Neurexin-3 in the paraventricular nucleus of the hypothalamus regulates body weight and glucose homeostasis independently of food intake.

Neurexin-3 (Nrxn3) has been genetically associated with obesity, but the underlying neural mechanisms remain poorly understood. This study aimed to investigate the role of Nrxn3 in the paraventricular nucleus of the hypothalamus (PVN) in regulating energy balance and glucose homeostasis. We found that Nrxn3 expression in the PVN was upregulated in response to metabolic stressors, including cold exposure and fasting. Using Cre-loxP technology, we selectively ablated Nrxn3 in CaMKIIα-expressing neurons of the PVN in male mice. This genetic manipulation resulted in marked weight gain attributable to increased adiposity and impaired glucose tolerance, without affecting food intake. Our findings identify PVN CaMKIIα-expressing neurons as a critical locus where Nrxn3 modulates energy balance by regulating adipogenesis and glucose metabolism, independently of appetite. These results reveal a novel neural mechanism potentially linking Nrxn3 dysfunction to obesity pathogenesis, suggesting that targeting PVN Nrxn3-dependent neural pathways may inform new therapeutic approaches for obesity prevention and treatment.

Are Aminoglycoside Antibiotics TRPing Your Metabolic Switches?

Transient receptor potential (TRP) channels are broadly implicated in the developmental programs of most tissues. Amongst these tissues, skeletal muscle and adipose are noteworthy for being essential in establishing systemic metabolic balance. TRP channels respond to environmental stimuli by supplying intracellular calcium that instigates enzymatic cascades of developmental consequence and often impinge on mitochondrial function and biogenesis. Critically, aminoglycoside antibiotics (AGAs) have been shown to block the capacity of TRP channels to conduct calcium entry into the cell in response to a wide range of developmental stimuli of a biophysical nature, including mechanical, electromagnetic, thermal, and chemical. Paradoxically, in vitro paradigms commonly used to understand organismal muscle and adipose development may have been led astray by the conventional use of streptomycin, an AGA, to help prevent bacterial contamination. Accordingly, streptomycin has been shown to disrupt both in vitro and in vivo myogenesis, as well as the phenotypic switch of white adipose into beige thermogenic status. In vivo, streptomycin has been shown to disrupt TRP-mediated calcium-dependent exercise adaptations of importance to systemic metabolism. Alternatively, streptomycin has also been used to curb detrimental levels of calcium leakage into dystrophic skeletal muscle through aberrantly gated TRPC1 channels that have been shown to be involved in the etiology of X-linked muscular dystrophies. TRP channels susceptible to AGA antagonism are critically involved in modulating the development of muscle and adipose tissues that, if administered to behaving animals, may translate to systemwide metabolic disruption. Regenerative medicine and clinical communities need to be made aware of this caveat of AGA usage and seek viable alternatives, to prevent contamination or infection in in vitro and in vivo paradigms, respectively.

The long-chain polyfluorinated alkyl substance perfluorohexane sulfonate (PFHxS) promotes bone marrow adipogenesis.

Per- and polyfluoroalkyl substances (PFAS) bioaccumulate in different organ systems, including bone. While existing research highlights the adverse impact of PFAS on bone density, a critical gap remains in understanding the specific effects on the bone marrow microenvironment, especially the bone marrow adipose tissue (BMAT). Changes in BMAT have been linked to various health consequences, such as the development of osteoporosis and the progression of metastatic tumors in bone. Studies presented herein demonstrate that exposure to a mixture of five environmentally relevant PFAS compounds promotes marrow adipogenesis in vitro and in vivo. We show that among the components of the mixture, PFHxS, an alternative to PFOS, has the highest propensity to accumulate in bone and effectively promote marrow adipogenesis. Utilizing RNAseq approaches, we identified the peroxisome proliferator-activated receptor (PPAR) signaling as a top pathway modulated by PFHxS exposure. Furthermore, we provide results suggesting the activation and involvement of PPAR-gamma (PPARγ) in PFHxS-mediated bone marrow adipogenesis, especially in combination with high-fat diet. In conclusion, our findings demonstrate the potential impact of elevated PFHxS levels, particularly in occupational settings, on bone health, and specifically bone marrow adiposity. This study contributes new insights into the health risks of PFHxS exposure, urging further research on the relationship between environmental factors, diet, and adipose tissue dynamics.

