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Colorectal cancer (CRC) is recognized as the third most lethal cancer worldwide. While existing treatment options demonstrate considerable efficacy, they are often constrained by non-selectivity and substantial side effects. Recent studies indicate that lipid metabolism significantly influences carcinogenesis, highlighting it as a promising avenue for developing targeted anticancer therapies. The purpose of the study was to see if acyl-coenzyme A: cholesterol acyltransferase 1 (ACAT1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), and stearoyl-CoA 9-desaturase (SCD1) are good metabolic targets and whether the use of inhibitors of these enzymes together with 5-fluorouracil (5-FU) would have a synergistic effect on CRC cell viability. To confirm that the correct lipid targets were chosen, the expression levels of ACAT1, HMGCR, and SCD1 were examined in CRC patients and cell models. At first, each compound (Avasimibe, Lovastatin, MF-438, and 5-FU was tested separately, and then each inhibitor was paired with 5-FU to assess the synergistic effect on cell viability. Gene expression of selected enzymes significantly increased in tissue samples obtained from CRC patients and cancer cell lines (HT-29). Inhibition of any of the selected enzymes reduced CRC cell growth in a dose-dependent manner. More importantly, the combination of 5-FU + Avasimibe (an ACAT1 inhibitor) and 5-FU + MF-438 (an SCD1 inhibitor) produced a stronger antiproliferative effect than the inhibitors alone. 5-FU combined either with Avasimibe or MF-438 showed a synergistic effect with an HSA score of 47.00 at a dose of 0.3 + 30 µM, respectively (2.66% viability rate vs. 46%; p < 0.001), and 39.34 at a dose of 0.3 + 0.06 µM (46% vs. 10.33%; p < 0.001), respectively. The association of 5-FU with Lovastatin (HMGCR inhibitor) did not significantly impact CRC cell viability in a synergistic manner. Inhibition of lipid metabolism combined with standard chemotherapy is a promising strategy that reduces CRC cell viability and allows for the use of a lower drug dose. The combination of 5-FU and Avasimibe has the greatest therapeutic potential among studied compounds.

Although lipid-derived acetyl-coenzyme A (CoA) is a major carbon source for histone acetylation, the contribution of fatty acid β-oxidation (FAO) to this process remains poorly characterized. To investigate this, we generated mitochondrial acetyl-CoA acetyltransferase 1 (ACAT1, distal FAO enzyme) knockout macrophages. 13 C-carbon tracing confirmed reduced FA-derived carbon incorporation into histone H3, and RNA sequencing identified diminished interferon-stimulated gene expression in the absence of ACAT1. Chromatin accessibility at the Stat1 locus was diminished in ACAT1 -/- cells. Chromatin immunoprecipitation analysis demonstrated reduced acetyl-H3 binding to Stat1 promoter/enhancer regions, and increasing histone acetylation rescued Stat1 expression. Interferon-β release was blunted in ACAT1 -/- and recovered by ACAT1 reconstitution. Furthermore, ACAT1-dependent histone acetylation required an intact acetylcarnitine shuttle. Last, obese subjects' monocytes exhibited increased ACAT1 and histone acetylation levels. Thus, our study identifies an intriguing link between FAO-mediated epigenetic control of type I interferon signaling and uncovers a potential mechanistic nexus between obesity and type I interferon signaling.

Recent therapeutic strategies have highlighted the potential of β-hydroxybutyrate (BHB) and α-ketoglutarate (α-KG) as effective anticancer agents, particularly for colon cancer. These metabolites can modulate cellular metabolism and induce epigenetic changes, inhibiting tumor growth. Nonetheless, certain cancer cells may utilize ketone bodies, like BHB as nutrient sources under hypoxic conditions, potentially reducing treatment efficacy. Understanding these mechanisms is crucial for optimizing cancer therapies. This study evaluated the effects of BHB and α-KG on HCT-116 colorectal cancer cell viability under normoxic and low-glucose hypoxic conditions. HCT-116 cell lines were treated with different doses of BHB and α-KG in normoxic and low-glucose hypoxic conditions, and then cell viability was assessed by the MTT assay. Moreover, the mRNA expression levels of SRC, hypoxia-inducible factor 1α (HIF-1α), acetyl-CoA acetyltransferase 1 (ACAT1), and sirtuin 2 (SIRT2) genes were determined using quantitative reverse transcriptase-polymerase chain reaction (q RT-PCR). BHB significantly increased the proliferation of HCT-116 colon cancer cells under low-glucose hypoxic conditions, while α-KG maintained cell viability in normoxic conditions but not in hypoxia. BHB treatment reduced SIRT2 mRNA levels and increased ACAT1, SRC, and HIF-1α expression. Conversely, α-KG decreased ACAT1, SRC, and HIF-1α expression and increased SIRT2 levels in normoxia but could not reverse gene expression during hypoxia. Our study demonstrated that BHB and α-KG exhibited complex interactions with colon cancer cell viability under varying oxygen and glucose conditions. While BHB promoted cell proliferation in hypoxic environments, α-KG showed protective effects in normoxic conditions. This research contributed to the growing body of evidence supporting the role of metabolic modulators in cancer therapy and emphasized the importance of understanding tumor microenvironments to optimize treatment outcomes. However, the need for further research into the metabolic pathways is underscored to enhance therapeutic strategies for cancer treatment., Competing Interests: Declarations. Conflict of interest: There is no conflict of interests to declare. Ethical approval: Not applicable. , (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aging and apolipoprotein E4 ( APOE4 ) are the two most significant risk factors for late-onset Alzheimer's disease (LOAD). Compared to APOE3 , APOE4 disrupts cholesterol homeostasis, increases cholesteryl esters (CEs), and exacerbates neuroinflammation in brain cells, including microglia. Targeting CEs and neuroinflammation could be a novel strategy to ameliorate APOE4 -dependent phenotypes. Toll-like receptor 4 (TLR4) is a key macromolecule in inflammation, and its regulation is associated with the cholesterol content of lipid rafts in cell membranes. We previously demonstrated that in normal microglia expressing APOE3, inhibiting the cholesterol storage enzyme acyl-CoA:cholesterol acyltransferase 1 (ACAT1/SOAT1) reduces CEs, dampened neuroinflammation via modulating the fate of TLR4. We also showed that treating myelin debris-loaded normal microglia with ACAT inhibitor F12511 reduced cellular CEs and activated ABC transporter 1 (ABCA1) for cholesterol efflux. This study found that treating primary microglia expressing APOE4 with F12511 also reduces CEs, activates ABCA1, and dampens LPS-dependent NFκB activation. In vivo, two-week injections of nanoparticle F12511, which consists of DSPE-PEG 2000 , phosphatidylcholine, and F12511, to aged female APOE4 mice reduced TLR4 protein content and decreased proinflammatory cytokines, including IL-1β in mice brains. Overall, our work suggests nanoparticle F12511 is a novel agent to ameliorate LOAD.

Maintaining cholesterol homeostasis is critical for preserving adipocyte function during the progression of obesity. Despite this, the regulatory role of cholesterol esterification in governing adipocyte expandability has been understudied. Acyl-coenzyme A (CoA):cholesterol acyltransferase/Sterol O-acyltransferase 1 (ACAT1/SOAT1) is the dominant enzyme to synthesize cholesteryl ester in most tissues. Our previous study demonstrated that knockdown of either ACAT1 or ACAT2 impaired adipogenesis. However, the underlying mechanism of how ACAT1 mediates adipogenesis remains unclear. Here, we reported that ACAT1 is the dominant isoform in white adipose tissue of both humans and mice, and knocking out ACAT1 reduced fat mass in mice. Furthermore, ACAT1-deficiency inhibited the early stage of adipogenesis via attenuating PPARγ pathway. Mechanistically, ACAT1 deficiency inhibited SREBP2-mediated cholesterol uptake and thus reduced intracellular and plasma membrane cholesterol levels during adipogenesis. Replenishing cholesterol could rescue adipogenic master gene-Pparγ's-transcription in ACAT1-deficient cells during adipogenesis. Finally, overexpression of catalytically functional ACAT1, not the catalytic-dead ACAT1, rescued cholesterol levels and efficiently rescued the transcription of PPARγ as well as the adipogenesis in ACAT1-deficient preadipocytes. In summary, our study revealed the indispensable role of ACAT1 in adipogenesis via regulating intracellular cholesterol homeostasis., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Abnormal differentiation of cells is a hallmark of malignancy. Induction of cancer-cell differentiation is emerging as a novel therapeutic strategy with low toxicity in hematological malignances, but whether such treatment can be used in solid tumors is not known. Here, we uncovered a novel function of acetyl coenzyme A acetyltransferase (ACAT1) in regulating the differentiation of glioblastoma (GBM) cells. Inhibition of ACAT1 promoted the differentiation of GBM cells into astrocytes but also delayed tumor growth. Mechanistically, suppression of ACAT1 restored mitochondrial function and led to metabolic "reprogramming" in GBM cells: reduction of fatty-acid oxidation and acetyl-CoA, but an increase in free fatty acids. Importantly, ACAT1 negatively regulated the choline metabolic pathway, which is crucial for the differentiation of GBM cells. Finally, we demonstrated that a naturally available substance, chlorogenic acid (CHA), could inhibit phosphorylation of ACAT1 and so delay GBM progression, CHA is a promising candidate to treat GBM because it could induce the differentiation of cancer cells., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Aging is the major risk factor for Alzheimer's disease (AD). In the aged brain, myelin debris accumulates and is cleared by microglia. Phagocytosed myelin debris increases neutral lipid droplet content in microglia. Neutral lipids include cholesteryl esters (CE) and triacylglycerol (TAG). To examine the effects of myelin debris on neutral lipid content in microglia, we added myelin debris to human HMC3 and mouse N9 cells. The results obtained when using 3 H-oleate as a precursor in intact cells reveal that myelin debris significantly increases the biosynthesis of CE but not TAG. Mass analyses have shown that myelin debris increases both CE and TAG. The increase in CE biosynthesis was abolished using inhibitors of the cholesterol storage enzyme acyl-CoA:cholesterol acyltransferase 1 (ACAT1/SOAT1). ACAT1 inhibitors are promising drug candidates for AD treatment. In myelin debris-loaded microglia, treatment with two different ACAT1 inhibitors, K604 and F12511, increased the mRNA and protein content of ATP-binding cassette subfamily A1 (ABCA1), a protein that is located at the plasma membrane and which controls cellular cholesterol disposal. The effect of the ACAT1 inhibitor on ABCA1 was abolished by preincubating cells with the liver X receptor (LXR) antagonist GSK2033. We conclude that ACAT1 inhibitors prevent the accumulation of cholesterol and CE in myelin debris-treated microglia by activating ABCA1 gene expression via the LXR pathway.

