Immunocytochemical expression of protein kinase C isoenzymes alpha, delta, epsilon and zeta in differentiating chick chondrocytes in vitro.
In our previous work we have investigated the expression of the serine-threonine kinase protein kinase C (PKC) in the vertebral column of mouse foetuses. In the present work we would verify the expression of four PKC-isoenzymes (alpha, delta, epsilon, zeta) in two distinct phases of the chondrogenesis and the endochondral osteogenesis in vitro. We performed primary cultures of chondrocytes collected from tibiae of 6-day old chick embryos. This cells were cultured for 20 days and than collected on coverslips (stage 1 culture). Other cells of the stage 1 were undergone further differentiation towards the phenotype of osteoblast-like cells (stage 2 culture), in accord to the protocol of Descalzi Cancedda et al. (1992). In stage 1 culture, PKC-epsilon was the most expressed isoform, whereas PKC-alpha exhibited the least intense positivity. In stage 2 culture, PKC-alpha was the most expressed isoform, whereas a marked decrease of PKC-epsilon expression was detected compared to stage 1. No relevant differences were evidenced as regards,the expression of PKC-zeta between the two considered cell culture stages. On these bases, it could be reasonable that these PKC-isoenzymes may be involved at different levels in chondrocytes differentiation as well as in the endochondral ossification process.
Grill
V
V
Department of Human Morphology, University of Trieste, Italy. grill@univ.trieste.it
Basa
M
M
Sandrucci
M A
MA
Narducci
P
P
Bareggi
R
R
Martelli
A M
AM
D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D002642:Chick Embryo; D019902:Chondrocytes / Q000166:cytology / Q000201:enzymology*; D019084:Fluorescent Antibody Technique, Indirect; D007091:Image Processing, Computer-Assisted; D007527:Isoenzymes / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology; D011493:Protein Kinase C / Q000378:metabolism*
D007527:Isoenzymes; D011493:Protein Kinase C