Reduction of bilirubin by targeting human heme oxygenase-1 through siRNA.
Neonatal hyperbilirubinemia is a common clinical condition caused mainly by the increased production and decreased excretion of bilirubin. Current treatment is aimed at reducing the serum levels of bilirubin. Heme oxygenase-1 (HO-1) is a rate-limiting enzyme that generates bilirubin. In this study we intended to suppress HO-1 using the RNA interference technique. Small interfering RNA (siRNA)-A, -B, and -C were designed based on human HO-1 (hHO-1) mRNA sequences. siRNA was transfected into a human hepatic cell line (HL-7702). hHO-1 transcription and protein levels were then determined. In addition, the inhibitory effect of siRNA on hHO-1 was assessed in cells treated with hemin or transfected with an hHO-1 plasmid. siRNA-C showed the most potent suppressive effect on hHO-1. This inhibition is dose and time dependent. Compared with control, both hemin and hHO-1 plasmids up-regulated hHO-1 expression in HL-7702 cells. However, the up-regulation was significantly attenuated by siRNA-C. Furthermore, the decrease in hHO-1 activity was coincident with the suppression of its transcription. Finally, siRNA-C was shown to reduce hHO-1 enzymatic activity and bilirubin levels. Thus, this study provides a novel therapeutic rationale by blocking bilirubin formation via siRNA for preventing and treating neonatal hyperbilirubinemia and bilirubin encephalopathy at an early clinical stage.
Xia
Zhen-Wei
ZW
Department of Pediatrics, Ruijin Hospital, Shanghai Jiatong University, Shanghai 200025, China. xzw63@hotmail.com
Li
Chun-E
CE
Jin
You-Xin
YX
Shi
Yi
Y
Xu
Li-Qing
LQ
Zhong
Wen-Wei
WW
Li
Yun-Zhu
YZ
Yu
Shan-Chang
SC
Zhang
Zi-Li
ZL
D001663:Bilirubin / Q000378:metabolism*; D002460:Cell Line; D015971:Gene Expression Regulation, Enzymologic; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism*; D006427:Hemin / Q000494:pharmacology; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics; D007647:Kernicterus / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics; D008099:Liver / Q000201:enzymology; D010084:Oxidation-Reduction; D034741:RNA, Small Interfering / Q000235:genetics / Q000627:therapeutic use; D015854:Up-Regulation
D034741:RNA, Small Interfering; D006427:Hemin; D051547:Heme Oxygenase-1; D001663:Bilirubin