Receptor-Interacting Protein Kinase 3 Deficiency Delays Cutaneous Wound Healing.

Andrew Godwin,Jeffrey Nicastro,Ping Wang,Zhimin Wang,Weng-Lang Yang,Archna Sharma,Gene F Coppa,Nikolaos Frangogiannis

doi:10.1371/journal.pone.0140514

Andrew Godwin, Jeffrey Nicastro + Show 6 more

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https://doi.org/10.1371/journal.pone.0140514

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Abstract

Wound healing consists of a complex, dynamic and overlapping process involving inflammation, proliferation and tissue remodeling. A better understanding of wound healing process at the molecular level is needed for the development of novel therapeutic strategies. Receptor-interacting protein kinase 3 (RIPK3) controls programmed necrosis in response to TNF-α during inflammation and has been shown to be highly induced during cutaneous wound repair. However, its role in wound healing remains to be demonstrated. To study this, we created dorsal cutaneous wounds on male wild-type (WT) and RIPK3-deficient (Ripk3 -/-) mice. Wound area was measured daily until day 14 post-wound and skin tissues were collected from wound sites at various days for analysis. The wound healing rate in Ripk3 -/- mice was slower than the WT mice over the 14-day course; especially, at day 7, the wound size in Ripk3 -/- mice was 53% larger than that of WT mice. H&E and Masson-Trichrome staining analysis showed impaired quality of wound closure in Ripk3 -/- wounds with delayed re-epithelialization and angiogenesis and defected granulation tissue formation and collagen deposition compared to WT. The neutrophil infiltration pattern was altered in Ripk3 -/- wounds with less neutrophils at day 1 and more neutrophils at day 3. This altered pattern was also reflected in the differential expression of IL-6, KC, IL-1β and TNF-α between WT and Ripk3 -/- wounds. MMP-9 protein expression was decreased with increased Timp-1 mRNA in the Ripk3 -/- wounds compared to WT. The microvascular density along with the intensity and timing of induction of proangiogenic growth factors VEGF and TGF-β1 were also decreased or delayed in the Ripk3 -/- wounds. Furthermore, mouse embryonic fibroblasts (MEFs) from Ripk3 -/- mice migrated less towards chemoattractants TGF-β1 and PDGF than MEFs from WT mice. These results clearly demonstrate that RIPK3 is an essential molecule to maintain the temporal manner of the normal progression of wound closure.

Highlights

Cutaneous wound healing is a complex and dynamic process involving multiple overlapping events following injury, including coagulation, inflammation, epithelialization, formation of granulation tissue, matrix deposition, and tissue remodeling [1,2,3]
We examined the effect of Receptor-interacting protein kinase 3 (RIPK3) deficiency on the progression of wound healing to different phases at days 7 and 14 post-wound by H&E staining analysis
Angiogenesis was evident and re-epithelialization had begun in WT wounds by day 7 (Fig 2A) whereas it was not evident in Ripk3-/- wounds (Fig 2B)

Summary

Introduction

Cutaneous wound healing is a complex and dynamic process involving multiple overlapping events following injury, including coagulation, inflammation, epithelialization, formation of granulation tissue, matrix deposition, and tissue remodeling [1,2,3]. Normal wound healing is orchestrated by an intricate system of growth factors, chemokines, cytokines, and angiogenic factors which bind to their specific receptors and activate and coordinate a complex network of various signal transduction pathways [4, 5] The disruption of this tightly regulated cascade of events may lead to impaired or delayed healing of acute cutaneous wounds and to the development of chronic non-healing wounds/ulcers [6, 7]. Certain chronic conditions predispose patients to poor wound healing and these include diabetes mellitus, venous and arterial insufficiency and long standing immobility or hospitalization and subsequent development of pressure ulcers [8] These chronic and slowly healing acute wounds account for significant levels of morbidity as well as severe decrease in quality of life and incur huge health care costs [9, 10]. A better understanding of the molecular mechanisms involved in wound healing is needed for the development of novel and effective therapies for patients with aberrant wound healing

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