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Wu X, Qian L, Zhao H, Lei W, Liu Y, Xu X, Li J, Yang Z, Wang D, Zhang Y, Zhang Y, Tang R, Yang Y, Tian Y. CXCL12/CXCR4: An amazing challenge and opportunity in the fight against fibrosis. Ageing Res Rev 2023; 83:101809. [PMID: 36442720 DOI: 10.1016/j.arr.2022.101809] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/24/2022] [Accepted: 11/24/2022] [Indexed: 11/26/2022]
Abstract
Fibrosis is a pathological process caused by abnormal wound healing response, which often leads to excessive deposition of extracellular matrix, distortion of organ architecture, and loss of organ function. Aging is an important risk factor for the development of organ fibrosis. C-X-C receptor 4 (CXCR4) is the predominant chemokine receptor on fibrocytes, C-X-C motif ligand 12 (CXCL12) is the only ligand of CXCR4. Accumulated evidence have confirmed that CXCL12/CXCR4 can be involved in multiple pathological mechanisms in fibrosis, such as inflammation, immunity, epithelial-mesenchymal transition, and angiogenesis. In addition, CXCL12/CXCR4 have also been shown to improve fibrosis levels in many organs including the heart, liver, lung and kidney; thus, they are promising targets for anti-fibrotic therapy. Notably, inhibitors of CXCL12 or CXCR4 also play an important role in various fibrosis-related diseases. In summary, this review systematically summarizes the role of CXCL12/CXCR4 in fibrosis, and this information is of great significance for understanding CXCL12/CXCR4. This will also contribute to the design of further studies related to CXCL12/CXCR4 and fibrosis, and shed light on potential therapies for fibrosis.
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Affiliation(s)
- Xue Wu
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Lu Qian
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Huadong Zhao
- Department of General Surgery, Tangdu Hospital, The Airforce Medical University, Xi'an, China
| | - Wangrui Lei
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Yanqing Liu
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Xiaoling Xu
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Jiawen Li
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Zhi Yang
- Department of General Surgery, Tangdu Hospital, The Airforce Medical University, Xi'an, China
| | - Du Wang
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Yuchen Zhang
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Yan Zhang
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Ran Tang
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China
| | - Yang Yang
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China.
| | - Ye Tian
- Deparment of Neurology, Xi'an No.3 Hospital, Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education. Faculty of Life Sciences and Medicine, Northwest University, Xi'an, China.
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Mu R, Campos de Souza S, Liao Z, Dong L, Wang C. Reprograming the immune niche for skin tissue regeneration - From cellular mechanisms to biomaterials applications. Adv Drug Deliv Rev 2022; 185:114298. [PMID: 35439569 DOI: 10.1016/j.addr.2022.114298] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 04/07/2022] [Accepted: 04/12/2022] [Indexed: 02/07/2023]
Abstract
Despite the rapid development of therapeutic approaches for skin repair, chronic wounds such as diabetic foot ulcers remain an unaddressed problem that affects millions of people worldwide. Increasing evidence has revealed the crucial and diverse roles of the immune cells in the development and repair of the skin tissue, prompting new research to focus on further understanding and modulating the local immune niche for comprehensive, 'perfect' regeneration. In this review, we first introduce how different immunocytes and certain stromal cells involved in innate and adaptive immunity coordinate to maintain the immune niche and tissue homeostasis, with emphasis on their specific roles in normal and pathological wound healing. We then discuss novel engineering approaches - particularly biomaterials systems and cellular therapies - to target different players of the immune niche, with three major aims to i) overcome 'under-healing', ii) avoid 'over-healing', and iii) promote functional restoration, including appendage development. Finally, we highlight how these strategies strive to manage chronic wounds and achieve full structural and functional skin recovery by creating desirable 'soil' through modulating the immune microenvironment.
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3
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A Beginner's Introduction to Skin Stem Cells and Wound Healing. Int J Mol Sci 2021; 22:ijms222011030. [PMID: 34681688 PMCID: PMC8538579 DOI: 10.3390/ijms222011030] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/06/2021] [Accepted: 10/11/2021] [Indexed: 02/06/2023] Open
Abstract
The primary function of the skin is that of a physical barrier against the environment and diverse pathogens; therefore, its integrity is essential for survival. Skin regeneration depends on multiple stem cell compartments within the epidermis, which, despite their different transcriptional and proliferative capacity, as well as different anatomical location, fall under the general term of skin stem cells (SSCs). Skin wounds can normally heal without problem; however, some diseases or extensive damage may delay or prevent healing. Non-healing wounds represent a serious and life-threatening scenario that may require advanced therapeutic strategies. In this regard, increased focus has been directed at SSCs and their role in wound healing, although emerging therapeutical approaches are considering the use of other stem cells instead, such as mesenchymal stem cells (MSCs). Given its extensive and broad nature, this review supplies newcomers with an introduction to SSCs, wound healing, and therapeutic strategies for skin regeneration, thus familiarizing the reader with the subject in preparation for future in depth reading.
