RESUMEN
Cholesterol metabolism reprogramming is one of the significant characteristics of hepatocellular carcinoma (HCC). Cholesterol increases the risk of epithelial-mesenchymal transition (EMT) in cancer. Sterol O-acyltransferases 1 (SOAT1) maintains the cholesterol homeostasis. However, the exact mechanistic contribution of SOAT1 to EMT in HCC remains unclear. Here we demonstrated that SOAT1 positively related to poor prognosis of HCC, EMT markers and promoted cell migration and invasion in vitro, which was mediated by the increased cholesterol in plasmalemma and cholesterol esters accumulation. Furthermore, we reported that SOAT1 disrupted cholesterol metabolism homeostasis to accelerate tumorigenesis and development in HCC xenograft and NAFLD-HCC. Also, we detected that nootkatone, a sesquiterpene ketone, inhibited EMT by targeting SOAT1 in vitro and in vivo. Collectively, our finding indicated that SOAT1 promotes EMT and contributes to hepatocarcinogenesis by increasing cholesterol esterification, which is suppressed efficiently by nootkatone. This study demonstrated that SOAT1 is a potential biomarker and therapeutic target in NAFLD-HCC and SOAT1-targeting inhibitors are expected to be the potential new therapeutic treatment for HCC.
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Carcinoma Hepatocelular , Colesterol , Transición Epitelial-Mesenquimal , Neoplasias Hepáticas , Esterol O-Aciltransferasa , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/genética , Humanos , Colesterol/metabolismo , Esterol O-Aciltransferasa/metabolismo , Esterol O-Aciltransferasa/genética , Animales , Ratones , Masculino , Ratones Desnudos , Línea Celular Tumoral , Movimiento Celular , Femenino , Ratones Endogámicos BALB C , Sesquiterpenos/farmacología , Regulación Neoplásica de la Expresión GénicaRESUMEN
OBJECTIVE: Excess cholesterol storage can induce the formation of cholesterol crystals in hepatocyte lipid droplets. Such crystals distinguish metabolic dysfunction associated steatohepatitis (MASH) from simple steatosis and may underlie its pathogenesis by causing cell damage that triggers liver inflammation. The mechanism linking cholesterol excess to its crystallization in lipid droplets is unclear. As cholesteryl esters localize to and accumulate in lipid droplets more readily than unesterified free cholesterol, we investigated whether cholesterol esterification by sterol O-acyltransferase (SOAT), also known as acyl co-A cholesterol acyltransferase (ACAT), is required for hepatocyte lipid droplet crystal formation. METHOD: Cholesterol crystals were measured in cholesterol loaded Hep3B hepatocytes, RAW264.7 macrophages, and mouse liver using polarizing light microscopy. We examined the effect of blocking SOAT activity on crystal formation and compared these results to features of cholesterol metabolism and the progression to intracellular crystal deposits. RESULTS: Cholesterol loading of Hep3B cells caused robust levels of lipid droplet localized crystal formation in a dose- and time-dependent manner. Co-treatment with SOAT inhibitors and genetic ablation of SOAT1 blocked crystal formation. SOAT inhibitor also blocked crystal formation in low density lipoprotein (LDL) treated Hep3B cells, acetylated LDL treated RAW 264.7 macrophages, and in the liver of mice genetically predisposed to hepatic cholesterol overload and in mice with cholesterol enriched diet-induced MASH. CONCLUSION: SOAT1-mediated esterification may underlie cholesterol crystals associated with MASH by concentrating it in lipid droplets. These findings imply that inhibiting hepatocyte SOAT1 may be able to alleviate cholesterol associated MASH. Moreover, that either a lipid droplet localized cholesteryl ester hydrolase is required for cholesterol crystal formation, or the crystals are composed of cholesteryl ester.
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Colesterol , Hepatocitos , Gotas Lipídicas , Esterol O-Aciltransferasa , Animales , Humanos , Masculino , Ratones , Colesterol/metabolismo , Ésteres del Colesterol/metabolismo , Cristalización , Esterificación , Hepatocitos/metabolismo , Gotas Lipídicas/metabolismo , Hígado/metabolismo , Hígado/patología , Ratones Endogámicos C57BL , Células RAW 264.7 , Esterol O-Aciltransferasa/metabolismo , Esterol O-Aciltransferasa/genéticaRESUMEN
The aim of this investigation was to evaluate the differential expression of the sterol O-acyltransferase 1 (SOAT1) protein in gallbladder cancer tissues and cells, investigate the impact of Avastin on the proliferation, migration, invasion capabilities of gallbladder cancer cells, and its potential to induce cell apoptosis. Immunohistochemical analysis of samples from 145 gallbladder cancer patients was conducted, along with analysis of SOAT1 protein, mRNA expression levels, and cholesterol content in gallbladder cancer cell lines SGC-996, NOZ, and gallbladder cancer (GBC)-SD using Western blot and q-PCR techniques. Furthermore, the effects of Avastin on the proliferation, migration, and invasion capabilities of these gallbladder cancer cell lines were studied, and its ability to induce cell apoptosis was evaluated using flow cytometry, Western blot, and immunohistochemical methods. Additionally, gene expression and pathway analysis were performed, and the synergistic therapeutic effects of Avastin combined with gemcitabine were tested in a gallbladder cancer xenograft model. The study found that SOAT1 expression was significantly upregulated in GBC tissues and positively correlated with lymph node metastasis and TNM staging. In vitro experiments demonstrated that Avastin significantly inhibited the proliferation, migration, and invasion capabilities of SGC-996 and GBC-SD cell lines and induced apoptosis. RNA sequencing analysis revealed multiple differentially expressed genes in cells treated with Avastin, primarily enriched in biological pathways such as signaling transduction, malignant tumors, and the immune system. In vivo, experiments confirmed that Avastin could effectively suppress tumor growth in a gallbladder cancer xenograft model and enhanced the treatment efficacy when used in combination with gemcitabine. Overall, these findings provide new insights and strategies for targeted therapy in gallbladder cancer.
