SCD1 Gene Expression Research Articles

Livogrit prevents Amiodarone-induced toxicity in experimental model of human liver (HepG2) cells and Caenorhabditis elegans by regulating redox homeostasis

Treatment with cationic amphiphilic drugs like Amiodarone leads to development of phospholipidosis, a type of lysosomal storage disorder characterized by excessive deposition of phospholipids. Such disorder in liver enhances accumulation of drugs and its metabolites, and dysregulates lipid profiles, which subsequently leads to hepatotoxicity. In the present study, we assessed pharmacological effects of herbal medicine, Livogrit, against hepatic phospholipidosis-induced toxicity. Human liver (HepG2) cells and in vivo model of Caenorhabditis elegans (N2 and CF1553 strains) were used to study effect of Livogrit on Amiodarone-induced phospholipidosis. In HepG2 cells, Livogrit treatment displayed enhanced uptake of acidic pH-based stains and reduced phospholipid accumulation, oxidative stress, AST, ALT, cholesterol levels, and gene expression of SCD-1 and LSS. Protein levels of LPLA2 were also normalized. Livogrit treatment restored Pgp functionality which led to decreased cellular accumulation of Amiodarone as observed by UHPLC analysis. In C. elegans, Livogrit prevented ROS generation, fat-6/7 gene overexpression, and lysosomal trapping of Amiodarone in N2 strain. SOD-3::GFP expression in CF1553 strain normalized by Livogrit treatment. Livogrit regulates phospholipidosis by regulation of redox homeostasis, phospholipid anabolism, and Pgp functionality hindered by lysosomal trapping of Amiodarone. Livogrit could be a potential therapeutic intervention for amelioration of drug-induced phospholipidosis and prevent hepatotoxicity.

Effect of lipoic acid on the expression of nonalcoholic fatty liver disease-associated genes in the liver of rats fed a hypercaloric choline-deficient diet

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver pathologies. Molecular mechanisms of NAFLD pathogenesis are complex and still require further clarification. Thus, this study aimed to investigate the impact of lipoic acid (LA), widely used as an antioxidant, on the development of different links of NAFLD, including de novo lipogenesis, antioxidant and xenobiotic-metabolizing enzymes by gene expression analysis. The experiment was carried out on three groups of male Wistar rats received control diet, hypercaloric choline-deficient diet (HCCD) or HCCD with LA (HCCD+LA). In the liver of rats the expression of acetyl-CoA carboxylase 1 (Acaca), fatty acid synthase (Fasn), stearoyl-CoA desaturase (Scd) and transcriptional regulators sterol-regulatory element-binding protein SREBP (Srebf1), carbohydrate response element-binding protein ChREBP (Mlxipl), peroxisome proliferator-activated receptor alpha PPARα (Ppara), heme oxygenase-1 HO-1 (Hmox1) and nuclear erythroid 2-related factor 2 Nrf2 (Nrf2), cytochrome P450 1A1 CYP1A1 (CYP1A1) and aryl hydrocarbon receptor AhR (AhR), cytochrome P450 2E1 CYP2E1 (CYP2E1) genes were evaluated. Supplementation of HCCD with LA led to an even greater than in HCCD group decrease in Scd gene expression by 88% (p<0.05), as well as a marked suppression of Ppara and Mlxipl by 37% (p<0.05) and 27% (p<0.05), to an 80% (p<0.05) elevation of Hmox1 gene expression relative to the HCCD group, had no pronounced effect on CYP1A1 and AhR gene expression but resulted in a 38% (p<0.05) suppression of CYP2E1 expression compared with that slightly elevated by HCCD. In conclusion, the current study showed that LA reduces lipogenesis de novo, restores the expression of Hmox1 gene of the antioxidant enzyme HO-1, diminished by the HCCD diet, and decreases HCCD-induced level of the expression of CYP2E1 gene of CYP2E1 enzyme, a potential source of free radicals.

Empagliflozin alters lipid metabolism in the myocardium and liver in a prediabetes model with severe dyslipidemia.

