51
|
Liang X, Pan J, Cao C, Zhang L, Zhao Y, Fan Y, Li K, Tao C, Wang Y. Transcriptional Response of Subcutaneous White Adipose Tissue to Acute Cold Exposure in Mice. Int J Mol Sci 2019; 20:ijms20163968. [PMID: 31443159 PMCID: PMC6720191 DOI: 10.3390/ijms20163968] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 08/09/2019] [Accepted: 08/13/2019] [Indexed: 02/06/2023] Open
Abstract
Beige adipose tissue has been considered to have potential applications in combating obesity and its related metabolic diseases. However, the mechanisms of acute cold-stimulated beige formation still remain largely unknown. Here, transcriptional analysis of acute cold-stimulated (4 °C for 4 h) subcutaneous white adipose tissue (sWAT) was conducted to determine the molecular signatures that might be involved in beige formation. Histological analysis confirmed the appearance of beige adipocytes in acute cold-treated sWAT. The RNA-sequencing data revealed that 714 genes were differentially expressed (p-value < 0.05 and fold change > 2), in which 221 genes were upregulated and 493 genes were downregulated. Gene Ontology (GO) analyses showed that the upregulated genes were enriched in the GO terms related to lipid metabolic process, fatty acid metabolic process, lipid oxidation, fatty acid oxidation, etc. In contrast, downregulated genes were assigned the GO terms of regulation of immune response, regulation of response to stimulus, defense response, etc. The expressions of some browning candidate genes were validated in cold-treated sWAT and 3T3-L1 cell browning differentiation. In summary, our results illustrated the transcriptional response of sWAT to acute cold exposure and identified the genes, including Acad11, Cyp2e1, Plin5, and Pdk2, involved in beige adipocyte formation in mice.
Collapse
Affiliation(s)
- Xiaojuan Liang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Jianfei Pan
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Chunwei Cao
- State Key Laboratory of Stem Cell and Reproductive Biology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Lilan Zhang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Ying Zhao
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Yiping Fan
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Kui Li
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, 100193 Beijing, China
| | - Cong Tao
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, 100193 Beijing, China.
| | - Yanfang Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, 100193 Beijing, China.
| |
Collapse
|
52
|
Gaudry MJ, Keuper M, Jastroch M. Molecular evolution of thermogenic uncoupling protein 1 and implications for medical intervention of human disease. Mol Aspects Med 2019; 68:6-17. [DOI: 10.1016/j.mam.2019.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 06/20/2019] [Accepted: 06/21/2019] [Indexed: 12/12/2022]
|
53
|
Intraperitoneal administration of follistatin promotes adipocyte browning in high-fat diet-induced obese mice. PLoS One 2019; 14:e0220310. [PMID: 31365569 PMCID: PMC6668797 DOI: 10.1371/journal.pone.0220310] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 07/12/2019] [Indexed: 11/19/2022] Open
Abstract
With rapid economic development, the prevalence of obesity has increased remarkably worldwide. Obesity can induce a variety of metabolic diseases, such as atherosclerosis, diabetes, hypertension and coronary heart disease, which significantly endanger the health and welfare of individuals. Brown and beige fat tissues play an important role in thermogenesis in mammals. Recent studies have shown that follistatin (FST) can potentially induce the browning of white adipose tissue (WAT). In this study, high-fat diet-induced obese mice were injected with follistatin for one week to explore the effects of follistatin on browning and metabolism and to determine the mechanism. The results showed that follistatin suppressed obesity caused by a high-fat diet and increased insulin sensitivity, energy expenditure, and subcutaneous fat browning. The beneficial effects remained even after a period of withdrawal. Follistatin promoted secretion of irisin from subcutaneous fat via the AMPK-PGC1α-irisin signal pathway, which induces browning of WAT, and activated the insulin pathway in beige fat thereby promoting metabolism.
