scholarly journals Free fatty acids: potential proinflammatory mediators in rheumatic diseases

2013 ◽  
Vol 74 (1) ◽  
pp. 303-310 ◽  
Author(s):  
Klaus W Frommer ◽  
Andreas Schäffler ◽  
Stefan Rehart ◽  
Angela Lehr ◽  
Ulf Müller-Ladner ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Fatty Acids ◽  
Endothelial Cells ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Synovial Fibroblasts ◽  
Human Chondrocytes ◽  
Fatty Acid Transport ◽  
Joint Diseases ◽  
Inflammatory Joint Diseases

ObjectivesDue to their role in inflammatory metabolic diseases, we hypothesised that free fatty acids (FFA) are also involved in inflammatory joint diseases. To test this hypothesis, we analysed the effect of FFA on synovial fibroblasts (SF), human chondrocytes and endothelial cells. We also investigated whether the toll-like receptor 4 (TLR4), which can contribute to driving arthritis, is involved in FFA signalling.MethodsRheumatoid arthritis SF, osteoarthritis SF, psoriatic arthritis SF, human chondrocytes and endothelial cells were stimulated in vitro with different FFA. Immunoassays were used to quantify FFA-induced protein secretion. TLR4 signalling was inhibited extracellularly and intracellularly. Fatty acid translocase (CD36), responsible for transporting long-chain FFA into the cell, was also inhibited.ResultsIn rheumatoid arthritis synovial fibroblasts (RASF), FFA dose-dependently enhanced the secretion of the proinflammatory cytokine IL-6, the chemokines IL-8 and MCP-1, as well as the matrix-degrading enzymes pro-MMP1 and MMP3. The intensity of the response was mainly dependent on the patient rather than on the type of disease. Both saturated and unsaturated FFA showed similar effects on RASF, while responses to the different FFA varied for human chondrocytes and endothelial cells. Extracellular and intracellular TLR4 inhibition as well as fatty acid transport inhibition blocked the palmitic acid-induced IL-6 secretion of RASF.ConclusionsThe data show that FFA are not only metabolic substrates but may also directly contribute to articular inflammation and degradation in inflammatory joint diseases. Moreover, the data suggest that, in RASF, FFA exert their effects via TLR4 and require extracellular and intracellular access to the TLR4 receptor complex.

Synovial fibroblasts and synovial macrophages from patients with rheumatoid arthritis and other inflammatory joint diseases show chromosomal aberrations

2003 ◽  
Vol 38 (1) ◽  
pp. 53-67 ◽  
Author(s):  
Raimund W. Kinne ◽  
Elke Kunisch ◽  
Volkmar Beensen ◽  
Thomas Zimmermann ◽  
Frank Emmrich ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Chromosomal Aberrations ◽  
Synovial Fibroblasts ◽  
Joint Diseases ◽  
Inflammatory Joint Diseases

901 A LINK BETWEEN FREE FATTY ACIDS, FATTY ACID TRANSPORT PROTEINS AND APOPTOSIS IN THE PATHOGENESIS OF NASH

2008 ◽  
Vol 48 ◽  
pp. S338
Author(s):  
L.P. Bechmann ◽  
N. Wiesemann ◽  
M. Schlensak ◽  
I. Wedemeier ◽  
M. Odenthal ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Transport Proteins ◽  
Fatty Acid Transport ◽  
Acid Transport ◽  
Fatty Acid Transport Proteins

scholarly journals Insulin-stimulated adipocytes secrete lactate to promote endothelial fatty acid uptake and transport

2021 ◽  
Author(s):  
Ayon Ibrahim ◽  
Michael D. Neinast ◽  
Kristina Li ◽  
Michael Noji ◽  
Boa Kim ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Endothelial Cells ◽  
Fatty Acid ◽  
Lactate Concentration ◽  
Lactate Production ◽  
Fatty Acid Uptake ◽  
Endothelial Barrier ◽  
Fatty Acid Transport ◽  
Acid Uptake ◽  
Uptake And Transport

