臭氧气浴对深Ⅱ度烧伤大鼠创面病理变化及组织细胞因子表达的影响

目的:探讨臭氧气浴干预对大鼠深Ⅱ度烧伤创面的病理变化及局部组织中细胞因子血小板源性生长因子(PDGF)、转化生长因子β_3(TGF-β_3)和肿瘤坏死因子α(TNF-α)表达的影响。方法:取80只雄性清洁级SD大鼠,随机分为臭氧气浴实验组和常规换药对照组各40只。建立背部深Ⅱ度烧伤模型,伤后3 d、7 d、14 d和21d,2组创面分别取材检测。创面常规换药,对照组的创面以生理盐水清洗和碘伏油纱包扎,隔日换药1次;臭氧气浴实验组在换药前将大鼠放入清洁泡沫盒内,打开臭氧发生器开关,以输出浓度为50 mg/L的臭氧熏蒸创面20min,关闭开关,再行创面常规换药,隔日1次,直至愈合。各时点每组大鼠创面打开时取1次创面中心组织标本,然后实验组行生理盐水棉球轻拭创面和臭氧气熏蒸,对照组仅用生理盐水棉球轻拭创面后再分别取材1次。标本行HE染色组织学观察和免疫组化染色半定量观察,结合图像数据分析及ELISA法检测2组创面组织中细胞因子PDGF、TGF-β_3和TNF-α含量。结果:创面大体观察可见,臭氧气浴实验组的创面平整,边缘清晰,炎性反应轻,肿胀和渗出程度均较对照组弱,创面愈合率高于常规换药对照组,2组比较差异有统计学意义。显微镜下观察HE染色组织可见臭氧气浴实验组的创面各时点炎性反应程度比常规换药对照组轻,而新生毛细血管、成纤维细胞和上皮细胞增生数量明显优于常规换药对照组。与对照组比较,臭氧气浴实验组各时点烧伤大鼠的创面组织匀浆上清液中PDGF和TGF-β_3表达量均高于常规换药对照组,而TNF-α表达量明显低于对照组,2组比较差异均有统计学意义。结论:臭氧气浴疗法干预大鼠深Ⅱ度烧伤创面,能改善局部病理变化,促进与创面愈合相关的细胞因子PDGF和TGF-β_3表达,同时减轻炎性介质TNF-α的表达。     

A comparative study of fibroblasts in healing freeze and burn injuries in rats.

In rats, the healing process of a full-thickness dermal freeze injury differs from that of a burn wound. Whereas burn wounds heal by wound contraction, the movement of surrounding normal skin over the defect, freeze wounds heal without wound contraction. That absence of contraction may be due to the freeze wound's lack of myofibroblasts, the cells reportedly associated with wound contraction. Myofibroblasts can be demonstrated histologically by staining the F-actin filaments of the stress fibers with NBD-phallacidin, a fluorescent reagent specific to F-actin filaments. Fibroblasts in normal dermis have no staining stress fibers. However, staining myofibroblasts are uniformly distributed in the granulation tissue of the healing burn and in the islands of granulation tissue between residual connective tissue fibers in the healing freeze wound. These residual dermal fibers were identified by their patterns of birefringence. Residual connective tissue matrix persists following cold trauma and acts like an internal splint. Burn trauma destroys cells and the connective tissue matrix, which is completely replaced with granulation tissue which undergoes wound contraction. Freeze trauma kills the cellular components of dermis, while some residual connective tissue fibers endure. This study shows that the connective tissue matrix can play an important role in the control of wound contraction.     

Morphologic examination of mesenchymal cells in healing wounds of normal and tight skin mice.

