PGE2 -EP3 axis promotes brown adipose tissue formation through stabilization of WTAP RNA methyltransferase.

Brown adipose tissue (BAT) functions as a thermogenic organ and is negatively associated with cardiometabolic diseases. N6 -methyladenosine (m6 A) modulation regulates the fate of stem cells. Here, we show that the prostaglandin E2 (PGE2 )-E-prostanoid receptor 3 (EP3) axis was activated during mouse interscapular BAT development. Disruption of EP3 impaired the browning process during adipocyte differentiation from pre-adipocytes. Brown adipocyte-specific depletion of EP3 compromised interscapular BAT formation and aggravated high-fat diet-induced obesity and insulin resistance in vivo. Mechanistically, activation of EP3 stabilized the Zfp410 mRNA via WTAP-mediated m6 A modification, while knockdown of Zfp410 abolished the EP3-induced enhancement of brown adipogenesis. EP3 prevented ubiquitin-mediated degradation of WTAP by eliminating PKA-mediated ERK1/2 inhibition during brown adipocyte differentiation. Ablation of WTAP in brown adipocytes abrogated the protective effect of EP3 overexpression in high-fat diet-fed mice. Inhibition of EP3 also retarded human embryonic stem cell differentiation into mature brown adipocytes by reducing the WTAP levels. Thus, a conserved PGE2 -EP3 axis promotes BAT development by stabilizing WTAP/Zfp410 signaling in a PKA/ERK1/2-dependent manner.

Extracellular Matrix Expression in Human Pancreatic Fat Cells of Patients with Normal Glucose Regulation, Prediabetes and Type 2 Diabetes.

Previously, we found that human pancreatic preadipocytes (PPAs) and islets influence each other and that the crosstalk with the fatty liver via the hepatokine fetuin-A/palmitate induces inflammatory responses. Here, we examined whether the mRNA-expression of pancreatic extracellular matrix (ECM)-forming and -degrading components differ in PPAs from individuals with normal glucose regulation (PPAs-NGR), prediabetes (PPAs-PD), and type 2 diabetes (PPAs-T2D), and whether fetuin-A/palmitate impacts ECM-formation/degradation and associated monocyte invasion. Human pancreatic resections were analyzed (immuno)histologically. PPAs were studied for mRNA expression by real-time PCR and protein secretion by Luminex analysis. Furthermore, co-cultures with human islets and monocyte migration assays in Transwell plates were conducted. We found that in comparison with NGR-PPAs, TIMP-2 mRNA levels were lower in PPAs-PD, and TGF-ß1 mRNA levels were higher in PPAs-T2D. Fetuin-A/palmitate reduced fibronectin, decorin, TIMP-1/-2 and TGF-ß1 mRNA levels. Only fibronectin was strongly downregulated by fetuin-A/palmitate independently of the glycemic status. Co-culturing of PPAs with islets increased TIMP-1 mRNA expression in islets. Fetuin-A/palmitate increased MMP-1, usherin and dermatopontin mRNA-levels in co-cultured islets. A transmigration assay showed increased monocyte migration towards PPAs, which was enhanced by fetuin-A/palmitate. This was more pronounced in PPAs-T2D. The expression of distinct ECM components differs in PPAs-PD and PPAs-T2D compared to PPAs-NGR, suggesting that ECM alterations can occur even in mild hyperglycemia. Fetuin-A/palmitate impacts on ECM formation/degradation in PPAs and co-cultured islets. Fetuin-A/palmitate also enhances monocyte migration, a process which might impact on matrix turnover.

Studies on the partial characterization of extracted glycosaminoglycans from fish waste and its potentiality in modulating obesity through in-vitro and in-vivo.

