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Angiotensin II increases Transient Receptor Potential Vanilloid 4 channel Expression and Phosphorylation in Hypothalamic Cell line 4B
Author(s) -
Saxena Ashwini,
Nedungadi Thekkethil Prashant,
Carreno Flavia,
Bachelor Martha,
Cunningham J. Thomas
Publication year - 2012
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.26.1_supplement.1104.2
Subject(s) - trpv4 , western blot , angiotensin ii , vasopressin , chemistry , medicine , transient receptor potential channel , endocrinology , phosphorylation , in vitro , messenger rna , tyrosine hydroxylase , immunohistochemistry , receptor , microbiology and biotechnology , biology , biochemistry , gene
We have previously demonstrated that in bile duct ligated rats, an animal model of inappropriate vasopressin (AVP) release, TRPV4 protein expression and membrane trafficking is increased in AVP neurons. Here, we used an in vitro approach with an immortalized AVP expressing cell line (4B cells) to investigate the possible regulation of TRPV4 by angiotensin II (Ang II), utilizing real‐time polymerase chain reaction (RT‐PCR), Western Blot (WB) and immunohistochemistry (IHC). We have characterized, for the first time, the presence of TRPV4 mRNA and protein 4B cells. After Ang II (1μM;1 hr) treatment, TRPV4 mRNA increased nearly 5‐ fold (Control vs. Ang II; 1.12±0.28 vs. 4.98±0.65; p<0.001). We noted increased TRPV4 immunoreactivity after 1 and 2 hours of Ang II treatment. Western Blot analysis showed significantly (p<0.001) increased TRPV4 levels in crude membrane fractions of Ang II treated cells compared to vehicle controls. Also, WB analysis revealed increased tyrosine phosphorylation of TRPV4 following Ang II treatment as compared to vehicle treated cells (p<0.001). Thus, 4B cells may be an appropriate in vitro model to investigate the translational and posttranslational regulation of TRPV4 in hypothalamic neurons.