Dose-Dependent Anti-Inflammatory and Neuroprotective Effects of anανβ3 Integrin-Binding Peptide

Abstract

Previous studies have shown that prevention of leukocyte infiltration by targeting integrins involved in transendothelial migration may suppress the clinical and pathological features of neuroinflammatory disease. This study was designed to investigate the effects of C16, an α ν β3 integrin-binding peptide, in an acute experimental allergic encephalomyelitis (EAE) rat model. Multiple histological and immunohistochemical staining, electron microscopy observation, ELISA assay, Western blot, and magnetic resonance imaging (MRI) were employed to assess the degree of inflammation, axonal loss, neuronal apoptosis, white matter demyelination, and extent of gliosis in the brain and spinal cord of differently treated EAE models. The results showed that C16 treatment could inhibit extensive leukocyte and macrophage accumulation and infiltration and reduce cytokine tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) expression levels. A significantly lower clinical score at the peak time of disease was also demonstrated in the C16 treated group. Moreover, astrogliosis, demyelination, neuronal death, and axonal loss were all alleviated in C16 treated EAE animals, which may be attributed to the improvement of microenvironment. The data suggests that C16 peptide may act as a protective agent by attenuating inflammatory progression and thus affecting the expression of some proinflammatory cytokines during neuroinflammatory disease.

Role of C16, angiopoietin‐1 and regeneration gene protein 2 in attenuating inflammation in an experimental rat model of autoimmune encephalomyelitis

“…However, its effects were not as evident or as beneficial as the immediate treatment (Han et al. ). Based on the abovementioned results, we came to the conclusion that early treatment applied at the time of EAE induction is more effective than delayed treatment (started at the time of clinical symptoms).…”

“…ELISAs for TGF‐β (R&D System, Minneapolis, MN, USA), and IFN‐γ (BioLegend, San Diego, CA, USA) were performed as previously described (Han et al. ; Zhang et al. ).…”

“…Bielschowsky silver staining was performed as previously described to estimate axonal loss (Fang et al 2013b;Han et al 2013;Zhang et al 2014). Axonal loss was assessed using the following scale: 0, no axonal loss; 1, a few foci of superficial axonal loss involving less than 25% of the tissue; 2, foci of deep axonal loss that encompassed over 25% of the tissue; and 3, diffuse and widespread axonal loss (Yin et al 2010).…”

“…Post-fixed tissues were placed in 1% osmium tetroxide overnight at 4°C and then washed three times with 0.1 M PB. Processing for electron microscopy was performed as previously described (Fang et al 2013b;Han et al 2013;Zhang et al 2014). Briefly, thin sections were cut, stained with uranyl acetate and lead citrate, and then the electron micrographs were analyzed for fiber diameter, myelin thickness and axon diameter using the SCION Imaging software.…”

“…Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) in which circulating leukocytes enter the brain and spinal cord producing inflammation, myelin damage and paralysis (Fang et al 2013b;Han et al 2013). MS is thought to affect more than 2.5 million individuals worldwide.…”