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Mycoplasma genitalium lipoproteins induce human monocytic cell expression of proinflammatory cytokines and apoptosis by activating nuclear factor kappaB.

Wu Y, Qiu H, Zeng Y, You X, Deng Z, Yu M, Zhu C - Mediators Inflamm. (2008)

Bottom Line: LPs were also found to increase the DNA-binding activity of NF-kappaB, a possible mechanism for the induction of cytokine mRNA expression and the cell apoptosis.These effects were abrogated by PDTC, an inhibitor of NF-kappaB.Our results indicate that M. genitalium-derived LP may be an important etiological factor of certain diseases due to the ability of LP to produce proinflammatory cytokines and induction of apoptosis, which is probably mediated through the activation of NF-kappaB.

View Article: PubMed Central - PubMed

Affiliation: Pathogenic Biology Institute, University of South China, 421001 Hengyang, China. yimouwu@sina.com

ABSTRACT
This study was designed to investigate the molecular mechanisms responsible for the induction of proinflammatory cytokines gene expression and apoptosis in human monocytic cell line THP-1 stimulated by lipoproteins (LPs) prepared from Mycoplasma genitalium. Cultured cells were stimulated with M. genitalium LP to analyze the production of proinflammatory cytokines and expression of their mRNA by ELISA and RT-PCR, respectively. Cell apoptosis was also detected by Annexin V-FITC-propidium iodide (PI) staining and acridine orange (AO)-ethidium bromide (EB) staining. The DNA-binding activity of nuclear factor-kappaB (NF-kappaB) was assessed by electrophoretic mobility shift assay (EMSA). Results showed that LP stimulated THP-1 cells to produce tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 in a dose-dependent manner. The mRNA levels were also upregulated in response to LP stimulation. LPs were also found to increase the DNA-binding activity of NF-kappaB, a possible mechanism for the induction of cytokine mRNA expression and the cell apoptosis. These effects were abrogated by PDTC, an inhibitor of NF-kappaB. Our results indicate that M. genitalium-derived LP may be an important etiological factor of certain diseases due to the ability of LP to produce proinflammatory cytokines and induction of apoptosis, which is probably mediated through the activation of NF-kappaB.

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Related in: MedlinePlus

The effect ofdifferent groups on the expression of TNF-α (a), IL-6 (b), andIL-1β (c) mRNA. THP-1 cells were stimulated for 18 hours and the mRNA levels weredetermined by RT-PCR. The levels of mRNA expression were inhibited upon theintroduction of 25 μM PDTC. The bottom photograph depicts the result of RT-PCRfor mRNA, and the top photograph depicts the β-actin positive control. Lane M:100 bp DNA marker; lane 1: 0.1 μg/mL LPS; lane 2: 3 μg/mL of LP; lane 3: 3 μg/mLof LP in combination with 25 μM PDTC; lane 4: 100 μL aqueous phase (negative control).
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fig3: The effect ofdifferent groups on the expression of TNF-α (a), IL-6 (b), andIL-1β (c) mRNA. THP-1 cells were stimulated for 18 hours and the mRNA levels weredetermined by RT-PCR. The levels of mRNA expression were inhibited upon theintroduction of 25 μM PDTC. The bottom photograph depicts the result of RT-PCRfor mRNA, and the top photograph depicts the β-actin positive control. Lane M:100 bp DNA marker; lane 1: 0.1 μg/mL LPS; lane 2: 3 μg/mL of LP; lane 3: 3 μg/mLof LP in combination with 25 μM PDTC; lane 4: 100 μL aqueous phase (negative control).

Mentions: Because the cytokine mRNA are regulated mainly at the transcriptionallevel, we examined the expression levels of TNF-α, IL-1β, and IL-6 mRNA usingRT-PCR. As shown in Figure 3, the addition of 3 μg/mL LP after 18-hour stimulationincreased these three genes' mRNA expression andβ-actin as an internal control wassimilar in all samples.