The healing process of an open wound as effected by wound contraction is complete by 3 weeks in the normal mouse. In contrast, its onset is delayed by 3 weeks and complete healing requires 6 weeks in the tight skin mouse (TSM), a mutant mouse strain with the autosomal dominant gene for tight skin. Possible mechanisms for this delay were evaluated. The frequency and distribution of myofibroblasts were studied during the 3-week delay in wound contraction by actin staining and electron microscopy. It was determined, by electron microscopy and phalloidin staining, that myofibroblasts were found in high density in noncontracting TSM wounds. Electron microscopy showed, however, that these myofibroblasts were surrounded by a pericellular matrix that separated their surface from adjacent collagen fibers. No pericellular matrix was found around cells in granulation tissue of normal mice. At 3 weeks, as TSM wounds began to contract, the number and intensity of cells stained by phalloidin in this tissue was less than that seen earlier. The pericellular matrix was fragmented at this time, and cell surface and collagen fiber associations were apparent. Finally, at 5 weeks, when wound contraction was well developed in the TSM, only a small area in the center of the healing wound beneath the epidermis contained phalloidin-positive myofibroblasts. Electron-microscopic examination of the residual granulation tissue at this time revealed the complete absence of the pericellular matrix. It is postulated that during the 3-week delay in wound closure, the presence of a localized pericellular matrix prevents the interaction between cells and collagen fibers necessary for the reorganization of collagen. It is also thought that the tightly adherent uninjured skin surrounding the healing wound may cause delayed wound closure. There was no evidence that the absence of myofibroblasts is responsible for delayed wound contraction.     

Role of the nuclear receptor coactivator AIB1/SRC-3 in angiogenesis and wound healing

The nuclear receptor coactivator amplified in breast cancer 1 (AIB1/SRC-3) has a well-defined role in steroid and growth factor signaling in cancer and normal epithelial cells. Less is known about its function in stromal cells, although AIB1/SRC-3 is up-regulated in tumor stroma and may, thus, contribute to tumor angiogenesis. Herein, we show that AIB1/SRC-3 depletion from cultured endothelial cells reduces their proliferation and motility in response to growth factors and prevents the formation of intact monolayers with tight junctions and of endothelial tubes. In AIB1/SRC-3(+/-) and (-/-) mice, the angiogenic responses to subcutaneous Matrigel implants was reduced by two-thirds, and exogenously added fibroblast growth factor (FGF) 2 did not overcome this deficiency. Furthermore, AIB1/SRC-3(+/-) and (-/-) mice showed similarly delayed healing of full-thickness excisional skin wounds, indicating that both alleles were required for proper tissue repair. Analysis of this defective wound healing showed reduced recruitment of inflammatory cells and macrophages, cytokine induction, and metalloprotease activity. Skin grafts from animals with different AIB1 genotypes and subsequent wounding of the grafts revealed that the defective healing was attributable to local factors and not to defective bone marrow responses. Indeed, wounds in AIB1(+/-) mice showed reduced expression of FGF10, FGFBP3, FGFR1, FGFR2b, and FGFR3, major local drivers of angiogenesis. We conclude that AIB1/SRC-3 modulates stromal cell responses via cross-talk with the FGF signaling pathway.     

Both constitutive and inducible prostaglandin H synthase affect dermal wound healing in mice

In an attempt to define the roles of prostaglandin H synthase 1 (PGHS-1, cyclooxygenase-1, COX-1) and prostaglandin H synthase 2 (PGHS-2, cyclooxygenase-2, COX-2) in wound healing, we investigated the healing of incisional dermal wounds in wild-type, PGHS-1 null, and PGHS-2 null mice. We measured tensile strength of the wounds, levels of PGHS-1 and PGHS-2 mRNA in the wound site, and histologic markers for the inflammatory, proliferative, and remodeling phases of wound healing. Although no gross visible differences were noted among healed wounds of the different mouse types, measurement of tensile strength showed that both PGHS-1 and PGHS-2 null wounds were weaker (75% and 70%, respectively) than wild-type wounds at 12 days after incision. At Day 8 the endothelial staining was 70% greater in the wounds of PGHS-2 null mice compared with their wild-type counterparts. In contrast at Day 12, staining for macrophages and myofibroblasts was less in PGHS-1 null wounds compared with wild-type and PGHS-2 null tissue. Compensatory expression of the alternate PGHS mRNA could be demonstrated by RT-PCR in the wounds of PGHS null mice on Days 1 and 4. We conclude that both PGHS-1 and PGHS-2 genes play distinct roles in the process of dermal wound healing.     