Recent studies suggest that empagliflozin reduces total and cardiovascular mortality in both diabetic and nondiabetic subjects. Although the exact mechanism is unclear, it is understood to positively affect myocardial energetics, including the metabolism of ketone bodies, lipids, and fatty acids. In this study, we compared empagliflozin effects on lipid metabolism in the heart and liver in a prediabetic rat model with severe dyslipidemia. Wistar rats served as the control group, while hereditary hypertriglyceridemic (HHTg) rats were used as a nonobese, prediabetic model. Rats were treated with or without empagliflozin at a dose of 10mg/kg body weight (BW) for 8weeks. In HHTg rats, empagliflozin decreased body weight and adiposity, improved glucose tolerance, and decreased serum triacylglycerols (TAGs) (p < 0.001). Empagliflozin decreased the activity and gene expression of the lipogenic enzyme SCD-1 (p < 0.001) in the myocardium, which may have led to a decrease in the ectopic accumulation of TAGs and lipotoxic diacylglycerols and lysophosphatidylcholines (p < 0.001). Changes in the myocardial phosphatidylcholine/phosphatidylethanolamine ratio (p < 0.01) and in the fatty acid profile of myocardial phospholipids may have contributed to the antifibrotic effects of empagliflozin. The anti-inflammatory effects of empagliflozin were evidenced by an increased IL-10/TNFα ratio (p < 0.001), a marked decrease in arachidonic acid metabolites (20-HETE, p < 0.001), and an increase in PUFA metabolites (14,15-EETs, p < 0.001) in the myocardium. However, empagliflozin did not significantly affect either the concentration or utilization of ketone bodies. In the liver, empagliflozin decreased lipogenesis and the accumulation of TAGs and lipotoxic intermediates. Its effect on arachidonic acid metabolites and alterations in n-3 PUFA metabolism was less pronounced than in the myocardium. Our findings suggest that empagliflozin treatment in the heart and liver reduced the accumulation of neutral lipids and lipotoxic intermediates and altered the metabolism of n-3 PUFA. In the heart, empagliflozin altered arachidonic acid metabolism, which is likely associated with the anti-inflammatory and antifibrotic effects of the drug. We assume that these alterations in lipid metabolism contribute to the cardioprotective effects of empagliflozin in prediabetic states with severe dyslipidemia.

Effects of Branched-Chain Fatty Acids Derived from Yak Ghee on Lipid Metabolism and the Gut Microbiota in Normal-Fat Diet-Fed Mice.

Branched-chain fatty acids (BCFAs) are natural components with a variety of biological activities. However, the regulation of lipid metabolism by BCFAs is unknown. It was dedicated to examining the impacts of BCFAs inferred from yak ghee on the expression of qualities related to lipid metabolism, natural pathways, and intestinal microbiota in mice. The treatment group (purified BCFAs from yak ghee) exhibited a decrease in cholesterol levels; a decrease in HMGCR levels; downregulation of FADS1, FADS2, ACC-α, FAS, GAPT4, GPAM, ACSL1, THRSP, A-FABP, and PPARα gene expression; and upregulation of SCD1, ACSS1, FABP1, CPT1, and DGAT-1 gene expression. Gut microbiota 16S rDNA sequencing analysis showed that the treatment group improved the gut microbiota by increasing the relative abundances and increasing the short-chain fatty acid levels produced by the genera Akkermansia, Clostridium, Lachnospiraceae, Lactobacillus, Anaerotaenia, and Prevotella. After adding BCFAs to cultured breast cancer cells, pathways that were downregulated were found to be related to fatty acid degradation and fatty acid metabolism, while 20 other pathways were upregulated. Our results suggest that BCFAs reduce body fat in mice by modulating intestinal flora and lipid metabolism and modulating fatty acid metabolism in breast cancer cells.

Investigating the Levels of Liver Lipogenic and Lipolytic Enzymes in Rat with High-Fat Diet and Sucrose Solution Underwent Progressive Resistance Training

Objective: Consuming too much fat or carbohydrates stimulates lipogenesis and excess fat is stored in non-fat tissues, including the liver, and manifests as obesity and fatty liver disease. This study aimed to investigate the effect of eight weeks of progressive resistance training (PRT) on the liver levels of some enzymes affecting lipid metabolism in rats fed a high-fat diet and sucrose solution.&#x0D; Materials and Methods: Twenty-four male wistar rats with 5 weeks of age were randomly divided into two groups: standard diet (SD) (n=8) and high-fat diet and sucrose solution (HFDS) (n=16). Twelve weeks later, HFDS group was divided into two groups: sedentary (HS) and PRT (HPRT). The PRT program was implemented 3 days a week for 8 weeks. Gene expression of AMPKα1, SCD-1, ATGL and FASN enzymes affecting lipid metabolism in liver tissue and its fat content were investigated.&#x0D; Results: HFDS significantly increased the body weight (P: 0.001) and significantly decreased the liver expression of ATGL and FASN (P: 0.001, P: 0.011). Eight weeks of PRT did not show a significant difference in the expression of AMPKα1, SCD-1, ATGL and FASN genes. Rats fed HFDS had considerably higher levels of triglyceride (TG) and total cholesterol (TC) in their liver tissue (P: 0.004, P: 0.001) and PRT did not affect them (P: 0.959, P: 0.809 respectively).&#x0D; Conclusion: It seems that eight weeks of PRT will not change liver lipid metabolism enzymes. Therefore, modifying the diet and changing it, will probably show different results after PRT.

