scholarly journals Ultrastructural Development of Adipose Tissue in Foetal Sheep

1978 ◽  
Vol 31 (5) ◽  
pp. 505 ◽  
Author(s):  
RT Gemmell ◽  
G Alexander

The development of subcutaneous and perirenal adipose tissue in foetal sheep of 40-150 days conceptual age was examined using electromicroscopy. Adipose tissue from both sites developed from pre-adipose cells of similar appearance, with few mitochondria, and commenced accumulating lipid on about day 70 of gestation. In the perirenal fat there was marked proliferation of mitochondria between days 80 and 90 and the tissue developed into-brown fat, cell profiles being characterized by many mitochondria with numerous distinct cristae, whereas in the subcutaneous cells which developed into white adipose tissue few mitochondria with fewer cristae were observed. Multilocular and unilocular cells occurred in both tissues near term. Nerves were first seen between brown adipose cells in a 130-day-old foetus and were frequently seen in older foetuses, but very few nerves were seen in the white adipose tissue.

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 904 ◽  
Author(s):  
Linjie Wang ◽  
Xin Yang ◽  
Yuehua Zhu ◽  
Siyuan Zhan ◽  
Zhe Chao ◽  
...  

Long noncoding RNAs (lncRNAs) play an important role in the thermogenesis and energy storage of brown adipose tissue (BAT). However, knowledge of the cellular transition from BAT to white adipose tissue (WAT) and the potential role of lncRNAs in goat adipose tissue remains largely unknown. In this study, we analyzed the transformation from BAT to WAT using histological and uncoupling protein 1 (UCP1) gene analyses. Brown adipose tissue mainly existed within the goat perirenal fat at 1 day and there was obviously a transition from BAT to WAT from 1 day to 1 year. The RNA libraries constructed from the perirenal adipose tissues of 1 day, 30 days, and 1 year goats were sequenced. A total number of 21,232 lncRNAs from perirenal fat were identified, including 5393 intronic-lncRNAs and 3546 antisense-lncRNAs. Furthermore, a total of 548 differentially expressed lncRNAs were detected across three stages (fold change ≥ 2.0, false discovery rate (FDR) < 0.05), and six lncRNAs were validated by qPCR. Furthermore, trans analysis found lncRNAs that were transcribed close to 890 protein-coding genes. Additionally, a coexpression network suggested that 4519 lncRNAs and 5212 mRNAs were potentially in trans-regulatory relationships (r > 0.95 or r < −0.95). In addition, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed that the targeted genes were involved in the biosynthesis of unsaturated fatty acids, fatty acid elongation and metabolism, the citrate cycle, oxidative phosphorylation, the mitochondrial respiratory chain complex, and AMP-activated protein kinase (AMPK) signaling pathways. The present study provides a comprehensive catalog of lncRNAs involved in the transformation from BAT to WAT and provides insight into understanding the role of lncRNAs in goat brown adipogenesis.


Endocrinology ◽  
2003 ◽  
Vol 144 (8) ◽  
pp. 3547-3554 ◽  
Author(s):  
Takayuki Masaki ◽  
Go Yoshimichi ◽  
Seiichi Chiba ◽  
Tohru Yasuda ◽  
Hitoshi Noguchi ◽  
...  

Abstract To examine the functional role of CRH in the regulation of energy homeostasis by leptin, we measured the effects of the CRH antagonist, α-helical CRH 8–41 (αCRH) on a number of factors affected by leptin activity. These included food intake, body weight, hypothalamic c-fos-like immunoreactivity (c-FLI), weight and histological characterization of white adipose tissue, and mRNA expressions of uncoupling protein (UCP) in brown adipose tissue (BAT) in C57Bl/6 mice. Central infusion of leptin into the lateral cerebroventricle (icv) caused significant induction of c-FLI in the paraventricular nucleus (PVN), ventromedial hypothalamic nucleus (VMH), dorsomedial hypothalamic nucleus, and arcuate nucleus. In all these nuclei, the effect of leptin on expression of cFLI in the PVN and VMH was decreased by treatment with αCRH. Administration of leptin markedly decreased cumulative food intake and body weight with this effect being attenuated by pretreatment with αCRH. In peripheral tissue, leptin up-regulated BAT UCP1 mRNA expression and reduced fat depositions in this tissue. Those changes in BAT were also decreased by treatment with αCRH. As a consequence of the effects on food intake or energy expenditure, treatment with αCRH attenuated the leptin-induced reduction of body adiposity, fat cell size, triglyceride contents, and ob mRNA expression in white adipose tissue. Taken together, these results indicate that CRH neurons in the PVN and VMH may be an important mediator for leptin that contribute to regulation of feeding, adiposity, and UCP expression.


2021 ◽  
Vol 22 (11) ◽  
pp. 5560
Author(s):  
Alejandro Álvarez-Artime ◽  
Belén García-Soler ◽  
Rosa María Sainz ◽  
Juan Carlos Mayo

In addition to its well-known role as an energy repository, adipose tissue is one of the largest endocrine organs in the organism due to its ability to synthesize and release different bioactive molecules. Two main types of adipose tissue have been described, namely white adipose tissue (WAT) with a classical energy storage function, and brown adipose tissue (BAT) with thermogenic activity. The prostate, an exocrine gland present in the reproductive system of most mammals, is surrounded by periprostatic adipose tissue (PPAT) that contributes to maintaining glandular homeostasis in conjunction with other cell types of the microenvironment. In pathological conditions such as the development and progression of prostate cancer, adipose tissue plays a key role through paracrine and endocrine signaling. In this context, the role of WAT has been thoroughly studied. However, the influence of BAT on prostate tumor development and progression is unclear and has received much less attention. This review tries to bring an update on the role of different factors released by WAT which may participate in the initiation, progression and metastasis, as well as to compile the available information on BAT to discuss and open a new field of knowledge about the possible protective role of BAT in prostate cancer.


