Effect of insulin and glucagon on in vitro glycerol production by white adipose tissue of hibernating jerboa (Jaculus orientalis)

Cryobiology ◽  
1987 ◽  
Vol 24 (6) ◽  
pp. 569
Author(s):  
R. Hoo-Paris ◽  
C. Moreau ◽  
C. Castex ◽  
B. Sutter
2021 ◽  
Vol 12 ◽  
Author(s):  
Chloé Buch ◽  
Tania Muller ◽  
Julia Leemput ◽  
Patricia Passilly-Degrace ◽  
Pablo Ortega-Deballon ◽  
...  

White adipose tissue (WAT) possesses the endocannabinoid system (ECS) machinery and produces the two major endocannabinoids (ECs), arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG). Accumulating evidence indicates that WAT cannabinoid 1 receptors (CB1R) are involved in the regulation of fat storage, tissue remodeling and secretory functions but their role in controlling lipid mobilization is unclear. In the present study, we used different strategies to acutely increase ECS activity in WAT and tested the consequences on glycerol production as a marker of lipolysis. Treating lean mice or rat WAT explants with JLZ195, which inhibits ECs degrading enzymes, induced an increase in 2-AG tissue contents that was associated with a CB1R-dependent decrease in lipolysis. Direct treatment of rat WAT explants with AEA also inhibited glycerol production while mechanistic studies revealed it could result from the stimulation of Akt-signaling pathway. Interestingly, AEA treatment decreased lipolysis both in visceral and subcutaneous WAT collected on lean subjects suggesting that ECS also reduces fat store mobilization in Human. In obese mice, WAT content and secretion rate of ECs were higher than in control while glycerol production was reduced suggesting that over-produced ECs may inhibit lipolysis activating local CB1R. Strikingly, our data also reveal that acute CB1R blockade with Rimonabant did not modify lipolysis in vitro in obese mice and human explants nor in vivo in obese mice. Taken together, these data provide physiological evidence that activation of ECS in WAT, by limiting fat mobilization, may participate in the progressive tissue remodeling that could finally lead to organ dysfunction. The present findings also indicate that acute CB1R blockade is inefficient in regulating lipolysis in obese WAT and raise the possibility of an alteration of CB1R signaling in conditions of obesity.


2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Anirban Mandal ◽  
Ajeet Kumar Jha ◽  
Dew Biswas ◽  
Shyamal Kanti Guha

Abstract Background The study was conducted to assess the characterization, differentiation, and in vitro cell regeneration potential of canine mesenteric white adipose tissue-derived mesenchymal stem cells (AD-MSCs). The tissue was harvested through surgical incision and digested with collagenase to obtain a stromal vascular fraction. Mesenchymal stem cells isolated from the stromal vascular fraction were characterized through flow cytometry and reverse transcription-polymerase chain reaction. Assessment of cell viability, in vitro cell regeneration, and cell senescence were carried out through MTT assay, wound healing assay, and β-galactosidase assay, respectively. To ascertain the trilineage differentiation potential, MSCs were stained with alizarin red for osteocytes, alcian blue for chondrocytes, and oil o red for adipocytes. In addition, differentiated cells were characterized through a reverse transcription-polymerase chain reaction. Results We observed the elongated, spindle-shaped, and fibroblast-like appearance of cells after 72 h of initial culture. Flow cytometry results showed positive expression for CD44, CD90, and negative expression for CD45 surface markers. Population doubling time was found 18–24 h for up to the fourth passage and 30±0.5 h for the fifth passage. A wound-healing assay was used to determine cell migration rate which was found 136.9 ± 4.7 μm/h. We observed long-term in vitro cell proliferation resulted in MSC senescence. Furthermore, we also found that the isolated cells were capable of differentiating into osteogenic, chondrogenic, and adipogenic lineages. Conclusions Mesenteric white adipose tissue was found to be a potential source for isolation, characterization, and differentiation of MSCs. This study might be helpful for resolving the problems regarding the paucity of information concerning the basic biology of stem cells. The large-scale use of AD-MSCs might be a remedial measure in regenerative medicine.


2020 ◽  
Vol 477 (8) ◽  
pp. 1373-1389
Author(s):  
Nusrat Hussain ◽  
Sheng-Ju Chuang ◽  
Manuel Johanns ◽  
Didier Vertommen ◽  
Gregory R. Steinberg ◽  
...  

