scholarly journals CREB Activation Induces Adipogenesis in 3T3-L1 Cells

2000 ◽  
Vol 20 (3) ◽  
pp. 1008-1020 ◽  
Author(s):  
Jane E. B. Reusch ◽  
Lilliester A. Colton ◽  
Dwight J. Klemm

ABSTRACT Obesity is the result of numerous, interacting behavioral, physiological, and biochemical factors. One increasingly important factor is the generation of additional fat cells, or adipocytes, in response to excess feeding and/or large increases in body fat composition. The generation of new adipocytes is controlled by several “adipocyte-specific” transcription factors that regulate preadipocyte proliferation and adipogenesis. Generally these adipocyte-specific factors are expressed only following the induction of adipogenesis. The transcription factor(s) that are involved in initiating adipocyte differentiation have not been identified. Here we demonstrate that the transcription factor, CREB, is constitutively expressed in preadipocytes and throughout the differentiation process and that CREB is stimulated by conventional differentiation-inducing agents such as insulin, dexamethasone, and dibutyryl cAMP. Stably transfected 3T3-L1 preadipocytes were generated in which we could induce the expression of either a constitutively active CREB (VP16-CREB) or a dominant-negative CREB (KCREB). Inducible expression of VP16-CREB alone was sufficient to initiate adipogenesis as determined by triacylglycerol storage, cell morphology, and the expression of two adipocyte marker genes, peroxisome proliferator activated receptor gamma 2, and fatty acid binding protein. Alternatively, KCREB alone blocked adipogenesis in cells treated with conventional differentiation-inducing agents. These data indicate that activation of CREB was necessary and sufficient to induce adipogenesis. Finally, CREB was shown to bind to putative CRE sequences in the promoters of several adipocyte-specific genes. These data firmly establish CREB as a primary regulator of adipogenesis and suggest that CREB may play similar roles in other cells and tissues.

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1971
Author(s):  
Xinyang Zhang ◽  
Bohan Cheng ◽  
Haixu Jiang ◽  
Chang Liu ◽  
Zhiping Cao ◽  
...  

The molecular mechanisms of transcription factor 21 (TCF21) in regulating chicken adipogenesis remain unclear. Thus, the current study was designed to investigate the signaling pathway mediating the effect of TCF21 on chicken adipogenesis. Immortalized chicken preadipocytes cell line (ICP), a preadipocyte cell line stably overexpressing TCF21 (LV-TCF21) and a control preadipocyte cell line (LV-control) were used in the current study. We found that the phosphorylation of c-Jun N-terminal kinases (JNK) was significantly elevated in LV-TCF21 compared to LV-control. After treating ICP cells with a JNK inhibitor SP600125, the differentiation of ICP was inhibited, as evidenced by decreased accumulation of lipid droplets and reduced expression of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding protein α (C/EBPα), adipocyte fatty acid binding protein (A-FABP), and lipoprotein lipase (LPL). Moreover, we found that the inhibition of JNK by SP600125 remarkably impaired the ability of TCF21 to drive adipogenesis. Taken together, our results suggest that TCF21 promotes the differentiation of adipocytes at least in part via activating MAPK/JNK pathway.


2006 ◽  
Vol 154 (1) ◽  
pp. 159-166 ◽  
Author(s):  
M Messager ◽  
C Carrière ◽  
X Bertagna ◽  
Y de Keyzer

