acyl-CoA Synthesis Research Articles

Regulatory mechanism of plnC in Lactiplantibacillus plantarum B1 on Plantaricin biosynthesis

The PlnC encoded by plnC is an essential response regulator in Plantaricin biosynthesis well-studied in Lactiplantibacillus plantarum. Since the known effects of plnC are not exhaustive, it is crucial to perfect a precise regulatory mechanism for plnC. Overexpression of plnC was found to transiently reduce bacterial activity during the logarithmic growth phase, however, it significantly increased the expression levels of bacteriocin genes within the pln locus by 1.45–2.35 times. After 16 h of incubation, the overexpression of plnC significantly increased the diameter of the inhibition zone from 10.89 ± 0.36 mm to 12.29 ± 0.33 mm, indicating a notable enhancement in bacteriocin activity (P < 0.05). The proteomic analysis further revealed that plnC affected multiple carbohydrate metabolic pathways, QS and HIF-1 signaling pathways, IMP/UMP biosynthesis, and ribosomal proteins, which resulted in promoting the synthesis of nucleotide precursors and exopolysaccharides, and accelerating ribosome translation rate. And the up-regulated synthesis of long-chain acyl-CoA is an important component that may inhibit PlnD (an inhibitory regulator opposite PlnC) during Plantaricin biosynthesis. These offer a critical basis for forward Plantaricin research and application.

Exploring Community Succession, Assembly Patterns, and Metabolic Functions of Ester-Producing-Related Microbiota during the Production of Nongxiangxing baijiu.

Esters are vital flavor compounds in Chinese Nongxiangxing baijiu and greatly affect the quality of baijiu. Microbial communities inhabiting fermented grains (FGs) have a marked impact on esters. However, the specific microorganisms and their assembly patterns remain unclear. This study utilized high-throughput sequencing and a culture-based method to reveal ester-producing microorganisms. A total of 33 esters were detected, including 19 ethyl esters, 9 linear chain esters, and 2 branched chain esters. A correlation analysis indicated that the bacterial genus Lactobacillus (relative abundance in average: 69.05%) and fungal genera Pichia (2.40%), Aspergillus (11.84%), Wickerhamomyces (0.60%), Thermomyces (3.57%), Saccharomycopsis (7.87%), Issatchenkia (0.96%), and Thermoascus (10.83%) were dominant and associated with esters production and their precursors. The numbers of esters positively correlated with them were 1, 17, 3, 2, 1, 1, 1, and 1, respectively. The modified stochasticity ratio (MST) index and Sloan neutral model revealed that bacteria were predominantly governed by deterministic processes while fungal assemblies were more stochastic. Saturnispora silvae and Zygosaccharomyces bailii were isolated and identified with ester synthesis potential. PICRUSt2 analysis showed that fungi in FG had a high potential for synthesizing ethanol, while 14 enzymes related to esters synthesis were all produced by bacteria, especially enzymes catalyzing the synthesis of acyl-CoA. In addition, ester synthesis was mainly catalyzed by carboxylesterase, acylglycerol lipase and triacylglycerol lipase. These findings may provide insights into ester production mechanism and potential strategies to improve the quality of Nongxiangxing baijiu.

HDAC10 inhibits non-small-cell lung cancer cell ferroptosis through the microRNA-223-5p-SLC7A11 axis.

