Sexually dimorphic responses to fat loss after caloric restriction or surgical lipectomy

2007 ◽  
Vol 293 (1) ◽  
pp. E316-E326 ◽  
Author(s):  
Haifei Shi ◽  
April D. Strader ◽  
Stephen C. Woods ◽  
Randy J. Seeley

White adipose tissue is the principal site for lipid accumulation. Males and females maintain distinctive white adipose tissue distribution patterns. Specifically, males tend to accumulate relatively more visceral fat, whereas females accumulate relatively more subcutaneous fat. The phenomenon of maintaining typical sex-specific fat distributions suggests sex-specific mechanisms that regulate energy balance and adiposity. We used two distinct approaches to reduce fat mass, caloric restriction (CR), and surgical fat removal (termed lipectomy) and assessed parameters involved in the regulation of energy balance. We found that male and female mice responded differentially to CR- and to lipectomy-induced fat loss. Females decreased energy expenditure during CR or after lipectomy. In contrast, males responded by eating more food during food return after CR or after lipectomy. Female CR mice conserved subcutaneous fat, whereas male CR mice lost adiposity equally in the subcutaneous and visceral depots. In addition, female mice had a reduced capability to restore visceral fat after fat loss. After CR, plasma leptin levels decreased in male but not in female mice. The failure to increase food intake after returning to ad libitum intake in females could be due to the relatively stable levels of leptin. In summary, we have found sexual dimorphisms in the response to fat loss that point to important underlying differences in the strategies by which male and female mice regulate body weight.

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Akhila Ramakrishna ◽  
Cheryl A Conover

Abstract Background: Adipose tissue is a heterogeneous endocrine organ with tremendous capability for expansion. The antithetical pathogenicity of visceral adipose tissue (VAT), compared to subcutaneous adipose tissue (SAT), has been linked to the metabolic stress of enlarging mature adipocytes and a limited ability to recruit new adipocytes. One of the major distinguishing features of VAT preadipocytes is the high expression of Pregnancy Associated Plasma Protein–A (PAPP-A) when compared to SAT. PAPP-A is a zinc metalloprotease that is secreted, and can associate with the cell surface in an autocrine or paracrine fashion. It is the only known physiological IGFBP-4 (Insulin-like Growth Factor Binding Protein) protease. It cleaves the IGF/IGFBP-4 complex, releasing IGF, making it more bio-available for receptor engagement and downstream signaling. The role of IGFs in adipogenic differentiation is well established. While there is quantitative depot-specific variability in PAPP-A expression among preadipocytes, mature adipocytes do not express any PAPP-A. These findings suggest that there may be a relationship between PAPP-A inhibition and adipogenic differentiation and maturation. Similar to human VAT, PAPP-A expression is highest in visceral fat in murine models. The PAPP-A KO mice, when fed a high fat diet, showed restrained visceral adiposity and decreased visceral adipocyte size, suggesting that PAPP-A could regulate adipogenesis locally in tissues that express high PAPP-A. Hypothesis: PAPP-A inhibition is a novel anti-obesity treatment strategy. Methods/Results: We fed 20 male and 20 female wild type mice 42% high fat diet (HFD) starting at 10 weeks of age. Concomitantly, we treated 10 mice in each group with either mAb-PA1/41 (a PAPP-A neutralizing monoclonal antibody) or IgG2a (control isotope), intraperitoneally at a dose of 30 mg/kg weekly for the duration of the HFD. At the end of 15 weeks, the mice were sacrificed and the adipose tissue, serum and solid organs were harvested. Compared to the control (IgG2a) mice, the mAb-PA1/41 treated male and female mice gained 40% less weight (P = 0.03) and had smaller visceral fat depots (mesenteric and pericardial). Also, when we looked at individual adipocyte size, the drug treated mice had 45% smaller mesenteric adipocytes (P = 0.002) and 44% smaller pericardial adipocytes (P= 0.003). Also, the visceral depots in the drug treated mice had 30% more cells (P = 0.006). In both groups, there was decreased liver lipid content (P=0.005). The mAb-PA1/41 treatment had no significant effect on subcutaneous fat depots. Conclusion: Pharmacologic inhibition of PAPP-A decreased weight gain, visceral fat depot weight, visceral adipocyte size, hepatic lipid deposition and increased visceral adipocyte cell number in both male and female mice that were fed a high fat diet.


Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1999-P ◽  
Author(s):  
HYE LIM NOH ◽  
SUJIN SUK ◽  
RANDALL H. FRIEDLINE ◽  
KUNIKAZU INASHIMA ◽  
DUY A. TRAN ◽  
...  

2021 ◽  
Vol 22 (11) ◽  
pp. 6025
Author(s):  
Masaki Kobayashi ◽  
Yusuke Deguchi ◽  
Yuka Nozaki ◽  
Yoshikazu Higami

Peroxisome proliferator-activated receptor γ coactivator-1 α (PGC-1α) regulates mitochondrial DNA replication and mitochondrial gene expression by interacting with several transcription factors. White adipose tissue (WAT) mainly comprises adipocytes that store triglycerides as an energy resource and secrete adipokines. The characteristics of WAT vary in response to systemic and chronic metabolic alterations, including obesity or caloric restriction. Despite a small amount of mitochondria in white adipocytes, accumulated evidence suggests that mitochondria are strongly related to adipocyte-specific functions, such as adipogenesis and lipogenesis, as well as oxidative metabolism for energy supply. Therefore, PGC-1α is expected to play an important role in WAT. In this review, we provide an overview of the involvement of mitochondria and PGC-1α with obesity- and caloric restriction-related physiological changes in adipocytes and WAT.


2015 ◽  
Vol 9 (11-12) ◽  
pp. 795 ◽  
Author(s):  
Ilker Akarken ◽  
Hüseyin Tarhan ◽  
Rahmi Gökhan Ekin ◽  
Özgür Çakmak ◽  
Gökhan Koç ◽  
...  

Introduction: We examined the relationship between stone disease and the amount of visceral adipose tissue measured with unenhanced computed tomography (CT).Methods: We included 149 patients with complaints of flank pain and kidney stones detected by CT, from August 2012 to April 2013. In addition, as the control group we included 139 healthy individuals, with flank pain within the same time period, with no previous history of urological disease and no current kidney stones identified by CT. Patients were analyzed for age, gender, body mass index, amount of visceral and subcutaneous adipose tissue, and serum level of low-density lipoprotein and triglyceride.Results: There were no differences between groups in terms of gender and age (p = 0.27 and 0.06, respectively). Respective measurements for the stone and control groups for body mass index were 29.1 and 27.6 kg/m2; for visceral fat measurement 186.0 and 120.2 cm2; and for subcutaneous fat measurements 275.9 and 261.9 cm2 (p = 0.01; 0.01 and 0.36, respectively). Using multivariate analysis, the following factors were identified as increasing the risk of kidney stone formation: hyperlipidemia (p = 0.003), hypertension (p = 0.001), and ratio of visceral fat tissue to subcutaneous fat tissue (p = 0.01). Our study has its limitations, including its retrospective nature, its small sample size, possible selection bias, and missing data. The lack of stone composition data is another major limitation of our study.Conclusion: The ratio of visceral to subcutaneous adipose tissue, in addition to obesity, hyperlipidemia, and hypertension, was identified as an emerging factor in the formation of kidney stones.


2018 ◽  
Vol 75 (6) ◽  
pp. 1042-1049
Author(s):  
Seongjoon Park ◽  
Erkhembayar Nayantai ◽  
Toshimitsu Komatsu ◽  
Hiroko Hayashi ◽  
Ryoichi Mori ◽  
...  

Abstract The orexigenic hormone neuropeptide Y (NPY) plays a pivotal role in the peripheral regulation of fat metabolism. However, the mechanisms underlying the effects of sex on NPY function have not been extensively analyzed. In this study, we examined the effects of NPY deficiency on fat metabolism in male and female mice. Body weight was slightly decreased, whereas white adipose tissue (WAT) mass was significantly decreased as the thermogenic program was upregulated in NPY-/- female mice compared with that in wild-type mice; these factors were not altered in response to NPY deficiency in male mice. Moreover, lack of NPY resulted in an increase in luteinizing hormone (LH) expression in the pituitary gland, with concomitant activation of the estradiol-mediated thermogenic program in inguinal WAT, and alleviated age-related modification of adiposity in female mice. Taken together, these data revealed a novel intracellular mechanism of NPY in the regulation of fat metabolism and highlighted the sexual dimorphism of NPY as a promising target for drug development to reduce postmenopausal adiposity.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A806-A806
Author(s):  
Rachel Bell ◽  
Elisa Villalobos ◽  
Mark Nixon ◽  
Allende Miguelez-Crespo ◽  
Matthew Sharp ◽  
...  

