scholarly journals KRAS Affects Adipogenic Differentiation by Regulating Autophagy and MAPK Activation in 3T3-L1 and C2C12 Cells

2021 ◽  
Vol 22 (24) ◽  
pp. 13630
Author(s):  
Wenjie Yu ◽  
Cheng-Zhen Chen ◽  
Yanxia Peng ◽  
Ze Li ◽  
Yan Gao ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Lipid Accumulation ◽  
Adipogenic Differentiation ◽  
Mammalian Target Of Rapamycin ◽  
C2c12 Cell ◽  
Small Gtpase ◽  
C2c12 Cells ◽  
Nuclear Antigen ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

Kirsten rat sarcoma 2 viral oncogene homolog (Kras) is a proto-oncogene that encodes the small GTPase transductor protein KRAS, which has previously been found to promote cytokine secretion, cell survival, and chemotaxis. However, its effects on preadipocyte differentiation and lipid accumulation are unclear. In this study, the effects of KRAS inhibition on proliferation, autophagy, and adipogenic differentiation as well as its potential mechanisms were analyzed in the 3T3-L1 and C2C12 cell lines. The results showed that KRAS was localized mainly in the nuclei of 3T3-L1 and C2C12 cells. Inhibition of KRAS altered mammalian target of rapamycin (Mtor), proliferating cell nuclear antigen (Pcna), Myc, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding protein beta (C/ebp-β), diacylglycerol O-acyltransferase 1 (Dgat1), and stearoyl-coenzyme A desaturase 1 (Scd1) expression, thereby reducing cell proliferation capacity while inducing autophagy, enhancing differentiation of 3T3-L1 and C2C12 cells into mature adipocytes, and increasing adipogenesis and the capacity to store lipids. Moreover, during differentiation, KRAS inhibition reduced the levels of extracellular regulated protein kinases (ERK), c-Jun N-terminal kinase (JNK), p38, and phosphatidylinositol 3 kinase (PI3K) activation. These results show that KRAS has unique regulatory effects on cell proliferation, autophagy, adipogenic differentiation, and lipid accumulation.

Evaluation of anti-adipogenic active homoisoflavonoids from Portulaca oleracea

2019 ◽  
Vol 74 (9-10) ◽  
pp. 265-273 ◽  
Author(s):  
Jung Im Lee ◽  
Jung Hwan Oh ◽  
Chang-Suk Kong ◽  
Youngwan Seo
Keyword(s):  
Fatty Acid ◽  
Crude Extract ◽  
Lipid Accumulation ◽  
Target Genes ◽  
Adipogenic Differentiation ◽  
Portulaca Oleracea ◽  
Fatty Acid Transport ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Fatty Acid Binding

Abstract This study was performed to isolate antiobesity components from the crude extract of Portulaca oleracea. The crude extract was partitioned into n-hexane, 85% aqueous methanol, n-butanol, and water fractions. Their effects on adipogenic differentiation were evaluated in 3T3-L1 cells. Among the solvent fractions from P. olearacea, the 85% aq. MeOH effectively reduced the levels of lipid accumulation. Further purification of 85% aq. MeOH led to the isolation of the known homoisoflavonoids 1–4, as the active substances. The administration of homoisoflavonoids to adipocyte cells decreased the lipid accumulation and glucose consumption and increased the release of glycerol into culture medium. In particular, homoisoflavonoid 3 effectively down-regulated the adipogenic transcription genes such as peroxisome proliferator activated receptor-γ (PPARγ) and CCAAT/enhancer-binding proteins (C/EBPα), and adipogenic target genes such as fatty acid binding protein 4 (FABP4), fatty acid transport protein 1 (FATP1), and acyl-CoA synthase 1 (ACS1).

scholarly journals BST204 Protects Dexamethasone-Induced Myotube Atrophy through the Upregulation of Myotube Formation and Mitochondrial Function

2021 ◽  
Vol 18 (5) ◽  
pp. 2367
Author(s):  
Ryuni Kim ◽  
Hyebeen Kim ◽  
Minju Im ◽  
Sun Kyu Park ◽  
Hae Jung Han ◽  
...  
Keyword(s):  
Mitochondrial Function ◽  
Inflammatory Responses ◽  
Mammalian Target Of Rapamycin ◽  
Inhibitory Effect ◽  
Peroxisome Proliferator ◽  
Protective Effects ◽  
Peroxisome Proliferator Activated Receptor ◽  
Dry Extract ◽  
Myotube Formation ◽  
Species Production

