scholarly journals TORC1 modulation in adipose tissue is required for organismal adaptation to hypoxia in Drosophila

2018 ◽  
Author(s):  
Byoungchun Lee ◽  
Elizabeth C. Barretto ◽  
Savraj S. Grewal
Keyword(s):  
Adipose Tissue ◽  
Normal Development ◽  
Fat Body ◽  
Lipid Storage ◽  
Hypoxia Tolerance ◽  
Whole Body ◽  
Adaptation To Hypoxia ◽  
Low Oxygen ◽  
Body Development ◽  
Drosophila Larvae

ABSTRACTAnimals often develop in conditions where environmental conditions such as food, oxygen and temperature fluctuate. The ability to adapt their metabolism to these fluctuations is important to ensure normal development and viability. In most animals, low oxygen (hypoxia) is deleterious, however some animals can alter their physiology to thrive under hypoxia. Here we show that TORC1 modulation in adipose tissue is required for organismal adaptation to hypoxia in Drosophila. We find that hypoxia rapidly suppresses TORC1 kinase signalling in Drosophila larvae via TSC-mediated inhibition of Rheb. We show that this hypoxia-mediated inhibition of TORC1 specifically in the larval fat body is essential for viable development to adulthood. Moreover, we find that these effects of TORC1 inhibition on hypoxia tolerance are mediated through remodeling of fat body lipid droplets and lipid storage. These studies identify the larval adipose tissue as a key hypoxia sensing tissue that coordinates whole-body development and survival to changes in environmental oxygen by modulating TORC1 and lipid storage.

scholarly journals PPA1 Regulates Systemic Insulin Sensitivity by Maintaining Adipocyte Mitochondria Function as a Novel PPARγ Target Gene

2021 ◽  
Author(s):  
Ye Yin ◽  
Yangyang Wu ◽  
Xu Zhang ◽  
Yeting Zhu ◽  
Yue Sun ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Mitochondrial Function ◽  
Metabolic Disorders ◽  
Target Gene ◽  
Fat Body ◽  
Whole Body ◽  
Inorganic Pyrophosphatase ◽  
Severe Insulin Resistance ◽  
Adipose Tissue Development ◽  
First Time

<a>Downregulation of mitochondrial function in adipose tissue is considered as one important driver for the development of obesity-associated metabolic disorders. Inorganic Pyrophosphatase 1 (PPA1) is an enzyme catalyzes the hydrolysis of PPi to Pi, and is required for anabolism to take place in cells. Although alternation of PPA1 has been related to some diseases, the importance of PPA1 in metabolic syndromes has never been discussed before. In this study, we found that global PPA1 knockout mice (PPA1<sup>+/-</sup>) showed impaired glucose tolerance and severe insulin resistance under HFD feeding. In addition, impaired adipose tissue development and ectopic lipid accumulation were also observed. Conversely, overexpression of PPA1 in adipose tissue by AAV injection can partly reverse the metabolic disorders in PPA1<sup>+/-</sup> mice, suggesting that impaired adipose tissue function is responsible for the metabolic disorders observed in PPA1<sup>+/- </sup>mice. Mechanistic studies revealed that PPA1 acted as a PPARγ target gene to maintain mitochondrial function in adipocytes. Furthermore, specific knockdown of PPA1 in fat body of <i>Drosophila</i> led to impaired mitochondria morphology, decreased lipid storage, and made <i>Drosophila</i> more sensitive to starvation. In conclusion, for the first time, our findings demonstrated the importance of PPA1 in maintaining adipose tissue function and whole body metabolic homeostasis.</a>

scholarly journals Adipose mitochondrial metabolism controls body growth by modulating cytokine and insulin signaling

2021 ◽  
Author(s):  
Shrivani Sriskanthadevan-Pirahas ◽  
Michael J Turingan ◽  
Joel S Chahal ◽  
Erin Thorson ◽  
Savraj Grewal
Keyword(s):  
Nutrient Availability ◽  
Insulin Signaling ◽  
Fat Body ◽  
Nutrient Sensing ◽  
Body Growth ◽  
Mitochondrial Metabolism ◽  
Whole Body ◽  
Mitochondrial Morphology ◽  
Dietary Nutrients ◽  
Drosophila Larvae

