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1.
BackgroundNaringin and its aglycone naringenin are citrus-derived flavonoids with several pharmacological effects. On the other hand, the mechanism for the anti-diabetic effects of naringenin and naringin are controversial and remain to be clarified further.ObjectiveThis study examined the relationship between glucose uptake and AMP-activated protein kinase (AMPK) phosphorylation by naringenin and naringin in high glucose-treated HepG2 cells.MethodsGlucose uptake was measured using the 2-NBDG fluorescent D-glucose analog. The phosphorylation levels of AMPK and GSK3β (Glycogen synthase kinase 3 beta) were observed by Western blotting. Molecular docking analysis was performed to evaluate the binding affinity of naringenin and naringin to the γ-subunit of AMPK.ResultsThe treatment with naringenin and naringin stimulated glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells. Both flavonoids increased glucose uptake by promoting the phosphorylation of AMPK at Thr172 and increased the phosphorylation of GSK3β. Molecular docking analysis showed that both naringenin and naringin bind to the γ-subunit of AMPK with high binding affinities. In particular, naringin showed higher binding affinity than the true modulator, AMP with all three CBS domains (CBS1, 3, and 4) in the γ-subunit of AMPK. Therefore, both naringenin and naringin could be positive modulators of AMPK activation, which enhance glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells.ConclusionsThe increased phosphorylation of AMPK at Thr172 by naringenin and naringin might enhance glucose uptake regardless of insulin stimulation in high glucose treated HepG2 cells.  相似文献   

2.
Treatment of AIDS (HIV) and hepatitis C virus needs protease inhibitors (PI) to prevent viral replication. Uses of PI in therapy are usually associated with a decrease in body weight and dyslipidemia. Acylation stimulating protein (ASP) is a protein synthesized in adipocytes to increase triglycerides biosynthesis, for that the relation of PI and ASP to adipogenesis is tested in this work. ASP expression was increased during 3T3-L1 differentiation and reached a peak at day 8 with cell maturation. Addition of PI during adipocytes differentiation dose dependently and significantly (p < 0.5) inhibited the degree of triglycerides (TG) accumulation. Moreover, presence of ASP (450 ng/mL) in media significantly (p < 0.5) stimulated the degree of TG accumulation and there was additive stimulation for ASP when added with insulin (10 µg/mL). Finally, when ASP in different doses (Low, 16.7; Medium, 45 and High, 450 ng/mL) incubated with a dose of ×150 PI, ASP partially inhibited the PI-inhibited adipogenesis and TG accumulation. The results in this study show that PI inhibit lipids accumulation and confirm role of ASP in TG biosynthesis and adipogenesis.  相似文献   

3.

Background

Fatty acid (FA) composition is the most important parameter affecting the flavor and nutritional value of the meat. The final and the only committed step in the biosynthesis of triglycerides is catalyzed by diacylglycerol acyltransferase 2 (DGAT2). The role of DGAT2 in lipid accumulation has been demonstrated in adipocytes, However, little is known about the effect of DGAT2 on the FA composition of these cells.

Methods

To investigate the role of DGAT2 in regulating lipid accumulation, FA composition and the expression of adipogenic genes, we cloned the open reading frame of the porcine DGAT2 gene and established 3T3-L1 cells that overexpressed DGAT2. Cells were then cultured in differentiation medium (DM) without FA, with a mixture of FAs (FA-DM), or containing a 13C stable isotope-labeled FA mixture (IFA-DM). The FA composition of adipocytes was analyzed by gas chromatography–mass spectrometry and gas chromatography-isotope ratio mass spectrometry. Quantitative PCR and western blotting were employed to detect expression of adipogenic genes in 3T3-L1 adipocytes cultured with FA-DM for 12 d.

Results

The triacylglyceride (TAG) content was significantly higher in 3T3-L1 adipocytes overexpressing DGAT2 than in control cells. When cultured in DM or FA-DM for 12 d, cells overexpressing DGAT2 showed a higher proportion of unsaturated FAs (C16:1 and C18:1). However, when cells overexpressing DGAT2 were cultured with FA-DM for 30 min, the FA composition was almost identical to that of controls. Further, the proportion of stable isotope-labeled FAs were similar in 3T3-L1 adipocytes overexpressing DGAT2 and control cells cultured in IFA-DM for 12 d. These results collectively indicate that the higher proportion of mono-unsaturated FAs, C16:1 and C18:1, may originate from de novo FA synthesis but not from the uptake of specific FAs from the medium. This hypothesis is further supported by evidence that both mRNA and protein expression of genes involved in FA synthesis (ACACA, FASN, SCD1, and A-FABP) were significantly higher in cells overexpressing DGAT2 than in control cells.