Background: N4-Acetylcytidine (ac4C), a highly conserved post-transcriptional mechanism, plays a pivotal role in RNA modification and tumor progression. However, the molecular mechanism by which ac4C modification mediates tumor immunosuppression remains elusive in triple-negative breast cancer (TNBC)., Methods: NAT10 expression was analyzed in TNBC samples in the level of mRNA and protein, and compared with the corresponding normal tissues. ac4C modification levels also measured in the TNBC samples. The effects of NAT10 on immune microenvironment and tumor metabolism were investigated. NAT10-mediated ac4C and its downstream regulatory mechanisms were determined in vitro and in vivo. The combination therapy of targeting NAT10 in TNBC was further explored., Results: The results revealed that the loss of NAT10 inhibited TNBC development and promoted T cell activation. Mechanistically, NAT10 upregulated JunB expression by increasing ac4C modification levels on its mRNA. Moreover, JunB further up-regulated LDHA expression and facilitated glycolysis. By deeply digging, remodelin, a NAT10 inhibitor, elevated the surface expression of CTLA-4 on T cells. The combination of remodelin and CTLA-4 mAb can further activate T cells and inhibite tumor progression., Conclusion: Taken together, our study demonstrated that the NAT10-ac4C-JunB-LDHA pathway increases glycolysis levels and creates an immunosuppressive tumor microenvironment (TME). Consequently, targeting this pathway may assist in the identification of novel therapeutic strategies to improve the efficacy of cancer immunotherapy., (© 2024. The Author(s).)

Acetyl CoA acetyltransferase 1 (ACAT1), a mitochondrial enzyme, is mainly involved in the formation and decomposition of ketones, isoleucine, and fatty acids. Previous clinical studies showed that mutations in the ACAT1 gene lead to ketoacidosis, Notably the role of ACAT1 in human cancer' pathogenesis varies depending on cancer type, and its specific role in gastric cancer remains largely unknown. In the current study, we found that the expression of ACAT1 in primary late-stage gastric cancer tumor tissues was significantly lower than in early-stage tumors. This observation was further confirmed in high-grade gastric cancer cell line MKN45. The expression of CD44 and OCT4 was decreased, while CD24 expression was increased by overexpressing ACAT1 in MKN45 gastric cancer cells. Moreover, the ability of gastric cancer cells to form colonies on soft agar was also reduced by ACAT1 overexpression. Likewise, overexpression of ACAT1 inhibited epithelial mesenchymal transition (EMT) in gastric cancer cells evidenced by increased expression of the epithelial marker E-Cadherin, decreased expression of mesenchymal marker vimentin, and decreased expression levels of SNAI 1/3. In addition, ACAT1 overexpression inhibited cell migration and invasion, improved the response to 5-Fluorouracil (5-FU) and etoposide. In contrast, inhibition of ACAT1 activity promoted the proliferation of gastric cancer cells. The xenotransplantation results in nude mice showed that overexpression of ACAT1 in gastric cancer cells inhibited tumor growth in vivo . In addition, the low expression of ACAT1 in gastric cancer was further validated by searching public databases and conducting bioinformatic analyses. Mechanistically, bioinformatic analysis found that the inhibitory effect of ACAT1 in gastric cancer may be related to the Adipocytokine Signaling Pathway, Ppar Signaling Pathway, Propanoate Metabolism and P53 Signaling Pathway. Correlation analysis indicated ACAT1 mRNA expression was correlated with immune infiltrates. Collectively, our data show that ACAT1 induces pronounced inhibitory effects on gastric cancer initiation and development, which may impact future strategies to treat this aggressive cancer., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 He, Li, Liu, Chang, Han, Han, Ma, Amin, Song and Zhou.)

Ketosis in dairy cows is often accompanied by the dysregulation of lipid homeostasis in the liver. Acetyl-coenzyme A acetyltransferase 2 (ACAT2) is specifically expressed in the liver and is important for regulating lipid homeostasis in ketotic cows. Lentinan (LNT) has a wide range of pharmacological activities, and this study investigates the protective effects of LNT on β-hydroxybutyrate (BHBA)-induced lipid metabolism disorder in bovine hepatocytes (BHECs) and elucidates the underlying mechanisms. BHECs were first pretreated with LNT to investigate the effect of LNT on BHBA-induced lipid metabolism disorder in BHECs. ACAT2 was then silenced or overexpressed to investigate whether this mediated the protective action of LNT against BHBA-induced lipid metabolism disorder in BHECs. Finally, BHECs were treated with LNT after silencing ACAT2 to investigate the interaction between LNT and ACAT2. LNT pretreatment effectively enhanced the synthesis and absorption of cholesterol, inhibited the synthesis of triglycerides, increased the expression of ACAT2, and elevated the contents of very low-density lipoprotein and low-density lipoprotein cholesterol, thereby ameliorating BHBA-induced lipid metabolism disorder in BHECs. The overexpression of ACAT2 achieved a comparable effect to LNT pretreatment, whereas the silencing of ACAT2 aggravated the effect of BHBA on inducing disorder in lipid metabolism in BHECs. Moreover, the protective effect of LNT against lipid metabolism disorder in BHBA-induced BHECs was abrogated upon silencing of ACAT2. Thus, LNT, as a natural protective agent, can enhance the regulatory capacity of BHECs in maintaining lipid homeostasis by upregulating ACAT2 expression, thereby ameliorating the BHBA-induced lipid metabolism disorder.

Trypanosoma cruzi is a parasite with a high capacity to adapt to the host. Animal models have already demonstrated that the tropism of this parasite occurs not only in cardiac/digestive tissues but also in adipose tissue (AT). That said, the consequences ofT. cruziinfection for AT and the implications of treatment with Benzonidazole in this tissue are under discussion. Here, we tested the hypothesis that T. cruzi infection in adipose tissue upon treatment with Benzonidazole (Bz) and the interaction of mononuclear immune cells (PBMC) influences the relative expression of ACAT1, FASN, and PNPLA2 genes. Thus, stem cells derived from adipose tissue (ADSC) after adipogenic differentiation were indirectly cultivated with PBMC after infection with the T. cruzi Y strain and treatment with Bz. We use the TcSAT-IAM system and RT-qPCR to evaluate the parasite load and the relative quantification (ΔCt) of the ACAT1, FASN, and PNPLA2 genes. Our results demonstrate that treatment with Bz did not reduce adipocyte infection in the presence (p-value: 0.5796) or absence (p-value: 0.1854) of cultivation with PBMC. In addition, even though there is no statistical difference when compared to the control group (AT), T. cruzi induces the FASN expression (Rq: 14.00). However, treatment with Bz in AT suggests the increases of PNPLA2 expression levels (Rq: 12.58), even in the absence of T. cruzi infection. During indirect cultivation with PBMC, T. cruzi smooths the expression of PNPLA2 (Rq: 0.824) and instigates the expression of ACAT1 (Rq: 1.632) and FASN (Rq: 1.394). Furthermore, the treatment with Bz during infection induces PNPLA2 expression (Rq: 1.871), maintaining FASN expression levels (Rq: 1.334). Given this, our results indicate that treatment with Benzonidazole did not decrease T. cruzi infection in adipose tissue. However, treating the adipocyte cells with Bz during the interaction with PBMC cells influences the lipid pathways scenario, inducing lipolytic metabolism through the expression of PNPLA2., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: To explore the clinical, biochemical and genetic characteristics of three children with Isoleucine metabolic disorders due to variants of HSD17B10 and ACAT1 genes., Methods: Two children with 17β hydroxysteroid dehydrogenase 10 (HSD17B10) deficiency and a child with β-ketothiolase deficiency (BKD) diagnosed at Shanghai Children's Hospital between 2014 and 2021 were selected as the study subjects. Clinical data of the children were collected. The children were subjected to blood acylcarnitine, urinary organic acid and genetic testing, and candidate variants were analyzed with bioinformatic tools., Results: The main symptoms of the three children had included epilepsy, developmental delay, hypotonia and acidosis. Their blood acylcarnitine methylcrotonyl carnitine (C5:1), 3-hydroxyisovalerylcarnitine (C5-OH) and 3-hydroxybutylcarnitine (C4OH) were increased to various extents, and urine organic acids including methyl crotonylglycine and 2-methyl-3-hydroxybutyric acid were significantly increased. Child 1 and child 2 were respectively found to harbor a c.347G>A (p.R116Q) variant and a c.274G>A (p.A92T) variant of the HSD17B10 gene, and child 3 was found to harbor compound heterozygous variants of the ACAT1 gene, namely c.547G>A (p.G183R) and a c.331G>C (p.A111P). Among these, the c.274G>A (p.A92T) and c.331G>C (p.A111P) variants were unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), they were respectively classified as variant of unknown significance (PP3&#95;Strong+PM2&#95;supporting) and likely pathogenic (PM3+PM2&#95;Supporting+PP3&#95;Moderate+PP4)., Conclusion: Both the HSD17B10 deficiency and BKD can lead to Isoleucine metabolism disorders, which may be difficult to distinguish clinically. Genetic testing can further confirm the diagnosis. Discoveries of the HSD17B10: c.274G>A (p.A92T) variant and the ACAT1: c.331G>C (p.A111P) variant have enriched the mutational spectrum of the two diseases.

