Dysregulation Of Fatty Acid Metabolism Research Articles

Structure based exploration of mitochondrial alpha carbonic anhydrase inhibitors as potential leads for anti-obesity drug development.

Obesity has emerged as a major health challenge globally in the last two decades. Dysregulated fatty acid metabolism and de novo lipogenesis are prime causes for obesity development which ultimately trigger other co-morbid pathological conditions thereby risking life longevity. Fatty acid metabolism and de novo lipogenesis involve several biochemical steps both in cytosol and mitochondria. Reportedly, the high catalytically active mitochondrial carbonic anhydrases (CAVA/CAVB) regulate the intercellular depot of bicarbonate ions and catalyze the rapid carboxylation of pyruvate and acetyl-co-A to acetyl-co-A and malonate respectively, which are the precursors of fatty acid synthesis and lipogenesis. Several in vitro and in vivo investigations indicate inhibition of mitochondrial carbonic anhydrase isoforms interfere in the functioning of pyruvate, fatty acid and succinate pathways. Targeting of mitochondrial carbonic anhydrase isoforms (CAVA/CAVB) could thereby modulate gluconeogenetic as well as lipogenetic pathways and pave way for designing of novel leads in the development pipeline of anti-obesity medications. The present review unveils a diverse chemical space including synthetic sulphonamides, sulphamates, sulfamides and many natural bioactive molecules which selectively inhibit the mitochondrial isoform CAVA/CAVB with an emphasis on major state-of-art drug design strategies. More than 60% similarity in the structural framework of the carbonic anhydrase isoforms has converged the drug design methods towards the development of isoform selective chemotypes. While the benzene sulphonamide derivatives selectively inhibit CAVA/CAVB in low nanomolar ranges depending on the substitutions on the phenyl ring, the sulpamates and sulpamides potently inhibit CAVB. The virtual screening and drug repurposing methods have also explored many non-sulphonamide chemical scaffolds which can potently inhibit CAVA. The review could pave way for the development of novel and effective anti-obesity drugs which can modulate the energy metabolism.

Landscape of the Lumbar Cartilaginous End Plate Microbiota and Metabolites in Patients with Modic Changes.

Modic changes (MCs), vertebral end plate and bone marrow damage observed by magnetic resonance imaging, are an independent risk factor for low back pain. The compositions of and interaction between microbiota and metabolites in the lumbar cartilaginous end plates (LCEPs) of patients with MCs have not been identified. Patients with lumbar disc degeneration who were undergoing lumbar spinal fusion surgery were recruited between April 2020 and April 2021. LCEPs were collected for 16S rRNA sequencing and liquid chromatography-mass spectrometry (LC/MS)-based targeted metabolomic profiling. Of the 54 patients recruited, 24 had no MCs and 30 had changes classified as Modic type 2 or 3. The primary goal was to identify specific genera of microbiota associated with MCs, and secondary goals included investigating differences in metabolites between patients with and without MCs and exploring the correlation between these metabolites and microorganisms. Investigation of the microbiota community structure revealed that both alpha diversity and beta diversity were significantly different between patients with and without MCs, and the abundances of 26 genera were significantly different between these 2 groups. Metabolomic analysis revealed that 26 metabolites were significantly different between the 2 groups. The unsaturated fatty acid pathway was found to be the main pathway related to MCs. Multiomic correlation analysis suggested that Caulobacteraceae (unclassified) and Mycobacterium, Clostridium, Blautia, and Bifidobacterium at the genus level were linked to dysregulation of fatty acid metabolism, contributing to the pathogenesis of MCs. Our study represents a foundational effort to examine the landscape of the microbiota and metabolites in patients with MCs, informing future studies on the pathogenesis of and targeted therapy for MCs. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Acyl-CoA Synthetase Medium-Chain Family Member 5–Mediated Fatty Acid Metabolism Dysregulation Promotes the Progression of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, with high incidence and mortality worldwide. Despite diagnostic and therapeutic advancements, HCC remains poorly responsive to treatment with a poor prognosis. Understanding the molecular mechanisms driving HCC is crucial for developing effective therapies. Emerging evidence indicates that dysregulated fatty acid metabolism contributes to HCC. Acyl-CoA medium-chain synthetase 5 (ACSM5), involved in fatty acid metabolism, is downregulated in HCC, however, its role is not well understood. In the study, we analyzed ACSM5 expression in HCC patient samples and cell lines. Using newly established ACSM5-overexpressing HCC cell lines, Huh7-ACSM5 and Hepa1-6-ACSM5, we investigated the effects and regulatory mechanisms of ACSM5. Our results showed that ACSM5 was significantly downregulated in HCC tumor tissues compared to non-tumor tissues. ACSM5 expression was regulated by DNA methylation, with a DNMT1 inhibitor effectively increasing ACSM5 expression and reducing promoter region methylation. Overexpression of ACSM5 in Huh7 cells reduced fatty acid accumulation, decreased cell proliferation, migration, and invasion in vitro, and inhibited tumor growth in mouse xenografts. Furthermore, ACSM5 overexpression also decreased STAT3 phosphorylation, subsequently affecting downstream cytokine TGFB and FGF12 mRNA levels. Our findings suggest that ACSM5 downregulation contributes to HCC progression, providing insights into its oncogenic role and highlighting its potential as a biomarker and therapeutic target for HCC.

