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Scientific Reports May 2024The E3 ubiquitin-ligase UHRF1 is an epigenetic regulator coordinating DNA methylation and histone modifications. However, little is known about how it regulates...
The E3 ubiquitin-ligase UHRF1 is an epigenetic regulator coordinating DNA methylation and histone modifications. However, little is known about how it regulates adipogenesis or metabolism. In this study, we discovered that UHRF1 is a key regulatory factor for adipogenesis, and we identified the altered molecular pathways that UHRF1 targets. Using CRISPR/Cas9-based knockout strategies, we discovered the whole transcriptomic changes upon UHRF1 deletion. Bioinformatics analyses revealed that key adipogenesis regulators such PPAR-γ and C/EBP-α were suppressed, whereas TGF-β signaling and fibrosis markers were upregulated in UHRF1-depleted differentiating adipocytes. Furthermore, UHRF1-depleted cells showed upregulated expression and secretion of TGF-β1, as well as the glycoprotein GPNMB. Treating differentiating preadipocytes with recombinant GPNMB led to an increase in TGF-β protein and secretion levels, which was accompanied by an increase in secretion of fibrosis markers such as MMP13 and a reduction in adipogenic conversion potential. Conversely, UHRF1 overexpression studies in human cells demonstrated downregulated levels of GPNMB and TGF-β, and enhanced adipogenic potential. In conclusion, our data show that UHRF1 positively regulates 3T3-L1 adipogenesis and limits fibrosis by suppressing GPNMB and TGF-β signaling cascade, highlighting the potential relevance of UHRF1 and its targets to the clinical management of obesity and linked metabolic disorders.
Topics: Animals; Humans; Mice; 3T3-L1 Cells; Adipocytes; Adipogenesis; CCAAT-Enhancer-Binding Proteins; Cell Differentiation; Eye Proteins; Fibrosis; Membrane Glycoproteins; Signal Transduction; Transforming Growth Factor beta; Ubiquitin-Protein Ligases
PubMed: 38789534
DOI: 10.1038/s41598-024-62508-y -
Cells May 2024Peroxisome proliferator-activated receptor alpha (PPARA) is a ligand-activated transcription factor that is a key mediator of lipid metabolism and metabolic stress in...
Peroxisome proliferator-activated receptor alpha (PPARA) is a ligand-activated transcription factor that is a key mediator of lipid metabolism and metabolic stress in the liver. Accumulating evidence shows that PPARA regulates the expression of various protein coding and non-coding genes that modulate metabolic stress in the liver. CBFA2/RUNX1 partner transcriptional co-repressor 3 (CBFA2T3) is a DNA-binding transcription factor that belongs to the myeloid translocation gene family. Many studies have shown that CBFA2T3 is associated with acute myeloid leukemia. Especially, CBFA2T3-GLIS2 fusion is a chimeric oncogene associated with a poor survival rate in pediatric acute megakaryocytic leukemia. A previous study identified that PPARA activation promoted induction in liver and that may have a modulatory role in metabolic stress. However, the effect of CBFA2T3 gene expression on metabolic stress is not understood. In this study, the PPARA ligand WY14643 activated expression in mouse liver. Glucose tolerance test and insulin tolerance test data showed that insulin resistance is increased in mice compared to mice. Hepatic CBFA2T3 modulates heat shock protein family A member 1b and carbonic anhydrase 5a expression. Histology analysis revealed lipid droplet and lipid accumulation in the liver of fasting mice but not mice. The expression of lipid accumulation-related genes, such as , , and , was increased in the liver of fasting mice. Especially, basal expression levels of mRNA were elevated in the liver of mice compared to mice. Much higher induction of mRNA was seen in the liver of mice after WY14643 administration. These results indicate that hepatic CBFA2T3 is a PPARA-sensitive gene that may modulate metabolic stress in mouse liver.
Topics: Animals; Lipid Metabolism; Liver; Mice; Fasting; PPAR alpha; Male; Mice, Inbred C57BL; Insulin Resistance; Mice, Knockout; Pyrimidines
PubMed: 38786053
DOI: 10.3390/cells13100831 -
PloS One 2024Cofactors interacting with PPARγ can regulate adipogenesis and adipocyte metabolism by modulating the transcriptional activity and selectivity of PPARγ signaling....