Long noncoding RNAs (LncRNAs) have been gaining attention as potential therapeutic targets for lung cancer. In this study, we investigated the expression and biological behavior of lncRNA DARS-AS1, its predicted interacting partner miR-302a-3p, and ACAT1 in nonsmall cell lung cancer (NSCLC). The transcript level of DARS-AS1, miR-302a-3p, and ACAT1 was analyzed using qRT-PCR. Endogenous expression of ACAT1 and the expression of-and changes in-AKT/ERK pathway-related proteins were determined using western blotting. MTS, Transwell, and apoptosis experiments were used to investigate the behavior of cells. The subcellular localization of DARS-AS1 was verified using FISH, and its binding site was verified using dual-luciferase reporter experiments. The binding of DARS-AS1 to miR-302a-3p was verified using RNA co-immunoprecipitation. In vivo experiments were performed using a xenograft model to determine the effect of DARS-AS1 knockout on ACAT1 and NSCLC. lncRNA DARS-AS1 was upregulated in NSCLC cell lines and tissues and the expression of lncRNA DARS-AS1 was negatively correlated with survival of patients with NSCLC. Knockdown of DARS-AS1 inhibited the malignant behaviors of NSCLC via upregulating miR-302a-3p. miR-302a-3p induced suppression of malignancy through regulating oncogene ACAT1. This study demonstrates that the DARS-AS1-miR-302a-3p-ACAT1 pathway plays a key role in NSCLC., (© 2024 Wiley Periodicals LLC.)

Colorectal cancer (CRC) ranks third in incidence and second in mortality worldwide. Metabolic disorders are known to be closely associated with CRC. Functional metabolomics aims to translate metabolomics-derived biomarkers to disease mechanisms. Previous work based on untargeted liquid chromatography identified 30 differential metabolites of CRC. Among them, only β-hydroxybutyrate (BHB) was elevated in CRC. Here, we first confirm the increased level of β-hydroxybutyrate by targeted metabolomic analysis using an independent cohort of 400 serum samples by UPLC-QQQ-MS/MS analysis. Using appropriate cell and animal models, we find that treatment with pathological levels of β-hydroxybutyrate expedites CRC proliferation and metastasis. Out of four major rate-limiting enzymes of ketolysis, only acetyl-coenzyme A acetyltransferase1 (ACAT1) expression is increased in paired human CRC tissues. These findings suggest probable clinical relevance for the functional implications of β-hydroxybutyrate in CRC. We demonstrate that β-hydroxybutyrate may exert its tumorigenic effects via regulation of ACAT1, due to induction of downstream isocitrate dehydrogenase1 (IDH1) acetylation. Genetic silencing of ACAT1 significantly suppresses the progression of CRC and abrogates the effects of β-hydroxybutyrate both in vitro and in vivo. Overall, this study suggests that targeting β-hydroxybutyrate and its major rate-limiting enzyme ACAT1 may provide a new avenue for therapeutic intervention in CRC., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Nonalcoholic fatty liver disease (NAFLD) is substantiated by the reprogramming of liver metabolic pathways that disrupts the homeostasis of lipid and glucose metabolism and thus promotes the progression of the disease. The metabolic pathways associated with NAFLD are regulated at different levels from gene transcription to various post-translational modifications including ubiquitination. Here, we used a novel orthogonal ubiquitin transfer platform to identify pyruvate dehydrogenase A1 (PDHA1) and acetyl-CoA acetyltransferase 1 (ACAT1), two important enzymes that regulate glycolysis and ketogenesis, as substrates of E3 ubiquitin ligase UBE3A/E6AP. We found that overexpression of UBE3A accelerated the degradation of PDHA1 and promoted glycolytic activities in HEK293 cells. Furthermore, a high-fat diet suppressed the expression of UBE3A in the mouse liver, which was associated with increased ACAT1 protein levels, while forced expression of UBE3A in the mouse liver resulted in decreased ACAT1 protein contents. As a result, the mice with forced expression of UBE3A in the liver exhibited enhanced accumulation of triglycerides, cholesterol, and ketone bodies. These results reveal the role of UBE3A in NAFLD development by inducing the degradation of ACAT1 in the liver and promoting lipid storage. Overall, our work uncovers an important mechanism underlying the regulation of glycolysis and lipid metabolism through UBE3A-mediated ubiquitination of PDHA1 and ACAT1 to regulate their stabilities and enzymatic activities in the cell.

Triple-negative breast cancer (TNBC) is a heterogeneous and aggressive disease with poor prognosis. Acetylation modifications affect a great number of biological processes of malignant tumors. The current study aims at revealing the role of acetylation-related mechanism in TNBC progression. Methyltransferase like-3 (METTL3) was found to be downregulated in TNBC cells via quantitative polymerase chain reaction (qPCR) and western blot analyses. Co-Immunoprecipitation (Co-IP) and GST pulldown assays revealed the interaction between acetyl-CoA acetyltransferase 1 (ACAT1) and METTL3. Through further immunoprecipitation (IP) assay, we determined that ACAT1 stabilizes METTL3 protein via inhibiting the degradation of ubiquitin-proteasome. Functionally, ACAT1 inhibits TNBC cell migration and invasion. Moreover, nuclear receptor subfamily 2 group F member 6 (NR2F6) regulates ACAT1 expression at transcriptional level. Finally, we demonstrated that NR2F6/ACAT/METTL3 axis suppresses the migration and invasion of TNBC cells via METTL3. In conclusion, NR2F6 transcriptionally activates ACAT1 and promotes the suppressive effects of ACAT1-mediated METTL3 acetylation on TNBC cell migration and invasion., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: Prostate cancer is a major health issue affecting the male population worldwide, and its etiology remains relatively unknown. As presented on the Gene Expression Profiling Interactive Analysis database, acetyl-CoA acetyltransferase 1 (ACAT1) acts as a prostate cancer-promoting factor. ACAT1 expression in prostate cancer tissues is considerably higher than that in normal tissues, leading to a poor prognosis in patients with prostate cancer. Here, we aimed to study the role of the ACAT1-fused in sarcoma (FUS) complex in prostate cancer and identify new targets for the diagnosis and treatment of the disease., Methods: We conducted immunohistochemical analysis of 57 clinical samples and in vitro and in vivo experiments using a mouse model and plasmid constructs to determine the expression of ACAT1 in prostate cancer., Results: The relationship between the expression of ACAT1 and the Gleason score was significant. The expression of ACAT1 was higher in tissues with a Gleason score of > 7 than in tissues with a Gleason score of ≤7 (P = 0.0011). In addition, we revealed that ACAT1 can interact with the FUS protein., Conclusions: In prostate cancer, ACAT1 promotes the expression of P62 and Nrf2 through FUS and affects reactive oxygen species scavenging. These effects are due to the inhibition of autophagy by ACAT1. That is, ACAT1 promotes prostate cancer by inhibiting autophagy and eliminating active oxygen species. The expression of ACAT1 is related to prostate cancer. Studying the underlying mechanism may provide a new perspective on the treatment of prostate cancer., (© 2022. The Author(s).)

Hypertension is a multifactorial disease that partially caused by genetic factors, including variation in genes related to lipid metabolism. ACAT1 gene is implicated in lipid metabolism for its encoding product, the enzyme acetyl-CoA acetyltransferase 1, catalyzing the synthesis of cholesteryl ester from cholesterol and playing an important role in the metabolism of cholesterol. Until now, there's little study on the relationship between ACAT1 variants and hypertension. Here, we report a link between ACAT1 rs1044925 and hypertension in Tongdao Dong population. Polymerase chain reaction-restriction fragment length polymorphism was used to detect the genotypes of the ACAT1 SNP rs1044925 in a total of 637 subjects, including 406 hypertensive patients and 231 normotensive controls. The genotypic and allelic frequencies of rs1044925 were significantly different between the normotensive and hypertensive subjects (P = .001). AC/CC genotypes of rs1044925 were associated with an increased risk of hypertension (AC/CC vs AA: adjusted odds ratio = 1.723, 95% confidence interval = 1.160-2.559, P = .007). However, the AC/CC genotypes showed no relationship with serum lipid levels. The results suggest that the C carriers of ACAT1 rs1044925 might increase the risk of hypertension in Tongdao Dong population, and the underlying mechanism needs to be further studied., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Objectives: Mitochondrial acetoacetyl-CoA thiolase (beta-ketothiolase, T2) is necessary for the catabolism of ketone bodies andisoleucine. T2 deficiency is an autosomal recessive metabolic disorder caused by variant in the ACAT1 gene. In this report, we describe two novel ACAT1 variant identified in a Chinese family., Case Presentation: The 9-month-old male proband was admitted to the pediatric intensive care unit for altered consciousness. At the time of admission, the patient had acidosis, drowsiness, and respiratory failure. Both urine organic acid analyses and LC-MS/MS suggested T2 deficiency. Novel compound heterozygous variant (c.871G>C and c.1016&#95;1017del) in the ACAT1 gene were detected in the proband by WES and verified through direct sequencing. Family analysis demonstrated that the first variant was transmitted from his father and the second variant was from his mother, indicating autosomal recessive inheritance. This report is the first to describe the association of these variant with T2 deficiency based on genetic testing. Although these variant were identified in the patient's elder sister and elder brother, they continue to be asymptomatic., Conclusions: We identified two novel ACAT1 variants associated with T2 deficiency. The identification expands the spectrum of known variant linked to the disorder., (© 2022 Walter de Gruyter GmbH, Berlin/Boston.)

