Nucleolin/C23 is a negative regulator of hydrogen peroxide-induced apoptosis in HUVECs.
Nucleolin plays important roles in chromatin structure, rDNA transcription, rRNA maturation, nucleocytoplasmic transport, and ribosome assembly. Although it has been shown to be anti-apoptotic, the underlying mechanisms remain unclear. In the current study, we first examined endogenous nucleolin expression in response to oxidative stress-induced apoptosis in human umbilical vascular endothelial cells (HUVECs). Flow cytometry and caspase activity assays showed that H(2)O(2) treatment caused apoptosis of the cells; reverse-transcription polymerase chain reaction and Western blotting revealed the downregulation of nucleolin expression and increased protein cleavage during this process. Overexpression of nucleolin protein by transfecting cells with the full-length nucleolin cDNA inhibited apoptosis, but nucleolin deficiency brought about by transfection with antisense oligonucleotide increased apoptosis of HUVECs. Concurrently, the expression of the apoptotic protein gene Bax was also downregulated following nucleolin overexpression. All these results indicate an important negative regulatory role for nucleolin in the apoptosis of endothelial cells, likely involving the Bax pathway.
Zhang
Bin
B
Department of Histology and Embryology, Xiangya School of Medicine, Central South University, Changsha, Hunan, 410008, People's Republic of China.
Wang
Haiyun
H
Jiang
Bimei
B
Liang
Pengfei
P
Liu
Meidong
M
Deng
Gonghua
G
Xiao
Xianzhong
X
D017209:Apoptosis / Q000187:drug effects*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016877:Oxidants / Q000494:pharmacology*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism; D000097796:Nucleolin
D006861:Hydrogen Peroxide; D016877:Oxidants; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D051028:bcl-2-Associated X Protein; D000097796:Nucleolin