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Zeigler AC, Nelson AR, Chandrabhatla AS, Brazhkina O, Holmes JW, Saucerman JJ. Computational model predicts paracrine and intracellular drivers of fibroblast phenotype after myocardial infarction. Matrix Biol 2020; 91-92:136-151. [PMID: 32209358 PMCID: PMC7434705 DOI: 10.1016/j.matbio.2020.03.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 02/14/2020] [Accepted: 03/16/2020] [Indexed: 01/09/2023]
Abstract
The fibroblast is a key mediator of wound healing in the heart and other organs, yet how it integrates multiple time-dependent paracrine signals to control extracellular matrix synthesis has been difficult to study in vivo. Here, we extended a computational model to simulate the dynamics of fibroblast signaling and fibrosis after myocardial infarction (MI) in response to time-dependent data for nine paracrine stimuli. This computational model was validated against dynamic collagen expression and collagen area fraction data from post-infarction rat hearts. The model predicted that while many features of the fibroblast phenotype at inflammatory or maturation phases of healing could be recapitulated by single static paracrine stimuli (interleukin-1 and angiotensin-II, respectively), mimicking the reparative phase required paired stimuli (e.g. TGFβ and endothelin-1). Virtual overexpression screens simulated with either static cytokine pairs or post-MI paracrine dynamic predicted phase-specific regulators of collagen expression. Several regulators increased (Smad3) or decreased (Smad7, protein kinase G) collagen expression specifically in the reparative phase. NADPH oxidase (NOX) overexpression sustained collagen expression from reparative to maturation phases, driven by TGFβ and endothelin positive feedback loops. Interleukin-1 overexpression had mixed effects, both enhancing collagen via the TGFβ positive feedback loop and suppressing collagen via NFκB and BAMBI (BMP and activin membrane-bound inhibitor) incoherent feed-forward loops. These model-based predictions reveal network mechanisms by which the dynamics of paracrine stimuli and interacting signaling pathways drive the progression of fibroblast phenotypes and fibrosis after myocardial infarction.
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Affiliation(s)
- Angela C Zeigler
- Department of Biomedical Engineering, University of Virginia, PO Box 800759, Charlottesville, VA 22908-0759, USA
| | - Anders R Nelson
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA; Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, USA
| | - Anirudha S Chandrabhatla
- Department of Biomedical Engineering, University of Virginia, PO Box 800759, Charlottesville, VA 22908-0759, USA
| | - Olga Brazhkina
- Department of Biomedical Engineering, University of Virginia, PO Box 800759, Charlottesville, VA 22908-0759, USA; Coulter Department of Biomedical Engineering, Emory University, Atlanta, GA, USA
| | - Jeffrey W Holmes
- Department of Biomedical Engineering, University of Virginia, PO Box 800759, Charlottesville, VA 22908-0759, USA; Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, USA; Department of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Jeffrey J Saucerman
- Department of Biomedical Engineering, University of Virginia, PO Box 800759, Charlottesville, VA 22908-0759, USA; Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, USA.
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Sass PA, Dąbrowski M, Charzyńska A, Sachadyn P. Transcriptomic responses to wounding: meta-analysis of gene expression microarray data. BMC Genomics 2017; 18:850. [PMID: 29115927 PMCID: PMC5678747 DOI: 10.1186/s12864-017-4202-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 10/08/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND A vast amount of microarray data on transcriptomic response to injury has been collected so far. We designed the analysis in order to identify the genes displaying significant changes in expression after wounding in different organisms and tissues. This meta-analysis is the first study to compare gene expression profiles in response to wounding in as different tissues as heart, liver, skin, bones, and spinal cord, and species, including rat, mouse and human. RESULTS We collected available microarray transcriptomic profiles obtained from different tissue injury experiments and selected the genes showing a minimum twofold change in expression in response to wounding in prevailing number of experiments for each of five wound healing stages we distinguished: haemostasis & early inflammation, inflammation, early repair, late repair and remodelling. During the initial phases after wounding, haemostasis & early inflammation and inflammation, the transcriptomic responses showed little consistency between different tissues and experiments. For the later phases, wound repair and remodelling, we identified a number of genes displaying similar transcriptional responses in all examined tissues. As revealed by ontological analyses, activation of certain pathways was rather specific for selected phases of wound healing, such as e.g. responses to vitamin D pronounced during inflammation. Conversely, we observed induction of genes encoding inflammatory agents and extracellular matrix proteins in all wound healing phases. Further, we selected several genes differentially upregulated throughout different stages of wound response, including established factors of wound healing in addition to those previously unreported in this context such as PTPRC and AQP4. CONCLUSIONS We found that transcriptomic responses to wounding showed similar traits in a diverse selection of tissues including skin, muscles, internal organs and nervous system. Notably, we distinguished transcriptional induction of inflammatory genes not only in the initial response to wounding, but also later, during wound repair and tissue remodelling.
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Affiliation(s)
- Piotr Andrzej Sass
- Department Molecular Biotechnology and Microbiology, Gdańsk University of Technology, Gdańsk, Poland
| | - Michał Dąbrowski
- Laboratory of Bioinformatics, Neurobiology Center, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Agata Charzyńska
- Laboratory of Bioinformatics, Neurobiology Center, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Paweł Sachadyn
- Department Molecular Biotechnology and Microbiology, Gdańsk University of Technology, Gdańsk, Poland.
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3
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Boyko TV, Longaker MT, Yang GP. Laboratory Models for the Study of Normal and Pathologic Wound Healing. Plast Reconstr Surg 2017; 139:654-662. [PMID: 28234843 DOI: 10.1097/prs.0000000000003077] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Current knowledge of wound healing is based on studies using various in vitro and in vivo wound models. In vitro models allow for biological examination of specific cell types involved in wound healing. In vivo models generally provide the full spectrum of biological responses required for wound healing, including inflammation and angiogenesis, and provide cell-cell interactions not seen in vitro. In this review, the authors aim to delineate the most relevant wound healing models currently available and to discuss their strengths and limitations in their approximation of the human wound healing processes to aid scientists in choosing the most appropriate wound healing models for designing, testing, and validating their experiments.
