Repetitive Hyperbaric Oxygenation Attenuates Reactive Astrogliosis and Suppresses Expression of Inflammatory Mediators in the Rat Model of Brain Injury
Repetitive HBOT downregulates CD40L expression after CSI. (a) Immunoblot analysis showed that CD40L was present as a single band with a molecular mass of about 36 kDa. After CSI expression of CD40L significantly () increased in respect to intact control (C) and sham-operated animals (S). However, compared to L group in LHBO group statistically significant reduction () of CD40L protein expression was observed. Bars represent mean ± SEM of CD40L protein content (relative to β-actin). Samples are from 4 animals per each group. Dot line represents mean of CD40L mRNA or protein level ± SEM (gray area) measured in control animals. Letters indicate significance levels () between lesioned (L) and intact control groups, L versus sham control (S) group, and L compared to lesioned group subjected to the HBO protocol (LHBO). The groups not sharing a common letter are statistically different. Level of significance was analyzed using Student’s -test. ((b) and (c)) In control cortex CD40L was localized in blood vessels ((c) asterisk). (d) At 10th day after CSI intense CD40L immunoreactivity occurred in perilesioned area: ((d), inset) in macrophages/microglia and neutrophils and (e) in protoplasmic astrocytes in close contact with endothelial cells via astrocytic end-feet (asterisk). (f) Repetitive HBOT decreased CD40L immunostaining in the injured cortex. (g) CD40L-positive astrocytes had fibrous form. Rectangles indicate where the high magnification images are taken from. Scale bar = 50 μm.