Viscoelastic Properties of Ovine Adipose Tissue Covering the Gluteus Muscles

2007 ◽  
Vol 129 (6) ◽  
pp. 924-930 ◽  
Author(s):  
Amit Gefen ◽  
Einat Haberman
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Time Course ◽  
Elastic Moduli ◽  
Tissue Injury ◽  
Numerical Models ◽  
Rate Dependency ◽  
Confined Compression ◽  
Short Term ◽  
Aggregate Modulus

Pressure-related deep tissue injury (DTI) is a life-risking form of pressure ulcers threatening immobilized and neurologically impaired patients. In DTI, necrosis of muscle and enveloping adipose tissues occurs under intact skin, owing to prolonged compression by bony prominences. Modeling the process of DTI in the buttocks requires knowledge on viscoelastic mechanical properties of the white adipose tissue covering the gluteus muscles. However, this information is missing in the literature. Our major objectives in this study were therefore to (i) measure short-term (HS) and long-term (HL) aggregate moduli of adipose tissue covering the glutei of sheep, (ii) determine the effects of preconditioning on HS and HL, and (iii) determine the time course of stress relaxation in terms of the transient aggregate modulus H(t) in nonpreconditioned (NPC) and preconditioned (PC) tissues. We tested 20 fresh tissue specimens (from 20 mature animals) in vitro: 10 specimens in confined compression for obtaining the complete H(t) response to a ramp-and-hold protocol (ramp rate of 300mm∕s), and 10 other specimens in swift indentations for obtaining comparable short-term elastic moduli at higher ramp rates (2000mm∕s). We found that HS in confined compression were 28.9±14.9kPa and 18.1±6.9kPa for the NPC and PC specimens, respectively. The HL property, 10.3±4.2kPa, was not affected by preconditioning. The transient aggregate modulus H(t) always reached the plateau phase (less than 10% difference between H(t) and HL) within 2min, which is substantially shorter than the times for DTI onset reported in previous animal studies. The short-term elastic moduli at high indentation rates were 22.6±10kPa and 15.8±9.4kPa for the NPC and PC test conditions, respectively. Given a Poisson’s ratio of 0.495, comparison of short-term elastic moduli between the high and slow rate tests indicated a strong deformation-rate dependency. The most relevant property for modeling adipose tissue as related to DTI is found to be HL, which is conveniently unaffected by preconditioning. The mechanical characteristics of white adipose tissue provided herein are useful for analytical as well as numerical models of DTI, which are essential for understanding this serious malady.

scholarly journals Peripheral Blood Mononuclear Cell Metabolism Acutely Adapted to Postprandial Transition and Mainly Reflected Metabolic Adipose Tissue Adaptations to a High-Fat Diet in Minipigs

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1816 ◽  
Author(s):  
Yuchun Zeng ◽  
Jérémie David ◽  
Didier Rémond ◽  
Dominique Dardevet ◽  
Isabelle Savary-Auzeloux ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Peripheral Blood ◽  
Time Course ◽  
Mononuclear Cells ◽  
Cell Metabolism ◽  
Whole Body ◽  
High Fat ◽  
Short Term ◽  
Peripheral Blood Mononuclear ◽  
First Time

Although peripheral blood mononuclear cells (PBMCs) are widely used as a valuable tool able to provide biomarkers of health and diseases, little is known about PBMC functional (biochemistry-based) metabolism, particularly following short-term nutritional challenges. In the present study, the metabolic capacity of minipig PBMCs to respond to nutritional challenges was explored at the biochemical and molecular levels. The changes observed in enzyme activities following a control test meal revealed that PBMC metabolism is highly reactive to the arrival of nutrients and hormones in the circulation. The consumption, for the first time, of a high fat–high sucrose (HFHS) meal delayed or sharply reduced most of the observed postprandial metabolic features. In a second experiment, minipigs were subjected to two-month HFHS feeding. The time-course follow-up of metabolic changes in PBMCs showed that most of the adaptations to the new diet took place during the first week. By comparing metabolic (biochemical and molecular) PMBC profiles to those of the liver, skeletal muscle, and adipose tissue, we concluded that although PBMCs conserved common features with all of them, their response to the HFHS diet was closely related to that of the adipose tissue. As a whole, our results show that PBMC metabolism, particularly during short-term (postprandial) challenges, could be used to evaluate the whole-body metabolic status of an individual. This could be particularly interesting for early diagnosis of metabolic disease installation, when fasting clinical analyses fail to diagnose the path towards the pathology.

