Regulation of leptin secretion from white adipocytes by free fatty acids

2003 ◽  
Vol 285 (3) ◽  
pp. E521-E526 ◽  
Author(s):  
Philippe G. Cammisotto ◽  
Yves Gélinas ◽  
Yves Deshaies ◽  
Ludwik J. Bukowiecki

Norepinephrine stimulates lipolysis and concurrently inhibits insulin-stimulated leptin secretion from white adipocytes. To assess whether there is a cause-effect relationship between these two metabolic events, the effects of fatty acids were investigated in isolated rat adipocytes incubated in buffer containing low (0.1%) and high (4%) albumin concentrations. Palmitic acid (1 mM) mimicked the inhibitory effects of norepinephrine (1 μM) on insulin (10 nM)-stimulated leptin secretion, but only at low albumin concentrations. Studies investigating the effects of the chain length of saturated fatty acids [from butyric (C4) to stearic (C18) acids] revealed that only fatty acids with a chain length superior or equal to eight carbons effectively inhibited insulin-stimulated leptin secretion. Long-chain mono- and polyunsaturated fatty acids constitutively present in adipocyte triglyceride stores (oleic, linoleic, γ-linolenic, palmitoleic, eicosapentanoic, and docosahexanoic acids) also completely suppressed leptin secretion. Saturated and unsaturated fatty acids inhibited insulin-stimulated leptin secretion with the same potency and without any significant effect on basal secretion. On the other hand, inhibitors of mitochondrial fatty acid oxidation (palmoxirate, 2-bromopalmitate, 2-bromocaproate) attenuated the stimulatory effects of insulin on leptin release without reversing the effects of fatty acids or norepinephrine, suggesting that fatty acids do not need to be oxidized by the mitochondria to inhibit leptin release. These results demonstrate that long-chain fatty acids mimic the effects of norepinephrine on leptin secretion and suggest that they may play a regulatory role as messengers between stimulation of lipolysis by norepinephrine and inhibition of leptin secretion.

2014 ◽  
Vol 457 (3) ◽  
pp. 415-424 ◽  
Author(s):  
Marthe H. R. Ludtmann ◽  
Plamena R. Angelova ◽  
Ying Zhang ◽  
Andrey Y. Abramov ◽  
Albena T. Dinkova-Kostova

Transcription factor Nrf2 affects fatty acid oxidation; the mitochondrial oxidation of long-chain (palmitic) and short-chain (hexanoic) saturated fatty acids is depressed in the absence of Nrf2 and accelerated when Nrf2 is constitutively activated, affecting ATP production and FADH2 utilization.


Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 322
Author(s):  
Jae-Eun Song ◽  
Tiago C. Alves ◽  
Bernardo Stutz ◽  
Matija Šestan-Peša ◽  
Nicole Kilian ◽  
...  

In the presence of high abundance of exogenous fatty acids, cells either store fatty acids in lipid droplets or oxidize them in mitochondria. In this study, we aimed to explore a novel and direct role of mitochondrial fission in lipid homeostasis in HeLa cells. We observed the association between mitochondrial morphology and lipid droplet accumulation in response to high exogenous fatty acids. We inhibited mitochondrial fission by silencing dynamin-related protein 1(DRP1) and observed the shift in fatty acid storage-usage balance. Inhibition of mitochondrial fission resulted in an increase in fatty acid content of lipid droplets and a decrease in mitochondrial fatty acid oxidation. Next, we overexpressed carnitine palmitoyltransferase-1 (CPT1), a key mitochondrial protein in fatty acid oxidation, to further examine the relationship between mitochondrial fatty acid usage and mitochondrial morphology. Mitochondrial fission plays a role in distributing exogenous fatty acids. CPT1A controlled the respiratory rate of mitochondrial fatty acid oxidation but did not cause a shift in the distribution of fatty acids between mitochondria and lipid droplets. Our data reveals a novel function for mitochondrial fission in balancing exogenous fatty acids between usage and storage, assigning a role for mitochondrial dynamics in control of intracellular fuel utilization and partitioning.