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Shi J, Shi S, Xie W, Zhao M, Li Y, Zhang J, Li N, Bai X, Cai W, Hu X, Hu D, Han J, Guan H. IL-10 alleviates lipopolysaccharide-induced skin scarring via IL-10R/STAT3 axis regulating TLR4/NF-κB pathway in dermal fibroblasts. J Cell Mol Med 2021; 25:1554-1567. [PMID: 33410606 PMCID: PMC7875929 DOI: 10.1111/jcmm.16250] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/09/2020] [Accepted: 12/16/2020] [Indexed: 11/28/2022] Open
Abstract
Hypertrophic scar (HS) is a severe fibrotic skin disease. It has always been a major problem in clinical treatment, mainly because its pathogenesis has not been well understood. The roles of bacterial contamination and prolonged wound inflammation were considered significant. IL‐10 is a potent anti‐inflammatory cytokine and plays a pivotal role in wound healing and scar formation. Here, we investigate whether IL‐10 alleviates lipopolysaccharide (LPS)‐induced inflammatory response and skin scarring and explore the possible mechanism of scar formation. Our results showed that the expression of TLR4 and pp65 was higher in HS and HS‐derived fibroblasts (HSFs) than their counterpart normal skin (NS) and NS‐derived fibroblasts (NSFs). LPS could up‐regulate the expression of TLR4, pp65, Col I, Col III and α‐SMA in NSFs, but IL‐10 could down‐regulate their expression in both HSFs and LPS‐induced NSFs. Blocking IL‐10 receptor (IL‐10R) or the phosphorylation of STAT3, their expression was up‐regulated. In addition, in vitro and in vivo models results showed that IL‐10 could alleviate LPS‐induced fibroblast‐populated collagen lattice (FPCL) contraction and scar formation. Therefore, IL‐10 alleviates LPS‐induced skin scarring via IL‐10R/STAT3 axis regulating TLR4/NF‐κB pathway in dermal fibroblasts by reducing ECM proteins deposition and the conversion of fibroblasts to myofibroblasts. Our results indicate that IL‐10 can alleviate the LPS‐induced harmful effect on wound healing, reduce scar contracture, scar formation and skin fibrosis. Therefore, the down‐regulation of inflammation may lead to a suitable scar outcome and be a better option for improving scar quality.
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Affiliation(s)
- Jihong Shi
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Shan Shi
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Wenbo Xie
- Queen Mary School, Nanchang University, Nanchang, China
| | - Ming Zhao
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Yan Li
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Jian Zhang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Na Li
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Xiaozhi Bai
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Weixia Cai
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Xiaolong Hu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Dahai Hu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Juntao Han
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Hao Guan
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
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Karim AS, Liu A, Lin C, Uselmann AJ, Eliceiri KW, Brown ME, Gibson ALF. Evolution of ischemia and neovascularization in a murine model of full thickness human wound healing. Wound Repair Regen 2020; 28:812-822. [PMID: 32686215 PMCID: PMC8592059 DOI: 10.1111/wrr.12847] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/16/2020] [Accepted: 06/28/2020] [Indexed: 11/30/2022]
Abstract
Translation of wound healing research is limited by the lack of an appropriate animal model, due to the anatomic and wound healing differences in animals and humans. Here, we characterize healing of grafted, full-thickness human skin in an in vivo model of wound healing. Full-thickness human skin, obtained from reconstructive operations, was grafted onto the dorsal flank of NOD.Cg-KitW41J Tyr + Prkdcscid Il2rgtm1Wjl /ThomJ mice. The xenografts were harvested 1 to 12 weeks after grafting, and histologic analyses were completed for viability, neovascularization, and hypoxia. Visual inspection of the xenograft shows drying and sloughing of the epidermis starting at week four. By week 12, the xenograft appears healed but has lost 63.05 ± 0.24% of the initial graft size. There is histologic evidence of epidermolysis as early as 2 weeks, which progresses until week 4, when new epidermis appears from the wound edges. Epidermal regeneration is complete by week 12, although the epidermis appears hypertrophied. An initial increase of infiltrating immune mouse cells into the xenograft normalizes to baseline 6 months after grafting. Neovascularization, as evidenced by positive staining for the proteins human CD31 and alpha smooth muscle actin, is present as early as 2 weeks after grafting at the interface between the xenograft and the mouse tissue. CD31 and alpha smooth muscle actin staining increased throughout the xenograft over the 12 weeks, leading to greater viability of the tissue. Likewise, there is increased Hypoxia Inducible Factor 1-alpha expression at the interface of viable and nonviable tissue, which suggest a hypoxia-driven process causing early graft loss. These findings illustrate human skin wound healing in an ischemic environment, providing a timeline for use of full thickness human skin after grafting in a murine model to study mechanisms underlying human skin wound healing.
