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. Author manuscript; available in PMC: 2014 Apr 2.
Published in final edited form as: Cell Metab. 2013 Apr 2;17(4):534–548. doi: 10.1016/j.cmet.2013.03.005

Figure 1. Changes in Serum A1AT Levels and NE Activity in Obese Mice and the Effect of Leptin on A1AT Expression.

Figure 1

(A) Schematic of the glycoprotein enrichment and quantitative serum proteomic approach for comparing serum protein profiles of male obese and lean mice. Serum α1-antitrypsin (A1AT) levels (B) or NE activity (C) in ob/ob mice (12-week-old male) and age-matched lean C57BL/6 controls were quantified by ELISA (A1AT) or a colorimetric assay (NE activity). Data are presented as mean ± SEM of 6 to 8 animals with triplicate samples. **P < 0.01. (D) Serum A1AT levels or (E) NE activity in male C67BL/6 mice at 7 weeks old fed 60% HFD for 2 to 17 weeks. Data are presented as mean ± SE of 5 to 9 animals with triplicate samples. *P < 0.05. (F and G) Leptin regulates A1AT expression in HepG2 cells. Cells were serum starved overnight and incubated with leptin (75 ng/ml) for the indicated times. (F) A1AT mRNA levels were determined by qRT-PCR and (G) A1AT protein levels were analyzed by Western blotting followed by quantification of band intensity. Results are presented as fold change relative to vehicle-treated control cells and are the mean ± SEM of 4 independent experiments. **P < 0.01. (H and I) Leptin stimulates A1AT expression in vivo. Alzet osmotic pumps were implanted subcutaneously into ob/ob male mice (10 weeks of age) and programmed to deliver vehicle or 10 μg/day of leptin for 7 days. Liver A1AT mRNA (H) and serum A1AT protein (I) were quantified by qRT-PCR and ELISA, respectively. Data are presented as mean ± SEM (n = 5). **P < 0.01. Also see Table S1 and Figure S1.