Lysophosphatidic Acid Triggers Apoptosis in HeLa Cells through the Upregulation of Tumor Necrosis Factor Receptor Superfamily Member 21

Figure 1

LPA induces apoptosis accompanied by upregulation of DR6 expression. (a) LPA treatment reduced cell viability in a concentration-dependent manner as determined by MTT assay. 10–25 μM LPA-induced significant cell viability reduction compared to control. , versus control; concentration of LPA at 50–100 μM caused more cell viability reduction. . (b) LPA-triggered apoptosis was determined by TUNEL staining. HeLa cells were treated by 25 μM LPA for 24 hrs. . The bar graphs on the right panel represent quantification of TUNEL assay, , versus control. (c and d) HeLa cells were exposed to different concentration of LPA for 18 hours. Activation of caspase-9, caspase-7, and caspase-3 and the cleavage of PARP (c), and expression levels of DR6, DR5, and TNFR (d) were determined by Western blot. The blot is a representative of 4 blots from 4 independent experiments (). The bar graphs on the right panel are densitometry analyses of DR6, DR5, and TNFR1 protein expression. , versus control.

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