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Affiliation(s)
- Aos S. Karim
- Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Aiping Liu
- Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Christie Lin
- OnLume Inc., Madison, Wisconsin
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin
| | - Adam J. Uselmann
- OnLume Inc., Madison, Wisconsin
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin
| | - Kevin W. Eliceiri
- OnLume Inc., Madison, Wisconsin
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin
| | - Matthew E. Brown
- Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Angela L. F. Gibson
- Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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6
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Cheikhi AM, Johnson ZI, Julian DR, Wheeler S, Feghali-Bostwick C, Conley YP, Lyons-Weiler J, Yates CC. Prediction of severity and subtype of fibrosing disease using model informed by inflammation and extracellular matrix gene index. PLoS One 2020; 15:e0240986. [PMID: 33095822 PMCID: PMC7584227 DOI: 10.1371/journal.pone.0240986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 10/06/2020] [Indexed: 11/19/2022] Open
Abstract
Fibrosis is a chronic disease with heterogeneous clinical presentation, rate of progression, and occurrence of comorbidities. Systemic sclerosis (scleroderma, SSc) is a rare rheumatic autoimmune disease that encompasses several aspects of fibrosis, including highly variable fibrotic manifestation and rate of progression. The development of effective treatments is limited by these variabilities. The fibrotic response is characterized by both chronic inflammation and extracellular remodeling. Therefore, there is a need for improved understanding of which inflammation-related genes contribute to the ongoing turnover of extracellular matrix that accompanies disease. We have developed a multi-tiered method using Naïve Bayes modeling that is capable of predicting level of disease and clinical assessment of patients based on expression of a curated 60-gene panel that profiles inflammation and extracellular matrix production in the fibrotic disease state. Our novel modeling design, incorporating global and parametric-based methods, was highly accurate in distinguishing between severity groups, highlighting the importance of these genes in disease. We refined this gene set to a 12-gene index that can accurately identify SSc patient disease state subsets and informs knowledge of the central regulatory pathways in disease progression.
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Affiliation(s)
- Amin M. Cheikhi
- McGowan Institute for Regenerative Medicine, Pittsburgh, PA, United States of America
| | - Zariel I. Johnson
- McGowan Institute for Regenerative Medicine, Pittsburgh, PA, United States of America
| | - Dana R. Julian
- McGowan Institute for Regenerative Medicine, Pittsburgh, PA, United States of America
- Department of Health Promotion and Development, University of Pittsburgh School of Nursing, Pittsburgh, PA, United States of America
| | - Sarah Wheeler
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
| | - Carol Feghali-Bostwick
- Department of Rheumatology & Immunology, Medical University of South Carolina, Charleston, SC, United States of America
| | - Yvette P. Conley
- McGowan Institute for Regenerative Medicine, Pittsburgh, PA, United States of America
| | - James Lyons-Weiler
- Genomic and Proteomic Core Laboratories, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Cecelia C. Yates
- McGowan Institute for Regenerative Medicine, Pittsburgh, PA, United States of America
- Department of Health Promotion and Development, University of Pittsburgh School of Nursing, Pittsburgh, PA, United States of America
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
- * E-mail:
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7
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Cui HS, Joo SY, Cho YS, Kim JB, Seo CH. CPEB1 or CPEB4 knockdown suppresses the TAK1 and Smad signalings in THP-1 macrophage-like cells and dermal fibroblasts. Arch Biochem Biophys 2020; 683:108322. [DOI: 10.1016/j.abb.2020.108322] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 02/21/2020] [Accepted: 02/22/2020] [Indexed: 01/03/2023]
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8
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Karim AS, Shaum K, Gibson AL. Indeterminate-Depth Burn Injury—Exploring the Uncertainty. J Surg Res 2020; 245:183-197. [DOI: 10.1016/j.jss.2019.07.063] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/31/2019] [Accepted: 07/19/2019] [Indexed: 01/08/2023]
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9
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Schreurs M, Suttorp CM, Mutsaers HAM, Kuijpers-Jagtman AM, Von den Hoff JW, Ongkosuwito EM, Carvajal Monroy PL, Wagener FADTG. Tissue engineering strategies combining molecular targets against inflammation and fibrosis, and umbilical cord blood stem cells to improve hampered muscle and skin regeneration following cleft repair. Med Res Rev 2019; 40:9-26. [PMID: 31104334 PMCID: PMC6972684 DOI: 10.1002/med.21594] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/17/2019] [Accepted: 04/19/2019] [Indexed: 12/18/2022]
Abstract
Cleft lip with or without cleft palate is a congenital deformity that occurs in about 1 of 700 newborns, affecting the dentition, bone, skin, muscles and mucosa in the orofacial region. A cleft can give rise to problems with maxillofacial growth, dental development, speech, and eating, and can also cause hearing impairment. Surgical repair of the lip may lead to impaired regeneration of muscle and skin, fibrosis, and scar formation. This may result in hampered facial growth and dental development affecting oral function and lip and nose esthetics. Therefore, secondary surgery to correct the scar is often indicated. We will discuss the molecular and cellular pathways involved in facial and lip myogenesis, muscle anatomy in the normal and cleft lip, and complications following surgery. The aim of this review is to outline a novel molecular and cellular strategy to improve musculature and skin regeneration and to reduce scar formation following cleft repair. Orofacial clefting can be diagnosed in the fetus through prenatal ultrasound screening and allows planning for the harvesting of umbilical cord blood stem cells upon birth. Tissue engineering techniques using these cord blood stem cells and molecular targeting of inflammation and fibrosis during surgery may promote tissue regeneration. We expect that this novel strategy improves both muscle and skin regeneration, resulting in better function and esthetics after cleft repair.
