Fatty Acid Synthase: Structure, Function, and Regulation

Aspirin enhances the antibacterial activity of colistin against multidrug-resistant Pseudomonas aeruginosa

Multidrug-resistant (MDR) Pseudomonas aeruginosa (PSA), recently reclassified by the World Health Organization (WHO) as a high-priority antimicrobial-resistant pathogen, continues to impose a substantial global health burden due to escalating resistance and stagnant therapeutic innovation. Colistin retains critical clinical utility against MDR P. aeruginosa infections; however, its dose-limiting nephrotoxicity and neurotoxicity necessitate strategies to optimise therapeutic indices. This study investigated the molecular mechanism underlying the synergistic activity of aspirin in potentiating colistin efficacy against MDR P. aeruginosa. In vitro analyses revealed marked synergistic bactericidal activity (FIC index ≤0.5), with metabolomic profiling demonstrating suppression of key metabolic pathways integral to bacterial membrane biogenesis, including glycerophospholipid metabolism and fatty acid biosynthesis. Ultrastructural imaging confirmed irreversible disruption of membrane integrity via combined treatment. In a rat model of P. aeruginosa-induced pneumonia, colistin-aspirin co-administration demonstrated superior efficacy to monotherapy, significantly reducing pulmonary bacterial load (3 to 4-log CFU/g reduction vs colistin alone; p < 0.01), attenuating histopathological injury, and suppressing pro-inflammatory cytokine levels (IL-6, IL-8, TNF-α) by 30-47%. Critically, this synergy enabled a reduction of colistin dosing to one-sixteenth while maintaining bactericidal potency. These findings provide mechanistic insights into aspirin-mediated colistin sensitisation and evidence supporting combinatorial regimens to circumvent colistin toxicity barriers. This work establishes a rational foundation for clinical translation of repurposed aspirin-colistin therapy against MDR P. aeruginosa infections.

Functional disparities of malonyl-ACP decarboxylase between Xanthomonas campestris and Xanthomonas oryzae

Xanthomonas campestris pv. campestris (Xcc) and X. oryzae pv. oryzae (Xoo) are crucial plant pathogenic bacteria, causing crucifer black rot and rice leaf blight, respectively. Both bacterial species encode a protein containing the YiiD_C domain, designated MadB, which exhibits an 87.5% sequence identity between their MadBs. The madB genes from either Xoo or Xcc successfully restored the growth defect in Ralstonia solanacearum and Escherichia coli fabH mutants in vivo. In vitro assays demonstrated that MadB proteins possess malonyl-ACP decarboxylase activity, although Xcc MadB exhibited lower activity compared with Xoo MadB. Mutation of madB in both Xoo and Xcc strains led to decreased pathogenicity in their respective host plants. Interestingly, the Xoo madB mutant exhibited a significant increase in branched-chain fatty acid production, whereas the Xcc madB mutant showed only minor changes in fatty acid composition. Despite the reduction in exopolysaccharide (EPS) synthesis due to madB mutation in both Xoo and Xcc, EPS production in the Xoo madB mutant could be restored by exogenous sodium acetate supplementation. In contrast, sodium acetate failed to restore EPS synthesis in the Xcc madB mutant. Biochemical and genetic analyses indicated that these divergent physiological roles arise from the distinct biochemical functions of MadB in the two bacteria. In Xoo, the fatty acid synthesis (FAS) pathway mediated by MadB operates independently of the FAS pathway mediated by FabH. Conversely, in Xcc, the FAS pathway mediated by FabH is the primary route, with MadB's pathway serving a supplementary and regulatory role. Further analysis of gene organization and expression regulation of madB in both bacteria corroborates these distinctions.

IMPORTANCE

Despite the high conservation of the mad gene within the Proteobacteria, the physiological roles of the Mad protein remain largely unclear. Xoo and Xcc are bacteria with very close phylogenetic relationships, both encoding malonyl-ACP decarboxylase (MadB). However, MadB demonstrates substantial physiological function variations between these two species. This study demonstrates that even in closely related bacteria, homologous genes have adopted different evolutionary pathways to adapt to diverse living environments, forming unique gene expression regulation mechanisms. This has led to the biochemical functional divergence of homologous proteins within their respective species, ultimately resulting in distinct physiological functions.

Dose-dependent effects of chlorpyrifos on liver injury, intestinal dysbiosis, and metabolic perturbations in C57BL/6J mice

The organophosphorus pesticide chlorpyrifos (CPF) is widely utilized in agriculture to protect crops from pests and diseases. Concerns regarding its extensive use have emerged due to the substance's persistence, bioaccumulation, endocrine disruption, and associated toxicity, which may lead to various adverse reactions. In this study, 32 male C57BL/6 J mice were orally administered varying doses of CPF over a period of two weeks. Metabolic perturbations resulting from subacute exposure to CPF were assessed using LC-MS/MS-based untargeted metabolomics, alongside biochemical analysis and histopathological techniques. The 16S rRNA gene sequencing method was employed to evaluate changes in the gut microbial community within the cecal contents of mice exposed to CPF. In vivo studies have shown that CPF exposure induced dose-dependent damage and dysregulation of the intestinal microbiota in mouse colonic tissues. This was characterized by significant alterations in the gut microbiota, increased intestinal permeability and elevated levels of lipopolysaccharides. These changes may have compromised intestinal barrier function and facilitated the transfer of intestinal microbial metabolites and endotoxins to the liver, subsequently leading to liver injury. Collectively, this study elucidates a potential mechanism by which CPF triggers liver injury through alterations in the intestinal microbial community and increased intestinal permeability. These findings not only enhance our understanding of the toxicological effects of CPF but also contribute to the assessment of health risks associated with CPF exposure.

Nutritional interventions to counteract the detrimental consequences of early-life stress

Exposure to stress during sensitive developmental periods comes with long term consequences for neurobehavioral outcomes and increases vulnerability to psychopathology later in life. While we have advanced our understanding of the mechanisms underlying the programming effects of early-life stress (ES), these are not yet fully understood and often hard to target, making the development of effective interventions challenging. In recent years, we and others have suggested that nutrition might be instrumental in modulating and possibly combatting the ES-induced increased risk to psychopathologies and neurobehavioral impairments. Nutritional strategies are very promising as they might be relatively safe, cheap and easy to implement. Here, we set out to comprehensively review the existing literature on nutritional interventions aimed at counteracting the effects of ES on neurobehavioral outcomes in preclinical and clinical settings. We identified eighty six rodent and ten human studies investigating a nutritional intervention to ameliorate ES-induced impairments. The human evidence to date, is too few and heterogeneous in terms of interventions, thus not allowing hard conclusions, however the preclinical studies, despite their heterogeneity in terms of designs, interventions used, and outcomes measured, showed nutritional interventions to be promising in combatting ES-induced impairments. Furthermore, we discuss the possible mechanisms involved in the beneficial effects of nutrition on the brain after ES, including neuroinflammation, oxidative stress, hypothalamus-pituitary-adrenal axis regulation and the microbiome-gut-brain axis. Lastly, we highlight the critical gaps in our current knowledge and make recommendations for future research to move the field forward.

