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1.
PLoS One ; 19(1): e0292013, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38271326

RESUMO

AIM: Radiation-induced fibrosis is a recognised consequence of radiotherapy, especially after multiple and prolonged dosing regimens. There is no definitive treatment for late-stage radiation-induced fibrosis, although the use of autologous fat transfer has shown promise. However, the exact mechanisms by which this improves radiation-induced fibrosis remain poorly understood. We aim to explore existing literature on the effects of autologous fat transfer on both in-vitro and in-vivo radiation-induced fibrosis models, and to collate potential mechanisms of action. METHOD: PubMed, Cochrane reviews and Scopus electronic databases from inception to May 2023 were searched. Our search strategy combined both free-text terms with Boolean operators, derived from synonyms of adipose tissue and radiation-induced fibrosis. RESULTS: The search strategy produced 2909 articles. Of these, 90 underwent full-text review for eligibility, yielding 31 for final analysis. Nine conducted in-vitro experiments utilising a co-culture model, whilst 25 conducted in-vivo experiments. Interventions under autologous fat transfer included adipose-derived stem cells, stromal vascular function, whole fat and microfat. Notable findings include downregulation of fibroblast proliferation, collagen deposition, epithelial cell apoptosis, and proinflammatory processes. Autologous fat transfer suppressed hypoxia and pro-inflammatory interferon-γ signalling pathways, and tissue treated with adipose-derived stem cells stained strongly for anti-inflammatory M2 macrophages. Although largely proangiogenic initially, studies show varying effects on vascularisation. There is early evidence that adipose-derived stem cell subgroups may have different functional properties. CONCLUSION: Autologous fat transfer functions through pro-angiogenic, anti-fibrotic, immunomodulatory, and extracellular matrix remodelling properties. By characterising these mechanisms, relevant drug targets can be identified and used to further improve clinical outcomes in radiation-induced fibrosis. Further research should focus on adipose-derived stem cell sub-populations and augmentation techniques such as cell-assisted lipotransfer.


Assuntos
Tecido Adiposo , Síndrome da Fibrose por Radiação , Humanos , Adipócitos/fisiologia , Transplante Autólogo , Fibrose
2.
Nat Rev Endocrinol ; 19(11): 626-638, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37587198

RESUMO

Adipose tissue is a dynamic component of the bone marrow, regulating skeletal remodelling and secreting paracrine and endocrine factors that can affect haematopoiesis, as well as potentially nourishing the bone marrow during periods of stress. Bone marrow adipose tissue is regulated by multiple factors, but particularly nutrient status. In this Review, we examine how bone marrow adipocytes originate, their function in normal and pathological states and how bone marrow adipose tissue modulates whole-body homoeostasis through actions on bone cells, haematopoietic stem cells and extra-medullary adipocytes during nutritional challenges. We focus on both rodent models and human studies to help understand the unique marrow adipocyte, its response to the external nutrient environment and its effects on the skeleton. We finish by addressing some critical questions that to date remain unanswered.


Assuntos
Tecido Adiposo , Células da Medula Óssea , Medula Óssea , Humanos , Adipócitos/fisiologia , Medula Óssea/patologia , Medula Óssea/fisiologia , Células da Medula Óssea/fisiologia , Obesidade/patologia , Redução de Peso
3.
Int Immunopharmacol ; 121: 110467, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37348228

