IL-1 Receptor Antagonist Reduced Chemical-Induced Keratinocyte Apoptosis through Antagonism to IL-1α/IL-1β

Extracellular interleukin 1 alpha (IL-1α) released from keratinocytes is one of the endpoints for in vitro assessments of skin irritancy. Although cells dying via primary skin irritation undergo apoptosis as well as necrosis, IL-1α is not released in apoptotic cells. On the other hand, active secretion has been identified in interleukin-1 receptor antagonist (IL-1ra), which was discovered to be a common, upregulated, differentially-expressed gene in a microarray analysis performed with keratinocytes treated using cytotoxic doses of chemicals. This study examined whether and how IL-1ra, particularly extracellularly released IL-1ra, was involved in chemically-induced keratinocyte cytotoxicity and skin irritation. Primary cultured normal adult skin keratinocytes were treated with cytotoxic doses of chemicals (hydroquinone, retinoic acid, sodium lauryl sulfate, or urshiol) with or without recombinant IL-1ra treatment. Mouse skin was administered irritant concentrations of hydroquinone or retinoic acid. IL-1ra (mRNA and/or intracellular/extracellularly released protein) levels increased in the chemically treated cultured keratinocytes with IL-1α and IL-1β mRNAs and in the chemically exposed epidermis of the mouse skin. Recombinant IL-1ra treatment significantly reduced the chemically-induced apoptotic death and intracellular/extracellularly released IL-1α and IL-1β in keratinocytes. Collectively, extracellular IL-1ra released from keratinocytes could be a compensatory mechanism to reduce the chemically-induced keratinocyte apoptosis by antagonism to IL-1α and IL-1β, suggesting potential applications to predict skin irritation.

Increased Skin Irritation by Hydroquinone and Rsetinoic Acid Used in Combination

BACKGROUND: Hydroquinone (HQ) is frequently combined with retinoic acid (RA) to enhance lightening efficacy, which may also affect skin irritancy. Although skin irritation leads to postinflammatory hyperpigmentation, little research has been performed to compare skin irritancy between each component and the combination. OBJECTIVE: This study was done to examine whether HQ-RA combination increased skin irritation induced by HQ or RA alone. METHODS: Patch testing was performed using maximum therapeutic and higher concentrations of HQ and RA in 10 volunteers, and then, it was performed using their popular therapeutic concentrations and combination in the other 20 volunteers. In vitro irritation was also assessed in primary cultured normal human keratinocytes treated with 80% and 50% cell survival doses of HQ, 80% cell survival dose of RA, and their combination. RESULTS: The combination in patch testing induced stronger erythema than the corresponding concentrations of HQ and RA, which was remarkable with use of combination of higher concentrations. In cultured keratinocytes, the RA combination significantly decreased cell viability, but increased cytotoxicity and extracellular interleukin 1 alpha release with corresponding doses of HQ. CONCLUSION: The results of patch tests and in vitro irritation assessment tests suggested that HQ and RA increased skin irritation when used in combination.

Three New Single Nucleotide Polymorphisms Identified by a Genome-Wide Association Study in Korean Patients with Vitiligo

Genetic susceptibility is involved in the pathogenesis of vitiligo. Association studies with a whole genome-based approach instead of a single or a few candidate genes may be useful for discovering new susceptible genes. Although the etiology of non-segmental and segmental types is different, the association between gene polymorphisms and vitiligo has been reported, without defining types or in non-segmental type. Whole genome-based single nucleotide polymorphisms (SNPs) were examined in patients with non-segmental and segmental types of vitiligo using the Affymetrix GeneChip 500K mapping array, and 10 functional classes of significant SNPs were selected. Genotyping and data analysis of selected 10 SNPs was performed using real-time PCR. Genotype and allele frequencies were significantly different between both types of vitiligo and three of the target SNPs, DNAH5 (rs2277046), STRN3 (rs2273171), and KIAA1005 (rs3213758). A stronger association was suggested between the mutation in KIAA1005 (rs3213758) and the segmental type compared to the non-segmental type of vitiligo. DNAH5 (rs2277046), STRN3 (rs2273171), and KIAA1005 (rs3213758) may be new vitiligo-related SNPs in Korean patients, either non-segmental or segmental type.

Comparison of Monocyte Selection Method by Immunomagnetic Adsorption or Adherence for the Generation of Dendritic cells / 대한수혈학회지

BACKGROUND: Dendritic cells (DCs) are the most potent stimulators of immune response including antitumor response. DCs are currently being pursued clinically in the development of cancer vaccines; therefore there are demands for large-scale and clinical-grade generation of DCs. In the present study, to find out the most efficient separation method of DC precursors, we compared two separation methods, namely, based on magnetic based selection and plastic adherence selection. METHODS: MNCs were collected by leukapheresis from healthful donors and separated by CD14 + immunomagnetic adsorption or plastic adherence. DC precursors separated using the two methods were differenciated in the same condition. Matured DCs were compared in terms of yield, viability, the expression of surface markers and ability to induce immune reaction. RESULTS: This study demonstrated that mature DCs from CD14 + monocytes separated using CD14 + immunomagnetic adsorption had higher expression of surface markers of DCs, yield (1.9 +/-0.5% vs. 0.5 +/-0.2%), viability (94.7 +/-2.5% vs. 72.8 +/-7.5%) and better functionality in inducing immune reaction than those from plastic adherent cells. CONCLUSION: These results demonstrated that CD14 + immunomagnetic adsorption was found to be more effective than the adherent selection for the generation of DCs. This study will allow researcher to facilitate choosing the appropriate protocol to obtain DCs.