Expression Of acetyl-CoA Carboxylase Research Articles

Apolipoprotein H: a novel regulator of fat accumulation in duck myoblasts

Apolipoprotein H (APOH) primarily engages in fat metabolism and inflammatory disease response. This study aimed to investigate the effects of APOH on fat synthesis in duck myoblasts (CS2s) by APOH overexpression and knockdown. CS2s overexpressing APOH showed enhanced triglyceride (TG) and cholesterol (CHOL) contents and elevated the mRNA and protein expression of AKT serine/threonine kinase 1 (AKT1), ELOVL fatty acid elongase 6 (ELOVL6), and acetyl-CoA carboxylase 1 (ACC1) while reducing the expression of protein kinase AMP-activated catalytic subunit alpha 1 (AMPK), peroxisome proliferator activated receptor gamma (PPARG), acyl-CoA synthetase long chain family member 1 (ACSL1), and lipoprotein lipase (LPL). The results showed that knockdown of APOH in CS2s reduced the content of TG and CHOL, reduced the expression of ACC1, ELOVL6, and AKT1, and increased the gene and protein expression of PPARG, LPL, ACSL1, and AMPK. Our results showed that APOH affected lipid deposition in myoblasts by inhibiting fatty acid beta-oxidation and promoting fatty acid biosynthesis by regulating the expression of the AKT/AMPK pathway. This study provides the necessary basic information for the role of APOH in fat accumulation in duck myoblasts for the first time and enables researchers to study the genes related to fat deposition in meat ducks in a new direction.

Grain oil quality formation and metabolism-related genes difference expression of Paeonia suffruticosa cv. 'Fengdan' grown at different altitudes.

We measured the morphological index, nutritional composition and the expression analysis of key genes during grain development of Paeonia suffruticosa cv. 'Fengdan' grown at altitudes of 100, 650 and 1010 m in Luo-yang. The aim of this study was to examine differences in grain yield traits and the transformation of soluble sugar, starch, soluble protein and fatty acid contents, as well as the related enzyme activity and differential expression of key genes in oil metabolism. The results showed that grain yield traits increased with altitudes and that the growth period of grain at the higher altitudes was longer than that at low and mid altitudes. The soluble sugar and starch in mature grains increased with altitudes, while soluble protein and crude fat did not change. During grain development, the activities of sucrose synthase (SS) and sucrose phosphate synthase (SPS) first decreased and then increased, with the lowest occurred at 90 d after flowering. The activities of pyruvate dehydrogenase (PDH), glutamic-pyruvic transaminase (GPT) and glutamic-oxalacetic transaminease (GOT) increased rapidly during 50-90 d after flowering and peaked at 90 d. The relative expression of acetyl-CoA carboxylase (ACCase) and stearoyl-ACP desaturase (SAD) peaked at 50 d after flowering, and ω-6 fatty acid desaturase 2 (FAD2) peaked at 90 d, in oil tree peony grain at different altitudes. There was a negative correlation of soluble sugar and starch with the accumulation of soluble protein and crude fat. SPS activity was positively correlated with the contents of soluble sugar and starch, and negatively correlated with the contents of soluble protein and crude fat during grain development. Activities of GPT and GOT were negatively associated with the content of soluble sugar and the content of starch, and had a highly significant positive correlation with the contents of soluble protein and crude fat. Activity of PDH was positively correlated with the content of soluble proteins and activities of GPT and GOT, and negatively correlated with the contents of soluble sugar and starch. It suggested that nutrient accumulation in the process of grain development of tree peony was transformed from sugar to crude fat and protein, and that metabolic enzymes, such as SPS, PDH, GPT and GOT, played an important role in this process. Palmitate acid, stearic acid and linoleic acid were negatively correlated with the relative increment of α-linolenic acid, indicating that fatty acid desaturation process in the grain development of tree peony was towards the direction of α-linolenic acid synthesis. The relative expression of ACCase, SAD, and FAD2 was positively correlated with the relative increment of α-linolenic acid accumulation, which played an important role in α-linolenic acid synthesis. The oil quality of tree peony grain was relatively stable at different altitudes, but grain production increased with altitude. Planting oil tree peony at mid to high altitudes could be an important strategy for the efficient use of marginal land in Luoyang.

Acetate-Induced Milk Fat Synthesis Is Associated with Activation of the mTOR Signaling Pathway in Bovine Mammary Epithelial Cells.

