胃癌和癌旁黏膜与距癌远端切缘胃黏膜基因表达谱差异的研究

目的用基因芯片技术研究胃癌 （T）和癌旁黏膜 （P）与距癌远端切缘胃黏膜 （C）基因表达谱差异,筛选与早期癌变相关的基因.方法利用国际学术界公认的标准化 Affymetrix公司生产的 U133A基因芯片分别检测 T和 P及 C基因表达谱,并利用生物信息学方法对检测结果进行分析.结果 （1）T与 C比较差异 4倍以上共有 766个基因,其中表达上调 [信号比的对数值 （SLR）〉2]有 530个,表达下调 （SLR〈- 2）有 236个;（2）P与 C比较差异 4倍以上共有 64个基因,其中表达上调 （SLR 〉2）有 50个,表达下调 （SLR〈- 2）有 14 个;（3）T和 P同时与 C比较 （T、 P两者之一差异 4倍以上 ）共有 143个相同的基因,其中表达上调 （SLR 〉2）有 108个,表达下调 （SLR〈- 2）有 35个.结论癌旁黏膜在基因表达水平上显示 143个基因与胃癌表达的基因相同,提示这些基因可能与早期胃癌癌变的启动和演化有关.     

胎儿皮肤附件形成与成纤维细胞生长因子-10和Bek基因表达的关系

目的探讨在不同发育阶段胎儿皮肤中成纤维细胞生长因子-10(FGF-10)及其受体Bek基因表达特征及其与皮肤附件形成的关系。方法用病理学技术检测不同发育阶段胎儿皮肤的结构特征，并提取不同胎龄(12～32周)胎儿皮肤的总RNA，用逆转录一聚合酶链反应(RT-PCR)方法检测FGF-10、Bek基因在不同胎龄标本中的表达变化。结果在早期发育的胎儿皮肤中。FGF-10和Bek基因表达较弱，随着胎龄的增长和发育的进展，特别在皮肤附件诱导形成阶段。两种基因表达逐渐增强，在胎儿发育后期，两种基因表达开始减弱。结论FGF-10与其受体Bek基因的特异表达方式及两者结合后引起的信号激活对皮肤附件的诱导形成和形态发生及皮肤生理功能的维持具有重要意义。     

脂蛋白基因在早期骨关节炎软骨下骨的表达

目的：研究早期骨关节炎软骨下骨脂蛋白相关的基因表达改变情况。方法：大鼠分为实验组（15只）和对照组（15只）.实验组切除右膝内侧半月板及内侧副韧带,对照组仅切开关节囊。于术后1、2、4周取右膝关节标本,采用全基因表达谱芯片技术研究软骨下骨全基因表达,利用差异基因分析的方法分析脂蛋白相关的基因表达改变情况。结果：软骨下骨Apoa5表达于建模术后1周上调,术后2周下调;Apoc2表达于术后2周上调;Apol3表达于术后1周上调,术后4周下调;Lrp1于术后1、2周下调;Lrp5于术后2周下调;Gpihbp1、Lpl、Tfpi、Vldlr表达于术后1周均上调;Lrpap1、RGD1309808于术后4周均下调。结论：脂蛋白相关基因的表达改变在早期膝关节骨关节炎的软骨下骨变化中可能起了重要作用。     

BC047440基因调控HepG2的NF-κB活性机制的实验研究

目的 应用基因芯片进行高通量分析沉默基因BC047440后相关基因表达谱的变化,以了解BC047440通过NF-κB信号途径上游的何种分子调控NF-κB活性.方法 应用博奥公司提供的人全基因组基因芯片检测沉默BC047440基因后相关基因表达谱的改变,利用其数据库和MAS分析系统进行分析筛选,寻找NF-κB发生表达改变的上游分子并进行RT-PCR验证.结果 沉默BC047440基因后有189个基因表达改变,其中130个基因上调表达2倍以上,59个基因下调表达超过50%,其中NF-κB信号途径上游分子中仅TRAF6下降为对照组的23.06%.RT-PCR验证TRAF6的mRNA的表达下降为对照组的29.5%,与基因芯片结果类似.结论 应用基因芯片可以高通量高效率地分析沉默BC047440基因后的基因表达谱,BC047440基因可通过调控上游分子TRAF6作用于NF-κB信号途径来调控肝癌增殖.     