Animals need to adapt their growth to fluctuations in nutrient availability to ensure proper development and survival. These adaptations often rely on specific nutrient-sensing tissues and their control of whole-body physiology through inter-organ communication. While the signaling mechanisms that underlie this communication are well studied, the contributions of metabolic alterations in the nutrient-sensing tissues are less clear. Here, we show how reprogramming of adipose mitochondrial metabolism controls whole-body growth in Drosophila larvae. We find that dietary nutrients alter fat body mitochondrial morphology to lower their bioenergetic activity, which we see can rewire fat body glucose metabolism. Strikingly, we find that genetic reduction of mitochondrial bioenergetics just in the fat body is sufficient to accelerate body growth and development. These growth effects are caused by inhibition of the fat-derived adipokine, TNFα/Eiger, which leads to enhanced systemic insulin signaling, the main hormonal stimulator of body growth. Our work reveals how reprogramming of mitochondrial metabolism in one nutrient-sensing tissue is able to couple whole body growth to nutrient availability.

scholarly journals STK25 regulates oxidative capacity and metabolic efficiency in adipose tissue

2018 ◽  
Vol 238 (3) ◽  
pp. 187-202 ◽  
Author(s):  
Silva Sütt ◽  
Emmelie Cansby ◽  
Alexandra Paul ◽  
Manoj Amrutkar ◽  
Esther Nuñez-Durán ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Mitochondrial Function ◽  
Oxidative Capacity ◽  
Dietary Lipids ◽  
Lipid Storage ◽  
Whole Body ◽  
Mitochondrial Activity ◽  
Metabolic Efficiency ◽  
High Fat ◽  
Inflammatory Infiltration

Whole-body energy homeostasis at over-nutrition critically depends on how well adipose tissue remodels in response to excess calories. We recently identified serine/threonine protein kinase (STK)25 as a critical regulator of ectopic lipid storage in non-adipose tissue and systemic insulin resistance in the context of nutritional stress. Here, we investigated the role of STK25 in regulation of adipose tissue dysfunction in mice challenged with a high-fat diet. We found that overexpression of STK25 in high-fat-fed mice resulted in impaired mitochondrial function and aggravated hypertrophy, inflammatory infiltration and fibrosis in adipose depots. Reciprocally, Stk25-knockout mice displayed improved mitochondrial function and were protected against diet-induced excessive fat storage, meta-inflammation and fibrosis in brown and white adipose tissues. Furthermore, in rodent HIB-1B cell line, STK25 depletion resulted in enhanced mitochondrial activity and consequently, reduced lipid droplet size, demonstrating an autonomous action for STK25 within adipocytes. In summary, we provide the first evidence for a key function of STK25 in controlling the metabolic balance of lipid utilization vs lipid storage in brown and white adipose depots, suggesting that repression of STK25 activity offers a potential strategy for establishing healthier adipose tissue in the context of chronic exposure to dietary lipids.

scholarly journals PPA1 Regulates Systemic Insulin Sensitivity by Maintaining Adipocyte Mitochondria Function as a Novel PPARγ Target Gene

2021 ◽  
Author(s):  
Ye Yin ◽  
Yangyang Wu ◽  
Xu Zhang ◽  
Yeting Zhu ◽  
Yue Sun ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Mitochondrial Function ◽  
Metabolic Disorders ◽  
Target Gene ◽  
Fat Body ◽  
Whole Body ◽  
Inorganic Pyrophosphatase ◽  
Severe Insulin Resistance ◽  
Adipose Tissue Development ◽  
First Time

