scholarly journals Metformin alleviates inflammation through suppressing FASN-dependent palmitoylation of Akt

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Wenfang Xiong ◽  
Kuo-Yang Sun ◽  
Yan Zhu ◽  
Xiaoqi Zhang ◽  
Yi-Hua Zhou ◽  
...  

AbstractMetformin, traditionally regarded as a hypoglycemic drug, has been studied in other various fields including inflammation. The specific mechanism of metformin’s effect on immune cells remains unclear. Herein, it is verified that LPS-induced macrophages are characterized by enhanced endogenous fatty acid synthesis and the inhibition of fatty acid synthase (FASN) downregulates proinflammatory responses. We further show that metformin could suppress such elevation of FASN as well as proinflammatory activation in macrophages. In vivo, metformin treatment ameliorates dextran sulfate sodium (DSS)-induced colitis through impairing proinflammatory activation of colonic lamina propria mononuclear cells (LPMCs). The reduction of FASN by metformin hinders Akt palmitoylation, which further disturbs Akt membrane attachment and its phosphorylation. Metformin-mediated suppression of FASN/Akt pathway and its downstream MAPK signaling contributes to its anti-inflammatory role in macrophages. From the perspective of immunometabolism, our work points towards metformin utilization as an effective and potential intervention against macrophages-involved inflammatory diseases.

2020 ◽  
Vol 41 (6) ◽  
pp. 778-789 ◽  
Author(s):  
Su-Hyeong Kim ◽  
Eun-Ryeong Hahm ◽  
Krishna B Singh ◽  
Sruti Shiva ◽  
Jacob Stewart-Ornstein ◽  
...  

Abstract Withaferin A (WA) is a promising phytochemical exhibiting in vitro and in vivo anticancer activities against prostate and other cancers, but the mechanism of its action is not fully understood. In this study, we performed RNA-seq analysis using 22Rv1 human prostate cancer cell line to identify mechanistic targets of WA. Kyoto Encyclopedia of Genes and Genomes pathway analysis of the differentially expressed genes showed most significant enrichment of genes associated with metabolism. These results were validated using LNCaP and 22Rv1 human prostate cancer cells and Hi-Myc transgenic mice as models. The intracellular levels of acetyl-CoA, total free fatty acids and neutral lipids were decreased significantly following WA treatment in both cells, which was accompanied by downregulation of mRNA (confirmed by quantitative reverse transcription-polymerase chain reaction) and protein levels of key fatty acid synthesis enzymes, including ATP citrate lyase, acetyl-CoA carboxylase 1, fatty acid synthase and carnitine palmitoyltransferase 1A. Ectopic expression of c-Myc, but not constitutively active Akt, conferred a marked protection against WA-mediated suppression of acetyl-CoA carboxylase 1 and fatty acid synthase protein expression, and clonogenic cell survival. WA was a superior inhibitor of cell proliferation and fatty acid synthesis in comparison with known modulators of fatty acid metabolism including cerulenin and etomoxir. Intraperitoneal WA administration to Hi-Myc transgenic mice (0.1 mg/mouse, three times/week for 5 weeks) also resulted in a significant decrease in circulating levels of total free fatty acids and phospholipids, and expression of ATP citrate lyase, acetyl-CoA carboxylase 1, fatty acid synthase and carnitine palmitoyltransferase 1A proteins in the prostate in vivo.