Mitochondrial ACSS1-K635 acetylation knock-in mice exhibit altered metabolism, cell senescence, and nonalcoholic fatty liver disease.

Acetyl-CoA synthetase short-chain family member 1 (ACSS1) uses acetate to generate mitochondrial acetyl-CoA and is regulated by deacetylation by sirtuin 3. We generated an ACSS1-acetylation (Ac) mimic mouse, where lysine-635 was mutated to glutamine (K635Q). Male Acss1K635Q/K635Q mice were smaller with higher metabolic rate and blood acetate and decreased liver/serum ATP and lactate levels. After a 48-hour fast, Acss1K635Q/K635Q mice presented hypothermia and liver aberrations, including enlargement, discoloration, lipid droplet accumulation, and microsteatosis, consistent with nonalcoholic fatty liver disease (NAFLD). RNA sequencing analysis suggested dysregulation of fatty acid metabolism, cellular senescence, and hepatic steatosis networks, consistent with NAFLD. Fasted Acss1K635Q/K635Q mouse livers showed increased fatty acid synthase (FASN) and stearoyl-CoA desaturase 1 (SCD1), both associated with NAFLD, and increased carbohydrate response element-binding protein binding to Fasn and Scd1 enhancer regions. Last, liver lipidomics showed elevated ceramide, lysophosphatidylethanolamine, and lysophosphatidylcholine, all associated with NAFLD. Thus, we propose that ACSS1-K635-Ac dysregulation leads to aberrant lipid metabolism, cellular senescence, and NAFLD.

Computational drug repositioning identifies niclosamide and tribromsalan as inhibitors of Mycobacterium tuberculosis and Mycobacterium abscessus

Tuberculosis (TB) is still a major global health challenge, killing over 1.5 million people each year, and hence, there is a need to identify and develop novel treatments for Mycobacterium tuberculosis (M. tuberculosis). The prevalence of infections caused by nontuberculous mycobacteria (NTM) is also increasing and has overtaken TB cases in the United States and much of the developed world. Mycobacterium abscessus (M. abscessus) is one of the most frequently encountered NTM and is difficult to treat. We describe the use of drug-disease association using a semantic knowledge graph approach combined with machine learning models that has enabled the identification of several molecules for testing anti-mycobacterial activity. We established that niclosamide (M. tuberculosis IC90 2.95 μM; M. abscessus IC90 59.1 μM) and tribromsalan (M. tuberculosis IC90 76.92 μM; M. abscessus IC90 147.4 μM) inhibit M. tuberculosis and M. abscessus in vitro. To investigate the mode of action, we determined the transcriptional response of M. tuberculosis and M. abscessus to both compounds in axenic log phase, demonstrating a broad effect on gene expression that differed from known M. tuberculosis inhibitors. Both compounds elicited transcriptional responses indicative of respiratory pathway stress and the dysregulation of fatty acid metabolism.

Dysregulated lipid metabolism is associated with kidney allograft fibrosis

BackgroundInterstitial fibrosis and tubular atrophy (IF/TA), a histologic feature of kidney allograft destruction, is linked to decreased allograft survival. The role of lipid metabolism is well-acknowledged in the area of chronic kidney diseases; however, its role in kidney allograft fibrosis is still unclarified. In this study, how lipid metabolism contributes to kidney allografts fibrosis was examined.MethodsA comprehensive bioinformatic comparison between IF/TA and normal kidney allograft in the Gene Expression Omnibus (GEO) database was conducted. Further validations through transcriptome profiling or pathological staining of human recipient biopsy samples and in rat models of kidney transplantation were performed. Additionally, the effects of enhanced lipid metabolism on changes in the fibrotic phenotype induced by TGF-β1 were examined in HK-2 cell.ResultsIn-depth analysis of the GEO dataset revealed a notable downregulation of lipid metabolism pathways in human kidney allografts with IF/TA. This decrease was associated with increased level of allograft rejection, inflammatory responses, and epithelial mesenchymal transition (EMT). Pathway enrichment analysis showed the downregulation in mitochondrial LC-fatty acid beta-oxidation, fatty acid beta-oxidation (FAO), and fatty acid biosynthesis. Dysregulated fatty acid metabolism was also observed in biopsy samples from human kidney transplants and in fibrotic rat kidney allografts. Notably, the areas affected by IF/TA had increased immune cell infiltration, during which increased EMT biomarkers and reduced CPT1A expression, a key FAO enzyme, were shown by immunohistochemistry. Moreover, under TGF-β1 induction, activating CPT1A with the compound C75 effectively inhibited migration and EMT process in HK-2 cells.ConclusionsThis study reveal a critical correlation between dysregulated lipid metabolism and kidney allograft fibrosis. Enhancing lipid metabolism with CPT1A agonists could be a therapeutic approach to mitigate kidney allografts fibrosis.