We investigated acute effects of two allosteric protein kinase B (PKB) inhibitors, MK-2206 and Akti-1/2, on insulin-stimulated lipogenesis in rat epididymal adipocytes incubated with fructose as carbohydrate substrate. In parallel, the phosphorylation state of lipogenic enzymes in adipocytes and incubated epididymal fat pads was monitored by immunoblotting. Preincubation of rat epididymal adipocytes with PKB inhibitors dose-dependently inhibited the following: insulin-stimulated lipogenesis, increased PKB Ser473 phosphorylation, increased PKB activity and decreased acetyl-CoA carboxylase (ACC) Ser79 phosphorylation. In contrast, the effect of insulin to decrease the phosphorylation of pyruvate dehydrogenase (PDH) at Ser293 and Ser300 was not abolished by PKB inhibition. Insulin treatment also induced ATP-citrate lyase (ACL) Ser454 phosphorylation, but this effect was less sensitive to PKB inhibitors than ACC dephosphorylation by insulin. In incubated rat epididymal fat pads, Akti-1/2 treatment reversed insulin-induced ACC dephosphorylation, while ACL phosphorylation by insulin was maintained. ACL and ACC purified from white adipose tissue were poor substrates for PKBα in vitro. However, effects of wortmannin and torin, along with Akti-1/2 and MK-2206, on recognized PKB target phosphorylation by insulin were similar to their effects on insulin-induced ACL phosphorylation, suggesting that PKB could be the physiological kinase for ACL phosphorylation by insulin. In incubated epididymal fat pads from wild-type versus ACC1/2 S79A/S212A knockin mice, effects of insulin to increase lipogenesis from radioactive fructose or from radioactive acetate were reduced but not abolished. Together, the results support a key role for PKB in mediating insulin-stimulated lipogenesis by decreasing ACC phosphorylation, but not by decreasing PDH phosphorylation.


1985 ◽  
Vol 5 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Christine M. Williams ◽  
Rodney Ellis

Male rats were treated with triiodothyronine in the drinking water for 12 days. In vitro rates of isoprenaline stimulated lipolysis were significantly greater in brown but not white adipose tissue. Rates of [14C]glucose incorporation into triacylglycerols were significantly reduced in BAT (brown adipose tissue) and WAT (white adipose tissue) under basal and isoprenaline stimulated conditions, in a second experiment, hyperthyroid animals showed impaired weight gain, despite increased food intake during t9 days' treatment. Energy expenditure on days 5 and 12, and BAT core temperature differences (TBAT – TCORE) on day 19, were significantly greater than in control animals. Epididymal white fat pad weight was reduced and interscapular brown fat pad weight increased by triiodothyronine treatment.


2012 ◽  
Vol 302 (6) ◽  
pp. E705-E713 ◽  
Author(s):  
Xin Cui ◽  
Yuhui Wang ◽  
Lingjun Meng ◽  
Weihua Fei ◽  
Jingna Deng ◽  
...  

Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) is a recessive disorder characterized by an almost complete loss of adipose tissue, insulin resistance, and fatty liver. BSCL2 is caused by loss-of-function mutations in the BSCL2/seipin gene, which encodes seipin. The essential role for seipin in adipogenesis has recently been established both in vitro and in vivo. However, seipin is highly upregulated at later stages of adipocyte development, and its role in mature adipocytes remains to be elucidated. We therefore generated transgenic mice overexpressing a short isoform of human BSCL2 gene (encoding 398 amino acids) using the adipocyte-specific aP2 promoter. The transgenic mice produced ∼150% more seipin than littermate controls in white adipose tissue. Surprisingly, the increased expression of seipin markedly reduced the mass of white adipose tissue and the size of adipocytes and lipid droplets. This may be due in part to elevated lipolysis rates in the transgenic mice. Moreover, there was a nearly 50% increase in the triacylglycerol content of transgenic liver. These results suggest that seipin promotes the differentiation of preadipocytes but may inhibit lipid storage in mature adipocytes.


2021 ◽  
Author(s):  
Wan-Qiu Peng ◽  
Gang Xiao ◽  
Bai-Yu Li ◽  
Ying-Ying Guo ◽  
Liang Guo ◽  
...  

L-Theanine is a nonprotein amino acid with much beneficial efficacy. We found that intraperitoneal treatment of the mice with L-Theanine(100mg/kg/day) enhanced adaptive thermogenesis and induced the browning of inguinal white adipose tissue (iWAT) with elevated expression of Prdm16, Ucp1 and other thermogenic genes. Meanwhile, administration of the mice with L-Theanine increased energy expenditure. In vitro studies indicated that L-Theanine induced the development of brown-like features in adipocytes. The shRNA-mediated depletion of Prdm16 blunted the role of L-Theanine in promoting the brown-like phenotypes in adipocytes and in the iWAT of mice. L-Theanine treatment enhanced AMPKα phosphorylation both in adipocytes and in iWAT. Knockdown of AMPKα ablolished L-Theanine-induced upregulation of Prdm16 and adipocytes browning. L-Theanine increased the α-ketoglutarate (α-KG) level in adipocytes, which may increase the transcription of Prdm16 by inducing active DNA demethylation on its promoter. AMPK activation was required for L-Theanine-induced increase of α-KG and DNA demethylation on Prdm16 promoter. Moreover, intraperitoneal administration with L-Theanine ameliorated obesity, improved glucose tolerance and insulin sensitivity, and reduced plasma triglyceride, total cholesterol and free fatty acid in the high fat diet-fed mice. Our results suggest a potential role of L-Theanine in combating diet-induced obesity in mice, which may involve L-Theanine-induced browning of white adipose tissue.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mingchen Xiong ◽  
Weijie Hu ◽  
Yufang Tan ◽  
Honghao Yu ◽  
Qi Zhang ◽  
...  

