Regulation of Human Beta-Defensin 3(hBD-3) in Human Keratinocyte(HaCaT) Cell Lines

ABSTRACT

BACKGROUND: The large surfaces of the skin are often initial site of contact between microorganism and human. The skin are coated with epidermis and epithelial cells can recognize microorganism and mount a fast defense through the production of various inducible antibiotic peptides. This leads to chracteristic broad spectrum of antimicrobial activity against bacteria, fungi, and viruses. Recent studies introduce us new peptides with antimicrobial activity such as P,-defensins and cathelicidins. They are expressed on the epithelia and polymorphonuclear leukocytes, which are first lines of defence from various invasive environments. Futhermore, they are considered very interesting and important endogenous antibiotics. Our previous study has shown that the expression of human defensin(hBD-2) mRNA, which is potent antibiotic peptide against Gram-negative bacteria(P. aeruginosa), was upregulated with ultraviolet(UV) irradiation, tumor necrosis factor-α(TNF-α) and lipopolysaccharide(LPS) in HaCaT cells. A novel hBD-3, 5-kDa, nonhemolytic antimicrobial peptide, was demonstrated a salt-insensitive broad spectrum of potent antimicrobial activity against many potentially pathogenic microbes in especially, multiresistant S. aureus. We have analyzed the expression patterns of hBD-3 in HaCaT cell lines. OBJECTIVE: This research have done in order to evaluate the expression and regulation of hBD-3 mRNA in human keratinocyte cell lines. METHODS: HaCaT cell lines were used to all culture experiments. Cultured human keratinocytes were stimulated with UV irradiation or TNF-α or LPS to determine whether hBD-3 mRNA production occurred. Reverse transcription-polymerase chain reaction (RT-PCR) was per-formed to amplify hBD-3 cDNA from stimulated keratinocytes in a time dependant manner, and densitometry was used to verify the specificity of RT-PCR amplication products. RESULTS: Expression of hBD-3 was upregulated with UV irradiation, TNF-α and LPS in Ha-CaT cells compared to control CONCLUSIONS: Human keratinocytes are capable to induce hBD-3 mRNA, as well as hBD-2, in response to UV irradiation, TNF-α and LPS. suggesting that these cells could play an important role against the bacterial infection and UV light damage in human skin.