Dynamic role of Scd1 gene during mouse oocyte growth and maturation

Mammalian reproductive ability is regulated by many factors, among which the fatty acid metabolism network provides energy for oocyte growth and primordial follicle formation during early mouse oogenesis. But the mechanism behind that is still unknown. Stearoyl-CoA desaturase 1 (Scd1) gene expression is increased during the oogenesis process, supporting the oocyte's healthy growth. Taking advantage of gene-edited mice lacking stearoyl-Coenzyme A desaturase 1 gene (Scd1−/−), we analyzed relative gene expression in perinatal ovaries from wildtype, and Scd1−/− mice. Scd1 deficiency dysregulates expression of meiosis-related genes (e.g., Sycp1, Sycp2, Sycp3, Rad51, Ddx4) and a variety of genes (e.g., Nobox, Lhx8, Bmp15, Ybx2, Dppa3, Oct4, Sohlh1, Zp3) associated with oocyte growth and differentiation, leading to a lower oocyte maturation rate. The absence of Scd1 significantly impedes meiotic progression, causes DNA damage, and inhibits damage repair in Scd1−/− ovaries. Moreover, we find that Scd1 absense dramatically disrupts the abundance of fatty acid metabolism genes (e.g., Fasn, Srebp1, Acaca) and the lipid droplet content. Thus, our findings substantiate a major role for Scd1 as a multifunctional regulator of fatty acid networks necessary for oocyte maintenance and differentiation during early follicular genesis.

Oleanolic Acid Inhibits SCD1 Gene Expression to Ameliorate Fructose-Induced Hepatosteatosis through SREBP1c-Dependent and -Independent Mechanisms.

The mechanisms of oleanolic acid (OA) regulating hepatic sterol regulatory element-binding protein (SREBP) 1c/stearoyl-CoA desaturase (SCD) 1 pathway to ameliorate fructose-induced hepatosteatosis are investigated. Rats treated with 10% w/v fructose solution are co-administered by OA for 5 weeks, and then sacrifice after fasting for 14 h. OA reverses the fructose-induced increase in hepatic triglyceride (TG) content and downregulates Scd1 mRNA expression. However, two upstream transcription factors, ChREBP and SREBP1c, remain at normal levels with or without fructose and/or OA. In vivo and in vitro studies using SREBP1c-/- mice and HepG2 cell models show that OA also inhibits SCD1 gene overexpression and high hepatic TG levels induced by fructose. On the other hand, in SCD1-/- mice, when the fructose diet is supplemented with high levels of oleic acid (OLA) to compensate for the deficiency of SCD1, OA inhibits hepatic SREBP1c and lipogenic gene expression and reduces hepatic OLA (C18:1) production to improve fructose and/or OLA induced liver lipid deposition. Furthermore, OA promotes PPARα and AMPK to enhance fatty acid oxidation in fructose + OLA-fed SCD1-/- mice. OA may inhibit SCD1 gene expression to ameliorate fructose-induced hepatosteatosis through SREBP1c-dependent and -independent mechanisms.

Green cabbage supplementation influences the gene expression and fatty acid levels of adipose tissue in Chinese Wanxi White geese.

Dietary green cabbage was evaluated for its impact on fatty acid synthetic ability in different adipose tissues during fattening of Wanxi White geese. A total of 256 Wanxi White geese at their 70 days were randomly allocated into 4 groups with 4 replicates and fed 0%, 15%, 30%, and 45% fresh green cabbage (relative to dry matter), respectively, in each group. Adipose tissues (subcutaneous and abdominal fat), liver and blood were collected from 4 birds in each replicate at their 70, 80, 90, and 100 days for fatty acid composition, relative gene expression and serum lipid analysis. Two-way or three-way analysis of variance was used for analysis. The contents of palmitic acid (C16:0), palmitoleic acid (C16:1), linoleic acid (C18:2), and alpha-linolenic acid (C18:3) were feeding time dependently increased. The C16:0 and stearic acid (C18:0) were higher in abdominal fat, while C16:1, oleic acid (C18:1), and C18:2 were higher in subcutaneous fat. Geese fed 45% green cabbage exhibited highest level of C18:3. Geese fed green cabbage for 30 d exhibited higher level of C16:0 and C18:0 in abdominal fat, while geese fed 30% to 45% green cabbage exhibited higher C18:3 in subcutaneous fat. The expression of Acsl1 (p = 0.003) and Scd1 (p<0.0001) were decreased with green cabbage addition. Interaction between feeding time and adipose tissue affected elongation of long-chain fatty acids family member 6 (Elovl6), acyl-CoA synthetase longchain family member 1 (Acsl1), and stearoly-coA desaturase 1 (Scd1) gene expression levels (p = 0.013, p = 0.003, p = 0.005). Feeding time only affected serum lipid levels of free fatty acid and chylomicron. Higher contents of C16:0, C18:1, and C18:3 were associated with greater mRNA expression of Scd1 (p<0.0001), while higher level of C18:2 was associated with less mRNA expression of Scd1 (p<0.0001). Considering content of C18:2 and C18:3, 30% addition of green cabbage could be considered for fattening for 30 days in Wanxi White geese.

Downregulation of Stearoyl-CoA Desaturase 1 (SCD-1) Promotes Resistance to Imatinib in Chronic Myeloid Leukemia.

