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Transient receptor potential vanilloid 4 channel (TRPV4) tyrosine phosphorylation and membrane expression are affected by angiotensin II treatment
Author(s) -
Spear Martha,
Cunningham J. Thomas,
Carreno Flavia Regina
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.1080.3
Subject(s) - angiotensin ii , vasopressin , medicine , endocrinology , phosphorylation , western blot , tyrosine phosphorylation , chemistry , trpv4 , transient receptor potential channel , pharmacology , receptor , biochemistry , gene
Inappropriate vasopressin (AVP) release causes dilutional hyponatremia associated with heart and liver failure. Although the mechanisms that mediate inappropriate AVP release are not clear, plasma angiotensin II (angio II) has been implicated as a factor in the pathogenesis of dilutional hyponatremia. Our previous studies have shown that increased TRPV4 expression in vasopressinergic neurons and elevated circulating AVP were blunted by normalization of the renin angiotensin system. To examine the effects of direct angio II treatment upon TRPV4 we utilized the rat hypothalamic AVP expressing neuronal cell line IVB. Cells were treated with angio II, harvested, and subjected to cellular fractionation. Western Blot analysis showed significant (p<0.001) increased TRPV4 levels in crude membrane fractions of treated cells (2h, 1μM angio II) compared to vehicle controls. Angiotensin treated cells (2h, 1μM angio II) were harvest and immuprecipitated with the anti‐phosphotyrosine, recombinant 4G10TM. Western Blot analysis of the immunocomplexes revealed that tyrosine phosphorylation of TRPV4 was increased compared to vehicle treated cells (p<0.001). Our findings indicate that tyrosine phosphorylation and membrane sorting of TRPV4 are modulated by angiotensin in vitro. This represents a possible modulatory mechanism, which may underlie TRPV4 involvement in dilutional hyponatremia. R01 HL062576