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Affiliation(s)
- Michaël Schreurs
- Department of Dentistry, Section of Orthodontics and Craniofacial Biology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - C Maarten Suttorp
- Department of Dentistry, Section of Orthodontics and Craniofacial Biology, Radboud University Medical Centre, Nijmegen, The Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | | | - Johannes W Von den Hoff
- Department of Dentistry, Section of Orthodontics and Craniofacial Biology, Radboud University Medical Centre, Nijmegen, The Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Edwin M Ongkosuwito
- Department of Dentistry, Section of Orthodontics and Craniofacial Biology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Paola L Carvajal Monroy
- Department of Oral & Maxillofacial Surgery, Special Dental Care and Orthodontics, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Frank A D T G Wagener
- Department of Dentistry, Section of Orthodontics and Craniofacial Biology, Radboud University Medical Centre, Nijmegen, The Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
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10
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Su Y, Nishimoto T, Hoffman S, Nguyen XX, Pilewski JM, Feghali-Bostwick C. Insulin-like growth factor binding protein-4 exerts antifibrotic activity by reducing levels of connective tissue growth factor and the C-X-C chemokine receptor 4. FASEB Bioadv 2018; 1:167-179. [PMID: 31482149 PMCID: PMC6720120 DOI: 10.1096/fba.2018-00015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The Insulin-like growth factor (IGF) system plays an important role in variety cellular biological functions; we previously reported levels of IGF binding proteins (IGFBP) -3 and -5 are increased in dermal and pulmonary fibrosis associated with the prototypic fibrosing disease systemic sclerosis (SSc), induce extracellular matrix (ECM) production, and promote fibrosis. We sought to examine the effects of another member of the family, IGFBP-4, on ECM production and fibrosis using cell-based, ex vivo organ culture and in vivo mouse lung fibrosis models. IGFBP-4 mRNA levels were significantly decreased in pulmonary fibroblasts of patients with SSc. ECM components were significantly reduced by endogenous and exogenous IGFBP-4. IGFBP-4 also blocked TGFβ-induced ECM production, and inhibited ECM production ex vivo in human lung and skin in organ culture. In vivo, IGFBP-4 reduced bleomycin-induced collagen production and histologic evidence of fibrosis. Silencing IGFBP-4 expression to mimic levels observed in SSc lung fibroblasts resulted in increased ECM production. IGFBP-4 reduced mRNA and protein levels of the chemokine receptor CXCR4 and the pro-fibrotic factor CTGF. Further, CTGF silencing potentiated the anti-fibrotic effects of IGFBP-4. Reduced IGFBP-4 levels in SSc lung fibroblasts may contribute to the fibrotic phenotype via loss of IGFBP-4 anti-fibrotic activity.
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Affiliation(s)
- YunYun Su
- Division of Rheumatology & Clinical Immunology, Department of Medicine, Medical University of South Carolina, Charleston, SC, U.S.A
| | - Tetsuya Nishimoto
- Deceased, Allergy, and Critical Care, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, U.S.A
| | - Stanley Hoffman
- Division of Rheumatology & Clinical Immunology, Department of Medicine, Medical University of South Carolina, Charleston, SC, U.S.A
| | - Xinh-Xinh Nguyen
- Division of Rheumatology & Clinical Immunology, Department of Medicine, Medical University of South Carolina, Charleston, SC, U.S.A
| | - Joseph M Pilewski
- Division of Pulmonary, Allergy, and Critical Care, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, U.S.A
| | - Carol Feghali-Bostwick
- Division of Rheumatology & Clinical Immunology, Department of Medicine, Medical University of South Carolina, Charleston, SC, U.S.A
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11
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Nishiguchi MA, Spencer CA, Leung DH, Leung TH. Aging Suppresses Skin-Derived Circulating SDF1 to Promote Full-Thickness Tissue Regeneration. Cell Rep 2018; 24:3383-3392.e5. [PMID: 30257200 PMCID: PMC6261459 DOI: 10.1016/j.celrep.2018.08.054] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 07/10/2018] [Accepted: 08/17/2018] [Indexed: 02/08/2023] Open
Abstract
Physicians have observed that surgical wounds in the elderly heal with thinner scars than wounds in young patients. Understanding this phenomenon may reveal strategies for promoting scarless wound repair. We show that full-thickness skin wounds in aged but not young mice fully regenerate. Exposure of aged animals to blood from young mice by parabiosis counteracts this regenerative capacity. The secreted factor, stromal-derived factor 1 (SDF1), is expressed at higher levels in wounded skin of young mice. Genetic deletion of SDF1 in young skin enhanced tissue regeneration. In aged mice, enhancer of zeste homolog 2 (EZH2) and histone H3 lysine 27 trimethylation are recruited to the SDF1 promoter at higher levels, and pharmacologic inhibition of EZH2 restores SDF1 induction and prevents tissue regeneration. Similar age-dependent EZH2-mediated SDF1 suppression occurs in human skin. Our findings counter the current dogma that tissue function invariably declines with age and suggest new therapeutic strategies in regenerative medicine.
