Physiological levels of 5 alpha-dihydrotestosterone depress wound immune function and impair wound healing following trauma-hemorrhage

HYPOTHESIS: Studies indicate that a depressed wound immune function contributes to an increased rate of wound complications and impaired wound healing following trauma-hemorrhage (T-H). Androgen, ie, 5 alpha-dihydrotestosterone, is responsible for producing the depressed systemic cell-mediated immune responses following T-H in males. The aim of the present study was to determine whether depletion of 5 alpha-dihydrotestosterone in males before T-H has any salutary effects on wound immune cell function and wound healing in male mice following T-H. DESIGN: Mice were castrated or sham castrated 14 days before midline laparotomy (ie, tissue trauma) and subcutaneous polyvinyl sponge implantation, followed by hemorrhage (mean +/- SEM blood pressure, 35 +/- 5 mm Hg for 90 minutes and resuscitation) or sham operation. At 24 hours thereafter, wound immune cells from the sponges were harvested and cultured with lipopolysaccharide A. Release of interleukin 1 beta (IL-1 beta) and IL-6 (in picograms per milliliter) was determined in the supernatants by enzyme-linked immunosorbent assay. In addition, IL-6 was assessed at the wound site by immunohistochemistry. Ten days after T-H, wound-breaking strength was measured. RESULTS: Precastration prevented the significantly suppressed capacity of wound immune cells to release IL-1 beta and IL-6. In addition, precastration normalized the elevated IL-6 expression at the wound site in the T-H mice. Moreover, wound-breaking strength was improved in castrated mice 10 days after T-H. CONCLUSIONS: Male sex steroids appear to be responsible for wound immune cell dysfunction following trauma and severe blood loss. Because decreasing androgen levels resulted in improved wound healing, our results suggest that the use of androgen receptor-blocking agents, eg, flutamide, following T-H might represent a novel adjunct for decreasing the rate of wound complications under those conditions.     

L-arginine: a unique amino acid for improving depressed wound immune function following hemorrhage

OBJECTIVE: To determine whether L-arginine has any salutary effects on wound immune cell function following trauma-hemorrhage. BACKGROUND: Depressed wound immune function contributes to an increased incidence of wound infections following hemorrhage. Although administration of L-arginine has been shown to restore depressed cell-mediated immune responses following hemorrhage potentially by maintaining organ blood flow, it remains unknown whether L-arginine has any salutary effects on the depressed local immune response at the wound site. METHODS: Male mice were subjected to a midline laparotomy and polyvinyl sponges were implanted subcutaneously in the abdominal wound prior to hemorrhage (35 +/- 5 mm Hg for 90 min and resuscitation) or sham operation. During resuscitation mice received 300 mg/kg body weight L-arginine or saline (vehicle). Sponges were harvested 24 h thereafter, wound fluid collected and wound immune cells cultured for 24 h in the presence of LPS. Pro- (IL-1 beta, IL-6) and anti-inflammatory (IL-10) cytokines were determined in the supernatants and the wound fluid. In addition, wounds were stained for IL-6 immunohistochemically. In a separate set of animals, skin and muscle blood flow was determined by microspheres. RESULTS: The capacity of wound immune cells to release IL-1 beta and IL-6 in vitro was significantly depressed in hemorrhaged mice receiving vehicle. Administration of L-arginine, however, improved wound immune cell function. In contrast, in vivo the increased IL-6 release at the wound site was decreased in L-arginine-treated mice following hemorrhage. Moreover, IL-10 levels were significantly increased in the wound fluid in hemorrhaged animals receiving L-arginine compared to vehicle-treated mice. In addition, the depressed skin and muscle blood flow after hemorrhage was restored by L-arginine. CONCLUSIONS: Thus, L-arginine might improve local wound cell function by decreasing the inflammatory response at the wound site. Since L-arginine protected wound immune cell function this amino acid might represent a novel and useful adjunct to fluid resuscitation for decreasing wound complications following hemorrhage.     