小鼠睾丸移植物中3种生精阶段特异性基因的表达

目的 采用逆转录-聚合酶链反应，探讨新生小鼠睾丸组织移植到裸鼠体内后，3种阶段特异性基因，缺失型无精子基因（Daz1）、磷酸甘油激酶2（Pgk2）和鱼精蛋白-2（Prm2）在不同发育阶段移植物中的表达情况。方法 将180只出生1-2d昆明小鼠睾丸移植到60只7-12周去势雄性免疫缺陷小鼠背部；在移植后不同时间段（分为3d、1周-8周和12周10个组）取出移植物，对在发育不同阶段表达的3种基因出现的时间及表达情况进行分析测定，并与相应各年龄段正常小鼠睾丸中的基因表达相比较。同时进行组织形态学观察，对比各种基因出现的时间与小鼠睾丸发育周期的吻合性。结果 在10个时间段取出的移植物中，所测定的3种基因表达趋势与在正常昆明小鼠睾丸中所见基本相同，并与小鼠发育周期基本吻合。结论 新生小鼠睾丸组织移植到免疫缺陷小鼠体内后，生精细胞的发育在形态学和几种受试基因出现的时间上与在正常小鼠中表现均相似。从而对该睾丸组织移植模型用于生精细胞异体异位生长发育研究及基因调控机制研究的可行性提供了进一步的理论依据。     

外胚叶发育不全基因信号途径与汗腺发育及修复的关系

目的 探讨外胚叶发育不全（ectodysplasin，EDA）基因信号途径与汗腺发育及修复的关系。方法通过对近期国内外相关文献的回顾，了解EDA基因的生物学特性、信号传导途径和促进汗腺发育的分子机制。结果大量实验证实EDA基因在胎儿发育早期参与了胚胎皮肤汗腺的形态和功能发生。结论EDA基因对皮肤汗腺的发生和结构的形成以及皮肤生理功能的维持具有重要意义，可为实现基因调控皮肤受损汗腺的完美修复找到一条新路。     

胎儿和出生后机体皮肤内p38MAPK及其MAPKKs基因表达变化的比较性研究

目的探讨p38丝裂素活化蛋白激酶(p38MAPK)及其上游信号分子MAPKKs(mkk3和mkk6)基因在不同胎龄的胎儿皮肤和出生后机体皮肤组织中表达的变化及其可能的生物学意义.方法用病理学技术检测不同发育时期皮肤的结构特征后,提取18例不同胎龄(13～32周)的胎儿皮肤和6例出生后机体皮肤组织的总RNA,分离mRNA,用RT-PCR方法检测这3种基因在不同组织中的表达变化规律.结果p38MAPK,mkk3和mkk6基因在不同发育阶段的皮肤组织中都有表达.在早期妊娠胎儿的皮肤组织中,这3种基因表达较强,随着胎儿的生长和发育,皮肤组织内这3种基因表达逐渐减弱.在出生后机体的皮肤细胞中,p38MAPK,mkk3和mkk6基因的表达量分别为妊娠早期皮肤的39.6%,63.5%和54.5%,基因表达明显减弱(P＜0.01).结论p38MAPK,mkk3和mkk6基因在不同发育阶段人皮肤组织内都有表达,显示细胞外信号引起的p38MAPK信号通路可能对皮肤的发生、结构功能的维持以及伤后修复十分重要.在早期妊娠胎儿皮肤中p38MAPK及其上游信号分子MAPKKs基因的高表达可能是胎儿皮肤组织细胞快速增殖,皮肤创面无瘢痕愈合的机制之一,但深层次机制还需进一步研究.     