Collapse
|
54
|
Shen B, Han S, Wang Y, Yang Z, Zou Z, Liu J, Zhao Z, Wu R, Wang C. Bta-miR-152 affects intracellular triglyceride content by targeting the UCP3 gene. J Anim Physiol Anim Nutr (Berl) 2019; 103:1365-1373. [PMID: 31355500 DOI: 10.1111/jpn.13162] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/26/2019] [Accepted: 06/27/2019] [Indexed: 12/27/2022]
Abstract
According to our previous studies, bta-miR-152, PRKAA1 and UCP3 are differentially expressed in mammary gland tissues of high milk fat and low milk fat cows, and the trend in bta-miR-152 expression is opposite from those of PRKAA1 and UCP3. To further identify the function and regulatory mechanism of bta-miR-152 in milk fat metabolism, we investigated the effect of bta-miR-152 on cellular triglyceride content in bovine mammary epithelial cells cultured in vitro, on the basis of bta-miR-152 overexpression and inhibition assays. The target genes of bta-miR-152 were identified through qPCR, Western blotting and dual luciferase reporter gene detection. Compared with that in the control group, the expression of UCP3 was significantly lower in the bta-miR-152 mimic group, the expression of PRKAA1 was decreased, and the intracellular TAG content was significantly increased. After transfection with bta-miR-152 inhibitor, the expression of UCP3 increased significantly, and the expression of PRKAA1 decreased, but the difference was not significant; in addition, the intracellular TAG content decreased significantly. Therefore, we concluded that bta-miR-152 affects the intracellular TAG content by targeting UCP3.
Collapse
Affiliation(s)
- Binglei Shen
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Shuo Han
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Yuxuan Wang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Zhuonina Yang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Ziwen Zou
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Juan Liu
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Zhihui Zhao
- Agricultural College, Guangdong Ocean University, Zhanjiang, China
| | - Rui Wu
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Changyuan Wang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, China
| |
Collapse
|
55
|
Adipose lipidomics and RNA-Seq analysis revealed the enhanced mitochondrial function in UCP1 knock-in pigs. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1375-1383. [PMID: 31271850 DOI: 10.1016/j.bbalip.2019.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 05/31/2019] [Accepted: 06/28/2019] [Indexed: 11/24/2022]
Abstract
Uncoupling protein 1 (UCP1) plays a key role in nonshivering thermogenesis and is involved in the pathogenesis of obesity. In a previous study, we generated adipocyte-specific UCP1 knock-in (UCP1-KI) pigs, which exhibited improved thermoregulatory ability and decreased fat deposition. To investigate whether UCP1 knock-in alters the lipid composition of adipose tissues, lipidomics of inguinal subcutaneous white adipose tissue (iWAT) and backfat from 6-month-old cold-treated UCP1-KI pigs and wild-type (WT) pigs were profiled. In addition, genome-wide RNA-sequencing of iWAT was performed to further study the genetic basis for lipid alterations. The results showed that iWAT and backfat from UCP1-KI pigs exhibited distinct lipidomic profiles, as the mild lipid alteration was observed in backfat of UCP1 knock-in pigs. Inguinal WAT from UCP1-KI pigs contained significantly decreased total triacylglycerol (p < 0.05), together with the downregulation of genes involved in fatty acid metabolism, suggesting the decreased lipogenesis in iWAT of UCP1-KI pigs. Significantly increased levels of total sphingolipids (p<0.05) were also observed in iWAT from UCP1-KI pigs. Notably, two mitochondrial-specific lipid species, cardiolipin CL72:8 (18:2) and CL74:9 (18:2), were found to be dramatically increased in iWAT from UCP1-KI pigs, suggesting enhanced mitochondrial function. This observation was further supported by the significant upregulation of numerous mitochondrial-related genes and significantly increased number of large mitochondria and mitochondrial cristae in iWAT of UCP1-KI pigs. Taken together, these data illustrate the specific role of UCP1 in lipid metabolism of fat tissues in pigs and provide new data for characterization of fat traits in UCP1-KI pigs.
Collapse
|
56
|
PRDM16 Represses the Pig White Lipogenesis through Promoting Lipolysis Activity. BIOMED RESEARCH INTERNATIONAL 2019; 2019:1969413. [PMID: 31312653 PMCID: PMC6595380 DOI: 10.1155/2019/1969413] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 05/27/2019] [Indexed: 12/12/2022]
Abstract
The positive regulatory domain containing 16 (PRDM16) gene is a dominant transcriptional regulator that favors the “browning” of white adipocytes in rodents. Since the “browning” of white fat is important in pig in terms of producing heat fighting against cold environment, avoiding obesity, and improving meat quality, understanding the critical role that PRDM16 gene played in pig adipose “browning” and energy metabolism is of great significance. However, the constitution of pig fat differs a lot from rodents and human as they do not have brown adipose tissue (BAT) even in the newborn piglets. In this study, we isolated porcine primary preadipocytes and investigated the function of PRDM16 during preadipocytes differentiation. Our results showed that overexpression of the PR domain of PRDM16 repressed the differentiation of porcine preadipocytes, indicated by oil red O staining and the deposition of the triglyceride. Overexpression of the PR domain significantly increased the level of lipolysis and mitochondrial oxidative capacity detected by Western blotting during differentiation. Furthermore, we purified the protein coded by the PR domain and demonstrated that this protein has the H3K9me1 methyltransferase activity. In conclusion, the PR domain of the porcine PRDM16 gene repressed the mature of the porcine preadipocytes by promoting its oxidative activity.
