Inhibition of dermal fibrosis in self-assembled skin equivalents by undifferentiated keratinocytes.
BACKGROUND
Previous studies showed that keratinocyte plays a major role in dermal cell behavior and hypertrophic scar formation. Further investigations showed that keratinocytes derived from normal skin and hypertrophic scar have different effects on dermal fibroblasts.


OBJECTIVE
To investigate the role of undifferentiated keratinocytes in epidermal-dermal interaction and dermal fibrosis.


METHODS
A tissue-engineered model of self-assembled reconstructed skin was used in this study to mimic interactions between dermal and epidermal cells. Transmission electron microscope, RT and Western blot analysis were performed to show extracellular matrix morphology, collagen synthesis and associated factors expression changes.


RESULTS
The dermal extracellular matrix co-cultured with undifferentiated keratinocytes was well distributed, collagen bundles were not seen, and the levels of collagen mRNA and protein expression declined to 46%, 20% of that in the presence of differentiated keratinocytes. Undifferentiated keratinocytes inhibited dermal fibrosis through down-regulation of TGFbeta1, promoting bFGF expression and desmosome formation.


CONCLUSIONS
Undifferentiated keratinocytes have the ability to preserve normal epidermal-dermal interaction and inhibit dermal fibrosis. Absence or diminution of undifferentiated keratinocytes may take part in initiating events leading to pathological fibrosis.
Wang
Xinwen
X
Research and Development Center for Tissue Engineering, School of Stomatology, FMMU, China; Department of Periodontology and Oral Medicine, School of Stomatology, FMMU, China.
Liu
Yuan
Y
Deng
Zhihong
Z
Dong
Rui
R
Liu
Yanli
Y
Hu
Shijie
S
Li
Yuan
Y
Jin
Yan
Y
D000293:Adolescent; D002450:Cell Communication; D002454:Cell Differentiation; D002478:Cells, Cultured; D002648:Child; D017439:Cicatrix, Hypertrophic / Q000378:metabolism / Q000473:pathology*; D018920:Coculture Techniques; D003094:Collagen / Q000235:genetics / Q000378:metabolism; D020405:Dermis / Q000378:metabolism / Q000648:ultrastructure*; D003896:Desmosomes / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000648:ultrastructure*; D005355:Fibrosis; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism; D053550:Keratin-10 / Q000378:metabolism; D053555:Keratin-5 / Q000378:metabolism; D015603:Keratinocytes / Q000378:metabolism / Q000648:ultrastructure*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D017768:Skin, Artificial; D023822:Tissue Engineering; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism
D019012:Integrin beta1; C507493:KRT10 protein, human; C503940:KRT5 protein, human; D053555:Keratin-5; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D016222:Fibroblast Growth Factor 2; D053550:Keratin-10; D003094:Collagen