Mitotic Clonal Expansion Research Articles

CSN-CRL Complexes: New Regulators of Adipogenesis

Recent discoveries revealed mechanistic insights into the control of adipogenesis by the Constitutive Photomorphogenesis 9 Signalosome (CSN) and its variants, CSNCSN7A and CSNCSN7B, which differ in the paralog subunits, CSN7A and CSN7B. CSNCSN7A and CSNCSN7B variants form permanent complexes with cullin-RING-ubiquitin ligases 3 and 4A (CRL3 and CRL4A), respectively. These complexes can be found in most eukaryotic cells and represent a critical reservoir for cellular functions. In an early stage of adipogenesis, mitotic clonal expansion (MCE), CSN-CRL1, and CSNCSN7B-CRL4A are blocked to ubiquitinate the cell cycle inhibitor p27KIP, leading to cell cycle arrest. In addition, in MCE CSN-CRL complexes rearrange the cytoskeleton for adipogenic differentiation and CRL3KEAP1 ubiquitylates the inhibitor of adipogenesis C/EBP homologous protein (CHOP) for degradation by the 26S proteasome, an adipogenesis-specific proteolysis. During terminal adipocyte differentiation, the CSNCSN7A-CRL3 complex is recruited to a lipid droplet (LD) membrane by RAB18. Currently, the configuration of the substrate receptors of CSNCSN7A-CRL3 on LDs is unclear. CSNCSN7A-CRL3 is activated by neddylation on the LD membrane, an essential adipogenic step. Damage to CSN/CUL3/CUL4A genes is associated with diverse diseases, including obesity. Due to the tremendous impact of CSN-CRLs on adipogenesis, we need strategies for adequate treatment in the event of malfunctions.

Arthrocolin B Impairs Adipogenesis via Delaying Cell Cycle Progression During the Mitotic Clonal Expansion Period.

Obesity and its related diseases severely threaten people's health, causing persistently high morbidity and mortality worldwide. The abnormal proliferation and hypertrophy of adipocytes mediate the expansion of adipose tissue, which is the main cause of obesity-related diseases. Inhibition of cell proliferation during the mitotic clonal expansion (MCE) period of adipogenesis may be a promising strategy for preventing and treating obesity. Arthrocolins are a series of fluorescent dye-like complex xanthenes from engineered Escherichia coli, with potential anti-tumor and antifungal activities. However, the role and underlying mechanisms of these compounds in adipocyte differentiation remain unclear. In this study, we discovered that arthrocolin B, a member of the arthrocolin family, significantly impeded adipogenesis by preventing the accumulation of lipid droplets and triglycerides, as well as by downregulating the expression of key factors involved in adipogenesis, such as SREBP1, C/EBPβ, C/EBPδ, C/EBPα, PPARγ, and FABP4. Moreover, we revealed that this inhibition might be a consequence of cell cycle arrest during the MCE of adipocyte differentiation, most likely by modulating the p53, AKT, and ERK pathways, upregulating the expression of p21 and p27, and repressing the expression of CDK1, CDK4, Cyclin A2, Cyclin D1, and p-Rb. Additionally, arthrocolin B could promote the expression of CPT1A during adipocyte differentiation, implying its potential role in fatty acid oxidation. Overall, our research concludes that arthrocolin B has the ability to suppress the early stages of adipocyte differentiation mainly by modulating the signaling proteins involved in cell cycle progression. This work broadens our understanding of the function and mechanisms of arthrocolins in regulation of adipogenesis and might provide a potential lead compound for treating the obesity.

Mealworm-Derived Protein Hydrolysates Enhance Adipogenic Differentiation via Mitotic Clonal Expansion in 3T3-L1 Cells.