Conclusions

In conclusion, our study revealed that TAG accumulation, the proportion of MUFAs, and the expression of adipogenic genes were higher in 3T3-L1 cells overexpressing DGAT2 than in control cells.  相似文献   

4.
Obesity has increased continuously in western countries during the last several decades and recently become a problem in developing countries. Currently, anti-obesity drugs originating from natural products are being investigated for their potential to overcome adverse effects associated with chemical drugs. Artemisinic acid, which was isolated from the well-known anti-malaria herb Artemisia annua (AA) L., was recently shown to possess anti-adipogenic effects in vitro. However, the anti-adipogenic effects of AA in animal models have not yet been investigated. Therefore, we conducted daily oral administration with AA water extract in a diet-induced obesity animal model and treated 3T3-L1 cells with AA to confirm the anti-adipogenic effects in the related protein expressions. We then evaluated the physiology, adipose tissue histology and mRNA expressions of many related genes. Inhibition of adipogenesis by the AA water extract was observed in vitro. In the animal model, weight gain was significantly lower in the AA treated group, but there were no changes in food intake volume or calories. Reductions in lipid droplet size and mRNA expression associated with adipogenesis were also observed in animal epididymal fat. This study is the first to report that AA has an anti-obese effects in vivo.  相似文献   

5.
为了研究葛根素(puerarin)对3T3-L1前体脂肪细胞分化的影响,探索其在成脂分化过程中的潜在作用机制,试验在脂肪形成过程中将0、10、50 μmol/L葛根素加入到诱导分化培养基中诱导分化,分别通过油红O染色法及甘油三酯酶法检测葛根素对3T3-L1脂肪细胞的脂滴积累、甘油三酯的影响;采用实时荧光定量PCR检测脂肪细胞中CCAAT-增强子结合蛋白α(C/EBPα)和过氧化物酶体增殖物激活受体γ(PPARγ)的mRNA表达量,Western blotting检测脂肪形成相关转录因子及Akt信号通路的蛋白水平的表达量。结果表明,10 μmol/L葛根素极显著增加了成熟脂肪细胞中脂滴和甘油三酯(TG)的积聚,极显著促进了脂肪形成相关转录因子C/EBPα和PPARγ的mRNA和蛋白水平的表达量(P<0.01)。进一步研究发现,与对照组相比,葛根素的刺激可增强Akt信号通路Ser473蛋白的磷酸化表达水平,表明葛根素对成脂分化过程的促进作用很大程度上是通过Akt信号通路的磷酸化来实现的。综上所述,葛根素能够促进3T3-L1前体脂肪细胞的分化,改善胰岛素敏感性,其作用机制与激活Akt信号通路Ser473位点的磷酸化水平有关。本试验结果可为研究胰岛素的效应机制提供新见解,为胰岛素抵抗相关疾病的治疗提供新思路。  相似文献   

6.

Background

Insulin secretion and tissue sensitivity to insulin is considered to be one of the factors controlling lipid metabolism post partum. The objective of this study was to compare glucose-induced blood insulin and metabolite responses in Estonian Holstein (EH, n = 14) and Estonian Red (ER, n = 14) cows.

Methods

The study was carried out using the glucose tolerance test (GTT) performed at 31 ± 1.9 days post partum during negative energy balance. Blood samples were obtained at -15, -5, 5, 10, 20, 30, 40, 50 and 60 min relative to infusion of 0.15 g/kg BW glucose and analysed for glucose, insulin, triglycerides (TG), non-esterified fatty acids (NEFA), cholesterol and β-hydroxybutyrate (BHB). Applying the MIXED Procedure with the SAS System the basal concentration of cholesterol, and basal concentration and concentrations at post-infusion time points for other metabolites, area under the curve (AUC) for glucose and insulin, clearance rate (CR) for glucose, and maximum increase from basal concentration for glucose and insulin were compared between breeds.

Results

There was a breed effect on blood NEFA (P < 0.05) and a time effect on all metabolites concentration (P < 0.01). The following differences were observed in EH compared to ER: lower blood insulin concentration 5 min after glucose infusion (P < 0.05), higher glucose concentration 20 (P < 0.01) and 30 min (P < 0.05) after infusion, and higher NEFA concentration before (P < 0.01) and 5 min after infusion (P < 0.05). Blood TG concentration in ER remained stable, while in EH there was a decrease from the basal level to the 40th min nadir (P < 0.01), followed by an increase to the 60th min postinfusion (P < 0.01).

