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Background: Hyperlipidemia is a lipid metabolism disorder with increasing incidence and prevalence worldwide. Abnormal lipid metabolism and inflammation are two significant characteristics of hyperlipidemia. The purpose of this study was to explore the role and mechanism of F-box only protein 28 (FBXO28) in hyperlipidemia., Methods: Mice were fed with high-fat diet (HFD) to elicit obesity, and 3T3-L1 preadipocytes were stimulated with MDI cocktail (IBMX, DEX and insulin) to evoke differentiation. In vivo and in vitro role of FBXO28 in hyperlipidemia was investigated by hematoxylin-eosin and oil Red O staining, the lipid biochemistry measurement, enzyme-linked immunosorbent assay, reverse transcription quantitative polymerase chain reaction and western blotting assays. The mechanism of FBXO28 explored by co-immunoprecipitation, immunofluorescence, ubiquitination and cycloheximide assays., Results: Low expression of FBXO28 was found in hyperlipidemia in silico, in vivo and in vitro. Upregulation of FBXO28 declined the body weight, fat accumulation, and serum lipid content in HFD-fed mice. Abnormal lipid accumulation, and the level of liposynthetic genes and beta-oxidation related genes were improved by overexpression of FBXO28 both in HFD-elicited mice and MDI-treated 3T3-L1 preadipocytes. Besides, overexpression of FBXO28 declined HFD-induced the level of proinflammatory factors and F4/80. Mechanically, FBXO28 directly bound RAB27A and promoted its ubiquitinated degradation. Thus, upregulation of RAB27A inverted the improved role of FBXO28 in abnormal lipid metabolism and inflammation in vivo and in vitro., Conclusion: FBXO28 ameliorated abnormal lipid metabolism and inflammation through the ubiquitinated degradation of RAB27A, thereby attenuating HFD-induced hyperlipidemia. The results could promote the treatment of hyperlipidemia, and the relevant diseases., (© 2024. The Author(s), under exclusive licence to Italian Society of Endocrinology (SIE).)

Neuregulin 4 (Nrg4) is an adipokine that belongs to the epidermal growth factor family and binds to ErbB4 tyrosine kinase receptors. In 3T3-L1 adipocytes, the downregulation of Nrg4 expression enhances inflammation and autophagy, resulting in insulin resistance. Here, we searched for the causes of this phenotype. Nrg4 knockdown (Nrg4 KD) adipocytes showed a significant reduction in mitochondrial content and elongation, along with a lower content of the mitochondria fusion protein mitofusin 2 (MFN2), and increased H 2 O 2 production compared to the control scrambled cells (Scr). The antioxidant N-acetylcysteine reversed the oxidative stress and reduced the gene expression of the pro-inflammatory cytokine tumor necrosis factor α (TNFα). Nrg4 KD adipocytes showed enhanced lipolysis and reduced lipogenesis, in addition to a significant reduction in several intermediates of the Krebs cycle. In summary, Nrg4 downregulation in adipocytes affects mitochondrial content and functioning, causing impaired cellular metabolism, which in turn results in oxidative stress, inflammation, and insulin resistance.

Background: Zinc (Zn), a fundamental trace element in human biology, exhibits pivotal roles in sustaining vital physiological processes and regulating metabolic homeostasis. Insufficient zinc intake has been linked to deleterious consequences on growth, reproductive functions, metabolic activities, and immune responses in both humans and animals. Oral zinc supplementation is usually performed to meet zinc requirement. Previous studies have shown that long-term supplementation of zinc in mice impaired AKT signaling and induced adipocyte hypertrophy in visceral adipose tissue., Methods: The presented study was conducted to investigate the role and mechanism of short-term zinc supplementation on lipids metabolism. Zinc sulfate was supplemented in the drinking water of C57/BL6J male mice at 30 ppm or 90 ppm for one week. Water consumption, food intake, and body weight were analyzed, adipose tissue and serum profile of metabolites were investigated, and the key genes related to lipid metabolism were analyzed., Results: Short-term zinc supplementation decreased visceral adipose tissue weight and adipocyte size compared to the control group, but no difference was observed in food intake, water consumption, and body weight between the two groups. Further studies revealed that short-term zinc supplementation significantly increased the serum insulin level while decreasing the serum NEFA content. In addition, zinc supplementation increased the expression of Atgl and Hsl in the visceral adipose tissue compared with the control mice. Furthermore, the phosphorylation level of HSL and protein level of PPARg in the epididymal adipose tissue increased by zinc supplementation compared with the control mice. In comparison, the protein level of FASN was down-regulated by short-term zinc supplementation in the epididymal adipose tissue, although the expression of lipogenic genes was not changed. The expression of F4/80 and Tnfa were increased in zinc-supplemented adipose tissue as compared with the control group., Conclusions: Our findings suggest that short-term zinc supplementation might reduce fat deposition by enhancing lipolysis in mice. Future studies could focus on the effect of intermittent zinc supplementation on fat reduction in both animal models and humans., Competing Interests: The authors declare that they have no competing interests.

The interactions between myogenic cells and adipocytes play an important role in improving carcass traits and the efficiency of energy utilization. However, there are few reports about the interaction between them mediated by small extracellular vesicles (sEV). In this study, sEV derived from porcine primary skeletal muscle stem cells (MuSCs) was found to be involved in the inhibition of porcine primary adipocyte viability, triglyceride content, Oil Red O enrichment and the expression of adipogenic genes. When the MuSCs were treated with insulin (INS) and oleic acid (OA), the effects of their secreted sEVs on adipose precursor cells were reversed, suggesting that the signaling effects of sEV are related to their own heterogeneity. Further by component heterogeneity analysis, miR-146a-5p was found to be enriched in sEVs of MuSCs and to regulate and suppress adipogenesis through its heterogeneity. This study provides an important mechanism and molecular target for small extracellular vesicles to regulate the interaction between muscle and adipose tissue and improve carcass traits at the intercellular level., (© 2024. The Author(s).)

Fibroblast growth factor 23 (FGF23) is a bone-secreted protein widely recognized as a critical regulator of skeletal and mineral metabolism. However, little is known about the nonskeletal production of FGF23 and its role in tissues other than bone. Growing evidence indicates that circulating FGF23 levels rise with a high-fat diet (HFD) and they are positively correlated with body mass index (BMI) in humans. In the present study, we show for the first time that increased circulating FGF23 levels in obese humans correlate with increased expression of adipose Fgf23 and both positively correlate with BMI. To understand the role of adipose-derived Fgf23, we generated adipocyte-specific Fgf23 knockout mice (AdipoqFgf23Δfl/Δfl) using the adiponectin-Cre driver, which targets mature white, beige, and brown adipocytes. Our data show that targeted ablation of Fgf23 in adipocytes prevents HFD-fed female mice from gaining body weight and fat mass while preserving lean mass but has no effect on male mice, indicating the presence of sexual dimorphism. These effects are observed in the absence of changes in food and energy intake. Adipose Fgf23 inactivation also prevents dyslipidemia, hyperglycemia, and hepatic steatosis in female mice. Moreover, these changes are associated with decreased respiratory exchange ratio and increased brown fat Ucp1 expression in knockout mice compared to HFD-fed control mice (Fgf23fl/fl). In conclusion, this is the first study highlighting that targeted inactivation of Fgf23 is a promising therapeutic strategy for weight loss and lean mass preservation in humans., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Skeletal muscle fat accumulation, a common complication of obesity, has garnered increasing attention. For livestock animals, intramuscular fat content is a key determinant of meat quality and directly influences consumer preferences for different meat products. However, genes effectively regulating intramuscular and intermuscular fat (IIMF) deposition remain largely unexplored. To address this gap, we employed transcriptome sequencing of muscle from pigs with high and low IIMF contents, uncovering Aldolase C (ALDOC) as a novel key gene controlling IIMF. ALDOC overexpression significantly enhanced the IIMF content both in vivo and in vitro. Mechanistic investigations revealed that ALDOC activates the AKT-mTORC1 axis to promote lipid accumulation in myotubes and intramuscular adipocytes. Notably, the mTORC1 inhibitor rapamycin abrogated ALDOC's proadipogenic effect. Our findings establish ALDOC as a novel key gene regulating IIMF deposition and identify the ALDOC-AKT-mTORC1 signaling pathway as a promising therapeutic target for treating skeletal muscle fat infiltration and improving pork quality.

