Role of Homeodomain-Interacting Protein Kinase 2 in the Pathogenesis of Tissue Fibrosis in Keloid-Derived Keratinocytes.

Epithelial-mesenchymal transition (EMT) plays a critical role in fibrotic keloid formation, which is characterized by excessive collagen and extracellular matrix synthesis and deposition. Growing evidence suggests that the serine/threonine kinase homeodomain-interacting protein kinase 2 (HIPK2) acts upstream of several major fibrosis signaling pathways; however, the role of HIPK2 in the keloid fibrogenesis remains unknown. In the current study, we investigated the roles of HIPK2 in the pathogenesis of keloids. Primary normal skin and keloid keratinocytes were cultured and pretreated with transforming growth factor (TGF)-ß1. Next, keratinocytes were transfected with scrambled small interfering RNA (siRNA) and anti-HIPK2 siRNA. The TGF-ß1-associated HIPK2 alterations were investigated by quantitative real-time polymerase chain reaction. Protein levels were analyzed by western blotting. The HIPK2 was markedly increased in the keloid-derived keratinocytes compared with normal skin keratinocytes. In addition, HIPK2 induced the expression of EMT markers in normal skin keratinocytes by TGF-ß1-SMAD family member 3 (SMAD3). The effect of TGF-ß1-related EMT markers and SMAD3 phosphorylation in response to added TGF-ß1 was significantly abrogated when the cells were transfected with HIPK2 siRNA. We conclude that HIPK2 is a crucial factor in the pathogenesis of keloids, suggesting that HIPK2 might be a novel potential drug target for antikeloid therapy.

NADPH oxidase-2 is a key regulator of human dermal fibroblasts: a potential therapeutic strategy for the treatment of skin fibrosis.

The proliferation of human skin dermal fibroblasts (HDFs) is a critical step in skin fibrosis, and transforming growth factor-beta1 (TGF-ß1) exerts pro-oxidant and fibrogenic effects on HDFs. In addition, the oxidative stress system has been implicated in the pathogenesis of skin disease. However, the role of NADPH oxidase as a mediator of TGF-ß1-induced effects in HDFs remains unknown. Thus, our aim was to investigate the role of NADPH in human skin dermal fibroblasts. Primary fibroblasts were cultured and pretreated with various stimulants. Real-time Q-PCR and Western blotting analyses were used for mRNA and protein detection. In addition, siRNA technology was applied for gene knock-down analysis. Hydrogen peroxide production and 2',7'-dichlorofluorescein diacetate (DCFDA) measurement assay were performed. Here, our findings demonstrated that HDFs express key components of non-phagocytic NADPH oxidase mRNA. TGF-ß1 induced NOX2 and reactive oxygen species formation via NADPH oxidase activity. In contrast, NOX3 was barely detectable, and other NOXs did not display significant changes. In addition, TGF-ß1 phosphorylated MAPKs and increased activator protein-1 (AP-1) in a redox-sensitive manner, and NOX2 suppression inhibited baseline and TGF-ß1-mediated stimulation of Smad2 phosphorylation. Moreover, TGF-ß1 stimulated cell proliferation, migration, collagen I and fibronectin expression, and bFGF and PAI-1 secretion: these effects were attenuated by diphenylene iodonium (DPI), an NADPH oxidase inhibitor, and NOX2 siRNA. Importantly, NOX2 siRNA suppresses collagen production in primary keloid dermal fibroblasts. These findings provide the proof of concept for NADPH oxidase as a potential target for the treatment of skin fibrosis.

[Clinical research of vacuum sealing drainage combined with artificial dermis for the treatment of ankle and foot soft tissue defects].

OBJECTIVE: To investigate the effect of vacuum sealing drainage (VSD) combined with artificial dermis for treatment of the ankle and foot soft tissue defects. METHODS: A total of 15 patients with skin and soft tissue defect of ankle and foot were treated from January 2011 to December 2013, including 10 males and 5 females, with an average age of 32.5 years old ranging from 3 to 55 years old, involving 8 cases by traffic accident, 2 cases by machine accident, 5 cases by crush injury;8 cases with soft tissue exposure, 2 cases with tendor exposure, 5 cases with bone exposure. VSD was used to cover the wounds and continuous negative pressure drainage after debridement, the wounds covered with artificial dermis after the second granulation tissue grew well, again VSD was used to cover the wounds and negative pressure suction was applied, after 7 to 14 days negative pressure closed drainage was removed, free skin graft was transplanted above the artificial dermis, sterile gauze was used to compression bandage. RESULTS: All cases were followed up for 3 to 14 months with an average of 6.5 months. Skin graft of 15 of patients survived after transplantation, artificial dermis graft interval was 7 to 14 days with an average of 9.5 days. There was no obvious scar hyperplasia and contracture, no obvious pigmentation, appearance and functional recovery. CONCLUSIONS: After the implantation of artificial dermis and traditional skin graft method need for 2 to 3 weeks, vacuum sealing drainage technique combined with artificial dermis in treatment of soft tissue defect of foot and ankle skin has advantages of simple operation, significantly shorten the time of the second phase of the skin, without flap to repair, little injury to donor skin area, wound healing quality high, clinical effect of satisfaction.