Kindlin-1 contributes to EGF-induced re-epithelialization in skin wound healing

Comparison effects of platelet-rich plasma on healing of infected and non-infected excision wounds by the modulation of the expression of inflammatory mediators: experimental research

INTRODUCTION

Microbial invasion in soft tissue is believed to cause infectious wounds and increase healthcare costs, anxiety, and distress. The current study was conducted to evaluate the effects of topical use of platelet-rich plasma (PRP) on infected wound-healing process in rats.

METHODS

Following the induction of a circular wound, the animals were divided into three groups, including (1) standard control: infected wounds treated with mupirocin (SDCL), (2) non-infected wounds treated with PRP (PRP), and (3) infected group in which the rats were infected with Staphylococcus epidermidis and Pseudomonas aeruginosa and treated with PRP (INF + PRP). To evaluate the effects of PRP on the wound-healing rate, total bacterial count, histopathological assessment, the serum concentrations of sialic acid, C-reactive protein, haptoglobin, and fibrinogen were assessed. Additionally, IL-1β, IL-6, TNF-α, IL-3, NF-κB, iNOS, PDGF, and EGF mRNA level expressions were assessed employing the qRT-PCR method.

RESULTS

The results indicated that topical application of PRP could significantly decrease total bacterial count, the level of C-reactive protein, and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) compared to the SDCL group. The administration of PRP also promoted re-epithelization rate by increasing the expression of EGF mRNA level.

CONCLUSION

We could recommend the use of PRP for the treatment of infected wounds owing to its efficiency in decreasing colonization of tissue bacteria, tissue inflammation, and stimulating wound heal-up.

Platelet-Released Growth Factors Induce Genes Involved in Extracellular Matrix Formation in Human Fibroblasts

Platelet concentrate products are increasingly used in many medical disciplines due to their regenerative properties. As they contain a variety of chemokines, cytokines, and growth factors, they are used to support the healing of chronic or complicated wounds. To date, underlying cellular mechanisms have been insufficiently investigated. Therefore, we analyzed the influence of Platelet-Released Growth Factors (PRGF) on human dermal fibroblasts. Whole transcriptome sequencing and gene ontology (GO) enrichment analysis of PRGF-treated fibroblasts revealed an induction of several genes involved in the formation of the extracellular matrix (ECM). Real-time PCR analyses of PRGF-treated fibroblasts and skin explants confirmed the induction of ECM-related genes, in particular transforming growth factor beta-induced protein (TGFBI), fibronectin 1 (FN1), matrix metalloproteinase-9 (MMP-9), transglutaminase 2 (TGM2), fermitin family member 1 (FERMT1), collagen type I alpha 1 (COL1A1), a disintegrin and metalloproteinase 19 (ADAM19), serpin family E member 1 (SERPINE1) and lysyl oxidase-like 3 (LOXL3). The induction of these genes was time-dependent and in part influenced by the epidermal growth factor receptor (EGFR). Moreover, PRGF induced migration and proliferation of the fibroblasts. Taken together, the observed effects of PRGF on human fibroblasts may contribute to the underlying mechanisms that support the beneficial wound-healing effects of thrombocyte concentrate products.

Epidermal Growth Factor in Aesthetics and Regenerative Medicine: Systematic Review

Introduction:

Epidermal Growth Factor (rhEGF) is a promising skin antiaging agent that successfully promotes skin wound repair, and it has been investigated in the past decade for these purposes. However, there are no updated systematic reviews, in English or English, that support the efficacy of rhEGF as a regenerative skin treatment or systematic reviews that compile the uses of rhEGF as facial aesthetic therapy and regenerative medicine.

Aim:

To describe the current state of facial aesthetic and regenerative medicine treatments in which rhEGF has been effectively used.

Materials and Methods:

An exhaustive search was carried out in “Medline” (via “PubMed”), “Cochrane,” “Bireme” through the Virtual Health Library (VHL), “Elsevier” via “Science Direct,” “Springer,” “SciELo,” “ResearchGate,” and Google Scholar. Studies related to the use of rhEGF in addressing skin disorders or skin aging are included.