<a>Downregulation of mitochondrial function in adipose tissue is considered as one important driver for the development of obesity-associated metabolic disorders. Inorganic Pyrophosphatase 1 (PPA1) is an enzyme catalyzes the hydrolysis of PPi to Pi, and is required for anabolism to take place in cells. Although alternation of PPA1 has been related to some diseases, the importance of PPA1 in metabolic syndromes has never been discussed before. In this study, we found that global PPA1 knockout mice (PPA1<sup>+/-</sup>) showed impaired glucose tolerance and severe insulin resistance under HFD feeding. In addition, impaired adipose tissue development and ectopic lipid accumulation were also observed. Conversely, overexpression of PPA1 in adipose tissue by AAV injection can partly reverse the metabolic disorders in PPA1<sup>+/-</sup> mice, suggesting that impaired adipose tissue function is responsible for the metabolic disorders observed in PPA1<sup>+/- </sup>mice. Mechanistic studies revealed that PPA1 acted as a PPARγ target gene to maintain mitochondrial function in adipocytes. Furthermore, specific knockdown of PPA1 in fat body of <i>Drosophila</i> led to impaired mitochondria morphology, decreased lipid storage, and made <i>Drosophila</i> more sensitive to starvation. In conclusion, for the first time, our findings demonstrated the importance of PPA1 in maintaining adipose tissue function and whole body metabolic homeostasis.</a>

scholarly journals Phosphoprotein enriched in astrocytes (PEA)-15 is a novel regulator of adipose tissue expansion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pola J. Verschoor ◽  
Fiona H. Greig ◽  
Justin J. Rochford ◽  
Giovanni Levate ◽  
Mirela Delibegovic ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
High Fat Diet ◽  
Tissue Expansion ◽  
Lipid Storage ◽  
Whole Body ◽  
High Fat ◽  
Serum Triglycerides ◽  
Hepatic Lipid Accumulation ◽  
Adipocyte Cell ◽  
First Time

AbstractExcessive expansion of adipose tissue in obesity typically leads to overflow and accumulation of lipids in other tissues, causing fatty liver disease and atherosclerosis. The intracellular protein, phosphoprotein enriched in astrocytes (PEA)-15 has been linked to metabolic disease but its role in lipid storage has not been examined. To delineate the role of PEA-15 in adipose tissue, we placed PEA-15−/− mice on a high fat diet. These mice developed increased body weight and greater white adipose tissue expansion compared to high fat diet-fed wild type mice. This was due to increased adipocyte cell size in PEA-15−/− mice consistent with greater lipid storage capacity. Surprisingly, PEA-15−/− mice exhibited improvements in whole body insulin sensitivity, lower hepatic weight and decreased serum triglycerides indicating a protective phenotype. To determine effects on atherosclerosis, PEA-15−/− mice were crossed with the ApoE−/− mice on a high fat diet. Strikingly, these mice were protected from atherosclerosis and had less hepatic lipid accumulation despite increased adiposity. Therefore, we reveal for the first time that PEA-15 plays a novel role in regulating the expansion of adipose tissue. Decreasing PEA-15 expression increases the sequestering of lipids in adipose tissue, protecting other tissues in obesity, thereby improving metabolic health.

Hypoxia Tolerance in Twelve Species of East African Cichlids: Potential for Low Oxygen Refugia in Lake Victoria

1995 ◽  
Vol 9 (5) ◽  
pp. 1274-1288 ◽  
Author(s):  
LAUREN J. CHAPMAN ◽  
LESLIE S. KAUFMAN ◽  
COLIN A. CHAPMAN ◽  
F. ELLIS MCKENZIE
Keyword(s):  
Lake Victoria ◽  
Hypoxia Tolerance ◽  
Low Oxygen ◽  
East African ◽  
East African Cichlids ◽  
African Cichlids

scholarly journals Weight Status and Visceral Adiposity Mediate the Relationship between Exclusive Breastfeeding Duration and Skin Carotenoids in Later Childhood

2021 ◽  
Author(s):  
Ruyu Liu ◽  
Caitlyn G Edwards ◽  
Corinne N Cannavale ◽  
Isabel R Flemming ◽  
Morgan R Chojnacki ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Exclusive Breastfeeding ◽  
Weight Status ◽  
Mediating Effect ◽  
Physical Growth ◽  
Breastfeeding Duration ◽  
Whole Body ◽  
Controlled Clinical Trial ◽  
The Impact ◽  
The Relationship

