Relationship between fat cell size and number and fatty acid composition in adipose tissue from different fat depots in overweight/obese humans

Hypolipidemic effect and modulation of hepatic enzymes by different edible oils in obese Wistar rats

The current study assessed the hypolipidemic effect and modulation of hepatic enzymes by different edible oils in obese Wistar rats. In order to conduct this study, 36 Wistar rats that were collected at 5 weeks of age and weighed an average of 70 g were split into two groups: 28 of them were fed a high-fat diet (HFD) and 8 of them were fed a control diet. After 5 weeks of feeding, rats from the HFD (obese, n = 4) and the control diet group (n = 4) were sacrificed. Subsequently, the rest of obese rats (n = 24) were separated into six groups, including the continuing high-fat (CHF) diet group, rice bran oil (RBO) diet group, olive oil (OO) diet group, soybean oil (SO) diet group, cod liver oil (CLO) diet group, and sunflower oil (SFO) diet group, and the continuing control diet group (n = 4). Rats from each group were sacrificed following an additional 5 weeks, and all analytical tests were carried out. The results found that the interventions of RBO, CLO, and SFO in obese rats reduced their body weight non-significantly when compared with CHF. It was also observed that a non-significant reduction in weight of the heart, AAT, and EAT occurred by RBO, OO, SO, and CLO, while SFO reduced the AAT level significantly (p < 0.05). Besides, RBO, OO, SO, CLO, and SFO decreased IBAT and liver fat significantly compared to CHF. Similarly, the administration of RBO, OO, SO, and CLO reduced ALT significantly. RBO reduced GGT (p < 0.05) significantly, but other oils did not. The given oil has the efficiency to reduce TC, TAG, and LDL-C but increase HDL-C significantly. These findings suggest that different edible oils can ameliorate obesity, regulate lipid profiles, and modulate hepatic enzymes.

Human Omental Mature Adipocytes used as Paclitaxel Reservoir for Cell-Based Therapy in Ovarian Cancer

Primary human omental adipocytes and ovarian cancer(OC) cells establish a bidirectional communication in which tumor driven lipolysis is induced in adipocytes and the resulting fatty acids are delivered to cancer cells within the tumor microenvironment. Despite meaningful improvement in the treatment of OC, its efficacy is still limited by hydrophobicity and untargeted effects related to chemotherapeutics. Herein, omental adipocytes are firstly used as a reservoir for paclitaxel, named Living Paclitaxel Bullets (LPB) and secondly benefit from the established dialogue between adipocytes and cancer cells to engineer a drug delivery process that target specifically cancer cells. These results show that mature omental adipocytes can successfully uptake paclitaxel and deliver it to OC cells in a transwell coculture based in vitro model. In addition, the efficacy of this proof-of-concept has been demonstrated in vivo and induces a significant inhibition of tumor growth on a xenograft tumor model. The use of mature adipocytes can be suitable for clinical prospection in a cell-based therapy system, due to their mature and differentiated state, to avoid risks related to uncontrolled cell de novo proliferation capacity after the delivery of the antineoplastic drug as observed with other cell types when employed as drug carriers.

Synergistic effect rescue animal model from NASH caused by diet-inflammation inducer

Excessive intake of pro-inflammatory fatty acids is related to the development of insulin resistance, impaired oxidative stress enzymes, and lipid disorders, leading to inflammation and development of non-alcoholic steatohepatitis (NASH). Diet and physical exercise are considered to prevent and treat metabolic disorders caused by chronic inflammatory states (responsible for insulin resistance and diabetes type 2) in individuals with obesity and nonalcoholic fatty liver diseases (NAFLD). Our investigation tested the hypothesis that Hass avocado oil, a monounsaturated fatty acid and a source of phytosterol, may improve liver and metabolic parameters without adverse effects when combined with physical exercise. Rats ingested a high-fat diet for seven weeks and were then subjected to more six weeks with a standard diet, Hass avocado-oil ingestion, and swimming. The intervention showed significantly improvements by synergistic effect between Hass avocado-oil and swimming exercise (P < 0.05), including improving adiponectin, leptin, and fasting blood glucose levels, alleviating insulin resistance, reducing serum TNF-α, improving glutathione enzyme levels, and decreasing lipotoxicity in the liver and blood and serum triacylglycerides in blood (P < 0.05). Liver tissue markers of apoptosis and necrosis such as CK-18 filaments and dimethylamine (DMA) were significantly higher in the intervention group (P < 0.05). We were unable to fully confirm our hypothesis. Although the synergistic effects between Hass avocado-oil and the swimming regimen offer a promising chance of recovering liver health by improving 10 health biological markers, we must not ignore the cellular damage due to apoptosis and necrosis in liver cells and DMA. The data on metabolomic profile and avocado-oil-treated livers highlight the need for further investigation.

Diabetes noninvasive diagnostics and monitoring through volatile biomarkers analysis in the exhaled breath using optical absorption spectroscopy

The review is aimed on the analysis the abilities of noninvasive diagnostics and monitoring of diabetes mellitus (DM) and DM-associated complications through volatile molecular biomarkers detection in the exhaled breath. The specific biochemical reactions in the body of DM patients and their associations with volatile molecular biomarkers in the breath are considered. The applications of optical spectroscopy methods, including UV, IR, and terahertz spectroscopy for DM-associated volatile molecular biomarkers measurements, are described. The applications of similar technique combined with machine learning methods in DM diagnostics using the profile of DM-associated volatile molecular biomarkers in exhaled air or "pattern-recognition" approach are discussed.

Dietary Assessment for Weight Management and Health Maintenance

An adequate dietary assessment is essential for improving the eating habits of the population and preventing health problems such as obesity and cardiovascular diseases [...].

Mimicking lipolytic, adipogenic, and secretory capacities of human subcutaneous adipose tissue by spheroids from distinct subpopulations of adipose stromal/stem cells

Background: Adipose tissue engineering may provide 3D models for the understanding of diseases such as obesity and type II diabetes. Recently, distinct adipose stem/stromal cell (ASC) subpopulations were identified from subcutaneous adipose tissue (SAT): superficial (sSAT), deep (dSAT), and the superficial retinacula cutis (sRC). This study aimed to test these subpopulations ASCs in 3D spheroid culture induced for adipogenesis under a pro-inflammatory stimulus with lipopolysaccharide (LPS). Methods: The samples of abdominal human subcutaneous adipose tissue were obtained during plastic aesthetic surgery (Protocol 145/09). Results: ASC spheroids showed high response to adipogenic induction in sSAT. All ASC spheroids increased their capacity to lipolysis under LPS. However, spheroids from dSAT were higher than from sSAT (p = 0.0045) and sRC (p = 0.0005). Newly formed spheroids and spheroids under LPS stimulus from sSAT showed the highest levels of fatty acid-binding protein 4 (FABP4) and CCAAT/enhancer-binding protein-α (C/EBPα) mRNA expression compared with dSAT and sRC (p < 0.0001). ASC spheroids from sRC showed the highest synthesis of angiogenic cytokines such as vascular endothelial growth factor (VEGF) compared with dSAT (p < 0.0228). Under LPS stimulus, ASC spheroids from sRC showed the highest synthesis of pro-inflammatory cytokines such as IL-6 compared with dSAT (p < 0.0092). Conclusion: Distinct physiological properties of SAT can be recapitulated in ASC spheroids. In summary, the ASC spheroid from dSAT showed the greatest lipolytic capacity, from sSAT the greatest adipogenic induction, and sRC showed greater secretory capacity when compared to the dSAT. Together, all these capacities form a true mimicry of SAT and hold the potential to contribute for a deeper understanding of cellular and molecular mechanisms in healthy and unhealthy adipose tissue scenarios or in response to pharmacological interventions.

Adipose tissue fatty acids as biomarkers for metabolic dysfunction in obese females: Implication of menopause and ageing

Fatty acids (FA) are biomarkers of metabolic dysfunction. Adipose tissue is the largest reservoir of FA and acts differently in obese individuals. Menopause by itself significantly alters metabolism, lipid metabolism dysregulation, and adipose tissue distribution. How adipose tissue FA alters an obese individual's metabolism depending on a female's menopausal status is yet poorly understood. Hence, the subcutaneous (scAT) and visceral adipose tissue (vAT) FA profile for 173 obese premenopausal and postmenopausal women was measured and associated with biochemical parameters. scAT and vAT FA profiles were distinct by themselves and in menopause. In total 816 associations were found with biochemical parameters, where only 58 were independent of the menopausal status. The associations found to emphasize the importance of assessing the adipose tissue FA profile and how their behavior changes with menopause. The FA are crucial in metabolic processes and can be helpful biomarkers in the prevention/treatment and follow-up of female obesity.

