[Expression of InnVit/FBXO11 in vitiligo and its role in tyrosinase export from endoplasmic reticulum].
OBJECTIVE
To investigate the roles of InnVit (FBX011) gene in melanocytes by detecting the expression of InnVit gene in vitiligo and analyzing the impact of InnVit gene on morphology of endoplasmic reticulum (ER) and the tyrosinase export from ER.


METHODS
The lesion tissues and the donor tissues were collected from 10 vitiligo patients to examine the InnVit gene expression by immunohistochemistry. Synthesized specific siRNA and constructed plasmid P3XF-P120 were separately transfected into cells for the silence and over-expression of InnVit gene with lipofectamine(TM) 2000. The untreated cells were used as control. Morphology of ER of cells from the above three groups was observed under electron microscope. Co-localization of tyrosinase and calreticulin was identified by confocal laser scanning microscopy. InnVit, tyrosinase and calreticulin were examined by Western blot.


RESULTS
In vitiligo patients, the expression of InnVit gene in the lesions was markedly lower than that in the donor tissues. The normal morphology of ER was found in the untreated and the plasmid groups whereas inflated ER was shown in siRNA group. And the relative inflation rate in siRNA group (1.97 +/- 0.48) was higher than that in the untreated group (1.28 +/- 0.09) and plasmid group (1.24 +/- 0.13) (both P = 0.001). In the untreated and the plasmid groups, tyrosinase was expressed beyond the scope marked by ER marker protein calreticulin partly, but co-localized with calreticulin in ER in the siRNA group. Western blot showed that, contrast to the untreated group (0.320 +/- 0.020), a lower expression level of InnVit in the siRNA group (0.030 +/- 0.004, P = 0.001) and a higher expression of InnVit in the plasmid group were shown (0.710 +/- 0.040, P = 0.001). No significant difference about the expression level of calreticulin was observed among the three groups (P > 0.05). As compared with the untreated group (0.350 +/- 0.030), a higher tyrosinase level in the siRNA group (1.040 +/- 0.060, P = 0.001) and in the plasmid group (0.720 +/- 0.030, P = 0.001) was found. And the former was higher than the latter (P = 0.001).


CONCLUSIONS
A lower expression of InnVit is observed in the lesion tissues than in the donor tissues from vitiligo patients. The InnVit gene can have an impact on the morphology of ER and tyrosinase export from ER. And it may further affect the function of melanocytes.
Guan
Cui-ping
CP
Department of Dermatology, Third People's Hospital of Hangzhou, Anhui Medical University, Anhui Medical University, Hangzhou 310009, China.
Lin
Fu-quan
FQ
Hong
Wei-song
WS
Fu
Li-fang
LF
Zhou
Miao-ni
MN
Xu
Wen
W
Xu
Ai-e
AE
D000328:Adult; D002478:Cells, Cultured; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D044783:F-Box Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D011484:Protein-Arginine N-Methyltransferases / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D012867:Skin / Q000473:pathology; D014820:Vitiligo / Q000235:genetics* / Q000378:metabolism; D055815:Young Adult
D044783:F-Box Proteins; D034741:RNA, Small Interfering; D014442:Monophenol Monooxygenase; C457579:FBXO11 protein, human; D011484:Protein-Arginine N-Methyltransferases