RESUMO
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.
Assuntos
Adipócitos , Adipogenia , Regiões Promotoras Genéticas , Fatores de Transcrição , Adipogenia/genética , Animais , Camundongos , Humanos , Adipócitos/metabolismo , Adipócitos/citologia , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Diferenciação Celular/genética , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/citologia , Masculino , Células 3T3-L1 , Camundongos Endogâmicos C57BL , Regulação da Expressão GênicaRESUMO
Postprandial IL-1ß surges are predominant in the white adipose tissue (WAT), but its consequences are unknown. Here, we investigate the role of IL-1ß in WAT energy storage and show that adipocyte-specific deletion of IL-1 receptor 1 (IL1R1) has no metabolic consequences, whereas ubiquitous lack of IL1R1 reduces body weight, WAT mass, and adipocyte formation in mice. Among all major WAT-resident cell types, progenitors express the highest IL1R1 levels. In vitro, IL-1ß potently promotes adipogenesis in murine and human adipose-derived stem cells. This effect is exclusive to early-differentiation-stage cells, in which the adipogenic transcription factors C/EBPδ and C/EBPß are rapidly upregulated by IL-1ß and enriched near important adipogenic genes. The pro-adipogenic, but not pro-inflammatory effect of IL-1ß is potentiated by acute treatment and blocked by chronic exposure. Thus, we propose that transient postprandial IL-1ß surges regulate WAT remodeling by promoting adipogenesis, whereas chronically elevated IL-1ß levels in obesity blunts this physiological function.
Assuntos
Adipócitos , Adipogenia , Tecido Adiposo Branco , Proteína beta Intensificadora de Ligação a CCAAT , Interleucina-1beta , Receptores Tipo I de Interleucina-1 , Adipogenia/efeitos dos fármacos , Adipogenia/genética , Animais , Interleucina-1beta/metabolismo , Humanos , Adipócitos/metabolismo , Adipócitos/citologia , Receptores Tipo I de Interleucina-1/metabolismo , Receptores Tipo I de Interleucina-1/genética , Camundongos , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Proteína beta Intensificadora de Ligação a CCAAT/genética , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/citologia , Proteína delta de Ligação ao Facilitador CCAAT/metabolismo , Proteína delta de Ligação ao Facilitador CCAAT/genética , Masculino , Camundongos Knockout , Células-Tronco/metabolismo , Células-Tronco/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Diferenciação Celular/efeitos dos fármacosRESUMO
BACKGROUND: Adipose tissue affects not only the meat quality of domestic animals, but also human health. Adipocyte differentiation is regulated by a series of regulatory genes and cyclins. Four and half-LIM protein (FHL2) is positively correlated with the hypertrophy of adipocytes and can cause symptoms such as obesity and diabetes. RESULT: In the transcriptome sequencing analysis of intramuscular adipocytes after three days of differentiation, the differentially expressed gene FHL2 was found. To further explore the biological significance of the differentially expressed gene FHL2, which was downregulated in the mature adipocytes. We revealed the function of FHL2 in adipogenesis through the acquisition and loss of function of FHL2. The results showed that the overexpression of FHL2 significantly increased the expression of adipogenic genes (PPARγ, C/EBPß) and the differentiation of intramuscular and subcutaneous adipocytes. However, silencing FHL2 significantly inhibited adipocyte differentiation. The overexpression of FHL2 increased the number of adipocytes stained with crystal violet and increased the mRNA expression of proliferation marker genes such as CCNE, PCNA, CCND and CDK2. In addition, it significantly increased the rate of EdU positive cells. In terms of apoptosis, overexpression of FHL2 significantly inhibited the expression of P53 and BAX in both intramuscular and subcutaneous adipocytes, which are involved in cell apoptosis. However, overexpression of FHL2 promoted the expression of BCL, but was rescued by the silencing of FHL2. CONCLUSIONS: In summary, FHL2 may be a positive regulator of intramuscular and subcutaneous adipocyte differentiation and proliferation, and acts as a negative regulator of intramuscular and subcutaneous adipocyte apoptosis. These findings provide a theoretical basis for the subsequent elucidation of FHL2 in adipocytes.
