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Yang R, Cao J, Speakman JR, Zhao Z. Limits to sustained energy intake. XXXIII. Thyroid hormones play important roles in milk production but do not define the heat dissipation limit in Swiss mice. J Exp Biol 2023; 226:jeb245393. [PMID: 37767758 DOI: 10.1242/jeb.245393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 09/22/2023] [Indexed: 09/29/2023]
Abstract
The limits to sustained energy intake set physiological upper boundaries that affect many aspects of human and animal performance. The mechanisms underlying these limits, however, remain unclear. We exposed Swiss mice to either supplementary thyroid hormones (THs) or the inhibitor methimazole during lactation at 21 or 32.5°C, and measured food intake, resting metabolic rate (RMR), milk energy output (MEO), serum THs and mammary gland gene expression of females, and litter size and mass of their offspring. Lactating females developed hyperthyroidism following exposure to supplementary THs at 21°C, but they did not significantly change body temperature, asymptotic food intake, RMR or MEO, and litter and mass were unaffected. Hypothyroidism, induced by either methimazole or 32.5°C exposure, significantly decreased asymptotic food intake, RMR and MEO, resulting in significantly decreased litter size and litter mass. Furthermore, gene expression of key genes in the mammary gland was significantly decreased by either methimazole or heat exposure, including gene expression of THs and prolactin receptors, and Stat5a and Stat5b. This suggests that endogenous THs are necessary to maintain sustained energy intake and MEO. Suppression of the thyroid axis seems to be an essential aspect of the mechanism by which mice at 32.5°C reduce their lactation performance to avoid overheating. However, THs do not define the upper limit to sustained energy intake and MEO at peak lactation at 21°C. Another, as yet unknown, factor prevents supplementary thyroxine exerting any stimulatory metabolic impacts on lactating mice at 21°C.
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Affiliation(s)
- Rui Yang
- College of Life and Environmental Science, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou 325035, China
| | - Jing Cao
- College of Life and Environmental Science, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou 325035, China
| | - John R Speakman
- Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Zhijun Zhao
- College of Life and Environmental Science, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou 325035, China
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Landaeta-Hernández AJ, Zambrano-Nava S, Verde O, Pinto-Santini L, Montero-Urdaneta M, Hernández-Fonseca JP, Fuenmayor-Morales C, Sonstegard TS, Huson HJ, Olson TA. Heat stress response in slick vs normal-haired Criollo Limonero heifers in a tropical environment. Trop Anim Health Prod 2021; 53:445. [PMID: 34427775 DOI: 10.1007/s11250-021-02856-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/09/2021] [Indexed: 12/01/2022]
Abstract
To assess the effect of hair type on the heat stress response, 20 Criollo Limonero heifers with slick (n = 11) or normal hair (n = 9) were studied. Under a high temperature-humidity index (THI) environment, heat stress response was assessed through physiological variables that included respiration rate (RR), heart rate (HR), ruminal frequency (RMF), rectal temperature (RT), saliva pH (SPH), and lymphocyte count (LC) in the morning (5:00 AM, 27.4 °C, 64% relative humidity, THI = 77) and afternoon (1:00 PM, 34.5 °C, 70% relative humidity, THI = 88). A case-control study using a split plot design was used. Data were analyzed using ANOVA (PROC MIXED SAS 2010) and a statistical model comprising the fixed effects of hair length, sampling hour, interaction of hair length by sampling hour, and the random effect of animal nested within hair type on physiological variables associated with heat stress response. Sampling hour influenced (P < 0.0001) RR, RT, and (P < 0.003) SPH. Hair length influenced RR (P < 0.01) and RT (P < 0.04) and tended to influence LC (P < 0.07). The interaction of sampling hour by hair influenced RR (P < 0.04), RT (P < 0.0002), and both SPH and LC (P < 0.05). During afternoon hours, slick-haired heifers had lower values for RR (81 ± 4.2 vs 102 ± 4.7 bpm; P < 0.01), RT (39.5 ± 0.1 vs 40.3 ± 0.1 C°; P < 0.002), and LC (60 ± 3.2 vs 72.3 ± 3.6; P < 0.09) than normal-haired heifers. In normal-haired heifers, SPH increased during afternoon compared to morning-hours (8.66 ± 0.1 vs 9.11 ± 0.1; P < 0.04). It was concluded that slick-coated heifers exhibited an enhanced capability to cope with heat stress compared to normal-haired heifers likely due to an enhanced capacity for heat dissipation.
