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Toxoplasma gondii down modulates cadherin expression in skeletal muscle cells inhibiting myogenesis.

Gomes AF, Guimarães EV, Carvalho L, Correa JR, Mendonça-Lima L, Barbosa HS - BMC Microbiol. (2011)

Bottom Line: Immunofluorescence and immunoblotting analysis of parasite-host cell interaction showed a 54% reduction in cadherin expression at 24 h of infection.Concomitantly, a reduction in M-cadherin mRNA levels was observed after 3 and 24 h of T. gondii-host cell interaction.These data suggest that T. gondii is able to down regulate M-cadherin expression, leading to molecular modifications in the host cell surface that interfere with membrane fusion and consequently affect the myogenesis process.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, (Av, Brasil 4365), Rio de Janeiro (21040-361), Brazil.

ABSTRACT

Background: Toxoplasma gondii belongs to a large and diverse group of obligate intracellular parasitic protozoa. Primary culture of mice skeletal muscle cells (SkMC) was employed as a model for experimental toxoplasmosis studies. The myogenesis of SkMC was reproduced in vitro and the ability of T. gondii tachyzoite forms to infect myoblasts and myotubes and its influence on SkMC myogenesis were analyzed.

Results: In this study we show that, after 24 h of interaction, myoblasts (61%) were more infected with T. gondii than myotubes (38%) and inhibition of myogenesis was about 75%. The role of adhesion molecules such as cadherin in this event was investigated. First, we demonstrate that cadherin localization was restricted to the contact areas between myocytes/myocytes and myocytes/myotubes during the myogenesis process. Immunofluorescence and immunoblotting analysis of parasite-host cell interaction showed a 54% reduction in cadherin expression at 24 h of infection. Concomitantly, a reduction in M-cadherin mRNA levels was observed after 3 and 24 h of T. gondii-host cell interaction.

Conclusions: These data suggest that T. gondii is able to down regulate M-cadherin expression, leading to molecular modifications in the host cell surface that interfere with membrane fusion and consequently affect the myogenesis process.

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Related in: MedlinePlus

Profile of M-cadherin mRNA expression by SkMC experimentally infected with T. gondii. (A) The arbitrary values presented in the graph are based on the densytometric analysis of the PCR gel image shown in panel B, corresponding to 3, 12 and 24 h of infection. Light bars indicate uninfected control cells and black bars indicate the infected cells. (B) Polyacrylamide, silver stained gels for visualization of the amplified M-cadherin and GAPDH mRNAs (from top to bottom, respectively). Lanes 1, 3 and 5 show the profiles of negative controls and lanes 2, 4 and 6 the profiles of infected cells (3, 12 and 24 h, respectively). NC, negative PCR control. Molecular size markers are indicated to the left. Student's T-test (*) p ≤ 0.05.
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Figure 7: Profile of M-cadherin mRNA expression by SkMC experimentally infected with T. gondii. (A) The arbitrary values presented in the graph are based on the densytometric analysis of the PCR gel image shown in panel B, corresponding to 3, 12 and 24 h of infection. Light bars indicate uninfected control cells and black bars indicate the infected cells. (B) Polyacrylamide, silver stained gels for visualization of the amplified M-cadherin and GAPDH mRNAs (from top to bottom, respectively). Lanes 1, 3 and 5 show the profiles of negative controls and lanes 2, 4 and 6 the profiles of infected cells (3, 12 and 24 h, respectively). NC, negative PCR control. Molecular size markers are indicated to the left. Student's T-test (*) p ≤ 0.05.

Mentions: M-cadherin gene expression in SkMC experimentally infected with T. gondii was analyzed by RT-PCR. M-cadherin mRNA was detected 2 and 3 days after plating and it was up regulated only after the induction of myotube formation, which corresponds to the second day of culture. After 3 h of infection with T. gondii M-cadherin mRNA levels were significantly reduced and after 12 h of interaction, no change in M-cadherin mRNA expression profile was observed. However, after 24 h, M-cadherin mRNA expression was down regulated when compared to the corresponding SkMC control from 3 day-old cell cultures (Figure 7A-C).