A novel gene signature related to fatty acid metabolism predicts prognosis, immune landscape, and drug sensitivity in early-stage lung squamous cell carcinoma.

Dysregulation of fatty acid metabolism (FAM) represents a significant metabolic alteration in tumorigenesis. However, the role of FAM-related genes (FAMRGs) in early-stage lung squamous cell carcinoma (LUSC) remains incompletely understood. A series of bioinformatic analyses and machine learning strategies were performed to construct a FAMRGs-based signature to predict prognosis and guide personalized treatment for early-stage LUSC patients. FAMRGs were screened through the Kyoto Encyclopedia of Genes and Genomes (KEGG) database and the Molecular Signature Database (MSigDB). Prognosis FAMRGs were identified using univariate Cox regression, and unsupervised clustering analysis facilitated the division of the cohort into different clusters. The least absolute shrinkage and selection operator (LASSO)-Cox regression and multivariate regression analysis were employed to develop a FAMRGs-based signature for predicting overall survival (OS). A nomogram was subsequently constructed to facilitate risk assessment for individual patients. Comprehensive analyses of metabolic pathways, immune infiltration, immunomodulators, and potentially applicable drugs were conducted across different FAMRGs-related risk groups. The FAMRGs-based signature, comprising nine genes (ACOT11, APOH, BMX, CYP2R1, DPEP3, FABP6, FADS2, GLYATL2, and THRSP), demonstrated robust predictive capabilities for prognosis in The Cancer Genome Atlas (TCGA)-LUSC dataset and validated across six independent Gene Expression Omnibus (GEO)-LUSC datasets. Notably, the FAMRGs-base signature exhibited superior prognostic capacity and accurate survival prediction compared to conventional clinicopathological features. Furthermore, the signature was closely associated with immune cell infiltration, human leukocyte antigen (HLA) genes, and immune checkpoint genes expression. Additionally, the signature demonstrated potential sensitivity to chemo-/target-therapy. The FAMRGs-based signature demonstrated superior sensitivity in predicting the prognosis of early-stage LUSC. Detecting FAMRGs may provide predictive targets for the development of clinical treatment strategies.

Association between polyunsaturated fatty acids in adipose tissue and mortality of colorectal cancer patients

IntroductionNutritional intake and dysregulation of fatty acid metabolism play a role in the progression of various tumors, but the consumption of fatty acids is difficult to assess accurately with dietary questionnaires. Biomarkers can objectively assess intake, storage and bioavailability. ObjectiveWe studied the association between the polyunsaturated fatty acid (PUFA) composition of abdominal subcutaneous adipose tissue (good indicator of dietary intake over 2–3 years) and all-cause mortality. MethodsIn the multicenter AGARIC study, samples from 203 patients with colorectal cancer (CRC) undergoing curative surgery, were harvested from subcutaneous adipose tissue, which were then analyzed for PUFA composition. ResultsAfter a median follow-up of 45 months, 76 patients died. These patients were more often men (72.4% versus 57.5%, P = 0.04), diabetic (32.9% versus 13.4%, P = 0.001), old (median: 74.5 versus 66.6 years, P < 0.001) and with high alcohol consumption (47.4% versus 30.7%, P = 0.005). An increased risk of death was observed with higher levels of 20:2 ω-6 (hazard ratiotertile3 vstertile1 (HRT3vsT1) 2.12; 95% confidence interval (CI) 1.01–4.42; p-trend = 0.04), 22:4 ω-6 (HRT3vsT1 = 3.52; 95% CI = 1.51–8.17; p-trend = 0.005), and 22:5 ω-6 (HRT3vsT1 = 3.50; 95% CI = 1.56–7.87; p-trend = 0.002). Conversely, the risk of death seemed lower when higher concentrations of 18:3 ω-6 (HRT3vsT1 = 0.52; 95% CI = 0.27–0.99; p-trend = 0.04) and the essential fatty acid, α-linolenic acid 18:3 ω-3 (HRT3vsT1 = 0.47; 95% CI = 0.24–0.93; p-trend = 0.03) were observed. ConclusionThe risk of death was increased in CRC patients with higher concentrations of certain ω-6 PUFAs and lower concentrations of α-linolenic acid in their subcutaneous adipose tissue. These results reflect dietary habits and altered fatty acid metabolism. Our exploratory results warrant confirmation in larger studies with further exploration of the mechanisms involved.