This study assessed the anti-obesity effects of Lactobacillus paracasei subsp. paracasei NTU 101 (NTU 101) both in vitro and in vivo. Initially, the cytotoxicity and lipid accumulation inhibitory effects of NTU 101 on 3T3-L1 cells were evaluated using the MTT assay and oil red O assay, respectively. Subsequently, the anti-obesity effects of NTU 101 were investigated in high-fat diet-induced obese rat. Moreover, western blotting was performed to measure the obesity-related protein expression of PPARα, PPARβ, PPARγ, C/EBPα, C/EBPβ, ATGL, p-p38 MAPK, p-ERK1/2, p-AMPK and CPT-1 in both 3T3-L1 adipocytes and adipose and liver tissues. Treatment with 16 × 10 8  CFU/mL NTU 101 reduced lipid accumulation in 3T3-L1 adipocytes by more than 50 %. Oral administration of NTU 101 significantly attenuated body weight gain, as well as adipose tissue weight. NTU 101 administration enhanced fatty acid oxidation increasing expression levels of PPARα, CPT-1, and p-AMPK proteins in liver tissue, while simultaneously inhibited adipogenesis by reducing PPARγ and C/EBPα proteins in adipose tissue. Furthermore, NTU 101 supplementation positively modulated the composition of gut microbiota, notably increasing the abundance of Akkermansiaceae. This present study suggests that NTU 101 exerts anti-obesity effects by regulating gut microbiota, fatty acid oxidation, lipolysis and adipogenesis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare no conflict of interest., (Copyright © 2024. Published by Elsevier Inc.)

Background/Objectives: Cancer cachexia is a multifactorial syndrome characterized by the progressive loss of skeletal muscle mass and adipose tissue. Dalbergia odorifer is widely used in traditional medicine in Korea and China to treat various diseases. However, its exact role and underlying mechanism in regulating cancer cachexia have not been elucidated yet. This research was conducted to investigate the effect of D. odorifer extract (DOE) in preventing the development of cancer-induced cachexia symptoms and figure out the relevant mechanisms. Methods: A cancer cachexia model was established in Balb/c mice using the CT26 colon carcinoma cell line. To evaluate the anti-cachexia effect of Dalbergia odorifer extract (DOE), CT26-bearing mice were orally administered with DOE at concentrations of 50 and 100 mg/kg BW for 14 days. C2C12 myotubes and 3T3L1 adipocytes were treated with 80% CT26 conditioned medium, DOE, and wortmannin, a particular AKT inhibitor to determine the influence of DOE in the AKT signaling pathway. Mice body weight, food intake, myofiber cross-sectional area, adipocyte size, myotube diameter, lipid accumulation, and relevant gene expression were analyzed. Results: The oral administration of DOE at doses of 50 and 100 mg/kg body weight to CT26 tumor-bearing mice resulted in a significant reduction in body weight loss, an increase in food intake, and a decrease in serum glycerol levels. Furthermore, DOE treatment led to an increase in muscle mass, larger muscle fiber diameter, and elevated expression levels of MyH2 and Igf1, while simultaneously reducing the expression of Atrogin1 and MuRF1. DOE also attenuated adipose tissue wasting, as evidenced by increased epididymal fat mass, enlarged adipocyte size, and upregulated Pparγ expression, alongside a reduction in Ucp1 and IL6 levels. In cachectic C2C12 myotubes and 3T3-L1 adipocytes induced by the CT26 conditioned medium, DOE significantly inhibited muscle wasting and lipolysis by activating the AKT signaling pathway. The treatment of wortmannin, a specific AKT inhibitor, effectively neutralized DOE's impact on the AKT pathway, myotube diameter, and lipid accumulation. Conclusions: DOE ameliorates cancer cachexia through the expression of genes involved in protein synthesis and lipogenesis, while suppressing those related to protein degradation, suggesting its potential as a plant-derived therapeutic agent in combating cancer cachexia.

Osteoporosis is a common skeletal disease, primarily associated with aging, that results from decreased bone density and bone volume. This reduction significantly increases the risk of fractures in osteoporosis patients compared to individuals with normal bone density. Additionally, the bone regeneration process in these patients is slow, making complete healing difficult. Along with the decline in bone volume and density, osteoporosis is characterized by an increase in marrow adipose tissue (MAT), which is fat within the bone. In this altered bone microenvironment, osteoblasts are influenced by various factors secreted by adipocytes. Notably, saturated fatty acids promote osteoclast activity, inhibit osteoblast differentiation, and induce apoptosis, further reducing osteoblast formation. In contrast, monounsaturated fatty acids inhibit osteoclast formation and mitigate the apoptosis caused by saturated fatty acids. Leveraging these properties, we aimed to investigate the effects of overexpressing stearoyl-CoA desaturase 1 (SCD1), an enzyme that converts saturated fatty acids into monounsaturated fatty acids, on osteogenic differentiation and bone regeneration in both in vivo and in vitro models. Through this novel approach, we seek to develop a stem cell-based therapeutic strategy that harnesses SCD1 to improve bone regeneration in the adipocyte-rich osteoporotic environment.

Chickens are the most abundant agricultural animals globally, with controlling abdominal fat deposition being a key objective in poultry breeding. While GWAS can identify genetic variants associated with abdominal fat deposition, the precise roles and mechanisms of these variants remain largely unclear. Here, we use male chickens from two lines divergently selected for abdominal fat deposition as experimental models. Through the integration of genomic, epigenomic, 3D genomic, and transcriptomic data, we build a comprehensive chromatin 3D regulatory network map to identify the genetic regulatory mechanisms that influence abdominal fat deposition in chickens. Notably, we find that the rs734209466 variant functions as an allele-specific enhancer, remotely enhancing the transcription of IGFBP2 and IGFBP5 by the binding transcription factor IRF4. This interaction influences the differentiation and proliferation of preadipocytes, which ultimately affects phenotype. This work presents a detailed genetic regulatory map for chicken abdominal fat deposition, offering molecular targets for selective breeding., (© 2024. The Author(s).)

Sparassis latifolia (SL) has been reported to exhibit anti-obesity effects in high-fat diet animal models, yet research into its mechanisms of action remains limited. Therefore, this study aimed to elucidate the mechanisms behind the anti-obesity activity of SL's 30% ethanol extract (SL30E) using 3T3-L1 cells in an in vitro setting. SL30E effectively mitigated the accumulation of lipid droplets and triacylglycerol. SL30E downregulated PPARγ and CEBPα protein levels. The diminishment of PPARγ and C/EBPα, facilitated by SL30E, was impeded by the knockdown of β-catenin using β-catenin-specific siRNA. Furthermore, SL30E was observed to increase the protein levels of ATGL and p-HSL, while it concurrently decreased the protein levels of perilipin-1. SL30E downregulated p62/SQSTM1 protein level and upregulated LC3-II protein level. Moreover, SL30E was demonstrated to elevate the protein levels of p-AMPK and PGC-1α. The results indicate that SL30E inhibits lipid accumulation by suppressing adipogenesis and inducing lipolysis, lipophagy, and thermogenesis in 3T3-L1 cells. These observations provide potential insights into the mechanisms underlying the anti-obesity effects of SL, contributing valuable information to the existing body of knowledge.

Obesity is an important risk factor for breast cancer in women before and after menopause. Adipocytes, key mediators in the tumor microenvironment, play a pivotal role in the relationship between obesity with cancer. However, the potential of dietary components in modulating this relationship remains underexplored. Genistein, a soy-derived isoflavone, has shown promise in reducing breast cancer risk, attenuating obesity-associated inflammation, and improving insulin resistance. However, there are no reports examining whether genistein has the ability to reduce the effects of obesity on breast tumor development. In this study, we constructed a mammary tumor model in ovariectomized obese mice and examined the effects of genistein on body condition and tumor growth. Moreover, the effects of genistein on the tumor microenvironment were examined via experimental observation of peritumoral adipocytes and macrophages. In addition, we further investigated the effect of genistein on adipocyte and breast cancer cell crosstalk via coculture experiments. Our findings indicate that dietary genistein significantly alleviates obesity, systemic inflammation, and metabolic disorders induced by a high-fat diet in ovariectomized mice. Notably, it also inhibits tumor growth in vivo. The impact of genistein extends to the tumor microenvironment, where it reduces the production of cancer-associated adipocytes (CAAs) and the recruitment of M2d-subtype macrophages. In vitro, genistein mitigates the transition of adipocytes into CAAs and inhibits the expression of inflammatory factors by activating PPAR-γ pathway and degrading nuclear NF-κB. Furthermore, it impedes the acquisition of invasive properties and epithelial‒mesenchymal transition in breast cancer cells under CAA-induced inflammation, disrupting the Wnt3a/β-catenin pathway. Intriguingly, the PPAR-γ inhibitor T0070907 counteracted the effects of genistein in the coculture system, underscoring the specificity of its action. Our study revealed that genistein can mitigate the adverse effects of obesity on breast cancer by modulating the tumor microenvironment. These findings provide new insights into how genistein intake and a soy-based diet can reduce breast cancer risk., (© 2024. The Author(s).)