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Neoplasias de la Vesícula Biliar , Esterol O-Aciltransferasa , Anciano , Animales , Femenino , Humanos , Masculino , Ratones , Persona de Mediana Edad , Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Neoplasias de la Vesícula Biliar/patología , Neoplasias de la Vesícula Biliar/tratamiento farmacológico , Neoplasias de la Vesícula Biliar/metabolismo , Neoplasias de la Vesícula Biliar/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Proteínas de Neoplasias/metabolismo , Proteínas de Neoplasias/genética , Esterol O-Aciltransferasa/metabolismo , Esterol O-Aciltransferasa/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Niemann-Pick disease type C1 (NPC1) is a lysosomal disorder due to impaired intracellular cholesterol transport out of the endolysosomal compartment.. Marked heterogeneity has been observed in individuals with the same NPC1 genotype, thus suggesting a significant effect of modifier genes. Prior work demonstrated that decreased SOAT1 activity decreased disease severity in an NPC1 mouse model. Thus, we hypothesized that a polymorphism associated with decreased SOAT1 expression might influence the NPC1 phenotype. Phenotyping and genomic sequencing of 117 individuals with NPC1 was performed as part of a Natural History trial. Phenotyping included determination of disease severity and disease burden. Significant clinical heterogeneity is present in individuals homozygous for the NPC1I1061T variant and in siblings. Analysis of the SOAT1 polymorphism, rs1044925 (A>C), showed a significant association of the C-allele with earlier age of neurological onset. The C-allele may be associated with a higher Annualized Severity Index Score as well as increased frequency of liver disease and seizures. A polymorphism associated with decreased expression of SOAT1 appears to be a genetic modifier of the NPC1 phenotype. This finding is consistent with prior data showing decreased phenotypic severity in Npc1-/-:Soat1-/- mice and supports efforts to investigate the potential of SOAT1 inhibitors as a potential therapy for NPC1.
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Enfermedad de Niemann-Pick Tipo C , Esterol O-Aciltransferasa , Enfermedad de Niemann-Pick Tipo C/genética , Enfermedad de Niemann-Pick Tipo C/metabolismo , Humanos , Masculino , Femenino , Esterol O-Aciltransferasa/genética , Esterol O-Aciltransferasa/metabolismo , Proteína Niemann-Pick C1 , Niño , Polimorfismo de Nucleótido Simple , Animales , Ratones , Fenotipo , Adolescente , Preescolar , Genes Modificadores , Adulto , Alelos , Índice de Severidad de la Enfermedad , Genotipo , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Adulto JovenRESUMEN
Ferroptosis, characterized by lipid peroxidation, plays a significant role in the pathogenesis of acute pancreatitis (AP). While sterol O-acyltransferase 2 (Soat2) is known for its crucial regulatory role in cholesterol homeostasis, its involvement in the development of AP remains unreported. We conducted this study to identify the pivotal role of Soat2 in AP using transcriptomic databases. Subsequently, we confirmed its alterations through both in vitro and in vivo experimental models. Furthermore, we performed intervention with the Soat2 inhibitor avasimibe to evaluate pancreatic tissue pathology and serum enzymatic levels and observe inflammatory cell infiltration through immunohistochemistry. Additionally, changes in indicators related to ferroptosis were also observed. The results showed that in the AP mouse model, the protein and mRNA levels of Soat2 were significantly increased. Following avasimibe administration, there was a decrease in serum amylase levels, reduction in pancreatic tissue pathological damage, and attenuation of inflammatory cell infiltration. Furthermore, avasimibe administration resulted in downregulation of ferroptosis-related indicators. In conclusion, our findings suggest that the Soat2 inhibitor avasimibe protects against AP in mice through inhibition of the ferroptosis.
