Antineuroinflammatory and neurotrophic effects of CNTF and C16 peptide in an acute experimental autoimmune encephalomyelitis rat model

Marong Fang,Jing Yang,Shu Han,Hong Jiang,Fan Zhang,Zhiying Hu,Daqiang He

doi:10.3389/fnana.2013.00044

Marong Fang, Jing Yang + Show 5 more

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https://doi.org/10.3389/fnana.2013.00044

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Abstract

Experimentalallergic encephalomyelitis (EAE) is an animal model for inflammatory demyelinating autoimmune disease, i.e., multiple sclerosis (MS). In the present study, we investigated the antineuroinflammatory/neuroprotective effects of C16, an ανβ3 integrin-binding peptide, and recombinant rat ciliary neurotrophic factor (CNTF), a cytokine that was originally identified as a survival factor for neurons, in an acute rodent EAE model. In this model, C16 peptide was injected intravenously every day for 2 weeks, and CNTF was delivered into the cerebral ventricles with Alzet miniosmotic pumps. Disease severity was assessed weekly using a scale ranging from 0 to 5. Multiple histological and molecular biological assays were employed to assess inflammation, axonal loss, neuronal apoptosis, white matter demyelination, and gliosis in the brain and spinal cord of different groups. Our results showed that the EAE induced rats revealed a significant increase in inflammatory cells infiltration, while C16 treatment could inhibit the infiltration of leukocytes and macrophages down to 2/3–1/3 of vehicle treated EAE control (P < 0.05). The delayed onset of disease, reduced clinical score (P < 0.01) in peak stage and more rapid recovery also were achieved in C16 treated group. Besides impairing inflammation, CNTF treatment also exerted direct neuroprotective effects, decreasing demyelination and axon loss score (P < 0.05 versus vehicle treated EAE control), and reducing the neuronal death from 40 to 50% to 10 to 20% (P < 0.05). Both treatments suppressed the expression of cytokine tumor necrosis factor-α and interferon-γ when compared with the vehicle control (P < 0.05). Combined treatment with C16 and CNTF produced more obvious functional recovery and neuroprotective effects than individually treatment (P < 0.05). These results suggested that combination treatment with C16 and CNTF, which target different neuroprotection pathways, may be an effective therapeutic alternative to traditional therapy.

Highlights

Multiple sclerosis (MS) is a central nervous system (CNS) autoimmune disease with symptoms that include neurological impairment and motor deficits (Hou et al, 2012)
EFFECTS OF TREATMENT WITH ciliary neurotrophic factor (CNTF) AND/OR C16 ON PERIVASCULAR/ PARENCHYMAL INFLAMMATION IN THE EAE RAT MODEL For determination of the types of inflammatory cells infiltrating these tissues, we performed immunostaining for the detection of CD4, a marker for extravasated T lymphocytes; CD45, a pan-leukocyte marker for leukocytes; and CD68, a marker for activated microglia and extravasated macrophages (Figure 1)
Treatment with either C16 or C16 plus CNTF markedly suppressed the infiltration of inflammatory cells in different cell types, but CNTF treatment did not result in obvious reduction of inflammation at week 8 post-immunization

Summary

Introduction

Multiple sclerosis (MS) is a central nervous system (CNS) autoimmune disease with symptoms that include neurological impairment and motor deficits (Hou et al, 2012). Experimental autoimmune encephalomyelitis (EAE) is the primary animal model of MS, characterized by microglial activation and lymphocyte infiltration (Arnon and Aharoni, 2009; Mix et al, 2010; Yin et al, 2012). Consequent demyelination, axonal injury, and neuronal loss underlie the disability and disease progression observed in EAE (Arnon and Aharoni, 2009). Current treatment strategies for EAE and MS mainly target injury sites at the CNS, interfering with both neuroinflammation and neurodegeneration (Arnon and Aharoni, 2009). Leukocyte-endothelium interactions have been recognized as playing an important role in this leukocyte infiltration process (Weerasinghe et al, 1998; Alon and Luscinskas, 2004). Previous studies have shown that integrin alpha V beta 3 (αυβ3) can modulate leukocyte adhesion to intercellular adhesion molecule-1 (ICAM-1) and enable leukocytes to migrate effectively across the endothelium (Weerasinghe et al, 1998)

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