Bacterial polyynes are highly active natural products with a broad spectrum of antimicrobial activities. However, their detailed mechanism of action remains unclear. By integrating comparative genomics, transcriptomics, functional genetics, and metabolomics analysis, we identified a unique polyyne resistance gene, masL (encoding acetyl-CoA acetyltransferase), in the biosynthesis gene cluster of antifungal polyynes (massilin A 1, massilin B 2, collimonin C 3, and collimonin D 4) of Massilia sp. YMA4. Crystallographic analysis indicated that bacterial polyynes serve as covalent inhibitors of acetyl-CoA acetyltransferase. Moreover, we confirmed that the bacterial polyynes disrupted cell membrane integrity and inhibited the cell viability of Candida albicans by targeting ERG10, the homolog of MasL. Thus, this study demonstrated that acetyl-CoA acetyltransferase is a potential target for developing antifungal agents., (© 2022. The Author(s).)

Background: Abnormal accumulation of acyl-CoA cholesterol acyltransferase-1 (ACAT1) and ACAT1-mediated cholesterol esterified with fatty acids (CE) contribute to cancer progression in various cancers. Our findings of increased CE and ACAT1 levels in epithelial ovarian cancer (EOC) cell lines prompted us to investigate whether such an increase occurs in primary clinical samples obtained from human subjects diagnosed with EOC. We evaluated the diagnostic/prognostic potential of ACAT1 and CE in EOC by: 1) assessing ACAT1 and CE levels in plasma, peritoneal fluid, and ovarian/tumor tissues; 2) assessing diagnostic performance by Receiver Operating Characteristic (ROC) analysis; and 3) comparing expression of ACAT1 and CE with that of tumor proliferation marker, Ki67., Methods: ACAT1 protein levels in plasma, peritoneal fluid and tissue were measured via enzyme-linked immunosorbent assay. Tissue expression of ACAT1 and Ki67 proteins were confirmed by immunohistochemistry and mRNA transcript levels were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). CE levels were assessed in plasma, peritoneal fluid (colorimetric assay) and in tissue (thin layer chromatography)., Results: Preoperative levels of ACAT1 and CE on the day of surgery were significantly higher in tissue and peritoneal fluid from EOC patients vs. the non-malignant group, which included subjects with benign tumors and normal ovaries; however, no significant differences were observed in plasma. In tissue and peritoneal fluid, positive correlations were observed between CE and ACAT1 levels, as well as between ACAT1/CE and Ki67., Conclusions: ACAT1 and CE accumulation may be linked to the aggressive potential of EOC; therefore, these mediators may be useful biomarkers for EOC prognosis and target-specific treatments., (© 2022. The Author(s).)

Background: Acetyl-CoA acyltransferase 1 (ACAT1) is a key enzyme catalyzing the production of mitochondrial ketone bodies. We have shown that ACAT1 is down-regulated in kidney renal clear cell carcinoma (KIRC) previously., Objective: To investigate the reasons for downregulation of ACAT1 in KIRC and explore the underlying mechanisms involved in metastatic inhibition regulated by ACAT1., Methods: The Gene Expression Omnibus (GEO) database was queried for meta-analysis of ACAT1 mRNA expression in KIRC. The UALCAN website was used to compare the methylation levels of the ACAT1 promoter region in KIRC and normal tissues. RT-qPCR was used to quantitate ACAT1 transcription levels. The GCBI and Tarbase V.8 databases were used to predict miRNAs that may target the mRNA of ACAT1. The correlation between mRNA expression of ACAT1, MMP7 (matrix metallopeptidase 7), CDH1 (E-cadherin), EpCAM (epithelial cell adhesion molecule), and VIM (vimentin) was analyzed. Extracellular MMP7 protein was quantitated using an ELISA assay., Results: The methylation level of the ACAT1 promoter region in KIRC was significantly higher than that in the normal kidney tissues. The ACAT1 mRNA expression in the KIRC cell lines was restored after treatment with 5-aza-dC (p < 0.05). MiR-21-5p is a conserved microRNA targeting ACAT1. It is expressed at a significantly higher level in KIRC than in normal tissues (p < 0.001). MiR-21-5p miRNA expression negatively correlates with ACAT1 mRNA expression. The expression of miR-21-5p is higher at the T3-T4 stages and in the histologic grades G3-G4. Patients with high miR-21-5p expression tended to have lower overall survival, suggesting that miR-21-5p could serve as a potentially valuable diagnostic biomarker for KIRC (AUC = 0.957; p < 0.001). A mimetic of miR-21-5p inhibited the expression of ACAT1 mRNA and protein. In addition, ACAT1 mRNA expression positively correlates with CDH1 and EpCAM but is negatively correlated with VIM. Overexpression of ACAT1 suppresses the secretion of MMP7 in KIRC cells., Conclusion: Expression of ACAT1 in KIRC is controlled at two levels, firstly by the hypermethylation of the ACAT1 promoter region and secondly by overexpression of miR-21-5p. Downregulation of ACAT1 expression correlates with epithelial-mesenchymal transition (EMT)., (© 2022. The Author(s) under exclusive licence to The Genetics Society of Korea.)

Thiolase plays important roles in lipid metabolism. It can be divided into degradative thiolases (thioase I) and biosynthetic thiolases (thiolases II), which are involved in fatty acid β-oxidation and acetoacetyl-CoA biosynthesis, respectively. The Saccharomyces cerevisiae genome harbors only one gene each for thioase I and thiolase II, namely, Pot1 and Erg10 , respectively. In this study, six thiolases (named AoErg10A to AoErg10F) were identified in Aspergillus oryzae genome using bioinformatics analysis. Quantitative reverse transcription-PCR (qRT-PCR) indicated that the expression of these six thiolases varied at different growth times and under different forms of abiotic stress. Subcellular localization analysis showed that AoErg10A was located in the cytoplasm, AoErg10B and AoErg10C were in the mitochondria, and AoErg10D, AoErg10E, and AoErg10F were in the peroxisome. Yeast heterologous complementation assays revealed that AoErg10A, AoErg10D, AoErg10E, AoErg10F, and cytoplasmic AoErg10B (AoErg10B ΔMTS ) recovered the phenotypes of S. cerevisiae erg10 weak and lethal mutants and that only AoErg10D, AoErg10E, and AoErg10F recovered the phenotype of the pot1 mutant that cannot use oleic acid as the carbon source. Overexpression of AoErg10s affected either the growth speed or the sporulation of the transgenic strains. In addition, the fatty acid and ergosterol content changed in all the AoErg10-overexpressing strains. This study revealed the function of six thiolases in A. oryzae and their effect on growth and fatty acid and ergosterol biosynthesis, which may lay the foundation for genetic engineering for lipid metabolism in A. oryzae or other fungi. IMPORTANCE Thiolases, including thioase I and thiolase II, play important roles in lipid metabolism. Aspergillus oryzae, one of the most industrially important filamentous fungi, has been widely used for manufacturing oriental fermented food such as sauce, miso, and sake for a long time. In addition, A. oryzae has a high capability in production of high lipid content and has been used for lipid production. Thus, it is very important to investigate the function of thiolases in A. oryzae. In this study, six thiolase (named AoErg10A to AoErg10F) were identified by bioinformatics analysis. Unlike other reported thiolases in fungi, three of the six thiolases showed dual functions of thioase I and thiolase II in S. cerevisiae, indicating that the lipid metabolism is more complex in A. oryzae. The reveal of function of these thiolases in A. oryzae can lay the foundation for genetic engineering for lipid metabolism in A. oryzae or other fungi.