Insulin stimulates adipose tissue to extract fatty acids from circulation and sequester them inside adipose cells. How fatty acids are transported across the capillary endothelial barrier, or how this process is regulated, remains unclear. We modeled the relationship of adipocytes and endothelial cells in vitro to test the role of insulin in fatty acid transport. Treatment of endothelial cells with insulin did not affect endothelial fatty acid uptake, but endothelial cells took up more fatty acids when exposed to media conditioned by adipocytes treated with insulin. Manipulations of this conditioned media indicated that the secreted factor is a small, hydrophilic, non-proteinaceous metabolite. Factor activity was correlated with lactate concentration, and inhibition of lactate production in adipocytes abolished the activity. Finally, lactate alone was sufficient to increase endothelial uptake of both free fatty acids and lipids liberated from chylomicrons, and to promote trans-endothelial transport, at physiologically relevant concentrations. Together, these data suggest that insulin drives adipocytes to secrete lactate, which then acts in a paracrine fashion to promote fatty acid uptake and transport across the neighboring endothelial barrier.

scholarly journals Oligonucleotide Therapies in the Treatment of Arthritis: A Narrative Review

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 902
Author(s):  
Susanne N. Wijesinghe ◽  
Mark A. Lindsay ◽  
Simon W. Jones
Keyword(s):  
Rheumatoid Arthritis ◽  
Articular Cartilage ◽  
Joint Diseases ◽  
Synovial Joint ◽  
Pharmacological Treatments ◽  
In Vivo Models ◽  
Inflammatory Joint Diseases ◽  
Joint Pathology ◽  
Cellular Pathways

Osteoarthritis (OA) and rheumatoid arthritis (RA) are two of the most common chronic inflammatory joint diseases, for which there remains a great clinical need to develop safer and more efficacious pharmacological treatments. The pathology of both OA and RA involves multiple tissues within the joint, including the synovial joint lining and the bone, as well as the articular cartilage in OA. In this review, we discuss the potential for the development of oligonucleotide therapies for these disorders by examining the evidence that oligonucleotides can modulate the key cellular pathways that drive the pathology of the inflammatory diseased joint pathology, as well as evidence in preclinical in vivo models that oligonucleotides can modify disease progression.

scholarly journals Investigation of the Membrane Fluidity Regulation of Fatty Acid Intracellular Distribution by Fluorescence Lifetime Imaging of Novel Polarity Sensitive Fluorescent Derivatives

2021 ◽  
Vol 22 (6) ◽  
pp. 3106
Author(s):  
Giada Bianchetti ◽  
Salome Azoulay-Ginsburg ◽  
Nimrod Yosef Keshet-Levy ◽  
Aviv Malka ◽  
Sofia Zilber ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Membrane Fluidity ◽  
Fluorescence Lifetime ◽  
Intracellular Distribution ◽  
Fluorescence Lifetime Imaging ◽  
Lifetime Imaging ◽  
Fatty Acid Derivatives ◽  
Polarity Sensitive

Free fatty acids are essential structural components of the cell, and their intracellular distribution and effects on membrane organelles have crucial roles in regulating the metabolism, development, and cell cycle of most cell types. Here we engineered novel fluorescent, polarity-sensitive fatty acid derivatives, with the fatty acid aliphatic chain of increasing length (from 12 to 18 carbons). As in the laurdan probe, the lipophilic acyl tail is connected to the environmentally sensitive dimethylaminonaphthalene moiety. The fluorescence lifetime imaging analysis allowed us to monitor the intracellular distribution of the free fatty acids within the cell, and to simultaneously examine how the fluidity and the microviscosity of the membrane environment influence their localization. Each of these probes can thus be used to investigate the membrane fluidity regulation of the correspondent fatty acid intracellular distribution. We observed that, in PC-12 cells, fluorescent sensitive fatty acid derivatives with increased chain length compartmentalize more preferentially in the fluid regions, characterized by a low microviscosity. Moreover, fatty acid derivatives with the longest chain compartmentalize in lipid droplets and lysosomes with characteristic lifetimes, thus making these probes a promising tool for monitoring lipophagy and related events.

scholarly journals Lipid Accumulation and Chronic Kidney Disease

Nutrients ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 722 ◽  
Author(s):  
Zhibo Gai ◽  
Tianqi Wang ◽  
Michele Visentin ◽  
Gerd Kullak-Ublick ◽  
Xianjun Fu ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Kidney Disease ◽  
Lipid Accumulation ◽  
Scavenger Receptor ◽  
Fatty Acid Uptake ◽  
Lipid Lowering ◽  
Fatty Acid Transport ◽  
Acid Uptake

