Neutrophil gelatinase-associated lipocalin acts as a protective factor against H(2)O(2) toxicity.
BACKGROUND
Lipocalin 2 (Lcn2, NGAL) is a member of the lipocalin superfamily for which a variety of functions have been reported. However, the precise biological roles of NGAL are not fully known. We have investigated the ability of NGAL to prevent H(2)O(2) toxicity, which is considered to be the classical inducer of oxidative stress caused by ROS generation in an in vitro model.


METHODS
NGAL cDNA was isolated from HepG2 cell line and cloned to pcDNA3.1(+) vector. The construct was transfected to CHO cell line. Stable clones were generated, and the expression of NGAL was determined by RT-PCR, Western blot analysis and ELISA. NGAL gene in A549 cell line was downregulated with the siRNA. CHO and A549 cells were intoxicated with H(2)O(2) and cell proliferation was performed by MTT assay. Apoptotic cells were detected by flow cytometry.


RESULTS
Cell proliferation was higher in CHO expressing NGAL in doses of 5 and 10 mM H(2)O(2) after 2h compared with the control. H(2)O(2) was also more toxic in the presence of NGAL siRNA compared with the control in A549 cell. Our results also revealed that NGAL protect cells from apoptosis.


CONCLUSIONS
Overall, our results revealed for the first time a new function for NGAL/Lcn2: acting as a protective factor against H(2)O(2) toxicity. In the future, NGAL may have the potential application to ameliorate the toxicity induced by oxidative stress conditions.
Roudkenar
Mehryar Habibi
MH
Research Center, Iranian Blood Transfusion Organization, Tehran Iran. Roudkenar@ibto.ir
Halabian
Raheleh
R
Ghasemipour
Zahra
Z
Roushandeh
Amaneh Mohammadi
AM
Rouhbakhsh
Mahdi
M
Nekogoftar
Mahin
M
Kuwahara
Yoshikazu
Y
Fukumoto
Manabu
M
Shokrgozar
Mohammad Ali
MA
D000209:Acute-Phase Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D017931:DNA Primers; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D000071068:Lipocalin-2; D054834:Lipocalins / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering
D000209:Acute-Phase Proteins; D017931:DNA Primers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D006861:Hydrogen Peroxide