Harnessing Clickable Acylated Glycerol Probes as Chemical Tools for Tracking Glycerolipid Metabolism.

Nutritional Evaluation of Almond Protein-Whey Protein Double System and Its Effect on Lipid Metabolism in HepG2 Cells

Metabolic reprogramming is one of the most critical hallmarks in cancer cells. In the past decades, mounting evidence has demonstrated that, besides the Warburg Effect, lipid metabolism dysregulation is also one of the essential characteristics of cancer cell metabolism. Lipids are water-insoluble molecules with diverse categories of phosphoglycerides, triacylglycerides, sphingolipids, sterols, etc. As the major utilization for energy storage, fatty acids are the primary building blocks for synthesizing triacylglycerides. And phosphoglycerides, sphingolipids, and sterols are the main components constructing biological membranes. More importantly, lipids play essential roles in signal transduction by functioning as second messengers or hormones. Much evidence has shown specific alterations of lipid metabolism in cancer cells. Consequently, the structural configuration of biological membranes, the energy homeostasis under nutrient stress, and the abundance of lipids in the intracellular signal transduction are affected by these alterations. Furthermore, lipid droplets accumulate in cancer cells and function adaptively to different types of harmful stress. This chapter reviews the regulation, functions, and therapeutic benefits of targeting lipid metabolism in cancer cells. Overall, this chapter highlights the significance of exploring more potential therapeutic strategies for malignant diseases by unscrambling lipid metabolism regulation in cancer cells.

A9.6 Effect of mPGES-1 targeting on lipid metabolism in human cells

Kinetic Analysis of Lipid Metabolism in Breast Cancer Cells via Nonlinear Optical Microscopy

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals used in various industrial and consumer products. They have gained attention due to their ubiquitous occurrence in the environment and potential for adverse effects on human health, often linked to immune suppression, hepatotoxicity, and altered cholesterol metabolism. This study aimed to explore the impact of ten individual PFAS, 3 H-perfluoro-3-[(3-methoxypropoxy) propanoic acid] (PMPP/Adona), ammonium perfluoro-(2-methyl-3-oxahexanoate) (HFPO-DA/GenX), perfluorobutanoic acid (PFBA), perfluorobutanesulfonic acid (PFBS), perfluorodecanoic acid (PFDA), perfluorohexanoic acid (PFHxA), perfluorohexanesulfonate (PFHxS), perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS) on the lipid metabolism in human hepatocyte-like cells (HepaRG). These cells were exposed to different concentrations of PFAS ranging from 10 µM to 5000 µM. Lipids were extracted and analyzed using liquid chromatography coupled with mass spectrometry (LC- MS-QTOF). PFOS at 10 µM and PFOA at 25 µM increased the levels of ceramide (Cer), diacylglycerol (DAG), N-acylethanolamine (NAE), phosphatidylcholine (PC), and triacylglycerol (TAG) lipids, while PMPP/Adona, HFPO-DA/GenX, PFBA, PFBS, PFHxA, and PFHxS decreased the levels of these lipids. Furthermore, PFOA and PFOS markedly reduced the levels of palmitic acid (FA 16.0). The present study shows distinct concentration-dependent effects of PFAS on various lipid species, shedding light on the implications of PFAS for essential cellular functions. Our study revealed that the investigated legacy PFAS (PFOS, PFOA, PFBA, PFDA, PFHxA, PFHxS, and PFNA) and alternative PFAS (PMPP/Adona, HFPO-DA/GenX and PFBS) can potentially disrupt lipid homeostasis and metabolism in hepatic cells. This research offers a comprehensive insight into the impacts of legacy and alternative PFAS on lipid composition in HepaRG cells.

An efficient regulation of fuel metabolism in response to internal and environmental stimuli is a vital task that requires an intact carnitine system. The carnitine system, comprehensive of carnitine, its derivatives, and proteins involved in its transformation and transport, is indispensable for glucose and lipid metabolism in cells. Two major functions have been identified for the carnitine system: (1) to facilitate entry of long-chain fatty acids into mitochondria for their utilization in energy-generating processes; (2) to facilitate removal from mitochondria of short-chain and medium-chain fatty acids that accumulate as a result of normal and abnormal metabolism. In cancer patients, abnormalities of tumor tissue as well as nontumor tissue metabolism have been observed. Such abnormalities are supposed to contribute to deterioration of clinical status of patients, or might induce cancerogenesis by themselves. The carnitine system appears abnormally expressed both in tumor tissue, in such a way as to greatly reduce fatty acid beta-oxidation, and in nontumor tissue. In this view, the study of the carnitine system represents a tool to understand the molecular basis underlying the metabolism in normal and cancer cells. Some important anticancer drugs contribute to dysfunction of the carnitine system in nontumor tissues, which is reversed by carnitine treatment, without affecting anticancer therapeutic efficacy. In conclusion, a more complex approach to mechanisms that underlie tumor growth, which takes into account the altered metabolic pathways in cancer disease, could represent a challenge for the future of cancer research. J. Cell. Physiol. 182:339–350, 2000. © 2000 Wiley-Liss, Inc.