RESUMO

Recently, emerging evidence has shown that LncRNA MEG3 is involved in adipocyte inflammation and insulin resistance progression, however, the specific mechanism of action remains unclear. In this study, we found that LncRNA MEG3 expression was increased in TNF-α stimulated 3T3-L1 mature adipocytes, and inflammatory factors IL-6 and MCP-1 secretion levels were increased, cell apoptosis and caspase3 activity was enhanced, ROS content was increased, and iNOS protein expression was increased. Moreover, TNF-α treatment attenuated glucose uptake, promoted triglyceride accumulation, inhibited GLUT4 protein expression at the plasma membrane, and reduced the phosphorylation levels of AMPK and ACC in the cells. Interestingly, we found that transfection of si-MEG3 reversed TNF-α caused inflammatory injury and insulin resistance of 3T3-L1 mature adipocytes. Next, we found that IGF2BP2 is an RNA binding protein of LncRNA MGE3 and transfection of si-IGF2BP2 reversed TNF-α caused inflammatory injury and insulin resistance in 3T3-L1 mature adipocytes, the same effects as transfection of si-MEG3. Mechanistically, LncRNA MGE3 was able to aggravate adipocyte inflammatory injury and dysregulation of insulin sensitivity by activating TLR4 pathway through upregulating the protein expression of IGF2BP2. In vivo findings showed that HFD mice with knockdown of MEG3 had reduced body weight, lower glucose concentrations and insulin levels in plasma, decreased inflammatory factors secretion, and reduced MEG3 and IGF2BP2 expression in epididymal adipose tissues and reduced fat accumulation in mice compared with HFD mice. Our results indicate that LncRNA MEG3 can aggravate chronic inflammation and insulin resistance in adipocytes by activating TLR4/NF-κB signaling pathway via targeting IGF2BP2.


Assuntos
Resistência à Insulina , RNA Longo não Codificante , Animais , Camundongos , Células 3T3-L1 , Adipócitos/fisiologia , Inflamação/metabolismo , NF-kappa B/metabolismo , RNA Longo não Codificante/metabolismo , Transdução de Sinais , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
4.
Anim Biotechnol ; 34(8): 3708-3717, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37149785

RESUMO

Intramuscular fat (IMF) positively influences various aspects of meat quality, while the subcutaneous fat (SF) has negative effect on carcass characteristics and fattening efficiency. Peroxisome proliferator-activated receptor gamma (PPARγ) is a key regulator of adipocyte differentiation, herein, through bioinformatic screen for the potential regulators of adipogenesis from two independent microarray datasets, we identified that PPARγ is a potentially regulator between porcine IMF and SF adipogenesis. Then we treated subcutaneous preadipocytes (SA) and intramuscular preadipocytes (IMA) of pig with RSG (1 µmol/L), and we found that RSG treatment promoted the differentiation of IMA via differentially activating PPARγ transcriptional activity. Besides, RSG treatment promoted apoptosis and lipolysis of SA. Meanwhile, by the treatment of conditioned medium, we excluded the possibility of indirect regulation of RSG from myocyte to adipocyte and proposed that AMPK may mediate the RSG-induced differential activation of PPARγ. Collectively, the RSG treatment promotes IMA adipogenesis, and advances SA lipolysis, this effect may be associated with AMPK-mediated PPARγ differential activation. Our data indicates that targeting PPARγ might be an effective strategy to promote intramuscular fat deposition while reduce subcutaneous fat mass of pig.


Assuntos
Adipogenia , PPAR gama , Suínos , Animais , Adipogenia/fisiologia , Rosiglitazona/farmacologia , PPAR gama/genética , Proteínas Quinases Ativadas por AMP/farmacologia , Adipócitos/fisiologia , Diferenciação Celular
6.
Plast Reconstr Surg ; 152(5): 1036-1046, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36912938

