Augmented expression and secretion of adipose-derived pigment epithelium-derived factor does not alter local angiogenesis or contribute to the development of systemic metabolic derangements

2014 ◽  
Vol 306 (12) ◽  
pp. E1367-E1377 ◽  
Author(s):  
Thomas V. Lakeland ◽  
Melissa L. Borg ◽  
Maria Matzaris ◽  
Amany Abdelkader ◽  
Roger G. Evans ◽  
...  

Impaired coupling of adipose tissue expansion and vascularization is proposed to lead to adipocyte hypoxia and inflammation, which in turn contributes to systemic metabolic derangements. Pigment epithelium-derived factor (PEDF) is a powerful antiangiogenic factor that is secreted by adipocytes, elevated in obesity, and implicated in the development of insulin resistance. We explored the angiogenic and metabolic role of adipose-derived PEDF through in vivo studies of mice with overexpression of PEDF in adipocytes (PEDF-aP2). PEDF expression in white adipocytes and PEDF secretion from adipose tissue was increased in transgenic mice, but circulating levels of PEDF were not increased. Overexpression of PEDF did not alter vascularization, the partial pressure of O2, cellular hypoxia, or gene expression of inflammatory markers in adipose tissue. Energy expenditure and metabolic substrate utilization, body mass, and adiposity were not altered in PEDF-aP2 mice. Whole body glycemic control was normal as assessed by glucose and insulin tolerance tests, and adipocyte-specific glucose uptake was unaffected by PEDF overexpression. Adipocyte lipolysis was increased in PEDF-aP2 mice and associated with increased adipose triglyceride lipase and decreased perilipin 1 expression. Experiments conducted in mice rendered obese by high-fat feeding showed no differences between PEDF-aP2 and wild-type mice for body mass, adiposity, whole body energy expenditure, glucose tolerance, or adipose tissue oxygenation. Together, these data indicate that adipocyte-generated PEDF enhances lipolysis but question the role of PEDF as a major antiangiogenic or proinflammatory mediator in adipose tissue in vivo.

2013 ◽  
Vol 66 (5-6) ◽  
pp. 259-262
Author(s):  
Goran Marusic ◽  
Dimitrije Jeremic ◽  
Sasa Vojinov ◽  
Natasa Filipovic ◽  
Milan Popov

In addition to the metabolic role of vitamin D, which is well known and clearly defined, there have been many hypotheses regarding its anti-proliferative and pro-apoptotic role. Epidemiology and Significance of Prostate Cancer. Prostate cancer is the second most common malignancy in men. Long period of cancerogenesis, available tumor markers and high incidence make this cancer ideal for preventive measures. Physiological Role of Vitamin D and its Effect on Prostate Cancer Cells. In vitro and in vivo studies have shown the anti-proliferative and pro-apoptopic role of vitamin D. Disorders of vitamin D metabolism are noted in vitamin D gene level, vitamin D receptor, vitamin D responsive elements and androgen receptors. We present the most important effect of those changes on vitamin D metabolism. Conclusion. Available studies on vitamin D level in serum, prostate tissue, observed activity of vitamin D enzymes and genetic changes give us only a slight insight into the basic mechanisms of vitamin D action in the development of prostate cancer; therefore, further investigations are needed.


1986 ◽  
Vol 251 (5) ◽  
pp. E576-E583 ◽  
Author(s):  
L. H. Storlien ◽  
D. E. James ◽  
K. M. Burleigh ◽  
D. J. Chisholm ◽  
E. W. Kraegen

High levels of dietary fat may contribute to both insulin resistance and obesity in humans but evidence is limited. The euglycemic clamp technique combined with tracer administration was used to study insulin action in vivo in liver and individual peripheral tissues after fat feeding. Basal and nutrient-stimulated metabolic rate was assessed by open-circuit respirometry. Adult male rats were pair-fed isocaloric diets high in either carbohydrate (69% of calories; HiCHO) or fat (59% of calories; HiFAT) for 24 +/- 1 days. Feeding of the HiFAT diet resulted in a greater than 50% reduction in net whole-body glucose utilization at midphysiological insulin levels (90-100 mU/l) due to both reduced glucose disposal and, to a lesser extent, failure to suppress liver glucose output. Major suppressive effects of the HiFAT diet on glucose uptake were found in oxidative skeletal muscles (29-61%) and in brown adipose tissue (BAT; 78-90%), the latter accounting for over 20% of the whole-body effect. There was no difference in basal metabolic rate but thermogenesis in response to glucose ingestion was higher in the HiCHO group. In contrast to their reduced BAT weight, the HiFAT group accumulated more white adipose tissue, consistent with reduced energy expenditure. HiFAT feeding also resulted in major decreases in basal and insulin-stimulated conversion of glucose to lipid in liver (26-60%) and brown adipose tissue (88-90%) with relatively less effect in white adipose (0-43%). We conclude that high-fat feeding results in insulin resistance due mainly to effects in oxidative skeletal muscle and BAT.(ABSTRACT TRUNCATED AT 250 WORDS)


Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 756
Author(s):  
Paweł A. Kołodziejski ◽  
Ewa Pruszyńska-Oszmałek ◽  
Tatiana Wojciechowicz ◽  
Maciej Sassek ◽  
Natalia Leciejewska ◽  
...  