Collapse
|
57
|
Abstract
Muscle nonshivering thermogenesis (NST) was recently suggested to play an important role in thermoregulation of species lacking brown adipose tissue (BAT). The mechanism, which is independent of muscle contractions, produces heat based on the activity of an ATPase pump in the sarcoplasmic reticulum (SERCA1a) and is controlled by the protein sarcolipin. To evaluate whether muscle NST could indeed play an important role in thermoregulation in species lacking BAT, we investigated the thermogenic capacities of newborn wild boar piglets. During cold exposure over the first 5 days of life, total heat production was improved while shivering intensity decreased, indicating an increasing contribution of NST. Sampling skeletal muscle tissue for analyses of SERCA activity as well as gene expression of SERCA1a and sarcolipin, we found an age-related increase in all three variables as well as in body temperature. Hence, the improved thermogenesis during the development of wild boars is not due to shivering but explained by the observed increase in SERCA activity. Our results suggest that muscle NST may be the primary mechanism of heat production during cold stress in large mammals lacking BAT, strengthening the hypothesis that muscle NST has likely played an important role in the evolution of endothermy.
Collapse
|
58
|
Lin R, Lin W, Chen Q, Huo J, Hu Y, Ye J, Xu J, Xiao T. Gene expression and promoter methylation of porcine uncoupling protein 3 gene. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2018; 32:170-175. [PMID: 30056670 PMCID: PMC6325394 DOI: 10.5713/ajas.18.0116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/27/2018] [Indexed: 12/02/2022]
Abstract
Objective Uncoupling protein 3 gene (UCP3) is a candidate gene associated with the meat quality of pigs. The aim of this study was to explore the regulation mechanism of UCP3 expression and provide a theoretical basis for the research of the function of porcine UCP3 gene in meat quality. Methods Bisulfite sequencing polymerase chain reaction (PCR) and quantitative real-time PCR (Q-PCR) were used to analyze the methylation of UCP3 5′-flanking region and UCP3 mRNA expression in the adipose tissue or skeletal muscle of three pig breeds at different ages (1, 90, 210-day-old Putian Black pig; 90-day-old Duroc; and 90-day-old Dupu). Results Results showed that two cytosine-guanine dinucleotide (CpG) islands are present in the promoter region of porcine UCP3 gene. The second CpG island located in the core promoter region contained 9 CpG sites. The methylation level of CpG island 2 was lower in the adipose tissue and skeletal muscle of 90-day-old Putian Black pigs compared with 1-day-old and 210-day-old Putian Black pigs, and the difference also existed in the skeletal muscle among the three 90-day-old pig breeds. Furthermore, the obvious changing difference of UCP3 mRNA expression was observed in the skeletal muscle of different groups. However, the difference of methylation status and expression level of UCP3 gene was not significant in the adipose tissue. Conclusion Our data indicate that UCP3 mRNA expression level was associated with the methylation status of UCP3 promoter in the skeletal muscle of pigs.
