| First Author | Benfenati V | Year | 2011 |
| Journal | Proc Natl Acad Sci U S A | Volume | 108 |
| Issue | 6 | Pages | 2563-8 |
| PubMed ID | 21262839 | Mgi Jnum | J:169095 |
| Mgi Id | MGI:4939848 | Doi | 10.1073/pnas.1012867108 |
| Citation | Benfenati V, et al. (2011) An aquaporin-4/transient receptor potential vanilloid 4 (AQP4/TRPV4) complex is essential for cell-volume control in astrocytes. Proc Natl Acad Sci U S A 108(6):2563-8 |
| abstractText | Regulatory volume decrease (RVD) is a key mechanism for volume control that serves to prevent detrimental swelling in response to hypo-osmotic stress. The molecular basis of RVD is not understood. Here we show that a complex containing aquaporin-4 (AQP4) and transient receptor potential vanilloid 4 (TRPV4) is essential for RVD in astrocytes. Astrocytes from AQP4-KO mice and astrocytes treated with TRPV4 siRNA fail to respond to hypotonic stress by increased intracellular Ca(2+) and RVD. Coimmunoprecipitation and immunohistochemistry analyses show that AQP4 and TRPV4 interact and colocalize. Functional analysis of an astrocyte-derived cell line expressing TRPV4 but not AQP4 shows that RVD and intracellular Ca(2+) response can be reconstituted by transfection with AQP4 but not with aquaporin-1. Our data indicate that astrocytes contain a TRPV4/AQP4 complex that constitutes a key element in the brain's volume homeostasis by acting as an osmosensor that couples osmotic stress to downstream signaling cascades. |