L-arginine improves wound healing after trauma-hemorrhage by increasing collagen synthesis

BACKGROUND: Several studies indicate impaired wound healing after trauma and shock. Wound immune cell dysfunction seems to be responsible for altered wound healing after trauma-hemorrhage (T-H). In this respect, administration of the amino acid L-arginine normalized wound immune cell function under those conditions. It remains unknown, however, whether L-arginine improves impaired wound healing after T-H. METHODS: To study this, male C3H/HeN mice were subjected to a midline laparotomy (i.e., soft tissue trauma induced), and polyvinyl sponges were implanted subcutaneously at the wound site before hemorrhage (35 +/- 5 mm Hg for 90 minutes) or were subjected to sham operation. During resuscitation, mice received 300 mg/kg body weight L-arginine or saline (vehicle). Seven days thereafter, hydroxyproline (OHP), a metabolite of collagen synthesis, was measured in the wound fluid using high-performance liquid chromatography. Collagen types I and III were determined in the wound by Western blot analysis. In addition, wound breaking strength was measured 10 days after T-H or sham operation. RESULTS: The results indicate that OHP was significantly decreased in T-H mice. L-arginine, however, restored depressed OHP in the wound fluid in the T-H animals. Similarly, L-arginine treatment prevented a significant depression of collagen I synthesis after T-H. Collagen III was not significantly affected by T-H or L-arginine. Most important, L-arginine increased maximal wound breaking strength after severe blood loss. Therefore, L-arginine improves wound healing after T-H by increasing collagen synthesis. CONCLUSION: Because L-arginine improves wound healing, the results suggest that L-arginine might represent a novel and useful adjunct to fluid resuscitation for decreasing wound complications after trauma and severe blood loss.     

Supplemental l-arginine enhances wound healing following trauma/hemorrhagic shock

To determine whether parenteral L-arginine supplementation enhances the impaired wound healing of rats subjected to trauma/hemorrhagic shock. Impaired wound healing after trauma and shock has been documented experimentally and clinically. L-arginine has been shown to enhance wound strength and collagen synthesis in rodents and humans. Its efficacy under conditions of impaired wound healing is less well defined. Forty-eight male Lewis rats were used in this study. Using a well-defined model, 24 rats underwent trauma/hemorrhagic shock before wounding. Twenty-four untreated rats served as controls. All animals underwent a dorsal skin incision with implantation of polyvinyl-alcohol sponges. Half of the animals in each group were assigned to receive 1 g/kg/day of L-arginine by intraperitoneal injection in three divided doses, while the other half received saline injections only. Animals were sacrificed 10 days postwounding, and wound-breaking strength (WBS) and wound sponge total hydroxyproline (OHP) and nitrite/nitrate (NO(x)) content were determined. Wound sponge RNA was collected and subjected to Northern blot analysis for procollagens I and III. Trauma/hemorrhage greatly decreased WBS with a concomitant diminution in collagen (OHP) deposition. L-arginine significantly enhanced WBS (19%) and increased OHP (21%) levels in control animals as well as in rats subjected to trauma/hemorrhage (WBS +29%, OHP 40%) compared with their saline-treated counterparts. Procollagen I and III mRNA levels were elevated by L-arginine treatment in both trauma/hemorrhage and control rats. Arginine treatment had no effect on wound fluid and plasma NO(x). The data demonstrate that the impaired healing subsequent to trauma/hemorrhage can be greatly alleviated by L-arginine supplementation.     

Transforming growth factor beta3 promotes fascial wound healing in a new animal model

HYPOTHESIS: Transforming growth factor beta(3) (TGF-beta(3)) promotes fascial wound healing in a new animal model, as measured by wound breaking strength, collagen deposition, and cellular proliferation. DESIGN/INTERVENTION: Bilateral, longitudinal incisions were made in the anterior rectus sheaths of 24 male New Zealand white rabbits. One incision was treated with 1 microg of TGF-beta(3); the contralateral incision served as a control. The wounds were harvested at 1, 2, 3, 4, 6, and 8 weeks after creation ("wounding"). MAIN OUTCOME MEASURES: Wound tissue was tested for breaking strength using a tensiometer and processed for histological examination of collagen deposition and cellular proliferation at all time points after wounding. Collagen deposition and cellular proliferation were measured in histological cross sections of wounds with Masson trichrome staining and proliferating cell nuclear antigen immunohistochemistry, respectively. RESULTS: At all time points after wounding, treatment with TGF-beta(3) significantly increased the wound breaking strength (up to 138%) and collagen deposition (up to 150%) over the control group. Cellular proliferation was increased during the first 3 weeks after wounding (up to 147%), but returned to baseline levels by the fourth week. CONCLUSIONS: Transforming growth factor beta(3) promotes fascial wound healing. In this new animal model of fascial wound healing, TGF-beta(3) increased fascia breaking strength, collagen deposition, and cellular proliferation. These results are similar to findings in cutaneous wound models and demonstrate, for the first time, a pharmacologic agent to accelerate fascial healing.     

