Search results for "Lipid metabolism"
showing 10 items of 359 documents
Elucidating the molecular physiology of lantibiotic NAI-107 production in Microbispora ATCC-PTA-5024.
2016
Background The filamentous actinomycete Microbispora ATCC-PTA-5024 produces the lantibiotic NAI-107, which is an antibiotic peptide effective against multidrug-resistant Gram-positive bacteria. In actinomycetes, antibiotic production is often associated with a physiological differentiation program controlled by a complex regulatory and metabolic network that may be elucidated by the integration of genomic, proteomic and bioinformatic tools. Accordingly, an extensive evaluation of the proteomic changes associated with NAI-107 production was performed on Microbispora ATCC-PTA-5024 by combining two-dimensional difference in gel electrophoresis, mass spectrometry and gene ontology approaches. R…
Impaired Kupffer Cell Self-Renewal Alters the Liver Response to Lipid Overload during Non-alcoholic Steatohepatitis
2020
International audience; Kupffer cells (KCs) are liver-resident macrophages that self-renew by proliferation in the adult independently from monocytes. However, how they are maintained during non-alcoholic steatohepatitis (NASH) remains ill defined. We found that a fraction of KCs derived from Ly-6C+ monocytes during NASH, underlying impaired KC self-renewal. Monocyte-derived KCs (MoKCs) gradually seeded the KC pool as disease progressed in a response to embryo-derived KC (EmKC) death. Those MoKCs were partly immature and exhibited a pro-inflammatory status compared to EmKCs. Yet, they engrafted the KC pool for the long term as they remained following disease regression while acquiring matur…
Mitochondrial Dysfunction, Oxidative Stress and Neuroinflammation in Neurodegeneration with Brain Iron Accumulation (NBIA)
2020
The syndromes of neurodegeneration with brain iron accumulation (NBIA) encompass a group of invalidating and progressive rare diseases that share the abnormal accumulation of iron in the basal ganglia. The onset of NBIA disorders ranges from infancy to adulthood. Main clinical signs are related to extrapyramidal features (dystonia, parkinsonism and choreoathetosis), and neuropsychiatric abnormalities. Ten NBIA forms are widely accepted to be caused by mutations in the genes PANK2, PLA2G6, WDR45, C19ORF12, FA2H, ATP13A2, COASY, FTL1, CP, and DCAF17. Nonetheless, many patients remain without a conclusive genetic diagnosis, which shows that there must be additional as yet undiscovered NBIA gen…
Age‐related ultrastructural changes of the basement membrane in the mouse blood‐brain barrier
2018
Abstract The blood‐brain barrier (BBB) is essential for a functional neurovascular unit. Most studies focused on the cells forming the BBB, but very few studied the basement membrane (BM) of brain capillaries in ageing. We used transmission electron microscopy and electron tomography to investigate the BM of the BBB in ageing C57BL/6J mice. The thickness of the BM of the BBB from 24‐month‐old mice was double as compared with that of 6‐month‐old mice (107 nm vs 56 nm). The aged BBB showed lipid droplets gathering within the BM which further increased its thickness (up to 572 nm) and altered its structure. The lipids appeared to accumulate toward the glial side of the BM. Electron tomography …
Arabidopsis Serine Decarboxylase 1 (SDC1) in Phospholipid and Amino Acid Metabolism
2018
Arabidopsis thaliana serine decarboxylase 1 (SDC1) catalyzes conversion of serine to ethanolamine, the first reaction step of phosphatidylcholine and phosphatidylethanolamine biosynthesis. However, an involvement of SDC1 in amino acid metabolism remains elusive despite that serine is the substrate of SDC1. Here, we showed that SDC1 localizes in mitochondria although phosphatidylcholine and phosphatidylethanolamine are known to be produced in the endoplasmic reticulum (ER). Moreover, we found that overexpression of SDC1 decreased levels of amino acid compounds derived from mitochondrial tricarboxylic acid cycle. These results suggest that mitochondria-localized SDC1 plays an important role i…
Activation of Mevalonate Pathway Via LKB1 is Essential for Stability of Treg Cells
2019
Summary: The function of regulatory T (Treg) cells depends on lipid oxidation. However, the molecular mechanism by which Treg cells maintain lipid metabolism after activation remains elusive. Liver kinase B1 (LKB1) acts as a coordinator by linking cellular metabolism to substrate AMP-activated protein kinase (AMPK). We show that deletion of LKB1 in Treg cells exhibited reduced suppressive activity and developed fatal autoimmune inflammation. Mechanistically, LKB1 induced activation of the mevalonate pathway by upregulating mevalonate genes, which was essential for Treg cell functional competency and stability by inducing Treg cell proliferation and suppressing interferon-gamma and interleuk…
Potential Role of ANGPTL4 in the Cross Talk between Metabolism and Cancer through PPAR Signaling Pathway
2017
The angiopoietin-like 4 (ANGPTL4) protein belongs to a superfamily of secreted proteins structurally related to factors modulating angiogenesis known as angiopoietins. At first, ANGPTL4 has been identified as an adipokine exclusively involved in lipid metabolism, because of its prevalent expression in liver and adipose tissue. This protein regulates lipid metabolism by inhibiting lipoprotein lipase (LPL) activity and stimulating lipolysis of white adipose tissue (WAT), resulting in increased levels of plasma triglycerides (TG) and fatty acids. Subsequently, ANGPTL4 has been shown to be involved in several nonmetabolic and metabolic conditions, both physiological and pathological, including …
Loss of c-Met signaling sensitizes hepatocytes to lipotoxicity and induces cholestatic liver damage by aggravating oxidative stress.
2016
Recent studies confirmed a critical importance of c-Met signaling for liver regeneration by modulating redox balance. Here we used liver-specific conditional knockout mice (MetKO) and a nutritional model of hepatic steatosis to address the role of c-Met in cholesterol-mediated liver toxicity. Liver injury was assessed by histopathology and plasma enzymes levels. Global transcriptomic changes were examined by gene expression microarray, and key molecules involved in liver damage and lipid homeostasis were evaluated by Western blotting. Loss of c-Met signaling amplified the extent of liver injury in MetKO mice fed with high-cholesterol diet for 30days as evidenced by upregulation of liver enz…
Assessing the Contribution of Relative Macrophage Frequencies to Subcutaneous Adipose Tissue
2021
Background: Macrophages play an important role in regulating adipose tissue function, while their frequencies in adipose tissue vary between individuals. Adipose tissue infiltration by high frequencies of macrophages has been linked to changes in adipokine levels and low-grade inflammation, frequently associated with the progression of obesity. The objective of this project was to assess the contribution of relative macrophage frequencies to the overall subcutaneous adipose tissue gene expression using publicly available datasets.Methods: Seven publicly available microarray gene expression datasets from human subcutaneous adipose tissue biopsies (n = 519) were used together with TissueDecod…
Protective effect of quercetin on high-fat diet-induced non-alcoholic fatty liver disease in mice is mediated by modulating intestinal microbiota imb…
2016
Gut microbiota is involved in obesity, metabolic syndrome and the progression of nonalcoholic fatty liver disease (NAFLD). It has been recently suggested that the flavonoid quercetin may have the ability to modulate the intestinal microbiota composition, suggesting a prebiotic capacity which highlights a great therapeutic potential in NAFLD. The present study aims to investigate benefits of experimental treatment with quercetin on gut microbial balance and related gut-liver axis activation in a nutritional animal model of NAFLD associated to obesity. C57BL/6J mice were challenged with high fat diet (HFD) supplemented or not with quercetin for 16 weeks. HFD induced obesity, metabolic syndrom…