离体冻伤模型创面愈合过程中基质细胞衍生因子1促表皮干细胞迁移的研究

Objective To study the promotion effect of stromal cell-derived factor 1 (SDF-1) on the migration of epidermal stem cells (ESC) in the healing process of frostbite-wound model ex vivo. Methods A three-dimensional model of full-thickness frostbite of skin was constructed (with slot-like wound) out of skin equivalent. The expression of SDF-1 in wound stroma was observed with immunohisto-chemistry staining on post injury days (PID) 3 and 7. The model frostbite wounds were divided into control group (treated with PBS 50 μL per wound) , SDF-1 group (treated with 100 ng/mL SDF-1, 50 μL per wound) , and AMD3100 group [treated with 100 ng/mL AMD3100 (50 μL per wound) for 30 minutes, and then SDF-1 50 μL was added per wound]. The redistribution of ESC around wound was observed. Results The expression of SDF-1 in wound stroma increased gradually on PID 3 and 7. Compared with those in control and AMD3100 groups, there were more ESC and epithelial cell layers, and more integrin β1-positive cells appeared at the basal layer of wound in SDF-1 group, and some of the positive cells migrated upward to epidermis. Conclusions SDF-1 contributes to wound repair through promoting ESC to migrate toward and gather around wound edge. This may be one of the mechanisms of ESC participating in wound repair.     

离体冻伤模型创面愈合过程中基质细胞衍生因子1促表皮干细胞迁移的研究

Objective To study the promotion effect of stromal cell-derived factor 1 (SDF-1) on the migration of epidermal stem cells (ESC) in the healing process of frostbite-wound model ex vivo. Methods A three-dimensional model of full-thickness frostbite of skin was constructed (with slot-like wound) out of skin equivalent. The expression of SDF-1 in wound stroma was observed with immunohisto-chemistry staining on post injury days (PID) 3 and 7. The model frostbite wounds were divided into control group (treated with PBS 50 μL per wound) , SDF-1 group (treated with 100 ng/mL SDF-1, 50 μL per wound) , and AMD3100 group [treated with 100 ng/mL AMD3100 (50 μL per wound) for 30 minutes, and then SDF-1 50 μL was added per wound]. The redistribution of ESC around wound was observed. Results The expression of SDF-1 in wound stroma increased gradually on PID 3 and 7. Compared with those in control and AMD3100 groups, there were more ESC and epithelial cell layers, and more integrin β1-positive cells appeared at the basal layer of wound in SDF-1 group, and some of the positive cells migrated upward to epidermis. Conclusions SDF-1 contributes to wound repair through promoting ESC to migrate toward and gather around wound edge. This may be one of the mechanisms of ESC participating in wound repair.     

基质细胞衍生因子1α诱导脂肪来源干细胞迁移促进糖尿病缺血下肢肌肉修复的实验研究

背景与目的：基质细胞衍生因子1α (SDF-1α)是一种定向诱导细胞迁移的趋化因子,研究显示,间充质干细胞（MSCs）在受损组织中可以沿着SDF-1梯度迁移到损伤部位并参与组织修复,然而目前尚缺乏SDF-1α诱导脂肪来源干细胞（ASCs）对糖尿病缺血下肢进行组织修复的体内研究。因此,本研究探讨SDF-1α促进大鼠脂肪来源干细胞（r ASCs）向糖尿病大鼠缺血下肢肌肉组织迁移及对组织修复的影响。方法：取SD大鼠脂肪组织分离培养rASCs,行细胞形态观察,鉴定成脂、成软骨及成神经分化能力,并使用带绿色荧光蛋白（GFP）的腺病毒转染和标记r ASCs。将大鼠用STZ法构建糖尿病模型,并结扎大鼠的右下肢股动脉造成下肢缺血后,随机分为两组,通过尾静脉向两组大鼠体内注射r ASCs,其中一组在患肢中段部位肌肉处注射SDF-1α蛋白（SDF-1α+rASCs组）,另一组则用同样方式注射等量磷酸盐缓冲溶液（rASCs组）。治疗后的第1、2周行大鼠双下肢血流量检测,计算及比较各组大鼠的缺血下肢-健侧下肢血流比值。在第4周时处死大鼠,取缺血部位的肌肉组织行HE染色,观察不同治疗方法组中肌肉组织的排列情况。...     