Habitual nappers and non-nappers differ in circadian rhythms of LIPE expression in abdominal adipose tissue explants

Background and purpose

Napping is a widespread practice worldwide and has in recent years been linked to increased abdominal adiposity. Lipase E or LIPE encodes the protein hormone-sensitive lipase (HSL), an enzyme that plays an important role in lipid mobilization and exhibits a circadian expression rhythm in human adipose tissue. We hypothesized that habitual napping may impact the circadian expression pattern of LIPE, which in turn may attenuate lipid mobilization and induce abdominal fat accumulation.

Methods

Abdominal adipose tissue explants from participants with obesity (n = 17) were cultured for a 24-h duration and analyzed every 4 h. Habitual nappers (n = 8) were selected to match non-nappers (n = 9) in age, sex, BMI, adiposity, and metabolic syndrome traits. Circadian LIPE expression rhythmicity was analyzed using the cosinor method.

Results

Adipose tissue explants exhibited robust circadian rhythms in LIPE expression in non-nappers. In contrast, nappers had a flattened rhythm. LIPE amplitude was decreased in nappers as compared with non-nappers (71% lower). The decrease in amplitude among nappers was related to the frequency of napping (times per week) where a lower rhythm amplitude was associated with a higher napping frequency (r = -0.80; P = 0.018). Confirmatory analyses in the activity of LIPE's protein (i.e., HSL) also showed a significant rhythm in non-nappers, whereas significance in the activity of HSL was lost among nappers.

Conclusion

Our results suggest that nappers display dysregulated circadian LIPE expression as well as dysregulated circadian HSL activity, which may alter lipid mobilization and contribute to increased abdominal obesity in habitual nappers.

β-Hydroxy-β-methyl Butyrate Regulates the Lipid Metabolism, Mitochondrial Function, and Fat Browning of Adipocytes

A growing number of in vivo studies demonstrated that β-hydroxy-β-methyl butyrate (HMB) can serve as a lipid-lowering nutrient. Despite this interesting observation, the use of adipocytes as a model for research is yet to be explored. To ascertain the effects of HMB on the lipid metabolism of adipocytes and elucidate the underlying mechanisms, the 3T3-L1 cell line was employed. Firstly, serial doses of HMB were added to 3T3-L1 preadipocytes to evaluate the effects of HMB on cell proliferation. HMB (50 µM) significantly promoted the proliferation of preadipocytes. Next, we investigated whether HMB could attenuate fat accumulation in adipocytes. The results show that HMB treatment (50 µM) reduced the triglyceride (TG) content. Furthermore, HMB was found to inhibit lipid accumulation by suppressing the expression of lipogenic proteins (C/EBPα and PPARγ) and increasing the expression of lipolysis-related proteins (p-AMPK, p-Sirt1, HSL, and UCP3). We also determined the concentrations of several lipid metabolism-related enzymes and fatty acid composition in adipocytes. The HMB-treated cells showed reduced G6PD, LPL, and ATGL concentrations. Moreover, HMB improved the fatty acid composition in adipocytes, manifested by increases in the contents of n6 and n3 PUFAs. The enhancement of the mitochondrial respiratory function of 3T3-L1 adipocytes was confirmed via Seahorse metabolic assay, which showed that HMB treatment elevated basal mitochondrial respiration, ATP production, H⁺ leak, maximal respiration, and non-mitochondrial respiration. In addition, HMB enhanced fat browning of adipocytes, and this effect might be associated with the activation of the PRDM16/PGC-1α/UCP1 pathway. Taken together, HMB-induced changes in the lipid metabolism and mitochondrial function may contribute to preventing fat deposition and improving insulin sensitivity.

The role of high serum triglyceride levels on pancreatic necrosis development and related complications

BACKGROUND

The relevance of elevated serum triglyceride (TG) levels in the early stages of acute pancreatitis (AP) not induced by hypertriglyceridemia (HTG) remains unclear. Our study aims to determine the role of elevated serum TG levels at admission in developing pancreatic necrosis.

METHODS

We analyzed the clinical data collected prospectively from patients with AP. According to TG levels measured in the first 24 h after admission, we stratified patients into four groups: Normal TG (< 150 mg/dL), Borderline-high TG (150-199 mg/dL), High TG (200-499 mg/dL) and Very high TG (≥ 500 mg/dL). We analyzed the association of TG levels and other risk factors with the development of pancreatic necrosis.

RESULTS

A total of 211 patients were included. In the Normal TG group: 122, in Borderline-high TG group: 38, in High TG group: 44, and in Very high TG group: 7. Pancreatic necrosis developed in 29.5% of the patients in the Normal TG group, 26.3% in the Borderline-high TG group, 52.3% in the High TG group, and 85.7% in the Very high TG group. The trend analysis observed a significant association between higher TG levels and pancreatic necrosis (p = 0.001). A multivariable analysis using logistic regression showed that elevated TG levels ≥ 200 mg/dL (High TG and Very high TG groups) were independently associated with pancreatic necrosis (OR: 3.27, 95% CI - 6.27, p < 0.001).

CONCLUSIONS

An elevated TG level at admission ≥ 200 mg/dl is independently associated with the development of pancreatic necrosis. The incidence of pancreatic necrosis increases proportionally with the severity of HTG.

Total Polyunsaturated Fatty Acid Level in Abdominal Adipose Tissue as an Independent Predictor of Recurrence-Free Survival in Women with Ovarian Cancer

Prognostic factors for epithelial ovarian cancers (EOCs) are in particular clinical factors such as pathology staging at diagnosis (FIGO stages), genetic mutation, or histological phenotypes. In the present study, FIGO stage, tumor residue after surgery, and body mass index were clinical predictors of recurrence-free survival (RFS). Nonetheless, a number of studies support a lipid metabolism disorder in ovarian cancer patients. The objective of this pilot study was to explore whether fatty acid composition of adipose reflecting the qualitative dietary intake and fatty acids metabolism may be associated with RFS. Forty-six women with EOCs and six with borderline ovarian tumors between March 2017 and January 2020 were included in this prospective study at Tours university teaching hospital (central France). The patients involved in the present study are part of the METERMUS trial (clinicaltrials.gov NCT03027479). Adipose tissue specimens from four abdominal locations (superficial and deep subcutaneous, visceral (pericolic), and omental) were collected during surgery or exploratory laparoscopy. A fatty acid profile of adipose tissue triglycerides was established by gas chromatography. Fatty acids composition was compared among the four locations using nonparametric Friedman’s ANOVA test for repeated measures. Median follow-up of EOC patients was 15 months and patients’ RFS was analyzed using Kaplan−Meier survival curves and log-rank test by separating patients into two groups according to median fatty acid levels. The content of long-chain saturated fatty acids (SFAs) was increased and that of long-chain polyunsaturated fatty acids (PUFAs) decreased in deep versus superficial subcutaneous adipose tissue in EOC patients. Nevertheless, the content of total SFAs was ~28%, monounsaturated fatty acids (MUFAs) ~55%, PUFAs n-6 ~11.5%, and PUFAs n-3 about 1.3%, whatever the adipose tissue. When EOC patients were separated into two groups by median fatty acid content, total PUFAs (n-6+n-3) levels, whatever the adipose tissue, were positively and independently associated with RFS. RFS was about two times longer in EOC patients with high versus low total PUFA content (median survival: 12 vs. 27 months, p = 0.01 to <0.0001 according to the tissue). Content of total PUFAs (n-6+n-3) in abdominal adipose tissue (visceral and subcutaneous) are new prognostic factors in EOC.

Cellular Senescence in Obesity and Associated Complications: a New Therapeutic Target

PURPOSE OF REVIEW

Obesity has increased worldwide recently and represents a major global health challenge. This review focuses on the obesity-associated cellular senescence in various organs and the role of these senescent cells (SnCs) in driving complications associated with obesity. Also, the ability to target SnCs pharmacologically with drugs termed senotherapeutics as a therapy for these complications is discussed.

RECENT FINDINGS

Several studies have shown a positive correlation between obesity and SnC burden in organs such as adipose tissue, liver, and pancreatic-β-cells. These SnCs produce several secretory factors which affect other cells and tissues in a paracrine manner resulting in organ dysfunction. The accumulation of SnCs in adipocytes affects their lipid storage and impairs adipogenesis. The inflammatory senescence-associated secretory phenotype (SASP) of SnCs downregulates the antioxidant capacity and mitochondrial function in tissues. Senescent hepatocytes cannot oxidize fatty acids, which leads to lipid deposition and senescence in β-cells decrease function. These and other adverse effects of SnCs contribute to insulin resistance and type-2 diabetes. The reduction in the SnC burden genetically or pharmacologically improves the complications associated with obesity. The accumulation of SnCs with age and disease accelerates aging. Obesity is a key driver of SnC accumulation, and the complications associated with obesity can be controlled by reducing the SnC burden. Thus, senotherapeutic drugs have the potential to be an effective therapeutic option.

