Moesin Is a Novel Biomarker of Endothelial Injury in Sepsis

Figure 4

LPS upregulates the MSN expression and phosphorylation in HMECs in a dose- and time-dependent manner. HMECs were treated with different doses (0, 1, 2, and 4 μg/ml) of LPS for 24 h or exposed to LPS (1 μg/ml) up to 72 h. The levels of MSN in the supernatants of cultured cells were measured by ELISA. To explore the secretion mechanisms of moesin in HMECs after LPS stimulation, three inhibitors of the main pathways of protein secretion were employed in the experiment. The dosage of inhibitors is as follows: the autophagy inhibitor 3-methyladenine (3-MA, 1 mM, Selleck, S2767), the exosome secretion inhibitor 5-(N,N-dimethyl)-amiloride DMA (DMA, 50 nM, APExBIO, C3505), and the protein transport inhibitor brefeldin A (BFA, 10 ng/ml, APExBIO, B1400). LPS increased MSN levels in the supernatants of cultured cells in a dose- and time-dependent manner (a, d). The relative levels of the MSN protein expression in cell lysates were determined by Western blotting. (b, e) And the semiquantification for WB was shown in (c, f). MSN secretion was inhibited by 3-MA (h), DMA (i), and BFA (g) to varying degrees. NS: not significant; , , and .

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