Adipocyte lipolysis: from molecular mechanisms of regulation to disease and therapeutics

Subchondral bone marrow adipose tissue lipolysis regulates bone formation in hand osteoarthritis

OBJECTIVE

Bone marrow adipose tissue (BMAT) is emerging as an important regulator of bone formation and energy metabolism. Lipolysis of BMAT releases glycerol and fatty acid substrates that are catabolized by osteoblasts. Here, we investigated whether BMAT lipolysis is involved in subchondral bone formation in hand osteoarthritis (OA).

METHODS

Subchondral BMAT lipolysis and bone marrow adipocyte (BMAd) morphology were studied in clinical specimens of carpometacarpal (CMC-1) and distal interphalangeal joint OA. BMAd size, osteoblast numbers and expression of lipolysis enzymes (ATGL, phospho-HSL, MGLL) were compared between regions of low and high bone formation. Free fatty acids, glycerol and bone biomarkers were measured in osteochondral explants.

RESULTS

Subchondral BMAd size was positively correlated with BMI (r = 0.60, [0.082,0.87]) and reduced in regions of high bone formation (-1149 µm2, [-1977,-726.2]). Osteoblast numbers were negatively correlated with BMAd size (r = -0.48, [-0.73,-0.12]). All lipolysis enzymes were expressed in both in BMAds and activated osteoblasts and the area percentages of ATGL (+2.26% [0.19,3.47]), phospho-HSL (+1.57% [0.31,6.48]) and MGLL (+4.04% [1.09,5.69]) were increased in regions of high bone formation. Secreted glycerol levels, but not free fatty acids, were correlated with bone formation markers pro-collagen type I (rho = 0.90) and alkaline phosphatase (rho = 0.78).

CONCLUSION

Our findings reveal a previously unrecognized role of BMAT lipolysis in regulating bone formation in hand OA, which may be modulated by BMI.

Metabolomics profiling in multi-ancestral individuals with type 2 diabetes in Singapore identified metabolites associated with renal function decline

AIMS/HYPOTHESIS

This study aims to explore the association between plasma metabolites and chronic kidney disease progression in individuals with type 2 diabetes.

METHODS

We performed a comprehensive metabolomic analysis in a prospective cohort study of 5144 multi-ancestral individuals with type 2 diabetes in Singapore, using eGFR slope as the primary outcome of kidney function decline. In addition, we performed genome-wide association studies on metabolites to assess how these metabolites could be genetically influenced by metabolite quantitative trait loci and performed colocalisation analysis to identify genes affecting both metabolites and kidney function.

RESULTS

Elevated levels of 61 lipids with long unsaturated fatty acid chains such as phosphatidylethanolamines, triacylglycerols, diacylglycerols, ceramides and deoxysphingolipids were prospectively associated with more rapid kidney function decline. In addition, elevated levels of seven amino acids and three lipids in the plasma were associated with a slower decline in eGFR. We also identified 15 metabolite quantitative trait loci associated with these metabolites, within which variants near TM6SF2, APOE and CPS1 could affect both metabolite levels and kidney functions.

CONCLUSIONS/INTERPRETATION

Our study identified plasma metabolites associated with prospective renal function decline, offering insights into the underlying mechanism by which the metabolite abnormalities due to fatty acid oversupply might reflect impaired β-oxidation and associate with future chronic kidney disease progression in individuals with diabetes.

ELF5 gene promotes milk lipid synthesis in goat mammary epithelial cells by transcriptomic analysis

E74-like factor 5 (ELF5) is an Ets transcription factor of epithelial development, while the function of ELF5 gene in goat milk fat synthesis remains to be elucidated. In goat mammary epithelial cells, we performed RNA sequencing and analyzed differentially expressed genes (DEGs) after ELF5 gene overexpression. ELF5 gene significantly up-regulated the synthesis of triglyceride, total cholesterol, free fatty acid, and lipid droplets. We obtained 929 DEGs after ELF5 gene overexpression in GMECs. Among the DEGs, SPP1, ELOVL1, PNPLA2, FOXO1, PTGS2, SEMA6A, ACSL5, and GPNMB genes that are related to lipid metabolism were identified. Enrichment analysis showed MAPK and FoxO signaling pathways were up-regulated by ELF5 gene overexpression in GMECs. These findings offer evidence that ELF5 gene could be a candidate gene for the regulation of milk lipid synthesis in goats, and provide molecular targets for the breeding of goats with high milk fat.

Human differentiated adipocytes can serve as surrogate mature adipocytes for adipocyte-derived extracellular vesicle analysis

Obesity is a growing global health concern, contributing to diseases such as cancer, autoimmune disorders, and neurodegenerative conditions. Adipose tissue dysfunction, characterized by abnormal adipokine secretion and chronic inflammation, plays a key role in these conditions. Adipose-derived extracellular vesicles (ADEVs) have emerged as critical mediators in obesity-related diseases. However, the study of mature adipocyte-derived EVs (mAdipo-EVs) is limited due to the short lifespan of mature adipocytes in culture, low EV yields, and the low abundance of these EV subpopulations in the circulation. Additionally, most studies rely on rodent models, which have differences in adipose tissue biology compared to humans. To overcome these challenges, we developed a standardized approach for differentiating human preadipocytes (preAdipos) into mature differentiated adipocytes (difAdipos), which produce high-yield, human adipocyte EVs (Adipo-EVs). Using visceral adipose tissue from bariatric surgical patients, we isolated the stromal vascular fraction (SVF) and differentiated preAdipos into difAdipos. Brightfield microscopy revealed that difAdipos exhibited morphological characteristics comparable to mature adipocytes (mAdipos) directly isolated from visceral adipose tissue, confirming their structural similarity. Additionally, qPCR analysis demonstrated decreased preadipocyte markers and increased mature adipocyte markers, further validating successful differentiation. Functionally, difAdipos exhibited lipolytic activity comparable to mAdipos, supporting their functional resemblance to native adipocytes. We then isolated preAdipo-EVs and difAdipo-EVs using tangential flow filtration and characterized them using bulk and single EV analysis. DifAdipo-EVs displayed classical EV and adipocyte-specific markers, with significant differences in biomarker expression compared to preAdipo-EVs. These findings demonstrate that difAdipos serve as a reliable surrogate for mature adipocytes, offering a consistent and scalable source of adipocyte-derived EVs for studying obesity and its associated disorders.

Unilocular adipocyte and lipid tracer for immunofluorescent images

Adipose tissue is a highly dynamic endocrine organ that serves as the body's primary energy reservoir through the storage and mobilization of lipids. Adipocyte cellular size has been recognized as an indicator of cellular status; hypertrophic adipocytes are more prone to insulin resistance and the secretion of pro-inflammatory cytokines. Thus, the size and number of lipids is important to consider both in the clinic with a biopsy and when developing disease models and regenerative tissue constructs. Tools available to analyze adipocyte size are finely tuned for hematoxylin-eosin images and tend to be challenged by confocal derived z-stack images which contain intensity gradients. Therefore, ImageJ manual analysis is the commonly utilized tool to measure these images. With there being heterogeneity in different researcher's analytical approach when conducted manually, the MATLAB script, PixCell, was developed to reduce the subjectivity and time involved in adipocyte size analysis. Given its stepwise thresholding and masking steps, PixCell retains on average a >80% accuracy when tested on excised human adipose tissue, adipocyte-laden collagen gels, and lipoaspirate seeded silk scaffolds. PixCell is able to consistently detect and measure lipids within regions of varying pixel intensities. This makes PixCell an appealing tool for use in both the clinical and pre-clinical setting, while greatly enhancing and streamlining the user experience of analyzing lipid sizes.

Non-canonical lysosomal lipolysis drives mobilization of adipose tissue energy stores with fasting

Physiological adaptations to fasting enable humans to survive for prolonged periods without food and involve molecular pathways that may drive life-prolonging effects of dietary restriction in model organisms. Mobilization of fatty acids and glycerol from adipocyte lipid stores by canonical neutral lipases, including the rate limiting adipose triglyceride lipase (Pnpla2/ATGL), is critical to the adaptive fasting response. Here we discovered an alternative mechanism of lipolysis in adipocytes involving a lysosomal program. We functionally tested lysosomal lipolysis with pharmacological and genetic approaches in mice and in murine and human adipocyte and adipose tissue explant culture, establishing dependency on lysosomal acid lipase (LIPA/LAL) and the microphthalmia/transcription factor E (MiT/TFE) family. Our study establishes a model whereby the canonical pathway is critical for rapid lipolytic responses to adrenergic stimuli operative in the acute stage of fasting, while the alternative lysosomal pathway dominates with prolonged fasting.

The BET inhibitor JQ1 targets fat metabolism and counteracts obesity

INTRODUCTION

Obesity, one of the most frequent health problems in the adult population, is a condition characterized by excessive white adipose tissue accumulation and accompanied by the increased risk to develop other disorders such as type II diabetes, cardiovascular disorders, physical disability, frailty and sarcopenia. Total fat mass frequently increases during aging, often coexisting with sarcopenia, thus resulting in an emerging condition defined sarcopenic obesity (SO). Our previous data demonstrated the relevant role of the bromo and extra-terminal domain (BET) proteins inhibitor JQ1 in attenuating inflammation and fibrosis in sarcopenic mice. Moreover, we preliminarily observed that JQ1 administration markedly reduces white adipose tissue mass, suggesting a potential role of BET proteins on visceral fat deposition during aging.