Background: Mongolian cattle are local breeds in northern China with excellent adaptability to harsh environmental conditions. Adipose tissues play essential roles in tolerance to cold and disease, but the associated cellular and molecular mechanisms are unclear., Methods: Single-nucleus RNA sequencing (snRNA-seq) was performed on the adipose tissues from the subcutaneous (SAT), greater omentum (OAT) and perirenal (PAT) of 3 healthy cattle. The adipogenic trajectory was analyzed, and the functional roles of gene of interest were verified in vitro., Results: There were different cell subpopulations in adipose tissues. The lipid-deposition adipocytes identified by the PTGER3 marker exhibited outstanding characteristics in SAT. In PAT and OAT, aldosterone was expressed to provide clues for the differential brown adipocytes. Among the DEGs by comparing OAT with SAT and PAT with OAT, C3 was significantly expressed in most of the cell populations in SAT. G0S2, LIPE, LPIN1, PTGER3 and RGCC took part in the adipogenic trajectory from preadipocyte commitment to mature adipocytes. S100A4 expression affected Ca 2+ signaling and the expression of UCP1 ~ 3, FABP4 and PTGER3., Conclusion: The cell heterogeneity and genes expressed in adipose tissues of Mongolian cattle not only determine the endocrine and energy storage, but contribute to adapt to cold and disease resistance., (© 2024. The Author(s).)

Triple negative breast cancer (TNBC) represents a heterogeneous subtype of breast cancer characterized by an unfavorable prognosis due to its aggressive biology. Cancer-associated adipocytes (CAAs) play an active role in tumor development, invasion and metastasis, and response to treatment by secreting various cytokines. CAAs secrete CCL2 and ADPN which significantly affect the efficacy of aPD-1 in treating breast cancer. Our recent research has demonstrated that Hesperidin, a natural phenolic compound, significantly inhibits CCL2, elevates ADPN secreted by CAAs in vitro and in vivo, remodels the immune microenvironment, and potentiates the efficacy of aPD-1 in triple-negative breast cancer. We used Oil red staining, Bodipy 493/503 staining and quantitative real-time PCR to verify the formation of CAAs. ELISA was used to detect levels of CCL2, ADPN secreted by CAAs. Changes in the number of immune cells in mouse tumor tissues were detected using flow cytometry and immunofluorescence. Our data suggest that Hesperidin PLGA nanoparticles significantly reduced CCL2 and increased ADPN secreted by CAAs, which concurrently decreased the recruitment of M2 macrophages, Tregs and MDSCs while increased the infiltration of CD8 + T cells, M1 macrophages and DCs into tumor, thus significantly potentiated the efficacy of aPD-1 in vivo. This study provides a new combined strategy for the clinical treatment of triple-negative breast cancer by interfering with CCL2, ADPN secreted by CAAs to enhance the efficacy of immunotherapy., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

4-cresol (4-methylphenol, p-cresol) is a xenobiotic substance negatively correlated with type 2 diabetes and associated with health improvement in preclinical models of diabetes. We aimed at refining our understanding of the physiological role of this metabolite and identifying potential signalling mechanisms. Functional studies revealed that 4-cresol does not deteriorate insulin sensitivity in human primary adipocytes and exhibits an additive effect to that of insulin on insulin sensitivity in mouse C2C12 myoblasts. Experiments in mouse isolated islets showed that 4-cresol potentiates glucose induced insulin secretion. We demonstrated the absence of off target effects of 4-cresol on a panel of 44 pharmacological compounds. Screening large panels of 241 G protein-coupled receptors (GPCRs) and 468 kinases identified binding of 4-cresol only to TNK1, EIF2AK4 (GCN2) and RPS6KA3 (RSK2), a kinase strongly expressed in human and rat pancreatic islets. Islet expression of RPS6KA3 is reduced in spontaneously diabetic rats chronically treated with 4-cresol and Rps6ka3 deficient mice exhibit reduction in both body weight and fasting glycemia, modest improvement in glycemic control and enhanced insulin release in vivo. Similar to low doses of 4-cresol, incubation of isolated rat islets with low concentrations of the RPS6KA3 inhibitor BIX 02565 stimulates both glucose induced insulin secretion and β-cell proliferation. These results provide further information on the role of low 4-cresol doses in the regulation of insulin secretion., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Brial et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Cultured or cultivated meat, animal muscle, and fat tissue grown in vitro, could transform the global meat market, reducing animal suffering while using fewer resources than traditional meat production and no antimicrobials at all. To ensure the appeal of cultured meat to future customers, cultured fat is essential for achieving desired mouthfeel, taste, and texture, especially in beef. In this work we show the establishment of primary bovine adipose-derived stem cell spheroids in static and dynamic suspension culture. Spheroids are successfully differentiated using a single-step protocol. Differentiated spheroids from dynamic cultures maintain stability and viability during 3D bioprinting in edible gellan gum. Also, the fatty acid composition of differentiated spheroids is significantly different from control spheroids. The cells are cultured antibiotic-free to minimize the use of harmful substances. This work presents a stable and bioprintable building block for cultured fat with a high cell density in a 3D dynamic cell culture system., (© 2024. The Author(s).)

An established hallmark of cancer cells is metabolic reprogramming, largely consisting in the exacerbated glucose uptake. Adipocytes in the tumor microenvironment contribute toward breast cancer (BC) progression and are highly responsive to metabolic fluctuations. Metabolic conditions characterizing obesity and/or diabetes associate with increased BC incidence and mortality. To explore BC-adipocytes interaction and define the impact of glucose in such dialogue, Mammary Adipose-derived Mesenchymal Stem Cells (MAd-MSCs) were differentiated into adipocytes and co-cultured with ER + BC cells while exposed to glucose concentration resembling hyperglycemia or normoglycemia in humans (25mM or 5.5mM). The transcriptome of both cell types in co-culture as in mono-culture was profiled by RNA-Seq to define the impact of adipocytes on BC cells and viceversa (i), the action of glucose on BC cells, adipocytes (ii) and their crosstalk (iii). Noteworthy, we provided evidence that co-culture with adipocytes in a glucose-rich environment determined a re-program of BC cell transcriptome driving lipid accumulation, a hallmark of BC aggressiveness, promoting stem-like properties and reducing Tamoxifen responsiveness. Moreover, our data point out to a transcriptional effect through which BC cells induce adipocytes de-lipidation, paralleled by pluripotency gain, as source of lipids when glucose lowering occurs. Thus, modulating plasticity of peri-tumoral adipocytes may represent a key point for halting BC progression in metabolically unbalanced patients., (© 2024. The Author(s).)

This study was conducted to analyze the viability of primary chicken embryo fibroblasts and the efficiency of adipogenic trans-differentiation for cultured meat production. In isolating chicken embryo fibroblasts (CEFs) from a heterogeneous cell pool containing chicken satellite cells (CSCs), over 90% of CEFs expressed CD29 and vimentin. The analysis of the proliferative capabilities of CEFs revealed no significant differences in EdU-positive cells (%), cumulative cell number, doubling time, and growth rate from passage 1 to passage 9 ( p > 0.05). This indicates that CEFs can be isolated by 2 h of pre-plating and survive stably up to passage 9, and that primary fibroblasts can serve as a valuable cell source for the cultured meat industry. Adipogenic trans-differentiation was induced up to passage 9 of CEFs. As passages increased, lipid accumulation and adipocyte size significantly decreased ( p < 0.05). The reduced differentiation rate of primary CEFs with increasing passages poses a major challenge to the cost and efficiency of cultured meat production. Thus, effective cell management and the maintenance of cellular characteristics for a long time are crucial for ensuring stable and efficient cultured fat production in the cultured meat industry.

Bone marrow and teeth contain mesenchymal stem cells (MSCs) that could be used for cell-based regenerative therapies. MSCs from these two tissues represent heterogeneous cell populations with varying degrees of lineage commitment. Although human bone marrow stem cells (hBMSCs) and human dental pulp stem cells (hDPSCs) have been extensively studied, it is not yet fully defined if their adipogenic potential differs. Therefore, in this study, we compared the in vitro adipogenic differentiation potential of hDPSCs and hBMSCs. Both cell populations were cultured in adipogenic differentiation media, followed by specific lipid droplet staining to visualise cytodifferentiation. The in vitro differentiation assays were complemented with the expression of specific genes for adipogenesis and osteogenesis-dentinogenesis, as well as for genes involved in the Wnt and Notch signalling pathways. Our findings showed that hBMSCs formed adipocytes containing numerous and large lipid vesicles. In contrast to hBMSCs, hDPSCs did not acquire the typical adipocyte morphology and formed fewer lipid droplets of small size. Regarding the gene expression, cultured hBMSCs upregulated the expression of adipogenic-specific genes (e.g., PPARγ2 , LPL , ADIPONECTIN ). Furthermore, in these cells most Wnt pathway genes were downregulated, while the expression of NOTCH pathway genes (e.g., NOTCH1 , NOTCH3 , JAGGED1 , HES5 , HEY2 ) was upregulated. hDPSCs retained their osteogenic/dentinogenic molecular profile (e.g., RUNX2 , ALP , COLIA1 ) and upregulated the WNT-specific genes but not the NOTCH pathway genes. Taken together, our in vitro findings demonstrate that hDPSCs are not entirely committed to the adipogenic fate, in contrast to the hBMSCs, which are more effective to fully differentiate into adipocytes.