Deciphering the Controversial Role of TP53 Inducible Glycolysis and Apoptosis Regulator (TIGAR) in Cancer Metabolism as a Potential Therapeutic Strategy

Tumor metabolism has emerged as a critical target in cancer therapy, revolutionizing our understanding of how cancer cells grow, survive, and respond to treatment. Historically, cancer research focused on genetic mutations driving tumorigenesis, but in recent decades, metabolic reprogramming has been recognized as a hallmark of cancer. The TP53 inducible glycolysis and apoptosis regulator, or TIGAR, affects a wide range of cellular and molecular processes and plays a key role in cancer cell metabolism by regulating the balance between glycolysis and antioxidant defense mechanisms. Cancer cells often exhibit a shift towards aerobic glycolysis (the Warburg effect), which allows rapid energy production and gives rise to biosynthetic intermediates for proliferation. By inhibiting glycolysis, TIGAR can reduce the proliferation rate of cancer cells, particularly in early-stage tumors or specific tissue types. This metabolic shift may limit the resources available for rapid cell division, thereby exerting a tumor-suppressive effect. However, this metabolic shift also leads to increased levels of reactive oxygen species (ROS), which can damage the cell if not properly managed. TIGAR helps protect cancer cells from excessive ROS by promoting the pentose phosphate pathway (PPP), which generates NADPH-a key molecule involved in antioxidant defense. Through its actions, TIGAR decreases the glycolytic flux while increasing the diversion of glucose-6-phosphate into the PPP. This reduces ROS levels and supports biosynthesis and cell survival by maintaining the balance of nucleotides and lipids. The role of TIGAR has been emerging as a prognostic and potential therapeutic target in different types of cancers. This review highlights the role of TIGAR in different types of cancer, evaluating its potential role as a diagnostic marker and a therapeutic target.

Arachidonic acid suppresses lung cancer cell growth and modulates lipid metabolism and the ERK/PPARγ signaling pathway

Lung cancer remains the leading cause of cancer-related mortality worldwide, necessitating the development of new treatment strategies. Arachidonic acid (ARA), a polyunsaturated fatty acid, shows promise in cancer therapy due to its potential anti-tumor effects, although its role in lung cancer remains unclear. This study investigated the effects and underlying mechanism of ARA on A549 and NCI-H1299 lung cancer cells. In vitro assays were used to assess cell viability, apoptosis, colony formation, lipid droplet formation, and changes in cellular lipid content. ARA dose-dependently suppressed cell viability, facilitated apoptosis, and suppressed colony formation in both lung cancer cell lines. Network pharmacology analysis was performed to identify potential gene targets and pathways, uncovering 61 overlapping genes between ARA and lung cancer-related targets, with mitogen-activated protein kinase 1 (MAPK1) emerging as a key gene. Enrichment analyses suggested that the effects of ARA might be mediated through lipid metabolism and the extracellular signal-regulated kinase (ERK)/peroxisome proliferator-activated receptor gamma (PPARγ) signaling pathway. In both lung cancer cell lines, ARA treatment inhibited lipid droplet formation and decreased the cellular lipids. Immunoblotting further confirmed that ARA treatment significantly increased ERK phosphorylation while reducing PPARγ and fatty acid synthase (FASN) protein levels. In vitro experiments using GW9662, a PPARγ antagonist, confirmed that inhibiting lipid droplet formation impairs lung cancer cell viability and promotes apoptosis. Furthermore, in vivo experiments demonstrated that ARA significantly reduced tumor size and weight in a lung cancer xenograft model, further validating its anti-tumor effects. The potential of ARA as a therapeutic agent for lung cancer might involve lipid metabolism and relevant signaling pathways. A future study exploring the full therapeutic potential of ARA and underlying mechanisms in lung cancer is needed.

Research progress on AMPK in the pathogenesis and treatment of MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD; formerly known as non-alcoholic fatty liver disease, NAFLD) has become one of the most prevalent chronic liver diseases worldwide, with its incidence continuously rising alongside the epidemic of metabolic disorders. AMP-activated protein kinase (AMPK), as a key regulator of cellular energy metabolism, influences multiple pathological processes associated with MASLD. This review systematically summarizes the regulatory roles of AMPK in lipid metabolism, inflammatory response, cell apoptosis, and fibrosis. Additionally, it discusses the latest developments of AMPK activators from preclinical to clinical studies, while analyzing the major challenges currently faced and potential strategies for resolution. A deeper understanding of AMPK regulatory mechanisms will contribute to the development of more effective therapeutic approaches for MASLD.

Differential effects of high-fat diet on salivary and gut microbiota

Objectives

Microorganisms contribute to the pathogenesis of obesity, while more studies focus on gut microbiome. However, the relationship between oral microbiota and obesity has yet to be elucidated. This study was designed to investigate the similarities and differences in the effects of a high-fat diet on salivary and gut microbiota through mouse experiments, exploring the hypothesis that oral microbial mechanisms may contribute to obesity.

Methods

An obese mouse model was established in male C57BL/6J mice by feeding a high-fat diet, confirmed by body weight records and blood glucose tests. This study evaluated the physiological effects of the high-fat diet on mice. 16S rRNA sequencing technology was used to analyze changes in salivary and gut microbiota, and gas chromatography-mass spectrometry was employed to evaluate 17 short-chain and medium-chain fatty acids quantitatively.

Results

The microbiota distribution in salivary was different between the high-fat diet (HFD) and normal chow diet (NCD) groups. At the genus level of salivary microbiota, Streptococcus and Escherichia were highly abundant in the HFD group. Rodentibacter and Turicibacter were more abundant in the NCD group. Regarding the gut microbiome, the diversity changes of gut microbiota are more significant than those of salivary microbiota. The HFD group had a significantly higher abundance of Kineothrix, Cryptobacteroides, and a lower abundance of CAG-485. Nine genera had consistent alterations in salivary and gut microbiota, among which Akkermansia, Lactobacillus, and Intestinimonas were significantly correlated with physiological indicators, and Muribaculum was significantly correlated with increased decanoic acid levels in the HFD group. The dysregulated nine genera were associated with significant upregulation of certain metabolic pathways of the HFD group, including the pentose phosphate, bacterial invasion of epithelial cells, and steroid biosynthesis pathways.

Conclusions

There are differences and similarities in the effects of HFD on salivary and gut microbiota. Certain genera of the oral-gut axis altered consistently by HFD may affect obesity through mechanisms involving metabolic pathways and inflammation.