Objective: ACTH is frequently produced in non-pituitary tumours, leading to the ectopic-ACTH syndrome, but the molecular mechanisms of its expression remain obscure. This study was aimed at understanding the transcription mechanisms of the ACTH-precursor gene in carcinoid tumours of the lung or thymus. Design: Transcripts coding for a series of corticotroph-associated transcription factor genes were detected, together with markers of the corticotroph phenotype. We studied a series of 41 carcinoid tumours including 15 with proven ectopic-ACTH syndrome. Methods: Specific RT-PCR reactions were designed for each gene including alternatively spliced isoforms. Results: The markers of the corticotroph phenotype were detected in all ACTH-positive tumours. Expression of the Tpit and Pitx1 genes were not restricted to ACTH-positive tumours but were also detected in many ACTH-negative carcinoids. Only a subset of ACTH-negative tumours expressed NAK-1/Nur77, and NeuroD1 expression was detected in <50% of the tumours regardless of their secretory status. The glucocorticoid receptor alpha was detected in every tumour in contrast to its beta isoform detectable in a few tumours only. Chicken ovalbumin upstream promoter-transcription factor 1 (COUP-TF1) and peroxisome proliferator-activated receptor (PPAR) γ2 were expressed in 50% of the tumours of each group whereas PPARγ1 was expressed in almost every tumour. Conclusions: ACTH-positive carcinoids do not share a characteristic expression pattern of the corticotroph-associated transcription factor genes, suggesting that the transcriptional mechanisms of the ACTH-precursor gene differ from those in normal pituitary corticotrophs. Expression of Tpit and Pitx1 genes in most carcinoids suggests that some aspects of the pituitary corticotroph phenotype may belong to general carcinoid differentiation.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Sae-Rom Yoo ◽  
Chang-Seob Seo ◽  
Hyeun-Kyoo Shin ◽  
Soo-Jin Jeong

Background. Oyaksungi-san (OYSGS) is a herbal formula that has been used for treating cardiovascular diseases in traditional Asian medicine. Here, we investigated the antiadipogenic effect of OYSGS extract in 3T3-L1 adipose cells.Methods. 3T3-L1 preadipocytes were differentiated into adipocytes with or without OYSGS. After differentiation, we measured Oil Red O staining, glycerol-3-phosphate dehydrogenase (GPDH) activity, leptin production, mRNA, and protein levels of adipogenesis-related factors.Results. OYSGS extract dramatically inhibited intracellular lipid accumulation in the differentiated adipocytes. It also significantly suppressed the (GPDH) activity, triglyceride (TG) content, and leptin production by reducing the expression of adipogenesis-related genes including lipoprotein lipase, fatty acid binding protein 4, CCAAT/enhancer-binding protein-alpha (C/EBP-α), and peroxisome proliferator-activated receptor gamma (PPAR-γ). Furthermore, OYSGS clearly enhanced phosphorylation of AMP-activated protein kinase (AMPK) as well as its substrate acetyl CoA (ACC) carboxylase.Conclusions. Our results demonstrate that OYSGS negatively controls TG accumulation in 3T3-L1 adipocytes. We suggest antiadipogenic activity of OYSGS and its potential benefit in preventing obesity.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Pimonrat Ketsawatsomkron ◽  
Deborah R Davis ◽  
Aline M Hilzendeger ◽  
Justin L Grobe ◽  
Curt D Sigmund

PPARG, a ligand-activated transcription factor plays a critical role in the regulation of blood pressure and vascular function. We hypothesized that smooth muscle cell (SMC) PPARG protects against hypertension (HT) and resistance vessel dysfunction. Transgenic mice expressing dominant negative PPARG (S-P467L) in SMC or non-transgenic controls (NT) were implanted with DOCA pellet and allowed ad libitum access to 0.15 M NaCl for 21 days in addition to regular chow and water. Blood pressure was monitored by telemetry and mesenteric arterial (MA) function was assessed by pressurized myograph. At baseline, 24-hour mean arterial pressure (MAP) was similar between NT and S-P467L mice, while the transgenic mice were tachycardic. DOCA-salt increased MAP to a much greater degree in S-P467L mice (Δ MAP; S-P467L: +34.2±6.0, NT: +13.3±5.7, p<0.05 vs NT). Heart rate was similarly decreased in both groups after DOCA-salt. Vasoconstriction to KCl, phenylephrine and endothelin-1 did not differ in MA from DOCA-salt treated NT and S-P467L, while the response to vasopressin was significantly reduced in S-P467L after DOCA-salt (% constriction at 10-8 M, S-P467L: 31.6±5.6, NT: 46.7±3.8, p<0.05 vs NT). Urinary copeptin, a surrogate marker for arginine vasopressin was similar in both groups regardless of treatment. Vasorelaxation to acetylcholine was slightly impaired in S-P467L MA compared to NT at baseline whereas this effect was further exaggerated after DOCA-salt (% relaxation at 10-5 M, S-P467L: 56.1±8.3, NT: 79.4±5.6, p<0.05 vs NT). Vascular morphology at luminal pressure of 75 mmHg showed a significant increase in wall thickness (S-P467L: 18.7±0.8, NT: 16.0±0.4, p<0.05 vs NT) and % media/lumen (S-P467L: 8.4±0.3, NT: 7.1±0.2, p<0.05 vs NT) in S-P467L MA after DOCA-salt. Expression of tissue inhibitor of metalloproteinases (TIMP)-4 and regulator of G-protein signaling (RGS)-5 transcript were 2- and 3.5-fold increased, respectively, in MA of NT with DOCA-salt compared to NT baseline. However, this induction was markedly blunted in S-P467L MA. We conclude that interference with PPARG function in SMC leads to altered gene expression crucial for normal vascular homeostasis, thereby sensitizing the mice to the effects of DOCA-salt induced HT and vascular dysfunction.


Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2433
Author(s):  
Cécilia Colson ◽  
Pierre-Louis Batrow ◽  
Nadine Gautier ◽  
Nathalie Rochet ◽  
Gérard Ailhaud ◽  
...  

Thermogenic brown and brite adipocytes convert chemical energy from nutrients into heat. Therapeutics that regulate brown adipocyte recruitment and activity represent interesting strategies to control fat mass such as in obesity or cachexia. The peroxisome proliferator-activated receptor (PPAR) family plays key roles in the maintenance of adipose tissue and in the regulation of thermogenic activity. Activation of these receptors induce browning of white adipocyte. The purpose of this work was to characterize the role of carnosic acid (CA), a compound used in traditional medicine, in the control of brown/brite adipocyte formation and function. We used human multipotent adipose-derived stem (hMADS) cells differentiated into white or brite adipocytes. The expression of key marker genes was determined using RT-qPCR and western blotting. We show here that CA inhibits the browning of white adipocytes and favors decreased gene expression of thermogenic markers. CA treatment does not affect β-adrenergic response. Importantly, the effects of CA are fully reversible. We used transactivation assays to show that CA has a PPARα/γ antagonistic action. Our data pinpoint CA as a drug able to control PPAR activity through an antagonistic effect. These observations shed some light on the development of natural PPAR antagonists and their potential effects on thermogenic response.


2020 ◽  
Vol 19 ◽  
pp. 153303381989367 ◽  
Author(s):  
Zhun Yu ◽  
Qi He ◽  
Guoping Xu

Background: Gene expression profiles from early-onset breast cancer and normal tissues were analyzed to explore the genes and prognostic factors associated with breast cancer. Methods: GSE109169 and GSE89116 were obtained from the database of Gene Expression Omnibus. We firstly screened the differentially expressed genes between tumor samples and normal samples from patients with early-onset breast cancer. Based on database for annotation, visualization and intergrated discovery (DAVID) tool, functional analysis was calculated. Transcription factor-target regulation and microRNA-target gene network were constructed using the tool of transcriptional regulatory relatitionships unraveled by sentence-based text mining (TRRUST) and miRWalk2.0, respectively. The prognosis-related survival information was compiled based on The Cancer Genome Atlas breast cancer clinical data. Results: A total of 708 differentially expressed genes from GSE109169 data sets and 358 differentially expressed genes from GSE89116 data sets were obtained, of which 122 common differentially expressed genes including 102 uniformly downregulated genes and 20 uniformly upregulated genes were screened. Protein–protein interaction network with a total of 83 nodes and 157 relationship pairs was obtained, and genes in protein–protein interaction, such as peroxisome proliferator-activated receptor γ, FGF2, adiponectin, and PCK1, were recognized as key nodes in protein–protein interaction. In total, 66 transcription factor–target relationship pairs were obtained, and peroxisome proliferator-activated receptor γ was the only one downregulated transcription factor. MicroRNA-target gene network contained 368 microRNA-target relationship pairs. Moreover, 16 differentially expressed genes, including 2 upregulations and 14 downregulations, were related to a significant correlation with the prognosis, including SQLE and peroxisome proliferator-activated receptor γ. Conclusions: SQLE and peroxisome proliferator-activated receptor γ might be important prognostic factors in breast cancers, and adiponectin might be important in breast cancer pathogenesis regulated by peroxisome proliferator-activated receptor γ.


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