[Expression and function of sphingosine kinases 1 and 2 in human keloid fibroblasts].
OBJECTIVE
To study the expression and function of sphingosine kinase (SphK) 1 and SphK2 in human keloid fibroblasts.


METHODS
Specimens of keloid and surrounding normal skin were collected from 12 patients with keloid during operation. Primary fibroblasts were isolated, cultured, and randomly divided into 3 groups: normal skin group, keloid group, and keloid with transforming growth factor (TGF)-beta1 group cultured with TGF-beta1 for 48 h. Immunofluorescence technique was used to detect the location of SphK1 and SphK2 protein. Real-time PCR and Western blotting were used to measure the mRNA and protein expression levels of SphK1 and SphK2.


RESULTS
Sphk1 protein was localized primarily in the nuclei of the fibroblasts, and Sphk2 protein was detected both in the cytoplasm and nuclei in the 3 groups. The mRNA and protein levels of Sphk1 in the keloid group were (0.0608 +/- 0.0190) and (0.8308 +/- 0.1093) respectively, both significantly higher than those of the normal skin group [(0.0383 +/- 0.0147) and (0.6800 +/- 0.1126) respectively, both P < 0.05], but significantly lower than those of the keloid fibroblasts with TGF-beta1 group [(0.0790 +/- 0.0280), P < 0.05, and (1.4267 +/- 0.1938), P < 0.01]. There was no significant differences in the Sphk2 mRNA and protein levels among these 3 groups (all P > 0.05).


CONCLUSIONS
Sphk1 plays a leading role in keloid pathogenesis. The SphK1 mRNA and protein levels are increased by TGF-beta1 stimulation in keloid fibroblasts, perhaps indicating that Sphk1 is involved in TGF-beta signal transduction pathway.
Zhang
Jing
J
Department of Plastic Surgery, Second Hospital of Shandong University, Jinan 250033, China.
Xu
Bin
B
Liu
Zhen-Zhong
ZZ
Wang
Wei
W
Wang
Li-Xia
LX
Zhang
Ji-Xun
JX
Cai
Jing-Long
JL
D000293:Adolescent; D000328:Adult; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007627:Keloid / Q000378:metabolism* / Q000473:pathology; D008297:Male; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D055815:Young Adult; D000099157:Sphingosine Kinase
D017853:Phosphotransferases (Alcohol Group Acceptor); D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D000099157:Sphingosine Kinase