Abstract 235: Interaction Between a Macrophage Chemokine Receptor, CCR2, and Its Ligand Plays a Crucial Role in Macrophage Recruitment Aand Regulated Inflammation in Normal Wound Healing

Background: Wound healing in chronic diseases, such as type 2 diabetes (T2D), is impaired due to dysregulated inflammation. Innate immune cells, particularly macrophages, play a significant role in regulated inflammation following tissue injury. After injury, CCR2+ monocytes are recruited to the peripheral wound. This recruitment is mediated in part by the CCR2 ligand, CCL2. Thus, we hypothesized that the CCL2/CCR2 interaction is vital for normal wound healing and appropriate inflammation, and that this signaling cascade is impaired in T2D. Methods: CCR2 -/- mice and littermate controls underwent 4mm hindlimb wounds, and wound closure was compared daily. Wound macrophages (CD3-CD19-NK1.1-CD11b+ cells) were analyzed on day 3 by flow cytometry for intracellular cytokine production. Adoptive transfer was performed using blood CD11b+ cells from WT C57BL/6 or CCR2 -/- mice isolated by magnetic sorting and transferred into CCR2 -/- mice via tail vein injection. Mice were then wounded and wound closure was compared between the two groups. C57BL/6 mice were maintained on normal or high fat diet for 12-14 weeks, wounds were created, and CD11b+ cells were isolated from wounds on day 2. ELISA for CCL2 was performed. Results: CCR2 -/- mice showed significantly impaired wound healing on days 2-7 compared with littermate controls. Macrophages isolated on day 3 from wounds of CCR2 -/- mice expressed significantly less inflammatory cytokines (IL-1β, TNF-α) by qPCR. Flow cytometry analysis revealed less Ly6C hi macrophages in the wounds, as well as macrophages that made significantly less IL-1β, NOS2, and TNF-α. When adoptive transfer was performed, wound healing was restored to normal in the mice that received WT compared to those that received CCR2 -/- CD11b+ cells (P< 0.01). Since CCR2 is important for normal wound inflammation, and we have previously shown that inflammation is impaired in the diet-induced obese (DIO) mice, we examined CCL2 in DIO wounds. CCL2 was significantly decreased in DIO wound macrophages on day 2. Conclusion: Appropriate CCR2/CCL2 interaction plays a crucial role in macrophage recruitment and regulated inflammation in normal wound healing. Impairment in CCR2/CCL2 signaling may be responsible, in part, for delayed early inflammation in T2D.

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Continuous Delivery of Stromal Cell-Derived Factor-1 from Alginate Scaffolds Accelerates Wound Healing

Cell Transplantation ◽

10.3727/096368909x481782 ◽

2010 ◽

Vol 19 (4) ◽

pp. 399-408 ◽

Cited By ~ 100

Author(s):

Sina Y. Rabbany ◽

Joseph Pastore ◽

Masaya Yamamoto ◽

Tim Miller ◽

Shahin Rafii ◽

...

Keyword(s):

Wound Healing ◽

Stromal Cell ◽

Wound Closure ◽

Tissue Injury ◽

Unmet Need ◽

Novel Therapy ◽

Yorkshire Pigs ◽

Stromal Cell Derived Factor

Proper wound diagnosis and management is an increasingly important clinical challenge and is a large and growing unmet need. Pressure ulcers, hard-to-heal wounds, and problematic surgical incisions are emerging at increasing frequencies. At present, the wound-healing industry is experiencing a paradigm shift towards innovative treatments that exploit nanotechnology, biomaterials, and biologics. Our study utilized an alginate hydrogel patch to deliver stromal cell-derived factor-1 (SDF-1), a naturally occurring chemokine that is rapidly overexpressed in response to tissue injury, to assess the potential effects SDF-1 therapy on wound closure rates and scar formation. Alginate patches were loaded with either purified recombinant human SDF-1 protein or plasmid expressing SDF-1 and the kinetics of SDF-1 release were measured both in vitro and in vivo in mice. Our studies demonstrate that although SDF-1 plasmid- and protein-loaded patches were able to release therapeutic product over hours to days, SDF-1 protein was released faster (in vivo Kd 0.55 days) than SDF-1 plasmid (in vivo Kd 3.67 days). We hypothesized that chronic SDF-1 delivery would be more effective in accelerating the rate of dermal wound closure in Yorkshire pigs with acute surgical wounds, a model that closely mimics human wound healing. Wounds treated with SDF-1 protein ( n = 10) and plasmid ( n = 6) loaded patches healed faster than sham ( n = 4) or control ( n = 4). At day 9, SDF-1-treated wounds significantly accelerated wound closure (55.0 ± 14.3% healed) compared to nontreated controls (8.2 ± 6.0%, p < 0.05). Furthermore, 38% of SDF-1-treated wounds were fully healed at day 9 (vs. none in controls) with very little evidence of scarring. These data suggest that patch-mediated SDF-1 delivery may ultimately provide a novel therapy for accelerating healing and reducing scarring in clinical wounds.

