Murine 3T3-L1 Cells Research Articles

S-Dihydrodaidzein and 3-(1,3-benzoxazol-2-yl)-benzamide, Two New Potential β-estrogen Receptor Ligands with Anti-adipogenic Activity.

The elucidation of molecular pathways associated with adipogenesis has evidenced the relevance of estrogen and estrogen receptor beta (ERβ). The positive effects of ERβ ligands on adipogenesis, energy expenditure, lipolysis, food intake, and weight loss, make ERβ an attractive target for obesity control. From ligand-based virtual screening, molecular docking, and molecular dynamic simulations, six new likely ERβ ligands (C1 to C6) have been reported with potential for pharmacological obesity treatment. In this study, the effect of molecules C1-C6 on adipogenesis using the murine 3T3-L1 cell line was evaluated. Cell viability was assessed by MTT assays. Lipid accumulation and gene expression were investigated by ORO staining and real-time quantitative RT-PCR experiments, respectively. Cell viability was not significantly affected by C1-C6 at concentrations up to 10 μM. Interestingly, treatment with 10 μM of C1 (S-Dihydrodaidzein) and C2 (3-(1,3-benzoxazol-2-yl)- benzamide) for 72 h inhibited adipocyte differentiation; moreover, ORO staining evidenced a reduced intracellular lipid accumulation (40% at day 7). Consistently, mRNA expression of the adipogenic markers, PPARγ and C/EBPα, was reduced by 50% and 82%, respectively, in the case of C1, and by 83% and 59%, in the case of C2. Altogether, these results show the two new potential β-estrogen receptor ligands, C1 and C2, to exhibit anti-adipogenic activity. They could further be used as lead structures for the development of more efficient drugs for obesity control.

Tetra methyl bisphenol F: another potential obesogen

Background/ObjectivesObesity and its associated metabolic diseases are increasing globally. Sedentary lifestyle, high caloric diet, and genetic predisposition are known to contribute to the onset of obesity. It is increasingly recognized that exposure to environmental chemicals such as Bisphenol A (BPA) may also play a significant role. BPA has been correlated with an array of adverse health effects, including obesity and metabolic disorders. Due to public concern, manufacturers are replacing BPA with structural analogues for which there is limited toxicological data. The objective of this study was to assess the effects of these BPA analogues on adipogenesis.MethodsThe adipogenic effects of Tetra Methyl Bisphenol F (TMBPF), Bisphenol F (BPF), Bisphenol AP (BPAP), and fluorine-9-bisphenol (BHPF) were evaluated in murine 3T3-L1 cells. The cells were treated with BPA and its analogues at concentrations from 0.01 µM to 20 µM, throughout differentiation, in the absence of Dexamethasone (Dex). Lipid accumulation, mRNA and protein levels of adipogenic markers was assessed.ResultsWe found that TMBPF, BPF and BPA increased 3T3-L1 lipid accumulation and the expression levels of adipogenic markers lipoprotein lipase (Lpl), fatty acid binding protein 4 (Fabp4) and perilipin (Plin) (1–20 µM; p < 0.05), whereas BHPF and BPAP had no effect in this model. Further, TMBPF induced adipogenesis to a greater extent than all the other chemicals including BPA (1–20 µM; p < 0.05). The effect mediated by TMBPF on expression levels of Fabp4, but not Plin, is likely mediated via peroxisome proliferator-activated receptor (PPAR) γ activation.ConclusionsOf the BPA analogues tested, BPF was most similar to BPA in its effects, while TMBPF was most adipogenic. In addition, TMBPF is likely a PPARγ agonist, it is likely an obesogenic chemical and may be a metabolic disruptor.

SAT667 Follicle-Stimulating Hormone Does Not Directly Regulate Adipogenesis Via The FSH Receptor In Mice

