title: Transient receptor potential vanilloid 6 (TRPV6) in the mouse brain: Distribution and estrous cycle-related changes in the hypothalamus.
abstract: Transient receptor potential vanilloid (TRPV) subfamily of cationic channels have emerged as novel players in neural regulation. Unlike other members of TRPV subfamily, TRPV5 and TRPV6 are highly Ca2+-selective. Although TRPV5/TRPV6 transcripts are expressed in mouse brain, understanding the full functional spectrum of these ion channels in the brain is however limited due to the lack of information on their neuroanatomical distribution. We have studied TRPV6 in mouse brain in further detail. In the hypothalamus, while Western blot analysis using TRPV6 specific antiserum showed a distinct ∼95 kDa band corresponding to the molecular weight of TRPV6, transcripts for TRPV6 were detected with RT-PCR. TRPV6-immunoreactive cells/fibers were observed in vascular organ of the lamina terminalis, olfactory bulb, amygdala, hippocampus, septohypothalamic, supraoptic, arcuate (ARC), dorsomedial, and subincertal nuclei. TRPV6-immunoreactive cells/fibers were also observed in the brainstem and cerebellum. Estrogen has emerged as a potential regulator of TRPV6 in peripheral tissues. TRPV6 gene promoter contains estrogen-response element, estrogen activates TRPV6 via estrogen receptor alpha (ERα), and ERα-expressing ARC neurons in mediobasal hypothalamus (MBH) serve as primary site for estradiol feedback. Using double immunofluorescence, co-expression of TRPV6 and ERα was observed in several ARC neurons. MBH of mice during different phases of estrous cycle were subjected to Western blot analysis of TRPV6. Compared to proestrus, a significant reduction (P<0.01) in intensity of TRPV6-immunoreactive band was observed in MBH during metestrus and diestrus phases. While the wide distribution of TRPV6-expressing elements in the brain suggests its role in a range of CNS functions, the ion channel may serve as novel component of the neural pathway mediating effects of estradiol in MBH.
authors.affiliation: School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Odisha 752050, India; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India.
authors.forename: Santosh
authors.initials: S
authors.lastname: Kumar
authors.affiliation: School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Odisha 752050, India; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India.
authors.forename: Uday
authors.initials: U
authors.lastname: Singh
authors.affiliation: School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Odisha 752050, India; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India.
authors.forename: Omprakash
authors.initials: O
authors.lastname: Singh
authors.affiliation: School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Odisha 752050, India; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India.
authors.forename: Chandan
authors.initials: C
authors.lastname: Goswami
authors.affiliation: School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Odisha 752050, India; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India. Electronic address: pssingru@gmail.com.
authors.forename: Praful S
authors.initials: PS
authors.lastname: Singru
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D047628:Estrogen Receptor alpha / Q000378:metabolism; D030762:Estrous Cycle / Q000502:physiology; D005260:Female; D005455:Fluorescent Antibody Technique; D008297:Male; D008807:Mice, Inbred BALB C; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D017385:Sequence Homology; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D047628:Estrogen Receptor alpha; D050916:TRPV Cation Channels; C422827:TRPV6 protein, human; C446923:Trpv6 protein, mouse
keywords: TRPV6; brain; estrous cycle-related changes; hypothalamus; mouse