当前位置: 首页 > 期刊 > 《中国修复重建外科杂志》 > 1999年第1期
编号:10222944
血小板源性伤口愈合因子促糖尿病大鼠伤口愈合与成纤维细胞前胶原Ⅰ型(α1)基因表达的关系
http://www.100md.com 《中国修复重建外科杂志》 1999年第1期
     作者:张艳 朱旭东 陈荣德

    单位:第三军医大学野战外科研究所(重庆,400042)

    关键词:血小板源性伤口愈合因子;伤口抗张力值;基因表达;前胶原Ⅰ型(α1)

    中国修复重建外科杂志/990115 【摘 要】 目的 研究外源性血小板源性伤口愈合因子(PDWHF)对糖尿病大鼠伤口愈合的作用及其机理。方法 通过糖尿病大鼠背部成对切口伤模型证实PDWHF应用于伤口局部的情况。结果 伤后7、10及14天,糖尿病治疗组及糖尿病自身对照组伤口抗张力值分别为100.94±12.74、244.02±48.02、535.08±36.26和65.66±11.76、110.74±27.44、271.46±29.80 N/m,两组间差异显著(P<0.01)。体外实验发现,生长融合的伤口成纤维细胞与PDWHF孵育4、8及12小时后,PDWHG组前胶原Ⅰ型(α1)mRNA分别较对照组高0.9、3.7及2.2倍。结论 PDWHF促糖尿病大鼠伤口愈合与其直接刺激修复细胞前胶原Ⅰ型(α1)基因表达相关。
, 百拇医药
    ACCELERATION OF WOUND HEALING IN DIABETIC RATS BY PDWHF AND ITS RELATION WITH ITS ACTIVITY TO STIMULATE PROCOLLAGEN Ⅰ (α1) GENE EXPRESSION

    Zhang Yan, Zhu Xudong, Chen Rongde.

    Department One, The Research Institute of Surgery, The Third Military Medical University. Chongqing, P.R.China 400042

    【Abstract】 Objective The effect of platelet-derived wound healing factor (PDWHF) on wound healing in diabetic rats was studied. Methods Forty-four male SD rats were randomly divided into 2 groups. Thirty-two rats of experimental group accepted intraperitoneal injection of alloxan (1.5 mg/10 g body weight). Within one or two days after injection, while the blood sugar of the rats was higher than 180 mg/dl, the animal model of diabetic rat should have been established. Then a dorsal incision was given to every rat. After the addition of PDWHF (the experimental group) or bovine albumin (the control group), the incision was sutured up. Seven, ten and fourteen days after operation, the breaking strength of the wound was measured. On another hand, specimen from the wound was taken for the culture of fibroblasts. When the cultured fibroblasts have been incubated with 10% PDWHF for 4、8 and 12 hours, the procollagen Ⅰ(α1) mRNA levels were examined respectively, and compared with those of control. Results Significant difference in wound breaking strength had been observed between PDWHF-treated incisions and the control on 7、 10 and 14 days after wounding (P<0.01). Experiment in vitro demonstrated that the procollagen Ⅰ (α1) mRNA levels in wound fibroblasts incubated with 10% PDWHF for 4、 8 and 12 hours were 0.9、 3.7 and 2.2 folds higher than those in fibroblasts in control. Conclusion It was suggested that direct stimulation of procollagen Ⅰ (α1) gene expression was one of the ways that PDWHF played its role in accelerating wound healing.
, 百拇医药
    【Key words】Platelet-derived wound healing factor Wound breaking strength Gene expression Procollagen Ⅰ(α1)

    糖尿病因可通过多种途径导致机体伤口愈合延迟,已证实补充外源性生长因子如表皮生长因子(epidermal growth factor, EGF)、血小板源性生长因子(platelet derived growth factor, PDGF)、碱性成纤维细胞生长因子(basic fibroblast growth factor, bFGF)、β-转化生长因子(transforming growth factor β, TGF-β)等可明显改善糖尿病伤口愈合受阻状况[1~3];血小板源性伤口愈合因子(platelet derived wound healing factor, PDWHF)由血小板在体外经凝血酶刺激后所释放的多种生长因子组成,主要成分有PDGF、TGF-β、血小板源性表皮生长因子(platelet derived epidernal growth factor, PDEGF)及EGF等。我们研究报道了这类多肽生长因子天然混合物在糖尿病大鼠伤口愈合中的作用,同时通过检测PDWHF对伤口成纤维细胞前胶原Ⅰ型(α1)基因表达的影响,对PDWHF的促进伤口愈合作用机理进行了探讨。
, http://www.100md.com
    1 材料与方法