BST204 is a purified ginseng dry extract that has an inhibitory effect on lipopolysaccharide-induced inflammatory responses, but its effect on muscle atrophy is yet to be investigated. In this study, C2C12 myoblasts were induced to differentiate for three days followed by the treatment of dexamethasone (DEX), a corticosteroid drug, with vehicle or BST204 for one day and subjected to immunoblotting, immunocytochemistry, qRT-PCR and biochemical analysis for mitochondrial function. BST204 alleviates the myotube atrophic effect mediated by DEX via the activation of protein kinase B/mammalian target of rapamycin (Akt/mTOR) signaling. Through this pathway, BST204 suppresses the expression of muscle-specific E3 ubiquitin ligases contributing to the enhanced myotube formation and enlarged myotube diameter in DEX-treated myotubes. In addition, BST204 treatment significantly decreases the mitochondrial reactive oxygen species production in DEX-treated myotubes. Furthermore, BST204 improves mitochondrial function by upregulating the expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) in DEX-induced myotube atrophy. This study provides a mechanistic insight into the effect of BST204 on DEX-induced myotube atrophy, suggesting that BST204 has protective effects against the toxicity of a corticosteroid drug in muscle and promising potential as a nutraceutical remedy for the treatment of muscle weakness and atrophy.

scholarly journals Zidovudine Impairs Adipogenic Differentiation through Inhibition of Clonal Expansion

2008 ◽  
Vol 52 (8) ◽  
pp. 2882-2889 ◽  
Author(s):  
Metodi V. Stankov ◽  
Reinhold E. Schmidt ◽  
Georg M. N. Behrens
Keyword(s):  
Adipogenic Differentiation ◽  
Clonal Expansion ◽  
Inhibitory Effect ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Triglyceride Accumulation ◽  
Thymidine Incorporation Assay ◽  
Human Preadipocytes ◽  
Incorporation Assay ◽  
The Impact

ABSTRACT Lipoatrophy is a prevalent side effect of treatment with thymidine analogues. We wished to confine the time point of the antiadipogenic effect of zidovudine (AZT) during adipogenesis and to evaluate the antiproliferative effect of AZT on adipocyte homeostasis. We investigated the effects of AZT on adipogenesis in 3T3-F442A cells and studied their proliferation, differentiation, viability, and adiponectin expression. Cells were exposed to AZT (1 μM, 3 μM, 6 μM, and 180 μM), stavudine (d4T; 3 μM), or dideoxycytosine (ddC; 0.1 μM) for up to 15 days. Differentiation was assessed by real-time PCR and quantification of triglyceride accumulation. Proliferation and clonal expansion were determined by a [3H]thymidine incorporation assay. When they were induced to differentiate in the presence of AZT at the maximum concentration in plasma (C max) and lower concentrations, 3T3-F442A preadipocytes failed to accumulate cytoplasmic triacylglycerol and failed to express normal levels of the later adipogenic transcription factors, CCAAT/enhancer-binding protein α and peroxisome proliferator-activated receptor γ. AZT exerted an inhibitory effect on the completion of the mitotic clonal expansion, which resulted in incomplete 3T3-F442A differentiation and, finally, a reduction in the level of adiponectin expression. In addition, AZT impaired the constitutive proliferation in murine and primary human subcutaneous preadipocytes. In contrast, incubation with d4T and ddC at the C max did not affect either preadipocyte proliferation or clonal expansion and differentiation. We conclude that the antiproliferative and antiadipogenetic effects of AZT on murine and primary human preadipocytes reveal the impact of the drug on fat tissue regeneration. These effects of the drug are expected to contribute to disturbed adipose tissue homeostasis and to be influenced by differential drug concentration and penetration in individual patients.

A Tale of Two Diseases: Exploring Mechanisms Linking Diabetes Mellitus with Alzheimer’s Disease

2021 ◽  
pp. 1-17
Author(s):  
Jessica Lynn ◽  
Mingi Park ◽  
Christiana Ogunwale ◽  
George K. Acquaah-Mensah
Keyword(s):  
Diabetes Mellitus ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Glycogen Synthase ◽  
Mammalian Target Of Rapamycin ◽  
Insulin Receptors ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Main Component ◽  
The Impact

