Search Results (8)

Nutrient-sensing nuclear receptors (NSNRs), including PPARs, FXR, LXRs, RAR/RXR, VDR, and related orphan receptors, integrate a molecular interface that allows diet to communicate directly with the genome. By binding fatty acids, bile acids, sterols, vitamins, polyphenols, and other food-derived metabolites, NSNRs translate qualitative and quantitative features of the diet into coordinated transcriptional programmes across metabolically active organs. This ligand-dependent signalling network integrates dietary information to orchestrate inter-organ lipid and glucose metabolism, mitochondrial function, thermogenesis, and immune response, thereby enabling the organism to adapt dynamically to fasting–feeding cycles. In this review, we synthesise current evidence on the integrated roles of major NSNRs in the liver, skeletal muscle, white and brown adipose tissue, and kidney, emphasising how receptor networks within and between metabolic organs collectively govern energy expenditure, substrate partitioning, and systemic metabolic flexibility. We propose a conceptual framework in which diet functions as an “external endocrine organ”, acting as the primary source of chemically diverse NSNR ligands, while metabolic tissues serve as secondary signal amplifiers and integrators. Through circulating lipid species, bile acids, oxysterols, and other metabolites, these organs engage in continuous bidirectional communication that reprograms NSNR activity across tissues. We then examine how the global shift from minimally processed, nutrient-rich foods to nutrient-poor, energy-dense ultra-processed diets leads to a reduction in NSNR ligand diversity, promoting hepatic steatosis, muscle metabolic inflexibility, adipose tissue dysfunction, renal lipotoxicity, and chronic low-grade inflammation, ultimately causing obesity, type 2 diabetes, and cardiometabolic disease. Finally, we explore strategies to restore NSNR function, including Mediterranean and plant-based dietary patterns, as well as diets enriched with ω-3 polyunsaturated fatty acids, monounsaturated fats, and polyphenols. By integrating molecular, physiological, and clinical evidence, this review aims to clarify how NSNR networks translate dietary cues into coordinated inter-organ metabolism and how nutrient-poor diets lead to metabolic diseases trough a loss of metabolic information, rather than merely by energy excess. This framework supports a paradigm shift from calorie-centred nutrition to diet quality as the main therapeutic target for preventing metabolic diseases and promoting health. Full article

Ceramides are central to stratum corneum barrier organization and hydration. Beyond topical replenishment, ceramide-stimulating strategies increasingly aim to enhance endogenous ceramide biosynthesis, processing, and homeostatic remodeling in coordination with keratinocyte differentiation. In this review, we summarize the three major metabolic routes that shape epidermal ceramide output—de novo synthesis, salvage, and sphingomyelin hydrolysis—and organize representative bioactive ingredients by their primary molecular targets rather than by origin. Specifically, we map ingredients to tractable regulatory nodes, including transcriptional “liposensors” (PPAR/LXR), the induction of biosynthetic/elongation and processing enzymes (e.g., SPT, CerS3, ELOVL4), the provision of structural substrates and precursors (e.g., linoleate-rich lipids and glycosylceramides), salvage-pathway sphingoid bases that can reshape ceramide subclass output, and metabolic sensing/stress-response pathways centered on AMPK–mTOR–SIRT1/autophagy. Across these mechanisms, agents spanning botanical and fermented extracts, vitamins, sphingoid intermediates, lipid precursors, and pathway modulators (including autophagy-focused probes) have been reported to increase ceramide abundance and, in some contexts, favor barrier-relevant ultra-long-chain species and ω-O-acylceramides that support lamellar organization and the corneocyte lipid envelope. Translational and clinical studies in dry, sensitive, and aged skin generally associate such interventions with improved barrier function and reduced dryness. Aligning ingredient selection with defined biosynthetic and processing checkpoints—and verifying outcomes with lipidomics alongside clinical endpoints—may accelerate the development of evidence-based, ceramide-stimulating cosmetics. Full article