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Affiliation(s)
- A J Landaeta-Hernández
- Universidad del Zulia, Facultad de Ciencias Veterinarias, Unidad de Investigaciones Zootécnicas (UNIZ), Maracaibo, Venezuela.
| | - S Zambrano-Nava
- Universidad del Zulia, Facultad de Ciencias Veterinarias, Unidad de Investigaciones Zootécnicas (UNIZ), Maracaibo, Venezuela.,Instituto Nacional de Investigaciones Agrícolas (INIA), Maracaibo, Venezuela
| | - O Verde
- Facultad de Ciencias Veterinarias, Universidad Central de Venezuela, Maracay, Venezuela
| | - L Pinto-Santini
- Facultad de Veterinaria, Universidad de La República, Montevideo, Uruguay
| | - M Montero-Urdaneta
- Universidad del Zulia, Facultad de Ciencias Veterinarias, Unidad de Investigaciones Zootécnicas (UNIZ), Maracaibo, Venezuela
| | - J P Hernández-Fonseca
- Facultad de Medicina, Unidad de Investigaciones Clínicas Dr. Américo Negrette, Universidad del Zulia, Maracaibo, Venezuela
| | - C Fuenmayor-Morales
- Universidad del Zulia, Facultad de Ciencias Veterinarias, Unidad de Investigaciones Zootécnicas (UNIZ), Maracaibo, Venezuela
| | - T S Sonstegard
- Acceligen of Recombinetics Inc, 3388 Mike Collins Drive, Eagan, MN, USA
| | - H J Huson
- Department of Animal Sciences, University of Cornell, Ithaca, NY, USA
| | - T A Olson
- Department of Animal Sciences, University of Florida, P.O. Box 110920, Gainesville, FL, 32611-0910, USA
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Abstract
The present review traces the road leading to discovery of L-thyroxine, thyroid hormone (3,5,3´-triiodo-L-thyronine, T3) and its cognate nuclear receptors. Thyroid hormone is a pleio-tropic regulator of growth, differentiation, and tissue homeostasis in higher organisms. The major site of the thyroid hormone action is predominantly a cell nucleus. T3 specific binding sites in the cell nuclei have opened a new era in the field of the thyroid hormone receptors (TRs) discovery. T3 actions are mediated by high affinity nuclear TRs, TRalpha and TRbeta, which function as T3-activated transcription factors playing an essential role as transcription-modulating proteins affecting the transcriptional responses in target genes. Discovery and characterization of nuclear retinoid X receptors (RXRs), which form with TRs a heterodimer RXR/TR, positioned RXRs at the epicenter of molecular endocrinology. Transcriptional control via nuclear RXR/TR heterodimer represents a direct action of thyroid hormone. T3 plays a crucial role in the development of brain, it exerts significant effects on the cardiovascular system, skeletal muscle contractile function, bone development and growth, both female and male reproductive systems, and skin. It plays an important role in maintaining the hepatic, kidney and intestine homeostasis and in pancreas, it stimulates the beta-cell proliferation and survival. The TRs cross-talk with other signaling pathways intensifies the T3 action at cellular level. The role of thyroid hormone in human cancers, acting via its cognate nuclear receptors, has not been fully elucidated yet. This review is aimed to describe the history of T3 receptors, starting from discovery of T3 binding sites in the cell nuclei to revelation of T3 receptors as T3-inducible transcription factors in relation to T3 action at cellular level. It also focuses on milestones of investigation, comprising RXR/TR dimerization, cross-talk between T3 receptors, and other regulatory pathways within the cell and mainly on genomic action of T3. This review also focuses on novel directions of investigation on relationships between T3 receptors and cancer. Based on the update of available literature and the author's experimental experience, it is devoted to clinicians and medical students.
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Chemical and Hormonal Effects on STAT5b-Dependent Sexual Dimorphism of the Liver Transcriptome. PLoS One 2016; 11:e0150284. [PMID: 26959237 PMCID: PMC4784907 DOI: 10.1371/journal.pone.0150284] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 02/11/2016] [Indexed: 12/21/2022] Open
Abstract
The growth hormone (GH)-activated transcription factor signal transducer and activator of transcription 5b (STAT5b) is a key regulator of sexually dimorphic gene expression in the liver. Suppression of hepatic STAT5b signaling is associated with lipid metabolic dysfunction leading to steatosis and liver cancer. In the companion publication, a STAT5b biomarker gene set was identified and used in a rank-based test to predict both increases and decreases in liver STAT5b activation status/function with high (≥ 97%) accuracy. Here, this computational approach was used to identify chemicals and hormones that activate (masculinize) or suppress (feminize) STAT5b function in a large, annotated mouse liver and primary hepatocyte gene expression compendium. Exposure to dihydrotestosterone and thyroid hormone caused liver masculinization, whereas glucocorticoids, fibroblast growth factor 15, and angiotensin II caused liver feminization. In mouse models of diabetes and obesity, liver feminization was consistently observed and was at least partially reversed by leptin or resveratrol exposure. Chemical-induced feminization of male mouse liver gene expression profiles was a relatively frequent phenomenon: of 156 gene expression biosets from chemically-treated male mice, 29% showed feminization of liver STAT5b function, while <1% showed masculinization. Most (93%) of the biosets that exhibited feminization of male liver were also associated with activation of one or more xenobiotic-responsive receptors, most commonly constitutive activated receptor (CAR) or peroxisome proliferator-activated receptor alpha (PPARα). Feminization was consistently associated with increased expression of peroxisome proliferator-activated receptor gamma (Pparg) but not other lipogenic transcription factors linked to steatosis. GH-activated STAT5b signaling in mouse liver is thus commonly altered by diverse chemicals, and provides a linkage between chemical exposure and dysregulated gene expression associated with adverse effects on the liver.