Conclusion

Our results imply that glucose-induced changes in insulin concentration and metabolite responses to insulin differ between EH and ER dairy cows.  相似文献   

7.

Background

Information on the genetic events leading to thyroid cancer in dogs is lacking.

Hypothesis/Objectives

Upregulation of the PI3K/Akt pathway has an important role in the tumorigenesis of thyroid carcinoma in dogs.

Animals

Fifty‐nine dogs with thyroid carcinoma and 10 healthy controls.

Methods

Quantitative RTPCR was performed for VEGFR‐1, VEGFR‐2, EGFR, PIK3CA, PIK3CB, PDPK1, PTEN, AKT1, AKT2, COX‐2, and CALCA. Mutation analysis was performed for known hotspots of RAS (N, K, H), PIK3CA, BRAF, RET, and for the entire coding region of PTEN.

Results

Forty‐three dogs (73%) had follicular cell thyroid carcinoma (FTC) and 16 dogs (27%) had medullary thyroid carcinoma (MTC). The relative mRNA expressions of VEGFR‐1 (P < .001), VEGFR‐2 (= .002), PDPK1 (< .001), AKT1 (= .009), and AKT2 (< .001) were increased in FTC, and those of EGFR (< .001), VEGFR‐1 (= .036), and PIK3CA (= .019) were increased in MTC when compared to normal thyroid glands. Mutation analysis of K‐RAS identified 2 activating missense mutations, which also have been described in thyroid cancer of humans. A G12R substitution was present in 1 FTC and an E63K substitution was present in 1 MTC. No functional mutations were found in the sequenced regions of H‐RAS, N‐RAS, PIK3CA, BRAF, RET, and PTEN.

Conclusions and Clinical Importance

The increased expression of several genes associated with PI3K/Akt signaling suggests the involvement of this pathway in the pathogenesis of thyroid carcinoma in dogs, warranting further research on pathway activation and gene amplification. The mutations most frequently associated with thyroid cancer in humans are rare in dogs.  相似文献   

8.
旨在通过诱导3T3-L1前脂肪细胞转分化为3T3-L1脂肪细胞,探讨二脒那秦(DIZE)内源性激活血管紧张素转化酶2(ACE 2)对细胞脂质沉积的抑制效应及机制。对3T3-L1前脂肪细胞转分化,将分化成功的3T3-L1脂肪细胞分为对照组、DIZE组(12.5、25 μmol·L-1处理),siACE2组和siACE2+DIZE组(siACE2干扰后+25 μmol·L-1 DIZE),作用48 h,取上清和细胞进行试验:1)测定细胞上清中三酰甘油和葡萄糖含量;2)油红O染色细胞,并进行定量分析;3) Western blot检测细胞内ACE2和脂肪酸合成关键酶或因子FAS、ACC和SREBP-1c及葡萄糖转运蛋白GLUT4与氧化分解关键酶CS的蛋白表达水平。结果显示:1)成功诱导得到了3T3-L1脂肪细胞,前脂肪细胞诱导至第14天,有95%以上细胞内出现脂滴;2)确定了DIZE作用浓度为12.5和25 μmol·L-1,处理时间为48 h,并用该药物浓度及时间处理3T3-L1脂肪细胞,细胞上清中三酰甘油含量显著降低(P<0.05),葡萄糖含量显著升高(P<0.05);25 μmol·L-1 DIZE处理组细胞脂滴减少,siACE2组无显著变化,siACE2+DIZE组脂滴蓄积介于对照组和DIZE组之间; 25 μmol·L-1 DIZE组ACE2蛋白水平显著高于对照组(P<0.05);siACE2组显著下调(P<0.05),siACE2+DIZE组较siACE2组无明显变化;3)与对照组相比25 μmol·L-1 DIZE组细胞中FAS、ACC和SREBP-1c蛋白表达下调,siACE2组和siACE2+DIZE组则表达均上调;4)与对照组相比,25 μmol·L-1 DIZE组GLUT4和CS蛋白表达水平显著上调(P<0.05),siACE2组和siACE2+DIZE组则均显著下调(P<0.05)。综上所述,DIZE处理通过介导脂肪细胞ACE2的内源性激活改善了脂肪细胞的脂肪沉积。其机理:一方面抑制脂质合成;另一方面促进葡萄糖摄取和氧化代谢,两方面协同减少了脂肪沉积。结果提示,ACE2或DIZE可作为防控脂肪沉积发生和发展的潜在靶点或药物。  相似文献   

9.