Feasibility Evaluation of Dried Whole Egg Powder Application in Tadpole (Lithobates catesbeianus) Feed: Effects on Growth, Metamorphosis Rate, Lipid Metabolism and Intestinal Flora

At present, studies on tadpole nutrition and metabolism are scarce. This study aimed at comparing the influence of two protein sources, fishmeal (FM) and dried whole egg powder (DWEP), on tadpoles from the perspective of growth, the metamorphosis rate, lipid metabolism, antioxidant properties and the intestinal flora. In this experiment, the control diet was set to contain no FM or DWEP. Based on the control diet, 5% and 10% FM or DWEP were included, respectively. The results of the experiment indicated that FM or DWEP inclusion significantly enhanced the growth performance and metamorphosis rate (p < 0.05); activated hepatic lipid metabolism, as manifested by enhanced LPL and HL activity; upregulated lipid metabolism-related gene expression (fasn, acc, acadl and cpt1α) (p < 0.05); and distinctly elevated the activity of SOD, CAT and GPX (p < 0.05), suggesting improved antioxidant capabilities (p < 0.05). Moreover, the inclusion of FM or DWEP elevated the relative abundance of Actinobacteria and Actinomyces and reduced the relative abundance of Proteobacteria. Unexpectedly, no significant differences were observed between the FM and DWEP groups regarding the above detected indices. This indicates that using DWEP to replace FM is a viable option.

The combination of gemcitabine and albumin-bound paclitaxel effectively inhibits de novo lipogenesis in pancreatic cancer cells by targeting the AMPK/SREBP1 pathway

Abnormal de novo lipogenesis and reprogramming of lipid metabolism have been associated with the development and progression of various cancers, including pancreatic cancer. Gemcitabine (GEM) combined with albumin-bound paclitaxel (nab-PTX) is the first-line chemotherapeutic agent for pancreatic cancer. There have been many studies on the molecular mechanisms of gemcitabine and paclitaxel in cancer treatment. Still, the effects of the combination on lipid metabolism and the specific mechanisms have not been explored. This study found that GEM combined with nab-PTX inhibited pancreatic cancer cell proliferation and de novo lipogenesis. The exact mechanism is that GEM combined with nab-PTX induces adenosine triphosphate (ATP) depletion and activates AMP-activated protein kinase (AMPK) in pancreatic cancer cells, which in turn inhibits sterol regulatory element-binding protein 1 (SREBP1) expression and nuclear translocation, and ultimately inhibits de novo lipogenesis in pancreatic cancer cells. In addition, we found that the novel lipid-lowering drug bempedoic acid (ETC-1002) significantly enhanced the inhibitory effect of GEM combined with nab-PTX on de novo lipogenesis in pancreatic cancer cells. These findings establish a link between GEM combined with nab-PTX and lipid metabolism, and the discovery of the novel lipid-lowering drug ETC-1002 provides a potential therapeutic strategy for pancreatic cancer.

Distinct lipidomic profiles but similar improvements in aerobic capacity following sprint interval training versus moderate-intensity continuous training in male adolescents

Background

Exercise-induced metabolic changes, especially lipidomic changes are generally associated with improvements in cardiovascular health. Despite numerous previous studies, the differences in lipidomic profile response to different types of exercise training remain unclear. This study aimed to investigate how two different exercise intensities affect aerobic capacity and serum lipidomic profiles in healthy adolescents.

Methods

Twenty-four healthy untrained male adolescents (13.08 ± 0.88 years old) were recruited and randomly assigned to moderate-intensity continuous training (MICT) group or sprint interval training (SIT) group to complete a specific training on a cycle ergometer for 6 weeks. Peak oxygen uptake (VO2peak) and body composition were measured, and blood samples were collected for serum lipoproteins and lipidomic analysis. Anthropometric, VO2peak, and serum biochemical data were analyzed using two-way repeated analysis of variance, while targeted lipidomic analysis was performed by principal component analysis and paired-sample t-test.

Results

VO2peak significantly improved from 39.05 ± 8.17 to 47.52 ± 8.51 [F (1, 44) = 14.75, p < 0.05] for MICT and from 40.13 ± 6.37 to 48.42 ± 7.01 [F (1, 44) = 14.75, p < 0.05] for SIT. A total of 28 lipids in MICT and 5 lipids in SIT showed significant changes out of 276 identified lipids (FC > 1.5 or <1/1.5, FDR <0.05). In MICT, 21 lipids, including sphingolipid (SP) and phospholipid (PL), decreased, while 7 lipids increased. In SIT, all 5 lipids, which were free fatty acid (FFA), decreased.

Conclusion

Although both MICT and SIT induced similar and significant improvements in VO2peak, serum lipid adaptations to the training differed. The primary changes in serum lipidomic intermediates for both types of training were reductions; however, SIT affected FFA, while MICT predominantly influenced SPs and PLs.

Integrated metabolomic and transcriptomic analysis revealed the transition of functional components in edible flower buds of Hemerocallis citrina Baroni

The edible flower buds of Hemerocallis citrina Baroni are used both as a vegetable and functional food. It has various health benefits due to the diversity of natural products. However, the establishment of functional components in the edible flower bud remains to be studied. We conducted a high-resolution metabolomic analysis of flower buds at three developmental stages, 1-2 cm, 4-6 cm, and edible (10-15 cm). Our analysis revealed 157 differential accumulated metabolites, including flavonoids (49), fatty acids (17) and terpenoids (13) while most of them decreased during flower bud development. Among them, 2 flavonoids, 2 long-chain fatty acids and 1 triterpene saponin are highly accumulated in edible flower buds. Furthermore, the expression levels of catalytic genes mirrored the changes in metabolite levels detected. These results track the dynamics of functional component accumulation during edible flower bud development, laying the theoretical basis for nutrition formation in H. citrina.

Polyphenol Profile and Antioxidant, Antityrosinase, and Anti-Melanogenesis Activities of Ethanol Extract of Bee Pollen

Background/Objective: Bee pollen, a rich nutritional food, was employed to develop a raw material for skin whitening. Methods: The polyphenol profile and antioxidant, antityrosinase, and anti-melanogenesis activities of the ethanol extracts of five species of bee pollens (EEBPs) were determined. Results: The results showed that there were a total of 121 phenolic compounds in these EEBPs. Each type of bee pollen had unique substances. The best anti-melanogenesis activity was observed for sunflower EEBP, about 25% at a concentration of 25 μg/mL BEEP. The anti-melanogenesis activities of EEBPs from high to low were sunflower, apricot, camellia, rapeseed, and lotus EEBPs. The anti-melanogenesis activity in B16F10 cells was positively correlated with the antityrosinase activity and total phenol content, with coefficients of 0.987 and 0.940. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis results of untargeted proteomics revealed that sunflower EEBP inhibited melanogenesis in B16F10 cells by reducing the expression of the proteins MAP2K1, NFKB2, RELB, RPS6KA3, CASP3, TRAF6, MAP2K5, MAPKAPK3, STRADA, CCNA2, and FASN involved in the cAMP, MAPK, and TNF signaling pathways, even though these pathways were not significantly different from the control group. Conclusions: The sunflower EEBP has high inhibition effect on melanogenesis than other species EEBPs. The results provide a basis for the future industrial development of a raw material for skin whitening.