Obesity is associated with energy metabolic disturbance and is caused by long-term excessive energy storage in white adipose tissue (WAT). The WAT browning potentially reduces excessive energy accumulation, contributing an attractive target to combat obesity. As a pivotal regulator of cell growth, the transcription factor E2F1 activity dysregulation leads to metabolic complications. The regulatory effect and underlying mechanism of E2F1 knockout on WAT browning, have not been fully elucidated. To address this issue, in this study, the in vivo adipose morphology, mitochondria quantities, uncoupling protein 1 (UCP-1), autophagy-related genes in WAT of wild-type (WT) and E2F1–/– mice were detected. Furthermore, we evaluated the UCP-1, and autophagy-related gene expression in WT and E2F1–/– adipocyte in vitro. The results demonstrated that E2F1 knockout could increase mitochondria and UCP-1 expression in WAT through autophagy suppression in mice, thus promoting WAT browning. Besides, adipocytes lacking E2F1 showed upregulated UCP-1 and downregulated autophagy-related genes expression in vitro. These results verified that E2F1 knockout exerted effects on inducing mice WAT browning through autophagy inhibition in vivo and in vitro. These findings regarding the molecular mechanism of E2F1-modulated autophagy in controlling WAT plasticity, provide a novel insight into the functional network with the potential therapeutic application against obesity.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Asma Ayari ◽  
Manuel Rosa-Calatrava ◽  
Steve Lancel ◽  
Johanna Barthelemy ◽  
Andrés Pizzorno ◽  
...  

AbstractLike all obligate intracellular pathogens, influenza A virus (IAV) reprograms host cell’s glucose and lipid metabolism to promote its own replication. However, the impact of influenza infection on white adipose tissue (WAT), a key tissue in the control of systemic energy homeostasis, has not been yet characterized. Here, we show that influenza infection induces alterations in whole-body glucose metabolism that persist long after the virus has been cleared. We report depot-specific changes in the WAT of IAV-infected mice, notably characterized by the appearance of thermogenic brown-like adipocytes within the subcutaneous fat depot. Importantly, viral RNA- and viral antigen-harboring cells are detected in the WAT of infected mice. Using in vitro approaches, we find that IAV infection enhances the expression of brown-adipogenesis-related genes in preadipocytes. Overall, our findings shed light on the role that the white adipose tissue, which lies at the crossroads of nutrition, metabolism and immunity, may play in influenza infection.


2016 ◽  
Vol 310 (1) ◽  
pp. R55-R65 ◽  
Author(s):  
Yun-Hee Lee ◽  
Sang-Nam Kim ◽  
Hyun-Jung Kwon ◽  
Krishna Rao Maddipati ◽  
James G. Granneman

De novo brown adipogenesis involves the proliferation and differentiation of progenitors, yet the mechanisms that guide these events in vivo are poorly understood. We previously demonstrated that treatment with a β3-adrenergic receptor (ADRB3) agonist triggers brown/beige adipogenesis in gonadal white adipose tissue following adipocyte death and clearance by tissue macrophages. The close physical relationship between adipocyte progenitors and tissue macrophages suggested that the macrophages that clear dying adipocytes might generate proadipogenic factors. Flow cytometric analysis of macrophages from mice treated with CL 316,243 identified a subpopulation that contained elevated lipid and expressed CD44. Lipidomic analysis of fluorescence-activated cell sorting-isolated macrophages demonstrated that CD44+ macrophages contained four- to five-fold higher levels of the endogenous peroxisome-proliferator activated receptor gamma (PPARγ) ligands 9-hydroxyoctadecadienoic acid (HODE), and 13-HODE compared with CD44− macrophages. Gene expression profiling and immunohistochemistry demonstrated that ADRB3 agonist treatment upregulated expression of ALOX15, the lipoxygenase responsible for generating 9-HODE and 13-HODE. Using an in vitro model of adipocyte efferocytosis, we found that IL-4-primed tissue macrophages accumulated lipid from dying fat cells and upregulated expression of Alox15. Furthermore, treatment of differentiating adipocytes with 9-HODE and 13-HODE potentiated brown/beige adipogenesis. Collectively, these data indicate that noninflammatory removal of adipocyte remnants and coordinated generation of PPARγ ligands by M2 macrophages provides localized adipogenic signals to support de novo brown/beige adipogenesis.


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