Nootkatone (NK), a grapefruit-derived aromatic compound, inhibited lipid accumulation by regulating JAK2-STAT signaling and antioxidant response in adipocyte.

Nootkatone (NK) is an aromatic compound derived from grapefruit. This study aimed to investigate the inhibitory effect of NK on lipid accumulation and its underlying mechanism in adipocytes. NK effectively inhibited adipogenic lipid storage by downregulating C/EBPα and PPARγ, while upregulating KLF2, an early inhibitory factor, downregulating C/EBPß, an early promoting factor. In addition, NK inhibited the JAK2-STAT signaling pathway by decreasing the phosphorylation of STAT3 and STAT5 in the early adipogenic stage. NK significantly reduced ROS generation while elevating antioxidant enzymes such as catalase and glutathione peroxidase. It activated NRF2-HO-1 signaling, responsible for antioxidant response, by increasing protein levels. Furthermore, NK regulated adipokines, increasing adiponectin and visfatin, while downregulating resistin. Collectively, NK inhibited adipogenic lipid accumulation through the suppression of JAK2-STAT signaling and the augmentation of antioxidant response. This study highlights the potential of NK as an edible agent to alleviate obesity and its associated metabolic diseases. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-024-01522-2.

Risk of Fat Mass- and Obesity-Associated Gene-Dependent Obesogenic Programming by Formula Feeding Compared to Breastfeeding.

It is the purpose of this review to compare differences in postnatal epigenetic programming at the level of DNA and RNA methylation and later obesity risk between infants receiving artificial formula feeding (FF) in contrast to natural breastfeeding (BF). FF bears the risk of aberrant epigenetic programming at the level of DNA methylation and enhances the expression of the RNA demethylase fat mass- and obesity-associated gene (FTO), pointing to further deviations in the RNA methylome. Based on a literature search through Web of Science, Google Scholar, and PubMed databases concerning the dietary and epigenetic factors influencing FTO gene and FTO protein expression and FTO activity, FTO's impact on postnatal adipogenic programming was investigated. Accumulated translational evidence underscores that total protein intake as well as tryptophan, kynurenine, branched-chain amino acids, milk exosomal miRNAs, NADP, and NADPH are crucial regulators modifying FTO gene expression and FTO activity. Increased FTO-mTORC1-S6K1 signaling may epigenetically suppress the WNT/ß-catenin pathway, enhancing adipocyte precursor cell proliferation and adipogenesis. Formula-induced FTO-dependent alterations of the N6-methyladenosine (m6A) RNA methylome may represent novel unfavorable molecular events in the postnatal development of adipogenesis and obesity, necessitating further investigations. BF provides physiological epigenetic DNA and RNA regulation, a compelling reason to rely on BF.

Sargassum horneri extract fermented by Lactiplantibacillus pentosus SH803 mediates adipocyte metabolism in 3T3-L1 preadipocytes by regulating oxidative damage and inflammation.

Sargassum horneri (S. horneri), a brown seaweed excessively proliferating along Asian coastlines, are damaging marine ecosystems. Thus, this study aimed to enhance nutritional value of S. horneri through lactic acid bacteria fermentation to increase S. horneri utilization as a functional food supplement, and consequently resolve coastal S. horneri accumulation. S. horneri supplemented fermentation was most effective with Lactiplantibacillus pentosus SH803, thus this product (F-SHWE) was used for further in vitro studies. F-SHWE normalized expressions of oxidative stress related genes NF-κB, p53, BAX, cytochrome C, caspase 9, and caspase 3, while non-fermented S. horneri (SHWE) did not, in a H2O2-induced HT-29 cell model. Moreover, in an LPS-induced HT-29 cell model, F-SHWE repaired expressions of inflammation marker genes ZO1, IL1ß, IFNγ more effectively than SHWE. For further functional assessment, F-SHWE was also treated in 3T3-L1 adipocytes. As a result, F-SHWE decreased lipid accumulation, along with gene expression of adipogenesis markers PPARγ, C/EBPα, C/EBPß, aP2, and Lpl; lipogenesis markers Lep, Akt, SREBP1, Acc, Fas; inflammation markers IFN-γ and NF-κB. Notably, gene expression of C/EBPß, IFN-γ and NF-κB were suppressed only by F-SHWE, suggesting the enhancing effect of fermentation on obesity-related properties. Compositional analysis attributed the protective effects of F-SHWE to acetate, an organic acid significantly higher in F-SHWE than SHWE. Therefore, F-SHWE is a novel potential anti-obesity agent, providing a strategy to reduce excess S. horneri populations along marine ecosystems.