创面愈合过程中创缘表皮干细胞的异位

目的观察创缘表皮干细胞在全层皮肤创面愈合过程中的分布特征,初步探讨其在创面愈合过程中的作用.方法将已行BrdU活体标记的 20只Wistar大鼠背部制备4个为2.54 cm2的全层皮肤创面,分别于伤后3、7、14和21 d(n=5)行组织学检查,动态观察创面愈合情况,并行β1整合素、角蛋白19(K19)与BrdU免疫组织化学法检测表皮干细胞在创面愈合过程中的分布情况.结果创面愈合率为83.75%(61/80).所有创面肉芽组织于各时相点均未见β1整合素、K19阳性细胞出现,但于创缘表皮的棘层或颗粒层均出现散在的β1整合素、K19和BrdU阳性细胞.且越接近创面阳性细胞越密集,组织学上与基底层的阳性细胞无直接联系;其数量随创面的缩小逐渐增加,直至创面愈合.创面上皮化后,阳性细胞逐渐减少,并随愈合创面表皮脚的出现而消失.而感染创面的阳性细胞数量明显少于未感染创面.结论表皮干细胞能主动参与创面的修复,创缘的表皮干细胞异位的主要功能可能是促进创面再上皮化.     

复合人表皮干细胞的猪脱细胞真皮基质对裸鼠全层皮肤缺损创面愈合的影响

目的:探讨复合人表皮干细胞（ESC）的猪脱细胞真皮基质（ADM）对裸鼠全层皮肤缺损创面愈合的影响。方法:采用实验研究方法。采用数码相机拍照观察猪ADM形态,采用苏木精-伊红（HE）染色观测猪ADM中细胞残留,采用扫描电子显微镜观察猪ADM表面结构,采用红外光谱仪分析猪ADM二级结构,采用动态光散射粒度分析仪分析猪ADM...     

表皮干细胞在糖尿病创面愈合过程中的动态变化

目的 观察糖尿病（diabetes mellitus，DM）大鼠创伤后不同时期表皮厚度、表皮干细胞（epidermalste mcells，ESCs）数量变化和分布特征及创面愈合率等动态变化，探讨ESCs与DM皮肤创面难愈之间的关系。方法 48只Wistar大鼠，雄性，体重180～200g。随机分为DM组和正常对照组，各24只。DM组大鼠制备DM大鼠慢性创面愈合模型。两组大鼠同时用特制打孔器在大鼠背部脊柱两侧约1．5cm制作直径1．8cm、面积2．54cm。的全层皮肤缺损（共计96个创面），分别在致伤后第3、7、14和21天拍摄创面，计算创面愈合率；取创缘及肉芽组织，行HE染色及角蛋白19（keratin19，K19）和β1整合素抗体免疫组织化学染色，显微图像分析系统测量表皮厚度、阳性部分面积及灰度值。结果 致伤后第3、7、14和21天，正常对照组大鼠创面愈合率分别为24．48％±3．37％、50．46％±1．26％、92．82％±2．12％和99．41％±0．66％，而DM组分别为2．43％±1．02％、40．59％±1．65％、80．77％±3．57％和85．40％±0．94％，两组同时期比较差异有统计学意义（P〈0．01）。致伤后第3、7、14和21天，正常对照组表皮厚度分别为26．43±3．21、33．29±3．52、31．53±3．35和26．01±3．19p．m，DM组表皮厚度分别为23．58±2．33、31．02±3．38、33．72±5．49和21．80±4．02p．m，致伤后第3、21天，二者比较差异有统计学意义（P〈0．01）。致伤后第3、7、14和21天，正常对照组K19染色的平均阳性单位（positiveunit，PU）值分别为91．68％、93．14％、72．27％和70．31％，而DM组分别为40．29％、40．79％、29．94％和10．37％；正常对照组β1整合素染色的平均PU值分别为49．60％、91．16％、77．13％和57．17％，DM组分别为38．94％、24．16％、61．36％和38．83％，与正常对照组同时期比较，DM组K19和β1整合素染色的平均PU值都降低，且差异有统计学意义（P〈0．05）。结论 ESCs数量少和活性低可能是DM创面难愈的重要机制之一。     