2007 ◽  
Vol 51 (10) ◽  
pp. 3537-3545 ◽  
Author(s):  
Methee Chayakulkeeree ◽  
Thomas H. Rude ◽  
Dena L. Toffaletti ◽  
John R. Perfect

ABSTRACT Fatty acid synthase in the yeast Cryptococcus neoformans is composed of two subunits encoded by FAS1 and FAS2 genes. We inserted a copper-regulated promoter (P CTR4-2 ) to regulate FAS1 and FAS2 expression in Cryptococcus neoformans (strains P CTR4-2 /FAS1 and P CTR4-2 /FAS2, respectively). Both mutants showed growth rates similar to those of the wild type in a low-copper medium in which FAS1 and FAS2 were expressed, but even in the presence of exogenous fatty acids, strains were suppressed in growth under high-copper conditions. The treatment of C. neoformans with fluconazole was shown to have an increased inhibitory activity and even became fungicidal when either FAS1 or FAS2 expression was suppressed. Furthermore, a subinhibitory dose of fluconazole showed anticryptococcal activity in vitro in the presence of cerulenin, a fatty acid synthase inhibitor. In a murine model of pulmonary cryptococcosis, a tissue census of yeast cells in P CTR4-2 /FAS2 strain at day 7 of infection was significantly lower than that in mice treated with tetrathiomolybdate, a copper chelator (P < 0.05), and a yeast census of P CTR4-2 /FAS1 strain at day 14 of infection in the brain was lower in the presence of more copper. In fact, no positive cultures from the brain were detected in mice (with or without tetrathiomolybdate treatment) infected with the P CTR4-2 /FAS2 strain, which implies that this mutant did not reach the brain in mice. We conclude that both FAS1 and FAS2 in C. neoformans are essential for in vitro and in vivo growth in conditions with and without exogenous fatty acids and that FAS1 and FAS2 can potentially be fungicidal targets for C. neoformans with a potential for synergistic behavior with azoles.


1994 ◽  
Vol 87 (4) ◽  
pp. 441-446 ◽  
Author(s):  
K. J. Simpson ◽  
S. Venkatesan ◽  
T. J. Peters

1. Chronic alcohol feeding with a low-fat diet (4.4% total calories) produced a two- to three-fold increase in hepatic triacylglycerol and esterified cholesterol compared with pair-fed low-fat diet controls. Plasma lipids were similar in both groups. 2. Hepatic fatty acid synthesis rates measured in vivo with 3H2O were significantly lower in the alcohol-fed animals than in controls. Activities of hepatic fatty acid synthase (EC 2.3.1.85) and acetyl-CoA carboxylase (EC 6.4.1.2) were reduced in the alcohol-fed rats. 3. These results indicate that enhanced hepatic fatty acid synthesis does not occur in rats fed alcohol and a low-fat diet for 4 weeks, and is thus not implicated in the pathogenesis of alcohol-induced fatty liver.


2020 ◽  
Author(s):  
Ganghua Tang ◽  
Shaoyu Liu ◽  
Ping Hu ◽  
Hui Ma ◽  
Xianhong Xiang ◽  
...  

Abstract BackgroundThe aim of this study was to evaluate the potential value of 2-[18F]fluoropropionic acid ([18F]FPA) for PET imaging of prostate cancer (PCa) and to confirm the correlation between [18F]FPA accumulation and fatty acid synthase (FASN) levels in PCa models. The results of the first [18F]FPA PET study of a PCa patient are reported.MethodsA PET imaging comparison of [18F]FDG and [18F]FPA was performed in LNCaP, PC-3 and DU145 tumors. Additionally, in vivo blocking experiments in those models were conducted with orlistat. Western blotting staining of FASN were performed in the those xenograft tumors.ResultsThe uptake of [18F]FPA in the LNCaP and PC-3 tumors was higher than that of [18F]FDG (P<0.05 and P<0.05), while [18F]FDG was significantly superior to [18F]FPA in detecting DU145 tumors (P<0.05). Grayscale scanning showed that FASN expression in the LNCaP and PC-3 tumors was 33.3% and 10.3% higher than that in the DU145 tumors, respectively. The accumulation (% ID/g) of [18F]FPA in the LNCaP , PC-3 and DU145 tumors decreased by 27.6, 40.5 and 11.7%, respectively, after treatment with orlistat. The [18F]FPA showed higher tumor/background ratios than [18F]FDG in the first PCa patient (P<0.05).ConclusionsThe [18F]FPA uptake in PCa models was positively correlated with FASN expression and could be reduced after administration of a single FASN inhibitor. In addition, the [18F]FPA is a potential broad-spectrum PET imaging agent, and the imaging effect of [18F]FPA may be superior to [18F]FDG in human PCa.


