|Nielsen, Forrest - Frosty|
Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2003
Publication Date: 3/23/2004
Citation: Hull, S.C., Burrack, A., Ek-Pangerl, K.E., Nardini, D.M., Hopps, J.L., Seaborn, C., Zimmerman, S.D., Nielsen, F.H. 2004. Low dietary silicon increases tnf-a and collagen gene promoter activity in mice [abstract]. Federation of American Societies for Experimental Biology Journal. 18:A527.
Technical Abstract: Sixteen transgenic mice containing the green fluorescent protein gene (GFP) linked to the A-1 (type I) collagen promoter were used. Weanling mice were fed a low silicon (Si) casein-corn diet. Mice ranging from 6 to 12.5 wks of age received a subcutaneous wound (PVA sponge implantation) and were randomly assigned to either a Si-low or Si-adequate diet (35 ppm Si). Skin from the shoulder area and heparinized blood were removed 3 weeks later. Plasma TNF-A was quantified by ELISA. Skin samples were pulverized using liquid nitrogen, solubilized, and centrifuged. Protein concentration of the supernatant was determined by a BCA Protein Assay and fluorescence measured. GFP is expressed if type I collagen promoter has been induced. TNF-A was significantly higher in the Si-low than Si-adequate mice (206.3 pg/mL vs 188.3 pg/mL). There were also significant differences by gender. Si-low females had higher TNF-A than Si-adequate females (211.6 pg/mL vs 187.1 pg/mL). There were no significant differences in plasma TNF-A between male mice. Mice fed Si-low diets exhibited higher skin fluorescence than mice fed the Si-adequate diets (0.518 vs 0.401). The higher TNF-A concentrations exhibited by animals fed the Si-low diet suggests that Si may affect TNF-A expression. The higher fluorescence in skin of mice fed the Si-low diet suggests that Si may also influence the expression of Type I collagen. FRI, University Wisconsin-Stout.