Results:

Overall, 49 articles were found, which described the use of rhEGF for skin regeneration and restructuring. Efficacy in the regeneration of skin wounds was verified through the intradermal and topical application of formulations with rhEGF. Most clinical trials in aesthetics point to an effective inversion of skin aging. However, uncontrolled or randomized trials abound, so that does not represent enough evidence to establish its efficiency. There are transient adverse effects for both cases.

Conclusion:

The rhEGF considers an effective therapeutic alternative for patients with recalcitrant skin wounds and skin aging, as it is a potent and specific mitogenic factor for the skin.

The wound healing effect of local leukocyte platelet-rich plasma after total hip arthroplasty: A randomized controlled trial

Rapid wound closure is important after arthroplasty procedures to prevent postoperative complications. Platelets are rich in growth factors and leukocytes contribute to innate immunity. We hypothesized that topical leukocyte platelet-rich plasma (L-PRP) derived from the blood of patients would be beneficial to wound healing. In this randomized controlled trial, patients subjected to elective total hip arthroplasty (THA) were assigned by concealed allocation either L-PRP application onto the sutured fascia or no application (control) after the THA intervention. In addition, all patients received 1.5 g protein/kg, 5 g L-arginine, 500 mg vitamin C and 44 mg zinc daily over the 4-week postoperative period to obtain optimal nutrition. The primary endpoint was complete healing of the skin incision. The secondary endpoints were blood transfusions, length of hospital stay, pain and wound infections. Sixteen patients in the L-PRP group and 17 patients in the control group completed the trial. L-PRP treatment accelerated complete wound healing after 3 weeks (seven in the L-PRP group vs. zero in the control group, p = 0.003) and after 4 weeks (12 in the L-PRP group vs. six in the control group, p = 0.037). No postoperative superficial wound infections occurred within 4 weeks, and there were no significant differences in the other secondary outcomes. L-PRP generated in 10 sex-matched healthy volunteers revealed increased concentrations of platelets (5.8-fold) and leukocytes (2.3-fold) compared with those in whole blood. Furthermore, the concentration of keratinocyte mitogen epidermal growth factor in L-PRP (380 ± 130 pg/ml, mean ± SD) was higher (p < 0.001) than that in serum (130 ± 26 pg/ml). In conclusion, a single intraoperative local application of L-PRP promoted wound healing after THA, possibly mediated by EGF receptor agonists.

The senescence-associated secretory phenotype: Fueling a wound that never heals

Wound healing is impaired with advanced age and certain chronic conditions, such as diabetes and obesity. Moreover, common cancer treatments, including chemotherapy and radiation, can cause unintended tissue damage and impair wound healing. Available wound care treatments are not always effective, as some wounds fail to heal or recur after treatment. Hence, a more thorough understanding of the pathophysiology of chronic, nonhealing wounds may offer new ideas for the development of effective wound care treatments. Cancers are sometimes referred to as wounds that never heal, sharing mechanisms similar to wound healing. We describe in this review how cellular senescence and the senescence-associated secretory phenotype (SASP) contribute to chronic wounds versus cancer.

Umbilical Cord Mesenchymal Stem Cells for Inflammatory Regulation After Excision and Grafting of Severe Burn Wounds in Rats

Severe burns predispose to shock and necessitate escharectomy and skin grafting. Previous studies show that mesenchymal stem cells are effective for burn wound healing and immune regulation. In this study, we combined escharectomy and skin grafting after burn injury with stem cell application, so as to examine the immune regulation of stem cells and the effect on the transplanted skin graft. SD rats were randomly divided into normal group, sham group, normal + hUCMSCs group, and normal + SB203580 group. Normal saline, hUCMSCs, and SB203580 were injected into the tail vein of each group, and serum inflammatory factors were detected by ELISA. The expression of p38 MAPK/NF-κB pathway proteins in rat liver was detected by western blot. Skin activity was detected by Trypan blue staining and western blot. Skin graft inflammatory infiltration was detected by histological analysis. We found that hUCMSCs could regulate the phosphorylation levels of P38MAPK and NF-B P65 proteins in the liver to reduce the inflammatory response. These effects could continue to reduce the production of inflammatory factors HMGB-1, IL-6, and TNF-α, and increase the anti-inflammatory factor IL-10. The infiltration of inflammatory cells in skin graft was significantly reduced in the normal + hUCMSCs group, and the macrophages in the hUCMSCs group polarized to the anti-inflammatory M2 direction in 3 days. However, the changes of skin graft activity and necroptosis markers protein RIP3 were not observed. The present study demonstrates the immunomodulatory effects of hUCMSCs on the systemic and skin graft microenvironment after excision.