Assuntos
Adipócitos , Adipogenia , Cabras , Proteínas com Homeodomínio LIM , Proteínas Musculares , Animais , Cabras/genética , Adipócitos/metabolismo , Adipócitos/citologia , Adipogenia/genética , Proteínas com Homeodomínio LIM/genética , Proteínas com Homeodomínio LIM/metabolismo , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Apoptose/genética , Diferenciação Celular/genética , Proliferação de Células , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Gordura Subcutânea/metabolismo , Gordura Subcutânea/citologia , Perfilação da Expressão GênicaRESUMO
Meat quality in goats is partly determined by the intramuscular fat (IMF) content, which is associated with the proliferation and differentiation of intramuscular preadipocytes. Emerging studies have suggested that miRNA plays a crucial role in adipocyte proliferation and differentiation. In our recent study, we observed the expression variations in miR-196a in the longissimus dorsi muscle of Jianzhou goats at different ages. However, the specific function and underlying mechanism of miR-196a in IMF deposition are still unclear. This study demonstrated that miR-196a significantly enhanced adipogenesis and apoptosis and reduced the proliferation of preadipocytes. Subsequently, RNA-seq was employed to determine genes regulated by miR-196a, and 677 differentially expressed genes were detected after miR-196a overexpression. The PI3K-Akt pathway was identified as activated in miR-196a regulating intramuscular adipogenesis via Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and further verified via Western blot and rescue assays. Lastly, using RT-qPCR, Western blot, dual-luciferase, and rescue assays, we found that miR-196a promoted adipogenesis and suppressed the proliferation of intramuscular preadipocytes by the downregulation of MAP3K1. In summary, these results suggest that miR-196a regulates IMF deposition by targeting MAP3K1 and activating the PI3K-Akt pathway and provide a theoretical foundation for improving goat meat quality through molecular breeding.
Assuntos
Adipócitos , Cabras , MicroRNAs , Transdução de Sinais , Animais , Adipócitos/metabolismo , Adipócitos/citologia , Adipogenia , Apoptose , Diferenciação Celular , Proliferação de Células , Cabras/genética , Cabras/metabolismo , Metabolismo dos Lipídeos/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismoRESUMO
This study investigated the effects of ascochlorin (ASC), a natural compound derived from the fungus Ascochyta viciae, on adipogenesis and obesity. We determined the effects of ASC on 3T3-L1 preadipocytes and whether it ameliorated to mitigate high-fat diet (HFD)-induced obesity in C57BL/6J mice. We found that ASC significantly inhibited the differentiation of preadipocytes by modulating the Wnt/ß-catenin signaling pathway, a key regulator of adipogenic processes. Treatment with ASC not only reduced the mRNA and protein expression of key adipogenic transcription factors such as C/EBPα and PPARγ, but also reduced lipid accumulation both in vitro and in vivo. In addition, treatment HFD-fed mice with ASC significantly reduced their weight gain and adiposity vs. control mice. These results suggest that ASC has considerable potential as a therapeutic agent for obesity, owing to its dual action of inhibiting adipocyte differentiation and reducing lipid accumulation. Thus, ASC represents a promising candidate as a natural anti-obesity agent.
Assuntos
Adipócitos , Adipogenia , Dieta Hiperlipídica , Obesidade , Via de Sinalização Wnt , Animais , Masculino , Camundongos , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adipogenia/efeitos dos fármacos , Alcenos , Fármacos Antiobesidade/farmacologia , beta Catenina/metabolismo , Diferenciação Celular/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Obesidade/etiologia , Fenóis/farmacologia , PPAR gama/metabolismo , PPAR gama/genética , Via de Sinalização Wnt/efeitos dos fármacosRESUMO
The aim of this study was to elucidate the effect of FAM13A on the differentiation of goat intramuscular precursor adipocytes and its mechanism of action. Here, we cloned the CDS region 2094 bp of the goat FAM13A gene, encoding a total of 697 amino acid residues. Functionally, overexpression of FAM13A inhibited the differentiation of goat intramuscular adipocytes with a concomitant reduction in lipid droplets, whereas interference with FAM13A expression promoted the differentiation of goat intramuscular adipocytes. To further investigate the mechanism of FAM13A inhibiting adipocyte differentiation, 104 differentially expressed genes were screened by RNA-seq, including 95 up-regulated genes and 9 down-regulated genes. KEGG analysis found that the RIG-I receptor signaling pathway, NOD receptor signaling pathway and toll-like receptor signaling pathway may affect adipogenesis. We selected the RIG-I receptor signaling pathway enriched with more differential genes as a potential adipocyte differentiation signaling pathway for verification. Convincingly, the RIG-I like receptor signaling pathway inhibitor (HY-P1934A) blocked this pathway to save the phenotype observed in intramuscular adipocyte with FAM13A overexpression. Finally, the upstream miRNA of FAM13A was predicted, and the targeted inhibition of miR-21-5p on the expression of FAM13A gene was confirmed. In this study, it was found that FAM13A inhibited the differentiation of goat intramuscular adipocytes through the RIG-I receptor signaling pathway, and the upstream miRNA of FAM13A (miR-21-5p) promoted the differentiation of goat intramuscular adipocytes. This work extends the genetic regulatory network of IMF deposits and provides theoretical support for improving human health and meat quality from the perspective of IMF deposits.
