Expression Pattern of Novel Human Beta-defensin mRNA in Human Organs

Objectives: Human beta-defensins (hBDs) belong to a group of antimicrobial peptide, expressed mainly in epithelial cells. Recently, 31 types of human hBDs have been discovered using a computational search strategy (Schutte at al:PNAS, 2002). The purpose of the present study was to evaluate the expression pattern of newly discovered hBDs in human organs. Methods: cDNA Panels (BD Biosciences, Clontech, CA, USA) were used for this study. Keratinocyte derived from normal foreskin (NHK) and oral epithelium (NOE), oral epithelial cell lines (SCC-9, KB) and fibroblasts derived from human gingiva were also used. Total RNA was extracted from cell culture and then was reverse-transcribed. In order to observe the mRNA level of hBDs, a quantitative RT-PCR assay was perform with LightCyclerTM using the double-stranded DNA dye SYBR Green I (Roche Molecular Biochemicals, Germany). The primers for hBDs (hBD-18~29) were designed based on NCBI date for the RT-PCR. To examine whether the expression is constitutive or inducible by inflammatory stimulation, LPS (10~1000ng/ml), TNF-a (40ng/ml), IFN-g (10ng/ml), IL-1 b (10ng/ml) and PMA(1~100nM) was added to the cell culture system. Individual experiments were performed in triplicates. Results: Expressions of hBD-18 and-29 were detected in all organs including non-epithelial tissues and cells such as skeletal muscle, leukocyte, and fibroblasts. NHK, NOE and oral epithelial cell lines expressed hBD-18, -25 and -29. hBD-18 and-29 were constitutively expressed by the stimulants. The expression of hBD-25 was down-regulated by the stimulation with LPS. Conclusion: The results indicate that several types of hBDs are expressed widely in human organs including epithelial and non-epithelial tissues. hBD-25 may be one of most specific one for skin and oral epithelia.