Fermitin family homolog 2 (Kindlin-2) affects vascularization during the wound healing process by regulating the Wnt/β-catenin signaling pathway in vascular endothelial cells

Kindlin-2 is a member of the FERM-containing cytoskeletal protein family that regulates cell–matrix interactions. Previous studies have shown that Kindlin-2 recruits focal adhesion proteins and regulates integration by binding to the focal adhesion region of the integrin β-segment. Although Kindlin-2 has been reported to be involved in various skin diseases and many kinds of tumors, its role in the skin wound healing process remains unclear. The aim of the present study was to investigate the role of Kindlin-2 in the regulation of wound healing. The effects of Kindlin-2 on wound healing were studied by a wound healing model, kindlin-2 (±) mice. The effects of Kindlin-2 on cell migration, cellular tube formation, and cell adhesion and spreading were evaluated in human umbilical vein endothelial cells (HUVECs) with downregulated Kindlin-2 expression. We found that the expression of kindlin-2 was elevated in wound healing tissues and that interfering with the expression of Kindlin-2 delayed the wound healing process and reduced neovascularization. We found that the wound healing of kindlin-2 (±) mice was delayed, with a decreased number of new blood vessels. Furthermore, depletion of Kindlin-2 impaired HUVEC spreading, migration and tube formation. Intriguingly, we found that kindlin-2 binds to β-catenin in the Wnt/β-catenin signaling pathway and cooperates with β-catenin to enter the nucleus from the cytoplasm, activating the downstream Wnt/β-catenin signaling pathway. Taken together, these results help to elucidate the mechanism of Kindlin-2 in the regulation of the wound healing process and provide a theoretical basis for further study of wound healing and abnormal healing.

Development of stabilized dual growth factor-loaded hyaluronate collagen dressing matrix

Patients with diabetes experience impaired growth factor production such as epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF), and they are reportedly involved in wound healing processes. Here, we report dual growth factor-loaded hyaluronate collagen dressing (Dual-HCD) matrix, using different ratios of the concentration of stabilized growth factors—stabilized-EGF (S-EGF) and stabilized-bFGF (S-bFGF). At first, the optimal concentration ratio of S-EGF to S-bFGF in the Dual-HCD matrix is determined to be 1:2 in type I diabetic mice. This Dual-HCD matrix does not cause cytotoxicity and can be used in vivo. The wound-healing effect of this matrix is confirmed in type II diabetic mice. Dual HCD enhances angiogenesis which promotes wound healing and thus, it shows a significantly greater synergistic effect than the HCD matrix loaded with a single growth factor. Overall, we conclude that the Dual-HCD matrix represents an effective therapeutic agent for impaired diabetic wound healing.

Identification of a novel collagen-like peptide by high-throughput screening for effective wound-healing therapy

Tissue regeneration and wound healing are still serious clinical complications globally and lack satisfactory cures. Inspired by the impressive regeneration ability of the post-injury earthworms and their widely accepted medicinal properties, we screened and identified a novel collagen-like peptide from the amputated earthworms using high-throughput techniques, including transcriptomics, proteomics, and mass spectrum. The identified collagen-like peptide col4a1 was cloned and expressed to comprehensively investigate the wound healing effect and underlying mechanism. It exerted significant effects on wound healing both in vitro and in vivo, including enhanced viability, proliferation, migration of fibroblasts, granulation, and collagen deposition. Moreover, the col4a1 functioned via binding with integrin α₂β₁ and upregulating the RAS/MAPK signaling pathway. This work demonstrates that the novel collagen-like peptide col4a1 obtained from the amputated earthworms enables enhanced wound healing and provides new opportunities for wound care.

