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Effects of Porphyromonas gingivalis lipopolysaccharide on the expression of key genes involved in cholesterol metabolism in macrophages

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Cardiovascular diseases are positively correlated with periodontal disease. However, the molecular mechanisms linking atherosclerosis and periodontal infection are not clear. This study aimed to determine whether Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) altered the expression of genes regulating cholesterol metabolism in macrophages in the presence of low-density lipoprotein (LDL).

Material and methods: THP-1-derived macrophages were exposed to different concentrations (0.1, 1, 10 µg/ml) of LPS in the presence of 50 µg/ml native LDL. Macrophages were also incubated with 1 µg/ml LPS for varying times (0, 24, 48, or 72 h) in the presence of native LDL. Foam cell formation was determined by oil red O staining and cholesterol content quantification. CD36, lectin-like oxidized LDL receptor-1 (LOX-1), ATP-binding cassette G1 (ABCG1), and acetyl CoA acyltransferase 1 (ACAT1) expression levels were measured by western blot and qRT-PCR.

Results: Foam cell formation was induced in a time- and concentration-dependent manner as assessed by both morphological and biochemical criteria. Pg-LPS caused downregulation of CD36 and ABCG1 but upregulation of ACAT1, while LOX-1 expression was not affected (p = 0.137).

Conclusions: Pg-LPS appears to be an important link in the development of atherosclerosis by mechanisms targeting cholesterol homeostasis, namely, excess cholesterol ester formation via ACAT1 and reduced cellular cholesterol efflux via ABCG1.

No MeSH data available.


Measurement of time-dependent ACAT1 and ABCG1 expression in Pg-LPS-treated macrophages. Cells were treated with Pg-LPS (1.0 µg/ml) and LDL (50 µg/ml) for increasing durations (0, 24, 48, or 72 h). A – ACAT1 and ABCG1 mRNA levels are presented as fold changes relative to the untreated control (0 h). B – Western blot analysis of ACAT1 and ABCG1 protein expression. The protein levels were normalized to β-actin as an internal control. *P < 0.05
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Figure 0006: Measurement of time-dependent ACAT1 and ABCG1 expression in Pg-LPS-treated macrophages. Cells were treated with Pg-LPS (1.0 µg/ml) and LDL (50 µg/ml) for increasing durations (0, 24, 48, or 72 h). A – ACAT1 and ABCG1 mRNA levels are presented as fold changes relative to the untreated control (0 h). B – Western blot analysis of ACAT1 and ABCG1 protein expression. The protein levels were normalized to β-actin as an internal control. *P < 0.05

Mentions: The incubation of THP-1-derived macrophages with 1 µg/ml Pg-LPS and LDL resulted in a maximal 4-fold change in ACAT1 mRNA expression and a 3-fold change in ACAT1 protein expression compared with the control level (Figure 6 A and B). In contrast, ABCG1 expression markedly decreased in a time-dependent manner. Specifically, ABCG1 protein expression was almost completely inhibited, with 93% reduction at 72 h.


Effects of Porphyromonas gingivalis lipopolysaccharide on the expression of key genes involved in cholesterol metabolism in macrophages
Measurement of time-dependent ACAT1 and ABCG1 expression in Pg-LPS-treated macrophages. Cells were treated with Pg-LPS (1.0 µg/ml) and LDL (50 µg/ml) for increasing durations (0, 24, 48, or 72 h). A – ACAT1 and ABCG1 mRNA levels are presented as fold changes relative to the untreated control (0 h). B – Western blot analysis of ACAT1 and ABCG1 protein expression. The protein levels were normalized to β-actin as an internal control. *P < 0.05
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5016584&req=5

Figure 0006: Measurement of time-dependent ACAT1 and ABCG1 expression in Pg-LPS-treated macrophages. Cells were treated with Pg-LPS (1.0 µg/ml) and LDL (50 µg/ml) for increasing durations (0, 24, 48, or 72 h). A – ACAT1 and ABCG1 mRNA levels are presented as fold changes relative to the untreated control (0 h). B – Western blot analysis of ACAT1 and ABCG1 protein expression. The protein levels were normalized to β-actin as an internal control. *P < 0.05
Mentions: The incubation of THP-1-derived macrophages with 1 µg/ml Pg-LPS and LDL resulted in a maximal 4-fold change in ACAT1 mRNA expression and a 3-fold change in ACAT1 protein expression compared with the control level (Figure 6 A and B). In contrast, ABCG1 expression markedly decreased in a time-dependent manner. Specifically, ABCG1 protein expression was almost completely inhibited, with 93% reduction at 72 h.

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Cardiovascular diseases are positively correlated with periodontal disease. However, the molecular mechanisms linking atherosclerosis and periodontal infection are not clear. This study aimed to determine whether Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) altered the expression of genes regulating cholesterol metabolism in macrophages in the presence of low-density lipoprotein (LDL).

Material and methods: THP-1-derived macrophages were exposed to different concentrations (0.1, 1, 10 &micro;g/ml) of LPS in the presence of 50 &micro;g/ml native LDL. Macrophages were also incubated with 1 &micro;g/ml LPS for varying times (0, 24, 48, or 72 h) in the presence of native LDL. Foam cell formation was determined by oil red O staining and cholesterol content quantification. CD36, lectin-like oxidized LDL receptor-1 (LOX-1), ATP-binding cassette G1 (ABCG1), and acetyl CoA acyltransferase 1 (ACAT1) expression levels were measured by western blot and qRT-PCR.

Results: Foam cell formation was induced in a time- and concentration-dependent manner as assessed by both morphological and biochemical criteria. Pg-LPS caused downregulation of CD36 and ABCG1 but upregulation of ACAT1, while LOX-1 expression was not affected (p = 0.137).

Conclusions: Pg-LPS appears to be an important link in the development of atherosclerosis by mechanisms targeting cholesterol homeostasis, namely, excess cholesterol ester formation via ACAT1 and reduced cellular cholesterol efflux via ABCG1.

No MeSH data available.