Noninvasive NMR/MRS Metabolic Parameters to Evaluate Metabolic Syndrome in Rats

(1) Background: Ectopic fat deposition and its effects, metabolic syndrome, have been significantly correlated to lifestyle and caloric consumption. There is no specific noninvasive evaluation tool being used in order to establish clinical markers for tracing the metabolic pathway implicated in obesity-related abnormalities that occur in the body as a result of a high-fat diet (HFD). The purpose of this work is to investigate in vivo ectopic fat distribution and in vitro metabolite profiles given by HFDs, as well as how they are inter-related, in order to find surrogate metabolic biomarkers in the development of metabolic syndrome utilizing noninvasive approaches. (2) Methods: Male Wistar rats were divided into a standard normal chow diet, ND group, and HFD group. After 16 weeks of different diet administration, blood samples were collected for proton nuclear magnetic resonance (¹H NMR) and biochemical analysis. Magnetic resonance imaging/proton magnetic resonance spectroscopy (MRI/¹H MRS) was performed on the abdomen, liver, and psoas muscle of the rats. (3) Results: Visceral fat showed the strongest relationship with blood cholesterol. Although liver fat content (LFC) was not associated with any biophysical profiles, it had the highest correlation with metabolites such as (-CH₂)_n very-low-density lipoprotein/low-density lipoprotein (VLDL/LDL), lactate, and N-acetyl glycoprotein of serum ¹H NMR. HFD showed no obvious influence on muscle fat accumulation. Acetoacetate, N-acetyl glycoprotein, lactate, (-CH₂)_n VLDL/LDL, and valine were the five possible metabolic biomarkers used to differentiate HFD from ND in the present study. (4) Conclusions: Our study has validated the influence of long-term HFD-induced ectopic fat on body metabolism as well as the metabolic profile deterioration both in vivo and in vitro.

Immersion optical clearing of adipose tissue in rats: ex vivo and in vivo studies

Optical clearing (OC) of adipose tissue has not been studied enough, although it can be promising in medical applications, including surgery and cosmetology, for example, to visualize blood vessels or increase the permeability of tissues to laser beams. The main objective of this work is to develop technology for OC of abdominal adipose tissue in vivo using hyperosmotic optical clearing agents (OCAs). The maximum OC effect (77%) was observed for ex vivo rat adipose tissue samples exposed to OCA on fructose basis for 90 minutes. For in vivo studies, the maximum effect of OC (65%) was observed when using OCA based on diatrizoic acid and dimethylsulfoxide for 120 minutes. Histological analysis showed that in vivo application of OCAs may induce a limited local necrosis of fat cells. The efficiency of OC correlated with local tissue damage through cell necrosis due to accompanied cell lipolysis.

Accelerated fatty acid composition MRI of epicardial adipose tissue: Development and application to eplerenone treatment in a mouse model of obesity-induced coronary microvascular disease

Purpose

To develop an accelerated MRI method to quantify the epicardial adipose tissue (EAT) fatty acid composition (FAC) and test the hypothesis that eplerenone (EPL) shifts the EAT FAC toward unsaturation in obese mice.

Methods

Undersampled multi‐echo gradient echo imaging employing a dictionary‐based compressed‐sensing reconstruction and iterative decomposition with echo asymmetry and least‐squares–based mapping (IDEAL) was developed, validated, and used to study EAT in obese mice scanned at 7T. Fully sampled and rate 2, 2.5, 3, and 3.5 undersampled image data were acquired, reconstructed, and assessed using RMSE and structural similarity (SSIM). Two groups of mice were studied: untreated (control, n = 10) and EPL‐treated (n = 10) mice fed a high‐fat high‐sucrose diet. MRI included imaging of EAT FAC, EAT volume, and myocardial perfusion reserve.

Results

Rate 3 acceleration provided RMSE <5% and structural similarity >0.85 for FAC MRI. After 6 weeks of diet, EPL‐treated compared to untreated mice had a reduced EAT saturated fatty acid fraction (0.27 ± 0.09 vs. 0.39 ± 0.07, P < 0.05) and increased EAT unsaturation degree (4.37 ± 0.32 vs. 3.69 ± 0.58, P < 0.05). Also, EAT volume in EPL‐treated compared to untreated mice was reduced (8.1 ± 0.6 mg vs. 11.4 ± 0.7 mg, P < 0.01), and myocardial perfusion reserve was improved (1.83 ± 0.15 vs. 1.61 ± 0.17, P < 0.05).

Conclusion

Rate 3 accelerated FAC MRI enabled accurate quantification of EAT FAC in mice. EPL treatment shifted the EAT FAC toward increased unsaturation and was associated with improvement of coronary microvascular function.

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Linseed, Baru, and Coconut Oils: NMR-Based Metabolomics, Leukocyte Infiltration Potential In Vivo, and Their Oil Characterization. Are There Still Controversies?

Different fatty acid proportions produce potential inflammatory and metabolic changes in organisms. However, the evidence for how each fatty acid mediates the metabolic pathway, and its lipid stability remains controversial. To resolve this controversy, the present study investigated the metabolic effects of cold-pressed linseed (LG), coconut (CG), and baru (BG) oils in comparison to those of soybean oil (SG) in mice, in terms of their oil characterization and stability. The quality analysis showed less oxidative behavior among PUFA-rich oils (SO, BO, and LO, with induction periods lower than 2 h compared to 39.8 h for CG), besides the high contents of tocopherols and carotenoids in SG and LG. In the experimental study, CG presented higher triglyceride (257.93 ± 72.30) and VLDL-cholesterol levels (51.59 ± 14.46, p < 0.05), while LG reduced LDL levels (59.29 ± 7.56, p < 0.05) when compared to SG (183.14 ± 22.06, 36.63 ± 4.41 and 131.63 ± 29.0, respectively). For visceral fats, the adiposity index was lower for BG (7.32 ± 3.13) and CG (9.58 ± 1.02, p < 0.05) in relation to SG (12.53 ± 2.80), and for leukocyte recruitment, CG presented lower polymorphonuclear (PMN) (p < 0.0001) and mononuclear (MN) (p < 0.05) cell infiltration, demonstrating anti-inflammatory potential. In NMR-based metabolomics, although CG presented higher values for the glucose, lactate, and LDL/VLDL ratio, this group also evidenced high levels of choline, a lipotropic metabolite. Our study emphasized the controversies of saturated fatty acids, which impair serum lipids, while alfa-linolenic acid presented cardioprotective effects. However, coconut oil also has a positive immunomodulatory pathway and was found to reduce visceral bodyfat in mice. Therefore, for future applications, we suggest a combination of lauric and al-fa-linolenic acid sources, which are present in coconut and linseed oil, respectively. This combination could be less obesogenic and inflammatory and exert cardioprotective action.

The role of comorbid hypertriglyceridemia and abdominal obesity in the severity of acute pancreatitis: a retrospective study

Background

The effect of comorbid hypertriglyceridemia (HTG) and abdominal obesity (AO) on acute pancreatitis (AP) remains unclear. The aim of this study was to explore the effect of comorbid HTG and AO and discuss which is the dominant disorder.

Methods

In this study, 1219 AP patients who presented with HTG or AO were stratified into four groups: non-HTG + non-AO, HTG + non-AO, non-HTG + AO, and HTG + AO.

Results

The 328 patients with comorbid HTG + AO were much younger (42.29 ± 11.77), mainly male (79.57%), and had higher TG levels, larger waist circumferences, and more past medical histories than the patients in the other three non-comorbid groups (P < 0.001). The comorbidity group developed more incidences of persistent organ failure and local complications (P < 0.05). Multivariate logistic regression analysis showed that AO (OR = 3.205, 95% CI = 1.570–6.544), mild HTG (OR = 2.746, 95% CI = 1.125–6.701), and moderate to very severe HTG (OR = 3.649, 95% CI = 1.403–9.493) were independent risk factors for persistent respiratory failure (P < 0.05). Age > 60 years (OR = 1.326, 95% CI = 1.047–1.679), AO (OR = 1.701, 95% CI = 1.308–2.212), diabetes mellitus (OR = 1.551, 95% CI = 1.063–2.261), mild HTG (OR = 1.549, 95% CI = 1.137–2.112), and moderate to very severe HTG (OR = 2.810, 95% CI = 1.926–4.100) were independent risk factors associated with local complications (P < 0.05). Moreover, HTG seemed to be more dangerous than AO. The higher the serum TG level was, the greater the likelihood of persistent respiratory failure and local complications.

Conclusions

Comorbid HTG and AO will aggravate the severity and increase the incidence of local complications of AP. HTG may play a dominant role of risk in the condition of comorbidity.

Chinese clinical trial registry

ChiCTR2100049566. Registered on 3^rd August, 2021. Retrospectively registered, https://www.chictr.org.cn/edit.aspx?pid=127374&htm=4.

Dietary Patterns Characterized by Fat Type in Association with Obesity and Type 2 Diabetes: A Longitudinal Study of UK Biobank Participants

BACKGROUND

The fat type consumed is considered a risk factor for developing obesity and type 2 diabetes (T2D). However, these associations have not been investigated using a dietary patterns approach, which can capture combinations of foods and fat type consumed.

