Refractory ulcers: the role of tumor necrosis factor-alpha

Evaluation of a Multifunctional Polyvinylpyrrolidone/Hyaluronic Acid-Based Bilayer Film Patch with Anti-Inflammatory Properties as an Enhancer of the Wound Healing Process

The management of acute and chronic wounds is still a socioeconomic burden for society due to the lack of suitable tools capable of supporting all the healing phases. The exponential spread of diabetes worldwide and the consequent increase of complicated diabetic ulcers require further efforts to develop scalable, low-cost, and easy-to-use treatments for tackling this emergency. Recently, we explored the fabrication of a polyvinylpyrrolidone/hyaluronic acid-based bilayer wound dressing, characterizing its physicochemical features and detailing its excellent antimicrobial activity. Here, we further demonstrate its biocompatibility on fibroblasts, keratinocytes, and red blood cells. The bilayer shows anti-inflammatory properties, statistically reducing the level of IL-6, IL-1β, and TNF-α, and a capacity to accelerate wound healing in vitro and in healthy and diabetic mice models compared to untreated mice. The outcomes suggest that this bilayer material can be an effective tool for managing different skin injuries.

11,12 Epoxyeicosatrienoic Acid Rescues Deteriorated Wound Healing in Diabetes

Epoxyeicosatrienoic acids (EET) facilitate regeneration in different tissues, and their benefit in dermal wound healing has been proven under normal conditions. In this study, we investigated the effect of 11,12 EET on dermal wound healing in diabetes. We induced diabetes by i.p. injection of streptozotocin 2 weeks prior to wound creation on the dorsal side of the mouse ear. 11,12 EET was applied every second day on the wound, whereas the control groups received only solvent. Epithelialization was monitored every second day intravitally up to wound closure. Wounds were stained for VEGF, CD31, TGF-β, TNF-α, SDF-1α, NF-κB, and Ki-67, and fibroblasts were counted after hematoxylin-eosin stain on days 3, 6, 9, and 16 after wounding. After induction of diabetes, wounds closed on day 13.00 ± 2.20 standard deviation (SD). Local 11,12 ETT application improved wound closure significantly to day 8.40 ± 1.39 SD. EET treatment enhanced VEGF and CD31 expression in wounds on day 3. It also seemed to raise TNF-α level on all days investigated as well as TGF-β level on days 3 and 6. A decrease in NF-κB could be observed on days 9 and 16 after EET application. The latter findings were not significant. SDF-1α expression was not influenced by EET application, and Ki-67 was significantly less in the EET group on day 9 after EET application. The number of fibroblasts was significantly increased on day 9 after the 11,12 EET application. 11,12 EET improve deteriorated wound healing in diabetes by enhancing neoangiogenesis, especially in the early phase of wound healing. Furthermore, they contribute to the dissolution of the initial inflammatory reaction, allowing the crucial transition from the inflammatory to proliferative phase in wound healing.

The role of anti-tumour necrosis factor in wound healing: A case report of refractory ulcerated necrobiosis lipoidica treated with adalimumab and review of the literature

Necrobiosis lipoidica is a chronic granulomatous disease historically associated with diabetes. Necrobiosis lipoidica commonly presents with erythematous papules or plaques on the anterior lower extremities, which can be ulcerated in up to 30% of patients. The pathophysiology of necrobiosis lipoidica is unknown but proposed to be predominantly linked to microangiopathy. No treatment option for necrobiosis lipoidica has shown consistent efficacy. Previous case reports have shown immune-modulating agents to be reasonable treatment options for ulcerative necrobiosis lipoidica. However, evidence for the tumour necrosis factor-alpha inhibitor, adalimumab, is limited and contradictory. We report a case of a 74-year-old type 2 diabetic female with a 2-year history of multiple ulcerated necrobiosis lipoidica plaques resistant to topical and systemic therapy. Treatment with adalimumab showed complete re-epithelization of all ulcers by week 28. Adalimumab may be an effective treatment option for ulcerated necrobiosis lipoidica that has failed traditional therapies. Further reports of adalimumab treatment of necrobiosis lipoidica and other chronic inflammatory wounds are needed.