IN VITRO ASSESSMENT OF THE BIOLOGICAL ACTIVITY OF A NEW REGENERATIVE AGENT PREPARED FROM THE CONCENTRATE OF DEPROTEINIZED DERMAL LAYER OF PORCINE SKIN

Background. Presently, a prospective direction for the development of regenerative medicine in the world is the search for regulatory molecules and the identification of molecular targets to stimulate the body's endogenous regenerative potential. The concentrate of the deproteinized dermal layer of porcine skin (СDDLPS) is a new therapeutic agent with restorative properties, the action of which is directed on the induction of the self resources of cells. Aim. The assessment of the effect of СDDLPS on the proliferative activity of mammalian cells of different histogenesis in vitro. Materials and Methods. To determine the amino acid composition of the СDDLPS liquid chromatography and biochemical methods were used. The biological effects and mechanisms of action of the drug were investigated by cell culture and molecular biological methods. The research was carried out using stable cell lines: human keratinocytes (HaCaT cell line), porcine endothelial cells (PAE cell line), bovine kidney cells (MDBK cell line) and mouse fibroblasts (3T3A31 cell line). Results. The cells of the bovine kidney MDBK cell line were the most sensitive to the effect of the CDDLPS. Also, the obtained results suggest that, depending on the concentration, the drug not only stimulates cell proliferation by 10–30 %, but also significantly enhances biosynthetic processes in cells, in particular, protein synthesis by 20–40 %. Conclusions. CDDLPS is an effective and affordable therapeutic agent with restorative properties, the biological activity of which manifests itself in the activation of cell biosynthetic and proliferative potentials and is comparable to effects of some growth factors, in particular epidermal growth factor

Platelet-Released Growth Factors and Platelet-Rich Fibrin Induce Expression of Factors Involved in Extracellular Matrix Organization in Human Keratinocytes

Platelet-released growth factor (PRGF) is a thrombocyte concentrate lysate which, like its clinically equivalent variations (e.g., Vivostat PRF^® (platelet-rich fibrin)), is known to support the healing of chronic and hard-to-heal wounds. However, studies on the effect of PRGF on keratinocytes remain scarce. This study aims to identify genes in keratinocytes that are significantly influenced by PRGF. Therefore, we performed a whole transcriptome and gene ontology (GO) enrichment analysis of PRGF-stimulated human primary keratinocytes. This revealed an increased expression of genes involved in extracellular matrix (ECM) organization. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) analysis confirmed the PRGF-mediated induction of selected ECM-related factors such as transforming growth factor beta-induced protein, fibronectin 1, matrix metalloproteinase-9, transglutaminase 2, fermitin family member 1, collagen type I alpha 1 and collagen type XXII alpha 1. PRGF-induced expression of the above factors was influenced by blockade of the epidermal growth factor receptor (EGFR), a receptor playing a crucial role in wound healing. A differential induction of the investigated factors was also detected in skin explants exposed to PRGF and in experimentally generated in vivo wounds treated with Vivostat PRF^®. Together, our study indicates that the induction of ECM-related factors may contribute to the beneficial wound-healing effects of PRGF-based formulations.

A Frog-Derived Immunomodulatory Peptide Promotes Cutaneous Wound Healing by Regulating Cellular Response

Wound healing-promoting peptides exhibit excellent therapeutic potential in regenerative medicine. However, amphibian-derived wound healing-promoting peptides and their mechanism of action remain to be further elucidated. We hereby characterized a wound healing-promoting peptide, Ot-WHP, derived from Chinese concave-eared frog Odorrana tormota. It efficiently promoted wound healing in a mouse model of full-thickness wounds. Ot-WHP significantly increased the number of neutrophils in wounds, and modestly promoted neutrophil phagocytosis and phorbol myristate acetate (PMA)-induced neutrophil extracellular trap formation. Ot-WHP also significantly increased the number of macrophages in wound sites, and directly induced chemokine, cytokine and growth factor production in macrophages by activating mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) signaling pathways. Of note, Ot-WHP did not act as a chemoattractant for neutrophils and macrophages, suggesting its chemotactic activity depends on inducing chemoattractant production in macrophages. Besides, Ot-WHP directly promoted keratinocyte migration by enhancing integrin expression and cell adhesion. In addition, Ot-WHP significantly enhanced the cross-talk between macrophages and keratinocytes/fibroblasts by promoting keratinocyte/fibroblast proliferation, and fibroblast-to-myofibroblast transition despite having no direct effects on keratinocyte/fibroblast proliferation, and fibroblast differentiation. Collectively, Ot-WHP directly elicited the production of regulatory factors in macrophages, consequently initiated and accelerated the inflammatory phase by recruiting neutrophils and macrophages to wounds, and in turn enhanced the cross-talk between macrophages and keratinocytes/fibroblasts, additionally promoted keratinocyte migration, and finally promoted cutaneous wound healing. Our findings provide a promising immunomodulator for acute wound management and new clues for understanding the mechanism of action of amphibian-derived wound healing-promoting peptides.