OBJECTIVES

This study aimed to investigate associations between dietary patterns with varying proportions of SFAs, MUFAs, or PUFAs and obesity, abdominal obesity, and self-reported T2D incidence.

METHODS

This study included UK Biobank participants with 2 or more 24-h dietary assessments, free from the outcome of interest at recruitment, and with outcome data at follow-up (n = 16,523; mean follow-up: 6.3 y). Reduced rank regression was used to derive dietary patterns with SFAs, MUFAs, and PUFAs (% of energy intake) as response variables. Logistic regression, adjusted for sociodemographic and health characteristics, was used to investigate the associations between dietary patterns and obesity [BMI (kg/m2) ≥30], abdominal obesity (waist circumference; men: ≥102 cm; women: ≥88 cm) and T2D incidence.

RESULTS

Two dietary patterns, DP1 and DP2, were identified: DP1 positively correlated with SFAs (r = 0.48), MUFAs (r = 0.67), and PUFAs (r = 0.56), characterized by higher intake of nuts, seeds, and butter and lower intake of fruit and low-fat yogurt; DP2 positively correlated with SFAs (r = 0.76) and negatively with PUFAs (r = -0.64) and MUFAs (r = -0.01), characterized by higher intake of butter and high-fat cheese and lower intake of nuts and seeds. Only DP2 was associated with higher obesity and abdominal obesity incidence (OR: 1.24; 95% CI: 1.02, 1.45; and OR: 1.19; 95% CI: 1.02, 1.38, respectively). Neither of the dietary patterns was associated with T2D incidence.

CONCLUSIONS

These findings provide evidence that a dietary pattern characterized by higher SFA and lower PUFA foods is associated with obesity and abdominal obesity incidence, but not T2D.

HMB Improves Lipid Metabolism of Bama Xiang Mini-Pigs via Modulating the Bacteroidetes-Acetic Acid-AMPKα Axis

Here, we used Bama Xiang mini-pigs to explore the effects of different dietary β-hydroxy-β-methylbutyrate (HMB) levels (0, 0.13, 0.64 or 1.28%) on lipid metabolism of adipose tissue. Results showed that HMB decreased the fat percentage of pigs (linearly, P < 0.05), and the lowest value was observed in the 0.13% HMB group. Moreover, the colonic acetic acid concentration and the relative Bacteroidetes abundance were increased in response to HMB supplementation (P < 0.05). Correlation analysis identified a positive correlation between the relative Bacteroidetes abundance and acetic acid production, and a negative correlation between fat percentage and the relative Bacteroidetes abundance or acetic acid production. HMB also upregulated the phosphorylation (p) of AMPKα, Sirt1, and FoxO1, and downregulated the p-mTOR expression. Collectively, these findings indicate that reduced fat percentage in Bama Xiang mini-pigs could be induced by HMB supplementation and the mechanism might be associated with the Bacteroidetes-acetic acid-AMPKα axis.

Putting ATM to BED: How Adipose Tissue Macrophages Are Affected by Bariatric Surgery, Exercise, and Dietary Fatty Acids

With increasing adiposity in obesity, adipose tissue macrophages contribute to adipose tissue malfunction and increased circulating proinflammatory cytokines. The chronic low-grade inflammation that occurs in obesity ultimately gives rise to a state of metainflammation that increases the risk of metabolic disease. To date, only lifestyle and surgical interventions have been shown to be somewhat effective at reversing the negative consequences of obesity and restoring adipose tissue homeostasis. Exercise, dietary interventions, and bariatric surgery result in immunomodulation, and for some individuals their effects are significant with or without weight loss. Robust evidence suggests that these interventions reduce chronic inflammation, in part, by affecting macrophage infiltration and promoting a phenotypic switch from the M1- to M2-like macrophages. The purpose of this review is to discuss the impact of dietary fatty acids, exercise, and bariatric surgery on cellular characteristics affecting adipose tissue macrophage presence and phenotypes in obesity.

Dissecting the Gene Expression Networks Associated with Variations in the Major Components of the Fatty Acid Semimembranosus Muscle Profile in Large White Heavy Pigs

Simple Summary

The amount and fatty acid composition of intramuscular fat are important features for the qualitative characteristics of processed and fresh meat products, but the knowledge of the key molecular drivers controlling these traits is still scant. To this aim, the present study investigated the co-expression networks of genes related to variations in the major fatty acids deposited in pig Semimembranosus muscle. Palmitic and palmitoleic acid contents were associated with a downregulation of genes involved in autophagy, mitochondrial fusion, and mitochondrial activity, suggesting that the deposition of these fatty acids may be enhanced in muscles with a reduced mitochondrial function. A higher proportion of oleic acid and a reduction in the percentages of n-6 and n-3 polyunsaturated fatty acids were related to changes in the mRNA levels of genes involved in Mitogen-Activated Protein Kinase (MAPK) signaling. The obtained results indicated gene expression networks and new candidate genes associated with the studied traits. Further studies are needed to confirm our results and identify in the discussed genes molecular markers for future selection schemes aimed at improving pork nutritional and technological quality. Furthermore, as pigs are considered reliable animal models for several human conditions, the obtained results may also be of interest for improving the knowledge of the molecular pathways associated with obesity and diabetes.

Abstract

To date, high-throughput technology such as RNA-sequencing has been successfully applied in livestock sciences to investigate molecular networks involved in complex traits, such as meat quality. Pork quality depends on several organoleptic, technological, and nutritional characteristics, and it is also influenced by the fatty acid (FA) composition of intramuscular fat (IMF). To explore the molecular networks associated with different IMF FA compositions, the Semimembranosus muscle (SM) from two groups of Italian Large White (ILW) heavy pigs divergent for SM IMF content was investigated using transcriptome analysis. After alignment and normalization, the obtained gene counts were used to perform the Weighted Correlation Network Analysis (WGCNA package in R environment). Palmitic and palmitoleic contents showed association with the same gene modules, comprising genes significantly enriched in autophagy, mitochondrial fusion, and mitochondrial activity. Among the key genes related to these FAs, we found TEAD4, a gene regulating mitochondrial activity that seems to be a promising candidate for further studies. On the other hand, the genes comprised in the modules associated with the IMF contents of oleic, n-6, and n-3 polyunsaturated FAs (PUFAs) were significantly enriched in Mitogen-Activated Protein Kinase (MAPK) signaling, in agreement with previous studies suggesting that several MAPK players may have a primary role in regulating lipid deposition. These results give an insight into the molecular cascade associated with different IMF FA composition in ILW heavy pigs. Further studies are needed to validate the results and confirm whether some of the identified key genes may be effective candidates for pork quality.

Omega-3 Polyunsaturated Fatty Acids Prevent Nonalcoholic Steatohepatitis (NASH) and Stimulate Adipogenesis

The increasing impact of obesity on global human health intensifies the importance of studies focusing on agents interfering with the metabolism and remodeling not only of the white adipose tissue (WAT) but also of the liver. In the present study, we have addressed the impact of n-3 PUFA in adipose cells' proliferation and adipogenesis, as well as in the hepatic lipid profile and morphology. Mice were induced to obesity by the consumption of a high-fat diet (HFD) for 16 weeks. At the 9th week, the treatment with fish oil (FO) was initiated and maintained until the end of the period. The FO treatment reduced the animals' body mass, plasma lipids, glucose, plasma transaminases, liver mass, triacylglycerol, and cholesterol liver content when compared to animals consuming only HFD. FO also decreased the inguinal (ing) WAT mass, reduced adipocyte volume, increased adipose cellularity (hyperplasia), and increased the proliferation of adipose-derived stromal cells (AdSCs) which corroborates the increment in the proliferation of 3T3-L1 pre-adipocytes or AdSCs treated in vitro with n-3 PUFA. After submitting the in vitro treated (n-3 PUFA) cells, 3T3-L1 and AdSCs, to an adipogenic cocktail, there was an increase in the mRNA expression of adipogenic transcriptional factors and other late adipocyte markers, as well as an increase in lipid accumulation when compared to not treated cells. Finally, the expression of browning-related genes was also higher in the n-3 PUFA treated group. We conclude that n-3 PUFA exerts an attenuating effect on body mass, dyslipidemia, and hepatic steatosis induced by HFD. FO treatment led to decreasing adiposity and adipocyte hypertrophy in ingWAT while increasing hyperplasia. Data suggest that FO treatment might induce recruitment (by increased proliferation and differentiation) of new adipocytes (white and/or beige) to the ingWAT, which is fundamental for the healthy expansion of WAT.