Gene expression and characterization of clonally derived murine embryonic brown and brite adipocytes.

White adipocytes store energy, while brown and brite adipocytes release heat via nonshivering thermogenesis. In this study, we characterized two murine embryonic clonal preadipocyte lines, EB5 and EB7, each displaying unique gene marker expression profiles. EB5 cells differentiate into brown adipocytes, whereas EB7 cells into brite (also known as beige) adipocytes. To draw a comprehensive comparison, we contrasted the gene expression patterns, adipogenic capacity, as well as carbohydrate and lipid metabolism of these cells to that of F442A, a well-known white preadipocyte and adipocyte model. We found that commitment to differentiation in both EB5 and EB7 cells can be induced by 3-Isobutyl-1-methylxanthine/dexamethasone (Mix/Dex) and staurosporine/dexamethasone (St/Dex) treatments. Additionally, the administration of rosiglitazone significantly enhances the brown and brite adipocyte phenotypes. Our data also reveal the involvement of a series of genes in the transcriptional cascade guiding adipogenesis, pinpointing GSK3ß as a critical regulator for both EB5 and EB7 adipogenesis. In a developmental context, we observe that, akin to brown fat progenitors, brite fat progenitors make their appearance in murine development by 11-12 days of gestation or potentially earlier. This result contributes to our understanding of adipocyte lineage specification during embryonic development. In conclusion, EB5 and EB7 cell lines are valuable for research into adipocyte biology, providing insights into the differentiation and development of brown and beige adipocytes. Furthermore, they could be useful for the characterization of drugs targeting energy balance for the treatment of obesity and metabolic diseases.

Novel perspectives on autophagy-oxidative stress-inflammation axis in the orchestration of adipogenesis.

Adipose tissue, an indispensable organ, fulfils the pivotal role of energy storage and metabolism and is instrumental in maintaining the dynamic equilibrium of energy and health of the organism. Adipocyte hypertrophy and adipocyte hyperplasia (adipogenesis) are the two primary mechanisms of fat deposition. Mature adipocytes are obtained by differentiating mesenchymal stem cells into preadipocytes and redifferentiation. However, the mechanisms orchestrating adipogenesis remain unclear. Autophagy, an alternative cell death pathway that sustains intracellular energy homeostasis through the degradation of cellular components, is implicated in regulating adipogenesis. Furthermore, adipose tissue functions as an endocrine organ, producing various cytokines, and certain inflammatory factors, in turn, modulate autophagy and adipogenesis. Additionally, autophagy influences intracellular redox homeostasis by regulating reactive oxygen species, which play pivotal roles in adipogenesis. There is a growing interest in exploring the involvement of autophagy, inflammation, and oxidative stress in adipogenesis. The present manuscript reviews the impact of autophagy, oxidative stress, and inflammation on the regulation of adipogenesis and, for the first time, discusses their interactions during adipogenesis. An integrated analysis of the role of autophagy, inflammation and oxidative stress will contribute to elucidating the mechanisms of adipogenesis and expediting the exploration of molecular targets for treating obesity-related metabolic disorders.

Lysine 2-hydroxyisobutyrylation levels determined adipogenesis and fat accumulation in adipose tissue in pigs.