Obesity and hyperlipidemia are the most prevalent independent risk factors of chronic kidney disease (CKD), suggesting that lipid accumulation in the renal parenchyma is detrimental to renal function. Non-esterified fatty acids (also known as free fatty acids, FFA) are especially harmful to the kidneys. A concerted, increased FFA uptake due to high fat diets, overexpression of fatty acid uptake systems such as the CD36 scavenger receptor and the fatty acid transport proteins, and a reduced β-oxidation rate underlie the intracellular lipid accumulation in non-adipose tissues. FFAs in excess can damage podocytes, proximal tubular epithelial cells and the tubulointerstitial tissue through various mechanisms, in particular by boosting the production of reactive oxygen species (ROS) and lipid peroxidation, promoting mitochondrial damage and tissue inflammation, which result in glomerular and tubular lesions. Not all lipids are bad for the kidneys: polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) seem to help lag the progression of chronic kidney disease (CKD). Lifestyle interventions, especially dietary adjustments, and lipid-lowering drugs can contribute to improve the clinical outcome of patients with CKD.

scholarly journals The regulation of glyceride synthesis in isolated white-fat cells. The effects of palmitate and lipolytic agents

1972 ◽  
Vol 128 (5) ◽  
pp. 1057-1067 ◽  
Author(s):  
E. D Saggerson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Fat Cells ◽  
Glyceride Synthesis ◽  
Glucose Incorporation ◽  
High Concentrations ◽  
Stimulation Of

1. 0.5mm-Palmitate stimulated incorporation of [U-14C]glucose into glyceride glycerol and fatty acids in normal fat cells in a manner dependent upon the glucose concentration. 2. In the presence of insulin the incorporation of 5mm-glucose into glyceride fatty acids was increased by concentrations of palmitate, adrenaline and 6-N-2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate up to 0.5mm, 0.5μm and 0.5mm respectively. Higher concentrations of these agents produced progressive decreases in the rate of glucose incorporation into fatty acids. 3. The effects of palmitate and lipolytic agents upon the measured parameters of glucose utilization were similar, suggesting that the effects of lipolytic agents are mediated through increased concentrations of free fatty acids. 4. In fat cells from 24h-starved rats, maximal stimulation of glucose incorporation into fatty acids was achieved with 0.25mm-palmitate. Higher concentrations of palmitate were inhibitory. In fat cells from 72h-starved rats, palmitate only stimulated glucose incorporation into fatty acids at high concentrations of palmitate (1mm and above). 5. The ability of fat cells to incorporate glucose into glyceride glycerol in the presence of palmitate decreased with increasing periods of starvation. 6. It is suggested that low concentrations of free fatty acids stimulate fatty acid synthesis from glucose by increasing the utilization of ATP and cytoplasmic NADH for esterification of these free fatty acids. When esterification of free fatty acids does not keep pace with their provision, inhibition of fatty acid synthesis occurs. Provision of free fatty acids far in excess of the esterification capacity of the cells leads to uncoupling of oxidative phosphorylation and a secondary stimulation of fatty acid synthesis from glucose.

Effect of insulin on free fatty acid uptake by hepatocytes in the duck

1984 ◽  
Vol 102 (3) ◽  
pp. 381-386 ◽  
Author(s):  
R. Gross ◽  
P. Mialhe
Keyword(s):  
Fatty Acids ◽  
Growth Hormone ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Glucose Metabolism ◽  
Free Fatty Acids ◽  
Fatty Acid Uptake ◽  
Acid Uptake ◽  
Low Doses ◽  
Higher Doses

ABSTRACT To elucidate the hypolipacidaemic effect of insulin in ducks, its action on the uptake of free fatty acids (FFA) by duck hepatocytes was determined. At low doses (10 mu./l) insulin stimulated FFA uptake. This effect was not observed with higher doses of insulin (20, 30 and 50 mu./l). Growth hormone at physiological concentrations and corticosterone (14·4 nmol/l) decreased basal activity, probably by reducing glucose metabolism and consequently α-glycerophosphate (α-GP) supply. Insulin was able to reverse the inhibition induced by GH and corticosterone on both FFA uptake and α-GP production. These results therefore suggest that the hypolipacidaemic effect of insulin may be partly mediated by its action on hepatic FFA uptake. J. Endocr. (1984) 102, 381–386

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