Abstract Disclosure: M. Loka: None. L. Ongaro Gambino: None. T. Uliasz: None. L.A. Jaffe: None. L. Kazak: None. D.J. Bernard: None. Rising rates of obesity are a serious public health challenge. Post-menopausal women are at higher risk of developing obesity and associated comorbidities than premenopausal women, with hormonal changes, such as reduced estrogens, likely to be contributing factors. Menopause is also characterized by increases in pituitary-derived follicle-stimulating hormone (FSH). Recent data suggest that FSH may directly stimulate adipogenesis and block thermogenesis in adipocytes. FSH reportedly decreased expression of thermogenic genes (Cox8b and Ucp1) in murine 3T3-L1 cells differentiated into adipocytes. FSH’s inhibitory effects were no longer apparent in the presence of an FSH-neutralizing antibody. The same FSH antibody reduced fat mass and increased lean mass in ovariectomized (OVX) female mice, a rodent model of menopause. In these studies, it was not established whether FSH acted directly through its canonical receptor (FSHR) in adipocytes to mediate its effects. To address this gap, we differentiated 3T3-L1 cells to adipocytes and treated with FSH. In contrast to the earlier report, FSH did not alter the expression of markers of lipogenesis (Cebpa and Pparg2) or thermogenesis (Cox8b and Ucp1) nor did it impact mitochondrial respiration or lipid accumulation. We also did not detect Fshr mRNA in these cells. We next differentiated the stromal vascular fraction from inguinal adipose tissue of adult male mice into white adipocytes. After 10 days of differentiation, FSH treatment did not alter expression of several markers of adipogenesis and did not affect lipid accumulation. To assess FSH actions in vivo, we generated adipocyte-specific Fshr knockout mice (Fshrfx/fx;Adipoq-Cre, hereafter cKO). Ten-week-old cKO and control female mice were OVX and maintained on standard chow. Eight to 10 weeks later, we performed glucose tolerance and insulin tolerance tests, and determined body composition by EchoMRI. Cre-mediated recombination of the floxed Fshr locus in adipocytes was successful, but did not alter body weight, fat or lean mass, or glucose metabolism in cKO relative to control OVX mice. Furthermore, using a newly developed FSHR-3xHA knockin mouse model, we detected FSHR protein expression in ovary, but not in inguinal and perigonadal white adipose depots or in intrascapular brown adipose tissue. We similarly failed to detect Fshr mRNA in various fat depots in control mice. Collectively, our results fail to show FSH effects on adipogenesis in vitro and challenge the hypothesis that FSH acts through the classical FSHR in adipocytes in vivo. Presentation: Saturday, June 17, 2023

The Receptor Tyrosine Kinase c-Met Promotes Lipid Accumulation in 3T3-L1 Adipocytes.

The receptor tyrosine kinase c-Met is elaborated in embryogenesis, morphogenesis, metabolism, cell growth, and differentiation. JNJ38877605 (JNJ) is an inhibitor of c-Met with anti-tumor activity. The c-Met expression and its role in adipocyte differentiation are unknown. Here, we investigated the c-Met expression and phosphorylation, knockdown (KD) effects, and pharmacological inhibition of c-Met by JNJ on fat accumulation in murine preadipocyte 3T3-L1 cells. During 3T3-L1 preadipocyte differentiation, strikingly, c-Met expression at the protein and mRNA levels and the protein phosphorylation on Y1234/1235 and Y1349 is crucial for inducing its kinase catalytic activity and activating a docking site for signal transducers were increased in a time-dependent manner. Of note, JNJ treatment at 20 μM that strongly inhibits c-Met phosphorylation without altering its total expression resulted in less lipid accumulation and triglyceride (TG) content with no cytotoxicity. JNJ further reduced the expression of adipogenic regulators, including CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), acetyl CoA carboxylase (ACC), and perilipin A. Moreover, JNJ treatment increased cAMP-activated protein kinase (AMPK) and liver kinase B-1 (LKB-1) phosphorylation but decreased ATP levels. Significantly, KD of c-Met suppressed fat accumulation and triglyceride (TG) quantity and reduced the expression of C/EBP-α, PPAR-γ, FAS, ACC, and perilipin A. Collectively, the present results demonstrate that c-Met is a novel, highly conserved mediator of adipogenesis regulating lipid accumulation in murine adipocytes.

Suppressive Effects of Flavonoids on Macrophage-Associated Adipocyte Inflammation in a Differentiated Murine Preadipocyte 3T3-L1 Cells Co-Cultured with a Murine Macrophage RAW264.7 Cells.

The suppressive effects of flavonoids on macrophage-associated adipocyte inflammation in a differentiated murine preadipocyte cell line (3T3-L1) co-cultured with a murine macrophage cell line (RAW264.7) were evaluated. Extracellular lipid accumulation was investigated via Oil Red O staining. The expression levels of adipogenesis- and inflammation-associated proteins, including CCAAT/enhancer-binding protein (C/EBP)-α, inducible nitric oxide synthase (iNOS), C/EBPβ, peroxisome proliferator-activated receptor γ (PPARγ), and cyclooxygenase-2 (COX-2), were determined via Western blotting. Proinflammatory cytokines, including monocyte chemoattractant protein 1 (MCP-1) and interleukin-6 (IL-6), were assessed using enzyme-linked immunosorbent assay kits. We found that silybin, formononetin, and diosmetin inhibited lipid accumulation and production of proinflammatory cytokines in the co-cultures of 3T3-L1 and RAW264.7 cells. Moreover, they inhibited the protein expression of PPARγ, C/EBPα, COX-2, C/EBPβ, and iNOS in the co-cultures of 3T3-L1 and RAW264.7 cells. These data support that silybin, formononetin, and diosmetin inhibit macrophage-associated adipocyte inflammation and lipid accumulation.