Glycosaminoglycans (GAGs) are bioactive polysaccharides or glycoconjugates found in the fish waste having significant health impacts. In the present study it has been attempted to extract GAGs from mackerel fish waste through chemical and enzymatic methods. Further, the extracted GAGs (e-GAGs) were analyzed for their composition (uronic acid, total sugar & sulfate), chemical characterization was carried out through techniques of scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) & Proton NMR. Further, probable major GAGs present was identified by enzymatic digestion. The biological potential of the extracted glycoconjugate was assessed further through in-vitro and in-vivo studies. In-vitro biological activity showed good lipase inhibition (IC50, 2.6 mg/mL) and bile acid binding properties (dose-dependent). Lipid accumulation lowered in the e-GAGs differentiated 3T3L1 preadipocyte cells have also been observed. The high fat fed animal (in-vivo) study showed ameliorative effect via reducing blood sugar∼1.28↓, lipid profile↓, plasma insulin∼3.5↓, improved glucose tolerance, and homeostatic model assessment for insulin resistance (HOMA-IR, ∼3.0↓). Furthermore, elimination of bile acid (BA) due to GAG-BA binding properties resultant in removal of elevated fecal triglyceride and cholesterol suggesting its lipid lowering activity. Regulation of various proteins linked to carbohydrate and lipid metabolism including fatty acid synthase (FAS), low density lipoproteins receptor (LDL-R), 7α-hydroxylase, glucose transporter-4 (GLUT4) and Peroxisome proliferator- activated receptor gamma (PPAR-γ) were significant (p < 0.05) with e-GAGs treatment when compared to HFD group. Thus, the e-GAGs showed potential hypolipidemic activity through elimination of bile acid binding property together with regulating the specific protein related to obesity and its associated complications.

Cellular Metabolism and Bioenergetic Function in Human Fibroblasts and Preadipocytes of Type 2 Familial Partial Lipodystrophy.

LMNA mutation is associated with type-2 familial partial lipodystrophy (FPLD2). The disease causes a disorder characterized by anomalous accumulation of body fat in humans. The dysfunction at the molecular level is triggered by a lamin A/C mutation, impairing the cell metabolism. In human fibroblasts and preadipocytes, a trend for ATP production, mainly supported by mitochondrial oxidative metabolism, is detected. Moreover, primary cell lines with FPLD2 mutation decrease the mitochondrial ATP production if compared with the control, even if no differences are observed in the oxygen consumption rate of bioenergetic parameters (i.e., basal and maximal respiration, spare respiratory capacity, and ATP turnover). Conversely, glycolysis is only inhibited in FPLD2 fibroblast cell lines. We notice that the amount of ATP produced in the fibroblasts is higher than in the preadipocytes, and likewise in the control, with respect to FPLD2, due to a more active oxidative phosphorylation (OXPHOS) and glycolysis. Moreover, the proton leak parameter, which characterizes the transformation of white adipose tissue to brown/beige adipose tissue, is unaffected by FPLD2 mutation. The metabolic profile of fibroblasts and preadipocytes is confirmed by the ability of these cell lines to increase the metabolic potential of both OXPHOS and glycolysis under energy required independently by the FPLD2 mutation.

Chlorophyll Derivatives from Marine Cyanobacteria with Lipid-Reducing Activities.

Marine organisms, particularly cyanobacteria, are important resources for the production of bioactive secondary metabolites for the treatment of human diseases. In this study, a bioassay-guided approach was used to discover metabolites with lipid-reducing activity. Two chlorophyll derivatives were successfully isolated, the previously described 132-hydroxy-pheophytin a (1) and the new compound 132-hydroxy-pheofarnesin a (2). The structure elucidation of the new compound 2 was established based on one- and two-dimensional (1D and 2D) NMR spectroscopy and mass spectrometry. Compounds 1 and 2 showed significant neutral lipid-reducing activity in the zebrafish Nile red fat metabolism assay after 48 h of exposure with a half maximal effective concentration (EC50) of 8.9 ± 0.4 µM for 1 and 15.5 ± 1.3 µM for 2. Both compounds additionally reduced neutral lipid accumulation in 3T3-L1 multicellular spheroids of murine preadipocytes. Molecular profiling of mRNA expression of some target genes was evaluated for the higher potent compound 1, which indicated altered peroxisome proliferator activated receptor gamma (PPARγ) mRNA expression. Lipolysis was not affected. Different food materials (Spirulina, Chlorella, spinach, and cabbage) were evaluated for the presence of 1, and the cyanobacterium Spirulina, with GRAS (generally regarded as safe) status for human consumption, contained high amounts of 1. In summary, known and novel chlorophyll derivatives were discovered from marine cyanobacteria with relevant lipid-reducing activities, which in the future may be developed into nutraceuticals.