OBJECTIVES

Starting from those observations, the aim of this study was to investigate the ability of JQ1 to reduce adiposity in a chronic diet-induced obesity (DIO) mouse model mimicking the human metabolic syndrome.

METHODS

Male C57BL/6J mice were divided in subgroups, either fed a standard diet or a high fat diet for 22 or 12 weeks, treated over the last 14 days with JQ1 or with vehicle.

RESULTS

The results showed that JQ1 administration reduces fat mass, preserving skeletal muscle mass and function. A direct JQ1 lipolytic effect was demonstrated on mature adipocyte cultures. JQ1-mediated loss of adipose tissue mass was not associated with systemic inflammation or with lipid accumulation in muscle and liver. JQ1 administration did not impinge on skeletal muscle metabolism and oxidative capability, as shown by the lack of significant impact on mitochondrial mass and biogenesis.

CONCLUSION

In conclusion, the current data highlight a potential benefit of JQ1 administration to counteract obesity, suggesting epigenetic modulation as a prospective target in the treatment of obesity and sarcopenic obesity, despite the underlying multiorgan molecular mechanism is still not completely elucidated.

The steroid hormone 20-hydroxyecdysone induces lipophagy via the brain-adipose tissue axis by promoting the adipokinetic hormone pathway

Lipophagy is a way to degrade lipids; however, the molecular mechanisms are not fully understood. Using the holometabolous lepidopteran insect Helicoverpa armigera, cotton bollworm, as a model, we revealed that the larval fat body undergoes lipophagy during metamorphosis, and lipophagy is essential for metamorphosis. The steroid hormone 20-hydroxyecdysone (20E) induced lipophagy by promoting the expression of the peptide hormone adipokinetic hormone (AKH, the insect analog of glucagon) and the adipokinetic hormone receptor (AKHR). Akh was highly expressed in the brain and Akhr was expressed in various tissues. The 20E upregulated the expression of Akh and Akhr by its nuclear receptor EcR during metamorphosis. AKH and AKHR increased glucose levels via gluconeogenesis and promoted lipophagy. The high glucose level induced acetylation of FOXO and nuclear localization to promote the expression of lipases and autophagy genes. Thus, the steroid hormone 20E induced lipophagy via the brain-adipose tissue axis by promoting the AKH pathway, which presented nutrients and energy to pupal and adult development during insect metamorphosis after feeding stops.

Lipid droplet targeting of the lipase coactivator ABHD5 and the fatty liver disease-causing variant PNPLA3 I148M is required to promote liver steatosis

The storage and release of triacylglycerol (TAG) in lipid droplets (LDs) is regulated by dynamic protein interactions. α/β Hydrolase domain-containing protein 5 (ABHD5; also known as CGI-58) is a membrane/LD-bound protein that functions as a co-activator of patatin-like phospholipase domain-containing 2 (PNPLA2; also known as adipose triglyceride lipase) the rate-limiting enzyme for TAG hydrolysis. The dysregulation of TAG hydrolysis is involved in various metabolic diseases such as metabolic dysfunction-associated steatotic liver disease (MASLD). We previously demonstrated that ABHD5 interacted with PNPLA3, a closely related family member to PNPLA2. Importantly, a common missense variant in PNPLA3 (I148M) is the greatest genetic risk factor for MASLD. PNPLA3 148M functions to sequester ABHD5 and prevent coactivation of PNPLA2, which has implications for initiating MASLD; however, the exact mechanisms involved are not understood. Here, we demonstrate that LD targeting of both ABHD5 and PNPLA3 I148M is required for the interaction. Molecular modeling demonstrates important residues in the C terminus of PNPLA3 for LD binding and fluorescence cross-correlation spectroscopy demonstrates that PNPLA3 I148M has greater association with ABHD5 than WT PNPLA3. Moreover, the C terminus of PNPLA3 is sufficient for functional targeting of PNPLAs to LD and the interaction with ABHD5. In addition, ABHD5 is a general binding partner of LD-bound PNPLAs. Finally, PNPLA3 I148M targeting to LD is required to promote steatosis in vitro and in the liver. Overall results suggest that the interaction of PNPLA3 I148M with ABHD5 on LD is required to promote liver steatosis.

PLIN1 suppresses glioma progression through regulating lipid metabolism

Glioma is a common and destructive brain tumor, which is highly heterogeneous with poor prognosis. Developing diagnostic and prognostic markers to identify and treat glioma early would significantly improve the therapeutic outcomes. Here, we conducted RNA next-generation sequencing with 33 glioma samples and 15 normal brain samples. We found Perilipin 1 (PLIN1) downregulated in glioma and correlated with poorer outcome. Subsequent experiments revealed that up regulation of PLIN1 led to repressed cell growth and invasion in glioma. Moreover, overexpression of PLIN1 increased lipid accumulation in glioma cells, with increasing expression of lipid biosynthesis related genes and decreasing expression of lipolysis related genes. Mechanically, we revealed that the PI3K/AKT axis could regulate PLIN1 levels in glioma, that inhibition of the activity of PI3K/AKT axis could increase PLIN1 levels in glioma. In conclusion, the dysregulation PI3K/AKT axis led to PLIN1 downregulation and the following tumor proliferation, invasion and lipid metabolism reprogramming in glioma.

Systemic metabolic crosstalk as driver of cancer cachexia

Cachexia is a complex metabolic disorder characterized by negative energy balance due to increased consumption and lowered intake, leading to progressive tissue wasting and inefficient energy distribution. Once considered as passive bystander, metabolism is now acknowledged as a regulator of biological functions and disease progression. This shift in perspective mirrors the evolving understanding of cachexia itself, no longer viewed merely as a secondary consequence of cancer but as an active process. However, metabolic dysregulations in cachexia are currently studied in an organ-specific manner, failing to be fully integrated into a comprehensive framework that explains their functional roles in disease progression. Thus, in this review, we aim to provide a general overview of the various metabolic alterations with a potential systemic impact.

Transcriptional regulation of adipocyte lipolysis by IRF2BP2

Adipocyte lipolysis controls systemic energy levels and metabolic homeostasis. Lipolysis is regulated by posttranslational modifications of key lipolytic enzymes. However, less is known about the transcriptional mechanisms that regulate lipolysis. Here, we identify interferon regulatory factor-2 binding protein 2 (IRF2BP2) as a transcriptional repressor of adipocyte lipolysis. Deletion of IRF2BP2 in human adipocytes increases lipolysis without affecting glucose uptake, whereas IRF2BP2 overexpression decreases lipolysis. RNA sequencing, and chromatin immunoprecipitation sequencing analyses show that IRF2BP2 represses lipolysis-related genes, including LIPE, which encodes hormone sensitive lipase, the rate-limiting enzyme in lipolysis. Adipocyte-selective deletion of Irf2bp2 in mice increases Lipe expression and free fatty acid levels, resulting in adipose tissue inflammation and glucose intolerance. Together, these findings demonstrate that IRF2BP2 restrains adipocyte lipolysis and opens avenues to target lipolysis for the treatment of metabolic disease.

Effectiveness of Early Versus Late Time-Restricted Eating Combined with Physical Activity in Overweight or Obese Women

AIMS

To evaluate the effectiveness of a dual approach involving time-restricted eating (TRE) at different times of the day combined with physical activity (PA) on functional capacity and metabolic health in overweight or obese women.

METHODS

Random allocation of sixty-one participants into four groups: early time-restricted eating plus physical activity (ETRE-PA, n = 15, 31.8 ± 10.76 years, 89.68 ± 13.40 kg, 33.5 ± 5.53 kg/m2), late time-restricted eating with physical activity (LTRE-PA, n = 15, 30.60 ± 7.94 years, 94.45 ± 15.36 kg, 34.37 ± 7.09 kg/m2), late time-restricted eating only (LTRE, n = 15, 27.93 ± 9.79 years, 88.32 ± 10.36 kg, 32.71 ± 5.15 kg/m2) and a control group (CG, n = 15, 36.25 ± 11.52 years, 89.01 ± 11.68 kg, 33.66 ± 6.18 kg/m2). The intervention lasted for 12 weeks in all groups. Both the ETRE-PA and LTRE-PA groups engaged in a rigorous combined aerobic and resistance-training program.

RESULTS

Significant reductions in body weight and body mass index were observed in the ETRE-PA and LTRE-PA groups compared to the CG and LTRE groups post-intervention (p < 0.0005). Only the ETRE-PA group exhibited a significant decrease in fat mass (p = 0.02), low-density lipoprotein cholesterol (p = 0.01), and aspartate aminotransferase (p = 0.002). Significant reductions in alanine aminotransferase levels were observed in the ETRE-PA (p = 0.004) and LTRE-PA (p = 0.02) groups. These two latter groups achieved higher performances in the 6-min walking test, bench press, 30-s squat, crunch test, vertical jump (p < 0.0005 for both), and leg extension (p < 0.02 for both) when compared to the LTRE and CG groups.

CONCLUSION

The integration of TRE with PA leads to greater improvements in body composition, lipid profile, and physical performance, with no significant differences between the ETRE-PA and LTRE-PA approaches. This combined strategy offers a promising solution for overweight and obese women.