Characterization of incisional wound healing in inducible nitric oxide synthase knockout mice

BACKGROUND: Excisional wound healing in inducible nitric oxide synthase knockout (iNOS-KO) mice has been previously shown to be impaired compared with their background strain controls. Incisional wounds were created in this experiment in both types of animals and paradoxically were found to heal with the same rapidity and breaking strength in both groups. METHODS: Dorsal 2.5 cm incisional wounds were created in iNOS-KO mice, as well as their parental strain controls (C57BL/6J). Standardized polyvinyl alcohol sponges were implanted in the wounds to allow for measurement of collagen deposition. Animals were harvested on postoperative days (PODs) 3, 5, 7, 10, 14, and 28, and their wounds subjected to tensiometric breaking strength analysis. Nonisotopic in situ hybridization quantitative analysis for iNOS, endothelial NOS (eNOS), basic fibroblast growth factor (bFGF), transforming growth factor-beta1 (TGF-beta1), vascular endothelial growth factor (VEGF), and interleukin-4 (IL-4) expression in the wounds was performed. Hydroxyproline levels were quantitated in the harvested polyvinyl alcohol sponges. Data were analyzed with the Students t test. RESULTS: No significant differences were found in breaking strengths or levels of hydroxyproline (and thus collagen) in iNOS-KO versus wild-type wounds at all tested time points. Flawed iNOS expression levels in iNOS-KO animals were similar to (functional) iNOS expression in wild-types. eNOS and bFGF expression nearly doubled on POD 7 in iNOS-KO incisions (P =.002, and.002), respectively and remained 200% to 300% elevated thereafter. TGF-beta1 expression was increased approximately 50% to 100% in iNOS-KO wounds on PODs 5 and 7 (P =.006 and.01, respectively). VEGF and IL-4 expression was elevated by 25% to 100% in wild-type compared with iNOS-KO animals at all time points (P <.01). CONCLUSIONS: The overexpression of TGF-beta1 and eNOS may represent mechanisms in iNOS-KO mice to compensate for their loss of functional iNOS, resulting in incisional wound healing equivalent to controls. Their impaired expression of VEGF and IL-4, on the other hand, may partially explain the delayed excisional wound healing noted in these animals.     

Effects of steroids and retinoids on wound healing

HYPOTHESIS: Anti-inflammatory corticosteroids significantly impair wound healing. Retinoids partially, but significantly, reverse this effect. Little is known about the mechanism of steroid retardation or retinoid reversal. We hypothesized that corticosteroids lower transforming growth factor-beta (TGF-beta) and insulin-like growth factor-I (IGF-I) levels and tissue deposition in wounds and that retinoids stimulate corticosteroid-impaired TGF-beta and IGF-I release and collagen production. DESIGN: Randomized controlled trial. SETTING: Wound healing research laboratory. PARTICIPANTS: Animal study. INTERVENTIONS: Four wire mesh wound cylinders were implanted subcutaneously into the backs of 72 male Sprague-Dawley rats. Wound healing was impaired by a single subcutaneous injection of 6 mg of methylprednisolone acetate (Depo-Medrol). Two preparations of retinoids were used in separate experiments: all-trans-retinoic acid and 9-cis-retinoic acid that were fed orally. MAIN OUTCOME MEASURES: Hydroxyproline content was measured in the healing tissue and TGF-beta and IGF-I levels were analyzed in the wound fluid. RESULTS: Methylprednisolone treatment significantly decreased TGF-beta and IGF-I levels in the wound fluid and hydroxyproline content in the tissue (P<.05). Oral all-trans- and 9-cis-retinoic acid partially reversed the TGF-beta and IGF-I decrease and significantly increased hydroxyproline content toward normal levels (P<.05). Oral all-trans-retinoic acid enhanced collagen deposition, TGF-beta and IGF-I levels over normal chow fed control animals (P<.05). CONCLUSIONS: Steroids and retinoids have antagonistic effects on growth factors and collagen deposition in wound healing. These effects can be relevant for treatment options in a clinical setting.     