Acetate is a precursor substance for fatty acid synthesis in bovine mammary epithelial cells (BMECs), and the mTOR signaling pathway plays an important role in milk fat synthesis. However, the mechanism of the regulatory effects of acetate on lipogenic genes via the mTOR signaling pathway in BMEC remains unknown. We hypothesized that acetate can enhance the expression of lipogenic genes and triglyceride (TG) production by activating the mTOR signaling pathway in BMECs. Therefore, the aim of this study was to investigate the network of acetate-regulated lipid metabolism by the mTOR signaling pathway in BMECs. These results showed that TG synthesis was elevated (p < 0.01) in BMECs with acetate treatment. The lipid droplets were increased in the acetate-treated groups compared with those in the control group through the Bodipy staining of the lipids. In addition, the fatty acid profile in BMECs treated with acetate was affected, with an elevation in the proportions of C14:0, C16:0, and C18:0. The mRNA levels of the sterol-response-element-binding protein 1 (SREBP1), stearoyl-CoA desaturase 1 (SCD1), and fatty acid synthase (FAS) genes involved in the lipogenesis and transcriptional factors were upregulated (p < 0.05) in BMECs with acetate treatment. Remarkably, the expression of acetyl-CoA carboxylase α (ACCα) and FAS rate-limiting enzymes involved in lipogenesis was upregulated in BMECs with acetate treatment. Moreover, the addition of acetate enhanced the key protein expression of S6K1, which is related to the mTOR signaling pathway. Taken together, our data suggest that TG accumulation and expression of lipogenic genes induced by acetate are associated with the activation of the mTOR signaling pathway, which provides new insights into the understanding of the molecular mechanism in the expression of mTOR-signaling-pathway-regulated lipogenic genes.

BIODEGRADED MANGO PEEL BASED DIETS ALTERS LIPOGENIC GENES AND mRNA EXPRESSION IN GROWING RABBITS.

This study investigated the effect of bio fermented mango peel meal (FMPM) on lipid metabolism – related gene expression in liver tissues and abdominal adipose tissue in weaned rabbits. Twenty (20) weaned New Zealand white rabbits were randomly assigned to four dietary groups with five (5) rabbits in each group in a completely randomized design experiment. The diets had a control(G1) supplemented with unfermented mango seed meal, an experiment diet of mango peel fermented by either of P. ostreatus, (G2) and P. rivulosis (G3) and combinations of P. ostreatus plus P. rivulosis 50:50 (G4).The results showed that FMPM supplementation down regulated the mRNA expression of fatty acid synthesis (FAS) and acetyl CoA carboxylase (ACC) in liver tissues and the lipoprotein lipase (LPL) expression in abdominal fat tissues (P< 0.05). The mRNA expression of perixisomeproliferators activated receptor - alpha (PPAR-α) compared to control group, was up regulated in the livers of rabbits on fermented diets (P<0.05). However gene expressions of PPAR-γ and L-FABP liver fatty acid binding protein were not altered (P> 0.05) in rabbits fed FMPM supplemented diets. These findings indicated that FMPM regulated lipid metabolism by either increasing or decreasing the expression of lipogenic genes and altering multiple pathways in the liver. This information provided new essential information and demonstrated great potential inherent in nutrigenomics in researching nutrients added to livestock diets.

Effects of dietary carbohydrate on growth, feed utilization, hepatic glucose and lipid metabolism in endangered Yangtze sturgeon (Acipenser dabryanus)

The aim of this study was to determine the effects of dietary carbohydrate levels on growth performance, feed utilization and metabolism of juvenile Yangtze sturgeon (Acipenser dabryanus). Six isonitrogenous (crude protein 45 %) and isolipidic (crude lipid 10 %) experimental diets were formulated containing 7.35 %, 10.2 %, 13.4 %, 16.5 %, 19.4 % and 22.4 % carbohydrate. Triplicate groups of 15 fish (initial weight, 51.4 ± 0.16 g) were fed twice daily for 8 weeks. The significantly higher (P < 0.05) growth performance was recorded in dietary 19.4 % group compared with the dietary 7.35 % and 10.2 % groups. Meanwhile, higher dietary carbohydrate (16.5 %, 19.4 % and 22.4 %) also significantly improved feed conversion ratio compared with the lowest one (7.35 %). Protein efficiency ratio exhibited similar tendency with growth performance. And the highest muscle crude protein was found in 19.4 % group and was significantly higher than the lower dietary carbohydrate groups (7.35 %, 10.2 %, 13.4 %) (P < 0.05). Liver glycogen content was positively correlated with dietary carbohydrate levels. The highest dietary carbohydrate level (22.4 %) led to much more lipid deposition in the body. Furthermore, the highest mRNA expression of Acetyl-CoA carboxylase and fatty acid synthesis were also recorded in dietary carbohydrate 22.4 % group. mRNA expression of glycolysis related genes hexokinase was significantly (P < 0.05) up-regulated by higher levels of carbohydrate (19.4 % and 22.4 %) compared with other treatments. Quadratic broken-line analysis of weight gain against carbohydrate levels showed that the optimal value was 20.6 % of diet for Yangtze sturgeon.