Non-small-cell lung cancer (NSCLC) is a leading attributor to cancer deaths. High HDAC10 and low microRNA (miR)-223-5p levels have been observed in NSCLC. But their roles remain elusive. This study illustrated their roles in NSCLC cell ferroptosis and the mechanism. HDAC10, miR-223-5p, and solute carrier family 7 member 11 (SLC7A11) levels in cells were determined by RT-qPCR. Iron ion content, reactive oxygen species (ROS), and glutathione (GSH) levels were tested using reagent kits, and levels of SLC7A11 and Acyl-CoA synthesis long chain family (ACSL4) were examined using Western blot. Chromatin immunoprecision was performed to analyze the enrichment of HDAC10 and acetylated lysine 9 of histone H3 (H3K9ac) on the miR-223-5p promoter. The targeted binding of miR-223-5p and SLC7A11 was analyzed by dual-luciferase assay. Joint experiments were designed to identify the role of miR-223-5p/SLC7A11 axis in HDAC10-regulated ferroptosis in NSCLC cells. HDAC10 was highly expressed in NSCLC cells. Silencing HDAC10 significantly reduced GSH and SLC7A11 levels, upregulated iron ion content, ROS levels, and ACSL4 expression, promoting cell ferroptosis. Mechanically, HDAC10 inhibited miR-223-5p expression through H3K9ac deacetylation of the miR-223-5p promoter, thereby targeting SLC7A11. The joint experimental results showed that overexpression of SLC7A11 or downregulation of miR-223-5p alleviated the promoting effect of silencing HDAC10 on ferroptosis in NSCLC cells. HDAC10 inhibits miR-223-5p expression through H3K9ac deacetylation of the miR-223-5p promoter, thereby promoting SLC7A11 expression and inhibiting ferroptosis in NSCLC cells.

Chain Extension of Piperazine in Ethanol: Synthesis of 2-(4-(2-(Phenylthio)ethyl)piperazinyl)acetonitriles and ACAT-1 Inhibitors.

A base-induced synthesis of 2-(4-(2-(phenylthio)ethyl)piperazinyl) acetonitriles by reaction of disulfides, 1-(chloromethyl)-4-aza-1-azonia bicyclo[2.2.2]octane chloride and trimethylsilyl cyanide is reported. The scope of the method is demonstrated with 30 examples. The reaction mechanism research indicates that the three-component reaction would be a SN2 reaction. The products exhibit good activities towards advanced synthesis of aqueous soluble acyl-CoA: cholesterol O-acyltransferase-1 (ACAT-1) inhibitors. Our work is superior as it uses less-odor disulfides as carbon sources and EtOH as solvent in a water and dioxygen insensitive reaction system, followed by a simple purification process.

Microbial inoculum effects on the rumen epithelial transcriptome and rumen epimural metatranscriptome in calves

Manipulation of the rumen microbial ecosystem in early life may affect ruminal fermentation and enhance the productive performance of dairy cows. The objective of this experiment was to evaluate the effects of dosing three different types of microbial inoculum on the rumen epithelium tissue (RE) transcriptome and the rumen epimural metatranscriptome (REM) in dairy calves. For this objective, 15 Holstein bull calves were enrolled in the study at birth and assigned to three different intraruminal inoculum treatments dosed orally once weekly from three to six weeks of age. The inoculum treatments were prepared from rumen contents collected from rumen fistulated lactating cows and were either autoclaved (control; ARF), processed by differential centrifugation to create the bacterial-enriched inoculum (BE), or through gravimetric separation to create the protozoal-enriched inoculum (PE). Calves were fed 2.5 L/d pasteurized waste milk 3x/d from 0 to 7 weeks of age and texturized starter until euthanasia at 9 weeks of age, when the RE tissues were collected for transcriptome and microbial metatranscriptome analyses, from four randomly selected calves from each treatment. The different types of inoculum altered the RE transcriptome and REM. Compared to ARF, 9 genes were upregulated in the RE of BE and 92 in PE, whereas between BE and PE there were 13 genes upregulated in BE and 114 in PE. Gene ontology analysis identified enriched GO terms in biological process category between PE and ARF, with no enrichment between BE and ARF. The RE functional signature showed different KEGG pathways related to BE and ARF, and no specific KEGG pathway for PE. We observed a lower alpha diversity index for RE microbiome in ARF (observed genera and Chao1 (p < 0.05)). Five microbial genera showed a significant correlation with the changes in host gene expression: Roseburia (25 genes), Entamoeba (two genes); Anaerosinus, Lachnospira, and Succiniclasticum were each related to one gene. sPLS-DA analysis showed that RE microbial communities differ among the treatments, although the taxonomic and functional microbial profiles show different distributions. Co-expression Differential Network Analysis indicated that both BE and PE had an impact on the abundance of KEGG modules related to acyl-CoA synthesis, type VI secretion, and methanogenesis, while PE had a significant impact on KEGGs related to ectoine biosynthesis and D-xylose transport. Our study indicated that artificial dosing with different microbial inocula in early life alters not only the RE transcriptome, but also affects the REM and its functions.