scholarly journals Direct Delivery of Metformin to Subcutaneous White Adipose Tissue and Brown Adipose Tissue for Combating Obesity

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1603-1603
Author(s):  
Mehrnaz Abbasi ◽  
Shu Wang
Keyword(s):  
Adipose Tissue ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
White Adipose Tissue ◽  
Time Course ◽  
Direct Injection ◽  
Area Under The Curve ◽  
P Value ◽  
Brown Adipose ◽  
Direct Delivery

Abstract Objectives Obesity and its comorbidities are major public health problems worldwide. The transformation of white adipose tissue (WAT) to brown adipose tissue (BAT); browning of WAT, may serve as a promising strategy for combating obesity. Metformin is not only the first line of drug for type 2 diabetes but also has an anti-obesity potential. Emerging evidence suggests that metformin can reduce body weight and enhance energy expenditure via activating BAT or browning of WAT. However, metformin delivery to adipose tissue is limited due to the lack of adipocyte-specific surface markers. Thus, the direct injection might be an alternative. Methods ApoE3-Leiden.human cholesteryl ester transfer protein (E3L.CETP) mice (5 mice/group) were fed a high-fat diet (HFD) for 15 weeks. From week 10 to 15, mice were randomly divided into 3 groups as 1. Metformin inguinal WAT (IgWAT) injection, 2. Metformin delivery to interscapular BAT (IBAT) and 3. Saline IgWAT injection (HFD control). Mice received injections twice per week (40 mg/kg/week). Bodyweight (BW), body composition, food intake, energy expenditure and glucose tolerance test (GTT) were measured. Gene expression of beige or brown makers was analyzed using real time-PCR. Results Compared to HFD control mice, IgWAT- and IBAT-treated mice lost 2.16% and 1.9% more of their body fat, respectively (P-value < 0.001). IgWAT- and IBAT-treated mice had 1.09- and 1.24-fold lower area under the curve calculated from the GTT time course than HFD control mice, respectively, but the differences were not statistically significant. The metabolic cage data indicated that both IgWAT- and IBAT-treated mice compared to HFD control mice had significantly decreased respiration exchange ratio (RER) (P < 0.0001). IgWAT-treated mice had significantly lower IgWAT weight than the HFD control mice (P < 0.05). IgWAT-treated compared to HFD control mice had 1.5-, 2-, 2.7- and 3-fold higher expression of UCP1, PRDM16, TMEM26 and Elovl3 in IgWAT, respectively. Conclusions This study demonstrated that local delivery of metformin to IgWAT and IBAT decreased BW and fat mass, which were associated with reduced RER and improved glucose homeostasis. Direct delivery of metformin to IgWAT and IBAT might be an efficient approach for combating obesity via inducing IgWAT browning and enhancing IBAT activity. Funding Sources NIH 1R15AT010395 and AHA 19AIREA34480011.

scholarly journals Cold-induced lipid dynamics and transcriptional programs in white adipose tissue

BMC Biology ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Ziye Xu ◽  
Wenjing You ◽  
Yanbing Zhou ◽  
Wentao Chen ◽  
Yizhen Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
White Adipose Tissue ◽  
Cold Exposure ◽  
Fatty Acid Elongation ◽  
Rna Seq ◽  
Short Term ◽  
Lipid Dynamics ◽  
Expression Of Genes

Abstract Background In mammals, cold exposure induces browning of white adipose tissue (WAT) and alters WAT gene expression and lipid metabolism to boost adaptive thermogenesis and maintain body temperature. Understanding the lipidomic and transcriptomic profiles of WAT upon cold exposure provides insights into the adaptive changes associated with this process. Results Here, we applied mass spectrometry and RNA sequencing (RNA-seq) to provide a comprehensive resource for describing the lipidomic or transcriptome profiles in cold-induced inguinal WAT (iWAT). We showed that short-term (3-day) cold exposure induces browning of iWAT, increases energy expenditure, and results in loss of body weight and fat mass. Lipidomic analysis shows that short-term cold exposure leads to dramatic changes of the overall composition of lipid classes WAT. Notably, cold exposure induces significant changes in the acyl-chain composition of triacylglycerols (TAGs), as well as the levels of glycerophospholipids and sphingolipids in iWAT. RNA-seq and qPCR analysis suggests that short-term cold exposure alters the expression of genes and pathways involved in fatty acid elongation, and the synthesis of TAGs, sphingolipids, and glycerophospholipids. Furthermore, the cold-induced lipid dynamics and gene expression pathways in iWAT are contrary to those previously observed in metabolic syndrome, neurodegenerative disorders, and aging, suggesting beneficial effects of cold-induced WAT browning on health and lifespan. Conclusion We described the significant alterations in the composition of glyphospholipids, glycerolipids, and sphingolipids and expression of genes involved in thermogenesis, fatty acid elongation, and fatty acid metabolism during the response of iWAT to short-term cold exposure. We also found that some changes in the levels of specific lipid species happening after cold treatment of iWAT are negatively correlated to metabolic diseases, including obesity and T2D.

