One of the most commonly observed adverse
effects of cyclosporin A (CsA) is the development
of gingival overgrowth (GO). Fibroblasts are
involved in GO, but the question why only a
percentage of patients undergoing CsA treatment
shows this side-effect remains unanswered. In a
previous study, CsA has been demonstrated to
induce over-expression of phospholipase C (PLC)
1 in fibroblasts of patients with clinical GO, in
cells from both enlarged and clinically healthy
gingival sites. In this work, we assessed the
expression of PLC isoforms to investigate
whether the exaggerated fibroblast response to
CsA related to increased PLC1 expression could
also be detected in CsA-treated patients without
clinical signs of GO. Our results support the
hypothesis of a multi-factorial origin of gingival
overgrowth, including specific changes within the
gingival tissues orchestrating fibroblastic hyperresponsiveness
as a consequence of a long-term in
vivo exposure to cyclosporin A.