Polycyclic aromatic hydrocarbons stress affects fatty acids profile and LacsA (long-chain acyl-CoA synthetize) gene expression in Dunaliella

ABSTRACT This study was conducted to evaluate the effects of different concentrations of two Polycyclic Aromatic Hydrocarbons (PAHs) on the profiles of soluble proteins and fatty acids and on LacsA (long-chain acyl-CoA synthesis) gene expression in Dunaliella tertiolecta and Dunaliella salina. The algae were treated with a control and three experimental concentrations (3000, 6000 and 9000 μg l‒1) of phenanthrene and anthracene. In D. salina treated with 6000 and 9000 μg l‒1 of anthracene, expression of LacsA and α-linolenic acid was higher than in the control treatment. Also, at 3000 and 6000 μg l‒1 of anthracene, there was a sharp increase in hexadecenoic acid and docosahexaenoic acid (omega-3). Dunaliella tertiolecta treated with 9000 μg l‒1of anthracene showed a stronger protein expression profile than other samples which was consistent with LacsA gene expression at the same dose of anthracene. In D. tertiolecta, α-linolenic acid and 11-octadecenoic acid increased significantly at 9000 µg l‒1 of anthracene compared to the control, and there were similar trends in proteins, LacsA gene expression and α-linolenic acid and 11-octadecenoic fatty acids content. Phenanthrene and anthracene have different molecular structures, and it seems that they also have different dose-dependent effects on synthesis/accumulation of fatty acids, SDS-PAGE profiles of proteins and LacsA gene expression in D. salina and D. tertiolecta. According to previous reports, the LacsA gene is mediated by α-linolenic acid, hexadecenoic acid and docosahexaenoic acid (omega-3) synthesis. Since PAHs tend to be accumulated in the cell membrane of the microalgae, microalgae produce various proteins and fatty acids to bioremediate these harmful substances. Our results indicated that Dunaliella spp. may be good candidates for biodegradation purposes as well as an adequate model as a biotechnological accumulator of fatty acids under exposure to PAHs.

Proteomes reveal the lipid metabolic network in the complex plastid of Phaeodactylum tricornutum.

Phaeodactylum tricornutum plastid is surrounded by four membranes, and its protein composition and function remain mysterious. In this study, the P. tricornutum plastid-enriched fraction was obtained and 2850 proteins were identified, including 92 plastid-encoded proteins, through label-free quantitative proteomic technology. Among them, 839 nuclear-encoded proteins were further determined to be plastidial proteins based on the BLAST alignments within Plant Proteome DataBase and subcellular localization prediction, in spite of the strong contamination by mitochondria-encoded proteins and putative plasma membrane proteins. According to our proteomic data, we reconstructed the metabolic pathways and highlighted the hybrid nature of this diatom plastid. Triacylglycerol (TAG) hydrolysis and glycolysis, as well as photosynthesis, glycan metabolism, and tocopherol and triterpene biosynthesis, occur in the plastid. In addition, the synthesis of long-chain acyl-CoAs, elongation, and desaturation of fatty acids (FAs), and synthesis of lipids including TAG are confined in the four-layered-membrane plastid based on the proteomic and GFP-fusion localization data. The whole process of generation of docosahexaenoic acid (22:6) from palmitic acid (16:0), via elongation and desaturation of FAs, occurs in the chloroplast endoplasmic reticulum membrane, the outermost membrane of the plastid. Desaturation that generates 16:4 from 16:0 occurs in the plastid stroma and outer envelope membrane. Quantitative analysis of glycerolipids between whole cells and isolated plastids shows similar composition, and the FA profile of TAG was not different. This study shows that the diatom plastid combines functions usually separated in photosynthetic eukaryotes, and differs from green alga and plant chloroplasts by undertaking the whole process of lipid biosynthesis.

