The origin and purpose of layers of subcutaneous adipose tissue in pigs and man

Author(s):  
Gary J. Hausman

AbstractAdipose tissue exists in many locations or depots that differ from one another based on numerous and various characteristics. The unique “layered” anatomical feature of subcutaneous adipose tissue (SAT) in man and the pig is reviewed and discussed. The origin of fetal pig adipose tissue subcutaneous layers is reviewed before the onset of adipogenesis and after the overt adipogenesis. Furthermore, the distinguishing characteristics of developing outer SAT layer (OSQ) and middle SAT layer (MSQ) in pigs are reviewed. These characteristics include adipocyte hypertrophy, metabolism and genetic regulation. The MSQ layer is the major layer in the pig and expands to the greatest degree in obesity and growth. Abdominal SAT in man is composed of deep SAT (dSAT) and superficial SAT (sSAT) layers. Clearly, dSAT expands disproportionally more than sSAT with increasing obesity in Caucasian males which precipitates a number of human pathologies associated with increased adiposity. We reviewed the considerable evidence that demonstrates the distinction between sSAT and dSAT which includes higher levels of saturated fatty acids (FAs) and greater levels of lipolysis in dSAT. Furthermore, dSAT expresses more metabolic and inflammatory genes. Studies comparing visceral adipose tissue (VAT) and dSAT indicate that both depots are implicated in insulin resistance (IR) and other human pathologies. Epigenetic studies of MSQ and dSAT have begun to indicate a role for DNA methylation in gene regulation of these depots. Further studies of dSAT and MSQ are warranted as they are clearly a major manifestation of obesity.

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 1032
Author(s):  
Lesgui Alviz ◽  
David Tebar-García ◽  
Raquel Lopez-Rosa ◽  
Eva M. Galan-Moya ◽  
Natalia Moratalla-López ◽  
...  

In diabetes mellitus type 2 (DM2), developed obesity is referred to as diabesity. Implementation of a healthy diet, such as the Mediterranean, prevents diabesity. Saffron is frequently used in this diet because of its bioactive components, such as crocetin (CCT), exhibit healthful properties. It is well known that obesity, defined as an excessive accumulation of fat, leads to cardiometabolic pathology through adiposopathy or hypertrophic growth of adipose tissue (AT).This is related to an impaired adipogenic process or death of adipocytes by obesogenic signals. We aimed to evaluate the effect of the pathogenic microenvironment and CCT, activating differentiation of healthy preadipocytes (PA). For this, we used human cryopreserved PA from visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) depots obtained from healthy and obese-DM2 donors. We studied the effect of a metabolically detrimental (diabesogenic) environment, generated by obese-DM2 adipocytes from VAT (VdDM) or SAT (SdDM), on the viability and accumulation of intracellular fat of adipocytes differentiated from healthy PA, in the presence or absence of CCT (1 or 10 μM). Intracellular fat was quantified by Oil Red O staining. Cytotoxicity was measured using the MTT assay. Our results showed that diabesogenic conditions induce cytotoxicity and provide a proadipogenic environment only for visceral PA. CCT at 10 μM acted as an antiadipogenic and cytoprotective compound.


2000 ◽  
Vol 83 (04) ◽  
pp. 545-548 ◽  
Author(s):  
Vanessa Van Harmelen ◽  
Johan Hoffstedt ◽  
Per Lundquist ◽  
Hubert Vidal ◽  
Veronika Stemme ◽  
...  

SummaryHigh plasma plasminogen activator inhibitor-1 (PAI-1) activity is a frequent finding in obesity and adipose tissue has recently been suggested to be a source of circulating PAI-1 in humans. In the present study, differences in adipose tissue gene expression and protein secretion rate of PAI-1 between subcutaneous and visceral adipose tissue was analysed in specimens obtained from 22 obese individuals. The secretion rate of PAI-1 was two-fold higher in subcutaneous adipose tissue than in visceral adipose tissue (292 ± 50 vs 138 ± 24 ng PAI-1/107 cells, P <0.05). In accordance with the secretion data, subcutaneous adipose tissue contained about three-fold higher levels of PAI-1 mRNA than visceral adipose tissue (2.43 ± 0.37 vs 0.81 ± 0.12 attomole PAI-1 mRNA/µg total RNA, P <0.001). PAI-1 secretion from subcutaneous but not from visceral adipose tissue correlated significantly with cell size (r = 0.43, P <0.05). In summary, subcutaneous adipose tissue secreted greater amounts of PAI-1 and had a higher PAI-1 gene expression than visceral adipose tissue from the same obese individuals. Bearing in mind that subcutaneous adipose tissue is the largest fat depot these finding may be important for the coagulation abnormalities associated with obesity.