Platycodon grandiflorus is a well-known and widely distributed traditional herbal medicine and functional food in Asia, with triterpenoids as the main bioactive component in its roots. Acetyl-CoA C-acetyltransferase (AACT) is the initiation enzyme in the mevalonate pathway and plays an important role in the biosynthesis of terpenoids., Objective: The objective of this study was to clone and identify the PgAACT function in P. grandiflorus., Methods: The full-length sequence of PgAACT genes was isolated and cloned from P. grandiflorus by polymerase chain reaction (PCR). The recombinant plasmid was constructed using the pET-32a vector and expressed in E. coli Transetta (DE3) cells. Subcellular localization of AACT was observed in the epidermal cells of N. tabacum. Quantitative reverse transcription-PCR (qRT-PCR) was used to identify the PgAACT gene transcription levels. After MeJA treatment, the changes in AACT gene expression were observed, and UHPLC-Q-Exactive Orbitrap MS/MS was used to detect the changes in P. grandiflorus saponins., Results: In this study, two full-length cDNAs encoding AACT1 (PgAACT1) and AACT2 (PgAACT2) were isolated and cloned from P. grandiflorus. The deduced PgAACT1 and PgAACT2 proteins contain 408 and 416 amino acids, respectively. The recombinant vectors were constructed, and the protein expression was improved by optimizing the reaction conditions. Sodium dodecyl sulphate-polycrylamide gel electrophloresis and western blot analysis showed that the PgAACT genes were successfully expressed, with molecular weights of the recombinant proteins of 61 and 63 kDa, respectively. Subcellular localization showed that the PgAACT genes were localized in the cytoplasm. Tissue specificity analysis of P. grandiflorus from different habitats showed that PgAACT genes were expressed in the roots, stems, and leaves. After MeJA treatment, the expression level of PgAACT genes and the content of total saponins of P. grandiflorus were significantly increased, suggesting that PgAACT genes play an important role in regulating plant defense systems., Conclusion: Cloning, expression, and functional analysis of PgAACT1 and PgAACT2 will be helpful in understanding the role of these two genes in terpene biosynthesis., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Cangzhu (Atractylodes lancea), a valuable and common traditional Chinese medicinal herb, is primarily used as an effective medicine with various health-promoting effects. The main pharmacological bioactive ingredients in the rhizome of A. lancea are terpenoids. Acetyl-CoA C-acetyltransferase (AACT) is the first enzyme in the terpenoid synthesis pathway and catalyzes two units of acetyl-CoA into acetoacetyl-CoA., Objective: The objective of the present work was to clone and identify function of AlAACT from Atractylodes lancea., Methods: A full-length cDNA clone of AlAACT was isolated using PCR and expressed in Escherichia coli. The expressed protein was purified using Ni-NTA agarose column using standard protocols. AlAACT was transiently expressed in N. benthamiana leaves to determine their subcellular location. The difference in growth between recombinant bacteria and control bacteria under different stresses was observed using the droplet plate experiment., Results: In this study, a full-length cDNA of AACT (AlAACT) was cloned from A. lancea, which contains a 1,227 bp open reading frame and encodes a protein with 409 amino acids. Bioinformatic and phylogenetic analysis clearly suggested that AlAACT shared high similarity with AACTs from other plants. The recombinant protein pET32a(+)/AlAACT was successfully expressed in Escherichia coli BL21 (DE3) cells induced with 0.4 mM IPTG at 30°C as the optimized condition. The recombinant enzyme pET-32a-AlAACT was purified using the Ni-NTA column based on the His-tag, and the molecular weight was determined to be 62 kDa through SDS-PAGE and Western Blot analysis. The recombinant protein was eluted with 100, 300, and 500 mM imidazole; most of the protein was eluted with 300 mM imidazole. Under mannitol stress, the recombinant pET-32a- AlAACT protein showed a substantial advantage in terms of growth rates compared to the control. However, this phenomenon was directly opposite under NaCl abiotic stress. Subcellular localization showed that AlAACT localizes to the nucleus and cytoplasm., Conclusion: The expression and purification of recombinant enzyme pET-32a-AlAACT were successful, and the recombinant strain pET-32a-AlAACT in showed better growth in a drought stress. The expression of AlAACT-EGFP fusion protein revealed its localization in both nuclear and cytoplasm compartments. This study provides an important foundation for further research into the effects of terpenoid biosynthesis in A. lancea., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Activation of enzymes by monovalent cations (M+) is a widespread phenomenon in biology. Despite this, there are few structure-based studies describing the underlying molecular details. Thiolases are a ubiquitous and highly conserved family of enzymes containing both K+-activated and K+-independent members. Guided by structures of naturally occurring K+-activated thiolases, we have used a structure-based approach to engineer K+-activation into a K+-independent thiolase. To our knowledge, this is the first demonstration of engineering K+-activation into an enzyme, showing the malleability of proteins to accommodate M+ ions as allosteric regulators. We show that a few protein structural features encode K+-activation in this class of enzyme. Specifically, two residues near the substrate-binding site are sufficient for K+-activation: A tyrosine residue is required to complete the K+ coordination sphere, and a glutamate residue provides a compensating charge for the bound K+ ion. Further to these, a distal residue is important for positioning a K+-coordinating water molecule that forms a direct hydrogen bond to the substrate. The stability of a cation-π interaction between a positively charged residue and the substrate is determined by the conformation of the loop surrounding the substrate-binding site. Our results suggest that this cation-π interaction effectively overrides K+-activation, and is, therefore, destabilised in K+-activated thiolases. Evolutionary conservation of these amino acids provides a promising signature sequence for predicting K+-activation in thiolases. Together, our structural, biochemical and bioinformatic work provide important mechanistic insights into how enzymes can be allosterically activated by M+ ions., (© 2021 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Bleomycin (BLM) injury is associated with the severity of acute lung injury (ALI) leading to fibrosis, a high-morbidity, and high-mortality respiratory disease of unknown etiology. BLM-induced ALI is marked by the activation of a potent fibrogenic cytokine transcription growth factor beta-1 (TGFβ-1), which is considered a critical cytokine in the progression of alveolar injury. Previously, our work demonstrated that a diet-derived compound curcumin (diferuloylmethane), represents its antioxidative and antifibrotic application in TGF-β1-mediated BLM-induced alveolar basal epithelial cells. However, curcumin-specific protein targets, as well as its mechanism using mass spectrometry-based proteomic approach, remain elusive. To elucidate the underlying mechanism, a quantitative proteomics approach and bioinformatics analysis were employed to identify the protein targets of curcumin in BLM or TGF-β1-treated cells. With subsequent in vitro experiments, curcumin-related pathways and cellular processes were predicted and validated. The current study discusses two separate proteomics experiments using BLM and TGF-β1-treated cells with the proteomics approach, various unique target proteins were identified, and proteomic analysis revealed that curcumin reversed the expressions of unique proteins like DNA topoisomerase 2-alpha (TOP2A), kinesin-like protein (KIF11), centromere protein F (CENPF), and so on BLM or TGF-β1 injury. For the first time, the current study reveals that curcumin restores TGF-β1 induced peroxisomes like PEX-13, PEX-14, PEX-19, and ACOX1. This was verified by subsequent in vitro assays. This study generated molecular evidence to deepen our understanding of the therapeutic role of curcumin at the proteomic level and may be useful to identify molecular targets for future drug discovery., (© 2021 International Union of Biochemistry and Molecular Biology.)

Polyhydroxyalkanoates (PHAs) provide biodegradable and bio-based alternatives to conventional plastics. Incorporation of 2-hydroxy acid monomers into polymer, in addition to 3-hydroxy acids, offers possibility to tailor the polymer properties. In this study, poly(D-lactic acid) (PDLA) and copolymer P(LA-3HB) were produced and characterized for the first time in the yeast Saccharomyces cerevisiae. Expression of engineered PHA synthase PhaC1437Ps6-19, propionyl-CoA transferase Pct540Cp, acetyl-CoA acetyltransferase PhaA, and acetoacetyl-CoA reductase PhaB1 resulted in accumulation of 3.6% P(LA-3HB) and expression of engineered enzymes PhaC1Pre and PctMe resulted in accumulation of 0.73% PDLA of the cell dry weight (CDW). According to NMR, P(LA-3HB) contained D-lactic acid repeating sequences. For reference, expression of PhaA, PhaB1, and PHA synthase PhaC1 resulted in accumulation 11% poly(hydroxybutyrate) (PHB) of the CDW. Weight average molecular weights of these polymers were comparable to similar polymers produced by bacterial strains, 24.6, 6.3, and 1 130 kDa for P(LA-3HB), PDLA, and PHB, respectively. The results suggest that yeast, as a robust and acid tolerant industrial production organism, could be suitable for production of 2-hydroxy acid containing PHAs from sugars or from 2-hydroxy acid containing raw materials. Moreover, the wide substrate specificity of PHA synthase enzymes employed increases the possibilities for modifying copolymer properties in yeast in the future., (© The Author(s) 2021. Published by Oxford University Press on behalf of Society of Industrial Microbiology and Biotechnology.)

The 3-oxoacyl-CoA thiolases catalyze the last step of the fatty acid β-oxidation pathway. In yeasts and plants, this pathway takes place exclusively in peroxisomes, whereas in animals it occurs in both peroxisomes and mitochondria. In contrast to baker's yeast Saccharomyces cerevisiae, yeast species from the Debaryomycetaceae family also encode a thiolase with predicted mitochondrial localization. These yeasts are able to utilize a range of hydroxyaromatic compounds via the 3-oxoadipate pathway the last step of which is catalyzed by 3-oxoadipyl-CoA thiolase and presumably occurs in mitochondria. In this work, we studied Oct1p, an ortholog of this enzyme from Candida parapsilosis. We found that the cells grown on a 3-oxoadipate pathway substrate exhibit increased levels of the OCT1 mRNA. Deletion of both OCT1 alleles impairs the growth of C. parapsilosis cells on 3-oxoadipate pathway substrates and this defect can be rescued by expression of the OCT1 gene from a plasmid vector. Subcellular localization experiments and LC-MS/MS analysis of enriched organellar fraction-proteins confirmed the presence of Oct1p in mitochondria. Phylogenetic profiling of Oct1p revealed an intricate evolutionary pattern indicating multiple horizontal gene transfers among different fungal groups., (© The Author(s) 2021. Published by Oxford University Press on behalf of FEMS.)

Hyperlipidemia is a risk factor for cardiovascular disease, and miR-21a-5p plays an important role in the occurrence and progression of hyperlipidemia. Here, we aimed to investigate the mechanism of aerobic exercise improved hyperlipidemia through enhancing miR-21a-5p expression. In this study, high-fat/high-cholesterol diet mice received 8 weeks of aerobic exercise intervention, then we collected plasma and liver samples, we found that there had a notable improvement in weight gain, blood lipid level, and liver steatosis in hyperlipidemia mice after 8 weeks of aerobic exercise intervention. Besides, aerobic exercise significantly up-regulated the expression of miR-21a-5p and provoked favorable changes in the expression of target genes. Knockdown of miR-21a-5p resulted in dysregulation of lipid metabolism and increased expression of FABP7, HMGCR, ACAT1, and OLR1. While aerobic exercise could alleviate miR-21a-5p knock-down induced lipid metabolism disorder. Taken together, these results demonstrated that aerobic exercise improved hyperlipidemia through miR-21a-5p-induced inhibition of target genes FABP7, HMGCR, ACAT1, and OLR1.