11,12 and 14,15 epoxyeicosatrienoic acid rescue deteriorated wound healing in ischemia

Introduction

Epoxyeicosatrienoic acids (EETs) are able to enhance angiogenesis and regulate inflammation that is especially important in wound healing under ischemic conditions. Thus, we evaluated the effect of local EET application on ischemic wounds in mice.

Methods

Ischemia was induced by cautherization of two of the three supplying vessels to the mouse ear. Wounding was performed on the ear three days later. Wounds were treated either with 11,12 or 14,15 EET and compared to untreated control and normal wounds. Epithelialization was measured every second day. VEGF, TNF-α, TGF-β, matrix metalloproteinases (MMP), tissue inhibitors of metalloproteinases (TIMP), Ki67, and SDF-1α were evaluated immunohistochemically in wounds on day 3, 6, and 9.

Results

Ischemia delayed wound closure (12.8 days ± 1.9 standard deviation (SD) for ischemia and 8.0 days ± 0.94 SD for control). 11,12 and14,15 EET application ameliorated deteriorated wound healing on ischemic ears (7.6 ± 1.3 SD for 11,12 EET and 9.2 ± 1.4 SD for 14,15 EET). Ischemia did not change VEGF, TNF-α, TGF-β, SDF-1α, TIMP, MMP7 or MMP9 level significantly compared to control. Local application of 11,12 as well as 14,15 EET induced a significant elevation of VEGF, TGF-β, and SDF-1α expression as well as proliferation during the whole phase of wound healing compared to control and ischemia alone.

Conclusion

In summary, EET improve impaired wound healing caused by ischemia as they enhance neovascularization and alter inflammatory response in wounds. Thus elevating lipid mediator level as 11,12 and 14,15 EET in wounds might be a successful strategy for amelioration of deranged wound healing under ischemia.

Interferon-gamma (IFN-γ) is Elevated in Wound Exudate from Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic recurrent inflammatory disease of apocrine glands which affects 1-4% of young adults. The purpose of this study was to investigate inflammatory cytokines in effluent from HS lesions and to identify potential local drivers of inflammation in HS. Wound fluid specimens from HS patients (n = 8) and age-matched chronic wound patients (n = 8) were selected for analysis. The hidradenitis suppurativa score (HSS) was used to determine the extent of HS activity. Cytokine analysis was conducted using Meso Scale Discovery cytokine and proinflammatory panels. Interferon-gamma (IFN-γ) was significantly elevated in the HS effluent compared to chronic wounds (1418 ± 1501 pg/ml compared to 102.5 ± 138 pg/ml, p = 0.027). HS effluent also had significantly higher levels of tumor necrosis factor-β (TNF-β) (9.24 ± 7.22 pg/ml compared to 1.65 ± 2.14 pg/ml, p = 0.03). There was no significant difference in any other cytokines. There was no significant difference in demographics in the HS compared to chronic wound cohorts. Mean HSS in the HS cohort was 68.88 (SD ± 41.45). In this proof-of-concept pilot study, IFN-γ was significantly elevated in HS effluent. TNF-β/LT-α levels were also elevated in HS, although the levels were more modest. Further studies should focus on molecular drivers of tissue injury in HS and the relationship between HS effluent cytokine profile and disease activity.

Wound healing delays in α-Klotho-deficient mice that have skin appearance similar to that in aged humans - Study of delayed wound healing mechanism

Skin atrophy and delayed wound healing are observed in aged humans; however, the molecular mechanism are still elusive. The aim of this study was to analyze the molecular mechanisms of delayed wound healing by aging using α-Klotho-deficient (kl/kl) mice, which have phenotypes similar to those of aged humans. The kl/kl mice showed delayed wound healing and impaired granulation formation compared with those in wild-type (WT) mice. The skin graft experiments revealed that delayed wound healing depends on humoral factors, but not on kl/kl skin tissue. The mRNA expression levels of cytokines related to acute inflammation including IL-1β, IL-6 and TNF-α were higher in wound lesions of kl/kl mice compared with the levels in WT mice by RT-PCR analysis. LPS-induced TNF-α production model using spleen cells revealed that TNF-α production was significantly increased in the presence of FGF23. Thus, higher levels of FGF23 in kl/kl mouse may have a role to increase TNF-α production in would lesion independently of α-Klotho protein, and impair granulation formation and delay wound healing.

