Search results for "acids"

Betulinic acid induces a novel cell death pathway that depends on cardiolipin modification

2016

Cancer is associated with strong changes in lipid metabolism. For instance, normal cells take up fatty acids (FAs) from the circulation, while tumour cells generate their own and become dependent on de novo FA synthesis, which could provide a vulnerability to target tumour cells. Betulinic acid (BetA) is a natural compound that selectively kills tumour cells through an ill-defined mechanism that is independent of BAX and BAK, but depends on mitochondrial permeability transition-pore opening. Here we unravel this pathway and show that BetA inhibits the activity of steroyl-CoA-desaturase (SCD-1). This enzyme is overexpressed in tumour cells and critically important for cells that utilize de n…

Yeast Cth2 protein represses the translation of ARE-containing mRNAs in response to iron deficiency

2018

In response to iron deficiency, the budding yeast Saccharomyces cerevisiae undergoes a metabolic remodeling in order to optimize iron utilization. The tandem zinc finger (TZF)-containing protein Cth2 plays a critical role in this adaptation by binding and promoting the degradation of multiple mRNAs that contain AU-rich elements (AREs). Here, we demonstrate that Cth2 also functions as a translational repressor of its target mRNAs. By complementary approaches, we demonstrate that Cth2 protein inhibits the translation of SDH4, which encodes a subunit of succinate dehydrogenase, and CTH2 mRNAs in response to iron depletion. Both the AREs within SDH4 and CTH2 transcripts, and the Cth2 TZF are es…

Lack of a peroxiredoxin suppresses the lethality of cells devoid of electron donors by channelling electrons to oxidized ribonucleotide reductase

2017

The thioredoxin and glutaredoxin pathways are responsible of recycling several enzymes which undergo intramolecular disulfide bond formation as part of their catalytic cycles such as the peroxide scavengers peroxiredoxins or the enzyme ribonucleotide reductase (RNR). RNR, the rate-limiting enzyme of deoxyribonucleotide synthesis, is an essential enzyme relying on these electron flow cascades for recycling. RNR is tightly regulated in a cell cycle-dependent manner at different levels, but little is known about the participation of electron donors in such regulation. Here, we show that cytosolic thioredoxins Trx1 and Trx3 are the primary electron donors for RNR in fission yeast. Unexpectedly,…

Inhibition of colon cancer growth by docosahexaenoic acid involves autocrine production of TNFα

2016

IF 7.932; International audience; The omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) has anti-inflammatory and anti-cancer properties. Among pro-inflammatory mediators, tumor necrosis factor a (TNF alpha) plays a paradoxical role in cancer biology with induction of cancer cell death or survival depending on the cellular context. The objective of the study was to evaluate the role of TNFa in DHA-mediated tumor growth inhibition and colon cancer cell death. The treatment of human colorectal cancer cells, HCT-116 and HCT-8 cells, with DHA triggered apoptosis in autocrine TNF alpha-dependent manner. We demonstrated that DHA-induced increased content of TNF alpha mRNA occurred thr…

A Pathology-Based Combined Model to Identify PAM50 Non-luminal Intrinsic Disease in Hormone Receptor-Positive HER2-Negative Breast Cancer

2019

No luminal; Subtipus intrínsec; Càncer de mama No luminal; Subtipo intrínseco; Cáncer de mama Non-luminal; Intrinsic subtype, Breast cancer Background: In hormone receptor-positive (HR+)/HER2-negative breast cancer, the HER2-enriched and Basal-like intrinsic subtypes are associated with poor outcome, low response to anti-estrogen therapy and high response to chemotherapy. To date, no validated biomarker exists to identify both molecular entities other than gene expression. Methods: PAM50 subtyping and immunohistochemical data were obtained from 8 independent studies of 1,416 HR+/HER2-negative early breast tumors. A non-luminal disease score (NOLUS) from 0 to 100, based on percentage of estr…

Genome-wide association mapping for milk fat composition and fine mapping of a QTL for de novo synthesis of milk fatty acids on bovine chromosome 13

2017

Background Bovine milk is widely regarded as a nutritious food source for humans, although the effects of individual fatty acids on human health is a subject of debate. Based on the assumption that genomic selection offers potential to improve milk fat composition, there is strong interest to understand more about the genetic factors that influence the biosynthesis of bovine milk and the molecular mechanisms that regulate milk fat synthesis and secretion. For this reason, the work reported here aimed at identifying genetic variants that affect milk fatty acid composition in Norwegian Red cattle. Milk fatty acid composition was predicted from the nation-wide recording scheme using Fourier tr…

2018

Defining functional domains and amino acid residues in G protein coupled receptors (GPCRs) represent an important way to improve rational drug design for this major class of drug targets. The cannabinoid type 1 (CB1) receptor is one of the most abundant GPCRs in the central nervous system and is involved in many physiological and pathophysiological processes. Interestingly, cannabinoid type 1 receptor with a phenylalanine 238 to leucine mutation (CB1F238L) has been already linked to a number of both in vitro and in vivo alterations. While CB1F238L causes significantly reduced presynaptic neurotransmitter release at the cellular level, behaviorally this mutation induces increased risk taking…

Palmitoylethanolamide Promotes a Proresolving Macrophage Phenotype and Attenuates Atherosclerotic Plaque Formation

2018

Objective— Palmitoylethanolamide is an endogenous fatty acid mediator that is synthetized from membrane phospholipids by N -acyl phosphatidylethanolamine phospholipase D. Its biological actions are primarily mediated by PPAR-α (peroxisome proliferator-activated receptors α) and the orphan receptor GPR55. Palmitoylethanolamide exerts potent anti-inflammatory actions but its physiological role and promise as a therapeutic agent in chronic arterial inflammation, such as atherosclerosis remain unexplored. Approach and Results— First, the polarization of mouse primary macrophages towards a proinflammatory phenotype was found to reduce N -acyl phosphatidylethanolamine phospholipase D expression …

Localization of the cannabinoid type-1 receptor in subcellular astrocyte compartments of mutant mouse hippocampus

2018

Astroglial type‐1 cannabinoid (CB1) receptors are involved in synaptic transmission, plasticity and behavior by interfering with the so‐called tripartite synapse formed by pre‐ and post‐synaptic neuronal elements and surrounding astrocyte processes. However, little is known concerning the subcellular distribution of astroglial CB1 receptors. In particular, brain CB1 receptors are mostly localized at cells' plasmalemma, but recent evidence indicates their functional presence in mitochondrial membranes. Whether CB1 receptors are present in astroglial mitochondria has remained unknown. To investigate this issue, we included conditional knock‐out mice lacking astroglial CB1 receptor expression …

Anatomical characterization of the cannabinoid CB1receptor in cell-type-specific mutant mouse rescue models

2016

Type 1 cannabinoid (CB1 ) receptors are widely distributed in the brain. Their physiological roles depend on their distribution pattern, which differs remarkably among cell types. Hence, subcellular compartments with little but functionally relevant CB1 receptors can be overlooked, fostering an incomplete mapping. To overcome this, knockin mice with cell-type-specific rescue of CB1 receptors have emerged as excellent tools for investigating CB1 receptors' cell-type-specific localization and sufficient functional role with no bias. However, to know whether these rescue mice maintain endogenous CB1 receptor expression level, detailed anatomical studies are necessary. The subcellular distribut…