不同胎龄胎儿皮肤和增生性瘢痕中细胞外信号调节激酶5及其mapkk基因表达的变化

目的探讨细胞外信号调节激酶5(extracellular-signal regulated protein kinase 5,erk5)及其上游信号分子mapkk(mek5)在不同胎龄的胎儿皮肤和不同形成时期的增生性瘢痕中的基因表达变化规律及其可能的生物学意义.方法用病理学技术检测不同发育时期的皮肤和增生性瘢痕的结构特征后,提取18例不同胎龄(13～32周)的胎儿皮肤、6例少儿皮肤、16例不同发生时期的增生性瘢痕(4个月-11年)和8例正常皮肤组织的总RNA后,分离mRNA,用RT-PCR方法检测这2种基因在不同组织中的表达变化特征.结果erk5和mek5基因在不同发育阶段的皮肤和增生性瘢痕中都有表达.在早期妊娠胎儿的皮肤中,这2种基因表达较强,随着胎龄的增加,基因表达水平逐渐降低,在少儿皮肤组织中,这两种基因的转录本含量明显减少(P<0.05).在正常皮肤和不同形成时期的增生性瘢痕中,mek5基因表达水平相近,相互间差异不显著,而erk5基因在正常皮肤中的表达水平较低,在增殖期和成熟期增生性瘢痕中表达水平明显增强(P<0.01).结论erk5与mek5基因在不同发育时期的皮肤组织内都有表达,显示erk5介导的信号通路可能对皮肤的发生、结构功能的维持以及伤后修复十分重要.在早期妊娠胎儿皮肤中erk5和mek5基因的高表达可能是胎儿皮肤组织细胞快速增殖,创面无瘢痕愈合的机制之一,而增生性瘢痕发生和形成也可能与erks基因表达增强有关.     

六味地黄丸对绝经后骨质疏松症肾阴虚证差异表达基因的影响

目的 探讨六味地黄丸对绝经后骨质疏松症肾阴虚证(POP)差异表达基因的影响。方法 用基因芯片技术比较POP肾阴虚证组与POP肾阳虚证组、POP无肾虚证组、健康对照组受试者外周血基因表达谱,筛选出差异表达基因;六味地黄丸治疗 POP肾阴虚证组3个月后,用基因芯片检测六味地黄丸对这些差异表达基因的影响。结果 ①基因芯片筛选POP肾阴虚证组与其他3组比较均有显著性差异的差异表达基因：ASB1、CLCF1、PROK2、GPR27、C3orf35、GSTM5、MUC12,其中ASB1、CLCF1、 PROK2、GPR27和C3orf35表达下调,GSTM5和MUC12表达上调。②六味地黄丸治疗POP肾阴虚证组3个月后,基因芯片检测 ASB1、CLCF1的表达显著上调,CLCF1参与JAK-STAT信号通路中JAK1、CBP显著下调、STAT4显著上调,而PROK2、GPR27、 C3orf35和GSTM5表达水平治疗前后比较无显著性差异。③六味地黄丸治疗POP肾阴虚证组3个月后,与治疗前相比,共有5701个差异表达基因,其中上调基因3072个,下调基因2629个。结论 六味地黄丸上调POP肾阴虚证差异基因ASB1、CLCF1 的表达,其治疗POP肾阴虚证的机理可能与其上调CLCF1介导JAK-STAT信号通路调控下游CBP表达有关。     

睾酮对前列腺癌LNCaP细胞雄激素反应性基因表达的影响

目的检测睾酮作用下雄激素依赖性前列腺癌细胞LNCaP中雄激素反应性基因（ARGs)的表达情况。方法检测不同浓度的睾酮对雄激素依赖性前列腺癌细胞LNCaP增殖的影响，采用基因芯片确定LNCaP细胞中受睾酮调控的基因。结果低浓度的睾酮促进LNCaP细胞的生长，并呈剂量依赖性，相反较高浓度的睾酮能够抑制LNCaP的增殖。在96个与前列腺癌有关的基因中，受睾酮刺激有19个基因表达上调，8个基因表达下调。结论睾酮诱导的雄激素反应性基因在前列腺癌的发展中起非常重要的作用，基因芯片有助于高通量分析基因表达水平的变化，为前列腺癌的研究提供了非常理想的工具。     

Epidermal stem cells are the source of sweat glands in human fetal skin: Evidence of synergetic development of stem cells, sweat glands, growth factors, and matrix metalloproteinases