The Innate Immune System in Acute and Chronic Wounds

Significance: This review article provides an overview of the critical roles of the innate immune system to wound healing. It explores aspects of dysregulation of individual innate immune elements known to compromise wound repair and promote nonhealing wounds. Understanding the key mechanisms whereby wound healing fails will provide seed concepts for the development of new therapeutic approaches.

Recent Advances: Our understanding of the complex interactions of the innate immune system in wound healing has significantly improved, particularly in our understanding of the role of antimicrobials and peptides and the nature of the switch from inflammatory to reparative processes. This takes place against an emerging understanding of the relationship between human cells and commensal bacteria in the skin.

Critical Issues: It is well established and accepted that early local inflammatory mediators in the wound bed function as an immunological vehicle to facilitate immune cell infiltration and microbial clearance upon injury to the skin barrier. Both impaired and excessive innate immune responses can promote nonhealing wounds. It appears that the switch from the inflammatory to the proliferative phase is tightly regulated and mediated, at least in part, by a change in macrophages. Defining the factors that initiate the switch in such macrophage phenotypes and functions is the subject of multiple investigations.

Future Directions: The review highlights processes that may be useful targets for further investigation, particularly the switch from M1 to M2 macrophages that appears to be critical as dysregulation of this switch occurs during defective wound healing.

Adalimumab treatment leads to reduction of tissue tumor necrosis factor-alpha correlated with venous leg ulcer improvement: a pilot study

Venous leg ulcers (VLUs) have higher tumor necrosis factor-α (TNF-α) levels compared with normal skin. Refractory VLUs of long duration have higher TNF-α levels compared with VLUs of shorter duration. As up to 75% of VLUs fail to heal with standard care, we sought to evaluate the role of anti-TNF-α therapy for patients with refractory VLUs. Evaluable data were obtained in four of five subjects with recalcitrant VLUs treated with 80 mg of subcutaneous adalimumab at week 0 and with 40 mg at week 2 along with compression therapy and were followed-up for 6 weeks. Wound biopsies taken at weeks 0 and 4 were stained with anti-TNF-α antibodies. Average 4-week percent wound size reduction was 20.5% ± 6.4%. Two patients had wound size reduction more than 25%, and their percent wound size reduction correlated to percent TNF-α staining score reductions (P = 0.02, R(2) = 0.999). VLU TNF-α level decrease 4 weeks post-adalimumab treatment correlated with wound healing.

Endoplasmic reticulum-resident chaperones modulate the inflammatory and angiogenic responses of endothelial cells

BACKGROUND

Wound healing depends on a well-balanced regulation of inflammation and angiogenesis. In chronic wounds the healing process is disturbed and inflammation persists. Regulation of wound closure is controlled by transmembrane and extracellular proteins, the folding and maturation of which occur in the endoplasmic reticulum (ER) by ER-resident chaperone machinery.

OBJECTIVES

To study the role of the ER-resident chaperones BiP/Grp78, its cochaperone Mdg1/ERdJ4, and Grp94 in chronic, nonhealing wounds.

METHODS

Immunohistochemical staining of these chaperones in individual human biopsies and investigation of the possible role of BiP and Mdg1 in endothelial cells, focusing on their inflammatory response and angiogenic potential.

RESULTS

In all chronic wounds investigated, the levels of these ER-resident chaperones were elevated in endothelial cells and leucocytes. The proangiogenic role of BiP has been shown in tumour growth studies before and was confirmed in this study. Proangiogenic activity of the cochaperone Mdg1 has been postulated before but could not be confirmed in this study. The chemokine tumour necrosis factor (TNF)-α was shown to trigger the presentation of proinflammatory adhesion molecules and the release of proinflammatory cytokines. Here we show that TNF-α does not affect endogenous chaperone levels, but that the ER-resident chaperones BiP and Mdg1 modulate the cellular TNF-α-induced proinflammatory response.