Facial Fat Fitness: A New Paradigm to Understand Facial Aging and Aesthetics

Traditionally, facial adipose tissue has been perceived and treated as a homogenous volume-occupying subcutaneous depot. However, recent research from across disciplines is converging to reveal a far more anatomically organized and functionally dynamic role of facial adipose tissue. In this narrative review, we will discuss new insights into adipocyte function and facial adipose anatomy that have far-reaching implications for the practice of aesthetic facial plastic surgery. These concepts are synthesized into a "facial fat fitness" model which can be used to explain clinical observations in facial aging and aesthetic surgery. Fat fitness relates to the quality of facial adipose tissue, as opposed to quantity, and describes whether adipose tissue is in a predominantly healthy hyperplastic or unhealthy hypertrophic state. Fat fitness is modulated by lifestyle factors, and may be impacted positively or negatively by facial aesthetic treatments. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Resolving the omega-3 methyl resonance with long echo time magnetic resonance spectroscopy in mouse adipose tissue at 9.4 T

Tissue omega-3 (ω-3) content is biologically important to disease; however, its quantification with magnetic resonance spectroscopy in vivo is challenging due to its low concentration. In addition, the ω-3 methyl resonance (≈ 0.98 ppm) overlaps that of the non-ω-3 (≈ 0.90 ppm), even at 9.4 T. We demonstrate that a Point-RESolved Spectroscopy (PRESS) sequence with an echo time (TE) of 109 ms resolves the ω-3 and non-ω-3 methyl peaks at 9.4 T. Sequence efficacy was verified on five oils with differing ω-3 fat content; the ω-3 content obtained correlated with that measured using 16.5 T NMR (R² = 0.97). The PRESS sequence was also applied to measure ω-3 content in visceral adipose tissue of three different groups (all n = 3) of mice, each of which were fed a different 20% w/w fat diet. The fat portion of the diet consisted of low (1.4%), medium (9.0%) or high (16.4%) ω-3 fat. The sequence was also applied to a control mouse fed a standard chow diet (5.6% w/w fat, which was 5.9% ω-3). Gas chromatography (GC) analysis of excised tissue was performed for each mouse. The ω-3 fat content obtained with the PRESS sequence correlated with the GC measures (R² = 0.96). Apparent T₂ times of methyl protons were assessed by obtaining spectra from the oils and another group of four mice (fed the high ω-3 diet) with TE values of 109 and 399 ms. Peak areas were fit to a mono-exponentially decaying function and the apparent T₂ values of the ω-3 and non-ω-3 methyl protons were 906 ± 148 and 398 ± 78 ms, respectively, in the oils. In mice, the values were 410 ± 68 and 283 ± 57 ms for ω-3 and non-ω-3 fats, respectively.

Healthy Obese Subjects Differ in Chronotype, Sleep Habits, and Adipose Tissue Fatty Acid Composition from Their Non-Healthy Counterparts

Obesity is not the same in all individuals and two different phenotypes have been described: metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO). The aim of this study was to identify factors that explain metabolic health status in a rigorously matched Spanish population. Subcutaneous and visceral fat, adipocyte size and fatty acid composition, cardiometabolic markers in serum, and lifestyle habits were assessed. Higher physical activity in the mornings (Odds Ratio (95% Confidence Interval) (OR (95% CI) = 1.54 (1.09–2.18), p = 0.01)), earlier bedtimes (8:30–10:30 pm) (OR = 2.11 (1.02–4.36), p = 0.04), a complete breakfast (OR = 1.59 (1.07–2.36), p = 0.02), and a greater number of meals per day (4.10 ± 0.05 vs. 3.93 ± 0.05, p < 0.01), were associated with the MHO phenotype. Concentrations of 20:5 n-3 eicosapentaenoic acid (0.26 ± 0.46 vs. 0.10% ± 0.11%, p = 0.04) and 18:3 n-6 gamma-linolenic acid (0.37 ± 0.24 vs. 0.23% ± 0.22%, p = 0.04) in subcutaneous adipocytes were higher and omental adipocyte size (187 094 ± 224 059 µm³ vs. 490 953 ± 229 049 µm³, p = 0.02) was lower in MHO subjects than in those with MUO. Visceral fat area differed between MHO and MUO subjects (135 ± 60 cm² vs. 178 ± 85 cm², p = 0.04, respectively). The study highlights specific lifestyle habits that could form part of obesity therapies, not only involving healthier eating habits but also earlier sleeping and exercise patterns.

Pineapple Vinegar Regulates Obesity-Related Genes and Alters the Gut Microbiota in High-Fat Diet (HFD) C57BL/6 Obese Mice

Obesity is a pandemic metabolic syndrome with increasing incidences every year. Among the significant factors that lead to obesity, overconsumption of high-fat food in daily intake is always the main contributor. Functional foods have shown a positive effect on disease prevention and provide health benefits, including counteracting obesity problem. Vinegar is one of the fermented functional beverages that have been consumed for many years, and different types of vinegar showed different bioactivities and efficacies. In this study, we investigated the potential effects of pineapple vinegar as an antiobesity agent on a high-fat diet- (HFD-) induced C57BL/6 obese mice. C57BL/6 mice were treated with pineapple vinegar (1 mL/kg BW and 0.08 mL/kg BW) for 12 weeks after 24 weeks of HFD incubation. Serum biochemistry profiles, antioxidant assays, qPCR, proteome profiler, and 16S metagenomic were done posttreatment. Our data showed that a high concentration of pineapple vinegar (1 mL/kg BW) treatment significantly (p < 0.05) reduced the bodyweight (∼20%), restored lipid profiles, increased the antioxidant activities, and reduced the oxidative stress. Besides, significant (p < 0.05) regulation of several adipokines and inflammatory-related genes was recorded. Through the regulation of gut microbiota, we found a higher abundance of Akkermansia muciniphila, a microbiota reported to be associated with obesity in the high concentration of pineapple vinegar treatment. Collectively, these data established the mechanism of pineapple vinegar as antiobesity in mice and revealed the potential of pineapple vinegar as a functional food for obesity.

Metabolic Differences between Subcutaneous and Visceral Adipocytes Differentiated with an Excess of Saturated and Monounsaturated Fatty Acids

Obesity is a major health problem in highly industrialized countries. High-fat diet (HFD) is one of the most common causes of obesity and obesity-related disorders. There are considerable differences between fat depots and the corresponding risks of metabolic disorders. We investigated the various effects of an excess of fatty acids (palmitic 16:0, stearic 18:0, and oleic acids 18:1n-9) on adipogenesis of subcutaneous- and visceral-derived mesenchymal stem cells (MSCs) and phenotypes of mature adipocytes. MSCs of white adipose tissue were acquired from adipose tissue biopsies obtained from subcutaneous and visceral fat depots from patients undergoing abdominal surgery. The MSCs were extracted and differentiated in vitro with the addition of fatty acids. Oleic acid stimulated adipogenesis, resulting in higher lipid content and larger adipocytes. Furthermore, oleic acid stimulated adipogenesis by increasing the expression of CCAAT enhancer binding protein β (CEBPB) and peroxisome proliferator activated receptor γ (PPARG). All of the examined fatty acids attenuated the insulin-signaling pathway and radically reduced glucose uptake following insulin stimulation. Visceral adipose tissue was shown to be more prone to generate inflammatory stages. The subcutaneous adipose tissue secreted a greater quantity of adipokines. To summarize, oleic acid showed the strongest effect on adipogenesis. Furthermore, all of the examined fatty acids attenuated insulin signaling and secretion of cytokines and adipokines.

A systematic review of precision nutrition and Mediterranean Diet: A personalized nutrition approaches for prevention and management of obesity related disorders

BACKGROUND AND AIMS

The Obesity is related to type 2 diabetes, and diseases with metabolic syndrome characteristics such as dyslipidemia, hypertension and cardiovascular illness. The nutrition is the most important environmental factor that modulates the phenotype type of obesity. The impacts of nutrients might modulate the gene expression. The recent studies have focused on the relationship between obesity in terms of gene-environment interactions.

METHODS

There is a relationship between genetic indicators, fat mass accumulation, body composition and Mediterranean diet. The evaluation of nutrition treatment or interventions together with the genetic state; provides to manage or prevent the development of chronic diseases.

RESULTS

As a result of nutrigenetic studies; specific nutrition factors in Mediterranean Diet have positive effects on gene expressions related to obesity. In the future, the rapidly-developing nutrition science and the optimal nutrition model special for individuals might play an important role in terms of health development and healing.

CONCLUSION

This metanalysis aimed to explain the current status and relationship between metabolic syndrome indicators that are related to obesity and the gene-nutrient interactions within the Mediterranean Diet.

Effect of the Fat Eaten at Breakfast on Lipid Metabolism: A Crossover Trial in Women with Cardiovascular Risk

Recent studies point out that not only the daily intake of energy and nutrients but the time of day when they are ingested notably regulates lipid metabolism and cardiovascular risk (CVR). Therefore, the aim of the study was to assess if the type of fat ingested at breakfast can modify lipid metabolism in women with CVR. A randomized, crossover clinical trial was performed. Sixty volunteers were randomly assigned to a (A) polyunsaturated fatty acid (PUFA)-rich breakfast, (B) saturated fatty acid (SFA)-rich breakfast, or (C) monounsaturated fatty acid (MUFA)-rich breakfast. Plasma lipoprotein and apolipoprotein subfractions were determined. Our data showed that the PUFA-rich breakfast decreased lipoprotein (a) (Lp(a)), very low-density lipoproteins (VLDL), and intermediate-density lipoproteins (IDL), and increased high-density lipoproteins (HDL). A similar trend was observed for the MUFA-rich breakfast, whereas the SFA-rich breakfast, although it decreased VLDL, also increased IDL and reduced HDL. The PUFA-rich breakfast also decreased β-lipoproteins and apolipoprotein-B. In summary, varying the type of fat eaten at breakfast is enough to significantly modify the lipid metabolism of women with CVR, which can be of great relevance to establish new therapeutic strategies for the treatment of these subjects.