1987 ◽  
Vol 241 (3) ◽  
pp. 783-791 ◽  
Author(s):  
J Vamecq

The enzyme targets for chlorpromazine inhibition of rat liver peroxisomal and mitochondrial oxidations of fatty acids were studied. Effects of chlorpromazine on total fatty acyl-CoA synthetase activity, on both the first and the third steps of peroxisomal beta-oxidation, on the entry of fatty acyl-CoA esters into the peroxisome and on catalase activity, which allows breakdown of the H2O2 generated during the acyl-CoA oxidase step, were analysed. On all these metabolic processes, chlorpromazine was found to have no inhibitory action. Conversely, peroxisomal carnitine octanoyltransferase activity was depressed by 0.2-1 mM-chlorpromazine, which also inhibits mitochondrial carnitine palmitoyltransferase activity in all conditions in which these enzyme reactions are assayed. Different patterns of inhibition by the drug were, however, demonstrated for both these enzyme activities. Inhibitory effects of chlorpromazine on mitochondrial cytochrome c oxidase activity were also described. Inhibitions of both cytochrome c oxidase and carnitine palmitoyltransferase are proposed to explain the decreased mitochondrial fatty acid oxidation with 0.4-1.0 mM-chlorpromazine reported by Leighton, Persico & Necochea [(1984) Biochem. Biophys. Res. Commun. 120, 505-511], whereas depression by the drug of carnitine octanoyltransferase activity is presented as the factor responsible for the decreased peroxisomal beta-oxidizing activity described by the above workers.


1991 ◽  
Vol 279 (1) ◽  
pp. 147-150 ◽  
Author(s):  
R Rognstad

The pathways of peroxisomal and mitochondrial fatty acid oxidation were monitored with the use of substrates which produce NAD3H. I used as marker substrates: D-[3-3H]3-hydroxybutyrate for mitochondrial NAD3H production, [2-3H]glycerol for cytosolic NAD3H production, and [2-3H]acetate to measure carbon-bound 3H which was also generated by the metabolism of the commercial 9,10-3H-labelled fatty acids. The assumption that peroxisomal NAD3H can be considered to be equivalent to cytosolic NAD3H was supported using a specific inhibitor of mitochondrial fatty acid oxidation. The approach involves determination of the specific yields, and the relative distribution on carbons 4 and 6, of 3H in glucose from the marker substrates and the labelled fatty acids. In hepatocytes from clofibrate-treated rats, the amount of palmitate or oleate oxidation which starts in the peroxisomes is comparable with that which starts in the mitochondria.


1989 ◽  
Vol 35 (11) ◽  
pp. 1031-1036 ◽  
Author(s):  
Malcolm C. Modrzakowski ◽  
William R. Finnerty

The microbial dissimilation of long-chain dialkyl ethers by Acinetobacter sp. H01-N involved a terminal methyl group oxidation of the dialkyl ether substrates, resulting in the formation of ether oxygen containing fatty acids of corresponding chain length. An internal carbon–carbon scission of the dialkyl ethers resulted in the formation of end-product ether fatty acids and corresponding dicarboxylic acids. Cellular carbon and energy were derived from the subsequent metabolism of the dicarboxylic acids. Dicarboxylic acid oxidation, activation, and identification of cellular dicarboxylic acids indicated dibasic acids as intermediates in the metabolism of dialkyl ethers.Key words: dialkyl ethers, dicarboxylic acids, fatty acids, Acinetobacter.


2009 ◽  
Vol 296 (3) ◽  
pp. E497-E502 ◽  
Author(s):  
A. Lombardi ◽  
P. de Lange ◽  
E. Silvestri ◽  
R. A. Busiello ◽  
A. Lanni ◽  
...  