2018 ◽  
Vol 217 (4) ◽  
pp. 1353-1368 ◽  
Author(s):  
Laura Montani ◽  
Jorge A. Pereira ◽  
Camilla Norrmén ◽  
Hartmut B.F. Pohl ◽  
Elisa Tinelli ◽  
...  

Myelination calls for a remarkable surge in cell metabolism to facilitate lipid and membrane production. Endogenous fatty acid (FA) synthesis represents a potentially critical process in myelinating glia. Using genetically modified mice, we show that Schwann cell (SC) intrinsic activity of the enzyme essential for de novo FA synthesis, fatty acid synthase (FASN), is crucial for precise lipid composition of peripheral nerves and fundamental for the correct onset of myelination and proper myelin growth. Upon FASN depletion in SCs, epineurial adipocytes undergo lipolysis, suggestive of a compensatory role. Mechanistically, we found that a lack of FASN in SCs leads to an impairment of the peroxisome proliferator-activated receptor (PPAR) γ–regulated transcriptional program. In agreement, defects in myelination of FASN-deficient SCs could be ameliorated by treatment with the PPARγ agonist rosiglitazone ex vivo and in vivo. Our results reveal that FASN-driven de novo FA synthesis in SCs is mandatory for myelination and identify lipogenic activation of the PPARγ transcriptional network as a putative downstream functional mediator.


2018 ◽  
Vol 315 (1) ◽  
pp. E63-E71 ◽  
Author(s):  
Stephen F. Previs ◽  
Kithsiri Herath ◽  
Andrea R. Nawrocki ◽  
Carlos G. Rodriguez ◽  
Deborah Slipetz ◽  
...  

An increased contribution of de novo lipogenesis (DNL) may play a role in cases of dyslipidemia and adipose accretion; this suggests that inhibition of fatty acid synthesis may affect clinical phenotypes. Since it is not clear whether modulation of one step in the lipogenic pathway is more important than another, the use of tracer methods can provide a deeper level of insight regarding the control of metabolic activity. Although [2H]water is generally considered a reliable tracer for quantifying DNL in vivo (it yields a homogenous and quantifiable precursor labeling), the relatively long half-life of body water is thought to limit the ability of performing repeat studies in the same subjects; this can create a bottleneck in the development and evaluation of novel therapeutics for inhibiting DNL. Herein, we demonstrate the ability to perform back-to-back studies of DNL using [2H]water. However, this work uncovered special circumstances that affect the data interpretation, i.e., it is possible to obtain seemingly negative values for DNL. Using a rodent model, we have identified a physiological mechanism that explains the data. We show that one can use [2H]water to test inhibitors of DNL by performing back-to-back studies in higher species [i.e., treat nonhuman primates with platensimycin, an inhibitor of fatty acid synthase]; studies also demonstrate the unsuitability of [13C]acetate.


2000 ◽  
Vol 3 (6) ◽  
pp. 525-531 ◽  
Author(s):  
Robb E. Wilentz ◽  
Lee A. Witters ◽  
Ellen S. Pizer