The experimental study on antisense TGF-beta 1 in inhibiting scar formation in III degree burn wound]

OBJECTIVE: To investigate the effect of antisense TGF-beta 1 in inhibiting scar formation during wound healing. METHODS: SD rats were divided into three groups after skin burn: group one was treated with antisense TGF-beta 1 oligonucleotide; group two was treated with antisense TGF-beta 1 recombinant plasmid and the control group. In different time, RT-PCR and immunohistochemistry were used to verify the expression of TGB beta 1 mRNA and protein. Type I Collagen mRNA expression was determined by hybridization in situ. Inflammatory reaction and collagen distribution were observed pathologically. RESULTS: In the groups received antisense ODN and recombinant plasmid, the expression of TGF-beta 1 mRNA and protein reduced during 14 days after burn. In the control group, type I collagen mRNA began to express at the second week and reached a peak at the fourth week, while the antisense groups kept low expression. The antisense group also showed mild inflammatory reaction and less synthesis of collagen. CONCLUSION: Antisense TGF-beta 1 could prevent the scar formation during wound healing.     

Profiles of inflammatory cytokines following colorectal surgery: Relationship with wound healing and outcome

Inflammation is an essential component of normal wound healing. This study has correlated systemic (plasma) and local (wound fluid) concentrations of inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor-alpha [TNF-alpha], and IL-1beta) with wound healing and surgical outcome following elective colorectal surgery. Paired plasma and wound fluid samples were collected (n = 44) postoperatively (days 1, 3, 5, 7) and analyzed by enzyme-linked immunosorbent assay (pg/mL). Cytokine levels were significantly greater in drain fluid than plasma on each postoperative day (POD); e.g., POD 1 : IL-6; drain fluid, median, 77,050 pg/mL (range 9,928-456,408); plasma, 241 pg/mL (22-1,333). Daily profiles of IL-6 and TNF-alpha were similar in drain fluid and plasma; IL-6 levels peaked on POD 1 decreasing to POD 7, and TNF-alpha levels increased from PODs 1 to 7. However, IL-1beta in plasma peaked on POD 1 and plateaued, whereas drain fluid showed two peaks (PODs 1 and 7). Only plasma levels of cytokines correlated to clinical parameters; IL-6 levels significantly correlated with postoperative complications; e.g., POD 5, complications 92(1-597) and no complications, 14(2-217). IL-6 also correlated with tumor pathology (Dukes stage, tumor depth, vascular invasion), and TNF-alpha levels correlated with the estimated blood loss during surgery. We conclude that local wound levels of cytokines correlated with the stage of wound healing, whereas systemic levels correlated with postoperative complications and tumor pathology.     

Molecular mechanisms underlying wound healing acceleration by Staphylococcus aureus peptidoglycan

Molecular mechanisms involved in wound healing acceleration by Staphylococcus aureus peptidoglycan were investigated with the use of polyvinyl alcohol sponges implanted under the dorsal skin of rats. Total collagen and RNA content and messenger RNA levels of alpha1(I) and alpha1(III) procollagen, transforming growth factor-beta1, and matrix metalloproteinase-1 were analyzed in saline solution- and S. aureus peptidoglycan-inoculated sponges at 4, 7, 14, and 21 days after implantation. S. aureus peptidoglycan-inoculated sponges on the fourth and seventh post-operative day were surrounded and penetrated by a thick capsule of reparative connective tissue. They were considerably heavier and contained more collagen and total RNA than saline solution-inoculated sponges. Histologically, the S. aureus peptidoglycan-inoculated sponges early on contained a denser infiltrate of polymorphonuclear cells than saline solution-inoculated sponges, and later fibroblasts, macrophages, collagen, and newly formed blood vessels were more abundant in the S. aureus peptidoglycan sponges. Matrix metalloproteinase-1 messenger RNA expression was elevated at 4 days in both sponge types. However, although matrix metalloproteinase-1 mRNA levels decreased to undetectable levels by 14 days in saline solution-inoculated sponges, they remained elevated throughout the 21-day study period in S. aureus peptidoglycan-inoculated sponges. No other significant differences in the parameters analyzed were detected. These results suggest that S. aureus peptidoglycan induces an accelerated but normal wound healing process in which the markedly increased early deposition of connective tissue is rapidly remodeled likely because of a sustained expression of matrix metalloproteinase-1.     

