Limits...
Glutamine starvation enhances PCV2 replication via the phosphorylation of p38 MAPK, as promoted by reducing glutathione levels.

Chen X, Shi X, Gan F, Huang D, Huang K - Vet. Res. (2015)

Bottom Line: The results show that glutamine promoted PK-15 cell viability.Meanwhile, p38 MAPK phosphorylation and PCV2 replication significantly decreased in p38-knockdown PK-15 cells.Our findings may contribute toward interpreting the possible pathogenic mechanism of PCV2 and provide a theoretical reference for application of glutamine in controlling porcine circovirus-associated diseases.

View Article: PubMed Central - PubMed

Affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China. cxx@njau.edu.cn.

ABSTRACT
Glutamine has a positive effect on ameliorating reproductive failure caused by porcine circovirus type 2 (PCV2). However, the mechanism by which glutamine affects PCV2 replication remains unclear. This study was conducted to investigate the effects of glutamine on PCV2 replication and its underlying mechanisms in vitro. The results show that glutamine promoted PK-15 cell viability. Surprisingly, glutamine starvation significantly increased PCV2 replication. The promotion of PCV2 replication by glutamine starvation disappeared after fresh media with 4 mM glutamine was added. Likewise, promotion of PCV2 was observed after adding buthionine sulfoximine (BSO). Glutamine starvation or BSO treatment increased the level of p38 MAPK phosphorylation and PCV2 replication in PK-15 cells. Meanwhile, p38 MAPK phosphorylation and PCV2 replication significantly decreased in p38-knockdown PK-15 cells. Promotion of PCV2 replication caused by glutamine starvation could be blocked in p38-knockdown PK-15 cells. Therefore, glutamine starvation increased PCV2 replication by promoting p38 MAPK activation, which was associated with the down regulation of intracellular glutathione levels. Our findings may contribute toward interpreting the possible pathogenic mechanism of PCV2 and provide a theoretical reference for application of glutamine in controlling porcine circovirus-associated diseases.

Show MeSH

Related in: MedlinePlus

PCV2 replication promoted by glutamine starvation could be blocked by p38 knockdown in PK-15 cells. PCV2-infected cells were transfected with p38-specific, control or non siRNA. After 5 h of transfection treatment, the medium was removed, and fresh basal medium with various concentrations of glutamine was added. After transfected-cells were cultured for another 72 h, the number of PCV2 log10 DNA copies per 106 cells (A) and the relative proportion of infected cells (B) were assayed by real-time PCR and immunofluorescence microscopy, respectively. Values are given as mean ± SD from three independent experiments. Groups were compared by a 1-way ANOVA followed by least-significant difference test. Significant changes are indicated by **(P < 0.01) and # (P < 0.05) in comparison with controls.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4363047&req=5

Fig8: PCV2 replication promoted by glutamine starvation could be blocked by p38 knockdown in PK-15 cells. PCV2-infected cells were transfected with p38-specific, control or non siRNA. After 5 h of transfection treatment, the medium was removed, and fresh basal medium with various concentrations of glutamine was added. After transfected-cells were cultured for another 72 h, the number of PCV2 log10 DNA copies per 106 cells (A) and the relative proportion of infected cells (B) were assayed by real-time PCR and immunofluorescence microscopy, respectively. Values are given as mean ± SD from three independent experiments. Groups were compared by a 1-way ANOVA followed by least-significant difference test. Significant changes are indicated by **(P < 0.01) and # (P < 0.05) in comparison with controls.

Mentions: The influence of glutamine starvation on PCV2 replication in p38-knockdown cells was evaluated to further investigate the role of p38 in the promotion of PCV2 replication by glutamine starvation. A significant increase of approximately 6% and 5% in the number of PCV2 log10 DNA copies per 106 cells as well as approximately 33% and 25% in the proportion of infected cells in the groups treated with non-siRNA and control siRNA (P < 0.01; Figure 8A), respectively, but no increase was detected in groups treated with p38-specific siRNA (P > 0.05), as compared with the controls without glutamine starvation. Between the groups with glutamine starvation and siRNA treatment, the number of PCV2 log10 DNA copies per 106 cells and the proportion of infected cells in groups treated with p38-specific siRNA decreased to normal levels as compared with groups treated with control siRNA. These results show that the promotion of PCV2 replication caused by glutamine starvation could be blocked in p38-knockdown cells.Figure 8


Glutamine starvation enhances PCV2 replication via the phosphorylation of p38 MAPK, as promoted by reducing glutathione levels.

