Gene expression, cytoskeletal changes and extracellular matrix synthesis in human osteoblasts treated with cyclosporin A.
Cyclosporin A (CyA) is an immunosuppressive agent used to prevent allograft rejection, but unfortunately it causes adverse effects such as bone diseases, osteoporosis and osteomalacia. These pathologies involve an imbalance between synthesis, degradation and mineralization of extracellular matrix. CyA can modify extracellular matrix components such as glycosaminoglycans (GAG) and collagen fibers. In addition, normal cell activity is dependent on cell morphology and substrate cell attachment. We treated normal human osteoblasts with CyA and analyzed: (i) gene expression by a microarray method; (ii) extracellular GAG and collagen after (3)H-glucosamine and Western blot analysis; and (iii) cytoskeletal changes, using actin and tubulin fluorescent antibodies. CyA increased intra- and extracellular GAG and extracellular GAG classes such as hyaluronic acid, chondroitin sulphate, and dermatan sulphate; there was no noteworthy effect on heparan sulphate and the ratio of non-sulphated to sulphated GAG. In osteoblast cultures the drug reduced cytoskeletal actin, while tubulin did not change. In vivo the osteoblasts showed morphological changes with different extracellular matrix synthesis. Microarray analysis indicated the inhibition of gene pathways related to Wnt signaling molecules, and the cytoskeletal and focal adhesion cascade. In in vitro human osteoblasts CyA modified gene expression related to cytoskeletal pattern organization and cell morphology. Since in bone pathologies osteoblasts show different morphology related to cell size, these data suggest that in vivo osteoblast different functions could be dependent on alteration of osteoblast differentiation.
Vertemati
Maurizio
M
Department of Human Morphology, University of Milan, Milan, Italy.
Minola
Ernesto
E
Dolci
Claudia
C
Stabellini
Giordano
G
Pezzetti
Furio
F
Moscheni
Claudia
C
Calastrini
Carla
C
Bramerio
Manuela
M
Palmieri
Annalisa
A
Vizzotto
Laura
L
D016572:Cyclosporine / Q000009:adverse effects*; D003599:Cytoskeleton / Q000187:drug effects* / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects* / Q000378:metabolism; D015870:Gene Expression; D017491:Genes, APC; D006025:Glycosaminoglycans / Q000096:biosynthesis*; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D020411:Oligonucleotide Array Sequence Analysis; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D051153:Wnt Proteins / Q000502:physiology
D006025:Glycosaminoglycans; D007166:Immunosuppressive Agents; D051153:Wnt Proteins; D016572:Cyclosporine