2021 ◽  
Vol 8 ◽  
Author(s):  
Xiaoyu Wang ◽  
Yifan Li ◽  
Mingyu Sun ◽  
Gaoyue Guo ◽  
Wanting Yang ◽  
...  

Mounting evidence has suggested the clinical significance of body composition abnormalities in the context of cirrhosis. Herein, we aimed to investigate the association between visceral adiposity and malnutrition risk in 176 hospitalized patients with cirrhosis. The adiposity parameters were obtained by computed tomography (CT) as follows: total adipose tissue index (TATI), visceral adipose tissue index (VATI), subcutaneous adipose tissue index (SATI), and visceral to subcutaneous adipose tissue area ratio (VSR). Malnutrition risk was screened using Royal Free Hospital-Nutritional Prioritizing Tool (RFH-NPT). Visceral adiposity was determined given a higher VSR based on our previously established cutoffs. Multivariate analysis implicated that male gender (OR = 2.884, 95% CI: 1.360–6.115, p = 0.006), BMI (OR = 0.879, 95% CI: 0.812–0.951, P = 0.001), albumin (OR = 0.934, 95% CI: 0.882–0.989, P = 0.019), and visceral adiposity (OR = 3.413, 95% CI: 1.344–8.670, P = 0.010) were independent risk factors of malnutrition risk. No significant difference was observed regarding TATI, SATI, and VATI among patients with low or moderate and high risk of malnutrition. In contrast, the proportion of male patients embracing visceral adiposity was higher in high malnutrition risk group compared with that in low or moderate group (47.27 vs. 17.86%, p = 0.009). Moreover, this disparity was of borderline statistical significance in women (19.05 vs. 5.88%, p = 0.061). Assessing adipose tissue distribution might potentiate the estimation of malnutrition risk in cirrhotics. It is pivotal to recognize visceral adiposity and develop targeted therapeutic strategies.


PLoS ONE ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. e0175133 ◽  
Author(s):  
Inga Schlecht ◽  
Wolfram Gronwald ◽  
Gundula Behrens ◽  
Sebastian E. Baumeister ◽  
Johannes Hertel ◽  
...  

2005 ◽  
Vol 288 (5) ◽  
pp. E930-E934 ◽  
Author(s):  
Neda Rasouli ◽  
Ulrika Raue ◽  
Leslie M. Miles ◽  
Tong Lu ◽  
Gina B. Di Gregorio ◽  
...  

Patients with insulin resistance often manifest increased intramyocellular lipid (IMCL) along with increased visceral adipose tissue. This study was designed to determine whether the insulin sensitizer drugs pioglitazone and metformin would improve glucose intolerance and insulin sensitivity by decreasing IMCL. In this study, 23 generally healthy subjects with impaired glucose tolerance were randomized to receive either pioglitazone 45 mg/day or metformin 2,000 mg/day for 10 wk. Before and after treatment, we measured insulin sensitivity and abdominal subcutaneous and visceral adipose tissue with CT scanning. In addition, muscle biopsies were performed for measurement of IMCL and muscle oxidative enzymes. After treatment with pioglitazone, 2-h glucose fell from 9.6 mmol/l (172 mg/dl) to 6.1 mmol/l (119 mg/dl), whereas there was no change in 2-h glucose with metformin. With pioglitazone treatment, there was a 65% increase in insulin sensitivity along with a 34% decrease in IMCL (both P ≤ 0.002). This decrease in IMCL was not due to increased muscle lipid oxidation, as there were no changes in muscle lipid oxidative enzymes. However, pioglitazone resulted in a 2.6-kg weight gain along with a significant decrease in the visceral-to-subcutaneous adipose tissue ratio. In contrast, metformin treatment resulted in no change in insulin sensitivity, IMCL, oxidative enzymes, or adipose tissue volumes. Pioglitazone improved glucose tolerance and insulin sensitivity by reducing IMCL. This reduction in IMCL was not due to an increase in muscle lipid oxidation but to a diversion of lipid from ectopic sites into subcutaneous adipose tissue.


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