Cryptotanshinone suppresses tumorigenesis by inhibiting lipogenesis and promoting reactive oxygen species production in KRAS‑activated pancreatic cancer cells.

Pyruvate dehydrogenase kinase 4 (PDK4) is an important regulator of energy metabolism. Previously, knockdown of PDK4 by specific small interfering RNAs (siRNAs) have been shown to suppress the expression of Kirsten rat sarcoma viral oncogene homolog (KRAS) and the growth of lung and colorectal cancer cells, indicating that PDK4 is an attractive target of cancer therapy by altering energy metabolism. The authors previously reported that a novel small molecule, cryptotanshinone (CPT), which inhibits PDK4 activity, suppresses the in vitro three-dimensional (3D)-spheroid formation and in vivo tumorigenesis of KRAS-activated human pancreatic and colorectal cancer cells. The present study investigated the molecular mechanism of CPT-induced tumor suppression via alteration of glutamine and lipid metabolism in human pancreatic and colon cancer cell lines with mutant and wild-type KRAS. The antitumor effect of CPT was more pronounced in the cancer cells containing mutant KRAS compared with those containing wild-type KRAS. CPT treatment decreased glutamine and lipid metabolism, affected redox regulation and increased reactive oxygen species (ROS) production in the pancreatic cancer cell line MIAPaCa-2 containing mutant KRAS. Suppression of activated KRAS by specific siRNAs decreased 3D-spheroid formation, the expression of acetyl-CoA carboxylase 1 and fatty acid synthase (FASN) and lipid synthesis. The suppression also reduced glutathione-SH/glutathione disulfide and increased the production of ROS. Knockdown of FASN suppressed lipid synthesis in MIAPaCa-2 cells, partially promoted ROS production and mildly suppressed 3D-spheroid formation. These results indicated that CPT reduced tumorigenesis by inhibiting lipid metabolism and promoting ROS production in a mutant KRAS-dependent manner. This PDK4 inhibitor could serve as a novel therapeutic drug for KRAS-driven intractable cancers via alteration of cell metabolism.

A soy glycinin derived octapeptide protects against MCD diet induced non-alcoholic fatty liver disease in mice

Soy glycinin derived octapeptide (SGP8) is a peptide obtained from degradation of the soy glycinin, whose amino acid sequence is IAVPGEVA. To determine the effect of SGP8 on non-alcoholic fatty liver disease (NAFLD), steatosis HepG2 cells were induced by 1 mmol/L free fatty acid (FFA) and C57BL/6J mice were fed with methionine-choline deficient (MCD) diet for 3 weeks to establish NAFLD model. The results of oil red O staining and total cholesterol (TC)/triglyceride (TG) contents showed that SGP8 could significantly reduce the lipid content of steatosis HepG2 cells. In vivo, SGP8 lowered plasma alanine aminotransferase (ALT) and low density lipoprotein (LDL) content, normalized hepatic superoxide dismutase (SOD) and malondialdehyde (MDA) production, and reduced the severity of liver inflammation. The results of Western blotting showed that SGP8 increased expression of Sirtuin-1 (SIRT1) and phosphorylation level of AMP activated protein kinase (AMPK) in hepatocytes. Through activation of SIRT1/AMPK pathway, SGP8 downregulated the expression of sterol regulatory element binding protein 1c (SREBP-1c) and its target genes ACC and FAS expression levels, and increased the phosphorylation level of acetyl CoA carboxylase (ACC). Furthermore, SGP8 also upregulated the expression of transcription factor peroxisome proliferator activated receptor α (PPARα), which was regulated by SIRT1/AMPK pathway, and its target gene CPT1 level. In conclusion, SGP8 might improve NAFLD by activating the SIRT1/AMPK pathway. Our data suggest that SGP8 may act as a novel and potent therapeutic agent against NAFLD.

Electroacupuncture improves follicular development and metabolism and regulates the expression of adiponectin, AMPK and ACC in an obese rat model of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by hyperandrogenism and follicular arrest. Electroacupuncture (EA) has been shown to be effective at improving hyperandrogenism and follicular arrest in PCOS; however, its mechanism of action remains to be deciphered. In this study, we investigated whether EA improved follicular development in an obese rat model of PCOS and regulated the expression of adiponectin, AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC). EA was administered at CV3, CV4 and ST40. Changes in body weight, paraovarian fat, estrus cycle, ovarian morphology, levels of related hormones, and glucose and lipid metabolism were evaluated. In addition, protein and mRNA expression of adiponectin, AMPK and ACC was measured. The body weight and paraovarian fat of rats in the EA group were reduced, while estrus cyclicity and ovarian morphology improved. Levels of free fatty acids, triglycerides, total cholesterol and low-density lipoprotein cholesterol were significantly reduced in the EA group, as well as blood glucose levels. Furthermore, levels of testosterone and luteinizing hormone were reduced in the EA group, while estradiol levels were increased. Protein and mRNA expression of adiponectin, AMPKα1 and liver kinase B1 (LKB1) was found to be increased in the EA group, while protein and mRNA expression of ACC were significantly reduced.Conclusion: Our findings suggest that EA improved follicular development and metabolism and regulated expression levels of adiponectin, AMPKα1, LKB1 and ACC in our obese rat model of PCOS.