The development of sweat glands is a complex biological process, and the extent of cellular trafficking between epidermal stem cells and the development of sweat glands is uncertain. Therefore, we studied the synergetic development effects of stem cells, sweat glands, growth factors, and matrix metalloproteinases (MMPs) in human skin. Human fetal skin was obtained from spontaneously aborted fetuses at 11-31 weeks of gestation. Paraffin sections were cut and stained with hematoxylin and eosin or immunostained with antibodies against beta(1) integrin, keratin (K)-19 and K7, MMP-2 and -7, and epidermal growth factor. In situ hybridization was used along with semiquantitative analysis of the positive expression of these proteins to analyze for mRNA expression of MMP-2 and -7. Histological studies revealed the fetal epidermis began to form a primary epidermal ridge at gestational age 13-14 weeks and these primordial basal cells became tightly packed to take the form of multiple hillocks between 14 and 16 weeks. Furthermore, these cells gave rise to chord-like columnar buds in the embryonic epidermis, and these buds gradually migrated downward into the dermis to form juvenile sweat glands at 18-20 weeks. Mature sweat glands were found in the fetal epidermis at the end of 24 weeks. beta(1) integrin and K19 immunoreactivities were first detected in those cells that gathered together to form primary epidermal ridges, including sweat gland cords, buds, and immature sweat gland cells. The positive immunostaining for K7 appeared in early sweat gland buds at 14-16 weeks, and from then on K7 was concentrated in developing sweat gland cords or cells. At 14-16 weeks, positive epidermal growth factor, MMP-2, and MMP-7 expression was first observed weakly in developing sweat gland buds. The immunoreactivity of these proteins was then gradually increased in the developing sweat gland buds and extracellular stroma from 14 to 20 weeks. The intensity of the positive signal peaked at 20-22 weeks of gestational age. After that, the intensity of immunostaining for MMP-2 and MMP-7 proteins was gradually weakened. However, the expression of epidermal growth factor did not show an apparent decrease. These results suggest that epidermal stem cells are the source of sweat glands. Epidermal growth factor is one of the main inducers in the development and maturity of sweat gland buds or cells and the local activated MMPs may play an important role in cleaving the major matrix components in the basement membrane.     

不同发育时期胎儿皮肤中基质金属蛋白酶-9,2及金属蛋白酶-2抑制因子基因表达的变化

目的:研究基质金属蛋白酶-9(MMP-9)、基质金属蛋白酶-2(MMP-2)及其组织抑制因子(TIMP-2)在不同胎龄的胎儿皮肤中表达的变化特征及其可能的生物学意义.方法:用病理学技术检测不同发育时期胎儿皮肤的结构特征后,提取18例不同胎龄(13～33周)的胎儿皮肤总RNA后,分离mRNA,用RT-PCR方法检测这3种基因在不同组织中的表达变化规律.结果:MMP-9、MMP-2和TIMP-2基因在不同发育时期的胎儿皮肤组织中的表达变化规律相似.在早期妊娠胎儿皮肤中,这3种基因表达较弱,随着胎儿生长发育,MMP-9,MMp-2和TIMP-2基因表达逐渐增强,妊娠晚期的皮肤组织内,这3种基因表达产物的灰密度比值分别是妊娠早期的8.8、2.4和3.1倍,基因表达水平显著升高(P＜0.05).结论:MMP-9,2和TIMP-2对皮肤的生长发育、结构功能的维持以及创面修复具有重要的调节作用.妊娠早期,TIMP-2基因低表达可能与胎儿皮肤创面无瘢痕愈合相关,而妊娠晚期皮肤中TIMP-2基因表达增强可能是创面愈合后形成瘢痕的机制之一.     

The interaction between epidermal growth factor and matrix metalloproteinases induces the development of sweat glands in human fetal skin