雷帕霉素对胰腺癌生长的抑制作用及其与基质细胞 衍生因子1α的关系

目的:探讨雷帕霉素对胰腺癌体内生长的抑制作用及其对基质细胞衍生因子1α(SDF-1α)的影响。方法:20只裸鼠胰腺注射胰腺癌SW1990细胞悬液后,随机均分为实验组与对照组,实验组裸鼠每日雷帕霉素(1.5mg/kg)腹腔注射,对照组以同样的方式给予等体积溶剂。3周后取移植瘤,比较两组肿瘤的生长情况,免疫组化法检测肿瘤组织单核-巨噬细胞、肿瘤相关巨噬细胞(TAM)浸润情况及p-m TOR、HIF-1α、SDF-1α蛋白的表达;Westonblot及q RT-PCR法检测肿瘤组织p-m TOR、HIF-1α、SDF-1α的蛋白与m RNA表达。结果:与对照组比较,实验组的肿瘤重量(0.3340g vs.1.7790g)与体积(0.2375mm3 vs.1.2662mm~3)均明显减小(均P0.05)。免疫组化结果显示,与对照组比较,实验组肿瘤组织浸润的单核-巨噬细胞、TAM计数均明显少(均P0.05);p-m TOR、HIF-1α、SDF-1α蛋白表达率均明显降低(均P0.05);肿瘤组织SDF-1α表达评分与TAM计数呈正相关(r=0.52,P0.05)。Westonblot与q RT-PCR结果显示,实验组肿瘤组织p-m TOR、HIF-1α、SDF-1α的蛋白与m RNA表达均低于对照组,除HIF-1αm RNA外(P0.05),其余差异均有统计学意义(均P0.05)。结论:雷帕霉素能抑制胰腺癌的体内生长,其机制可能与抑制m TOR通路活性而下调SDF-1α蛋白表达,进而减少肿瘤微环境中的TAM有关。     

SDF-1对创缘表皮干细胞定向趋化及促创面愈合效应的研究

目的：观察干细胞趋化因子SDF-1在创面愈合过程中调控表皮干细胞定向迁移促进创面愈合的过程。方法：制作大鼠背部全层皮肤缺损模型,随机分为三个实验组：①SDF-1组;②AMD3100（CXCR4受体的拮抗剂）组;③空白对照组。分别于致伤后1天、3天、5天、7天和12天照相计算伤后不同时间创面占初始创面的百分比并取材。运用HE染色和免疫组化技术观察创缘表皮干细胞定向迁移分化的特点,寻找其规律。结果：与其他两个处理组相比,SDF-1处理组愈合时间缩短,其创缘皮表皮基底层细胞分裂增殖旺盛,创缘表皮干细胞数目明显多于其他两组。结论：在创面愈合过程中,SDF-1可以调控表皮干细胞向创缘迁移,加速创面上皮化。     

不同来源的表皮干细胞促进皮肤创面愈合的研究

目的 观察表皮干细胞(ESCs)及去分化来源的表皮干细胞(DESCs)对皮肤创面愈合的促进作用及其异同.方法 由新鲜人包皮标本以贴壁法分离ESCs,随机分为3组,第1组作为原代ESCs:第2组传代培养至第6代时可见细胞成熟呈表皮细胞(ECs)形态,由原来的大克隆生长的小圆细胞形态变为较为肥大的不规则型细胞,无法形成克隆样增殖;其细胞表型也由β1整合素、CK19强阳性、CK10阴性变为β1整合素、CK19阴性,而CK10强阳性,予以100μg/L的碱性成纤维细胞生长因子(bFGF)培养48 h进行去分化诱导,48 h后ECs周边开始出现小圆细胞并呈克隆样生长,β1整合素、CK19、CK10等细胞表型也趋于与ESCs一致,即DESCs;第3组传代培养至第6代获得ECs.3组细胞皆以D-Hanks液重悬调其终质量浓度为2×106个/ml.将12只裸鼠每只背部左右各制备1个直径6 mm创面,共24个创面.将全部创面随机等分为4组,每组6个,分别以ESCs、DESCs、Ecs及生理盐水(NS)各0.2 ml进行创面注射.于术后0、3、7 d测量创面面积进行统计学分析,并于术后7 d行创面取材苏木素-伊红(HE)染色.结果 ESCs组与DESCs组在术后3 d时创面面积分别为(11.758±2.544)、(11.515±1.351)mm2,7 d时创面面积分别为(1.795±1.063)、(2.043±1.138)mm2,修复速度要明显快于ECs组与NS组[3 d时创面面积分别为(17.857±1.722)、(16.192±2.256)mm2,7 d时创面面积分别为(5.367±1.219)、(5.070±1.357)mm2,P＜0.01];而ESCs与DESCs组之间创面修复速度比较差异无统计学意义(P＞0.05);ECs组与NS组之间比较差异无统计学意义(P＞0.05).HE染色提示ESCs组与DESCs组的创面愈合质量优于ECs组与NS组,可见有皮肤附属腺的再生且纤维瘢痕组织较少.结论 ESCs与DESCs皆有促进创面愈合的作用,相互之间无明显差异.

