[Regulative effects of aquaporin 4 expression by rhein in rhubarb to intestinal epithelial cell line LoVo].
OBJECTIVE
To investigate the effects of rhein on regulating aquaporin4 (AQP4) to LoVo cells cultured with RPMI-1640 medium containing rhein.


METHODS
LoVo cells were cultured with RPMI-1640 medium containing different concentration rhein for 24 hours and were cultured with RPMI-1640 containing rhein (20 mg/L) for different time. Four groups were assigned as LoVo cells were cultured respectively with RPMI-1640 medium containing different concentration rhein (40, 20, 10 mg/L and control group), while six groups were assigned as LoVo cells were cultured with RPMI-1640 medium containing rhein (20 mg/L) for different time (3, 6, 12, 24, 48 h and control group). The location of AQP4 protein in LoVo cells was definited by immuocytochemistry dying. Western blotting and semiquantitative RT-PCR were adopted to detect the relative expression of AQP4 protein and mRNA.


RESULTS
AQP4 was located mainly in plasma membrane of LoVo cells while partly in cytoplasm. The relative expression of AQP4 protein and mRNA decreased with the increasing of rhein concentration; there was no significant difference of the relative expression of AQP4 in 10 mg/L group compared with that in control group, but it decreased significantly in 40 and 20 mg/L groups. The relative expression of AQP4 in 3 and 6 h groups was lower than that in control group but there was no statistical significance, however that in 12, 24, 48 h groups was lower significantly compared with that in control group.


CONCLUSIONS
Rhein can inhibit the genetic transcription and the translation of AQP4 gene in LoVo cells, which demonstrates that the change of AQP4 expression regulated by rhein may be related to the cathartic effect of rhubarb.
Zhang
Wen-Sheng
WS
Fourth Military Medical University, Xijing Hospital, Xi'an 710032, China.
Li
Feng
F
Bao
Jun-Qiang
JQ
Wang
Sheng-Chun
SC
Shang
Gang-Wei
GW
Li
Jun-Chang
JC
Wang
Chang-Hai
CH
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000880:Anthraquinones / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D051401:Aquaporin 4 / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D006801:Humans; D007150:Immunohistochemistry; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012250:Rheum / Q000737:chemistry*; D013997:Time Factors
D000880:Anthraquinones; D000972:Antineoplastic Agents, Phytogenic; D051401:Aquaporin 4; D004365:Drugs, Chinese Herbal; D012333:RNA, Messenger; C020491:rhein