Dementias, including the type associated with Alzheimer’s disease (AD), are on the rise worldwide. Similarly, type 2 diabetes mellitus (T2DM) is one of the most prevalent chronic diseases globally. Although mechanisms and treatments are well-established for T2DM, there remains much to be discovered. Recent research efforts have further investigated factors involved in the etiology of AD. Previously perceived to be unrelated diseases, commonalities between T2DM and AD have more recently been observed. As a result, AD has been labeled as “type 3 diabetes”. In this review, we detail the shared processes that contribute to these two diseases. Insulin resistance, the main component of the pathogenesis of T2DM, is also present in AD, causing impaired brain glucose metabolism, neurodegeneration, and cognitive impairment. Dysregulation of insulin receptors and components of the insulin signaling pathway, including protein kinase B, glycogen synthase kinase 3β, and mammalian target of rapamycin are reported in both diseases. T2DM and AD also show evidence of inflammation, oxidative stress, mitochondrial dysfunction, advanced glycation end products, and amyloid deposition. The impact that changes in neurovascular structure and genetics have on the development of these conditions is also being examined. With the discovery of factors contributing to AD, innovative treatment approaches are being explored. Investigators are evaluating the efficacy of various T2DM medications for possible use in AD, including but not limited to glucagon-like peptide-1 receptor agonists, and peroxisome proliferator-activated receptor-gamma agonists. Furthermore, there are 136 active trials involving 121 therapeutic agents targeting novel AD biomarkers. With these efforts, we are one step closer to alleviating the ravaging impact of AD on our communities.

scholarly journals Conjugated linoleic acids attenuate FSH- and IGF1-stimulated cell proliferation; IGF1, GATA4, and aromatase expression; and estradiol-17β production in buffalo granulosa cells involving PPARγ, PTEN, and PI3K/Akt

Reproduction ◽  
2012 ◽  
Vol 144 (3) ◽  
pp. 373-383 ◽  
Author(s):  
Isha Sharma ◽  
Dheer Singh
Keyword(s):  
Cell Proliferation ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Cell Function ◽  
Endocrine System ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Beneficial Effects ◽  
Tensin Homolog ◽  
Estradiol 17Β

Conjugated linoleic acid (CLA) has drawn much interest in last two decades in the area ranging from anticancer activity to obesity. A number of research papers have been published recently with regard to CLA's additional biological functions as reproductive benefits. However, not much is known how this mixture of isomeric compounds mediates its beneficial effects particularly on fertility. In this study, we demonstrated the cross talk between downstream signaling of CLA and important hormone regulators of endocrine system, i.e. FSH and IGF1, on buffalo granulosa cell function (proliferation and steroidogenesis). Experiments were performed in primary serum-free buffalo granulosa cell culture, where cells were incubated with CLA in combination with FSH (25 ng/ml) and IGF1 (50 ng/ml). Results showed that 10 μM CLA inhibits FSH- and IGF1-induced granulosa cell proliferation; aromatase,GATA4, andIGF1mRNA; and estradiol-17β production. Western blot analysis of total cell lysates revealed that CLA intervenes the IGF1 signaling by decreasing p-Akt. In addition, CLA was found to upregulate peroxisome proliferator-activated receptor-gamma (PPARG) and phosphatase and tensin homolog (PTEN) level in granulosa cells. Further study using PPARG- and PTEN-specific inhibitors supports the potential role of CLA in granulosa cell proliferation and steroidogenesis involving PPARG, PTEN, and PI3K/Akt pathway.

scholarly journals TM4SF5 Knockout Protects Mice from Diet-Induced Obesity Partly by Regulating Autophagy in Adipose Tissue

2021 ◽  
Author(s):  
Cheoljun Choi ◽  
Yeonho Son ◽  
Jinyoung Kim ◽  
Yoon Keun Cho ◽  
Abhirup Saha ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Oxidative Metabolism ◽  
Metabolic Diseases ◽  
Mammalian Target Of Rapamycin ◽  
Regulatory Function ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Brown Adipose ◽  
Mtorc1 Signaling ◽  
Mitochondrial Oxidative Metabolism

Transmembrane 4 L six family member 5 (TM4SF5) functions as a sensor for lysosomal arginine levels and activates the mammalian target of rapamycin complex 1 (mTORC1). While the mTORC1 signaling pathway plays a key role in adipose tissue metabolism, the regulatory function of TM4SF5 in adipocytes remains unclear. This study aimed to establish a TM4SF5 knockout (KO) mouse model and investigated the effects of TM4SF5 KO on mTORC1 signaling-mediated autophagy and mitochondrial metabolism in adipose tissue. TM4SF5 expression was higher in inguinal white adipose tissue (iWAT) than in brown adipose tissue and significantly upregulated by a high-fat diet (HFD). TM4SF5 KO reduced mTORC1 activation and enhanced autophagy and lipolysis in adipocytes. RNA-seq analysis of TM4SF5 KO mouse iWAT showed that the expression of genes involved in peroxisome proliferator-activated receptor alpha signaling pathways and mitochondrial oxidative metabolism was upregulated. Consequently, TM4SF5 KO reduced adiposity and increased energy expenditure and mitochondrial oxidative metabolism. TM4SF5 KO prevented HFD-induced glucose intolerance and inflammation in adipose tissue. Collectively, our study demonstrated that TM4SF5 regulates autophagy and lipid catabolism in adipose tissue and suggested that TM4SF5 could be therapeutically targeted for the treatment of obesity-related metabolic diseases.

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