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Topical Wound Healing Activity of Myricetin Isolated from Tecomaria capensis v. aurea

Molecules ◽

10.3390/molecules25214870 ◽

2020 ◽

Vol 25 (21) ◽

pp. 4870

Author(s):

Abdelsamed I. Elshamy ◽

Naglaa M. Ammar ◽

Heba A. Hassan ◽

Walaa A. El-Kashak ◽

Salim S. Al-Rejaie ◽

...

Keyword(s):

Wound Healing ◽

Inflammatory Cytokines ◽

Group Treatment ◽

Wound Closure ◽

Burn Injury ◽

Control Group ◽

Albino Rats ◽

Large Area ◽

Blood Capillaries ◽

Tnf Α

Wounds and burn injury are major causes of death and disability worldwide. Myricetin is a common bioactive flavonoid isolated naturally from the plant kingdom. Herein, a topical application of naturally isolated myricetin from the shoots of Tecomaria capensis v. aurea on excisional wound healing that was performed in albino rats. The wounded rats were treated every day with 10 and 20% myricetin for 14 days. During the experiment, the wound closure percentage was estimated at days 0, 7, and 14. Effects of myricetin on the inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and cluster of differentiation 68 (CD68) in the serum were evaluated using immunosorbent assay kits. The percentage of wound closure and contraction was delayed in wounded rats (67.35%) and was remarkably increased after treatment of wounded rats with myricetin; the treatment with 20% myricetin was the most potent (98.76%). Histological findings exhibited that 10% myricetin caused the formation of a large area of scarring at the wound enclosure and stratified squamous epithelium without the formation of papillae as in the control group. Treatment with 20% myricetin exhibited less area of scarring at the wound enclosure as well as re-epithelialization with a high density of fibroblasts and blood capillaries in the wound. Level elevations of serum pro-inflammatory cytokines, IL-1β, and TNF-α and macrophage CD68 were decreased in wounded rats treated with myricetin. Thus, it can be suggested that the enhancements in inflammatory cytokines as well as systemic reorganization after myricetin treatment may be recommended to play a crucial part in the promotion of wound healing. The findings suggest that treatment with a higher dose of myricetin was better in improving wound curing in rats. It could serve as a potent anti-inflammatory agent and can be used as an adjunctive or alternative agent in the future.

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Role of Nitric Oxide in Wound Healing

Biological Research For Nursing ◽

10.1177/1099800402004001002 ◽

2002 ◽

Vol 4 (1) ◽

pp. 5-15 ◽

Cited By ~ 26

Author(s):

Beverly B. Childress ◽

Joyce K. Stechmiller

Keyword(s):

Nitric Oxide ◽

Wound Healing ◽

Growth Factors ◽

Animal Studies ◽

Chronic Wounds ◽

Current Knowledge ◽

Wound Care ◽

Impaired Wound Healing ◽

Normal Wound Healing ◽

Age Related

Chronic wounds mainly affect elderly individuals and persons with comorbid diseases due to a compromised immune status. An age-related decline in immune function deters proper healing of wounds in an orderly and timely manner. Thus, older adults with 1 or more concomitant illnesses are more likely to experience and suffer from a nonhealing wound, which may drastically decrease their quality of life and financial resources. Novel therapies in wound care management rely heavily on our current knowledge of wound healing physiology. It is well established that normal wound healing occurs sequentially and is strictly regulated by pro-inflammatory cytokines and growth factors. A multitude of commercial products such as growth factors are available; however, their effectiveness in healing chronic wounds has yet to be proven. Recently, investigators have implicated nitric oxide (NO) in the exertion of regulatory forces on various cellular activities of the inflammatory and proliferative phases of wound healing. Gene therapy in animal studies has shown promising results and is furthering our understanding of impaired wound healing. The purpose of this article is to review the literature on NO and its role in wound healing. A discussion of the physiology of normal healing and the pathophysiology of chronic wounds is provided.