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Células Acinares , Ferroptosis , Pancreatitis , Esterol O-Aciltransferasa , Animales , Ferroptosis/efectos de los fármacos , Pancreatitis/tratamiento farmacológico , Pancreatitis/patología , Pancreatitis/metabolismo , Células Acinares/efectos de los fármacos , Células Acinares/metabolismo , Células Acinares/patología , Masculino , Ratones , Esterol O-Aciltransferasa/antagonistas & inhibidores , Esterol O-Aciltransferasa/metabolismo , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad , Páncreas/patología , Páncreas/efectos de los fármacos , Páncreas/metabolismo , HumanosRESUMEN
We have identified the biosynthetic gene cluster (hvm) for the sterol O-acyltransferase inhibitor helvamide (1) from the genome of Aspergillus rugulosus MST-FP2007. Heterologous expression of hvm in A. nidulans produced a previously unreported analog helvamide B (5). An α-ketoglutarate-dependent oxygenase Hvm1 was shown to catalyze intramolecular cyclization of 1 to yield 5. The biosynthetic branch to the related hancockiamides and helvamides was found to be controlled by the substrate selectivity of monomodular nonribosomal peptide synthetases.
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Ácidos Cetoglutáricos , Oxigenasas , Oxigenasas/genética , Oxigenasas/metabolismo , Esterol O-Aciltransferasa/genética , Esterol O-Aciltransferasa/metabolismo , Ciclización , Familia de Multigenes , Péptido Sintasas/metabolismoRESUMEN
Recently, evidence has shown that microRNA-100-3p (miR-100-3p) has been revealed as a tumor suppressor in diverse human diseases, while its capability in lung cancer warrants further validation. In this work, we aimed to discuss the impact of sevoflurane on biological functions of lung cancer cells by modulating the miR-100-3p/sterol O-acyltransferase 1 (SOAT1) axis. Lung cancer cell lines (A549 and H460) were treated with various concentrations of sevoflurane. Cell viability, proliferation, migration, and invasion were evaluated using MTT, colony formation, wound healing, and transwell assays. Moreover, miR-100-3p and SOAT1 expressions were evaluated by reverse transcription-quantitative polymerase chain reaction in lung cancer cells. The target interaction between miR-100-3p and SOAT1 was predicted by bioinformatics analysis and verified by the dual-luciferase reporter gene assay. The findings of our work demonstrated that sevoflurane impeded the abilities on viability, proliferation, migration, and invasion of A549 and H460 cells. The expression of miR-100-3p was reduced, and SOAT1 expression was elevated in lung cancer cells. miR-100-3p targeted SOAT1. Besides, sevoflurane could lead to expressed improvement of miR-100-3p or limitation of SOAT1. Downregulation of miR-100-3p or upregulation of SOAT1 restored the suppression of sevoflurane on abilities of viability, proliferation, migration, and invasion in A549 and H460 cells. In the rescue experiment, downregulation of SOAT1 reversed the impacts of downregulation of miR-100-3p on sevoflurane on lung cancer cells. Collectively, our study provides evidence that sevoflurane restrained the proliferation and invasion in lung cancer cells by modulating the miR-100-3p/SOAT1 axis. This article provides a new idea for further study of the pathogenesis of lung cancer.
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Antineoplásicos , Neoplasias Pulmonares , Sevoflurano , Sevoflurano/farmacología , Proliferación Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , MicroARNs/metabolismo , Esterol O-Aciltransferasa/metabolismo , Línea Celular Tumoral , Células A549 , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Antineoplásicos/farmacología , Transducción de SeñalRESUMEN
Cholesterol is a key component of all mammalian cell membranes. Disruptions in cholesterol metabolism have been observed in the context of various diseases, including neurodegenerative disorders such as Alzheimer's disease (AD). The genetic and pharmacological blockade of acyl-CoA:cholesterol acyltransferase 1/sterol O-acyltransferase 1 (ACAT1/SOAT1), a cholesterol storage enzyme found on the endoplasmic reticulum (ER) and enriched at the mitochondria-associated ER membrane (MAM), has been shown to reduce amyloid pathology and rescue cognitive deficits in mouse models of AD. Additionally, blocking ACAT1/SOAT1 activity stimulates autophagy and lysosomal biogenesis; however, the exact molecular connection between the ACAT1/SOAT1 blockade and these observed benefits remain unknown. Here, using biochemical fractionation techniques, we observe cholesterol accumulation at the MAM which leads to ACAT1/SOAT1 enrichment in this domain. MAM proteomics data suggests that ACAT1/SOAT1 inhibition strengthens the ER-mitochondria connection. Confocal and electron microscopy confirms that ACAT1/SOAT1 inhibition increases the number of ER-mitochondria contact sites and strengthens this connection by shortening the distance between these two organelles. This work demonstrates how directly manipulating local cholesterol levels at the MAM can alter inter-organellar contact sites and suggests that cholesterol buildup at the MAM is the impetus behind the therapeutic benefits of ACAT1/SOAT1 inhibition.
