The immune response of human keratinocytes to Trichophyton rubrum conidia is partially mediated by toll-like receptor-2, 4, dectin-1 and cytokines / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of Trichophyton rubrum exposure on the expressions of toll-like receptor-2 (TLR-2), TLR-4 and dendritic cell associated C-type lectin-1 (Dectin-1) and cytokine secretions in human keratinocytes cell line HaCaT.</p><p><b>METHODS</b>The mRNA of TLR-2,4, and dectin-1 in the HaCaT co-cultured with the conidia of Trichophyton rubrum conidia for 24 h was measured with real-time PCR. The mean fluorescence intensity and the percentage of cells positive for TLR-2, 4, and dectin-1 was detected during the co-culture using flow cytometry. The cytokine secretion profiles in the cell culture supernatant was analyzed using a cytokine antibody array.</p><p><b>RESULTS</b>The TLR-2,4, and dectin-1 mRNA expressions, mean fluorescence intensity and percentage of positive cells for TLR-2,4, and dectin-1 all increased in HaCaT cells in response to Trichophyton rubrum conidia exposure. The results of cytokine antibody array demonstrated obviously increased secretions of IL-8, I-309, IFN-γ, IL-6, and IL-13 in the culture supernatant of HaCaT cells in response to Trichophyton rubrum exposure.</p><p><b>CONCLUSION</b>The immune responses and immunological recognition of human keratinocytes to Trichophyton rubrum conidia are partially mediated by up-regulating the expressions of TLR-2, TLR-4 and dectin-1 and secretions of multiple cytokines.</p>

Changes of cathepsin B in human photoaging skin both in vivo and in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cathepsin B plays an important role in cell cycle, extracellular matrix changes and cutaneous tumorigenesis: whether it plays a role in photoaged skin remains unknown. This study aimed to investigate the role of cathepsin B in skin photoaging in vivo and in vitro.</p><p><b>METHODS</b>The expressions of cathepsin B were compared with immunohistochemical methods in solar exposed skin and solar protected skin of six healthy Chinese volunteers. The mRNA and protein expression of cathepsin B in ultraviolet light A (UVA) induced premature senescence fibroblasts in vitro were detected by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting technique.</p><p><b>RESULTS</b>Decreased expression of cathepsin B was observed in photoaged skin compared with that of the solar protected skin. In the UVA induced, premature senescence fibroblasts, a lower expression of cathepsin B was detected by Western blotting and a decreased synthesis of cathepsin B mRNA in the same cells was revealed by real-time RT-PCR.</p><p><b>CONCLUSIONS</b>The results demonstrated a significant negative correlation between skin photoaging and cathepsin B in vitro and in vivo. We propose that cathepsin B, besides matrix metalloproteinases and antioxidant enzymes, is involved in the process of skin photoaging in that it contributes to extracellular matrix remodelling and is a dominant protease in cellular apoptosis and senescence.</p>