This study aims to investigate the role of adaptor protein complex 1 sigma 3 (AP1S3) in breast cancer (BRCA) progression, focusing on its regulatory effects on lipid metabolism and the PI3K/AKT/mTOR signaling pathway. AP1S3 expression levels in BRCA cells were analyzed using the TCGA transcriptome database, with associated pathways identified through GO and KEGG analyses. The effects of AP1S3 on BRCA cell (MDA-MB-231 and MDA-MB-436) proliferation and migration were detected using CCK-8, colony formation, wound healing, and Transwell migration assays. Additionally, the regulatory effect of AP1S3 on lipid metabolism in BRCA cells was evaluated by measuring lipid droplet accumulation, free fatty acid (FFA) levels and total cholesterol (TC) content. AP1S3 was significantly upregulated in BRCA cells and correlated with poor patient prognosis. Functional studies demonstrated that AP1S3 knockdown substantially inhibited BRCA cell proliferation and migration. Mechanistically, AP1S3 facilitated lipid metabolism and tumor progression by activating the PI3K/AKT/mTOR pathway. AP1S3 silencing resulted in decreased lipid accumulation and downregulation of lipid metabolism-related genes. This study highlights the crucial involvement of AP1S3 in BRCA progression through its modulation of lipid metabolism and the PI3K/AKT/mTOR pathway. These findings suggest that targeting AP1S3 could provide novel insights and therapeutic avenues for treating metastatic BRCA.

Excessive accumulation of lipid droplets (LDs), their dynamics, and lipotoxicity are critical factors in the progression of metabolic disorders, including diabetic nephropathy. This study investigates the effects of yomogi tea (Mugwort tea), specifically its leaf infusion (YL) and powdered infusion (YP), on lipid metabolism in human kidney proximal tubular epithelial HK-2 cells under lipotoxic conditions induced by palmitic acid (PA). Both YL and YP significantly reduced intracellular triglyceride (TG) and free fatty acid (FFA) levels, with YP showing a trend toward greater efficacy. Mechanistic analysis revealed that yomogi tea regulates lipid metabolism by significantly downregulating mRNA expression of FAS and upregulating that of the lipolytic ATGL, while SCD-1 mRNA expression remained largely unchanged. Furthermore, yomogi tea reduced LD size and neutral lipid content, potentially enhancing lipid hydrolysis efficiency and mitigating lipotoxic effects. These findings highlight the potential of yomogi tea as a natural agent for regulating lipid metabolism and reducing lipotoxicity, offering promise for managing lipid metabolism-related disorders.

MiR-205 modulates abnormal lipid metabolism of hepatoma cells via targeting acyl-CoA synthetase long-chain family member 1 (ACSL1) mRNA

In recent years, the relationship between lipid metabolism and tumour immunotherapy has been thoroughly investigated. An increasing number of studies have shown that abnormal gene expression and ectopic levels of metabolites related to fatty acid synthesis or fatty acid oxidation affect tumour metastasis, recurrence, and drug resistance. Tumour immunotherapy that aims to promote an antitumour immune response has greatly improved the outcomes for tumour patients. However, lipid metabolism reprogramming in tumour cells or tumour microenvironment-infiltrating immune cells can influence the antitumour response of immune cells and induce tumor cell immune evasion. The recent increase in the prevalence of obesity-related cancers has drawn attention to the fact that obesity increases fatty acid oxidation in cancer cells and suppresses the activation of immune cells, thereby weakening antitumour immunity. This article reviews the changes in lipid metabolism in cells in the tumour microenvironment and describes the relationship between lipid metabolism reprogramming in multiple cell types and tumour immunotherapy.

Diverse acyl-CoA species and acyltransferase isoenzymes are components of a complex system that synthesizes glycerophospholipids and triacylglycerols. Saccharomyces cerevisiae has four main acyl-CoA species, two main glycerol-3-phosphate 1-O-acyltransferases (Gat1p, Gat2p), and two main 1-acylglycerol-3-phosphate O-acyltransferases (Lpt1p, Slc1p). The in vivo contribution of these isoenzymes to phospholipid heterogeneity was determined using haploids with compound mutations: gat1Δlpt1Δ, gat2Δlpt1Δ, gat1Δslc1Δ, and gat2Δslc1Δ. All mutations mildly reduced [3H]palmitic acid incorporation into phospholipids relative to triacylglycerol. Electrospray ionization tandem mass spectrometry identified few differences from wild type in gat1Δlpt1Δ, dramatic differences in gat2Δslc1Δ, and intermediate changes in gat2Δlpt1Δ and gat1Δslc1Δ. Yeast expressing Gat1p and Lpt1p had phospholipids enriched with acyl chains that were unsaturated, 18 carbons long, and paired for length. These alterations prevented growth at 18.5°C and in 10% ethanol. Therefore, Gat2p and Slc1p dictate phospholipid acyl chain composition in rich media at 30°C. Slc1p selectively pairs acyl chains of different lengths.