Acyl-CoA synthetase expression in human skeletal muscle is reduced in obesity and insulin resistance.

Upon intramuscular entry, fatty acids are converted to amphiphatic fatty acyl-CoAs by action of the acyl-CoA synthetase (ACS) enzymes. While it has been reported that insulin resistant skeletal muscle shows an accumulation of fatty acyl-CoAs, the role of the enzymes which catalyze their synthesis is still sparsely studied in human muscle, in particular the influence of obesity, and insulin resistance. We analyzed muscle biopsies obtained from normal weight controls (n = 7, average BMI 24), males/females with obesity (n = 7, average BMI 31), and males/females with obesity and type 2 diabetes (T2D) (n = 7, average BMI 34), for relevant ACS (long-chain acyl-CoA synthetase 1 (ACSL1), -3 (ACSL3) and - 4 (ACSL4), fatty acid transport protein 1 (FATP1) and - 4 (FATP4)). The mRNA expression was determined by real-time PCR, and total oleoyl-CoA synthetase activity was measured. In the males/females with obesity and T2D, the response to 16 weeks of exercise training with minor weight loss was evaluated. ACSL1 is the dominantly expressed ACS isoform in human skeletal muscle. The content of total ACS mRNA, as well as ACSL1 mRNA, were lower in muscle of males/females with obesity and T2D. Exercise training in the males/females with obesity and T2D increased the total ACS enzyme activity, along with a lowering of the HOMA-IR index. The capacity for synthesis of fatty acyl-CoAs is lower in skeletal muscle of obese males/females with T2D. This suggests a decreased ability to convert fatty acids to fatty acyl-CoAs, which in turn may affect their entry into storage or metabolic pathways in muscle. Thus, the accumulation of fatty acyl-CoAs in the obese or insulin resistant state that has been shown in previous reports is not likely to result from increased fatty acid acylation. The upregulation of ACS activity by exercise training appears beneficial and occurred concomitantly with increased insulin sensitivity.

Pre-transplant and longitudinal changes in faecal microbiome characteristics are associated with subsequent development of chronic graft-versus-host disease.

The role of the gastrointestinal microbiome in predisposing to chronic graft-versus-host disease (cGVHD), an immune-mediated haematopoietic cell transplant (HCT) complication, is not well defined. We examined the relationship of the host faecal microbiome with subsequent cGVHD development by analysing baseline stool samples as well as post-HCT changes in microbiome composition and metabolite pathway analyses. We analysed pre-transplant baseline samples from 11 patients who subsequently developed cGVHD compared to 13 controls who did not develop acute GVHD or cGVHD at any time. We found a significant differential abundance of multiple taxa at baseline between cGVHD versus controls, including the Actinobacteria phylum and Clostridium genus. A subgroup analysis of longitudinal samples within each patient revealed a greater loss of alpha diversity from baseline to post-engraftment in patients who subsequently developed cGVHD. Metabolic pathways analysis revealed that two pathways associated with short-chain fatty acid metabolism were enriched in cGVHD patient microbiomes: β-oxidation and acyl-CoA synthesis, and γ-aminobutyrate shunt. In contrast, a tryptophan catabolism pathway was enriched in controls. Our findings show a distinct pattern of baseline microbiome and metabolic capacity that may play a role in modulating alloreactivity in patients developing cGVHD. These findings support the therapeutic potential of microbiome manipulation for cGVHD prevention.