RESUMO

BACKGROUND: Lipedema, diagnosed most often in women, is a progressive disease characterized by the disproportionate and symmetrical distribution of adipose tissue, primarily in the extremities. Although numerous results from in vitro and in vivo studies have been published, many questions regarding the pathology and genetic background of lipedema remain unanswered. METHODS: In this study, adipose tissue-derived stromal/stem cells were isolated from lipoaspirates derived from nonobese and obese donors with or without lipedema. Growth and morphology, metabolic activity, differentiation potential, and gene expression were evaluated using quantification of lipid accumulation, metabolic activity assay, live-cell imaging, reverse transcription polymerase chain reaction, quantitative polymerase chain reaction, and immunocytochemical staining. RESULTS: The adipogenic potential of lipedema and nonlipedema adipose tissue-derived stromal/stem cells did not rise in parallel with the donors' body mass index and did not differ significantly between groups. However, in vitro differentiated adipocytes from nonobese lipedema donors showed significant upregulation of adipogenic gene expression compared with nonobese controls. All other genes tested were expressed equally in lipedema and nonlipedema adipocytes. The adiponectin/leptin ratio was significantly reduced in adipocytes from obese lipedema donors compared with their nonobese lipedema counterparts. Increased stress fiber-integrated smooth muscle actin was visible in lipedema adipocytes compared with nonlipedema controls and appeared enhanced in adipocytes from obese lipedema donors. CONCLUSIONS: Not only lipedema per se but also body mass index of donors affect adipogenic gene expression substantially in vitro. The significantly reduced adiponectin/leptin ratio and the increased occurrence of myofibroblast-like cells in obese lipedema adipocyte cultures underscores the importance of attention to the co-occurrence of lipedema and obesity. These are important findings toward accurate diagnosis of lipedema. CLINICAL RELEVANCE STATEMENT: Our study highlights not only the difficulty in lipedema diagnostics but also the tremendous need for further studies on lipedema tissue. Although lipedema might seem to be an underestimated field in plastic and reconstructive surgery, the power it holds to provide better treatment to future patients can not be promoted enough.


Assuntos
Leptina , Lipedema , Humanos , Feminino , Leptina/metabolismo , Lipedema/diagnóstico , Lipedema/patologia , Adiponectina/metabolismo , Adipócitos/fisiologia , Obesidade/complicações , Células Cultivadas
7.
Front Immunol ; 14: 1083191, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36936928

RESUMO

Although the adipose tissue (AT) is a central metabolic organ in the regulation of whole-body energy homeostasis, it is also an important endocrine and immunological organ. As an endocrine organ, AT secretes a variety of bioactive peptides known as adipokines - some of which have inflammatory and immunoregulatory properties. As an immunological organ, AT contains a broad spectrum of innate and adaptive immune cells that have mostly been studied in the context of obesity. However, overwhelming evidence supports the notion that AT is a genuine immunological effector site, which contains all cell subsets required to induce and generate specific and effective immune responses against pathogens. Indeed, AT was reported to be an immune reservoir in the host's response to infection, and a site of parasitic, bacterial and viral infections. In addition, besides AT's immune cells, preadipocytes and adipocytes were shown to express innate immune receptors, and adipocytes were reported as antigen-presenting cells to regulate T-cell-mediated adaptive immunity. Here we review the current knowledge on the role of AT and AT's immune system in host defense against pathogens. First, we will summarize the main characteristics of AT: type, distribution, function, and extraordinary plasticity. Second, we will describe the intimate contact AT has with lymph nodes and vessels, and AT immune cell composition. Finally, we will present a comprehensive and up-to-date overview of the current research on the contribution of AT to host defense against pathogens, including the respiratory viruses influenza and SARS-CoV-2.


Assuntos
COVID-19 , Imunidade Inata , Humanos , SARS-CoV-2 , Tecido Adiposo , Adipócitos/fisiologia
8.
Anim Biotechnol ; 34(8): 3589-3598, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36866843

