The vascular and neuronal effects of astrocytic HmgB1 in the cerebral cortex
LE3 .A278 2022
Bachelor of Science
Astrocytes surround brain capillaries using endfoot processes, which contribute to the regulation of the blood brain barrier. Astrocytes are involved in initiating synaptogenesis and regulating synapse formation. An astrocyte specific knockout of HmgB1 was performed using Cre dependent gene knockout in mouse models. After genetic manipulation, brain sections were immunostained using NeuN and Tbr1 neuron markers. Distribution of neurons within the cerebral cortex was assessed using Fiji software and showed potential differences in cortical neuron distribution. To further evaluate this, immunostaining was used to explore the counts of cortical neurons in different layers of the cortex using Ctip2 and Pou3F2 neuron markers. Neuronal cells were visible and counted using Fiji and showed a significant difference in Pou3F2+ cells in the cortex relative to wild types (N = 4, P = 0.0396, α = 0.05). This analysis was repeated using Ctip2 where there was a non-significant decrease in Ctip2+ cells in mutant mice (N = 4, P = 0.0616, α = 0.05). Claudin-5 immunostaining was executed and used to calculate percent coverage of claudin-5 on CD31. The results show that HmgB1 in astrocytes is required in order for proper coverage of claudin-5 over CD31 in large cortical venules. This study presents novel insights into the roles of astrocytic HmgB1 in post-natal development of the neurovascular unit.
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