The risk of developing type 2 diabetes (T2D) is heterogeneous among individuals with obesity. Functional decline of adipocyte precursor cells (APCs) and accumulation of senescent cells in the subcutaneous adipose tissue contributes to the progression toward T2D. LncRNAs regulate cell senescence and may be implicated in determining this abnormality in APCs. Here, we report that APCs from individuals with obesity show a gradual increase in multiple senescence markers, which worsens in parallel with the progression from normal glucose tolerance (NGT) to impaired glucose tolerance (IGT) or T2D. Transcriptomic analysis identified PANDAR as the top-ranked lncRNA differentially expressed in APCs from individuals with obesity and T2D and non-obese subjects. Q-PCR confirmed PANDAR up-regulation in APCs from individuals with obesity, at progressively increased levels in those who developed, respectively, IGT and T2D. Bisulfite sequencing and luciferase assays revealed that, in parallel with glucose tolerance deterioration, the -1317 CpG at the PANDAR promoter became hypo-methylated in obesity, resulting in enhanced PANDAR induction by p53. PANDAR silencing in senescent APCs from individuals with obesity and T2D caused repression of senescence programs and cell cycle re-entry. PANDAR transcription in white blood cells (WBCs) mirrored that in APCs. Also, individuals with obesity exhibited rescue of PANDAR transcription in WBCs following bariatric surgery, accompanied by enhanced methylation at the regulatory PANDAR -1317 CpG. In conclusion, PANDAR dysregulation is a newly identified mechanism determining the early senescence of APCs from individuals with obesity, which worsens along the progression toward T2D. In the future, PANDAR targeting may represent a valuable strategy to delay this progression., (© 2024 The Author(s). The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Adipose tissue is distributed in diverse locations throughout the human body. Not much is known about the extent to which anatomically distinct adipose depots are functionally distinct, specialized organs, nor whether depot-specific characteristics result from intrinsic developmental programs, as opposed to reversible physiological responses to differences in tissue microenvironment. We used DNA microarrays to compare mRNA expression patterns of isolated human adipocytes and cultured adipose stem cells, before and after ex vivo adipocyte differentiation, from seven anatomically diverse adipose tissue depots. Adipocytes from different depots display distinct gene expression programs, which are most closely shared with anatomically related depots. mRNAs whose expression differs between anatomically diverse groups of depots (e.g., subcutaneous vs. internal) suggest important functional specializations. These depot-specific differences in gene expression were recapitulated when adipocyte progenitor cells from each site were differentiated ex vivo, suggesting that progenitor cells from specific anatomic sites are deterministically programmed to differentiate into depot-specific adipocytes. Many developmental transcription factors show striking depot-specific patterns of expression, suggesting that adipocytes in each anatomic depot are programmed during early development in concert with anatomically related tissues and organs. Our results support the hypothesis that adipocytes from different depots are functionally distinct and that their depot-specific specialization reflects distinct developmental programs., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Clemons et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Our research explores the detrimental effects of microplastic (MP) exposure on adipose tissue aging and function, emphasizing the potential health risks associated with environmental pollutants. Utilizing both in vivo and in vitro models, we discovered that MPs accumulate in adipose tissues, leading to cellular senescence, inflammation, and hindered adipogenic differentiation. Notably, our findings demonstrate that MPs prompt an aging response in both epididymal and inguinal white adipose tissue, increase senescence-associated β-galactosidase activity, and upregulate key senescence and inflammatory markers. Furthermore, we show that MPs disrupt normal adipogenic differentiation by reducing lipid droplet formation and downregulating critical adipogenic markers. These insights highlight the urgent need for further investigation into the long-term consequences of MP pollution on biological aging and underscore the importance of developing public health strategies to mitigate these effects., (© 2024. The Author(s).)

The crosstalk between adipose tissue and the liver is finely controlled to maintain metabolic health. Yet, how adipose tissue controls toxic free fatty acid overflow into the liver remains incompletely understood. Here, we show that adipocyte activating transcription factor 3 (ATF3) was induced in human or mouse obesity. Adipocyte Atf3 -/- (Atf3 Adi-/- ) mice developed obesity, glucose intolerance, and metabolic dysfunction-associated steatohepatitis (MASH) in chow diet, high-fat diet, or Western diet-fed mice. Blocking fatty acid flux by inhibiting hepatocyte CD36, but not the restoration of hepatic AMPK signaling, prevented the aggravation of MASH in Atf3 Adi-/- mice. Further studies show that the loss of adipocyte ATF3 increased lipolysis via inducing adipose triglyceride lipase, which in turn induced lipogenesis and inflammation in hepatocytes. Moreover, Atf3 Adi-/- mice had reduced energy expenditure and increased adipose lipogenesis and inflammation. Our data demonstrate that adipocyte ATF3 is a gatekeeper in counteracting MASH development under physiological and pathological conditions., (© 2024. The Author(s).)

Exploration of factors originating from brown adipose tissue that govern the thermogenic adipocyte differentiation is imperative for comprehending the regulatory framework underlying brown fat biogenesis and for devising therapeutic approaches for metabolic disorders associated with obesity. Prior evidence has illuminated the pivotal role of long noncoding RNAs (lncRNAs) in orchestrating thermogenesis within adipose tissue. Here, we aimed to explore and identify the critical lncRNA that could promote thermogenic adipocyte differentiation and to provide a novel strategy to treat obesity-related metabolic diseases in the future. In this study, through amalgamation with our previous lncRNA microarray data from small extracellular vesicles derived from BAT (sEV-BAT), we have identified sEV-BAT-enriched lncRNA AK029592 as a critical constituent of the thermogenic program, which actively fostered beige adipocyte differentiation and enhanced the thermogenic capacities of adipose tissue. Moreover, lncRNA AK029592 could sponge miR-199a-5p in adipocytes to stimulate thermogenic gene expression. Consequently, we concluded lncRNA AK029592 as a crucial lncRNA component of the thermogenic program that regulated beige adipocyte differentiation and white adipose tissue browning, thereby providing a novel therapeutic target and strategy in combating obesity and related metabolic diseases., (© The Author(s) 2024. Published by Oxford University Press.)

Background: Studying the molecular mechanisms of lipodystrophy can provide valuable insights into the pathophysiology of insulin resistance (IR), type 2 diabetes (T2D), and other clustering diseases [metabolic syndrome (MetS)] and its underlying adipocentric disease (MetS disease)., Methods: A high-confidence lipodystrophy gene panel comprising 50 genes was created, and their expressions were measured in the visceral and subcutaneous (both peripheral and abdominal) adipose depots of MetS and non-MetS individuals at a tertiary care medical facility., Results: Most lipodystrophy genes showed significant downregulation in MetS individuals compared to non-MetS individuals in both subcutaneous and visceral depots. In the abdominal compartment, all the genes showed relatively higher expression in visceral depot as compared to their subcutaneous counterpart, and this difference narrowed with increasing severity of MetS. Their expression level shows an inverse correlation with T2D, MetS, and HOMA-IR and with other T2D-related intermediate traits. Results also demonstrated that individualization of MetS patients could be done based on adipose tissue expression of just 12 genes., Conclusion: Adipose tissue expression of lipodystrophy genes shows an association with MetS and its intermediate phenotypic traits. Mutations of these genes are known to cause congenital lipodystrophy syndromes, whereas their altered expression in adipose tissue contributes to the pathogenesis of IR, T2D, and MetS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Saxena, Tiwari, Gupta, Mandia, Banshiwal, Lamoria, Anjana, Radha, Mohan and Mathur.)

Inflammatory Bowel Diseases (IBDs) are associated with aberrant immune function, widespread inflammation, and altered intestinal blood flow. Perivascular adipose tissue (PVAT) surrounding the mesenteric vasculature can modulate vascular function and control the local immune cell population, but its structure and function have never been investigated in IBD. We used an IL10 -/- mouse model of colitis that shares features with human IBD to test the hypothesis that IBD is associated with (1) impaired ability of PVAT to dilate mesenteric arteries and (2) changes in PVAT resident adipocyte and immune cell populations. Pressure myography and electrical field stimulation of isolated mesenteric arteries show that PVAT not only loses its anti-contractile effect but becomes pro-contractile in IBD. Quantitative immunohistochemistry and confocal imaging studies found significant adipocyte hyperplasia and increased PVAT leukocytes, particularly macrophages, in IBD. PCR arrays suggest that these changes occur alongside the altered cytokine and chemokine gene expression associated with altered NF-κB signaling. Collectively, these results show that the accumulation of macrophages in PVAT during IBD pathogenesis may lead to local inflammation, which ultimately contributes to increased arterial constriction and decreased intestinal blood flow with IBD.