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Affiliation(s)
- Mailyn A Nishiguchi
- Department of Dermatology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Casey A Spencer
- Department of Dermatology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Denis H Leung
- School of Economics, Singapore Management University, Singapore 188065, Singapore
| | - Thomas H Leung
- Department of Dermatology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA; Corporal Michael Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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12
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Xue M, Zhao R, Lin H, Jackson C. Delivery systems of current biologicals for the treatment of chronic cutaneous wounds and severe burns. Adv Drug Deliv Rev 2018; 129:219-241. [PMID: 29567398 DOI: 10.1016/j.addr.2018.03.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 02/08/2018] [Accepted: 03/13/2018] [Indexed: 12/15/2022]
Abstract
While wound therapy remains a clinical challenge in current medical practice, much effort has focused on developing biological therapeutic approaches. This paper presents a comprehensive review of delivery systems for current biologicals for the treatment of chronic wounds and severe burns. The biologicals discussed here include proteins such as growth factors and gene modifying molecules, which may be delivered to wounds free, encapsulated, or released from living systems (cells, skin grafts or skin equivalents) or biomaterials. Advances in biomaterial science and technologies have enabled the synthesis of delivery systems such as scaffolds, hydrogels and nanoparticles, designed to not only allow spatially and temporally controlled release of biologicals, but to also emulate the natural extracellular matrix microenvironment. These technologies represent an attractive field for regenerative wound therapy, by offering more personalised and effective treatments.
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13
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Abstract
LEARNING OBJECTIVES After studying this article, the participant should be able to: 1. Explain the epidemiology of severe burn injury in the context of socioeconomic status, gender, age, and burn cause. 2. Describe challenges with burn depth evaluation and novel methods of adjunctive assessment. 3. Summarize the survival and functional outcomes of severe burn injury. 4. State strategies of fluid resuscitation, endpoints to guide fluid titration, and sequelae of overresuscitation. 5. Recognize preventative measures of sepsis. 6. Explain intraoperative strategies to improve patient outcomes, including hemostasis, restrictive transfusion, temperature regulation, skin substitutes, and Meek skin grafting. 7. Translate updates in the pathophysiology of hypertrophic scarring into novel methods of clinical management. 8. Discuss the potential role of free tissue transfer in primary and secondary burn reconstruction. SUMMARY Management of burn-injured patients is a challenging and unique field for plastic surgeons. Significant advances over the past decade have occurred in resuscitation, burn wound management, sepsis, and reconstruction that have improved outcomes and quality of life after thermal injury. However, as patients with larger burns are resuscitated, an increased risk of nosocomial infections, sepsis, compartment syndromes, and venous thromboembolic phenomena have required adjustments in care to maintain quality of life after injury. This article outlines a number of recent developments in burn care that illustrate the evolution of the field to assist plastic surgeons involved in burn care.
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14
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Abstract
Hypertrophic scar (HTS) is a common outcome of deep dermal wound healing mainly followed mechanical, chemical, and thermal injuries in the skin. Because of the lack of the most effective prevention and treatment, it is particularly important to establish an ideal dermal animal model for improving the understanding of the pathogenesis and exploring therapeutic approaches of HTS. Compared to other dermal fibrotic animal models in rabbits, red Duroc pigs, guinea pigs, rats, and mice, the approach that uses normal human split-thickness skin grafted onto nude or other immunodeficient mice which develop scars that resemble human HTS offers the advantages of lower cost, easier manipulation, and shorter research period. In this chapter, we will introduce the detailed procedures to create the ideal dermal fibrotic mouse model.
