Triglyceride Lipase Research Articles

Novel candidate genes and genetic basis analysis of kernel starch content in tropical maize

BackgroundStarch is the most abundant carbohydrate in maize grains, serving as a primary energy source for both humans and animals, and playing a crucial role in various industrial applications. Increasing the starch content of maize grains is beneficial for improving the grain yield and quality. To gain insight into the genetic basis of starch content in maize kernels, a multiparent population (MPP) was constructed and evaluated for starch content in three different environments.ResultsThe integration of QTL mapping and genome-wide association analysis (GWAS) identified two SNPs, 8_166371888 and 8_178656036, which overlapped the QTL interval of qSC8-1, identified in the tropical maize line YML46. The phenotypic variance explained (PVE) by the QTL qSC8-1 was12.17%, while the SNPs 8_166371888 and 8_178656036 explained 10.19% and 5.72% of the phenotypic variance. Combined GWAS and QTL analyses led to the identification of two candidate genes, Zm00001d012005 and Zm00001d012687 located on chromosome 8.ConclusionsThe candidate geneZm00001d012005 encodes histidine kinase, which is known to play a role in starch accumulation in rice spikes. Related histidine kinases, such as AHK1, are involved in endosperm transfer cell development in barley, which affects grain quality. Zm00001d012687 encodes triacylglycerol lipase, which reduces seed oil content. Since oil content in cereal kernels is negatively correlated with starch content, this gene is likely involved in regulating the starch content in maize kernels. These findings provide insights into the genetic mechanisms underlying kernel starch content and establish a theoretical basis for breeding maize varieties with high starch content.

Characterization of the putative yeast mitochondrial triacylglycerol lipase Tgl2.

Mitochondria derive the majority of their lipids from other organelles through contact sites. These lipids, primarily phosphoglycerolipids, are the main components of mitochondrial membranes. In the cell, neutral lipids like triacylglycerides (TAGs) are stored in lipid droplets, playing an important role in maintaining cellular health. Enzymes like lipases mobilize these TAGs according to cellular needs. Neutral lipids have not yet been reported to play an important role in mitochondria so the presence of a putative TAG lipase - Tgl2, in yeast mitochondria is surprising. Moreover, TGL2 and MCP2, a high-copy suppressor for ERMES deficient cells, display genetic interactions suggesting a potential link of both proteins to lipid metabolism. In this study, we characterize in detail Tgl2. We show that Tgl2 forms dimers through intermolecular disulfide bridges and a cysteine-dependent high molecular weight complex. Furthermore, we could identify the lipase motif and catalytic triad of Tgl2 through in silico comparison with other lipases. Mutating each of the three catalytically active residues resulted in variants that failed to rescue the growth phenotype of mcp2Δ tgl2Δ double deletion strain supporting the assumption that these residues are indeed essential for the protein's function. Additionally, we discovered that the catalytically active aspartate residue (D259) is important for protein stability. Steady state level analyses with unstable variants of Tgl2 led to the identification of Yme1 as the protease responsible for its quality control. Finally, we provide evidence that the overall increase in TAGs in cells lacking Mcp2 and Tgl2 originates from the mitochondria. Collectively, our study provides new insights into a key player in mitochondrial lipid homeostasis.

Comparative Proteomics of Resistant and Susceptible Strains of Frankliniella occidentalis to Abamectin.

Western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae) is an invasive agricultural pest with developed resistance to abamectin in some strains due to frequent treatment with the pesticide. In this study, we examined differentially expressed proteins (DEPs) between abamectin-resistant (AbaR; under abamectin selective pressure) and susceptible strains (AbaS; without abamectin selective pressure) of F. occidentalis. Proteins were isolated from second instar larvae of both strains and separated via two-dimensional polyacrylamide gel electrophoresis. Nano-flow liquid chromatography-tandem mass spectrometry identified selected protein spot features. From 70 DEPs, 43 spot features were identified: A total of 23 showed an increase in abundance, and 20 were down-regulated in response to abamectin pressure. The enzymatic and structural proteins were classified into the functional groups of macromolecular metabolisms, signaling and cellular processes, immune system, genetic information processing, and exoskeleton-related proteins. The up-regulation of exoskeleton-related proteins may contribute to forming a thicker cuticle, potentially hindering abamectin penetration, which is an interesting finding that needs further investigation. Two novel proteins, triacylglycerol lipase and cuticle protein CPF 2, were only expressed in AbaR. This work provides insights into abamectin resistance mechanisms in F. occidentalis, which will provide important information for developing insecticide resistance management approaches for this pest.

