Science Topics – 141

Unconventional role of voltage-gated proton channels in regulation of microglial ROS production

Takafumi Kawai (Yasushi Okamura)

Voltage gated proton channel (Hv1/VSOP) has been believed to support reactive oxygen species (ROS) production in a variety of immune cells including microglia by maintaining intracellular pH during respiratory burst. Here, we first found that Hv1/VSOP has also paradoxical suppressive role in microglial ROS production, which has not been observed in other types of cells. We also identified the mechanism underlying such suppressive function. Furthermore, the previous studies suggested that Hv1/VSOP enhances brain damage from ischemic stroke by supporting microglial ROS production. On the other hand, we found that such effect of Hv1/VSOP on infarct volume in brain ischemia depends on the age of animals. Taken together, some competitive regulatory mechanisms appear to underlie the function of Hv1/VSOP in microglial ROS production and such regulatory mechanisms may be differently controlled in different physiological conditions of animals in vivo.

Kawai T, Okochi Y, Ozaki T, Imura Y, Koizumi S, Yamazaki M, Abe M, Sakimura K, Yamashita T, Okamura Y.
Unconventional role of voltage-gated proton channels (Hv1/VSOP) in regulation of microglial ROS production.
J Neurochem. 2017 Sep;142(5):686-699

＜Figure Legends＞
We found that Hv1/VSOP has also paradoxical suppressive role in microglial ROS production.

Laboratory of Integrative Physiology, Graduate School of Medicine, Osaka University