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Affiliation(s)
- Tatiana V Boyko
- Stanford and Palo Alto, Calif.; and Buffalo, N.Y.,From the Hagey Laboratory for Pediatric Regenerative Medicine, the Department of Surgery, and the Institute of Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine; the Palo Alto VA Health Care System; and the Department of Surgery, University at Buffalo, State University of New York
| | - Michael T Longaker
- Stanford and Palo Alto, Calif.; and Buffalo, N.Y.,From the Hagey Laboratory for Pediatric Regenerative Medicine, the Department of Surgery, and the Institute of Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine; the Palo Alto VA Health Care System; and the Department of Surgery, University at Buffalo, State University of New York
| | - George P Yang
- Stanford and Palo Alto, Calif.; and Buffalo, N.Y.,From the Hagey Laboratory for Pediatric Regenerative Medicine, the Department of Surgery, and the Institute of Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine; the Palo Alto VA Health Care System; and the Department of Surgery, University at Buffalo, State University of New York
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4
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Sugiyama A, Okada M, Yamawaki H. Pathophysiological roles of canstatin on myofibroblasts after myocardial infarction in rats. Eur J Pharmacol 2017; 807:32-43. [PMID: 28438649 DOI: 10.1016/j.ejphar.2017.04.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 03/13/2017] [Accepted: 04/19/2017] [Indexed: 12/19/2022]
Abstract
Myofibroblasts play an important role during remodeling process after myocardial infarction through proliferation, migration, production and degradation of extracellular matrix (ECM) and contraction. Canstatin, a 24kDa polypeptide, is cleaved from α2 chain of type IV collagen, which is a major component of basement membrane around cardiomyocytes. We examined the effects of canstatin on myofibroblasts isolated from the areas of myocardial infarction. Myocardial infarction model was made by ligating left anterior descending artery of Wistar rats. Two weeks after the operation, the cells were isolated by an explant method and identified as myofibroblasts with immunofluorescence staining. Cell counting assay was performed to examine cell proliferation. Boyden chamber assay was performed to examine cell migration. Expression and phosphorylation of proteins were detected by Western blotting. Collagen gel contraction assay was performed to measure cell contractility. Canstatin stimulated proliferation, secretion of matrix metalloproteinases, expression of cyclooxygenase (COX)-2, and inhibited collagen gel contraction in myofibroblasts. Canstatin increased Akt phosphorylation. LY294002, a phosphoinositide-3-kinase/Akt inhibitor, inhibited the canstatin-induced proliferation. NS-398, a COX-2 inhibitor, suppressed the inhibitory effect of canstatin on collagen gel contraction. Canstatin expression in areas of myocardial infarction 2 weeks after surgery decreased. We for the first time demonstrate that canstatin is an endogenous bioactive molecule regulating the various functions of myofibroblasts after myocardial infarction. The decrease of canstatin expression in the maturated areas of myocardial infarction might lead to stabilization of scar tissues perhaps in part through the reduction of proliferation and ECM degradation as well as the stimulation of contractility in myofibroblasts.
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Affiliation(s)
- Akira Sugiyama
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Japan
| | - Muneyoshi Okada
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Japan.
| | - Hideyuki Yamawaki
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Japan
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5
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Re-Epithelialization of Pathological Cutaneous Wounds Is Improved by Local Mineralocorticoid Receptor Antagonism. J Invest Dermatol 2016; 136:2080-2089. [PMID: 27262545 DOI: 10.1016/j.jid.2016.05.101] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/02/2016] [Accepted: 05/11/2016] [Indexed: 11/24/2022]
Abstract
Impaired cutaneous wound healing is a social burden. It occurs as a consequence of glucocorticoid treatment in several pathologies. Glucocorticoids (GC) bind not only to the glucocorticoid receptor but also to the mineralocorticoid receptor (MR), both expressed by keratinocytes. In addition to its beneficial effects through the glucocorticoid receptor, GC exposure may lead to inappropriate MR occupancy. We hypothesized that dermatological use of MR antagonists (MRA) might be beneficial by overcoming the negative impact of GC treatment on pathological wounds. The potent GC clobetasol, applied as an ointment to mouse skin, or added to cultured human skin explants, induced delayed wound closure and outgrowth of epidermis with reduced proliferation of keratinocytes. Delayed wound re-epithelialization was rescued by local MRA application. Normal skin was unaffected by MRA. The benefit of MR blockade is explained by the increased expression of MR in clobetasol-treated mouse skin. Blockade of the epithelial sodium channel by phenamil also rescued cultured human skin explants from GC-impaired growth of the epidermis. MRA application over post-biopsy wounds of clobetasol-treated skin zones of healthy volunteers (from the Interest of Topical Spironolactone's Administration to Prevent Corticoid-induced Epidermal Atrophy clinical trial) also accelerated wound closure. In conclusion, we propose repositioning MRA for cutaneous application to improve delayed wound closure occurring in pathology.
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Abstract
Currently, the exact role of telocytes within fascial structures is unknown. The morphology, distribution and behaviour of fascial telocytes as well as the mutual relationship between telocytes and other cellular fascia constituents should be definitely a subject of further studies. It will contribute to better understanding of the role of the fascial system in health and diseases, may shed light on the regeneration potential of these tissues and may help to find targets for future treatments for locomotor disorders, including fascial diseases. Last but not least, confirmation of the presence of telocytes within fascia may contribute to optimise the use of fascia as a graft material.
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7
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Jaźwińska A, Sallin P. Regeneration versus scarring in vertebrate appendages and heart. J Pathol 2016; 238:233-46. [PMID: 26414617 PMCID: PMC5057359 DOI: 10.1002/path.4644] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/15/2015] [Accepted: 09/18/2015] [Indexed: 12/15/2022]
Abstract
Injuries to complex human organs, such as the limbs and the heart, result in pathological conditions, for which we often lack adequate treatments. While modern regenerative approaches are based on the transplantation of stem cell-derived cells, natural regeneration in lower vertebrates, such as zebrafish and newts, relies predominantly on the intrinsic plasticity of mature tissues. This property involves local activation of the remaining material at the site of injury to promote cell division, cell migration and complete reproduction of the missing structure. It remains an unresolved question why adult mammals are not equally competent to reactivate morphogenetic programmes. Although organ regeneration depends strongly on the proliferative properties of cells in the injured tissue, it is apparent that various organismic factors, such as innervation, vascularization, hormones, metabolism and the immune system, can affect this process. Here, we focus on a correlation between the regenerative capacity and cellular specialization in the context of functional demands, as illustrated by appendages and heart in diverse vertebrates. Elucidation of the differences between homologous regenerative and non-regenerative tissues from various animal models is essential for understanding the applicability of lessons learned from the study of regenerative biology to clinical strategies for the treatment of injured human organs.