Differential expression of inflammatory mediators in radiation-impaired wound healing

BACKGROUND: Radiation impairs healing, although the underlying mechanisms are not clearly defined. Normal healing requires a fine balance of promoting and inhibiting factors. We hypothesize that there may be a down-regulation of promoting factors (nitric oxide) and, in turn, an up-regulation of healing inhibiting factors (TNF-alpha and IFN-gamma) in the wound after radiation. MATERIAL AND METHODS: Groups of 10 rats were irradiated using single dose 12 or 24 Gy electron radiation at the dorsal skin. Control rats were sham-irradiated. On Day 5 a skin incision in the irradiated area was performed and polyvinyl alcohol sponges were inserted subcutaneously. Rats were sacrificed 10 days later to determine the wound-breaking strength and reparative collagen deposition. Nitrite and nitrate (index of NO synthesis), TNF-alpha, and IFN-gamma were measured within the wound fluid. Expression of the inducible NO-synthase (iNOS) was investigated by immunohistochemistry. Wound-derived fibroblasts were tested in vitro for NO and collagen synthesis. RESULTS: Irradiation significantly reduced wound collagen deposition and wound-breaking strength (P < 0.05). Impaired healing was reflected in diminished wound NO synthesis and iNOS expression (P < 0.01). TNF-alpha and IFN-gamma were increased in irradiated wounds (P < 0.05). Ex vivo, NO synthesis and collagen deposition by fibroblasts from irradiated rats were decreased (P < 0.01). In vitro irradiation of fibroblasts from nonirradiated rats decreased both NO and collagen production (P < 0.01). CONCLUSION: Radiation-impaired healing is reflected in an imbalance of promoting and inhibiting factors, leading to increased levels of TNF-alpha and IFN-gamma and decreased NO expression in the wound.     

MHC-class-II-deficiency impairs wound healing

BACKGROUND: MHC-class-II-deficient mice lack T helper cell dependent immune reactions. T cell related immune functions are critical for normal wound healing. We hypothesized that MHC-II-deficiency compromises wound repair by affecting the normal wound immune response. MATERIAL AND METHODS: Groups of 10 male MHC-class II-knockout mice and wild-type controls underwent dorsal skin incision. Polyvinyl alcohol sponges were then inserted subcutaneously. The mice were sacrificed 10 days later to determine wound breaking strength and reparative collagen deposition. Activity of T cells and macrophages isolated from the spleens and from the healing wounds was investigated. Fibroblasts derived from the wounds were tested ex vivo for proliferative activity and collagen synthesis. RESULTS: Wound collagen deposition and wound breaking strength were impaired in MHC-class-II-knockout mice (P < 0.05). Impaired healing was reflected in diminished mitogen-reactivity of splenic T-cells (P < 0.01), and decreased CD4 expression in wounds. In addition, basal and LPS + IFN-gamma-induced synthesis of TNF-alpha and nitric oxide by wound-derived macrophages was impaired. Exvivo, fibroblast proliferation and fibroblast collagen production from MHC-II-deficient mice was decreased. CONCLUSION: MHC-II-deficiency compromises wound healing. This may be a reflection of impaired wound immune cell function and decreased activity of wound fibroblasts.     

