Differential acceleration of healing of surgical incisions in the rabbit gastrointestinal tract by platelet-derived growth factor and transforming growth factor, type beta

Anastomotic dehiscence is a major cause of morbidity and mortality in gastrointestinal surgery. A unique model system of a gastric incision was developed to test the potential of polypeptide growth factors to enhance wound healing. Paired, deep partial-thickness incisions to but not including the gastric mucosa were made. A single topical application of transforming growth factor, type beta 1 (TGF-beta), platelet-derived growth factor, or control vehicle at the time of wounding was given. Wound breaking strength and detailed histologic analyses of wounds were evaluated as a function of time after wounding. TGF-beta (0.1 to 2.0 micrograms/wound) demonstrated a bimodal, dose-dependent acceleration of wound breaking strength 7 days after gastric wounding. An approximate 4-day acceleration of gastric wound breaking strength by TGF-beta (2 micrograms/wound) was seen at 7 and 11 days. Wounds treated with platelet-derived growth factor (10 micrograms/wound) displayed an increased cellular response but no enhancement of breaking strength at 7 and 11 days. These results demonstrate the ability of TGF-beta to accelerate gastrointestinal tissue repair by topical application and suggest significant potential for the use of growth factors in enhancing repair of surgical wounds of the gastrointestinal tract.     

Kinetics of interleukin-1 and tumor necrosis factor secretion by rabbit macrophages recovered from the peritoneal cavity after surgery

Macrophages play a crucial role in wound healing after surgical injury, both as scavenger cells responsible for wound debridement and as cells that secrete soluble factors such as interleukin-1 (IL-1) and tumor necrosis factor (TNF). IL-1 and TNF alter many of the biological activities of cells that appear in postsurgical wounds. In this study, we determined the kinetics of IL-1 and TNF production by rabbit macrophages harvested from postsurgical peritoneal exudate (postsurgical macrophages) at several time points after peritoneal surgery. To further characterize the level of functional activities of postsurgical macrophages, the IL-1 and TNF levels were determined with or without stimulating the cells with lipopolysaccharide (LPS) and phorbol myristate acetate (PMA). After surgery, the number of macrophages harvested by peritoneal lavage increased, reached peak levels on postsurgical day 3, and then decreased. IL-1 levels secreted by macrophages cultured without stimuli were elevated on postsurgical day 14 compared to the values on day 3 and 7. TNF concentrations peaked on days 1 and 14. In the conditioned culture media from LPS-PMA-stimulated macrophages, the levels of both IL-1 and TNF peaked on postsurgical days 3 and 14. These data suggest that the susceptibility of postsurgical macrophages to stimuli changes during the wound healing process with maximum sensitivity to the stimuli present during the early phase of peritoneal repair (day 3).     

Wound repair by bone marrow stromal cells through growth factor production

We have previously shown that treatment with bone marrow stromal cells (BMSCs) augments the healing of fascial wounds in the rat. However, the biochemical mechanism by which BMSCs improve wound healing was not investigated. Growth factors have been shown to play a key role in repairing damaged tissue. In this study, we investigated whether BMSCs are capable of producing growth factors that play a critical role in healing of the damaged tissue. Growth factor expression in BMSCs stimulated with pro-inflammatory cytokines or wound superfusate was measured by RT-PCR and growth factor-specific quantitative sandwich enzyme-linked immunosorbent assay (ELISA). RT-PCR analysis demonstrated that BMSCs are capable of expressing transforming growth factor beta-1 (TGF-beta1), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) platelet-derived growth factor (PDGF), keratinocyte growth factor (KGF), fibroblast growth factor (FGF), and hepatocyte growth factor (HGF) constitutively or upon stimulation with LPS, IL-1alpha, or TNF-alpha. Quantitative analysis of growth factor production by ELISA showed that BMSCs do not secrete TGF-beta1, EGF or VEGF in response to uninjured fascia tissue superfusate; however, production of these growth factors is significantly increased when cells were stimulated with wound tissue superfusate. The ability of wound to stimulate growth factor production in BMSCs could be detected as early as day 1 and lasted through day 7 after wounding. Thus, growth factor production by BMSCs in response to wound microenvionment suggests that BMSCs might augment wound healing through the responsive secretion of growth factors that enhance angiogenesis and promote wound repair.     

