Lipid Droplet Deposition Research Articles

Salidroside-Mitigated Inflammatory Injury of Hepatocytes with Non-Alcoholic Fatty Liver Disease via Inhibition TRPM2 Ion Channel Activation.

PurposeOxidative stress plays an important role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). TRPM2 ion channel functions as a molecular sensor for oxidative stress. The aim of this study was to examine the protective effects of Salidroside, a powerful antioxidative plant, on TRPM2 in an established in vitro model of NAFLD.MethodsNAFLD model was established by palmitic acid (PA) in hepatic L02 cell lines and was added to the media at a final concentration of 400 μM. Cells were used as normal group, PA group and PA receiving varied concentrations of Salidroside (75μg/mL, 150μg/mL, 300μg/mL). After treating 24 hrs, MTT assay was used to detect cell viability, and ALT level was measured using an appropriate kit assay. Intracellular lipid accumulation was observed by Oil red O staining. Cytosolic Ca2+ concentrations were evaluated by flow cytometer with Fluo-3/AM. Quantitative RT-PCR was used to measure the mRNA expression of TRPM2, IL-1β and IL-6, and the protein expressions of TRPM2, p-CaMKII and autophagy (LC3B, p62) were determined using Western blot.ResultsTreatment with Salidroside effectively restored liver injury and alleviated lipid droplet deposition in a dose-dependent manner, which was associated with inhibition of TRPM2/Ca2+/CaMKII pathway. Additionally, autophagic clearance was enhanced by intervention with Salidroside in a dose-dependent manner. Further investigation indicated that Salidroside down-regulated the mRNA expression of IL-1β and IL-6-pro-inflammatory cytokines.ConclusionThese results suggest that Salidroside could alleviate inflammatory injury and steatosis via autophagy activation mediated by downregulation of the TRPM2/Ca2+/CaMKII pathway. Targeting the TRPM2 ion channel is a novel treatment strategy for oxidative stress-induced liver in NAFLD.

Gastric mucosal devitalization improves blood pressure, renin and cardiovascular lipid deposition in a rat model of obesity.

Background and study aims In lieu of the drawbacks of metabolic surgery, a method of mimicking resection of the gastric mucosa could be of value to those with obesity-related cardiovascular disease (CVD). Our study aims to investigate the effect of gastric mucosal devitalization (GMD) on blood pressure (BP) and cardiovascular lipid deposition in a rat model of obesity. Methods GMD of 70 % of the stomach was achieved by argon plasma coagulation. GMD was compared to sleeve gastrectomy (SG) and sham (SH) in a high-fat-diet-induced rat model of obesity (48 rats). At 8 weeks, we measured noninvasive BP, renin, vessel relaxation and ghrelin receptor regulation in the aorta. In addition, we quantified cardiac lipid deposition and lipid droplet deposition in cardiac muscle and aorta. Results GMD and SG were observed to have similar reductions in body weight, visceral adiposity, and serum lipid profile compared to SH rats. GMD resulted in a significant reduction in arterial BP compared to SH. Furthermore, there were significant reductions in plasma renin activity and percentage of phenylnephrine constriction to acetylcholine at the aortic ring in GMD rats compared to SH, providing insights into the mechanisms behind the reduced BP. Interestingly, the reduced BP occurred despite a reduction in endothelial ghrelin recteptor activation. Cardiac lipid content was significantly reduced in GMD rats. Lipid deposition, as illustrated by Nile Red stain, was reduced in cardiac muscle and the aorta. Conclusion GMD resulted in a significant improvement in BP, renin and cardiovascular lipid deposition. GMD deserves further attention as a method of treating obesity-related CVD.

Glucagon-like peptide-1 analog protects proximal tubules injury from lysosomal dysfunction and impaired autophagic flux

