Neutralizing anti-interleukin-1β antibodies modulate fetal blood–brain barrier function after ischemia

• Published in: Neurobiology of disease 2015-01, Vol.73, p.118-129
• Main Authors: Chen, Xiaodi, Sadowska, Grazyna B, Zhang, Jiyong, Kim, Jeong-Eun, Cummings, Erin E, Bodge, Courtney A, Lim, Yow-Pin, Makeyev, Oleksandr, Besio, Walter G, Gaitanis, John, Threlkeld, Steven W, Banks, William A, Stonestreet, Barbara S
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Neutralizing - pharmacology; Antibodies, Neutralizing - therapeutic use; Blood Pressure - drug effects; Blood-Brain Barrier - drug effects; Blood-Brain Barrier - physiopathology; Blood–brain barrier; Brain; Brain - embryology; Brain - metabolism; Capillary Permeability - drug effects; Carotid Stenosis - complications; Cytokines; Cytokines - metabolism; Disease Models, Animal; Embryo, Mammalian; Enzyme-Linked Immunosorbent Assay; Female; Fetal Hypoxia - drug therapy; Fetal Hypoxia - etiology; Fetal Hypoxia - pathology; Heart Rate, Fetal - drug effects; Interleukin-1beta - immunology; Interleukin-1beta - metabolism; Interleukin-1β; Ischemia–reperfusion; Mice; Monoclonal antibody; Neurology; Ovine fetus; Pregnancy; Regional Blood Flow - drug effects; Sheep; Tight Junction Proteins - metabolism
• ISSN: 0969-9961; 1095-953X
• DOI: 10.1016/j.nbd.2014.09.007

Abstract We have previously shown that increases in blood–brain barrier permeability represent an important component of ischemia–reperfusion related brain injury in the fetus. Pro-inflammatory cytokines could contribute to these abnormalities in blood–brain barrier function. We have generated pharmacological quantities of mouse anti-ovine interleukin-1β monoclonal antibody and shown that this antibody has very high sensitivity and specificity for interleukin-1β protein. This antibody also neutralizes the effects of interleukin-1β protein in vitro. In the current study, we hypothesized that the neutralizing anti-interleukin-1β monoclonal antibody attenuates ischemia–reperfusion related fetal blood–brain barrier dysfunction. Instrumented ovine fetuses at 127 days of gestation were studied after 30 min of carotid occlusion and 24 h of reperfusion. Groups were sham operated placebo-control- (n = 5), ischemia-placebo- (n = 6), ischemia-anti-IL-1β antibody- (n = 7), and sham-control antibody- (n = 2) treated animals. Systemic infusions of placebo (0.154 M NaCl) or anti-interleukin-1β monoclonal antibody (5.1 ± 0.6 mg/kg) were given intravenously to the same sham or ischemic group of fetuses at 15 min and 4 h after ischemia. Concentrations of interleukin-1β protein and anti-interleukin-1β monoclonal antibody were measured by ELISA in fetal plasma, cerebrospinal fluid, and parietal cerebral cortex. Blood–brain barrier permeability was quantified using the blood-to-brain transfer constant ( Ki ) with α-aminoisobutyric acid in multiple brain regions. Interleukin-1β protein was also measured in parietal cerebral cortices and tight junction proteins in multiple brain regions by Western immunoblot. Cerebral cortical interleukin-1β protein increased ( P < 0.001) after ischemia–reperfusion. After anti-interleukin-1β monoclonal antibody infusions, plasma anti-interleukin-1β monoclonal antibody was elevated ( P < 0.001), brain anti-interleukin-1β monoclonal antibody levels were higher ( P < 0.03), and interleukin-1β protein concentrations ( P < 0.03) and protein expressions ( P < 0.001) were lower in the monoclonal antibody-treated group than in placebo-treated-ischemia–reperfusion group. Monoclonal antibody infusions attenuated ischemia–reperfusion-related increases in Ki across the brain regions ( P < 0.04), and Ki showed an inverse linear correlation (r = − 0.65, P < 0.02) with anti-interleukin-1β monoclonal antibody concentrations in the parietal cortex, but had littl