FATP1 Exerts Variable Effects on Adipogenic Differentiation and Proliferation in Cells Derived From Muscle and Adipose Tissue.

In livestock, intramuscular adipose tissue is highly valued whereas adipose tissue in other depots is considered as waste. Thus, genetic factors that favor fat deposition in intramuscular compartments over that in other adipose depots are highly desirable in meat-producing animals. Fatty acid transport 1 (FATP1) has been demonstrated to promote cellular fatty acid uptake and metabolism; however, whether it also influences cellular lipid accumulation remains unclear. In the present study, we investigated the effects of FATP1 on the differentiation and proliferation of adipocytes in five types of cells derived from muscle and adipose tissue and estimated the effects of FATP1 on intramuscular fat (IMF) deposition. We showed that FATP1 is mainly expressed in heart and muscle tissue in buffaloes as well as cells undergoing adipogenic differentiation. Importantly, we found that FATP1 promoted the adipogenic differentiation of muscle-derived cells (buffalo myocytes and intramuscular preadipocytes and mouse C2C12 cells) but did not affect, or even inhibited, that of adipose-derived cells (buffalo subcutaneous preadipocytes and mouse 3T3-L1 cells, respectively). Correspondingly, our results further indicated that FATP1 promotes IMF deposition in mice in vivo. Meanwhile, FATP1 was found to enhance the proliferative activity of all the assessed cells, except murine 3T3-L1 cells. These results provide new insights into the potential effects of FATP1 on IMF deposition, especially regarding its positive effects on meat quality in buffaloes and other livestock.

Oncostatin M promotes lipolysis in white adipocytes

ABSTRACT Oncostatin M (OSM) is a member of the glycoprotein 130 cytokine family that is involved in chronic inflammation and increased in adipose tissue under obesity and insulin resistance. OSM was shown to inhibit adipogenesis, suppress browning, and contribute to insulin resistance in cultured white adipocytes. In contrast, OSM may have a metabolically favourable role on adipocytes in mouse models of obesity and insulin resistance. However, a putative role of OSM in modulating lipolysis has not been investigated in detail to date. To address this, cultured white adipocytes of mouse or human origin were exposed to 10 or 100 ng/ml of OSM for various time periods. In murine 3T3-L1 cells, OSM stimulation directly activated hormone-sensitive lipase (HSL) and other players of the lipolytic machinery, and dose-dependently increased free fatty acid and glycerol release. In parallel, OSM attenuated insulin-mediated suppression of lipolysis and induced phosphorylation of serine-residues on the insulin receptor substrate-1 (IRS1) protein. Key experiments were verified in a second murine and a human adipocyte cell line. Inhibiton of extracellular signal-regulated kinase (ERK)-1/2 activation, abolished OSM-mediated HSL phosphorylation and lipolysis. In conclusion, OSM signalling directly promotes lipolysis in white adipocytes in an ERK1/2-dependent manner.

Inhibitory Effect of Water Soluble Fraction of Monascus-Fermented Rice on Lipid Accumulation in 3T3 L1 Adipocyte

Excessive lipid accumulation in the body causes people to become overweight and obese, conditions that are associated with an amplified risk of serious diseases. The fungi of genus Monascus produce various secondary metabolites such as monacolins, citrinin and fungal pigments, which are water-insoluble and have inhibitory potency for the lipid accumulation in adipocytes. However, water-soluble adipogenesis inhibitors derived from Monascus-fermented products have not yet been reported. In this study, we investigated the inhibitory activity against intracellular lipid accumulation of water-soluble fractions of Monascus-fermented red mold rice (RMR) and red mold barley (RMB) on murine 3T3-L1 cells. Water soluble fractions of ten different Monascus strains were used and the inhibitory activity of their water-soluble fractions on lipid accumulation by differentiated 3T3-L1 cells was evaluated for 8 days using oil red staining. The water-soluble fraction from Monascus pilosus NBRC4507 fermented RMR cultivated at 30C for 14 days was selected since it showed comparatively the lowest relative lipid accumulation (62±1.2%), which indicated the highest inhibitory activity of lipid accumulation in adipocytes. To study the presence of monacolin and citrinin in the water soluble fractions, thin-layer chromatography was done and the results showed that the water-soluble fractions tested were free from both monacolin and citrinin. Therefore, the present study strongly suggested that the water-soluble components, except for monacolin and citrinin, in the water soluble fraction obtained from Monascus pilosus NBRC4507-fermented rice can be used as functional food material to control overweight and obesity.