    1.1 主要材料

    1.1.1 PDWHF液 改进Knighton方法[4]制备PDWHF应用液,取人新鲜血小板浓缩液,用血小板缓冲液洗涤后,调节浓度为1×109个细胞/ml的细胞悬液,加入凝血酶(1 U/ml),离心去除纤维蛋白和残余血小板,上清液经80℃温育30分钟后,再离心除去热变性蛋白,考马斯亮蓝法测定蛋白浓度,制成5 mg/ml的PDWHF应用液,-20℃贮存备用。

    1.1.2 凝血酶 由美国Sigma公司提供,含前胶原Ⅰ型(α1)cDNA重组质粒Hf 677菌株63422(美国ATCC公司)。

    1.2 实验方法及过程

    1.2.1 动物的分组、致伤及治疗 随机选择44只雄性SD大鼠,体重200~250 g,分为正常组(n=12)及糖尿病组(n=32)。正常组大鼠腹腔注射1.5 ml生理盐水,糖尿病组大鼠腹腔注射新鲜配制四氧嘧啶(1.5 mg/10 g体重),测得血糖值大于1 800 mg/L 2天后,即可致伤[5]。致伤在无菌条件下进行,大鼠麻醉、脱毛后,沿脊椎方向用外科方法作两条深达筋膜长约4 cm的平行切口,伤口距脊椎垂直距离约1 cm,缝合伤口。在糖尿病治疗组切口伤基底处注入20 μl含0.5%胶原的PDWHF液,糖尿病自身对照组及正常组伤口基底注入20 μl含0.5%胶原牛血清白蛋白(5 mg/ml)液。
, 百拇医药
    1.2.2 伤口抗张力值的测定 伤后7、10及14天,分别从正常组、糖尿病组中随机选取大鼠3只及8只活杀,沿伤口垂直方向剪取伤口中央段1 cm宽皮条,在张力仪上测定伤口抗张力值。

    1.2.3 PDWHF对伤口成纤维细胞前胶原Ⅰ型基因表达的影响

    按我们实验室所建的方法培养伤口修复细胞[6],生长融合后,用Hank's液洗两次,对照组加入20 μl含1%FCS 1640液,PDWHF组加入含10% PDWHF、1% FCS 1640液,37℃,5% CO2条件下孵育0.5、4、8及12小时后,取出培养细胞,每一时相点每组细胞总数大于1×107/ml,按Total RNA Isolatiom Kit标准程序提取细胞中的总RNA,260及280 nm定量、检测纯度后,-20℃保存。

    前胶原Ⅰ型(α1)分子量为1 800(1.8 kDa) cDNA片段来源于质粒Hf677ECORⅠ酶切位点,用随机引物法将α-32P-dCTP掺入到探针中,标记产物比活度大于1×109/ng DNA。
, 百拇医药
    用真空加样器将对照组、PDWHF治疗组细胞总RNA各20 μg点接到尼龙膜(Boehringer, Germany)上,同一组别平行点接两个样品,80℃真空干燥2小时,装入杂交袋中。按《分子克隆指南》标准程序行斑点杂交及放射自显影[7],显影胶片用计算机定量扫描处理。

    2 结果

    2.1 伤后不同天数治疗组与对照组伤口开裂力的比较

    伤后不同天数各组伤口抗张力值见附表。从附表可见,糖尿病治疗组与正常组和糖尿病自身对照组比较,差异均非常显著(P<0.01)。

    附表 伤后各组伤口抗张力值(N/m, ±s)

    Tab Values of tension resistance in different group after injury(N/m, ±s)
, http://www.100md.com
    时间(天)

    Time (days)

    正常组

    Normal

    糖尿病治疗组Therapeutic

    糖尿病自身对照组Diabetes

    7

    168.56±19.60

    100.94±12.74

    65.66±11.76

    10

    388.08±46.06
, http://www.100md.com
    244.02±48.02

    110.74±27.44

    14

    576.24±51.94

    535.08±36.26

    271.46±29.80

    2.2 PDWHF对伤口成纤维细胞前胶原Ⅰ型mRNA水平量的影响

    按每微克总RNA对应的扫描相数值,比较PDWHF作用不同时间后伤口成纤维细胞前胶原Ⅰ型(α1)mRNA水平量,比较结果见附图。PDWHF作用4、8及12小时后,实验组前胶原Ⅰ型RNA量分别较对照组多0.9、3.7和2.2倍,根据实验作用剂量,可在刺激后8小时观察到最佳效果。
, http://www.100md.com
    附图 各时间点斑点杂交放射自显影图谱定量比较