RESUMO

TEA domain transcription factor 1 (TEAD1), also called TEF-1, acts as a transcriptional enhancer to regulate muscle-specific gene expression. However, the role of TEAD1 in regulating intramuscular preadipocyte differentiation in goats is unclear. The aim of this study was to obtain the sequence of TEAD1 gene and elucidate the effect of TEAD1 on goat intramuscular preadipocyte differentiation in vitro and its possible mechanism. The results showed that the goat TEAD1 gene CDS region sequence was 1311 bp. TEAD1 gene was widely expressed in goat tissues, with the highest expression in brachial triceps (p < 0.01). The expression of TEAD1 gene in goat intramuscular adipocytes at 72 h was extremely significantly higher than that at 0 h (p < 0.01). Overexpression of goat TEAD1 inhibited the accumulation of lipid droplets in goat intramuscular adipocyte. The relative expression of differentiation marker genes SREBP1, PPARγ, C/EBPß were significantly down-regulated (all p < 0.01), but PREF-1 was significantly up-regulated (p < 0.01). Binding analysis showed that there were multiple binding sites between the DNA binding domain of goat TEAD1 and the promoter binding region of SREBP1, PPARγ, C/EBPß and PREF-1. In conclusion, TEAD1 negatively regulates the differentiation of goat intramuscular preadipocytes.


Assuntos
Cabras , Fatores de Transcrição de Domínio TEA , Animais , Cabras/fisiologia , PPAR gama/metabolismo , Adipócitos/fisiologia , Músculo Esquelético/metabolismo , Diferenciação Celular/genética , Adipogenia/genética
9.
Anim Biotechnol ; 34(4): 1196-1208, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34939903

RESUMO

Fibroblast growth factor 1(FGF1) has been proved to bind to specific signal molecules and activate intracellular signal transduction, leading to proliferation or differentiation of cells. However, the role of FGF1 in goat adipocytes is still unclear. Here, we investigated its role in lipogenesis of goats, which depends on the activation of FGFRs. In goat intramuscular and subcutaneous adipocytes, we observed that adipocytes accumulation was inhibited by interfering of FGF1, the expression of C/EBPα, C/EBPß, LPL, Pref-1, PPARγ, AP2, KLF4, KLF6, KLF10 and KLF17 were significantly down-regulated (p < 0.05). When the FGF1 was up-regulated, the opposite result was found, while the expression of C/EBPß, LPL, PPARγ, SREBP1, AP2, KLF4, KLF7, KLF15, KLF16 and KLF17 were increased significantly (p < 0.05) in goat intramuscular and subcutaneous adipocytes. The expression level of FGFR1 was significantly and decreased with the interference of FGF1, and increased with the overexpression of FGF1. But in goat subcutaneous adipocytes, only the expression of FGFR2 was consistent with the expression of FGF1. Interference methods confirmed that FGFR1 or FGFR2 and FGF1 have the similarly promoting function in adipocytes differentiation. With the co-transfection technology, we confirmed that FGF1 promoted the differentiation of intramuscular and subcutaneous adipocytes might via FGFR1 or FGFR2, respectively.


Assuntos
Fator 1 de Crescimento de Fibroblastos , Cabras , Animais , Fator 1 de Crescimento de Fibroblastos/genética , Fator 1 de Crescimento de Fibroblastos/metabolismo , Cabras/fisiologia , PPAR gama/metabolismo , Diferenciação Celular/fisiologia , Adipócitos/fisiologia
10.
Anim Biotechnol ; 34(2): 268-279, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34346296

RESUMO

Intramuscular fat is positively related to meat quality including tenderness, flavor, and juiciness. Long noncoding RNA (LncRNA) plays a vital role in regulating adipogenesis. However, it is largely unknown about lncRNAs associated with porcine intramuscular adipocyte adipogenesis. In the present study, we focus on a novel LncRNA, which is named lncIMF2, associated with adipogenesis by our previous RNA-sequence analysis and bioinformatics analysis. We demonstrated LncIMF2 knockdown inhibited the proliferation of porcine intramuscular adipocytes while expression of cell cycle-related genes was decreased. Besides, we found LncIMF2 knockdown inhibited expression of adipogenic differentiation marker genes including PPARγ (Peroxisome proliferator-activated reporter gamma) and ATGL (Adipose triglyceride lipase). Similarly, overexpression of LncIMF2 promotes proliferation and differentiation of porcine intramuscular preadipocytes. Moreover, we proved that IncIMF2 acts as a molecular sponge for MicroRNA-217 (miR-217), which has been found associated with adipogenesis, thereby affecting the expression of the miR-217 target gene. Collectively, our findings will contribute to a deeper understanding of the role of LncRNA in pig IMF deposition for the improvement of meat quality.