Cofactors interacting with PPARγ can regulate adipogenesis and adipocyte metabolism by modulating the transcriptional activity and selectivity of PPARγ signaling. ZFP407 was previously demonstrated to regulate PPARγ target genes such as GLUT4, and its overexpression improved glucose homeostasis in mice. Here, using a series of molecular assays, including protein-interaction studies, mutagenesis, and ChIP-seq, ZFP407 was found to interact with the PPARγ/RXRα protein complex in the nucleus of adipocytes. Consistent with this observation, ZFP407 ChIP-seq peaks significantly overlapped with PPARγ ChIP-seq peaks, with more than half of ZFP407 peaks overlapping with PPARγ peaks. Transcription factor binding motifs enriched in these overlapping sites included CTCF, RARα/RXRγ, TP73, and ELK1, which regulate cellular development and function within adipocytes. Site-directed mutagenesis of frequent PPARγ phosphorylation or SUMOylation sites did not prevent its regulation by ZFP407, while mutagenesis of ZFP407 domains potentially necessary for RXR and PPARγ binding abrogated any impact of ZFP407 on PPARγ activity. These data suggest that ZFP407 controls the activity of PPARγ, but does so independently of post-translational modifications, likely by direct binding, establishing ZFP407 as a newly identified PPARγ cofactor. In addition, ZFP407 ChIP-seq analyses identified regions that did not overlap with PPARγ peaks. These non-overlapping peaks were significantly enriched for the transcription factor binding motifs of TBX19, PAX8, HSF4, and ZKSCAN3, which may contribute to the PPARγ-independent functions of ZFP407 in adipocytes and other cell types.
Topics: Animals; Humans; Mice; 3T3-L1 Cells; Adipocytes; Binding Sites; DNA-Binding Proteins; Phosphorylation; PPAR gamma; Protein Binding; Retinoid X Receptor alpha; Signal Transduction; Sumoylation; Transcription Factors
PubMed: 38781157
DOI: 10.1371/journal.pone.0294003 -
PloS One 2024The purpose of this study is to assess the bioactive peptides derived from the defatted lemon basil seeds hydrolysate (DLSH) for their ability to inhibit pancreatic...
Lemon basil seed-derived peptide: Hydrolysis, purification, and its role as a pancreatic lipase inhibitor that reduces adipogenesis by downregulating SREBP-1c and PPAR-γ in 3T3-L1 adipocytes.
The purpose of this study is to assess the bioactive peptides derived from the defatted lemon basil seeds hydrolysate (DLSH) for their ability to inhibit pancreatic lipase, decrease intracellular lipid accumulation, and reduce adipogenesis. Response surface methodology (RSM) was employed to optimize trypsin hydrolysis conditions for maximizing lipase inhibitory activity (LI). A hydrolysis time of 387.06 min, a temperature of 49.03°C, and an enzyme concentration of 1.61% w/v, resulted in the highest LI with an IC50 of 368.07 μg/mL. The ultrafiltration of the protein hydrolysate revealed that the fraction below 0.65kDa exhibited the greatest LI potential. Further purification via RP-HPLC identified the Gly-Arg-Ser-Pro-Asp-Thr-His-Ser-Gly (GRSPDTHSG) peptide in the HPLC fraction F1 using mass spectrometry. The peptide was synthesized and demonstrated LI with an IC50 of 0.255 mM through a non-competitive mechanism, with a constant (Ki) of 0.61 mM. Docking studies revealed its binding site with the pancreatic lipase-colipase complex. Additionally, GRSPDTHSG inhibited lipid accumulation in 3T3-L1 cells in a dose-dependent manner without cytotoxic effects. Western blot analysis indicated downregulation of PPAR-γ and SREBP-1c levels under GRSPDTHSG treatment, while an increase in AMPK-α phosphorylation was observed, suggesting a role in regulating cellular lipid metabolism. Overall, GRSPDTHSG demonstrates potential in attenuating lipid absorption and adipogenesis, suggesting a prospective application in functional foods and nutraceuticals.
Topics: Mice; Animals; Adipogenesis; 3T3-L1 Cells; Seeds; PPAR gamma; Adipocytes; Hydrolysis; Lipase; Peptides; Sterol Regulatory Element Binding Protein 1; Ocimum basilicum; Down-Regulation; Molecular Docking Simulation
PubMed: 38776280
DOI: 10.1371/journal.pone.0301966 -
Analytica Chimica Acta Jun 2024Peroxisome proliferator-activated receptors (PPARs) belong to the superfamily of nuclear receptors and represent the targets for the therapeutical treatment of type 2...
