Meningothelial cells (MECs) line the arachnoid layer of the meninges including the meninges that surround the optic nerve. These cells form the innermost layer of the arachnoid and, thus, are in direct contact with the cerebrospinal fluid (CSF). Clinical manifestations showed that the production of cytokines in patients who had optic neuritis and clinically-definite multiple sclerosis (CDMS) is much greater in the CSF than systemically, which underscores the autonomy of the immune responses in the CSF.

To investigate the potential immunological role of MECs, the secretion of interleukin 6 (IL-6) and interleukin 8 (IL-8) in culture supernatant of meningothelial cell line Ben-Men 1 cells (BMCs) was detected with ELISA analysis after the stimulation of lipopolysaccharide (LPS), phorbol 12-myristate 13-acetate (PMA) as well as Rotenone, a mitochondrial complex I inhibitor, for 24 hours. Nuclear factor κB (NF-κB) activation was observed under fluorescence microscope and by western blot. The phagocytosis of Fitc- conjugated latex beads was estimated by using fluorescence microscope as well as Flow Cytometry. Horseradish peroxidase (HRP) uptake was used to estimate the pinocytosis of the BMCs.

Results  the secretion of IL-6 and IL-8 of BMCs increased dose dependently after the insults stimulation and transcription factors NF-κB were activated in this process which could be blocked by proteasome inhibitor MG132. The phagocytosis of BMCs was enhanced by 100ng/mL PMA and 100ng/mL LPS. The pinocytosis of BMCs was increased by 1μg/mL PMA and 0.1, 0.5, 10μM Rotenone.

Conclusion  MECs were involved in the immune responses in CSF which might play a vital role in the process of neurodegenerative diseases including optic nerve disorders.