Lipid metabolism and m6A RNA methylation are altered in lambs supplemented rumen-protected methionine and lysine in a low-protein diet

BackgroundMethionine or lysine has been reported to influence DNA methylation and fat metabolism, but their combined effects in N6-methyl-adenosine (m6A) RNA methylation remain unclarified. The combined effects of rumen-protected methionine and lysine (RML) in a low-protein (LP) diet on lipid metabolism, m6A RNA methylation, and fatty acid (FA) profiles in the liver and muscle of lambs were investigated. Sixty-three male lambs were divided into three treatment groups, three pens per group and seven lambs per pen. The lambs were fed a 14.5% crude protein (CP) diet (adequate protein [NP]), 12.5% CP diet (LP), and a LP diet plus RML (LP + RML) for 60 d.ResultsThe results showed that the addition of RML in a LP diet tended to lower the concentrations of plasma leptin (P = 0.07), triglyceride (P = 0.05), and non-esterified FA (P = 0.08). Feeding a LP diet increased the enzyme activity or mRNA expression of lipogenic enzymes and decreased lipolytic enzymes compared with the NP diet. This effect was reversed by supplementation of RML with a LP diet. The inclusion of RML in a LP diet affected the polyunsaturated fatty acids (PUFA), n-3 PUFA, and n-6 PUFA in the liver but not in the muscle, which might be linked with altered expression of FA desaturase-1 (FADS1) and acetyl-CoA carboxylase (ACC). A LP diet supplemented with RML increased (P < 0.05) total m6A levels in the liver and muscle and were accompanied by decreased expression of fat mass and obesity-associated protein (FTO) and alkB homologue 5 (ALKBH5). The mRNA expressions of methyltransferase-like 3 (METTL3) and methyltransferase-like 14 (METTL14) in the LP + RML diet group were lower than those in the other two groups. Supplementation of RML with a LP diet affected only liver YTH domain family (YTHDF2) proteins (P < 0.05) and muscle YTHDF3 (P = 0.09), which can be explained by limited m6A-binding proteins that were mediated in mRNA fate.ConclusionsOur findings showed that the inclusion of RML in a LP diet could alter fat deposition through modulations of lipogenesis and lipolysis in the liver and muscle. These changes in fat metabolism may be associated with the modification of m6A RNA methylation.Graphical abstractA systematic graph illustrates the mechanism of dietary methionine and lysine influence on lipid metabolism and M6A. The green arrow with triangular heads indicates as activation and brown-wine arrows with flat heads indicates as suppression.

Inhibiting M1 Macrophage Polarization, Using Small Interfering Forkhead Box Class Family Protein 1 (FOXO1)-Loaded Selenium Nanoparticles, Alleviates Hepatic Steatosis

Lipid deposition is a key predisposing factor of nonalcoholic fatty liver disease (NAFLD). FOXO1 is obviously expressed in polarized M1 macrophages and may cause liver cell steatosis. Thus, silencing FOXO1 during M1 macrophage polarization using small interfering RNA (siRNA) technology may alleviate lipid deposition in liver cells. However, a lack of effective and biocompatible carriers is challenging for such siRNA-delivery to macrophages. To improve this, RGDfC peptide-modified selenium nanoparticles (RGDfC-Se NPs) were fabricated as a siFOXO1 delivery carrier system. We showed that RGDfC-Se NPs effectively increased siFOXO1 cellular uptake and silenced FOXO1 expression in human peripheral blood monocyte-like macrophages (THP-1 cells). Additionally, RGDfC-Se@siFOXO1 blocked M1 polarization in these cells. Also, FOXO-1-suppressed cell supernatants extenuated lipid deposition in LO2 liver cells probably by down-regulating the expression of lipid deposition-related fat metabolic enzymes acetyl-CoA carboxylase 1 and fatty acid synthase. Furthermore, our in vivo analyses showed that RGDfC-Se@siFOXO1 attenuated hepatic steatosis by inhibiting M1 macrophage polarization in mouse liver tissue. Our studies represent a new strategy and clinic treatment target for NAFLD.