HIF3A Inhibition Triggers Browning of White Adipocytes via Metabolic Rewiring.

Maintenance of energy balance between intake and expenditure is a prerequisite of human health, disrupted in severe metabolic diseases, such as obesity and type 2 diabetes (T2D), mainly due to accumulation of white adipose tissue (WAT). WAT undergoes a morphological and energetic remodelling toward brown adipose tissue (BAT) and the BAT activation has anti-obesity potential. The mechanisms or the regulatory factors able to activate BAT thermogenesis have been only partially deciphered. Identifying novel regulators of BAT induction is a question of great importance for fighting obesity and T2D. Here, we evaluated the role of Hif3α in murine pre-adipocyte 3T3-L1 cell line, a versatile and well characterized biological model of adipogenesis, by gain- and loss-of function approaches and in thermogenesis-induced model in vivo. HIF3A is regulated by inflammation, it modulates lypolysis in adipose tissue of obese adults, but its role in energy metabolism has not previously been investigated. We characterized gene and protein expression patterns of adipogenesis and metabolic activity in vitro and mechanistically in vivo. Overexpression of Hif3α in differentiating adipocytes increases white fat cells, whereas silencing of Hif3α promotes “browning” of white cells, activating thermogenesis through upregulation of Ucp1, Elovl3, Prdm16, Dio2 and Ppargc1a genes. Investigating cell metabolism, Seahorse Real-Time Cell Metabolism Analysis showed that silencing of Hif3α resulted in a significant increase of mitochondrial uncoupling with a concomitant increase in acetyl-CoA metabolism and Sirt1 and Sirt3 expression. The causal Hif3α/Ucp1 inverse relation has been validated in Cannabinoid receptor 1 (CB1) knockout, a thermogenesis-induced model in vivo. Our data indicate that Hif3α inhibition triggers “browning” of white adipocytes activating the beneficial thermogenesis rewiring energy metabolism in vitro and in vivo. HIF3A is a novel player that controls the energy metabolism with potential applications in developing therapy to fight metabolic disorders, as obesity, T2D and ultimately cancer.

Characterization of Per- and Polyfluorinated Alkyl Substances Present in Commercial Anti-fog Products and Their In Vitro Adipogenic Activity.

Anti-fog sprays and solutions are used on eyeglasses to minimize the condensation of water vapor, particularly while wearing a mask. Given their water-repellent properties, we sought to characterize per- and polyfluorinated alkyl substance (PFAS) compounds in four anti-fog spray products, five anti-fog cloth products, and two commercial fluorosurfactant formulations suspected to be used in preparing anti-fog products. Fluorotelomer alcohols (FTOHs) and fluorotelomer ethoxylates (FTEOs) were detected in all products and formulations. While 6:2 FTOH and the 6:2 FTEO polymeric series were predominant, one anti-fog cloth and one formulation contained 8:2, 10:2, 12:2, 14:2, and 16:2 FTOH and FTEO polymeric series. PFAS concentrations varied in samples and were detected at levels up to 25,000 μg/mL in anti-fog sprays and 185,000 μg (g cloth)-1 in anti-fog cloth products. The total organic fluorine (TOF) measurements of anti-fog products ranged from 190 to 20,700 μg/mL in sprays and 44,200 to 131,500 μg (g cloth)-1 in cloths. Quantified FTOHs and FTEOs accounted for 1-99% of TOF mass. In addition, all four anti-fog sprays and both commercial formulations exhibited significant cytotoxicity and adipogenic activity (either triglyceride accumulation and/or pre-adipocyte proliferation) in murine 3T3-L1 cells. Results suggest that FTEOs are a significant contributor to the adipogenic activity exhibited by the anti-fog sprays. Altogether, these results suggest that FTEOs are present in commercial products at toxicologically relevant levels, and more research is needed to fully understand the health risks from using these PFAS-containing products.