Cuticular wax in wheat: biosynthesis, genetics, and the stress response

All terrestrial plants possess a hydrophobic cuticle in the outermost layer of their aerial organs that is composed of cutin and wax. The cuticle serves as the first barrier between the plant and the surrounding environment and plays a key role in the resistance of plants to abiotic and biotic stressors. Additionally, they are closely associated with plant growth and development. Cuticular wax has attracted considerable attention as the main mediator of cuticular functions. In this review, we summarize the advances in the research investigating wheat cuticular wax, focusing on three aspects that include biosynthesis, genetics, and stress responses. Additionally, we discuss the applications of cuticular wax in wheat breeding.

Asperuloside activates hepatic NRF2 signaling to stimulate mitochondrial metabolism and restore lipid homeostasis in high fat diet-induced MAFLD

BACKGROUND

Nutrient overload predisposes the development of metabolic dysfunction-associated fatty liver disease (MAFLD). However, there are no specific pharmacological therapies for MAFLD. Asperuloside (ASP), an iridoid glycoside extracted from Eucommia ulmoides leaves, can alleviate obesity and MAFLD. However, the underlying mechanism and pharmacological effects of ASP on ameliorating MAFLD remain largely investigated. This study aimed to explore the effects of ASP in ameliorating MAFLD and to unravel its underlying mechanism using a high fat diet-induced MAFLD mice model.

METHODS

Six-week-old C57BL/6 male mice were fed a high fat diet for 12 weeks to induce MAFLD, followed by daily ASP treatment (50 mg/kg via oral gavage) for 7 weeks. HepG2 cells were used for in vitro studies. Nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor, ML385, was employed to explore the mechanisms of ASP's action.

RESULTS

ASP stimulated lipolysis and inhibited de novo lipogenesis, contributing to alleviating lipid deposition in obese mice livers and HepG2 cells. ASP restored ATP production and reversed the impairments of mitochondrial energetics and biogenesis in obese mice livers and HepG2 cells. ASP attenuated oxidative stress in obese mice livers and HepG2 cells, exhibiting its antioxidant value. Impressively, ASP significantly promotes Nrf2 nuclear translocation and Nrf2/ARE binding, thereby activating Nrf2/ARE pathway in obese mice livers and HepG2 cells, demonstrating its potential as a hepatic Nrf2 activator. Nrf2 inhibition abolishes the protective effects of ASP against lipid deposition, oxidative stress and mitochondrial dysfunction, emphasizing the critical role of ASP-activated hepatic Nrf2 signaling in ameliorating MAFLD.

CONCLUSIONS

This study provides the first line of evidence demonstrating the pivotal role of ASP-stimulated Nrf2 activation in alleviating MAFLD, emphasizing its potential as a hepatic Nrf2 activator targeting fatty liver diseases. These findings offer new evidence of ASP-stimulated mitochondrial metabolism and lipolysis in MAFLD, paving the way for the development of ASP as a therapeutic agent and dietary supplement to attenuate MAFLD progression.

Revealing the adaptation mechanism of different color morphs of sea cucumber Apostichopus japonicus to light intensities from the perspective of metabolomics

Global warming has multi-dimensional and complex impacts on the Earth's system, among which changes in light intensities cannot be overlooked. Sea cucumbers are a marine biological resource with significant economic and ecological value. Their presence and activity help maintain the balance and stability of marine ecosystems. The variation in light intensities have important ecological effects on sea cucumbers. Light intensities can alter the synthesis and degradation of metabolic substances within the bodies of Apostichopus japonicus by changing their body color. Their changes affect the production of microorganisms in the environment, thereby achieving the goal of bioremediation. This study investigated metabolic variations in green, purple, and white sea cucumber Apostichopus japonicus under different light conditions (0 lx and 910 lx) with a 12-h light and 12-h dark photoperiod. The findings indicated that the sea cucumbers displayed more diverse metabolic alterations under 910 lx illumination compared to 0 lx. Specifically, these color morphs primarily responded to changes in light intensities through "tryptophan metabolism" and "biosynthesis of steroid hormones". Additionally, high light intensities environment exacerbated the consumption of fatty acids by sea cucumbers. Different color morphs of sea cucumbers have differences in key metabolites in response to changes in light intensities. Green and white sea cucumbers primarily adapt to environment through phospholipids, while purple sea cucumbers mainly utilize fatty acids. These results enhance our comprehension of how sea cucumbers adapt ecologically to varying light intensities, and they offer valuable insights for systematically uncovering the regulatory processes that marine animals employ in response to environmental changes.

Role of ACSBG1 in Brain Lipid Metabolism and X-Linked Adrenoleukodystrophy Pathogenesis: Insights from a Knockout Mouse Model

"Bubblegum" acyl-CoA synthetase (ACSBG1) is a pivotal player in lipid metabolism during mouse brain development, facilitating the activation of long-chain fatty acids (LCFA) and their incorporation into lipid species that are crucial for brain function. ACSBG1 converts LCFA into acyl-CoA derivatives, supporting vital metabolic processes. Fruit fly mutants lacking ACSBG1 exhibited neurodegeneration and had elevated levels of very long-chain fatty acids (VLCFA), characteristics of human X-linked adrenoleukodystrophy (XALD). To explore ACSBG1's function and potential as a therapeutic target in XALD, we created an ACSBG1 knockout (Acsbg1-/-) mouse and examined the effects on brain FA metabolism during development. Phenotypically, Acsbg1-/- mice resembled wild type (w.t.) mice. ACSBG1 expression was found mainly in tissue affected pathologically in XALD, namely the brain, adrenal gland and testis. ACSBG1 depletion did not significantly reduce the total ACS enzyme activity in these tissue types. In adult mouse brain, ACSBG1 expression was highest in the cerebellum; the low levels detected during the first week of life dramatically increased thereafter. Unexpectedly, lower, rather than higher, saturated VLCFA levels were found in cerebella from Acsbg1-/- vs. w.t. mice, especially after one week of age. Developmental changes in monounsaturated ω9 FA and polyunsaturated ω3 FA levels also differed between w.t. and Acsbg1-/- mice. ACSBG1 deficiency impacted the developmental expression of several cerebellar FA metabolism enzymes, including those required for the synthesis of ω3 polyunsaturated FA, precursors of bioactive signaling molecules like eicosanoids and docosanoids. These changes in membrane lipid FA composition likely affect membrane fluidity and may thus influence the body's response to inflammation. We conclude that, despite compelling circumstantial evidence, it is unlikely that ACSBG1 directly contributes to the pathology of XALD, decreasing its potential as a therapeutic target. Instead, the effects of ACSBG1 knockout on processes regulated by eicosanoids and/or docosanoids should be further investigated.