Triacylglycerol mobilization underpins mitochondrial stress recovery.

Mitochondria are central to myriad biochemical processes, and thus even their moderate impairment could have drastic cellular consequences if not rectified. Here, to explore cellular strategies for surmounting mitochondrial stress, we conducted a series of chemical and genetic perturbations to Saccharomyces cerevisiae and analysed the cellular responses using deep multiomic mass spectrometry profiling. We discovered that mobilization of lipid droplet triacylglycerol stores was necessary for strains to mount a successful recovery response. In particular, acyl chains from these stores were liberated by triacylglycerol lipases and used to fuel biosynthesis of the quintessential mitochondrial membrane lipid cardiolipin to support new mitochondrial biogenesis. We demonstrate that a comparable recovery pathway exists in mammalian cells, which fail to recover from doxycycline treatment when lacking the ATGL lipase. Collectively, our work reveals a key component of mitochondrial stress recovery and offers a rich resource for further exploration of the broad cellular responses to mitochondrial dysfunction.

Scopoletin ameliorates hyperlipidemia and hepatic steatosis via AMPK, Nrf2/HO-1 and NF-κB signaling pathways.

Scopoletin (SC) is one of the important phenolic coumarin constituents derived from many edible plants and fruits, and exerts a wide range of biological activities. In the present study, we investigated the effects of SC on tyloxapol (TY)-induced hyperlipidemia and hepatic steatosis in C57BL/6j mice and free fatty acid (FFA) 0.5mM-stimulated lipid accumulation in human L02 cells. Our results showed that TY injection significantly increased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), triglyceride (TG), total cholesterol (TC), low density lipoprotein (LDL-C) as well as malondialdehyde (MDA) in the livers of the mice (p<0.001, respectively), and decreased serum levels of high density lipoprotein (HDL-C), IL-10 levels as well as superoxide dismutase (SOD) in the livers (p<0.001, respectively). On the other hand, SC pretreatment reversed these changes. SC obviously alleviated TY-induced liver steatosis by upregulating the AMP-activated kinase (AMPK), acetyl-CoA carboxylase (ACC) phosphorylation, and significantly downregulated sterol regulatory element binding protein (SREBP)1c and fatty acid synthase (FAS), stearoyl-CoA desaturase 1 (SCD1), Lipin 1, phospho-hormone-sensitive triglyceride lipase (p-HSL) proteins and SREBP-2, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) mRNA expressions. In the meantime, SC upregulated the expressions of the lipolysis-associated genes LDL receptor (LDLR), adipose triglyceride lipase (ATGL), and HSL. In addition, SC significantly inhibited TNF-α, F4/80, caspase-1 (cas-1), cas-1p10, IL-1β, Kelch-like ECH-associated protein 1 (Keap1) expressions, nuclear factor-kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) translocation, and increased heme oxygenase 1 (HO-1) expressions in TY-induced hyperlipidemia and hepatic steatosis mice. The in vivo results were similar to that those in the in vitro experiment, for example, SC markedly lowered TG and TC levels and protected lipid accumulation via AMPK, NF-κB, and Nrf2/HO-1 signaling pathway in FFA-induced L02 cells. These results indicate that SC has protective potential against hyperlipidemia and hepatic steatosis, and the underlying mechanism may be closely associated with AMPK activation and Nrf2/HO-1 and NF-κB inhibition.

Olanzapine exposure disordered lipid metabolism, gut microbiota and behavior in zebrafish (Danio rerio).

Olanzapine (OLZ) is widely used in the treatment of schizophrenia, and its metabolic side effects have garnered significant attention in recent years. Despite this, the specific side effects of OLZ and the underlying mechanisms remain inadequately understood. To address this gap, zebrafish (Danio rerio) were exposed to OLZ at concentrations of 35.5, 177.5, and 355.5μg/L. The results indicated that exposure to OLZ significantly increased body weight, total cholesterol (TC), low-density lipoprotein (LDL), and triglycerides (TG). Histological analysis revealed notable lipid accumulation in the liver. Furthermore, lipid synthesis genes, including sterol regulatory element binding protein (srebp), acetyl CoA carboxylase (acc), and fatty acid synthesis gene (fas), were up-regulated. In contrast, genes related to lipid decomposition, such as lipoprotein lipase (lpl), hormone-sensitive triglyceride lipase (hsl), and carnitine palmitoyltransferase 1b (cpt1b), were down-regulated. Subsequent analysis of zebrafish behavior showed reduced motor activity, sociability, and anxiety-like behavior in OLZ-exposed zebrafish, consistent with the results of neurotransmitter related gene expression. Following OLZ treatment, the expression of tryptophan hydroxylase (tph), tyrosine hydroxylase (th), dopamine transporter (dat), glutaminase (glsa), and glutamic acid decarboxylase 1b (gad1b) was upregulated. Additionally, the diversity of intestinal flora decreased after OLZ exposure, and the structure of the intestinal microbiota changed significantly compared to the control group. At the genus level, the abundance of Plesiomonas was upregulated, while the abundances of Bacillus and Cetobacterium were downregulated in the OLZ-exposed group. Furthermore, the results of the correlation analysis indicated that lipid metabolism and behavioral changes were closely associated with the microbiota. This study clarified the side effects of OLZ, and also provided a basis for the reasonable discharge concentration of OLZ in water and clinical drug use.