Abstract：

Objective To investigate the enhancing effect of epithelial stem cells (ESCs) and dedifferentiation derived epithelial stem cells (DESCs) in the healing of epidermal wound. Methods ESCs were isolated from the fresh circumcised foreskins by using adherence method and randomly divided into three cohorts: ESCs cohort, DESCs cohort and epithelial cells (ECs) cohort. The final cell density was adjusted to 2 × 106/ml with D-Hanks in each group. The model of BALB/C mice full-thickness skin loss wounds was established. Two circular 6 mm-diameter skin loss wounds were cut on every BALB/C mouse back. Twenty-four wounds of 12 BALB/C mice were divided equally and randomly into 4 groups:DESCs, ESCs, ECs and NS. The cell suspensions of DESCs, ESCs and ECs were injected respectively into the wound edges with the density of 2 × 106/ml. And the volme was 0. 2 ml per treatment wound. The same volume of normal saline was injected in NS group. On the postoperative day 0, 3, 7, all of the wound areas were measured and analyzed statistically. On the postoperative 7 day, the sections were made and observed by using hematoxylin and eosin (HE) staining. Results The wound areas in DESCs group and ESCs group were ( 11. 758 ± 2. 544) and ( 11.515 ± 1.351 ) mm2 on the 3rd day postoperatively, and ( 1. 795 ±1. 063) and (2. 043 ± 1. 138) mm2 on the 7th day postoperatively, respectively. The wound areas in ECs group and NS group were ( 17. 857 ± 1. 722) and ( 16. 192 ±2. 256) mm2 on the 3rd day postoperatively,and ( 1. 795 ± 1. 063) and (2. 043 ± 1. 138) mm2 on the 7th day postoperatively, respectively. There was statistically significant difference in wound area between ESCs or DESCs group and ECs, NS groups on the 3rd, 7th day postoperatively ( P ＜ 0. 01 ), but there was no statistically significant difference between DESCs and ESCs groups ( P ＞ 0. 05 ). HE staining showed the repairing quality of treatment wounds was superior to that in the control wounds, and regenerating glands and less fibrous connective tissues were seen in ESCs and EDSCs groups. Conclusion Both ESCs and DESCs could promote the wound repair.     

