
- Kent and Medway Medical School, Canterbury CT2 7FS, UK
| | - Guoliang Hao
- Henan SCOPE Research Institute of Electrophysiology Co., Ltd., Kaifeng 475000, China; (X.D.); (G.H.)
- Burdon Sanderson Cardiac Science Centre, BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Yimei Du
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
- Research Center of Ion Channelopathy, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
- Correspondence:
| |
Collapse
|
3
|
A Cellular Assay for the Identification and Characterization of Connexin Gap Junction Modulators. Int J Mol Sci 2021; 22:ijms22031417. [PMID: 33572565 PMCID: PMC7866863 DOI: 10.3390/ijms22031417] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 12/18/2022] Open
Abstract
Connexin gap junctions (Cx GJs) enable the passage of small molecules and ions between cells and are therefore important for cell-to-cell communication. Their dysfunction is associated with diseases, and small molecules acting as modulators of GJs may therefore be useful as therapeutic drugs. To identify GJ modulators, suitable assays are needed that allow compound screening. In the present study, we established a novel assay utilizing HeLa cells recombinantly expressing Cx43. Donor cells additionally expressing the Gs protein-coupled adenosine A2A receptor, and biosensor cells expressing a cAMP-sensitive GloSensor luciferase were established. Adenosine A2A receptor activation in the donor cells using a selective agonist results in intracellular cAMP production. The negatively charged cAMP migrates via the Cx43 gap junctions to the biosensor cells and can there be measured by the cAMP-dependent luminescence signal. Cx43 GJ modulators can be expected to impact the transfer of cAMP from the donor to the biosensor cells, since cAMP transit is only possible via GJs. The new assay was validated by testing the standard GJ inhibitor carbenoxolon, which showed a concentration-dependent inhibition of the signal and an IC50 value that was consistent with previously reported values. The assay was demonstrated to be suitable for high-throughput screening.
Collapse
|
4
|
Stone E, Zhou Y, Jelinek H, Mclachlan CS. Baseline Framingham risk score does not predict future ECG-derived QRS duration over an average of 3.3 years. INTERNATIONAL JOURNAL OF ARRHYTHMIA 2020. [DOI: 10.1186/s42444-020-00024-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Prolonged electrocardiogram (ECG) QRS duration has been associated with increased cardiovascular risk. It is unclear whether the main predictor of cardiovascular risk, the Framingham risk score also predicts short-term changes in ECG QRS duration. Our aim is to determine whether baseline Framingham risk score is associated with baseline or changes in QRS duration.
Methods
A retrospective cross-sectional analysis was performed using observational data obtained from two hundred two participants. Framingham risk score was calculated using an online risk calculator. QRS duration was obtained using a 10 s trace from a Welch Allyn PC-based 12-lead ECG system.
Results
Average follow-up duration was 3.3 ± 1.1 years. Mean QRS change was 1.8 ± 11.4 ms. Specifically, among two hundred two participants, there are 104 subjects with a greater QRS duration at follow-up, while 98 subjects had the same or a shorter follow-up QRS duration. Baseline Framingham risk score did not significantly predict an increase in QRSd with an odds ratio of 1.04 (P = 0.230). Regression analysis of QRS duration at baseline and Framingham risk at baseline had a weak association (R2 = 0.020; P = 0.043). The Framingham risk score at follow-up was likewise has a weak association with follow-up QRS duration (R2 = 0.045; P = 0.002).
Conclusions
Our results do not demonstrate a statistically significant association between Framingham risk parameters and future QRS duration changes over longitudinal time. QRS duration had variable changes between baseline and follow-up. This might suggest that a longer period of follow-up is required to document more stable increases in QRS duration associated with ventricular pathology. A larger population study is needed to confirm our observations.
