Elevation of High-Mobility Group Protein Box-1 in Serum Correlates with Severity of Acute Intracerebral Hemorrhage

Figure 3

Heme could stimulate the secretion of HMGB1 by cultured microglia. Data are expressed as mean ± standard deviation, $n=6$. (a) Microglia were cultured with various concentrations of heme (0 $\mu$M, 10 $\mu$M, 20 $\mu$M, and 30 $\mu$M) for 24 hours. Thereafter, the culture medium was replaced, and the cells were further cultured for 12 hours before collection of the supernatant for ELISA determination of HMGB1 levels. **versus 0 $\mu$M; $P<.01\text{;}$^##versus 10 $\mu$M, 20 $\mu$M; $P<.01$. (b) Microglia were treated with 30 $\mu$M of heme for various lengths of time (0 h, 4 h, 8 h, 24 h, and 48 h). Thereafter, the culture medium was replaced, and the cells were further cultured for another 12 hours before collection of the supernatant for ELISA determination of HMGB1 levels. **versus 0 h; $P<.01\text{;}$^##versus 4 h, 8 h, or 24 h; $P<.01$. (c) Microglia were treated with 30 $\mu$M of heme, 30 $\mu$M of FeCl₃, or 30 $\mu$M of FeSO₄ for 24 hours. Thereafter, the culture medium was replaced, and the cells were further cultured for another 12 hours before collection of the supernatant for ELISA determination of HMGB1 levels. **versus control; $P<.01$.

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