Atherosclerosis, a leading contributor to cardiovascular diseases (CVDs), is characterized by foam cell formation driven by excessive lipid accumulation in macrophages and vascular smooth muscle cells. This study elucidates the anti-atherosclerotic potential of AWLNH (P3) and PHDL (P4) peptides by assessing their effects on foam cell formation, lipid metabolism, and oxidative stress regulation. P3 and P4 effectively suppressed intracellular lipid accumulation in RAW264.7 macrophages and human aortic smooth muscle cells (hASMCs), thereby mitigating foam cell formation. Mechanistically, both peptides modulated cholesterol homeostasis by downregulating cholesterol influx mediators, cluster of differentiation 36 (CD36), and class A1 scavenger receptor (SR-A1), while upregulating cholesterol efflux transporters ATP-binding cassette subfamily A member 1 (ABCA1) and ATP-binding cassette subfamily G member 1 (ABCG1). The activation of peroxisome proliferator-activated receptor-gamma (PPAR-γ) and liver X receptor-alpha (LXR-α) further substantiated their role in promoting cholesterol efflux and restoring lipid homeostasis. Additionally, P3 and P4 peptides exhibited potent antioxidative properties by attenuating reactive oxygen species (ROS) generation through activation of the HO-1/Nrf2 signaling axis. HO-1 silencing via siRNA transfection abolished these effects, confirming HO-1-dependent regulation of oxidative stress and lipid metabolism. Collectively, these findings highlight P3 and P4 peptides as promising therapeutic agents for atherosclerosis by concurrently targeting foam cell formation, cholesterol dysregulation, and oxidative stress, warranting further exploration for potential clinical applications. Full article

Macrophage polarization is influenced by lipids, which also exert significant control over macrophage functions. Lipids and their metabolites are players in intricate signaling pathways that modulate macrophages’ responses to pathogens, phagocytosis, ferroptosis, and inflammation. This review focuses on lipid metabolism and macrophage functions and addresses potential molecular targets for the treatment of macrophage-related diseases. While lipogenesis is crucial for lipid accumulation and phagocytosis in M1 macrophages, M2 macrophages likely rely on fatty acid β-oxidation to utilize fatty acids as their primary energy source. Cholesterol metabolism, regulated by factors such as SREBPs, PPARs, and LXRs, is associated with the cholesterol efflux capacity and the formation of foam cells (M2-like macrophages). Foam cells, which are targets for atherosclerosis, are associated with an increase in inflammatory cytokines. Lipolysis and fatty acid uptake markers, such as CD36, also contribute to the production of cytokines. Enhancing the immune system through the inhibition of lipid-metabolism-related factors can potentially serve as a targeted approach against tumor cells. Cyclooxygenase inhibitors, which block the conversion of arachidonic acid into various inflammatory mediators, influence macrophage polarization and have generated attention in cancer research. Full article

Bile acid (BA) synthesis from cholesterol by hepatocytes is inhibited by inflammatory cytokines. Whether liver inflammation also affects BA side chain shortening and conjugation was investigated. In human liver cell lines (IHH, HepG2, and HepaRG), agonists of nuclear receptors including the farnesoid X receptor (FXR), liver X receptor (LXR), and peroxisome proliferator-activated receptors (PPARs) did not affect the expression of BA-related peroxisomal enzymes. In contrast, hepatocyte nuclear factor 4α (HNF4α) inhibition down-regulated acyl-CoA oxidase 2 (ACOX2). ACOX2 was repressed by fibroblast growth factor 19 (FGF19), which was prevented by extracellular signal-regulated kinase (ERK) pathway inhibition. These changes were paralleled by altered BA synthesis (HPLC-MS/MS). Cytokines able to down-regulate cholesterol-7α-hydroxylase (CYP7A1) had little effect on peroxisomal enzymes involved in BA synthesis except for ACOX2 and bile acid-CoA:amino acid N-acyltransferase (BAAT), which were down-regulated, mainly by oncostatin M (OSM). This effect was prevented by Janus kinase (JAK) inhibition, which restored BA side chain shortening and conjugation. The binding of OSM to the extracellular matrix accounted for a persistent effect after culture medium replacement. In silico analysis of four databases (n = 201) and a validation cohort (n = 90) revealed an inverse relationship between liver inflammation and ACOX2/BAAT expression which was associated with changes in HNF4α levels. In conclusion, BA side chain shortening and conjugation are inhibited by inflammatory effectors. However, other mechanisms involved in BA homeostasis counterbalance any significant impact on the serum BA profile. Full article