Sensing of Long-Chain Fatty Acyl-CoA Esters by AMPK

Fatty acids are utilized to maintain cellular energy/adenine nucleotide balance under times of energetic stress such as during endurance exercise or fasting. It has long been recognized that fatty acids stimulate their own oxidation through a mechanism involving allosteric inhibition of acetyl-CoA carboxylase (ACC) and reductions in malonyl-CoA. We have recently described a parallel pathway by which long-chain fatty acid-CoAs bind to and activate the AMP-activated protein kinase (AMPK) at the allosteric drug and metabolic (ADaM) binding site. Increases in AMPK activity lead to the phosphorylation and inhibition of ACC which is essential for fatty acids to stimulate fatty acid oxidation. Here, we describe the methods to detect fatty acyl-CoA-induced activation of AMPK in cell-free assays, primary mouse hepatocytes, and in the liver of mice. These methodologies will be useful to allow further investigations into the importance of this fatty acid sensing axis in regulating metabolism and provide a framework for future studies investigating whether there may be other natural ligands targeting the ADaM binding site of AMPK.

Supernatants from Newly Isolated Lacticaseibacillus paracasei P4 Ameliorate Adipocyte Metabolism in Differentiated 3T3-L1 Cells

Background:Lacticaseibacillus paracasei (L. paracasei) strains and their postbiotics show potential for managing metabolic disorders such as diabetes and obesity. Two newly isolated L. paracasei strains, M2.1 and P4, were yielded from Formica rufa anthills in Sinite Kamani National Park, Bulgaria. Their metabolic effects on mature 3T3-L1 adipocytes were investigated. Methods: Mature 3T3-L1 adipocytes were treated for 24 h with 10% (v/v) cell-free supernatants (CFSs) of M2.1 or P4. Two experimental (M2.1, P4) and two control groups (mature, untreated adipocytes and mature adipocytes, treated with 10% (v/v) MRS broth) were analyzed for intracellular lipid accumulation, glucose uptake, and the mRNA expression of lipid metabolism and beta-oxidation-related genes. Fold changes in gene expression were assessed using RT-qPCR. Results: Both M2.1 and P4 CFSs enhanced glucose uptake by over 30% compared to the control. P4 demonstrated a more favorable effect by significantly upregulating adipose triglyceride lipase-patatin-like phospholipase domain containing 2, adiponectin, and peroxisomal beta-oxidation enzymes-acyl-coenzyme A oxidase 1, palmitoyl. Intracellular lipid accumulation increased only with M2.1, while P4 supported improved lipid turnover without promoting excessive lipid storage or lipolysis. Conclusions: P4 CFS exhibits the potential to improve adipocyte metabolism by enhancing glucose uptake, promoting beta-oxidation, and increasing adiponectin expression, offering a promising strategy for managing metabolic dysfunctions.

Swertiamarin ameliorates type 2 diabetes by activating ADRB3/UCP1 thermogenic signals in adipose tissue

BACKGROUND AND PURPOSE

Swertiamarin (STM), a secoiridoid glycoside from Swertia chirayita (Roxb.) H. Karst, has been shown to decrease body weight, blood glucose, and blood lipids by inhibiting adipose tissue hypertrophy. However, the underlying mechanisms remain unclear. In particular, adipose thermogenesis is a novel avenue for exploring the pharmacological effects of STM. We aim to investigate the efficacy of STM on type 2 diabetes mellitus (T2DM), with a focus on underlying mechanisms, particularly the activation of ADRB3/UCP1 thermogenic signaling pathways.

METHODS

T2DM model was established by a high-fat diet (HFD) and streptozotocin (STZ) in C57BL/6 J male mice. Mice were given to either 100 or 200 mg kg-1/day of STM, or 200 mg kg-1/day of metformin (Glucophage) via intragastric administration for 7 weeks. In vitro, 3T3-L1 cells were differentiated into adipocytes. Molecular markers related to ADRB3-UCP1 signals, lipolysis, and mitochondrial function were detected.

RESULTS

STM-treated diabetic mice showed a reduction of body weight, fat mass, and blood glucose/lipids and an improvement in insulin sensitivity. Bioinformatics analysis indicated STM promoted lipid metabolism and mitochondrial function, features by closely associated with adipose thermogenesis. STM upregulated the lipolysis-related genes and p-HSL protein in inguinal subcutaneous white adipose tissue (igSWAT) and brown adipose tissue (BAT). STM-treated mice processed a more active energy metabolism. Additionally, the ADRB3-UCP1 signals, mitochondrial-related genes, and oxidative phosphorylation were improved in igSWAT and BAT. In vitro, we found STM interacted with ADRB3, increasing glucose uptake, glycerol release, ADRB3-UCP1 signals, p-HSL expression, mitochondrial content, oxidative phosphorylation complex expression with improved mitochondrial Δψm, as well as reduced lipid accumulation in adipocytes. All these effects were reversed upon ADRB3 inhibition.

CONCLUSION

This study identifies a previously unknown role of STM activating ADRB3/UCP1 signals in adipose tissue, suggesting a potential strategy for treating T2DM.

Lipids and adipocytes involvement in tumor progression with a focus on obesity and diet

The adipose tissue is a complex organ that can play endocrine, metabolic, and immune regulatory roles in cancer. In particular, adipocytes provide metabolic substrates for cancer cell proliferation and produce signaling molecules that can stimulate cell adhesion, migration, invasion, angiogenesis, and inflammation. Cancer cells, in turn, can reprogram adipocytes towards a more inflammatory state, resulting in a vicious cycle that fuels tumor growth and evolution. These mechanisms are enhanced in obesity, which is associated with the risk of developing certain tumors. Diet, an exogenous source of lipids with pro- or anti-inflammatory functions, has also been connected to cancer risk. This review analyzes how adipocytes and lipids are involved in tumor development and progression, focusing on the relationship between obesity and cancer. In addition, we discuss how diets with varying lipid intakes can affect the disease outcomes. Finally, we introduce novel metabolism-targeted treatments and adipocyte-based therapies in oncology.

Exercise-regulated lipolysis: Its role and mechanism in health and diseases

Exercise has received considerable attention because of its importance not just in regulating physiological function, but also in ameliorating multiple pathological processes. Among these processes, lipolysis may play an important role in exercise-induced benefits. It is generally accepted that active lipolysis contributes to breakdown of fats, leading to the release of free fatty acids (FFAs) that serve as an energy source for muscles and other tissues during exercise. However, the significance of lipolysis in the context of exercise has not been fully understood. This review comprehensively outlines the potential regulatory mechanisms by which exercise stimulates lipolysis. The potential roles of exercise-mediated lipolysis in various physiological and pathological processes are also summarized. Additionally, we also discussed the potential non-classical effects of key lipolytic effectors induced by exercise. This will enhance our understanding of how exercise improves lipolytic function to bring about beneficial effects, offering new insights into potential therapeutic avenues for promoting health and alleviating diseases.

Asperuloside activates hepatic NRF2 signaling to stimulate mitochondrial metabolism and restore lipid homeostasis in high fat diet-induced MAFLD

BACKGROUND

Nutrient overload predisposes the development of metabolic dysfunction-associated fatty liver disease (MAFLD). However, there are no specific pharmacological therapies for MAFLD. Asperuloside (ASP), an iridoid glycoside extracted from Eucommia ulmoides leaves, can alleviate obesity and MAFLD. However, the underlying mechanism and pharmacological effects of ASP on ameliorating MAFLD remain largely investigated. This study aimed to explore the effects of ASP in ameliorating MAFLD and to unravel its underlying mechanism using a high fat diet-induced MAFLD mice model.

METHODS

Six-week-old C57BL/6 male mice were fed a high fat diet for 12 weeks to induce MAFLD, followed by daily ASP treatment (50 mg/kg via oral gavage) for 7 weeks. HepG2 cells were used for in vitro studies. Nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor, ML385, was employed to explore the mechanisms of ASP's action.

RESULTS

ASP stimulated lipolysis and inhibited de novo lipogenesis, contributing to alleviating lipid deposition in obese mice livers and HepG2 cells. ASP restored ATP production and reversed the impairments of mitochondrial energetics and biogenesis in obese mice livers and HepG2 cells. ASP attenuated oxidative stress in obese mice livers and HepG2 cells, exhibiting its antioxidant value. Impressively, ASP significantly promotes Nrf2 nuclear translocation and Nrf2/ARE binding, thereby activating Nrf2/ARE pathway in obese mice livers and HepG2 cells, demonstrating its potential as a hepatic Nrf2 activator. Nrf2 inhibition abolishes the protective effects of ASP against lipid deposition, oxidative stress and mitochondrial dysfunction, emphasizing the critical role of ASP-activated hepatic Nrf2 signaling in ameliorating MAFLD.

CONCLUSIONS

This study provides the first line of evidence demonstrating the pivotal role of ASP-stimulated Nrf2 activation in alleviating MAFLD, emphasizing its potential as a hepatic Nrf2 activator targeting fatty liver diseases. These findings offer new evidence of ASP-stimulated mitochondrial metabolism and lipolysis in MAFLD, paving the way for the development of ASP as a therapeutic agent and dietary supplement to attenuate MAFLD progression.