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Affiliation(s)
- Anna Jaźwińska
- Department of Biology, University of Fribourg, Switzerland
| | - Pauline Sallin
- Department of Biology, University of Fribourg, Switzerland
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Mahoney VM, Mezzano V, Morley GE. A review of the literature on cardiac electrical activity between fibroblasts and myocytes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 120:128-33. [PMID: 26713556 DOI: 10.1016/j.pbiomolbio.2015.12.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/12/2015] [Accepted: 12/16/2015] [Indexed: 12/13/2022]
Abstract
Myocardial injuries often lead to fibrotic deposition. This review presents evidence supporting the concept that fibroblasts in the heart electrically couple to myocytes.
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Affiliation(s)
- Vanessa M Mahoney
- Leon H. Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Valeria Mezzano
- Leon H. Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Gregory E Morley
- Leon H. Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA.
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Foley TT, Ehrlich HP. Mast cells prevent dexamethasone-induced cell death of cultured fibroblasts: relationship to gap junctional intercellular communications. Plast Reconstr Surg 2014; 133:638e-644e. [PMID: 24776565 DOI: 10.1097/prs.0000000000000103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Dexamethasone, a common therapy for reducing hypertrophic scar, sometimes fails. However, in cell culture, all dexamethasone-treated fibroblasts die. In co-cultures, gap junction intercellular communications between mast cells and fibroblasts promote profibrotic activities. Does the co-culture of mast cells with fibroblasts prevent dexamethasone-induced fibroblast death? METHODS Survival of fibroblasts co-cultured with RMC-1 cells, a rat mast cell line, receiving dexamethasone was studied. RMC-1 cells pretreated with a secretagogue that degranulated mast cells and/or with a long-acting gap junction intercellular communications inhibitor were compared to untreated RMC-1 cells co-cultured with fibroblasts and dexamethasone. RESULTS Fibroblasts alone treated with dexamethasone all died in 3 hours. Fibroblasts co-cultured with intact RMC-1 cells or with degranulated RMC-1 cells in dexamethasone all survived. No fibroblasts survived, co-cultured with RMC-1 cells unable to form gap junction intercellular communications with fibroblasts. CONCLUSIONS Dexamethasone-treated fibroblasts, forming gap junction intercellular communications with mast cells, may explain why dexamethasone therapy sometimes fails. Gap junction intercellular communications between scar mast cells and fibroblasts or myofibroblasts apparently blocks the death of these cell populations. Preventing gap junction intercellular communications between mast cells and fibroblasts by including anti-gap junction intercellular communication agents may enhance the effectiveness of steroid therapy in treating excessive scarring.
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Affiliation(s)
- Theodore T Foley
- Harrisburg and Hershey, Pa. From Leber & Wolf Plastic Surgery Limited; and the Division of Plastic Surgery, Department of Surgery, The Pennsylvania State University, College of Medicine
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10
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Regulating inflammation using acid-responsive electrospun fibrous scaffolds for skin scarless healing. Mediators Inflamm 2014; 2014:858045. [PMID: 24795507 PMCID: PMC3984856 DOI: 10.1155/2014/858045] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 02/18/2014] [Accepted: 02/18/2014] [Indexed: 12/26/2022] Open
Abstract
Skin injury in adult mammals brings about a series of events and inflammation in the wounded area is initiated first and provides lots of inflammatory factors, which is critical for the final scar formation. While the postinjured skin of fetus and nude mice heals scarlessly owing to the absence of inflammation or immunodeficient, we designed a feasible acid-responsive ibuprofen-loaded poly(L-lactide) (PLLA) fibrous scaffolds via doping sodium bicarbonate to prevent excessive inflammation and achieve scarless healing finally. The morphological results of in vivo experiments revealed that animals treated with acid-responsive ibuprofen-loaded PLLA fibrous scaffolds exhibited alleviative inflammation, accelerated healing process, and regulated collagen deposition via interference in the collagen distribution, the α-smooth muscle actin (α-SMA), and the basic fibroblast growth factor (bFGF) expression. The lower ratios of collagen I/collagen III and TGF-β1/TGF-β3 and higher ratio of matrix metalloproteinase-1 (MMP-1)/tissue inhibitor of metalloproteinase-1 (TIMP-1) in acid-responsive ibuprofen-loaded PLLA fibrous scaffolds group were confirmed by real-time qPCR as well. These results suggest that inhibiting the excessive inflammation will result in regular collagen distribution and appropriate ratio between the factors, which promote or suppress the scar formation, then decrease the scar area, and finally achieve the scarless healing.
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11
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Grek CL, Rhett JM, Ghatnekar GS. Cardiac to cancer: connecting connexins to clinical opportunity. FEBS Lett 2014; 588:1349-64. [PMID: 24607540 DOI: 10.1016/j.febslet.2014.02.047] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 02/25/2014] [Accepted: 02/26/2014] [Indexed: 12/26/2022]
Abstract
Gap junctions and their connexin components are indispensable in mediating the cellular coordination required for tissue and organ homeostasis. The critical nature of their existence mandates a connection to disease while at the same time offering therapeutic potential. Therapeutic intervention may be offered through the pharmacological and molecular disruption of the pathways involved in connexin biosynthesis, gap junction assembly, stabilization, or degradation. Chemical inhibitors aimed at closing connexin channels, peptide mimetics corresponding to short connexin sequences, and gene therapy approaches have been incredibly useful molecular tools in deciphering the complexities associated with connexin biology. Recently, therapeutic potential in targeting connexins has evolved from basic research in cell-based models to clinical opportunity in the form of human trials. Clinical promise is particularly evident with regards to targeting connexin43 in the context of wound healing. The following review is aimed at highlighting novel advances where the pharmacological manipulation of connexin biology has proven beneficial in animals or humans.
