TY - JOUR
T1 - Blood glutathione peroxidase-1 mRNA levels can be used as molecular biomarkers to determine dietary selenium requirements in rats
AU - Sunde, Roger A.
AU - Thompson, Kevin M.
AU - Evenson, Jacqueline K.
AU - Thompson, Britta M.
N1 - Funding Information:
This research was supported in part by USDA #95–37200-1799, by the University of Missouri Agricultural Experiment Station and the Food for the 21 Century Program, and by the University of Wisconsin Agricultural Experiment Station grant WIS04909. st
PY - 2009/11
Y1 - 2009/11
N2 - Transcript (mRNA) levels are increasingly being used in medicine as molecular biomarkers for disease and disease risk, including use of whole blood as a target tissue for analysis. Development of blood molecular biomarkers for nutritional status, too, has potential application that parallels opportunities in medicine, including providing solid data for individualized nutrition. We previously reported that blood glutathione peroxidase-1 (Gpx1) mRNA was expressed at levels comparable to major tissues in rats and humans. To determine the efficacy of using blood Gpx1 mRNA to assess selenium (Se) status and requirements, we fed graded levels of Se (0-0.3 μg Se/g as selenite) to weanling male rats. Se status was determined by liver Se concentration and selenoenzyme activity, and selenoprotein mRNA abundance in liver and blood was determined by ribonuclease protection analysis. Liver Se and plasma glutathione peroxidase-3 and liver Gpx1 activities indicated that minimal Se requirements were at 0.08 μg Se/g diet. When total RNA was isolated from whole blood, Gpx1 mRNA in Se-deficient rats decreased to 10% of levels in Se-adequate (0.2 μg Se/g diet) rats. With Se supplementation, blood Gpx1 mRNA levels increased sigmoidally to a plateau with a minimum Se requirement of 0.08 μg Se/g diet, whereas glutathione peroxidase-4 mRNA levels were unaffected. Similarly, Gpx1 mRNA in RNA isolated from fractionated red blood cells decreased in Se-deficient rats to 23% of Se-adequate levels, with a minimum Se requirement of 0.09 μg Se/g diet. Additional studies showed that the preponderance of whole blood Gpx1 mRNA arises from erythroid cells, most likely reticulocytes and young erythrocytes. In summary, whole blood selenoprotein mRNA levels can be used as molecular biomarkers for assessing Se requirements, illustrating that whole blood has potential as a target tissue in development of molecular biomarkers for use in nutrition as well as in medicine.
AB - Transcript (mRNA) levels are increasingly being used in medicine as molecular biomarkers for disease and disease risk, including use of whole blood as a target tissue for analysis. Development of blood molecular biomarkers for nutritional status, too, has potential application that parallels opportunities in medicine, including providing solid data for individualized nutrition. We previously reported that blood glutathione peroxidase-1 (Gpx1) mRNA was expressed at levels comparable to major tissues in rats and humans. To determine the efficacy of using blood Gpx1 mRNA to assess selenium (Se) status and requirements, we fed graded levels of Se (0-0.3 μg Se/g as selenite) to weanling male rats. Se status was determined by liver Se concentration and selenoenzyme activity, and selenoprotein mRNA abundance in liver and blood was determined by ribonuclease protection analysis. Liver Se and plasma glutathione peroxidase-3 and liver Gpx1 activities indicated that minimal Se requirements were at 0.08 μg Se/g diet. When total RNA was isolated from whole blood, Gpx1 mRNA in Se-deficient rats decreased to 10% of levels in Se-adequate (0.2 μg Se/g diet) rats. With Se supplementation, blood Gpx1 mRNA levels increased sigmoidally to a plateau with a minimum Se requirement of 0.08 μg Se/g diet, whereas glutathione peroxidase-4 mRNA levels were unaffected. Similarly, Gpx1 mRNA in RNA isolated from fractionated red blood cells decreased in Se-deficient rats to 23% of Se-adequate levels, with a minimum Se requirement of 0.09 μg Se/g diet. Additional studies showed that the preponderance of whole blood Gpx1 mRNA arises from erythroid cells, most likely reticulocytes and young erythrocytes. In summary, whole blood selenoprotein mRNA levels can be used as molecular biomarkers for assessing Se requirements, illustrating that whole blood has potential as a target tissue in development of molecular biomarkers for use in nutrition as well as in medicine.
UR - http://www.scopus.com/inward/record.url?scp=70350537000&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70350537000&partnerID=8YFLogxK
U2 - 10.3181/0906-RM-182
DO - 10.3181/0906-RM-182
M3 - Article
C2 - 19855070
AN - SCOPUS:70350537000
SN - 1535-3702
VL - 234
SP - 1271
EP - 1279
JO - Experimental Biology and Medicine
JF - Experimental Biology and Medicine
IS - 11
ER -