Lipid droplet targeting of ABHD5 and PNPLA3 I148M is required to promote liver steatosis

The storage and release of triacylglycerol (TAG) in lipid droplets (LDs) is regulated by dynamic protein interactions. α/β hydrolase domain-containing protein 5 (ABHD5; also known as CGI-58) is a membrane/LD bound protein that functions as a co-activator of Patatin Like Phospholipase Domain Containing 2 (PNPLA2; also known as Adipose triglyceride lipase, ATGL) the rate-limiting enzyme for TAG hydrolysis. The dysregulation of TAG hydrolysis is involved in various metabolic diseases such as metabolic dysfunction-associated steatotic liver disease (MASLD). We previously demonstrated that ABHD5 interacted with PNPLA3, a closely related family member to PNPLA2. Importantly, a common missense variant in PNPLA3 (I148M) is the greatest genetic risk factor for MASLD. PNPLA3 148M functions to sequester ABHD5 and prevent co-activation of PNPLA2, which has implications for initiating MASLD; however, the exact mechanisms involved are not understood. Here we demonstrate that LD targeting of both ABHD5 and PNPLA3 I148M is required for the interaction. Molecular modeling demonstrates important resides in the C-terminus of PNPLA3 for LD binding and fluorescence cross-correlation spectroscopy demonstrates that PNPLA3 I148M greater associates with ABHD5 than WT PNPLA3. Moreover, the C-terminus of PNPLA3 is sufficient for functional targeting of PNPLAs to LD and the interaction with ABHD5. In addition, ABHD5 is a general binding partner of LD-bound PNPLAs. Finally, PNPLA3 I148M targeting to LD is required to promote steatosis in vitro and in the liver. Overall results suggest that PNPLA3 I148M is a gain of function mutation and that the interaction with ABHD5 on LD is required to promote liver steatosis.

First transcriptome analysis of the venom glands of the scorpion Hottentotta zagrosensis (Scorpions: Buthidae) with focus on venom lipolysis activating peptides

Introduction

Scorpion venom is a rich source of biological active peptides and proteins. Transcriptome analysis of the venom gland provides detailed insights about peptide and protein venom components. Following the transcriptome analysis of different species in our previous studies, our research team has focused on the Hottentotta zagrosensis as one of the endemic scorpions of Iran to obtain information about its venom proteins, in order to develop biological research focusing on medicinal applications of scorpion venom components and antivenom production. To gain insights into the protein composition of this scorpion venom, we performed transcriptomic analysis.

Methods

Transcriptomic analysis of the venom gland of H. zagrosensis, prepared from the Khuzestan province, was performed through Illumina paired-end sequencing (RNA-Seq), Trinity de novo assembly, CD-Hit-EST clustering, and annotation of identified primary structures using bioinformatics approaches.

Results

Transcriptome analysis showed the presence of 96.4% of complete arthropod BUSCOs, indicating a high-quality assembly. From total of 45,795,108 paired-end 150 bp trimmed reads, the clustering step resulted in the generation of 101,180 de novo assembled transcripts with N50 size of 1,149 bp. 96,071 Unigenes and 131,235 transcripts had a significant similarity (E-value 1e-3) with known proteins from UniProt, Swissprot, Animal toxin annotation project, and the Pfam database. The results were validated using InterProScan. These mainly correspond to ion channel inhibitors, metalloproteinases, neurotoxins, protease inhibitors, protease activators, Cysteine-rich secretory proteins, phospholipase A enzymes, antimicrobial peptides, growth factors, lipolysis-activating peptides, hyaluronidase, and, phospholipase D. Our venom gland transcriptomic approach identified several biologically active peptides including five LVP1-alpha and LVP1-beta isoforms, which we named HzLVP1_alpha1, HzLVP1_alpha2, HzLVP1_alpha3, HzLVP1_beta1, and HzLVP1_beta and have extremely characterized here.

Discussion

Except for HzLVP1_beta1, all other identified LVP1s are predicted to be stable proteins (instability index <40). Moreover, all isoform of LVP1s alpha and beta subunits are thermostable, with the most stability for HzLVP1_alpha2 (aliphatic index = 71.38). HzLVP1_alpha2 has also the highest half-life. Three-dimensional structure of all identified proteins compacts with three disulfide bridges. The extra cysteine residue may allow the proteins to form a hetero- or homodimer. LVP1 subunits of H. zagrosensis potentially interact with adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), two key enzymes in regulation of lipolysis in adipocytes, suggesting pharmacological properties of these identified proteins.

Euglena Attenuates High-Fat-Diet-Induced Obesity and Especially Glucose Intolerance

Background: Obesity, a global disease, can lead to different chronic diseases and a series of social health problems. Lifestyle changes, especially dietary changes, are the most effective way to treat obesity. Euglena, a novel food, has attracted much attention. Previous studies have shown that Euglena is an important modulator of the host immune response. In this study, the effects of Euglena as a nutritional intervention in high-fat-diet-induced obese C57BL/6J mice were investigated regarding adipose tissue accumulation and lipid and glucose metabolism by gavage at the dose of 100 mg/kg bodyweight for 9 weeks. This study is one of the few to investigate, in detail, the preventive effects of dietary Euglena on obesity. Methods: Five-week-old male C57BL/6J mice were fed with a high-fat diet (HFD) to induce obesity. An obesity model was created by feeding the high-fat diet for a period of 10 weeks. Obese mice were randomized into 2 groups with the same mean body weight, and no significant differences were observed between the groups: (1) the mice in the HEG group were maintained on a high-fat diet and daily gavaged with Euglena (100 mg/kg body weight) dissolved in saline (n = 7); and (2) the mice in the HFD group were maintained on a high-fat diet and daily gavaged with saline with the same volume (n = 7). The experiment finished after a nine-week period. Results: The results showed that Euglena could reduce the accumulation of white body fat, including subcutaneous fat and visceral fat, and mainly targeted subcutaneous fat. Euglena also reduced adipocyte particle size expansion, promoted lipolysis in adipose (adipose triglyceride lipase and hormone-sensitive triglyceride lipase) and liver tissue (reduced non-esterified fatty acid content), and improved obesity-induced ectopic fat deposition and glucose tolerance. Conclusions: Our findings suggest that Euglena, as a nutritional intervention in HFDs, efficiently reduces body weight and white adipose tissue deposition. The mechanism of Euglena is mainly though enhancing lipolysis. It is worth noting that Euglena β-glucan recovers the hyperglycemia and accumulation of ectopic fat within the liver induced by HFD. Our study is one of the few studies to report in detail the preventive effects of dietary Euglena on obesity in vivo. This study revealed that Euglena also has an important ameliorative effect on obesity and metabolic disorders, which laid a theoretical foundation for its future application in functional foods.

Recent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: A comprehensive review

Anthocyanins, found in various pigmented plants as secondary metabolites, represent a class of dietary polyphenols known for their bioactive properties, demonstrating health-promoting effects against several chronic diseases. Among these, cyanidin-3-O-glucoside (C3G) is one of the most prevalent types of anthocyanins. Upon consumption, C3G undergoes phases I and II metabolism by oral epithelial cells, absorption in the gastric epithelium, and gut transformation (phase II & microbial metabolism), with limited amounts reaching the bloodstream. Obesity, characterized by excessive body fat accumulation, is a global health concern associated with heightened risks of disability, illness, and mortality. This comprehensive review delves into the biodegradation and absorption dynamics of C3G within the gastrointestinal tract. It meticulously examines the latest research findings, drawn from in vitro and in vivo models, presenting evidence underlining C3G's bioactivity. Notably, C3G has demonstrated significant efficacy in combating obesity, by regulating lipid metabolism, specifically decreasing lipid synthesis, increasing fatty acid oxidation, and reducing lipid accumulation. Additionally, C3G enhances energy homeostasis by boosting energy expenditure, promoting the activity of brown adipose tissue, and stimulating mitochondrial biogenesis. Furthermore, C3G shows potential in managing various prevalent obesity-related conditions. These include cardiovascular diseases (CVD) and hypertension through the suppression of reactive oxygen species (ROS) production, enhancement of endogenous antioxidant enzyme levels, and inhibition of the nuclear factor-kappa B (NF-κB) signaling pathway and by exercising its cardioprotective and vascular effects by decreasing pulmonary artery thickness and systolic pressure which enhances vascular relaxation and angiogenesis. Type 2 diabetes mellitus (T2DM) and insulin resistance (IR) are also managed by reducing gluconeogenesis via AMPK pathway activation, promoting autophagy, protecting pancreatic β-cells from oxidative stress and enhancing glucose-stimulated insulin secretion. Additionally, C3G improves insulin sensitivity by upregulating GLUT-1 and GLUT-4 expression and regulating the PI3K/Akt pathway. C3G exhibits anti-inflammatory properties by inhibiting the NF-κB pathway, reducing pro-inflammatory cytokines, and shifting macrophage polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. C3G demonstrates antioxidative effects by enhancing the expression of antioxidant enzymes, reducing ROS production, and activating the Nrf2/AMPK signaling pathway. Moreover, these mechanisms also contribute to attenuating inflammatory bowel disease and regulating gut microbiota by decreasing Firmicutes and increasing Bacteroidetes abundance, restoring colon length, and reducing levels of inflammatory cytokines. The therapeutic potential of C3G extends beyond metabolic disorders; it has also been found effective in managing specific cancer types and neurodegenerative disorders. The findings of this research can provide an important reference for future investigations that seek to improve human health through the use of naturally occurring bioactive compounds.