Chronic myeloid leukemia (CML) is a malignant hematopoietic stem cell disease resulting in the fusion of BCR and ABL genes and characterized by the presence of the reciprocal translocation t(9;22)(q34;q11). BCR-ABL, a product of the BCR-ABL fusion gene, is a structurally active tyrosine kinase and plays an important role in CML disease pathogenesis. Imatinib mesylate (IMA) is a strong and selective BCR-ABL tyrosine kinase inhibitor. Although IMA therapy is an effective treatment, patients may develop resistance to IMA therapy over time. This study investigated the possible genetic resistance mechanisms in patients developing resistance to IMA. We did DNA sequencing in order to detect BCR-ABL mutations, which are responsible for IMA resistance. Moreover, we analyzed the mRNA expression levels of genes responsible for apoptosis, such as BCL-2, P53, and other genes (SCD-1, PTEN). In a group of CML patients resistant to IMA, when compared with IMA-sensitive CML patients, a decrease in SCD-1 gene expression levels and an increase in BCL-2 gene expression levels was observed. In this case, the SCD-1 gene was thought to act as a tumor suppressor. The present study aimed to investigate the mechanisms involved in IMA resistance in CML patients and determine new targets that can be beneficial in choosing the effective treatment. Finally, the study suggests that the SCD-1 and BCL-2 genes may be mechanisms responsible for resistance.

Effect of Schizochytrium limacinum supplementation to a low fish-meal diet on growth performance, lipid metabolism, apoptosis, autophagy and intestinal histology of Litopenaeus vannamei

In this experiment, we aimed to evaluate the relationship between the addition of Schizochytrium limacinum to low fish meal diets on growth performance, apoptosis, autophagy, lipid metabolism, and intestinal health of Lipenaeus vanamei. The diet containing 25% fish meal was used as a positive control (FM) and the other three diets contained 15% fish meal and were supplemented with 0, 0.3, and 0.6% S. Limacinum (LF, LFLD, LFHD). The shrimp (0.22 ± 0.00 g) were divided into four replicates of 40 shrimp per tank and fed four times daily to apparent satiation for 8 weeks. Results showed that the final weight (FBW) and weight gain rate (WGR) of shrimp fed FM and LFHD diets were significantly increased compared to those fed the LFLD diet (P&amp;lt;0.05), and there was no significant difference in survival rate (SR) and feed conversion rate (FCR) among the groups (P&amp;gt;0.05). Supplementation of S. Limacinum in low fish meal diets had no effects on shrimp body composition (P&amp;lt;0.05). There were significant differences (P&amp;lt;0.05) in low-density lipoprotein (LDL-C) glucose (GLU), triglycerides (TG), and total cholesterol (TC) in the hemolymph of shrimp fed the LF diet compared to those fed the LFLD and LFHD diets. HE staining and transmission electron microscopy (TEM) results showed that the microvilli height, mucosal folds height, mucosal folds width and muscle layer thickness in the intestine of shrimp fed the LF diet were significantly reduced compared to those fed the other three diets (P&amp;lt;0.05). Swelling of the endoplasmic reticulum and irregular mitochondria in the gut of shrimp fed the LF diet was also observed by TEM, and the endoplasmic reticulum and mitochondria of shrimp fed the LFHD diet returned to a healthy state. Hepatopancreas genes expression results were showed that the gene expression of 5′ -AMP-activated protein kinase (ampk), stearoyl-CoA desaturase (scd1), acetyl-CoA carboxylase 1 (acc1), and malonyl-CoA decarboxylase (mcd) of shrimp fed the LF diet was significantly increased compared to those fed the FM diet (P&amp;lt;0.05). The gene expression of sterol regulatory element-binding protein (srbep) and carnitine palmitoyl transferase 1 (cpt-1) of shrimp fed the LFLD diet was significantly increased compared to those fed the LF diet (P&amp;lt;0.05). The gene expression of acc1, mcd and scd1 of shrimp fed the LFHD diet was significantly reduced compared to those fed the LF diet (P&amp;lt;0.05). Results of genes expression associated with apoptosis in the hepatopancreas showed that the gene expression of B lymphocytoma-2 (bcl-2), BCL2 associated X apoptosis regulator (bax) and cysteinyl aspartate specific proteinase 8 (caspase 8) of shrimp fed the LF diet was significantly reduced compared to those fed the FM diet (P&amp;lt;0.05). The gene expression of bcl-2 of shrimp fed the LFHD diet was significantly reduced compared to those fed the LF diet (P&amp;lt;0.05). Genes related to autophagy in the hepatopancreas showed that the expression of autophagy-related protein 12 (atg 12), autophagy-related protein 13 (atg 13) and beclin1 of shrimp fed LF the diet was significantly reduced compared to those fed the FM diet (P&amp;lt;0.05). The gene expression of atg 12 and atg 13 of shrimp fed the LFHD diet was significantly increased compared to those fed the LF diet (P&amp;lt;0.05). In summary, reducing fish meal is detrimental to the growth performance and intestinal health of shrimp, and 0.6% S. Limacinum supplementation can improve the growth performance, promotes hepatopancreas lipid metabolism, reduces apoptosis, promotes autophagy and improve intestinal health of Litopenaeus vannamei.