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Park SH, Wiwi C, Waxman D. Signalling cross-talk between hepatocyte nuclear factor 4alpha and growth-hormone-activated STAT5b. Biochem J 2006; 397:159-68. [PMID: 16584384 PMCID: PMC1479742 DOI: 10.1042/bj20060332] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In the present study, we have characterized signalling cross-talk between STAT5b (signal transducer and activator of transcription 5b) and HNF4alpha (hepatocyte nuclear factor 4alpha), two major regulators of sex-dependent gene expression in the liver. In a HepG2 liver cell model, HNF4alpha strongly inhibited beta-casein and ntcp (Na+/taurocholate cotransporting polypeptide) promoter activity stimulated by GH (growth hormone)-activated STAT5b, but had no effect on interferon-gamma-stimulated STAT1 transcriptional activity. By contrast, STAT5b synergistically enhanced the transcriptional activity of HNF4alpha towards the ApoCIII (apolipoprotein CIII) promoter. The inhibitory effect of HNF4alpha on STAT5b transcription was associated with the inhibition of GH-stimulated STAT5b tyrosine phosphorylation and nuclear translocation. The short-chain fatty acid, butyrate, reversed STAT5b transcriptional inhibition by HNF4alpha, but did not reverse the inhibition of STAT5b tyrosine phosphorylation. HNF4alpha inhibition of STAT5b tyrosine phosphorylation was not reversed by pervanadate or by dominant-negative phosphotyrosine phosphatase 1B, suggesting that it does not result from an increase in STAT5b dephosphorylation. Rather, HNF4alpha blocked GH-stimulated tyrosine phosphorylation of JAK2 (Janus kinase 2), a STAT5b tyrosine kinase. Thus STAT5b and HNF4alpha exhibit bi-directional cross-talk that may augment HNF4alpha-dependent gene transcription while inhibiting STAT5b transcriptional activity via the inhibitory effects of HNF4alpha on JAK2 phosphorylation, which leads to inhibition of STAT5b signalling initiated by the GH receptor at the cell surface.
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Affiliation(s)
- Soo-Hee Park
- Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, MA 02215, U.S.A
| | - Christopher A. Wiwi
- Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, MA 02215, U.S.A
| | - David J. Waxman
- Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, MA 02215, U.S.A
- To whom correspondence should be addressed (email )
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Yamashita H, Iwase H, Toyama T, Fujii Y. Naturally occurring dominant-negative Stat5 suppresses transcriptional activity of estrogen receptors and induces apoptosis in T47D breast cancer cells. Oncogene 2003; 22:1638-52. [PMID: 12642867 DOI: 10.1038/sj.onc.1206277] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Signal transducer and activator of transcription (Stat) 5 regulates growth, differentiation, and survival of mammary and hematopoietic cells. The role of Stat5 in breast cancer has not been established, although Stat5 is critical for some hematopoietic malignancies. We detected for the first time that Stat5b is constitutively activated in human breast cancer cell lines, and analysed the role of Stat5 in estrogen receptor(ER)-positive breast cancer cell lines using dominant-negative variants of Stat5. Two distinct carboxyl-truncated Stat5a derivatives were generated. Stat5aDelta740 corresponded to a naturally occurring alternative splice variant, and Stat5aDelta713 was analogous to an 80 kDa Stat5a product of a nuclear protease. Stat5aDelta740 and Stat5aDelta713 displayed comparable dominant-negative properties and suppressed transcriptional activity of wild-type Stat5a and Stat5b equally well. Cotransfection experiments revealed that Stat5aDelta740 completely blocked transcriptional activity of endogenous estrogen receptor in T47D and MCF7 cells, and of both ER alpha and ER beta in COS-7 cells. Stat5aDelta740 was selected for adenoviral delivery, and high-efficiency expression of tyrosine phosphorylated Stat5aDelta740 was achieved in infected cells. Adenoviral-mediated Stat5aDelta740 induced apoptosis in T47D cells but not in caspase-3-negative MCF7 cells. The present study indicates that overexpression of a dominant-negative variant of Stat5 suppresses ER transcriptional activity and induces apoptosis in estrogen-responsive breast cancer tissue culture cells.
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Affiliation(s)
- Hiroko Yamashita
- Department of Surgery II, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
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