Mycoplasma genitalium lipoproteins induce human monocytic cell expression of proinflammatory cytokines and apoptosis by activating nuclear factor kappaB.

Wu Y, Qiu H, Zeng Y, You X, Deng Z, Yu M, Zhu C - Mediators Inflamm. (2008)

The effect ofdifferent groups on the expression of TNF-α (a), IL-6 (b), andIL-1β (c) mRNA. THP-1 cells were stimulated for 18 hours and the mRNA levels weredetermined by RT-PCR. The levels of mRNA expression were inhibited upon theintroduction of 25 μM PDTC. The bottom photograph depicts the result of RT-PCRfor mRNA, and the top photograph depicts the β-actin positive control. Lane M:100 bp DNA marker; lane 1: 0.1 μg/mL LPS; lane 2: 3 μg/mL of LP; lane 3: 3 μg/mLof LP in combination with 25 μM PDTC; lane 4: 100 μL aqueous phase (negative control).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2366083&req=5

fig3: The effect ofdifferent groups on the expression of TNF-α (a), IL-6 (b), andIL-1β (c) mRNA. THP-1 cells were stimulated for 18 hours and the mRNA levels weredetermined by RT-PCR. The levels of mRNA expression were inhibited upon theintroduction of 25 μM PDTC. The bottom photograph depicts the result of RT-PCRfor mRNA, and the top photograph depicts the β-actin positive control. Lane M:100 bp DNA marker; lane 1: 0.1 μg/mL LPS; lane 2: 3 μg/mL of LP; lane 3: 3 μg/mLof LP in combination with 25 μM PDTC; lane 4: 100 μL aqueous phase (negative control).
Mentions: Because the cytokine mRNA are regulated mainly at the transcriptionallevel, we examined the expression levels of TNF-α, IL-1β, and IL-6 mRNA usingRT-PCR. As shown in Figure 3, the addition of 3 μg/mL LP after 18-hour stimulationincreased these three genes' mRNA expression andβ-actin as an internal control wassimilar in all samples.

Bottom Line: LPs were also found to increase the DNA-binding activity of NF-kappaB, a possible mechanism for the induction of cytokine mRNA expression and the cell apoptosis.These effects were abrogated by PDTC, an inhibitor of NF-kappaB.Our results indicate that M. genitalium-derived LP may be an important etiological factor of certain diseases due to the ability of LP to produce proinflammatory cytokines and induction of apoptosis, which is probably mediated through the activation of NF-kappaB.

View Article: PubMed Central - PubMed

Affiliation: Pathogenic Biology Institute, University of South China, 421001 Hengyang, China. yimouwu@sina.com

ABSTRACT
This study was designed to investigate the molecular mechanisms responsible for the induction of proinflammatory cytokines gene expression and apoptosis in human monocytic cell line THP-1 stimulated by lipoproteins (LPs) prepared from Mycoplasma genitalium. Cultured cells were stimulated with M. genitalium LP to analyze the production of proinflammatory cytokines and expression of their mRNA by ELISA and RT-PCR, respectively. Cell apoptosis was also detected by Annexin V-FITC-propidium iodide (PI) staining and acridine orange (AO)-ethidium bromide (EB) staining. The DNA-binding activity of nuclear factor-kappaB (NF-kappaB) was assessed by electrophoretic mobility shift assay (EMSA). Results showed that LP stimulated THP-1 cells to produce tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 in a dose-dependent manner. The mRNA levels were also upregulated in response to LP stimulation. LPs were also found to increase the DNA-binding activity of NF-kappaB, a possible mechanism for the induction of cytokine mRNA expression and the cell apoptosis. These effects were abrogated by PDTC, an inhibitor of NF-kappaB. Our results indicate that M. genitalium-derived LP may be an important etiological factor of certain diseases due to the ability of LP to produce proinflammatory cytokines and induction of apoptosis, which is probably mediated through the activation of NF-kappaB.

Show MeSH
Related in: MedlinePlus