Incidence of spiromesifen resistance and resistance mechanisms in Tetranychus urticae populations collected from strawberry production areas in Turkey

Tetranychus urticae Koch is a serious pest of strawberries and its remarkable ability to develop resistance has often caused failure in chemical control. In the present study, resistance to spiromesifen was detected in two out of nine field-populations of T. urticae collected from important strawberry production areas in Turkey, with resistance ratio's mounting to 60- and 140-fold. Synergism assays showed the involvement of detoxification enzymes, especially cytochrome P450 monooxygenases, in resistance against spiromesifen in field-collected T. urticae populations. We further selected the most resistant field-collected population (POP14) with spiromesifen and obtained an extremely resistant population (LC50 > 5000 mg a.i./L). Gene expression analysis with qPCR supported the involvement of cytochrome P450s in spiromesifen resistance in this selected population. In addition, we also detected a higher expression of acetyl-CoA carboxylase (ACCase), the target-site of spiromesifen, in the spiromesifen-selected population. Furthermore, a F1640L mutation in the conserved region of CT-domain of ACCase was uncovered in the most resistant field populations, but the role of this mutation in spiromesifen resistance needs further validation. Overall, spiromesifen still seems to be an effective tool in the control of T. urticae in strawberry production areas of Turkey, but resistance is on the rise and should be considered a serious threat.

Response of Trypanosoma brucei to Exogenous Fatty Acids in Low Lipid Conditions

Trypanosoma brucei is an extracellular parasite that causes African Sleeping Sickness and is endemic to the sub‐Saharan African region. The parasite's extracellular nature forces the parasite to adapt to its host's environment. One of the regulatory mechanisms is to regulate fatty acid synthesis enzymes in response to exogenous fatty acids. Our previous study showed that the insect‐host procyclic form (PF) T. brucei regulates the activity and expression level of acetyl‐CoA carboxylase (ACC) when grown in media containing different lipid levels. PF in low lipid media has an elevated ACC activity but lower ACC protein level than in high lipid media. We also observed that the addition of C18:0 to PF in low lipid media reduced ACC activity and increased growth rate, which showed an environmental response to the exogenous fatty acid level. Here, we observe the growth and the ACC level of low lipid‐adapted PF T. brucei after treatment with fatty acids of different chain lengths. We did not observe a significant change in the ACC protein level; however, we observed significant growth differences with the addition of different fatty acids, and some of these effects were cell density‐dependent. These data suggested that adding fatty acids changes ACC's activity and pattern of PF growth in low lipid but does not change PF's ACC expression level. Future studies will investigate whether different fatty acids regulate ACC activity by phosphorylation, allosteric regulation, or a combination of both mechanisms.

USP22 regulates lipidome accumulation by stabilizing PPAR\u03b3 in hepatocellular carcinoma

Elevated de novo lipogenesis is considered to be a crucial factor in hepatocellular carcinoma (HCC) development. Herein, we identify ubiquitin-specific protease 22 (USP22) as a key regulator for de novo fatty acid synthesis, which directly interacts with deubiquitinates and stabilizes peroxisome proliferator-activated receptor gamma (PPARγ) through K48-linked deubiquitination, and in turn, this stabilization increases acetyl-CoA carboxylase (ACC) and ATP citrate lyase (ACLY) expressions. In addition, we find that USP22 promotes de novo fatty acid synthesis and contributes to HCC tumorigenesis, however, this tumorigenicity is suppressed by inhibiting the expression of PPARγ, ACLY, or ACC in in vivo tumorigenesis experiments. In HCC, high expression of USP22 positively correlates with PPARγ, ACLY or ACC expression, and associates with a poor prognosis. Taken together, we identify a USP22-regulated lipogenesis mechanism that involves the PPARγ-ACLY/ACC axis in HCC tumorigenesis and provide a rationale for therapeutic targeting of lipogenesis via USP22 inhibition.

Influence of Nutrient (NPK) Factors on Growth, and Pharmacodynamic Component Biosynthesis of Atractylodes chinensis: An Insight on Acetyl-CoA Carboxylase (ACC), 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGR), and Farnesyl Pyrophosphate Synthase (FPPS) Signaling Responses.