Liposomal gene transfer of keratinocyte growth factor improves wound healing by altering growth factor and collagen expression

BACKGROUND: Growth factors affect the complex cascade of wound healing; however, interaction between different growth factors during dermal and epidermal regeneration are still not entirely defined. In the present study, we thought to determine the interaction between keratinocyte growth factor (KGF) administered as liposomal cDNA with other dermal and epidermal growth factors and collagen synthesis in an acute wound. MATERIALS AND METHODS: Rats received an acute wound and were divided into two groups to receive weekly subcutaneous injections of liposomes plus the Lac-Z gene (0.22 microg, vehicle), or liposomes plus the KGF cDNA (2.2 microg) and Lac-Z gene (0.22 microg). Histological and immunohistochemical techniques were used to determine growth factor, collagen expression, and dermal and epidermal structure. RESULTS: KGF cDNA increased insulin-like growth factor-I (IGF-I), insulin-like growth factor binding protein-3 (IGFBP-3), and fibroblast growth factor (FGF), decreased transforming growth factor-beta (TGF-beta), while it had no effect on platelet-derived growth factor (PDGF) levels in the wound. KGF cDNA significantly increased collagen Type IV at both the wound edge as well as the wound bed, while it had no effect on collagen Type I and III. KGF cDNA increased re-epithelialization, improved dermal regeneration, and increased neovascularization. CONCLUSIONS: Exogenous administered KGF cDNA causes increases in IGF-I, IGF-BP3, FGF, and collagen IV and decreases TGF-beta concentration. KGF gene transfer accelerates wound healing without causing an increase in collagen I or III.     

Differential regulation of chondrocyte metabolism by oncostatin M and interleukin-6

OBJECTIVE: To determine the effects of interleukin (IL)-6 and oncostatin M (OSM) added separately or in combination with IL-1beta on human osteoarthritic (OA) chondrocytes in alginate beads. DESIGN: Human chondrocytes were isolated from OA cartilage and cultured in alginate beads for 12 days, in the absence or in the presence of increasing amounts of IL-6 (20-500ng/ml) with its soluble receptor or OSM (0.1-10ng/ml) and with or without IL-1beta (1.7ng/ml). Aggrecan (AGG), transforming growth factor-beta1 (TGF-beta1), stromelysin-1 [matrix metalloprotease (MMP)-3], tissue inhibitor of metalloproteinases-1 (TIMP-1), macrophage inflammatory protein-1 beta (MIP-1beta), IL-6 and IL-8 productions were assayed by specific enzyme amplified sensitivity immunoassays. Prostaglandin (PG)E(2) was measured by a specific radioimmunoassay and nitrite (NO(2)(-)) by a spectrophotometric method based upon the Griess reaction. RESULTS: OSM, but not IL-6, decreased basal AGG and TGF-beta1 synthesis. Although IL-6 stimulated basal TIMP-1 production, it did not significantly modify MMP-3/TIMP-1 ratio. In contrast, 10ng/ml OSM highly increased TIMP-1 production, and decreased by half the ratio MMP-3/TIMP-1. IL-1beta highly stimulated *NO, IL-8, IL-6, MIP-1beta and PGE(2) synthesis but decreased AGG and TGF-beta1 production. Neither IL-6 nor OSM modulated IL-1beta-inhibitory effect on AGG production. IL-6, but not OSM, reversed IL-1beta-induced TGF-beta1 inhibition. At 1-10ng/ml, OSM significantly decreased IL-1beta-stimulated IL-8, MIP-1beta, PGE(2) and *NO production but amplified IL-1beta stimulating effect on IL-6 production. IL-6 had no effect on these parameters. CONCLUSIONS: OSM and IL-6, two glycoprotein 130 binding cytokines, show different activity profiles on OA chondrocytes, indicating that these cytokines could play different roles in the OA disease process.     

Simultaneous detections of 27 cytokines during cerebral wound healing by multiplexed bead-based immunoassay for wound age estimation