Leukotriene C4 synthase is a novel PPARγ target gene, and leukotriene C4 and D4 activate adipogenesis through cysteinyl LT1 receptors in adipocytes

Leukotriene (LT) C4 synthase (LTC4S) catalyzes the conversion from LTA4 to LTC4, which is a proinflammatory lipid mediator in asthma and other inflammatory diseases. LTC4 is metabolized to LTD4 and LTE4, all of which are known as cysteinyl (Cys) LTs and exert physiological functions through CysLT receptors. LTC4S is expressed in adipocytes. However, the function of CysLTs and the regulatory mechanism in adipocytes remain unclear. In this study, we investigated the expression of LTC4S and production of CysLTs in murine adipocyte 3T3-L1 cells and their underlying regulatory mechanisms. Expression of LTC4S and production of LTC4 and CysLTs increased during adipogenesis, whereas siRNA-mediated suppression of LTC4S expression repressed adipogenesis by reducing adipogenic gene expression. The CysLT1 receptor, one of the two LTC4 receptors, was expressed in adipocytes. LTC4 and LTD4 increased the intracellular triglyceride levels and adipogenic gene expression, and their enhancement was suppressed by co-treatment with pranlukast, a CysLT1 receptor antagonist. Moreover, the expression profiles of LTC4S gene/protein during adipogenesis resembled those of peroxisome proliferator-activated receptor (PPAR) γ. LTC4S expression was further upregulated by treatment with troglitazone, a PPARγ agonist. Promoter-luciferase and chromatin immunoprecipitation assays showed that PPARγ directly bound to the PPAR response element of the LTC4S gene promoter in adipocytes. These results indicate that the LTC4S gene expression was enhanced by PPARγ, and LTC4 and LTD4 activated adipogenesis through CysLT1 receptors in 3T3-L1 cells. Thus, LTC4S and CysLT1 receptors are novel potential targets for the treatment of obesity.

Meteorin-Like Protein (Metrnl) in Obesity, during Weight Loss and in Adipocyte Differentiation.

Meteorin-like protein (Metrnl) is an adipo-myokine with pleiotropic effects in adipose tissue (AT). Its systemic regulation in obesity and under weight loss is unclear. Circulating Metrnl concentrations were analyzed by ELISA in severely obese patients undergoing bariatric surgery (BS) or low calorie diet (LCD). Metrnl mRNA expression was analyzed in human and murine tissues and cell lines by quantitative real-time PCR. About 312 morbidly obese individuals underwent BS (n = 181; BMI 53.4 + 6.8 kg/m2) or LCD (n = 131; BMI 43.5 + 6.7 kg/m2). Serum samples were obtained at baseline and 3, 6, and 12 months after intervention. AT specimen from subcutaneous and visceral adipose tissue were resected during BS. Serum Metrnl levels were lower in type 2 diabetic patients and negatively correlated with HbA1c. In BS and LCD patients, Metrnl concentrations significantly increased after 3 months and returned to baseline levels after 12 months. There was no gender-specific effect. Metrnl mRNA expression did not differ between visceral and subcutaneous AT in n = 130 patients. In contrast, Metrnl gene expression in mice was highest in intra-abdominal AT followed by subcutaneous, peri-renal, and brown AT. In the murine 3T3-L1 cell line, Metrnl expression was high in pre-adipocytes and mature adipocytes with a transient downregulation during adipocyte differentiation. Metrnl expression remained unaffected upon treatment with glucose, insulin, fatty acids, bile acids, and incretins. Polyunsaturated omega-3 and omega-6 fatty acids downregulated Metrnl expression. Systemic Metrnl is transiently upregulated during massive weight loss and gene expression in adipocytes is differentially regulated.

Effect of Eicosapentaenoic Acid Supplementation on Murine Preadipocytes 3T3-L1 Cells Activated with Lipopolysaccharide and/or Tumor Necrosis Factor-α.

The beneficial effect of n-3 fatty acids can be related to anti-inflammatory properties. The aim of the study was to analyzed the effect of eicosapentaenoic acid (EPA) on 3T3-L1 cells (murine embryonic fibroblasts‒preadipocytes) activated with inflammatory factors (IF). Cells were incubated with 50 µmol of EPA for 48 h, and then activated with lipopolysaccharide (LPS) or tumor necrosis factor-α (TNF-α). The level of cycloxygenase-2 (Prostaglandin-Endoperoxide Synthase 2, PTGS2, COX-2), cytosolic prostaglandin synthase E2 (cPGES), fatty acid binding protein 4 (FABP4), toll-like receptor 4 (TLR4), glucose receptor type 4 (GLUT-4), and cannabinoid receptor 2 (CB2) was determined using Western blot analysis. The phospholipase A2 (Pla2g4a), and prostaglandin-Endoperoxide Synthase 2 (Ptgs2) gene expression was analyzed by real-time qPCR. After EPA and IF activation, a significant decrease in the COX-2, cPGES, and TRL4 protein levels was observed. Incubation of cells with EPA and IF resulted in a decrease in Ptgs2 and an increase in the Pla2g4a gene. A significant increase in the CB2 protein was observed in adipocytes co-treated with EPA and IF. The results indicated an anti-inflammatory properties of EPA. Interestingly, the activation of the GLUT4 receptor by EPA suggests an unique role of this FA in the regulation of the adipocyte metabolism and prevention of insulin resistance.