In the planting of crops, especially medicinal plants, formula fertilization is important for improving the utilization rate of elements, soil quality, crop yield, and quality. Therefore, it is important to study targeted fertilizer application schemes for sustainable agricultural development and environmental protection. In this study, an L9(34) orthogonal design was used to conduct a field experiment to study the effects of NPK combined application on the growth and pharmacodynamic component biosynthesis of Atractylodes chinensis (DC.) Koidz. Results showed that after applying a base fertilizer at the seedling stage (late May), topdressing at the vegetative stage (late June) and fruit stage (late August) was beneficial to the growth and development of A. chinensis. The high concentrations of phosphorus were conducive to the accumulation of yield and effective components, and the best harvest time was after late October. Principal component analysis (PCA) showed that the comprehensive score of T6 treatment was the highest, indicating that the optimal fertilization scheme for the high yield and high quality of A. chinensis was (N2P3K1): N 180, P2O5 225, and K2O 105 kg⋅ha–1. A signaling response analysis showed that during the growth and development of A. chinensis, the T6 fertilization scheme had clear effects on the activity and gene expression of the key enzymes acetyl-CoA carboxylase (ACC) and farnesyl pyrophosphate synthase (FPPS). Under the T4 [(N2P1K2): N 180, P2O5 75, and K2O 210 kg⋅ha–1] fertilization scheme, the activity and gene expression of the key enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) were higher. Moreover, ACC was closely related to the synthesis of the polyacetylene component atractylodin, and FPPS played an important regulatory role in the synthesis of sesquiterpene components atractylenolide II, β-eudesmol, and atractylon. In summary, the high phosphorus fertilization scheme T6 could notably increase the yield of A. chinensis, and promote the accumulation of polyacetylene and sesquiterpene volatile oils by increasing the expression of ACC and FPPS. Therefore, we postulate that the precise application of nutrients (NPK) plays a vital role in the yield formation and quality regulation of A. chinensis.

Acute intermittent hypoxia drives hepatic de novo lipogenesis in humans and rodents

Background and aimsNon-alcoholic fatty liver disease (NAFLD) is the most common chronic liver condition. It is tightly associated with an adverse metabolic phenotype (including obesity and type 2 diabetes) as well as with obstructive sleep apnoea (OSA) of which intermittent hypoxia is a critical component. Hepatic de novo lipogenesis (DNL) is a significant contributor to hepatic lipid content and the pathogenesis of NAFLD and has been proposed as a key pathway to target in the development of pharmacotherapies to treat NAFLD. Our aim is to use experimental models to investigate the impact of hypoxia on hepatic lipid metabolism independent of obesity and metabolic disease. MethodsHuman and rodent studies incorporating stable isotopes and hyperinsulinaemic euglycaemic clamp studies were performed to assess the regulation of DNL and broader metabolic phenotype by intermittent hypoxia. Cell-based studies, including pharmacological and genetic manipulation of hypoxia-inducible factors (HIF), were used to examine the underlying mechanisms. ResultsHepatic DNL increased in response to acute intermittent hypoxia in humans, without alteration in glucose production or disposal. These observations were endorsed in a prolonged model of intermittent hypoxia in rodents using stable isotopic assessment of lipid metabolism. Changes in DNL were paralleled by increases in hepatic gene expression of acetyl CoA carboxylase 1 and fatty acid synthase. In human hepatoma cell lines, hypoxia increased both DNL and fatty acid uptake through HIF-1α and -2α dependent mechanisms. ConclusionsThese studies provide robust evidence linking intermittent hypoxia and the regulation of DNL in both acute and sustained in vivo models of intermittent hypoxia, providing an important mechanistic link between hypoxia and NAFLD.

High Hydrostatic Pressure Extract of Mulberry Leaf Attenuated Obesity-Induced Inflammation in Rats.

Low-grade inflammation might be a link between obesity and obesity-associated metabolic dysfunction, including diabetes, hepatic steatosis, and other health complications. This study investigated whether the supplementation of high hydrostatic pressure extract of mulberry (Morus alba L.) leaves (HML) to obese rats could counteract obesity-related inflammation. Three-week-old male Sprague-Dawley rats were separated into three groups as follows: (a) a normal diet, (b) 45% high-fat (HF) diet, and HF diet containing 0.4% HML (c) or 0.8% HML (d) (IACUC No. 17-033). After 14 weeks of HML supplementation, adipose tissue mass, mRNA expression of adipogenic genes, such as aP2, peroxisome proliferator-activated receptor γ (PPARγ), and sterol regulatory element binding protein 1c (SREBP1c), and macrophage recruitment were significantly decreased in HF-fed obese rats. Serum concentrations of nitric oxide and mRNA levels of arginase1 (Arg1), CD11c, and inducible nitric oxide synthase (iNOS) involved in adipose tissue macrophage M1 polarization were also significantly reduced by HML. Moreover, HML alleviated the serum and hepatic lipid profiles and reduced hepatic lipogenic gene expression of acetyl-CoA carboxylase (ACC), cluster of differentiation 36 (CD36), CPT1, fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD1), and SREBP1c, and inflammation-associated genes, including IL1β, interleukin 6 (IL6), and tumor necrosis factor α (TNFα). Serum IL6 and TNFα levels were remarkedly suppressed in the 0.8% HML group. These results suggested that the favorable effect of HML on obesity-associated inflammation might be related in part to the decrease in adipose tissue and hepatic fat deposition and inflammation.