Biological characteristics of a new long-chain fatty acid transport protein 1 from Trichinella spiralis and its participation in lipid metabolism, larval moulting, and development

Long-chain fatty acid transport protein 1 (FATP1) is a member of the fatty acid transporter family. It facilitates transmembrane transport of fatty acids and participates in lipid metabolism. Lipids are essential components of the cell and organelle membranes of Trichinella spiralis. The nematode has lost the capacity to synthesise the necessary lipids de novo and has instead evolved to obtain fatty acids and their derivatives from its host. This study aims to ascertain the primary biological characteristics and roles of T. spiralis FATP1 (TsFATP1) in lipid metabolism, larval moulting, and the development of this nematode. The results show that TsFATP1 is highly expressed at enteral T. spiralis stages, mainly localised at the cuticle, the stichosome and the intrauterine embryos of the parasite. The silencing of the TsFATP1 gene by TsFATP1-specific dsRNA significantly decreases the expression levels of TsFATP1 in the worm. It reduces the contents of ATP, triglycerides, total cholesterol, and phospholipids both in vitro and in vivo. RNAi inhibits lipid metabolism, moulting, and the growth of this nematode. The results demonstrate that TsFATP1 plays an essential role in lipid metabolism, moulting, and the development of T. spiralis. It could also be a target candidate for the anti-Trichinella vaccine and drugs.

Fatty acid metabolism-related enzymes in colorectal cancer metastasis: from biological function to molecular mechanism

Colorectal cancer (CRC) is a highly aggressive and life-threatening malignancy that metastasizes in ~50% of patients, posing significant challenges to patient survival and treatment. Fatty acid (FA) metabolism regulates proliferation, immune escape, metastasis, angiogenesis, and drug resistance in CRC. FA metabolism consists of three pathways: de novo synthesis, uptake, and FA oxidation (FAO). FA metabolism-related enzymes promote CRC metastasis by regulating reactive oxygen species (ROS), matrix metalloproteinases (MMPs), angiogenesis and epithelial-mesenchymal transformation (EMT). Mechanistically, the PI3K/AKT/mTOR pathway, wnt/β-catenin pathway, and non-coding RNA signaling pathway are regulated by crosstalk of enzymes related to FA metabolism. Given the important role of FA metabolism in CRC metastasis, targeting FA metabolism-related enzymes and their signaling pathways is a potential strategy to treat CRC metastasis.

BI-7273, a BRD9 inhibitor, reduces lipid accumulation by downregulating the AKT/mTOR/SREBP1 signaling pathway

Increases in de novo lipogenesis that disturbed lipid homeostasis and caused lipid accumulation are a major cause of NAFLD and obesity. SREBP1 is a crucial regulatory factor controlling the expression of rate-limiting enzymes of lipid synthesis. A reduction in SREBP1expression can reduce lipid accumulation. Thus, we utilized an SREBP1-luciferase-KI HEK293 cell line constructed by our lab to screen 200 kinds of epigenetic drugs for their ability to downregulate SREBP1expression. BI-7273, an inhibitor of bromodomain-containing protein 9 (BRD9), was screened and found to decrease SREBP1 expression. What is more, BI-7273 has been confirmed that it could reduce lipid accumulation in HepG2 cells by BODIPY staining, and significantly decrease the protein expression of SREBP1 and FASN. To explore the potential mechanism BI-7273 reducing lipid accumulation, RNA sequencing (RNA-seq) was performed and demonstrated that BI-7273 reduced lipid accumulation by downregulating the AKT/mTOR/SREBP1 pathway in vitro. Finally, these results were verified in NAFLD and obesity mouse model induced by high fat diet (HFD). The results indicated that BI-7273 could decrease mouse body weight and improve insulin sensitivity, but also exhibited a strong negative correlation with serum lipid levels, and also demonstrated that BI-7273 reduced lipid accumulation via AKT/mTOR/SREBP1 pathway in vivo. In conclusion, our results revealed that BI-7273 decreases lipid accumulation by downregulating the AKT/mTOR/SREBP1 pathway in vivo and in vitro. This is the first report demonstrating the protective effect of this BRD9 inhibitor against NAFLD and obesity. BRD9 may be a novel target for the discovery of effective drugs to treat lipid metabolism disorders.

Role of ACSBG1 in brain lipid metabolism and X-linked adrenoleukodystrophy pathogenesis: Insights from a knockout mouse model

The "bubblegum" acyl-CoA synthetase (ACSBG1) is a pivotal player in lipid metabolism during the development of the mouse brain, facilitating the activation of long-chain fatty acids (LCFAs) and their integration into essential lipid species crucial for brain function. Through its enzymatic activity, ACSBG1 converts LCFAs into acyl-CoA derivatives, supporting vital processes like membrane formation, myelination, and energy production. Its regulatory role significantly influences neuronal growth, synaptic plasticity, and overall brain development, highlighting its importance in maintaining lipid homeostasis and proper brain function. Originally discovered in the fruit fly brain, ACSBG1 attracted attention for its potential implication in X-linked adrenoleukodystrophy (XALD) pathogenesis. Studies using Drosophila melanogaster lacking the ACSBG1 homolog, bubblegum, revealed adult neurodegeneration with elevated levels of very long-chain fatty acids (VLCFA). To explore ACSBG1's role in fatty acid (FA) metabolism and its relevance to XALD, we created an ACSBG1 knockout (Acsbg1-/-) mouse model and examined its impact on lipid metabolism during mouse brain development. Phenotypically, Acsbg1-/- mice resembled wild type (w.t.) mice. Despite its primary expression in tissues affected by XALD, brain, adrenal gland and testis, ACSBG1 depletion did not significantly reduce total ACS enzyme activity in these tissues when using LCFA or VLCFA as substrates. However, analysis unveiled intriguing developmental and compositional changes in FA levels associated with ACSBG1 deficiency. In the adult mouse brain, ACSBG1 expression peaked in the cerebellum, with lower levels observed in other brain regions. Developmentally, ACSBG1 expression in the cerebellum was initially low during the first week of life but increased dramatically thereafter. Cerebellar FA levels were assessed in both w.t. and Acsbg1-/- mouse brains throughout development, revealing notable differences. While saturated VLCFA levels were typically high in XALD tissues and in fruit flies lacking ACSBG1, cerebella from Acsbg1-/- mice displayed lower saturated VLCFA levels, especially after about 8 days of age. Additionally, monounsaturated ω9 FA levels exhibited a similar trend as saturated VLCFA, while ω3 polyunsaturated FA levels were elevated in Acsbg1-/- mice. Further analysis of specific FA levels provided additional insights into potential roles for ACSBG1. Notably, the decreased VLCFA levels in Acsbg1-/- mice primarily stemmed from changes in C24:0 and C26:0, while reduced ω9 FA levels were mainly observed in C18:1 and C24:1. ACSBG1 depletion had minimal effects on saturated long-chain FA or ω6 polyunsaturated FA levels but led to significant increases in specific ω3 FA, such as C20:5 and C22:5. Moreover, the impact of ACSBG1 deficiency on the developmental expression of several cerebellar FA metabolism enzymes, including those required for synthesis of ω3 polyunsaturated FA, was assessed; these FA can potentially be converted into bioactive signaling molecules like eicosanoids and docosanoids. In conclusion, despite compelling circumstantial evidence, it is unlikely that ACSBG1 directly contributes to the pathology of XALD. Instead, the effects of ACSBG1 knockout on processes regulated by eicosanoids and/or docosanoids should be further investigated.