Assuntos
MicroRNAs , RNA Longo não Codificante , Suínos , Animais , Adipogenia/genética , RNA Longo não Codificante/metabolismo , Diferenciação Celular/genética , Adipócitos/fisiologia , MicroRNAs/genética
11.
Anim Biotechnol ; 34(7): 2736-2744, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36001396

RESUMO

Intramuscular fat (IMF) content is one of the most significant factors influencing beef quality in terms of tenderness, flavor, and juiciness. Thus, internal factors affecting IMF deposition have received considerable attention for decades. In this study, we demonstrated a long non-coding RNA, lnc210, promoted adipogenic differentiation of buffalo intramuscular adipocytes. lnc210 was rich in adipose tissue and showed increased expression with the adipogenic differentiation of buffalo intramuscular adipocytes. lnc210 was mainly expressed in the nucleus of adipocytes. Full-length lnc210 was obtained by rapid amplification of cDNA ends technology. lnc210 overexpression promoted lipid accumulation by upregulating the mRNA expression of peroxisome proliferator-activated receptor gamma (PPARG) and CCAAT enhancer binding protein alpha (C/EBPα) in buffalo intramuscular adipocytes. These results provide a basis for an in-depth analysis of the role of lnc210 in accelerating IMF deposition in buffaloes.


Assuntos
Búfalos , RNA Longo não Codificante , Bovinos , Animais , Búfalos/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Adipócitos/fisiologia , Adipogenia/genética , Tecido Adiposo , Diferenciação Celular/genética
12.
Anim Biotechnol ; 34(7): 3216-3236, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36200856

RESUMO

Intramuscular fat (IMF) is closely related to the meat quality of livestock and poultry. As a new cell culture technique in vitro, cell co-culture has been gradually applied to the related research of IMF formation because it can simulate the changes of microenvironment in vivo during the process of IMF cell formation. In the co-culture model, in addition to studying the effects of skeletal muscle cells on the proliferation and differentiation of IMF, we can also consider the role of many secretion factors in the formation of IMF, thus making the cell research in vitro closer to the real level in vivo. This paper reviewed the generation and origin of IMF, summarized the existing co-culture methods and systems, and discussed the advantages and disadvantages of each method as well as the challenges faced in the establishment of the system, with emphasis on the current status of research on the formation of IMF for human and animal based on co-culture technology.


Assuntos
Adipócitos , Adipogenia , Humanos , Animais , Técnicas de Cocultura , Adipócitos/fisiologia , Diferenciação Celular , Carne , Músculo Esquelético/fisiologia , Tecido Adiposo/fisiologia
13.
Plast Reconstr Surg ; 151(5): 1005-1015, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36534068