Peptide hormones play a prominent role in controlling energy homeostasis and metabolism. They have been implicated in controlling appetite, the function of the gastrointestinal and cardiovascular systems, energy expenditure, and reproduction. Furthermore, there is growing evidence indicating that peptide hormones and their receptors contribute to energy homeostasis regulation by interacting with white and brown adipose tissue. In this article, we review and discuss the literature addressing the role of selected peptide hormones discovered in the 21st century (adropin, apelin, elabela, irisin, kisspeptin, MOTS-c, phoenixin, spexin, and neuropeptides B and W) in controlling white and brown adipogenesis. Furthermore, we elaborate how these hormones control adipose tissue functions in vitro and in vivo.


2019 ◽  
Author(s):  
Lu Zhang ◽  
Chris E. Shannon ◽  
Terry M. Bakewell ◽  
Muhammad A. Abdul-Ghani ◽  
Marcel Fourcaudot ◽  
...  

AbstractObjectiveThe angiopoietin-like protein (ANGPTL) family represents a promising therapeutic target for dyslipidemia, which is a feature of obesity and type 2 diabetes (T2DM). The aim of the present study was to determine the metabolic role of ANGPTL8 and to investigate its nutritional, hormonal and molecular regulation in key metabolic tissues.MethodsThe metabolism of ANGPTL8 knockout mice (ANGPTL8−/−) was examined in mice following chow and high-fat diets (HFD). The regulation of ANGPTL8 expression by insulin and glucose was quantified using a combination of in vivo insulin clamp experiments in mice and in vitro experiments in hepatocytes and adipocytes. The role of AMPK signaling was examined, and the transcriptional control of ANGPTL8 was determined using bioinformatic and luciferase reporter approaches.ResultsThe ANGPTL8−/−mice had improved glucose tolerance and displayed reduced fed and fasted plasma triglycerides. However, there was no reduction in steatosis in ANGPTL8−/−mice after the HFD. Insulin acutely activated ANGPTL8 expression in liver and adipose tissue, which was mediated by C/EBPβ. Using insulin clamp experiments we observed that glucose further enhanced ANGPTL8 expression in the presence of insulin in adipocytes only. The activation of AMPK signaling potently suppressed the effect of insulin on ANGPTL8 expression in hepatocytes.ConclusionThese data show that ANGPTL8 plays an important metabolic role in mice that may extend beyond triglyceride metabolism. The finding that insulin and glucose have distinct roles in regulating ANGPTL8 expression in liver and adipose tissue may provide important clues about the function of ANGPTL8 in these tissues.


2020 ◽  
Vol 318 (5) ◽  
pp. E613-E624
Author(s):  
Lu Zhang ◽  
Chris E. Shannon ◽  
Terry M. Bakewell ◽  
Muhammad A. Abdul-Ghani ◽  
Marcel Fourcaudot ◽  
...  

The angiopoietin-like protein (ANGPTL) family represents a promising therapeutic target for dyslipidemia, which is a feature of obesity and type 2 diabetes (T2DM). The aim of the present study was to determine the metabolic role of ANGPTL8 and to investigate its nutritional, hormonal, and molecular regulation in key metabolic tissues. The regulation of Angptl8 gene expression by insulin and glucose was quantified using a combination of in vivo insulin clamp experiments in mice and in vitro experiments in primary and cultured hepatocytes and adipocytes. The role of AMPK signaling was examined, and the transcriptional control of Angptl8 was determined using bioinformatic and luciferase reporter approaches. The metabolism of Angptl8 knockout mice (ANGPTL8−/−) was examined following chow and high-fat diets (HFD). Insulin acutely increased Angptl8 expression in liver and adipose tissue, which involved the CCAAT/enhancer-binding protein (C/EBPβ) transcription factor. In insulin clamp experiments, glucose further enhanced Angptl8 expression in the presence of insulin in adipose tissue. The activation of AMPK signaling antagonized the effect of insulin on Angptl8 expression in hepatocytes and adipocytes. The ANGPTL8−/− mice had improved glucose tolerance and displayed reduced fed and fasted plasma triglycerides. However, there was no change in body weight or steatosis in ANGPTL8−/− mice after the HFD. These data show that ANGPTL8 plays important metabolic roles in mice that extend beyond triglyceride metabolism. The finding that insulin, glucose, and AMPK signaling regulate Angptl8 expression may provide important clues about the distinct function of ANGPTL8 in these tissues.


1998 ◽  
Vol 275 (2) ◽  
pp. E249-E258 ◽  
Author(s):  
Dympna Gallagher ◽  
Daniel Belmonte ◽  
Paul Deurenberg ◽  
Zimian Wang ◽  
Norman Krasnow ◽  
...  