Collapse
|
5
|
Soleilhac E, Comte M, da Costa A, Barette C, Picoli C, Mortier M, Aubry L, Mouthon F, Fauvarque MO, Charvériat M. Quantitative Automated Assays in Living Cells to Screen for Inhibitors of Hemichannel Function. SLAS DISCOVERY 2020; 26:420-427. [PMID: 32914684 DOI: 10.1177/2472555220954388] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In vertebrates, intercellular communication is largely mediated by connexins (Cx), a family of structurally related transmembrane proteins that assemble to form hemichannels (HCs) at the plasma membrane. HCs are upregulated in different brain disorders and represent innovative therapeutic targets. Identifying modulators of Cx-based HCs is of great interest to better understand their function and define new treatments. In this study, we developed automated versions of two different cell-based assays to identify new pharmacological modulators of Cx43-HCs. As HCs remain mostly closed under physiological conditions in cell culture, depletion of extracellular Ca2+ was used to increase the probability of opening of HCs. The first assay follows the incorporation of a fluorescent dye, Yo-Pro, by real-time imaging, while the second is based on the quenching of a fluorescent protein, YFPQL, by iodide after iodide uptake. These assays were then used to screen a collection of 2242 approved drugs and compounds under development. This study led to the identification of 11 candidate hits blocking Cx43-HC, active in the two assays, with 5 drugs active on HC but not on gap junction (GJ) activities. To our knowledge, this is the first screening on HC activity and our results suggest the potential of a new use of already approved drugs in central nervous system disorders with HC impairments.
Collapse
Affiliation(s)
| | - Marjorie Comte
- University Grenoble Alpes, CEA, Inserm, IRIG, BGE, Grenoble, France
| | | | - Caroline Barette
- University Grenoble Alpes, CEA, Inserm, IRIG, BGE, Grenoble, France
| | | | - Magda Mortier
- University Grenoble Alpes, CEA, Inserm, IRIG, BGE, Grenoble, France
| | - Laurence Aubry
- University Grenoble Alpes, CEA, Inserm, IRIG, BGE, Grenoble, France
| | | | | | | |
Collapse
|
6
|
Picoli C, Soleilhac E, Journet A, Barette C, Comte M, Giaume C, Mouthon F, Fauvarque MO, Charvériat M. High-Content Screening Identifies New Inhibitors of Connexin 43 Gap Junctions. Assay Drug Dev Technol 2020; 17:240-248. [PMID: 31314551 DOI: 10.1089/adt.2019.927] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Gap junctions (GJs) are dynamic structures composed of hexamers of connexins (Cxs), a class of transmembrane proteins enabling channel-mediated direct intercellular communication through cell-cell diffusion of ions and small metabolites. In defined conditions, Cxs also work as hemichannels allowing exchanges between the cytoplasm and the extracellular medium. The most common GJ channel is formed by connexin 43 (Cx43) and plays an important role in physiological and pathological processes in excitable tissues, such as heart and brain. Hence, Cx43 has been largely envisioned as a new therapeutic target in cancer, neurological and psychiatric indications, or cardiovascular diseases. Identifying new pharmacological inhibitors of Cx43 GJs with different mechanisms of action and from diverse chemical classes is thus highly challenging. We present here a high-content screening method, based on the evaluation of fluorescent dye transfer rates between adjacent cells to monitor the function of GJs in U251 glioblastoma cells expressing high levels of Cx43. This assay was validated using well-described pharmacological GJ inhibitors such as mefloquine. The method was adapted to screen a library of 1,280 Food and Drug Administration- and European Medicines Agency-approved drugs that led to the selection of both known and new inhibitors of GJ channel function. We further focused on a specific class of microtubule-targeting agents, confirming that a proper tubulin network is required for functional Cx43 GJ channels.
Collapse
Affiliation(s)
| | - Emmanuelle Soleilhac
- 2Univ. Grenoble Alpes, CEA, Inserm, IRIG BGE-Genetics and Chemogenomics, Grenoble, France
| | - Agnès Journet
- 2Univ. Grenoble Alpes, CEA, Inserm, IRIG BGE-Genetics and Chemogenomics, Grenoble, France
| | - Caroline Barette
- 2Univ. Grenoble Alpes, CEA, Inserm, IRIG BGE-Genetics and Chemogenomics, Grenoble, France
| | - Marjorie Comte
- 2Univ. Grenoble Alpes, CEA, Inserm, IRIG BGE-Genetics and Chemogenomics, Grenoble, France
| | | | | | - Marie-Odile Fauvarque
- 2Univ. Grenoble Alpes, CEA, Inserm, IRIG BGE-Genetics and Chemogenomics, Grenoble, France
| | | |
Collapse
|
7
|
Zhong C, Chang H, Wu Y, Zhou L, Wang Y, Wang M, Wu P, Qi Z, Zou J. Up-regulated Cx43 phosphorylation at Ser368 prolongs QRS duration in myocarditis. J Cell Mol Med 2018; 22:3537-3547. [PMID: 29664174 PMCID: PMC6010859 DOI: 10.1111/jcmm.13631] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 03/14/2018] [Indexed: 01/26/2023] Open
Abstract
Prolongation of QRS duration in electrocardiogram is one of the risk factors for morbidity and mortality in many kinds of cardiac diseases. However, its molecular mechanism is unknown. In this study, utilizing experimental autoimmune myocarditis (EAM) as a disease model, we show that the prolongation of QRS duration is accompanied by elevated phosphorylation of connexin 43 (Cx43) at Ser368 (pS368Cx43). In cultured cells, inflammatory cytokine IL‐1β activates p38 MAPK to up‐regulate pS368Cx43 and impairs cell‐to‐cell communication. In isolated hearts of normal rats, perfusion of IL‐1β not only increases pS368Cx43 but also impairs cell‐to‐cell communication and prolongs QRS duration. Furthermore, blockade of p38 MAPK down‐regulates pS368Cx43, improves cell‐to‐cell communication and reduces QRS duration in EAM. These findings suggest that up‐regulation of pS368Cx43 by IL‐1β via p38 MAPK contributes to the prolongation of QRS duration and could be a therapeutic target for myocarditis‐induced prolongation of QRS duration.