scholarly journals A Single Bout of Fasting (24 h) Reduces Basal Cytokine Expression and Minimally Impacts the Sterile Inflammatory Response in the White Adipose Tissue of Normal Weight F344 Rats

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Kristin J. Speaker ◽  
Madeline M. Paton ◽  
Stewart S. Cox ◽  
Monika Fleshner
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Visceral Obesity ◽  
Normal Weight ◽  
Sterile Inflammation ◽  
Short Term ◽  
Stress Injury ◽  
Dietary Strategy ◽  
Access To Food ◽  
F344 Rats

Sterile inflammation occurs when inflammatory proteins are increased in blood and tissues by nonpathogenic states and is a double-edged sword depending on its cause (stress, injury, or disease), duration (transient versus chronic), and inflammatory milieu. Short-term fasting can exert a host of health benefits through unknown mechanisms. The following experiment tested if a 24 h fast would modulate basal and stress-evoked sterile inflammation in plasma and adipose. Adult male F344 rats were either randomized toad libitumaccess to food or fasted for 24 h prior to 0 (control), 10, or 100, 1.5 mA-5 s intermittent, inescapable tail shocks (IS). Glucose, nonesterified free fatty acids (NEFAs), insulin, leptin, and corticosterone were measured in plasma and tumor necrosis factor- (TNF-)α, interleukin- (IL-) 1β, IL-6, and IL-10 in plasma, and subcutaneous, intraperitoneal, and visceral compartments of white adipose tissue (WAT). In control rats, a 24 h fast reduced all measured basal cytokines in plasma and visceral WAT, IL-1βand IL-6 in subcutaneous WAT, and IL-6 in intraperitoneal WAT. In stressed rats (IS), fasting reduced visceral WAT TNF-α, subcutaneous WAT IL-1β, and plasma insulin and leptin. Short-term fasting may thus prove to be a useful dietary strategy for reducing peripheral inflammatory states associated with visceral obesity and chronic stress.

Metabolic and cellular plasticity in white adipose tissue I: effects of β3-adrenergic receptor activation

2005 ◽  
Vol 289 (4) ◽  
pp. E608-E616 ◽  
Author(s):  
James G. Granneman ◽  
Pipeng Li ◽  
Zhengxian Zhu ◽  
Yuyan Lu
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Mitochondrial Biogenesis ◽  
Time Course ◽  
Target Genes ◽  
Cellular Proliferation ◽  
Receptor Activation ◽  
Gene Profiling ◽  
Acid Oxidation ◽  
Catabolic Activity

Selective agonists of β3-adrenergic receptors (Adrb3) exhibit potent anti-diabetes properties in rodent models when given chronically, yet the mechanisms involved are poorly understood. A salient feature of chronic Adrb3 activation is pronounced remodeling of white adipose tissue (WAT), which includes mitochondrial biogenesis and elevation of metabolic rate. To gain insights into potential mechanisms underlying WAT remodeling, the time course of remodeling induced by the Adrb3 agonist CL-316,243 (CL) was analyzed using histological, physiological, and global gene profiling approaches. The results indicate that continuous CL treatment induced a transient proinflammatory response that was followed by cellular proliferation among stromal cells and multilocular adipoctyes. CL treatment strongly fragmented the central lipid storage droplet of mature adipocytes and induced mitochondrial biogenesis within these cells. Mitochondrial biogenesis was correlated with the upregulation of genes involved in fatty acid oxidation and mitochondrial electron transport activity. The elevated catabolic activity of WAT was temporally correlated with upregulation of peroxisome proliferator-activated receptor-α and its target genes, suggesting involvement of this transcription factor in coordinating the gene program that elevates WAT catabolic activity.

scholarly journals Buenos Aires, June 2021 Inhibition of Mitochondrial Fission by Drp-1 Blockade by Short-Term Leptin and Mdvi-1 Treatment Improves White Adipose Tissue Abnormalities in Obesity and Diabetes