Water extract of Artemisia scoparia Waldst. & Kitam suppresses LPS-induced cytokine production and NLRP3 inflammasome activation in macrophages and alleviates carrageenan-induced acute inflammation in mice

Ethnopharmacological relevanceArtemisia scoparia Waldst. & Kitam (A. scoparia) is a perennial herbal plant that is widely used as a folk remedy in Asian countries. Several studies have demonstrated that A. scoparia has various physiological effects, including anti-inflammation, anti-hypertension, anti-obesity, anti-hepatotoxicity, and anti-oxidant effects.Aim of the study: The objective of the present study was to examine the anti-inflammatory effects of water extract of A. scoparia (WAS). Materials and methodsMurine bone marrow-derived macrophages (BMDMs), human monocyte THP-1 and murine fibroblast 3T3-L1 cells were used for the in vitro experiments. Cell viability and cytokine production were determined by the MTT assay and ELISA, respectively. RT-PCR was performed to determine iNOS gene expression and the Griess reaction was used to measure nitrite levels. iNOS protein expression, activation of NF-κB and MAPKs, and cleavage of caspase-1 and IL-1β were determined by Western blot analysis. A carrageenan-induced mouse model of acute inflammation was used in the in vivo experiments. ResultsPretreatment with WAS concentration-dependently suppressed gene expression and IL-6, TNF-α, CXCL1 and iNOS protein levels in BMDMs stimulated with LPS. In addition, pretreatment with WAS inhibited LPS-induced production of IL-6 and TNF-α in THP-1 cells and CXCL1 in 3T3-L1. Furthermore, LPS induced phosphorylation of p65 in BMDMs, and this induction was dramatically suppressed by WAS pretreatment. We further investigated whether WAS regulates activation of the NLRP3 inflammasome, which is known to be essential for IL-1β processing. WAS inhibited the production of IL-1β, but not IL-6, in response to adenosine triphosphate (ATP) and monosodium uric acid (MSU) crystals in LPS-primed BMDMs. Cleavage of caspase-1 and IL-1β was also reduced by WAS. We finally evaluated the in vivo anti-inflammatory effects of WAS in a mouse model of carrageenan-induced acute inflammation. Subcutaneous administration of WAS reduced production of the inflammatory cytokines IL-6, TNF-α, CXCL1, and IL-1β. Recruitment of immune cells, mostly neutrophils, was also reduced by administration of WAS. Infiltration of inflammatory cells and edema in the submucosa of air pouch tissues were markedly improved in the WAS-treated groups. ConclusionsOur results indicate that WAS possesses potent anti-inflammatory properties. These findings suggest that A. scoparia is a candidate functional food targeting several inflammatory diseases.

Evaluation of lipid and cholesterol-lowering effect of bioflavonoids from bergamot extract

Several natural products have been reported to be involved in the suppression of adipogenesis. In this study, we reveal that a bergamot extract (BE) decreased the accumulation of intracellular lipids in murine pre-adipocytes 3T3-L1 cells during adipogenic differentiation. Both the inhibition of HMG-CoA reductase activity and the differentiation and proliferation of adipocytes could be used as a strategy for the treatment and prevention of obesity. The results of this study show a reduction of HMG-CoA activity and of lipid droplet accumulation in the presence of the BE, suggesting the potential of BE as an anti-adipogenic agent to lower the content of cholesterol and body fat and prevent a gain in body weight. Moreover, BE as the result of high percentages of flavonoid compounds such as neoriocitrin, naringin and neohesperidin, the main flavonoids contained in BE, led to significant inhibition of DPPH free radical, demonstrating a strong radical scavenging activity.