Re-epithelialization of adult skin wounds: Cellular mechanisms and therapeutic strategies

Cutaneous wound healing in adult mammals is a complex multi-step process involving overlapping stages of blood clot formation, inflammation, re-epithelialization, granulation tissue formation, neovascularization, and remodelling. Re-epithelialization describes the resurfacing of a wound with new epithelium. The cellular and molecular processes involved in the initiation, maintenance, and completion of epithelialization are essential for successful wound closure. A variety of modulators are involved, including growth factors, cytokines, matrix metalloproteinases, cellular receptors, and extracellular matrix components. Here, we focus on cellular mechanisms underlying keratinocyte migration and proliferation during epidermal closure. Inability to re-epithelialize is a clear indicator of chronic non-healing wounds, which fail to proceed through the normal phases of wound healing in an orderly and timely manner. This review summarizes the current knowledge regarding the management and treatment of acute and chronic wounds, with a focus on re-epithelialization, offering some insights into novel future therapies.

Adipose mesenchymal stem cell-derived exosomes promote cell proliferation, migration, and inhibit cell apoptosis via Wnt/β-catenin signaling in cutaneous wound healing

Cutaneous wounds, a type of soft tissue injury, are difficult to heal in aging. Differentiation, migration, proliferation, and apoptosis of skin cells are identified as key factors during wound healing processes. Mesenchymal stem cells have been documented as possible candidates for wound healing treatment because their use could augment the regenerative capacity of many tissues. However, the effects of exosomes derived from adipose-derived stem cell (ADSC-exos) on cutaneous wound healing remain to be carefully elucidated. In this present study, HaCaT cells were exposed to hydrogen peroxide (H₂ O ₂ ) for the establishment of the skin lesion model. Cell Counting Kit-8 assay, migration assay, and flow cytometry assay were conducted to detect the biological function of ADSC-exos in skin lesion model. Finally, the possible mechanism was further investigated using Western blot assay. The successful construction of the skin lesion model was confirmed by results of the enhanced cell apoptosis of HaCaT cells induced by H ₂ O ₂ , the increased Bax expression and decreased Bcl-2 expression. CD9 and CD63 expression evidenced the existence of ADSC-exos. The results of functional experiments demonstrated that ADSC-exos could prompt cell proliferation and migration of HaCaT cells, and repress cell apoptosis of HaCaT cells. In addition, the activation of Wnt/β-catenin signaling was confirmed by the enhanced expression of β-catenin at the protein level. Collectively, our findings suggest that ADSC-exos play a positive role in cutaneous wound healing possibly via Wnt/β-catenin signaling. Our study may provide new insights into the therapeutic target for cutaneous wound healing.

Visfatin Promotes Wound Healing through the Activation of ERK1/2 and JNK1/2 Pathway

Visfatin, a member of the adipokine family, plays an important role in many metabolic and stress responses. The mechanisms underlying the direct therapeutic effects of visfatin on wound healing have not been reported yet. In this study, we examined the effects of visfatin on wound healing in vitro and in vivo. Visfatin enhanced the proliferation and migration of human dermal fibroblasts (HDFs) and keratinocytes the expression of wound healing-related vascular endothelial growth factor (VEGF) in vitro and in vivo. Treatment of HDFs with visfatin induced activation of both extracellular signal-regulated kinases 1 and 2 (ERK1/2) and c-Jun N-terminal kinases 1 and 2 (JNK1/2) in a time-dependent manner. Inhibition of ERK1/2 and JNK1/2 led to a significant decrease in visfatin-induced proliferation and migration of HDFs. Importantly, blocking VEGF with its neutralizing antibodies suppressed the visfatin-induced proliferation and migration of HDFs and human keratinocytes, indicating that visfatin induces the proliferation and migration of HDFs and human keratinocytes via increased VEGF expression. Moreover, visfatin effectively improved wound repair in vivo, which was comparable to the wound healing activity of epidermal growth factor (EGF). Taken together, we demonstrate that visfatin promotes the proliferation and migration of HDFs and human keratinocytes by inducing VEGF expression and can be used as a potential novel therapeutic agent for wound healing.