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15
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Zhu Z, Ding J, Ma Z, Iwashina T, Tredget EE. Systemic depletion of macrophages in the subacute phase of wound healing reduces hypertrophic scar formation. Wound Repair Regen 2016; 24:644-56. [PMID: 27169512 DOI: 10.1111/wrr.12442] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 05/07/2016] [Indexed: 02/05/2023]
Abstract
Hypertrophic scars are caused by trauma or burn injuries to the deep dermis and can cause cosmetic disfigurement and psychological issues. Studies suggest that M2-like macrophages are pro-fibrotic and contribute to hypertrophic scar formation. A previous study from our lab showed that M2 macrophages were present in developing hypertrophic scar tissues in vivo at 3-4 weeks after wounding. In this study, the effect of systemic macrophage depletion on scar formation was explored at subacute phase of wound healing. Thirty-six athymic nude mice that received human skin transplants were randomly divided into macrophage depletion group and control group. The former received intraperitoneal injections of clodronate liposomes while the controls received sterile saline injections on day 7, 10, and 13 postgrafting. Wound area, scar thickness, collagen abundance and collagen bundle structure, mast cell infiltration, myofibroblast formation, M1, and M2 macrophages together with gene expression of M1 and M2 related factors in the grafted skin were investigated at 2, 4, and 8 weeks postgrafting. The transplanted human skin from the control group developed contracted, elevated, and thickened scars while the grafted skin from the depletion group healed with significant less contraction and elevation. Significant reductions in myofibroblast number, collagen synthesis, and hypertrophic fiber morphology as well as mast cell infiltration were observed in the depletion group compared to the control group. Macrophage depletion significantly reduced M1 and M2 macrophage number in the depletion group 2 weeks postgrafting as compared to the control group. These findings suggest that systemic macrophage depletion in subacute phase of wound healing reduces scar formation, which provides evidence for the pro-fibrotic role of macrophages in fibrosis of human skin as well as insight into the potential benefits of specifically depleting M2 macrophages in vivo.
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Affiliation(s)
- Zhensen Zhu
- Wound Healing Research Group, Division of Plastic and Reconstructive Surgery
- Department of Burn and Reconstructive Surgery, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Jie Ding
- Wound Healing Research Group, Division of Plastic and Reconstructive Surgery
| | - Zengshuan Ma
- Wound Healing Research Group, Division of Plastic and Reconstructive Surgery
| | - Takashi Iwashina
- Wound Healing Research Group, Division of Plastic and Reconstructive Surgery
| | - Edward E Tredget
- Wound Healing Research Group, Division of Plastic and Reconstructive Surgery
- Division of Plastic Surgery, Department of Surgery, University of Alberta, Edmonton, Canada
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16
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Kishimoto Y, Kishimoto AO, Ye S, Kendziorski C, Welham NV. Modeling fibrosis using fibroblasts isolated from scarred rat vocal folds. J Transl Med 2016; 96:807-16. [PMID: 27111284 PMCID: PMC4920689 DOI: 10.1038/labinvest.2016.43] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 02/02/2016] [Accepted: 02/19/2016] [Indexed: 12/11/2022] Open
Abstract
Following injury, pathologically activated vocal fold fibroblasts (VFFs) can engage in disordered extracellular matrix (ECM) remodeling, leading to VF fibrosis and impaired voice function. Given the importance of scar VFFs to phenotypically appropriate in vitro modeling of VF fibrosis, we pursued detailed characterization of scar VFFs obtained from surgically injured rat VF mucosae, compared with those obtained from experimentally naïve, age-matched tissue. Scar VFFs initially exhibited a myofibroblast phenotype characterized by increased proliferation, increased Col1a1 transcription and collagen, type I synthesis, increased Acta2 transcription and α-smooth muscle actin synthesis, and enhanced contractile function. These features were most distinct at passage 1 (P1); we observed a coalescence of the scar and naïve VFF phenotypes at later passages. An empirical Bayes statistical analysis of the P1 cell transcriptome identified 421 genes that were differentially expressed by scar, compared with naïve, VFFs. These genes were primarily associated with the wound response, ECM regulation, and cell proliferation. Follow-up comparison of P1 scar VFFs and their in vivo tissue source showed substantial transcriptomic differences. Finally, P1 scar VFFs responded to treatment with hepatocyte growth factor and transforming growth factor-β3, two biologics with reported therapeutic value. Despite the practical limitations inherent to working with early passage cells, this experimental model is easily implemented in any suitably equipped laboratory and has the potential to improve the applicability of preclinical VF fibrosis research.
