TY - JOUR
T1 - Selenium supplementation increases liver MnSOD expression
T2 - Molecular mechanism for hepato-protection
AU - Shilo, Shani
AU - Pardo, Michal
AU - Aharoni-Simon, Michal
AU - Glibter, Sagit
AU - Tirosh, Oren
N1 - Funding Information:
This research was supported by a Grant from the Dorset Foundation, UK, to O.T.
PY - 2008/1
Y1 - 2008/1
N2 - Selenium is recognized as essential in animal and human nutrition. Several hypotheses have been advanced for its biological activity. The aim of this study was to investigate the in vivo effect of selenium on rat liver manganese superoxide dismutase (MnSOD), a key antioxidant enzyme, under naïve and inflammatory conditions. Rats received sodium selenite supplementation and LPS injection. Whole-liver samples, isolated hepatocytes, Kupffer cells and blood samples were subjected to protein, RNA and biochemical analysis. Liver enrichment with selenium increased whole-liver MnSOD levels due to an increase in MnSOD transcription in hepatocytes. This was due to an increase in the ratio of specificity protein 1 to activating enhancer binding protein 2 DNA-binding activity. The inflammatory stimulus further elevated MnSOD levels in the whole-liver that was abrogated in sodium selenite supplementation due to reduced transcription of MnSOD in Kupffer cells. Moreover, selenium enrichment decreased Kupffer cells IL-6 transcription in LPS-injected animals. Anti-inflammatory activity of selenium was demonstrated by normalized blood levels of ALT and IL-6 in LPS-injected animals. In conclusion, selenium up-regulates hepatocytes MnSOD expression, probably improving their anti-oxidant defense, while decreasing MnSOD and IL-6 transcription in Kupffer cells in the presence of inflammatory stimuli, attenuating their inflammatory response. This selective mechanism may explain the anti-inflammatory and hepato-protective effect of selenium.
AB - Selenium is recognized as essential in animal and human nutrition. Several hypotheses have been advanced for its biological activity. The aim of this study was to investigate the in vivo effect of selenium on rat liver manganese superoxide dismutase (MnSOD), a key antioxidant enzyme, under naïve and inflammatory conditions. Rats received sodium selenite supplementation and LPS injection. Whole-liver samples, isolated hepatocytes, Kupffer cells and blood samples were subjected to protein, RNA and biochemical analysis. Liver enrichment with selenium increased whole-liver MnSOD levels due to an increase in MnSOD transcription in hepatocytes. This was due to an increase in the ratio of specificity protein 1 to activating enhancer binding protein 2 DNA-binding activity. The inflammatory stimulus further elevated MnSOD levels in the whole-liver that was abrogated in sodium selenite supplementation due to reduced transcription of MnSOD in Kupffer cells. Moreover, selenium enrichment decreased Kupffer cells IL-6 transcription in LPS-injected animals. Anti-inflammatory activity of selenium was demonstrated by normalized blood levels of ALT and IL-6 in LPS-injected animals. In conclusion, selenium up-regulates hepatocytes MnSOD expression, probably improving their anti-oxidant defense, while decreasing MnSOD and IL-6 transcription in Kupffer cells in the presence of inflammatory stimuli, attenuating their inflammatory response. This selective mechanism may explain the anti-inflammatory and hepato-protective effect of selenium.
KW - Hepato-protection
KW - Inflammation
KW - Liver cells
KW - MnSOD
KW - Selenium
UR - http://www.scopus.com/inward/record.url?scp=37049017555&partnerID=8YFLogxK
U2 - 10.1016/j.jinorgbio.2007.07.027
DO - 10.1016/j.jinorgbio.2007.07.027
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 17804075
AN - SCOPUS:37049017555
SN - 0162-0134
VL - 102
SP - 110
EP - 118
JO - Journal of Inorganic Biochemistry
JF - Journal of Inorganic Biochemistry
IS - 1
ER -