Adipocytes secrete adipokines, bioactive molecules crucial for various physiological processes, such as enhancing insulin sensitivity, promoting wound healing, supporting hair growth, and exhibiting anti-aging effects on the skin. With the growing global demand for sustainable and alternative protein sources, insect-derived proteins, particularly from Tenebrio molitor (mealworms), have gained attention due to their high nutritional value and functional bioactivities. This study aims to explore the potential of mealworm-derived protein hydrolysates as novel bioactive materials for promoting adipogenesis and improving adipokine expression, with applications in metabolic health and skin regeneration. Protein hydrolysates (<1 kDa) were prepared using enzymatic hydrolysis with three proteases (alcalase, flavourzyme, and neutrase) and evaluated for their adipogenic activity in 3T3-L1 preadipocytes. Among them, the flavourzyme-derived hydrolysate (Fh-T) exhibited the most significant effects, enhancing adipogenic differentiation and lipid accumulation. Fh-T facilitated adipogenesis by promoting mitotic clonal expansion (MCE) during the early stage of differentiation, which was associated with the upregulation of C/EBPδ and the downregulation of p27. These findings underscore the potential of mealworm-derived protein hydrolysates, particularly Fh-T, as sustainable and functional ingredients for use in glycemic control, skin health, and tissue regeneration. This study provides valuable insights into the innovative use of alternative protein sources in functional foods and cosmeceuticals.

Citral, a major component of lemon myrtle (Backhousia citriodora) essential oil, inhibits adipogenesis in 3T3-L1 preadipocytes during mitotic clonal expansion

Lemon myrtle essential oil (LMEO), a popular food-flavoring and perfume, has anti-inflammatory and antioxi-dant properties, and contains citral in abundance. Citral-enriched essential oils exhibit anti-obesity effects; how-ever, the effect of LMEO on adipogenesis and the precise mechanism of citral have not been elucidated. This study evaluated the anti-adipogenic activity of commercial LMEO and its components, geranial, neral and citral (a mixture of geranial and neral), in 3T3-L1 cell differentiation and identified the anti-adipogenic mechanism of citral. Treatment of 3T3-L1 preadipocytes with various concentrations of LMEO, neral, geranial, and citral for 24 h and 48 h showed that LMEO (12.5–25 μg/mL) inhibited 3-isobutyl-1-methylxanthine, dexamethasone, and insulin (MDI)-induced differentiation of preadipocytes. Citral, accounting for 88.67% of total compounds in LMEO, also suppressed MDI-induced differentiation and expression of adipogenic transcription factors (PPARγ, C/EBPα, and Fabp4). Additionally, citral inhibited the early stages of differentiation, particularly mitotic clonal expansion (MCE), by deactivating cell cycle-related factors (cyclins and cyclin-dependent kinases) and arresting the cell cycle at G0/G1 phase, which was caused by inhibiting upstream signaling pathways, especially PI3K/AKT pathway. Therefore, regulation of early stages of adipogenesis, especially MCE, is a key mechanism underlying the anti-adipogenic activity of citral. LMEO and citral can be potentially used as anti-obesity agents.

Bta-miR-484 Inhibits Bovine Intramuscular Adipogenesis by Regulating Mitotic Clonal Expansion via the MAP3K9/JNK/CCND1 Axis.

Intramuscular fat (IMF) content is a critical indicator of the beef nutritional value and flavor. In this study, we focused on bta-miR-484, a microRNA that is differentially expressed during the adipogenic differentiation of bovine intramuscular adipocytes and is negatively correlated with the IMF content across different cattle breeds. Our findings demonstrate that bta-miR-484 inhibits adipogenic differentiation without altering the fatty acid composition of bovine intramuscular adipocytes. miRNA pull-down and dual-luciferase reporter assays confirmed that MAP3K9 is a target gene of bta-miR-484. Furthermore, bta-miR-484 suppresses the JNK signaling pathway by targeting MAP3K9, leading to decreased CCND1 expression, which impedes the mitotic clonal expansion (MCE) process and inhibits intramuscular adipocyte differentiation. In summary, this study uncovers a novel mechanism by which bta-miR-484 regulates bovine IMF content and provides the first exploration of MCE during intramuscular adipocyte adipogenic differentiation. These findings offer valuable theoretical insights into beef cattle breeding and molecular improvements.

Effects of Flavanone Derivatives on Adipocyte Differentiation and Lipid Accumulation in 3T3-L1 Cells.

