DNA damage effects on human skin keratinocytes induced by sulphur mustard / 军事医学

Objective To investigate the toxic effects and mechanisms of sulphur mustard on DNA damage of human immortalized epidermal keratinocytes (HacaT cells).Methods The inhibitory effect of sulphur mustard on the proliferation of HacaT cells was detected by CCK-8 method.The apoptosis index of cells was measured by Annexin V-FITC method.The effects of sulphur mustard on DNA damage were detected by single cell gel electrophoresis.The expression levels of DNA damage and repair related proteins were detected by Western blot.Results The proliferation rate of HacaT cells was inhibited in a dose-dependent manner after treatment with sulphur mustard for 24 h (IC50 value was 121 mol/L).The apoptotic and comet tailing rates of cells treated with sulphur mustard also increased in a dose-dependent manner.The expression levels of DNA damage and repair related proteins were changed after treatment with sulphur mustard.Conclusion Sulphur mustard has significant cytotoxic effect on HacaT cells,and can induce apoptosis and DNA damage.In addition,ATM-P53-γH2AX-PARP signaling pathway plays an important role in the repair of DNA damage induced by sulphur mustard.

Diphlorethohydroxycarmalol Suppresses Ultraviolet B-Induced Matrix Metalloproteinases via Inhibition of JNK and ERK Signaling in Human Keratinocytes

Skin aging is the most readily observable process involved in human aging. Ultraviolet B (UVB) radiation causes photo-oxidation via generation of reactive oxygen species (ROS), thereby damaging the nucleus and cytoplasm of skin cells and ultimately leading to cell death. Recent studies have shown that high levels of solar UVB irradiation induce the synthesis of matrix metalloproteinases (MMPs) in skin fibroblasts, causing photo-aging and tumor progression. The MMP family is involved in the breakdown of extracellular matrix in normal physiological processes such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes such as arthritis and metastasis. We investigated the effect of diphlorethohydroxycarmalol (DPHC) against damage induced by UVB radiation in human skin keratinocytes. In UVB-irradiated cells, DPHC significantly reduced expression of MMP mRNA and protein, as well as activation of MMPs. Furthermore, DPHC reduced phosphorylation of ERK and JNK, which act upstream of c-Fos and c-Jun, respectively; consequently, DPHC inhibited the expression of c-Fos and c-Jun, which are key components of activator protein-1 (AP-1, up-regulator of MMPs). Additionally, DPHC abolished the DNA-binding activity of AP-1, and thereby prevented AP-1-mediated transcriptional activation. These data demonstrate that by inactivating ERK and JNK, DPHC inhibits induction of MMPs triggered by UVB radiation.

Study on chemical hypoxia-mimetic (CoCl_2) agent-induced inflammatory reaction in human keratinocytes / 中国药理学通报

Aim To explore the effect of chemical hypoxia-mimetic agent,cobalt chloride(CoCl2)on inflammatory reaction in human keratinocytes(HaCat cells).Methods After HaCat cells were treated with CoCl2 at different concentrations to set up a chemical hypoxia-induced cell model of skin injury,cell viability,intracellular reactive oxygen species(ROS),mitochondrial membrane potential(MMP),the levels of both interleukin 6(IL-6)and interleukin 8(IL-8)as well as the expression of heme oxygenase-1(HO-1)were detected.Results The viability of HaCat cells was reduced by CoCl2 at the concentrations from 500 to 3 000 ?mol?L-1,and the higher CoCl2 doses,the lower cell viability was.CoCl2 induced oxidative stress reaction(increasing ROS production and decreasing MMP).CoCl2 induced inflammatory reaction,enhancing the release of IL-6 and IL-8.CoCl2 at concentrations from 1 000 to 3 000 ?mol?L-1 upregulated HO-1 expression in HaCat cells.Conclusion CoCl2 induces not only oxidative stress,but also inflammatory reaction,increasing the release of both IL-6 and IL-8,as well as HO-1 expression.