Impact of Leuconostoc SD23 intake in obese pregnant rats: benefits for maternal metabolism

Maternal obesity (MO) during pregnancy and lactation leads to maternal and offspring metabolic dysfunction. Recent research has suggested that probiotics might be a novel approach to counteract these unwanted MO effects. The aim of this research was to analyze the impact of Leuconostoc SD23, a probiotic isolated from aguamiel (traditional Mexican drink), on MO metabolism in rats at the end of lactation (21 days). From weaning through lactation, control female Wistar rats (C) ate chow (5% fat) or high-energy obesogenic diet (MO; 25% fat). Half the C and MO mothers received a daily dose (1 × 1010 CFU/ml) of probiotic orally, control with probiotic (CP) and MO with probiotic (MOP), 1 month before mating and through pregnancy and lactation. Histological analyses of the liver, white adipose tissue and small intestine, body composition, glucose, insulin, triglycerides, and leptin were determined in mothers at the end of lactation. Maternal weight during pregnancy was greater in MO than C mothers, but similar at the end of lactation. Probiotic intervention had no effect on maternal weight. However, at the end of lactation, percentage of body fat was higher in MO than C, CP, and MOP. Serum glucose, homeostasis model assessment of insulin resistance, and triglycerides were higher in MO versus C, CP, and MOP. MO small intestine villus height was higher versus MOP, C, and CP. Leuconostoc SD23 did not present adverse effects in C. Conclusions: maternal administration of Leuconostoc SD23 has beneficial effects on maternal metabolism, which holds possibilities for preventing adverse offspring metabolic programming.

The role of ADP-ribose metabolism in metabolic regulation, adipose tissue differentiation, and metabolism

In this review, Szanto et al. summarize the metabolic regulatory roles of PARP enzymes and their associated pathologies.

Poly(ADP-ribose) polymerases (PARPs or ARTDs), originally described as DNA repair factors, have metabolic regulatory roles. PARP1, PARP2, PARP7, PARP10, and PARP14 regulate central and peripheral carbohydrate and lipid metabolism and often channel pathological disruptive metabolic signals. PARP1 and PARP2 are crucial for adipocyte differentiation, including the commitment toward white, brown, or beige adipose tissue lineages, as well as the regulation of lipid accumulation. Through regulating adipocyte function and organismal energy balance, PARPs play a role in obesity and the consequences of obesity. These findings can be translated into humans, as evidenced by studies on identical twins and SNPs affecting PARP activity.

Antiadipogenesis of Oroxylum indicum (L.) Kurz Extract via PPARγ2 in 3T3-L1 Adipocytes

Oroxylum indicum is regarded as a traditional food with medicinal properties and is used widely throughout Asia. It has previously been demonstrated that O. indicum extract (OIE) was able to suppress the differentiation of 3T3-L1 preadipocytes to adipocytes. However, the mechanism underlying the antiadipogenesis of this plant has not been fully investigated. The present study aimed to explore the impact of OIE at 50 to 200 μg mL⁻¹ on the molecular mechanism involved in the antiadipogenic activity in 3T3-L1 cells at day 0 of their differentiation to adipocytes. The morphology and biochemistry of the cells on day 12 were investigated and compared to the relevant controls. Adiponectin was measured using enzyme-linked immunosorbent assay (ELISA). The mRNA expression of peroxisome proliferator-activated receptor-gamma 2 (PPARγ2), sterol regulatory element-binding proteins 1c (SREBP-1c), fatty acid synthetase (FAS), glucose transporter (GLUT4), and leptin in adipocytes was determined by real-time PCR. The results demonstrated that the OIE at 200 μg mL⁻¹ exhibited strongest suppression on intracellular lipid accumulation. The levels of adiponectin were dramatically increased in the untreated adipocytes, whereas significantly decreased in the 200 μg mL⁻¹ OIE-treated adipocytes (P < 0.05). Expression of the mRNAs revealed that OIE-treated adipocytes at 200 μg mL⁻¹ significantly inhibited the expression of PPARγ2 and SREBP-1c and lowered the level of expression of GLUT4, FAS, and leptin compared to the control (P < 0.05). These findings suggest that OIE inhibits adipocyte differentiation along with the downregulation of PPARγ2, SREBP-1c, and GLUT4, leading to the decrease in the expression of FAS and adipokine (leptin and adiponectin). Thus, OIE might be developed for hyperlipidemia and obesity prevention.

Specific knockout of p85α in brown adipose tissue induces resistance to high-fat diet-induced obesity and its metabolic complications in male mice

Objective

An increase in mass and/or brown adipose tissue (BAT) functionality leads to an increase in energy expenditure, which may be beneficial for the prevention and treatment of obesity. Moreover, distinct class I PI3K isoforms can participate in metabolic control as well as in systemic dysfunctions associated with obesity. In this regard, we analyzed in vivo whether the lack of p85α in BAT (BATp85αKO) could modulate the activity and insulin signaling of this tissue, thereby improving diet-induced obesity and its associated metabolic complications.

Methods

We generated BATp85αKO mice using Cre-LoxP technology, specifically deleting p85α in a conditional manner. To characterize this new mouse model, we used mice of 6 and 12 months of age. In addition, BATp85αKO mice were submitted to a high-fat diet (HFD) to challenge BAT functionality.

Results

Our results suggest that the loss of p85α in BAT improves its thermogenic functionality, high-fat diet–induced adiposity and body weight, insulin resistance, and liver steatosis. The potential mechanisms involved in the improvement of obesity include (1) increased insulin signaling and lower activation of JNK in BAT, (2) enhanced insulin receptor isoform B (IRB) expression and association with IRS-1 in BAT, (3) lower production of proinflammatory cytokines by the adipose organ, (4) increased iWAT browning, and (5) improved liver steatosis.

Conclusions

Our results provide new mechanisms involved in the resistance to obesity development, supporting the hypothesis that the gain of BAT activity induced by the lack of p85α has a direct impact on the prevention of diet-induced obesity and its associated metabolic complications.

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The lack of p85α in brown adipose tissue confers obesity resistance.

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BATp85αKO mice show improved thermogenic function, fatty liver and insulin resistance.

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High IRB levels in BAT and iWAT browning might explain the improvement of obesity.

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Increase in BAT functionality has a direct impact on the prevention of obesity.

Adipocyte size in morbidly obese women and its relation to type 2 diabetes

Aim of the study: The aim was to perform a morphometric analysis of subcutaneous and visceral adipose tissue of morbidly obese women and to determine the relationship between adipocyte size and the development of type 2 diabetes (T2D).

Materials and methods: White adipose tissue of morbidly obese women was obtained from subcutaneous and omental adipose tissue during bariatric surgery. The same tissues were obtained at judicial autopsy in non-obese (lean) non-diabetic patients. The harvested tissue was embedded in paraffin and 5 μm thick hematoxylin-eosin stained sections were analyzed by the Olympus cellSens system. Statistical evaluation was performed by GraphPad Prism 6.1 software.

Results: We found a relationship between adipocyte size and the presence of T2D. The most pronounced changes were seen in visceral adipocytes (cell diameter increased from 61.9 μm in controls to 79.5 μm in patients with T2D). Also, the size of the subcutaneous adipocytes increased against the control. A statistically significant difference between diabetic and non-diabetic patients was not proven in subcutaneous adipocytes. We also observed differences in the distribution of adipocyte mean diameters. Whilst in the control group there was a normal (Gaussian) distribution, in the morbidly obese we found an asymmetric distribution with a positive skewness to the right.

Conclusion: We have demonstrated that in morbidly obese women a significant increase in visceral adipocyte size is associated with the development of both insulin resistance and T2D.

