Limits...
Functional interleukin-17 receptor A is expressed in central nervous system glia and upregulated in experimental autoimmune encephalomyelitis.

Das Sarma J, Ciric B, Marek R, Sadhukhan S, Caruso ML, Shafagh J, Fitzgerald DC, Shindler KS, Rostami A - J Neuroinflammation (2009)

Bottom Line: IL-17A signals through its receptor, IL-17RA, which is expressed in many peripheral tissues; however, expression of IL-17RA in the central nervous system (CNS) and its role in CNS inflammation are not well understood.Specifically, astrocytes and microglia express IL-17RA in vitro, and IL-17A treatment induces biological responses in these cells, including significant upregulation of MCP-1, MCP-5, MIP-2 and KC chemokine secretion.Exogenous IL-17A does not significantly alter the expression of IL-17RA in glial cells, suggesting that upregulation of chemokines by glial cells is due to IL-17A signaling through constitutively expressed IL-17RA.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA. dassarmaj@iiserkol.ac.in

ABSTRACT

Background: Interleukin-17A (IL-17A) is the founding member of a novel family of inflammatory cytokines that plays a critical role in the pathogenesis of many autoimmune diseases, including multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). IL-17A signals through its receptor, IL-17RA, which is expressed in many peripheral tissues; however, expression of IL-17RA in the central nervous system (CNS) and its role in CNS inflammation are not well understood.

Methods: EAE was induced in C57Bl/6 mice by immunization with myelin oligodendroglial glycoprotein. IL-17RA expression in the CNS was compared between control and EAE mice using RT-PCR, in situ hybridization, and immunohistochemistry. Cell-type specific expression was examined in isolated astrocytic and microglial cell cultures. Cytokine and chemokine production was measured in IL-17A treated cultures to evaluate the functional status of IL-17RA.

Results: Here we report increased IL-17RA expression in the CNS of mice with EAE, and constitutive expression of functional IL-17RA in mouse CNS tissue. Specifically, astrocytes and microglia express IL-17RA in vitro, and IL-17A treatment induces biological responses in these cells, including significant upregulation of MCP-1, MCP-5, MIP-2 and KC chemokine secretion. Exogenous IL-17A does not significantly alter the expression of IL-17RA in glial cells, suggesting that upregulation of chemokines by glial cells is due to IL-17A signaling through constitutively expressed IL-17RA.

Conclusion: IL-17RA expression is significantly increased in the CNS of mice with EAE compared to healthy mice, suggesting that IL-17RA signaling in glial cells can play an important role in autoimmune inflammation of the CNS and may be a potential pathway to target for therapeutic interventions.

Show MeSH

Related in: MedlinePlus

IL-17RA expression in the CNS of EAE mice. (A) Clinical profile of EAE. Female C57BL/6 mice (n = 8) were immunized with MOG35–55 and scored daily. Data represent mean clinical scores ± SEM. One experiment of three is shown. (B-G). CNS inflammation and demyelination. Mice were sacrificed at day 20 p.i., spinal cords were harvested and 5 μm sections were stained with H&E (B, D, F) or LFB (myelin stain; C, E, G). Magnifications are 40× (B-E) and 100× (F, G). EAE mice had significant cellular infiltration (arrows; D, F) and demyelination (arrows; E, G). No inflammation or demyelination occurred in control mice (B, C). (H) IL-17RA expression is up-regulated in the inflamed CNS of EAE mice. EAE and control mice (n = 5) were sacrificed at day 20 p.i. and IL-17RA expression from isolated spinal cords was assessed by RT-PCR using a primer set from exon boundary 1–2. Expression of IL-17RA in EAE mice is upregulated > 5-fold (*** P < 0.0001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2689857&req=5

Figure 2: IL-17RA expression in the CNS of EAE mice. (A) Clinical profile of EAE. Female C57BL/6 mice (n = 8) were immunized with MOG35–55 and scored daily. Data represent mean clinical scores ± SEM. One experiment of three is shown. (B-G). CNS inflammation and demyelination. Mice were sacrificed at day 20 p.i., spinal cords were harvested and 5 μm sections were stained with H&E (B, D, F) or LFB (myelin stain; C, E, G). Magnifications are 40× (B-E) and 100× (F, G). EAE mice had significant cellular infiltration (arrows; D, F) and demyelination (arrows; E, G). No inflammation or demyelination occurred in control mice (B, C). (H) IL-17RA expression is up-regulated in the inflamed CNS of EAE mice. EAE and control mice (n = 5) were sacrificed at day 20 p.i. and IL-17RA expression from isolated spinal cords was assessed by RT-PCR using a primer set from exon boundary 1–2. Expression of IL-17RA in EAE mice is upregulated > 5-fold (*** P < 0.0001).

Mentions: Mounting evidence suggests that IL-17A causes pathology in autoimmunity, but little is known about mechanisms of IL-17RA signaling. To examine if CNS inflammation alters IL-17RA expression locally, we utilized the EAE model induced in C57BL/6 mice with MOG35–55. As shown in Figure 2A, these mice developed the classical clinical profile of EAE. Spinal cords were harvested at the peak of disease (day 20) for histopathological studies and RNA extraction. In agreement with clinical findings, we observed inflammatory demyelinating lesions in EAE mice (Figure 2D–G). Quantitative RT-PCR using a standard curve (expressing the gene from the exon boundary 1 – 2) demonstrated nearly 5-fold more IL-17RA expression in EAE spinal cords than healthy controls (Figure 2H). These results suggest that inflamed CNS may have heightened responsiveness to IL-17A.


