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 percent) 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.
Key Research Laboratory of Wound Repair, Burn Institute, 304th Clinical Department, General Hospital of PLA, Beijing 100037, China. chenwei304@yahoo.com
Wei
W
Chen
Xiao-Bing
XB
Fu
Shi-Li
SL
Ge
Tong-Zhu
TZ
Sun
Zhi-Yong
ZY
Sheng
D000818:Animals; D002921:Cicatrix / Q000196:embryology / Q000235:genetics*; D004817:Epidermis / Q000196:embryology / Q000378:metabolism*; D005333:Fetus / Q000196:embryology; D016222:Fibroblast Growth Factor 2 / Q000032:analysis; D038681:Follistatin / Q000032:analysis; D005784:Gene Amplification; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats; D012867:Skin / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000032:analysis; D053773:Transforming Growth Factor beta1; D014945:Wound Healing / Q000235:genetics*
D038681:Follistatin; D012333:RNA, Messenger; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D016222:Fibroblast Growth Factor 2