Flavanones, a class of flavonoids, are abundant in fruits, vegetables, and herbs. They are known to have several biological activities, such as anti-inflammatory and anti-cancer activities, but their effects on obesity remain unclear. Obesity is closely associated with adipocyte differentiation and lipid accumulation in adipose tissue. Therefore, in this study, we examined the effects of flavanone derivatives on adipocyte differentiation and lipid accumulation by using 3T3-L1 cells. Among the 15 flavanone derivatives studied, 4'-phenylflavanone (4PF), with a biphenyl structure, significantly inhibited adipocyte differentiation-related lipid accumulation in 3T3-L1 cells; this inhibition of lipid accumulation was dose-dependent. Gene expression analysis showed that 4PF suppressed the expression of adipogenic marker genes. Although the induction of peroxisome proliferator activator γ2 (Pparγ2), a master regulator of adipocyte differentiation, and its target genes during adipocyte differentiation was attenuated in 4PF-treated cells, 4PF did not directly regulate Pparγ2 gene expression and its activation. In contrast, 4PF suppressed mitotic clonal expansion (MCE), which is associated with changes in the expression of proliferation-related genes at the early stages of adipocyte differentiation. Taken together, these results suggest that 4PF inhibits lipid accumulation because it suppresses MCE during adipocyte differentiation. Thus, our findings may help in the development of anti-obesity drugs.

Flavopiridol inhibits adipogenesis and improves metabolic homeostasis by ameliorating adipose tissue inflammation in a diet-induced obesity model

Flavopiridol inhibits adipogenesis and improves metabolic homeostasis by ameliorating adipose tissue inflammation in a diet-induced obesity model

Caveolin-2 controls preadipocyte survival in the mitotic clonal expansion for adipogenesis

Caveolin-2 controls preadipocyte survival in the mitotic clonal expansion for adipogenesis

Anti-obesity effect of standardized ethanol extract from the leaves of Adenocaulon himalaicum Edgew. via regulation of adipogenesis and lipid accumulation in 3T3-L1 cells and high-fat diet-induced obese mice

Anti-obesity effect of standardized ethanol extract from the leaves of Adenocaulon himalaicum Edgew. via regulation of adipogenesis and lipid accumulation in 3T3-L1 cells and high-fat diet-induced obese mice

The powerful potential of amino acid menthyl esters for anti-inflammatory and anti-obesity therapies.

Our newly developed menthyl esters of valine and isoleucine exhibit anti-inflammatory properties beyond those of the well-known menthol in macrophages stimulated by lipopolysaccharide (LPS) and in a mouse model of colitis induced by sodium dextran sulfate. Unlike menthol, which acts primarily through the cold-sensitive TRPM8 channel, these menthyl esters displayed unique mechanisms that operate independently of this receptor. They readily penetrated target cells and efficiently suppressed LPS-stimulated tumour necrosis factor-alpha (Tnf) expression mediated by liver X receptor (LXR), a key nuclear receptor that regulates intracellular cholesterol and lipid balance. The menthyl esters showed affinity for LXR and enhanced the transcriptional activity through their non-competitive and potentially synergistic agonistic effect. This effect can be attributed to the crucial involvement of SCD1, an enzyme regulated by LXR, which is central to lipid metabolism and plays a key role in the anti-inflammatory response. In addition, we discovered that the menthyl esters showed remarkable efficacy in suppressing adipogenesis in 3T3-L1 adipocytes at the mitotic clonal expansion stage in an LXR-independent manner as well as in mice subjected to diet-induced obesity. These multiple capabilities of our compounds establish them as formidable allies in the fight against inflammation and obesity, paving the way for a range of potential therapeutic applications.

Deletion of Impdh2 in adipocyte precursors limits the expansion of white adipose tissue and enhances metabolic health with overnutrition

Deletion of Impdh2 in adipocyte precursors limits the expansion of white adipose tissue and enhances metabolic health with overnutrition

Isoeugenol Inhibits Adipogenesis in 3T3-L1 Preadipocytes with Impaired Mitotic Clonal Expansion.

Isoeugenol (IEG), a natural component of clove oil, possesses antioxidant, anti-inflammatory, and antibacterial properties. However, the effects of IEG on adipogenesis have not yet been elucidated. Here, we showed that IEG blocks adipogenesis in 3T3-L1 cells at an early stage. IEG inhibits lipid accumulation in adipocytes in a concentration-dependent manner and reduces the expression of mature adipocyte-related factors including PPARγ, C/EBPα, and FABP4. IEG treatment at different stages of adipogenesis showed that IEG inhibited adipocyte differentiation by suppressing the early stage, as confirmed by lipid accumulation and adipocyte-related biomarkers. The early stage stimulates growth-arrested preadipocytes to enter mitotic clonal expansion (MCE) and initiates their differentiation into adipocytes by regulating cell cycle-related factors. IEG arrested 3T3-L1 preadipocytes in the G0/G1 phase of the cell cycle and attenuated cell cycle-related factors including cyclinD1, CDK6, CDK2, and cyclinB1 during the MCE stage. Furthermore, IEG suppresses reactive oxygen species (ROS) production during MCE and inhibits ROS-related antioxidant enzymes, including superoxide dismutase1 (SOD1) and catalase. The expression of cell proliferation-related biomarkers, including pAKT and pERK1/2, was attenuated by the IEG treatment of 3T3-L1 preadipocytes. These findings suggest that it is a potential therapeutic agent for the treatment of obesity.

