Characterization of Smad3 knockout mouse derived skin cells

Treatment with a red-laser-based wound therapy device exerts positive effects in models of delayed keratinocyte and fibroblast wound healing

BACKGROUND

Light therapy is widely used in medicine. Specifically, photobiomodulation has been shown to exert beneficial effects in wound healing disorders, which present a major challenge in health care. The study's aim was providing information on the effect of a novel, red-laser-based wound therapy device (WTD) on keratinocytes and fibroblasts during wound healing under optimal and non-optimal conditions.

METHODS

The scratch wound assay was employed as a wound healing model for mechanical damage with readjustment of specific cell milieus, explicitly chronic TH1 inflammation and TH2-dominant conditions. Furthermore, gene expression analysis of pro-inflammatory cytokines (IL1A, IL6, CXCL8), growth factors (TGFB1, PDGFC), transcription factors (NFKB1, TP53) and heat shock proteins (HSP90AA1, HSPA1A, HSPD1) as well as desmogleins (DSG1, DSG3) in keratinocytes and collagen (COL1A1, COL3A1) in fibroblasts was performed after WTD treatment.

RESULTS

It was shown that WTD treatment is biocompatible and supports scratch wound closure under non-optimal conditions. A distinct enhancement of desmoglein and collagen gene expression as well as induction of early growth factor gene expression was observed under chronic inflammatory conditions. Moreover, WTD increased HSPD1 transcript levels in keratinocytes and augmented collagen expression in fibroblasts during wound healing under TH2 conditions. WTD treatment also alleviated the inflammatory response in keratinocytes and induced early growth factor gene expression in fibroblasts under physiological conditions.

CONCLUSION

Positive effects described for wound treatment with WTD could be replicated in vitro and seem to be to be conferred by a direct influence on cellular processes taking place in keratinocytes and fibroblasts during wound healing.

Simulated microgravity altered the proliferation, apoptosis, and extracellular matrix formation of L929 fibroblasts and the transforming growth factor-β1/Smad3 signaling pathway

Exposure to microgravity can adversely affect the fitness of astronauts. The integrity of the skin plays a crucial role in protecting against mechanical forces and infections, fluid imbalance, and thermal dysregulation. In brief, the skin wound may cause unknown challenges to the implementation of space missions. Wound healing is a physiological process that relies on the synergistic action of inflammatory cells, extracellular matrix (ECM), and various growth factors to maintain the integrity of skin after trauma. Fibroblasts are present almost throughout the entire process of wound repair, especially in the scar formation at the endpoint of wound healing. However, there is limited knowledge about the extent to which fibroblasts are affected by the lack of gravity during wound healing. In this study, we utilized the rotary cell culture system, a ground-based facility that mimics the weightless condition, to study the alterations of L929 fibroblast cells under simulated microgravity (SMG). Our results demonstrated that the SM condition exerted negative influences on the proliferation and ECM formation of the L929 fibroblast. Whereas, the apoptosis of fibroblast was significantly upregulated upon exposure to SMG conditions. Moreover, the transforming growth factor-β1/Smad3 (TGF-β1/smad3) signaling pathway of L929 fibroblast related to wound repair was also altered significantly under a weightless environment. Overall, our study provided evidence that fibroblasts are strongly sensitive to SMG and elucidated the potential value of the TGF-β1/Smad3 signaling pathway modulating wound healing in the future practice of space medicine.

Keratinocyte and Fibroblast Wound Healing In Vitro Is Repressed by Non-Optimal Conditions but the Reparative Potential Can Be Improved by Water-Filtered Infrared A

It is a general goal to improve wound healing, especially of chronic wounds. As light therapy has gained increasing attention, the positive influence on healing progression of water-filtered infrared A (wIRA), a special form of thermal radiation, has been investigated and compared to the detrimental effects of UV-B irradiation on wound closure in vitro. Models of keratinocyte and fibroblast scratches help to elucidate effects on epithelial and dermal healing. This study further used the simulation of non-optimal settings such as S. aureus infection, chronic inflammation, and anti-inflammatory conditions to determine how these affect scratch wound progression and whether wIRA treatment can improve healing. Gene expression analysis for cytokines (IL1A, IL6, CXCL8), growth (TGFB1, PDGFC) and transcription factors (NFKB1, TP53), heat shock proteins (HSP90AA1, HSPA1A, HSPD1), keratinocyte desmogleins (DSG1, DSG3), and fibroblast collagen (COL1A1, COL3A1) was performed. Keratinocyte and fibroblast wound healing under non-optimal conditions was found to be distinctly reduced in vitro. wIRA treatment could counteract the inflammatory response in infected keratinocytes as well as under chronic inflammatory conditions by decreasing pro-inflammatory cytokine gene expression and improve wound healing. In contrast, in the anti-inflammatory setting, wIRA radiation could re-initiate the acute inflammatory response necessary after injury to stimulate the regenerative processes and advance scratch closure.