ATGL regulates renal fibrosis by reprogramming lipid metabolism during the transition from AKI to CKD.

Acute kidney injury (AKI) can progress to chronic kidney disease (CKD) and subsequently to renal fibrosis. Poor repair of renal tubular epithelial cells (TECs) after injury is the main cause of renal fibrosis. Studies have shown that restoring damaged fatty acid β-oxidation (FAO) can reduce renal fibrosis. Adipose triglyceride lipase (ATGL) is a key enzyme that regulates lipid hydrolysis. This study, for the first time, demonstrated that ATGL was downregulated in the renal TEC in the AKI-CKD transition mouse model. Moreover, treatment with the ATGL inhibitor atglistatin exacerbated lipid accumulation and downregulated the FAO level and mitochondrial function, while it increased the level of oxidative stress injury and apoptosis, resulting in aggravated renal fibrosis. In contrast, ATGL overexpression suppressed lipid accumulation, improved the FAO level and mitochondrial function, and attenuated oxidative stress and apoptosis, thereby ameliorating fibrosis invitro and invivo. In summary, ATGL regulates renal fibrosis by reprogramming lipid metabolism in renal TECs. This study provided new avenues and targets for treating CKD.

Total Saponins from Panax japonicus Mediate the Paracrine Interaction between Adipocytes and Macrophages to Promote Lipolysis in the Adipose Tissue during Aging via the NLRP3 Inflammasome/GDF3/ATGL Axis

Adipocytic lipolysis is strongly related to the increase of visceral fat, decrease of exercise capacity, and various other metabolic syndromes during aging. It is significantly influenced by the paracrine relationship between adipocytes and the adipose tissue macrophages (ATMs), and the cytokines secreted by ATMs have endocrine effects on adjacent tissues. We previously reported that the total saponins from Panax japonicus (TSPJs) can enhance lipid metabolism. In this work, we for the first time proved that TSPJs promoted adipocytic lipolysis by preventing NLRP3 activation in ATMs to inhibit the expression of GDF3. The decrease of GDF3 by TSPJs restored the expression of the adipose triglyceride lipase (ATGL) and phosphorylated hormone-sensitive lipase (p-HSL), both of which are known to decrease with aging. Thus, the NLRP3 inflammasome/GDF3/ATGL axis may be a worthy target in developing future clinical solutions for aging-related obesity.

Lipid droplet targeting of the lipase co-activator ABHD5 and the fatty liver disease-causing variant PNPLA3 I148M is required to promote liver steatosis.

The storage and release of triacylglycerol (TAG) in lipid droplets (LDs) is regulated by dynamic protein interactions. α/β hydrolase domain-containing protein 5 (ABHD5; also known as CGI-58) is a membrane/LD bound protein that functions as a co-activator of Patatin Like Phospholipase Domain Containing 2 (PNPLA2; also known as Adipose triglyceride lipase, ATGL) the rate-limiting enzyme for TAG hydrolysis. The dysregulation of TAG hydrolysis is involved in various metabolic diseases such as metabolic dysfunction-associated steatotic liver disease (MASLD). We previously demonstrated that ABHD5 interacted with PNPLA3, a closely related family member to PNPLA2. Importantly, a common missense variant in PNPLA3 (I148M) is the greatest genetic risk factor for MASLD. PNPLA3 148M functions to sequester ABHD5 and prevent co-activation of PNPLA2, which has implications for initiating MASLD; however, the exact mechanisms involved are not understood. Here we demonstrate that LD targeting of both ABHD5 and PNPLA3 I148M is required for the interaction. Molecular modeling demonstrates important resides in the C-terminus of PNPLA3 for LD binding and fluorescence cross-correlation spectroscopy demonstrates that PNPLA3 I148M greater associates with ABHD5 than WT PNPLA3. Moreover, the C-terminus of PNPLA3 is sufficient for functional targeting of PNPLAs to LD and the interaction with ABHD5. In addition, ABHD5 is a general binding partner of LD-bound PNPLAs. Finally, PNPLA3 I148M targeting to LD is required to promote steatosis in vitro and in the liver. Overall results suggest that the interaction of PNPLA3 I148M with ABHD5 on LD is required to promote liver steatosis.