Bioinformatics Analysis of miR-181a and Its Role in Adipogenesis, Obesity, and Lipid Metabolism Through Review of Literature

The miRNAs regulate various biological processes in the mammalian body system. The role of miR-181a in the development, progression, and expansion of cancers is well-documented. However, the role of miR-181a in adipogenesis; lipid metabolism; obesity; and obesity-related issues such as diabetes mellitus needs to be explored. Therefore, in the present study, the literature was searched and bioinformatics tools were applied to explore the role of miR-181a in adipogenesis. The list of adipogenic and lipogenic target genes validated through different publications were extracted and compiled. The network and functional analysis of these target genes was performed through in-silico analysis. The mature sequence of miR-181a of different species were extracted from and were found highly conserved among the curated species. Additionally, we also used various bioinformatics tools such as target gene extraction from Targetscan, miRWalk, and miRDB, and the list of the target genes from these different databases was compared, and common target genes were predicted. These common target genes were further subjected to the enrichment score and KEGG pathways analysis. The enrichment score of the vital KEGG pathways of the target genes is the key regulator of adipogenesis, lipogenesis, obesity, and obesity-related syndromes in adipose tissues. Therefore, the information presented in the current review will explore the regulatory roles of miR-181a in fat tissues and its associated functions and manifestations.

Adipocyte metabolic state regulates glial phagocytic function

Obesity and type 2 diabetes are well-established risk factors for neurodegenerative disorders1-4, yet the underlying mechanisms remain poorly understood. The adipocyte-brain axis is crucial for brain function, as adipocytes secrete signaling molecules, including lipids and adipokines, that impinge on neural circuits to regulate feeding and energy expenditure5. Disruptions in the adipocyte-brain axis are associated with neurodegenerative conditions6, but the causal links are not fully understood. Neural debris accumulates with age and injury, and glial phagocytic function is crucial for clearing this debris and maintaining a healthy brain microenvironment7-9. Using adult Drosophila, we investigate how adipocyte metabolism influences glial phagocytic activity in the brain. We demonstrate that a prolonged obesogenic diet increases adipocyte fatty acid oxidation and ketogenesis. Genetic manipulations that mimic obesogenic diet-induced changes in adipocyte lipid and mitochondrial metabolism unexpectedly reduce the expression of the phagocytic receptor Draper in Drosophila microglia-like cells in the brain. We identify Apolpp-the Drosophila equivalent of human apolipoprotein B (ApoB)-as a critical adipocyte-derived signal that regulates glial phagocytosis. Additionally, we show that Lipoprotein Receptor 1 (LpR1), the LDL receptor on phagocytic glia, is required for glial capacity to clear injury-induced neuronal debris. Our findings establish that adipocyte-brain lipoprotein signaling regulates glial phagocytic function, revealing a novel pathway that links adipocyte metabolic disorders with neurodegeneration.

The Release of Lipolytic Hormones during Various High-Intensity Interval and Moderate-Intensity Continuous Training Regimens and Their Effects on Fat Loss

To investigate the release of lipolytic hormones during various high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), and their effects on fat loss. 39 young women categorized as obese (with a body fat percentage (BFP) ≥30%) were randomly allocated to one of the following groups: all-out sprint interval training (SIT, n =10); supramaximal HIIT (HIIT120, 120%V̇O2peak, n = 10); HIIT (HIIT90, 90%V̇O2peak, n = 10), or MICT, (60%V̇O2peak, n = 9) for a twelve-week observation period consisting of 3 to 4 exercise sessions per week. Serum epinephrine (EPI) and growth hormone (GH) were measured during the 1st, 20th, and 44th training sessions. Body weight (BW), body mass index (BMI), whole-body fat mass (FM) and BFP were assessed pre- and post-intervention. Following the 1st and 20th sessions, significant increases in EPI (p < 0.05) were observed post-exercise in HIIT120 and HIIT90, but not in SIT and MICT. In the 44th session, the increased EPI was found in SIT, HIIT120, and HIIT90, but not in MICT (p < 0.05). For the GH, a significant increase was observed post-exercise in all groups in the three sessions. The increased EPI and GH returned to baselines 3 hours post-exercise. After the 12-week intervention, significant reductions in FM and BFP were found in all groups, while reductions in BW and BMI were only found in the SIT and HIIT groups. Greater reductions in FM and BFP, in comparison to MICT, were observed in the SIT and HIIT groups (p < 0.05). 12-week SIT, HIIT120, and HIIT90, in comparison to MICT, were more efficacious in fat reduction in obese women, partly benefiting from the greater release of lipolytic hormones during training sessions.

Team players in the pathogenesis of metabolic dysfunctions-associated steatotic liver disease: The basis of development of pharmacotherapy

Nutrient metabolism is regulated by several factors. Social determinants of health with or without genetics are the primary regulator of metabolism, and an unhealthy lifestyle affects all modulators and mediators, leading to the adaptation and finally to the exhaustion of cellular functions. Hepatic steatosis is defined by presence of fat in more than 5% of hepatocytes. In hepatocytes, fat is stored as triglycerides in lipid droplet. Hepatic steatosis results from a combination of multiple intracellular processes. In a healthy individual nutrient metabolism is regulated at several steps. It ranges from the selection of nutrients in a grocery store to the last step of consumption of ATP as an energy or as a building block of a cell as structural component. Several hormones, peptides, and genes have been described that participate in nutrient metabolism. Several enzymes participate in each nutrient metabolism as described above from ingestion to generation of ATP. As of now several publications have revealed very intricate regulation of nutrient metabolism, where most of the regulatory factors are tied to each other bidirectionally, making it difficult to comprehend chronological sequence of events. Insulin hormone is the primary regulator of all nutrients' metabolism both in prandial and fasting states. Insulin exerts its effects directly and indirectly on enzymes involved in the three main cellular function processes; metabolic, inflammation and repair, and cell growth and regeneration. Final regulators that control the enzymatic functions through stimulation or suppression of a cell are nuclear receptors in especially farnesoid X receptor and peroxisome proliferator-activated receptor/RXR ligands, adiponectin, leptin, and adiponutrin. Insulin hormone has direct effect on these final modulators. Whereas blood glucose level, serum lipids, incretin hormones, bile acids in conjunction with microbiota are intermediary modulators which are controlled by lifestyle. The purpose of this review is to overview the key players in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) that help us understand the disease natural course, risk stratification, role of lifestyle and pharmacotherapy in each individual patient with MASLD to achieve personalized care and target the practice of precision medicine. PubMed and Google Scholar databases were used to identify publication related to metabolism of carbohydrate and fat in states of health and disease states; MASLD, cardiovascular disease and cancer. More than 1000 publications including original research and review papers were reviewed.

Lipases are differentially regulated by hormones to maintain free fatty acid homeostasis for insect brain development

BACKGROUND

Free fatty acids (FFAs) play vital roles as energy sources and substrates in organisms; however, the molecular mechanism regulating the homeostasis of FFA levels in various circumstances, such as feeding and nonfeeding stages, is not fully clarified. Holometabolous insects digest dietary triglycerides (TAGs) during larval feeding stages and degrade stored TAGs in the fat body during metamorphosis after feeding cessation, which presents a suitable model for this study.

RESULTS

This study reported that two lipases are differentially regulated by hormones to maintain the homeostasis of FFA levels during the feeding and nonfeeding stages using the lepidopteran insect cotton bollworm Helicoverpa armigera as a model. Lipase member H-A-like (Lha-like), related to human pancreatic lipase (PTL), was abundantly expressed in the midgut during the feeding stage, while the monoacylglycerol lipase ABHD12-like (Abhd12-like), related to human monoacylglycerol lipase (MGL), was abundantly expressed in the fat body during the nonfeeding stage. Lha-like was upregulated by juvenile hormone (JH) via the JH intracellular receptor methoprene-tolerant 1 (MET1), and Abhd12-like was upregulated by 20-hydroxyecdysone (20E) via forkhead box O (FOXO) transcription factor. Knockdown of Lha-like decreased FFA levels in the hemolymph and reduced TAG levels in the fat body. Moreover, lipid droplets (LDs) were small, the brain morphology was abnormal, the size of the brain was small, and the larvae showed the phenotype of delayed pupation, small pupae, and delayed tissue remodeling. Knockdown of Abhd12-like decreased FFA levels in the hemolymph; however, TAG levels increased in the fat body, and LDs remained large. The development of the brain was arrested at the larval stage, and the larvae showed a delayed pupation phenotype and delayed tissue remodeling.

CONCLUSIONS

The differential regulation of lipases expression by different hormones determines FFAs homeostasis and different TAG levels in the fat body during the feeding larval growth and nonfeeding stages of metamorphosis in the insect. The homeostasis of FFAs supports insect growth, brain development, and metamorphosis.

Dietary fatty acid pattern and its association with metabolic profile among overweight and obese adults

BACKGROUND

Numerous studies have revealed the role of dietary fatty acids in human health. However, few studies have evaluated dietary fatty acid patterns and their association with metabolic parameters. The current study aimed to explore the association between dietary fatty acid patterns and risk factors for metabolic syndrome (MetS) among overweight and obese adults.

METHODS

This cross-sectional study involved 340 participants who were overweight or obese. The study included assessments of body composition and anthropometric measurements. Dietary fatty acid consumption was evaluated using a validated Food Frequency Questionnaire (FFQ) containing 168 items. Additionally, biochemical parameters, including serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), fasting serum glucose (FSG), and insulin levels, were measured using enzymatic methods. Fatty acid patterns were determined by principal component analysis (PCA), and the association between these dietary FA patterns and risk factors related to MetS components was assessed using logistic regression.