Cysteine dioxygenase type 1 promotes adipogenesis via interaction with peroxisome proliferator-activated receptor gamma.

Mammalian cysteine dioxygenase type 1 (CDO1) is an essential enzyme for taurine biosynthesis and the biodegradation of toxic cysteine. As previously suggested, Cdo1 may be a marker of liposarcoma progression and adipogenic differentiation, but the role of Cdo1 in adipogenesis has yet been reported. In this study, we found that the expression of Cdo1 is dramatically elevated during adipogenic differentiation of 3T3-L1 pre-adipocytes and mouse bone marrow-derived mesenchymal stem cells (mBMSCs). Conversely, knockdown of Cdo1 inhibited expression of adipogenic specific genes and lipid droplet formation in 3T3-L1 cells and mBMSCs. Mechanistically, we found Cdo1 interacted with Pparγ in response to adipogenic stimulus. Further, depletion of Cdo1 reduced the recruitment of Pparγ to the promoters of C/EBPα and Fabp4. Collectively, our finding indicates that Cdo1 may be a co-activator of Pparγ in adipogenesis, and may contribute to the development of disease associated with excessive adipose tissue.

Coordinate functional regulation between microsomal prostaglandin E synthase-1 (mPGES-1) and peroxisome proliferator-activated receptor γ (PPARγ) in the conversion of white-to-brown adipocytes.

Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated nuclear receptor and a master regulator of adipogenesis. Microsomal prostaglandin E (PGE) synthase-1 (mPGES-1) is an inducible enzyme that couples with cyclooxygenase-2 for the biosynthesis of PGE2. In this study we demonstrate the existence of a coordinate functional interaction between PPARγ and mPGES-1 in controlling the process of pre-adipocyte differentiation in white adipose tissue (WAT). Adipocyte-specific PPARγ knock-out mice carrying an aP2 promoter-driven Cre recombinase transgene showed a blunted response to the adipogenic effects of a high fat diet. Pre-adipocytes from these knock-out mice showed loss of PPARγ and were resistant to rosiglitazone-induced WAT differentiation. In parallel, WAT from these mice showed increased expression of uncoupling protein 1, a mitochondrial enzyme that dissipates chemical energy as heat. Adipose tissue from mice lacking PPARγ also showed mPGES-1 up-regulation and increased PGE2 levels. In turn, PGE2 suppressed PPARγ expression and blocked rosiglitazone-induced pre-adipocyte differentiation toward white adipocytes while directly elevating uncoupling protein 1 expression and pre-adipocyte differentiation into mature beige/brite adipocytes. Consistently, pharmacological mPGES-1 inhibition directed pre-adipocyte differentiation toward white adipocytes while suppressing differentiation into beige/brite adipocytes. This browning effect was reproduced in knockdown experiments using a siRNA directed against mPGES-1. The effects of PGE2 on pre-adipocyte differentiation were not seen in mice lacking PPARγ in adipose tissue and were not mirrored by other eicosanoids (i.e. leukotriene B4). Taken together, these findings identify PGE2 as a key regulator of white-to-brown adipogenesis and suggest the existence of a coordinate regulation of adipogenesis between PPARγ and mPGES-1.