Rac1蛋白调控表皮干细胞迁移促进创面愈合的研究

目的 观察Rac1蛋白对表皮干细胞(ESC)迁移运动的调控作用,为完善创面愈合的基础理论以及指导临床应用提供参考.方法 将慢病毒空载体FUGW单独和分别与Rac1蛋白抑制型突变体Rac1T17N、Rac1蛋白活化型突变体Rac1Q61L融合后转染入ESC,按照随机数字表法分为3部分进行如下实验.(1)将ESC分别接种于Ⅰ型胶原溶液(20 μg/mL)、Ⅳ胶原溶液(20 μg/mL)或纤连蛋白溶液(10 μg/mL)包被的24孔细胞培养板,采用CytoTox 96 比色试剂盒检测ESC对不同基质的黏附率.(2)选取上述黏附于Ⅳ型胶原的1000个ESC,四甲基异硫氰酸罗丹明标记的鬼笔环肽染色,激光扫描共聚焦显微镜下观察黏附细胞的形态延展并比较面积大小.(3)选用Transwell小室,上室加入ESC、下室中加入含基质细胞衍生因子1(SDF-1)的限定性角质形成细胞无血清培养液(以不加SDF-1的培养液为对照),倒置相差显微镜下观察ESC的趋化能力,结果以细胞迁移变化率表示.(4)将ESC接种于6孔细胞培养板孵育12 h,加入含4 μg/mL丝裂霉素C的培养液继续孵育2 h,于单层贴壁细胞划痕,6、12 h后统计剩余划痕宽度百分率.对数据进行t检验.结果 与转染FUGW的ESC比较,转染Rac1Q61L的ESC对Ⅰ型胶原的黏附率明显增加(t＝5.302,P<0.05),转染Rac1T17N的ESC对Ⅰ型胶原(t＝13.741,P<0.05)、Ⅳ型胶原(t＝15.676,P<0.05)及纤连蛋白(t＝8.256,P<0.05)的黏附率均明显下降.激光扫描共聚焦显微镜下观察,与转染FUGW的ESC比较,转染Rac1Q61L的ESC面积明显增大,细胞边缘有层板状伪足伸出;转染Rac1T17N的ESC面积显著缩小.在趋化因子SDF-1作用下,与转染FUGW的ESC比较,转染Rac1Q61L的ESC迁移变化率升高43.4%,转染Rac1T17N的ESC迁移变化率下降78.0%;无SDF-1作用时,与转染FUGW的ESC比较,转染Rac1T17N的ESC迁移变化率下降55.2%,转染Rac1Q61L的ESC迁移变化率未见明显变化(升高1.7%).划痕后6、12 h,转染Rac1Q61L的ESC剩余划痕宽度百分率分别为(39±9)%、(6±5)%,低于转染FUGW的ESC[(43±5)%,t=1.027,P>0.05;(18±7)%,t=4.389,P<0.05];划痕后6、12 h,转染Rac1T17N的ESC剩余划痕宽度百分率分别为(81±9)%、(71±11)%,明显高于转染FUGW的ESC(t值分别为11.386、11.726,P值均小于0.05).结论 Rac1蛋白可通过影响ESC的黏附、延展以及趋化能力调控细胞迁移,并可能因此参与ESC促进创面愈合的进程.

Abstract：

Objective To investigate modulatory role of Rac1 protein in epidermal stem cell (ESC) migration during wound healing,in order to provide a reference for enriching basic theory of wound healing and guiding clinical application. Methods Constitutively active mutant of Rac1 protein (Rac1Q61L) or dominant negative isoform of Rac1 protein (Rac1T17N) was transfected into ESC using a retroviral vector FUGW,and retroviral vector FUGW transfected into ESC in singles was used as blank control. The cells were divided into 3 parts according to the random number table and treated as follows. First,equal numbers of cells were inoculated into 24-well plates coated with collagen Ⅰ (20 μg/mL),collagen Ⅳ (20 μg/mL) or fibronectin (10 μg/mL). Cells adhered to above matrices were quantitated using CytoTox 96 colorimetric kit. Second,1000 cells adhered to collagen Ⅳ,after being stained with tetramethyl rhodamine isothiocyanate-phalloidin,were collected for observation of cell morphology and comparison of spreading area under confocal laser scanning microscope. Third,ESC with density of 2×105 cells per well were placed in upper compartment of Transwell chamber,DK-SFM culture medium alone or that containing stromal cell derived factor 1 (SDF-1) was added into lower compartment of Transwell chamber. Migration of ESC was observed using inverted phase contrast microscope,and the result was denoted as migration rate. Lastly,ESC with density of 7.5×105 cells per well was inoculated into 6-well plates for 12 hours,and treated with 4 μg/mL mitomycin C for 2 hours. The remaining scratch width of monolayer was respectively measured 6 hours or 12 hours after scratching to calculate the percentage of remaining scratch width. Data were processed with t test.Results Compared with that of blank control,the number of Rac1Q61L-transfected cells adhered to collagen Ⅰ was significantly increased (t＝5.302,P<0.05),while the number of Rac1T17N-transfected cells adhered to collagen Ⅰ,Ⅳ,and fibronectin were all obviously decreased (with t value respectively 13.741,15.676,8.256,P values all below 0.05). Confocal laser scanning microscope showed that spreading area of Rac1Q61L-transfected ESC (with laminate pseudopodia on edge) and Rac1T17N-transfected ESC was respectively larger and smaller as compared with that of blank control. With SDF-1 effect,the migration rate of Rac1T17N-transfected ESC was decreased by 78.0% and Rac1Q61L-transfected ESC was increased by 43.4% as compared with that of blank control. Without SDF-1 effect,the migration rate of Rac1T17N-transfected ESC was decreased by 55.2%,while the migration rate of Rac1Q61L-transfected ESC was close to that of blank control. Six or 12 hours after scratching,the percentage of remaining scratch width in Rac1Q61L-transfected ESC was lower as compared with that in blank control[(39±9)% vs. (43±5)%,(6±5)% vs. (18±7)%,with t value respectively 1.027,4.389,with P value respectively above and below 0.05],while that in Rac1T17N-transfected ESC[(81±9)%,(71±11)%,respectively]was obviously higher as compared with that in blank control (with t value respectively 11.386,11.726,P values all below 0.05). Conclusions Rac1 protein may control the migration of ESC by regulating its adhesion,spreading,and chemotaxis,and it plays an active role in wound healing accelerated by ESC.     