The ongoing obesity epidemic has raised awareness of the complex physiology of adipose tissue. Abnormal adipocyte differentiation results in the development of systemic metabolic disorders such as insulin resistance and diabetes. The conjugation of NEDD8 (neural precursor cell expressed, developmentally downregulated 8) to target protein, termed neddylation, has been shown to mediate adipogenesis. However, much remains unknown about its role in adipogenesis. Here, we demonstrated that neddylation and its targets, the cullin (CUL) family members, are differentially regulated during mouse and human adipogenesis. Inhibition of neddylation by MLN4924 significantly reduced adipogenesis of 3T3-L1 and human stromal vascular cells. Deletion of NAE1, a subunit of the only NEDD8 E1 enzyme, suppressed neddylation and impaired adipogenesis. Neddylation deficiency did not affect mitotic cell expansion. Instead, it disrupted CREB/CEBPβ/PPARγ signaling, essential for adipogenesis. Interestingly, among the neddylation-targeted CUL family members, deletion of CUL3, but not CUL1, CUL2, or CUL4A, largely replicated the adipogenic defects observed with neddylation deficiency. A PPARγ agonist minimally rescued the adipogenic defects caused by the deletion of NAE1 and CUL3. In conclusion, our study demonstrates that neddylation and its targeted CUL3 are crucial for adipogenesis. These findings provide potential targets for therapeutic intervention in obesity and metabolic disorders.

Adipose tissue engineering (ATE) has been gaining increasing interest over the past decades, offering promise for new and innovative breast reconstructive strategies. Animal-derived gelatin-methacryloyl (Gel-MA) has already been applied in a plethora of TE strategies. However, due to clinical concerns, related to the potential occurrence of immunoglobulin E-mediated immune responses and pathogen transmission, a shift towards defined, reproducible recombinant proteins has occurred. In the present study, a recombinant protein based on human collagen type I, enriched with arginine-glycine-aspartic acid was functionalized with photo-crosslinkable methacryloyl moieties (RCPhC1-MA), processed into 3D scaffolds and compared with frequently applied Gel-MA from animal origin using an indirect printing method applying poly-lactic acid as sacrificial mould. For both materials, similar gel fractions (>65%) and biodegradation times were obtained. In addition, a significantly lower mass swelling ratio (17.6 ± 1.5 versus 24.3 ± 1.4) and mechanical strength (Young's modulus: 1.1 ± 0.2 kPa versus 1.9 ± 0.3 kPa) were observed for RCPhC1-MA compared to Gel-MA scaffolds. In vitro seeding assays showed similar cell viabilities (>80%) and a higher initial cell attachment for the RCPhC1-MA scaffolds. Moreover, the seeded adipose-derived stem cells could be differentiated into the adipogenic lineage for both Gel-MA and RCPhC1-MA scaffolds, showing a trend towards superior differentiation for the RCPhC1-MA scaffolds based on the triglyceride and Bodipy assay. RCPhC1-MA scaffolds could result in a transition towards the exploitation of non-animal-derived biomaterials for ATE, omitting any regulatory concerns related to the use of animal derived products., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

White adipose tissue (WAT) is essential for lipid storage and systemic energy homeostasis. Understanding adipocyte formation and stability is key to developing therapies for obesity and metabolic disorders. Through a high-throughput cDNA screen, we identified PATZ1, a POZ/BTB and AT-Hook Containing Zinc Finger 1 protein, as an important adipogenic transcription factor. PATZ1 is expressed in human and mouse adipocyte precursor cells (APCs) and adipocytes. In cellular models, PATZ1 promotes adipogenesis via protein-protein interactions and DNA binding. PATZ1 ablation in mouse adipocytes and APCs leads to a reduced APC pool, decreased fat mass, and hypertrophied adipocytes. ChIP-Seq and RNA-seq analyses show that PATZ1 supports adipogenesis by interacting with transcriptional machinery at the promoter regions of key early adipogenic factors. Mass-spec results show that PATZ1 associates with GTF2I, with GTF2I modulating PATZ1's function during differentiation. These findings underscore PATZ1's regulatory role in adipocyte differentiation and adiposity, offering insights into adipose tissue development., (© 2024. The Author(s).)

GULP1 is an engulfment adaptor protein containing a phosphotyrosine-binding (PTB) domain, and existing studies have shown that it can promote glucose uptake in 3T3-L1 adipocytes. To further explore key metabolically related differential genes downstream of GULP1, this study conducted transcriptome analysis on adipocytes and skeletal muscle cells overexpressing GULP1. Subsequently, abnormally expressed genes were subjected to bioinformatic analysis, and real-time fluorescent quantitative PCR (qRT-PCR) was used for mutual validation with transcriptome sequencing. The results indicated that, with a threshold of P < 0.05 and |Log 2 FoldChange| ≥ 1 for screening differentially expressed genes, compared with control cells, there were 278 upregulated and 263 downregulated genes in adipocytes overexpressing GULP1. Metabolism-related GO (Gene Ontology) terms included cholesterol biosynthetic process, cholesterol metabolic process, response to lipopolysaccharide, lipid metabolic process, etc. A total of 52 metabolically related differentially expressed genes were enriched in 10 KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways, with lipid metabolism being highly enriched. In skeletal muscle cells overexpressing GULP1, there were 280 upregulated and 302 downregulated genes, with metabolism-related GO terms including hormone metabolic process, response to lipopolysaccharide, one-carbon metabolic process, etc. A total of 86 metabolically related differentially expressed genes were enriched in 10 KEGG pathways, with amino acid metabolism, lipid metabolism, and carbohydrate metabolism being highly enriched. GULP1's biological functions are extensive, including lipid metabolism and oncology. This study, through transcriptomics and bioinformatic analysis, identified key metabolically related differential genes downstream of GULP1, obtained metabolically related differential genes and signaling pathways after GULP1 overexpression, providing important theoretical basis for future research on GULP1 downstream target genes.

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer. Recent studies indicated that cancer-associated adipocytes (CAAs) play crucial roles in tumor progression; however, the precise mechanism remains unknown. Here, we analyzed specific exosomal microRNAs (miRNA) signatures derived from pancreatic CAAs to investigate their role in cancer progression., Methods: CAAs were generated by co-culturing human adipocytes with human pancreatic cancer cells, and exosomes were isolated from the CAA-conditioned medium (CAA-CM). Small RNA-seq analysis was used to identify differentially expressed miRNAs in these exosomes. The effects of miRNAs on cell proliferation, migration/invasion, and drug sensitivity were examined. Luciferase reporter assays, real-time polymerase chain reaction, and western blotting were performed to investigate the molecular mechanisms of the miRNAs. The clinical relevance of the miRNAs was investigated using publicly available data and our cohort of patients with PDAC., Results: miR-199a-3p expression was significantly increased in CAA-CM-derived exosomes. CAA-derived exosomes transferred miR-199a-3p to pancreatic cancer cells. Transfection with miR-199a-3p increased the proliferation, invasion, migration, and drug resistance of pancreatic cancer cells by downregulating SOCS7, increasing STAT3 phosphorylation, and upregulating SAA1 expression. High tissue miR-199a-3p expression is correlated with poor prognosis in patients with PDAC. Liquid biopsies revealed that exosomal miR-199a-3p could accurately differentiate patients with PDAC from healthy controls. Multivariate survival analysis indicated that miR-199a is an independent prognostic factor for PDAC., Conclusion: miR-199a-3p in CAA-derived exosomes contributes to the malignant transformation of pancreatic cancer via the SOCS7/STAT3/SAA1 pathway, suggesting its potential as a biomarker and therapeutic target for PDAC., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Lipid droplets (LDs) are dynamic storage organelles with central roles in lipid and energy metabolism. They consist of a core of neutral lipids, such as triacylglycerol, which is surrounded by a monolayer of phospholipids and specialized surface proteins. The surface composition determines many of the LD properties, such as size, subcellular distribution, and interaction with partner organelles. Considering the diverse energetic and metabolic demands of various cell types, it is not surprising that LDs are highly heterogeneous within and between cell types. Despite their diversity, all LDs share a common biogenesis mechanism. However, adipocytes have evolved specific adaptations of these basic mechanisms, enabling the regulation of lipid and energy metabolism at both the cellular and organismal levels. Here, we discuss recent advances in the understanding of both the general mechanisms of LD biogenesis and the adipocyte-specific adaptations controlling these fascinating organelles.