Exposure to 6-PPD quinone enhances lipid accumulation through activating metabolic sensors of SBP-1 and MDT-15 in Caenorhabditis elegans

Although it has been shown that exposure to 6-PPDQ can cause toxicity on environmental organisms, its possible effects on metabolic state remain largely unclear. We here determined the effect of 6-PPDQ exposure on lipid accumulation in Caenorhabditis elegans. We observed increase in triglyceride content, enhancement in lipid accumulation, and increase in size of lipid droplets in 6-PPDQ (1–10 μg/L) exposed nematodes. This detected lipid accumulation was associated with both increase in fatty acid synthesis reflected by increased expressions of fasn-1 and pod-2 and inhibition in mitochondrial and peroxisomal fatty acid β-oxidation indicated by decreased expressions of acs-2, ech-2, acs-1, and ech-3. The observed lipid accumulation in 6-PPDQ (1–10 μg/L) exposed nematodes was also related to the increase in synthesis of monounsaturated fatty acylCoAs reflected by altered expressions of fat-5, fat-6, and fat-7. Exposure to 6-PPDQ (1–10 μg/L) further increased expressions of sbp-1 and mdt-15 encoding two metabolic sensors to initiate the lipid accumulation and to regulate the lipid metabolism. Moreover, the observed increase in triglyceride content, enhancement in lipid accumulation, and alterations in fasn-1, pod-2, acs-2, and fat-5 expressions in 6-PPDQ exposed nematodes were obviously inhibited by sbp-1 and mdt-15 RNAi. Our observations demonstrated the risk of 6-PPDQ at environmentally relevant concentration in affecting lipid metabolic state in organisms.

ACSL5, a prognostic factor in acute myeloid leukemia, modulates the activity of Wnt/β-catenin signaling by palmitoylation modification.

Acyl-CoA synthetase long chain family member 5 (ACSL5), is a member of the acyl-CoA synthetases (ACSs) family that activates long chain fatty acids by catalyzing the synthesis of fatty acyl-CoAs. The dysregulation of ACSL5 has been reported in some cancers, such as glioma and colon cancers. However, little is known about the role of ACSL5 in acute myeloid leukemia (AML). We found that the expression of ACSL5 was higher in bone marrow cells from AML patients compared with that from healthy donors. ACSL5 level could serve as an independent prognostic predictor of the overall survival of AML patients. In AML cells, the ACSL5 knockdown inhibited cell growth both in vitro and in vivo. Mechanistically, the knockdown of ACSL5 suppressed the activation of the Wnt/β-catenin pathway by suppressing the palmitoylation modification of Wnt3a. Additionally, triacsin c, a pan-ACS family inhibitor, inhibited cell growth and robustly induced cell apoptosis when combined with ABT-199, the FDA approved BCL-2 inhibitor for AML therapy. Our results indicate that ACSL5 is a potential prognosis marker for AML and a promising pharmacological target for the treatment of molecularly stratified AML.

LsSpt23p is a regulator of triacylglycerol synthesis in the oleaginous yeast Lipomyces starkeyi

The oleaginous yeast Lipomyces starkeyi has considerable potential in industrial application, since it can accumulate a large amount of triacylglycerol (TAG), which is produced from sugars under nitrogen limitation condition. However, the regulation of lipogenesis in L. starkeyi has not been investigated in depth. In this study, we compared the genome sequences of wild-type and mutants with increased TAG productivity, and identified a regulatory protein, LsSpt23p, which contributes to the regulation of TAG synthesis in L. starkeyi. L. starkeyi mutants overexpressing LsSPT23 had increased TAG productivity compared with the wild-type strain. Quantitative real-time PCR analysis showed that LsSpt23p upregulated the expression of GPD1, which encodes glycerol 3-phosphate dehydrogenase; the Kennedy pathway genes SCT1, SLC1, PAH1, DGA1, and DGA2; the citrate-mediated acyl-CoA synthesis pathway-related genes ACL1, ACL2, ACC1, FAS1, and FAS2; and OLE1, which encodes ∆9 fatty acid desaturase. Chromatin immunoprecipitation-quantitative PCR assays indicated that LsSpt23p acts as a direct regulator of SLC1 and PAH1, all the citrate-mediated acyl-CoA synthesis pathway-related genes, and OLE1. These results indicate that LsSpt23p regulates TAG synthesis. Phosphatidic acid is a common substrate of phosphatidic acid phosphohydrolase, which is used for TAG synthesis, and phosphatidate cytidylyltransferase 1 for phospholipid synthesis in the Kennedy pathway. LsSpt23p directly regulated PAH1 but did not affect the expression of CDS1, suggesting that the preferred route of carbon is the Pah1p-mediated TAG synthesis pathway under nitrogen limitation condition. The present study contributes to understanding the regulation of TAG synthesis, and will be valuable in future improvement of TAG productivity in oleaginous yeasts. KEY POINTS: LsSpt23p was identified as a positive regulator of TAG biosynthesis LsSPT23 overexpression enhanced TAG biosynthesis gene expression and TAG production LsSPT23M1108T overexpression mutant showed fivefold higher TAG production than control.