2021 ◽  
Author(s):  
Paola Finocchietto ◽  
Hernán Perez ◽  
Guillermo Blanco ◽  
Verónica Miksztowicz ◽  
Clarisa Marotte ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Mitochondrial Dysfunction ◽  
White Adipose Tissue ◽  
Mitochondrial Biogenesis ◽  
Blood Glucose Concentration ◽  
Mitochondrial Dynamics ◽  
Short Term ◽  
Obesity And Diabetes

Background. Obesity and type 2 diabetes are chronic diseases characterized by insulin resistance, mitochondrial dysfunction and morphology abnormalities. Objective . Herein, we investigated if dysregulation of mitochondrial dynamics and biogenesis is involved in an animal model of obesity and diabetes. Methods . The effect of short-term leptin and mdivi-1 –a selective inhibitor of Drp-1 fission-protein– treatment on mitochondrial dynamics and biogenesis was evaluated in epididymal white adipose tissue (WAT) from male ob/ob mice. Results . An increase in Drp-1 protein levels and a decrease in Mfn2 and OPA-1 protein expression were observed with enhanced and sustained mitochondrial fragmentation in ob/ob mice compared to wt C57BL/6 animals (p<0.05). The content of mitochondrial DNA and mRNA expression of PGC-1α –both parameters of mitochondrial biogenesis– were reduced in ob/ob mice (p<0.05). Leptin and mdivi-1 treatment significantly increased mitochondrial biogenesis, improved fusion-to-fission balance and attenuated mitochondrial dysfunction, thus inducing white-to-beige adipocyte transdifferentiation. Measurements of glucose and lipid oxidation in adipocytes revealed that both leptin and mdivi-1 increase substrates oxidation while in vivo determination of blood glucose concentration showed decreased levels by 50% in ob/ob mice, almost to the wt level. Conclusions. Pharmacological targeting of Drp-1 fission protein may be a potential novel therapeutic tool for obesity and type 2 diabetes.

scholarly journals Short-term High-fat Overfeeding Does Not Induce NF-κB Inflammatory Signaling in Subcutaneous White Adipose Tissue

2020 ◽  
Vol 105 (7) ◽  
pp. 2162-2176
Author(s):  
Rebecca Dewhurst-Trigg ◽  
Alex J Wadley ◽  
Rachel M Woods ◽  
Lauren B Sherar ◽  
Nicolette C Bishop ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Body Mass ◽  
White Adipose Tissue ◽  
Density Lipoprotein ◽  
Total Content ◽  
Lipoprotein Cholesterol ◽  
High Fat ◽  
Short Term ◽  
Inflammatory Signaling ◽  
Phosphorylation Of Proteins

Abstract Context It is unclear how white adipose tissue (WAT) inflammatory signaling proteins respond during the early stages of overnutrition. Objective To investigate the effect of short-term, high-fat overfeeding on fasting abdominal subcutaneous WAT total content and phosphorylation of proteins involved in nuclear factor-κB (NF-κB) inflammatory signaling, systemic metabolic and inflammatory biomarkers. Design Individuals consumed a high-fat (65% total energy from total fat), high-energy (50% above estimated energy requirements) diet for 7 days. Results Fifteen participants (aged 27 ± 1 years; body mass index 24.4 ± 0.6 kg/m2) completed the study. Body mass increased following high-fat overfeeding (+1.2 ± 0.2 kg; P &lt; 0.0001). However, total content and phosphorylation of proteins involved in NF-κB inflammatory signaling were unchanged following the intervention. Fasting serum glucose (+0.2 ± 0.0 mmol/L), total cholesterol (+0.4 ± 0.1 mmol/L), low-density lipoprotein cholesterol (+0.3 ± 0.1 mmol/L), high-density lipoprotein cholesterol (+0.2 ± 0.0 mmol/L), and lipopolysaccharide-binding protein (LBP; +4.7 ± 2.1 µg/mL) increased, whereas triacylglycerol concentrations (−0.2 ± 0.1 mmol/L) decreased following overfeeding (all P &lt; 0.05). Systemic biomarkers (insulin, soluble cluster of differentiation 14 [CD14], C-reactive protein, interleukin-6, tumor necrosis factor-α and monocyte chemoattractant protein-1) and the proportion and concentration of circulating CD14+ monocytes were unaffected by overfeeding. Conclusion Acute lipid oversupply did not impact on total content or phosphorylation of proteins involved in WAT NF-κB inflammatory signaling, despite modest weight gain and metabolic alterations. Systemic LBP, which is implicated in the progression of low-grade inflammation during the development of obesity, increased in response to a 7-day high-fat overfeeding period.

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