Fenofibrate enhances lipid deposition via modulating PPARγ, SREBP-1c, and gut microbiota in ob/ob mice fed a high-fat diet.

Obesity is characterized by lipid accumulation in distinct organs. Presently, fenofibrate is a commonly used triglyceride-lowering drug. This study is designed to investigate whether long-term fenofibrate intervention can attenuate lipid accumulation in ob/ob mouse, a typical model of obesity. Our data demonstrated that fenofibrate intervention significantly decreased plasma triglyceride level by 21.0%, increased liver index and hepatic triglyceride content by 31.7 and 52.1%, respectively, and elevated adipose index by 44.6% compared to the vehicle group. As a PPARα agonist, fenofibrate intervention significantly increased the expression of PPARα protein in the liver by 46.3% and enhanced the expression of LDLR protein by 3.7-fold. However, fenofibrate dramatically increased the expression of PPARγ and SREBP-1c proteins by ~2.1- and 0.9-fold in the liver, respectively. Fenofibrate showed no effects on the expression of genes-related to fatty acid β-oxidation. Of note, it significantly increased the gene expression of FAS and SCD-1. Furthermore, fenofibrate modulated the gut microbiota. Collectively, long-term fenofibrate induces lipid accumulation in liver and adipose tissues in ob/ob mice by enhancing the expression of adipogenesis-related proteins and gut microbiota. These data suggest that fenofibrate may have limited effects on attenuating lipid deposition in obese patients.

Effect of Gegen Qinlian Decoction on methylation and expression of Scd1gene in adipose tissue of insulin resistant rats and correlations between methylation and physiological and biochemical parameters

This study aimed to explore the effect of Gegen Qinlian Decoction(GQD) on the methylation and mRNA expression level of stearoyl CoA desaturase(SCD) gene in the adipose tissue of rats with insulin resistance(IR) induced by high-fat diet as well as the correlations between methylation and physiological and biochemical indicators. The animals were divided into seven groups, namely, blank control(C) group, IR model group, low-(1.65 g·kg~(-1)), medium-(4.95 g·kg~(-1)), and high(14.85 g·kg~(-1))-dose GQD(GQDL, GQDM, and GQDH) groups, rosiglitazone(RGN, 5 mg·kg~(-1)) group, and simvastatin(SVT, 10 mg·kg~(-1)) group. The rat epididymal adipose tissue was collected for detecting all the cytosine methylation levels in two fragments of Scd1 gene by bisulfite sequencing PCR(BSP). Scd1-1 was located in CG shores and Scd1-2 in CG islands, including the transcriptional start site(TSS). The Scd1 mRNA level was determined by quantitative real-time PCR(q-PCR). Spearman correlation coefficient was used to analyze the correlations between amplified fragment C methylation and physiological and biochemical indicators. The results showed that GQDM remarkably reversed the elevated CG7 methylation in the TSS upstream region of Scd1-2 triggered by high-fat diet. GQDL significantly reversed the lowered total CG methylation in the downstream region of Scd1-2 induced by the high-fat diet. GQD did not significantly improve the decreased Scd1 mRNA expression caused by high-fat diet. Changes in methylation of the total CG, CG5 and CT11 of Scd1-1 in CG shores exhibited significant negative correlations with the serum triglyceride(TG) but positive correlation with the Scd1 mRNA level. The methylation of several C sites in the TSS upstream region of Scd1-2 was positively correlated with physiological and biochemical parameters. The methylation of several CG sites in the TSS downstream region of Scd1-2 was negatively associated with physiological and biochemical parameters. Besides, the methylation of several CH sites in the downstream fragment was positively correlated with physiological and biochemical parameters. All these have demonstrated that GQD may exert the therapeutic effect by regulating the methylation of CG7 in the TSS upstream region and total CG site in the TSS downstream region of Scd1 gene. The methylation of total CG, CG5 and CT11 sites in CG shores of Scd1 gene may be important targets for regulating Scd1 mRNA level and affecting serum TG.

Xanthophyll β-cryptoxanthin treatment inhibits hepatic steatosis without altering vitamin A status in β-carotene 9',10'-oxygenase knockout mice.