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Enfermedad de Alzheimer , Colesterol , Animales , Ratones , Enfermedad de Alzheimer/metabolismo , Colesterol/metabolismo , Retículo Endoplásmico/metabolismo , Mamíferos/metabolismo , Mitocondrias/metabolismo , Esteroles/metabolismo , Acetil-CoA C-Aciltransferasa/metabolismo , Esterol O-Aciltransferasa/metabolismoRESUMEN
Background Alopecia areata is a chronic inflammatory skin disease. Oxidative stress may contribute to the pathogenesis of this condition. Aim To evaluate the serum oxidative stress markers and antioxidant capacity in patients with alopecia areata. Methods This cross-sectional study was performed on 40 patients with alopecia areata and 40 healthy controls. The fasting blood sugar, C-reactive protein, lipid profile, and serum oxidative markers, including advanced glycation end products and advanced oxidation protein products, were measured in this study. Also, antioxidant enzymes, including paraoxonase-1, lecithin-cholesterol acyltransferase and serum ferric-reducing antioxidant power, were determined. Results The serum levels of advanced glycation end products and advanced oxidation protein products were significantly higher in patients with alopecia areata, compared to the controls (P < 0.001), whereas the levels of ferric-reducing antioxidant power, paraoxonase-1 and lecithin-cholesterol acyltransferase were significantly lower in patients with alopecia areata, compared to the controls (P < 0.001). The mean fasting blood sugar level was significantly higher in patients with alopecia areata, compared to the controls. The ferric reducing antioxidant power level was significantly associated with the percentage of hair loss (P = 0.01, r = 0.4) and the serum C-reactive protein level (P = 0.03, r = -0.3) in patients with alopecia areata. Limitations Since the current study had a cross-sectional design, no cause-effect relationship was established between alopecia areata and oxidative stress. The sample size of our study was also small. Conclusion Based on the present results, the oxidant-antioxidant enzymatic system is impaired in alopecia areata due to the increased oxidative products and decreased antioxidant activity.
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Alopecia Areata , Antioxidantes , Humanos , Antioxidantes/metabolismo , Alopecia Areata/metabolismo , Estudios Transversales , Proteína C-Reactiva , Arildialquilfosfatasa , Productos Avanzados de Oxidación de Proteínas/metabolismo , Glucemia , Lecitinas , Esterol O-Aciltransferasa/metabolismo , Estrés Oxidativo , Biomarcadores , Enfermedad CrónicaRESUMEN
Metabolic syndrome is associated with the development of chronic kidney disease (CKD). We previously demonstrated that aged kidneys are prone to developing tertiary lymphoid tissues (TLTs) and sustain inflammation after injury, leading to CKD progression; however, the relationship between renal TLT and metabolic syndrome is unknown. In this study, we demonstrated that a high-fat diet (HFD) promoted renal TLT formation and inflammation via sterol O-acyltransferase (SOAT) 1-dependent mechanism. Mice fed a HFD prior to ischemic reperfusion injury (IRI) exhibited pronounced renal TLT formation and sustained inflammation compared to the controls. Untargeted lipidomics revealed the increased levels of cholesteryl esters (CEs) in aged kidneys with TLT formation after IRI, and, consistently, the Soat1 gene expression increased. Treatment with avasimibe, a SOAT inhibitor, attenuated TLT maturation and renal inflammation in HFD-fed mice subjected to IRI. Our findings suggest the importance of SOAT1-dependent CE accumulation in the pathophysiology of CKDs associated with TLT.
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Enfermedades Metabólicas , Síndrome Metabólico , Insuficiencia Renal Crónica , Daño por Reperfusión , Animales , Ratones , Síndrome Metabólico/metabolismo , Dieta Alta en Grasa/efectos adversos , Esterol O-Aciltransferasa/genética , Esterol O-Aciltransferasa/metabolismo , Riñón/metabolismo , Tejido Linfoide/metabolismo , Inflamación/metabolismo , Fibrosis , Insuficiencia Renal Crónica/metabolismo , Enfermedades Metabólicas/metabolismo , Daño por Reperfusión/metabolismo , Ratones Endogámicos C57BLRESUMEN
The mechanistic details behind the activation of lecithin-cholesterol acyltransferase (LCAT) by apolipoprotein A-I (apoA-I) and its mimetic peptides are still enigmatic. Resolving the fundamental principles behind LCAT activation will facilitate the design of advanced HDL-mimetic therapeutic nanodiscs for LCAT deficiencies and coronary heart disease and for several targeted drug delivery applications. Here, we have combined coarse-grained molecular dynamics simulations with complementary experiments to gain mechanistic insight into how apoA-Imimetic peptide 22A and its variants tune LCAT activity in peptide-lipid nanodiscs. Our results highlight that peptide 22A forms transient antiparallel dimers in the rim of nanodiscs. The dimerization tendency considerably decreases with the removal of C-terminal lysine K22, which has also been shown to reduce the cholesterol esterification activity of LCAT. In addition, our simulations revealed that LCAT prefers to localize to the rim of nanodiscs in a manner that shields the membrane-binding domain (MBD), αA-αA', and the lid amino acids from the water phase, following previous experimental evidence. Meanwhile, the location and conformation of LCAT in the rim of nanodiscs are spatially more restricted when the active site covering the lid of LCAT is in the open form. The average location and spatial dimensions of LCAT in its open form were highly compatible with the electron microscopy images. All peptide 22A variants studied here had a specific interaction site in the open LCAT structure flanked by the lid and MBD domain. The bound peptides showed different tendencies to form antiparallel dimers and, interestingly, the temporal binding site occupancies of the peptide variants affected their in vitro ability to promote LCAT-mediated cholesterol esterification.