The role of glucagon-like peptide-1 analog (GLP-1) in autophagic flux and lysosomal dysfunction in obesityrelated glomerulopathy (ORG) remains poorly understood. Here, we demonstrated that exposure to a high-fat diet (HFD) resulted in ectopic lipid accumulation, increased 24-hour urinary albumin, and vacuolated tubular cells. The apoptotic cell content in renal tubules was remarkably increased in the HFD group, compared to CON mice, as evident from TUNEL staining and caspase-3 expression, and significantly decreased upon switching to the normal chow diet and GLP-1 treatment. Compared to the control group, significant accumulation of Oil red O staining and CD36 and PLIN2 was observed in tubular cells of HFD mice. In the HFDG and HFD-C groups, lipid droplet deposition in tubular cells were inhibited. LC3 and p62 levels were markedly increased in proximal tubules of HFD mice, and palmitic acid impaired autophagic flux in HK2 cells. Electron microscopy revealed that non-functional lysosomal residue merged with the functional lysosome in the HFD group. GLP-1 treatment and a normal chow diet led to inhibition of enlarged lysosomal residue and restored autophagic flux. In conclusion, impaired lysosome and autophagic flux may be ameliorated by GLP-1 treatment and replacement with a normal chow diet.

P2.03-59 The Role of Radiation Dose-Dependent Lipid Metabolism Reprogramming on Radiation Survival/Resistance in Lung Cancer Cells

Radiotherapy plays a more and more important role in the management of lung cancer. However, radioresistance still limits the long-term control of tumors. Exploration of the dynamic changes of metabolic reprogramming in surviving/resistant lung cancer cells exposed to increased doses of radiation is helpful to elucidate the metabolic mechanism of radiation resistance in lung cancer cells, to develop new targets for the clinical intervention and the early detection of radiation resistance. Lung cancer cells A549, H520 and H460 were treated in vitro with fractionated radiation (2 Gy) to a cumulative total dose of 40Gy, 60Gy or 80Gy. Cellular radiation sensitivity was verified by colony survival assay and comet experiments. Cell proliferation was determined by EdU assay. Transcriptome sequencing and metabolomic analysis were performed to identify differentially expressed genes and metabolites in radiation-resistant cells and their parental cells. Oil Red O staining was used to detect lipid droplet content. RT-PCR and WB were used to detect the expression of genes related to lipid metabolism. Lung cancer cell sublines that had been exposed to 20, 30 or 40 fractions of 2Gy had a significant increase in radioresistance as compared with their parental cells. Furthermore, this radioresistance of cells increased with the increase of previous radiation dose exposure. We found that lipid droplet deposition and the expression of lipid metabolism genes, such as fatty acid oxidation-related genes and glycerol metabolism-related genes, showed an increasing trend with previous radiation dose in surviving/resistant lung cancer cells exposed to radiation. Metabolomic analysis revealed that lipid metabolites such as glycerol and oxaloacetic acid also increased significantly. Inhibition of carnitine palmitoyltransferase 1A (CPT1A) by Etomoxir, a fatty acid oxidation inhibitor, significantly enhanced the radiosensitivity and decreased the DNA repair ability of various surviving/resistant lung cancer cells exposed to radiation. The surviving/resistant lung cancer cells generated by sequential irradiation provide models for future investigations of the dose-dependent mechanisms of radioresistance in a preclinical setting. Radiation dose-dependent lipid metabolism reprogramming may contribute to radiation survival/resistance in lung cancer cells. Support: 81572279, 2016J004, LC2016PY016, 2018CR033.

Effects of fluoride on the histology, lipid metabolism, and bile acid secretion in liver of Bufo gargarizans larvae

In our study, Bufo gargarizans (B. gargarizans) larvae were exposed to control, 0.5, 5, 10 and 50 mg/L of NaF from Gs 26 to 42. At Gs 42, we evaluated the changes of liver histology and the mRNA levels of target genes in liver. In addition, we also examined the composition and content of fatty acids. Histological analysis revealed that fluoride caused liver injury, such as the increase of number of melanomacrophage centres, atrophy of nucleus, dilation of bile canaliculus, and decrease of quantity, degradation and deposition of lipid droplets. The results of RT-qPCR indicated that exposure to 5, 10 and 50 mg/L of NaF significantly decreased the transcript levels of genes related to fatty acid synthesis (FASN, FAE, MECR, KAR and TECR) in liver. Besides, mRNA expression of genes involved in fatty acid β-oxidation (ECHS1, HADHA, SCP2, CPT2, ACAA1 and ACAA2) and oxidative stress (SOD, GPx, MICU1 and HSP90) was significantly downregulated in 0.5, 5, 10 and 50 mg/L of NaF treatment groups. Also, in the relative expression of genes associated with synthesis and secretion of bile acid, BSEP significantly increased at 0.5, 5 and 50 mg/L of NaF while HSD3B7 significantly reduced in 0.5, 5, 10 and 50 mg/L of NaF. Finally, the fatty acid extraction and GC-MS analysis showed that the content of saturated fatty acids (SFAs) was decreased and the content of polyunsaturated fatty acids (PUFAs) was increased in all fluoride treatment groups. Taken together, the present results indicated that fluoride-induced the histological alterations of liver might be linked to the disorder of lipid metabolism, oxidative damage.