Identification and validation of novel prognostic fatty acid metabolic gene signatures in colon adenocarcinoma through systematic approaches.

Colorectal cancer (CRC) belongs to the class of significantly malignant tumors found in humans. Recently, dysregulated fatty acid metabolism (FAM) has been a topic of attention due to its modulation in cancer, specifically CRC. However, the regulatory FAM pathways in CRC require comprehensive elucidation. The clinical and gene expression data of 175 fatty acid metabolic genes (FAMGs) linked with colon adenocarcinoma (COAD) and normal cornerstone genes were gathered through The Cancer Genome Atlas (TCGA)-COAD corroborating with the Molecular Signature Database v7.2 (MSigDB). Initially, crucial prognostic genes were selected by uni- and multi-variate Cox proportional regression analyses; then, depending upon these identified signature genes and clinical variables, a nomogram was generated. Lastly, to assess tumor immune characteristics, concomitant evaluation of tumor immune evasion/risk scoring were elucidated. A 8-gene signature, including ACBD4, ACOX1, CD36, CPT2, ELOVL3, ELOVL6, ENO3, and SUCLG2, was generated, and depending upon this, CRC patients were categorized within high-risk (H-R) and low-risk (L-R) cohorts. Furthermore, risk and age-based nomograms indicated moderate discrimination and good calibration. The data confirmed that the 8-gene model efficiently predicted CRC patients' prognosis. Moreover, according to the conjoint analysis of tumor immune evasion and the risk scorings, the H-R cohort had an immunosuppressive tumor microenvironment, which caused a substandard prognosis. This investigation established a FAMGs-based prognostic model with substantially high predictive value, providing the possibility for improved individualized treatment for CRC individuals.

Glycerolipid Metabolism Via the MGA-MYC-NME1-PGP Axis As a Key Regulator of Oxidative Phosphorylation in Richter's Transformation

Despite advances in targeted therapies for chronic lymphocytic leukemia (CLL), Richter's transformation (RT) remains a clinical challenge. RT is an aggressive shift from CLL to lymphoma, associated with metabolic changes and aberrations in the MYC transcriptional network. Genomic analysis of paired CLL and RT cases revealed recurrent mutations or deletions in the MYC suppressor Max-gene-associated (MGA) increase from 5% (CLL) to 30% (RT) cases, highlighting its critical yet unexplored role as a driver event. We recently developed a murine RT model using B cell-restricted in vitro editing of LSK progenitors from Cd19Cre-Cas9-del(13q)-Sf3b1 ( Sf3b1-K700E) with Mga-targeting sgRNAs. This murine model demonstrated upregulation of Mga targets Myc and Nme1 (nucleoside diphosphate kinase), a distinct OXPHOS-based transcription signature, increased oxygen consumption rate, elevated ROS levels, suggesting a significant link between the Mga-Myc-Nme1 axis and OXPHOS dysregulation in RT. Given the crucial role of metabolic reprogramming in cancer, we seek to understand the molecular mechanisms of metabolites driving OXPHOS and accelerating CLL transformation. Unraveling these processes could revolutionize therapeutic approaches for managing RT in clinical settings. To identify metabolites driving dysregulated OXPHOS in RT, we first conducted paired RNA-seq and unlabeled metabolomic profiling on normal and RT mouse splenic B cells (n=3/group). To translate our discovery from the murine RT model to human disease, we performed metabolomic profiling using MEC1 and Nalm6 cell lines with MGA deletion. Our metabolomic analysis of murine RT cells revealed 44 upregulated metabolites, including TCA cycle substrates (glutamine fold change (FC)=9.6, p=0.001;asparagine FC= 4.0, p=0.006), fatty-acid intermediates (glycerol-3P FC=11.7, p=0.003; carnitine FC=4.3, p=0.02; palmitate FC= 4.1, p= 0.08), and glycolysis intermediates (3-phosphoglycerate FC= 4.0, p=0.03; UDP-glucose FC=12.7, p=0.02; glycine FC=4.7, p=0.03). Moreover, integrated metabolite analysis (MetaboAnalyst v5.0) identified 63 common upregulated metabolites in MGA KO (knockout) human cell lines and murine RT, enriching glycerolipid, and fatty acid oxidation, associated pathways, indicating a potential role for MGA deletion in driving dysregulated fatty acid metabolism. Pathway enrichment analysis using integrated RNA-seq and metabolite analyses showed that the glycerolipid pathway was one of the most enriched pathways among mouse RT and B-cell lines (Nalm6 and MEC1) with MGA KO. Additionally, two key fatty-acid enzymes, fatty acid synthetase (FASN) and phosphoglycerate phosphatase (PGP), displayed significant mRNA and protein changes, as validated by qPCR and immunoblotting. Furthermore, elevated lipid accumulation and increased free glycerol were confirmed based on lipi-green flow cytometry and glycerol-bioluminescent assays, suggesting an important role of glycerolipid metabolism in MGA KO-associated OXPHOS. PGP, a glycerol-3-phosphatase, regulates glycerol-3-P levels, a key intermediate in glucose, lipid, and energy metabolism. Overexpression of MYC and NME1 increases PGP levels in B-cell lines (MEC1, Nalm6, and Jeko), confirming PGP as a direct target of the MGA-MYC-NME1 axis. To determine the role of PGP in MGA KO (knock-out) cells, we used CRISPR/Cas9 to KO PGP in MEC1, Nalm6, and JeKo cell lines. KO of PGP decreased cell growth and reduced OXPHOS compared to controls based on CCK8 absorbance and Seahorse Mitostress assays respectively. Moreover, PGP KO downregulated the mTOR (p4E-BP1) pathway, emphasizing the significance of dysregulated glycerol and fatty acid metabolism in CLL to RT-driven OXPHOS. Our study reveals key metabolites driving RT and highlights the crucial role of the MGA-MYC-NME1-PGP axis in regulating OXPHOS in Mga KO RT cells. Our results thus suggest targeting glycerolipid metabolism and related pathways may offer effective strategies to conquer RT