Collapse
Affiliation(s)
- Ruiyi Lin
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Weimin Lin
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Qiaohui Chen
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Jianchao Huo
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Yuping Hu
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Junxiao Ye
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Jingya Xu
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Tianfang Xiao
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| |
Collapse
|
59
|
Fuller-Jackson JP, Henry BA. Adipose and skeletal muscle thermogenesis: studies from large animals. J Endocrinol 2018; 237:R99-R115. [PMID: 29703782 DOI: 10.1530/joe-18-0090] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 04/05/2018] [Indexed: 12/30/2022]
Abstract
The balance between energy intake and energy expenditure establishes and preserves a 'set-point' body weight. The latter is comprised of three major components including metabolic rate, physical activity and thermogenesis. Thermogenesis is defined as the cellular dissipation of energy via heat production. This process has been extensively characterised in brown adipose tissue (BAT), wherein uncoupling protein 1 (UCP1) creates a proton leak across the inner mitochondrial membrane, diverting protons away from ATP synthesis and resulting in heat dissipation. In beige adipocytes and skeletal muscle, thermogenesis can occur independent of UCP1. Beige adipocytes have been shown to produce heat via UCP1 as well as via both futile creatine and calcium cycling pathways. On the other hand, the UCP1 homologue UCP3 is abundant in skeletal muscle and post-prandial thermogenesis has been associated with UCP3 and the futile calcium cycling. This review will focus on the differential contributions of adipose tissue and skeletal muscle in determining total thermogenic output and energy expenditure in large mammals. Sheep and pigs do not have a circumscribed brown fat depot but rather possess white fat depots that contain brown and beige adipocytes interspersed amongst white adipose tissue. This is representative of humans, where brown, beige and white adipocytes have been identified in the neck and supraclavicular regions. This review will describe the mechanisms of thermogenesis in pigs and sheep and the relative roles of skeletal muscle and adipose tissue thermogenesis in controlling body weight in larger mammals.
Collapse
Affiliation(s)
| | - Belinda A Henry
- Metabolism, Diabetes and Obesity Program, Monash Biomedicine Discovery Institute, Department of Physiology, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
60
|
Jin S, Yang L, He T, Fan X, Wang Y, Ge K, Geng Z. Polymorphisms in the uncoupling protein 3 gene and their associations with feed efficiency in chickens. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2018; 31:1401-1406. [PMID: 29879809 PMCID: PMC6127571 DOI: 10.5713/ajas.18.0217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 05/29/2018] [Indexed: 01/08/2023]
Abstract
Objective The uncoupling protein 3 (UCP3) is a member of the mitochondrial anion carrier superfamily and has crucial effects on growth and feed efficiency in many species. Therefore, the objective of the present study was to examine the association of polymorphisms in the UCP3 gene with feed efficiency in meat-type chickens. Methods Six single nucleotide polymorphisms (SNPs) of the UCP3 gene were chosen to be genotyped using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry in meat-type chicken populations with 724 birds in total. Body weight at 49 (BW49) and 70 days of age (BW70) and feed intake (FI) in the interval were collected, then body weight gain (BWG) and feed conversion ratio (FCR) were calculated individually. Results One SNP with a low minor allele frequency (<1%) was removed by quality control and data filtering. The results showed that rs13997809 of UCP3 was significantly associated with BWG and FCR (p<0.05), and that rs13997811 had significant effects on BW70 and BWG (p<0.05). Rs13997812 of UCP3 was strongly associated with BW70, FI, and FCR (p<0.05). Furthermore, individuals with AA genotype of rs13997809 had significantly higher BWG and lower FCR (p<0.05) than those with AT genotype. The GG individuals showed strongly higher BW70 and BWG than AA birds in rs13997811 (p<0.05). Birds with the TT genotype of rs13997812 had significantly greater BW70 and lower FCR compared with the CT birds (p<0.05). In addition, the TAC haplotype based on rs13997809, rs13997811, and rs13997812 showed significant effects on BW70, FI, and FCR (p<0.05). Conclusion Our results therefore demonstrate important roles for UCP3 polymorphisms in growth and feed efficiency that might be used in meat-type chicken breeding programs.
Collapse
Affiliation(s)
- Sihua Jin
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China
| | - Lei Yang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China
| | - Tingting He
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China
| | - Xinfeng Fan
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China
| | - Yiqiu Wang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China
| | - Kai Ge
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China
| | - Zhaoyu Geng
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China
| |
Collapse
|
61
|
Jastroch M, Oelkrug R, Keipert S. Insights into brown adipose tissue evolution and function from non-model organisms. ACTA ACUST UNITED AC 2018. [PMID: 29514888 DOI: 10.1242/jeb.169425] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Brown adipose tissue (BAT) enables adaptive thermoregulation through heat production that is catalyzed by mitochondrial uncoupling protein 1 (UCP1). BAT is frequently studied in rodent model organisms, and recently in adult humans to treat metabolic diseases. However, complementary studies of many non-model species, which have diversified to many more ecological niches, may significantly broaden our understanding of BAT regulation and its physiological roles. This Review highlights the research on non-model organisms, which was instrumental to the discovery of BAT function, and the unique evolutionary history of BAT/UCP1 in mammalian thermogenesis. The comparative biology of BAT provides a powerful integrative approach that could identify conserved and specialized functional changes in BAT and UCP1 by considering species diversity, ecology and evolution, and by fusing multiple scientific disciplines such as physiology and biochemistry. Thus, resolving the complete picture of BAT biology may fail if comparative studies of non-model organisms are neglected.