BACKGROUND
Peroxisome proliferator-activated receptors (PPARs) belong to the superfamily of nuclear receptors and represent the targets for the therapeutical treatment of type 2 diabetes, dyslipidemia and hyperglycemia associated with metabolic syndrome. Some medicinal plants have been traditionally used to treat this kind of metabolic diseases. Today only few drugs targeting PPARs have been approved and for this reason, the rapid identification of novel ligands and/or chemical scaffolds starting from natural extracts would benefit of a selective affinity ligand fishing assay.
RESULTS
In this paper we describe the development of a new ligand fishing assay based on size exclusion chromatography (SEC) coupled to LC-MS for the analysis of complex samples such as botanical extracts. The known PPARα and PPARγ ligands, WY-14643 and rosiglitazone respectively, were used for system development and evaluation. The system has found application on an Allium lusitanicum methanolic extract, containing saponins, a class of chemical compounds which have attracted interest as PPARs ligands because of their hypolipidemic and insulin-like properties.
SIGNIFICANCE
A new SEC-AS-MS method has been developed for the affinity screening of PPARα and PPARγ ligands. The system proved to be highly specific and will be used to improve the throughput for the identification of new selective metabolites from natural souces targeting PPARα and PPARγ.
Topics: PPAR gamma; PPAR alpha; Plant Extracts; Ligands; Chromatography, Gel; Mass Spectrometry; Rosiglitazone; Humans; Biological Products; Pyrimidines
PubMed: 38772654
DOI: 10.1016/j.aca.2024.342666 -
Molecular Metabolism Jul 2024The prevalence of metabolic diseases is increasing globally at an alarming rate; thus, it is essential that effective, accessible, low-cost therapeutics are developed....
OBJECTIVE
The prevalence of metabolic diseases is increasing globally at an alarming rate; thus, it is essential that effective, accessible, low-cost therapeutics are developed. Peroxisome proliferator-activated receptors (PPARs) are transcription factors that tightly regulate glucose homeostasis and lipid metabolism and are important drug targets for the treatment of type 2 diabetes and dyslipidemia. We previously identified LDT409, a fatty acid-like compound derived from cashew nut shell liquid, as a novel pan-active PPARα/γ/δ compound. Herein, we aimed to assess the efficacy of LDT409 in vivo and investigate the molecular mechanisms governing the actions of the fatty acid mimetic LDT409 in diet-induced obese mice.
METHODS
C57Bl/6 mice (6-11-month-old) were fed a chow or high fat diet (HFD) for 4 weeks; mice thereafter received once daily intraperitoneal injections of vehicle, 10 mg/kg Rosiglitazone, 40 mg/kg WY14643, or 40 mg/kg LDT409 for 18 days while continuing the HFD. During treatments, body weight, food intake, glucose and insulin tolerance, energy expenditure, and intestinal lipid absorption were measured. On day 18 of treatment, tissues and plasma were collected for histological, molecular, and biochemical analysis.
RESULTS
We found that treatment with LDT409 was effective at reversing HFD-induced obesity and associated metabolic abnormalities in mice. LDT409 lowered food intake and hyperlipidemia, while improving insulin tolerance. Despite being a substrate of both PPARα and PPARγ, LDT409 was crucial for promoting hepatic fatty acid oxidation and reducing hepatic steatosis in HFD-fed mice. We also highlighted a role for LDT409 in white and brown adipocytes in vitro and in vivo where it decreased fat accumulation, increased lipolysis, induced browning of WAT, and upregulated thermogenic gene Ucp1. Remarkably, LDT409 reversed HFD-induced weight gain back to chow-fed control levels. We determined that the LDT409-induced weight-loss was associated with a combination of increased energy expenditure (detectable before weight loss was apparent), decreased food intake, increased systemic fat utilization, and increased fecal lipid excretion in HFD-fed mice.
CONCLUSIONS
Collectively, LDT409 represents a fatty acid mimetic that generates a uniquely favorable metabolic response for the treatment of multiple abnormalities including obesity, dyslipidemia, metabolic dysfunction-associated steatotic liver disease, and diabetes. LDT409 is derived from a highly abundant natural product-based starting material and its development could be pursued as a therapeutic solution to the global metabolic health crisis.
Topics: Animals; Mice; Mice, Inbred C57BL; Obesity; Diet, High-Fat; Male; Fatty Acids; Fatty Liver; PPAR alpha; Lipid Metabolism; Peroxisome Proliferator-Activated Receptors; Liver; Non-alcoholic Fatty Liver Disease
PubMed: 38763495
DOI: 10.1016/j.molmet.2024.101958 -
Free Radical Biology & Medicine Aug 2024Androgen receptor (AR)-targeting therapy induces oxidative stress in prostate cancer. However, the mechanism of oxidative stress induction by AR-targeting therapy...