TG-interacting factor 1 regulates mitotic clonal expansion during adipocyte differentiation

TG-interacting factor 1 regulates mitotic clonal expansion during adipocyte differentiation

Epigallocatechin gallate suppresses mitotic clonal expansion and adipogenic differentiation of preadipocytes through impeding JAK2/STAT3-mediated transcriptional cascades

Epigallocatechin gallate suppresses mitotic clonal expansion and adipogenic differentiation of preadipocytes through impeding JAK2/STAT3-mediated transcriptional cascades

Inhibition of the RPS6KA1/FoxO1 signaling axis by hydroxycitric acid attenuates HFD-induced obesity through MCE suppression

Inhibition of the RPS6KA1/FoxO1 signaling axis by hydroxycitric acid attenuates HFD-induced obesity through MCE suppression

AP-1/C-FOS and AP-1/FRA2 differentially regulate early and late adipogenic differentiation of mesenchymal stem cells.

Obesity is defined as an abnormal accumulation of adipose tissue in the body and is a major global health problem due to increased morbidity and mortality. Adipose tissue is made up of adipocytes, which are fat-storing cells, and the differentiation of these fat cells is known as adipogenesis. Several transcription factors (TFs)such as CEBPβ, CEBPα, PPARγ, GATA, and KLFhave been reported to play a key role in adipogenesis. In this study, we report one more TFAP-1, which is found to be involved in adipogenesis. Human mesenchymal stem cells were differentiated into adipocytes, and the expression pattern of different subunits of AP-1 was examined during adipogenesis. It was observed that C-FOS was predominantly expressed at an early stage (Day 2), whereas FRA2 expression peaked at later stages (Days 6 and 8) of adipogenesis. Chromatin immunoprecipitation-sequencing analysis revealed that C-FOS binds mainly to the promoters of WNT1, miR-30a, and ANAPC7and regulates their expression during mitotic clonal expansion. In contrast, FRA2 binds to the promoters of CIDEA, NOTCH1, ARAF, and MYLK, regulating their expression and lipid metabolism. Data obtained clearly indicatethat the differential expression of C-FOS and FRA2 is crucial for different stages of adipogenesis. This also raises the possibility of considering AP-1 as a therapeutic target for treating obesity and related disorders.

Cinnamyl Alcohol Attenuates Adipogenesis in 3T3-L1 Cells by Arresting the Cell Cycle.

Cinnamyl alcohol (CA) is an aromatic compound found in several plant-based resources and has been shown to exert anti-inflammatory and anti-microbial activities. However, the anti-adipogenic mechanism of CA has not been sufficiently studied. The present study aimed to investigate the effect and mechanism of CA on the regulation of adipogenesis. As evidenced by Oil Red O staining, Western blotting, and real-time PCR (RT-PCR) analyses, CA treatment (6.25-25 μM) for 8 d significantly inhibited lipid accumulation in a concentration-dependent manner and downregulated adipogenesis-related markers (peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), fatty acid binding protein 4 (FABP4), adiponectin, fatty acid synthase (FAS)) in 3-isobutyl-1-methylxanthine, dexamethasone, and insulin(MDI)-treated 3T3-L1 adipocytes. In particular, among the various differentiation stages, the early stage of adipogenesis was critical for the inhibitory effect of CA. Cell cycle analysis using flow cytometry and Western blotting showed that CA effectively inhibited MDI-induced initiation of mitotic clonal expansion (MCE) by arresting the cell cycle in the G0/G1 phase and downregulating the expression of C/EBPβ, C/EBPδ, and cell cycle markers (cyclin D1, cyclin-dependent kinase 6 (CDK6), cyclin E1, CDK2, and cyclin B1). Moreover, AMP-activated protein kinase α (AMPKα), acetyl-CoA carboxylase (ACC), and extracellular signal-regulated kinase 1/2 (ERK1/2), markers of upstream signaling pathways, were phosphorylated during MCE by CA. In conclusion, CA can act as an anti-adipogenic agent by inhibiting the AMPKα and ERK1/2 signaling pathways and the cell cycle and may also act as a potential therapeutic agent for obesity.