Insulin resistance (IR) is one of the leading causes of Type 2 diabetes mellitus (T2DM). Inflammation, as a result of the disordered immune response, plays important roles in IR and T2DM. Interleukin-4-induced gene 1 (IL4I1) has been shown to regulate immune response and be involved in inflammation progress. However, there was little known about its roles in T2DM. Here, high glucose (HG)-treated HepG2 cells were used for T2DM investigation in vitro. Our results indicated that the expression of IL4I1 was up-regulated in peripheral blood samples of T2DM-patients and HG-induced HepG2 cells. The silencing of IL4I1 alleviated the HG-evoked IR through elevating the expressions of p-IRS1, p-AKT and GLUT4, and enhancing glucose consumption. Furthermore, IL4I1 knockdown inhibited inflammatory response by reducing the levels of inflammatory mediators, and suppressed the accumulation of lipid metabolites triglyceride (TG) and palmitate (PA) in HG-induced cells. Notably, IL4I1 expression was positively correlated with aryl hydrocarbon receptor (AHR) in peripheral blood samples of T2DM-patients. The silencing of IL4I1 inhibited the AHR signaling by reducing the HG-induced expressions of AHR and CYP1A1. Subsequent experiments confirmed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), an agonist of AHR, reversed the suppressive effects of IL4I1 knockdown on HG-caused inflammation, lipid metabolism and IR in cells. In conclusion, we found that the silencing of IL4I1 attenuated inflammation, lipid metabolism and IR in HG-induced cells via inhibiting AHR signaling, suggesting that IL4I1 might be a potential therapy target for T2DM.

BackgroundThe alteration of lipid metabolism in cancer cells is recognized as one of the most important metabolic hallmarks of cancer. Membrane rafts defined as plasma membrane microdomains enriched in cholesterol and sphingolipids serve as platforms for signaling regulation in cancer. The main purpose of this study was to evaluate the effect of the cholesterol metabolite, 4-cholesten-3-one, on lipid metabolism and membrane raft integrity in two breast cancer cell lines, MCF-7 and MDA-MB-231. Its ability to reduce cell viability and migration has also been investigated.MethodsRT-qPCR was performed to evaluate the expression of enzymes involved in lipogenesis and cholesterol synthesis, and ABCG1 and ABCA1 transporters involved in cholesterol efflux. Its effect on cell viability and migration was studied using the MTT assay, the wound healing assay and the Transwell migration assay, respectively. The effect of 4-cholesten-3-one on membrane rafts integrity was investigated by studying the protein expression of flotillin-2, a membrane raft marker, and raft-enriched EGFR by western blot.ResultsInterestingly, we found that 4-cholesten-3-one treatment decreased mRNA expression of different enzymes including ACC1, FASN, SCD1 and HMGCR. We further demonstrated that 4-cholesten-3-one increased the expression of ABCG1 and ABCA1. We also found that 4-cholesten-3-one decreased the viability of MCF-7 and MDA-MB-231 cells. This effect was neutralized after treatment with LXR inverse agonist or after LXRβ knockdown by siRNA. As a result, we also demonstrated that 4-cholesten-3-one disrupts membrane rafts and cell migration capacity.ConclusionOur results show that 4-cholesten-3-one exerts promising antitumor activity by altering LXR-dependent lipid metabolism in breast cancer cells without increasing lipogenesis.

Internal tandem duplication in FMS-like tyrosine kinase 3 (FLT3/ITD), is a common type of activating mutation and frequently detected in AML. FLT3/ITD is associated with poor prognosis of AML. In this study, we investigated the regulation of FLT3/ITD mutation on sterol regulatory element-binding protein (SREBP) and the therapeutic vulnerabilities of lipid metabolism in FLT3/ITD leukemia. With the transcriptomics analysis we found that FLT3/ITD controlled lipid metabolism via the transcription factor SREBP. The analysis of TCGA_LAML dataset revealed that a gene signature involved in fatty acid and cholesterol metabolism, which is regulated by SREBP, was upregulated in FLT3/ITD patients compared with FLT3/wild-type patients. The upregulation of SREBP protein expression in FLT3/ITD leukemia was confirmed using a genetically engineered mouse model. We further demonstrated that FLT3/ITD regulates the protein degradation of SREBP through the PI3K/AKT-GSK3β axis. The metabolomics analysis further showed that FLT3/ITD primarily regulates glycerophospholipid synthesis, which contribute to the key structure lipid in the membrane, specifically, the cardiolipin. Moreover, pharmacologic inhibition of SREBP activation and its downstream enzyme fatty acid synthase (FASN) sensitized FLT3-ITD AMLs to the treatment of FLT3 inhibitor quizartinib. Collectively, our findings reveal a novel regulation of FLT3-ITD in metabolic reprogramming and indicate a targetable vulnerability in a subset of refractory leukemia. Citation Format: Yumin Hu, Feng Yin, Mingyue Zhao, Wenhua Lu, Tiantian Yu. A novel regulatory role of FLT3/ITD mutation in lipid metabolism of leukemia cells: The mechanism and therapeutic implications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 429.

Proteomics analysis of the protective effect of canola (Brassica campestris L.) bee pollen flavonoids on the tert-butyl hydroperoxide-induced EA.hy926 cell injury model