The contribution of TRPV4 channels to astrocyte volume regulation and brain edema formation

Publication date: Available online 24 October 2018Source: NeuroscienceAuthor(s): Helena Pivonkova, Zuzana Hermanova, Denisa Kirdajova, Thuraya Awadova, Jan Malinsky, Lukas Valihrach, Daniel Zucha, Mikael Kubista, Andrea Galisova, Daniel Jirak, Miroslava AnderovaAbstractTransient receptor potential vanilloid type 4 (TRPV4) channels are involved in astrocyte volume regulation; however, only limited data exists about its mechanism in astrocytes in situ. We performed middle cerebral artery occlusion in adult mice, where we found twice larger edema 1 day after the insult in trpv4-/- mice compared to the controls, which was quantified using magnetic resonance imaging. This result suggests disrupted volume regulation in the brain cells in trpv4-/- mice leading to increased edema formation. The aim of our study was to elucidate whether TRPV4 channels-based volume regulation occurs in astrocytes in situ and whether the disrupted volume regulation in trpv4-/- mice might lead to higher edema formation after brain ischemia. For our experiments, we used trpv4-/- mice crossed with transgenic mice expressing enhanced green fluorescent protein (EGFP) under the control of the glial fibrillary acidic protein promoter, which leads to astrocyte visualization by EGFP expression. For quantification of astrocyte volume changes, we used 2D and 3D morphometrical approaches and a quantification algorithm based on fluorescence intensity changes during volume alterations induced by hypotonicity or by ox...

Source: Neuroscience - October 25, 2018 Category: Neuroscience Source Type: research