Abstract Glucocorticoids play a critical role in metabolic homeostasis. Chronic or excessive activation of the glucocorticoid receptor (GR) in adipose tissue contributes to metabolic disorders such as glucose intolerance and insulin resistance. Steroid-metabolising enzymes in adipose, such as 11β-HSD1 or 5α-reductase, modulate the activation of GR by converting primary glucocorticoids into more or less potent ligands. Carbonyl reductase 1 (CBR1) is a novel regulator of glucocorticoid metabolism, converting corticosterone/cortisol to 20β-dihydrocorticosterone/cortisol (20β-DHB/F); a metabolite which retains GR activity. CBR1 is abundant in adipose tissue and increased in obese adipose of mice and humans1 and increased Cbr1 expression is associated with increased fasting glucose1. We hypothesised that increased Cbr1/20β-DHB in obese adipose contributes to excessive GR activation and worsens glucose tolerance. We generated a novel murine model of adipose-specific Cbr1 over-expression (R26-Cbr1Adpq) by crossing conditional knock-in mice with Adiponectin-Cre mice. CBR1 protein and activity were doubled in subcutaneous adipose tissue of male and female R26-Cbr1Adpq mice compared with floxed controls; corresponding to a two-fold increase 20β-DHB (1.6 vs. 4.2ng/g adipose; P=0.0003; n=5-7/group). There were no differences in plasma 20β-DHB or corticosterone. Bodyweight, lean or fat mass, did not differ between male or female R26-Cbr1Adpq mice and floxed controls. Lean male R26-Cbr1Adpq mice had higher fasting glucose (9.5±0.3 vs. 8.4±0.3mmol/L; P=0.04) and worsened glucose tolerance (AUC 1819±66 vs. 1392±14; P=0.03). Female R26-Cbr1Adpq mice also had a worsened glucose tolerance but fasting glucose was not altered with genotype. There were no differences in fasting insulin or non-esterified fatty acid between genotypes in either sex. Expression of GR-induced genes Pnpla2, Gilz and Per1, were increased in adipose of R26-Cbr1Adpq mice. Following high-fat diet induced obesity, no differences in bodyweight, lean or fat mass, with genotype were observed in male and female mice, and genotype differences in fasting glucose and glucose tolerance were abolished. In conclusion, adipose-specific over-expression of Cbr1 in lean male and female mice led to increased levels of 20β-DHB in adipose but not plasma, and both sexes having worsened glucose tolerance. The influence of adipose CBR1/20β-DHB on glucose tolerance was not associated with altered fat mass or bodyweight and was attenuated by high-fat diet-induced obesity. These metabolic consequences of Cbr1 manipulation require careful consideration given the wide variation in CBR1 expression in the human population, the presence of inhibitors and enhancers in many foodstuffs and the proposed use of inhibitors as an adjunct for cancer treatment regimens. Reference: Morgan et al., Scientific Reports. 2017; 7.


2021 ◽  
Author(s):  
Dhanya Dhanyalayam ◽  
Kezia Lizardo ◽  
Neelam Oswal ◽  
Hariprasad Thangavel ◽  
Enriko Dolgov ◽  
...  

Coronavirus disease-2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2; CoV2) is a deadly contagious infectious disease. For those who survived COVID-19, post-COVID cardiac damage poses a major threat for the progression of cardiomyopathy and heart failure. Currently, the number of COVID-related cases and deaths is increasing in Latin America, where a major COVID comorbidity is Chagas heart disease (caused by the parasite Trypanosoma cruzi). Here, we investigated the effect of T. cruzi infection on the pathogenesis and severity of CoV2 infection and, conversely, the effect of CoV2 infection on heart pathology during coinfection. We used transgenic human angiotensin-converting enzyme 2 (huACE2) mice infected with CoV2, T. cruzi, or coinfected with both in this study. Our study shows for the first time that white adipose tissue (WAT) serves as a reservoir for CoV2 and the persistence of CoV2 in WAT alters adipose tissue morphology and adipocyte physiology. Our data demonstrate a correlation between the loss of fat cells and the pulmonary adipogenic signaling and pathology in CoV2 infection. The viral load in the lungs is inversely proportional to the viral load in WAT, which differs between male and female mice. Our findings also suggest that adiponectin-PPAR signaling may differently regulate Chagas cardiomyopathy in coinfected males and females. We conclude that adipogenic signaling may play important roles in cardio-pulmonary pathogenesis during CoV2 infection and T. cruzi coinfection. The levels of adiponectin isomers differ between male and female mice during CoV2 infection and coinfection with T. cruzi, which may differently regulate inflammation, viral load, and pathology in the lungs of both the sexes. Our findings are in line with other clinical observations that reported that males are more susceptible to COVID-19 than females and suffer greater pulmonary damage.