Assuntos
Adipócitos , Diferenciação Celular , Cabras , Transdução de Sinais , Animais , Cabras/genética , Cabras/metabolismo , Adipócitos/metabolismo , Adipócitos/citologia , Diferenciação Celular/genética , MicroRNAs/genética , Adipogenia/genética , Proteína DEAD-box 58/genética , Proteína DEAD-box 58/metabolismoRESUMO
Graves' orbitopathy (GO), a manifestation of Graves' disease, is characterized by orbital fibroblastinduced inflammation, leading to fibrosis or adipogenesis. Histone deacetylase (HDAC) serves a central role in autoimmune diseases and fibrosis. The present study investigated HDAC inhibition in orbital fibroblasts from patients with GO to evaluate its potential as a therapeutic agent. Primary cultured orbital fibroblasts were treated with an HDAC inhibitor, panobinostat, under the stimulation of IL1ß, TGFß or adipogenic medium. Inflammatory cytokines, and fibrosis and adipogenesisrelated proteins were analyzed using western blotting. The effects of panobinostat on HDAC mRNA expression were measured in GO orbital fibroblasts, and specific HDACs were inhibited using small interfering RNA transfection. Panobinostat significantly reduced the IL1ßinduced production of inflammatory cytokines and TGFßinduced production of fibrosisrelated proteins. It also suppressed adipocyte differentiation and adipogenic transcription factor production. Furthermore, it significantly attenuated HDAC7 mRNA expression in GO orbital fibroblasts. In addition, the silencing of HDAC7 led to antiinflammatory and antifibrotic effects. In conclusion, by inhibiting HDAC7 gene expression, panobinostat may suppress the production of inflammatory cytokines, profibrotic proteins and adipogenesis in GO orbital fibroblasts. The present in vitro study suggested that HDAC7 could be a potential therapeutic target for inhibiting the inflammatory, adipogenic and fibrotic mechanisms of GO.
Assuntos
Fibroblastos , Oftalmopatia de Graves , Inibidores de Histona Desacetilases , Histona Desacetilases , Humanos , Oftalmopatia de Graves/metabolismo , Oftalmopatia de Graves/tratamento farmacológico , Oftalmopatia de Graves/genética , Oftalmopatia de Graves/patologia , Inibidores de Histona Desacetilases/farmacologia , Fibroblastos/metabolismo , Fibroblastos/efeitos dos fármacos , Histona Desacetilases/metabolismo , Histona Desacetilases/genética , Células Cultivadas , Panobinostat/farmacologia , Citocinas/metabolismo , Adipogenia/efeitos dos fármacos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Fator de Crescimento Transformador beta/metabolismo , Diferenciação Celular/efeitos dos fármacos , Interleucina-1beta/metabolismoRESUMO
The distinct anatomic environment in which adipose tissues arise during organogenesis is a principle determinant of their adult expansion capacity. Metabolic disease results from a deficiency in hyperplastic adipose expansion within the dermal/subcutaneous depot; thus, understanding the embryonic origins of dermal adipose is imperative. Using single-cell transcriptomics throughout murine embryogenesis, we characterized cell populations, including Bcl11b + cells, that regulate the development of dermal white adipose tissue (dWAT). We discovered that BCL11b expression modulates the Wnt signaling microenvironment to enable adipogenic differentiation in the dermal compartment. Subcutaneous and visceral adipose arises from a distinct population of Nefl + cells during embryonic organogenesis, whereas Pi16 + /Dpp4 + fibroadipogenic progenitors support obesity-stimulated hypertrophic expansion in the adult. Together, these results highlight the unique regulatory pathways used by anatomically distinct adipose depots, with important implications for human metabolic disease.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Proteínas Repressoras , Animais , Camundongos , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas Supressoras de Tumor/metabolismo , Proteínas Supressoras de Tumor/genética , Adipogenia/genética , Tecido Adiposo Branco/embriologia , Tecido Adiposo Branco/metabolismo , Via de Sinalização Wnt/genética , Tecido Adiposo/metabolismo , Tecido Adiposo/embriologia , Diferenciação Celular/genética , HumanosRESUMO
