The chemokine CCL11 (also known as eotaxin-1) is a potent eosinophil chemoattractant that mediates allergic diseases such as asthma, atopic dermatitis, and inflammatory bowel diseases. Previous studies demonstrated that concentrations of CCL11 are elevated in the sera and cerebrospinal fluids (CSF) of patients with neuroinflammatory disorders, including multiple sclerosis. Moreover, the levels of CCL11 in plasma and CSF increase with age, and CCL11 suppresses adult neurogenesis (nerve growth) in the central nervous system (CNS), resulting in memory impairment. However, the precise source and function of CCL11 in the CNS are not fully understood. In this study, we found that activated astrocytes release CCL11, whereas microglia predominantly express the CCL11 receptor. CCL11 significantly promoted the migration of microglia, and induced microglial production of reactive oxygen species by upregulating nicotinamide adenine dinucleotide phosphate-oxidase 1 (NOX1), thereby promoting excitotoxic neuronal death. These effects were reversed by inhibition of NOX1. Our findings suggest that CCL11 released from activated astrocytes triggers oxidative stress via microglial NOX1 activation and potentiates glutamate-mediated neurotoxicity, which may be involved in the pathogenesis of various neurological disorders.
Parajuli B, Horiuchi H, Mizuno T, Takeuchi H, Suzumura A. CCL11 enhances excitotoxic neuronal death by producing reactive oxygen species in microglia. Glia. 2015. doi: 10.1002/glia.22892. [Epub ahead of print]
You aske how can progressive nerve damage occur and there are a number of ideas. In this study a cytokine that can act as a chemical attractant. This produced by astrocytes and works on microglial tomake molecules that promote nerve damage, Aditionally, it has been demonstrated that exposing young mice to CCL11 or the blood plasma of older mice decreases their neurogenesis and cognitive performance on behavioural tasks thought to be dependent on neurogenesis in the hippocampus.