BACKGROUND: The development of sweat glands is a very complicated biological process involving many factors. In this study, we explore the interrelationship among epidermal growth factor (EGF), matrix metalloproteinase 2 (MMP-2), matrix metalloproteinase 7 (MMP-7), and the development of sweat glands in human embryos. Furthermore, we hope to elucidate the mechanism(s) underlying the induction of epidermal stem cells into sweat gland cells. MATERIALS AND METHODS: Skin biopsies of human embryos obtained from spontaneous abortions at different gestational ages from 11 to 31 weeks were used in this study. The dynamic expression of EGF, MMP-2, MMP-7, and keratin-7 (K7) in developing sweat gland cells or extracellular stroma surrounding the sweat gland cells was examined with SP immunohistochemical methods. The localization of the cellular sources of MMP-2 and MMP-7 was examined with in situ hybridization. RESULTS: At 14-20 weeks of gestation, a gradual increase in EGF immunoreactivity was observed not only in developing sweat gland buds but also in extracellular stroma surrounding the buds, and the expression intensity of EGF peaked at 20-22 weeks of gestational age. All mRNA-positive buds or cells in developing sweat glands contained corresponding immunoreactive proteins. Positive immunostaining for K7 appeared in early sweat gland buds at 14-16 weeks of gestation, and from then on, the positive signal of K7 was concentrated in developing sweat gland cords or cells. CONCLUSIONS: The morphogenesis of sweat glands in human fetal skin begins at 14-16 weeks of gestational age, and is essentially complete by 24 weeks. There is a close relationship among EGF, extracellular matrix remodeling, and morphogenesis of the sweat glands. EGF is one of the inducers in the development and maturity of sweat gland buds or cells.     

The interaction between epidermal growth factor (EGF) and matrix metalloproteinase induces the development of sweat glands in human fetal skin

Objective:The development of sweat glands is a very complicated biological process involving many factors. In this study, we explore the inter-relationship between epidermal growth factor (EGF),matrix metalloproteinases (MMP-2,MMP-7) and development of sweat glands in human embryos. Furthermore, we hope to elucidate the mechanism(s) underlying the induction of epidermal stem cells into sweat gland cells. Methods:Skin biospies of human embryos obtained from spontaneous abortions at different gestational ages from 11 to 31 weeks were used in this study. The dynamical expression of EGF, MMP-2, MMP-7 and keratin-7 (K7) in developing sweat gland cells or extracellular stroma surrounding the sweat gland cells were examined with S-P immunohistochemical methods.The localization of the cellular sources of MMP-2 and MMP 7 was examined with in situ hybridization. Results:At 14-20 wk of gestation, a gradual increase in EGF immunoreactivity was observed not only in developing sweat gland buds but also in extracellular stroma surrounding the buds,and the expression intensity peaked at 20-22 wk of gesta- tional age. All mRNA-positive buds or cells in developing sweat glands contained corresponding immunoreactive proteins. Positive immunostaining for K7 appeared in early sweat gland buds at 14-16wk of gestation, and from then on, K7 was concentrated in developing sweat gland cords or cells. Conclusions: The morphogenesis of sweat gland in human fetal skin begins at 14-16wk of gestational age, and essentially completes by 24wk. There is a close relationship among EGF,extracellular matrix remodeling and morphogenesis of sweat glands, and EGF is one of the inducers in the development and maturity of sweat gland buds or cells.     

Analysis of differentially expressed genes in fetal skin of scarless and scar-forming periods of gestational rats

Objective: To study the differences of gene expression between earlier gestational skin and later gestational skin of rats with the aids of single primer amplification (SPA) and high-density oligonucleotide DNA array to understand the molecular mechanism of scarless healing. Methods: Total RNAs were isolated from fetal rat skin of the scarless (E15) and scar-forming (E18) periods of gestation (term =21.5 days). The RNAs from earlier gestational skin (EGS) and later gestational skin (LGS) were both reversely transcribed to cDNAs, then labeled with the incorporation of fluorescent dCTP for preparing the hybridization probes by SPA method. The mixed probes were then hybridized to the oligonucleotide DNA arrays which contained 5 705 probes representing 5 705 rat genes. After highly stringent washing, these DNA arrays were scanned for fluorescent signals to display the differentially expressed genes between the 2 groups of skin. Results: Among 5 705 rat genes, there were 53 genes (0.93%) with differentially expressed levels between EGS and LGS groups, 27 genes, including fibroblast growth factor 2 ( FGF2 ) and follistatin were up-regulated (0.47%) and 26 genes were down-regulated (0.46%) in fetal skin during scarless period versus scar-forming period. Higher expressions of FGF2 and follistatin in EGS than those in LGS were also revealed by RT-PCR method. Conclusions: High-density oligonucleotide DNA array provided a powerful tool for investigating differential gene expression in earlier and later gestational fetal skins. This technology validates that the mechanism of fetal scarless healing is very complicate and the change of many gene expressions is associated with fetal scarless healing.     