β-cryptoxanthin (BCX), one of the major carotenoids detected in human circulation, can protect against the development of fatty liver disease. BCX can be metabolized through β-carotene-15,15'-oxygenase (BCO1) and β-carotene-9',10'-oxygenase (BCO2) cleavage pathways to produce both vitamin A and apo-carotenoids, respectively, which are considered important signaling molecules in a variety of biological processes. Recently, we have demonstrated that BCX treatment reduced hepatic steatosis severity and hepatic total cholesterol levels in both wide type and BCO1-/-/BCO2-/- double knock out (KO) mice. Whether the protective effect of BCX is seen in single BCO2-/- KO mice is unclear. In the present study, male BCO2-/- KO mice at 1 and 5 months of age were assigned to two groups by age and weight-matching as follows: (I) -BCX control diet alone (AIN-93 purified diets); (II) +BCX 10 mg (supplemented with 10 mg of BCX/kg of diet) for 3 months. At 4 and 8 months of age, hepatic steatosis and inflammatory foci were evaluated by histopathology. Retinoids and BCX concentrations in liver tissue were analyzed by high-performance liquid chromatography (HPLC). Hepatic protein expressions of SIRT1, acetylated and total FoxO1, PGC1α, and PPARα were determined by the Western blot analysis. Real-time PCR for gene expressions (MCAD, SCD1, FAS, TNFα, and IL-1β gene expression relative to β-actin) was conducted in the liver. Steatosis was detected at 8 months but not at 4 months of age. Moreover, BCX supplementation significantly reduced the severity of steatosis in the livers of BCO2 KO mice, which was associated with changes in hepatic SIRT1 acetylation of FOXO1, PGC1α protein expression and PPARα protein expression in BCO2-/- KO mice. HPLC analysis showed that hepatic BCX was detected in BCX supplemented groups, but there were no differences in the hepatic levels of retinol and retinyl palmitate (RP) among all groups. The present study provided experimental evidence that BCX intervention can reduce liver steatosis independent of BCO2.

Human adipocyte differentiation and composition of disease-relevant lipids are regulated by miR-221-3p

MicroRNA-221-3p (miR-221-3p) is associated with both metabolic diseases and cancers. However, its role in terminal adipocyte differentiation and lipid metabolism are uncharacterized. miR-221-3p or its inhibitor was transfected into differentiating or mature human adipocytes. Triglyceride (TG) content and adipogenic gene expression were monitored, global lipidome analysis was carried out, and mechanisms underlying the effects of miR-221-3p were investigated. Finally, cross-talk between miR-221-3p expressing adipocytes and MCF-7 breast carcinoma (BC) cells was studied, and miR-221-3p expression in tumor-proximal adipose biopsies from BC patients analyzed. miR-221-3p overexpression inhibited terminal differentiation of adipocytes, as judged from reduced TG storage and gene expression of the adipogenic markers SCD1, GLUT4, FAS, DGAT1/2, AP2, ATGL and AdipoQ, whereas the miR-221-3p inhibitor increased TG storage. Knockdown of the predicted miR-221-3p target, 14-3-3γ, had similar antiadipogenic effects as miR-221-3p overexpression, indicating it as a potential mediator of mir-221-3p function. Importantly, miR-221-3p overexpression inhibited de novo lipogenesis but increased the concentrations of ceramides and sphingomyelins, while reducing diacylglycerols, concomitant with suppression of sphingomyelin phosphodiesterase, ATP citrate lyase, and acid ceramidase. miR-221-3p expression was elevated in tumor proximal adipose tissue from patients with invasive BC. Conditioned medium of miR-221-3p overexpressing adipocytes stimulated the invasion and proliferation of BC cells, while medium of the BC cells enhanced miR-221-3p expression in adipocytes. Elevated miR-221-3p impairs adipocyte lipid storage and differentiation, and modifies their ceramide, sphingomyelin, and diacylglycerol content. These alterations are relevant for metabolic diseases but may also affect cancer progression.

Inhibitory efficacy of lutein on adipogenesis is associated with blockage of early phase regulators of adipocyte differentiation

A comprehensive molecular mechanistic role of lutein on adipogenesis is not well understood. The present study focused to evaluate the effect of lutein at the early and late phase of adipocyte differentiation in vitro using a 3T3-L1 cell model. The effect of purified carotenoid on the viability of normal and differentiated 3T3-L1 cells was analyzed by WST-1 assay. Oil Red O and Nile red staining were employed to observe lipid droplets in mature adipocytes. The effect of lutein on gene and protein expression of major transcription factors and adipogenic markers was analyzed by RT-PCR and western blotting, respectively. The role of lutein on mitotic clonal expansion was analyzed by flow cytometry. The results showed a significant reduction (p < 0.05) in the accumulation of lipid droplets in lutein-treated (5 μM) cells. Inhibition in lipid accumulation was associated with down-regulated expression of CEBP-α and PPAR-γ at gene and protein levels. Subsequently, lutein repressed gene expression of FAS, FABP4, and SCD1 in mature adipocytes. Interestingly, it blocks the protein expression of CEBP-α and PPAR-γ in the initial stages of adipocyte differentiation. This early-stage inhibition of adipocyte differentiation is linked with repressed phosphorylation AKT and ERK. Further, upregulated cyclin D and down-regulated CDK4 and CDK2 in lutein treated adipocytes enumerate its role in delaying the cell cycle progression at the G0/G1 phase. Our results emphasize that adipogenesis inhibitory efficacy of lutein is potentiated by halting early phase regulators of adipocyte differentiation, which strengthens the competency of lutein besides its inevitable presence in the human body.