Collapse
Affiliation(s)
- Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, D-85764 Neuherberg, Germany .,German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany.,Department of Animal Physiology, Faculty of Biology, Philipps University of Marburg, D-35032 Marburg, Germany
| | - Rebecca Oelkrug
- Department of Molecular Endocrinology, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23562 Lübeck, Germany
| | - Susanne Keipert
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, D-85764 Neuherberg, Germany.,German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany
| |
Collapse
|
62
|
Abstract
Brown adipose tissue (BAT), the specialized heat-producing organ found in many placental mammals including humans, may be accessible for clinical drug intervention to help combat metabolic diseases. Understanding the biology of BAT and its thermogenic uncoupling protein 1 (UCP1) will benefit from an assessment of its evolution, answering where UCP1 originated and how it has been modified and integrated into cellular energy metabolism. Here, we review topical insights regarding the molecular evolution of UCP1-also reconstructing the proximate and ultimate factors selecting for brown fat thermogenesis in placental mammals. This new thinking on "old" events will assist our understanding of how thermogenic mitochondrial uncoupling was integrated into the physiology of the brown adipocyte. Recent comparative studies examining the occurrence of UCP1 in vertebrates not only identified the ancient (pre-mammal) rise of UCP1 but also its repeated downfall during mammalian evolution as evidenced by multiple independent gene loss and/or inactivation events. Together with the comparative physiology of various species, we may be able to find conditions that favor UCP1 thermogenesis and, learning from these insights, identify molecular networks that will be useful to pharmacologically stimulate the tissue.
Collapse
Affiliation(s)
- Michael J Gaudry
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Kevin L Campbell
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Neuherberg, Germany. .,German Center for Diabetes Research (DZD), München-Neuherberg, Germany.
| |
Collapse
|
63
|
Nowack J, Giroud S, Arnold W, Ruf T. Muscle Non-shivering Thermogenesis and Its Role in the Evolution of Endothermy. Front Physiol 2017; 8:889. [PMID: 29170642 PMCID: PMC5684175 DOI: 10.3389/fphys.2017.00889] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 10/20/2017] [Indexed: 01/20/2023] Open
Abstract
The development of sustained, long-term endothermy was one of the major transitions in the evolution of vertebrates. Thermogenesis in endotherms does not only occur via shivering or activity, but also via non-shivering thermogenesis (NST). Mammalian NST is mediated by the uncoupling protein 1 in the brown adipose tissue (BAT) and possibly involves an additional mechanism of NST in skeletal muscle. This alternative mechanism is based on Ca2+-slippage by a sarcoplasmatic reticulum Ca2+-ATPase (SERCA) and is controlled by the protein sarcolipin. The existence of muscle based NST has been discussed for a long time and is likely present in all mammals. However, its importance for thermoregulation was demonstrated only recently in mice. Interestingly, birds, which have evolved from a different reptilian lineage than mammals and lack UCP1-mediated NST, also exhibit muscle based NST under the involvement of SERCA, though likely without the participation of sarcolipin. In this review we summarize the current knowledge on muscle NST and discuss the efficiency of muscle NST and BAT in the context of the hypothesis that muscle NST could have been the earliest mechanism of heat generation during cold exposure in vertebrates that ultimately enabled the evolution of endothermy. We suggest that the evolution of BAT in addition to muscle NST was related to heterothermy being predominant among early endothermic mammals. Furthermore, we argue that, in contrast to small mammals, muscle NST is sufficient to maintain high body temperature in birds, which have enhanced capacities to fuel muscle NST by high rates of fatty acid import.