RETRACTED ARTICLE: FABP4 contributes to renal interstitial fibrosis via mediating inflammation and lipid metabolism

Fatty acid binding protein 4 (FABP4), a subtype of fatty acid-binding protein family, shows critical roles in metabolism and inflammation. However, its roles on regulating renal interstitial fibrosis (RIF) remain unclear. In this work, LPS-stimulated in vitro models on NRK-52E and NRK-49F cells, and in vivo UUO models in rats and mice were established. The results showed that comparing with control groups or sham groups, the expression levels of α-SMA, COL1A, COL3A, IL-1β, IL-6, and TNF-α in LPS-stimulated cells or UUO animals were significantly increased. Meanwhile, the levels of TC, TG, and free fatty acid were also significantly increased as well as the obvious lipid droplets, and the serum levels of BUN, Cr were significantly increased with large amounts of collagen deposition in renal tissues. Further investigation showed that compared with control groups or sham groups, the expression levels of FABP4 in LPS-stimulated cells and UUO animals were significantly increased, resulting in down- regulating the expression levels of PPARγ, upregulating the levels of p65 and ICAM-1, and decreasing the expression levels of ACADM, ACADL, SCP-2, CPT1, EHHADH, and ACOX1. To deeply explore the mechanism of FABP4 in RIF, FABP4 siRNA and inhibitor interfered cell models, and UUO model on FABP4 knockout (KO) mice were used. The results showed that the expression levels of α-SMA, COL1A, and COL3A were significantly decreased, the deposition of lipid droplets decreased, and the contents of TC, TG, and free fatty acids were significantly decreased after gene silencing. Meanwhile, the expression levels of PPAR-γ, ACADM, ACADL, SCP-2, CPT1, EHHADH, and ACOX1 were upregulated, the levels of p65 and ICAM-1 were downregulated, and the mRNA levels of IL-1β, IL-6, and TNF-α were decreased. Our results supported that FABP4 contributed to RIF via promoting inflammation and lipid metabolism, which should be considered as one new drug target to treat RIF.

Downregulation of sirtuin 3 by palmitic acid increases the oxidative stress, impairment of mitochondrial function, and apoptosis in liver cells.

Elevated levels of saturated fatty acids show a strong cytotoxic effect in liver cells. Sirtuin 3 (SIRT3), a mitochondrially localized member of NAD+ -dependent deacetylase has been shown to protect hepatocytes against the oxidative stress. The role of SIRT3 on the cytotoxicity caused by fatty acids in liver cells is not fully understood. The aim of this study was to evaluate the expression level of SIRT3, oxidative stress, and mitochondrial impairments in human hepatoma HepG2 cells exposed to palmitic acid (PA). Our results showed that PA treatment caused the deposition of lipid droplets and resulted in an increased expression of tumor necrosis factor-α in a dose-dependent manner. Excessive accumulation of PA induces the reactive oxygen species formation and apoptosis while dissipating the mitochondrial transmembrane potential. The level of SIRT3 expression in both nuclear and mitochondrial fractions in HepG2 cells was decreased with the increase in PA concentrations. However, in the cytosolic fraction, the SIRT3 was undetectable. In conclusion, our results showed that PA caused an increase in inflammation and oxidative stress in HepG2 cells. The exposure of PA also resulted in the decline in transmembrane potential and an increase in apoptosis. The underexpression of nuclear and mitochondrial SIRT3 by PA suggests that the PA target the process that regulates the stress-related gene expression and mitochondrial functions.