BACKGROUND: Excessive backfat deposition lowering carcass grade is a major concern in the pig industry, especially in most breeds of obese type pigs. The mechanisms involved in adipogenesis and fat accumulation in pigs remain unclear. Lysine 2-hydroxyisobutyrylation (Khib), is a novel protein post-translational modification (PTM), which play an important role in transcription, energy metabolism and metastasis of cancer cells, but its role in adipogenesis and fat accumulation has not been shown. RESULTS: In this study, we first analyzed the modification levels of acetylation (Kac), Khib, crotonylation (Kcr) and succinylation (Ksu) of fibro-adipogenic progenitors (FAPs), myogenic precursors (Myo) and mesenchymal stem cells (MSCs) with varied differentiation potential, and found that only Khib modification in FAPs was significantly higher than that in MSCs. Consistently, in parallel with its regulatory enzymes lysine acetyltransferase 5 (KAT5) and histone deacetylase 2 (HDAC2) protein levels, the Khib levels increased quadratically (P < 0.01) during adipogenic differentiation of FAPs. KAT5 knockdown in FAPs inhibited adipogenic differentiation, while HDAC2 knockdown enhanced adipogenic differentiation. We also demonstrated that Khib modification favored to adipogenic differentiation and fat accumulation by comparing Khib levels in FAPs and backfat tissues both derived from obese-type pigs (Laiwu pigs) and lean-type pigs (Duroc pigs), respectively. Accordingly, the expression patterns of KAT5 and HDAC2 matched well to the degree of backfat accumulation in obese- and lean-type pigs. CONCLUSIONS: From the perspective of protein translational modification, we are the first to reveal the role of Khib in adipogenesis and fat deposition in pigs, and provided new clues for the improvement of fat accumulation and distribution as expected via genetic selection and nutritional strategy in obese-type pigs.

Addressing chemically-induced obesogenic metabolic disruption: selection of chemicals for in vitro human PPARα, PPARγ transactivation, and adipogenesis test methods.

Whilst western diet and sedentary lifestyles heavily contribute to the global obesity epidemic, it is likely that chemical exposure may also contribute. A substantial body of literature implicates a variety of suspected environmental chemicals in metabolic disruption and obesogenic mechanisms. Chemically induced obesogenic metabolic disruption is not yet considered in regulatory testing paradigms or regulations, but this is an internationally recognised human health regulatory development need. An early step in the development of relevant regulatory test methods is to derive appropriate minimum chemical selection lists for the target endpoint and its key mechanisms, such that the test method can be suitably optimised and validated. Independently collated and reviewed reference and proficiency chemicals relevant for the regulatory chemical universe that they are intended to serve, assist regulatory test method development and validation, particularly in relation to the OECD Test Guidelines Programme. To address obesogenic mechanisms and modes of action for chemical hazard assessment, key initiating mechanisms include molecular-level Peroxisome Proliferator-Activated Receptor (PPAR) α and γ agonism and the tissue/organ-level key event of perturbation of the adipogenesis process that may lead to excess white adipose tissue. Here we present a critical literature review, analysis and evaluation of chemicals suitable for the development, optimisation and validation of human PPARα and PPARγ agonism and human white adipose tissue adipogenesis test methods. The chemical lists have been derived with consideration of essential criteria needed for understanding the strengths and limitations of the test methods. With a weight of evidence approach, this has been combined with practical and applied aspects required for the integration and combination of relevant candidate test methods into test batteries, as part of an Integrated Approach to Testing and Assessment for metabolic disruption. The proposed proficiency and reference chemical list includes a long list of negatives and positives (20 chemicals for PPARα, 21 for PPARγ, and 11 for adipogenesis) from which a (pre-)validation proficiency chemicals list has been derived.

Endocrine disruption of adipose physiology: Screening in SGBS cells.

The increasing use of industrial chemicals has raised concerns regarding exposure to endocrine-disrupting chemicals (EDCs), which interfere with developmental, reproductive and metabolic processes. Of particular concern is their interaction with adipose tissue, a vital component of the endocrine system regulating metabolic and hormonal functions. The SGBS (Simpson Golabi Behmel Syndrome) cell line, a well-established human-relevant model for adipocyte research, closely mimics native adipocytes' properties. It responds to hormonal stimuli, undergoes adipogenesis and has been successfully used to study the impact of EDCs on adipose biology. In this study, we screened human exposure-relevant doses of various EDCs on the SGBS cell line to investigate their effects on viability, lipid accumulation and adipogenesis-related protein expression. Submicromolar doses were generally well tolerated; however, at higher doses, EDCs compromised cell viability, with cadmium chloride (CdCl2) showing the most pronounced effects. Intracellular lipid levels remained unaffected by EDCs, except for tributyltin (TBT), used as a positive control, which induced a significant increase. Analysis of adipogenesis-related protein expression revealed several effects, including downregulation of fatty acid-binding protein 4 (FABP4) by dibutyl phthalate, upregulation by CdCl2 and downregulation of perilipin 1 and FABP4 by perfluorooctanoic acid. Additionally, TBT induced dose-dependent upregulation of C/EBPα, perilipin 1 and FABP4 protein expression. These findings underscore the importance of employing appropriate models to study EDC-adipocyte interactions. Conclusions from this research could guide strategies to reduce the negative impacts of EDC exposure on adipose tissue.

