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Low-dose plasmid DNA treatment increases plasma vasopressin and regulates blood pressure in experimental endotoxemia.

Malardo T, Batalhão ME, Panunto-Castelo A, Almeida LP, Padilha E, Fontoura IC, Silva CL, Carnio EC, Coelho-Castelo AA - BMC Immunol. (2012)

Bottom Line: The beneficial effect of the plasmid DNA on MAP was associated with decreased expression of IL-6 in liver and increased concentration of plasma vasopressin (AVP), a known vasoconstrictor that has been investigated in hemorrhagic shock management.No difference was observed in relation to nitric oxide (NO) production.Our results demonstrate for the first time that plasmid DNA vector at low doses presents anti-inflammatory property and constitutes a novel approach with therapeutic potential in inflammatory diseases.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry and Immunology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto SP 14049-900, Brazil.

ABSTRACT

Background: Although plasmid DNA encoding an antigen from pathogens or tumor cells has been widely studied as vaccine, the use of plasmid vector (without insert) as therapeutic agent requires further investigation.

Results: Here, we showed that plasmid DNA (pcDNA3) at low doses inhibits the production of IL-6 and TNF-α by lipopolysaccharide (LPS)-stimulated macrophage cell line J774. These findings led us to evaluate whether plasmid DNA could act as an anti-inflammatory agent in a Wistar rat endotoxemia model. Rats injected simultaneously with 1.5 mg/kg of LPS and 10 or 20 μg of plasmid DNA had a remarkable attenuation of mean arterial blood pressure (MAP) drop at 2 hours after treatment when compared with rats injected with LPS only. The beneficial effect of the plasmid DNA on MAP was associated with decreased expression of IL-6 in liver and increased concentration of plasma vasopressin (AVP), a known vasoconstrictor that has been investigated in hemorrhagic shock management. No difference was observed in relation to nitric oxide (NO) production.

Conclusion: Our results demonstrate for the first time that plasmid DNA vector at low doses presents anti-inflammatory property and constitutes a novel approach with therapeutic potential in inflammatory diseases.

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Related in: MedlinePlus

Administration of DNA in rats injected with LPS decreases liver expression of IL-6 and TNF-α. Animals were injected with LPS and plasmid DNA at doses of 5 or 10 μg. At 2 (A) or 4 (B) hours after injection of LPS, relative amounts of mRNA for IL-6 (A) and TNF-α (B) from liver were determined. Results are expressed as mean ± SD of at least two independent experiments. *, P < 0.05 versus control group injected with LPS only.
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Figure 3: Administration of DNA in rats injected with LPS decreases liver expression of IL-6 and TNF-α. Animals were injected with LPS and plasmid DNA at doses of 5 or 10 μg. At 2 (A) or 4 (B) hours after injection of LPS, relative amounts of mRNA for IL-6 (A) and TNF-α (B) from liver were determined. Results are expressed as mean ± SD of at least two independent experiments. *, P < 0.05 versus control group injected with LPS only.

Mentions: To explain the mechanism involved in the plasmid-induced attenuation of MAP drop in LPS-stimulated rats, we determined the gene expression of liver IL-6 and TNF-α and plasma concentration of AVP and NO, key mediators in endotoxemia. Similar to in vitro experiments, low doses of plasmid DNA (5 and 10 μg) induced a significant decrease of TNF-α and IL-6 message in the livers of LPS-injected rats. IL-6 was diminished at 2 hours after LPS injection when compared with the rats administered with LPS only (Figure 3), whereas no significant difference was detected at 4 hours after LPS injection (data not shown). In contrast, low doses of plasmid DNA induced a significant reduction in the TNF-α at 4 hours of experiment, but not at 2 hours, when compared with the group treated with LPS only (Figure 3). As the fall in MAP occurs in the first two hours after injection of LPS, we suggested that the decrease of IL-6 may be important in reducing the pressure drop observed in animals treated with plasmid DNA. Like IL-6, two hours after LPS administration, we observed that all tested dose of plasmid DNA significantly enhanced the LPS effect on AVP production, whereas only the doses of 10 and 20 μg of plasmid led to a significant increase in NO (Figure 4). Interestingly, the concentrations of AVP were low after 4 h of LPS injection, whereas high concentrations of NO were maintained (Figure 4).


