title: Modulation of telomerase activity in fish muscle by biological and environmental factors.
abstract: Telomerase expression has long been linked to promotion of tumor growth and cell proliferation in mammals. Interestingly, telomerase activity (TA) has been detected in skeletal muscle for a variety of fish species. Despite this being a unique feature in fish, very few studies have investigated the potential role of TA in muscle. The present study was set to prove the concepts that muscle telomerase in fish is related to body growth, and more specifically, to muscle cell proliferation and apoptosis in vivo. Moreover, muscle TA can be influenced by biotic factors and modulated by environmental stress. Using three fish species, mangrove red snapper (Lutjanus argentimaculatus), orange-spotted grouper (Epinephelus coioides), and marine medaka (Oryzias melastigma), the present work reports for the first time that fish muscle TA was sensitive to the environmental stresses of starvation, foodborne exposure to benzo[a]pyrene, and hypoxia. In marine medaka, muscle TA was coupled with fish growth during early life stages. Upon sexual maturation, muscle TA was confounded by sex (female>male). Muscle TA was significantly correlated with telomerase reverse transcriptase (TERT) protein expression (Pearson correlation r=0.892; p≤0.05), which was coupled with proliferating cell nuclear antigen (PCNA) cell proliferation, but not associated with apoptosis (omBax/omBcl2 ratio) in muscle tissue. The results reported here have bridged the knowledge gap between the existence and function of telomerase in fish muscle. The underlying regulatory mechanisms of muscle TA in fish warrant further exploration for comparison with telomerase regulation in mammals.
authors.affiliation: State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR.
authors.forename: Drew Ryan
authors.initials: DR
authors.lastname: Peterson
authors.affiliation: State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR.
authors.forename: Helen Oi Lam
authors.initials: HOL
authors.lastname: Mok
authors.affiliation: State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR; Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, Research Centre for the Oceans and Human Health, City University of Hong Kong, Shenzhen Research Institute, Shenzhen 518057, China. Electronic address: bhdwtau@cityu.edu.hk.
authors.forename: Doris Wai Ting
authors.initials: DWT
authors.lastname: Au
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D004777:Environment; D005260:Female; D005399:Fishes / Q000378:metabolism* / Q000502:physiology; D008297:Male; D009132:Muscles / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D019098:Telomerase / Q000378:metabolism*
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D019098:Telomerase
keywords: Growth; Mammals; Skeletal muscle; TERT; Teleost; Telomerase