Background/Objective: This study examined the anti-obesity effect of royal jelly (RJ) in rats fed with a high-fat diet by targeting the major pathways involved in adipogenesis and lipolysis. In addition, it examined whether this effect is AMPK-dependent. Methods: Five groups of adult male albino rats were used (n = 6 each as 1); the control rats were fed with a normal diet (2.9 kcal), and the other groups were as follows: control + RJ (300 mg/kg), HFD (4.75 kcal), HFD + RJ (300 mg/kg), and HFD + RJ (300 mg/kg) + dorsomorphin (an AMPK inhibitor) (0.2 mg/kg). Results: RJ was administered orally to all rats. With no changes in food and energy intake, RJ significantly reduced gains in body weight, fat weight, body mass index (BMI), the Lee index, abdominal circumference (AC), and the adiposity index (AI). It also reduced fasting glucose and insulin levels, HOMA-IR, and the circulatory levels of free fatty acids (FFAs), triglycerides, cholesterol, and LDL-c in the HFD-fed rats. RJ also increased serum glycerol levels and adiponectin levels, but reduced the serum levels of leptin, IL-6, and TNF-α. Moreover, RJ reduced the secretion of IL-6 and TNF-α from isolated WAT. At the tissue level, the HFD + RJ rats exhibited a smaller adipocyte size compared to the HFD rats. At the molecular level, RJ increased the phosphorylation of AMPK, SREBP1, and ACC-1 and increased the mRNA and protein levels of HSL and ATG in the WAT of the HFD rats. In concomitance, RJ increased the mRNA levels of PGC-α1, reduced the protein levels of PPARγ, and repressed the transcriptional activities of PPARγ, SREBP1, and C/EBPαß in the WAT of these rats. All the aforementioned effects of RJ were prevented by co-treatment with dorsomorphin. Conclusions: RJ exerts a potent anti-obesity effect in rats that is mediated by the AMPk-dependent suppression of WAT adipogenesis and the stimulation of lipolysis.
Assuntos
Adipogenia , Fármacos Antiobesidade , Dieta Hiperlipídica , Ácidos Graxos , Lipólise , Obesidade , Animais , Lipólise/efeitos dos fármacos , Masculino , Adipogenia/efeitos dos fármacos , Fármacos Antiobesidade/farmacologia , Ratos , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , PPAR gama/metabolismoRESUMO
BACKGROUND: Osteoporosis (OP) is a systemic bone disease characterized by reduced bone mass and deterioration of bone microstructure, leading to increased bone fragility. Platelets can take up and release cytokines, and a high platelet count has been associated with low bone density. Obesity is strongly associated with OP, and adipose tissue can influence platelet function by secreting adipokines. However, the biological relationship between these factors remains unclear. METHODS: We conducted differential analysis to identify OP platelet-related plasma proteins. And, making comprehensive analysis, including functional enrichment, protein-protein interaction network analysis, and Friends analysis. The key protein, Tetranectin (TNA/CLEC3B), was identified through screening. Then, we analyzed TNA's potential roles in osteogenic and adipogenic differentiation using multiple RNA-seq data sets and validated its effect on osteoclast differentiation and bone resorption function through in vitro experiments. RESULTS: Six OP-platelet-related proteins were identified via differential analysis. Then, we screened the key protein TNA, which was found to be highly expressed in adipose tissue. RNA-seq data suggested that TNA may promote early osteoblast differentiation. In vitro experiments showed that knockdown of TNA expression significantly increased the expression of osteoclast markers, thereby promoting osteoclast differentiation and bone resorption. CONCLUSIONS: We identified TNA as a secreted protein that inhibits osteoclast differentiation and bone resorption. While, it potentially promoted early osteoblast differentiation from bioinformatic results. TNA may play a role in bone metabolism through the adipose-bone axis.