Olaparib induces browning of in vitro cultures of human primary white adipocytes

Mitochondrial biogenesis is a key feature of energy expenditure and organismal energy balance. Genetic deletion of PARP1 or PARP2 was shown to induce mitochondrial biogenesis and energy expenditure. In line with that, PARP inhibitors were shown to induce energy expenditure in skeletal muscle. We aimed to investigate whether pharmacological inhibition of PARPs induces brown or beige adipocyte differentiation. SVF fraction of human pericardial adipose tissue was isolated and human adipose-derived mesenchymal stem cells (hADMSCs) were differentiated to white and beige adipocytes. A subset of hADMSCs were differentiated to white adipocytes in the presence of Olaparib, a potent PARP inhibitor currently in clinical use, to induce browning. Olaparib induced morphological changes (smaller lipid droplets) in white adipocytes that is a feature of brown/beige adipocytes. Furthermore, Olaparib induced mitochondrial biogenesis in white adipocytes and enhanced UCP1 expression. We showed that Olaparib treatment inhibited nuclear and cytosolic PAR formation, induced NAD⁺/NADH ratio and consequently boosted SIRT1 and AMPK activity and the downstream transcriptional program leading to increases in OXPHOS. Olaparib treatment did not induce the expression of beige adipocyte markers in white adipocytes, suggesting the formation of brown or brown-like adipocytes. PARP1, PARP2 and tankyrases are key players in the formation of white adipose tissue. Hereby, we show that PARP inhibition induces the transdifferentiation of white adipocytes to brown-like adipocytes suggesting that PARP activity could be a determinant of the differentiation of these adipocyte lineages.

Organ Failure Due to Systemic Injury in Acute Pancreatitis

Acute pancreatitis may be associated with both local and systemic complications. Systemic injury manifests in the form of organ failure, which is seen in approximately 20% of all cases of acute pancreatitis and defines "severe acute pancreatitis." Organ failure typically develops early in the course of acute pancreatitis, but also may develop later due to infected pancreatic necrosis-induced sepsis. Organ failure is the most important determinant of outcome in acute pancreatitis. We review here the current understanding of the risk factors, pathophysiology, timing, impact on outcome, and therapy of organ failure in acute pancreatitis. As we discuss the pathophysiology of severe systemic injury, the distinctions between markers and mediators of severity are highlighted based on evidence supporting their causality in organ failure. Emphasis is placed on clinically relevant end points of organ failure and the mechanisms underlying the pathophysiological perturbations, which offer insight into potential therapeutic targets to treat.

Carboxyl Ester Lipase May Not Mediate Lipotoxic Injury during Severe Acute Pancreatitis

Acute lipolysis of visceral fat or circulating triglycerides may worsen acute pancreatitis (AP)-associated local and systemic injury. The pancreas expresses pancreatic triacylglycerol lipase (PNLIP), pancreatic lipase-related protein 2 (PNLIPRP2), and carboxyl ester lipase (CEL), which may leak into the visceral fat or systemic circulation during pancreatitis. We, thus, aimed to determine the pancreatic lipase(s) regulating lipotoxicity during AP. For this AP, associated fat necrosis was analyzed using Western blot analysis. Bile acid (using liquid chromatography-tandem mass spectrometry) and fatty acid (using gas chromatography) concentrations were measured in human fat necrosis. The fat necrosis milieu was simulated in vitro using glyceryl trilinoleate because linoleic acid is increased in fat necrosis. Bile acid requirements to effectively hydrolyze glyceryl trilinoleate were studied using exogenous or overexpressed lipases. The renal cell line (HEK 293) was used to study lipotoxic injury. Because dual pancreatic lipase knockouts are lethal, exocrine parotid acini lacking lipases were used to verify the results. PNLIP, PNLIPRP2, and CEL were increased in fat necrosis. Although PNLIP and PNLIPRP2 were equipotent in inducing lipolysis and lipotoxic injury, CEL required bile acid concentrations higher than in human fat necrosis. The high bile acid requirements for effective lipolysis make CEL an unlikely mediator of lipotoxic injury in AP. It remains to be explored whether PNLIP or PNLIPRP2 worsens AP severity in vivo.

Perivascular adipose tissue modulates carotid plaque formation induced by disturbed flow in mice

OBJECTIVE

Emerging evidence shows that perivascular adipose tissue (PVAT) is crucially involved in inflammation and cardiovascular diseases. However, controversial results have been reported regarding the effect of PVAT in atherosclerosis. This study aimed to determine the role of PVAT in disturbed blood flow (d-flow)-induced carotid plaque formation.

METHODS

ApoE^-/- male mice underwent partial carotid ligation (PCL) to induce d-flow in the left carotid artery (LCA) and were fed a high-fat diet for 2 weeks. Oil Red O and hematoxylin and eosin stains were used to determine adipose tissue. Thoracic PVAT from ApoE^-/- or wild-type female mice were transplanted to the LCA of PCL-treated ApoE^-/- mice. Carotid arteries were stained with Sudan IV to detect atherosclerotic lesions. Quantitative real-time reverse transcription polymerase chain reaction and immunofluorescence staining were performed to assess macrophage infiltration.

RESULTS

By 2 weeks of the high-fat diet after PCL surgery, de novo adipose tissue was formed around the ligated LCA, where atherosclerotic plaques were also observed. Quantitative real-time reverse transcription polymerase chain reaction analysis of the newly formed PVAT revealed a similar transcription profile to native PVAT. Treatment with bisphenol A diglycidyl ether, a peroxisome proliferator-activated receptor γ inhibitor, diminished PVAT formation but increased plaque size and macrophage infiltration. Transplantation of thoracic PVAT from wild-type mice (PVAT-T^WT) rather than from ApoE^-/- mice (PVAT-T^ApoE-/-) nearly abrogated LCA plaque macrophage content without affecting plaque size. Mechanistically, PVAT-T^ApoE-/- showed higher messenger RNA levels of inflammatory cytokines compared with PVAT-T^WT.

CONCLUSIONS

Our findings suggest that regulated PVAT formation may confer protection against atherosclerosis-prone shear stress, probably through attenuation of focal inflammation.

Seafood intake and the development of obesity, insulin resistance and type 2 diabetes

We provide an overview of studies on seafood intake in relation to obesity, insulin resistance and type 2 diabetes. Overweight and obesity development is for most individuals the result of years of positive energy balance. Evidence from intervention trials and animal studies suggests that frequent intake of lean seafood, as compared with intake of terrestrial meats, reduces energy intake by 4–9 %, sufficient to prevent a positive energy balance and obesity. At equal energy intake, lean seafood reduces fasting and postprandial risk markers of insulin resistance, and improves insulin sensitivity in insulin-resistant adults. Energy restriction combined with intake of lean and fatty seafood seems to increase weight loss. Marine n-3 PUFA are probably of importance through n-3 PUFA-derived lipid mediators such as endocannabinoids and oxylipins, but other constituents of seafood such as the fish protein per se, trace elements or vitamins also seem to play a largely neglected role. A high intake of fatty seafood increases circulating levels of the insulin-sensitising hormone adiponectin. As compared with a high meat intake, high intake of seafood has been reported to reduce plasma levels of the hepatic acute-phase protein C-reactive protein level in some, but not all studies. More studies are needed to confirm the dietary effects on energy intake, obesity and insulin resistance. Future studies should be designed to elucidate the potential contribution of trace elements, vitamins and undesirables present in seafood, and we argue that stratification into responders and non-responders in randomised controlled trials may improve the understanding of health effects from intake of seafood.

Effect of Exercise on Fatty Acid Metabolism and Adipokine Secretion in Adipose Tissue

Increased physical activity is an optimal way to maintain a good health. During exercise, triacylglycerols, an energy reservoir in adipose tissue, are hydrolyzed to free fatty acids (FAs) which are then released to the circulation, providing a fuel for working muscles. Thus, regular physical activity leads to a reduction of adipose tissue mass and improves metabolism. However, the reduction of lipid reservoir is also associated with many other interesting changes in adipose tissue FA metabolism. For example, a prolonged exercise contributes to a decrease in lipoprotein lipase activity and resultant reduction of FA uptake. This results in the improvement of mitochondrial function and upregulation of enzymes involved in the metabolism of polyunsaturated fatty acids. The exercise-induced changes in adipocyte metabolism are associated with modifications of FA composition. The modifications are adipose tissue depot-specific and follow different patterns in visceral and subcutaneous adipose tissue. Moreover, exercise affects adipokine release from adipose tissue, and thus, may mitigate inflammation and improve insulin sensitivity. Another consequence of exercise is the recently described phenomenon of adipose tissue “beiging,” i.e., a switch from energy-storing white adipocyte phenotype to thermogenic FA oxidizing beige adipocytes. This process is regulated by myokines released during the exercise. In this review, we summarize published evidence for the exercise-related changes in FA metabolism and adipokine release in adipose tissue, and their potential contribution to beneficial cardiovascular and metabolic effects of physical activity.