RESULTS

Factor analysis conducted in this study explored three dietary fatty acid patterns: saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), and long-chain combined fatty acids (LC-CFA). Those at the highest tertile of the SFA pattern had lower diastolic blood pressure (DBP) (P = 0.03). Low-density lipoprotein cholesterol (LDL) was lower in the second and third tertiles (P ≤ 0.05). Also, higher fasting blood glucose (FBS) was observed in the second and third tertiles (P < 0.05), and the homeostatic model assessment of insulin resistance (HOMA-IR) was higher in the third tertile (P = 0.049). In the PUFA pattern, FBS was lower in the third tertile (P = 0.03). In the LC-CFA pattern, lower TC was achieved in higher tertiles (P = 0.04).

CONCLUSION

Our findings demonstrated that consuming high and moderate SFA patterns is associated with higher FBS and HOMA-IR. Also, increased consumption of SCFAs is related to lower DPB and LDL. Individuals who consumed more PUFA, especially linoleic acid, had lower FBS. These outcomes might be beneficial in managing MetS and leading to a new field of research.

Adipose Triglyceride Lipase-Mediated Adipocyte Lipolysis Exacerbates Acute Pancreatitis Severity in Mouse Models and Patients

Dyslipolysis of adipocytes plays a critical role in various diseases. Adipose triglyceride lipase (ATGL) is a rate-limiting enzyme in adipocyte autonomous lipolysis. However, the degree of adipocyte lipolysis related to the prognoses in acute pancreatitis (AP) and the role of ATGL-mediated lipolysis in the pathogenesis of AP remain elusive. Herein, the visceral adipose tissue consumption rate in the acute stage was measured in both patients with AP and mouse models. Lipolysis levels and ATGL expression were detected in cerulein-induced AP models. CL316,243, a lipolysis stimulator, and adipose tissue-specific ATGL knockout mice were used to further investigate the role of lipolysis in AP. The ATGL-specific inhibitor, atglistatin, was used in C57Bl/6N and ob/ob AP models. This study indicated that increased visceral adipose tissue consumption rate in the acute phase was independently associated with adverse prognoses in patients with AP, which was validated in mouse AP models. Lipolysis of adipocytes was elevated in AP mice. Stimulation of lipolysis aggravated AP. Genetic blockage of ATGL specifically in adipocytes alleviated the damage to AP. The application of atglistatin effectively protected against AP in both lean and obese mice. These findings demonstrated that ATGL-mediated adipocyte lipolysis exacerbates AP and highlighted the therapeutic potential of ATGL as a drug target for AP.

Transcriptional regulation of adipocyte lipolysis by IRF2BP2

Adipocyte lipolysis controls systemic energy levels and metabolic homeostasis. Lipolysis is regulated by post-translational modifications of key lipolytic enzymes. However, less is known about the transcriptional mechanisms that regulate lipolysis. Here, we identify the transcriptional factor interferon regulatory factor-2 binding protein 2 (IRF2BP2) as a repressor of adipocyte lipolysis. Deletion of IRF2BP2 in primary human adipocytes increases lipolysis without affecting glucose uptake, whereas IRF2BP2 overexpression decreases lipolysis. RNA-seq and ChIP-seq analyses reveal that IRF2BP2 directly represses several lipolysis-related genes, including LIPE ( HSL , hormone sensitive lipase), which encodes the rate-limiting enzyme in lipolysis. Adipocyte-selective deletion of Irf2bp2 in mice increases Lipe expression and free fatty acid levels, resulting in elevated adipose tissue inflammation and glucose intolerance. Altogether, these findings demonstrate that IRF2BP2 restrains adipocyte lipolysis and opens new avenues to target lipolysis for the treatment of metabolic disease.

Thermal facial image analyses reveal quantitative hallmarks of aging and metabolic diseases

Although human core body temperature is known to decrease with age, the age dependency of facial temperature and its potential to indicate aging rate or aging-related diseases remains uncertain. Here, we collected thermal facial images of 2,811 Han Chinese individuals 20-90 years old, developed the ThermoFace method to automatically process and analyze images, and then generated thermal age and disease prediction models. The ThermoFace deep learning model for thermal facial age has a mean absolute deviation of about 5 years in cross-validation and 5.18 years in an independent cohort. The difference between predicted and chronological age is highly associated with metabolic parameters, sleep time, and gene expression pathways like DNA repair, lipolysis, and ATPase in the blood transcriptome, and it is modifiable by exercise. Consistently, ThermoFace disease predictors forecast metabolic diseases like fatty liver with high accuracy (AUC > 0.80), with predicted disease probability correlated with metabolic parameters.

Bee (Apis mellifera L. 1758) wax restores adipogenesis and lipid accumulation of 3T3-L1 cells in cancer-associated cachexia condition

Cachexia is associated with various diseases, such as heart disease, infectious disease, and cancer. In particular, cancer-associated cachexia (CAC) accounts for more than 20% of mortality in cancer patients worldwide. Adipose tissue in CAC is characterized by adipocyte atrophy, mainly due to excessively increased lipolysis and impairment of adipogenesis. CAC is well known for the loss of skeletal muscle mass and/or fat mass. CAC induces severe metabolic alterations, including protein, lipid, and carbohydrate metabolism. The objectives of this study were to evaluate the effects of bee wax (Apis mellifera L. 1758) (BW) extract on adipogenesis, lipolysis, and mitochondrial oxygen consumption through white adipocytes, 3T3-L1. To achieve this study, cancer-associated cachexia condition was established by incubation of 3T3-L1 with colon cancer cell line CT26 cultured media. BW extract recovered the reduced adipogenesis under cachectic conditions in CT26 media. Treatment of BW showed increasing lipid accumulation as well as adipogenic gene expression and its target gene during adipogenesis. The administration of BW to adipocytes could decrease lipolysis. Also, BW could significantly downregulated the mitochondrial fatty acid oxidation-related genes, oxygen consumption rate, and extracellular acidification rate. Our results suggest that BW could improve metabolic disorders such as CAC through the activation of adipogenesis and inhibition of lipolysis in adipocytes, although we need further validation in vivo CAC model to check the effects of BW extract. Therefore, BW extract supplements could be useful as an alternative medicine to reverse energy imbalances.

Rose Petal Extract Ameliorates Obesity in High Fat Diet-Induced Obese Mice

In Asia, Rosa spp. has been used in traditional medicine for the treatment of osteoarthritis, rheumatoid arthritis, and edema. In this study, we investigated the effect of rose petal extract (RPE) on high fat diet (HFD)-induced obesity in mice. C57BL/6J mice were fed with either an AIN-93G diet (normal control), a 60% HFD, or a HFD plus supplementation with RPE at 100 or 200 mg/kg body weight (HFD+R100, HFD+R200) for 14 weeks. The HFD increased the body weight gain, liver and fat weight, lipid profiles (total cholesterol, triglyceride, high density lipoprotein cholesterol, and low density lipoprotein cholesterol), and the serum aspartate aminotransferase and alanine aminotransferase levels of mice, while RPE supplementation significantly decreased these parameters compared with the HFD group. Furthermore, the HFD increased the protein expressions of adipogenesis- and lipogenesis-related factors and decreased the protein expression of lipolysis- and energy metabolism-related factors. Conversely, RPE supplementation significantly decreased the protein expression of adipogenesis- and lipogenesis-related factors and increased the protein expression of lipolysis- and energy metabolism-related factors compared to the HFD group. Taken together, the results provide preliminary evidence for the potential protective effects of the RPE against obesity.

In Vitro Nonalcoholic Fatty Liver Disease Model Elucidating the Effect of Immune Environment on Disease Progression and Alleviation

Nonalcoholic fatty liver disease (NAFLD), which is a major cause of chronic liver disease, is characterized by fat accumulation in the liver. Existing models struggle to assess medication effects on liver function in the context of NAFLD's unique inflammatory environment. We address this by developing a 3D in vitro NAFLD model using HepG2 and THP-1 cells (mimicking liver and Kupffer cells) cocultured using transwell and hydrogel system. This mimics liver architecture and allows for manipulation of the immune environment. We demonstrate that the model recapitulates key NAFLD features: steatosis (induced by fatty acids), oxidative stress, inflammation, and impaired liver function embodying the interrelationship between NAFLD and the surrounding immune environment. This versatile model offers a valuable tool for preclinical NAFLD research by incorporating a disease-relevant immune environment.

Obesity, dyslipidemia, and cardiovascular disease: A joint expert review from the Obesity Medicine Association and the National Lipid Association 2024

Background

This joint expert review by the Obesity Medicine Association (OMA) and National Lipid Association (NLA) provides clinicians an overview of the pathophysiologic and clinical considerations regarding obesity, dyslipidemia, and cardiovascular disease (CVD) risk.

Methods

This joint expert review is based upon scientific evidence, clinical perspectives of the authors, and peer review by the OMA and NLA leadership.

Results

Among individuals with obesity, adipose tissue may store over 50% of the total body free cholesterol. Triglycerides may represent up to 99% of lipid species in adipose tissue. The potential for adipose tissue expansion accounts for the greatest weight variance among most individuals, with percent body fat ranging from less than 5% to over 60%. While population studies suggest a modest increase in blood low-density lipoprotein cholesterol (LDL-C) levels with excess adiposity, the adiposopathic dyslipidemia pattern most often described with an increase in adiposity includes elevated triglycerides, reduced high density lipoprotein cholesterol (HDL-C), increased non-HDL-C, elevated apolipoprotein B, increased LDL particle concentration, and increased small, dense LDL particles.