压应力对表皮干细胞增殖与分化的影响

目的：初步观察压应力对表皮干细胞增殖分化的影响。方法：以大鼠的皮肤扩张动物模型为在体观察对象;4、8、12kPa的压应力予体外培养的大鼠表皮干细胞进行间歇加压（每天3次,每次2h,共1周）为离体观察对象。利用免疫组化染色、免疫荧光双染、细胞克隆形成率等技术与方法检测β1整合素、角蛋白19（K19）、角蛋白14（K14）、角蛋白10（K10）、α6整合素、CD71的表达特征,以及压应力对表皮千细胞增殖分化的影响。结果：组织学观察显示,扩张皮肤的表皮层明显增厚;表皮层的β1整合素、K19、K14阳性细胞数量于扩张的第5天开始增多,至15d达峰值后下降,扩张完成后20d趋于正常;棘层和颗粒层不仅可见上述阳性细胞,且出现α6整合素^bri／CD71^dim细胞的表达。体外培养的表皮干细胞,8kPa、12kPa的压应力作用1周后,细胞克隆形成率分别为48．67％、49．36％,明显高于4kPa组（23．17％）与对照组（23．00％）,8kPa、12kPa组可见K10阳性细胞表达。结论：表皮干细胞具有压应力敏感性,适当的压应力可诱导表皮干细胞增殖与分化。     

大鼠骨髓间充质干细胞诱导分化为表皮细胞的实验观察

目的:研究表皮生长因子(Epidermal growth factor,EGF)加条件培养基体外诱导大鼠 MSCs 向表皮细胞定向分化的可行性。方法:采用 Ficoll-Paque 淋巴细胞分离液分离扩增大鼠骨髓 MSCs,免疫细胞化学染色及流式细胞仪进行鉴定。传至第3代的大鼠 MSCs 用表皮生长因子(EGF)、条件培养基等定向诱导 MSCs 分化为表皮细胞;免疫细胞化学对细胞角蛋白 CK5/8、19(Cytokeratin5/8、19)阳性表达细胞进行检测。结果:从大鼠骨髓中分离培养的 MSCs 增殖能力强,细胞表面标志 CD34、CD45阴性,CD29、CD44阳性,流式细胞仪检测显示细胞纯度高,诱导后7d 细胞免疫化学显示角蛋白5/8、19染色阳性,具有表皮细胞特征。结论:从大鼠骨髓中分离培养出的问充质干细胞,具有自我更新和增殖能力强的特点,经诱导可定向分化表达角蛋白。     

人骨髓间质干细胞向表皮细胞分化的研究

目的探讨人骨髓间质干细胞（MSC）在体外培养条件下能否定向诱导分化为表皮细胞。方法抽取无造血系统恶性疾病的成人骨髓标本，采用Percoll细胞分离液（1．073g／ml）分离MSC，在体外传代培养至第3代，分为对照组和实验组。两组分别用普通L-DMEM培养基和含表皮生长因子、胰岛素、维甲酸、氯化钙的L-DMEM培养基诱导7d。在倒置相差显微镜下每天观察两组细胞的形态；采用免疫组织化学法检测P63和广谱细胞角蛋白（PCK）的表达情况。结果实验组细胞由长梭形逐渐转变为扁圆形或形态不规则，部分细胞P63和PCK呈阳性表达；对照组细胞持续呈长梭形，P63和PCK未见表达。结论人骨髓MSC在体外可诱导分化为表皮细胞。     

