Effects of in vitro TLR4 knockdown on cellular lipid accumulation. A: small interfering (si)RNA was used to knockdown TLR4 expression in the H9C2 cell line. Western blots for TLR4 of triplicate untreated control cell samples, triplicate samples treated with TLR4 siRNA, and triplicate samples treated with control siRNA compared with β-tubulin are shown. B: densitometry of the Western blots shown in A, normalized to β-tubulin, shown as the percent expression of control. *P < 0.05 compared with samples treated with control siRNA. C: oil red O staining of untreated control H9C2 cells treated with oleate, H9C2 cells treated with control siRNA + oleate, and H9C2 cells treated with TLR4 siRNA + oleate. D: quantification of oil red O staining of the H9C2 cell samples shown in C. *P < 0.05, TLR4 siRNA + oleate-treated samples compared with control siRNA + oleate-treated samples.