Immunoblotting of molecules involved in mechano-signal-transduction. PDL cells were seeded on flexible bottom cell culture dishes, strained with averaged 2.5% and followed by westernblot analysis. The numerical expression values were always denoted in relation to unstrained controls (A) The modulation of expression levels of the MAP-kinases p42/44 following strain application were detected with the monoclonal rabbit anti-p42/44 antibody, and the numerical changes of increase and decrease in expression were denoted by arrows in the graph. The phosphorylation levels of Thr202/Tyr204 of p42/44 were assessed by immunoblotting, using an antibody against phospho- Thr202/Tyr204. The numerical changes in the activation status of pp42/44 in consequence of strain application were visualised by arrows in the graph. (B) The strain-induced expression levels of the MAP-kinase p38 were detected with a monoclonal rabbit anti-p38 antibody, and the expression changes increase or decrease were marked in the graph by arrows. The strain-induced activation status of phospho-p38 (pp38) was detected by immunoblotting using an antibody against phospho- Thr180/Tyr182 of p38, and the modulation of expression levels was notified with numerical values and arrows in the graph. Data of each graph represent the mean of three individual experiments (n = 3), mean +/- SD and means were subjected to the Students T-test. All compared mean values with p < 0.01 were considered as statistical significant and are marked with an asterisk. The depicted western blots exemplify the protein expression changes of one biological replicate.