RESUMO

BACKGROUND: The pathophysiology of adipose proliferation or differentiation in extremity lymphedema has not been thoroughly studied. This study investigated the impacts of the lymph harvested from lymphedematous limbs on the adipogenesis of adipose-derived stem cells (ASCs). METHODS: ASCs were isolated from the adipose tissue of normal extremities and cultured with lymph collected from Cheng lymphedema grade III to IV patients or adipogenic differentiation medium (ADM) and further subjected to differentiation and proliferation assay. The expression of adipogenesis genes was examined by real-time polymerase chain reaction to investigate the effect of lymph on ASCs. The level of adipogenic cytokines in the lymph was also evaluated. RESULTS: The adipocytes were significantly larger in lymphedema fat tissue compared with that in normal fat tissues ( P < 0.00). The adipogenesis of ASCs cultured in lymph was significantly enhanced compared with in ADM ( P = 0.008) on day 10, suggesting that the adipogenesis of ASCs was promoted under the lymph-cultured environment. The expression of adipogenesis genes, peroxisome proliferator-activated receptor ( P = 0.02), CAAT/enhancer-binding protein α ( P = 0.008); fatty-acid binding protein ( P = 0.004), and lipoprotein lipase ( P = 0.003), was statistically elevated when the ASCs were cultured with lymph. The insulin content in lymph was statistically higher in lymph ( P < 0.001) than in plasma. CONCLUSIONS: The adipogenesis of ASCs was promoted under the lymph-cultured environment with statistically increased adipogenesis genes of peroxisome proliferator-activated receptor, CAAT/enhancer-binding protein α, fatty-acid binding protein, and lipoprotein lipase. The excess lymph accumulated in the lymphedematous extremity contained a greater insulin/insulin-like growth factor-2. These adipogenic factors promoted the expression of early adipogenesis genes and led ASCs to undergo adipogenesis and differentiated into adipocytes. CLINICAL RELEVANCE STATEMENT: The accumulation of adipose tissue in the lymphedema region was contributed from the content of excess lymph.


Assuntos
Insulinas , Linfedema , Humanos , Adipogenia/fisiologia , Lipase Lipoproteica/metabolismo , Lipase Lipoproteica/farmacologia , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/farmacologia , Adipócitos/fisiologia , Tecido Adiposo , Diferenciação Celular/genética , Células-Tronco/fisiologia , Insulinas/metabolismo , Insulinas/farmacologia , Células Cultivadas
14.
Adv Mater ; 35(8): e2207686, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36502507

RESUMO

Obesity treatment is a global public health challenge due to inadequate weight loss and weight regain even after endeavors with multimodal treatments. Considering the abundance of resident macrophages in adipose tissues, precise regulation of the interactions between macrophages and adipocytes may provide chances for immunotherapy of obesity. Herein, inspired by the phagocytosis of macrophages to clear apoptotic cells in homeostasis, an immunotherapy strategy for obesity treatment is proposed for the first time through apoptotic camouflage of adipocytes by PA Au BPs to activate macrophages for clearance, where PA Au BPs are gold nanobipyramids engineered with adipose-targeting and apoptotic cell-mimicking functions. During clearance, the macrophage is switched from pro-inflammatory M1 to anti-inflammatory M2, remarkably modulating the immune microenvironment of adipose tissues to prevent weight regain. After inguinal injection with PA Au BPs, the body weights of obese mice are effectively decreased by 24.4% and can be decreased by 33.3% when combined with photothermal lipolysis, and little weight regain is associated with these treatments. This study demonstrates that the strategy of camouflaging adipocytes with apoptotic features holds great potential for obesity immunotherapy.


Assuntos
Adipócitos , Tecido Adiposo , Animais , Camundongos , Adipócitos/fisiologia , Obesidade , Aumento de Peso , Imunoterapia , Camundongos Endogâmicos C57BL
15.
Nat Metab ; 4(12): 1684-1696, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36443525

RESUMO

Childhood obesity is a serious public health crisis and a critical factor that determines future obesity prevalence. Signals affecting adipocyte development in early postnatal life have a strong potential to trigger childhood obesity; however, these signals are still poorly understood. We show here that mitochondrial (mt)RNA efflux stimulates transcription of nuclear-encoded genes for mitobiogenesis and thermogenesis in adipocytes of young mice and human infants. While cytosolic mtRNA is a potential trigger of the interferon (IFN) response, young adipocytes lack such a response to cytosolic mtRNA due to the suppression of IFN regulatory factor (IRF)7 expression by vitamin D receptor signalling. Adult and obese adipocytes, however, strongly express IRF7 and mount an IFN response to cytosolic mtRNA. In turn, suppressing IRF7 expression in adult adipocytes restores mtRNA-induced mitobiogenesis and thermogenesis and eventually mitigates obesity. Retrograde mitochondrion-to-nucleus signalling by mtRNA is thus a mechanism to evoke thermogenic potential during early adipocyte development and to protect against obesity.