Effects of taurine on metabolomics of bovine mammary epithelial cells under high temperature conditions

High temperature induces heat stress, adversely affecting the growth and lactation performance of cows. Research has shown the protective effect of taurine against hepatotoxicity both in vivo and in vitro. This study aimed to investigate the effect of taurine on the metabolomics of mammary epithelial cells of dairy cows under high-temperature conditions. Mammary epithelial cells were exposed to 0 mmol/L (HS, control), 8 mmol/L (HT-8), and 32 mmol/L (HT-32) of taurine, then incubated at 42°C for 6 h. Metabolomics analysis was conducted using Liquid Chromatograph Mass Spectrometer (LC-MS). Compared with the HS group, 2,873 and 3,243 metabolites were detected in the HT-8 group in positive and negative ion modes. Among these, 108 and 97 metabolites were significantly upregulated in positive and negative ion modes, while 60 and 166 metabolites were downregulated. Notably, 15 different metabolites such as palmitic acid, adenine and hypoxanthine were screened out in the HT-8 group. Compared with the HS group, 2,873 and 3,243 metabolites were, respectively, detected in the HT-32 group in the positive and negative ion modes. Among those metabolites, 206 metabolites were significantly up-regulated, while 206 metabolites were significantly downregulated in the positive mode. On the other hand, 497 metabolites were significantly upregulated in the negative mode, while 517 metabolites were reported to be downregulated. Noteworthy, 30 distinct metabolites, such as palmitic acid, phytosphingosine, hypoxanthine, nonanoic acid, and octanoic acid, were screened out in the HT-32 group. KEGG enrichment analysis showed that these metabolites were mainly involved in lipid metabolism, purine metabolism and other biological processes. Overall, our study indicates that taurine supplementation alters the metabolites primarily associated with purine metabolism, lipid metabolism and other pathways to alleviate heat stress in bovine mammary epithelial cells.

Tolypocladium sinense Mycelium Polysaccharide Alleviates Obesity, Lipid Metabolism Disorder, and Inflammation Caused by High Fat Diet via Improving Intestinal Barrier and Modulating Gut Microbiota

SCOPE

Tolypocladium sinense is a fungus isolated from Cordyceps. Cordyceps has some medicinal value and is also a daily health care product. This study explores the preventive effects of T. sinense mycelium polysaccharide (TSMP) on high-fat diet-induced obesity and chronic inflammation in mice.

METHODS AND RESULTS

Here, the study establishes an obese mouse model induced by high-fat diet. In this study, the mice are administered TSMP daily basis to evaluate its effect on alleviating obesity. The results show that TSMP can significantly inhibit obesity and alleviate dyslipidemia by regulating the expression of lipid metabolism-related genes such as liver kinase B1 (LKB1), phosphorylated AMP-activated protein kinase (pAMPK), peroxisome proliferator activated receptor α (PPARα), fatty acid synthase (FAS), and hydroxymethylglutaryl-CoA reductase (HMGCR) in the liver. TSMP can increase the protein expression of zona occludens-1 (ZO-1), Occludin, and Claudin-1 in the colon, improve the intestinal barrier dysfunction, and reduce the level of serum LPS, thereby reducing the inflammatory response. 16S rDNA sequencing shows that TSMP alters the intestinal microbiota by increasing the relative abundance of Akkermansia, Lactobacillus, and Prevotellaceae_NK3B31_group, while decreasing the relative abundance of Faecalibaculum.

CONCLUSION

The findings show that TSMP can inhibit obesity and alleviates obesity-related lipid metabolism disorders, inflammatory responses, and oxidative stress by modulating the gut microbiota and improving intestinal barrier.

JAK/STAT Inhibition Normalizes Lipid Composition in 3D Human Epidermal Equivalents Challenged with Th2 Cytokines

Derangement of the epidermal barrier lipids and dysregulated immune responses are key pathogenic features of atopic dermatitis (AD). The Th2-type cytokines interleukin IL-4 and IL-13 play a prominent role in AD by activating the Janus Kinase/Signal Transduction and Activator of Transcription (JAK/STAT) intracellular signaling axis. This study aimed to investigate the role of JAK/STAT in the lipid perturbations induced by Th2 signaling in 3D epidermal equivalents. Tofacitinib, a low-molecular-mass JAK inhibitor, was used to screen for JAK/STAT-mediated deregulation of lipid metabolism. Th2 cytokines decreased the expression of elongases 1, 3, and 4 and serine-palmitoyl-transferase and increased that of sphingolipid delta(4)-desaturase and carbonic anhydrase 2. Th2 cytokines inhibited the synthesis of palmitoleic acid and caused depletion of triglycerides, in association with altered phosphatidylcholine profiles and fatty acid (FA) metabolism. Overall, the ceramide profiles were minimally affected. Except for most sphingolipids and very-long-chain FAs, the effects of Th2 on lipid pathways were reversed by co-treatment with tofacitinib. An increase in the mRNA levels of CPT1A and ACAT1, reduced by tofacitinib, suggests that Th2 cytokines promote FA beta-oxidation. In conclusion, pharmacological inhibition of JAK/STAT activation prevents the lipid disruption caused by the halted homeostasis of FA metabolism.