Identifying Serum Metabolomic Markers Associated with Skin Disease Activity in Patients with Psoriatic Arthritis.

Psoriatic arthritis (PsA) is a chronic, systemic, immune-mediated inflammatory disease causing cutaneous and musculoskeletal inflammation that affects 25% of patients with psoriasis. Current methods for evaluating PsA disease activity are not accurate enough for precision medicine. A metabolomics-based approach can elucidate psoriatic disease pathogenesis, providing potential objective biomarkers. With the hypothesis that serum metabolites are associated with skin disease activity, we aimed to identify serum metabolites associated with skin activity in PsA patients. We obtained serum samples from patients with PsA (n = 150) who were classified into mild, moderate and high disease activity groups based on the Psoriasis Area Severity Index. We used solid-phase microextraction (SPME) for sample preparation, followed by data acquisition via an untargeted liquid chromatography-mass spectrometry (LC-MS) approach. Disease activity levels were predicted using identified metabolites and machine learning algorithms. Some metabolites tentatively identified include eicosanoids with anti- or pro-inflammatory properties, like 12-Hydroxyeicosatetraenoic acid, which was previously implicated in joint disease activity in PsA. Other metabolites of interest were associated with dysregulation of fatty acid metabolism and belonged to classes such as bile acids, oxidized phospholipids, and long-chain fatty acids. We have identified potential metabolites associated with skin disease activity in PsA patients.

Abstract P3052: RNA Binding Protein Csdc2 Is Required For Metabolic And Cardiac Stress Responses

Post transcriptional gene regulation (PTGR) mediated by networks of microRNAs and RNA binding proteins (RBP's) controls mRNA processing, localization, and expression. Hundreds of microRNAs and RBPs are expressed in heart, and much remains unknown regarding PTGR’s influence on cardiovascular health and disease. Through bioinformatic analyses, we identified Csdc2 as a cardiac-enriched RBP that is consistently downregulated in failing hearts. Csdc2’s paralog, Carshp1, controls metabolic gene expression in liver through PPARα. We hypothesize that Csdc2 plays key roles in cardio-metabolic stress. To address this, we first assessed mRNA-seq changes in neonatal rat cardiomyocytes after overexpression and knockdown of Csdc2. Pathway analyses revealed reciprocal dysregulation of fatty acid metabolism, ion channels, and cytoskeletal and sarcomere genes. We generated constitutive Csdc2-KO mice, which are viable with no overt baseline phenotypes. Cardiac phenotyping revealed that Csdc2-KO mice have slightly decreased PR interval (~10%, p=1.3e-4, n=16-22) but maintain normal cardiac structure/function. To assess Csdc2’s potential role in metabolic stress, mice were fed a high-fat-diet for 10 weeks and monitored for lean/fat mass and insulin/glucose tolerances. Csdc2-KO mice gained 20% more weight than wildtype littermates (p=0.04, n=13-18) and developed insulin resistance (p&lt;0.01). To test if Csdc2 loss influences cardiac stress, normal chow cohorts were subjected to microsurgery-induced myocardial infarction (MI); Csdc2-KO mice showed ~2-fold increase in mortality within two weeks (70% versus 40% for wildtype). Echocardiographic measures support that Csdc2-KO hearts have larger infarcts, dilation without compensatory remodeling and worse systolic function. Together, these data highlight Csdc2 as a disease-relevant RBP that controls cardio-metabolic stress responses.