DISORDER OF LIPID METABOLISM IN CHRONIC KIDNEY DISEASE

Chronic kidney disease is a proven risk factor for the development and progression of lipid metabolism disorders. These disorders are based on an increase in the blood plasma content of cholesterol, triglycerides, low—density lipoproteins and a decrease in the level of high-density lipoproteins, apoproteins of the A family (ApoA-I and ApoA-II). There is a decrease in the activity of enzymes: lipoprotein lipase, hepatic triglyceride lipase, lecithin-cholesterol-acetyltransferase.

Effects of orally exposed SiO2 nanoparticles on lipid profiles in gut-liver axis of mice.

Recently we proposed the possibility of orally exposed nanoparticles (NPs) to alter metabolite homeostasis by changing metabolism pathways, in addition to intestinal damages, but relatively few studies investigated the changes of metabolite profiles in multi-organs. This study investigated the influences of orally exposed SiO2 NPs on lipid profiles in gut-liver axis. To this end, we treated mice with 16, 160 or 1600 mg/kg bodyweight SiO2 NPs via intragastric route. After 5 days exposure (once a day), we observed that SiO2 NPs induced minimal pathological changes but increased most of the trace elements. Furthermore, lipid staining was gradually decreased in intestines and livers with the increase of NP levels. Consistently, lipidomics results showed that most of the lipid classes in mouse intestines and livers were decreased following SiO2 NP administration. We further identified the lipid classes significantly decreased in both intestines and livers, such as phosphatidylserine (PS), phosphatidylglycerol (PG), and phosphatidylethanolamine (PE). Only a few lipid classes, such as anandamide, showed opposite trends in these organs. For metabolism pathway, SiO2 NPs suppressed autophagy, showing as a significant decrease of microtubule-associated protein 1 A/1B light chain 3 (LC3) and adipose triglyceride lipase (Atgl), accompanying with an accumulation of P62, in both intestines and livers. However, lysosomal-associated membrane protein 2 (Lamp2) showed different trend, that it was significantly increased in intestines but decreased in livers. Combined, our results indicated that intragastric administration of SiO2 NPs altered trace element balance and lipid profiles, accompanying with a change of autophagic lipolysis proteins, in mouse gut-liver axis.

Maternal lipid mobilization is essential for embryonic development in the malaria vector Anopheles gambiae.

Lipid metabolism is an essential component in reproductive physiology. While lipid mobilization has been implicated in the growth of Plasmodium falciparum malaria parasites in their Anopheles vectors, the role of this process in the reproductive biology of these mosquitoes remains elusive. Here, we show that impairing lipolysis in Anopheles gambiae, the major malaria vectors, leads to embryonic lethality. Embryos derived from females in which we silenced the triglyceride lipase AgTL2 or the lipid storage droplet AgLSD1 develop normally during early embryogenesis but fail to hatch due to severely impaired metabolism. Embryonic lethality is efficiently recapitulated by exposing adult females to broad-spectrum lipase inhibitors prior to blood feeding, unveiling lipolysis as a potential target for inducing mosquito sterility. Our findings provide mechanistic insights into the importance of maternal lipid mobilization in embryonic health that may inform studies on human reproduction.

Histidine and soy isoflavones co-ingestion induces browning of white adipose tissue and promotes lipolysis in female rats.