Conclusions

Obesity increases CVD risk, at least partially due to promotion of an adiposopathic, atherogenic lipid profile. Obesity also worsens other cardiometabolic risk factors. Among patients with obesity, interventions that reduce body weight and improve CVD outcomes are generally associated with improved lipid levels. Given the modest improvement in blood LDL-C with weight reduction in patients with overweight or obesity, early interventions to treat both excess adiposity and elevated atherogenic cholesterol (LDL-C and/or non-HDL-C) levels represent priorities in reducing the risk of CVD.

Global perspective on nonalcoholic fatty liver disease and nonalcoholic steatohepatitis - prevalence, clinical impact, economic implications and management strategies

BACKGROUND

The metabolically-based liver disease, nonalcoholic fatty liver disease (NAFLD), is the most common cause of chronic liver disease currently affecting 38% of the world's adult population. NAFLD can be progressive leading to nonalcoholic steatohepatitis (NASH), liver transplantation, liver cancer, liver-related mortality and is associated with decreased quality of life from impaired physical functioning and increased healthcare resource utilisation. However, screening for NAFLD is cost-prohibitive but screening for high risk NAFLD (NAFLD with F2 fibrosis or greater) is imperative.

AIM

To review the global perspective on NAFLD and NASH METHODS: We retrieved articles from PubMed using search terms NAFLD, prevalence, clinical burden, economic burden and management strategies.

RESULTS

NAFLD/NASH shows geographical variation across the globe. Highest prevalence rates are in South America and the Middle East and North Africa; lowest prevalence is in Africa. NAFLD's economic impact is from direct and indirect medical costs and loss in worker productivity. It is projected that, over the next two decades, the total cost of NAFLD and diabetes will exceed $1.5 trillion (USD). Risk stratification algorithms identifying "high risk NAFLD" were made following non-invasive tests for NAFLD identification and fibrosis development. These algorithms should be used in primary care and endocrinology settings so timely and appropriate interventions (lifestyle and cardiometabolic risk factor management) can be initiated.

CONCLUSIONS

To reduce the burgeoning burden of NAFLD/NASH, management should include risk stratification algorithms for accurate identification of patients, linkage to appropriate settings, and initiation of effective treatment regimens.

Inflammation-mediated metabolic regulation in adipose tissue

Chronic inflammation of adipose tissue is a prominent characteristic of many metabolic diseases. Lipid metabolism in adipose tissue is consistently dysregulated during inflammation, which is characterized by substantial infiltration by proinflammatory cells and high cytokine concentrations. Adipose tissue inflammation is caused by a variety of endogenous factors, such as mitochondrial dysfunction, reactive oxygen species (ROS) production, endoplasmic reticulum (ER) stress, cellular senescence, ceramides biosynthesis and mediators of lipopolysaccharides (LPS) signaling. Additionally, the gut microbiota also plays a crucial role in regulating adipose tissue inflammation. Essentially, adipose tissue inflammation arises from an imbalance in adipocyte metabolism and the regulation of immune cells. Specific inflammatory signals, including nuclear factor-κB (NF-κB) signaling, inflammasome signaling and inflammation-mediated autophagy, have been shown to be involved in the metabolic regulation. The pathogenesis of metabolic diseases characterized by chronic inflammation (obesity, insulin resistance, atherosclerosis and nonalcoholic fatty liver disease [NAFLD]) and recent research regarding potential therapeutic targets for these conditions are also discussed in this review.

Positive Effects of Physical Activity on Insulin Signaling

Physical activity is integral to metabolic health, particularly in addressing insulin resistance and related disorders such as type 2 diabetes mellitus (T2DM). Studies consistently demonstrate a strong association between physical activity levels and insulin sensitivity. Regular exercise interventions were shown to significantly improve glycemic control, highlighting exercise as a recommended therapeutic strategy for reducing insulin resistance. Physical inactivity is closely linked to islet cell insufficiency, exacerbating insulin resistance through various pathways including ER stress, mitochondrial dysfunction, oxidative stress, and inflammation. Conversely, physical training and exercise preserve and restore islet function, enhancing peripheral insulin sensitivity. Exercise interventions stimulate β-cell proliferation through increased circulating levels of growth factors, further emphasizing its role in maintaining pancreatic health and glucose metabolism. Furthermore, sedentary lifestyles contribute to elevated oxidative stress levels and ceramide production, impairing insulin signaling and glucose metabolism. Regular exercise induces anti-inflammatory responses, enhances antioxidant defenses, and promotes mitochondrial function, thereby improving insulin sensitivity and metabolic efficiency. Encouraging individuals to adopt active lifestyles and engage in regular exercise is crucial for preventing and managing insulin resistance and related metabolic disorders, ultimately promoting overall health and well-being.

Obesity, dyslipidemia, and cardiovascular disease: A joint expert review from the Obesity Medicine Association and the National Lipid Association 2024

BACKGROUND

This joint expert review by the Obesity Medicine Association (OMA) and National Lipid Association (NLA) provides clinicians an overview of the pathophysiologic and clinical considerations regarding obesity, dyslipidemia, and cardiovascular disease (CVD) risk.

METHODS

This joint expert review is based upon scientific evidence, clinical perspectives of the authors, and peer review by the OMA and NLA leadership.

RESULTS

Among individuals with obesity, adipose tissue may store over 50% of the total body free cholesterol. Triglycerides may represent up to 99% of lipid species in adipose tissue. The potential for adipose tissue expansion accounts for the greatest weight variance among most individuals, with percent body fat ranging from less than 5% to over 60%. While population studies suggest a modest increase in blood low-density lipoprotein cholesterol (LDL-C) levels with excess adiposity, the adiposopathic dyslipidemia pattern most often described with an increase in adiposity includes elevated triglycerides, reduced high-density lipoprotein cholesterol (HDL-C), increased non-HDL-C, elevated apolipoprotein B, increased LDL particle concentration, and increased small, dense LDL particles.

CONCLUSIONS

Obesity increases CVD risk, at least partially due to promotion of an adiposopathic, atherogenic lipid profile. Obesity also worsens other cardiometabolic risk factors. Among patients with obesity, interventions that reduce body weight and improve CVD outcomes are generally associated with improved lipid levels. Given the modest improvement in blood LDL-C with weight reduction in patients with overweight or obesity, early interventions to treat both excess adiposity and elevated atherogenic cholesterol (LDL-C and/or non-HDL-C) levels represent priorities in reducing the risk of CVD.

Adipose tissue rearrangement in cancer cachexia: The involvement of β3-adrenergic receptor associated pathways

Cancer-associated cachexia (CAC) is a complex multiple organ syndrome that significantly contributes to reduced quality of life and increased mortality among many cancer patients. Its multifactorial nature makes its early diagnosis and effective therapeutic interventions challenging. Adipose tissue is particularly impacted by cachexia, typically through increased lipolysis, browning and thermogenesis, mainly at the onset of the disease. These processes lead to depletion of fat mass and contribute to the dysfunction of other organs. The β-adrenergic signalling pathways are classical players in the regulation of adipose tissue metabolism. They are activated upon sympathetic stimulation inducing lipolysis, browning and thermogenesis, therefore contributing to energy expenditure. Despite accumulating evidence suggesting that β3-adrenergic receptor stimulation may be crucial to the adipose tissue remodelling during cachexia, the literature remains controversial. Moreover, there is limited knowledge regarding sexual dimorphism of adipose tissue in the context of cachexia. This review paper aims to present the current knowledge regarding adipose tissue wasting during CAC, with a specific focus on the role of the β3-adrenergic receptor, placing it as a potential therapeutic target against cachexia.

Unraveling the rationale and conducting a comprehensive assessment of KD025 (Belumosudil) as a candidate drug for inhibiting adipogenic differentiation-a systematic review

Rho-associated kinases (ROCKs) are crucial during the adipocyte differentiation process. KD025 (Belumosudil) is a newly developed inhibitor that selectively targets ROCK2. It has exhibited consistent efficacy in impeding adipogenesis across a spectrum of in vitro models of adipogenic differentiation. Given the novelty of this treatment, a comprehensive systematic review has not been conducted yet. This systematic review aims to fill this knowledge void by providing readers with an extensive examination of the rationale behind KD025 and its impacts on adipogenesis. Preclinical evidence was gathered owing to the absence of clinical trials. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the study's quality was assessed using the Joanna Briggs Institute (JBI) Checklist Critical Appraisal Tool for Systematic Reviews. In various in vitro models, such as 3T3-L1 cells, human orbital fibroblasts, and human adipose-derived stem cells, KD025 demonstrated potent anti-adipogenic actions. At a molecular level, KD025 had significant effects, including decreasing fibronectin (Fn) expression, inhibiting ROCK2 and CK2 activity, suppressing lipid droplet formation, and reducing the expression of proadipogenic genes peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα). Additionally, KD025 resulted in the suppression of fatty acid-binding protein 4 (FABP4 or AP2) expression, a decrease in sterol regulatory element binding protein 1c (SREBP-1c) and Glut-4 expression. Emphasis must be placed on the fact that while KD025 shows potential in preclinical studies and experimental models, extensive research is crucial to assess its efficacy, safety, and potential therapeutic applications thoroughly and directly in human subjects.