Role of apigenin in targeting metabolic syndrome: A systematic review.

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that has a high prevalence worldwide. Apigenin is a flavonoid present in several vegetables and fruits and has anti-inflammatory, anti-oxidant, and anti-MetS properties. This study aims to systematically review the effects of apigenin against MetS and the relevant molecular and cellular mechanisms of action, pharmacokinetics features, and potential structure-activity relationship. Electronic databases including Scopus, PubMed, Science Direct and Cochrane Library were searched for in vivo, and in vitro, and human studies with the following keywords: "apigenin" and "metabolic syndrome or insulin resistance syndrome", "fatty liver", "hypertension or blood pressure", "diabetes or blood glucose", "dyslipidemia", "heart or cardiovascular " and "obesity" in title/abstract. Data were collected from 2000 until 2021 (up to April). Only papers published in the English language were included. Forty-six full-text articles out of 1016 retrieved papers were reviewed and underwent quality assessment by investigators. Anti-obesity activity of apigenin is mainly through attenuating adipocyte differentiation by suppressing the mitotic clonal expansion and the adipogenesis-related factors. Its anti-diabetic effects can be exerted through inhibition of protein tyrosine phosphatase1B expression, maintaining the activity of anti-oxidant enzymes, reducing intracellular ROS production, cellular DNA damage, protein carbonylation, and attenuating β-cell apoptosis. Moreover, apigenin could attenuate dyslipidemia and subsequent atherosclerotic conditions through down-regulating sterol regulatory element-binding proteins (SREBP)-1c, SREBP-2, stearyl-CoA desaturase-1, and 3-hydroxy-3-methyl-glutaryl-CoA reductase. Apigenin as a dietary bioactive compound would be a promising candidate for improving MetS and its components.

Anti-obesity effects of a standardized ethanol extract of Eisenia bicyclis by regulating the AMPK signaling pathway in 3T3-L1 cells and HFD-induced mice.

Obesity requires treatment to mitigate the potential development of further metabolic disorders, including diabetes, hyperlipidemia, tumor growth, and non-alcoholic fatty liver disease. We investigated the anti-obesity effect of a 30% ethanol extract of Eisenia bicyclis (Kjellman) Setchell (EEB) on 3T3-L1 preadipocytes and high-fat diet (HFD)-induced obese C57BL/6 mice. Adipogenesis transcription factors including peroxisome proliferator-activated receptor (PPAR)γ, CCAAT/enhancer-binding protein-alpha (C/EBPα), and sterol regulatory element-binding protein-1 (SREBP-1) were ameliorated through the AMP-activated protein kinase (AMPK) pathway by EEB treatment in differentiated 3T3-L1 cells. EEB attenuated mitotic clonal expansion by upregulating cyclin-dependent kinase inhibitors (CDKIs) while downregulating cyclins and CDKs. In HFD-fed mice, EEB significantly decreased the total body weight, fat tissue weight, and fat in the tissue. The protein expression of PPARγ, C/EBPα, and SREBP-1 was increased in the subcutaneous fat and liver tissues, while EEB decreased the expression levels of these transcription factors. EEB also inhibited lipogenesis by downregulating acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) expression in the subcutaneous fat and liver tissues. Moreover, the phosphorylation of AMPK and ACC was downregulated in the HFD-induced mouse group, whereas the administration of EEB improved AMPK and ACC phosphorylation; thus, EEB treatment may be related to the AMPK pathway. Histological analysis showed that EEB reduced the adipocyte size and fat accumulation in subcutaneous fat and liver tissues, respectively. EEB promotes thermogenesis in brown adipose tissue and improves insulin and leptin levels and blood lipid profiles. Our results suggest that EEB could be used as a potential agent to prevent obesity.

Anti-adipogenic action of a novel oxazole derivative through activation of AMPK pathway

Anti-adipogenic action of a novel oxazole derivative through activation of AMPK pathway