INVOLVEMENT OF HUMAN BETA-DEFENSIN-2 IN INTRACELLULAR SIGNALING: IN VITRO STUDY
D. Lytvyn, E. Zhuravel, N. Markeeva, M. Soldatkina, T. Dudchenko, P.
Pogrebnoy*
R.E. Kavetsky Institute of Experimental Pathology, Oncology and
Radiobiology NAS of Ukraine, Kyiv, Ukraine
Abstract. Aim: To analyze involvement of human beta-defensin-2 (hBD-2) in
intracellular signaling in vitro. Materials and Methods: A431cells were
cultured in the presence of 1 µg/ml of recombinant hBD-2 and/or 10 ng/ml EGF. For
evaluation of expression of mRNAs for p70S6 kinase, isoforms alpha and beta, RT-PCR
analysis was applied. Expression and activity of p70S6K, phosphorylation of PDK1, ERK,
JNK, p38 kinases and EGF receptor (EGFR) was evaluated using Western blot analysis. Results:
30 min incubation of A431 cells with 1 µg/ml of hBD-2 didn’t influence
autophosphorylation level of EGFR, but resulted in activation of p70S6K, 12 h
treatment – in prominently increased level of mRNA for alpha and beta-isoforms of p70S6
kinase, whilst 24 h treatment – in elevation of p70S6K synthesis on protein level.
Up-stream kinase phosphorylating p70S6K, PDK1, is also phosporylated upon influence of
exogenous hBD-2 in vitro.Conclusion: Our data point on the involvement of
PDK1-p70S6K pathway in mediation of action of hBD-2 in A431 cells.