Transforming Growth Factor Beta (TGFβ1) and Epidermal Growth Factor (EGF) as Biomarkers of Leishmania (V) braziliensis Infection and Early Therapeutic Response in Cutaneous Leishmaniasis: Studies in Hamsters

Introduction: In cutaneous leishmaniasis, the host immune response is responsible for the development of skin injuries but also for resolution of the disease especially after antileishmanial therapy. The immune factors that participate in the regulation of inflammation, remodeling of the extracellular matrix, cell proliferation and differentiation may constitute biomarkers of diseases or response to treatment. In this work, we analyzed the production of the growth factors EGF, TGFβ1, PDGF, and FGF during the infection by Leishmania parasites, the development of the injuries and the early response to treatment. Methodology: Golden hamsters were infected with L. (V) braziliensis. The growth factors were detected in skin scrapings and biopsies every 2 weeks after infected and then at day 7 of treatment with different drug candidates by RT-qPCR. The parasitic load was also quantified by RT-qPCR in skin biopsies sampled at the end of the study. Results: The infection by L. (V) braziliensis induced the expression of all the growth factors at day 15 of infection. One month after infection, EGF and TGFβ1 were expressed in all hamsters with inverse ratio. While the EGF and FGF levels decreased between day 15 and 30 of infection, the TGFβ1 increased and the PGDF levels did not change. The relative expression of EGF and TGFβ1 increased notably after treatment. However, the increase of EGF was associated with clinical cure while the increase of TGFβ1 was associated with failure to treatment. The amount of parasites in the cutaneous lesion at the end of the study decreased according to the clinical outcome, being lower in the group of cured hamsters and higher in the group of hamsters that had a failure to the treatment. Conclusions: A differential profile of growth factor expression occurred during the infection and response to treatment. Higher induction of TGFβ1 was associated with active disease while the higher levels of EGF are associated with adequate response to treatment. The inversely EGF/TGFβ1 ratio may be an effective biomarker to identify establishment of Leishmania infection and early therapeutic response, respectively. However, further studies are needed to validate the utility of the proposed biomarkers in field conditions.

Knockdown of the KINDLIN-2 Gene and Reduced Expression of Kindlin-2 Affects Vascular Permeability in Angiogenesis in a Mouse Model of Wound Healing

Background

Angiogenesis is an important component of wound healing and tissue repair. Kindlin-2 is an integrin-associated protein, encoded by the KINDLIN-2 gene, which has been shown to affect cell adhesion and migration of cells, including endothelial cells. The aim of this study was to use a mouse model of wound healing to evaluate the effects of expression of KINDLIN-2 on angiogenesis in wound healing in vivo.

Material/Methods

Thirty-six male C57BL/6 mice were studied in an established model that used a wound created on the back. Mice were divided randomly into three groups: the normal group (n=12) received injections of normal (0.9%) saline; the KINDLIN-2(−) group (n=12) received injections of adeno-associated virus with small interfering (si)RNA targeting the KINDLIN-2 gene (AAV-KINDLIN-2-siRNA); and the control (group (n=12) received injections of adeno-associated virus containing a scrambled RNA sequence (AAV-control-RNA). Wound healing was analyzed by biochemical examination of the exudates and histology. Evans blue dye was injected into the caudal vein of each mouse, two weeks after wound healing to assess neovascular permeability.

Results

Wound healing was significantly delayed in the KINDLIN-2 gene knockdown mice (AAV-KINDLIN-2-siRNA) compared with that of the normal group and the control group, and neovascular permeability was increased. In the AAV-KINDLIN-2-siRNA group, blood vessels were shorter and thinner compared with the normal group and the control group.

Conclusions

In a mouse model of wound healing, KINDLIN-2 gene knockdown inhibited wound healing, and increased neovascular permeability in vivo.

Topical epidermal growth factor spray for the treatment of chronic diabetic foot ulcers: A phase III multicenter, double-blind, randomized, placebo-controlled trial

AIMS

This study was conducted to evaluate the efficacy and safety of a novel spray-applied growth factor therapy containing recombinant human epidermal growth factor (rhEGF) for the treatment of chronic diabetic foot ulcers (DFU).