Chen X, Shi X, Gan F, Huang D, Huang K - Vet. Res. (2015)

PCV2 replication promoted by glutamine starvation could be blocked by p38 knockdown in PK-15 cells. PCV2-infected cells were transfected with p38-specific, control or non siRNA. After 5 h of transfection treatment, the medium was removed, and fresh basal medium with various concentrations of glutamine was added. After transfected-cells were cultured for another 72 h, the number of PCV2 log10 DNA copies per 106 cells (A) and the relative proportion of infected cells (B) were assayed by real-time PCR and immunofluorescence microscopy, respectively. Values are given as mean ± SD from three independent experiments. Groups were compared by a 1-way ANOVA followed by least-significant difference test. Significant changes are indicated by **(P < 0.01) and # (P < 0.05) in comparison with controls.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4363047&req=5

Fig8: PCV2 replication promoted by glutamine starvation could be blocked by p38 knockdown in PK-15 cells. PCV2-infected cells were transfected with p38-specific, control or non siRNA. After 5 h of transfection treatment, the medium was removed, and fresh basal medium with various concentrations of glutamine was added. After transfected-cells were cultured for another 72 h, the number of PCV2 log10 DNA copies per 106 cells (A) and the relative proportion of infected cells (B) were assayed by real-time PCR and immunofluorescence microscopy, respectively. Values are given as mean ± SD from three independent experiments. Groups were compared by a 1-way ANOVA followed by least-significant difference test. Significant changes are indicated by **(P < 0.01) and # (P < 0.05) in comparison with controls.
Mentions: The influence of glutamine starvation on PCV2 replication in p38-knockdown cells was evaluated to further investigate the role of p38 in the promotion of PCV2 replication by glutamine starvation. A significant increase of approximately 6% and 5% in the number of PCV2 log10 DNA copies per 106 cells as well as approximately 33% and 25% in the proportion of infected cells in the groups treated with non-siRNA and control siRNA (P < 0.01; Figure 8A), respectively, but no increase was detected in groups treated with p38-specific siRNA (P > 0.05), as compared with the controls without glutamine starvation. Between the groups with glutamine starvation and siRNA treatment, the number of PCV2 log10 DNA copies per 106 cells and the proportion of infected cells in groups treated with p38-specific siRNA decreased to normal levels as compared with groups treated with control siRNA. These results show that the promotion of PCV2 replication caused by glutamine starvation could be blocked in p38-knockdown cells.Figure 8

Bottom Line: The results show that glutamine promoted PK-15 cell viability.Meanwhile, p38 MAPK phosphorylation and PCV2 replication significantly decreased in p38-knockdown PK-15 cells.Our findings may contribute toward interpreting the possible pathogenic mechanism of PCV2 and provide a theoretical reference for application of glutamine in controlling porcine circovirus-associated diseases.

View Article: PubMed Central - PubMed

Affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China. cxx@njau.edu.cn.

ABSTRACT
Glutamine has a positive effect on ameliorating reproductive failure caused by porcine circovirus type 2 (PCV2). However, the mechanism by which glutamine affects PCV2 replication remains unclear. This study was conducted to investigate the effects of glutamine on PCV2 replication and its underlying mechanisms in vitro. The results show that glutamine promoted PK-15 cell viability. Surprisingly, glutamine starvation significantly increased PCV2 replication. The promotion of PCV2 replication by glutamine starvation disappeared after fresh media with 4 mM glutamine was added. Likewise, promotion of PCV2 was observed after adding buthionine sulfoximine (BSO). Glutamine starvation or BSO treatment increased the level of p38 MAPK phosphorylation and PCV2 replication in PK-15 cells. Meanwhile, p38 MAPK phosphorylation and PCV2 replication significantly decreased in p38-knockdown PK-15 cells. Promotion of PCV2 replication caused by glutamine starvation could be blocked in p38-knockdown PK-15 cells. Therefore, glutamine starvation increased PCV2 replication by promoting p38 MAPK activation, which was associated with the down regulation of intracellular glutathione levels. Our findings may contribute toward interpreting the possible pathogenic mechanism of PCV2 and provide a theoretical reference for application of glutamine in controlling porcine circovirus-associated diseases.

Show MeSH
Related in: MedlinePlus