Quantification of 27 cytokines following cerebral wounding was performed for wound age estimation. The cytokines evaluated included interleukin (IL)-1alpha, IL-1beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IL-12 p40, IL-12 p70, IL-15, IL-17, IL-18, basic fibroblast growth factor (bFGF), granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), Interferon-gamma (IFN-gamma), keratinocyte derived cytokine (KC), leukemia inhibitory factor (LIF), macrophage-colony stimulating factor (M-CSF), monokine inducible by interferon gamma (MIG), macrophage inflammatory protein (MIP)-1 alpha, MIP 2, platelet-derived growth factor BB (PDGF BB), regulated upon activation, normal T-cell expressed, and secreted (Rantes), tumor necrosis factor-alpha (TNF-alpha), and vascular endothelial growth factor (VEGF). The proliferation of glial cells as well as the infiltration of inflammatory cells were also evaluated. Although astroglia proliferated from 72 hours post-injury, inflammatory cell dynamics were generally steady. Among cytokines analyzed in the present study, IL-1beta, IL-5, IL-6, IL-12 p40, G-CSF, IFN-gamma, KC, LIF, MIP2, and PDGF BB increased during the early phase of cerebral wound healing, and M-CSF increased during the middle phase, while IL-15, IL-18, and MIG increased during the late phase. In contrast, IL-1alpha, IL-10, IL-12 p70, and TNF-alpha were suppressed throughout the cerebral wound healing process. Based on our findings, quantitative cytokine analyses at the cerebral wound site may be a useful tool for wound age estimation. Further, this study suggests that multiplex data gained from the same sample using a single methodology demonstrates highly accurate cytokine interactions during the process of cerebral wound healing.     

Characterization of wound cytokines in the sponge matrix model

Although different populations of inflammatory cells infiltrate the healing wound, the mechanisms by which they influence the healing process in vivo are poorly defined. In vitro studies suggest that these cells may mediate wound healing by releasing various cytokines within the wound. We measured the levels of interleukin (IL) 1, IL-2, IL-3, IL-4, IL-6, tumor necrosis factor, and macrophage colony-stimulating factor within a subcutaneously implanted polyurethane sponge on various days after injury. Significantly higher levels of IL-1, IL-6, tumor necrosis factor, and macrophage colony-stimulating factor were detected in the wound fluid compared with basal serum levels in nonwounded mice. Tumor necrosis factor, macrophage colony-stimulating factor, and IL-6 peaked earlier than IL-1; however, the levels of these cytokines had fallen by the 13th day after wounding. Interleukin 2, IL-3, and IL-4 could not be detected in the wound fluid, and the wound fluid inhibited the proliferation of the IL-2-dependent cell lines CTLL-2 and HT-2 in response to recombinant IL-2. We hypothesize that tumor necrosis factor, macrophage colony-stimulating factor, IL-1, and IL-6, which are secreted at the site of injury, interact to promote tissue remodeling. The decrease in the levels of these cytokines by the 13th day after wounding may be the result of a regulatory process by the healed wound.     

Cytokines and growth factors in wound drainage fluid from patients undergoing incisional hernia repair

Knowing the dynamics of growth factor and cytokine secretion within the site of a surgical operation is important, as they play a crucial role in the pathophysiology of wound healing and are a target for modifying the repair response. The aim of this study was to evaluate the production of several cytokines and growth factors in the drainage wound fluid from patients undergoing incisional hernia repair: namely, interleukin (IL)-6, IL-10, IL-1alpha, IL-1 ra, interferon-gamma, vascular endothelial growth factors and basic fibroblast growth factor. Ten female patients with abdominal midline incisional hernia undergoing surgical repair were included in this study. In all cases, a closed-suction drain was inserted in the wound below the fascia and removed on postoperative day 4. Wound fluid was collected on postoperative days 1-4 and the amount was recorded each time. Growth factors and cytokines production was evaluated as the whole amount produced over a 24-hour period. In all patients, the amount of drain fluid from surgical wounds was more copious the first day after surgery, it decreased significantly afterward. The presence of all cytokines was highest on postoperative day 1, decreasing over the following days. More specifically, the production of IL-1 ra, IL-6, IL-1alpha, and IL-10 on postoperative day 1 fell sharply on postoperative days 3 and 4, whereas, after an initial reduction, interferon-gamma showed an increase from day 2 onward. Vascular endothelial-derived growth factor production increased progressively after the operation reaching statistical significance only on day 4. As for basic fibroblast growth factor, it showed an opposite pattern: it was higher on postoperative day 1 decreasing thereafter. This analysis of cytokine and growth factor production in the drain fluid will lead us to a better evaluation of the events that follow a surgical wound and to a better understanding of the healing process.     