Assuntos
Adipócitos Bege , Obesidade Pediátrica , Criança , Adulto , Humanos , Animais , Camundongos , Adipócitos Bege/metabolismo , RNA Mitocondrial/metabolismo , Adipócitos/fisiologia , Transdução de Sinais
16.
Proc Natl Acad Sci U S A ; 119(33): e2204470119, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35939672

RESUMO

Most mammalian cells have an intrinsic circadian clock that coordinates metabolic activity with the daily rest and wake cycle. The circadian clock is known to regulate cell differentiation, but how continuous daily oscillations of the internal clock can control a much longer, multiday differentiation process is not known. Here, we simultaneously monitor circadian clock and adipocyte-differentiation progression live in single cells. Strikingly, we find a bursting behavior in the cell population whereby individual preadipocytes commit to differentiate primarily during a 12-h window each day, corresponding to the time of rest. Daily gating occurs because cells irreversibly commit to differentiate within only a few hours, which is much faster than the rest phase and the overall multiday differentiation process. The daily bursts in differentiation commitment result from a differentiation-stimulus driven variable and slow increase in expression of PPARG, the master regulator of adipogenesis, overlaid with circadian boosts in PPARG expression driven by fast, clock-driven PPARG regulators such as CEBPA. Our finding of daily bursts in cell differentiation only during the circadian cycle phase corresponding to evening in humans is broadly relevant, given that most differentiating somatic cells are regulated by the circadian clock. Having a restricted time each day when differentiation occurs may open therapeutic strategies to use timed treatment relative to the clock to promote tissue regeneration.


Assuntos
Adipócitos , Adipogenia , Relógios Circadianos , Ritmo Circadiano , PPAR gama , Adipócitos/citologia , Adipócitos/fisiologia , Adipogenia/genética , Adipogenia/fisiologia , Animais , Relógios Circadianos/genética , Relógios Circadianos/fisiologia , Ritmo Circadiano/genética , Ritmo Circadiano/fisiologia , Humanos , Camundongos , PPAR gama/genética , PPAR gama/metabolismo
18.
Food Chem Toxicol ; 161: 112842, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35101577

RESUMO

In vitro models of adipogenesis are phenotypic assays that most closely mimic the increase of adipose tissue in obesity. Current models, however, often lack throughput and sensitivity and even report conflicting data regarding adipogenic potencies of many chemicals. Here, we describe a ten-day long adipogenesis model using high content analysis readouts for adipocyte number, size, and lipid content on primary human mesenchymal stem cells (MSC) sensitive enough to compare bisphenol A derivatives quantitatively in a robust and high throughput manner. The number of adipocytes was the most sensitive endpoint capable of detecting changes of 20% and was used to develop a benchmark concentration model (BMC) to quantitatively compare eight bisphenols (tested at 0.1-100 µM). The model was applied to evaluate mixtures of bisphenols obtaining the first experimental evidence of their additive effect on human MSC adipogenesis. Using the relative potency factors (RPFs), we show how a mixture of bisphenols at their sub-active concentrations induces a significant adipogenic effect due to its additive nature. The final active concentrations of bisphenols in tested mixtures reached below 1 µM, which is within the concentration range observed in humans. These results point to the need to consider the toxicity of chemical mixtures.


