scholarly journals A lipid droplet-peroxisome network drives longevity by monounsaturated fatty acids via modulating ether lipid synthesis and ferroptosis

Author(s):  
Anne Brunet ◽  
Katharina Papsdorf ◽  
Amir Hosseini ◽  
Jason Miklas ◽  
Matias Cabruja ◽  
...  

Abstract Dietary mono-unsaturated fatty acids (MUFAs) are linked to human longevity and extend lifespan in several species1-12. But the mechanisms by which MUFAs promote longevity remain unclear. Here we show that an organelle hub involving lipid droplets and peroxisomes is critical for lifespan extension by MUFAs in C. elegans. MUFA accumulation increases lipid droplet number in fat storage tissues, and lipid droplet synthesis is necessary for MUFA-mediated longevity. Interestingly, the number of lipid droplets in young individuals can predict their remaining lifespan. MUFA accumulation also increases the number of peroxisomes, and peroxisome activity is required for MUFA-mediated longevity. By performing a targeted screen, we uncover a functional network between lipid droplets and peroxisomes in longevity. Interestingly, our screen also identifies ether lipids as critical components of the lipid droplet-peroxisome network. Using lipidomics, we find that the ratio of MUFAs to polyunsaturated fatty acids (PUFAs) in ether lipids is increased by MUFA accumulation. Ether lipids are involved in ferroptosis, a non-apoptotic form of cell death13-17, and MUFAs promote longevity in part via suppression of ferroptosis. Our results identify a mechanism of action for MUFAs to extend lifespan and uncover an organelle network involved in the homeostasis of MUFA-rich ether lipids. Our work also opens new avenues for lipid-based interventions to delay aging.

2013 ◽  
Vol 12 (11) ◽  
pp. 1517-1529 ◽  
Author(s):  
Xiaoli Du ◽  
Caroline Barisch ◽  
Peggy Paschke ◽  
Cornelia Herrfurth ◽  
Oliver Bertinetti ◽  
...  

ABSTRACT Across all kingdoms of life, cells store energy in a specialized organelle, the lipid droplet. In general, it consists of a hydrophobic core of triglycerides and steryl esters surrounded by only one leaflet derived from the endoplasmic reticulum membrane to which a specific set of proteins is bound. We have chosen the unicellular organism Dictyostelium discoideum to establish kinetics of lipid droplet formation and degradation and to further identify the lipid constituents and proteins of lipid droplets. Here, we show that the lipid composition is similar to what is found in mammalian lipid droplets. In addition, phospholipids preferentially consist of mainly saturated fatty acids, whereas neutral lipids are enriched in unsaturated fatty acids. Among the novel protein components are LdpA, a protein specific to Dictyostelium , and Net4, which has strong homologies to mammalian DUF829/Tmem53/NET4 that was previously only known as a constituent of the mammalian nuclear envelope. The proteins analyzed so far appear to move from the endoplasmic reticulum to the lipid droplets, supporting the concept that lipid droplets are formed on this membrane.


2007 ◽  
Vol 194 (2) ◽  
pp. 283-291 ◽  
Author(s):  
Eleftheria Diakogiannaki ◽  
Shalinee Dhayal ◽  
Caroline E Childs ◽  
Philip C Calder ◽  
Hannah J Welters ◽  
...  