#3566 ACSS2 AGGRAVATES RENAL TUBULAR INFLAMMATION BY INDUCING THE DYSREGULATION OF FATTY ACID METABOLISM AND MITOCHONDRIAL OXIDATIVE STRESS IN DIABETIC MICE

Abstract Background and Aims Treatment options for diabetic nephropathy (DN) are currently limited. Chronic renal inflammation has been widely recognized as a major promoter of DN. The tubular epithelial cells are a major source of IL-1β in diabetic db/db mice. Inhibition of Acetyl CoA Synthase 2 (ACSS2) has been shown to promote high-fat diet-induced liver injuries, but the underlying mechanism of action of ACSS2 in diabetic renal injuries has not been elucidated. Method Streptozotocin (STZ) was intraperitoneally injected to establish the diabetic mouse model. We investigated the effects of ACSS2 on diabetes-induced renal tubular injury in transgenic mice with global acss2 knockout (acss2−/−). PAS staining was carried out to evaluate pathological injury of kidneys in mice. The renal tissue immunostaining was conducted to detect IL-1β expression and macrophage distribution in kidney tissues of mice. HK-2 cell culture model was achieved by high glucose stimulation in vitro. Real-time PCR analysis was applied to evaluate gene expression of inflammatory factors IL-1β, TNF-α, and MCP-1. Western Blot and immunofluorescence staining were conducted to the activation of the NLRP3 pathway and mitochondrial reactive oxygen species (ROS). Results ACSS2 was upregulated in STZ-induced diabetic renal tubular cells, which is significantly co-expressed in IL-1β-positive renal tubular cells of STZ-induced diabetic mice. The mice with acss2−/- exhibited decreased renal tubular inflammation and inhibited NOD-like receptor protein 3 (NLRP3) inflammasome activation as evidenced by elevated protein levels of NLRP3 and cleaved caspase-1 when compared with diabetic wild-type mice. The selective inhibition of ACSS2 protected HK-2 cells in vitro when exposed to a high glucose environment by downregulating NLRP3 inflammasome and ameliorating mitochondrial oxidative stress. Mechanistically, we showed that mitochondrial dysfunction preceded inflammatory response in vitro. The elimination of mitochondrial ROS using mitochondria-targeted antioxidants (mito-TEMPO) reversed HG-mediated NLRP3 inflammation activation in HK-2 cells, which recapitalized the phenotype observed in acss2-/- mice. We also found that cytoplasm ACSS2, which was increased after HG stimulation, induced fatty acid synthase (FASN) mediated overproduction of free fatty acid. Downregulating FASN using FASN-small interfering RNA restored mitochondrial function, and suppressed NLRP3 inflammasome activation. Conclusion In conclusion, diabetes-induced ACSS2 upregulation led to subsequent FASN-mediated dysregulation of fatty acid metabolism and mitochondrial ROS overproduction, eventually causing NLRP3 inflammasome activation and renal inflammation. Therefore, our findings established the role of ACSS2 in diabetes-induced inflammation of renal tubular epithelium and unveiled the underlying mechanism of its action. ACSS2 appears as a promising target for treating diabetic renal tubular epithelial inflammation.

Integration analysis based on fatty acid metabolism robustly predicts prognosis, dissecting immunity microenvironment and aiding immunotherapy for soft tissue sarcoma.

Background: Soft tissue sarcoma (STS) is a highly malignant tumor with a dismal prognosis. Presently, the dysregulation of fatty acid metabolism has received increasing attention in tumor research, but fewer reports are relevant to STS. Methods: Based on fatty acid metabolism-related genes (FRGs), a novel risk score for STS was developed utilizing univariate analysis and least absolute shrinkage selection operator (LASSO) Cox regression analyses in the STS cohort, which were further validated using the external validation cohort from other databases. Furthermore, independent prognostic analysis, C-index, ROC curves, and nomogram were carried out to investigate the predictive performance of fatty acid-related risk scores. We also analysed the differences in enrichment pathways, the immune microenvironment, gene mutations, and immunotherapy response between the two distinct fatty acid score groups. Moreover, the real-time quantitative polymerase chain reaction (RT-qPCR) was used to further verify the expression of FRGs in STS. Results: A total of 153 FRGs were retrieved in our study. Next, a novel fatty acid metabolism-related risk score (FAS) was constructed based on 18 FRGs. The predictive performance of FAS was also verified in external cohorts. In addition, the independent analysis, C-index, ROC curve, and nomograph also revealed that FAS could serve as an independent prognostic factor for the STS patients. Meanwhile, our results demonstrated that the STS cohort in two distinct FAS groups had different copy number variations, immune cell infiltration, and immunotherapy responses. Finally, the in vitro validation results demonstrated that several FRGs included in the FAS exhibited abnormal expression in STS. Conclusion: Altogether, our work comprehensively and systematically clarifies fatty acid metabolism's potential roles and clinical significance in STS. The novel individualized score based on fatty acid metabolism may be provided as a potential marker and treatment strategy in STS.

A Novel Fatty Acid Metabolism-Associated Risk Model for Prognosis Prediction in Acute Myeloid Leukaemia.