Identification of ACSF gene family as therapeutic targets and immune-associated biomarkers in hepatocellular carcinoma.

Acyl-CoA synthetases (ACSs) are responsible for acyl-CoA synthesis from nonpolar hydrophilic fatty acids and play a vital role in many metabolic processes. As a category of ACS isozymes, members of ACS family (AACS, ACSF2-3, AASDH) participate in lipid metabolism; however, their expression patterns, regulatory mechanisms and effects in hepatocellular carcinoma (HCC) are poorly understood. Here, through evaluating the expression profiles of ACSF gene family, we found that upregulated AACS might be more significant and valuable in development and progression of HCC. Consequently, the mRNA expression levels of AACS and ACSF2 was accordantly increased in HCC. Kaplan-Meier plotter revealed that HCC patients with high level of AACS were highly related to a shorter overall survival time and relapse-free survival. Genetic alterations using cBioPortal revealed that the alteration rate of AACS were 5%. We also found that the functions of ACSF gene family were linked to several cancer-associated pathways, including long-term potentiation, phospholipase D signaling pathway and purine metabolism. TIMER database indicated that the AACS and ACSF2 had a strong relationship with the infiltration of six types of immune cells (macrophages, neutrophils, CD8+ T-cells, B-cells, CD4+ T-cells and dendritic cells). Next, Diseasemeth database revealed that the global methylation levels of ACSF2 was higher in HCC patients. In conclusion, this study firstly demonstrated that Acyl-CoA synthesis gene family, in particular, AACS, could be associated with immune microenvironment, thereby influencing the development and prognosis of patients with HCC.

Insulin-induced palmitoylation regulates the Cardiac Na+/Ca2+ exchanger NCX1

The cardiac Na+/Ca2+ Exchanger (NCX1) controls Ca2+ extrusion from the cytosol by mediating bidirectional exchange of Na+ for Ca2+, and therefore controls cardiac relaxation. Insulin regulates Ca2+ handling in cardiac tissue through NCX1, however how insulin changes NCX1 activity is poorly understood. Palmitoylation is the only post-translational modification identified to alter NCX1 activity. Here we show that insulin triggers local structural re-arrangements within existing NCX1 dimers by inducing their palmitoylation, thus tunes NCX1 inactivation through a zDHHC5-dependent mechanism in multiple cell types. By activating fatty acid and fatty acyl CoA synthesis insulin promotes palmitoylation of the zDHHC5 active site, which leads to enhanced NCX1 palmitoylation. Our findings represent a new mechanism to regulate the palmitoylation of numerous zDHHC5 substrates.

Analysis of Wheat Wax Regulation Mechanism by Liposome and Transcriptome.

