The transcription of the human UCP3 (uncoupling protein-3) gene in skeletal muscle is tightly regulated by metabolic signals related to fatty acid availability. However, changes in thyroid status also modulate UCP3 gene expression, albeit by unknown mechanisms. We created transgenic mice bearing the entire human UCP3 gene to investigate the effect of thyroid hormones on human UCP3 gene expression. Treatment of human UCP3 transgenic mice with thyroid hormones induced the expression of the human gene in skeletal muscle. In addition, transient transfection experiments demonstrate that thyroid hormones activate the transcription of the human UCP3 gene promoter when MyoD and the TR (thyroid hormone receptor) were co-transfected. The action of thyroid hormones on UCP3 gene transcription is mediated by the binding of the TR to a proximal region in the UCP3 gene promoter that contains a direct repeat structure. An intact DNA sequence of this site is required for thyroid hormone responsiveness and TR binding. Chromatin immunoprecipitation assays revealed that the TR binds this element in vivo. The murine Ucp3 gene promoter was also dependent on MyoD and responsive to thyroid hormone in transient transfection assays. However, it was much less sensitive to thyroid hormone than the human UCP3 promoter. In summary, UCP3 gene transcription is activated by thyroid hormone treatment in vivo, and this activation is mediated by a TRE (thyroid hormone response element) in the proximal promoter region. Such regulation suggests a link between UCP3 gene expression and the effects of thyroid hormone on mitochondrial function in skeletal muscle.
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http://dx.doi.org/10.1042/BJ20041073 | DOI Listing |
J Appl Physiol (1985)
December 2024
Center for Hyperbaric Medicine and Environmental Physiology, Department of Anesthesiology, Duke University School of Medicine, Durham, NC, 27710, USA.
Breathing hyperoxic gas is common in diving and accelerates fatigue after prolonged and repeated exposure. The mechanism(s) remain unknown but may be related to increased oxidants that interfere with skeletal muscle calcium trafficking or impair aerobic ATP production. To determine these possibilities, C57BL/6J mice were exposed to hyperbaric oxygen (HBO) for 4-h on three consecutive days or remained in room air.
View Article and Find Full Text PDFJ Cachexia Sarcopenia Muscle
February 2025
Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong.
Background: Cigarette smoking is known to affect muscle function and exercise capacity, including muscle fatigue resistance. Most studies showed diminished cross-sectional area and fibre type shifting in slow-twitch muscles such as the soleus, while effects on fast-twitch muscles were seldom reported and the differential responses between muscle types in response to exposure to cigarette smoke (CS) were largely unknown. This study aimed to elucidate the histomorphological, biochemical and transcriptomic changes induced by CS on both slow-twitch and fast-twitch muscles.
View Article and Find Full Text PDFAnim Biotechnol
November 2024
Animal and Poultry Production, Department of Animal Wealth Development, Faculty of Veterinary Medicine, Benha University, Toukh, Egypt.
Ginger rich in polyphenols, possesses various biomedical properties. Researchers investigated the effects of dietary ginger supplementation on turkey performance traits, biochemical parameters, haematological parameters and mRNA gene expression. Ginger root powder was administered at different doses (0, 10, 20 and 40 g/kg) to the turkeys.
View Article and Find Full Text PDFJ Comp Physiol B
October 2024
School of Life Sciences, Shandong University, No. 72 Binhai Road, Jimo District, Qingdao, Shandong Province, 266237, China.
Sports Med
October 2024
Institute for Health and Sport (iHeS), Victoria University, Melbourne, VIC, Australia.
Background: The growing interest in how exercise and carbohydrate (CHO) restriction may modify molecular responses that promote endurance adaptations has led to many interesting controversies.
Objective: We conducted a systematic review and a meta-analysis regarding the effect of low-carbohydrate availability (LOW) pre-, during, or post-exercise, on the mRNA content of commonly measured genes involved in mitochondrial biogenesis (PGC-1α, TFAM mRNA) and metabolism (PDK4, UCP3 and GLUT4 mRNA), and on muscle glycogen levels, compared with a high-CHO (CON) condition.
Methods: MEDLINE, Scopus, and Web of Science databases were searched following the PRISMA 2020 guidelines (with an end date of November 2023).
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