Combined Use of Bicyclol and Berberine Alleviates Mouse Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD), ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), is a liver disease worldwide without approved therapeutic drugs. Anti-inflammatory and hepatoprotective drug bicyclol and multi-pharmacological active drug berberine, respectively, have shown beneficial effects on NAFLD in murine nutritional models and patients, though the therapeutic mechanisms remain to be illustrated. Here, we investigated the combined effects of bicyclol and berberine on mouse steatosis induced by Western diet (WD), and NASH induced by WD/CCl4. The combined use of these was rather safe and better reduced the levels of transaminase in serum and triglycerides and cholesterol in the liver than their respective monotherapy, accompanied with more significantly attenuating hepatic inflammation, steatosis, and ballooning in mice with steatosis and NASH. The combined therapy also significantly inhibited fibrogenesis, characterized by the decreased hepatic collagen deposition and fibrotic surface. As per mechanism, bicyclol enhanced lipolysis and β-oxidation through restoring the p62-Nrf2-CES2 signaling axis and p62-Nrf2-PPARα signaling axis, respectively, while berberine suppressed de novo lipogenesis through downregulating the expression of acetyl-CoA carboxylase and fatty acid synthetase, along with enrichment of lipid metabolism-related Bacteroidaceae (family) and Bacteroides (genus). Of note, the combined use of bicyclol and berberine did not influence each other but enhanced the overall therapeutic role in the amelioration of NAFLD. Conclusion: Combined use of bicyclol and berberine might be a new available strategy to treat NAFLD.

Amelioration of lipid accumulations and metabolism disorders in differentiation and development of 3T3-L1 adipocytes through mulberry leaf water extract

BackgroundObesity is a worldwide problem that resulted from the excessive fat accumulation in adipose tissue, leading to the impairment of individual health. Mulberry leaf is an important traditional Chinese medicine and has been used to alleviate obesity for a long term. However, its underlying molecular mechanisms have not been fully elucidated yet. PurposeIn this study, we aimed to investigate the inhibition effects of mulberry leaf water extract (MLWE) on lipid accumulation during the process of differentiation of 3T3-L1 preadipocytes and development of mature adipocytes through the combination of molecular biology assays and metabolomic analysis. MethodsThe quality consistency and main chemical ingredients of MLWE were analyzed by high performance liquid chromatography and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), respectively. Oil red O staining was used to mirror lipid accumulation. Lipogenesis-, lipolysis- and inflammation-related genes were evaluated by real-time PCR and western blot, respectively. Untargeted metabolomics were performed by LC-MS/MS. ResultsPrepared method and quality of MLWE were stable and reliable. A total of 34 compounds were identified and 14 of them were undoubtedly confirmed. MLWE supplementation could dose-dependently inhibit the aggregation of lipid droplets, and the expressions of sterol regulatory element-binding protein (SREBP)-1c, peroxisome proliferator-activated receptor (PPAR) γ, acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), tumor necrosis factor (TNF)-α and interleukin (IL)-6, and increase the expressions of adenosine monophosphate-activated protein kinase (AMPK), hormone-sensitive lipase (HSL) and IL-10 in the differentiation of preadipocytes. Furthermore, MLWE treatment could dose-dependently decrease the level of triglycerides and the expressions of ACC, FAS, TNF-α, and IL-6, and up-regulate the level of glycerol and the expressions of PPARα, adiponectin (ADPN), adiponectin receptor (AdipoR) 1, AdipoR2, AMPK, HSL, and IL-10 in the development of mature adipocytes. Untargeted metabolomics showed that a total of 5 and 18 differential metabolites were reversed by MLWE intervention in the differentiation of preadipocytes and the development of mature adipocytes, respectively, which involved in the biosynthesis of unsaturated fatty acids, arachidonic acid metabolism and glycerophospholipids metabolism. ConclusionTaken together, this study firstly verified that MLWE could effectively alleviate lipid accumulation and inflammation by regulating ADPN/AMPK-mediated signaling pathways and relevant metabolic disturbances including biosynthesis of unsaturated fatty acids, arachidonic acid metabolism and glycerophospholipids metabolism.

Lithium Chloride Promotes Milk Protein and Fat Synthesis in Bovine Mammary Epithelial Cells via HIF-1α and β-Catenin Signaling Pathways.

