Expression of protein kinase C isoforms in cultured human Tenon's capsule fibroblast cells

Members of the protein kinase C (PKC) family are involved in physiological and pathophysiological processes, and exert an important role in signal transduction. The aim of the present study was to determine which of the 12 protein kinase C (PKC) isoforms (PKC alpha, PKC beta I, PKC beta II, PKC gamma, PKC delta, PKC epsilon, PKC eta, PKC theta, PKC mu, PKC zeta, PKC lambda and PKC iota) were expressed in vitro in cultured human Tenon's capsule fibroblasts (HTFs). HTFs from cell passages three to five were investigated for the presence of the 12 PKC isoforms at the cellular, mRNA and protein levels using laser scanning confocal microscopy (LSCM), reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis, respectively. These analyses yielded similar results for several of the PKC isoforms (PKC alpha, PKC delta, PKC epsilon, PKC eta, PKC mu, PKC zeta, PKC lambda and PKC iota); however, PKC beta I, PKC beta II, PKC gamma, and PKC theta were not expressed in the cultured HTFs. LSCM revealed that eight PKC isoforms, PKC alpha, PKC theta, PKC epsilon, PKC eta, PKC mu, PKC zeta, PKC lambda and PKC iota appeared almost exclusively in the cytoplasm of the cells. Notably, PKC delta was expressed particularly well in the cytoskeleton. The present study revealed that all 12 PKC isoforms were expressed and that eight of the isoforms were present in cultured HTFs. These results will be of value when determining specific roles for the PKC isoforms in HTF proliferation, which may provide a novel therapeutic target for bleb scarring in glaucoma filtering surgery.