Assuntos
Tecido Adiposo , Biomarcadores , Diferenciação Celular , Lectinas Tipo C , Osteoclastos , Osteoporose , Biomarcadores/metabolismo , Tecido Adiposo/metabolismo , Humanos , Osteoporose/metabolismo , Osteoporose/genética , Diferenciação Celular/fisiologia , Osteoclastos/metabolismo , Lectinas Tipo C/metabolismo , Lectinas Tipo C/genética , Osso e Ossos/metabolismo , Osteogênese/fisiologia , Reabsorção Óssea/metabolismo , Reabsorção Óssea/genética , Osteoblastos/metabolismo , Adipogenia/fisiologia , Adipogenia/genética , Animais , Plaquetas/metabolismoRESUMO
BACKGROUND: Comprehensive analysis of clinical evidence for breast cancer adipogenesis with prognosis is lacking. This study aims to consolidate the latest evidence on the relationship between adipogenesis and breast cancer outcomes. DATA SOURCES: Medline, Web of Science, Embase, Scopus, Clinicaltrials.gov, Cochrane library. METHODS: A systematic review was conducted according to the PRISMA guidelines. Studies that reported the correlation between tumor adipogenesis and cancer recurrence or empirical pathological markers were included for meta-analysis. The standard reference for pathological markers determination was set as histopathological examination. The PROSPERO ID was CRD489135. RESULTS: Eleven studies were included in this systematic review and meta-analysis. Several adipogenesis biomarkers involved in the synthesis, elongation, and catabolism of fatty acids, such as FASN, Spot 14, pS6K1, lipin-1, PLIN2, Elovl6, and PPARγ, were identified as the potential biomarkers for predicting outcomes. Through meta-analysis, the predictive value of adipogenesis biomarkers for 5-year recurrence rate was calculated, with a pooled predictive risk ratio of 2.19 (95% CI: 1.11-4.34). In terms of empirical pathological markers, a negative correlation between adipogenesis biomarkers and ki-67 was observed (RR: 0.69, 95% CI: 0.61-0.79). However, no significant correlation was found between the adipogenesis and ER, PR, HER2, or p53 positivity. CONCLUSIONS: Biomarker of adipogenesis in breast cancer is a significant predictor of long-term recurrence, and this prediction is independent of HR, HER2, and ki-67. The diverse roles of adipogenesis in different breast cancer subtypes highlight the need for further research to uncover specific biomarkers that can used for diagnosis and prediction. PROTOCOL REGISTRATION: PROSPERO ID: CRD489135.
Assuntos
Adipogenia , Biomarcadores Tumorais , Neoplasias da Mama , Recidiva Local de Neoplasia , Humanos , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/diagnóstico , Feminino , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Biomarcadores Tumorais/metabolismo , Prognóstico , Perilipina-2/metabolismoRESUMO
BACKGROUND: Obesity poses a significant global health challenge, given its association with the excessive accumulation of adipose tissue (AT) and various systemic disruptions. Within the adipose microenvironment, expansion and enrichment with immune cells trigger the release of inflammatory mediators and growth factors, which can disrupt tissues, including bones. While obesity's contribution to bone loss is well established, the direct impact of obese AT on osteoblast maturation remains uncertain. This study aimed to explore the influence of the secretomes from obese and lean AT on osteoblast differentiation and activity. METHODS: SAOS-2 cells were exposed to the secretomes obtained by culturing human subcutaneous AT from individuals with obesity (OATS) or lean patients, and their effects on osteoblasts were evaluated. RESULTS: In the presence of the OATS, mature osteoblasts underwent dedifferentiation, showing an increased proliferation accompanied by a morphological shift towards a mesenchymal phenotype, with detrimental effects on osteogenic markers and the calcification capacity. Concurrently, the OATS promoted the expression of mesenchymal and adipogenic markers, inducing the formation of cytoplasmic lipid droplets in SAOS-2 cells exposed to an adipogenic differentiation medium. Additionally, TGF-ß1 emerged as a key mediator of these effects, as the OATS was enriched with this growth factor. CONCLUSIONS: Our findings demonstrate that obese subcutaneous AT promotes the dedifferentiation of osteoblasts and increases the adipogenic profile in these cells.
Assuntos
Adipogenia , Tecido Adiposo , Desdiferenciação Celular , Obesidade , Osteoblastos , Fenótipo , Transdução de Sinais , Fator de Crescimento Transformador beta1 , Humanos , Osteoblastos/metabolismo , Osteoblastos/patologia , Obesidade/patologia , Obesidade/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Secretoma/metabolismo , Diferenciação Celular , Proliferação de Células , Osteogênese , MasculinoRESUMO
Prostate apoptosis response-4 (Par-4, also known as PAWR) is a ubiquitously expressed tumor suppressor protein that induces apoptosis selectively in cancer cells, while leaving normal cells unaffected. Our previous studies indicated that genetic loss of Par-4 promoted hepatic steatosis, adiposity, and insulin-resistance in chow-fed mice. Moreover, low plasma levels of Par-4 are associated with obesity in human subjects. The mechanisms underlying obesity in rodents and humans are multi-faceted, and those associated with adipogenesis can be functionally resolved in cell cultures. We therefore used pluripotent mouse embryonic fibroblasts (MEFs) or preadipocyte cell lines responsive to adipocyte differentiation cues to determine the potential role of Par-4 in adipocytes. We report that pluripotent MEFs from Par-4-/- mice underwent rapid differentiation to mature adipocytes with an increase in lipid droplet accumulation relative to MEFs from Par-4+/+ mice. Knockdown of Par-4 in 3T3-L1 pre-adipocyte cultures by RNA-interference induced rapid differentiation to mature adipocytes. Interestingly, basal expression of PPARγ, a master regulator of de novo lipid synthesis and adipogenesis, was induced during adipogenesis in the cell lines, and PPARγ induction and adipogenesis caused by Par-4 loss was reversed by replenishment of Par-4. Mechanistically, Par-4 downregulates PPARγ expression by directly binding to its upstream promoter, as judged by chromatin immunoprecipitation and luciferase-reporter studies. Thus, Par-4 transcriptionally suppresses the PPARγ promoter to regulate adipogenesis.