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Affiliation(s)
- Christina L Grek
- FirstString Research, Inc., 300 W. Coleman Blvd., Suite 203, Mount Pleasant, SC, United States
| | - J Matthew Rhett
- Department of Surgery, Division of General Surgery, Medical University of South Carolina, Charleston, SC, United States
| | - Gautam S Ghatnekar
- FirstString Research, Inc., 300 W. Coleman Blvd., Suite 203, Mount Pleasant, SC, United States.
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12
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Rhett JM, Fann SA, Yost MJ. Purinergic signaling in early inflammatory events of the foreign body response: modulating extracellular ATP as an enabling technology for engineered implants and tissues. TISSUE ENGINEERING PART B-REVIEWS 2014; 20:392-402. [PMID: 24279914 DOI: 10.1089/ten.teb.2013.0554] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Purinergic signaling is a ubiquitous and vital aspect of mammalian biology in which purines--mainly adenosine triphosphate (ATP)--are released from cells through loss of membrane integrity (cell death), exocytosis, or transport/diffusion across membrane channels, and exert paracrine or autocrine signaling effects through three subclasses of well-characterized receptors: the P1 adenosine receptors, the P2X ionotropic nucleotide receptors, and the P2Y metabotropic receptors. ATP and its metabolites are released by damaged and stressed cells in injured tissues. The early events of wound healing, hemostasis, and inflammation are highly regulated by these signals through activation of purinergic receptors on platelets and neutrophils. Recent data have demonstrated that ATP signaling is of particular importance to targeting leukocytes to sites of injury. This is particularly relevant to the subject of implanted medical devices, engineered tissues, and grafts as all these technologies elicit a wound healing response with varying degrees of encapsulation, rejection, extrusion, or destruction of the tissue or device. Here, we review the biology of purinergic signaling and focus on ATP release and response mechanisms that pertain to the early inflammatory phase of wound healing. Finally, therapeutic options are explored, including a new class of peptidomimetic drugs based on the ATP-conductive channel connexin43.
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Affiliation(s)
- J Matthew Rhett
- Division of General Surgery, Department of Surgery, Medical University of South Carolina , Charleston, South Carolina
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13
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Christ GJ, Saul JM, Furth ME, Andersson KE. The pharmacology of regenerative medicine. Pharmacol Rev 2013; 65:1091-133. [PMID: 23818131 DOI: 10.1124/pr.112.007393] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Regenerative medicine is a rapidly evolving multidisciplinary, translational research enterprise whose explicit purpose is to advance technologies for the repair and replacement of damaged cells, tissues, and organs. Scientific progress in the field has been steady and expectations for its robust clinical application continue to rise. The major thesis of this review is that the pharmacological sciences will contribute critically to the accelerated translational progress and clinical utility of regenerative medicine technologies. In 2007, we coined the phrase "regenerative pharmacology" to describe the enormous possibilities that could occur at the interface between pharmacology, regenerative medicine, and tissue engineering. The operational definition of regenerative pharmacology is "the application of pharmacological sciences to accelerate, optimize, and characterize (either in vitro or in vivo) the development, maturation, and function of bioengineered and regenerating tissues." As such, regenerative pharmacology seeks to cure disease through restoration of tissue/organ function. This strategy is distinct from standard pharmacotherapy, which is often limited to the amelioration of symptoms. Our goal here is to get pharmacologists more involved in this field of research by exposing them to the tools, opportunities, challenges, and interdisciplinary expertise that will be required to ensure awareness and galvanize involvement. To this end, we illustrate ways in which the pharmacological sciences can drive future innovations in regenerative medicine and tissue engineering and thus help to revolutionize the discovery of curative therapeutics. Hopefully, the broad foundational knowledge provided herein will spark sustained conversations among experts in diverse fields of scientific research to the benefit of all.
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Affiliation(s)
- George J Christ
- Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA.
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Degen KE, Gourdie RG. Embryonic wound healing: a primer for engineering novel therapies for tissue repair. ACTA ACUST UNITED AC 2013; 96:258-70. [PMID: 23109321 DOI: 10.1002/bdrc.21019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Scar is the default tissue repair used by the body in response to most injuries-a response that occurs in wounds ranging in seriousness from minor skin cuts to complete severance of the spinal cord. By contrast, before the third trimester of pregnancy embryonic mammals tend to heal without scarring due to a variety of mechanisms and factors that are uniquely in operation during development in utero. The goal of tissue engineering is to develop safe and clinically effective biological substitutes that restore, maintain, or improve tissue function in patients. This review provides a comparative overview of wound healing during development and maturation and seeks to provide a perspective on just how much the embryo may be able teach us in the engineering of new therapies for tissue repair.
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Affiliation(s)
- Katherine E Degen
- School of Biomedical Engineering Science, Virginia Tech, Blacksburg, USA
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15
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Garbern JC, Mummery CL, Lee RT. Model systems for cardiovascular regenerative biology. Cold Spring Harb Perspect Med 2013; 3:a014019. [PMID: 23545574 DOI: 10.1101/cshperspect.a014019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
There is an urgent clinical need to develop new therapeutic approaches to treat heart failure, but the biology of cardiovascular regeneration is complex. Model systems are required to advance our understanding of biological mechanisms of cardiac regeneration as well as to test therapeutic approaches to regenerate tissue and restore cardiac function following injury. An ideal model system should be inexpensive, easily manipulated, easily reproducible, physiologically representative of human disease, and ethically sound. In this review, we discuss computational, cell-based, tissue, and animal models that have been used to elucidate mechanisms of cardiovascular regenerative biology or to test proposed therapeutic methods to restore cardiac function following disease or injury.