Oxidative stress in peroxisomes induced by androgen receptor inhibition through peroxisome proliferator-activated receptor promotes enzalutamide resistance in prostate cancer.
Androgen receptor (AR)-targeting therapy induces oxidative stress in prostate cancer. However, the mechanism of oxidative stress induction by AR-targeting therapy remains unclear. This study investigated the mechanism of oxidative stress induction by AR-targeting therapy, with the aim to develop novel therapeutics targeting oxidative stress induced by AR-targeting therapy. Intracellular reactive oxygen species (ROS) was examined by fluorescence microscopy and flow cytometry analysis. The effects of silencing gene expression and small molecule inhibitors on gene expression and cytotoxic effects were examined by quantitative real-time PCR and cell proliferation assay. ROS induced by androgen depletion co-localized with peroxisomes in prostate cancer cells. Among peroxisome-related genes, PPARA was commonly induced by AR inhibition and involved in ROS production via PKC signaling. Inhibition of PPARα by specific siRNA and a small molecule inhibitor suppressed cell proliferation and increased cellular sensitivity to the antiandrogen enzalutamide in prostate cancer cells. This study revealed a novel pathway by which AR inhibition induced intracellular ROS mainly in peroxisomes through PPARα activation in prostate cancer. This pathway is a promising target for the development of novel therapeutics for prostate cancer in combination with AR-targeting therapy such as antiandrogen enzalutamide.
Topics: Male; Humans; Phenylthiohydantoin; Nitriles; Peroxisomes; Oxidative Stress; Drug Resistance, Neoplasm; Benzamides; Receptors, Androgen; Reactive Oxygen Species; PPAR alpha; Cell Proliferation; Prostatic Neoplasms; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Signal Transduction; Androgen Receptor Antagonists; RNA, Small Interfering
PubMed: 38762061
DOI: 10.1016/j.freeradbiomed.2024.05.030 -
Senolytic combination of dasatinib and quercetin attenuates renal damage in diabetic kidney disease.Phytomedicine : International Journal... Jul 2024Senolytic combination of dasatinib and quercetin (DQ) is the most studied senolytics drugs used to treat various age-related diseases. However, its protective activity...
BACKGROUND
Senolytic combination of dasatinib and quercetin (DQ) is the most studied senolytics drugs used to treat various age-related diseases. However, its protective activity against diabetic kidney disease (DKD) and underlying mechanisms are uncertain.
PURPOSE
To investigate the functions and potential mechanisms of the senolytics DQ on DKD.
METHODS
Diabetic db/db mice were administrated DQ or transfected with over-expressed PPARα or shPPARα vector. The positive control group was administered irbesartan. Renal function and fibrotic changes in kidney tissue were tested. Single-cell RNA-seq (scRNA-seq) was conducted to analyze the differential transcriptome between the diabetic and control mice. Molecular docking simulation was used to assess the combination of DQ and potential factors. Moreover, tubular epithelial cells under high-glucose (HG) conditions were incubated with DQ and transfected with or without over-expressed PPARα/siPPARα vector.
RESULTS
DQ significantly improved renal function, histopathological and fibrotic changes, alleviated lipid deposition, and increased ATP levels in mice with DKD. DQ reduced multiple fatty acid oxidation (FAO) pathway-related proteins and up-regulated PPARα in db/db mice. Overexpression of PPARα upregulated the expression of PPARα-targeting downstream FAO pathway-related proteins, restored renal function, and inhibited renal fibrosis in vitro and in vivo. Moreover, molecular docking and dynamics simulation analyses indicated the nephroprotective effect of DQ via binding to PPARα. Knockdown of PPARα reversed the effect of DQ on the FAO pathway and impaired the protective effect of DQ during DKD.
CONCLUSION
For the first time, DQ was found to exert a renal protective effect by binding to PPARα and attenuating renal damage through the promotion of FAO in DKD.
Topics: Animals; Diabetic Nephropathies; Quercetin; PPAR alpha; Mice; Dasatinib; Molecular Docking Simulation; Male; Kidney; Mice, Inbred C57BL; Diabetes Mellitus, Experimental
PubMed: 38761776
DOI: 10.1016/j.phymed.2024.155705 -
BMC Nutrition May 2024The present study was designed to investigate the influence of different dietary lipids (sheep's fat, olive oil, coconut oil, and corn oil) on specific biomarkers...