Ezetimibe Enhances Macrophage-to-Feces Reverse Cholesterol Transport in Golden Syrian Hamsters Fed a High-Cholesterol Diet

The aim of this work was to evaluate reverse cholesterol transport (RCT) in hamster, animal model expressing CETP under a high cholesterol diet (HF) supplemented with Ezetimibe using primary labelled macrophages. We studied three groups of hamsters (n=8/group) for 4 weeks: 1) chow diet group: Chow, 2) High cholesterol diet group: HF and 3) HF group supplemented with 0.01% of ezetimibe: HF+0.01%Ezet. Following intraperitoneal injection of 3H-cholesterol-labelled hamster primary macrophages, we measured the in vivo macrophage-to-feces RCT. .HF group exhibited an increase of triglycerides (TG), cholesterol, glucose in plasma and higher TG and cholesterol content in liver (p<0.01) compared to Chow group. Ezetimibe induced a significant decrease in plasma cholesterol with a lower LDL and VLDL cholesterol (p<0.001) and in liver cholesterol (p<0.001) and TG (p<0.01) content compared to HF. In vivo RCT essay showed an increase of tracer level in plasma and liver (p<0.05) but not in feces in HF compared to Chow group. The amount of labelled total sterol and cholesterol in liver and feces was significantly reduced (p<0.05) and increased (p=0.05) respectively with Ezetimibe treatment. No significant increase was obtained for labelled feces bile acids in HF+0.01%Ezet compared to HF. Ezetimibe decreased SCD1 gene expression and increased SR-B1 (p<0.05) in liver but did not affect NPC1L1 nor ABCG5 and ABCG8 expression in jejunum. In conclusion, ezetimibe exhibited an atheroprotective effect by enhancing RCT in hamster and decreasing LDL cholesterol. Ours findings showed also a hepatoprotective effect of ezetimibe by decreasing hepatic fat content. Significance Statement This work was assessed to determine the effect of ezetimibe treatment on high cholesterol diet induced disturbances and especially the effect on reverse cholesterol transport in animal model with CETP activity and using labelled primary hamster macrophages. We were able to demonstrate that ezetimibe exhibited an atheroprotective effect by enhancing RCT and by decreasing LDL cholesterol in hamster. We showed also a hepatoprotective effect of ezetimibe by decreasing hepatic fat content.

The effect of simvastatin on gene expression of low-density lipoprotein receptor, sterol regulatory element-binding proteins, stearoyl-CoA desaturase 1 mRNA in rat hepatic tissues

The study aimed to assess the effect of simvastatin on gene expression of LDLR, SREBPs, and SCD1 in rat hepatic tissues fed with high-fat diets (HFD) and its association with some biochemical parameters. Thirty-two male Wister albino rats were divided into four equal groups (three test and one control groups). The biochemical parameters were determined by using spectrophotometer techniques and the Elisa method. Low-density lipoprotein receptor, sterol regulatory element-binding proteins, stearoyl-CoA desaturase1, Beta-actin were analysed by real-time quantitative polymerase chain reaction (RT-PCR) method. At the end of study, the livers of the rats were separated and changes of hepatic tissue were determined. LDLR, SREBP2, and SCD1 expression increased significantly when compared G1 versus G4 and G2 versus G4. The expression of LDLR, SREBP2, and SCD1 also increased significantly when compared G2 versus G3, G1versus G3 and G1 versus G3 and G2 versus G3. The serum level of cholesterol, triglyceride, glucose, LDL, and HDL increased significantly when compared G1 versus G3. LDL showed significantly decreased when compared G1 versus G2. Cholesterol, glucose and HDL and triglyceride levels were increased significantly when compared G1 versus G4 and G2. Treatment of rats with HFD and simvastatin 20 mg/kg, triglyceride and LDL were almost the same as a control group and LDLR expression increased 98% in liver tissue. Gene expressions may be up-regulated in liver tissue and they showed different effects on biochemical parameters.

Reversal of obesity and liver steatosis in mice via inhibition of aryl hydrocarbon receptor and altered gene expression of CYP1B1, PPARα, SCD1, and osteopontin.