Acute myeloid leukaemia (AML) is the most common acute leukaemia in adults, with an unfavourable outcome and a high rate of recurrence due to its heterogeneity. Dysregulation of fatty acid metabolism plays a crucial role in the development of several tumours. However, the value of fatty acid metabolism (FAM) in the progression of AML remains unclear. In this study, we obtained RNA sequencing and corresponding clinicopathological information from the TCGA and GEO databases. Univariate Cox regression analysis and subsequent LASSO Cox regression analysis were utilized to identify prognostic FAM-related genes and develop a potential prognostic risk model. Kaplan-Meier analysis was used for prognostic significances. We also performed ROC curve to illustrate that the risk model in prognostic prediction has good performance. Moreover, significant differences in immune infiltration landscape were found between high-risk and low-risk groups using ESTIMATE and CIBERSOT algorithms. In the end, differential expressed genes (DEGs) were analyzed by gene set enrichment analysis (GSEA) to preliminarily explore the possible signaling pathways related to the prognosis of FAM and AML. The results of our study may provide potential prognostic biomarkers and therapeutic targets for AML patients, which is conducive to individualized precision therapy.

Associations Among Microvascular Dysfunction, Fatty Acid Metabolism, and Diabetes

Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels resulting from impaired insulin secretion or insulin resistance. Diabetes poses a major global health concern, because of its increasing prevalence and substantial morbidity and mortality. This review explores the relationships between altered fatty acid metabolism and microcirculatory impairments in diabetes. Dysregulation of fatty acid metabolism in diabetes leads to changes in fatty acid profiles, abnormal lipid accumulation, and increased oxidative stress. These changes contribute to microvascular dysfunction through mechanisms such as endothelial dysfunction, impaired nitric oxide availability, inflammation, and oxidative damage. Understanding this intricate interplay is essential for identifying novel therapeutic strategies to alleviate vascular complications in diabetes. By targeting specific pathways involved in fatty acid metabolism and microvascular dysfunction, interventions can be developed to improve patient outcomes. This review is aimed at contributing to future research and the development of effective strategies for preventing and managing diabetes-associated microcirculatory impairments, to ultimately enhance the quality of life for people living with diabetes.

NAFLD and HBV interplay - related mechanisms underlying liver disease progression.

Non-alcoholic fatty liver disease (NAFLD) and Hepatitis B virus infection (HBV) constitute common chronic liver diseases with worldwide distribution. NAFLD burden is expected to grow in the coming decade, especially in western countries, considering the increased incidence of diabetes and obesity. Despite the organized HBV vaccinations and use of anti-viral therapies globally, HBV infection remains endemic and challenging public health issue. As both NAFLD and HBV have been associated with the development of progressive fibrosis, cirrhosis and hepatocellular carcinoma (HCC), the co-occurrence of both diseases has gained great research and clinical interest. The causative relationship between NAFLD and HBV infection has not been elucidated so far. Dysregulated fatty acid metabolism and lipotoxicity in NAFLD disease seems to initiate activation of signaling pathways that enhance pro-inflammatory responses and disrupt hepatocyte cell homeostasis, promoting progression of NAFLD disease to NASH, fibrosis and HCC and can affect HBV replication and immune encountering of HBV virus, which may further have impact on liver disease progression. Chronic HBV infection is suggested to have an influence on metabolic changes, which could lead to NAFLD development and the HBV-induced inflammatory responses and molecular pathways may constitute an aggravating factor in hepatic steatosis development. The observed altered immune homeostasis in both HBV infection and NAFLD could be associated with progression to HCC development. Elucidation of the possible mechanisms beyond HBV chronic infection and NAFLD diseases, which could lead to advanced liver disease or increase the risk for severe complications, in the case of HBV-NAFLD co-existence is of high clinical significance in the context of designing effective therapeutic targets.

New Insights into Ferroptosis Initiating Therapies (FIT) by Targeting the Rewired Lipid Metabolism in Ovarian Cancer Peritoneal Metastases

Ovarian cancer is one of the most lethal gynecological cancers worldwide. The poor prognosis of this malignancy is substantially attributed to the inadequate symptomatic biomarkers for early diagnosis and effective remedies to cure the disease against chemoresistance and metastasis. Ovarian cancer metastasis is often relatively passive, and the single clusters of ovarian cancer cells detached from the primary ovarian tumor are transcoelomic spread by the peritoneal fluid throughout the peritoneum cavity and omentum. Our earlier studies revealed that lipid-enriched ascitic/omental microenvironment enforced metastatic ovarian cancer cells to undertake metabolic reprogramming and utilize free fatty acids as the main energy source for tumor progression and aggression. Intriguingly, cell susceptibility to ferroptosis has been tightly correlated with the dysregulated fatty acid metabolism (FAM), and enhanced iron uptake as the prominent features of ferroptosis are attributed to the strengthened lipid peroxidation and aberrant iron accumulation, suggesting that ferroptosis induction is a targetable vulnerability to prevent cancer metastasis. Therefore, the standpoints about tackling altered FAM in combination with ferroptosis initiation as a dual-targeted therapy against advanced ovarian cancer were highlighted herein. Furthermore, a discussion on the prospect and challenge of inducing ferroptosis as an innovative therapeutic approach for reversing remedial resistance in cancer interventions was included. It is hoped this proof-of-concept review will indicate appropriate directions for speeding up the translational application of ferroptosis-inducing compounds (FINs) to improve the efficacy of ovarian cancer treatment.