Functional interleukin-17 receptor A is expressed in central nervous system glia and upregulated in experimental autoimmune encephalomyelitis.

Das Sarma J, Ciric B, Marek R, Sadhukhan S, Caruso ML, Shafagh J, Fitzgerald DC, Shindler KS, Rostami A - J Neuroinflammation (2009)

IL-17RA expression in the CNS of EAE mice. (A) Clinical profile of EAE. Female C57BL/6 mice (n = 8) were immunized with MOG35–55 and scored daily. Data represent mean clinical scores ± SEM. One experiment of three is shown. (B-G). CNS inflammation and demyelination. Mice were sacrificed at day 20 p.i., spinal cords were harvested and 5 μm sections were stained with H&E (B, D, F) or LFB (myelin stain; C, E, G). Magnifications are 40× (B-E) and 100× (F, G). EAE mice had significant cellular infiltration (arrows; D, F) and demyelination (arrows; E, G). No inflammation or demyelination occurred in control mice (B, C). (H) IL-17RA expression is up-regulated in the inflamed CNS of EAE mice. EAE and control mice (n = 5) were sacrificed at day 20 p.i. and IL-17RA expression from isolated spinal cords was assessed by RT-PCR using a primer set from exon boundary 1–2. Expression of IL-17RA in EAE mice is upregulated > 5-fold (*** P < 0.0001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2689857&req=5

Figure 2: IL-17RA expression in the CNS of EAE mice. (A) Clinical profile of EAE. Female C57BL/6 mice (n = 8) were immunized with MOG35–55 and scored daily. Data represent mean clinical scores ± SEM. One experiment of three is shown. (B-G). CNS inflammation and demyelination. Mice were sacrificed at day 20 p.i., spinal cords were harvested and 5 μm sections were stained with H&E (B, D, F) or LFB (myelin stain; C, E, G). Magnifications are 40× (B-E) and 100× (F, G). EAE mice had significant cellular infiltration (arrows; D, F) and demyelination (arrows; E, G). No inflammation or demyelination occurred in control mice (B, C). (H) IL-17RA expression is up-regulated in the inflamed CNS of EAE mice. EAE and control mice (n = 5) were sacrificed at day 20 p.i. and IL-17RA expression from isolated spinal cords was assessed by RT-PCR using a primer set from exon boundary 1–2. Expression of IL-17RA in EAE mice is upregulated > 5-fold (*** P < 0.0001).
Mentions: Mounting evidence suggests that IL-17A causes pathology in autoimmunity, but little is known about mechanisms of IL-17RA signaling. To examine if CNS inflammation alters IL-17RA expression locally, we utilized the EAE model induced in C57BL/6 mice with MOG35–55. As shown in Figure 2A, these mice developed the classical clinical profile of EAE. Spinal cords were harvested at the peak of disease (day 20) for histopathological studies and RNA extraction. In agreement with clinical findings, we observed inflammatory demyelinating lesions in EAE mice (Figure 2D–G). Quantitative RT-PCR using a standard curve (expressing the gene from the exon boundary 1 – 2) demonstrated nearly 5-fold more IL-17RA expression in EAE spinal cords than healthy controls (Figure 2H). These results suggest that inflamed CNS may have heightened responsiveness to IL-17A.

Bottom Line: IL-17A signals through its receptor, IL-17RA, which is expressed in many peripheral tissues; however, expression of IL-17RA in the central nervous system (CNS) and its role in CNS inflammation are not well understood.Specifically, astrocytes and microglia express IL-17RA in vitro, and IL-17A treatment induces biological responses in these cells, including significant upregulation of MCP-1, MCP-5, MIP-2 and KC chemokine secretion.Exogenous IL-17A does not significantly alter the expression of IL-17RA in glial cells, suggesting that upregulation of chemokines by glial cells is due to IL-17A signaling through constitutively expressed IL-17RA.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA. dassarmaj@iiserkol.ac.in

ABSTRACT

Background: Interleukin-17A (IL-17A) is the founding member of a novel family of inflammatory cytokines that plays a critical role in the pathogenesis of many autoimmune diseases, including multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). IL-17A signals through its receptor, IL-17RA, which is expressed in many peripheral tissues; however, expression of IL-17RA in the central nervous system (CNS) and its role in CNS inflammation are not well understood.

Methods: EAE was induced in C57Bl/6 mice by immunization with myelin oligodendroglial glycoprotein. IL-17RA expression in the CNS was compared between control and EAE mice using RT-PCR, in situ hybridization, and immunohistochemistry. Cell-type specific expression was examined in isolated astrocytic and microglial cell cultures. Cytokine and chemokine production was measured in IL-17A treated cultures to evaluate the functional status of IL-17RA.

Results: Here we report increased IL-17RA expression in the CNS of mice with EAE, and constitutive expression of functional IL-17RA in mouse CNS tissue. Specifically, astrocytes and microglia express IL-17RA in vitro, and IL-17A treatment induces biological responses in these cells, including significant upregulation of MCP-1, MCP-5, MIP-2 and KC chemokine secretion. Exogenous IL-17A does not significantly alter the expression of IL-17RA in glial cells, suggesting that upregulation of chemokines by glial cells is due to IL-17A signaling through constitutively expressed IL-17RA.

Conclusion: IL-17RA expression is significantly increased in the CNS of mice with EAE compared to healthy mice, suggesting that IL-17RA signaling in glial cells can play an important role in autoimmune inflammation of the CNS and may be a potential pathway to target for therapeutic interventions.

Show MeSH
Related in: MedlinePlus