Assuntos
Células 3T3-L1 , Adipócitos , Adipogenia , Proteínas Reguladoras de Apoptose , PPAR gama , Animais , PPAR gama/metabolismo , PPAR gama/genética , Adipogenia/genética , Camundongos , Adipócitos/metabolismo , Adipócitos/citologia , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Reguladoras de Apoptose/genética , Diferenciação Celular , Humanos , Transcrição Gênica , Regiões Promotoras Genéticas/genética , Fibroblastos/metabolismoRESUMO
Epithelial-to-mesenchymal transition (EMT) plays a major role in breast cancer progression and the development of drug resistance. We have previously demonstrated a trans-differentiation therapeutic approach targeting invasive dedifferentiated cancer cells. Using a combination of PPARγ agonists and MEK inhibitors, we forced the differentiation of disseminating breast cancer cells into post-mitotic adipocytes. Utilizing murine breast cancer cells, we demonstrated a broad class effect of PPARγ agonists and MEK inhibitors in inducing cancer cell trans-differentiation into adipocytes. Both Rosiglitazone and Pioglitazone effectively induced adipogenesis in cancer cells, marked by PPARγ and C/EBPα upregulation, cytoskeleton rearrangement, and lipid droplet accumulation. All tested MEK inhibitors promoted adipogenesis in the presence of TGFß, with Cobimetinib showing the most prominent effects. A metastasis ex vivo culture from a patient diagnosed with triple-negative breast cancer demonstrated a synergistic upregulation of PPARγ with the combination of Pioglitazone and Cobimetinib. Our results highlight the potential for new therapeutic strategies targeting cancer cell plasticity and the dedifferentiation phenotype in aggressive breast cancer subtypes. Combining differentiation treatments with standard therapeutic approaches may offer a strategy to overcome drug resistance.
Assuntos
Diferenciação Celular , PPAR gama , Pioglitazona , PPAR gama/metabolismo , PPAR gama/agonistas , Humanos , Animais , Camundongos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Pioglitazona/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adipogenia/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Rosiglitazona/farmacologia , Azetidinas/farmacologia , Neoplasias da Mama/patologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Piperidinas/farmacologiaRESUMO
Embryonic stem cells are crucial for studying developmental biology due to their self-renewal and pluripotency capabilities. This research investigates the differentiation of mouse ESCs into adipocytes, offering insights into obesity and metabolic disorders. Using a monolayer differentiation approach over 30 days, lipid accumulation and adipogenic markers, such as Cebpb, Pparg, and Fabp4, confirmed successful differentiation. RNA sequencing revealed extensive transcriptional changes, with over 15,000 differentially expressed genes linked to transcription regulation, cell cycle, and DNA repair. This study utilized Robust Rank Aggregation to identify critical regulatory genes like PPARG, CEBPA, and EP300. Network analysis further highlighted Atf5, Ccnd1, and Nr4a1 as potential key players in adipogenesis and its mature state, validated through RT-PCR. While key adipogenic factors showed plateaued expression levels, suggesting early differentiation events, this study underscores the value of ESCs in modeling adipogenesis. These findings contribute to our understanding of adipocyte differentiation and have significant implications for therapeutic strategies targeting metabolic diseases.