Low-dose plasmid DNA treatment increases plasma vasopressin and regulates blood pressure in experimental endotoxemia.

Malardo T, Batalhão ME, Panunto-Castelo A, Almeida LP, Padilha E, Fontoura IC, Silva CL, Carnio EC, Coelho-Castelo AA - BMC Immunol. (2012)

Administration of DNA in rats injected with LPS decreases liver expression of IL-6 and TNF-α. Animals were injected with LPS and plasmid DNA at doses of 5 or 10 μg. At 2 (A) or 4 (B) hours after injection of LPS, relative amounts of mRNA for IL-6 (A) and TNF-α (B) from liver were determined. Results are expressed as mean ± SD of at least two independent experiments. *, P < 0.05 versus control group injected with LPS only.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3526548&req=5

Figure 3: Administration of DNA in rats injected with LPS decreases liver expression of IL-6 and TNF-α. Animals were injected with LPS and plasmid DNA at doses of 5 or 10 μg. At 2 (A) or 4 (B) hours after injection of LPS, relative amounts of mRNA for IL-6 (A) and TNF-α (B) from liver were determined. Results are expressed as mean ± SD of at least two independent experiments. *, P < 0.05 versus control group injected with LPS only.
Mentions: To explain the mechanism involved in the plasmid-induced attenuation of MAP drop in LPS-stimulated rats, we determined the gene expression of liver IL-6 and TNF-α and plasma concentration of AVP and NO, key mediators in endotoxemia. Similar to in vitro experiments, low doses of plasmid DNA (5 and 10 μg) induced a significant decrease of TNF-α and IL-6 message in the livers of LPS-injected rats. IL-6 was diminished at 2 hours after LPS injection when compared with the rats administered with LPS only (Figure 3), whereas no significant difference was detected at 4 hours after LPS injection (data not shown). In contrast, low doses of plasmid DNA induced a significant reduction in the TNF-α at 4 hours of experiment, but not at 2 hours, when compared with the group treated with LPS only (Figure 3). As the fall in MAP occurs in the first two hours after injection of LPS, we suggested that the decrease of IL-6 may be important in reducing the pressure drop observed in animals treated with plasmid DNA. Like IL-6, two hours after LPS administration, we observed that all tested dose of plasmid DNA significantly enhanced the LPS effect on AVP production, whereas only the doses of 10 and 20 μg of plasmid led to a significant increase in NO (Figure 4). Interestingly, the concentrations of AVP were low after 4 h of LPS injection, whereas high concentrations of NO were maintained (Figure 4).

Bottom Line: The beneficial effect of the plasmid DNA on MAP was associated with decreased expression of IL-6 in liver and increased concentration of plasma vasopressin (AVP), a known vasoconstrictor that has been investigated in hemorrhagic shock management.No difference was observed in relation to nitric oxide (NO) production.Our results demonstrate for the first time that plasmid DNA vector at low doses presents anti-inflammatory property and constitutes a novel approach with therapeutic potential in inflammatory diseases.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry and Immunology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto SP 14049-900, Brazil.

ABSTRACT

Background: Although plasmid DNA encoding an antigen from pathogens or tumor cells has been widely studied as vaccine, the use of plasmid vector (without insert) as therapeutic agent requires further investigation.

Results: Here, we showed that plasmid DNA (pcDNA3) at low doses inhibits the production of IL-6 and TNF-α by lipopolysaccharide (LPS)-stimulated macrophage cell line J774. These findings led us to evaluate whether plasmid DNA could act as an anti-inflammatory agent in a Wistar rat endotoxemia model. Rats injected simultaneously with 1.5 mg/kg of LPS and 10 or 20 μg of plasmid DNA had a remarkable attenuation of mean arterial blood pressure (MAP) drop at 2 hours after treatment when compared with rats injected with LPS only. The beneficial effect of the plasmid DNA on MAP was associated with decreased expression of IL-6 in liver and increased concentration of plasma vasopressin (AVP), a known vasoconstrictor that has been investigated in hemorrhagic shock management. No difference was observed in relation to nitric oxide (NO) production.

Conclusion: Our results demonstrate for the first time that plasmid DNA vector at low doses presents anti-inflammatory property and constitutes a novel approach with therapeutic potential in inflammatory diseases.

Show MeSH
Related in: MedlinePlus