The SerpinB2 Gene is Highly Responsive to LPS
When RAW264.7 macrophages were exposed to LPS, SerpinB2 mRNA was detectable as early as 30 min following LPS challenge, reaching maximal levels at 24 hrs (Fig. 1A). A similar strong induction of LPS-inducible SerpinB2 mRNA expression has been reported previously in murine peritoneal macrophages and human peripheral blood mononuclear cells [4]; [32]. LPS-induced SerpinB2 expression involves both an increase in gene transcription and stabilization of the mRNA [5]; [29]; [42]–[44]. SerpinB2 protein expression was also induced as has been reported in other cell types [31], and detectable after 8 hrs of LPS treatment (Fig. 1).
10.1371/journal.pone.0057855.g001 Figure 1  LPS induction of SerpinB2 mRNA and protein expression in murine macrophage cells.
RAW264.7 macrophages were treated for the indicated times with 100 ng/ml LPS. (A) qPCR analysis of murine SerpinB2 mRNA levels, relative to β-actin. The plot is representative of at least two independent experiments performed in triplicate. (B) Immunoblot analysis of SerpinB2 protein expression in whole cell lysates. Blot was reprobed for GAPDH as a loading control.