BMP and activin membrane-bound inhibitor (BAMBI) inhibits the adipogenesis of porcine preadipocytes through Wnt/ß-catenin signaling pathway.

The process of differentiation from preadipocytes to adipocytes contributes to adipose tissue expansion in obesity. Blocking adipogenesis may be conducive to the etiology of obesity-related diseases. BMP and activin membrane-bound inhibitor (BAMBI) is a transmembrane protein, which was identified as a target of ß-catenin in colorectal and hepatocellular tumor cells. However, whether BAMBI affects adipogenesis by Wnt/ß-catenin signaling remains to be explored. In this study, we distinguish BAMBI as an inhibitor of preadipocytes differentiation. We found that BAMBI was downregulated during preadipocytes differentiation. Knockdown of BAMBI increased adipogenesis and blocked Wnt/ß-catenin signaling by repressing ß-catenin accumulation. In BAMBI overexpression cells, lipid accumulation was reduced by promoting nuclear translocation of ß-catenin. Lithium chloride (LiCl) is an activator of Wnt/ß-catenin signaling, which is an inhibitor of glycogen synthetase kinase-3 (GSK-3), maintaining the stability of ß-catenin in cytosolic. We showed BAMBI strengthened the anti-adipogenic effects of LiCl. In addition, the results indicated that BAMBI was upregulated by ß-catenin. These observations illuminated that BAMBI inhibits adipogenesis by a feedback loop (BAMBI→ß-catenin nuclear translocation→BAMBI), which forms with Wnt/ß-catenin signaling.

The growth factor-like adipokine tartrate-resistant acid phosphatase 5a interacts with the rod G3 domain of adipocyte-produced nidogen-2.

The adipokine tartrate resistant acid phosphatase (TRAP) 5a isoform exerts a growth factor-effect on pre-adipocytes. This study aimed to identify potential TRAP 5a interacting proteins in pre-adipocytes using pull down assays in combination with mass spectrometry. Nidogen-2, a protein shown to be expressed intracellularly and for secretion by pre-adipocytes, was shown to interact, through its globular G3 domain, with TRAP 5a in vitro. In vivo, TRAP 5a interacted with nidogen-2 in cultured 3T3-L1 mouse pre-adipocytes, as well as with transforming growth factor-ß (TGF-ß) interacting protein (TRIP-1), which is a protein that has previously been suggested to interact with TRAP in bone. In addition, TRAP 5a and nidogen-2 co-localized in adipose tissue cells in situ. These results indicate that TRAP 5a interacts with nidogen-2 and TRIP-1 in pre-adipocytic cells.

The role of Sirtuin 1 in regulation of fibrotic genes expression in pre-adipocytes.

Purpose: Considering inhibition of pre-adipocyte cells differentiation in adipose tissue fibrosis, we aimed to explore whether Sirt1 and Hif-1α in pre-adipocytes have a significant effect on fibrotic gene expression. Methods: 3T3-L1 pre-adipocytes were transfected with SIRT1-specific siRNA, confirmed by real-time polymerase chain reaction (RT-PCR) and western blotting. Additionally, cells were treated with varying concentrations of resveratrol and sirtinol as the activator and inhibitor of Sirt1, respectively. Involvement of Hif-1α was evaluated by treatment with echinomycin. Subsequently, we assessed the gene and protein expressions related to fibrosis in the extracellular matrix of adipose tissue, including collagen VI (Col VI), lysyl oxidase (Lox), matrix metalloproteinase-2 (Mmp-2), Mmp-9, and osteopontin (Opn) in pre-adipocytes through RT-PCR and western blot. Results: The current study demonstrated that Sirt1 knockdown and reduced enzyme activity significantly increased the expression of Col VI, Lox, Mmp-2, Mmp-9, and Opn genes in the treated 3T3-L1 cells compared to the control group. Interestingly, resveratrol significantly decreased the gene expression related to the fibrosis pathway. Inhibition of Hif-1α by echinomycin led to a significant reduction in Col VI, Mmp-2, and Mmp-9 gene expression in the treated group compared to the control. Conclusion: This study highlights that down-regulation of Sirt1 might be a predisposing factor in the emergence of adipose tissue fibrosis by enhancing the expression of extracellular matrix (ECM) components. Activation of Sirt1, similar to suppressing of Hif-1α in pre-adipocytes may be a beneficial approach for attenuating fibrotic gene expression. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-024-01389-4.

