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Rescue from acute neuroinflammation by pharmacological chemokine-mediated deviation of leukocytes.

Berghmans N, Heremans H, Li S, Martens E, Matthys P, Sorokin L, Van Damme J, Opdenakker G - J Neuroinflammation (2012)

Bottom Line: However, in view of unsatisfactory results and severe side effects, complementary therapies are needed.We have examined the effect of chlorite-oxidized oxyamylose (COAM), a potent antiviral polycarboxylic acid on EAE.These results demonstrate novel actions of COAM as an anti-inflammatory agent with beneficial effects on EAE through cell deviation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Rega Institute for Medical Research, Department of Microbiology and Immunology, University of Leuven, Leuven, Belgium.

ABSTRACT

Background: Neutrophil influx is an important sign of hyperacute neuroinflammation, whereas the entry of activated lymphocytes into the brain parenchyma is a hallmark of chronic inflammatory processes, as observed in multiple sclerosis (MS) and its animal models of experimental autoimmune encephalomyelitis (EAE). Clinically approved or experimental therapies for neuroinflammation act by blocking leukocyte penetration of the blood brain barrier. However, in view of unsatisfactory results and severe side effects, complementary therapies are needed. We have examined the effect of chlorite-oxidized oxyamylose (COAM), a potent antiviral polycarboxylic acid on EAE.

Methods: EAE was induced in SJL/J mice by immunization with spinal cord homogenate (SCH) or in IFN-γ-deficient BALB/c (KO) mice with myelin oligodendrocyte glycoprotein peptide (MOG₃₅₋₅₅). Mice were treated intraperitoneally (i.p.) with COAM or saline at different time points after immunization. Clinical disease and histopathology were compared between both groups. IFN expression was analyzed in COAM-treated MEF cell cultures and in sera and peritoneal fluids of COAM-treated animals by quantitative PCR, ELISA and a bioassay on L929 cells. Populations of immune cell subsets in the periphery and the central nervous system (CNS) were quantified at different stages of disease development by flow cytometry and differential cell count analysis. Expression levels of selected chemokine genes in the CNS were determined by quantitative PCR.

Results: We discovered that COAM (2 mg i.p. per mouse on days 0 and 7) protects significantly against hyperacute SCH-induced EAE in SJL/J mice and MOG₃₅₋₅₅-induced EAE in IFN-γ KO mice. COAM deviated leukocyte trafficking from the CNS into the periphery. In the CNS, COAM reduced four-fold the expression levels of the neutrophil CXC chemokines KC/CXCL1 and MIP-2/CXCL2. Whereas the effects of COAM on circulating blood and splenic leukocytes were limited, significant alterations were observed at the COAM injection site.

Conclusions: These results demonstrate novel actions of COAM as an anti-inflammatory agent with beneficial effects on EAE through cell deviation. Sequestration of leukocytes in the non-CNS periphery or draining of leukocytes out of the CNS with the use of the chemokine system may thus complement existing treatment options for acute and chronic neuroinflammatory diseases.

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The clinical course of hyperacute EAE in COAM-treated mice. (A) SJL/J mice were immunized subcutaneously with syngeneic SCH for induction of hyperacute EAE and treated i.p. at day 0 with 2 mg COAM. Mean disease scores were calculated for COAM-treated (n = 10, filled squares) or saline-treated (n = 10, open squares) animals. One significant data point is indicated by an asterisk at day 14. (B) When two injections with COAM were given on days 0 and 7 after immunization, significant reduction of disease scores (asterisks) were observed from day 12 onwards. The clinical course of hyperacute EAE in these mice is shown as mean daily group score ± SEM. Dead animals were scored grade 6 from the day of death until the end of the study. Black vertical arrows indicate time points of COAM administration. * P <0.05 for comparison with saline-treated group (Wilcoxon test). COAM, chlorite-oxidized oxyamylose; EAE, experimental autoimmune encephalomyelitis; SCH, spinal cord homogenate; SEM, standard error of the mean.
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Figure 1: The clinical course of hyperacute EAE in COAM-treated mice. (A) SJL/J mice were immunized subcutaneously with syngeneic SCH for induction of hyperacute EAE and treated i.p. at day 0 with 2 mg COAM. Mean disease scores were calculated for COAM-treated (n = 10, filled squares) or saline-treated (n = 10, open squares) animals. One significant data point is indicated by an asterisk at day 14. (B) When two injections with COAM were given on days 0 and 7 after immunization, significant reduction of disease scores (asterisks) were observed from day 12 onwards. The clinical course of hyperacute EAE in these mice is shown as mean daily group score ± SEM. Dead animals were scored grade 6 from the day of death until the end of the study. Black vertical arrows indicate time points of COAM administration. * P <0.05 for comparison with saline-treated group (Wilcoxon test). COAM, chlorite-oxidized oxyamylose; EAE, experimental autoimmune encephalomyelitis; SCH, spinal cord homogenate; SEM, standard error of the mean.