Collapse
Affiliation(s)
- Chunlian Zhong
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - He Chang
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China.,Department of Cardiology, Affiliated Cardiovascular Hospital of Xiamen University, Xiamen, China
| | - Yang Wu
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China.,Department of Cardiology, Affiliated Cardiovascular Hospital of Xiamen University, Xiamen, China
| | - Li Zhou
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Yan Wang
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China.,Department of Cardiology, Affiliated Cardiovascular Hospital of Xiamen University, Xiamen, China
| | - Mingyan Wang
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Peng Wu
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Zhi Qi
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Jun Zou
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| |
Collapse
|
8
|
Lobastova L, Kraus D, Glassmann A, Khan D, Steinhäuser C, Wolff C, Veit N, Winter J, Probstmeier R. Collective cell migration of thyroid carcinoma cells: a beneficial ability to override unfavourable substrates. Cell Oncol (Dordr) 2016; 40:63-76. [PMID: 27826898 DOI: 10.1007/s13402-016-0305-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2016] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Tumor cell invasion and metastasis are life threatening events. Invasive tumor cells tend to migrate as collective sheets. In the present in vitro study we aimed to (i) assess whether collective tumor cells gain benefits in their migratory potential compared to single cells and (ii) to identify its putative underlying molecular mechanisms. METHODS The migratory potential of single and collective carcinoma cells was assessed using video time lapse microscopy and cell migration assays in the absence and presence of seven potential gap junction inhibitors or the Rac1 inhibitor Z62954982. The perturbation of gap junctions was assessed using a dye diffusion assay. In addition, LDH-based cytotoxicity and RT-PCR-based expression analyses were performed. RESULTS Whereas single breast, cervix and thyroid carcinoma cells were virtually immobile on unfavourable plastic surfaces, we found that they gained pronounced migratory capacities as collectives under comparable conditions. Thyroid carcinoma cells, that were studied in more detail, were found to express specific subsets of connexins and to form active gap junctions as revealed by dye diffusion analysis. Although all potential gap junction blockers suppressed intercellular dye diffusion in at least one of the cell lines tested, only two of them were found to inhibit collective cell migration and none of them to inhibit single cell migration. In the presence of the Rac1 inhibitor Z62954982 collective migration, but not single cell migration, was found to be reduced up to 20 %. CONCLUSIONS Our data indicate that collective migration enables tumor cells to cross otherwise unfavourable substrate areas. This capacity seems to be independent of intercellular communication via gap junctions, whereas Rac1-dependent intracellular signalling seems to be essential.