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis largely owing to its inefficient diagnosis, rapid progress, and tenacious drug resistance. Here, we aimed to analyze the expressive patterns of proteins and phosphorylation in PDAC tissue samples and compare them to normal pancreatic tissue to investigate the underlying mechanisms and to reveal potential protein targets for diagnosis and drug development. Liquid chromatography coupled to mass spectrometry (LC-MS) based proteomics and phosphoproteomics analyses were performed using 20 pairs of patient-derived PDAC tissue and normal pancreatic tissue samples. Protein identification and quantification were conducted using MaxQuant software. Bioinformatics analysis was used to retrieve PDAC-relevant pathways and gene ontology (GO) terms. 4985 proteins and 3643 phosphoproteins were identified with high confidence; of these, 322 proteins and 235 phosphoproteins were dysregulated in PDAC. Several pathways, including several extracellular matrix-related pathways, were found to be strongly associated with PDAC. Further, the expression levels of filamin A (FLNA), integrin alpha-V (ITGAV), thymidine phosphorylase (TYMP), medium-chain specific acyl-CoA dehydrogenase, mitochondrial (ACADM), short-chain specific acyl-CoA dehydrogenase, mitochondrial (ACADS), and acetyl-CoA acetyltransferase, mitochondrial (ACAT1) were examined through western blot and immunohistochemistry analysis, and the results confirmed the validity of the proteomics analysis results. These findings provide comprehensive insight into the dysregulated regulative networks in PDAC tissue samples at the protein and phosphorylation levels, and they provide clues for further pathological studies and drug-target development.

Objective: To explore the genetic etiology of a child suspected for β-ketothiolase deficiency by neonatal screening., Methods: All coding exons and flanking sequences of the ACAT1 gene were subjected to targeted capture and high-throughput sequencing. Suspected variants were verified by Sanger sequencing and bioinformatic analysis., Results: The child was found to harbor compound heterozygous variants of the ACAT1 gene, namely c.121-3C>G and c.275G>A (p. Gly92Asp). The c.121-3C>G variant was also detected in his father and two sisters, while the c.275G>A (p. Gly92Asp) was a de novo variant. A c.334+ 172C>G (rs12226047) polymorphism was also detected in his mother and two sisters. Sanger sequencing has verified that the c.275G>A (p. Gly92Asp) and c.334+172C>G (rs12226047) variants are located on the same chromosome. Bioinformatics analysis suggested both c.121-3C>G and c.275G>A (p.G92D) variants to be damaging. Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.275G>A variant of the ACAT1 gene was predicted to be pathogenic (PS2+ PM2+ PM3+ PP3+PP4), the c.121-3C>G variant to be likely pathogenic (PM2+ PM3+ PP3+PP4)., Conclusion: The c.121-3C>G and c.275G>A variants of the ACAT1 gene probably underlay the pathogenesis of the child. Above finding has enriched the variant spectrum of the ACAT1 gene.

The wide use of malachite green (MG) as a dye has caused substantial concern owing to its toxicity. Bacillus cereus can against the toxic effect of MG and efficiently decolourise it. However, detailed information regarding its underlying adaptation and degradation mechanisms based on proteomic data is scarce. In this study, the isobaric tags for relative and absolute quantitation (iTRAQ)-facilitated quantitative method was applied to analyse the molecular mechanisms by which B. cereus degrades MG. Based on this analysis, 209 upregulated proteins and 198 downregulated proteins were identified with a false discovery rate of 1% or less during MG biodegradation. Gene ontology and KEGG analysis determined that the differentially expressed proteins were enriched in metabolic processes, catalytic activity, antioxidant activity, and responses to stimuli. Furthermore, real-time qPCR was utilised to further confirm the regulated proteins involved in benzoate degradation. The proteins BCE&#95;4076 (Acetyl-CoA acetyltransferase), BCE&#95;5143 (Acetyl-CoA acetyltransferase), BCE&#95;5144 (3-hydroxyacyl-CoA dehydrogenase), BCE&#95;4651 (Enoyl-CoA hydratase), and BCE&#95;5474 (3-hydroxyacyl-CoA dehydrogenase) involved in the benzoate degradation pathway may play an important role in the biodegradation of MG by B. cereus. The results of this study not only provide a comprehensive view of proteomic changes in B. cereus upon MG loading but also shed light on the mechanism underlying MG biodegradation by B. cereus.

Sandalwood (Santalum album L.) is famous for its unique fragrance derived from the essential oil of heartwood, whose major components are santalols. To understand the mechanism underlying the biosynthesis of santalols, in this study, we cloned two related genes involved in the mevalonate pathway in S. album coding for acetyl-CoA C-acetyl transferase (AACT) and 3-hydroxy-3-methyglutary-CoA synthase (HMGS). These genes were characterized and functionally analyzed, and their expression profiles were also assessed. An AACT gene designated as SaAACT (GenBank accession No. MH018694) and a HMGS gene designated as SaHMGS (GenBank accession No. MH018695) were successfully cloned from S. album. The deduced SaAACT and SaHMGS proteins contain 415 and 470 amino acids, and the corresponding size of their open-reading frames is 1538 bp and 1807 bp, respectively. Phylogenetic trees showed that the SaAACT protein had the closest relationship with AACT from Hevea brasiliensis and the SaHMGS proteins had the highest homology with HMGS from Siraitia grosvenorii. Functional complementation of SaAACT and SaHMGS in a mutant yeast strain deficient in these proteins confirmed that SaAACT and SaHMGS cDNA encodes functional SaAACT and SaHMGS that mediate mevalonate biosynthesis in yeast. Tissue-specific expression analysis revealed that both genes were constitutively expressed in all examined tissues (roots, sapwood, heartwood, young leaves, mature leaves and shoots) of S. album, both genes showing highest expression in roots. After S. album seedlings were treated with 100 μM methyl jasmonate, the expression levels of SaAACT and SaHMGS genes increased, suggesting that these genes were responsive to this elicitor. These studies provide insight that would allow further analysis of the role of genes related to the sandalwood mevalonate pathway in the regulation of biosynthesis of sandalwood terpenoids and a deeper understanding of the molecular mechanism of santalol biosynthesis.

Cell-to-cell fusion is crucial for the development and propagation of most eukaryotic organisms. Despite this importance, the molecular mechanisms mediating this process are only poorly understood in biological systems. In particular, the step of plasma membrane merger and the contributing proteins and physicochemical factors remain mostly unknown. Earlier studies provided the first evidence of a role of membrane sterols in cell-to-cell fusion. By characterizing different ergosterol biosynthesis mutants of the fungus Neurospora crassa , which accumulate different ergosterol precursors, we show that the structure of the sterol ring system specifically affects plasma membrane merger during the fusion of vegetative spore germlings. Genetic analyses pinpoint this defect to an event prior to engagement of the fusion machinery. Strikingly, this effect is not observed during sexual fusion, suggesting that the specific sterol precursors do not generally block membrane merger, but rather impair subcellular processes exclusively mediating fusion of vegetative cells. At a colony-wide level, the altered structure of the sterol ring system affects a subset of differentiation processes, including vegetative sporulation and steps before and after fertilization during sexual propagation. Together, these observations corroborate the notion that the accumulation of particular sterol precursors has very specific effects on defined cellular processes rather than nonspecifically disturbing membrane functioning. Given the phenotypic similarities of the ergosterol biosynthesis mutants of N. crassa during vegetative fusion and of Saccharomyces cerevisiae cells undergoing mating, our data support the idea that yeast mating is evolutionarily and mechanistically more closely related to vegetative than sexual fusion of filamentous fungi., (Copyright © 2020 by the Genetics Society of America.)

Because of their function of catalyzing the rearrangement of the carbon chains, thiolases have attracted increasing attentions over the past decades. The 3-ketoacyl-CoA thiolase (KAT) is a member of the thiolase, which is capable of catalyzing the Claisen condensation reaction between the two acyl-CoAs, thereby achieving carbon chain elongation. In this way, diverse value-added compounds might be synthesized starting from simple small CoA thioesters. However, most KATs are hampered by low stability and poor substrate specificity, which has hindered the development of large-scale biosynthesis. In this review, the common characteristics in the three-dimensional structure of KATs from different sources are summarized. Moreover, structure-guided rational engineering is discussed as a strategy for enhancing the performance of KATs. Finally, we reviewed the metabolic engineering applications of KATs for producing various energy-storage molecules, such as n-butanol, fatty acids, dicarboxylic acids, and polyhydroxyalkanoates. KEY POINTS: • Summarize the structural characteristics and catalyzation mechanisms of KATs. • Review on the rational engineering to enhance the performance of KATs. • Discuss the applications of KATs for producing energy-storage molecules.

The main objective of the present study was to investigate the toxic effect of long-term exposure to DDT (2,2-dichlorodiphenyl-1,1,1-trichloroethane) on rat livers. Female Wistar rats were treated with once-weekly i.p. doses of DDT (10 and 50 mg/kg) for 12 weeks. Histological analysis revealed significant changes in the liver structure, especially at a dose of 50 mg/kg, which consistent with a fibrotic state. Long-term DDT exposure increased micro RNA-21 (miR-21) level and decreased Acetyl-CoA acetyltransferase 1 ( Acat1 ) mRNA and protein levels in a dose-dependent manner. A dual-luciferase reporter assay confirmed the regulation of the rat Acat1 3'-UTR by miR-21. Previous studies have described the involvement of ACAT1 in fibrogenesis; thus, regulation of the Acat1 gene by miR-21 may play a role in DDT exposure-mediated liver fibrosis.