Disulfide-bond A oxidoreductase-like protein protects against ectopic fat deposition and lipid-related kidney damage in diabetic nephropathy

Ectopic fat deposition (EFD) in the kidney has been shown to play a causal role in diabetic nephropathy; however, the mechanism underlying EFD remains elusive. By transcriptome analysis, we found decreased expression levels of disulfide-bond A oxidoreductase-like protein (DsbA-L) in the kidneys of diabetic mice (induced by high-fat diet plus Streptozotocin) compared with control mice. Increased expression of adipocyte differentiation-related protein and abnormal levels of collagen I, fibronectin, and phosphorylated 5'AMP-activated kinase (p-AMPK), adipose triglyceride lipase (p-ATGL), and HMG-CoA reductase (p-HMGCR) were also observed in diabetic mice. These alterations were accompanied by deposition of lipid droplets in the kidney, and were more pronounced in diabetic DsbA-L knockout mice. Invitro, overexpression of DsbA-L ameliorated high glucose-induced intracellular lipid droplet deposition in a human proximal tubular cell line, and DsbA-L siRNA aggravated lipid droplet deposition and reduced the levels of p-AMPK, p-ATGL, and p-HMGCR. High glucose and palmitic acid treatment enhanced the expression of interleukin-1β and interleukin-18; these enhancements were further increased after treatment with DsbA-L siRNA but alleviated by co-treatment with an AMPK activator. In kidney biopsy tissue from patients with diabetic nephropathy, DsbA-L expression was negatively correlated with EFD and tubular damage. Collectively, these results suggest that DsbA-L has a protective role against EFD and lipid-related kidney damage in diabetic nephropathy. Activation of the AMPK pathway is a potential mechanism underlying DsbA-L action in the kidney.

Visfatin serum concentration and hepatic mRNA expression in chronic hepatitis C.

Aim of the studyChronic hepatitis C (CHC) is a viral disease with metabolic disturbances involved in its pathogenesis. Adipokines may influence the inflammatory response and contribute to development of metabolic abnormalities in CHC. Visfatin exerts immunomodulatory and insulin-mimetic effects. The aim was to measure visfatin serum concentrations and its mRNA hepatic expression in non-obese CHC patients and to assess the relationships with metabolic and histological parameters.Material and methodsIn a group of 63 non-obese CHC patients (29 M/34 F) infected with genotype 1b aged 46.6 ±14.6 years, body mass index (BMI) 24.8 ±3.0 kg/m2, serum visfatin levels and its mRNA hepatic expression were examined and the subsequent associations with metabolic and histopathological features were assessed.ResultsSerum visfatin levels were significantly higher in CHC patients compared to controls (22.7 ±5.7 vs. 17.8 ±1.5 ng/ml, p < 0.001). There was no difference in serum visfatin and its mRNA hepatic expression regardless of sex, BMI, insulin sensitivity and lipids concentrations. There was no mutual correlation between serum visfatin and visfatin mRNA hepatic expression. Hepatic visfatin mRNA levels but not visfatin serum levels were higher in patients with steatosis (1.35 ±0.75 vs. 0.98 ±0.34, p = 0.009).ConclusionsSerum visfatin levels may reflect its involvement in chronic inflammatory processes accompanying HCV infection. Increased visfatin mRNA hepatic expression in patients with steatosis seems to be a compensatory mechanism enabling hepatocytes to survive metabolic abnormalities resulting from virus-related lipid droplet deposition prerequisite to HCV replication.

Anti-diabetic effects of blue honeyberry on high-fed-diet-induced type II diabetic mouse.

BACKGROUND/OBJECTIVEThe blue honeysuckle berry (Lonicera caerulea var. edulis L.) is a small deciduous shrub belonging to the Caprifoliaceae family that is native to Russia, China, Japan, and Korea. The berry of this shrub is edible, sweet and juicy and is commonly known as the blue honeyberry (BHB). This study examined the anti-diabetic potential of BHB on high-fat-diet-induced mild diabetic mice. The hypoglycemic, and nephroprotective effects of the 12-week oral administration of blue honeyberry extract were analyzed.MATERIALS/METHODSThe hypoglycemic effects were based on the observed changes in insulin, blood glucose, and glycated hemoglobin (HbA1c). Furthermore, the changes in the weight of the pancreas, including its histopathology and immunohistochemical investigation were also performed. Moreover, the nephroprotective effects were analyzed by observing the changes in kidney weight, its histopathology, blood urea nitrogen (BUN), and serum creatinine levels.RESULTSThe results showed that the high-fat diet (HFD)-induced control mice showed a noticeable increase in blood glucose, insulin, HbA1c, BUN, and creatinine levels. Furthermore, growth was observed in lipid droplet deposition related to the degenerative lesions in the vacuolated renal tubules with the evident enlargement and hyperplasia of the pancreatic islets. In addition, in the endocrine pancreas, there was an increase in the insulin-and glucagon-producing cells, as well as in the insulin/glucagon cell ratios. On the other hand, compared to the HFD-treated mice group, all these diabetic and related complications were ameliorated significantly in a dose-dependent manner after 84 days of the continuous oral administration of BHBe at 400, 200 and 100 mg/kg, and a dramatic resettlement in the hepatic glucose-regulating enzyme activities was observed.CONCLUSIONSBy assessing the key parameters for T2DM, the present study showed that the BHBe could act as a potential herbal agent to cure diabetes (type II) and associated ailments in HFD-induced mice.