Long-chain saturated and monounsaturated fatty acids differ in their propensity to induce β-cell death in vitro with palmitate (C16:0) being cytotoxic, whereas palmitoleate (C16:1n-7) is cytoprotective. We now show that this cytoprotective capacity extends to a poorly metabolised C16:1n-7 derivative, methyl-palmitoleate (0.25 mM palmitate alone: 92 ± 4% death after 18 h; palmitate plus 0.25 mM methyl-palmitoleate: 12 ± 2%; P < 0.001). Palmitoleate and its methylated derivative also acted as mitogens in cultured β-cells (5-bromo-2-deoxyuridine incorporation – control: 0.15 ± 0.01 units; 0.25 mM palmitoleate: 0.22 ± 0.01 units; P < 0.05). It has been proposed that alterations in neutral lipid synthesis (particularly triacylglycerol (TAG) formation) might mediate the differential responses to saturated and unsaturated fatty acids and we have examined this proposition. Palmitate and palmitoleate both promoted β-cell phospholipid remodelling and increased TAG formation (control: 0.9 ± 0.1 nmol TAG/106 cells; 0.25 mM palmitate: 1.55 ± 0.07; 0.25 mM palmitoleate: 1.4 ± 0.05; palmitate plus palmitoleate: 2.3 ± 0.1). By contrast, methyl-palmitoleate failed to influence TAG levels (0.25 mM methyl-palmitoleate alone: 0.95 ± 0.06 nmol TAG/106 cells; methyl-palmitoleate plus palmitate: 1.5 ± 0.05) or its fatty acid composition in β-cells exposed to palmitate. The results suggest that monounsaturated fatty acids can promote cell viability and mitogenesis by a mechanism that does not require their metabolism and is independent of alterations in TAG formation.


2014 ◽  
Vol 13 (4) ◽  
pp. 517-526 ◽  
Author(s):  
Xiaoli Du ◽  
Cornelia Herrfurth ◽  
Thomas Gottlieb ◽  
Steffen Kawelke ◽  
Kristin Feussner ◽  
...  

ABSTRACT Triacylglycerol (TAG), the common energy storage molecule, is formed from diacylglycerol and a coenzyme A-activated fatty acid by the action of an acyl coenzyme A:diacylglycerol acyltransferase (DGAT). In order to conduct this step, most organisms rely on more than one enzyme. The two main candidates in Dictyostelium discoideum are Dgat1 and Dgat2. We show, by creating single and double knockout mutants, that the endoplasmic reticulum (ER)-localized Dgat1 enzyme provides the predominant activity, whereas the lipid droplet constituent Dgat2 contributes less activity. This situation may be opposite from what is seen in mammalian cells. Dictyostelium Dgat2 is specialized for the synthesis of TAG, as is the mammalian enzyme. In contrast, mammalian DGAT1 is more promiscuous regarding its substrates, producing diacylglycerol, retinyl esters, and waxes in addition to TAG. The Dictyostelium Dgat1, however, produces TAG, wax esters, and, most interestingly, also neutral ether lipids, which represent a significant constituent of lipid droplets. Ether lipids had also been found in mammalian lipid droplets, but the role of DGAT1 in their synthesis was unknown. The ability to form TAG through either Dgat1 or Dgat2 activity is essential for Dictyostelium to grow on bacteria, its natural food substrate.


2020 ◽  
Vol 16 (2) ◽  
pp. 142-154 ◽  
Author(s):  
Hadi Emamat ◽  
Zahra Yari ◽  
Hossein Farhadnejad ◽  
Parvin Mirmiran

Recent evidence has highlighted that fat accumulation, particularly abdominal fat distribution, is strongly associated with metabolic disturbance. It is also well-recognized that the metabolic responses to variations in macronutrients intake can affect body composition. Previous studies suggest that the quality of dietary fats can be considered as the main determinant of body-fat deposition, fat distribution, and body composition without altering the total body weight; however, the effects of dietary fats on body composition have controversial results. There is substantial evidence to suggest that saturated fatty acids are more obesogen than unsaturated fatty acids, and with the exception of some isomers like conjugate linoleic acid, most dietary trans fatty acids are adiposity enhancers, but there is no consensus on it yet. On the other hand, there is little evidence to indicate that higher intake of the n-3 and the n-6 polyunsaturated fatty acids can be beneficial in attenuating adiposity, and the effect of monounsaturated fatty acids on body composition is contradictory. Accordingly, the content of this review summarizes the current body of knowledge on the potential effects of the different types of dietary fatty acids on body composition and adiposity. It also refers to the putative mechanisms underlying this association and reflects on the controversy of this topic.


