FIG. 1.

Effect of mild heat stress (MHS) on co-cultures of primary osteoblasts (pOBs) and outgrowth endothelial cells (OECs). (A) Immunofluorescent staining for CD31 analysis of the effects of MHS on the formation of capillary-like structures in a co-culture system. After 1 day of co-cultivation, cells were treated under MHS conditions (at 41°C for 1 h) twice a week. After 7 and 14 days, co-cultures were stained immunohistochemically for the endothelial marker CD31, and the formation of capillary-like structures was detected by using a Leica confocal laser scanning microscope. (B) Quantification of the formation of capillary-like structures in a co-culture system. Angiogenic structures were quantified by comparing the total area and length of angiogenic structures in mild heat-stressed co-cultures after 7 and 14 days (n=3; nine images in total were analyzed for each treatment). (*p<0.05).