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Apolipoproteína A-I , Fosfatidilcolina-Esterol O-Aciltransferasa , Fosfatidilcolina-Esterol O-Aciltransferasa/química , Fosfatidilcolina-Esterol O-Aciltransferasa/metabolismo , Apolipoproteína A-I/química , Fosfolípidos/metabolismo , Lecitinas , Esterol O-Aciltransferasa/metabolismo , Lipoproteínas HDL/química , Dominio Catalítico , Péptidos , Colesterol/metabolismoRESUMEN
Background: The etiopathogenesis of abdominal aortic aneurysm (AAA) is still unclarified, but vascular inflammation and matrix metalloproteases activation have a recognized role in AAA development and progression. Circulating lipoproteins are involved in tissue inflammation and repair, particularly through the regulation of intracellular cholesterol, whose excess is associated to cell damage and proinflammatory activation. We analyzed lipoprotein metabolism and function in AAA and in control vasculopathic patients, to highlight possible non-atherosclerosis-related, specific abnormalities. Methods: We measured fluorometrically serum esterified/total cholesterol ratio, as an index of lecithin-cholesterol acyltransferase (LCAT) activity, and cholesteryl ester transfer protein (CETP) activity in patients referred to vascular surgery either for AAA (n=30) or stenotic aortic/peripheral atherosclerosis (n=21) having similar burden of cardiovascular risk factors and disease. We measured high-density lipoprotein (HDL)-cholesterol efflux capacity (CEC), through the ATP-binding cassette G1 (ABCG1) and A1 (ABCA1) pathways and serum cell cholesterol loading capacity (CLC), by radioisotopic and fluorimetric methods, respectively. Results: We found higher LCAT (+23%; p < 0.0001) and CETP (+49%; p < 0.0001) activity in AAA sera. HDL ABCG1-CEC was lower (-16%; p < 0.001) and ABCA1-CEC was higher (+31.7%; p < 0.0001) in AAA. Stratification suggests that smoking may partly contribute to these modifications. CEC and CETP activity correlated with CLC only in AAA. Conclusions: We demonstrated that compared to patients with stenotic atherosclerosis, patients with AAA had altered HDL metabolism and functions involved in their anti-inflammatory and tissue repair activity, particularly through the ABCG1-related intracellular signaling. Clarifying the relevance of this mechanism for AAA evolution might help in developing new diagnostic parameters and therapeutic targets for the early management of this condition.
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Aneurisma de la Aorta Abdominal , Aterosclerosis , Adenosina Trifosfato , Antiinflamatorios , Colesterol/metabolismo , Proteínas de Transferencia de Ésteres de Colesterol , HDL-Colesterol , Homeostasis , Humanos , Inflamación/metabolismo , Lecitinas , Lipoproteínas/metabolismo , Metaloproteasas/metabolismo , Esterol O-Aciltransferasa/metabolismoRESUMEN
BACKGROUND: Although cholesterol metabolism is a common pathway for the development of antitumor drugs, there are no specific targets and drugs for clinical use. Here, based on our previous study of sterol O-acyltransferase 1 (SOAT1) in hepatocelluar carcinoma, we sought to screen an effective targeted drug for precise treatment of hepatocelluar carcinoma and, from the perspective of cholesterol metabolism, clarify the relationship between cholesterol regulation and tumorigenesis and development. METHODS: In this study, we developed a virtual screening integrated affinity screening technology for target protein drug screening. A series of in vitro and in vivo experiments were used for drug activity verification. Multi-omics analysis and flow cytometry analysis were used to explore antitumor mechanisms. Comparative analysis of proteome and transcriptome combined with survival follow-up information of patients reveals the clinical therapeutic potential of screened drugs. RESULTS: We screened three compounds, nilotinib, ABT-737, and evacetrapib, that exhibited optimal binding with SOAT1. In particular, nilotinib displayed a high affinity for SOAT1 protein and significantly inhibited tumor activity both in vitro and in vivo. Multi-omics analysis and flow cytometry analysis indicated that SOAT1-targeting compounds reprogrammed the cholesterol metabolism in tumors and enhanced CD8+ T cells and neutrophils to suppress tumor growth. CONCLUSIONS: Taken together, we reported several high-affinity SOAT1 ligands and demonstrated their clinical potential in the precision therapy of liver cancer, and also reveal the potential antitumor mechanism of SOAT1-targeting compounds.