CONCLUSIONS

According to the presented data we assume that in chronic wounds upregulated levels of ER-resident chaperones might contribute to persistent inflammation in chronic wounds. Therapies to downregulate chaperone levels might provide a tool that switches the imbalanced chronic wound microenvironment from inflammation to healing.

Topical application of recombinant platelet-derived growth factor increases the rate of healing and the level of proteins that regulate this response

A bipedicle ischaemic rat skin flap model was used to study the effects of daily topical applications of platelet-derived growth factor (PDGF) on the healing of ischaemic wounds. Levels of tumour necrosis factor-alpha (TNFA), interleukin 1-beta (IL1B) and both the latent and active forms of matrix metalloproteinase 2 (MMP2) and 9 (MMP9) were measured. Full-thickness wounds were made on a total of 72 adult male Sprague-Dawley rats. Each group of 18 rats with normal and ischaemic wounds received either vehicle or 0·01% recombinant PDGF-BB. Additional applications were made on the wounds on a daily basis. Wound areas were measured at 0, 1, 3, 5, 7 9 and 13 days after wounding. Ischaemia caused a delay in wound healing as well as an increase in TNFA, IL1B and both the pro and active forms of MMP2 and MMP9. PDGF accelerated the rate of wound healing in both normal and ischaemic wounds and negated the effect of ischaemia. PDGF reduced the TNFA concentration in both normal and ischaemic wounds, and the rate of wound healing closely resembled the pattern of TNFA protein expression. PDGF also reduced both the magnitude and duration of the increases in IL1B and both the pro and active forms of MMP2 and MMP9 induced by ischaemia.

Delayed wound repair in sepsis is associated with reduced local pro-inflammatory cytokine expression

Sepsis is one of the main causes for morbidity and mortality in hospitalized patients. Moreover, sepsis associated complications involving impaired wound healing are common. Septic patients often require surgical interventions that in-turn may lead to further complications caused by impaired wound healing. We established a mouse model to the study delayed wound healing during sepsis distant to the septic focus point. For this reason cecal ligation and puncture (CLP) was combined with the creation of a superficial wound on the mouse ear. Control animals received the same procedure without CPL. Epithelialization was measured every second day by direct microscopic visualization up to complete closure of the wound. As interplay of TNF-α, TGF-β, matrix metalloproteinases (MMP), and tissue inhibitors of metalloproteinases (TIMP) is important in wound healing in general, TNF-α, TGF-β, MMP7, and TIMP1 were assessed immunohistochemical in samples of wounded ears harvested on days 2, 6, 10 and 16 after wounding. After induction of sepsis, animals showed a significant delay in wound epithelialization from day 2 to 12 compared to control animals. Complete wound healing was attained after mean 12.2± standard deviation (SD) 3.0 days in septic animals compared to 8.7± SD 1.7 days in the control group. Septic animals showed a significant reduction in local pro-inflammatory cytokine level of TNF-α on day 2 and day 6 as well as a reduced expression of TGF-β on day 2 in wounds. A significant lower expression of MMP7 as well as TIMP1 was also observed on day 2 after wounding. The induction of sepsis impairs wound healing distant to the septic focus point. We could demonstrate that expression of important cytokines for wound repair is deregulated after induction of sepsis. Thus restoring normal cytokine response locally in wounds could be a good strategy to enhance wound repair in sepsis.