Background/ObjectivesObesity is a global epidemic and the underlying basis for numerous comorbidities. We report that the aryl hydrocarbon receptor (AHR) plays a key role in the metabolism of obesity. The AHR is a promiscuous, ligand-activated nuclear receptor primarily known for regulating genes involved in xenobiotic metabolism and T cell polarization. The aims of the work reported here were to understand the underlying mechanism of AHR-based obesity and to determine whether inhibition of AHR activity would reverse obesity.MethodsMice were fed control (low fat) and Western (high fat) diets with and without the AHR antagonist alpha-naphthoflavone (aNF). Gene expression of identified AHR-regulated genes from liver and adipose tissue was characterized. To determine the role of the AHR in obesity reversal, selected mice in control and Western diet regimens were switched at midpoint to the respective control and Western diets containing aNF, and the identified AHR-regulated genes characterized.ResultsAHR inhibition prevented obesity in mice on a 40-week diet regimen. The likely AHR-regulated and cross-regulated downstream effectors of AHR-based obesity were shown to be CYP1B1, PPARα-target genes, SCD1, and SPP1 (osteopontin). Western diet caused an increase of mRNA and protein expression of the Cyp1b1, Scd1, and Spp1, and PPARα-target genes in the liver, and inhibition of the AHR maintained expression of these genes near control levels. The body weight of obese mice on Western diet switched to Western diet containing aNF decreased to that of mice on control diet concurrently with a reduction in the expression of liver CYP1B1, PPARα-target genes, SCD1, and SPP1. AHR inhibition prevented hypertrophy and hyperplasia in visceral adipose tissue and limited expression levels of CYP1B1 and SPP1 to that of mice on control diet.ConclusionsAHR inhibition prevents and reverses obesity by likely reducing liver expression of the Cyp1b1, Scd1, Spp1, and PPARα-target genes; and the AHR is a potentially potent therapeutic target for the treatment and prevention of obesity and linked diseases.

PSV-33 Marbling and expression of genes involved in lipid metabolism in the muscle of Nellore and Nellore × Angus steers fed whole shelled corn diets

Abstract The objective was to evaluate marbling and the expression of genes involved in lipid metabolism in the muscle of Nellore and Nellore × Angus steers fed whole shelled corn (WSC) diets. Thirty-two steers with initial average body weight of 353 ±25.3 kg were used in a completely randomized design using a 2 × 2 factorial design (2 breeds and 2 diets). One diet had 80% of WSC and 20% of a soybean meal and mineral-based supplement. The other diet had 74% of WSC, 20% of the same supplement, and 6% of sugarcane bagasse. Immediately after the slaughter of steers (around 450 kg of body weight), longissimus thoracis (LT) muscle samples were collected, frozen in liquid nitrogen, and stored at −80°C for gene expression analyses using RT-qPCR. Twenty-four hours after slaughter, samples were taken from LT muscle to analyze marbling score. The model included breed, diet, and their interaction as fixed effects and animals as random effect. There was no effect of breed (364 and 358; P = 0.80) and diet (355 and 367; P = 0.56) on LT marbling. Nellore × Angus steers had greater expression of LPL, FASN, and CPT2 (Table 1), which means a greater lipid turnover. The expression of SCD1 gene tended to increase (P = 0.06) in muscle of Nellore steers fed WSCB diet, while in Nellore × Angus muscle, this diet tended to decreased SCD1 expression. Regarding diet, steers fed WSC had lower expression of FABP4, and greater expression of ACOX1. In conclusion, Nellore × Angus had greater fatty acid uptake, synthesis, and oxidation that did not result in greater intramuscular fat. In addition, animals fed whole shelled corn diet with sugarcane bagasse did not increase expression of SREBF1 and lipogenic genes, and consequently did not increase marbling. Funded by Capes, Fapemig and INCT-Ciência Animal.

Beneficial effects of troxerutin on metabolic disorders in non-obese model of metabolic syndrome.

BackgroundTroxerutin (TRX) has a beneficial effect on blood viscosity and platelet aggregation, and is currently used for the treatment of chronic varicosity. Recently, TRX can improve lipid abnormalities, glucose intolerance and oxidative stress in high-fat diet-induced metabolic disorders. In this study, we tested the effect of TRX on metabolic syndrome-associated disorders using a non-obese model of metabolic syndrome–the Hereditary Hypertriglyceridaemic rats (HHTg).MethodsAdult male HHTg rats were fed standard diet without or with TRX (150 mg/kg bwt/day for 4 weeks).ResultsCompared to untreated rats, TRX supplementation in HHTg rats decreased serum glucose (p<0.05) and insulin (p<0.05). Although blood lipids were not affected, TRX decreased hepatic cholesterol concentrations (p<0.01) and reduced gene expression of HMGCR, SREBP2 and SCD1 (p<0.01), involved in cholesterol synthesis and lipid homeostasis. TRX-treated rats exhibited decreased lipoperoxidation and increased activity of antioxidant enzymes SOD and GPx (p<0.05) in the liver. In addition, TRX supplementation increased insulin sensitivity in muscles and epididymal adipose tissue (p<0.05). Elevated serum adiponectin (p<0.05) and decreased muscle triglyceride (p<0.05) helped improve insulin sensitivity. Among the beneficial effects of TRX were changes to cytochrome P450 family enzymes. Hepatic gene expression of CYP4A1, CYP4A3 and CYP5A1 (p<0.01) decreased, while there was a marked elevation in gene expression of CYP1A1 (p<0.01).ConclusionOur results indicate that TRX improves hepatic lipid metabolism and insulin sensitivity in peripheral tissues. As well as ameliorating oxidative stress, TRX can reduce ectopic lipid deposition, affect genes involved in lipid metabolism, and influence the activity of CYP family enzymes.