Mentions: Monophasic hyperacute EAE in SJL/J mice was induced by immunization with syngeneic SCH in CFA and mice were treated by injection of COAM (2 mg i.p.) at various time points. Control mice consisted of EAE-induced animals treated with excipiens and untreated naive mice were used to measure background levels of all parameters. The first signs of hyperacute EAE appeared between days 11 and 13 after immunization. Mice treated with a single dose of COAM on the day of immunization (day 0) had significantly less severe clinical signs at day 14 (P < 0.05; indicated by single asterisk in Figure 1, panel A) and decreased incidence of the disease to 50% (P <0.05) (Figure 1A, Table 1) compared to saline-treated control animals. These results indicate that a single injection of COAM results in effects that last several days. By contrast, a single i.p. injection of COAM on day 8 after immunization was ineffective in this animal model (Table 1). Mice treated with COAM on days 0 and 7 after immunization exhibited a stronger reduction of hyperacute EAE compared to those treated with a single dose of COAM at day 0 (Figure 1A and1B), with significantly reduced severity of clinical signs and mortality rates (P <0.05 and P <0.01, respectively) compared to saline–treated mice (90% mortality) (Table 1). These in vivo results indicated that two i.p. injections of COAM at days 0 and 7 after immunization provided partial protection against SCH-induced hyperacute EAE and this significantly decreased the mean daily disease score from the onset of clinical signs until the termination of the experiment at day 40. This effect was dose-dependent (with decreased survival rates after treatment with 0.5 mg per mouse).


Rescue from acute neuroinflammation by pharmacological chemokine-mediated deviation of leukocytes.

Berghmans N, Heremans H, Li S, Martens E, Matthys P, Sorokin L, Van Damme J, Opdenakker G - J Neuroinflammation (2012)

The clinical course of hyperacute EAE in COAM-treated mice. (A) SJL/J mice were immunized subcutaneously with syngeneic SCH for induction of hyperacute EAE and treated i.p. at day 0 with 2 mg COAM. Mean disease scores were calculated for COAM-treated (n = 10, filled squares) or saline-treated (n = 10, open squares) animals. One significant data point is indicated by an asterisk at day 14. (B) When two injections with COAM were given on days 0 and 7 after immunization, significant reduction of disease scores (asterisks) were observed from day 12 onwards. The clinical course of hyperacute EAE in these mice is shown as mean daily group score ± SEM. Dead animals were scored grade 6 from the day of death until the end of the study. Black vertical arrows indicate time points of COAM administration. * P <0.05 for comparison with saline-treated group (Wilcoxon test). COAM, chlorite-oxidized oxyamylose; EAE, experimental autoimmune encephalomyelitis; SCH, spinal cord homogenate; SEM, standard error of the mean.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 1: The clinical course of hyperacute EAE in COAM-treated mice. (A) SJL/J mice were immunized subcutaneously with syngeneic SCH for induction of hyperacute EAE and treated i.p. at day 0 with 2 mg COAM. Mean disease scores were calculated for COAM-treated (n = 10, filled squares) or saline-treated (n = 10, open squares) animals. One significant data point is indicated by an asterisk at day 14. (B) When two injections with COAM were given on days 0 and 7 after immunization, significant reduction of disease scores (asterisks) were observed from day 12 onwards. The clinical course of hyperacute EAE in these mice is shown as mean daily group score ± SEM. Dead animals were scored grade 6 from the day of death until the end of the study. Black vertical arrows indicate time points of COAM administration. * P <0.05 for comparison with saline-treated group (Wilcoxon test). COAM, chlorite-oxidized oxyamylose; EAE, experimental autoimmune encephalomyelitis; SCH, spinal cord homogenate; SEM, standard error of the mean.
Mentions: Monophasic hyperacute EAE in SJL/J mice was induced by immunization with syngeneic SCH in CFA and mice were treated by injection of COAM (2 mg i.p.) at various time points. Control mice consisted of EAE-induced animals treated with excipiens and untreated naive mice were used to measure background levels of all parameters. The first signs of hyperacute EAE appeared between days 11 and 13 after immunization. Mice treated with a single dose of COAM on the day of immunization (day 0) had significantly less severe clinical signs at day 14 (P < 0.05; indicated by single asterisk in Figure 1, panel A) and decreased incidence of the disease to 50% (P <0.05) (Figure 1A, Table 1) compared to saline-treated control animals. These results indicate that a single injection of COAM results in effects that last several days. By contrast, a single i.p. injection of COAM on day 8 after immunization was ineffective in this animal model (Table 1). Mice treated with COAM on days 0 and 7 after immunization exhibited a stronger reduction of hyperacute EAE compared to those treated with a single dose of COAM at day 0 (Figure 1A and1B), with significantly reduced severity of clinical signs and mortality rates (P <0.05 and P <0.01, respectively) compared to saline–treated mice (90% mortality) (Table 1). These in vivo results indicated that two i.p. injections of COAM at days 0 and 7 after immunization provided partial protection against SCH-induced hyperacute EAE and this significantly decreased the mean daily disease score from the onset of clinical signs until the termination of the experiment at day 40. This effect was dose-dependent (with decreased survival rates after treatment with 0.5 mg per mouse).