Influence of continuous or intermittent negative pressure on bacterial proliferation potency in vitro

Negative pressure wound therapy is helpful and effective in the treatment of intractable skin ulcers and defects, not only acute wounds. However, application of negative pressure wound therapy for an infected wound is still controversial. The authors developed an in-vitro model of negative pressure wound therapy and investigated the influence of various types of negative pressure environment on the proliferation potency of non-pathogenic Escherichia coli. E. coli in Luria-Bertani liquid media was cultured at 37°C under different environments, which were normal atmosphere in group 1, continuous negative pressure of 75 mmHg in group 2, intermittent negative pressure of 75 mmHg with cycle time of 1 minute aspiration and 1 minute abeyance in group 3, with the one of 3 minutes aspiration and 3 minutes abeyance in group 4. The relative amounts of E. coli in each group were investigated at different times. The proliferation potency of E. coli was higher under negative pressure than under normal atmosphere; higher under intermittent negative pressure than under continuous negative pressure; and higher under intermittent negative pressure with a short cycle than with a long cycle. It is important to consider the possibility that the intermittent and continuous mode of negative pressure wound therapy may promote proliferation of bacteria in an infected wound with no blood flow like necrotic tissue.

Modulation of inflammation by Cicaderma ointment accelerates skin wound healing

Skin wound healing is a natural and intricate process that takes place after injury, involving different sequential phases such as hemostasis, inflammatory phase, proliferative phase, and remodeling that are associated with complex biochemical events. The interruption or failure of wound healing leads to chronic nonhealing wounds or fibrosis-associated diseases constituting a major health problem where, unfortunately, medicines are not very effective. The objective of this study was to evaluate the capacity of Cicaderma ointment (Boiron, Lyon, France) to accelerate ulcer closure without fibrosis and investigate wound healing dynamic processes. We used a necrotic ulcer model in mice induced by intradermal doxorubicin injection, and after 11 days, when the ulcer area was maximal, we applied Vaseline petroleum jelly or Cicaderma every 2 days. Topical application of Cicaderma allowed a rapid recovery of mature epidermal structure, a more compact and organized dermis and collagen bundles compared with the Vaseline group. Furthermore, the expression of numerous cytokines/molecules in the ulcer was increased 11 days after doxorubicin injection compared with healthy skin. Cicaderma rapidly reduced the level of proinflammatory cytokines, mainly tumor necrosis factor (TNF)-α and others of the TNF pathway, which can be correlated to a decrease of polymorphonuclear recruitment. It is noteworthy that the modulation of inflammation through TNF-α, macrophage inflammatory protein-1α, interleukin (IL)-12, IL-4, and macrophage-colony-stimulating factor was maintained 9 days after the first ointment application, facilitating the wound closure without affecting angiogenesis. These cytokines seem to be potential targets for therapeutic approaches in chronic wounds. Our results confirm the use of Cicaderma for accelerating skin wound healing and open new avenues for sequential treatments to improve healing.

A prospective pilot study of ultrasound therapy effectiveness in refractory venous leg ulcers

Venous insufficiency is the most common cause of leg ulcers in the United States. Venous leg ulcers cost the health care system billions of dollars annually, and healing rates are less than 70% with standard of care; therefore, new therapies are needed to increase healing times and minimize associated costs. Non contact ultrasound therapy has been used to treat a variety of chronic wounds including venous leg ulcers, and it is thought that ultrasound has an effect on decreasing the bacterial count in wounds, although the exact mechanism of action of ultrasound is yet to be determined. We conducted an open labelled pilot study of 10 refractory venous ulcers of large size to determine the effect of non contact ultrasound on wound closure, bacterial counts, expression of inflammatory cytokines and pain reduction. We lacked a sham control group but we compared the baseline and end of treatment assessments and noted the differences. We found a significant reduction in wound area (P = 0·0039) over the 4-week treatment period. We also found a decline in individual and total bacterial counts; however, these differences were not significant. For all patients, there was also a trend toward reduced inflammatory cytokine expression compared with baseline levels; however, this reduction did not reach statistical significance. Interestingly, there was a correlation between healing and change in cytokine expression, which showed statistically significance for tumour necrosis factor (TNF)-αP = 0·0395, IL-1a P = 0·0351, IL-6 P = 0·0508, IL-8 P = 0·0990. Pain as measured by the visual analogue scale (VAS) was reduced from 4 at the baseline to 2·7 by the end of the study. In conclusion, we found that patients treated with ultrasound therapy and compression therapy show clinical improvement over the course of 4 weeks and had a decrease in inflammatory cytokines, bacterial counts and pain.