Lithium is one of the trace elements with many physiological properties, such as being anti-cancer, anti-viral, and anti-inflammatory. However, little is known about its effect on milk synthesis during lactation. Therefore, we selected different concentrations (5mM, 10mM, and 20mM) of lithium chloride (LiCl) and assessed the effect of LiCl on bovine mammary epithelial (MAC-T) cells that underwent 4days of differentiation induction. Moreover, we analyzed the effect of LiCl on the expression of genes related to milk fat and milk protein synthesis. Herein, LiCl (5-20mM) significantly increased the expression of β-casein, promoted mRNA expression and phosphorylated protein expression of the signal transduction molecule and activator of transcription 5β (STAT5-β), and inhibited mRNA and protein expression of suppressor of cytokine signaling 2 (SOCS2). In contrast, 5 and 10mM LiCl significantly inhibited expression of SOCS3. LiCl at concentration of 5-20mM enhanced phosphorylation level of mTOR protein; at 10mM and 20mM, LiCl significantly promoted expression and phosphorylation of downstream ribosomal protein S6 kinase beta-1 (S6K1) protein. Considering milk fat synthesis, mRNA expression of acetyl CoA carboxylase (ACC) and lipoprotein lipase (LPL) genes was considerably increased in the presence of LiCl (5-20mM). Additionally, increased protein expression levels of stearoyl-CoA desaturase (SCD), peroxisome proliferator-activated receptor-γ (PPARγ), and sterol regulatory element-binding protein 1 (SREBP1) were observed at all LiCl concentrations tested. Subsequently, LiCl (5-20mM) significantly promoted protein expression and phosphorylation of β-catenin, while 10mM and 20mM of LiCl significantly promoted protein expression of hypoxia-inducible factor-1α (HIF-1α). Collectively, it has been shown that 10mM LiCl can effectively activate HIF-1α, β-catenin, and β-catenin downstream signaling pathways. Conversely, at 10mM, LiCl inhibited SOCS2 and SOCS3 protein expression through JAK2/STAT5, mTOR, and SREBP1 signaling pathways, improving synthesis of milk protein and fat. Therefore, LiCl can be used as a potential nutrient to regulate milk synthesis in dairy cows.

Research on the mechanism of hypoxia promoting the migration of lung adenocarcinoma A549 cells

Objective: To investigate the mechanism that hypoxia promotes the migration of lung adenocarcinoma A549 cells. Methods: A549 cells were cultured and cells that knockdown of acetyl-CoA carboxylase 1 (ACC1) were obtained by transfection with lentivirus, and cells that knockdown of sterol regulatory element-binding proteins-1 (SREBP-1) were obtained by treated with si-RNA. A549 cells were treated with hypoxia combined with hypoxia inducible factor-1α (HIF-1α) inhibitor PX-478 (25 μmol); Hypoxia combined with linoleic acid (LA) (20 μmol) treated A549 cells with ACC1 knockdown, and A549 cells with SREBP-1 knockdown were treated by hypoxia. Transwell migration assay was used to detect cell migration. Western blot was conducted to detect HIF-1α, ACC1 and epithelial mesenchymal transition (EMT) related proteins, Vimentin, E-Cadherin and SREBP-1; Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was performed to detect the changes of ACC1 and SREBP-1 mRNA in A549 cells after hypoxia and HIF-1α inhibitor PX-478 (25 μmol) treatment. Each experiment was repeated three times. Results: Compared with the normoxic control group, hypoxia promoted the migration of A549 cells (P＜0.01), and up-regulated the expressions of ACC1, HIF-1α (all P＜0.01) and SREBP-1 (P＜0.05). PX-478 (25 μmol) inhibited the migration of A549 cells induced by hypoxia and down-regulated the expression of SREBP-1 (all P＜0.05). ACC1 mRNA and SREBP-1 mRNA levels were increased after hypoxia treatment of A549 cells (all P＜0.05). The levels of ACC1 mRNA and SREBP-1 mRNA were decreased after A549 cells treated with hypoxia combined with PX-478 (25 μmol) for 24 h (P＜0.05, P＜0.01). Knockdown of SREBP-1 in A549 cells was obtained by transfection with si-RNA. Transwell migration assay showed the number of cell migration in si-SREBP-1 group was less than that in normoxia control group (P＜0.01). The si-SREBP-1 group and the si-NC group were treated with hypoxia. Compared with the control group, the number of cell migration in the si-SREBP-1 group was decreased (P＜0.01), however, the difference was not statistically significant compared with the normoxia si-SREBP-1 group (P＞0.05). Western blot showed that the expression of ACC1 in the si-SREBP-1 group was lower than that in the control group (P＜0.01). Compared with the control group, the expression of ACC1 was decreased after si-SREBP-1 group treated with hypoxia (P＜0.01). Knockdown of ACC1 inhibited the migration of A549 cells (P＜0.05). After knockdown of ACC1, the migration number of A549 cells under normoxia and 5% O2 conditions had no significant difference (P＞0.05). Application of LA under hypoxia condition rescued ACC1-knockdown induced inhibitory effect on hypoxia-promoted A549 cell migration (P＜0.05). Conclusion: Hypoxia promotes migration of lung adenocarcinoma A549 cells by regulating fatty acid metabolism through HIF-1α/SREBP-1/ACC1 pathway.