Dysregulated hepatic lipid metabolism and gut microbiota associated with early-stage NAFLD in ASPP2-deficiency mice

Growing evidence indicates that lipid metabolism disorders and gut microbiota dysbiosis were related to the progression of non-alcoholic fatty liver disease (NAFLD). Apoptosis-stimulating p53 protein 2 (ASPP2) has been reported to protect against hepatocyte injury by regulating the lipid metabolism, but the mechanisms remain largely unknown. In this study, we investigate the effect of ASPP2 deficiency on NAFLD, lipid metabolism and gut microbiota using ASPP2 globally heterozygous knockout (ASPP2+/-) mice. ASPP2+/- Balb/c mice were fed with methionine and choline deficient diet for 3, 10 and 40 day to induce an early and later-stage of NAFLD, respectively. Fresh fecal samples were collected and followed by 16S rRNA sequencing. HPLC-MRM relative quantification analysis was used to identify changes in hepatic lipid profiles. The expression level of innate immunity-, lipid metabolism- and intestinal permeability-related genes were determined. A spearman's rank correlation analysis was performed to identify possible correlation between hepatic medium and long-chain fatty acid and gut microbiota in ASPP2-deficiency mice. Compared with the WT control, ASPP2-deficiency mice developed moderate steatosis at day 10 and severe steatosis at day 40. The levels of hepatic long chain omega-3 fatty acid, eicosapentaenoic (EPA, 20:5 n-3) and docosahexaenoic (DHA, 22:6 n-3), were decreased at day 10 and increased at day 40 in ASPP+/- mice. Fecal microbiota analysis showed significantly increased alpha and beta diversity, as well as the composition of gut microbiota at the phylum, class, order, family, genus, species levels in ASPP2+/- mice. Moreover, ASPP-deficiency mice exhibited impaired intestinal barrier function, reduced expression of genes associated with chemical barrier (REG3B, REG3G, Lysozyme and IAP), and increased expression of innate immune components (TLR4 and TLR2). Furthermore, correlation analysis between gut microbiota and fatty acids revealed that EPA was significantly negatively correlated with Bifidobacterium family. Our findings suggested that ASPP2-deficiency promotes the progression of NAFLD, alterations in fatty acid metabolism and gut microbiota dysbiosis. The long chain fatty acid EPA was significantly negatively correlated with Bifidobacterial abundance, which is a specific feature of NAFLD in ASPP2-deficiency mice. Totally, the results provide evidence for a mechanism of ASPP2 on dysregulation of fatty acid metabolism and gut microbiota dysbiosis.

Identification and analysis of dysregulated fatty acid metabolism genes in breast cancer subtypes.

Breast cancer is one of the most aggressive and lethal types of transformation among women. An anomaly of normal fatty acid metabolism is acknowledged as a critical trigger for malignant transformations including breast cancer, but the prospect of targeting fatty acid metabolism for the treatment of malignancy has remained unrecognized so far. It has been observed that specific fatty acid metabolism genes are involved in the commencement and development of breast cancer. These specific genes have also been observed to be related to different isotypes/molecular subtypes of breast cancer. The main purpose of this study was to scrutinize the prognostic significance, functional role, and expression pattern of fatty acid metabolism genes. In-Silico tools like TCGA BrCA, Gepia2, Ualcan Analysis, UCSC Xena, Kaplan-Meier plotter, Bc-gene EXminer, String, gene ontology, and KEGG databases, were used to assess the expression pattern of the fatty acid metabolism genes in breast cancer patients and also among the different molecular sub-types of breast cancer. Differential gene expression analysis revealed dysregulation of FABP4, FABP5, PLIN1,PLIN2, PLIN4, PLIN5, LPIN1, MGLL, PNPLA2, PNPLA7, ACSL1, and ACOX2 showing a fold change > ± 1.5. Also, most of these genes show downregulation in Ualcan analysis of different isotypes/molecular subtypes of breast cancer. The study reveals that the screened genes i.e., FABP4, FABP5, PLIN1,PLIN2, PLIN4, PLIN5, LPIN1, MGLL, PNPLA2, PNPLA7, ACSL1, and ACOX2 can be used as biomarkers that reveal poor prognosis and may serve as therapeutic targets for the treatment of breast cancer.