Hepato-morpholoy and biochemical studies on the liver of albino rats after exposure to glyphosate-Roundup\xae

BackgroundThe object of this work was to evaluate of the hepatic effects of the herbicides glyphosate-Roundup® by different doses in both sexes of albino rats.MethodsForty animals divided into four groups with ten animals for each (both sexes) were treated orally with vehicle (controls) and 25, 50, and 100 mg/kg bwt of glyphosate-Roundup® (treated groups) for 15 days daily.ResultsThe most conspicuous changes occurred on the liver treated groups due to glyphosate toxicity were the increase of enzymes activities of ALT and AST, cellular infiltration, many signs of nucleus degeneration, focal necrosis, rarified cytoplasm, disorganization of cellular organelles, and deposition of lipid droplets. The increase in the amount of collagenous fibers and the number of the mast cell were also observed.ConclusionOur results indicated that the administration of glyphosate-Roundup® in different doses may cause adverse effects on the histopathological, ultrastructure, and biochemical alternations on the liver of the albino rats.

Interventional Potential of Recombinant Feline Hepatocyte Growth Factor in a Mouse Model of Non-alcoholic Steatohepatitis.

Background and Aims: Hepatocyte growth factor (HGF) is a multifunctional pleiotropic protein involved in tissue regeneration, protection, angiogenesis, anti-inflammatory and anti-fibrotic responses, and tumorigenesis, through binding to its receptor MET. Recombinant HGF protein has been shown to mitigate various liver disease models, such as alcohol-induced liver injury, hepatic ischemia-reperfusion injury, and fibrosis. This study aimed to investigate the anti-inflammatory, anti-fibrotic, and anti-lipogenic effects of exogenous administration of feline HGF on a non-alcoholic steatohepatitis (NASH) mouse model.Methods: Wild-type C57BL/6 mice were fed a choline-deficient amino acid defined (CDAA) diet for 3 weeks to create the mouse model of NASH, which displays hepatic steatosis, inflammation, injury, and very mild fibrosis. One mg/kg of recombinant feline HGF was administered intravenously daily in the last 7 days of the total 3 weeks of CDAA diet feeding. Then, hepatic steatosis, inflammation, injury, and fibrogenic gene expression was examined.Results: After 3 weeks of a CDAA diet-feeding, the vehicle-treated mice exhibited evident deposition of lipid droplets in hepatocytes, inflammatory cell infiltration, and hepatocyte ballooning along with increased serum ALT levels whereas recombinant HGF-treated mice showed reduced hepatic steatosis, inflammation, and ballooned hepatocytes with a reduction of serum ALT levels. Recombinant HGF administration promoted hepatocyte proliferation. Increased hepatic lipid accumulation was accompanied by elevated expression of lipogenesis genes Fasn and Dgat1 in vehicle-treated mice. In HGF-treated mice, these genes were reduced with a decrease of lipid accumulation in the liver. Consistent with the anti-inflammatory property of HGF, augmented macrophage infiltration and upregulation of chemokines, Cxcl1, Ccl2, and Ccl5 in the CDAA diet fed mice, were suppressed by the addition of the HGF treatment. Finally, we examined the fibrotic response. The vehicle-treated mice had mild fibrosis with upregulation of Col1a1, Acta2, Timp1, Tgfb1, and Serpine1 expression. Recombinant HGF treatment significantly suppressed fibrogenic gene expression and collagen deposition in the liver.Conclusion: Recombinant feline HGF treatment suppressed the progression of NASH in a CDAA diet feeding mouse model.This suggests that recombinant HGF protein has therapeutic potential for NASH.

Plin4-Dependent Lipid Droplets Hamper Neuronal Mitophagy in the MPTP/p-Induced Mouse Model of Parkinson's Disease.