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Ongstad EL, O'Quinn MP, Ghatnekar GS, Yost MJ, Gourdie RG. A Connexin43 Mimetic Peptide Promotes Regenerative Healing and Improves Mechanical Properties in Skin and Heart. Adv Wound Care (New Rochelle) 2013; 2:55-62. [PMID: 24527326 DOI: 10.1089/wound.2011.0341] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Indexed: 01/26/2023] Open
Abstract
SIGNIFICANCE Evidence is building that the gap junction protein connexin43 (Cx43) is an important molecule in regenerative healing of skin and heart. Excess scarring from skin wound healing is a continuing clinical problem. Humans generally lack the ability to regenerate tissue following injury, and some degree of fibrotic repair occurs. In the skin, this results in unsightly scars with inferior mechanical properties. In the heart, scarring causes disruption in the contractility of cardiac muscle and increases the risk of deadly arrhythmia. Therapies that tip the balance of wound healing away from scar tissue and toward regeneration would thus represent a significant medical advance. RECENT ADVANCES A cell-permeant peptide, αCT1 (alpha connexin carboxyl-terminal peptide), based on the carboxyl-terminus of connexin43, has been shown to elicit changes in gap junction organization and intracellular communication. In the skin, αCT1 applied at acute time points results in decreased inflammatory response, reduced area of scar progenitor tissue, and restoration of more normal dermal structure and mechanical strength. αCT1 application to infarcted hearts improved cardiac contractility, reduced the propensity for arrhythmia, and increased conduction velocity through the injured heart. CRITICAL ISSUES Application of therapies like αCT1 could reduce cutaneous scarring and improve mechanical properties of healed skin and the contractile function and electrical stability of the heart following injury or surgery. FUTURE DIRECTIONS αCT1 is a potential therapy for cutaneous wounds that could lead to reduced scarring and improvements in the mechanical properties of healed skin. For injured myocardial tissues, this Cx43 mimetic peptide may also provide a therapeutic approach for targeting pathological fibrosis and reducing the likelihood of sudden death from cardiac arrhythmias.
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Affiliation(s)
- Emily L Ongstad
- Department of Bioengineering, Clemson University , Clemson, South Carolina
| | - Michael P O'Quinn
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina , Charleston, South Carolina
| | | | - Michael J Yost
- Department of Surgery, Medical University of South Carolina , Charleston, South Carolina
| | - Robert G Gourdie
- Department of Bioengineering, Clemson University , Clemson, South Carolina. ; Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina , Charleston, South Carolina
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Masuzaki R, Zhao SR, Csizmadia E, Yannas I, Karp SJ. Scar formation and lack of regeneration in adult and neonatal liver after stromal injury. Wound Repair Regen 2012; 21:122-30. [PMID: 23228176 DOI: 10.1111/j.1524-475x.2012.00868.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 09/25/2012] [Indexed: 11/28/2022]
Abstract
Known as a uniquely regenerative tissue, the liver shows a remarkable capacity to heal without scarring after many types of acute injury. In contrast, during chronic liver disease, the liver responds with fibrosis, which can progress to cirrhosis and ultimately liver failure. The cause of this shift from a nonfibrotic to a fibrotic response is unknown. We hypothesized that stromal injury is a key event that prevents restoration of normal liver architecture. To test this, we developed a model of stromal injury using a surgical incision through the normal liver in adult and neonatal mice. This injury produces minimal cell death but locally complete stromal (extracellular matrix) disruption. The adult liver responds with inflammation and stellate cell activation, culminating in fibrosis characterized by collagen deposition. This sequence of events is remarkably similar to the fibrotic response leading to cirrhosis. Studies in neonates reveal a similar fibrotic response to a stromal injury. These findings suggest that extracellular matrix disruption leads not to regeneration but rather to scar, similar to other mammalian organs. These findings may shed light on the pathogenesis of chronic liver disease, and suggest therapeutic strategies.
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Affiliation(s)
- Ryota Masuzaki
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232-4761, USA
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18
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Ontsuka K, Kotobuki Y, Shiraishi H, Serada S, Ohta S, Tanemura A, Yang L, Fujimoto M, Arima K, Suzuki S, Murota H, Toda S, Kudo A, Conway SJ, Narisawa Y, Katayama I, Izuhara K, Naka T. Periostin, a matricellular protein, accelerates cutaneous wound repair by activating dermal fibroblasts. Exp Dermatol 2012; 21:331-6. [PMID: 22509828 DOI: 10.1111/j.1600-0625.2012.01454.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cutaneous wound repair is a highly ordered and well-coordinated process involving various cell lineages and many molecular effectors. Cell-matrix interactions through integrin molecules provide key signals important for wound repair. Periostin is a matricellular protein that may provide signals important during tissue development and remodelling by interacting with several integrin molecules, via the phosphatidylinositol 3-kinase/Akt and MAP kinase pathways. In this study, we examined the role of periostin in the process of cutaneous wound repair using periostin-deficient mice and by analysing the effects of periostin on dermal fibroblasts. We first determined the expression profile and localization of periostin in a well-characterized wound repair model mice. Periostin was robustly deposited in the granulation tissues beneath the extended epidermal wound edges and at the dermal-epidermal junctions in wounded mice. Moreover, periostin-deficient mice exhibited delayed in vivo wound repair, which could be improved by direct administration of exogenous periostin. In vitro analyses revealed that loss of periostin impaired proliferation and migration of dermal fibroblasts, but exogenous supplementation or enforced periostin expression enhanced their proliferation. Combined, these results demonstrate that periostin accelerates the process of cutaneous wound repair by activating fibroblasts.
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Affiliation(s)
- Kanako Ontsuka
- Division of Medical Biochemistry, Department of Biomolecular Sciences, Saga Medical School, Saga, Japan
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19
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The role of cardiac fibroblasts in the transition from inflammation to fibrosis following myocardial infarction. Vascul Pharmacol 2012; 58:182-8. [PMID: 22885638 DOI: 10.1016/j.vph.2012.07.003] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 07/03/2012] [Accepted: 07/07/2012] [Indexed: 12/19/2022]
Abstract
Cardiac fibroblasts (CF) play a pivotal role in the repair and remodeling of the heart that occur following myocardial infarction (MI). The transition through the inflammatory, granulation and maturation phases of infarct healing is driven by cellular responses to local levels of cytokines, chemokines and growth factors that fluctuate in a temporal and spatial manner. In the acute inflammatory phase early after MI, CF contribute to the inflammatory milieu through increased secretion of proinflammatory cytokines and chemokines, and they promote extracellular matrix (ECM) degradation by increasing matrix metalloproteinase (MMP) expression and activity. In the granulation phase, CF migrate into the infarct zone, proliferate and produce MMPs and pro-angiogenic molecules to facilitate revascularization. Fibroblasts also undergo a phenotypic change to become myofibroblasts. In the maturation phase, inflammation is reduced by anti-inflammatory cytokines, and increased levels of profibrotic stimuli induce myofibroblasts to synthesize new ECM to form a scar. The scar is contracted through the mechanical force generated by myofibroblasts, preventing cardiac dilation. In this review we discuss the transition from myocardial inflammation to fibrosis with particular focus on how CF respond to alterations in proinflammatory and profibrotic signals. By furthering our understanding of these events, it is hoped that new therapeutic interventions will be developed that selectively reduce adverse myocardial remodeling post-MI, while sparing essential repair mechanisms.
