scholarly journals The role of Ethanolamine Phosphate Phospholyase in regulation of Astrocyte Lipid Homeostasis

2021 ◽  
pp. 100830
Author(s):  
Cory J. White ◽  
Jessica M. Ellis ◽  
Michael J. Wolfgang
2020 ◽  
Vol 28 (3) ◽  
pp. 360-370
Author(s):  
Stanislav N. Kotlyarov ◽  
Anna A. Kotlyarova

Despite all achievements of the modern medicine, the problem of chronic obstructive pulmonary disease (COPD) does not lose its relevance. The current paradigm suggests a key role of macrophages in inflammation in COPD. Macrophages are known to be heterogeneous in their functions. This heterogeneity is determined by their immunometabolic profile and also by peculiarities of lipid homeostasis of cells. Aim. To analyze the role of the ABCA1 transporter, a member of the ABC A subfamily, in the pathogenesis of COPD. The expression of ABCA1 in lung tissues is on the second place after the liver, which shows the important role of the carrier and of lipid homeostasis in the function of lungs. Analysis of the literature shows that participation of the transporter in inflammation consists in regulation of the content of cholesterol in the lipid rafts of the membranes, in phagocytosis and apoptosis. Conclusion. Through regulation of the process of reverse transport of cholesterol in macrophages of lungs, ABCA1 can change their inflammatory response, which makes a significant contribution to the pathogenesis of COPD.


Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1740
Author(s):  
Yuning Pang ◽  
Xiang Xu ◽  
Xiaojun Xiang ◽  
Yongnan Li ◽  
Zengqi Zhao ◽  
...  

A high-fat diet often leads to excessive fat deposition and adversely affects the organism. However, the mechanism of liver fat deposition induced by high fat is still unclear. Therefore, this study aimed at acetyl-CoA carboxylase (ACC) to explore the mechanism of excessive liver deposition induced by high fat. In the present study, the ORF of ACC1 and ACC2 were cloned and characterized. Meanwhile, the mRNA and protein of ACC1 and ACC2 were increased in liver fed with a high-fat diet (HFD) or in hepatocytes incubated with oleic acid (OA). The phosphorylation of ACC was also decreased in hepatocytes incubated with OA. Moreover, AICAR dramatically improved the phosphorylation of ACC, and OA significantly inhibited the phosphorylation of the AMPK/ACC pathway. Further experiments showed that OA increased global O-GlcNAcylation and agonist of O-GlcNAcylation significantly inhibited the phosphorylation of AMPK and ACC. Importantly, the disorder of lipid metabolism caused by HFD or OA could be rescued by treating CP-640186, the dual inhibitor of ACC1 and ACC2. These observations suggested that high fat may activate O-GlcNAcylation and affect the AMPK/ACC pathway to regulate lipid synthesis, and also emphasized the importance of the role of ACC in lipid homeostasis.


2015 ◽  
Vol 14 (2) ◽  
pp. 286-287 ◽  
Author(s):  
Beatriz Barranco-Fragoso ◽  
Paloma Almeda-Valdes ◽  
Nancy Aguilar-Olivos ◽  
Nahum Méndez-Sánchez

2020 ◽  
Vol 117 (51) ◽  
pp. 32443-32452
Author(s):  
Ryan J. Schulze ◽  
Eugene W. Krueger ◽  
Shaun G. Weller ◽  
Katherine M. Johnson ◽  
Carol A. Casey ◽  
...  

Hepatocytes metabolize energy-rich cytoplasmic lipid droplets (LDs) in the lysosome-directed process of autophagy. An organelle-selective form of this process (macrolipophagy) results in the engulfment of LDs within double-membrane delimited structures (autophagosomes) before lysosomal fusion. Whether this is an exclusive autophagic mechanism used by hepatocytes to catabolize LDs is unclear. It is also unknown whether lysosomes alone might be sufficient to mediate LD turnover in the absence of an autophagosomal intermediate. We performed live-cell microscopy of hepatocytes to monitor the dynamic interactions between lysosomes and LDs in real-time. We additionally used a fluorescent variant of the LD-specific protein (PLIN2) that exhibits altered fluorescence in response to LD interactions with the lysosome. We find that mammalian lysosomes and LDs undergo interactions during which proteins and lipids can be transferred from LDs directly into lysosomes. Electron microscopy (EM) of primary hepatocytes or hepatocyte-derived cell lines supports the existence of these interactions. It reveals a dramatic process whereby the lipid contents of the LD can be “extruded” directly into the lysosomal lumen under nutrient-limited conditions. Significantly, these interactions are not affected by perturbations to crucial components of the canonical macroautophagy machinery and can occur in the absence of double-membrane lipoautophagosomes. These findings implicate the existence of an autophagic mechanism used by mammalian cells for the direct transfer of LD components into the lysosome for breakdown. This process further emphasizes the critical role of lysosomes in hepatic LD catabolism and provides insights into the mechanisms underlying lipid homeostasis in the liver.