Agent-based model of inflammation and wound healing: insights into diabetic foot ulcer pathology and the role of transforming growth factor-β1

Inflammation and wound healing are inextricably linked and complex processes, and are deranged in the setting of chronic, nonhealing diabetic foot ulcers (DFU). An ideal therapy for DFU should both suppress excessive inflammation while enhancing healing. We reasoned that biological simulation would clarify mechanisms and help refine therapeutic approaches to DFU. We developed an agent-based model (ABM) capable of reproducing qualitatively much of the literature data on skin wound healing, including changes in relevant cell populations (macrophages, neutrophils, fibroblasts) and their key effector cytokines (tumor necrosis factor-alpha [TNF], interleukin [IL]-1beta, IL-10, and transforming growth factor [TGF]-beta1). In this simulation, a normal healing response results in tissue damage that first increases (due to wound-induced inflammation) and then decreases as the collagen levels increase. Studies by others suggest that diabetes and DFU are characterized by elevated TNF and reduced TGF-beta1, although which of these changes is a cause and which one is an effect is unclear. Accordingly, we simulated the genesis of DFU in two ways, either by (1) increasing the rate of TNF production fourfold or (2) by decreasing the rate of TGF-beta1 production 67% based on prior literature. Both manipulations resulted in increased inflammation (elevated neutrophils, TNF, and tissue damage) and delayed healing (reduced TGF-beta1 and collagen). Our ABM reproduced the therapeutic effect of platelet-derived growth factor/platelet releasate treatment as well as DFU debridement. We next simulated the expected effect of administering (1) a neutralizing anti-TNF antibody, (2) an agent that would increase the activation of endogenous latent TGF-beta1, or (3) latent TGF-beta1 (which has a longer half-life than active TGF-beta1), and found that these therapies would have similar effects regardless of the initial assumption of the derangement that underlies DFU (elevated TNF vs. reduced TGF-beta1). In silico methods may elucidate mechanisms of and suggest therapies for aberrant skin healing.     

转化生长因子β1与白细胞介素6mRNA在糖尿病溃疡创面 …

目的 研究转化生长因子β１（ＴＧＦ－β１）与白细胞介素６（ＩＬ－６）ｍＲＮＡ在糖尿病溃疡创面组织中的变化规律以及与组织修复结局的关系。方法 采用逆转录ＰＣＲ（ＲＴ－ＰＣＲ）技术和病理学方法,研究ＴＧＦ－β１和ＩＬ－６两种生长因子ｍＲＮＡ在糖尿病患者正常皮肤与溃疡创面的不同表达。结果 在模板量相同以及反应条件一致的情况下,溃疡创面组织ＴＧＦ－β１ 和ＩＬ－６ｍＲＮＡ表达的不同,以及两种因子产生减少或     

NPWT促进糖尿病足溃疡创面愈合分子机制的初步研究

目的通过检测与创面愈合进程相关的组织基因表达,探讨采用负压创面治疗(nagetive pressure wound therapy,NPWT),促进糖尿病足溃疡(diabetic foot ulcer, DFU)愈合的作用机制。方法将纳入的50例DFU患者随机分成NPWT组(25例)和对照组(25例)。对照组接受局部湿敷治疗。两组患者治疗前后10 d均取创面肉芽行组织活检,利用RT-PCR检测转移生长因子-β1(transforminggrowth factor beta 1, TGF-β1)、血管内皮生长因子(vascular endothelial growth factor, VEGF)、肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)、白介素-1β(interleukin-1β, IL-1β)、基质金属蛋白酶-1(matrix metalloproteinase-1, MMP-1)、基质金属蛋白酶-9(matrixmetalloproteinase-9, MMP-9)和基质金属蛋白酶抑制剂-1(tissue inhibitor of metalloproteinase-1, TIMP-1)的mRNA表达,并进行对比分析。结果治疗后10 d,NPWT组患者创面肉芽组织中VEGF、TGF-β1和TIMP-1 mRNA的表达较治疗前显著增加,IL-1β、TNF-α、MMP-1和MMP-9 mRNA的表达显著下降(P<0.05);而对照组上述各项指标的mRNA表达,治疗前后均无显著变化(P>0.05)。结论 NPWT可能通过影响生长因子、炎症细胞因子和基质金属蛋白酶的表达来促进DFU愈合。