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20
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Chablais F, Jazwinska A. The regenerative capacity of the zebrafish heart is dependent on TGFβ signaling. Development 2012; 139:1921-30. [PMID: 22513374 DOI: 10.1242/dev.078543] [Citation(s) in RCA: 191] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Mammals respond to a myocardial infarction by irreversible scar formation. By contrast, zebrafish are able to resolve the scar and to regenerate functional cardiac muscle. It is not known how opposing cellular responses of fibrosis and new myocardium formation are spatially and temporally coordinated during heart regeneration in zebrafish. Here, we report that the balance between the reparative and regenerative processes is achieved through Smad3-dependent TGFβ signaling. The type I receptor alk5b (tgfbr1b) is expressed in both fibrotic and cardiac cells of the injured heart. TGFβ ligands are locally induced following cryoinjury and activate the signaling pathway both in the infarct area and in cardiomyocytes in the vicinity of the trauma zone. Inhibition of the relevant type I receptors with the specific chemical inhibitor SB431542 qualitatively altered the infarct tissue and completely abolished heart regeneration. We show that transient scar formation is an essential step to maintain robustness of the damaged ventricular wall prior to cardiomyocyte replacement. Taking advantage of the reversible action of the inhibitor, we dissected the multifunctional role of TGFβ signaling into three crucial processes: collagen-rich scar deposition, Tenascin C-associated tissue remodeling at the infarct-myocardium interface, and cardiomyocyte proliferation. Thus, TGFβ signaling orchestrates the beneficial interplay between scar-based repair and cardiomyocyte-based regeneration to achieve complete heart regeneration.
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Affiliation(s)
- Fabian Chablais
- Unit of Anatomy, Department of Medicine, University of Fribourg, Rte A. Gockel 1, 1700 Fribourg, Switzerland
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21
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Cardiac telocytes - their junctions and functional implications. Cell Tissue Res 2012; 348:265-79. [PMID: 22350946 PMCID: PMC3349856 DOI: 10.1007/s00441-012-1333-8] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 01/10/2012] [Indexed: 12/11/2022]
Abstract
Telocytes (TCs) form a cardiac network of interstitial cells. Our previous studies have shown that TCs are involved in heterocellular contacts with cardiomyocytes and cardiac stem/progenitor cells. In addition, TCs frequently establish ‘stromal synapses’ with several types of immunoreactive cells in various organs (www.telocytes.com). Using electron microscopy (EM) and electron microscope tomography (ET), we further investigated the interstitial cell network of TCs and found that TCs form ‘atypical’ junctions with virtually all types of cells in the human heart. EM and ET showed different junction types connecting TCs in a network (puncta adhaerentia minima, processus adhaerentes and manubria adhaerentia). The connections between TCs and cardiomyocytes are ‘dot’ junctions with nanocontacts or asymmetric junctions. Junctions between stem cells and TCs are either ‘stromal synapses’ or adhaerens junctions. An unexpected finding was that TCs have direct cell–cell (nano)contacts with Schwann cells, endothelial cells and pericytes. Therefore, ultrastructural analysis proved that the cardiac TC network could integrate the overall ‘information’ from vascular system (endothelial cells and pericytes), nervous system (Schwann cells), immune system (macrophages, mast cells), interstitium (fibroblasts, extracellular matrix), stem cells/progenitors and working cardiomyocytes. Generally, heterocellular contacts occur by means of minute junctions (point contacts, nanocontacts and planar contacts) and the mean intermembrane distance is within the macromolecular interaction range (10–30 nm). In conclusion, TCs make a network in the myocardial interstitium, which is involved in the long-distance intercellular signaling coordination. This integrated interstitial system appears to be composed of large homotropic zones (TC–TC junctions) and limited (distinct) heterotropic zones (heterocellular junctions of TCs).
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22
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Effects of Diabetes on Matrix Protein Expression and Response to Cyclic Strain by Cardiac Fibroblasts. Cell Mol Bioeng 2012. [DOI: 10.1007/s12195-012-0222-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
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23
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Gourdie RG, Myers TA, McFadden A, Li YX, Potts JD. Self-organizing tissue-engineered constructs in collagen hydrogels. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2012; 18:99-106. [PMID: 22214557 PMCID: PMC5152913 DOI: 10.1017/s1431927611012372] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A novel self-organizing behavior of cellularized gels composed of collagen type 1 that may have utility for tissue engineering is described. Depending on the starting geometry of the tissue culture well, toroidal rings of cells or hollow spheroids were prompted to form autonomously when cells were seeded onto the top of gels and the gels released from attachment to the culture well 12 to 24 h after seeding. Cells within toroids assumed distinct patterns of alignment not seen in control gels in which cells had been mixed in. In control gels, cells formed complex three-dimensional arrangements and assumed relatively higher levels of heterogeneity in expression of the fibronectin splice variant ED-A--a marker of epithelial mesenchymal transformation. The tissue-like constructs resulting from this novel self-organizing behavior may have uses in wound healing and regenerative medicine, as well as building blocks for the iterative assembly of synthetic biological structures.