Senescence induces proteolytically-active PAPP-A secretion and association with extracellular vesicles in human pre-adipocytes.

Senescence is a cellular response to various stressors characterized by irreversible cell cycle arrest, resistance to apoptosis and expression of a senescence-associated secretory phenotype (SASP). Interestingly, studies where senescent cells were deleted in mice produced beneficial effects similar to those where the zinc metalloproteinase, PAPP-A, was deleted in mice. In this study, we investigated the effect of senescence on PAPP-A secretion and activity in primary cultures of adult human pre-adipocytes. Cultured pre-adipocytes were isolated from subcutaneous (Sub) and omental (Om) fat. Senescence was induced with low dose etoposide. PAPP-A protein was measured by an ultrasensitive PAPP-A ELISA. PAPP-A proteolytic activity was measured by a specific substrate cleavage assay. Senescence significantly increased PAPP-A levels in both Sub and Om conditioned medium (CM) 8- to 15-fold over non-senescent CM. Proteolytic activity reflected PAPP-A protein with 12- to 18-fold greater activity in senescent CM versus non-senescent CM. Furthermore, PAPP-A was found at high levels on the surface of extracellular vesicles secreted by senescent pre-adipocytes and was proteolytically active. In conclusion, we identified enzymatically active PAPP-A as a component of human pre-adipocyte SASP. This recognition warrants further investigation of PAPP-A as a new biomarker for senescence and a potential therapeutic target to control of the spread of senescence in adipose tissue.

Coptis chinensis, and extracts of guava and mulberry leaves present good inhibiting potential on obesity and associated metabolic disorders in high-fat diet obesity mice model.

This study aimed to investigate the anti-obesity effects of Coptis chinensis (CC), BALASAN (combinational guava leaf extract and mulberry leaf extract), and CC/BALASAN (CC/BAL) on high-fat diet-induced obese C57BL/6 mice and to explore possible mediating mechanisms in 3T3-L1 pre-adipocytes. Oil red-O stain was used to test the effects of CC, BALASAN, and CC/BAL on the differentiation of 3T3-L1 pre-adipocytes. Additionally, real-time PCR was used to detect the expression of genes involved in adipocyte differentiation and inflammation-related genes in adipose tissue of mice that were fed a high-fat diet. CC, BALASAN, and CC/BAL inhibited the differentiation of 3T3-L1 pre-adipocytes and exhibited excellent inhibitory ability against the expression of PPARγ and RXRα genes associated with adipocyte differentiation. Replenishing mice with a high-fat diet with CC, BALASAN, and CC/BAL reduced body weight gaining and blood glucose and plasma cholesterol levels. CC also effectively reduced liver weight, whereas BALASAN and CC/BAL had no inhibitory effect. In addition, CC effectively inhibited the expression of C/EBP-α in adipose tissue. Interestingly, BALASAN not only inhibited the expression of C/EBP-α, but also that of PPARγ, RXRα, and TNFα. Such data indicated that CC, BALASAN, and CC/BAL may have potentially beneficial effects against obesity and associated metabolic disorders by down-regulating the PPARγ/RXRα pathway.

Sfrp5 expression and secretion in adipocytes are up-regulated during differentiation and are negatively correlated with insulin resistance.