Fatty acid synthase (FASN) signalome: A molecular guide for precision oncology

The initial excitement generated more than two decades ago by the discovery of drugs targeting fatty acid synthase (FASN)-catalyzed de novo lipogenesis for cancer therapy was short-lived. However, the advent of the first clinical-grade FASN inhibitor (TVB-2640; denifanstat), which is currently being studied in various phase II trials, and the exciting advances in understanding the FASN signalome are fueling a renewed interest in FASN-targeted strategies for the treatment and prevention of cancer. Here, we provide a detailed overview of how FASN can drive phenotypic plasticity and cell fate decisions, mitochondrial regulation of cell death, immune escape and organ-specific metastatic potential. We then present a variety of FASN-targeted therapeutic approaches that address the major challenges facing FASN therapy. These include limitations of current FASN inhibitors and the lack of precision tools to maximize the therapeutic potential of FASN inhibitors in the clinic. Rethinking the role of FASN as a signal transducer in cancer pathogenesis may provide molecularly driven strategies to optimize FASN as a long-awaited target for cancer therapeutics.

miR-122/PPARβ axis is involved in hypoxic exercise and modulates fatty acid metabolism in skeletal muscle of obese rats

Hypoxic exercise is an effective intervention for obesity, because it promotes weight loss by regulating fatty acid (FA) metabolism. The regulation of peroxisome proliferator-activated receptor β (PPARβ) by miR-122 may be involved in this process, but the detailed mechanisms are unknown. In order to address this issue, we probed how miR-122 affected the expression of factors associated with FA metabolism in skeletal muscle of obese rats undergoing hypoxic training. By injecting adeno-associated virus 9 containing miR-122 overexpression vector or miR-122 inhibitor into skeletal muscles of rats with a 4-week hypoxic exercise regimen, the miR-122 expression level can be regulated. Body composition and blood lipid levels were analyzed, and PPARβ, carnitine palmitoyltransferase 1b (CPT1b), acetylCoA carboxylase 2 (ACC2), and FA synthase (FAS) mRNA and protein levels were evaluated using quantitative reverse transcription quantitative PCR(RT-qPCR) and Western blot analysis. We found that miR-122 overexpression increased low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels and decreased PPARβ, ACC2, and FAS expression. Conversely, miR-122 inhibition decreased TG level, increased high-density lipoprotein cholesterol (HDL-C) level, and upregulated PPARβ, ACC2, FAS, and CPT1b. These data indicated that the negative regulation of PPARβ by miR-122 promotes FA metabolism by altering the levels of the factors related to FA metabolism in skeletal muscle of obese rat under hypoxic training, thus providing molecular-level insight into the beneficial effects of this intervention.

Cornelian Cherry (Cornus mas L.) Fruit Extract Lowers SREBP-1c and C/EBPα in Liver and Alters Various PPAR-α, PPAR-γ, LXR-α Target Genes in Cholesterol-Rich Diet Rabbit Model

Cornelian cherry (Cornus mas L.) fruits, abundant in iridoids and anthocyanins, are natural products with proven beneficial impacts on the functions of the cardiovascular system and the liver. This study aims to assess and compare whether and to what extent two different doses of resin-purified cornelian cherry extract (10 mg/kg b.w. or 50 mg/kg b.w.) applied in a cholesterol-rich diet rabbit model affect the levels of sterol regulatory element-binding protein 1c (SREBP-1c) and CCAAT/enhancer binding protein α (C/EBPα), and various liver X receptor-α (LXR-α), peroxisome proliferator-activated receptor-α (PPAR-α), and peroxisome proliferator-activated receptor-γ (PPAR-γ) target genes. Moreover, the aim is to evaluate the resistive index (RI) of common carotid arteries (CCAs) and aortas, and histopathological changes in CCAs. For this purpose, the levels of SREBP-1c, C/EBPα, ATP-binding cassette transporter A1 (ABCA1), ATP-binding cassette transporter G1 (ABCG1), fatty acid synthase (FAS), endothelial lipase (LIPG), carnitine palmitoyltransferase 1A (CPT1A), and adiponectin receptor 2 (AdipoR2) in liver tissue were measured. Also, the levels of lipoprotein lipase (LPL), visceral adipose tissue-derived serine protease inhibitor (Vaspin), and retinol-binding protein 4 (RBP4) in visceral adipose tissue were measured. The RI of CCAs and aortas, and histopathological changes in CCAs, were indicated. The oral administration of the cornelian cherry extract decreased the SREBP-1c and C/EBPα in both doses. The dose of 10 mg/kg b.w. increased ABCA1 and decreased FAS, CPT1A, and RBP4, and the dose of 50 mg/kg b.w. enhanced ABCG1 and AdipoR2. Mitigations in atheromatous changes in rabbits' CCAs were also observed. The obtained outcomes were compared to the results of our previous works. The beneficial results confirm that cornelian cherry fruit extract may constitute a potentially effective product in the prevention and treatment of obesity-related disorders.

Direct structural analysis of a single acyl carrier protein domain in fatty acid synthase from the fungus Saccharomyces cerevisiae

Acyl carrier protein (ACP) is the work horse of polyketide (PKS) and fatty acid synthases (FAS) and acts as a substrate shuttling domain in these mega enzymes. In fungi, FAS forms a 2.6 MDa symmetric assembly with six identical copies of FAS1 and FAS2 polypeptides. However, ACP spatial distribution is not restricted by symmetry owing to the long and flexible loops that tether the shuttling domain to its corresponding FAS2 polypeptide. This symmetry breaking has hampered experimental investigation of substrate shuttling route in fungal FAS. Here, we develop a protein engineering and expression method to isolate asymmetric fungal FAS proteins containing odd numbers of ACP domains. Electron cryomicroscopy (cryoEM) observation of the engineered complex reveals a non-uniform distribution of the substrate shuttling domain relative to its corresponding FAS2 polypeptide at 2.9 Å resolution. This work lays the methodological foundation for experimental study of ACP shuttling route in fungi.

Revolutionizing Tuberculosis Treatment: Uncovering New Drugs and Breakthrough Inhibitors to Combat Drug-Resistant Mycobacterium tuberculosis

Tuberculosis (TB) is a global health threat that causes significant mortality. This review explores chemotherapeutics that target essential processes in Mycobacterium tuberculosis, such as DNA replication, protein synthesis, cell wall formation, energy metabolism, and proteolysis. We emphasize the need for new drugs to treat drug-resistant strains and shorten the treatment duration. Emerging targets and promising inhibitors were identified by examining the intricate biology of TB. This review provides an overview of recent developments in the search for anti-TB drugs with a focus on newly validated targets and inhibitors. We aimed to contribute to efforts to combat TB and improve therapeutic outcomes.

Reconstruction of a fatty acid synthesis cycle from acyl carrier protein and cofactor structural snapshots

Fatty acids (FAs) play a central metabolic role in living cells as constituents of membranes, cellular energy reserves, and second messenger precursors. A 2.6 MDa FA synthase (FAS), where the enzymatic reactions and structures are known, is responsible for FA biosynthesis in yeast. Essential in the yeast FAS catalytic cycle is the acyl carrier protein (ACP) that actively shuttles substrates, biosynthetic intermediates, and products from one active site to another. We resolve the S. cerevisiae FAS structure at 1.9 Å, elucidating cofactors and water networks involved in their recognition. Structural snapshots of ACP domains bound to various enzymatic domains allow the reconstruction of a full yeast FA biosynthesis cycle. The structural information suggests that each FAS functional unit could accommodate exogenous proteins to incorporate various enzymatic activities, and we show proof-of-concept experiments where ectopic proteins are used to modulate FAS product profiles.