Author(s):  
Catherine E. Allen ◽  
Paul A. Tyler ◽  
Cindy L. Van Dover

Specimens of the chemoautotrophic symbiont-bearing hydrothermal vent clam Calyptogena pacifica were collected from hydrothermal vents at the Endeavour segment of the Juan de Fuca Ridge. Total lipid was extracted from gill, foot and mantle tissues, and lipid class and fatty acid composition determined by thin layer chromatography with flame ionization detection (TLC–FID), gas chromatography (GC) and gas chromatography with mass spectrometry (GC–MS). An abundance of n–7 monounsaturated fatty acids (MUFA), especially in the gill, reflected the large contribution of chemoautotrophic symbiotic bacteria to the nutrition of this clam. The absence of n–8 MUFA suggests that C. pacifica does not contain methanotrophic symbiotic bacteria. Low levels of highly unsaturated fatty acids (HUFA) such as 20:5 n–3 and 22:6 n–3 were detected in C. pacifica and their presence is attributed to a source other than chemoautotrophic symbiotic bacteria. Significant levels of non-methylene interrupted dienoic fatty acids and eicosatrienoic acid (20:3) were also detected in C. pacifica and it is suggested that these fatty acids are synthesized from n–7 MUFA as alternatives to HUFA. In contrast to shallow water bivalves, elevated levels of triglyceride were detected in the gills compared to the mantle.


2018 ◽  
Author(s):  
Zhe Cao ◽  
Yan Hao ◽  
Yiu Yiu Lee ◽  
Pengfei Wang ◽  
Xuesong Li ◽  
...  

AbstractExogenous metabolites from microbial and dietary origins have profound effects on host metabolism. Here, we report that a sub-population of lipid droplets (LDs), which are conserved organelles for fat storage, is defined by metabolites-driven targeting of theC. elegansseipin ortholog, SEIP-1. Loss of SEIP-1 function reduced the size of a subset of LDs while over-expression of SEIP-1 had the opposite effect. Ultrastructural analysis revealed SEIP-1 enrichment in an endoplasmic reticulum (ER) subdomain, which co-purified with LDs. Analyses ofC. elegansand bacterial genetic mutants indicated a requirement of polyunsaturated fatty acids (PUFAs) and microbial cyclopropane fatty acids (CFAs) for SEIP-1 enrichment, as confirmed by dietary supplementation experiments. In mammalian cells, heterologous expression of SEIP-1 promoted lipid droplet expansion from ER subdomains in a conserved manner. Our results suggest that microbial and polyunsaturated fatty acids serve unexpected roles in regulating cellular fat storage by enforcing LD diversity.


2019 ◽  
Vol 218 (4) ◽  
pp. 1319-1334 ◽  
Author(s):  
Hanaa Hariri ◽  
Natalie Speer ◽  
Jade Bowerman ◽  
Sean Rogers ◽  
Gang Fu ◽  
...  

Lipid droplets (LDs) serve as cytoplasmic reservoirs for energy-rich fatty acids (FAs) stored in the form of triacylglycerides (TAGs). During nutrient stress, yeast LDs cluster adjacent to the vacuole/lysosome, but how this LD accumulation is coordinated remains poorly understood. The ER protein Mdm1 is a molecular tether that plays a role in clustering LDs during nutrient depletion, but its mechanism of function remains unknown. Here, we show that Mdm1 associates with LDs through its hydrophobic N-terminal region, which is sufficient to demarcate sites for LD budding. Mdm1 binds FAs via its Phox-associated domain and coenriches with fatty acyl–coenzyme A ligase Faa1 at LD bud sites. Consistent with this, loss of MDM1 perturbs free FA activation and Dga1-dependent synthesis of TAGs, elevating the cellular FA level, which perturbs ER morphology and sensitizes yeast to FA-induced lipotoxicity. We propose that Mdm1 coordinates FA activation adjacent to the vacuole to promote LD production in response to stress, thus maintaining ER homeostasis.


Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1899 ◽  
Author(s):  
Aline Boveto Santamarina ◽  
Giovana Jamar ◽  
Laís Vales Mennitti ◽  
Helena de Cássia César ◽  
Verdiana Vera de Rosso ◽  
...  

Nutrigenomics is an emerging field in obesity since epigenetic markers can be modified by environmental factors including diet. Considering juçara composition—rich in anthocyanins, monounsaturated fatty acids (MUFAs) and fibers—it has the potential for epigenetic modulation. We evaluated the juçara supplementation modulating the serum fatty acids profile and epigenetic markers in monocytes of adult obese humans. It was a randomized double-blind, controlled trial with 27 obese (Body mass index between 30.0 and 39.9 kg/m2) participants of both genders aged from 31 to 59 years, divided into juçara group (5 g juçara freeze-dried pulp) or placebo group (5 g of maltodextrin) for 6 weeks. Before and after supplementation, blood samples were collected. The serum and monocytes cells obtained were cultured and stimulated with lipopolysaccharides as proinflammatory stimulus. After 24 h of incubation, the cells and supernatants were collected and analyzed. Juçara improved the serum fatty acids profile on unsaturated fatty acids levels. The epigenetic markers evaluated were improved post-treatment. Also, the methylated DNA level was increased after treatment. We find that juçara supplementation is a predictor of methyl CpG binding proteins 2 (MeCP2) in monocytes. Concluding, juçara supplementation improved the serum fatty acids profile, modulating the epigenetic markers in monocytes from obese individuals.


2020 ◽  
Vol 77 (4) ◽  
pp. 810-824.e8 ◽  
Author(s):  
Charles P. Najt ◽  
Salmaan A. Khan ◽  
Timothy D. Heden ◽  
Bruce A. Witthuhn ◽  
Minervo Perez ◽  
...  

2000 ◽  
Vol 279 (1) ◽  
pp. H35-H46 ◽  
Author(s):  
Yong-Fu Xiao ◽  
Sterling N. Wright ◽  
Ging Kuo Wang ◽  
James P. Morgan ◽  
Alexander Leaf

Voltage-gated cardiac Na+ channels are composed of α- and β1-subunits. In this study β1-subunit was cotransfected with the α-subunit of the human cardiac Na+ channel (hH1α) in human embryonic kidney (HEK293t) cells. The effects of this coexpression on the kinetics and fatty acid-induced suppression of Na+currents were assessed. Current density was significantly greater in HEK293t cells coexpressing α- and β1-subunits ( I Na,αβ) than in HEK293t cells expressing α-subunit alone ( I Na,α). Compared with I Na,α, the voltage-dependent inactivation and activation of I Na,αβ were significantly shifted in the depolarizing direction. In addition, coexpression with β1-subunit prolonged the duration of recovery from inactivation. Eicosapentaenoic acid [EPA, C20:5(n–3)] significantly reduced I Na,αβ in a concentration-dependent manner and at 5 μM shifted the midpoint voltage of the steady-state inactivation by −22 ± 1 mV. EPA also significantly accelerated channel transition from the resting state to the inactivated state and prolonged the recovery time from inactivation. Docosahexaenoic acid [C22:6(n–3)], α-linolenic acid [C18:3(n–3)], and conjugated linoleic acid [C18:2(n–6)] at 5 μM significantly inhibited both I Na,αβ and I Na,α.In contrast, saturated and monounsaturated fatty acids had no effects on I Na,αβ. This finding differs from the results for I Na,α, which was significantly inhibited by both saturated and unsaturated fatty acids. Our data demonstrate that functional association of β1-subunit with hH1α modifies the kinetics and fatty acid block of the Na+ channel.


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