LEP inhibits intramuscular adipogenesis through the AMPK signaling pathway in vitro.

Leptin can indirectly regulate fatty-acid metabolism and synthesis in muscle in vivo and directly in incubated muscle ex vivo. In addition, non-synonymous mutations in the bovine leptin gene (LEP) are associated with carcass intramuscular fat (IMF) content. However, the effects of LEP on lipid synthesis of adipocytes have not been clearly studied at the cellular level. Therefore, this study focused on bovine primary intramuscular preadipocytes to investigate the effects of LEP on the proliferation and differentiation of intramuscular preadipocytes, as well as its regulatory mechanism in lipid synthesis. The results showed that both the LEP and leptin receptor gene (LEPR) were highly expressed in IMF tissues, and their mRNA expression levels were positively correlated at different developmental stages of intramuscular preadipocytes. The overexpression of LEP inhibited the proliferation and differentiation of intramuscular preadipocytes, while interference with LEP had the opposite effect. Additionally, LEP significantly promoted the phosphorylation level of AMPKα by promoting the protein expression of CAMKK2. Meanwhile, rescue experiments showed that the increasing effect of AMPK inhibitors on the number of intramuscular preadipocytes was significantly weakened by the overexpression of LEP. Furthermore, the overexpression of LEP could weaken the promoting effect of AMPK inhibitor on triglyceride content and droplet accumulation, and prevent the upregulation of adipogenic protein expression (SREBF1, FABP4, FASN, and ACCα) caused by AMPK inhibitor. Taken together, LEP acted on the AMPK signaling pathway by regulating the protein expression of CAMKK2, thereby downregulating the expression of proliferation-related and adipogenic-related genes and proteins, ultimately reducing intramuscular adipogenesis.

A meta-analysis approach for annotation and identification of lncRNAs controlling perirenal fat deposition in suckling lambs.

Long non-coding RNAs (lncRNAs) are being studied in farm animals due to their association with traits of economic interest, such as fat deposition. Based on the analysis of perirenal fat transcriptomes, this research explored the relevance of these regulatory elements to fat deposition in suckling lambs. To that end, meta-analysis techniques have been implemented to efficiently characterize and detect differentially expressed transcripts from two different RNA-seq datasets, one including samples of two sheep breeds that differ in fat deposition features, Churra and Assaf (n = 14), and one generated from Assaf suckling lambs with different fat deposition levels (n = 8). The joint analysis of the 22 perirenal fat RNA-seq samples with the FEELnc software allowed the detection of 3953 novel lncRNAs. After the meta-analysis, 251 differentially expressed genes were identified, 21 of which were novel lncRNAs. Additionally, a co-expression analysis revealed that, in suckling lambs, lncRNAs may play a role in controlling angiogenesis and thermogenesis, processes highlighted in relation to high and low fat deposition levels, respectively. Overall, while providing information that could be applied for the improvement of suckling lamb carcass traits, this study offers insights into the biology of perirenal fat deposition regulation in mammals.

Lactobacillus paracasei subsp. paracasei NTU 101 prevents obesity by regulating AMPK pathways and gut microbiota in obese rat.

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, PPARß, PPARγ, C/EBPα, C/EBPß, 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 × 108 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.

Vestigial like 4 regulates the adipogenesis of classical brown adipose tissue.