Toxoplasma gondii down modulates cadherin expression in skeletal muscle cells inhibiting myogenesis.

Gomes AF, Guimarães EV, Carvalho L, Correa JR, Mendonça-Lima L, Barbosa HS - BMC Microbiol. (2011)

Profile of M-cadherin mRNA expression by SkMC experimentally infected with T. gondii. (A) The arbitrary values presented in the graph are based on the densytometric analysis of the PCR gel image shown in panel B, corresponding to 3, 12 and 24 h of infection. Light bars indicate uninfected control cells and black bars indicate the infected cells. (B) Polyacrylamide, silver stained gels for visualization of the amplified M-cadherin and GAPDH mRNAs (from top to bottom, respectively). Lanes 1, 3 and 5 show the profiles of negative controls and lanes 2, 4 and 6 the profiles of infected cells (3, 12 and 24 h, respectively). NC, negative PCR control. Molecular size markers are indicated to the left. Student's T-test (*) p ≤ 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3116462&req=5

Figure 7: Profile of M-cadherin mRNA expression by SkMC experimentally infected with T. gondii. (A) The arbitrary values presented in the graph are based on the densytometric analysis of the PCR gel image shown in panel B, corresponding to 3, 12 and 24 h of infection. Light bars indicate uninfected control cells and black bars indicate the infected cells. (B) Polyacrylamide, silver stained gels for visualization of the amplified M-cadherin and GAPDH mRNAs (from top to bottom, respectively). Lanes 1, 3 and 5 show the profiles of negative controls and lanes 2, 4 and 6 the profiles of infected cells (3, 12 and 24 h, respectively). NC, negative PCR control. Molecular size markers are indicated to the left. Student's T-test (*) p ≤ 0.05.
Mentions: M-cadherin gene expression in SkMC experimentally infected with T. gondii was analyzed by RT-PCR. M-cadherin mRNA was detected 2 and 3 days after plating and it was up regulated only after the induction of myotube formation, which corresponds to the second day of culture. After 3 h of infection with T. gondii M-cadherin mRNA levels were significantly reduced and after 12 h of interaction, no change in M-cadherin mRNA expression profile was observed. However, after 24 h, M-cadherin mRNA expression was down regulated when compared to the corresponding SkMC control from 3 day-old cell cultures (Figure 7A-C).

Bottom Line: Immunofluorescence and immunoblotting analysis of parasite-host cell interaction showed a 54% reduction in cadherin expression at 24 h of infection.Concomitantly, a reduction in M-cadherin mRNA levels was observed after 3 and 24 h of T. gondii-host cell interaction.These data suggest that T. gondii is able to down regulate M-cadherin expression, leading to molecular modifications in the host cell surface that interfere with membrane fusion and consequently affect the myogenesis process.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, (Av, Brasil 4365), Rio de Janeiro (21040-361), Brazil.

ABSTRACT

Background: Toxoplasma gondii belongs to a large and diverse group of obligate intracellular parasitic protozoa. Primary culture of mice skeletal muscle cells (SkMC) was employed as a model for experimental toxoplasmosis studies. The myogenesis of SkMC was reproduced in vitro and the ability of T. gondii tachyzoite forms to infect myoblasts and myotubes and its influence on SkMC myogenesis were analyzed.

Results: In this study we show that, after 24 h of interaction, myoblasts (61%) were more infected with T. gondii than myotubes (38%) and inhibition of myogenesis was about 75%. The role of adhesion molecules such as cadherin in this event was investigated. First, we demonstrate that cadherin localization was restricted to the contact areas between myocytes/myocytes and myocytes/myotubes during the myogenesis process. Immunofluorescence and immunoblotting analysis of parasite-host cell interaction showed a 54% reduction in cadherin expression at 24 h of infection. Concomitantly, a reduction in M-cadherin mRNA levels was observed after 3 and 24 h of T. gondii-host cell interaction.

Conclusions: These data suggest that T. gondii is able to down regulate M-cadherin expression, leading to molecular modifications in the host cell surface that interfere with membrane fusion and consequently affect the myogenesis process.

Show MeSH
Related in: MedlinePlus