Growth factor expression in cartilage wound healing: temporal and spatial immunolocalization in a rabbit auricular cartilage wound model

OBJECTIVE: The ability of cartilage to regenerate following injury is limited, potentially leading to osteoarthritis. Integrative cartilage repair, necessary for durable restoration of cartilage lesions, can be regarded as a wound healing process. Little is known about the effects of growth factors regulating acute cartilage wound healing in vivo. In this study the temporal expression patterns of growth factors and proteoglycan content in cartilage wound edges in vivo were studied. DESIGN: Cartilage wounds were created in rabbit ear cartilage using a 6 mm biopsy punch. Specimens were subsequently harvested 1, 3, 7, 14 and 28 days after surgery. Paraffin sections were thionin stained to visualize proteoglycan loss and replacement. Immunohistochemical staining of TGFbeta1, TGFbeta3, IGF-1, IGF-II and FGF-2 was used to define growth factor expression at the cartilage wound sites. RESULTS: Almost no effect of cartilage wounding was observed one day after surgery. A decrease of proteoglycan content, with a maximal loss at day 7, and a subsequent restoration was observed at the wound edges. Growth factor expression increased simultaneously. Maximal immunostaining for IGF1, IGFII, FGF2 and TGF-beta3 was observed at day 7, followed by a gradual decrease. Increased expression of TGFbeta1 lasted from day 3 until day 14. CONCLUSION: We have demonstrated the ability of chondrocytes to increase growth factor expression and to restore the rapid decrease in proteoglycan content in the initial phase following acute wounding. A temporal increase in intracellular growth factor expression suggests an autocrine and/or paracrine metabolic stimulation, which can be regarded a sign of chondrocytes repair capacity.     

Epidermal growth factor increases granulation tissue formation dose dependently

Recent studies have shown that epidermal growth factor (EGF) stimulated the rate of formation of granulation tissue in a model of wound repair (A. Buckley, et al., Proc. Nat. Acad. Sci. USA 82: 7340, 1985). Because pharmacologic doses of EGF were used previously, the relationship of EGF concentration to physiologic effects was determined in this study. Rats were implanted with subcutaneous polyvinyl alcohol sponges containing slow-release pellets formulated to release 0, 0.1, 1.0, or 10 micrograms of EGF/day. Tissue response was judged by the degree of histologic organization and vascularity, as well as several quantitative parameters: wet weight, hydroxyproline content, protein content, and DNA concentration. Each of these parameters showed consistent increases by Day 5 after implantation, when inflammation and edema had subsided. Compared with placebo controls, hydroxyproline (collagen) content was significantly increased by as little as 1 microgram/day of EGF, and DNA content was significantly increased by all dose levels of EGF. Endogenous EGF concentration in experimental granulation tissue was found to be fairly constant (30-40 ng/g wet wt); however, the increasing cellularity of the sponges may have reduced the local concentration of free EGF to low levels. Pellets releasing as little as 4 ng/hr of EGF into the surrounding tissue were able to accelerate wound healing, suggesting that the availability of this growth factor may be a rate-limiting step in wound repair.     

Serum and drainage fluid vascular endothelial growth factor levels in early surgical wounds

BACKGROUND: Wound healing relies on a coordinated expression and release of growth factors controlling angiogenesis. We measured vascular endothelial growth factor (VEGF) levels in serum and early wound fluid following primary sutured and mesh repair of abdominal hernias. MATERIALS AND METHODS: Thirty-seven patients were studied measuring serum and wound drainage fluid VEGF by enzyme-linked immunosorbent assay preoperatively and on the 1st, 3rd, 5th and 7th postoperative days. RESULTS: Serum and wound fluid VEGF levels increased significantly by the 3rd postoperative day and continued to rise during the conduct of the study with wound fluid concentrations always exceeding serum levels. The kinetics of VEGF increases were similar in both types of hernia repair; however, serum and wound levels rose slightly earlier in the mesh repair group. CONCLUSIONS: Steadily increasing levels of VEGF are detected during the early proliferative phase of wound healing in both serum and wound fluid. It is unknown whether either is predictive for delayed hernia recurrence.     

Acceleration of wound healing with topically applied deoxyribonucleosides.