Brown adipose tissue (BAT) is mammals' primary non-shivering thermogenesis organ, and the molecular mechanisms regulating BAT growth and adipogenesis are largely unknown. The Hippo-YAP pathway has been well-known for controlling organ size, and Vestigial like 4 (VGLL4) is a transcriptional regulator that modulates the Hippo-YAP pathway by competing against YAP for binding to TEAD proteins. In this study, we dissected the function of VGLL4 in regulating BAT development. We generated a conventional Vgll4 mutant mouse line, in which the two Tondu (TDU) domains of VGLL4 were disrupted. We found that deletion of the TDU domains of VGLL4 resulted in perinatal lethality and paucity of the interscapular BAT. Histological and magnetic resonance imaging studies confirmed that the adipogenesis of BAT was impaired in Vgll4 mutants. Adeno-associated virus (AAV) mediated, brown adipocyte-specific overexpression of VGLL4 increased BAT volume and protected the adult male mice from acute cold stress. Genomic studies suggest that VGLL4/TEAD1 complex directly regulates the myogenic and adipogenic gene expression programs of BAT. In conclusion, our data identify VGLL4 as a previously unrecognized adipogenesis factor that regulates classical BAT development.

MicroRNA-21 modulates brown adipose tissue adipogenesis and thermogenesis in a mouse model of polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS), the most common endocrine disorder in premenopausal women, is associated with increased obesity, hyperandrogenism, and altered brown adipose tissue (BAT) thermogenesis. MicroRNAs play critical functions in brown adipocyte differentiation and maintenance. We aim to study the role of microRNA-21 (miR-21) in altered energy homeostasis and BAT thermogenesis in a PCOS mouse model of peripubertal androgen exposure. METHODS: Three-week-old miR-21 knockout (miR21KO) or wild-type (WT) female mice were treated with dihydrotestosterone (DHT) or vehicle for 90 days. Body composition was determined by EchoMRI. Energy expenditure (EE), oxygen consumption (VO2), carbon dioxide production (VCO2), and respiratory exchange ratio (RER) were measured by indirect calorimetry. Androgen receptor (AR), and markers of adipogenesis, de novo lipogenesis, angiogenesis, extracellular matrix remodeling, and thermogenesis were quantified by RT-qPCR and/or Western-blot. RESULTS: MiR-21 ablation attenuated DHT-mediated increase in body weight while having no effect on fat or BAT mass. MiR-21 ablation attenuated DHT-mediated BAT AR upregulation. MiR-21 ablation did not alter EE; however, miR21KO DHT-treated mice have reduced VO2, VCO2, and RER. MiR-21 ablation reversed DHT-mediated decrease in food intake and increase in sleep time. MiR-21 ablation decreased some adipogenesis (Adipoq, Pparγ, and Cebpß) and extracellular matrix remodeling (Mmp-9 and Timp-1) markers expression in DHT-treated mice. MiR-21 ablation abolished DHT-mediated increases in thermogenesis markers Cpt1a and Cpt1b, while decreasing CIDE-A expression. CONCLUSIONS: Our findings suggest that BAT miR-21 may play a role in regulating DHT-mediated thermogenic dysfunction in PCOS. Modulation of BAT miR-21 levels could be a novel therapeutic approach for the treatment of PCOS-associated metabolic derangements.

Polycystic ovary syndrome (PCOS) is a common hormone disorder in premenopausal women, often linked to obesity and abnormal brown fat tissue activity. Women with PCOS have elevated male hormones, which are responsible for many metabolic problems. Our study focuses on understanding the role of microRNA-21 (miR-21) in the energy balance and brown fat tissue activity in a PCOS mouse model. We studied female mice with and without miR-21, treating them with a male hormone. We measured body composition and energy expenditure. We also analyzed the levels of specific genes and proteins related to fat tissue and energy production. Our findings showed that mice lacking miR-21 had less weight gain in response to male hormones, without fat or brown fat tissue mass changes. They also had reduced energy production, changed eating habits, and altered expression of genes related to fat tissue and energy production. In conclusion, our study suggests that miR-21 in brown fat tissue may regulate the energy imbalance caused by male hormones in PCOS. Adjusting miR-21 levels in brown fat tissue could be a new way to address the metabolic issues associated with PCOS.

The expression of NFAT family genes in subcutaneous adipose tissue before and after weight loss in obese individuals.