Epidemiological studies have shown that both lipid metabolism disorder and mitochondrial dysfunction are correlated with the pathogenesis of neurodegenerative diseases (NDDs), including Parkinson’s disease (PD). Emerging evidence suggests that deposition of intracellular lipid droplets (LDs) participates in lipotoxicity and precedes neurodegeneration. Perilipin family members were recognized to facilitate LD movement and cellular signaling interactions. However, the direct interaction between Perilipin-regulated LD deposition and mitochondrial dysfunction in dopaminergic (DA) neurons remains obscure. Here, we demonstrate a novel type of lipid dysregulation involved in PD progression as evidenced by upregulated expression of Plin4 (a coating protein and regulator of LDs), and increased intracellular LD deposition that correlated with the loss of TH-ir (Tyrosine hydroxylase-immunoreactive) neurons in the MPTP/p-induced PD model mouse mesencephalon. Further, in vitro experiments showed that inhibition of LD storage by downregulating Plin4 promoted survival of SH-SY5Y cells. Mechanistically, reduced LD storage restored autophagy, leading to alleviation of mitochondrial damage, which in turn promoted cell survival. Moreover, the parkin-poly-Ub-p62 pathway was involved in this Plin4/LD-induced inhibition of mitophagy. These findings were further confirmed in primary cultures of DA-nergic neurons, in which autophagy inhibitor treatment significantly countermanded the ameliorations conferred by Plin4 silencing. Collectively, these experiments demonstrate that a dysfunctional Plin4/LD/mitophagy axis is involved in PD pathology and suggest Plin4-LDs as a potential biomarker as well as therapeutic strategy for PD.

Toxicological effects and behavioural and biochemical responses of Oreochromis mossambicus gills and its cholinesterase to copper: a biomarker application

Gills are both morphologically and physiologically complex whereby they perform several functions such as gas exchange, ion and water exchange, acid base balance, nitrogenous waste excretion, and other metabolic transformations. They are one of the first fish organs to be exposed to heavy metals in the aquatic environment. The exposure of Oreochromis mossambicus to copper showed deleterious effects to normal fish behaviours and varying degrees of gill damage when visualized under inverted light microscopy (stained with haematoxylin–eosin), scanning electron microscopy, and transmission electron microscopy. Abnormalities of the nucleus shape, swollen cells, lipid droplet deposition, and an increase in vacuolation on the affected gills were observed with the degree of damage associated with CuSO4 exposure concentration. CuSO4 exposure in O. mossambicus also gave various patterns of inhibitory effects on cholinesterase (ChE) depending on the concentration of exposure and the organs exposed. Copper exposure altered ChE activity extracted from the gills of O. mossambicus with 99.9% of inhibition at the highest exposure concentration of CuSO4 (20 mg/L). Hence, this study suggests the potential of this fish to become a sentinel species that permits the detection of lower copper contamination levels.

The differentiation of preadipocytes and gene expression related to adipogenesis in ducks (Anas platyrhynchos).

Meat quality is closely related to adipose tissues in ducks, and adipogenesis is controlled by a complex network of transcription factors tightly acting at different stages of differentiation especially in ducks. The aim of this study was to establish the preadipocyte in vitro culture system and understand the biological characteristics of expansion of duck adipocyte tissue at the cellular and molecular level. We isolated pre-adipocytes from the subcutaneous fat of three breeds of duck and differentiated them into mature adipocytes using a mixture of insulin, rosiglitazone, dexamethasone, 3-isobutyl-1-methylxanthine, and oleic acid over 0,2, 4, 6, and 8 days. Successful differentiation was confirmed from the development of lipid droplets and their response to Oil Red O, and increasing numbers of lipid droplets were stained red over time. The expression of key marker genes, including peroxisome proliferator activated receptor γ (PPARγ), CCAAT/enhancer binding protein-α (C/EBPα), adipocyte fatty acid binding protein 4 (FABP4), and fatty acid synthetase (FAS), gradually increased during pre-adipocyte differentiation. Furthermore, it was verified by interference experiments that the knockdown of PPARγ directly reduced lipid production. Meanwhile we analyzed the role of unsaturated fatty acids in the production of poultry fat using different concentrations of oleic acid and found that lipid droplet deposition was highest when the concentration of oleic acid was 300 μM. We also compared the level of differentiated pre-adipocytes that were isolated from Jianchang ducks (fatty-meat duck), Cherry Valley ducks (lean-meat duck) and White-crested ducks (egg-producing duck). The proliferation and differentiation rate of pre-adipocytes derived from Jianchang ducks was higher than that of White-crested ducks. These results provide the foundation for further research into waterfowl adipogenesis.