The expression characteristics and biological significance of bFGF, EGF,TGF-β isoforms and their receptors in skins from fetus and adult

To observe the localization and expression characteristics of alpha-smooth muscle actin (AS-MA), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), transforming growth factor-β(TGF-β) isoforms, and their receptors in fetal and adult skins in order to explore their potential biological significance.Methods: The expression and the distribution of ASMA, bFGF, EGF, TGF-βisoforms, and their receptors were detected with immunohistochemistry and histopathology methods in 36 skin specimens. Among them, 30 specimens belonged to fetuses at different developmental stages and 6 were from adults. Results:Positive immunohistochemical signals of ASMA, bFGF, EGF, and TGF-βisoforms and their receptors could be found in fetal and postnatal skins.These factors were mainly distributed in the cytoplasm and extracellular matrix of epidermal cells, endothelial cells,hair follicle epithelial cells and some fibroblasts. Receptors of these factors were mostly located in the cellular membrane of the above mentioned cells, while protein particles of ASMA could be observed in myofibroblasts and sweat gland cells. Along with ascent in gestational age, the positive cellular rates of bFGF, EGF, TGF-βisoforms, their receptors, and ASMA in skin were elevated progressively. In skins specimens obtained from fetuses of late-trimester (29-31 week gestation) and adult, the positive rates of these proteins were significantly raised in comparison with skin of fetuses of early-trimester. Conclusion: The endogenous bFGF, EGF, three TGF-βisoforms and their receptors might be involved in the development of the skin in embryonic stage and in the cutaneous structure and function,and also wound healing in adult stage. The relative lack of these factors and their receptors might be one reason why the wound of fetus heal by regeneration rather than by scarring.     

Ontogeny of expression of basic fibroblast growth factor and its receptors in human fetal skin

The wounds in skin of early gestational fetus healwithout scar formation by a process resemblingregeneration rather than repair.1The ability torepair congenital anomalies in uterus such as cleft lipwith scarless healing will revolutionize the field ofreconstructive plastic surgery. Furthermore, if thebiological properties of scarless fetal healing aredetermined, these characteristics mightbe replicated inthe adult environment with tremendous clinicalbenefits. This non-scarring phenomenon is ge…     

基因芯片技术筛选人不同发育阶段表皮干细胞差异表达基因的研究

目的 分析人不同发育阶段表皮干细胞基因表达变化特征,探讨其可能的生物学意义.方法 收集胎龄28～32周胎儿、4～12岁少儿、35～55岁成人3组正常皮肤组织标本,每组10例.采用胰蛋白酶和乙二胺四乙酸联合消化法分离表皮,Ⅳ型胶原快速黏附法分离、纯化表皮干细胞,免疫细胞化学染色法行整合素β1、角蛋白19单克降抗体检测鉴定.Trizol一步法分别提取各组细胞总RNA,琼脂糖甲醛变性凝胶电泳质检.制备探针并与表达谱芯片进行杂交,扫描芯片荧光信号图像.对芯片图像进行分析,以2倍差异表达值筛选差异表达基因.选择明显上调或下凋的基因,用实时RT-PGR技术进一步验证相关基因.结果 与少儿组比较,成人组差异表达基因1808个,其中上调的基因1089个、下调的基因719个,已知基因1462个、未知基因346个.少儿组样本与胎儿组比较,差异表达基因4534个,其中上调的基因1783个、下调的基因2751个,已知基因3577个、未知基因957个.根据基因功能分类,成人组与少儿组差异表达基因可分为128类,少儿组与胎儿组差异表达基因可分为216类.1104个基因在胎儿组、少儿组与成人组样本中呈持续差异表达,根据基因功能分为32类.实验检测到持续差异表达基因中,有94个差异表达基因呈持续上调状,75个差异表达基因呈持续下调趋势.实时RT-PCR验证结果与芯片筛选结果一致.结论 体外培养的胎儿、少儿与成人表皮干细胞基因表达谱有明显不同,其差异可能与不同发育阶段人表皮干细胞的增殖分化能力及皮肤创伤修复能力不同密切相关.

