Coexpression analysis of angiogenesis, proliferation, apoptosis, autophagy and SHH pathway genes involved in skin expansion.

Skin and soft tissue expansion is a widely used technique in plastic surgery. However, the regulatory mechanisms associated with cellular processes involved in skin expansion are not well elucidated. In the present study, we aimed at exploring the transcriptome changes associated with skin expansion and profiling the difference in gene expression between the skin tissue in the top of the dilator and the skin tissue in the side of the dilator. A mouse model of skin expansion was established and RNA sequencing (RNA-Seq) was performed on samples collected at different time points. Differential expression analysis was performed using the DESeq2 package while STEM was used for time series clustering profiling. The regulatory networks were established and the functions of sets of genes were analyzed. The mRNA expression levels of candidate genes were validated by the quantitative RT-PCR. Among the skin tissue in the top of the dilator and normal samples at days 1, 3, 7, 14 and 28, 53 commonly upregulated and 7 commonly downregulated genes were identified while among the skin tissue in the side of the dilator and normal samples, 98 downregulated and 255 upregulated genes were identified. Genes differentially expressed among the skin tissue in the top of the dilator and normal samples were involved in coagulation and proliferation-associated pathways while those among the skin tissue in the side of the dilator and normal samples were involved in the inflammation, immune response, and defense response. Among the skin tissue in the top of the dilator and the skin tissue in the side of the dilator samples, 161 were constantly upregulated while 27 were constantly downregulated; these genes were enriched in the biological processes of cell adhesion and regulation of cell proliferation (n = 11). Furthermore, we identified that SHH signaling genes formed a coexpression regulatory network with cellular proliferation, apoptosis, autophagy and angiogenesis-related genes in the expanded skin. In conclusion, our findings can promote research and understanding of the mechanism of skin expansion and will find application in plastic surgery.

A Crossover Reconstruction Between the Forehead Expansion and Upper Eyelid Skin.

BACKGROUND: In cosmetic surgery, the authors have successfully used forehead expansion for reconstruction of the upper eyelid, and have found it to be indispensable for reconstruction of the upper eyelid. In such an operation, preserving the eyebrow is often a problem, and they suggest an approach in 2 stages, which allows us to both save the eyebrow and use the expander flap at the same time. In the last 6 years, they have performed 5 forehead expansions for total upper eyelid skin reconstruction, achieving very good aesthetic outcomes. METHODS: Firstly, the authors measure the defect and choose an appropriate expander implant for the forehead. Secondly, they cut out the pathologically changed-turned red or scarred-skin to protect the eyebrow. Next they get out the tissue expander and use the tissue flap to repair the upper eyelid defect, while the eyebrow is under the expander flap, covered by skin, which they originally cut from the upper eyelid. Three weeks later they can cut down the pedicel and the flap becomes the new upper eyelid skin. RESULTS: The authors find that the new upper eyelid skin may be vascularized by dermatological vessels from the expander flap. The forehead expander flap is reliable and particularly well suited for an upper eyelid, with numerous advantages. In this way, they make maximal use of the expander flap and no additional incision is needed. LEVEL OF EVIDENCE: Level IV, therapeutic study.