As a barrier for plants to contact with the outside world, epidermal wax plays an important role in resisting biotic and abiotic stresses. In this study, we analyzed the effect of wax content on leaf permeability by measuring the wax loss rate in the leaf. To further clarify the wax composition of the wheat epidermis and its molecular regulation mechanism, we applied untargeted lipidomic and transcriptome analysis on the leaf epidermis wax of Jimai 22 low-wax mutant (waxless) and multi-wax mutant (waxy). Our research showed that the mutant waxy has a slow loss rate, which can maintain higher leaf water content. 31 lipid subclasses and 1,367 lipid molecules were identified. By analyzing the wax differences of the two mutants, we found that the main lipid components of leaf epidermis wax in Jimai 22 were WE (C19-C50), DG (C27-C53), MG (C31-C35), and OAHFA (C31-C52). Carbon chain length analysis showed that, in wheat epidermis wax, WE was dominated by C44 molecules, DG was mainly concentrated in C47, C45, C37, and C31 molecules, C48 played a leading role in OAHFA, and C35 and C31 played a major role in MG. Among them, DG, MG, and OAHFA were detected in wheat leaf wax for the first time, and they were closely related to stress resistance. Compared with the waxy, 6,840 DEGs were detected in the mutant waxless, 3,181 DEGs were upregulated, and 3,659 DEGs were downregulated. The metabolic pattern of main waxy components in the wheat epidermis was constructed according to KEGG metabolic pathway and 46 related genes were screened, including KSC, TER, FAR, WSD1, CER1, MAH1, ALDH7A1, CYP704B1, ACOT1_2_4, CYP86, MGLL, GPAT, ALDH, DPP1, dgkA, plsC, and E2.3.1.158 related genes. The screened wax-related genes were confirmed to be highly reliable by qRT-PCR. In addition, we found TER gene TraesCS6B03G1132900LC in wheat mutant waxless leaves for the first time, which inhibited the synthesis of long-chain acyl-CoA (n+2) by downregulating its expression. These results provide valuable reference information for further study of wheat epidermis wax heredity and molecular regulation.

Citrate-Mediated Acyl-CoA Synthesis Is Required for the Promotion of Growth and Triacylglycerol Production in Oleaginous Yeast Lipomyces starkeyi.

The oleaginous yeast Lipomyces starkeyi is an excellent producer of triacylglycerol (TAG) as a feedstock for biodiesel production. To understand the regulation of TAG synthesis, we attempted to isolate mutants with decreased lipid productivity and analyze the expression of TAG synthesis-related genes in this study. A mutant with greatly decreased lipid productivity, sr22, was obtained by an effective screening method using Percoll density gradient centrifugation. The expression of citrate-mediated acyl-CoA synthesis-related genes (ACL1, ACL2, ACC1, FAS1, and FAS2) was decreased in the sr22 mutant compared with that of the wild-type strain. Together with a notion that L. starkeyi mutants with increased lipid productivities had increased gene expression, there was a correlation between the expression of these genes and TAG synthesis. To clarify the importance of citrate-mediated acyl-CoA synthesis pathway on TAG synthesis, we also constructed a strain with no ATP-citrate lyase responsible for the first reaction of citrate-mediated acyl-CoA synthesis and investigated the importance of ATP-citrate lyase on TAG synthesis. The ATP-citrate lyase was required for the promotion of cell growth and TAG synthesis in a glucose medium. This study may provide opportunities for the development of an efficient TAG synthesis for biodiesel production.

Correction of imbalance of essentialaminoacids of blood plasma in Patients with stableangina

Introduction. Ischemic heart disease is the leading nosology calunit in the structure of cardiovascular diseases interms of disability and mortality among the population of Ukraine. The purpose. To improve the treatment of patients with stable angina by studying the effect of L-arginine on the balance of essential amino acids in blood plasma. Material and methods. It was examined 85 patients with stable angina. They were divided into two groups: group Ipatients received antianginal basic therapy, group II patients received basic antianginal therapy and L-arginine. The amino acid spectrum of patients' blood plasma was studied by ion-exchange liquid column chromatography, using an automatic amino acid analyzer T-339 Microtechna (Czech Republic, Prague). Results and discussion. In patients with stable angina who received basic therapy and L-arginine, in contrast to patients who received only basic therapy, plasma levels of arginine became normalized, which probably contributes to the synthesis of NO. The level of valine, leucine and isoleucine, which provide the synthesis of acyl-CoA and succinyl-CoA, became also normalized.Conclusion. Administration of L-arginine to patients with stable angina together with antianginal therapy helps to correct plasma amino acid imbalances, which is likely to effectively affect the course of the disease and prognosis.

