Interferon-beta-1b protects against multiple sclerosis-induced endothelial cells apoptosis.

Disruption of the blood-brain-barrier (BBB) due to endothelial cell (EC) injury is an essential step in formation of multiple sclerosis (MS) lesions. We investigated the role of endothelial cell (EC) apoptosis in the pathophysiology of MS, studying the therapeutic effect of IFN-beta-1b against MS sera-induced endothelial apoptosis. Human umbilical vein endothelial cells were treated with sera from patients with active MS (in relapse), MS in remission, or sera from healthy volunteers (each n = 5). Apoptosis was assessed by annexin V-propidium iodide staining. Effects of IFN-beta-1b on EC apoptosis were tested at increasing doses (10, 100, and 1000 U/ml). Nitrite (NO₂-⁻) levels were determined in culture supernatants. EC apoptosis was increased by sera from exacerbating MS patients, but not remission, compared to healthy individuals (p less than 0.001). Effects were blocked by IFN-beta-1b at 10 U/ml (p less than 0.05), but not higher doses, and was associated with increased NO/NO₂- production (less than 0.05). EC apoptosis leading to disruption of the BBB may play a role in MS etiology and represents a novel therapeutic mechanism of action for IFN-beta-1b in MS therapy.