Bottom Line: However, in view of unsatisfactory results and severe side effects, complementary therapies are needed.We have examined the effect of chlorite-oxidized oxyamylose (COAM), a potent antiviral polycarboxylic acid on EAE.These results demonstrate novel actions of COAM as an anti-inflammatory agent with beneficial effects on EAE through cell deviation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Rega Institute for Medical Research, Department of Microbiology and Immunology, University of Leuven, Leuven, Belgium.

ABSTRACT

Background: Neutrophil influx is an important sign of hyperacute neuroinflammation, whereas the entry of activated lymphocytes into the brain parenchyma is a hallmark of chronic inflammatory processes, as observed in multiple sclerosis (MS) and its animal models of experimental autoimmune encephalomyelitis (EAE). Clinically approved or experimental therapies for neuroinflammation act by blocking leukocyte penetration of the blood brain barrier. However, in view of unsatisfactory results and severe side effects, complementary therapies are needed. We have examined the effect of chlorite-oxidized oxyamylose (COAM), a potent antiviral polycarboxylic acid on EAE.

Methods: EAE was induced in SJL/J mice by immunization with spinal cord homogenate (SCH) or in IFN-γ-deficient BALB/c (KO) mice with myelin oligodendrocyte glycoprotein peptide (MOG₃₅₋₅₅). Mice were treated intraperitoneally (i.p.) with COAM or saline at different time points after immunization. Clinical disease and histopathology were compared between both groups. IFN expression was analyzed in COAM-treated MEF cell cultures and in sera and peritoneal fluids of COAM-treated animals by quantitative PCR, ELISA and a bioassay on L929 cells. Populations of immune cell subsets in the periphery and the central nervous system (CNS) were quantified at different stages of disease development by flow cytometry and differential cell count analysis. Expression levels of selected chemokine genes in the CNS were determined by quantitative PCR.

Results: We discovered that COAM (2 mg i.p. per mouse on days 0 and 7) protects significantly against hyperacute SCH-induced EAE in SJL/J mice and MOG₃₅₋₅₅-induced EAE in IFN-γ KO mice. COAM deviated leukocyte trafficking from the CNS into the periphery. In the CNS, COAM reduced four-fold the expression levels of the neutrophil CXC chemokines KC/CXCL1 and MIP-2/CXCL2. Whereas the effects of COAM on circulating blood and splenic leukocytes were limited, significant alterations were observed at the COAM injection site.

Conclusions: These results demonstrate novel actions of COAM as an anti-inflammatory agent with beneficial effects on EAE through cell deviation. Sequestration of leukocytes in the non-CNS periphery or draining of leukocytes out of the CNS with the use of the chemokine system may thus complement existing treatment options for acute and chronic neuroinflammatory diseases.

Show MeSH
Related in: MedlinePlus