Beige adipocytes arise from white adipocytes in response to cold or other stimuli, known as browning of white adipose. Beige adipocytes play a role similar to that of brown adipocytes, express high levels of uncoupling protein 1 (UCP1), and are responsible for energy consumption via heat production, thus aiding in fat loss. Although histidine (His) and soy isoflavone (Iso) co-ingestion reportedly reduces food intake, body weight, and fat accumulation in female rats, the underlying mechanism remains unclear. Therefore, this study aimed to elucidate the mechanisms whereby histidine and soy isoflavone (His-Iso) co-ingestion suppresses fat accumulation. Female rats were fed a control diet or diet containing Iso, His, or His-Iso for 2 weeks, followed by sampling of periovarian white adipose tissue (poWAT) and retroperitoneal white adipose tissue (rWAT) and adipocyte morphology analysis. Additionally, the expression of browning- and lipid metabolism-related genes was examined. Histochemical analysis revealed the presence of multicellular lipid droplets, representative of beige adipocytes, in the poWAT and rWAT of rats in the His-Iso co-ingestion group. Quantitative PCR analysis showed that His-Iso co-ingestion upregulated brown adipocyte and beige adipocyte markers, including UCP1, indicating that His-Iso intake induces beige adipocytes. Moreover, His-Iso co-ingestion upregulated genes related to fatty acid oxidation (carnitine palmitoyl transferase 1A) and lipolysis (adipose triglyceride lipase) in WATs. In conclusion, His-Iso co-ingestion increases UCP1 expression and morphological changes to beige adipocytes, and suppresses fat accumulation by promotion of lipolysis and fatty acid oxidation in WAT.

Nuclear lipid droplets: a novel regulator of nuclear homeostasis and ageing.

Aging is a fundamental driver of numerous life-threatening diseases, significantly compromising cellular structures and functions, including the integrity of the nucleus. A consistent feature of aging across diverse species is the progressive accumulation of lipid droplets (nLDs) within the nuclear compartment, which disrupts nuclear architecture and functionality. Notably, aging is accompanied by a marked increase in nLD accumulation at the nuclear envelope. Interventions known to extend lifespan, such as caloric restriction and reduced insulin signaling, significantly reduce both the rate of accumulation and the size of nLDs. The triglyceride lipase ATGL-1, which localizes to the nuclear envelope, plays a critical role in limiting nLD buildup and maintaining nuclear lipid balance, especially in long-lived mutant worms. These findings establish excessive nuclear lipid deposition as a key hallmark of aging, with profound implications for nuclear processes such as chromatin organization, DNA repair, and gene regulation. In addition, ATGL-1 emerges as a promising therapeutic target for preserving nuclear health, extending organismal healthspan, and combating age-related disorders driven by lipid dysregulation.

Characterization of tea polysaccharides from Tieguanyin oolong tea and their hepatoprotective effects via AMP-activated protein kinase-mediated signaling pathways.

In the present study, we succeeded in extracting tea polysaccharide (TPS) from Tieguanyin oolong tea, and the TPS was characterized. TPS is an acidic heteropolysaccharide containing rhamnose, arabinose, galactose, glucose (Glc), xylose, mannose, galacturonic acid, and guluronic acid. We found that TPS supplementation partially reversed the elevated levels of serum alanine aminotransferase, total cholesterol, and low-density lipoprotein cholesterol in high-fat diet (HD)-induced nonalcoholic fatty liver disease (NAFLD) mice (p<0.05), and hepatic steatosis and impaired Glc tolerance were also ameliorated. After HD intervention, the activity of Adenosine 5'-monophosphate-activated protein kinase (AMPK) and its downstream genes, including Sirtuin 1 (SIRT1), sterol regulatory element-binding protein-1c (SREBP1c), acetyl-coenzyme A carboxylase 1 (ACC1), and adipose triglyceride lipase (ATGL), was significantly inhibited (p<0.05). TPS can increase the expression of these genes. The hepatoprotective effects of TPS in AMPK-/- mice almost completely disappeared. Moreover, the expression levels of SIRT1, SREBP1c, ACC1, and ATGL did not significantly change after TPS supplementation (p>0.05). Therefore, our findings suggest that TPS protects the liver from hepatic glucolipid metabolism disorders in HD-induced NAFLD mice by activating AMPK-mediated signaling pathways.

Revised dietary exposure assessment of the food enzyme triacylglycerol lipase from the genetically modified Aspergillus oryzae strain NZYM-FL.

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) is produced with the genetically modified Aspergillus oryzae strain NZYM-FL by Novozymes A/S. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that, under the intended conditions of use, this food enzyme did not give rise to safety concerns. Due to the implementation of a new methodology to estimate the dietary exposure to food enzymes in 2016, the European Commission requested EFSA to revise the exposure assessment of this food enzyme by using this new methodology. In this assessment, EFSA realigned the intended uses of this food enzyme to two food manufacturing processes and recalculated the dietary exposure. As the food enzyme-total organic solids (TOS) are removed in one food manufacturing process, the dietary exposure to the food enzyme-TOS was estimated only for the remaining process. It was calculated to be up to 0.492 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level previously reported (340 mg TOS/kg bw per day, the mid-dose tested), the Panel derived a margin of exposure of at least 691. Based on the revised exposure estimate, the margin of exposure calculated thereof and the previous evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Revised dietary exposure assessment of the food enzyme triacylglycerol lipase from the genetically modified Aspergillus oryzae strain NZYM-LH.