2012 ◽  
Vol 92 (3) ◽  
pp. 1061-1085 ◽  
Author(s):  
Nada A. Abumrad ◽  
Nicholas O. Davidson

Intestinal lipid transport plays a central role in fat homeostasis. Here we review the pathways regulating intestinal absorption and delivery of dietary and biliary lipid substrates, principally long-chain fatty acid, cholesterol, and other sterols. We discuss the regulation and functions of CD36 in fatty acid absorption, NPC1L1 in cholesterol absorption, as well as other lipid transporters including FATP4 and SRB1. We discuss the pathways of intestinal sterol efflux via ABCG5/G8 and ABCA1 as well as the role of the small intestine in high-density lipoprotein (HDL) biogenesis and reverse cholesterol transport. We review the pathways and genetic regulation of chylomicron assembly, the role of dominant restriction points such as microsomal triglyceride transfer protein and apolipoprotein B, and the role of CD36, l-FABP, and other proteins in formation of the prechylomicron complex. We will summarize current concepts of regulated lipoprotein secretion (including HDL and chylomicron pathways) and include lessons learned from families with genetic mutations in dominant pathways (i.e., abetalipoproteinemia, chylomicron retention disease, and familial hypobetalipoproteinemia). Finally, we will provide an integrative view of intestinal lipid homeostasis through recent findings on the role of lipid flux and fatty acid signaling via diverse receptor pathways in regulating absorption and production of satiety factors.


Glia ◽  
2014 ◽  
Vol 62 (9) ◽  
pp. 1502-1512 ◽  
Author(s):  
Jennifer Zenker ◽  
Mark Stettner ◽  
Salla Ruskamo ◽  
Enric Domènech-Estévez ◽  
Hasna Baloui ◽  
...  

2017 ◽  
Vol 18 (1) ◽  
Author(s):  
Amanda B. Chai ◽  
Alaina J. Ammit ◽  
Ingrid C. Gelissen

2021 ◽  
Vol 22 (4) ◽  
pp. 1583
Author(s):  
Igor A. Butovich ◽  
Amber Wilkerson ◽  
Seher Yuksel

Previous studies on ablation of several key genes of meibogenesis related to fatty acid elongation, omega oxidation, and esterification into wax esters have demonstrated that inactivation of any of them led to predicted changes in the meibum lipid profiles and caused severe abnormalities in the ocular surface and Meibomian gland (MG) physiology and morphology. In this study, we evaluated the effects of Soat1 ablation that were expected to cause depletion of the second largest class of Meibomian lipids (ML)—cholesteryl esters (CE)—in a mouse model. ML of the Soat1-null mice were examined using liquid chromatography high-resolution mass spectrometry and compared with those of Soat1+/− and wild-type mice. Complete suppression of CE biosynthesis and simultaneous accumulation of free cholesterol (Chl) were observed in Soat1-null mice, while Soat1+/− mutants had normal Chl and CE profiles. The total arrest of the CE biosynthesis in response to Soat1 ablation transformed Chl into the dominant lipid in meibum accounting for at least 30% of all ML. The Soat1-null mice had clear manifestations of dry eye and MG dysfunction. Enrichment of meibum with Chl and depletion of CE caused plugging of MG orifices, increased meibum rigidity and melting temperature, and led to a massive accumulation of lipid deposits around the eyes of Soat1-null mice. These findings illustrate the role of Soat1/SOAT1 in the lipid homeostasis and pathophysiology of MG.


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