Promotion of lipogenesis by PPARγ-activated FXR expression in adipocytes

Farnesoid X receptor (FXR), a bile acid receptor, is known to be involved in the promotion of adipogenesis. However, the regulation mechanism of FXR-promoted adipogenesis remains unclear. In this study, we investigated the regulation mechanism of FXR-mediated activation of adipogenesis in murine adipocyte 3T3-L1 cells. Chenodeoxycholic acid (CDCA), a potent FXR agonist, enhanced the accumulation of intracellular triglycerides and the expression of the adipogenic and lipogenic genes, while guggulsterone, an FXR antagonist, suppressed CDCA-activated adipogenesis. Moreover, troglitazone, a peroxisome proliferator-activated receptor (PPAR) γ agonist, elevated the expression of the FXR gene during adipogenesis, similar to that of the PPARγ gene. Chromatin immunoprecipitation assay demonstrated that PPARγ bound to the PPAR-responsive element of the FXR gene in a PPARγ agonist-dependent manner. Furthermore, FXR activation induced the expression of the stearoyl-CoA desaturase (SCD) gene in adipocytes. The FXR-response element (FXRE) was found in the SCD gene promoter, and FXR bound to the FXRE of the SCD gene promoter, and its binding efficiency was enhanced by CDCA in adipocytes. These results indicate that FXR assisted lipogenesis through the enhanced expression of SCD in a PPARγ-dependent manner in adipocytes, making this study the first to identify the role of FXR in the promotion of lipogenesis by PPARγ activation.

Effects of steviol on cytotoxicity, adipogenesis, ROS concentration and gene expression in 3T3-L1 Cell Line

AbstractThe increasing prevalence of diabetes mellitus has become one of the world's most serious public health problems. This reflects an increase in associated risk factors such as being overweight or obese. Currently available therapies are associated with a number of adverse effects, so there is a need to search for new substances that can support the treatment.Stevia rebaudiana Bertoni is a plant famous for its sweetness due to the content of steviol glycosides that are derivatives of diterpene – steviol. Stevia and its glycosides are becoming popular in the world of science due to their anti-diabetic potential. However, the mechanisms responsible for its action are not fully understood and require further investigation.The aim of this study was to evaluate the effects of steviol on adipogenesis, intracellular ROS generation and the gene expression, as well as cytotoxicity in murine 3T3-L1 cell line. Cell viability, adipocyte differentiation, intracellular ROS generation and the influence on gene expression in the presence of steviol (in concentrations of 1–100 μM) was determined using MTT assay, Oil Red O staining, NBT methods and RT-PCR. It was found that steviol in concentrations up to 100 μM did not affect proliferation of cells. Also, there were no effects on lipid accumulation and intracellular ROS generation with examined concentrations (0–100 μM). The agent reduced the expression of genes regulating adipogenesis and lipogenesis processes: PPARγ (at concentrations of 10 and 100μM, by 38.1 and 45.3%), C/EBPα (at concentrations of 1, 10 and 100μM, by 36.9, 61.9 and 45.3%), SREBP-1 (at concentrations of 10 and 100μM, by 49.8 and 37.2%), LPL (at concentrations of 1, 10 and 100μM, by 45, 33.7, 30.8%), aP2 (at concentrations of 1, 10 and 100μM, by 36.9, 23.8, 52.4%), FAS (at concentrations of 1, 10 and 100μM, by 55.4, 22.4, 55.6%), LEP (at concentrations of 1, 10 and 100μM, by 27.5, 59.2, 68.6%), ADIPQ (at concentration of 100μM, by 55.6%) and RSTN (at concentrations of 1, 10 and 100μM, by 36.9, 61.9, 63.9%). Steviol lowered the expression of gene coding glucose transporter GLUT4 (at concentrations of 10 and 100μM, by 33.7 and 37.2%).The results of this study seem to confirm that the mechanisms of anti-diabetic effects of steviol may be related to inhibition of expression of genes responsible for adipogenesis, lipogenesis and glucose transport in cells.The presented work is an integral part of the research project(National Science Centre, Poland, NCN 2017/27/B/NZ29/00677)

Anti-tumoral Effects of Recombinant Lactococcus lactis Strain Secreting IL-17A Cytokine.