HYPOTHESIS: We hypothesized that a topical mixture of purified deoxyribonucleosides would accelerate wound healing in an open wound model. DESIGN: Full-thickness 6-mm wounds were made on the ears of young adult rabbits. In some experiments, 2 of the 3 arteries in each ear were divided to induce wound ischemia. INTERVENTIONS: An equiweight mixture containing all 4 of the major deoxyribonucleosides (deoxyadenosine, deoxycytidine, deoxyguanosine, and thymidine), designated PN105, or other subgroups of deoxyribonucleosides, or vehicle (saline) was applied to wounds on 1 ear every 2 days, with the other ear serving as a control. MAIN OUTCOME MEASURES: Wound tissue was processed for histological examination 7 days after the initial wounding. Granulation tissue formation and epithelialization were measured in histological cross sections of wounds. RESULTS: Treatment of wounds with PN105 resulted in a 191% increase in total new granulation tissue (P<.05) and a higher incidence of complete wound reepithelialization (67% vs 37%; P<.05) when compared with controls, and a similar increase under ischemic conditions on day 7. Wound ischemia markedly impairs healing; PN 105 treatment resulted in a 242% increase in the amount of new granulation tissue formed by day 7 in ischemic wounds, relative to the appropriate controls (P<.05). All 4 of the major deoxyribonucleosides were required for optimum activity; mixtures with 3 or 2 were less active or inactive. CONCLUSIONS: Topically applied deoxyribonucleosides reproducibly accelerate wound healing in normal and ischemic wounds, and to a magnitude equivalent to that of recombinant growth factors such as platelet-derived growth factor, previously studied in this model. In view of their safety, availability, and efficacy, deoxyribonucleosides hold considerable promise for improving healing of chronic wounds.     

Medial collateral ligament healing in macrophage metalloelastase (MMP-12)-deficient mice.

Medial collateral ligament (MCL) injuries heal by a wound repair scar response controlled by a complex cellular and cytokine environment. Many enzymes participate in wound repair, particularly the matrix metalloproteinases. We hypothesize macrophage metalloelastase (MME/MMP-12) deficiency results in impaired healing of MCL injury. One hundred fifty MME-deficient and 150 WT (MME+/+) mice underwent knee MCL transection with the opposite knee as a sham operated control. Mice were sacrificed at 3, 7, 28, 42, and 56 days. At each of the five time points, 15 mice were utilized for biological and 15 were utilized for biomechanical testing. Outcome measures were the presence of macrophages to represent the inflammatory phase of wound healing, collagen synthesis to assay for matrix repair, and biomechanical testing for repair strength. Immunohistochemistry demonstrated significantly fewer macrophages in cut MCLs from MME-deficient mice versus wild-type (WT) mice at 3, 7, 28, and 42 days (all p相似文献   

Topical insulin application improves healing by regulating the wound inflammatory response

Inflammation, the initiating stage of wound healing, is characterized by increased endothelial permeability, infiltration of inflammatory cells, and secretion of numerous growth factors and chemokines. By controlling wound contamination and infection, as well as inducing the repairing process, inflammatory response plays an irreplaceable role during wound healing. We utilized a variety of approaches to observe the effect of insulin on wound inflammatory response, specifically the effect of insulin on the function of wound macrophages. We also investigated whether insulin‐regulated inflammatory response contributed to insulin‐induced healing. Mice excisional wounds treated with insulin showed advanced infiltration and resolution of macrophages, which correlated with the expression of monocyte chemotactic protein‐1, a potent chemotactic factor for macrophages. Blockage of monocyte chemotactic protein‐1 resulted in reduced macrophages infiltration and impaired wound healing despite the presence of insulin. In vitro studies showed insulin‐facilitated monocytes/macrophages chemotaxis, pinocytosis/phagocytosis, and secretion of inflammatory mediators as well. Our study strongly suggests that insulin is a potent healing accelerant. Regulating wound inflammatory response, especially the quantity and function of macrophages, is one of the mechanisms explaining insulin‐induced accelerated wound healing.     

Renal microenvironments and macrophage phenotypes determine progression or resolution of renal inflammation and fibrosis

Chronic kidney disease involves renal inflammation, interstitial fibrosis, and tubular and vascular atrophy. Macrophages seem to foster all of these histomorphological abnormalities, but their specific contributions remain controversial. Recruited monocytes differentiate into different tissue macrophage phenotypes, but current classifications are largely based on in vitro studies that do not adequately mirror tissue environments in vivo. To overcome this limitation, we propose to classify tissue macrophages according to their predominant roles in the phases of wound healing tissue environments, that is, inflammation, epithelial healing, mesenchymal healing, and fibrolysis. In this review, we discuss the evidence on respective macrophage phenotypes in renal pathology. This view sheds light on several aspects of renal remodeling in kidney disease: (1) renal infection or cell necrosis induces proinflammatory 'M1' macrophages that exacerbate renal cell damage, (2) uptake of apoptotic cells induces anti-inflammatory 'M2c/suppressor' macrophages that promote epithelial and vascular repair, (3) insufficient vascular and epithelial healing despite abundant growth factor secretion promotes profibrotic 'M2a/wound healing' macrophages that accelerate fibrogenesis, and (4) theoretically, fibrolytic macrophages should exist and await investigation.     