Different Statistical Approaches to Characterization of Adipocyte Size in Offspring of Obese Rats: Effects of Maternal or Offspring Exercise Intervention

Adipocyte size (AS) shows asymmetric distribution related to current metabolic state, e.g., adipogenesis or lipolysis. We profiled AS distribution using different statistical approaches in offspring (F1) of control (C) and obese (MO) mothers (F0) with and without F0 or F1 exercise. Offspring from F0 exercise were designated CF0ex and MOF0ex. Exercised F1 of sedentary mothers were designated CF1ex and MOF1ex. F1 retroperitoneal fat cross-sectional AS was measured by median, cumulative distributions, data dispersion and extreme values based on gamma distribution modeling. F1 metabolic parameters: body weight, retroperitoneal fat, adiposity index (AI), serum leptin, triglycerides (TG) and insulin resistance index (IRI) were measured. Male and female F1 AS showed different cumulative distribution between C and MO (p < 0.0001) therefore comparisons were performed among C, CF0ex and CF1ex groups and MO, MOF0ex and MOF1ex groups. MO AI was higher than C (p < 0.05) and male MOF1ex AI lower than MO (p < 0.05). Median AS was higher in male and female MO vs. C (p < 0.05). Male and female MOF0ex and MOF1ex reduced median AS (p < 0.05). Lower AS dispersion was observed in male CF1ex and MOF1ex vs. CF0ex and MOF0ex, respectively. MO reduced small and increased large adipocyte proportions vs. C (p < 0.05); MOF0ex increased small and MOF1ex the proportion of large adipocytes vs. MO (p < 0.05). MOF0ex reduced male IRI and female TG vs. MO (p < 0.05). MOF1ex reduced male and female leptin (p < 0.05); CF1ex reduced male leptin (p < 0.05). Conclusions: several factors, diet, physical activity and gender modify AS distribution. Conventional AS distribution methods normally do not include analyzes of extreme, large and small adipocytes, which characterize different phenotypes. Maternal high fat diet affects F1 AS distribution, which was programmed during development. F0ex and F1ex have gender specific F1 beneficial effects. AS distribution characterization helps explain adipose tissue metabolic changes in different physiological conditions and will aid design of efficacious interventions to prevent and/or recuperate adverse developmental programming outcomes. Finally, precise identification of effects of specific interventions as exercise of F0 and/or F1 are needed to improve outcomes in obese women and their obesity prone offspring.

Visceral fat and insulin resistance - what we know?

One of the most significant challenges of current medicine is the increasing prevalence of obesity worldwide that is accompanied by a wide range of chronic health complications and increased mortality. White adipose tissue actively contributes to metabolic regulation by production of a variety of hormones and cytokines, commonly referred to as adipokines. The spectrum and quantity of adipokines produced by the adipose tissue of obese patients is directly or indirectly involved in much obesity-related pathology (type 2 diabetes mellitus, cardiovascular disease, inflammatory response). One of the underlying mechanisms linking obesity, diabetes, and cardiovascular complications is subclinical inflammation, primarily arising in visceral adipose tissue. Adipocyte size, number and polarization of lymphocytes and infiltrated macrophages are closely related to metabolic and obesity-related diseases. The storage capacity of hypertrophic adipocytes in obese patients is limited. This results in chronic energy overload and leads to increased apoptosis of adipocytes that in turn stimulates the infiltration of visceral adipose tissue by immune cells, in particular macrophages. These cells produce many proinflammatory factors; while the overall production of anti-inflammatory cytokines and adipokines is decreased. The constant release of proinflammatory factors into the circulation then contributes to a subclinical systemic inflammation, which is directly linked to the metabolic and cardiovascular complications of obesity.

3D Chemical Shift-Encoded MRI for Volume and Composition Quantification of Abdominal Adipose Tissue During an Overfeeding Protocol in Healthy Volunteers

BACKGROUND

Overweight and obesity are major worldwide health concerns characterized by an abnormal accumulation of fat in adipose tissue (AT) and liver.

PURPOSE

To evaluate the volume and the fatty acid (FA) composition of the subcutaneous adipose tissue (SAT) and the visceral adipose tissue (VAT) and the fat content in the liver from 3D chemical-shift-encoded (CSE)-MRI acquisition, before and after a 31-day overfeeding protocol.

STUDY TYPE

Prospective and longitudinal study.

SUBJECTS

Twenty-one nonobese healthy male volunteers.

FIELD STRENGTH/SEQUENCE

A 3D spoiled-gradient multiple echo sequence and STEAM sequence were performed at 3T.

ASSESSMENT

AT volume was automatically segmented on CSE-MRI between L2 to L4 lumbar vertebrae and compared to the dual-energy X-ray absorptiometry (DEXA) measurement. CSE-MRI and MR spectroscopy (MRS) data were analyzed to assess the proton density fat fraction (PDFF) in the liver and the FA composition in SAT and VAT. Gas chromatography-mass spectrometry (GC-MS) analyses were performed on 13 SAT samples as a FA composition countermeasure.

STATISTICAL TESTS

Paired t-test, Pearson's correlation coefficient, and Bland-Altman plots were used to compare measurements.

RESULTS

SAT and VAT volumes significantly increased (P < 0.001). CSE-MRI and DEXA measurements were strongly correlated (r = 0.98, P < 0.001). PDFF significantly increased in the liver (+1.35, P = 0.002 for CSE-MRI, + 1.74, P = 0.002 for MRS). FA composition of SAT and VAT appeared to be consistent between localized-MRS and CSE-MRI (on whole segmented volume) measurements. A significant difference between SAT and VAT FA composition was found (P < 0.001 for CSE-MRI, P = 0.001 for MRS). MRS and CSE-MRI measurements of the FA composition were correlated with the GC-MS results (for ndb: r_MRS/GC-MS  = 0.83 P < 0.001, r_{CSE-MRI/GC-MS}  = 0.84, P = 0.001; for nmidb: r_MRS/GC-MS  = 0.74, P = 0.006, r_{CSE-MRI/GC-MS}  = 0.66, P = 0.020) DATA CONCLUSION: The follow-up of liver PDFF, volume, and FA composition of AT during an overfeeding diet was demonstrated through different methods. The CSE-MRI sequence associated with a dedicated postprocessing was found reliable for such quantification.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:1587-1599.

Comparison of MRI-derived vs. traditional estimations of fatty acid composition from MR spectroscopy signals

INTRODUCTION

The composition of fatty acids in the body is gaining increasing interest, and can be followed up noninvasively by quantitative magnetic resonance spectroscopy (MRS). However, current MRS quantification methods have been shown to provide different quantitative results in terms of lipid signals, with possible varying outcomes for a given biological examination. Quantitative magnetic resonance imaging using multigradient echo sequence (MGE-MRI) has recently been added to MRS approaches. In contrast, these methods fit the undersampled magnetic resonance temporal signal with a simplified model function (expressing the triglyceride [TG] spectrum with only three TG parameters), specific implementations and prior knowledge. In this study, an adaptation of an MGE-MRI method to MRS lipid quantification is proposed.

METHODS

Several versions of the method - with time data fully or undersampled, including or excluding the spectral peak T₂ knowledge in the fitting - were compared theoretically and on Monte Carlo studies with a time-domain, peak-fitting approach. Robustness, repeatability and accuracy were also inspected on in vitro oil acquisitions and test-retest in vivo subcutaneous adipose tissue acquisitions, adding results from the reference LCModel method.

RESULTS

On simulations, the proposed method provided TG parameter estimates with the smallest variability, but with a possible bias, which was mitigated by fitting on undersampled data and considering peak T₂ values. For in vitro measurements, estimates for all approaches were correlated with theoretical values and the best concordance was found for the usual MRS method (LCModel and peak fitting). Limited in vivo test-retest variability was found (4.1% for PUFAindx, 0.6% for MUFAindx and 3.6% for SFAindx), as for LCModel (7.6% for PUFAindx, 7.8% for MUFAindx and 3.0% for SFAindx).

CONCLUSION

This study shows that fitting the three TG parameters directly on MRS data is one valuable solution to circumvent the poor conditioning of the MRS quantification problem.

Spheroid Culture System Confers Differentiated Transcriptome Profile and Functional Advantage to 3T3-L1 Adipocytes

This study highlights functional differences between 2-D monolayer and 3-D spheroid 3T3-L1 adipocyte culture models and explores the underlying genomic mechanisms responsible for the different phenotypes present. The spheroids showed higher triglyceride accumulation than the monolayer culture and further increase with larger spheroid size. Whole transcriptome analysis indicated significant differential expression of genes related to adipogenesis, including adipocytokine signaling, fatty acid metabolism, and PPAR-γ signaling. Spheroids also showed downregulation of matrix metalloproteinases (MMPs), integrin, actin-cytoskeleton associated genes, and Rho/GTPase3 expression relative to 2-D monolayer, indicating suppression of the Rho-ROCK pathway and thereby promoting adipogenic differentiation. When exposed to linoleic acid (500 μM) and TNF-α (125 ng/mL) to promote chronic adiposity, linoleic acid treatment resulted in increased intracellular triglycerides and subsequent TNF-α treatment resulted in significantly altered adipocytokine signaling, fatty acid metabolism, and PPAR signaling, in addition to upregulation of multiple MMPs in spheroids vs. monolayer. Overall, 3-D spheroids showed enhanced adipogenic phenotype as indicated by triglyceride synthesis and transcriptome changes while retaining sensitivity to a pro-inflammatory stimulus. The 3-D spheroid culture thus may provide a simple, convenient, and sensitive in vitro model to study adipocyte response to metabolic stresses relevant to clinical pathologies.