    0.5、4、8及12小时为PDWHF作用时间

    Fig Quantitative comparison of autoradiograph of blot-hybridation in different times 0.5、 4、 8、 12 hours after the PHWHF acting

    3 讨论

    糖尿病可通过多种途径干扰伤口愈合的正常进程,其中机理十分复杂,至今尚不完全清楚。单核巨噬细胞功能低下,伤口微环境生长因子种类与数量正常平衡失调至少是其中的重要原因。Doxey等[8,9]观察到糖尿病小鼠伤口处多种细胞因子PDGF、角质细胞生长因子(keratinocyte growth factor, KGF)、bFGF、aFGF的基因调控规律与正常小鼠伤口愈合中的调控规律不同,表达时间延迟,表达强度下降。补充外源性生长因子如aFGF、bFGF、TGF-α、TGF-β及EGF/胰岛素,可明显改善糖尿病伤口愈合多项参数,其中PDGF、TGF-α、FGF配伍使用效果较各自单独使用更佳,提示多种生长因子配伍使用治疗难愈创面更为合理有效[1~3]。我们的研究证实PDWHF作为多种生长因子PDGF、TGF-β、EGF、胰岛素样生长因子-1(insulin-like growth factor 1, IGF-1)、PDEGF、血小板因子-4(platelet factor 4, PGF-4)等的天然混合物,可明显改善糖尿病机体伤口愈合受阻状况,说明无需纯化,PDWHF即可作为促愈剂使用。
, http://www.100md.com
    皮肤伤口愈合程度直接取决于跨越沉积到伤口边缘处的Ⅰ型胶原(α1)合成量,且伤口肉芽组织胶原合成发生在基因转录水平。糖尿病伤口肉芽组织Ⅰ型胶原(α1)基因表达受阻是伤口愈合迟缓的重要环节,胶原基因表达受阻可由伤口肉芽组织中能表达胶原基因的细胞数目减少和表达强度本身降低所造成。体外实验中证实PDWHF可直接促进伤口修复细胞、血管内皮细胞生长。因此,增加肉芽组织细胞密度是PDWHF促愈合作用的重要环节,在PDWHF的多种成分中PDGF、bFGF、EGF等与此相关。PDWHF是否可直接刺激修复细胞表达Ⅰ型胶原基因,还未见文献报道。刺激胶原基因开放是TGF-β的特有性质[10], 我们的实验中PDWHF作用于体外培养的修复细胞8小时后,实验组与对照组前胶原Ⅰ型mRNA水平量间差异达最大值,相差3.7倍,说明PDWHF中的其它成份不会阻碍TGF-β活性发挥,可见直接促进修复细胞开放Ⅰ型胶原(α1)基因是PDWHF发挥促愈合作用的重要环节之一。

, 百拇医药     4 参考文献

    [1] Phillips LG, Abalullen KM, Geldner PD, et al. Application of basic fibroblast growth factor may reverse diabetic wound healing impaiment. Ann Plast Surg, 1993;31:331

    [2] Brown RL, Breeden MP, Greenhalgh DG. PDGF and TGF alph act synergistically to improve wound healling in the genetically diabetic mouse. J Surg Res, 1994;56:562

    [3] Mwllin PN, Cashen DE, Ronan JJ, et al. Acidic fibroblast growth factor accelerates dermal wound healing in diabetic mouse. J Invest Dermal, 1995;104:850
, http://www.100md.com
    [4] Knighton DR, Ciresi K, Fiegel VD, et al. Stimulation of repair in chronic, nonhealing, cutaneouce ulcer using platelet-derived wound healing formula. Surg Gyn & Obst, 1990;170:56

    [5] Civington DS, Xue H, Pizzini R, et al. Streptozocin and alloxan are comparable agents in the diabetic model impaired wound healing. Diabetes Res, 1993;23:47

    [6] 朱旭东,张 艳,陈荣德.伤口修复细胞的培养方法.中国修复重建外科杂志,1994;8(3):157
, 百拇医药
    [7] J 萨姆布鲁克,EF 费里奇, T 曼尼阿蒂斯主编.分子克隆实验指南.北京:科学出版社,1992:372~374

    [8] Doxey DL, Ng MC, Dill RE, et al. Platelet-derived growth factor levels in wound of diabetic rats. Life Sci, 1995;57:1 111

    [9] Werner S, Breeden M, Hubner G, et al. Induction of keratinocyte growth factor expression is reduced and delayed during wound healing in the genetically diabetic mouse. J Invest Dermal, 1994;103:469

    [10] Clark R AF, Nielsen LD, Welch MP, et al. Collagen matrices attenuante the collagen synthetic response of cultured fibroblasts to TGF-β. J Cell Sci, 1995;108:1 251, 百拇医药