Investigators have expressed interest in the associations between resting energy expenditure (REE) and body mass for over a century. Traditionally, descriptive models using regression analysis are applied, linking REE with metabolically active compartments such as body cell mass (BCM) and fat-free body mass (FFM). Recently developed whole body magnetic resonance imaging (MRI) and echocardiography methods now allow estimation of all major organs and tissue volumes in vivo. Because measured values are available for REE, BCM, and FFM content of individual organs and tissues, it should now be possible to develop energy expenditure-body composition estimation models based on MRI-measured organ-tissue volumes. Specifically, the present investigation tested the hypothesis that in vivo estimation of whole body REE, BCM, and FFM is possible using MRI- and echocardiography-derived organ volumes combined with previously reported organ-tissue metabolic rates and chemical composition. Thirteen subjects (5 females, 8 males) had REE, BCM, and FFM measured by indirect calorimetry, whole body40K counting, and dual-energy X-ray absorptiometry, respectively. Models developed from estimated and measured variables were highly correlated, with no significant differences between those estimated and measured [e.g., calculated vs. measured REE: r = 0.92, P < 0.001; (mean ± SD) 6,962 ± 1,455 and 7,045 ± 1,450 kJ/day, respectively ( P = not significant)]. Strong associations were observed between REE, individual or combined organ weights, BCM, and FFM that provide new insights into earlier observed metabolic phenomona. The present approach, the first to establish an energy expenditure-body composition link with a mechanistic model in vivo, has the potential to greatly expand our knowledge of energy expenditure-body size relationships in humans.


2018 ◽  
Vol 8 (1) ◽  
pp. 62 ◽  
Author(s):  
Julianna Maria Santos ◽  
Fazle Hussain

Background: Reduced levels of magnesium can cause several diseases and increase cancer risk. Motivated by magnesium chloride’s (MgCl2) non-toxicity, physiological importance, and beneficial clinical applications, we studied its action mechanism and possible mechanical, molecular, and physiological effects in prostate cancer with different metastatic potentials.Methods: We examined the effects of MgCl2, after 24 and 48 hours, on apoptosis, cell migration, expression of epithelial mesenchymal transition (EMT) markers, and V-H+-ATPase, myosin II (NMII) and the transcription factor NF Kappa B (NFkB) expressions.Results: MgCl2 induces apoptosis, and significantly decreases migration speed in cancer cells with different metastatic potentials.  MgCl2 reduces the expression of V-H+-ATPase and myosin II that facilitates invasion and metastasis, suppresses the expression of vimentin and increases expression of E-cadherin, suggesting a role of MgCl2 in reversing the EMT. MgCl2 also significantly increases the chromatin condensation and decreases NFkB expression.Conclusions: These results suggest a promising preventive and therapeutic role of MgCl2 for prostate cancer. Further studies should explore extending MgCl2 therapy to in vivo studies and other cancer types.Keywords: Magnesium chloride, prostate cancer, migration speed, V-H+-ATPase, and EMT.


2002 ◽  
Vol 130 (2) ◽  
pp. 233-240 ◽  
Author(s):  
E. GRUNEBAUM ◽  
M. BLANK ◽  
S. COHEN ◽  
A. AFEK ◽  
J. KOPOLOVIC ◽  
...  

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2114
Author(s):  
Yusheng Liang ◽  
Nana Ma ◽  
Danielle N. Coleman ◽  
Fang Liu ◽  
Yu Li ◽  
...  

The objective was to perform a proof-of-principle study to evaluate the effects of methionine (Met) and arginine (Arg) supply on protein abundance of amino acid, insulin signaling, and glutathione metabolism-related proteins in subcutaneous adipose tissue (SAT) explants under ceramide (Ce) challenge. SAT from four lactating Holstein cows was incubated with one of the following media: ideal profile of amino acid as the control (IPAA; Lys:Met 2.9:1, Lys:Arg 2:1), increased Met (incMet; Lys:Met 2.5:1), increased Arg (incArg; Lys:Arg 1:1), or incMet plus incArg (Lys:Met 2.5:1 Lys:Arg 1:1) with or without 100 μM exogenous cell-permeable Ce (N-Acetyl-d-sphingosine). Ceramide stimulation downregulated the overall abundance of phosphorylated (p) protein kinase B (AKT), p-mechanistic target of rapamycin (mTOR), and p-eukaryotic elongation factor 2 (eEF2). Without Ce stimulation, increased Met, Arg, or Met + Arg resulted in lower p-mTOR. Compared with control SAT stimulated with Ce, increased Met, Arg, or Met + Arg resulted in greater activation of mTOR (p-mTOR/total mTOR) and AKT (p-AKT/total AKT), with a more pronounced response due to Arg. The greatest protein abundance of glutathione S-transferase Mu 1 (GSTM1) was detected in response to increased Met supply during Ce stimulation. Ceramide stimulation decreased the overall protein abundance of the Na-coupled neutral amino acid transporter SLC38A1 and branched-chain alpha-ketoacid dehydrogenase kinase (BCKDK). However, compared with controls, increased Met or Arg supply attenuated the downregulation of BCKDK induced by Ce. Circulating ceramides might affect amino acid, insulin signaling, and glutathione metabolism in dairy cow adipose tissue. Further in vivo studies are needed to confirm the role of rumen-protected amino acids in regulating bovine adipose function.


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