We have examined the patterns of Sfrp5 (secreted frizzled-related protein 5) mRNA expression and protein secretion during adipocyte differentiation, and investigated the potential role of Sfrp5 in IR (insulin resistance) in adipocytes. 3T3-L1 pre-adipocytes were induced for differentiation, and RT-PCR (reverse transcription-PCR) and ELISA assays were used to determine Sfrp5 mRNA expression and protein secretion. The results showed that with the differentiation and maturity of pre-adipocytes, transcription and protein secretion of Sfrp5 gradually increased, peaking on the 9th day of differentiation. Sfrp5 mRNA expression in mature adipocytes was decreased by 20, 22 and 32 upon treatment with dexamethasone, insulin and TNF (tumour necrosis factor) respectively, whereas Sfrp5 protein secretion was decreased by 15, 17 and 30%, correspondingly. In contrast, Sfrp5 mRNA expression in mature adipose was increased by 34 and 19% upon treatment with rosiglitazone and metformin respectively, whereas Sfrp5 protein secretion was increased by 10 and 6%, correspondingly. In conclusion, Sfrp5 mRNA expression and protein secretion depend on the differentiation of adipocytes. The dysregulation of Sfrp5 expression and secretion is directly correlated with IR. Up-regulation of Sfrp5 expression and secretion in adipocytes may be one crucial mechanism by which rosiglitazone and metformin improve insulin sensitivity.

ACAT2 Is a Novel Negative Regulator of Pig Intramuscular Preadipocytes Differentiation.

Intramuscular fat (IMF) is considered as the fat deposited between muscle fibers. The extracellular matrix microenvironment of adipose tissue is of critical importance for the differentiation, remodeling and function of adipocytes. Therefore, in this study we extracted the muscle tissue centrifugal fluid (MTF) of the longissimus dorsi of Erhualian pigs to mimic the microenvironment of intramuscular pre-adipocytes. MTF of pigs with low intramuscular fat level can inhibit pig intramuscular pre-adipocytes differentiation. Then, proteomics technology (iTRAQ) was used to analyze the MTF with different IMF content, and it was found that individuals with high IMF had low ACAT2 (Acyl-CoA: cholesterol acyltransferases 2) levels, while individuals with low IMF had high ACAT2 levels. Significant changes took place in the pathways involved in coenzyme A, which are closely related to fat and cholesterol metabolism. Therefore, we speculate that ACAT2, as an important element involved in cholesterol metabolism, may become a potential molecular marker for the mechanism of pig intramuscular preadipocytes differentiation. Overexpression of ACAT2 in pig intramuscular pre-adipocytes can inhibit their differentiation, while adding ACAT2 inhibitor avasimibe can rescue the process. Knockdown of srebp2 or ldlr, which are two key genes closely related to ACAT2 and cholesterol metabolism, can inhibit pig intramuscular pre-adipocytes differentiation. Overall, our results suggest that ACAT2 is a novel negative regulator of intramuscular adipocyte differentiation through regulation of pparγ, cebpα signaling and srebp2/ldlr signaling involved in cholesterol metabolism.

EGCG Prevents the Onset of an Inflammatory and Cancer-Associated Adipocyte-like Phenotype in Adipose-Derived Mesenchymal Stem/Stromal Cells in Response to the Triple-Negative Breast Cancer Secretome.

