title: Human skeletal dysplasia caused by a constitutive activated transient receptor potential vanilloid 4 (TRPV4) cation channel mutation.
abstract: The transient receptor potential vanilloid 4 (TRPV4) cation channel, a member of the TRP vanilloid subfamily, is expressed in a broad range of tissues where it participates in the generation of Ca²⁺ signals and/or depolarization of the membrane potential. Regulation of TRPV4 abundance at the cell surface is critical for osmo- and mechanotransduction. Defects in TRPV4 are the cause of several human diseases, including brachyolmia type 3 (MIM:113500) (also known as brachyrachia or spondylometaphyseal dysplasia Kozlowski type [MIM:118452]), and metatropic dysplasia (MIM:156530) (also called metatropic dwarfism or parastremmatic dwarfism [MIM:168400]). These bone dysplasia mutants are characterized by severe dwarfism, kyphoscoliosis, distortion and bowing of the extremities, and contractures of the large joints. These diseases are characterized by a combination of decreased bone density, bowing of the long bones, platyspondyly, and striking irregularities of endochondral ossification with areas of calcific stippling and streaking in radiolucent epiphyses, metaphyses, and apophyses. In this review, we discuss the potential effect of the mutation on the regulation of TRPV4 functions, which are related to human diseases through deviated function. In particular, we emphasize how the constitutive active TRPV4 mutant affects endochondral ossification with a reduced number of hypertrophic chondrocytes and the presence of cartilage islands within the zone of primary mineralization. In addition, we summarize current knowledge about the role of TRPV4 in the pathogenesis of several diseases.
authors.affiliation: Department of Biology Education Chungbuk National University Cheongju 361-763, Korea. jin95324@cbu.ac.kr
authors.forename: Sang Sun
authors.initials: SS
authors.lastname: Kang
authors.forename: Sung Hwa
authors.initials: SH
authors.lastname: Shin
authors.forename: Chung-Kyoon
authors.initials: CK
authors.lastname: Auh
authors.forename: Jaesun
authors.initials: J
authors.lastname: Chun
mesh_terms: D006801:Humans; D009154:Mutation; D010009:Osteochondrodysplasias / Q000235:genetics*; D010012:Osteogenesis / Q000235:genetics; D050916:TRPV Cation Channels / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D050916:TRPV Cation Channels; C416986:TRPV4 protein, human