表皮干细胞仿生膜对毛囊细胞修复创面的影响

目的 选择新生1d大鼠表皮干细胞(ESCs)接种在胶原修饰几丁质膜(C-CBM),构建具有生物活性的覆盖物,评估其修复效果及应用前景.方法 将16只裸鼠随机分4组(n=4):Ⅰ型胶原组(A组)、几丁质膜组(B组)、几丁质膜+ ESCs组(C组)和Ⅰ型胶原修饰几丁质膜+ESCs组(D组),制备裸鼠背部全层皮肤缺损模型,术后定期取材,组织包埋切片,苏木素-伊红(HE)染色,免疫组织化学检测CD34和CD200表达,观察创面早期滤泡性毛囊增生情况.结果 6周创面愈合皮肤以D组修复较好,肉眼观察创面较厚、红润,有皮纹;A组和B组的修复则较薄、呈淡紫色,易出血;C组愈合较慢;并发现表皮巢形成有规律地增多,D组＞C组＞B组＞A组;D组CD34和CD200在手术后3d开始有毛囊干细胞增生,CD34表达延续到第4周,CD200表达延续到第6周,而C组CD34出现在第4周后,CD200出现在7d,D组是C组的2倍,A组和B组新生毛囊干细胞较少.结论 ESCs在C-CBM上生长良好,细胞可利用胶原的天然材料的黏附性,充分扩展,并参与创面修复,这些结果显示仿生膜有可能成为诱导性生物材料.     

分层共同培养诱导骨髓间充质干细胞向表皮细胞分化的研究

目的 探讨体外联合HaCaT细胞共同培养诱导骨髓间充质干细胞(MSCs)向表皮细胞分化的可行性.方法 用聚碳酸酯细胞插入板分层后联合共同培养HaCaT细胞与MSCs,观察培养3、6、9d后的细胞形态,进行角蛋白(CK-19、CK-10)、整合素(α6、β1)染色并用流式细胞仪统计细胞阳性率.结果 共同培养后细胞形态变化明显,共培养3、6d后表皮细胞标志物CK-19、α6整合素、β1整合素免疫荧光染色阳性,细胞阳性率分别为9.3％、8.2％、11.5％和21.7％、34.1％、39.6％,CK10表达呈阴性;共培养9d后CK-19、α6整合素、β1整合素、表达较前减少,阳性率为12.2％、18.6％、16.3％,CK1O出现阳性表达,细胞阳性率为10.7％.结论 分层联合HaCaT细胞共同培养可以诱导骨髓干细胞向表皮细胞进行分化.     

Wnt-1重组腺病毒对人表皮干细胞分化的影响

目的 了解Wnt-1重组腺病毒对人表皮干细胞(ESC)分化趋势的影响.方法 将Wnt-1重组腺病毒导入人ESC(实验组)后,检测细胞直径及增殖情况、ESC多种分子标记物的表达、培养上清液中基质金属蛋白酶2(MMP-2)和MMP-7的含量.以正常ESC为对照组.结果 对照组、实验组ESC直径接近(P＞0.05).对照组ESC为(1.18±0.10)×106个/mL,实验组为(1.45±0.09)× 105个/mL,后者明显高于前者(P＜0.05).2组ESC分子标记物角蛋白5(K5)、K6、K7、K8、K14、CD44、癌胚抗原、雌激素受体、孕激素受体的表达量组间比较,差异均无统计学意义(P＞0.05);对照组K10表达量为0,实验组为(60±3)%;对照组K18为(13.8±1.7)%,实验组表达明显增强[(34.3±2.1)%.P＜0.05];对照组K19为(24.4±1.5)%,实验组减弱至(17.1±1.8)%(P＜0.05).实验组ESC培养上清液中MMP-2和MMP-7含量均明显高于对照组(P＜0.01).结论 Wnt-1重组腺病毒具有诱使人ESC向腺样上皮细胞分化的趋势.