Relaxin induces vascular endothelial growth factor expression and angiogenesis selectively at wound sites

Relaxin is a reproductive hormone that has historically been characterized as being responsible for pubic ligament loosening and cervical ripening. Recently, relaxin has been associated with neovascularization of the endometrial lining of the uterus, potentially via specific induction of vascular endothelial growth factor. Previously conducted clinical studies using partially purified porcine relaxin have described relaxin's ability to stimulate the healing of ischemic wounds, suggesting that relaxin may also have angiogenic effects at sites of ischemic wound healing. In the present study, relaxin's angiogenic effects in the context of wound repair were tested in rodent models of angiogenesis and wound healing. Relaxin showed an ability to stimulate new blood vessel formation, particularly at ischemic wound sites, and to induce both vascular endothelial growth factor and basic fibroblast growth factor specifically in cells, presumably including macrophages, collected from wound sites. Resident macrophages collected from nonwound sites, such as the lung, did not show altered expression of these cytokines following relaxin administration. Because angiogenic wound cells are frequently macrophages, THP-1 cells, a cell line of monocyte lineage that binds relaxin specifically, were tested for and shown to induce vascular endothelial growth factor and basic fibroblast growth factor in response to relaxin. In conclusion, relaxin may be useful in the treatment of ischemic wounds by stimulating angiogenesis via the induction of vascular endothelial growth factor and basic fibroblast growth factor in wound macrophages.     

Amnion-derived cellular cytokine solution promotes macrophage activity

Activated macrophages play a significant role in wound healing and infected tissue repair. In this study, we investigate the recruitment of macrophages into the wound, and the effects on the bactericidal/phagocyte activity after exposure to amnion-derived cellular cytokine solution (ACCS). To evaluate the influence of ACCS on the migratory behavior of macrophages, cell migration was assayed quantitatively using a Boyden chamber. Chemotactic migration activity of macrophages through the membrane determined the influence of ACCS. In the presence of ACCS, macrophages demonstrated a statistically significant (P < 0.05) increase in migration as compared with controls. Subsequently, groups of macrophages were exposed to different concentrations of ACCS solution. The killing and phagocytic activity of each group was compared with the control after exposure to Escherichia coli. Macrophage activity following activation by higher concentrations of ACCS demonstrated significantly increased phagocytosis as well as a trend correlation between percentage ACCS concentration and bactericidal activity. These cell types, critical to normal wound healing, may be influenced by ACCS to accelerate migration and enhance bactericidal/phagocytic activity in wounds.     

重组人粒细胞巨噬细胞集落刺激因子对深Ⅱ度烧伤创面的治疗作用

目的 了解重组人粒细胞巨噬细胞集落刺激因子(rhGM-CSF)凝胶剂治疗深Ⅱ度烧伤创面的有效性和安全性. 方法采用多中心、随机、双盲、安慰剂平行对照的研究方法,将深Ⅱ度烧伤创面作为目标创面,把321例烧伤患者(实际完成302例)分为用药组200例,创面涂rhGM-CSF凝胶;对照组102例,创面涂安慰剂.观察用药后两组患者的全身情况和不良反应,以及不同时相点创面愈合时间、愈合率、总有效率. 结果用药后两组患者生命体征,血、尿常规及肝、肾功能,创面分泌物、创缘反应比较,差异均无统计学意义(P>0.05),无不良反应.用药组创面愈合时间的中位数为17 d,低于对照组(20 d,P<0.01).用药第8、14、20、28天,用药组平均创面愈合率分别为24.5%、70.5%、95.3%、99.6%,均高于对照组(15.1%、51.4%、84.6%、97.1%,P<0.01).用药8、14、20 d用药组的总有效率显著高于对照组(P<0.01). 结论 rhGM-CSF凝胶剂能促进深Ⅱ度烧伤创面愈合,并且有一定的安全性.     

重组人表皮生长因子促进大鼠皮肤创面愈合的研究

目的观察重组人表皮生长因子(rhEGF)对皮肤创面愈合的作用。方法制作大鼠背部创伤模型,采用自身平行对照,将34只大鼠背部的68个创面分成rhEGF治疗组与盐水对照组,观察大体形态和组织学改变、创面愈合时间和愈合率,测定伤后不同时间创面羟脯氨酸(OHP)含量和Ⅰ型Ⅲ型胶原比例,进行细胞DNA周期分析。结果经rhEGF治疗的创面愈合速度较盐水对照明显加快,2组平均愈合时间为(17.2±1.3)d和(20.5±1.6)d(P<0.01);外用rhEGF使创面肉芽组织生成增多,再上皮化明显,显著增加创面中OHP含量,降低Ⅰ型Ⅲ型胶原比例,加速细胞DNA复制。结论外用rhEGF可缩短创面愈合时间,增加肉芽组织及OHP含量,降低Ⅰ型Ⅲ型胶原比例,加速细胞DNA复制,明显促进皮肤创面的修复。     

