Decreased expressions of thrombospondin 2 in cyclosporin A-induced gingival overgrowth.
OBJECTIVE
Cyclosporin A (CsA) is known to elicit fibrous gingival overgrowth with changes of blood vessel profiles. In this study, we examined the expression of several angiogenic and angiostatic genes during the development of CsA-induced gingival overgrowth.


METHODS
For the development of gingival overgrowth, Sprague-Dawley rats received subcutaneous injections of CsA in daily doses of 5, 10, 15 mg/kg body weight for 6 weeks, and another group received 10 mg/kg of CsA for 3, 6, and 12 weeks. Human gingival tissues were obtained from three CsA-treated patients following the gingivectomy procedure and from three healthy patients following the crown-lengthening procedure as a control. Gingival fibroblasts were isolated from the healthy gingival tissues of the rat or the human, and cultured with 250-1000 ng/ml of CsA.


RESULTS
Reverse transcription-polymerase chain reaction (RT-PCR) analyses showed that expressions of some angiogenic genes such as angiopoietin 1, basic fibroblast growth factor, and vascular endothelial growth factor, and angiostatic genes such as angiopoietin 2, brain-specific angiogenesis inhibitor 1 and 2, and thrombospondin 1 were not changed significantly in both gingival tissues and cultured fibroblast cells under the CsA treatments. However, expression of thrombospondin 2 (TSP2) decreased dose- and time-dependently in rat and human gingival tissues. Western blot analyses showed that the expression of TSP2 protein was dose-dependently reduced by the CsA treatments in human cultured gingival fibroblasts.


CONCLUSIONS
These results indicate that the decrease in angiostatic TSP2 expression may be attributed to the CsA-induced gingival vascularization rather than to the increased expression of angiogenic genes. It suggests that TSP2 is involved in the development of CsA-induced gingival overgrowth with the gingival vascularization.
Department of Dental Pharmacology Dental Science Research Institute, Chonnam National University, Kwangju 501-190, South Korea. jtkoh@chonnam.chonnam.ac.kr
Jeong Tae
JT
Koh
Ok Joon
OJ
Kim
Young Seob
YS
Park
Sun Hun
SH
Kim
Won Jae
WJ
Kim
Hyun Ju
HJ
Chung
Shee Eun
SE
Lee
Byung Chul
BC
Jeong
Ji Yeon
JY
Jung
Kyung Keun
KK
Kim
D020533:Angiogenesis Inhibitors / Q000032:analysis; D042683:Angiopoietin-1 / Q000032:analysis; D042702:Angiopoietin-2 / Q000032:analysis; D000818:Animals; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000032:analysis*; D016572:Cyclosporine / Q000008:administration & dosage / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D016222:Fibroblast Growth Factor 2 / Q000032:analysis; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005881:Gingiva / Q000187:drug effects / Q000378:metabolism; D019214:Gingival Overgrowth / Q000139:chemically induced* / Q000378:metabolism; D006801:Humans; D011506:Proteins / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019699:Thrombospondins / Q000032:analysis* / Q000037:antagonists & inhibitors; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis; D000099262:Thrombospondin 2
D020533:Angiogenesis Inhibitors; D042683:Angiopoietin-1; D042702:Angiopoietin-2; D015815:Cell Adhesion Molecules; D016572:Cyclosporine; D016222:Fibroblast Growth Factor 2; D011506:Proteins; D019699:Thrombospondins; D042461:Vascular Endothelial Growth Factor A; D000099262:Thrombospondin 2; C448783:HIAF-1 protein, human