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Affiliation(s)
- Robert G. Gourdie
- Department of Regenerative Medicine and Cell Biology, Clemson-MUSC Bioengineering Program, MUSC, Charleston, SC 29425, USA
| | - Tereance A. Myers
- Department of Regenerative Medicine and Cell Biology, Clemson-MUSC Bioengineering Program, MUSC, Charleston, SC 29425, USA
| | - Alex McFadden
- Department of Cell Biology and Anatomy, Program in Bioengineering, University of South Carolina, School of Medicine, Columbia, SC 29209, USA
| | - Yin-xiong Li
- South China Institute of Stem Cell & Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Jay D. Potts
- Department of Cell Biology and Anatomy, Program in Bioengineering, University of South Carolina, School of Medicine, Columbia, SC 29209, USA
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Becker DL, Thrasivoulou C, Phillips ARJ. Connexins in wound healing; perspectives in diabetic patients. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:2068-75. [PMID: 22155211 DOI: 10.1016/j.bbamem.2011.11.017] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 11/07/2011] [Accepted: 11/18/2011] [Indexed: 11/19/2022]
Abstract
Skin lesions are common events and we have evolved to rapidly heal them in order to maintain homeostasis and prevent infection and sepsis. Most acute wounds heal without issue, but as we get older our bodies become compromised by poor blood circulation and conditions such as diabetes, leading to slower healing. This can result in stalled or hard-to-heal chronic wounds. Currently about 2% of the Western population develop a chronic wound and this figure will rise as the population ages and diabetes becomes more prevalent [1]. Patient morbidity and quality of life are profoundly altered by chronic wounds [2]. Unfortunately a significant proportion of these chronic wounds fail to respond to conventional treatment and can result in amputation of the lower limb. Life quality and expectancy following amputation is severely reduced. These hard to heal wounds also represent a growing economic burden on Western society with published estimates of costs to healthcare services in the region of $25B annually [3]. There exists a growing need for specific and effective therapeutic agents to improve healing in these wounds. In recent years the gap junction protein Cx43 has been shown to play a pivotal role early on in the acute wound healing process at a number of different levels [4-7]. Conversely, abnormal expression of Cx43 in wound edge keratinocytes was shown to underlie the poor rate of healing in diabetic rats, and targeting its expression with an antisense gel restored normal healing rates [8]. The presence of Cx43 in the wound edge keratinocytes of human chronic wounds has also been reported [9]. Abnormal Cx43 biology may underlie the poor healing of human chronic wounds and be amenable therapeutic intervention [7]. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Affiliation(s)
- David L Becker
- Department of Cell and Developmental Biology, University College, London, WC1E 6BT, UK.
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25
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Lafontant PJ, Burns AR, Grivas JA, Lesch MA, Lala TD, Reuter SP, Field LJ, Frounfelter TD. The giant danio (D. aequipinnatus) as a model of cardiac remodeling and regeneration. Anat Rec (Hoboken) 2011; 295:234-48. [PMID: 22095914 DOI: 10.1002/ar.21492] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Accepted: 08/24/2011] [Indexed: 12/22/2022]
Abstract
The paucity of mammalian adult cardiac myocytes (CM) proliferation following myocardial infarction (MI) and the remodeling of the necrotic tissue that ensues, result in non-regenerative repair. In contrast, zebrafish (ZF) can regenerate after an apical resection or cryoinjury of the heart. There is considerable interest in models where regeneration proceeds in the presence of necrotic tissue. We have developed and characterized a cautery injury model in the giant danio (GD), a species closely related to ZF, where necrotic tissue remains part of the ventricle, yet regeneration occurs. By light and transmission electron microscopy (TEM), we have documented four temporally overlapping processes: (1) a robust inflammatory response analogous to that observed in MI, (2) concomitant proliferation of epicardial cells leading to wound closure, (3) resorption of necrotic tissue and its replacement by granulation tissue, and (4) regeneration of the myocardial tissue driven by 5-EDU and [(3) H]thymidine incorporating CMs. In conclusion, our data suggest that the GD possesses robust repair mechanisms in the ventricle and can serve as an important model of cardiac inflammation, remodeling and regeneration.
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Zaruba MM, Zhu W, Soonpaa MH, Reuter S, Franz WM, Field LJ. Granulocyte colony-stimulating factor treatment plus dipeptidylpeptidase-IV inhibition augments myocardial regeneration in mice expressing cyclin D2 in adult cardiomyocytes. Eur Heart J 2011; 33:129-37. [PMID: 21849352 DOI: 10.1093/eurheartj/ehr302] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
AIMS Although pharmacological interventions that mobilize stem cells and enhance their homing to damaged tissue can limit adverse post-myocardial infarction (MI) remodelling, cardiomyocyte renewal with this approach is limited. While experimental cell cycle induction can promote cardiomyocyte renewal following MI, this process must compete with the more rapid processes of scar formation and adverse remodelling. The current study tested the hypothesis that the combination of enhanced stem cell mobilization/homing and cardiomyocyte cell cycle induction would result in increased myocardial renewal in injured hearts. METHODS AND RESULTS Myocardial infarction was induced by coronary artery ligation in adult MHC-cycD2 transgenic mice (which exhibit constitutive cardiomyocyte cell cycle activity) and their non-transgenic littermates. Mice were then treated with saline or with granulocyte colony-stimulating factor (G-CSF) plus the dipeptidylpeptidase-IV (DPP-IV) inhibitor Diprotin A (DipA) for 7 days. Infarct thickness and cardiomyocyte number/infarct/section were significantly improved in MHC-cycD2 mice with G-CSF plus DipA treatment when compared with MHC-cycD2 transgene expression or G-CSF plus DipA treatment alone. Echocardiographic analyses revealed that stem cell mobilization/homing and cardiomyocyte cell cycle activation had an additive effect on functional recovery. CONCLUSION These data strongly suggest that G-CSF plus DPP-IV inhibition, combined with cardiomyocyte cell cycle activation, leads to enhanced myocardial regeneration following MI. The data are also consistent with the notion that altering adverse post-injury remodelling renders the myocardium more permissive for cardiomyocyte repopulation.
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Affiliation(s)
- Marc-Michael Zaruba
- Medical Department I, Klinikum Grossh, Ludwig-Maximilians University, Marchioninistrasse 15, Munich 81377, Germany.