再论成纤维细胞生长因子与软组织创伤修复

目的 近一步论证成纤维细胞生长因子（ＦＧＦ）对创伤修复的作用。方法 根据基础研究和临床试验结果,并结合相关文献报道,从胚胎发育、组织学、动物实验、临床研究以及展望五年方面进行论证。结果 大量基础和临床研究表明,组织的胚胎发育需要ＦＧＦ的作用。外用ＦＧＦ对加速创面愈合速度和提高愈合质量具有明显效应。结论 ＦＧＦ是一种对创面愈合具有显著调控作用的生物活性蛋白,具有广阔的临床应用前景。     

神经生长因子调控烧伤创面的实验研究

目的 研究神经生长因子（ＮＧＦ）在烧伤创面愈合的作用,探索烧伤创面愈合机制。方法２０ｋｇ小白家猪６只为实验对象。用控温控压电烫仪在每只猪背部制成２４个直径为２．５ｃｍ的圆形深Ⅱ度烧伤创面。分为四组,分别为创面局部应用１、２．５和５μｇ／ｍｌ的ＮＧＦ实验组和不含ＮＧＦ的生理盐水对照组。在用药后３、５和９天分别取创面组织进行表皮生长因子（ＥＧＦ）受体,ＥＧＦ,ＮＧＦ受体,ＮＧＦ,ＣＤ６８,ＣＤ３免疫组     

The combined effect of recombinant human epidermal growth factor and erythropoietin on full‐thickness wound healing in diabetic rat model

Diabetic wound is a chronic wound in which normal process of wound healing is interrupted. Lack of blood supply, infection and lack of functional growth factors are assumed as some of the conditions that lead to non‐healing environment. Epidermal growth factor (EGF) acts primarily to stimulate epithelial cell growth across wound. Erythropoietin (EPO) is a haematopoietic factor, which stimulates the production, differentiation and maturation of erythroid precursor cells. This study hypothesised combining these two factors, non‐healing process of diabetic wound will be compensated and eventually lead to acceleration of wound healing compared with single growth factor treatment. A total of 30 diabetic Sprague–Dawley rats were divided into three treatment groups (single treatment of rh‐EPO or rh‐EGF or combined treatment on a full‐thickness skin wound). To assess the wound healing effects of the components, the wound size and the healing time were measured in each treatment groups. The skin histology was examined by light microscopy and immunohistochemical analysis of proliferating markers was performed. The combined treatment with rh‐EPO and rh‐EGF improved full‐thickness wound significantly (P < 0·05) accelerating 50% healing time with higher expression of Ki‐67 compared with single growth factor‐treated groups. The combined treatment failed to accelerate the total healing time when compared with single growth factor treatments. However, the significant improvement were found in wound size reduction in the combined treatment group on day 4 against single growth factor‐treated groups (P < 0·05). This study demonstrated that the combined treatment of rh‐EPO and rh‐EGF improved the wound healing possibly through a synergistic action of each growth factor. This application provides further insight into combined growth factor therapy on non‐healing diabetic wounds.     

Changes in growth factor levels in human wound fluid.

BACKGROUND. It has been suggested that platelet-derived growth factor (PDGF) plays a central role in wound healing. Analysis of human wound fluid revealed the presence of PDGF AA (30 kd) and monocyte/macrophage-derived growth factor (MDGF) (12 to 14 kd) in the immediate postoperative period. METHODS. The amount of PDGF AA present was assayed by Western blot analysis. The chemotactic and mitogenic potential of purified wound fluid containing PDGF AA and MDGF was determined on a responsive cell line. The biologic activity of MDGF was assayed with a cell line that is unresponsive to the PDGF AA found in wound fluid. RESULTS. Both the concentration and the biologic activity were highest in the immediate postoperative period and declined to negligible levels by 24 hours after surgery. The chemotactic activity of MDGF was highest in the immediate postoperative period and declined during the first 24 hours in a manner similar to that of the combined PDGF AA and MDGF activity. CONCLUSIONS. These data demonstrate the changing levels of PDGF and MDGF in human wound fluid over time, supporting the cascade model of wound repair. By demonstrating that MDGF acts on cell lines unresponsive to the PDGF AA found in wound fluid, these data suggest that MDGF may also play an important role in wound healing.