BACKGROUND: Triple-negative breast cancer (TNBC) cells secretome induces a pro-inflammatory microenvironment within the adipose tissue, which hosts both mature adipocytes and adipose-derived mesenchymal stem/stromal cells (ADMSC). The subsequent acquisition of a cancer-associated adipocyte (CAA)-like phenotype is, however, unknown in ADMSC. While epidemiological studies suggest that consuming a polyphenol-rich diet reduces the incidence of some obesity-related cancers, the chemopreventive impact of green tea-derived epigallocatechin-3-gallate (EGCG) against the cues that trigger the CAA phenotype remain undocumented in ADMSC. METHODS: Human ADMSC were exposed to human TNBC-derived MDA-MB-231 conditioned media (TNBC cells secretome) supplemented or not with EGCG. Differential gene expression was assessed through RNA-Seq analysis and confirmed by RT-qPCR. Protein expression levels and the activation status of signal transduction pathways mediators were determined by Western blotting. ADMSC chemotaxis was assessed by a real-time cell migration assay. RESULTS: The TNBC cells secretome induced in ADMSC the expression of the CAA cytokines CCL2, CCL5, IL-1ß, and IL-6, and of immunomodulators COX2, HIF-1α, VEGFα, and PD-L1. The epithelial-to-mesenchymal biomarker Snail was found to control the CAA phenotype. EGCG inhibited the induction of CAA genes and the activation status of Smad2 and NF-κB. The induced chemotactic response was also inhibited by EGCG. CONCLUSION: The induction of an inflammatory and CAA-like phenotype in ADMSC can be triggered by the TNBC cells secretome, while still efficiently prevented by diet-derived polyphenols.

miR-146a-5p modulates cellular senescence and apoptosis in visceral adipose tissue of long-lived Ames dwarf mice and in cultured pre-adipocytes.

MicroRNAs (miRNAs) are potent regulators of multiple biological processes. Previous studies have demonstrated that miR-146a-5p increases in normal mice during aging, while long-living Ames dwarf (df/df) mice maintain youthful levels of this miRNA. The aim of this study was to elucidate the involvement of miR-146a-5p in modulating cellular senescence and apoptosis in visceral adipose tissue of df/df mice and cultured pre-adipocytes. To test the effects of miR-146a-5p overexpression on visceral adipose tissue, wild-type, and df/df mice, were treated with miRNA-negative control-base and df/df were transfected with 4 or 8 µg/g of a miR-146a-5p mimetic, respectively. Effects of miR-146a-5p overexpression were also evaluated in 3T3-L1 cells cultured under high and normal glucose conditions. Treatment with miR-146a-5p mimetic increased cellular senescence and inflammation and decreased pro-apoptotic factors in visceral adipose tissue of df/df mice. The miR-146a-5p mimetic induced similar effects in 3T3-L1 cells cultivated at normal but not high glucose levels. Importantly, 3T3-L1 HG cells in high glucose conditions showed significantly higher expression of miR-146a-5p than 3T3-L1 grown in normal glucose conditions. These results indicate that miR-146a-5p can be a marker for cellular senescence. This miRNA represents one of the significant SASP factors that if not precisely regulated, can accentuate inflammatory responses and stimulate senescence in surrounding non-senescent cells. The role of miR-146a-5p is different in healthy versus stressed cells, suggesting potential effects of this miRNA depend on overall organismal health, aging, and metabolic state.

Anti-Obesity Effect of Nostoc commune Ethanol Extract In Vitro and In Vivo.

Nostoc commune is an edible terrestrial blue-green alga. It has shown many beneficial effects on human health. This study aimed to investigate the phytochemical assay of N. commune ethanol extract (NEE) and its anti-obesity effects. The effect of a high-calorie diet on lipid accumulation in 3T3-L1 preadipocytes is investigated, and a Wistar rat model is used to demonstrate the anti-obesity effect of NEE and its mechanism. The results showed that the NEE has phytochemical compounds, such as total polyphenol, total flavonoids, and total terpenoids. NEE was also shown to suppress cell proliferation and lipid accumulation (26.9%) in 3T3-L1 preadipocytes. Furthermore, NEE reduced the body weight (13.5%), fat tissue weight (13.3%), and the serum FFA (19.4%), TG (14.2%), TC (11.8%), and LDL-C (16.4%) of rats. In histopathology, NEE was shown to diminish the size of adipocytes and hepatic lipid droplets. The NEE downregulated the mRNA expression of adipogenesis (PPAR-γ, SREBP-1c) and lipid lysis-related genes (ATGL, HSL) in epididymal adipose tissue. The NEE also upregulated the mRNA expression of ß-oxidation related genes (AMPK, CPT-1, PPAR-α) in the liver. Overall, this study suggests NEE has the potential to be developed as a functional food for anti-obesity.