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Reduction of ARNT in myeloid cells causes immune suppression and delayed wound healing

AJP Cell Physiology ◽

10.1152/ajpcell.00306.2013 ◽

2014 ◽

Vol 307 (4) ◽

pp. C349-C357 ◽

Cited By ~ 11

Author(s):

Christopher Scott ◽

James Bonner ◽

Danqing Min ◽

Philip Boughton ◽

Rebecca Stokes ◽

...

Keyword(s):

Wound Healing ◽

Myeloid Cells ◽

Myeloid Cell ◽

Delayed Wound Healing ◽

Impaired Wound Healing ◽

Environmental Signals ◽

Aryl Hydrocarbon ◽

Normal Wound Healing ◽

Full Benefit ◽

The Difference

Aryl hydrocarbon receptor nuclear translocator (ARNT) is a transcription factor that binds to partners to mediate responses to environmental signals. To investigate its role in the innate immune system, floxed ARNT mice were bred with lysozyme M-Cre recombinase animals to generate lysozyme M-ARNT (LAR) mice with reduced ARNT expression. Myeloid cells of LAR mice had altered mRNA expression and delayed wound healing. Interestingly, when the animals were rendered diabetic, the difference in wound healing between the LAR mice and their littermate controls was no longer present, suggesting that decreased myeloid cell ARNT function may be an important factor in impaired wound healing in diabetes. Deferoxamine (DFO) improves wound healing by increasing hypoxia-inducible factors, which require ARNT for function. DFO was not effective in wounds of LAR mice, again suggesting that myeloid cells are important for normal wound healing and for the full benefit of DFO. These findings suggest that myeloid ARNT is important for immune function and wound healing. Increasing ARNT and, more specifically, myeloid ARNT may be a therapeutic strategy to improve wound healing.

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Eradication of Mature Bacterial Biofilms with Concurrent Improvement in Chronic Wound Healing Using Silver Nanoparticle Hydrogel Treatment

Biomedicines ◽

10.3390/biomedicines9091182 ◽

2021 ◽

Vol 9 (9) ◽

pp. 1182

Author(s):

Hanif Haidari ◽

Richard Bright ◽

Sanjay Garg ◽

Krasimir Vasilev ◽

Allison J. Cowin ◽

...

Keyword(s):

Wound Healing ◽

Wound Repair ◽

Wound Closure ◽

In Vivo Studies ◽

Release Mechanism ◽

Impaired Wound Healing ◽

Biofilm Model ◽

Infected Wounds ◽

Delivery Platform

Biofilm-associated infections are a major cause of impaired wound healing. Despite the broad spectrum of anti-bacterial benefits provided by silver nanoparticles (AgNPs), these materials still cause controversy due to cytotoxicity and a lack of efficacy against mature biofilms. Herein, highly potent ultrasmall AgNPs were combined with a biocompatible hydrogel with integrated synergistic functionalities to facilitate elimination of clinically relevant mature biofilms in-vivo combined with improved wound healing capacity. The delivery platform showed a superior release mechanism, reflected by high biocompatibility, hemocompatibility, and extended antibacterial efficacy. In vivo studies using the S. aureus wound biofilm model showed that the AgNP hydrogel (200 µg/g) was highly effective in eliminating biofilm infection and promoting wound repair compared to the controls, including silver sulfadiazine (Ag SD). Treatment of infected wounds with the AgNP hydrogel resulted in faster wound closure (46% closure compared to 20% for Ag SD) and accelerated wound re-epithelization (60% for AgNP), as well as improved early collagen deposition. The AgNP hydrogel did not show any toxicity to tissue and/or organs. These findings suggest that the developed AgNP hydrogel has the potential to be a safe wound treatment capable of eliminating infection and providing a safe yet effective strategy for the treatment of infected wounds.

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Defect of Interferon γ Leads to Impaired Wound Healing through Prolonged Neutrophilic Inflammatory Response and Enhanced MMP-2 Activation

International Journal of Molecular Sciences ◽

10.3390/ijms20225657 ◽

2019 ◽

Vol 20 (22) ◽

pp. 5657 ◽

Cited By ~ 2

Author(s):

Emi Kanno ◽

Hiromasa Tanno ◽

Airi Masaki ◽

Ayako Sasaki ◽

Noriko Sato ◽

...