Endogenous fatty acid synthesis has been observed in some rapidly proliferating cells and tissues, both normal and neoplastic, and probably supports membrane synthesis. Sterol regulatory element binding proteins (SREBPs) are transcription factors that regulate the expression of genes for both cholesterol and fatty acid synthesis. The inactive precursor form resides in cytoplasmic membranes. Intracellular lipid depletion triggers proteolytic cleavage of SREBP, allowing the amino terminus to enter the nucleus and activate the expression of enzymes, including acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), major biosynthetic enzymes for fatty acid synthesis. The expression patterns of ACC, FAS, SREBP, and Ki-67 in fetal tissues were compared to determine whether SREBP is likely to participate in the regulation of proliferation-associated fatty acid synthesis during fetal growth. Tissues from 22 fetuses, 12 first-trimester and 10 second-trimester (range 7.0 to 21.6 weeks), were studied. Serial 5-μm sections were stained with antibodies to ACC, FAS, SREBP, and Ki-67 and were compared. ACC, FAS, SREBP, and Ki-67 were coexpressed in the proliferative compartments of the intestines, skin, and kidney. ACC, FAS, and Ki-67 were coexpressed with little SREBP in lung and cytotrophoblast. SREBP, ACC, and FAS were coexpressed without Ki-67 in hepatocytes, ganglion cells, and intermediate trophoblast. The close linkage of SREBP, ACC, FAS, and Ki-67 in some proliferating fetal tissues suggests that in these tissues SREBP participates in the transcriptional regulation of lipogenic genes during proliferation. SREBP, ACC, and FAS coexpression without Ki-67 occurs in differentiated tissues that may synthesize fatty acids for other functions.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xudong Huang ◽  
Ling Pan ◽  
Zhixiang Zuo ◽  
Mei Li ◽  
Lingxing Zeng ◽  
...  

AbstractThe molecular mechanism underlying pancreatic ductal adenocarcinoma (PDAC) malignancy remains unclear. Here, we characterize a long intergenic non-coding RNA LINC00842 that plays a role in PDAC progression. LINC00842 expression is upregulated in PDAC and induced by high concentration of glucose via transcription factor YY1. LINC00842 binds to and prevents acetylated PGC-1α from deacetylation by deacetylase SIRT1 to form PGC-1α, an important transcription co-factor in regulating cellular metabolism. LINC00842 overexpression causes metabolic switch from mitochondrial oxidative catabolic process to fatty acid synthesis, enhancing the malignant phenotypes of PDAC cells. High LINC00842 levels are correlated with elevated acetylated- PGC-1α levels in PDAC and poor patient survival. Decreasing LINC00842 level and inhibiting fatty acid synthase activity significantly repress PDAC growth and invasiveness in mouse pancreatic xenograft or patient-derived xenograft models. These results demonstrate that LINC00842 plays a role in promoting PDAC malignancy and thus might serve as a druggable target.


1982 ◽  
Vol 208 (3) ◽  
pp. 611-618 ◽  
Author(s):  
M R Grigor ◽  
A Geursen ◽  
M J Sneyd ◽  
S M Warren

1. The rate of mammary-gland lipogenesis measured in vivo from 3H2O was suppressed after decreasing the milk demand by decreasing the number of pups from ten to two or three, as well as by giving diets containing lipid [Grigor & Warren (1980) Biochem. J. 188, 61-65]. 2. The specific activities of the lipogenic enzymes fatty acid synthase, glucose 6-phosphate dehydrogenase and ‘malic’ enzyme increased between 6- and 10-fold in the mammary gland and between 2- and 3-fold in the livers during the first 10 days of lactation. The increases in specific activity coupled with the doubling of liver mass which occurred during pregnancy and lactation resulted in considerable differences in total liver activities when compared with virgin animals. 3. Although consumption of a diet containing 20% peanut oil suppressed the activities of the three lipogenic enzymes in the livers, only the ‘malic’ enzyme was affected in the mammary glands. 4. In contrast, decreased milk demand did not affect the specific activities of any of the liver enzymes, whereas it resulted in suppression of all three lipogenic enzymes of the mammary glands. There was no effect on either the cytoplasmic malate dehydrogenase or the lactate dehydrogenase of the mammary gland. 5. In all the experiments performed, the activity of the fatty acid synthase correlated with the amount of material precipitated by the rabbit antibody raised against rat fatty acid synthase.


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