大鼠背部脊柱两侧全层皮肤圆形创面增生性瘢痕愈合过程中臭氧的作用**☆

背景：预防硬膜外瘢痕的形成,可减少腰椎手术失败综合征的发生。臭氧应用于腰椎间盘突出症的治疗已取得较好的临床效果。 目的：观察臭氧对大鼠伤口瘢痕愈合过程的影响。 方法：外科切口法制备大鼠背部脊柱两侧圆形全层皮肤创面增生性瘢痕模型,分为3组,纯氧组及臭氧组分别注射纯氧及30~40 mg/L臭氧,总量均为5 mL,空白组不注射任何药物,每周2次,4周后取瘢痕/肉芽组织标本,利用苏木精-伊红染色及免疫组化方法,对比观察各组标本瘢痕/肉芽组织外观及肿瘤坏死因子α、碱性成纤维细胞生长因子表达的变化。 结果与结论：与空白组及纯氧组相比,臭氧组愈后瘢痕面积较小,上皮生成较多,炎性细胞浸润较少,胶原纤维较纤细,且断裂较多;臭氧组肿瘤坏死因子α阳性细胞数较低(P < 0.01),碱性成纤维细胞生长因子阳性细胞数较高(P < 0.01)。提示臭氧通过其抗炎作用,减少炎性细胞浸润,并可通过抑制成纤维细胞及巨噬细胞释放的肿瘤坏死因子α以及提高碱性成纤维细胞生长因子的表达,减少胶原的过度合成,从而起到抑制肉芽组织炎症及瘢痕组织增生的作用。关键词：臭氧;瘢痕;伤口愈合;肿瘤坏死因子α;碱性成纤维细胞生长因子 缩略语注释：TNF-α: tumor necrosis fact-alpha,肿瘤坏死因子α;bFGF: basic fibroblast growth factor,碱性成纤维细胞生长因子 doi:10.3969/j.issn.1673-8225.2012.15.012     

Evaluation of a collagen-glycosaminoglycan dermal substitute in the dog palate

Tissue shortage complicates surgery of cleft lip and palate. The healing of defects on the palate impairs growth of the dentoalveolar complex because of scar tissue formation. Implantation of a matrix into the wound might overcome this adverse effect. Integra with and without a silicone top layer was implanted into standardized full-thickness wounds (? 6 mm) in the palatal mucoperiosteum in beagle dogs. In some wounds, the silicone layer was removed after 14 days. Control wounds did not have an implant. At 2 and 4 weeks post-surgery, the wounds were assessed for epithelialization, inflammation (hematoxylin and eosin, leucocyte protein L1), number of myofibroblasts (alpha smooth muscle actin), and general histological characteristics. Wounds filled with Integra without the silicone layer showed fewer myofibroblasts and inflammatory cells than the sham wounds. Collagen fibers were more randomly orientated in these wounds than in the sham group. Wound closure was found to be retarded, and many inflammatory cells were present when Integra with silicone was implanted. The silicone layer was lost within 4 weeks in these wounds. We conclude that, in the moist oral environment, the silicone of Integra is not required. Re-epithelialization and tissue integration proceed more favorably without it. Further research in the dentoalveolar development with Integra will be conducted in a simulated cleft palate repair in the dog model.     

When the Smad signaling pathway is impaired, fibroblasts advance open wound contraction

In wound healing transforming growth factor β1 (TGFβ1), utilizing the Smad signaling pathway, advances connective tissue deposition, the transformation of fibroblasts into myofibroblasts and wound contraction. The compound SB-505124 disrupts the Smad signaling pathway by blocking activin receptor-like kinase phosphorylation of select Smad signaling proteins. Four full thickness excisional square 2 × 2 cm wounds were made on the rat dorsum. On day 2, the pair of wounds on the left received 1 μM SB-505124 in gel, and the pair on the right, controls, received gel alone. Wounds were covered with nonocclusive dressings and treated redressed daily for 4 days. No differences in day 14 wound sizes between treatment groups were found. H&E stained sections revealed increased cell density in SB-505124 treated wounds. Polarized light microscopy showed collagen fiber bundles birefringence intensity and organization were equivalent between treatment groups. Myofibroblast populations, identified by α-smooth muscle actin staining, were the norm in controls but absent in SB-505124 treated wounds, which was confirmed by Western blot analysis. Blocking the Smad signaling pathway diminished connective tissue deposition and generated a deficiency in myofibroblast numbers, but wound contraction was unimpaired. The absence of myofibroblasts may be related to the blocking of the Smad signaling pathway or it may be related to the generation of less tension in treated wounds, related to reduce deposited connective tissue. These findings support the notion that wound contraction does not require the generation of myofibroblast contractile forces, but rather the organization of newly deposited collagen fiber bundles by forces related to fibroblast locomotion.     