Keyword(s):

Wound Healing ◽

Wound Closure ◽

Inflammatory Responses ◽

Breaking Strength ◽

Neutrophil Accumulation ◽

T Helper 1 ◽

Impaired Wound Healing ◽

Expression Levels ◽

Ifn Γ

Interferon (IFN)-γ is mainly secreted by CD4+ T helper 1 (Th1), natural killer (NK) and NKT cells after skin injury. Although IFN-γ is well known regarding its inhibitory effects on collagen synthesis by fibroblasts in vitro, information is limited regarding its role in wound healing in vivo. In the present study, we analyzed how the defect of IFN-γ affects wound healing. Full-thickness wounds were created on the backs of wild type (WT) C57BL/6 and IFN-γ-deficient (KO) mice. We analyzed the percent wound closure, wound breaking strength, accumulation of leukocytes, and expression levels of COL1A1, COL3A1, and matrix metalloproteinases (MMPs). IFN-γKO mice exhibited significant attenuation in wound closure on Day 10 and wound breaking strength on Day 14 after wound creation, characteristics that are associated with prolonged neutrophil accumulation. Expression levels of COL1A1 and COL3A1 mRNA were lower in IFN-γKO than in WT mice, whereas expression levels of MMP-2 (gelatinase) mRNA were significantly greater in IFN-γKO than in WT mice. Moreover, under neutropenic conditions created with anti-Gr-1 monoclonal antibodies, wound closure in IFN-γKO mice was recovered through low MMP-2 expression levels. These results suggest that IFN-γ may be involved in the proliferation and maturation stages of wound healing through the regulation of neutrophilic inflammatory responses.

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POST-OPERATTVE CHANGES IN PROIEINASE INHIBITORS IN NORMAL AND IMPAIRED WOUND HEALING

10.1055/s-0038-1644860 ◽

1987 ◽

Author(s):

M Reitz ◽

H Sauer ◽

G Witzke ◽

M Neher

Keyword(s):

Wound Healing ◽

Marked Reduction ◽

Mean Value ◽

Striking Difference ◽

Impaired Wound Healing ◽

Normal Wound Healing ◽

At Iii ◽

Group A ◽

Group B ◽

Tissue Trauma

Tissue trauma after surgery activates blood coagulation. This results in a change and in the consumption of important inhibitors.We investigated the oonoentraticn of antithrorfoin III (AT III), ∝ 1-antitrypsin (∝l-AT), ∝ 2- macrogloublin (∝ 2-M) and Cl-inactivator (Cl-INH) in the blood plasma by means ofradial iirmunodiffusicn in 16 patients before surgery, after surgery and cn the 1st, 3rd and 7th days after surgery. In 11 patients normal wound healing wasobserved (group A), while in 5 patients amplicationsoccurred (group B). AT III: Fall in concentration upto the 3rd day after surgery, then a rise in concentration. In the patients with impaired wound healing there was a particularly marked reduction in AT III cn the 3rd day.∝ 1-AT: Fall in concentration after surgery, followed by a rise in concentration. In impaired wound healing a lower mean value was determined on the 3rd day after surgery than in normal wound healing. ∝ 2-M: Fall in concentration up to the 3rd day after surgery, followed by a slight increase in concentration. No striking difference between the normal group and the group with complications. Cl-INH: Fall in concentration after surgery, followed by arise in concentration; in the patients with impaired wound healing there was adelayed rise in concentration.

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Restoration of the healing microenvironment in diabetic wounds with matrix-binding IL-1 receptor antagonist

Communications Biology ◽

10.1038/s42003-021-01913-9 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Jean L. Tan ◽

Blake Lash ◽

Rezvan Karami ◽

Bhavana Nayer ◽

Yen-Zhen Lu ◽

...

Keyword(s):

Wound Healing ◽

Receptor Antagonist ◽

Wound Closure ◽

Chronic Wounds ◽

Tissue Injury ◽

Interleukin 1 ◽

Inflammatory Cells ◽

Clinical Problem ◽

Knockout Mouse Model ◽

Extracellular Matrix Components

AbstractChronic wounds are a major clinical problem where wound closure is prevented by pathologic factors, including immune dysregulation. To design efficient immunotherapies, an understanding of the key molecular pathways by which immunity impairs wound healing is needed. Interleukin-1 (IL-1) plays a central role in regulating the immune response to tissue injury through IL-1 receptor (IL-1R1). Generating a knockout mouse model, we demonstrate that the IL-1–IL-1R1 axis delays wound closure in diabetic conditions. We used a protein engineering approach to deliver IL-1 receptor antagonist (IL-1Ra) in a localised and sustained manner through binding extracellular matrix components. We demonstrate that matrix-binding IL-1Ra improves wound healing in diabetic mice by re-establishing a pro-healing microenvironment characterised by lower levels of pro-inflammatory cells, cytokines and senescent fibroblasts, and higher levels of anti-inflammatory cytokines and growth factors. Engineered IL-1Ra has translational potential for chronic wounds and other inflammatory conditions where IL-1R1 signalling should be dampened.