Collapse
Affiliation(s)
- Julia Nowack
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Sylvain Giroud
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Walter Arnold
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| |
Collapse
|
64
|
Reconstitution of UCP1 using CRISPR/Cas9 in the white adipose tissue of pigs decreases fat deposition and improves thermogenic capacity. Proc Natl Acad Sci U S A 2017; 114:E9474-E9482. [PMID: 29078316 DOI: 10.1073/pnas.1707853114] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Uncoupling protein 1 (UCP1) is localized on the inner mitochondrial membrane and generates heat by uncoupling ATP synthesis from proton transit across the inner membrane. UCP1 is a key element of nonshivering thermogenesis and is most likely important in the regulation of body adiposity. Pigs (Artiodactyl family Suidae) lack a functional UCP1 gene, resulting in poor thermoregulation and susceptibility to cold, which is an economic and pig welfare issue owing to neonatal mortality. Pigs also have a tendency toward fat accumulation, which may be linked to their lack of UCP1, and thus influences the efficiency of pig production. Here, we report application of a CRISPR/Cas9-mediated, homologous recombination (HR)-independent approach to efficiently insert mouse adiponectin-UCP1 into the porcine endogenous UCP1 locus. The resultant UCP1 knock-in (KI) pigs showed an improved ability to maintain body temperature during acute cold exposure, but they did not have alterations in physical activity levels or total daily energy expenditure (DEE). Furthermore, ectopic UCP1 expression in white adipose tissue (WAT) dramatically decreased fat deposition by 4.89% (P < 0.01), consequently increasing carcass lean percentage (CLP; P < 0.05). Mechanism studies indicated that the loss of fat upon UCP1 activation in WAT was linked to elevated lipolysis. UCP1 KI pigs are a potentially valuable resource for agricultural production through their combination of cold adaptation, which improves pig welfare and reduces economic losses, with reduced fat deposition and increased lean meat production.
Collapse
|
65
|
Nowack J. Fighting the cold as pigs do. J Exp Biol 2017. [DOI: 10.1242/jeb.147587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
66
|
Gaudry MJ, Campbell KL. Evolution of UCP1 Transcriptional Regulatory Elements Across the Mammalian Phylogeny. Front Physiol 2017; 8:670. [PMID: 28979209 PMCID: PMC5611445 DOI: 10.3389/fphys.2017.00670] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 08/23/2017] [Indexed: 01/22/2023] Open
Abstract
Uncoupling protein 1 (UCP1) permits non-shivering thermogenesis (NST) when highly expressed in brown adipose tissue (BAT) mitochondria. Exclusive to placental mammals, BAT has commonly been regarded to be advantageous for thermoregulation in hibernators, small-bodied species, and the neonates of larger species. While numerous regulatory control motifs associated with UCP1 transcription have been proposed for murid rodents, it remains unclear whether these are conserved across the eutherian mammal phylogeny and hence essential for UCP1 expression. To address this shortcoming, we conducted a broad comparative survey of putative UCP1 transcriptional regulatory elements in 139 mammals (135 eutherians). We find no evidence for presence of a UCP1 enhancer in monotremes and marsupials, supporting the hypothesis that this control region evolved in a stem eutherian ancestor. We additionally reveal that several putative promoter elements (e.g., CRE-4, CCAAT) identified in murid rodents are not conserved among BAT-expressing eutherians, and together with the putative regulatory region (PRR) and CpG island do not appear to be crucial for UCP1 expression. The specificity and importance of the upTRE, dnTRE, URE1, CRE-2, RARE-2, NBRE, BRE-1, and BRE-2 enhancer elements first described from rats and mice are moreover uncertain as these motifs differ substantially—but generally remain highly conserved—in other BAT-expressing eutherians. Other UCP1 enhancer motifs (CRE-3, PPRE, and RARE-3) as well as the TATA box are also highly conserved in nearly all eutherian lineages with an intact UCP1. While these transcriptional regulatory motifs are generally also maintained in species where this gene is pseudogenized, the loss or degeneration of key basal promoter (e.g., TATA box) and enhancer elements in other UCP1-lacking lineages make it unlikely that the enhancer region is pleiotropic (i.e., co-regulates additional genes). Importantly, differential losses of (or mutations within) putative regulatory elements among the eutherian lineages with an intact UCP1 suggests that the transcriptional control of gene expression is not highly conserved in this mammalian clade.
Collapse
Affiliation(s)
- Michael J Gaudry
- Department of Biological Sciences, University of ManitobaWinnipeg, MB, Canada
| | - Kevin L Campbell
- Department of Biological Sciences, University of ManitobaWinnipeg, MB, Canada
| |
Collapse
|