Evalution of blood-brain barrier biomarkers in experimental cerebral i̇schemia model

The aim of this study is to add new biomarkers to the literature and clinical use with the biochemical and histological evaluations of occludin, claudin-5, JAM-A which are blood-brain barrier tight junction proteins and S100B which is an indicator of astrocyte damage, on an experimantal rat focal cerebral ischemia model. According to ischemia times, eight animals in each group (n=8); A total of 40 Wistar Albino male rats were used, which were examined in five groups: group A (15 h), group B (45 h), group C (6 h), group D (24 h), control group. A new focal cerebral ischemia model was created by occlusion of the right commun carotid artery and external carotid artery. After their ischemia period expired, rats were sacrificed after blood and brain tissues were taken to examine occludin, claudin-5, JAM-A and S100B levels. Brain tissues were also subjected to histological examination, the percentage of pycnotic nuclei, apoptotic index and occludin, JAM-A, S100B immunoreactivity intensities were examined. The obtained data were analyzed using SPSS and Jamovi programs. Serum JAM-A and serum claudin-5 levels, percentage of pycnotic nuclei, apoptotic index values, and occludin, JAM-A and S100B immunoreactivity intensity variables showed statistically significant differences between the groups (p<0.05). As a result, in our experimental focal cerebral ischemia model, serum JAM-A, one of the tight junction proteins, showed more significant and rapid increases compared to occludin and claudin-5 proteins. These data prove that JAM-A can be a guiding biomarker in estimating the prognosis and complications of ischemic stroke, which is one of the important causes of mortality and morbidity, and in determining the treatment modality. Keywords:JAM-A, Occludin, Claudin-5, S100B, Ischemia, Stroke