Pathogenesis of non-alcoholic fatty liver disease mediated by YAP.

This study aimed to investigate the mechanism of the interaction between Yes-associated protein (YAP) and transforming growth factor-β (TGF-β)/Smad signaling pathways in the development of non-alcoholic fatty liver disease (NAFLD). Serum samples of monkeys with biopsy-proven NAFLD and healthy normal monkeys were used to measure fasting plasma glucose (FPG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG) and albumin (ALB) with the BECKMAN CX5 PRO. Hematoxylin-eosin staining (H&E) was used for pathologic analysis, Masson trichrome staining was used to assess for fibrosis staging, and Oil Red O staining was used to detect lipid droplet deposition. According to an NAFLD activity score of <4 points and >4 points, the samples were divided into groups: the steatosis group and fibrosing NASH group. Furthermore, monkeys with a fibrosis stage <2 were assigned to the mild fibrosis group, while monkeys with fibrosis stage ≥2 were assigned to the significant fibrosis group. Moreover, the fibrosis stage was subdivided as follows: stages 1a, 1c and 2-3. Immunohistochemistry and real-time quantitative PCR were used to quantify protein and gene expression, respectively. In the present study, 54 monkeys with NAFLD and 23 normal monkeys were recruited. Serum FPG and TG levels were higher in fibrosing NASH monkeys compared with simple steatosis and normal monkeys, and differences between simple steatosis and normal monkeys were not statistically significant (p>0.05). YAP increased in NAFLD, which mainly localized in the nuclei of hepatocytes, perivascular cells and bile duct cells; the accumulation of YAP correlated with the severity of hepatocyte injury. Compared with normal monkeys, the expression of TGF-β, α-smooth muscle actin (α-SMA), Drosophila mothers against decapentaplegic protein 3 (Smad3) and connective tissue growth factor (CTGF) in the liver of simple steatosis monkeys significantly increased (p<0.01). Compared with simple steatosis monkeys, the expression of TGF-β, α-SMA, Smad3 and CTGF in fibrosing NASH significantly increased (p<0.01). However, the expression of Drosophila mothers against decapentaplegic protein 7 (Smad7) in the liver of fibrosing NASH monkeys significantly decreased (p<0.01). With the severity of liver fibrosis, the expression of TGF-β, α-SMA, Smad3 and CTGF gradually increased, and the difference was statistically significant (p<0.01). However, there was no significant difference in the expression of Smad3 between fibrosis stage 1a and 1c. Compared with normal monkeys, the expression of Smad7 in the liver of monkeys with fibrosis significantly decreased (p<0.01), but was significantly higher at fibrosis stage 1c than at fibrosis stage 1a and 2. The YAP and TGF-β signaling pathways and the interaction between them promote the development and progression of NAFLD.

CRISPR/Cas9-based Pten knock-out and Sleeping Beauty Transposon-mediated Nras knock-in induces hepatocellular carcinoma and hepatic lipid accumulation in mice

ABSTRACTBoth Pten and Nras are downstream mediators of receptor tyrosine kinase activation that plays important roles in controlling cell survival and proliferation. Here, we investigated whether and how Pten loss cross-talks with Nras activation in driving liver cancer development in mice. Somatic disruption of hepatic Pten and overexpression of Nras were achieved in out-bred immunocompetent CD-1 mice through a hydrodynamic delivery of plasmids carrying Sleeping Beauty transposon-based integration of Nras and the CRISPR/Cas9-mediated Pten knockout system. Concurrent Pten knockout and Nras knock-in induced hepatocellular carcinoma, while individual gene manipulation failed. Tumor development was associated with liver fibrosis, hyperlipidemia, hepatic deposition of lipid droplets and glycogen, and hepatomegaly. At the molecular level, lipid droplet formation was primarily contributed by upregulated expression of genes responsible for lipogenesis and fatty acid sequestration, such as Srebpf1, Acc, Pparg and its downstream targets. Our findings demonstrated that Pten disruption was synergized by Nras overexpression in driving hepatocyte malignant transformation, which correlated with extensive formation of lipid droplets.