Abstract：

Objective To analyze expression characteristics of human skin epidermal stem cell at different developmental stages, and to explore its biological significance. Methods Health skin samples from 28-32 w fetuses(F group) , 4-12 y children(C group) , and 35-55 y adult(A group) were harvested,with 10 cases in each group. Epidermis were separated using trypsin digestion and EDTA, and human epidermal stem cells were isolated and purified with type Ⅳ collagen attachment method. The monoclonal antibody of integrin β1 and keratin 19 were used for detection and identification of epidermal stem cells by immunohistochemical staining. Total RNA was extracted from above cells by Trizol one-step method, and were detected by formaldehyde denaturing agarose gel electrophoresis. Probes were prepared and hybridized into cDNA microarray for scanning fluorescent signals and analysis of images, with two-fold differential expression value for screening. Significantly up/down-regulated genes were selected for verification by real time RT-PCR. Results By comparing expression profile between A and C groups, a total of 1808 genes with differential expression were detected, including 1089 up-regulated genes and 719 down-regulated genes, and they were classified into 128 categories. Among them, 1462 genes were known (found in GeneBank), 346 genes were unknown. A total of 4534 genes with differential expression were detected between C and F groups, in which 1783 genes were up-regulated and 2751 genes were down-regulated, and they were classified into 216 categories. Among them, 3577 genes were known (found in GeneBank), and 957 genes were unknown. There were 1104 genes with differential expression consistently detected in F, C and A groups,which were classified into 32 categories according to gene function. Among them, 94 genes were consistently up-regulated and 75 genes consistently down-regulated. Test results of real time RT-PCR were in accordance with above-mentioned results. Conclusions Gene expression profiles of epidermal stem cells cultured in vitro, harvested from fetuses, children, and adult, exhibit obvious difference. This may be closely related to different stages of proliferation and differentiation of human epidermal stem cell and self-repair ability of wound at different developmental stages.     

胎儿和少儿皮肤内碱性成纤维细胞生长因子及其受体的基因表达

目的　探讨不同胎龄的胎儿和少儿皮肤中碱性成纤维细胞生长因子 (bFGF)及其两种受体 (bek和flg)基因表达的变化。 方法　提取 18例不同胎龄 ( 13～ 3 2周 )的胎儿皮肤和 6例少儿皮肤的总RNA后 ,分离mRNA ,用逆转录 聚合酶链反应 (RT PCR)方法检测这 3种基因在不同组织中的表达。结果　在早期妊娠胎儿的皮肤中 ,bFGF ,flg和bek基因表达较强 ,随着胎儿的生长和发育 ,皮肤组织内这 3种基因表达逐渐降低 ,在少儿皮肤中 3种基因的表达量分别为晚期妊娠胎儿皮肤的 62 .5 % ,5 9.5 %和 5 2 .9% ,基因表达显著降低 ( P <0 .0 5 )。结论　bFGF及其受体基因可能在皮肤的发生、结构功能的维持以及伤后修复中起重要作用。这 3种基因在胎儿皮肤中表达水平较高可能与胎儿皮肤细胞增殖较快 ,皮肤创面愈合迅速有关。     

Novel differences in the expression of inflammation‐associated genes between mid‐ and late‐gestational dermal fibroblasts

While cutaneous wounds of late‐gestational fetuses and on through adulthood result in scar formation, wounds incurred early in gestation have been shown to heal scarlessly. Unique properties of fetal fibroblasts are believed to mediate this scarless healing process. In this study, microarray analysis was used to identify differences in the gene expression profiles of cultured fibroblasts from embryonic day 15 (E15; midgestation) and embryonic day 18 (E18; late‐gestation) skin. Sixty‐two genes were differentially expressed and 12 of those genes are associated with inflammation, a process that correlates with scar formation in fetal wounds. One of the differentially expressed inflammatory genes was cyclooxygenase‐1 (COX‐1). COX‐1 was more highly expressed in E18 fibroblasts than in E15 fibroblasts, and these differences were confirmed at the gene and protein level. Differences in COX‐1 protein expression were also observed in fetal skin by immunohistochemical and immunofluorescence staining. The baseline differences in gene expression found in mid‐ and late‐gestational fetal fibroblasts suggest that developmental alterations in fibroblasts could be involved in the transition from scarless to fibrotic fetal wound healing. Furthermore, baseline differences in the expression of inflammatory genes by fibroblasts in E15 and E18 skin may contribute to inflammation and scar formation late in gestation.