The Effect of Low Temperature Storage on the Lipid Quality of Fish, Either Alone or Combined with Alternative Preservation Technologies

Marine foods are highly perishable products due to their high content of polyunsaturated fatty acids, which can be readily oxidized to form peroxides and secondary oxidation products, thus conferring such foods undesirable organoleptic characteristics and generating harmful compounds that are detrimental to the health of consumers. The use of preservation methods that minimize lipid oxidation is required in the fishing and aquaculture industries. Low temperature storage (chilling or freezing) is one of the most commonly used preservation methods for fish and seafood, although it has been shown that the oxidation of the lipid fraction of such products is partially but not completely inhibited at low temperatures. The extent of lipid oxidation depends on the species and the storage temperature and time, among other factors. This paper reviews the effect of low temperature storage on the lipid quality of fish, either alone or in combination with other preservation techniques. The use of antioxidant additives, high hydrostatic pressure, irradiation, ozonation, ultrasounds, pulsed electric fields, and the design of novel packaging can help preserve chilled or frozen fish products, although further research is needed to develop more efficient fish preservation processes from an economic, nutritional, sensory, and sustainable standpoint.

Tissue fibrosis associated depletion of lipid-filled cells

Fibrosis is primarily described as the deposition of excessive extracellular matrix, but in many tissues it also involves a loss of lipid or lipid-filled cells. Lipid-filled cells are critical to tissue function and integrity in many tissues including the skin and lungs. Thus, loss or depletion of lipid-filled cells during fibrogenesis, has implications for tissue function. In some contexts, lipid-filled cells can impact ECM composition and stability, highlighting their importance in fibrotic transformation. Recent papers in fibrosis address this newly recognized fibrotic lipodystrophy phenomenon. Even in disparate tissues, common mechanisms are emerging to explain fibrotic lipodystrophy. These findings have implications for fibrosis in tissues composed of fibroblast and lipid-filled cell populations such as skin, lung, and liver. In this review, we will discuss the roles of lipid-containing cells, their reduction/loss during fibrotic transformation, and the mechanisms of that loss in the skin and lungs.

Sex-Specific Effects of Long-Term Antipsychotic Drug Treatment on Adipocyte Tissue and the Crosstalk to Liver and Brain in Rats

Antipsychotic drug (APD) medication can lead to metabolic dysfunctions and weight gain, which together increase morbidity and mortality. Metabolically active visceral adipose tissue (VAT) in particular plays a crucial role in the etiopathology of these metabolic dysregulations. Here, we studied the effect of 12 weeks of drug medication by daily oral feeding of clozapine and haloperidol on the perirenal fat tissue as part of VAT of male and female Sprague Dawley rats in the context of complex former investigations on brain, liver, and blood. Adipocyte area values were determined, as well as triglycerides, non-esterified fatty acids (NEFAs), glucose, glycogen, lactate, malondialdehyde equivalents, ferric iron and protein levels of Perilipin-A, hormone-sensitive-lipase (HSL), hepcidin, glucose transporter-4 (Glut-4) and insulin receptor-ß (IR-ß). We found increased adipocyte mass in males, with slightly higher adipocyte area values in both males and females under clozapine treatment. Triglycerides, NEFAs, glucose and oxidative stress in the medicated groups were unchanged or slightly decreased. In contrast to controls and haloperidol-medicated rats, perirenal adipocyte mass and serum leptin levels were not correlated under clozapine. Protein expressions of perilipin-A, Glut-4 and HSL were decreased under clozapine treatment. IR-ß expression changed sex-specifically in the clozapine-medicated groups associated with higher hepcidin levels in the perirenal adipose tissue of clozapine-treated females. Taken together, clozapine and haloperidol had a smaller effect than expected on perirenal adipose tissue. The perirenal adipose tissue shows only weak changes in lipid and glucose metabolism. The main changes can be seen in the proteins examined, and probably in their effect on liver metabolism.

The molecular mechanism of obesity: The science behind natural exercise yoga and healthy diets in the treatment of obesity

The review centers on the scientific evidence underlying obesity, providing a detailed examination of the role of perilipin in this condition. It explores potential causes of obesity and delves into therapeutic approaches involving exercise, yoga, and herbal treatments. The paper discusses natural sources that can contribute to combating obesity and underscores the importance of exercise in a scientific context for overcoming obesity. Additionally, it includes information on herbal ingredients that aid in reducing obesity. The review also examines the impact of exercise type and intensity at various time intervals on muscle development. It elucidates triglyceride hydrolysis through different enzymes and the deposition of fatty acids in adipose tissue. The mechanisms by which alpha/beta hydrolase domain-containing protein 5 (ABHD5) and hormone-sensitive lipase (HSL) target and activate their functions are detailed. The inflammatory response in obesity is explored, encompassing inflammatory markers, lipid storage diseases, and their classification with molecular mechanisms. Furthermore, the hormonal regulation of lipolysis is elaborated upon in the review.

GULP1 deficiency reduces adipogenesis and glucose uptake via downregulation of PPAR signaling and disturbing of insulin/ERK signaling in 3T3-L1 cells

Obesity and metabolic disorders caused by alterations in lipid metabolism are major health issues in developed, affluent societies. Adipose tissue is the only organ that stores lipids and prevents lipotoxicity in other organs. Mature adipocytes can affect themselves and distant metabolism-related tissues by producing various adipokines, including adiponectin and leptin. The engulfment adaptor phosphotyrosine-binding domain-containing 1 (GULP1) regulates intracellular trafficking of glycosphingolipids and cholesterol, suggesting its close association with lipid metabolism. However, the role of GULP1 in adipocytes remains unknown. Therefore, this study aimed to investigate the function of GULP1 in adipogenesis, glucose uptake, and the insulin signaling pathway in adipocytes. A 3T3-L1 cell line with Gulp1 knockdown (shGulp1) and a 3T3-L1 control group (U6) were established. Changes in shGulp1 cells due to GULP1 deficiency were examined and compared to those in U6 cells using microarray analysis. Glucose uptake was monitored via insulin stimulation in shGulp1 and U6 cells using a 2-NBDG glucose uptake assay, and the insulin signaling pathway was investigated by western blot analysis. Adipogenesis was significantly delayed, lipid metabolism was altered, and several adipogenesis-related genes were downregulated in shGulp1 cells compared to those in U6 cells. Microarray analysis revealed significant inhibition of peroxisome proliferator-activated receptor signaling in shGulp1 cells compared with U6 cells. The production and secretion of adiponectin as well as the expression of adiponectin receptor were decreased in shGulp1 cells. In particular, compared with U6 cells, glucose uptake via insulin stimulation was significantly decreased in shGulp1 cells through the disturbance of ERK1/2 phosphorylation. This is the first study to identify the role of GULP1 in adipogenesis and insulin-stimulated glucose uptake by adipocytes, thereby providing new insights into the differentiation and functions of adipocytes and the metabolism of lipids and glucose, which can help better understand metabolic diseases.

The Effects of Two Servings of a Thermogenic Supplement on Metabolism, Hemodynamic Variables, and Mood State Outcomes in Young Overweight Adults

Introduction We examined if acute ingestion of a novel thermogenic supplement influences resting energy expenditure (REE), mood, and hemodynamic function. Methods Forty-six adults completed this randomized, placebo-controlled, double-blind, crossover study. Participants underwent two conditions: placebo (PL) and treatment (TX) containing 300 mg of caffeine and 3 g of acetyl-L-carnitine. REE, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and mood states were assessed at baseline and 30, 60, and 120 minutes post-ingestion. Data were analyzed using repeated measures analysis of variance. Results A significant condition-by-time interaction was observed for REE. At the 30-, 60-, and 120-minute post-ingestion timepoints, REE was 202 ± 26, 238 ± 40, and 209 ± 29 kcal/d greater in the TX condition compared to PL. No significant differences were observed for SBP and HR but a significant interaction indicated that DBP was elevated at 30 minutes in the TX vs. PL, though values remained within normal ranges. Significant interactions were observed for perceived alertness, concentration, energy, and focus, with increases in TX. Conclusion These data provide evidence that acute consumption of the thermogenic dietary supplement OxyShred (EHPlabs, Salt Lake City, Utah, USA) stimulates increases in REE that are sustained for ≥ two hours, along with increasing perceived alertness, concentration, energy, and focus. Changes in hemodynamic function are minimal and within normal ranges.

Screening of Genes Related to Fat Deposition of Pekin Ducks Based on Transcriptome Analysis

Subcutaneous fat deposition is an important index with which to evaluate meat-producing ducks, and affects their meat quality and feed conversion rate. Studying the differentially expressed genes in subcutaneous fat will help to comprehensively understand the potential mechanisms regulating fat deposition in ducks. In this study, 72 Nankou 1 Pekin Ducks and 72 Jingdian Pekin Ducks (half male and half female) at 42 days of age were selected for slaughter performance and transcriptome analysis. The results showed that the breast-muscle yield of Nankou 1 ducks was significantly higher than that of Jingdian ducks, but that the abdominal fat yield and subcutaneous fat yield were higher than that of Jingdian ducks. Thousands of DEGs, including many important genes involved in fat metabolism regulation, were detected by transcriptome. KEGG enrichment analysis showed that the DEGs were significantly enriched on pathways such as regulation of lipolysis in adipocytes, primary bile acid biosynthesis, and biosynthesis of unsaturated fatty acids. SCD, FGF7, LTBP1, PNPLA3, ADCY2, and ACOT8 were selected as candidate genes for regulating subcutaneous fat deposition. The results indicated that Nankou 1 had superior fat deposition ability compared to Jingdian ducks, and that the candidate genes regulated fat deposition by regulating fat synthesis and decomposition.