Acetyl-CoA C-acetyltransferase synthase gene (AACT) cDNA, DNA and promoter were cloned from Sanghuangporus baumii. The gene ORF (1260 bp) encoded 419 amino acids. The AACT DNA includes five exons (1-84 bp, 140-513 bp, 570-1027 bp, 1090-1282 bp, 1344-1494 bp) and four introns (85-139 bp, 514-569 bp, 1028-1089 bp, 1283-1343 bp). The molecular weight of AACT protein is 43.40 kDa, it is hydrophilic with a theoretical isoelectric point of 8.96. Furthermore, The region of the transcription start site is 1997-2047 bp of AACT promoter, and it contained promoter elements (TATA Boxs, CAAT Boxs, CAAT-box, ABRE, G-Boxs, Sp1, MSA-like, LTR). AACT recombinant protein (43.40 KDa + Tag protein 22.68 KDa) was subjected in SDS-PAGE. AACT the transcription levels of in different development stages were investigated. The expression of AACT in primordia (2.4-fold) and 15 d mycelia (2.3- fold) were significantly higher than 9 d mycelia (contral). The expression level of the AACT downstream genes and triterpenoids content were determined at different developmental stages. Triterpenoid content reached its peak on day 15(7.21 mg/g)., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: 2-methylacetoacetyl-coenzyme A thiolase deficiency (MATD; deficiency of mitochondrial acetoacetyl-coenzyme A thiolase T2/ "beta-ketothiolase") is an autosomal recessive disorder of ketone body utilization and isoleucine degradation due to mutations in ACAT1., Methods: We performed a systematic literature search for all available clinical descriptions of patients with MATD. Two hundred forty-four patients were identified and included in this analysis. Clinical course and biochemical data are presented and discussed., Results: For 89.6% of patients at least one acute metabolic decompensation was reported. Age at first symptoms ranged from 2 days to 8 years (median 12 months). More than 82% of patients presented in the first 2 years of life, while manifestation in the neonatal period was the exception (3.4%). 77.0% (157 of 204 patients) of patients showed normal psychomotor development without neurologic abnormalities., Conclusion: This comprehensive data analysis provides a systematic overview on all cases with MATD identified in the literature. It demonstrates that MATD is a rather benign disorder with often favourable outcome, when compared with many other organic acidurias.

Ergosterol plays an important role in maintaining cell membrane sterol homeostasis in fungi, and as such, it is considered an effective target in antifungal chemotherapy. In yeast, the enzyme acetyl-coenzyme A (CoA) acetyltransferase (ERG10) catalyzes the Claisen condensation of two acetyl-CoA molecules to acetoacetyl-CoA in the ergosterol biosynthesis pathway and is reported as being critical for cell viability. Using yeast ERG10 for alignment, two orthologues, Af ERG10A (AFUB&#95;000550) and Af ERG10B (AFUB&#95;083570), were discovered in the opportunistic fungal pathogen Aspergillus fumigatus Despite the essentiality of Af ERG10B having been previously validated, the biological function of Af ERG10A remains unclear. In this study, we have characterized recombinant Af ERG10A as a functional acetyl-CoA acetyltransferase catalyzing both synthetic and degradative reactions. Unexpectedly, Af ERG10A localizes to the mitochondria in A. fumigatus , as shown by C-terminal green fluorescent protein (GFP) tag fusion. Both knockout and inducible promoter strategies demonstrate that Aferg10A is essential for the survival of A. fumigatus The reduced expression of Aferg10A leads to severe morphological defects and increased susceptibility to oxidative and cell wall stresses. Although the catalytic mechanism of acetyl-CoA acetyltransferase family is highly conserved, the crystal structure of Af ERG10A and its complex with CoA are solved, revealing four substitutions within the CoA binding site that are different from human orthologues. Taken together, our combination of genetic and structural studies demonstrates that mitochondrial Af ERG10A is essential for A. fumigatus cell viability and could be a potential drug target to feed the antifungal drug development pipeline. IMPORTANCE A growing number of people worldwide are suffering from invasive aspergillosis caused by the human opportunistic fungal pathogen A. fumigatus Current therapeutic options rely on a limited repertoire of antifungals. Ergosterol is an essential component of the fungal cell membrane as well as a target of current antifungals. Approximately 20 enzymes are involved in ergosterol biosynthesis, of which acetyl-CoA acetyltransferase (ACAT) is the first enzyme. Two ACATs in A. fumigatus are Af Erg10A and Af Erg10B. However, the biological function of Af Erg10A is yet to be investigated. In this study, we showed that Af Erg10A is localized in the mitochondria and is essential for A. fumigatus survival and morphological development. In combination with structural studies, we validated Af Erg10A as a potential drug target that will facilitate the development of novel antifungals and improve the efficiency of existing drugs., (Copyright © 2020 Zhang et al.)

While hundreds of consistently altered metabolic genes had been identified in hepatocellular carcinoma (HCC), the prognostic role of them remains to be further elucidated. Messenger RNA expression profiles and clinicopathological data were downloaded from The Cancer Genome Atlas-Liver Hepatocellular Carcinoma and GSE14520 data set from the Gene Expression Omnibus database. Univariate Cox regression analysis and lasso Cox regression model established a novel four-gene metabolic signature (including acetyl-CoA acetyltransferase 1, glutamic-oxaloacetic transaminase 2, phosphatidylserine synthase 2, and uridine-cytidine kinase 2) for HCC prognosis prediction. Patients in the high-risk group shown significantly poorer survival than patients in the low-risk group. The signature was significantly correlated with other negative prognostic factors such as higher α-fetoprotein. The signature was found to be an independent prognostic factor for HCC survival. Nomogram including the signature shown some clinical net benefit for overall survival prediction. Furthermore, gene set enrichment analyses revealed several significantly enriched pathways, which might help explain the underlying mechanisms. Our study identified a novel robust four-gene metabolic signature for HCC prognosis prediction. The signature might reflect the dysregulated metabolic microenvironment and provided potential biomarkers for metabolic therapy and treatment response prediction in HCC., (© 2019 Wiley Periodicals, Inc.)

Acyl-coenzyme A: cholesterol acyltransferase 1 (ACAT1) is an enzyme that converts cholesterol to cholesteryl esters. A recent in vivo study reported that inhibiting ACAT1 enzyme activity upregulates the membrane cholesterol levels of T cells, enhancing their cytotoxic function. In the present study, we investigated whether the presence of the ACAT1 single nucleotide polymorphism rs11545566 in transplant donors affected the risk of graft-versus-host disease (GVHD) in 116 adult patients who underwent bone marrow transplantation from human leukocyte antigen-identical sibling donors, and who received GVHD prophylaxis with short-term methotrexate and cyclosporine. The frequencies of the AA, AG, and GG genotypes in the donors were 31%, 45%, and 24%, respectively. The cumulative incidences of grade II-IV acute GVHD on day 100 in patients whose donors had AA vs. non-AA genotypes were 6% and 18%, respectively, and those of extensive chronic GVHD at 2 years were 7% and 32%, respectively. Multivariate analyses demonstrated that donor rs11545566 non-AA genotypes showed a trend toward a higher incidence of grade II-IV acute GVHD (P = 0.079), and were significantly associated with a higher incidence of extensive chronic GVHD (P = 0.021). These results suggest that donor ACAT1 rs11545566 genotype may be predictive of GVHD.

Backgound: Obesity and dyslipidemia are major risk factors associated with non-alcoholic fatty liver disease (NAFLD). NAFLD refers to the accumulation of fat in more than 5% of the liver without alcohol consumption. NAFLD is the most common liver disease and is rapidly becoming a global public health problem. Maoberry (Antidesma bunius) is a fruit rich in antioxidants, especially phenolic compounds, which are reported to have benefits for patients with NAFLD., Methods: We evaluated the effect of Maoberry extract on fat metabolism in liver tissues of high fat diet-induced rats. Five (5) groups (n = 12) of male Sprague-Dawley (SD) rats were divided into those given a high fat diet with no treatment (HF), different dosages of Maoberry extracts (0.38 [ML], 0.76 [MM) and 1.52 [MH] g/kg body weight) and 10 mg/kg statin (STAT). The rats were fed a high fat diet for 4 weeks to induce obesity and subsequently continued more for 12 weeks with treatments of Maoberry extracts or STAT. The levels of triglyceride, liver enzymes, oxidative stress and inflammation markers, triglyceride synthesis regulators, and pathology of the liver in high fat diet-induced rats were investigated., Results: Feeding Maoberry extract in MH groups resulted in decreasing levels of serum alanine aminotransferase (ALT), liver triglyceride, liver thiobarbituric acid reactive substances (TBARS) and mRNA expression of tumour necrosis factor (TNF)-α, interleukin (IL)-6, glycerol-3-phosphate acyltransferase (GPAT)-1 and acetyl-coenzyme A carboxylase (ACC) compared with the HF group (P < 0.05). Moreover, histopathological study of the liver showed reduced fat droplets in the Maoberry extract treatment groups, especially in MH groups and STAT treatment groups., Conclusions: The improvements of fat metabolism in liver tissues of rats fed a high-fat diet were observed in Maoberry extracts treatment groups. The underline mechanism that link to fat metabolism might be through the process accompanied with down-regulated the gene expression of key enzymes of lipid production, antioxidant activity, and anti-inflammation properties of Maoberry extracts which contains high levels of phenolic and flavonoid compounds.