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Affiliation(s)
- Yo Kishimoto
- Department of Surgery, Division of Otolaryngology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
| | - Ayami Ohno Kishimoto
- Department of Surgery, Division of Otolaryngology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
| | - Shuyun Ye
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Christina Kendziorski
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Nathan V. Welham
- Department of Surgery, Division of Otolaryngology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
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17
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Alrobaiea SM, Ding J, Ma Z, Tredget EE. A Novel Nude Mouse Model of Hypertrophic Scarring Using Scratched Full Thickness Human Skin Grafts. Adv Wound Care (New Rochelle) 2016; 5:299-313. [PMID: 27366591 PMCID: PMC4900225 DOI: 10.1089/wound.2015.0670] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/08/2015] [Indexed: 02/06/2023] Open
Abstract
Objective: Hypertrophic scar (HTS) is a dermal form of fibroproliferative disorder that develops following deep skin injury. HTS can cause deformities, functional disabilities, and aesthetic disfigurements. The pathophysiology of HTS is not understood due to, in part, the lack of an ideal animal model. We hypothesize that human skin with deep dermal wounds grafted onto athymic nude mice will develop a scar similar to HTS. Our aim is to develop a representative animal model of human HTS. Approach: Thirty-six nude mice were grafted with full thickness human skin with deep dermal scratch wound before or 2 weeks after grafting or without scratch. The scratch on the human skin grafts was made using a specially designed jig that creates a wound >0.6 mm in depth. The xenografts were morphologically analyzed by digital photography. Mice were euthanized at 1, 2, and 3 months postoperatively for histology and immunohistochemistry analysis. Results: The mice developed raised and firm scars in the scratched xenografts with more contraction, increased infiltration of macrophage, and myofibroblasts compared to the xenografts without deep dermal scratch wound. Scar thickness and collagen bundle orientation and morphology resembled HTS. The fibrotic scars in the wounded human skin were morphologically and histologically similar to HTS, and human skin epithelial cells persisted in the remodeling tissues for 1 year postengraftment. Innovation and Conclusions: Deep dermal injury in human skin retains its profibrotic nature after transplantation, affording a novel model for the assessment of therapies for the treatment of human fibroproliferative disorders of the skin.
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Affiliation(s)
- Saad M. Alrobaiea
- Wound Healing Research Group, Department of Surgery, University of Alberta, Edmonton, Canada
| | - Jie Ding
- Wound Healing Research Group, Department of Surgery, University of Alberta, Edmonton, Canada
| | - Zengshuan Ma
- Wound Healing Research Group, Department of Surgery, University of Alberta, Edmonton, Canada
| | - Edward E. Tredget
- Wound Healing Research Group, Department of Surgery, University of Alberta, Edmonton, Canada
- Divisions of Plastic and Reconstructive Surgery and Critical Care, University of Alberta, Edmonton, Canada
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18
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Leavitt T, Hu MS, Marshall CD, Barnes LA, Lorenz HP, Longaker MT. Scarless wound healing: finding the right cells and signals. Cell Tissue Res 2016; 365:483-93. [PMID: 27256396 DOI: 10.1007/s00441-016-2424-8] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 05/02/2016] [Indexed: 02/06/2023]
Abstract
From the moment we are born, every injury to the skin has the potential to form a scar, many of which can impair form and/or function. As such, scar management constitutes a billion-dollar industry. However, effectively promoting scarless wound healing remains an elusive goal. The complex interactions of wound healing contribute to our inability to recapitulate scarless wound repair as it occurs in nature, such as in fetal skin and the oral mucosa. However, many new advances have occurred in recent years, some of which have translated scientific findings from bench to bedside. In vivo lineage tracing has helped establish a variety of novel cellular culprits that may act as key drivers of the fibrotic response. These newly characterized cell populations present further targets for therapeutic intervention, some of which have previously demonstrated promising results in animal models. Here, we discuss several recent studies that identify exciting approaches for diminishing scar formation. Particular attention will also be paid to the canonical Wnt/β-catenin signaling pathway, which plays an important role in both embryogenesis and tissue repair. New insights into the differential effects of Wnt signaling on heterogeneous fibroblast and keratinocyte populations within the skin further demonstrate methods by which wound healing can be re-directed to a more fetal scarless phenotype. Graphical abstract Recent approaches to reducing scar formation. Representation showing novel scientific approaches for decreasing scar formation, including the targeting of pro-fibrotic cell populations based on surface molecule expression (e.g. DPP4(+) fibroblasts, ADAM12(+) pericytes). Modulation of cellular mechanotransduction pathways are another means to reduce scar formation, both at the molecular level or, macroscopically with dressings designed to offload tension, at cutaneous wound sites (ADAM12 a disintegrin and metalloprotease 12, DPP4 dipeptidyl peptidase-4, FAK focal adhesion kinase).
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Affiliation(s)
- Tripp Leavitt
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 257 Campus Drive, Stanford, CA 94305-5461, USA
- Boston University School of Medicine, Boston, MA, USA
| | - Michael S Hu
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 257 Campus Drive, Stanford, CA 94305-5461, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Surgery, John A. Burns School of Medicine, University of Hawai'i, Honolulu, HI, USA
| | - Clement D Marshall
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 257 Campus Drive, Stanford, CA 94305-5461, USA
| | - Leandra A Barnes
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 257 Campus Drive, Stanford, CA 94305-5461, USA
| | - H Peter Lorenz
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 257 Campus Drive, Stanford, CA 94305-5461, USA
| | - Michael T Longaker
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, 257 Campus Drive, Stanford, CA 94305-5461, USA.