Interleukin-17A (IL-17A) is a pro-inflammatory cytokine produced by TH17 cells that participates and contributes in host defense and autoimmune disease. We have recently reported antitumor properties of the probiotic strain of Lactobacillus casei BL23 in mice and TH17 cells was shown to play an important role in this beneficial effect. In order to better understand the role of IL-17A in cancer, we constructed a recombinant strain of Lactococcus lactis producing this cytokine and we determined its biological activity in: (i) a bioassay test for the induction of IL-6 production by murine fibroblasts 3T3 L1 cells line and (ii) in a mouse allograft model of human papilloma virus (HPV)-induced cancer. Our data show that recombinant L. lactis produces and efficiently secretes biologically active IL-17A cytokine. Interestingly, ∼26% of mice intranasally treated with L. lactis-IL-17A and challenged with TC-1 cells remained tumor free over the experiment, in contrast to control mice treated with the wild type strain of L. lactis which developed 100% of aggressive tumors. In addition, the median size of the ∼74% tumor-bearing mice treated with recombinant L. lactis-IL-17A, was significantly lower than mice treated with L. lactis-wt. Altogether, our results demonstrate that intranasal administration with L. lactis secreting IL-17A results in a partial protection against TC-1-induced tumors in mice, confirming antitumor effects of this cytokine in our cancer model.

An ameloblastin C-terminus variant is present in human adipose tissue

ObjectiveTranscriptional regulatory elements in the ameloblastin (AMBN) promoter indicate that adipogenesis may influence its expression. The objective here was to investigate if AMBN is expressed in adipose tissue, and have a role during differentiation of adipocytes. DesignAMBN expression was examined in adipose tissue and adipocytes by real-time PCR and ELISA. Distribution of ameloblastin was investigated by immunofluorescence in sections of human subcutaneous adipose tissue. The effect of recombinant proteins resembling AMBN and its processed products on proliferation of primary human pre-adipocytes and murine 3T3-L1 cell lines was measured by [3H]-thymidine incorporation. The effect on adipocyte differentiation was evaluated by the expression profile of the adipogenic markers PPARγ and leptin, and the content of lipids droplets (Oil-Red-O staining). ResultsAMBN was found to be expressed in human adipose tissue, human primary adipocytes, and in 3T3-L1 cells. The C-terminus of the AMBN protein and a 45 bp shorter splice variant was identified in human subcutaneous adipose tissue. The expression of AMBN was found to increase four-fold during differentiation of 3T3-L1 cells. Administration of recombinant AMBN reduced the proliferation, and enhanced the expression of PPARγ and leptin in 3T3-L1 and human pre-adipocytes, respectively. ConclusionsThe AMBN C-terminus variant was identified in adipocytes. This variant may be encoded from a short splice variant. Increased expression of AMBN during adipogenesis and its effect on adipogenic factors suggests that AMBN also has a role in adipocyte development.

Carvacrol reduces adipogenic differentiation by modulating autophagy and ChREBP expression.

ObjectiveObesity is the result of white adipose tissue accumulation where excess of food energy is stored to form triglycerides. De novo lipogenesis (DNL) is the continuous process of new fat production and is driven by the transcription factor ChREBP. During adipogenesis, white adipocytes change their morphology and the entire cell volume is occupied by one large lipid droplet. Recent studies have implicated an essential role of autophagy in adipogenic differentiation, cytoplasmic remodelling and mitochondria reorganization. The phenolic monoterpenoid carvacrol (2-methyl-5-[1-methylethyl]phenol), produced by numerous aromatic plants, has been shown to reduce lipid accumulation in murine 3T3-L1 cells during adipogenic differentiation by modulating genes associated with adipogenesis and inflammation. Therefore, the aim of this study was to evaluate whether carvacrol could affect autophagy and ChREBP expression during adipogenic differentiation.MethodsThe study was carried on by using the murine 3T3-L1 and the human WJ-MSCs (Wharton’s jelly-derived mesenchymal stem cells) cell lines. Cells undergoing adipogenic differentiation were untreated or treated with carvacrol. Adipogenic differentiation was assessed by analyzing cellular lipid accumulation with Oil-Red O staining and by ultrastructural examination with TEM. Autophagy was evaluated by western immunoblotting of autophagy markers LC3B and p62/SQSTM and by ultrastructural examination of autophagic bodies. Autophagic flux was evaluated by using autophagy inhibitor cloroquine (CQ). ChREBP expression levels was assessed by both western blotting and immunoelectron microscopy and ChREBP activity by analysis of adipogenic target genes expression.ResultsWe found that carvacrol reduced adipogenic differentiation of about 40% and 30% in, respectively, 3T3-L1 and in WJ-MSCs cells. The effect of carvacrol on adipogenic differentiation correlated with both reduction of autophagy and reduction of ChREBP expression.ConclusionThe results support the notion that carvacrol, through its effect on autophagy (essential for adipocyte maturation) and on ChREBP activity, could be used as a valuable adjuvant to reduce adipogenic differentiation.