Assuntos
Adipócitos , Adipogenia , Diferenciação Celular , Células-Tronco Embrionárias Murinas , Animais , Adipogenia/genética , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Células-Tronco Embrionárias Murinas/citologia , Diferenciação Celular/genética , Adipócitos/metabolismo , Adipócitos/citologia , PPAR gama/metabolismo , PPAR gama/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/genética , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Transcrição Gênica , Regulação da Expressão GênicaRESUMO
The global obesity epidemic, exacerbated by the sedentary lifestyle fostered by the COVID-19 pandemic, presents a growing socioeconomic burden due to decreased physical activity and increased morbidity. Current obesity treatments show promise, but they often come with expensive medications, frequent injections, and potential side effects, with limited success in improving obesity through increased energy expenditure. This study explores the potential of a refined sulfated polysaccharide (SPSL), derived from the brown seaweed Scytosiphon lomentaria (SL), as a safe and effective anti-obesity treatment by promoting energy expenditure. Chemical characterization revealed that SPSL, rich in sulfate and L-fucose content, comprises nine distinct sulfated glycan structures. In vitro analysis demonstrated potent anti-lipogenic properties in adipocytes, mediated by the downregulation of key adipogenic modulators, including 5' adenosine monophosphate-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor γ (PPARγ) pathways. Inhibiting AMPK attenuated the anti-adipogenic effects of SPSL, confirming its involvement in the mechanism of action. Furthermore, in vivo studies using zebrafish models showed that SPSL increased energy expenditure and reduced lipid accumulation. These findings collectively highlight the therapeutic potential of SPSL as a functional food ingredient for mitigating obesity-related metabolic dysregulation by promoting energy expenditure. Further mechanistic and preclinical investigations are warranted to fully elucidate its mode of action and evaluate its efficacy in obesity management, potentially offering a novel, natural therapeutic avenue for this global health concern.
Assuntos
Adipogenia , Metabolismo Energético , Fucose , Alimento Funcional , Obesidade , Polissacarídeos , Alga Marinha , Peixe-Zebra , Animais , Metabolismo Energético/efeitos dos fármacos , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Polissacarídeos/química , Polissacarídeos/farmacologia , Alga Marinha/química , Fucose/metabolismo , Adipogenia/efeitos dos fármacos , Camundongos , Adipócitos/metabolismo , Adipócitos/efeitos dos fármacos , Humanos , Sulfatos/química , Sulfatos/metabolismo , PPAR gama/metabolismo , Fármacos Antiobesidade/farmacologia , Fármacos Antiobesidade/química , Fármacos Antiobesidade/uso terapêutico , Células 3T3-L1 , Proteínas Quinases Ativadas por AMP/metabolismoRESUMO
Cell identities are defined by intrinsic transcriptional networks and spatio-temporal environmental factors. Here, we explored multiple factors that contribute to the identity of adipose stem cells, including anatomic location, microvascular neighborhood, and sex. Our data suggest that adipose stem cells serve a dual role as adipocyte precursors and fibroblast-like cells that shape the adipose tissue's extracellular matrix in an organotypic manner. We further find that adipose stem cells display sexual dimorphism regarding genes involved in estrogen signaling, homeobox transcription factor expression and the renin-angiotensin-aldosterone system. These differences could be attributed to sex hormone effects, developmental origin, or both. Finally, our data demonstrate that adipose stem cells are distinct from mural cells, and that the state of commitment to adipogenic differentiation is linked to their anatomic position in the microvascular niche. Our work supports the importance of sex and microvascular function in adipose tissue physiology.
Assuntos
Adipócitos , Tecido Adiposo , Fibroblastos , Caracteres Sexuais , Células-Tronco , Animais , Feminino , Adipócitos/citologia , Adipócitos/metabolismo , Masculino , Tecido Adiposo/citologia , Tecido Adiposo/metabolismo , Fibroblastos/metabolismo , Fibroblastos/citologia , Células-Tronco/metabolismo , Células-Tronco/citologia , Camundongos , Diferenciação Celular , Adipogenia/genética , Camundongos Endogâmicos C57BL , Matriz Extracelular/metabolismo , HumanosRESUMO
OBJECTIVE: Alternative polyadenylation (APA) is a co-transcriptional process that leads to isoform diversity in the 3' ends of mRNAs. APA is known to occur during differentiation, and its dysregulation is observed in diseases like cancer and autoimmune disorders. It has been previously reported that differentiation of 3T3-L1 cells to adipocytes leads to an overall lengthening of mRNAs, but the proteins involved in this regulation have not been identified. The expression levels of subunits of the cleavage and polyadenylation (C/P) complex can regulate the choice of poly(A) site, which in turn can affect different cellular activities. In this paper, we studied the change in levels of C/P proteins during 3T3-L1 differentiation. RESULTS: We observed that while the RNA expression of these proteins is unchanged during differentiation, the protein levels of some subunits do change, including a decrease in levels of CPSF73, the nuclease that cuts at the poly(A) site. However, overexpression of CPSF73 alone does not affect the efficiency and rate of differentiation.