Isolation and characterization of Lipomyces starkeyi mutants with greatly increased lipid productivity following UV irradiation

The oleaginous yeast Lipomyces starkeyi is an intriguing lipid producer that can produce triacylglycerol (TAG), a feedstock for biodiesel production. We previously reported that the L.starkeyi mutant E15 with high levels of TAG production compared with the wild-type was efficiently obtained using Percoll density gradient centrifugation. However, considering its use for biodiesel production, it is necessary to further improve the lipid productivity of the mutant. In this study, we aimed to obtain mutants with better lipid productivity than E15, evaluate its lipid productivity, and analyze lipid synthesis-related gene expression in the wild-type and mutant strains. The mutants E15-11, E15-15, and E15-25 exhibiting higher lipid productivity than E15 were efficiently isolated from cells exposed to ultraviolet light using Percoll density gradient centrifugation. They exhibited approximately 4.5-fold higher lipid productivity than the wild-type on day 3. The obtained mutants did not exhibit significantly different fatty acid profiles than the wild-type and E15 mutant strains. E15-11, E15-15, and E15-25 exhibited higher expression of acyl-CoA synthesis- and Kennedy pathway-related genes than the wild-type and E15 mutant strains. Activation of the pentose phosphate pathway, which supplies NADPH, was also observed. These results suggested that the increased expression of acyl-CoA synthesis- and Kennedy pathway-related genes plays a vital role in lipid productivity in the oleaginous yeast L.starkeyi.

The effect of L-arginine on the balance of essential amino acids in plasma of the patients with stable angina

Background. Despite the significant achievements of clinical medicine in the prevention, diagnosis and treatment of coronary heart disease, the levels of morbidity, disability and mortality among the population of Ukraine from this pathology remain consistently high. The purpose. To improve the treatment of patients with stable angina by studying the effect of L-arginine on the balance of essential amino acids in blood plasma. Material and methods. It was examined 67 patients with stable angina. They were divided into two groups: group Ipatients received antianginal basic therapy, group II patients received basic antianginal therapy and L-arginine. The amino acid spectrum of patients' blood plasma was studied by ion-exchange liquid column chromatography, using an automatic amino acid analyzer T-339 Microtechna (Czech Republic, Prague). Results and discussion. In patients with stable angina who received basic therapy and L-arginine, in contrast to patients who received only basic therapy, plasma levels of arginine became normalized, which probably contributes to the synthesis of NO. The level of valine, leucine and isoleucine, which provide the synthesis of acyl-CoA and succinyl-CoA, became also normalized. Conclusion. Administration of L-arginine to patients with stable angina together with antianginal therapy helps to correct plasma amino acid imbalances, which is likely to effectively affect the course of the disease and prognosis.

Discovery of a benzimidazole series as the first highly potent and selective ACSL1 inhibitors

Long-chain acyl-CoA synthetase-1 (ACSL1), an enzyme that catalyzes the synthesis of long-chain acyl-CoA from the corresponding fatty acids, is believed to play essential roles in lipid metabolism. Structure activity relationship studies based on HTS hit compound 1 delivered the benzimidazole series as the first selective and highly potent ACSL1 inhibitors. Representative compound 13 exhibited not only remarkable inhibitory activity against ACSL1 (IC50 = 0.042 μM) but also excellent selectivity for the other ACSL isoforms. In addition, compound 13 demonstrated an in vivo suppression effect against the production of long-chain acyl-CoAs in mouse.