Transient receptor potential vanilloid 4 modulates ion balance through the isotocin pathway in zebrafish (Danio rerio)
Journal
American Journal of Physiology - Regulatory Integrative and Comparative Physiology
Journal Volume
318
Journal Issue
4
Pages
R751-R759
Date Issued
2020
Author(s)
Abstract
Isotocin controls ion regulation through modulating the functions of ionocytes (also called mitochondria-rich cells or chloride cells). However, little is known about the upstream molecule of the isotocin system. Herein, we identify transient receptor potential vanilloid 4 (TRPV4), which regulates the mRNA and protein expressions of isotocin and affects ion regulation through the isotocin pathway. Double immunohistochemical results showed that TRPV4 is expressed in isotocinergic neurons in the hypothalamus of the adult zebrafish brain. To further elucidate the roles of TRPV4, we manipulated TRPV4 protein expression and evaluated its ionoregulatory functions in zebrafish embryos. TRPV4 gene knockdown with morpholino oligonucleotides decreased ionic contents (Na+, Cl-, and Ca2+) of whole larvae and the H+-secreting function of larval skin of zebrafish. mRNA expressions of ionocyte-related transporters, including H+-ATPase, the epithelial Ca2+ channel, and the Na+-Cl- cotransporter, were also suppressed in trpv4 morphants. Numbers of ionocytes (H+-ATPase-rich cells and Na+K+-ATPase-rich cells) and epidermal stem cells in zebrafish larval skin also decreased after trpv4 knockdown. Our results showed that TRPV4 modulates ion balance through the isotocin pathway. Copyright ? 2020 the American Physiological Society
Subjects
calcium channel; calcium ion; chloride ion; ion; isotocin; messenger RNA; proton transporting adenosine triphosphatase; sodium chloride cotransporter; sodium ion; vanilloid receptor 4; calcium; chloride; isotocin; oxytocin; sodium; TRPV4 protein, zebrafish; vanilloid receptor; zebrafish protein; adult; animal cell; animal tissue; Article; brain nerve cell; cells by body anatomy; controlled study; embryo; epidermis cell; gene expression regulation; gene knockdown; hypothalamus; immunohistochemistry; ionocyte; isotocin gene; isotocinergic nerve cell; larva; nonhuman; priority journal; protein analysis; protein expression; protein function; skin secretion; stem cell; trpv4 gene; zebra fish; animal; electrolyte balance; genetics; ion transport; metabolism; nerve cell; physiology; transgenic animal; zebra fish; Animals; Animals, Genetically Modified; Calcium; Chlorides; Gene Expression Regulation; Ion Transport; Larva; Neurons; Oxytocin; Sodium; TRPV Cation Channels; Water-Electrolyte Balance; Zebrafish; Zebrafish Proteins
SDGs
Type
journal article