Involvement of human beta-defensin-2 in intracellular signaling: in vitro study.
OBJECTIVE
To analyze involvement of human beta-defensin-2 (hBD-2) in intracellular signaling in vitro.


METHODS
A431cells were cultured in the presence of 1 microg/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 mug/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.


CONCLUSIONS
Our data point on the involvement of PDK1-p70S6K pathway in mediation of action of hBD-2 in A431 cells.
Lytvyn
D
D
R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology NAS of Ukraine, Kyiv, Ukraine.
Zhuravel
E
E
Markeeva
N
N
Soldatkina
M
M
Dudchenko
T
T
Pogrebnoy
P
P
D064413:3-Phosphoinositide-Dependent Protein Kinases; D004789:Enzyme Activation; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000819:agonists; D006801:Humans; D009369:Neoplasms / Q000201:enzymology*; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D023083:beta-Defensins / Q000494:pharmacology*
C106641:DEFB4A protein, human; D023083:beta-Defensins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D064413:3-Phosphoinositide-Dependent Protein Kinases; C578562:PDPK1 protein, human; D017346:Protein Serine-Threonine Kinases; D038762:Ribosomal Protein S6 Kinases, 70-kDa