Clinical experimental study of Arnebia Root oil in increasing FGF expression and promoting wound surface healing

Objective:To investigate the effection of Arnebia Root oil on the FGF expression in wound surface and the ability to promote wound surface healing. Methods:24 wound surfaces of patients were divided into two groups. Experimental group was treated by Arnebia Root oil and the control was treated by petrolatum gauze. Histology, histochemistry, electron microscope methods and healing rate measurement were used to show the FGF expression and wound healing process. Results:Endogenous FGF were expressed in both of the groups, in which of the experimental group was higher than that of the control group, the wound surface healing rate of experimental group was also higher and paralleled with FGF expression. Conclusion:Arnebia Root oil has effects to promote FGF expression and enhances wound surface repair. The wound healing mechanism between the action of Arnebia Root oil and function of FGF need further investigating.     

Platelet-derived growth factor-beta receptor activation is essential for fibroblast and pericyte recruitment during cutaneous wound healing

Connective tissue remodeling provides mammals with a rapid mechanism to repair wounds after injury. Inappropriate activation of this reparative process leads to scarring and fibrosis. Here, we studied the effects of platelet-derived growth factor receptor-beta blockade in vivo using the platelet-derived growth factor receptor (PDGFR)-beta inhibitor imatinib mesylate on tissue repair. After 7 days, healing of wounds was delayed with significantly reduced wound closure and concomitant reduction in myofibroblast frequency, expression of fibronectin ED-A, and collagen type I. Using a collagen type I transgenic reporter mouse, we showed that inhibiting PDGFR-beta activation restricted the distribution of collagen-synthesizing cells to wound margins and dramatically reduced cell proliferation in vivo. By 14 days, treated wounds were fully closed. Blocking PDGFR-beta signaling did not prevent the differentiation of myofibroblasts in vitro but potently inhibited fibroblast proliferation and migration. In addition, PDGFR-beta inhibition in vivo was accompanied by abnormal microvascular morphogenesis reminiscent of that observed in PDGFR-beta-/- mice with significantly reduced immunostaining of the pericyte marker NG2. Imatinib treatment also inhibited pericyte proliferation and migration in vitro. This study highlights the significance of PDGFR-beta signaling for the recruitment, proliferation, and functional activities of fibro-blasts and pericytes during the early phases of wound healing.     

Bioactive glass modulation of intestinal epithelial cell restitution

Repair of superficial injury to the gastrointestinal mucosa involves the process of restitution, the rapid migration of epithelial cells across damaged areas. The effect of 45S5 bioactive glass on epithelial restitution was assessed using a novel co-culture model incorporating wounded intestinal epithelial cell monolayers and sub-epithelial myofibroblasts to simulate in vivo conditions that occur during superficial mucosal ulceration. Epithelial wound healing was not increased by culture medium conditioned with bioactive glass, with 1% (w/v) bioactive glass inhibiting cell migration. Epithelial wounds co-cultured with myofibroblasts grown on surfaces coated with 0.1% (w/v) bioactive glass increased wound healing compared with co-cultures containing no bioactive glass. Myofibroblasts grown on surfaces coated with bioactive glass secreted significantly increased amounts of basic fibroblast growth factor but did not increase epithelial cell proliferation, indicating the wound healing observed was due to restitution. These data from a model of superficial mucosal injury suggest bioactive glass may function as a stimulant of paracrine mucosal signaling networks that promotes rapid epithelial repair.     