Assuntos
Células 3T3-L1 , Adipogenia , Diferenciação Celular , Animais , Camundongos , Adipogenia/genética , Poliadenilação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Adipócitos/metabolismo , Fator de Especificidade de Clivagem e Poliadenilação/metabolismo , Fator de Especificidade de Clivagem e Poliadenilação/genéticaRESUMO
Arctigenin (Ar) is a promising therapeutic candidate for postmenopausal osteoporosis (PMOP). This study explores its mechanism by examining its effects on adipogenesis and osteogenesis in ovariectomized (OVX) rats. In vitro, Ar effectively suppressed the adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) from OVX rats, reducing lipid droplet formation and downregulating proteins associated with lipid synthesis. In vivo, Ar treatment significantly reduced bone loss, inhibited adipocyte development, improved lipid metabolism, and promoted bone formation in OVX rats. Mechanistically, Ar inhibited the phosphorylation of Mitogen-Activated Protein Kinase 1 (MEK1), downregulated Peroxisome Proliferator-Activated Receptor gamma (PPARγ), promoted the accumulation of ß-catenin in the nucleus, and prevented the direct binding of PPARγ to ß-catenin in BMSCs. This regulation of the PPARγ/Wnt signaling axis underlies its dual role in inhibiting adipogenesis and promoting osteogenesis. Notably, co-treatment with rosiglitazone (RGZ) reversed the effects of Ar on adipogenesis and osteogenesis without affecting MEK1 inhibition. These findings offer valuable insights into arctigenin's potential as a therapeutic strategy for PMOP by modulating MEK1 signaling and regulating the PPARγ/Wnt axis.
Assuntos
Adipogenia , Furanos , Lignanas , MAP Quinase Quinase 1 , Células-Tronco Mesenquimais , Osteogênese , Ovariectomia , PPAR gama , Ratos Sprague-Dawley , Via de Sinalização Wnt , beta Catenina , Animais , PPAR gama/metabolismo , Osteogênese/efeitos dos fármacos , Feminino , Adipogenia/efeitos dos fármacos , Lignanas/farmacologia , Lignanas/química , Ratos , Via de Sinalização Wnt/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Furanos/farmacologia , Furanos/química , MAP Quinase Quinase 1/metabolismo , beta Catenina/metabolismo , Medula Óssea/metabolismo , Medula Óssea/efeitos dos fármacos , HumanosRESUMO
The ratio of free fatty acid (FFA) turnover decreases significantly with the expansion of white adipose tissue. Adipose tissue and dietary saturated fatty acid levels significantly correlate with an increase in fat cell size and number. The G0/G1 switch gene 2 increases lipid content in adipocytes and promotes adipocyte hypertrophy through the restriction of triglyceride (triacylglycerol: TAG) turnover. Hypoxia in obese adipose tissue due to hypertrophic adipocytes results in excess deposition of extracellular matrix (ECM) components. Cluster of differentiation (CD) 44, as the main receptor of the extracellular matrix component regulates cell-cell and cell-matrix interactions including diet-induced insulin resistance. Excess TAGs, sterols, and sterol esters are surrounded by the phospholipid monolayer surface and form lipid droplets (LDs). Once LDs are formed, they grow up because of the excessive amount of intracellular FFA stored and reach a final size. The ratio of FFA turnover/lipolysis decreases significantly with increases in the degree of obesity. Dysfunctional adipose tissue is unable to expand further to store excess dietary lipids, increased fluxes of plasma FFAs lead to ectopic fatty acid deposition and lipotoxicity. Reduced neo-adipogenesis and dysfunctional lipid-overloaded adipocytes are hallmarks of hypertrophic obesity linked to insulin resistance. Obesity-associated adipocyte death exhibits feature of necrosis-like programmed cell death. Adipocyte death is a prerequisite for the transition from hypertrophic to hyperplastic obesity. Increased adipocyte number in obesity has life-long effects on white adipose tissue mass. The positive correlation between the adipose tissue volume and magnetic resonance imaging proton density fat fraction estimation is used for characterization of the obesity phenotype, as well as the risk stratification and selection of appropriate treatment strategies. In obese patients with type 2 diabetes, visceral adipocytes exposed to chronic/intermittent hyperglycemia develop a new microRNAs' (miRNAs') expression pattern. Visceral preadipocytes memorize the effect of hyperglycemia via changes in miRNAs' expression profile and contribute to the progression of diabetic phenotype. Nonsteroidal anti-inflammatory drugs, metformin, and statins can be beneficial in treating the local or systemic consequences of white adipose tissue inflammation. Rapamycin inhibits leptin-induced LD formation. Collectively, in this chapter, the concept of adipose tissue remodeling in response to adipocyte death or adipogenesis, and the complexity of LD interactions with the other cellular organelles are reviewed. Furthermore, clinical perspective of fat cell turnover in obesity is also debated.