Abstract Background Breastfeeding is associated with healthier weight and nutrient status in early life. However, the impact of breastfeeding on carotenoid status beyond infancy, and the influence of adiposity, is unknown. Objective The aim of the study was to retrospectively investigate the relationship between breastfeeding and carotenoid status, and the mediating effect of weight status and adiposity on this relationship among school-aged children. Methods This was a secondary analysis of baseline data collected from a randomized-controlled clinical trial. (ClinicalTrials.gov Identifier: NCT03521349). 7–12-year-old (n = 81) children were recruited from East-Central Illinois. Dual-energy x-ray absorptiometry (DXA) was used to assess visceral adipose tissue (VAT) and whole-body adiposity (%Fat). Weight was obtained to calculated body mass index percentile (BMI %ile). Skin carotenoids were assessed via reflection spectroscopy. Macular carotenoids were assessed as macular pigment optical density (MPOD). Dietary, birth, and breastfeeding information was self-reported by parents. Results Skin carotenoids were inversely related to %Fat (P &lt; 0.01), VAT (P &lt; 0.01) and BMI %ile (P &lt; 0.01). VAT and BMI %ile significantly mediated this relationship between exclusive breastfeeding duration and skin carotenoids, following adjustment for dietary carotenoids, energy intake, and mother education. Conclusions Weight status and adipose tissue distribution mediate the positive correlation between exclusive breastfeeding duration and skin carotenoids among children aged 7–12 years. The results indicate the need to support breastfeeding and healthy physical growth in childhood for optimal carotenoid status.

scholarly journals DsbA-L deficiency in T cells promotes diet-induced thermogenesis through suppressing IFN-γ production

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Haiyan Zhou ◽  
Xinyi Peng ◽  
Jie Hu ◽  
Liwen Wang ◽  
Hairong Luo ◽  
...  
Keyword(s):  
T Cells ◽  
Adipose Tissue ◽  
T Cell ◽  
Energy Homeostasis ◽  
Metabolic Diseases ◽  
Therapeutic Potential ◽  
Whole Body ◽  
Brown Adipose ◽  
Ifn Γ ◽  
Diet Induced Thermogenesis

AbstractAdipose tissue-resident T cells have been recognized as a critical regulator of thermogenesis and energy expenditure, yet the underlying mechanisms remain unclear. Here, we show that high-fat diet (HFD) feeding greatly suppresses the expression of disulfide-bond A oxidoreductase-like protein (DsbA-L), a mitochondria-localized chaperone protein, in adipose-resident T cells, which correlates with reduced T cell mitochondrial function. T cell-specific knockout of DsbA-L enhances diet-induced thermogenesis in brown adipose tissue (BAT) and protects mice from HFD-induced obesity, hepatosteatosis, and insulin resistance. Mechanistically, DsbA-L deficiency in T cells reduces IFN-γ production and activates protein kinase A by reducing phosphodiesterase-4D expression, leading to increased BAT thermogenesis. Taken together, our study uncovers a mechanism by which T cells communicate with brown adipocytes to regulate BAT thermogenesis and whole-body energy homeostasis. Our findings highlight a therapeutic potential of targeting T cells for the treatment of over nutrition-induced obesity and its associated metabolic diseases.

scholarly journals Role of Perivascular Adipose Tissue-Derived Adiponectin in Vascular Homeostasis

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1485
Author(s):  
Adrian Sowka ◽  
Pawel Dobrzyn
Keyword(s):  
Endothelial Cells ◽  
Adipose Tissue ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Vascular Wall ◽  
Whole Body ◽  
Perivascular Adipose Tissue

Studies of adipose tissue biology have demonstrated that adipose tissue should be considered as both passive, energy-storing tissue and an endocrine organ because of the secretion of adipose-specific factors, called adipokines. Adiponectin is a well-described homeostatic adipokine with metabolic properties. It regulates whole-body energy status through the induction of fatty acid oxidation and glucose uptake. Adiponectin also has anti-inflammatory and antidiabetic properties, making it an interesting subject of biomedical studies. Perivascular adipose tissue (PVAT) is a fat depot that is conterminous to the vascular wall and acts on it in a paracrine manner through adipokine secretion. PVAT-derived adiponectin can act on the vascular wall through endothelial cells and vascular smooth muscle cells. The present review describes adiponectin’s structure, receptors, and main signaling pathways. We further discuss recent studies of the extent and nature of crosstalk between PVAT-derived adiponectin and endothelial cells, vascular smooth muscle cells, and atherosclerotic plaques. Furthermore, we argue whether adiponectin and its receptors may be considered putative therapeutic targets.

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