表皮细胞迁移与创面愈合

创面愈合是动态的、严格有序的生物学过程,再上皮化在其中起着非常重要的作用。皮肤创面的再上皮化主要依赖于表皮细胞从创缘向创面中心的迁移。创面形成后由于局部血液循环障碍和创周细胞氧耗的增加,导致创面形成低氧的微环境,低氧已经被证明能够促进表皮细胞迁移和创面愈合。创面形成后由于跨上皮电势差的消失产生内源性的直流电场,此电场是创面愈合过程中指导表皮细胞向创面中心迁移的最重要的方向信号。此外,创面形成后产生的炎症因子一氧化氮被证实也能够促进表皮细胞迁移和创面愈合。综上所述,低氧、电场和一氧化氮可通过促进表皮细胞向创面中心迁移进而加快创面愈合过程。     

选择性去细胞猪皮在深Ⅱ度烧伤创面中的应用

目的将选择性去细胞猪皮用于深Ⅱ度烧伤创面早期包扎,观察其创面保护和促愈效果。方法 41例烧伤患者,男性29例,女性12例,年龄18～53岁,平均（31.4±9.7）岁,烧伤面积5%～39%。伤后2～4d,2%创面清创后以选择性去细胞猪皮覆盖,其余创面常规换药,以同体同侧或对侧创面作为对照,隔日换药,观察创面愈合情况,计算伤后2周创面愈合率,记录创面愈合时间。结果选择性去细胞猪皮与创面基底贴敷良好,创周无红肿等炎症反应表现,14～21d逐渐干燥、脱落,创面愈合。伤后2周创面愈合率（82.34±20.13）%,对照组为（76.21±22.52）%。创面平均愈合时间（17.8±4.3）d,对照组为（21.2±5.6）d。两者相比差异均有统计学意义。结论选择性去细胞猪皮对于清创后的深Ⅱ度烧伤创面有较好的保护和促愈作用,效果优于常规换药方法。     

Platelet-derived growth factor-BB and transforming growth factor beta 1 selectively modulate glycosaminoglycans, collagen, and myofibroblasts in excisional wounds.

Recombinant platelet-derived growth factor (PDGF) and transforming growth factor beta 1 (TGF-beta 1) influence the rate of extracellular matrix formed in treated incisional wounds. Because incisional healing processes are difficult to quantify, a full-thickness excisional wound model in the rabbit ear was developed to permit detailed analyses of growth-factor-mediated tissue repair. In the present studies, quantitative and qualitative differences in acute inflammatory cell influx, glycosaminoglycan (GAG) deposition, collagen formation, and myofibroblast generation in PDGF-BB (BB homodimer)- and TGF-beta 1-treated wounds were detected when analyzed histochemically and ultrastructurally. Although both growth factors significantly augmented extracellular matrix formation and healing in 10-day wounds compared with controls (P less than 0.002). PDGF-BB markedly increased macrophage influx and GAG deposition, whereas TGF-beta 1 selectively induced significantly more mature collagen bundles at the leading edge of new granulation tissue (P = 0.007). Transforming growth factor-beta 1-treated wound fibroblasts demonstrated active collagen fibrillogenesis and accretion of subfibrils at the ultrastructural level. Myofibroblasts, phenotypically modified fibroblasts considered responsible for wound contraction, were observed in control, but were absent in early growth-factor-treated granulating wounds. These results provide important insights into the mechanisms of soft tissue repair and indicate that 1) PDGF-BB induces an inflammatory response and provisional matrix synthesis within wounds that is qualitatively similar but quantitatively increased compared with normal wounds; 2) TGF-beta 1 preferentially triggers synthesis and more rapid maturation of collagen within early wounds; and 3) both growth factors inhibit the differentiation of fibroblasts into myofibroblasts, perhaps because wound contraction is not required, due to increased extracellular matrix synthesis.     