2000 ◽  
Vol 113 (23) ◽  
pp. 4203-4210 ◽  
Author(s):  
D. Malide ◽  
G. Ramm ◽  
S.W. Cushman ◽  
J.W. Slot

We used an improved cryosectioning technique in combination with quantitative immunoelectron microscopy to study GLUT4 compartments in isolated rat white adipose cells. We provide clear evidence that in unstimulated cells most of the GLUT4 localizes intracellularly to tubulovesicular structures clustered near small stacks of Golgi and endosomes, or scattered throughout the cytoplasm. This localization is entirely consistent with that originally described in brown adipose tissue, strongly suggesting that the GLUT4 compartments in white and brown adipose cells are morphologically similar. Furthermore, insulin induces parallel increases (with similar magnitudes) in glucose transport activity, approximately 16-fold, and cell-surface GLUT4, approximately 12-fold. Concomitantly, insulin decreases GLUT4 equally from all intracellular locations, in agreement with the concept that the entire cellular GLUT4 pool contributes to insulin-stimulated exocytosis. In the insulin-stimulated state, GLUT4 molecules are not randomly distributed on the plasma membrane, but neither are they enriched in caveolae. Importantly, the total number of GLUT4 C-terminal epitopes detected by the immuno-gold method is not significantly different between basal and insulin-stimulated cells, thus arguing directly against a reported insulin-induced unmasking effect. These results provide strong morphological evidence (1) that GLUT4 compartments are similar in all insulin-sensitive cells and (2) for the concept that GLUT4 translocation almost fully accounts for the increase in glucose transport in response to insulin.


1992 ◽  
Vol 262 (1) ◽  
pp. E105-E109 ◽  
Author(s):  
L. A. Cassis

To determine if insulin has the ability to regulate components of the renin-angiotensin system, renin and angiotensinogen mRNA and plasma concentrations were determined in 4-wk streptozotocin (STZ)-diabetic rats. In another group of STZ-diabetic rats, replacement insulin therapy was given over the 4-wk period, and the above parameters were examined. In STZ-diabetic rats, there was a significant regression of white adipose tissue that was accompanied by an increase in the yield of RNA obtained. Changes in white adipose tissue were reversed by insulin replacement therapy in STZ-diabetic rats. There were no changes in brown adipose tissue weight or RNA yield in STZ-diabetic rats. Plasma renin activity (PRA) was significantly decreased in STZ-diabetic rats; however, plasma angiotensinogen concentration was not significantly affected by diabetes. PRA was restored to control levels in STZ-diabetic rats with insulin replacement. Kidney renin mRNA as well as liver, epididymal, and interscapular fat angiotensinogen mRNA were significantly decreased in STZ-diabetic rats. Renin and angiotensinogen mRNA were not significantly different from control in all tissues examined in STZ-diabetic rats with insulin replacement therapy. Results from this study suggest a downregulation of the renin-angiotensin system in 4-wk STZ-diabetic rats at the level of mRNA expression that is restored by replacement therapy with insulin; therefore, insulin may directly or indirectly regulate the renin-angiotensin system.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256768
Author(s):  
Patrick Munro ◽  
Samah Rekima ◽  
Agnès Loubat ◽  
Christophe Duranton ◽  
Didier F. Pisani ◽  
...  

White adipocytes store energy differently than brown and brite adipocytes which dissipate energy under the form of heat. Studies have shown that adipocytes are able to respond to bacteria thanks to the presence of Toll-like receptors at their surface. Despite this, little is known about the involvement of each class of adipocytes in the infectious response. We treated mice for one week with a β3-adrenergic receptor agonist to induce activation of brown adipose tissue and brite adipocytes within white adipose tissue. Mice were then injected intraperitoneally with E. coli to generate acute infection. The metabolic, infectious and inflammatory parameters of the mice were analysed during 48 hours after infection. Our results shown that in response to bacteria, thermogenic activity promoted a discrete and local anti-inflammatory environment in white adipose tissue characterized by the increase of the IL-1RA secretion. More generally, activation of brown and brite adipocytes did not modify the host response to infection including no additive effect with fever and an equivalent bacteria clearance and inflammatory response. In conclusion, these results suggest an IL-1RA-mediated immunomodulatory activity of thermogenic adipocytes in response to acute bacterial infection and open a way to characterize their effect along more chronic infection as septicaemia.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Danielle Yi ◽  
Hai P Nguyen ◽  
Jennie Dinh ◽  
Jose A Viscarra ◽  
Ying Xie ◽  
...  

Brown adipose tissue is a metabolically beneficial organ capable of dissipating chemical energy into heat, thereby increasing energy expenditure. Here, we identify Dot1l, the only known H3K79 methyltransferase, as an interacting partner of Zc3h10 that transcriptionally activates the Ucp1 promoter and other BAT genes. Through a direct interaction, Dot1l is recruited by Zc3h10 to the promoter regions of thermogenic genes to function as a coactivator by methylating H3K79. We also show that Dot1l is induced during brown fat cell differentiation and by cold exposure and that Dot1l and its H3K79 methyltransferase activity is required for thermogenic gene program. Furthermore, we demonstrate that Dot1l ablation in mice using Ucp1-Cre prevents activation of Ucp1 and other target genes to reduce thermogenic capacity and energy expenditure, promoting adiposity. Hence, Dot1l plays a critical role in the thermogenic program and may present as a future target for obesity therapeutics.


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