2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Christine Vrakas ◽  
Sheri E Keleman ◽  
Rosario Scalia ◽  
Michael V Autieri

Uncontrolled inflammation leads to many of the chronic diseases associated with obesity. Due to a lack of oxygen in the tissue, expanding adipose tissue becomes hypoxic and pro-inflammatory. Adipocytes release pro-angiogenic factors in an effort to restore blood flow to the tissue. Presently, little is known about the potential for endogenously expressed anti-inflammatory cytokines to attenuate inflammation and also provide pro-angiogenic effects. IL-19 is uniquely anti-inflammatory, pro-angiogenic and is both expressed by and targets various cells types. IL-19 expression in adipocytes and stromal vascular cells is increased in visceral compared to subcutaneous fat, and is also increased in visceral fat on high fat diet (HFD) compared to normal chow diet. There is no known mechanism to explain the role of IL-19 in adipose tissue expansion, and we hypothesized that IL-19 may have pro-angiogenic and anti-inflammatory properties in expanding adipose tissue. We have identified a gene regulatory factor, Interleukin Enhancer-Binding Factor 3 (ILF3) that is induced in adipocytes and stromal vascular cells by HFD and IL-19 treatment. We found that both IL-19 and VEGF induce ILF3 expression in cultured human endothelial cells (hECs). Proliferation is significantly reduced when ILF3 is knocked down using siRNA in hECs. Furthermore, when ILF3 is knocked down and hECs are stimulated with VEGF several angiogenic cytokines are also decreased. Through immunohistochemistry we found that ILF3 translocates from the nucleus to the cytoplasm in visceral fat of C57BL/6 mice fed a HFD, and remains in the nucleus when fed a normal chow diet. In summary IL-19 may be a unique HFD responsive adipokine functioning to reduce inflammation and increase angiogenesis in expanding adipose tissue. The angiogenic function of IL-19 may work through induction of the gene regulatory factor, ILF3.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Eung Ju Kim ◽  
Hong Seog Seo ◽  
Sungeun Kim ◽  
Jin Oh Na ◽  
Jae Hyoung Park ◽  
...  

Background: Visceral adipose tissue is thought to confer increased cardiovascular risk through leukocyte infiltration and increased adipose macrophage activity. Previous positron emission tomography (PET) studies using fluorodeoxyglucose (FDG) demonstrated that increased FDG uptake could reflect the severity of inflammation in atherosclerotic plaque. We hypothesized that active atherosclerotic change in the major arteries would accompany increased inflammation within visceral fat and it could be detected in humans using combined FDG PET/computed tomography (CT). Methods: We observed 44 consecutive subjects with cardiovascular disease. For all of them, an one-hour PET/CT (from brain to foot) was performed after injection of FDG (370–555 MBq). FDG uptake in the aorta or its major branches was evaluated visually and semiquantitatively. Maximal standard uptake values (SUV) of the highest regions of interest were calculated in the subcutaneous fat and visceral fat area, separately. Results: Significant FDG uptake in the arterial wall was noted in 21 patients (plaque positive; PP group), all of whom have experienced acute cardiovascular events (acute coronary syndrome or ischemic stroke) within a week. The other 23 patients (plaque negative; PN group) had chronic stable angina or asymptomatic carotid stenosis. Visceral fat SUV was significantly higher as compared to subcutaneous fat SUV (0.49± 0.15 vs. 0.15± 0.05, p< 0.001) in PP group, whereas there was no significant difference in PN group (0.18± 0.07 vs. 0.16± 0.03, p= 0.622). When we compared two groups, PP group showed higher visceral fat SUV than PN group (p< 0.001). In terms of subcutaneous fat SUV, the results were similar in two groups (p= 0.773). Conclusions: We demonstrated that atherosclerotic plaque inflammation was associated with increased inflammation within visceral fat. Our results need to be confirmed by comparison with histologic or other imaging findings. Further evaluation to determine whether metabolic activity of visceral adipose tissue is a marker or mediator of vascular inflammation is also needed.


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