BACKGROUND AND AIMS: Adipose tissue (AT) serves as a vital energy storage site and plays a pivotal role in metabolic regulation, exhibiting a high response to insulin. Impairment in this response may closely associate with obesity, and NFAT (nuclear factor of activated T cells) family genes may be involved in the process. However, human data linking NFAT and AT remains elusive. The aim of this study was to assess the expression of NFAT family genes and markers of adipogenesis in subcutaneous adipose tissue (SAT) among normal-weight and overweight/obese individuals before and after weight loss, in relation to insulin sensitivity. METHODS AND RESULTS: The study included 45 participants, 15 normal-weight (control group) and 30 overweight or obese, who underwent a 12-week dietary intervention (DI) program. Before and after the program hyperinsulinemic-euglycemic clamp and SAT biopsy were conducted. Before DI, a positive correlations was observed in the expression of NFATc1, NFATc4, and NFAT5 with insulin sensitivity. The expression of NFAT family genes and markers of adipogenesis in SAT was lower in individuals with overweight or obesity compared to normal-weight. Additionally, a positive correlation was noted between NFAT family genes and adipogenesis markers both before and after weight loss. Following the DI program, there was an increase in the expression of NFATc3, NFATc4, and NFAT5 in SAT. CONCLUSION: Decreased SAT expression of NFAT genes in obesity is partly reversed in response to weight loss. NFAT genes in SAT are associated with insulin sensitivity and adipogenesis. Registration number for clinical trial: NCT01393210.

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.

Nuclear Receptor Subfamily 4 Group A Member 1 (NR4A1) Promotes the Adipogenesis of Intramuscular Preadipocytes through PI3K/AKT Pathway in Goats.

As a transcription factor, Nuclear Receptor Subfamily 4 Group A Member 1 (NR4A1) binds to downstream target genes to participate in cell proliferation and cell differentiation. We found that the NR4A1 reached the highest expression at 60 h after the differentiation of goat intramuscular preadipocytes. Overexpression of goat NR4A1 increased the number of intracellular lipid droplets and up-regulated the expression of adipocyte-differentiation-related marker genes including AP2, SREBP1, ACC, GPAM, and DGAT2, while the relative expression levels of Pref-1 and HSL were significantly decreased. On the contrary, after NR4A1 was knocked down by siRNA, the number of intracellular lipid droplets and the relative expression levels of LPL, CEBPα, CEBPß, ACC, and DGAT2 were significantly decreased, and the relative expression levels of Pref-1 and HSL were significantly up-regulated. These results suggest that NR4A1 promotes the differentiation of goat intramuscular preadipocytes. Transcriptome sequencing was carried out after overexpression of goat NR4A1, and the KEGG enrichment analysis result showed that the most differentially expressed genes were related to adipocyte differentiation and were enriched in the PI3K-Akt signaling pathway. LY249002, an inhibitor of the PI3K-Akt signaling pathway, was introduced and decreased the number of intracellular lipid droplets, and the relative expression levels of C/EBPα, SREBP1, AP2, C/EBPß, GPAM, ACC, DGAT1, DGAT2, and ATGL were decreased accordingly. The above results indicate that overexpression of goat NR4A1 may promote the differentiation of intramuscular preadipocytes through the PI3K-Akt signaling pathway.

Regulatory role of exosome-derived miRNAs and other contents in adipogenesis.

Intramuscular fat (IMF) content significantly impacts meat quality. influenced by complex interactions between skeletal muscle cells and adipocytes. Adipogenesis plays a pivotal role in IMF formation. Exosomes, extracellular membranous nanovesicles, facilitate intercellular communication by transporting proteins, nucleic acids (DNA and RNA), and other biomolecules into target cells, thereby modulating cellular behaviors. Recent studies have linked exosome-derived microRNAs (miRNAs) and other cargo to adipogenic processes. Various cell types, including skeletal muscle cells, interact with adipocytes via exosome secretion and uptake. Exosomes entering adipocytes regulate adipogenesis by modulating key signaling pathways, thereby influencing the extent and distribution of IMF deposition. This review comprehensively explores the origin, formation, and mechanisms of exosome action, along with current research and their applications in adipogenesis. Emphasis is placed on exosome-mediated regulation of miRNAs, non-coding RNAs (ncRNAs), proteins, lipids, and other biomolecules during adipogenesis. Leveraging exosomal contents for genetic breeding and treating obesity-related disorders is discussed. Insights gathered contribute to advancing understanding and potential therapeutic applications of exosome-regulated adipogenesis mechanisms.