METHODS

This study was a phase III double-blind, randomized, placebo-controlled trial. 167 adult patients at six medical centers were randomized to receive routine wound care plus either topical spray treatment with 0.005% rhEGF (n = 82) or an equivalent volume of saline spray (n = 85) twice a day until ulcer healing or for up to 12 weeks.

RESULTS

Demographics, medical status, and wound characteristics were comparable between rhEGF and placebo groups. More patients in the rhEGF group significantly had complete wound healing compared to placebo (73.2% versus 50.6%, respectively; P = .001). Wound healing velocity was faster in the rhEGF group (P = .029) regardless of HbA1c levels. The rhEGF group had a shorter median time to 50% ulcer size reduction (21 versus 35 days; hazard ratio = 3.13, P < .001) and shorter time to complete ulcer healing (56 versus 84 days; hazard ratio = 2.13, P < .001).

CONCLUSIONS

This study confirms that application of spray-applied rhEGF in DFU patients results in faster healing velocity and higher complete healing rate regardless of HbA1c levels.

Kindlins: Roles in development and cancer progression

The Kindlins are FERM domain proteins comprising three members (Kindlin-1, -2 and -3) which are evolutionarily conserved. Kindlins bind with β-integrin cytoplasmic tails and execute broad biological functions including directed cell migration, proliferation, differentiation and survival. In light of more and more evidence point to the importance of Kindlin family members in normal development and human diseases especially in cancers, we aim to portrait the profile of Kindlins in the regulation of embryonic development and cancer progression. We first summarize all the known binding proteins for individual member of Kindlin family. We then outline the Kindlin-regulated signaling pathways including Wnt/β-catenin, TGFβ, EGFR, and Hedgehog signalings. Furthermore, we descript the pivotal role of Kindlins in embryonic development in detail with notions that Kindlin-1 is highly expressed in endo/ectodermal originated tissues, Kindlin-2 is highly expressed in mesoderm-derived tissues and Kindlin-3 is highly expressed in mesoderm- and ectoderm-derived tissues. Deregulation of Kindlins is generally reported in cancers from different organs. We also briefly descript the role of Kindlins in other diseases. Finally, we update the recent understanding of how Kindlins are regulated and modified as well as the degradation mechanism of Kindlins, respectively.

Tobacco exposure and wound healing in head and neck surgical wounds

OBJECTIVE

Smoking impairs wound healing, yet the underlying pathophysiological mechanisms are unclear. We evaluated tobacco-altered healing in head and neck surgery by studying the association between biomarkers and tobacco exposure, as well as cutaneous perfusion by smoking status.

STUDY DESIGN

Prospective cohort study, tertiary/academic care center, 2011 to present.

METHODS

Patients who required head and neck surgery were enrolled prospectively. Postsurgical drain fluid was collected 24 hours postoperatively. Biomarkers associated with postulated mechanisms of smoking-impaired healing were assayed. These included interleukin-1, -6, and -8; tumor necrosis factor- alpha; transforming growth factor-beta; epidermal growth factor (EGF); basic fibroblastic growth factor (bFGF); C-reactive protein; vascular endothelial growth factor; soluble FMS-like tyrosine kinase-1 (sFLT-1); and placental growth factor. Tobacco exposure and clinical outcomes were recorded. Two sample two-sided t tests evaluated the differences in cytokine levels by tobacco exposure. In a second cohort, cutaneous vascular assessment via indocyanine green angiography was compared by smoking status.

RESULTS

Twenty-eight patients were enrolled with drain fluid collection. Twenty-one subjects were current/former smokers, whereas seven were never smokers. EGF was higher in never smokers than smokers in a statistically significant manner (P = 0.030). Likewise, sFLT-1 was significantly higher in never smokers (P = 0.011). Cutaneous angiography revealed nonsmokers to have significantly higher cutaneous perfusion than smokers.

CONCLUSION

In this head and neck surgical cohort, significantly higher EGF and sFLT-1 levels in wound fluid were associated with never smoking, suggesting that smoking has adverse effects on the inflammatory phase of wound healing. Cutaneous angiography supports the detrimental effect of smoking on skin perfusion. These findings suggest the need for further study as well as therapeutic targets for smokers undergoing surgery.

LEVEL OF EVIDENCE

2b. Laryngoscope, 128:618-625, 2018.