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27
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Palatinus JA, Rhett JM, Gourdie RG. The connexin43 carboxyl terminus and cardiac gap junction organization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:1831-43. [PMID: 21856279 DOI: 10.1016/j.bbamem.2011.08.006] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2011] [Revised: 07/25/2011] [Accepted: 08/03/2011] [Indexed: 12/09/2022]
Abstract
The precise spatial order of gap junctions at intercalated disks in adult ventricular myocardium is thought vital for maintaining cardiac synchrony. Breakdown or remodeling of this order is a hallmark of arrhythmic disease of the heart. The principal component of gap junction channels between ventricular cardiomyocytes is connexin43 (Cx43). Protein-protein interactions and modifications of the carboxyl-terminus of Cx43 are key determinants of gap junction function, size, distribution and organization during normal development and in disease processes. Here, we review data on the role of proteins interacting with the Cx43 carboxyl-terminus in the regulation of cardiac gap junction organization, with particular emphasis on Zonula Occludens-1. The rapid progress in this area suggests that in coming years we are likely to develop a fuller understanding of the molecular mechanisms causing pathologic remodeling of gap junctions. With these advances come the promise of novel approach to the treatment of arrhythmia and the prevention of sudden cardiac death. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Affiliation(s)
- Joseph A Palatinus
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA
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28
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Palatinus JA, Rhett JM, Gourdie RG. Enhanced PKCε mediated phosphorylation of connexin43 at serine 368 by a carboxyl-terminal mimetic peptide is dependent on injury. Channels (Austin) 2011; 5:236-40. [PMID: 21532342 DOI: 10.4161/chan.5.3.15834] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The gap junction (GJ) protein connexin (Cx43) is important for organized action potential propagation between mammalian cardiomyocytes. Disruption of the highly ordered distribution of Cx43 GJs is characteristic of cardiac tissue after ischemic injury. We recently demonstrated that epicardial administration of a peptide mimetic of the Cx43 carboxyl-terminus reduced pathologic remodeling of Cx43 GJs and protected against induced arrhythmias following ventricular injury. Treatment of injuries with the carboxyl-terminal peptide was associated with an increase in phosphorylation at serine 368 of the Cx43 carboxyl-terminus. Here, we report that Cx43 peptide treatment of uninjured hearts does not prompt a similar increase in phosphorylation. Moreover, we show that peptide treatment of undisturbed cultured HeLa cells expressing a Cx43 construct also exhibit no changes in Cx43 phosphorylation at serine 368. However, in parallel with the results in vivo, a trend of increasing phosphorylation at serine 368 was observed in Cx43-expressing HeLa cells following scratch wounding of cultured monolayers. These results suggest that peptide-enhanced phosphorylation of the Cx43 carboxyl-terminus is dependent on injury-mediated cellular responses.
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Affiliation(s)
- Joseph A Palatinus
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA
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29
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Jourdan-LeSaux C, Zhang J, Lindsey ML. Extracellular matrix roles during cardiac repair. Life Sci 2010; 87:391-400. [PMID: 20670633 PMCID: PMC2946433 DOI: 10.1016/j.lfs.2010.07.010] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 06/30/2010] [Accepted: 07/16/2010] [Indexed: 02/06/2023]
Abstract
The cardiac extracellular matrix (ECM) provides a platform for cells to maintain structure and function, which in turn maintains tissue function. In response to injury, the ECM undergoes remodeling that involves synthesis, incorporation, and degradation of matrix proteins, with the net outcome determined by the balance of these processes. The major goals of this review are a) to serve as an initial resource for students and investigators new to the cardiac ECM remodeling field, and b) to highlight a few of the key exciting avenues and methodologies that have recently been explored. While we focus on cardiac injury and responses of the left ventricle (LV), the mechanisms reviewed here have pathways in common with other wound healing models.
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Affiliation(s)
- Claude Jourdan-LeSaux
- Division of Cardiology, Department of Medicine, The University of Texas Health Science Center at San Antonio
| | - Jianhua Zhang
- Division of Cardiology, Department of Medicine, The University of Texas Health Science Center at San Antonio
| | - Merry L. Lindsey
- Division of Cardiology, Department of Medicine, The University of Texas Health Science Center at San Antonio
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30
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Hurley JR, Balaji S, Narmoneva DA. Complex temporal regulation of capillary morphogenesis by fibroblasts. Am J Physiol Cell Physiol 2010; 299:C444-53. [PMID: 20505042 DOI: 10.1152/ajpcell.00572.2009] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Interactions between endothelial and stromal cells are important for vascularization of regenerating tissue. Fibroblasts (FBs) are responsible for expression of angiogenic growth factors and matrix metalloproteinases, as well as collagen deposition and fibrotic myocardial remodeling. Recently, self-assembling peptide nanofibers were described as a promising environment for cardiac regeneration due to its synthetic nature and control over physiochemical properties. In this study, peptide nanofibers were used as a model system to quantify the dual role of fibroblasts in mediating angiogenesis chemically via expression of angiogenic factors and mechanically via cell-mediated scaffold disruption, extracellular matrix deposition, and remodeling. Human microvascular endothelial cells (ECs), FBs, or cocultures were cultured in three-dimensional nanofibers for up to 6 days. The peptide nanofiber microenvironment supported cell migration, capillary network formation, and cell survival in the absence of detectable scaffold contraction and proteolytic degradation. FBs enhanced early capillary network formation by "assisting" EC migration and increasing vascular endothelial growth factor and Angiopoietin-1 expression in a temporal manner. EC-FB interactions attenuated FB matrix metalloproteinase-2 expression while increasing collagen I deposition, resulting in greater construct stiffness and a more stable microenvironment in cocultures. Whereas FBs are critical for initial steps of angiogenesis in the absence of external angiogenic stimulation, coordinated efforts by ECs and FBs are required for a balance between cell-mediated scaffold disruption, extracellular matrix deposition, and remodeling at later time points. The findings of this study also emphasize the importance of developing a microenvironment that supports cell-cell interactions and cell migration, thus contributing toward an optimal environment for successful cardiac regeneration strategies.
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Affiliation(s)
- Jennifer R Hurley
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0048, USA
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Abstract
Cardiac fibroblasts are emerging as key components of normal cardiac function, as well as the response to stressors and injury. These most numerous cells of the heart interact with myocytes via paracrine mechanisms, alterations in extracellular matrix homeostasis, and direct cell-cell interactions. It is possible that they are a contributor to the inability of adult myocytes to proliferate and may influence cardiac progenitor biology. Furthering our understanding of how cardiac fibroblasts and myocytes interact may provide an avenue to novel treatments for heart failure prevention. This review discusses the most recent concepts in cardiac fibroblast-myocyte communication and areas of potential future research.
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Affiliation(s)
- Rahul Kakkar
- Cardiology Division, Massachusetts General Hospital, Department of Medicine, Harvard Medical School, Boston, MA, USA
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32
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Lindsey ML, Borg TK. Understanding the role of the extracellular matrix in cardiovascular development and disease: where do we go from here? J Mol Cell Cardiol 2009; 48:431-2. [PMID: 19781548 DOI: 10.1016/j.yjmcc.2009.09.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2009] [Accepted: 09/15/2009] [Indexed: 12/31/2022]
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