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) is produced with the genetically modified Aspergillus oryzae strain NZYM-LH by Novozymes A/S. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that, under the intended conditions of use, this food enzyme did not give rise to safety concerns. Due to the implementation of a new methodology to estimate the dietary exposure to food enzymes in 2016, the European Commission requested EFSA to revise the exposure assessment of this food enzyme by using this new methodology. In this assessment, EFSA realigned the intended uses of this food enzyme to two food manufacturing processes and recalculated the dietary exposure. Dietary exposure to the food enzyme-TOS was calculated to be up to 0.284 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level previously reported (1080 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 3803. Based on the revised exposure estimate, the margin of exposure calculated thereof and the previous evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Revised dietary exposure assessment of the food enzyme triacylglycerol lipase from the genetically modified Aspergillus oryzae strain NZYM-AL.

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) is produced with the genetically modified Aspergillus oryzae strain NZYM-AL by Novozymes A/S. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that, under the intended conditions of use, this food enzyme did not give rise to safety concerns. Due to the implementation of a new methodology to estimate the dietary exposure to food enzymes in 2016, the European Commission requested EFSA to revise the exposure assessment of this food enzyme by using this new methodology. In this assessment, EFSA realigned the intended uses of this food enzyme to four food manufacturing processes. The dietary exposure was calculated to be up to 0.089 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level previously reported (49.1 mg TOS/kg bw per day, the lowest dose tested), the Panel derived a margin of exposure of at least 552. Based on the revised exposure estimate, the margin of exposure calculated thereof and the previous evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

The repression of the lipolytic inhibitor G0s2 enhancers affects lipid metabolism.

The G0/G1 switch gene 2 (G0s2) is a selective inhibitor of adipose triglyceride lipase (ATGL) which is the rate-limiting enzyme for triglycerides (TGs) hydrolysis in adipocytes, and regulates the mobilization of TGs in adipocytes and hepatocytes. The expression and functional disorders of G0S2 are associated with various metabolic diseases and related pathological states, such as obesity and metabolic syndrome and non-alcoholic fatty liver disease (NAFLD). However, the extent to which the transcriptional regulatory mechanisms mediated by the interaction between the G0s2 gene promoter and enhancer regions are involved remains unknown. Here, through the analysis of epigenomic data (H3K27ac, H3K4me1, and DHS-seq) and luciferase reporter assays, we identified three active enhancers of G0s2 in 3T3-L1 adipocytes. Subsequently, using the dCas9-KRAB system for epigenetic inhibition of G0S2-En2, -En4, and -En5 revealed the functional role of these enhancers in regulating G0s2 expression and lipid droplet biosynthesis. Additionally, transcriptome analyses revealed that inhibition of G0S2-En5 downregulated pathways associated with lipid metabolism and lipid biosynthesis. Furthermore, overexpression of transcription factors (TFs) and motif mutation experiments identified that PPARG and RXRA regulate the activity of G0S2-En5. Taken together, we identified functional enhancers regulating G0s2 expression and elucidated the important role of the G0S2-En5 in lipid droplet biogenesis.

Application of glucose to prepare Aspergillus oryzae koji as an adjunct to prevent rancidity in cheese products.

Koji made using Aspergillus oryzae shows potential for application as a cheese adjunct; however, flavor defects resulting from volatile free fatty acid (FFA) accumulation should be avoided. Hence, a modified glucose-containing whey solid medium was used to culture A. oryzae AHU 7139, and the triacylglycerol (TG) lipase activity and lipase gene (tglA and mdlB) expression were compared with those of a culture using a conventional whey solid medium. The results showed that TG lipase activity and the expression of both lipase genes were reduced in the modified medium. Moreover, the expression level of farA, a positive transcription factor of the lipase genes, was also reduced. The cheese adjunct prepared by culturing the AHU 7139 strain in the modified medium lowered the FFA content in the cheese products, resulting in comparable FFA levels with those in the adjunct-free cheese. Thus, adding glucose is recommended to prepare the koji adjunct for cheesemaking.