Reactive oxygen species, when produced in a controlled manner, are physiological modulators of healthy white adipose tissue (WAT) expansion and metabolic function. By contrast, unbridled production of oxidants is associated with pathological WAT expansion and the establishment of metabolic dysfunctions, most notably insulin resistance and type 2 diabetes mellitus. NADPH oxidases (NOXs) produce oxidants in an orderly fashion and are present in adipocytes and in other diverse WAT-constituent cell types. Recent studies have established several links between aberrant NOX-derived oxidant production, adiposity, and metabolic homeostasis. The objective of this review is to highlight the physiological roles attributed to diverse NOX isoforms in healthy WAT and summarize current knowledge of the metabolic consequences related to perturbations in their adequate oxidant production. We detail WAT-related alterations in preclinical investigations conducted in NOX-deficient murine models. In addition, we review clinical studies that have employed NOX inhibitors and currently available data related to human NOX mutations in metabolic disturbances. Future investigations aimed at understanding the integration of NOX-derived oxidants in the regulation of the WAT cellular redox network are essential for designing successful redox-related precision therapies to curb obesity and attenuate obesity-associated metabolic pathologies., (© 2024 The Author(s). Obesity published by Wiley Periodicals LLC on behalf of The Obesity Society.)

Obesity is associated with the development of local adipose tissue (AT) and systemic inflammation. Most adipokines are upregulated with obesity and have pro-inflammatory properties. Few are downregulated and possess beneficial anti-inflammatory effects. The apolipoprotein M (APOM) is an adipokine whose expression is low during obesity and associated with a metabolically healthy AT. Here, the role of adipose-derived APOM on obesity-associated AT inflammation was investigated by measuring the expression of pro-inflammatory genes in human and mouse models. In 300 individuals with obesity, AT APOM mRNA level was negatively associated with plasma hs-CRP. The inflammatory profile was assessed in Apom -/- and WT mice fed a normal chow diet (NCD), or a high-fat diet (HFD) to induce AT inflammation. After HFD, mice had a higher inflammatory profile in AT and liver, and a 50% lower Apom gene expression compared with NCD-fed mice. Apom deficiency was associated with a higher inflammatory signature in AT compared with WT mice but not in the liver. Adeno-associated viruses encoding human APOM were used to induce APOM overexpression: in vivo, in WT mice AT prior to HFD; in vitro, in human adipocytes which conditioned media was applied to ThP-1 macrophages. The murine AT overexpressing APOM gene had a reduced inflammatory profile. The macrophages treated with APOM-enriched media from adipocytes exhibited lower IL6 and MCP1 gene expression compared with macrophages treated with control media, independently of S1P. Our study highlights the protective role of adipocyte APOM against obesity-induced AT inflammation., Competing Interests: Conflict of interests The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Loss of terminal differentiation is a hallmark of cancer and offers a potential mechanism for differentiation therapy. Polycomb repressive complex 2 (PRC2) serves as the methyltransferase for K27 of histone H3 that is crucial in development. While PRC2 inhibitors show promise in treating various cancers, the underlying mechanisms remain incompletely understood. Here, we demonstrated that the inhibition or depletion of PRC2 enhanced adipocyte differentiation in malignant rhabdoid tumors and mesenchymal stem cells, through upregulation of peroxisome proliferator-activated receptor gamma (PPARG) and CEBPA. Mechanistically, PRC2 directly represses their transcription through H3K27 methylation, as both genes exhibit a bivalent state in mesenchymal stem cells. KO of PPARG compromised C/EBPα expression and impeded the PRC2 inhibitor-induced differentiation into adipocytes. Furthermore, the combination of the PPARγ agonist rosiglitazone and the PRC2 inhibitor MAK683 exhibited a higher inhibition on Ki67 positivity in tumor xenograft compared to MAK683 alone. High CEBPA, PLIN1, and FABP4 levels positively correlated with favorable prognosis in sarcoma patients in The Cancer Genome Atlas cohort. Together, these findings unveil an epigenetic regulatory mechanism for PPARG and highlight the essential role of PPARγ and C/EBPα in the adipocyte differentiation of malignant rhabdoid tumors and sarcomas with a potential clinical implication., Competing Interests: Conflict of interest W. Q., L. C., and Y. A. are inventors on a pending patent application describing compositions and methods for treating or characterizing cancer. The remaining authors declare no potential conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

A key organismal response to overnutrition involves the development of new adipocytes through the process of adipogenesis. Preadipocytes sense changes in the systemic nutrient status and metabolites can directly modulate adipogenesis. We previously identified a role of de novo nucleotide biosynthesis in adipogenesis induction, whereby inhibition of nucleotide biosynthesis suppresses the expression of the transcriptional regulators PPARγ and C/EBPα. Here, we set out to identify the global transcriptomic changes associated with the inhibition of nucleotide biosynthesis. Through RNA sequencing (RNAseq), we discovered that mitochondrial signatures were the most altered in response to inhibition of nucleotide biosynthesis. Blocking nucleotide biosynthesis induced rounded mitochondrial morphology, and altered mitochondrial function, and metabolism, reducing levels of tricarboxylic acid cycle intermediates, and increasing fatty acid oxidation (FAO). The loss of mitochondrial function induced by suppression of nucleotide biosynthesis was rescued by exogenous expression of PPARγ. Moreover, inhibition of FAO restored PPARγ expression, mitochondrial protein expression, and adipogenesis in the presence of nucleotide biosynthesis inhibition, suggesting a regulatory role of nutrient oxidation in differentiation. Collectively, our studies shed light on the link between substrate oxidation and transcription in cell fate determination., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Repositioning of FDA approved/clinical phase drugs has recently opened a new opportunity for rapid approval of drugs, as it shortens the overall process of drug discovery and development. In previous studies, we predicted the possibility of better activity profiles of flavopiridol, the FDA approved orphan drug with better fit value 2.79 using a common feature pharmacophore model for anti-adipogenic compounds (CFMPA). The present study aimed to investigate the effect of flavopiridol on adipocyte differentiation and to determine the underlying mechanism. Flavopiridol inhibited adipocyte differentiation in different cell models like 3T3-L1, C3H10T1/2, and hMSCs at 150 nM. Flavopiridol was around 135 times more potent than its parent molecule rohitukine. The effect was mediated through down-regulation of key transcription factors of adipogenesis i.e. Peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), and their downstream targets, including adipocyte protein -2 (aP2) and fatty acid synthase (FAS). Further, results revealed that flavopiridol arrested the cell cycle in G1/S phase during mitotic clonal expansion by suppressing cell cycle regulatory proteins i.e. Cyclins and CDKs. Flavopiridol inhibited insulin-stimulated signalling in the early phase of adipocyte differentiation by downregulation of AKT/mTOR pathway. In addition, flavopiridol improved mitochondrial function in terms of increased oxygen consumption rate (OCR) in mature adipocytes. In the mouse model of diet-induced obesity, flavopiridol attenuated obesity-associated adipose tissue inflammation and improved serum lipid profile, glucose tolerance as well as insulin sensitivity. In conclusion, the FDA approved drug flavopiridol could be placed as a potential drug candidate for the treatment of cancer and obesity comorbid patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2024. Published by Elsevier Masson SAS.)

Fatty acid desaturase (FADS1) variant-rs174550 strongly regulates polyunsaturated fatty acid (PUFA) biosynthesis. Additionally, the FADS1 is related to mitochondrial function. Thus, we investigated whether changes in mitochondrial function are associated with the genetic variation in FADS1 (rs174550) in human adipocytes isolated from individuals consuming diets enriched with either dietary alpha-linolenic (ALA) or linoleic acid (LA). Two cohorts of men homozygous for the genotype of FADS1 (rs174550) were studied: FADSDIET2 dietary intervention study with ALA- and LA-enriched diets and Kuopio Obesity Surgery study (KOBS), respectively. We could demonstrate that differentiated human adipose-derived stromal cells from subjects with the TT genotype had higher mitochondrial metabolism compared with subjects with the CC genotype of FADS1-rs174550 in the FADSDIET2. Responses to PUFA-enriched diets differed between the genotypes of FADS1-rs174550, showing that ALA, but not LA, -enriched diet stimulated mitochondrial metabolism more in subjects with the CC genotype when compared with subjects with the TT genotype. ALA, but not LA, proportion in plasma phospholipid fraction correlated positively with adipose tissue mitochondrial-DNA amount in subjects with the CC genotype of FADS1-rs174550 in the KOBS. These findings demonstrate that the FADS1-rs174550 is associated with modification in mitochondrial function in human adipocytes. Additionally, subjects with the CC genotype, when compared with the TT genotype, benefit more from the ALA-enriched diet, leading to enhanced energy metabolism in human adipocytes. Altogether, the FADS1-rs174550 could be a genetic marker to identify subjects who are most suitable to receive dietary PUFA supplementation, establishing also a personalized therapeutic strategy to improve mitochondrial function in metabolic diseases., Competing Interests: Conflicts of interest The authors declare that they have no conflicts of interest regarding the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: The objective was to study metabolic characteristics and transcriptome of renal sinus adipose tissue (RSAT) located around renal arteries and veins., Methods: Adipose tissue biopsies from RSAT, omental (OAT), and subcutaneous (SAT) depots were obtained from healthy kidney donors (20 female, 20 male). Adipocyte glucose uptake rate and cell size were measured, and gene expression analyses using transcriptomics were performed., Results: RSAT adipocytes were significantly smaller, with a higher basal glucose uptake rate, than adipocytes from SAT and OAT. Transcriptomic analyses revealed 29 differentially expressed genes between RSAT and OAT (RSAT: 23 lower, 6 higher) and 1214 differentially expressed genes between RSAT and SAT (RSAT: 859 lower, 355 higher). RSAT demonstrated molecular resemblance to OAT, both exhibiting lower metabolic gene expression and higher expression of immune-related pathways, including IL-17, TNFα, and NF-κB signaling than SAT. Weighted gene coexpression network analysis associated RSAT with immune response and nucleic acid transport processes. Despite its location near the renal hilum, RSAT closely resembled OAT and there was a lack of expression in the classical brown adipose tissue genes. Gene enrichment analyses suggest an inflammatory environment in RSAT compared with SAT and, to some extent, OAT., Conclusions: The findings suggest specific RSAT functions that could impact renal function and, possibly, the development of renal and cardiometabolic disorders., (© 2024 The Author(s). Obesity published by Wiley Periodicals LLC on behalf of The Obesity Society.)