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Linfocitos T CD8-positivos , Carcinoma , Colesterol/metabolismo , Humanos , Esterol O-Aciltransferasa/química , Esterol O-Aciltransferasa/metabolismoRESUMEN
Mutations in the LCAT gene cause familial LCAT deficiency (Online Mendelian Inheritance in Man ID: #245900), a very rare metabolic disorder. LCAT is the only enzyme able to esterify cholesterol in plasma, whereas sterol O-acyltransferases 1 and 2 are the enzymes esterifying cellular cholesterol in cells. Despite the complete lack of LCAT activity, patients with familial LCAT deficiency exhibit circulating cholesteryl esters (CEs) in apoB-containing lipoproteins. To analyze the origin of these CEs, we investigated 24 carriers of LCAT deficiency in this observational study. We found that CE plasma levels were significantly reduced and highly variable among carriers of two mutant LCAT alleles (22.5 [4.0-37.8] mg/dl) and slightly reduced in heterozygotes (218 [153-234] mg/dl). FA distribution in CE (CEFA) was evaluated in whole plasma and VLDL in a subgroup of the enrolled subjects. We found enrichment of C16:0, C18:0, and C18:1 species and a depletion in C18:2 and C20:4 species in the plasma of carriers of two mutant LCAT alleles. No changes were observed in heterozygotes. Furthermore, plasma triglyceride-FA distribution was remarkably similar between carriers of LCAT deficiency and controls. CEFA distribution in VLDL essentially recapitulated that of plasma, being mainly enriched in C16:0 and C18:1, while depleted in C18:2 and C20:4. Finally, after fat loading, chylomicrons of carriers of two mutant LCAT alleles showed CEs containing mainly saturated FAs. This study of CEFA composition in a large cohort of carriers of LCAT deficiency shows that in the absence of LCAT-derived CEs, CEs present in apoB-containing lipoproteins are derived from hepatic and intestinal sterol O-acyltransferase 2.
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Deficiencia de la Lecitina Colesterol Aciltransferasa , Fosfatidilcolina-Esterol O-Aciltransferasa/metabolismo , Esterol O-Aciltransferasa/metabolismo , Apolipoproteínas B , Colesterol/metabolismo , Ésteres del Colesterol , Humanos , Deficiencia de la Lecitina Colesterol Aciltransferasa/genética , Lipoproteínas , Fosfatidilcolina-Esterol O-Aciltransferasa/genética , Esterol O-Aciltransferasa 2RESUMEN
Cholesterol biosynthesis occurs in the endoplasmic reticulum (ER). Its lego-like construction from water-soluble small metabolites via intermediates of increasing complexity to water-insoluble cholesterol requires numerous distinct enzymes. Dysfunction of the involved enzymes can cause several human inborn defects and diseases. Here, we review recent structures of three key cholesterol biosynthetic enzymes: Squalene epoxidase (SQLE), NAD(P)-dependent steroid dehydrogenase-like (NSDHL), and 3ß-hydroxysteroid Δ8-Δ7 isomerase termed EBP. Moreover, we discuss structures of acyl-CoA:cholesterol acyltransferase (ACAT) enzymes, which are responsible for forming cholesteryl esters from cholesterol to maintain cholesterol homeostasis in the ER. The structures of these enzymes reveal their catalytic mechanism and provide a molecular basis to develop drugs for treating diseases linked to their dysregulation.
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Colesterol , Esterol O-Aciltransferasa , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Colesterol/metabolismo , Retículo Endoplásmico/metabolismo , Humanos , Metabolismo de los Lípidos , Esterol O-Aciltransferasa/metabolismo , Agua/metabolismoRESUMEN
Targeting molecular alterations as an effective treatment for isocitrate dehydrogenase-wildtype glioblastoma (GBM) patients has not yet been established. Sterol-O-Acyl Transferase 1 (SOAT1), a key enzyme in the conversion of endoplasmic reticulum cholesterol to esters for storage in lipid droplets (LD), serves as a target for the orphan drug mitotane to treat adrenocortical carcinoma. Inhibition of SOAT1 also suppresses GBM growth. Here, we refined SOAT1-expression in GBM and IDH-mutant astrocytoma, CNS WHO grade 4 (HGA), and assessed the distribution of LD in these tumors. Twenty-seven GBM and three HGA specimens were evaluated by multiple GFAP, Iba1, IDH1 R132H, and SOAT1 immunofluorescence labeling as well as Oil Red O staining. To a small extent SOAT1 was expressed by tumor cells in both tumor entities. In contrast, strong expression was observed in glioma-associated macrophages. Triple immunofluorescence labeling revealed, for the first time, evidence for SOAT1 colocalization with Iba1 and IDH1 R132H, respectively. Furthermore, a notable difference in the amount of LD between GBM and HGA was observed. Therefore, SOAT1 suppression might be a therapeutic option to target GBM and HGA growth and invasiveness. In addition, the high expression in cells related to neuroinflammation could be beneficial for a concomitant suppression of protumoral microglia/macrophages.