Collapse
Affiliation(s)
- Liudmila Lobastova
- Neuro- and Tumor Cell Biology Group, Department of Nuclear Medicine, University Hospital Bonn, Sigmund-Freud-Str. 25, D-53105, Bonn, Germany
| | - Dominik Kraus
- Department of Prosthodontics, Preclinical Education, and Material Science, University of Bonn, Bonn, Germany
| | | | - Dilaware Khan
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christina Wolff
- Neuro- and Tumor Cell Biology Group, Department of Nuclear Medicine, University Hospital Bonn, Sigmund-Freud-Str. 25, D-53105, Bonn, Germany
| | - Nadine Veit
- Neuro- and Tumor Cell Biology Group, Department of Nuclear Medicine, University Hospital Bonn, Sigmund-Freud-Str. 25, D-53105, Bonn, Germany
| | - Jochen Winter
- Oral Cell Biology Group, Department of Periodontology, Operative and Preventive Dentistry, University of Bonn, Bonn, Germany
| | - Rainer Probstmeier
- Neuro- and Tumor Cell Biology Group, Department of Nuclear Medicine, University Hospital Bonn, Sigmund-Freud-Str. 25, D-53105, Bonn, Germany.
| |
Collapse
|
9
|
Marsh A, Casey-Green K, Probert F, Withall D, Mitchell DA, Dilly SJ, James S, Dimitri W, Ladwa SR, Taylor PC, Singer DRJ. Simvastatin Sodium Salt and Fluvastatin Interact with Human Gap Junction Gamma-3 Protein. PLoS One 2016; 11:e0148266. [PMID: 26863535 PMCID: PMC4749215 DOI: 10.1371/journal.pone.0148266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 01/15/2016] [Indexed: 11/26/2022] Open
Abstract
Finding pleiomorphic targets for drugs allows new indications or warnings for treatment to be identified. As test of concept, we applied a new chemical genomics approach to uncover additional targets for the widely prescribed lipid-lowering pro-drug simvastatin. We used mRNA extracted from internal mammary artery from patients undergoing coronary artery surgery to prepare a viral cardiovascular protein library, using T7 bacteriophage. We then studied interactions of clones of the bacteriophage, each expressing a different cardiovascular polypeptide, with surface-bound simvastatin in 96-well plates. To maximise likelihood of identifying meaningful interactions between simvastatin and vascular peptides, we used a validated photo-immobilisation method to apply a series of different chemical linkers to bind simvastatin so as to present multiple orientations of its constituent components to potential targets. Three rounds of biopanning identified consistent interaction with the clone expressing part of the gene GJC3, which maps to Homo sapiens chromosome 7, and codes for gap junction gamma-3 protein, also known as connexin 30.2/31.3 (mouse connexin Cx29). Further analysis indicated the binding site to be for the N-terminal domain putatively 'regulating' connexin hemichannel and gap junction pores. Using immunohistochemistry we found connexin 30.2/31.3 to be present in samples of artery similar to those used to prepare the bacteriophage library. Surface plasmon resonance revealed that a 25 amino acid synthetic peptide representing the discovered N-terminus did not interact with simvastatin lactone, but did bind to the hydrolysed HMG CoA inhibitor, simvastatin acid. This interaction was also seen for fluvastatin. The gap junction blockers carbenoxolone and flufenamic acid also interacted with the same peptide providing insight into potential site of binding. These findings raise key questions about the functional significance of GJC3 transcripts in the vasculature and other tissues, and this connexin's role in therapeutic and adverse effects of statins in a range of disease states.
Collapse
Affiliation(s)
- Andrew Marsh
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | | | - Fay Probert
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - David Withall
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Daniel A. Mitchell
- Division of Metabolic and Vascular Health, Clinical Sciences Research Laboratories, Warwick Medical School, University of Warwick, Coventry, CV2 2DX, United Kingdom
| | - Suzanne J. Dilly
- Tangent Reprofiling Ltd, c/o SEEK, Central Point, 45 Beech Street, London, EC2Y 8AD, United Kingdom
| | - Sean James
- University Hospital Coventry and Warwickshire, Clifford Bridge Road, Coventry CV2 2DX, United Kingdom
| | - Wade Dimitri
- University Hospital Coventry and Warwickshire, Clifford Bridge Road, Coventry CV2 2DX, United Kingdom
| | - Sweta R. Ladwa
- Tangent Reprofiling Ltd, c/o SEEK, Central Point, 45 Beech Street, London, EC2Y 8AD, United Kingdom
| | - Paul C. Taylor
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Donald R. J. Singer
- University Hospital Coventry and Warwickshire, Clifford Bridge Road, Coventry CV2 2DX, United Kingdom
- Fellowship of Postgraduate Medicine, 11 Chandos St, London W1G 9EB, United Kingdom
- Division of Metabolic and Vascular Health, Clinical Sciences Research Laboratories, Warwick Medical School, University of Warwick, Coventry, CV2 2DX, United Kingdom
| |
Collapse
|