In vitro effects of bioflavonoids rich lemon extract on pre-adipocyte differentiation.

Lemon fruit is a source of bioactive compounds, which has many beneficial effects on health. Obesity is characterized by over-accumulation of adipose tissue as a result of increased adipocyte size and number. Adipogenesis is mediated and assisted by various transcription factors that induce lipid-metabolizing enzymes followed by an increase of perilipin expression and lipid droplets generation. Here, we evaluate the effect of lemon extract (LE) as radical scavenger and the consequent regulation of adipocyte differentiation and lipid accumulation. 3T3-L1 murine pre-adipocytes were differentiated and treated with different LE concentrations. The high percentages of flavonoid contained in LE led to a significant inhibition of DPPH radical and reactive oxygen species, demonstrating a strong radical scavenger activity. Treatment of 3T3-cells with LE showed a significant decrease of perilipin expression, subsequently confirmed by the reduction of lipid droplet accumulation, resulting from Oil Red O Staining and by the downregulation of PPARγ and DGAT-1mRNA.

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.

Qing-Luo-Yin Alleviated Monocytes/Macrophages-Mediated Inflammation in Rats with Adjuvant-Induced Arthritis by Disrupting Their Interaction with (Pre)-Adipocytes Through PPAR-γ Signaling.

BACKGROUND: The Chinese herbal formula Qing-Luo-Yin (QLY) has been successfully used in rheumatoid arthritis treatment for decades. It exhibits notable immune and metabolism regulatory properties. Thereby, we investigated its effects on the interplay between (pre)-adipocytes and monocytes/macrophages under adjuvant-induced arthritis (AIA) circumstances. METHODS: Fat reservoir and histological characteristics of white fat tissues (WAT) in AIA rats receiving QLY treatment were examined upon sacrifice. Metabolic parameters, clinical indicators, and oxidative stress levels were determined using corresponding kits, while mRNA/protein expression was investigated by PCR and immunoblotting methods. M1 macrophage distribution in WAT was assessed by flow cytometry. The effects of QLY on (pre)-adipocytes were further validated by experiments in vitro. RESULTS: Compared with normal healthy controls, body weight and circulating triglyceride were declined in AIA rats, but serological levels of free fatty acids and low-density lipoprotein cholesterol were increased. mRNA IL-1ß and iNOS expression in white blood cells and rheumatoid factor, C-reactive protein, anti-cyclic citrullinated peptide antibody, MCP-1 and IL-1ß production in serum/WAT were up-regulated. Obvious CD86+CD11b+ macrophages were enriched in WAT. Meanwhile, expression of PPAR-γ and SIRT1 and secretion of adiponectin and leptin in these AIA rats were impaired. QLY restored all these pathological changes. Of note, it significantly stimulated PPAR-γ expression in the treated AIA rats. Accordingly, QLY-containing serum promoted SCD-1, PPAR-γ, and SIRT1 expression in pre-adipocytes cultured in vitro. AIA rats-derived peripheral blood mononuclear cells suppressed PPAR-γ and SCD-1 expression in co-cultured pre-adipocytes, but serum from AIA rats receiving QLY treatment did not exhibit this potential. The changes on PPAR-γ expression eventually resulted in varied adipocyte differentiation statuses. PPAR-γ selective inhibitor T0070907 abrogated QLY-induced MCP-1 production decline in LPS-primed pre-adipocytes and reduced adiponectin secretion. CONCLUSION: QLY was potent in promoting PPAR-γ expression and consequently disrupted inflammatory feedback in WAT by altering monocytes/macrophages polarization and adipocytes differentiation.