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Neutrophil function in the healing wound: adding insult to injury?

Thrombosis and Haemostasis ◽

10.1160/th03-11-0720 ◽

2004 ◽

Vol 92 (08) ◽

pp. 275-280 ◽

Cited By ~ 127

Author(s):

Julia Dovi ◽

Anna Szpaderska ◽

Luisa DiPietro

Keyword(s):

Wound Healing ◽

Innate Immune System ◽

Functional Role ◽

Wound Closure ◽

Inflammatory Cells ◽

Neutrophil Function ◽

Innate Immune ◽

Normal Wound Healing ◽

Healing Wound

SummaryCells of the innate immune system, including neutrophils and macrophages, are a highly visible component of normal wound healing in adult mammals. The role of inflammatory cells in the healing wound has been widely investigated, and evidence for both positive and negative influences exists. Several recent investigations support the emerging paradigm that robust inflammation is detrimental to wound closure. This developing information suggests that the functional role of inflammatory cells in wound healing must be reevaluated.

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Hair follicle stem cells promote cutaneous wound healing through the SDF-1α/CXCR4 axis: an animal model

Journal of Wound Care ◽

10.12968/jowc.2020.29.9.526 ◽

2020 ◽

Vol 29 (9) ◽

pp. 526-536

Author(s):

Abazar Yari ◽

Fatemeh Heidari ◽

Sanaz Joulai Veijouye ◽

Maliheh Nobakht

Keyword(s):

Stem Cells ◽

Flow Cytometry ◽

Wound Healing ◽

Hair Follicle ◽

Wound Closure ◽

Expression Level ◽

Control Group ◽

Cutaneous Wound Healing ◽

Cutaneous Wound ◽

Cxcr4 Axis

Objective: An appropriate source of adult stem cells for therapeutic use is stem cells deriving from the hair follicle bulge. Following injury, ischaemic tissues produce a variety of cytokines and growth factors that are essential for tissue repair. This study sought to investigate the temporal effects of hair follicle bulge stem cells (HFSCs) on cutaneous wound healing in rats using the SDF-1α/CXCR4 axis. Method: HFSCs obtained from rat vibrissa, labeled with DiI and then special markers, were detected using flow cytometry. The animals were divided into five groups: control (non-treated, n=18), sham (PBS, n=18), AMD (treated with AMD3100, n=18), HFSC + AMD (treated with HFSCs + AMD3100, n=18) and HFSC (treated with HFSCs, n=18). A full-thickness excisional wound model was created and DiI-labeled HFSCs were injected around the wound bed. Wound healing was recorded with digital photographs. The animals were sacrificed 3, 7 and 14 days after the surgery and were used for histological (H&E, Masson's trichrome staining) and molecular (ELISA and q-PCR) assays. Results: The flow cytometry results demonstrated that HFSCs were CD34-positive, nestin-positive, but Kr15-negative. The morphological analysis of the HFSC-treated wounds showed accelerated wound closure. The histological analysis of the photomicrographs exhibited more re-epithelialisation and dermal structural regeneration in the HFSC-treated wounds compared with the control group. In the HFSC + AMD group, the histological parameters improved on the same days, but showed a significant decrease compared with the HFSC group in all the days assayed. In the AMD group, there was a significant reduction in the noted parameters. qRT-PCR and ELISA showed a high expression level of SDF-1α, CXCR4 and VEGFR-2 in the HFSC-treated wounded skin tissue, but the expression of CXCR4 and VEGFR-2 showed a significant reduction in the HFSC + AMD group compared with the HFSC group. Conclusions: Based on the findings of this study, HFSC transplantation affects wound closure parameters and the expression of SDF-1α and CXCR4. As the SDF-1α expression level increases in the injured area, the HFSCs contribute to wound repair through the SDF-1α/CXCR4 axis. This result is extremely valuable because it raises the possibility of wounds healed by isolating autologous HFSCs from the patient.

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