Human mutations in neuropeptide Y (NPY) have been linked to high body mass index but not altered dietary patterns 1 . Here we uncover the mechanism by which NPY in sympathetic neurons 2,3 protects from obesity. Imaging of cleared mouse brown and white adipose tissue (BAT and WAT, respectively) established that NPY + sympathetic axons are a smaller subset that mostly maps to the perivasculature; analysis of single-cell RNA sequencing datasets identified mural cells as the main NPY-responsive cells in adipose tissues. We show that NPY sustains the proliferation of mural cells, which are a source of thermogenic adipocytes in both BAT and WAT 4-6 . We found that diet-induced obesity leads to neuropathy of NPY + axons and concomitant depletion of mural cells. This defect was replicated in mice with NPY abrogated from sympathetic neurons. The loss of NPY in sympathetic neurons whitened interscapular BAT, reducing its thermogenic ability and decreasing energy expenditure before the onset of obesity. It also caused adult-onset obesity of mice fed on a regular chow diet and rendered them more susceptible to diet-induced obesity without increasing food consumption. Our results indicate that, relative to central NPY, peripheral NPY produced by sympathetic nerves has the opposite effect on body weight by sustaining energy expenditure independently of food intake., (© 2024. The Author(s).)

Aims: Endothelin-1 (ET-1) is elevated in patients with obesity and adipose tissue of obese mice fed high-fat diet (HFD); however, its contribution to the pathophysiology of obesity is not fully understood. Genetic loss of endothelin type B receptors (ET B ) improves insulin sensitivity in rats and leads to increased circulating adiponectin, suggesting that ET B activation on adipocytes may contribute to obesity pathophysiology. We hypothesized that elevated ET-1 in obesity promotes insulin resistance by reducing the secretion of insulin sensitizing adipokines, via ET B receptor., Methods: Male adipocyte-specific ET B receptor knockout (adET B KO), overexpression (adET B OX), or control littermates were fed either normal diet (NMD) or high-fat diet (HFD) for 8 weeks., Results: RNA-sequencing of epididymal adipose (eWAT) indicated differential expression of over 5500 genes (p < 0.05) in HFD compared to NMD controls, and changes in 1077 of these genes were attenuated in HFD adET B KO mice. KEGG analysis indicated significant increase in metabolic signaling pathway. HFD adET B KO mice had significantly improved glucose and insulin tolerance compared to HFD control. In addition, adET B KO attenuated changes in plasma adiponectin, insulin, and leptin that is observed in HFD versus NMD control mice. Treatment of primary adipocytes with ET-1 caused a reduction in adiponectin production that was attenuated in cells pretreated with an ET B antagonist., Conclusion: These data indicate elevated ET-1 in adipose tissue of mice fed HFD inhibits adiponectin production and causes insulin resistance through activation of the ET B receptor on adipocytes., (© 2024 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.)

Resistance to endocrine therapy is a major clinical challenge in estrogen receptor (ER)-positive breast cancer. Obesity is associated with the clinical response to ER-positive breast cancers; however, the mechanism underlying obesity-induced resistance to endocrine therapy in ER-positive breast cancers remains unclear. In this study, we investigated the molecular mechanisms underlying obesity-induced resistance to tamoxifen (TAM), an anti-estrogen agent, in the ER-positive breast cancer cell line MCF-7 using differentiated adipocyte-conditioned medium (D-CM). Treatment of the cells with D-CM promoted TAM resistance by reducing TAM-induced apoptosis. The expression levels of the ERα target genes were higher in D-CM-treated cells than those in untreated ones. In contrast, when the cells were cultured in the presence of TAM, the expression levels were decreased, with or without D-CM. Moreover, the expression of the markers for cancer stem-like cells (CSCs) and mammosphere formation was enhanced by co-treating with D-CM and TAM, compared with TAM alone. The phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway was activated in MCF-7 cells by D-CM treatment, even in the presence of TAM. Inhibition of the PI3K/Akt/mTOR pathway decreased the expression levels of the CSC markers, suppressed mammosphere formation, and resensitized to TAM via inducing apoptosis in D-CM-treated cells. These results indicate that the conditioned medium of differentiated adipocytes promoted TAM resistance by inducing the CSC phenotype through activation of the PI3K/Akt/mTOR pathway in ER-positive breast cancer cells. Thus, the PI3K/Akt/mTOR pathway may be a therapeutic target in obese patients with ER-positive breast cancers., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Identifying specific markers of adipose stem and progenitor cells (ASPCs) in vivo is crucial for understanding the biology of white adipose tissues (WAT). PDGFRα-positive perivascular stromal cells represent the best candidates for ASPCs. This cell lineage differentiates into myofibroblasts that contribute to the impairment of WAT function. However, ASPC marker protein(s) that are functionally crucial for maintaining WAT homeostasis are unknown. We previously identified Meflin as a marker of mesenchymal stem cells (MSCs) in bone marrow and tissue-resident perivascular fibroblasts in various tissues. We also demonstrated that Meflin maintains the undifferentiated status of MSCs/fibroblasts. Here, we show that Meflin is expressed in WAT ASPCs. A lineage-tracing experiment showed that Meflin + ASPCs proliferate in the WAT of obese mice induced by a high-fat diet (HFD), while some of them differentiate into myofibroblasts or mature adipocytes. Meflin knockout mice fed an HFD exhibited a significant fibrotic response as well as increases in adipocyte cell size and the number of crown-like structures in WAT, accompanied by impaired glucose tolerance. These data suggested that Meflin expressed by ASPCs may have a role in reducing disease progression associated with WAT dysfunction., (© 2024 The Author(s). Genes to Cells published by Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.)

Obesity is defined as an abnormal accumulation of adipose tissue in the body and is a major global health problem due to increased morbidity and mortality. Adipose tissue is made up of adipocytes, which are fat-storing cells, and the differentiation of these fat cells is known as adipogenesis. Several transcription factors (TFs) such as CEBPβ, CEBPα, PPARγ, GATA, and KLF have been reported to play a key role in adipogenesis. In this study, we report one more TF AP-1, which is found to be involved in adipogenesis. Human mesenchymal stem cells  were differentiated into adipocytes, and the expression pattern of different subunits of AP-1 was examined during adipogenesis. It was observed that C-FOS was predominantly expressed at an early stage (Day 2), whereas FRA2 expression peaked at later stages (Days 6 and 8) of adipogenesis. Chromatin immunoprecipitation-sequencing analysis revealed that C-FOS binds mainly to the promoters of WNT1, miR-30a, and ANAPC7 and regulates their expression during mitotic clonal expansion. In contrast, FRA2 binds to the promoters of CIDEA, NOTCH1, ARAF, and MYLK, regulating their expression and lipid metabolism. Data obtained clearly indicate that the differential expression of C-FOS and FRA2 is crucial for different stages of adipogenesis. This also raises the possibility of considering AP-1 as a therapeutic target for treating obesity and related disorders., (© 2024 Wiley Periodicals LLC.)