Fabrication and characterization of nanoemulsion-coated microgels: Electrostatic deposition of lipid droplets on alginate beads

Nanoemulsion-coated microgels were formed by electrostatic deposition of protein-stabilized lipid droplets onto the surfaces of alginate beads. Initially, oil-in-water nanoemulsions stabilized by whey protein isolate (WPI) were fabricated using high-pressure microfluidization, and calcium alginate beads were fabricated by injection of an alginate solution into a calcium solution. The surface potential of the protein-stabilized lipid droplets changed from positive to negative as the pH was increased from 2 to 8, whereas that of the alginate beads remained negative at all pH values. Confocal microscopy, light scattering, turbidity and ζ-potential measurements indicated that a thin layer of lipid droplets adsorbed to the surfaces of the alginate beads at pH values below the isoelectric point of the proteins, which was attributed to electrostatic attraction between the cationic droplets and anionic beads. The apparent shear viscosity of emulsion-bead mixtures was appreciably higher than emulsions with the same fat content at high droplet concentrations (≥20%). This study may provide a novel approach of improving the mouthfeel and texture of foods and beverages, or of reducing the overall fat content of emulsion-based products.

Inhibition of chitin oligosaccharide on dyslipidemia and the potential molecular mechanism exploration

The inhibitory effect of NACOS on dyslipidemia and potential molecular mechanisms by in vitro and in vivo experiments were investigated. For in vitro study, four experimental groups were designed by using HepG2 cells, including the control group, palmitic acid (PA) treatment alone group, NACOS treatment alone group and NACOS + PA treatment group. For in vivo study, male C57BL/6 mice were divided into four groups (n=5) at random including the normal control group (NCD), high fat diet (HFD) group, NACOS treatment alone group, NACOS+HFD group, which were treated for 20 weeks. The used methods in this study were as follows: the observation of lipid droplet deposition in HepG2 cells by oil red O staining, the detection of mRNA levels of lipid metabolism-related regulators and inflammatory cytokine by RT-PCR method, the monitoring of MAPKs and PI3K/Akt pathway activation by Western blotting method. The in vitro study shows that, NACOS had no toxicity on the viability of HepG2 cells at 25-100 μg/mL and significantly reduced the deposition of lipid droplet. Also, based on both in vitro and in vivo investigation, NACOS evidently down-regulated the expression of lipid metabolism-related regulators (PGC1α, Cox5b, Mcad) and inflammatory cytokine (IL-1β) at mRNA level (P<0.05 or 0.01), and suppressed the activation of p38, ERK1/2 and Akt in HepG2 cells and lever tissues from HFD-fed mice (P<0.05 or 0.01). Based on the above, NACOS may inhibit the oxidation of liver mitochondrial fatty acid and the lipid biosynthesis, block the inflammatory responses and prevent the HepG2 cells and C57BL/6 mice from lipidemia.

Histological Study of the Effects of Olanzapine on the Liver of Adult Male Albino Rat with and without Vitamin C

Introduction: Olanzapine is an atypical antipsychotic drug widely used in treatment of schizophrenia for prolonged time.Aim of the work: The present study was carried out to evaluate the effect of olanzapine on the liver and the possible protective effect of vitamin C.Material and Methods: Forty adult male albino rats were used in this work. They were divided into: Group I as a control, group II was given Olanzapine (2mg/kg B. wt. orally once daily) for one month, group III was given Olanzapine (at the same previous dose) plus vitamin C (15 mg /Kg. B. wt of orally once daily) for one month and group IV was given only vitamin C (for the same dose and period of the previous group). At the end of the experiment, liver specimens were processed for histological study by light and electron microscopes. Also blood samples were collected for estimation of liver enzymes.Result: Significant increase in the level of liver enzymes was observed in Olanzapine treated group. While the microscopic examination of the liver sections of this group revealed several histological changes including, dilatation and congestion of central veins and blood sinusoids, inflammatory cellular infiltration in the portal areas and cytoplasmic vacuolation of hepatocytes that present mainly around the central veins. Mitochondrial degeneration, bile ducts dilatation and excessive deposition of lipid droplets were also observed. These changes were ameliorated by vitamin C administration.Conclusion: Results of this experimental work revealed that administration of vitamin C greatly reduced the histological alterations induced by Olanzapine, suggesting that vitamin C has a protective effect on the liver.