Different Dietary Sources of Selenium Alleviate Hepatic Lipid Metabolism Disorder of Heat-Stressed Broilers by Relieving Endoplasmic Reticulum Stress

As global warming continues, the phenomenon of heat stress (HS) in broilers occurs frequently. The alleviating effect of different selenium (Se) sources on HS-induced hepatic lipid metabolism disorders in broilers remains unclear. This study compared the protective effects of four Se sources (sodium selenite; selenium yeast; selenomethionine; nano-Se) on HS-induced hepatic lipid metabolism disorder and the corresponding response of selenotranscriptome in the liver of broilers. The results showed that HS-induced liver injury and hepatic lipid metabolism disorder, which were reflected in the increased activity of serum alanine aminotransferase (ALT), the increased concentration of triacylglycerol (TG) and total cholesterol (TC), the increased activity of acetyl-CoA carboxylase (ACC), diacylglycerol O-acyltransferase (DGAT) and fatty acid synthase (FAS), and the decreased activity of hepatic lipase (HL) in the liver. The hepatic lipid metabolism disorder was accompanied by the increased mRNA expression of lipid synthesis related-genes, the decreased expression of lipidolysis-related genes, and the increased expression of endoplasmic reticulum (ER) stress biomarkers (PERK, IRE1, ATF6, GRP78). The dietary supplementation of four Se sources exhibited similar protective effects. Four Se sources increased liver Se concentration and promoted the expression of selenotranscriptome and several key selenoproteins, enhanced liver antioxidant capacity and alleviated HS-induced ER stress, and thus resisted the hepatic lipid metabolism disorders of broilers exposed to HS. In conclusion, dietary supplementation of four Se sources (0.3 mg/kg) exhibited similar protective effects on HS-induced hepatic lipid metabolism disorders of broilers, and the protective effect is connected to the relieving of ER stress.

Fatty acid- and retinol-binding protein 6 does not control worm fatty acid content in Caenorhabditis elegans but might play a role in Haemonchus contortus parasitism

BACKGROUND

Nematodes have lost the ability to synthesise necessary lipids de novo and have complementally evolved the capacity to acquire fatty acids and their derivatives from a diet or host animal. Nematode-specific fatty acid- and retinol-binding protein (FAR) family is one approach that facilitates lipid acquisition, representing an Achilles heel and potential target against roundworms of socioeconomic significance. However, little is known about their detailed functional roles in either free-living or parasitic nematodes.

METHODS

A genome-wide identification and curation were performed to screen the FAR family members of Haemonchus contortus. Their transcription patterns in worms were also analysed to identify the targets. Ligand binding assay and molecular docking were conducted to verify the fatty acid binding activities of FAR proteins of interest. RNA interference (RNAi) and heterologous expression (rescuing) experiments were designed to explore the potential roles of the selected FAR protein in nematodes. Localisation of the protein was shown in sections of paraffin-embedded worms after an immunohistochemistry (IHC) assay.

RESULTS

Here, an orthologue of far-6 in the model organism Caenorhabditis elegans (Ce-far-6) was functionally characterised in a parasitic nematode, H. contortus (Hc-far-6). It is demonstrated that knockdown of Ce-far-6 gene did not affect worm fat content, reproduction, or lifespan, but decreased worm body length at an early life stage of C. elegans. In particular, the Ce-far-6 mutant associated phenotype was completely rescued by Hc-far-6, suggesting a conserved functional role. Surprisingly, there were distinct tissue expression patterns of FAR-6 in the free-living C. elegans and parasitic H. contortus. High transcriptional level of Hc-far-6 and dominant expression of FAR-6 in the intestine of the parasitic stage of H. contortus link this gene/protein to nematode parasitism.

CONCLUSIONS

These findings substantially enhance our understanding of far genes and the associated lipid biology of this important parasitic nematode at a molecular level, and the approaches established are readily applicable to the studies of far genes in a broad range of parasites.

The Impact of Nicotine along with Oral Contraceptive Exposure on Brain Fatty Acid Metabolism in Female Rats

Smoking-derived nicotine (N) and oral contraceptive (OC) synergistically exacerbate ischemic brain damage in females, and the underlying mechanisms remain elusive. In a previous study, we showed that N + OC exposure altered brain glucose metabolism in females. Since lipid metabolism complements glycolysis, the current study aims to examine the metabolic fingerprint of fatty acids in the brain of female rats exposed to N+/-OC. Adolescent and adult Sprague-Dawley female rats were randomly (n = 8 per group) exposed to either saline or N (4.5 mg/kg) +/-OC (combined OC or placebo delivered via oral gavage) for 16-21 days. Following exposure, brain tissue was harvested for unbiased metabolomic analysis (performed by Metabolon Inc., Morrisville, NC, USA) and the metabolomic profile changes were complemented with Western blot analysis of key enzymes in the lipid pathway. Metabolomic data showed significant accumulation of fatty acids and phosphatidylcholine (PC) metabolites in the brain. Adolescent, more so than adult females, exposed to N + OC showed significant increases in carnitine-conjugated fatty acid metabolites compared to saline control animals. These changes in fatty acyl carnitines were accompanied by an increase in a subset of free fatty acids, suggesting elevated fatty acid β-oxidation in the mitochondria to meet energy demand. In support, β-hydroxybutyrate was significantly lower in N + OC exposure groups in adolescent animals, implying a complete shunting of acetyl CoA for energy production via the TCA cycle. The reported changes in fatty acids and PC metabolism due to N + OC could inhibit post-translational palmitoylation of membrane proteins and synaptic vesicle formation, respectively, thus exacerbating ischemic brain damage in female rats.

Metabolism in Cancer Stem Cells: Targets for Clinical Treatment

Cancer stem cells (CSCs) have high tumorigenicity, high metastasis and high resistance to treatment. They are the key factors for the growth, metastasis and drug resistance of malignant tumors, and are also the important reason for the occurrence and recurrence of tumors. Metabolic reprogramming refers to the metabolic changes that occur when tumor cells provide sufficient energy and nutrients for themselves. Metabolic reprogramming plays an important role in regulating the growth and activity of cancer cells and cancer stem cells. In addition, the immune cells or stromal cells in the tumor microenvironment (TME) will change due to the metabolic reprogramming of cancer cells. Summarizing the characteristics and molecular mechanisms of metabolic reprogramming of cancer stem cells will provide new ideas for the comprehensive treatment of malignant tumors. In this review, we summarized the changes of the main metabolic pathways in cancer cells and cancer stem cells.