Assuntos
Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Compostos Benzidrílicos/toxicidade , Ensaios de Triagem em Larga Escala/métodos , Células-Tronco Mesenquimais/efeitos dos fármacos , Fenóis/toxicidade , Adaptação Biológica , Adipócitos/fisiologia , Adipogenia/fisiologia , Diferenciação Celular , Humanos
19.
Sci Rep ; 12(1): 2297, 2022 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-35145150

RESUMO

In high-yielding dairy cows, the rapidly increasing milk production after parturition can result in a negative nutrient balance, since feed intake is insufficient to cover the needs for lactation. Mobilizing body reserves, mainly adipose tissue (AT), might affect steroid metabolism. We hypothesized, that cows differing in the extent of periparturient lipomobilization, will have divergent steroid profiles measured in serum and subcutaneous (sc)AT by a targeted metabolomics approach and steroidogenic enzyme profiles in scAT and liver. Fifteen weeks antepartum, 38 multiparous Holstein cows were allocated to a high (HBCS) or normal body condition (NBCS) group fed differently until week 7 antepartum to either increase (HBCS BCS: 3.8 ± 0.1 and BFT: 2.0 ± 0.1 cm; mean ± SEM) or maintain BCS (NBCS BCS: 3.0 ± 0.1 and BFT: 0.9 ± 0.1 cm). Blood samples, liver, and scAT biopsies were collected at week -7, 1, 3, and 12 relative to parturition. Greater serum concentrations of progesterone, androsterone, and aldosterone in HBCS compared to NBCS cows after parturition, might be attributed to the increased mobilization of AT. Greater glucocorticoid concentrations in scAT after parturition in NBCS cows might either influence local lipogenesis by differentiation of preadipocytes into mature adipocytes and/or inflammatory response.


Assuntos
Tecido Adiposo/metabolismo , Aldosterona/genética , Aldosterona/metabolismo , Androsterona/genética , Androsterona/metabolismo , Bovinos/metabolismo , Indústria de Laticínios , Metabolômica , Período Periparto/sangue , Período Periparto/metabolismo , Progesterona/genética , Progesterona/metabolismo , RNA Mensageiro/sangue , RNA Mensageiro/metabolismo , Adipócitos/fisiologia , Aldosterona/sangue , Androsterona/sangue , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Animais , Diferenciação Celular , Ingestão de Alimentos/fisiologia , Feminino , Glucocorticoides/metabolismo , Lactação , Lipogênese , Progesterona/sangue
20.
Int J Mol Sci ; 23(4)2022 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-35216117

RESUMO

Stem cells (SC) are largely known for their potential to restore damaged tissue through various known mechanisms. Among these mechanisms is their ability to transfer healthy mitochondria to injured cells to rescue them. This mitochondrial transfer plays a critical role in the healing process. To determine the optimal parameters for inducing mitochondrial transfer between cells, we assessed mitochondrial transfer as a function of seeding density and in two-dimensional (2D) and semi three-dimensional (2.5D) culture models. Since mitochondrial transfer can occur through direct contact or secretion, the 2.5D culture model utilizes collagen to provide cells with a more physiologically relevant extracellular matrix and offers a more realistic representation of cell attachment and movement. Results demonstrate the dependence of mitochondrial transfer on cell density and the distance between donor and recipient cell. Furthermore, the differences found between the transfer of mitochondria in 2D and 2.5D microenvironments suggest an optimal mode of mitochondria transport. Using these parameters, we explored the effects on mitochondrial transfer between SCs and tumorigenic cells. HEK293 (HEK) is an immortalized cell line derived from human embryonic kidney cells which grow rapidly and form tumors in culture. Consequently, HEKs have been deemed tumorigenic and are widely used in cancer research. We observed mitochondrial transfer from SCs to HEK cells at significantly higher transfer rates when compared to a SC-SC co-culture system. Interestingly, our results also revealed an increase in the migratory ability of HEK cells when cultured with SCs. As more researchers find co-localization of stem cells and tumors in the human body, these results could be used to better understand their biological relationship and lead to enhanced therapeutic applications.


Assuntos
Tecido Adiposo/fisiologia , Microambiente Celular/fisiologia , Células-Tronco Mesenquimais/fisiologia , Mitocôndrias/fisiologia , Adipócitos/fisiologia , Carcinogênese/patologia , Contagem de Células/métodos , Linhagem Celular , Técnicas de Cocultura/métodos , Células HEK293 , Humanos
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