Abstract:

Objective To detect the expression and function of cysteinyl leukotriene receptors （CysLTRs） in keratinocytes. Methods Human keratinocytes were isolated from the tissue of foreskin by digestion with dispaseⅡ and trypsin, and subjected to primary culture. By using confocal laser scanning microscopy and reverse transcriptase PCR, the localization and expression of CysLTRs were studied in keratinocytes, respectively．Some primarily cultured keratinocytes were pretreated with leukotriene D4 （30 nmol/L）, MK571 （300 nmol/L）, and BAYu9773 for 5 minutes followed by the detection of intracellular calcium level using the Ca2+ indicator dye Fura-2/AM as well as cell proliferation by MTT assay. Results The expressions of CysLTR1 and CysLTR2 were observed in cultured keratinocytes, and they were mainly located on cell membrane, partly in cytoplasm and nuclei. Compared with non-stimulated cells, a significant increase was noted in the expression of CysLTRs, especially in the nuclei of keratinocytes stimulated by LTD4 （P < 0.05）, together with an elevation in intracellular calcium level （42.27 ± 3.00 mmol/L, P < 0.01） and acceleration in cell proliferation （P < 0.01）. However, both MK571 and BAYu9773 could completely block the effect of LTD4 on intracellular calcium level and cell proliferation, and there was no significant difference in the blocking effect between MK571 and BAYu9773. Conclusions Functional CysLTRs are expressed in human keratinocytes, and they can increase the intracellular calcium level in, and cell proliferation of, keratinocytes.