title: PKC-zeta expression is lower in osteoblasts from arthritic patients: IL1-beta and TNF-alpha induce a similar decrease in non-arthritic human osteoblasts.
abstract: Protein kinase C (PKC) is a family of enzymes detected in a diverse range of cell types where they regulate various cellular functions such as proliferation, differentiation, cytoskeletal remodelling, cytokine production, and receptor-mediated signal transduction. In this study we have analyzed the expression of 11 PKC isoforms (-alpha, -beta(I), -beta(II), -gamma, -delta, -eta, -theta, -epsilon, -zeta, -iota/lambda, and -micro) in osteoblasts from patients with osteoarthritis (OA) and rheumatoid arthritis (RA) in comparison with osteoblasts from post-traumatic (PT) patients. By Western blotting analysis, nine isoforms, -alpha, -beta(I), -beta(II), -delta, -theta, - epsilon, -zeta, - iota/lambda, and -micro, were detected in osteoblasts. In RA and OA patients, PKC -theta and -micro were greater expressed whereas PKC-epsilon and -zeta decreased when compared with normal cells. The subcellular distribution and quantitative differences were confirmed by immuno-electron microscopy. Furthermore, we demonstrated that treatment with the proinflammatory cytokines, IL-1beta and TNF-alpha, significantly decreased PKC-zeta expression in PT osteoblasts. This suggests that proinflammatory cytokines can modulate the expression of this PKC isoform in osteoblasts in a way which is similar to changes detected in arthritic patients.
authors.affiliation: IGM-CNR, Sezione di Bologna c/o IOR, via di Barbiano 1/10, 40136 Bologna, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Zini
authors.forename: Alberto
authors.initials: A
authors.lastname: Bavelloni
authors.forename: Gina
authors.initials: G
authors.lastname: Lisignoli
authors.forename: Sonia
authors.initials: S
authors.lastname: Ghisu
authors.forename: Aurelio
authors.initials: A
authors.lastname: Valmori
authors.forename: Alberto Maria
authors.initials: AM
authors.lastname: Martelli
authors.forename: Andrea
authors.initials: A
authors.lastname: Facchini
authors.forename: Nadir Mario
authors.initials: NM
authors.lastname: Maraldi
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000201:enzymology* / Q000473:pathology; D002478:Cells, Cultured / Q000187:drug effects / Q000201:enzymology; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D005270:Femur Head / Q000201:enzymology / Q000648:ultrastructure; D025981:Hip Injuries / Q000473:pathology; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology*; D007527:Isoenzymes / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D016253:Microscopy, Immunoelectron; D008875:Middle Aged; D010003:Osteoarthritis / Q000201:enzymology* / Q000473:pathology; D010006:Osteoblasts / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D011493:Protein Kinase C / Q000032:analysis / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D000099221:Protein Kinase C zeta
chemical_list: D053583:Interleukin-1beta; D007527:Isoenzymes; D011493:Protein Kinase C; D014409:Tumor Necrosis Factor-alpha; D000099221:Protein Kinase C zeta