Impaired fatty acid synthesis affects immune cells activation: Focus on sterol regulatory element binding factor-1c on T lymphocytes

2017 ◽  
Vol 27 (1) ◽  
pp. e9-e10
Author(s):  
F. Bonacina ◽  
G. Cermenati ◽  
D. Caruso ◽  
A.L. Catapano ◽  
N. Mitro ◽  
...  
Keyword(s):  
Fatty Acid ◽  
T Lymphocytes ◽  
Fatty Acid Synthesis ◽  
Immune Cells ◽  
Regulatory Element ◽  
Acid Synthesis ◽  
Binding Factor ◽  
Sterol Regulatory Element ◽  
Impaired Fatty Acid

Impaired fatty acid synthesis affects immune cells activation: focus on sterol regulatory element binding factor-1c on T lymphocytes

2017 ◽  
Vol 263 ◽  
pp. e23
Author(s):  
Fabrizia Bonacina ◽  
Gaia Cermenati ◽  
Donatella Caruso ◽  
Alberico Luigi Catapano ◽  
Nico Mitro ◽  
...  
Keyword(s):  
Fatty Acid ◽  
T Lymphocytes ◽  
Fatty Acid Synthesis ◽  
Immune Cells ◽  
Regulatory Element ◽  
Acid Synthesis ◽  
Binding Factor ◽  
Sterol Regulatory Element ◽  
Impaired Fatty Acid

scholarly journals Sterol regulatory element binding protein and dietary lipid regulation of fatty acid synthesis in the mammary epithelium

2010 ◽  
Vol 299 (6) ◽  
pp. E918-E927 ◽  
Author(s):  
Michael C. Rudolph ◽  
Jenifer Monks ◽  
Valerie Burns ◽  
Meridee Phistry ◽  
Russell Marians ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Regulatory Element ◽  
Acid Synthesis ◽  
De Novo Lipogenesis ◽  
Mrna Levels ◽  
Sterol Regulatory Element

The lactating mammary gland synthesizes large amounts of triglyceride from fatty acids derived from the blood and from de novo lipogenesis. The latter is significantly increased at parturition and decreased when additional dietary fatty acids become available. To begin to understand the molecular regulation of de novo lipogenesis, we tested the hypothesis that the transcription factor sterol regulatory element binding factor (SREBF)-1c is a primary regulator of this system. Expression of Srebf1c mRNA and six of its known target genes increased ≥2.5-fold at parturition. However, Srebf1c-null mice showed only minor deficiencies in lipid synthesis during lactation, possibly due to compensation by Srebf1a expression. To abrogate the function of both isoforms of Srebf1, we bred mice to obtain a mammary epithelial cell-specific deletion of SREBF cleavage-activating protein (SCAP), the SREBF escort protein. These dams showed a significant lactation deficiency, and expression of mRNA for fatty acid synthase ( Fasn), insulin-induced gene 1 ( Insig1), mitochondrial citrate transporter ( Slc25a1), and stearoyl-CoA desaturase 2 ( Scd2) was reduced threefold or more; however, the mRNA levels of acetyl-CoA carboxylase-1α ( Acaca) and ATP citrate lyase ( Acly) were unchanged. Furthermore, a 46% fat diet significantly decreased de novo fatty acid synthesis and reduced the protein levels of ACACA, ACLY, and FASN significantly, with no change in their mRNA levels. These data lead us to conclude that two modes of regulation exist to control fatty acid synthesis in the mammary gland of the lactating mouse: the well-known SREBF1 system and a novel mechanism that acts at the posttranscriptional level in the presence of SCAP deletion and high-fat feeding to alter enzyme protein.

scholarly journals Oleanolic Acid Diminishes Liquid Fructose-Induced Fatty Liver in Rats: Role of Modulation of Hepatic Sterol Regulatory Element-Binding Protein-1c-Mediated Expression of Genes Responsible for De Novo Fatty Acid Synthesis

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Changjin Liu ◽  
Ying Li ◽  
Guowei Zuo ◽  
Wenchun Xu ◽  
Huanqing Gao ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Target Genes ◽  
Nuclear Protein ◽  
De Novo ◽  
Binding Protein ◽  
Regulatory Element ◽  
Acid Synthesis ◽  
Element Binding Protein ◽  
Sterol Regulatory Element

Oleanolic acid (OA), contained in more than 1620 plants and as an aglycone precursor for naturally occurred and synthesized triterpenoid saponins, is used in China for liver disorders in humans. However, the underlying liver-protecting mechanisms remain largely unknown. Here, we found that treatment of rats with OA (25 mg/kg/day, gavage, once daily) over 10 weeks diminished liquid fructose-induced excess hepatic triglyceride accumulation without effect on total energy intake. Attenuation of the increased vacuolization and Oil Red O staining area was evident on histological examination of liver in OA-treated rats. Hepatic gene expression profile demonstrated that OA suppressed fructose-stimulated overexpression of sterol regulatory element-binding protein-(SREBP-) 1/1c mRNA and nuclear protein. In accord, overexpression of SREBP-1c-responsive genes responsible for fatty acid synthesis was also downregulated. In contrast, overexpressed nuclear protein of carbohydrate response element-binding protein and its target genes liver pyruvate kinase and microsomal triglyceride transfer protein were not altered. Additionally, OA did not affect expression of peroxisome proliferator-activated receptor-gamma- and -alpha and their target genes. It is concluded that modulation of hepatic SREBP-1c-mediated expression of the genes responsible for de novo fatty acid synthesis plays a pivotal role in OA-elicited diminishment of fructose-induced fatty liver in rats.

Lipogenic Enzymes Fatty Acid Synthase and Acetyl-Coenzyme A Carboxylase are Coexpressed with Sterol Regulatory Element Binding Protein and Ki-67 in Fetal Tissues

2000 ◽  
Vol 3 (6) ◽  
pp. 525-531 ◽  
Author(s):  
Robb E. Wilentz ◽  
Lee A. Witters ◽  
Ellen S. Pizer
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Synthase ◽  
Regulatory Element ◽  
Expression Patterns ◽  
Acid Synthesis ◽  
Ki 67 ◽  
Endogenous Fatty Acid ◽  
Fetal Tissues ◽  
Sterol Regulatory Element

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.

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