BACKGROUND
The present study was designed to investigate the influence of different dietary lipids (sheep's fat, olive oil, coconut oil, and corn oil) on specific biomarkers associated with metabolic syndrome in both healthy and diabetic rats.
METHODS
The study designed for 45 days, utilized a male diabetic wistar rat (body weight, 180-220 g) model induced by streptozotocin (45 mg/kg bw). The rats were divided into two sections: five non-diabetic and five diabetic groups, each containing six rats. The first group in each section serving as the control, received a standard diet. Both non-diabetic or diabetic groups, were provided with a standard diet enriched with 15% sheep fat, 15% coconut oil, 15% olive oil, and 15% corn oil, respectively for a duration of 45 days.
RESULTS
Post-supplementation, both healthy and diabetic control rats exhibited a higher food intake compared to rats supplemented with lipid diet; notably food intake was higher in diabetic control than healthy control. However, rats fed with coconut oil, olive oil and sheep fat showed weight gain at the end of the experiment, in both healthy and diabetic groups. Coconut oil supplementation significantly (p ≤ 0.05) increased HDL-C and total cholesterol level in diabetic groups compared to healthy group, it was confirmed by an increased PPAR-α and ABCA-1 protein level. Olive oil significantly decreased triglyceride, total cholesterol, and LDL-C levels in diabetic rats when compared to sheep fat or coconut oil. Corn oil significantly decreased fasting glucose, total cholesterol and LDL-C levels compared to all other groups. Corn and olive oil supplemented normal groups, found with significant increase in hepatic glucose-lipid oxidative metabolism associated protein, like FGF-21, MSH, ABCA-1, PPAR-γ and decreased lipogenesis proteins like, SREBP and PPAR-α levels. In contrast, sheep grease and coconut oil increased SREBP and PPAR-α expression in both normal and diabetic groups. Most notably, normal and diabetic groups pretreated with sheep grease resulted in increased inflammatory (MCP-1, IL-1β, TLR-4, TNF-α), and oxidative stress markers (LPO, GSH, GPx, SOD and CAT) linked with metabolic complications.
CONCLUSION
The combination or alternative use of olive oil and corn oil in daily diet may play a significant role in preventing proinflammatory condition associated with insulin resistance and cardiovascular diseases.
PubMed: 38755663
DOI: 10.1186/s40795-024-00881-7 -
Scientific Reports May 2024Xanthine oxidoreductase (XOR) contributes to reactive oxygen species production. We investigated the cytoprotective mechanisms of XOR inhibition against high glucose...
Xanthine oxidoreductase (XOR) contributes to reactive oxygen species production. We investigated the cytoprotective mechanisms of XOR inhibition against high glucose (HG)-induced glomerular endothelial injury, which involves activation of the AMP-activated protein kinase (AMPK). Human glomerular endothelial cells (GECs) exposed to HG were subjected to febuxostat treatment for 48 h and the expressions of AMPK and its associated signaling pathways were evaluated. HG-treated GECs were increased xanthine oxidase/xanthine dehydrogenase levels and decreased intracellular AMP/ATP ratio, and these effects were reversed by febuxostat treatment. Febuxostat enhanced the phosphorylation of AMPK, the activation of peroxisome proliferator-activated receptor (PPAR)-gamma coactivator (PGC)-1α and PPAR-α and suppressed the phosphorylation of forkhead box O (FoxO)3a in HG-treated GECs. Febuxostat also decreased nicotinamide adenine dinucleotide phosphate oxidase (Nox)1, Nox2, and Nox4 expressions; enhanced superoxide dismutase activity; and decreased malondialdehyde levels in HG-treated GECs. The knockdown of AMPK inhibited PGC-1α-FoxO3a signaling and negated the antioxidant effects of febuxostat in HG-treated GECs. Despite febuxostat administration, the knockdown of hypoxanthine phosphoribosyl transferase 1 (HPRT1) also inhibited AMPK-PGC-1α-FoxO3a in HG-treated GECs. XOR inhibition alleviates oxidative stress by activating AMPK-PGC-1α-FoxO3a signaling through the HPRT1-dependent purine salvage pathway in GECs exposed to HG conditions.
Topics: Humans; Glucose; Xanthine Dehydrogenase; Endothelial Cells; AMP-Activated Protein Kinases; Purines; Signal Transduction; Febuxostat; Kidney Glomerulus; Oxidative Stress; Reactive Oxygen Species
PubMed: 38750091
DOI: 10.1038/s41598-024-61436-1