Fatty acid mimetics (FAM) are bioactive molecules acting through the binding sites of endogenous fatty acid metabolites on enzymes, transporters, and receptors. Due to the special characteristics of these binding sites, FAMs share common chemical features. Pharmacological modulation of fatty acid signaling has therapeutic potential in multiple pathologies, and several FAMs have been developed as drugs. We aimed to elucidate the promiscuity of FAM drugs on lipid-activated transcription factors and tested 64 approved compounds for activation of RAR, PPARs, VDR, LXR, FXR, and RXR. The activity screening revealed nuclear receptor agonism of several FAM drugs and considerable promiscuity of NSAIDs, while other compound classes evolved as selective. These screening results were not anticipated by three well-established target prediction tools, suggesting that FAMs are underrepresented in bioactivity data for model development. The screening dataset may therefore valuably contribute to such tools. Oxaprozin (RXR), tianeptine (PPARδ), mycophenolic acid (RAR), and bortezomib (RAR) exhibited selective agonism on one nuclear receptor and emerged as attractive leads for the selective optimization of side activities. Additionally, their nuclear receptor agonism may contribute relevant and valuable polypharmacology. Full article

The obesity epidemic is well recognized as a significant global health issue. A better understanding of the energy homeostasis mechanisms could help to identify promising anti-obesity therapeutic strategies. It is well established that the hypothalamus plays a pivotal role governing energy balance. The hypothalamus consists of tightly interconnected and specialized neurons that permit the sensing and integration of several peripheral inputs, including metabolic and hormonal signals for an appropriate physiological response. Current evidence shows that thyroid hormones (THs) constitute one of the key endocrine factors governing the regulation and the integration of metabolic homeostasis at the hypothalamic level. THs modulate numerous genes involved in the central control of metabolism, as TRH (Thyrotropin-Releasing Hormone) and MC4R (Melanocortin 4 Receptor). THs act through their interaction with thyroid hormone receptors (TRs). Interestingly, TH signaling, especially regarding metabolic regulations, involves TRs crosstalk with other metabolically linked nuclear receptors (NRs) including PPAR (Peroxisome proliferator-activated receptor) and LXR (Liver X receptor). In this review, we will summarize current knowledge on the important role of THs integration of metabolic pathways in the central regulation of metabolism. Particularly, we will shed light on the crosstalk between TRs and other NRs in controlling energy homeostasis. This could be an important track for the development of attractive therapeutic compounds. Full article

Sepsis causes severe dysregulation of organ functions, via the development of oxidative stress and inflammation. These pathophysiological mechanisms are mimicked in mice injected with bacterial lipopolysaccharide (LPS). Here, protective properties of argan oil against LPS-induced oxidative stress and inflammation are explored in the murine model. Mice received standard chow, supplemented with argan oil (AO) or olive oil (OO) for 25 days, before septic shock was provoked with a single intraperitoneal injection of LPS, 16 hours prior to animal sacrifice. In addition to a rise in oxidative stress and inflammatory markers, injected LPS also caused hepatotoxicity, accompanied by hyperglycemia, hypercholesterolemia and hyperuremia. These LPS-associated toxic effects were blunted by AO pretreatment, as corroborated by normal plasma parameters and cell stress markers (glutathione: GSH) and antioxidant enzymology (catalase, CAT; superoxide dismutase, SOD and glutathione peroxidase, GPx). Hematoxylin–eosin staining revealed that AO can protect against acute liver injury, maintaining a normal status, which is pointed out by absent or reduced LPS-induced hepatic damage markers (i.e., alanine aminotransferase (ALT) and aspartate transaminase (AST)). Our work also indicated that AO displayed anti-inflammatory activity, due to down-regulations of genes encoding pro-inflammatory cytokines Interleukin-6 (IL-6) and Tumor Necrosis Factor-α (TNF-α) and in up-regulations of the expression of anti-inflammatory genes encoding Interleukin-4 (IL-4) and Interleukin-10 (IL-10). OO provided animals with similar, though less extensive, protective changes. Collectively our work adds compelling evidence to the protective mechanisms of AO against LPS-induced liver injury and hence therapeutic potentialities, in regard to the management of human sepsis. Activations of IL-4/Peroxisome Proliferator-Activated Receptors (IL-4/PPARs) signaling and, under LPS, an anti-inflammatory IL-10/Liver X Receptor (IL-10/LXR) route, obviously indicated the high potency and plasticity of the anti-inflammatory properties of argan oil. Full article