Mitochondrial acetoacetyl-CoA thiolase (T2, encoded by the ACAT1 gene) deficiency is an inherited disorder of ketone body and isoleucine metabolism. It typically manifests with episodic ketoacidosis. The presence of isoleucine-derived metabolites is the key marker for biochemical diagnosis. To date, 105 ACAT1 variants have been reported in 149 T2-deficient patients. The 56 disease-associated missense ACAT1 variants have been mapped onto the crystal structure of T2. Almost all these missense variants concern residues that are completely or partially buried in the T2 structure. Such variants are expected to cause T2 deficiency by having lower in vivo T2 activity because of lower folding efficiency and/or stability. Expression and activity data of 30 disease-associated missense ACAT1 variants have been measured by expressing them in human SV40-transformed fibroblasts. Only two variants (p.Cys126Ser and p.Tyr219His) appear to have equal stability as wild-type. For these variants, which are inactive, the side chains point into the active site. In patients with T2 deficiency, the genotype does not correlate with the clinical phenotype but exerts a considerable effect on the biochemical phenotype. This could be related to variable remaining residual T2 activity in vivo and has important clinical implications concerning disease management and newborn screening., (© 2019 The Authors. Human Mutation Published by Wiley Periodicals, Inc.)

Methylacetoacetyl-coenzyme A thiolase (MAT) deficiency is an autosomal recessive disease caused by a defect of mitochondrial acetoacetyl-CoA thiolase (T2). There is an error of isoleucine catabolism and ketone body utilization due to mutations in the acetyl-Coenzyme A acetyltransferase 1 (ACAT1) gene. We report a case of a 14 months old Sabahan boy with beta deficiency who presented with severe sepsis and ketoacidosis who subsequently recovered.

Background: Deregulation of cholesterol metabolism represents a hallmark of prostate cancer (PCa) and promotes its development., Objective: To compare cholesterol metabolism on individual paired normal and tumour prostate tissues obtained from patients with PCa., Design, Setting, and Participants: Between 2008 and 2012, normal and tumour paired tissue samples were collected from radical prostatectomy specimens from a cohort of 69 patients treated for localised PCa., Outcome Measurements and Statistical Analysis: Tumour and normal tissues were subjected to gene analysis, sterol measurement, and immunohistochemistry. The Wilcoxon paired test and Spearman test were applied for comparison and correlation analyses, respectively. Principal component analysis was also carried out to investigate relationships between quantitative variables., Results and Limitations: Overall, cholesterol concentrations were not significantly different between tissue pairs. However, tumour samples were significantly associated with downregulated de novo cholesterol synthesis, but exhibited 54.7% overexpression of SCARB1 that could increase high-density lipoprotein uptake in PCa. Tumour tissues showed different trafficking of available cholesterol, with significantly lower ACAT1, and an altered efflux via APOE. Furthermore, cholesterol metabolism in tumour tissues was characterised by higher accumulation of 7α-hydroxycholesterol (OHC), 7βOHC, and 7-ketosterol, and a lower level of 27OHC., Conclusions: Focusing on individually paired prostate tissues, our results highlighted several differences between normal and tumour samples linked to a metabolic shift in cholesterol flux. PCa samples exhibited a specific tissue signature characterised by higher SCARB1 expression, higher accumulation of OHC species, and clear downregulation of de novo cholesterol synthesis., Patient Summary: Comparing normal and tumour tissues from the same prostates, our study identified a set of alterations in prostate cancer samples in terms of their use of cholesterol. These included higher cholesterol uptake, accumulation of oxidised cholesterol derivatives, and autonomous cellular production of cholesterol. Together, these data provide promising clinical targets to fight prostate cancer., (Copyright © 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Background: The shortage of food based feedstocks has been one of the stumbling blocks in industrial biomanufacturing. The acetone bioproduction from the traditional acetone-butanol-ethanol fermentation is limited by the non-specificity of products and competitive utilization of food-based substrates. Using genetically modified Escherichia coli to produce acetone as sole product from the cost-effective non-food based substrates showed great potential to overcome these problems., Results: A novel acetone biosynthetic pathway were constructed based on genes from Clostridium acetobutylicum (thlA encoding for thiolase, adc encoding for acetoacetate decarboxylase, ctfAB encoding for coenzyme A transferase) and Escherichia coli MG1655 (atoB encoding acetyl-CoA acetyltransferase, atoDA encoding for acetyl-CoA: acetoacetyl-CoA transferase subunit α and β). Among these constructs, one recombinant MG1655 derivative containing the hybrid pathway consisting of thlA, atoDA, and adc, produced the highest level of acetone from acetate. Reducing the gluconeogenesis pathway had little effect on acetone production, while blocking the TCA cycle by knocking out the icdA gene enhanced the yield of acetone significantly. As a result, acetone concentration increased up to 113.18 mM in 24 h by the resting cell culture coupling with gas-stripping methods., Conclusions: An engineered E. coli strain with optimized hybrid acetone biosynthetic pathway can utilize acetate as substrate efficiently to synthesize acetone without other non-gas byproducts. It provides a potential method for industrial biomanufacturing of acetone by engineered E. coli strains from non-food based substrate.

Background: As an essential platform chemical mostly used for rubber synthesis, isoprene is produced in industry through chemical methods, derived from petroleum. As an alternative, bio-production of isoprene has attracted much attention in recent years. Previous researches were mostly focused on key enzymes to improve isoprene production. In this research, besides screening of key enzymes, we also paid attention to expression intensity of non-key enzymes., Results: Firstly, screening of key enzymes, IDI, MK and IspS, from other organisms and then RBS optimization of the key enzymes were carried out. The strain utilized IDI sa was firstly detected to produce more isoprene than other IDIs. IDI sa expression was improved after RBS modification, leading to 1610-fold increase of isoprene production. Secondly, RBS sequence optimization was performed to reduce translation initiation rate value of non-key enzymes, ERG19 and MvaE. Decreased ERG19 and MvaE expression and increased isoprene production were detected. The final strain showed 2.6-fold increase in isoprene production relative to the original strain. Furthermore, for the first time, increased key enzyme expression and decreased non-key enzyme expression after RBS sequence optimization were obviously detected through SDS-PAGE analysis., Conclusions: This study prove that desired enzyme expression and increased isoprene production were obtained after RBS sequence optimization. RBS optimization of genes could be a powerful strategy for metabolic engineering of strain. Moreover, to increase the production of engineered strain, attention should not only be focused on the key enzymes, but also on the non-key enzymes.

Background: Alzheimer´s disease (AD) is a chronic and progressive disease which impacts caregivers, families and societies physically, psychologically and economically. Currently available drugs can only improve cognitive symptoms, have no impact on progression and are not curative, so identifying and studying new drug targets is important. There are evidences which indicate disturbances in cholesterol homeostasis can be related with AD pathology, especially the compartmentation of intracellular cholesterol and cytoplasmic cholesterol esters formed by acyl-CoA: cholesterol acyltransferase 1 (ACAT1) can be implicated in the regulation of amyloid-beta (Aβ) peptide, involved in AD. Blocking ACAT1 activity, beneficial effects are obtained, so it has been suggested that ACAT1 can be a potential new therapeutic target. The present review discusses the role of cholesterol homeostasis in AD pathology, especially with ACAT inhibitors, and how they have been raised as a therapeutic approach. In addition, the genetic relationship of ACAT and AD is discussed., Conclusion: Although there are several lines of evidence from cell-based and animal studies that suggest that ACAT inhibition is an effective way of reducing cerebral Aβ, there is still an information gap in terms of mechanisms and concerns to cover before passing to the next level. Additionally, an area of interest that may be useful in understanding AD to subsequently propose new therapeutic approaches is pharmacogenetics; however, there is still a lot of missing information in this area., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

BACKGROUND Acyl-coenzymeA: cholesterol acyltransferase (ACAT) 1, a key enzyme converting excess free cholesterol to cholesterol esters, has been demonstrated to be associated with the pathogenesis of Alzheimer disease (AD). However, the mechanism underlying the protective role of ACAT1 blockage in AD progression remains elusive. MATERIAL AND METHODS Human neuroblastoma SH-SY5Y cells were treated for 24 h with increasing concentrations of aggregated Aβ₂₅₋₃₅ (5, 15, 25, and 45 μmol) with or without the ACAT1 siRNA pretreatment. Cell viability analysis was measured by CCK-8 assay. The genome-wide correlation between ACAT1 and all other probe sets was measured by the Pearson correlation coefficient (r). Western blotting was used to detect the ACAT1 protein expression in the hippocampus of APP/PSN transgenic AD mice. The mRNA level for each target was analyzed by qPCR. Western blotting was used to detect the ACAT1, cyclo-oxygenase-2 (Cox2), Calcium voltage-gated channel subunits (CACNAs), and ERK/PKC proteins in SH-SY5Y cells with or without the ACAT1 siRNA pretreatment in the presence of Aβ₂₅₋₃₅. RESULTS The expression of ACAT1 was significantly increased in the hippocampus of APP/PSN mice, and also showed an increasing trend when SH-SY5Y cells were exposed to Aβ₂₅₋₃₅. Silencing ACAT1 significantly attenuated Aβ-induced cytotoxicity and cell apoptosis in SH-SY5Y cells. The genome-wide correlation analysis showed that Ptgs2 had the most significant correlation with Acat1 in the hippocampus of BXD RI mice. We further determined the regulatory effect of ACAT1 on COX2 expression by silencing or over-expressing ACAT1 in SH-SY5Y cells and found that silencing ACAT1 played a protective role in AD progression by regulating CACNAs and PKC/ERK signaling cascades. CONCLUSIONS Silencing ACAT1 attenuates Aβ₂₅₋₃₅-induced cytotoxicity and cell apoptosis in SH-SY5Y cells, which may due to the synergistic effect of ACAT1 and COX2 through PKC/ERK pathways.