Objective: Picalm (phosphatidylinositol-binding clathrin assembly protein), a ubiquitously expressed clathrin-adapter protein, is a well-known susceptibility gene for Alzheimer's disease, but its role in white adipose tissue (WAT) function has not yet been studied. Transcriptome analysis revealed differential expression of Picalm in WAT of diabetes-prone and diabetes-resistant mice, hence we aimed to investigate the potential link between Picalm expression and glucose homeostasis, obesity-related metabolic phenotypes, and its specific role in insulin-regulated GLUT4 trafficking in adipocytes., Methods: Picalm expression and epigenetic regulation by microRNAs (miRNAs) and DNA methylation were analyzed in WAT of diabetes-resistant (DR) and diabetes-prone (DP) female New Zealand Obese (NZO) mice and in male NZO after time-restricted feeding (TRF) and alternate-day fasting (ADF). PICALM expression in human WAT was evaluated in a cross-sectional cohort and assessed before and after weight loss induced by bariatric surgery. siRNA-mediated knockdown of Picalm in 3T3-L1-cells was performed to elucidate functional outcomes on GLUT4-translocation as well as insulin signaling and adipogenesis., Results: Picalm expression in WAT was significantly lower in DR compared to DP female mice, as well as in insulin-sensitive vs. resistant NZO males, and was also reduced in NZO males following TRF and ADF. Four miRNAs (let-7c, miR-30c, miR-335, miR-344) were identified as potential mediators of diabetes susceptibility-related differences in Picalm expression, while 11 miRNAs (including miR-23a, miR-29b, and miR-101a) were implicated in TRF and ADF effects. Human PICALM expression in adipose tissue was lower in individuals without obesity vs. with obesity and associated with weight-loss outcomes post-bariatric surgery. siRNA-mediated knockdown of Picalm in mature 3T3-L1-adipocytes resulted in amplified insulin-stimulated translocation of the endogenous glucose transporter GLUT4 to the plasma membrane and increased phosphorylation of Akt and Tbc1d4. Moreover, depleting Picalm before and during 3T3-L1 differentiation significantly suppressed adipogenesis, suggesting that Picalm may have distinct roles in the biology of pre- and mature adipocytes., Conclusions: Picalm is a novel regulator of GLUT4-translocation in WAT, with its expression modulated by both genetic predisposition to diabetes and dietary interventions. These findings suggest a potential role for Picalm in improving glucose homeostasis and highlight its relevance as a therapeutic target for metabolic disorders., Competing Interests: Declaration of competing interest MB received honoraria as a consultant and speaker from Amgen, AstraZeneca, Bayer, Boehringer-Ingelheim, Lilly, Novo Nordisk, Novartis, and Sanofi. All other authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. All other authors declare that there are no conflicts of interests., (Copyright © 2024 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

The functional differences between preadipocytes and fully differentiated mature adipocytes derived from stromal vascular fraction stem cells, as well as primary adipocytes have been analysed by evaluating their response to the obesogenic factor (a saturated fatty acid) and TNF-triggered inflammation. The analysis of single adipocytes shows that the saturated fatty acid (palmitic acid) accumulation is accompanied by inflammation and considerably dependent on the stage of the adipogenesis. In particular, preadipocytes show the exceptional potential for palmitic acid uptake resulting in their hypertrophy and the elevated cellular expression of the inflammation marker (ICAM-1). Our research provides new information on the impact of obesogenic factors on preadipocytes that is important in the light of childhood obesity prevention., Competing Interests: Declaration of competing interest All the authors declare no competing financial interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: The mitochondrial pyruvate carrier (MPC) occupies a critical node in intermediary metabolism, prompting interest in its utility as a therapeutic target for the treatment of obesity and cardiometabolic disease. Dysregulated nutrient metabolism in adipose tissue is a prominent feature of obesity pathophysiology, yet the functional role of adipose MPC has not been explored. We investigated whether the MPC shapes the adaptation of adipose tissue to dietary stress in female and male mice., Methods: The impact of pharmacological and genetic disruption of the MPC on mitochondrial pathways of triglyceride assembly (lipogenesis and glyceroneogenesis) was assessed in 3T3L1 adipocytes and murine adipose explants, combined with analyses of adipose MPC expression in metabolically compromised humans. Whole-body and adipose-specific glucose metabolism were subsequently investigated in male and female mice lacking adipocyte MPC1 (Mpc1 AD-/- ) and fed either standard chow, high-fat western style, or high-sucrose lipid restricted diets for 24 weeks, using a combination of radiolabeled tracers and GC/MS metabolomics., Results: Treatment with UK5099 or siMPC1 impaired the synthesis of lipids and glycerol-3-phosphate from pyruvate and blunted triglyceride accumulation in 3T3L1 adipocytes, whilst MPC expression in human adipose tissue was negatively correlated with indices of whole-body and adipose tissue metabolic dysfunction. Mature adipose explants from Mpc1 AD-/- mice were intrinsically incapable of incorporating pyruvate into triglycerides. In vivo, MPC deletion restricted the incorporation of circulating glucose into adipose triglycerides, but only in female mice fed a zero fat diet, and this associated with sex-specific reductions in tricarboxylic acid cycle pool sizes and compensatory transcriptional changes in lipogenic and glycerol metabolism pathways. However, whole-body adiposity and metabolic health were preserved in Mpc1 AD-/- mice regardless of sex, even under conditions of zero dietary fat., Conclusions: These findings highlight the greater capacity for mitochondrially driven triglyceride assembly in adipose from female versus male mice and expose a reliance upon MPC-gated metabolism for glucose partitioning in female adipose under conditions of dietary lipid restriction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Nobiletin has been reported to protect against obesity-related metabolic disorders by enhancing the circadian rhythm; however its effects on lipid metabolism in adipose tissue are unclear. In this study, mice were fed with high-fat diet (HFD) for four weeks firstly and gavaged with 50 or 200 mg/kg bodyweight/day nobiletin at Zeitgeber time (ZT) 4 for another four weeks while still receiving HFD. At the end of the 8-week experimental period, the mice were sacrificed at ZT4 or ZT8 on the same day. Mature 3T3-L1 adipocytes were treated with nobiletin in the presence or absence of siBmal1, siRora, siRorc, SR8278 or SR9009. Nobiletin reduced the weight of white adipose tissue (WAT) and the size of adipocytes in WAT. At ZT4, nobiletin decreased the TG, TC and LDL-c levels and increased serum FFA level and glucose tolerance. Nobiletin triggered the lipolysis of mesenteric and epididymal WAT at both ZT4 and ZT16. Nobiletin increased the level of RORγ at ZT16, that of BMAL1 and PPARγ at ZT4, and that of ATGL at both ZT4 and ZT16. Nobiletin increased lipolysis and ATGL levels in 3T3-L1 adipocytes in Bmal1- or Rora/c- dependent manner. Dual luciferase assay indicated that nobiletin enhanced the transcriptional activation of RORα/γ on Atgl promoter and decreased the repression of RORα/γ on PPARγ-binding PPRE. Promoter deletion analysis indicated that nobiletin inhibited the suppression of PPARγ-mediated Atgl transcription by RORα/γ. Taken together, nobiletin elevated lipolysis in WAT by increasing ATGL levels through activating the transcriptional activity of RORα/γ and decreasing the repression of RORα/γ on PPARγ-binding PPRE., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024. Published by Elsevier Inc.)

Here, we report that Caveolin-2 (Cav-2) is a cell cycle regulator in the mitotic clonal expansion (MCE) for adipogenesis. For the G2/M phase transition and re-entry into the G1 phase, dephosphorylated Cav-2 by protein tyrosine phosphatase 1B (PTP1B) controlled epigenetic activation of Ccnb1, Cdk1, and p21 in a lamin A/C-dependent manner, thereby ensuring the survival of preadipocytes. Cav-2, associated with lamin A/C, recruited the repressed promoters of Ccnb1 and Cdk1 for activation, and disengaged the active promoter of p21 from lamin A/C for inactivation through histone H3 modifications at the nuclear periphery. Cav-2 deficiency abrogated the histone H3 modifications and impeded the transactivation of Ccnb1, Cdk1, and p21, leading to a delay in mitotic entry, retardation of re-entry into G1 phase, and the apoptotic cell death of preadipocytes. Re-expression of Cav-2 restored the G2/M phase transition and G1 phase re-entry, preadipocyte survival, and adipogenesis in Cav-2-deficient preadipocytes. Our study uncovers a novel mechanism by which cell cycle transition and apoptotic cell death are controlled for adipocyte hyperplasia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Excessive abdominal fat deposition negatively impacts poultry meat production and carcass yield. Identification of novel adipogenesis regulators may help improve production performance declines caused by excessive fat deposition. NUMB Endocytic Adaptor Protein (NUMB) typically functions as a cell fate determinant and plays a significant role in cell development and various diseases. Here, we found that NUMB is abundantly expressed in chicken abdominal fat depots and is induced in cultured adipocytes following adipogenic treatment. The gain- and loss-of-function experiments demonstrated that NUMB promotes the proliferation and G1/S transition of chicken adipocytes, enhances adipocyte differentiation, and increases the expression of PPARγ1 transcript. Through mRNA-seq analysis and molecular experiments, we further confirmed that NUMB inhibits the transcriptional activation of the NOTCH1 pathway and the expression of the downstream transcription factor HES1 by inducing NOTCH1 degradation. Nevertheless, the inhibition of the NOTCH1/HES1 axis alone cannot fully explain NUMB's role in adipogenesis, as NUMB also regulates the expression of multiple adipogenic transcription factors such as E2F1, EGR2, and NR4A3. Our data suggest that NUMB is a potent activator of adipogenesis and enhances our understanding of its regulatory mechanisms in chicken abdominal fat deposition., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)