LED红光对糖尿病大鼠创面愈合的影响

目的探讨LED红光照射对糖尿病大鼠创面愈合的作用及相关机制。 方法将30只4周龄雄性SD大鼠按随机数字表法分为正常创面组、糖尿病创面组、红光治疗糖尿病创面组,每组10只。红光治疗糖尿病创面组及糖尿病创面组大鼠高脂饮食4周,正常创面组大鼠正常饮食。饲养4周后对红光治疗糖尿病创面组及糖尿病创面组大鼠按50 mg/kg的量腹腔注射10 mg/mL的链脲佐菌素(STZ)制作糖尿病大鼠模型,2组大鼠均造模成功。造模成功后在3组大鼠的背部两侧各制造2个1.5 cm×1.5 cm的全层皮肤缺损创面,每2 d对大鼠创面进行酒精消毒1次,红光治疗糖尿病创面组大鼠每次消毒后对创面进行LED红光照射5 min,能量密度为20 J/cm²,另外2组大鼠不进行LED红光照射。在观察第7、10、14、21天,观察红光治疗糖尿病创面组大鼠创面有无出现皮疹、红肿、水疱、烫伤等光照不良反应;肉眼观察3组大鼠创面愈合情况;统计3组大鼠创面愈合率。观察第10天从各组随机取2只大鼠,处死后取背部创面组织,固定后,进行苏木精-伊红染色观察创面新生血管情况及肉芽组织生长情况;采用免疫荧光法检测各组大鼠创面组织中CD34、血管内皮细胞生长因子(VEGF)表达情况。数据比较采用单因素方差分析和LSD-t检验。 结果观察第7、10、14、21天,红光治疗糖尿病创面组大鼠经LED红光照射后皮肤未见皮疹、红肿、水疱、烫伤等光照不良反应。在各个观察时间点,肉眼观察正常创面组及红光治疗糖尿病创面组创面愈合情况均优于糖尿病创面组,且正常创面组创面愈合情况略优于红光治疗糖尿病创面组;观察第7、10、14、21天,正常创面组的创面愈合率分别为(34.62±2.116)%、(53.83±7.92)%、(70.20±5.41)%、(95.65±2.58)%,红光治疗糖尿病创面组创面愈合率分别为(31.76±2.44)%、(50.48±4.54)%、(66.26±11.35)%、(93.96±2.80)%,糖尿病创面组创面愈合率分别为(23.67±4.18)%、(42.71±3.40)%、(53.77±7.74)%、(84.07±4.43)%,3组比较差异均有统计学意义(F＝34.69、10.35、10.32、34.40,P<0.05);观察第7、10、14、21天,正常创面组及红光治疗糖尿病创面组创面愈合率始终高于糖尿病创面组,差异均有统计学意义(P<0.05);观察第7、10天,正常创面组创面愈合率高于红光治疗糖尿病创面组,差异均有统计学意义(t＝2.80、3.26,P<0.05),观察第14、21天,正常创面组创面愈合率仍高于红光治疗糖尿病创面组,但差异均无统计学意义(t＝1.16、1.40,P>0.05)。观察第10天,创面组织苏木精-伊红染色显示,正常创面组内含大量新生毛细血管,肉芽组织内胶原及细胞排列紧密有序;红光治疗糖尿病创面组见较多新生毛细血管,肉芽组织内胶原及细胞较多,但少于正常创面组;而糖尿病创面组新生血管最少,肉芽组织内细胞及胶原稀疏。免疫荧光法检测创面组织中CD34、VEGF表达情况可见,正常创面组CD34、VEGF表达高于红光治疗糖尿病创面组,而红光治疗糖尿病创面组表达高于糖尿病创面组。 结论LED红光可促进糖尿病大鼠创面组织中CD34、VEGF表达,促进血管新生,进而促进创面愈合。     

Apoptosis mediates the decrease in cellularity during the transition between granulation tissue and scar.

Granulation tissue formation and contraction is an important step of second intention wound healing. Granulation tissue develops from the connective tissue surrounding the damaged or missing area and its cellular components are mainly small vessel and inflammatory cells as well as fibroblasts and myofibroblasts. As the wound closes and evolves into a scar, there is an important decrease in cellularity; in particular myofibroblasts disappear. The question arises as to which process is responsible for this cellular loss. During a previous investigation on the expression of alpha-smooth muscle actin in myofibroblasts (Darby I, Skalli O, Gabbiani G, Lab Invest, 1990, 63:21-29), we have observed that in late phases of wound healing, many myofibroblasts show changes compatible with apoptosis and suggested that this type of cell death could be responsible for the disappearance of myofibroblasts. We have now tested this hypothesis by means of morphometry at the electron microscopic level and by in situ end labeling of fragmented DNA. Our results indicate that the number of myofibroblastic and vascular cells undergoing apoptosis increases as the wound closes and support the assumption that this is the mechanism of granulation tissue evolution into a scar. The regulation of apoptotic phenomena during wound healing may be important in scar establishment and development of pathological scarring.