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Neoplasias de la Corteza Suprarrenal , Carcinoma Corticosuprarrenal , Neoplasias Encefálicas , Glioblastoma , Glioma , Esterol O-Aciltransferasa/metabolismo , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Glioma/metabolismo , Humanos , Isocitrato Deshidrogenasa/genética , MutaciónRESUMEN
BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide characterized by disparities in age, gender, race and anatomic sites. The mechanism underlying pathogenesis, progression and disparities of CRC remains unclear. This study aims to reveal the association of expression levels of enzymes related to cholesteryl ester (CE) metabolism with pathogenesis, progression and disparities of CRC. METHODS: The differences in gene expression levels were analyzed for enzymes in CE synthesis (acyl CoA: cholesterol acyltransferase 1 and 2, ACAT1, and ACAT2), and in CE hydrolysis (neutral cholesterol ester hydrolase, NCEH1 and lysosomal acid lipase, LAL) on TNMplot platform between CRC and normal colorectal tissues (NCT) in a large cohort. The differences in protein expression levels for these enzymes were determined by Immunochemistry (IHC) performed on tissue microarray containing 96 pairs of CRC and benign colorectal tissues (BCT) from different patient populations. The expression level represented as IHC score of each enzyme was compared between CRC and BCT in entire population and populations stratified by race, gender and anatomic sites. Student's t-test, Fisher exact test and ANOVA were used for data analysis. Significant p value was set at P<0.05. RESULTS: The gene expression level of ACAT1 was significantly lower in CRC than in NCT (P = 2.15e-119). The gene expression level of ACAT2 was not statistically different between CRC and NCT. The gene expression level of LIPA (encoding LAL) was significantly higher in CRC than in NCT (P = 2.01e-14). No data was found for the gene expression level of NCEH1. The IHC score of ACAT1was significantly lower in CRC than in BCT in all studied populations and in sub site of colon, but not in that of rectum. The IHC score of ACAT2 was not statistically different between CRC and BCT. IHC score of NCEH1 was significantly higher in CRC than in BCT only in African American (AA) population. The IHC score of LAL was significantly higher in CRC than in BCT in all studied populations and in all sub sites. In addition, decreased ACAT1 in CRC significantly correlated to progression of CRC: the lower IHC score of ACAT1, the more advanced clinical stage of CRC will be. CONCLUSIONS: This study revealed that altered expression levels in enzymes related to CE metabolism highly correlate to the pathogenesis, clinical progression and disparities of CRC. The results will add revenue in elucidating mechanisms underlying progression of CRC, and shed light on seeking biomarkers and exploring therapeutic targets for CRC in a new direction.
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Ésteres del Colesterol , Neoplasias Colorrectales , Ésteres del Colesterol/metabolismo , Neoplasias Colorrectales/genética , Humanos , Esterol Esterasa/genética , Esterol Esterasa/metabolismo , Esterol O-Aciltransferasa/genética , Esterol O-Aciltransferasa/metabolismoRESUMEN
BACKGROUND: Sterol O-acyltransferase 2 (Soat2) encodes acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT2), which synthesizes cholesteryl esters in hepatocytes and enterocytes fated either to storage or to secretion into nascent triglyceride-rich lipoproteins. OBJECTIVES: We aimed to unravel the molecular mechanisms leading to reduced hepatic steatosis when Soat2 is depleted in mice. METHODS: Soat2-/- and wild-type mice were fed a high-fat, a high-carbohydrate, or a chow diet, and parameters of lipid and glucose metabolism were assessed. RESULTS: Glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), oral glucose tolerance (OGTT), and insulin tolerance tests significantly improved in Soat2-/- mice, irrespective of the dietary regimes (2-way ANOVA). The significant positive correlations between area under the curve (AUC) OGTT (r = 0.66, p < 0.05), serum fasting insulin (r = 0.86, p < 0.05), HOMA-IR (r = 0.86, p < 0.05), Adipo-IR (0.87, p < 0.05), hepatic triglycerides (TGs) (r = 0.89, p < 0.05), very-low-density lipoprotein (VLDL)-TG (r = 0.87, p < 0.05) and the hepatic cholesteryl esters in wild-type mice disappeared in Soat2-/- mice. Genetic depletion of Soat2 also increased whole-body oxidation by 30% (p < 0.05) compared to wild-type mice. CONCLUSION: Our data demonstrate that ACAT2-generated cholesteryl esters negatively affect the metabolic control by retaining TG in the liver and that genetic inhibition of Soat2 improves liver steatosis via partitioning of lipids into secretory (VLDL-TG) and oxidative (fatty acids) pathways.