Triiodothyronine regulates energy metabolism and thermogenesis. Among triiodothyronine derivatives, 3,5-diiodo-l-thyronine (T2) has been shown to exert marked effects on energy metabolism by acting mainly at the mitochondrial level. Here we investigated the capacity of T2 to affect both skeletal muscle mitochondrial substrate oxidation and thermogenesis within 1 h after its injection into hypothyroid rats. Administration of T2 induced an increase in mitochondrial oxidation when palmitoyl-CoA (+104%), palmitoylcarnitine (+80%), or succinate (+30%) was used as substrate, but it had no effect when pyruvate was used. T2 was able to 1) activate the AMPK-ACC-malonyl-CoA metabolic signaling pathway known to direct lipid partitioning toward oxidation and 2) increase the importing of fatty acids into the mitochondrion. These results suggest that T2 stimulates mitochondrial fatty acid oxidation by activating several metabolic pathways, such as the fatty acid import/β-oxidation cycle/FADH2-linked respiratory pathways, where fatty acids are imported. T2 also enhanced skeletal muscle mitochondrial thermogenesis by activating pathways involved in the dissipation of the proton-motive force not associated with ATP synthesis (“proton leak”), the effect being dependent on the presence of free fatty acids inside mitochondria. We conclude that skeletal muscle is a target for T2, and we propose that, by activating processes able to enhance mitochondrial fatty acid oxidation and thermogenesis, T2 could play a role in protecting skeletal muscle against excessive intramyocellular lipid storage, possibly allowing it to avoid functional disorders.


1997 ◽  
Vol 267 (2) ◽  
pp. 143-154 ◽  
Author(s):  
G Martı́nez ◽  
G Jiménez-Sánchez ◽  
P Divry ◽  
C Vianey-Saban ◽  
E Riudor ◽  
...  

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Markus Blaess ◽  
Lars Kaiser ◽  
Oliver Sommerfeld ◽  
René Csuk ◽  
Hans-Peter Deigner

AbstractRash, photosensitivity, erythema multiforme, and the acute generalized exanthematous pustulosis (AGEP) are relatively uncommon adverse reactions of drugs. To date, the etiology is not well understood and individual susceptibility still remains unknown. Amiodarone, chlorpromazine, amitriptyline, and trimipramine are classified lysosomotropic as well as photosensitizing, however, they fail to trigger rash and pruritic papules in all individuals. Lysosomotropism is a common charcteristic of various drugs, but independent of individuals. There is evidence that the individual ability to respond to external oxidative stress is crosslinked with the elongation of long-chain fatty acids to very long-chain fatty acids by ELOVLs. ELOVL6 and ELOVL7 are sensitive to ROS induced depletion of cellular NADPH and insufficient regeneration via the pentose phosphate pathway and mitochondrial fatty acid oxidation. Deficiency of NADPH in presence of lysosomotropic drugs promotes the synthesis of C16-ceramide in lysosomes and may contribute to emerging pruritic papules of AGEP. However, independently from a lysosomomotropic drug, severe depletion of ATP and NAD(P)H, e.g., by UV radiation or a potent photosensitizer can trigger likewise the collapse of the lysosomal transmembrane proton gradient resulting in lysosomal C16-ceramide synthesis and pruritic papules. This kind of papules are equally present in polymorphous light eruption (PMLE/PLE) and acne aestivalis (Mallorca acne). The suggested model of a compartmentalized ceramide metabolism provides a more sophisticated explanation of cutaneous drug adverse effects and the individual sensitivity to UV radiation. Parameters such as pKa and ClogP of the triggering drug, cutaneous fatty acid profile, and ceramide profile enables new concepts in risk assessment and scoring of AGEP as well as prophylaxis outcome.


1963 ◽  
Vol 09 (02) ◽  
pp. 346-353 ◽  
Author(s):  
Paul Didisheim ◽  
R Sougin Mibashan

Summary1. Long-chain saturated fatty acids accelerate the clotting of blood by activating Hageman factor (HF, factor XII). Their effect is proportional to their chain length.2. The hypothesis is discussed that long-chain saturated fatty acids in the circulating blood of man may exert a similar effect, and may thus be one of the factors in the etiology of clinical thrombosis.


2009 ◽  
Vol 2009 ◽  
pp. 1-3 ◽  
Author(s):  
Marcello Marcì ◽  
Patrizia Ajovalasit

We report about an infant affected by dilated cardiomyopathy (CMP) in whom metabolic investigations evidenced medium-chain-acyl-CoA dehydrogenase deficiency (MCADD), that is one of three types of inherited disorders of mitochondrial fatty-acid -oxidation. Long-chain and very long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficits are recognized as responsible of hypertrophic or, less frequently, dilated cardiomyopathy (CMP) in childhood. Otherwise, to our knowledge, no case of MCADD associated to dilated CMP has been reported in literature.


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