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA.
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19
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Zhu Z, Ding J, Tredget EE. The molecular basis of hypertrophic scars. BURNS & TRAUMA 2016; 4:2. [PMID: 27574672 PMCID: PMC4963951 DOI: 10.1186/s41038-015-0026-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 12/30/2015] [Indexed: 02/05/2023]
Abstract
Hypertrophic scars (HTS) are caused by dermal injuries such as trauma and burns to the deep dermis, which are red, raised, itchy and painful. They can cause cosmetic disfigurement or contractures if craniofacial areas or mobile region of the skin are affected. Abnormal wound healing with more extracellular matrix deposition than degradation will result in HTS formation. This review will introduce the physiology of wound healing, dermal HTS formation, treatment and difference with keloids in the skin, and it also review the current advance of molecular basis of HTS including the involvement of cytokines, growth factors, and macrophages via chemokine pathway, to bring insights for future prevention and treatment of HTS.
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Affiliation(s)
- Zhensen Zhu
- Wound Healing Research Group, Division of Plastic and Reconstructive Surgery, University of Alberta, Edmonton, Alberta Canada
- Department of Burn and Reconstructive Surgery, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong China
| | - Jie Ding
- Wound Healing Research Group, Division of Plastic and Reconstructive Surgery, University of Alberta, Edmonton, Alberta Canada
| | - Edward E. Tredget
- Wound Healing Research Group, Division of Plastic and Reconstructive Surgery, University of Alberta, Edmonton, Alberta Canada
- Division of Plastic Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta Canada
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20
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Zhu Z, Ding J, Ma Z, Iwashina T, Tredget EE. The natural behavior of mononuclear phagocytes in HTS formation. Wound Repair Regen 2016; 24:14-25. [PMID: 26519112 DOI: 10.1111/wrr.12378] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 10/17/2015] [Indexed: 02/05/2023]
Abstract
Hypertrophic scars (HTS) are caused by trauma or burn injuries to the deep dermis and are considered fibrosis in the skin. Monocytes, M1 and M2 macrophages are mononuclear phagocytes. Studies suggest that M2 macrophages are profibrotic and might contribute to HTS formation. Our lab has established a human HTS-like nude mouse model, in which the grafted human skin develops red, raised, and firm scarring, resembling HTS seen in humans. In this study, we observed the natural behavior of mononuclear phagocyte system in this nude mouse model of dermal fibrosis at multiple time points. Thirty athymic nude mice received human skin grafts and an equal number of mice received mouse skin grafts as controls. The grafted skin and blood were harvested at 1, 2, 3, 4, and 8 weeks. Wound area, thickness, collagen morphology and level, the cell number of myofibroblasts, M1- and M2-like macrophages in the grafted skin, as well as monocyte fraction in the blood were investigated at each time points. Xenografted mice developed contracted and thickened scars grossly. The xenografted skin resembled human HTS tissue based on enhanced thickness, fibrotic orientation of collagen bundles, increased collagen level, and infiltration of myofibroblasts. In the blood, monocytes dramatically decreased at 1 week postgrafting and gradually returned to normal in the following 8 weeks. In the xenografted skin, M1-like macrophages were found predominantly at 1-2 weeks postgrafting; whereas, M2-like macrophages were abundant at later time points, 3-4 weeks postgrafting coincident with the development of fibrosis in the human skin tissues. This understanding of the natural behavior of mononuclear phagocytes in vivo in our mouse model provides evidence for the role of M2-like macrophages in fibrosis of human skin and suggests that macrophage depletion in the subacute phases of wound healing might reduce or prevent HTS formation.
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Affiliation(s)
- Zhensen Zhu
- Division of Plastic and Reconstructive Surgery, Wound Healing Research Group, University of Alberta, Edmonton, Alberta, Canada
- Department of Burn and Reconstructive Surgery, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China
| | - Jie Ding
- Division of Plastic and Reconstructive Surgery, Wound Healing Research Group, University of Alberta, Edmonton, Alberta, Canada
| | - Zengshuan Ma
- Division of Plastic and Reconstructive Surgery, Wound Healing Research Group, University of Alberta, Edmonton, Alberta, Canada
| | - Takashi Iwashina
- Division of Plastic and Reconstructive Surgery, Wound Healing Research Group, University of Alberta, Edmonton, Alberta, Canada
| | - Edward E Tredget
- Division of Plastic and Reconstructive Surgery, Wound Healing Research Group, University of Alberta, Edmonton, Alberta, Canada
- Division of Plastic Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
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