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Hígado Graso , Insulinas , Esterol O-Aciltransferasa , Animales , Ésteres del Colesterol/metabolismo , Hígado Graso/metabolismo , Glucosa/metabolismo , Insulinas/metabolismo , Lipoproteínas VLDL/metabolismo , Hígado/metabolismo , Masculino , Ratones , Ratones Noqueados , Esterol O-Aciltransferasa/genética , Esterol O-Aciltransferasa/metabolismo , Triglicéridos , Esterol O-Aciltransferasa 2RESUMEN
Discoid-reconstituted high-density lipoprotein (d-rHDL) is advantageous for tumor-targeted drug delivery due to its small size, long circulation, and efficient internalization into cancer cells. Nevertheless, an allosteric reaction catalyzed by serum lecithin-cholesterol acyltransferase (LCAT) may cause drug leakage from d-rHDL and reduce its targeting efficiency. Conversely, similar "structural weakening" catalyzed by acyl-coenzyme A-cholesterol acyltransferase (ACAT) inside tumor cells can stimulate precise intracellular drug release. Therefore, we synthesized and characterized a pH-sensitive n-butyraldehyde bi-cholesterol (BCC) to substitute for cholesterol in the d-rHDL particle, and bovine serum albumin (BSA) was used as the targeting agent. This dual pH- and ACAT-sensitive d-rHDL (d-d-rHDL) was small with a disk-like appearance. Morphological transformation observation, in vitro release assays, and differences in internalization upon LCAT treatment confirmed that BCC effectively inhibited the remodeling behavior and enhanced the tumor-targeting efficiency. The accumulation of d-d-rHDL in HepG2 cells was significantly higher than that in LO2 cells, and accumulation was inhibited by free BSA. The pH sensitivity was verified, and d-d-rHDL achieved efficient drug release in vitro and inside tumor cells after exposure to acidic conditions and ACAT. Confocal laser scanning microscopy demonstrated that d-d-rHDL escaped from lysosomes and became distributed evenly throughout cells. Moreover, in vivo imaging assays in a tumor-bearing mouse model demonstrated tumor-targeting properties of d-d-rHDL, and paclitaxel-loaded d-d-rHDL showed strong anticancer activity in these mice. This dual-sensitive d-d-rHDL thus combines structural stability in plasma and an intracellular pH/ACAT-triggered drug release to facilitate inhibition of tumor growth.
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Antineoplásicos/farmacología , Materiales Biocompatibles/farmacología , Lipoproteínas HDL/farmacología , Fosfatidilcolina-Esterol O-Aciltransferasa/química , Esterol O-Aciltransferasa/química , Regulación Alostérica/efectos de los fármacos , Animales , Antineoplásicos/química , Antineoplásicos/metabolismo , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Concentración de Iones de Hidrógeno , Lipoproteínas HDL/química , Lipoproteínas HDL/metabolismo , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/metabolismo , Neoplasias Hepáticas Experimentales/patología , Ensayo de Materiales , Ratones , Estructura Molecular , Fosfatidilcolina-Esterol O-Aciltransferasa/metabolismo , Esterol O-Aciltransferasa/metabolismoRESUMEN
BACKGROUND: Prostate cancer (PCa) is the most frequent cancer in men. The prognosis of PCa is heterogeneous with many clinically indolent tumors and rare highly aggressive cases. Reliable tissue markers of prognosis are lacking. Active cholesteryl ester synthesis has been associated with prostate cancer aggressiveness. Sterol-O-Acyl transferases (SOAT) 1 and 2 catalyze cholesterol esterification in humans. OBJECTIVE: To investigate the value of SOAT1 and SOAT2 tissue expression as prognostic markers in high risk PCa. PATIENTS AND METHODS: Formalin-fixed paraffin-embedded tissue samples from 305 high risk PCa cases treated with radical prostatectomy were analyzed for SOAT1 and SOAT2 protein expression by semi-quantitative immunohistochemistry. The Kaplan-Meier method and Cox proportional hazards modeling were used to compare outcome. MAIN OUTCOME MEASURE: Biochemical recurrence (BCR) free survival. RESULTS: SOAT1 expression was high in 73 (25%) and low in 219 (75%; not evaluable: 13) tumors. SOAT2 was highly expressed in 40 (14%) and at low levels in 249 (86%) samples (not evaluable: 16). By Kaplan-Meier analysis, we found significantly shorter median BCR free survival of 93 months (95% confidence interval 23.6-123.1) in patients with high SOAT1 vs. 134 months (112.6-220.2, Log-rank p < 0.001) with low SOAT1. SOAT2 expression was not significantly associated with BCR. After adjustment for age, preoperative PSA, tumor stage, Gleason score, resection status, lymph node involvement and year of surgery, high SOAT1 but not SOAT2 expression was associated with shorter BCR free survival with a hazard ratio of 2.40 (95% CI 1.57-3.68, p < 0.001). Time to clinical recurrence and overall survival were not significantly associated with SOAT1 and SOAT2 expression CONCLUSIONS: SOAT1 expression is strongly associated with BCR free survival alone and after multivariable adjustment in high risk PCa. SOAT1 may serve as a histologic marker of prognosis and holds promise as a future treatment target.