Background

A leptin-like immunoreactive substance has been found in chicken eggs and has been implicated in serving as a maternal signal to program offspring growth and metabolism. In the present study, we investigated the effects of in ovo leptin administration on hatch weight, serum and hepatic concentrations of metabolites and hormones, as well as on the expression of genes involved in hepatic lipid metabolism and the predicted microRNAs (miRNAs) targeting the affected genes. To this end we injected fertile eggs with either 0.5 μg of recombinant murine leptin or vehicle (PBS) before incubation.

Results

Prenatally leptin-exposed chicks showed lower hatch weight, but higher liver weight relative to the body weight, compared to the control group. In ovo leptin treatment increased the hepatic content and serum concentration of leptin in newly hatched chickens. The hepatic contents of triglycerides (TG) and total cholesterol (Tch) were decreased, whereas the serum levels of TG, Tch and apolipoprotein B (ApoB) were increased. The hepatic mRNA expression of sterol regulator element binding protein 1 (SREBP-1c), SREBP-2, hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) and cholesterol 7α-hydroxylase 1 (CYP7A1) was significantly up-regulated, as was the protein content of both SREBP-1c and SREBP-2 in hepatic nuclear extracts of leptin-treated chickens. Moreover, out of 12 miRNAs targeting SREBP-1c and/or HMGCR, five were significantly up-regulated in liver of leptin-treated chicks, including gga-miR-200b and gga-miR-429, which target both SREBP-1c and HMGCR.

Conclusions

These results suggest that leptin in ovo decreases hatch weight, and modifies hepatic leptin secretion and lipid metabolism in newly hatched broiler chickens, possibly via microRNA-mediated gene regulation.  相似文献   

10.
Thirty two Merino lambs (15 weeks old) fed barley straw and fish oil enriched concentrate were used to assess the effect of vitamin E (6 g kg−1 DM) and naringin (1.5-3 g kg−1 DM) on plasma lipid peroxidation (TBARS), total antioxidant status (TAS), immune response, plasma cholesterol, and triglycerides. After 21 days feeding the experimental diets, lambs were subjected to a 4 h transportation stress period and then held 4 more hours without feed. TBARS values before stress were lower for animals consuming vitamine E and naringin when compared to control lambs (P < 0.05). However, after stress all groups presented similar levels of TBARS. TAS decreased (P < 0.05) in all groups in response to stress with values recovering (P < 0.05) to pre-stress values following 4 h of rest. A rise (P < 0.05) in serum concentrations of triacylglycerol following 21 d of fish oil supplementation was dampened in lambs consuming vitamin E or naringin. Both pre-stress TBARS and triacylglycerol-reducing effects of naringin added to fish oil enriched concentrate for fattening lambs are reported.  相似文献   

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旨在鉴定非编码RNA circNMT1,明确其组织和细胞的表达模式,以及探究过表达circNMT1对脂肪细胞分化的影响。本试验以30月龄中国沼泽水牛(信阳水牛,n=3)的心、肝、脾、肺、肾、背最长肌、背部皮下脂肪组织和前体脂肪细胞以及3T3-L1细胞为试验材料。通过半定量PCR和实时荧光定量PCR (real-time quantitative PCR,qRT-PCR)技术对circNMT1进行鉴定、细胞定位并明确其时空表达模式。进一步分别将其过表达到3T3-L1和水牛前体脂肪细胞中,利用形态学方法及定量方法检测过表达后脂滴累积情况,同时采用qRT-PCR检测脂肪标志基因相对表达水平的变化。结果表明,circNMT1是真实存在且稳定表达的circRNA,在水牛前体脂肪细胞的细胞核和细胞质中均表达,且在脂肪组织和成熟的脂肪细胞中高表达(P<0.001)。功能获得性试验表明,在3T3-L1细胞和水牛脂肪细胞,circNMT1显著促进脂肪细胞的脂滴积累,并且显著提高成脂标志基因PPARGC/EBPαFABP4的相对表达水平(P<0.01)。circNMT1可能是水牛脂肪细胞分化的正调控因子,这为circNMT1在水牛脂肪细胞中的调节作用提供了新见解。  相似文献   

14.
BackgroundSulforaphane (SFN) is an isothiocyanate compound present in cruciferous vegetables. Although the anti-inflammatory effects of SFN have been reported, the precise mechanism related to the inflammatory genes is poorly understood.ObjectivesThis study examined the relationship between the anti-inflammatory effects of SFN and the differential gene expression pattern in SFN treated ob/ob mice.MethodsNitric oxide (NO) level was measured using a Griess assay. The inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression levels were analyzed by Western blot analysis. Pro-inflammatory cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-1β, and IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). RNA sequencing analysis was performed to evaluate the differential gene expression in the liver of ob/ob mice.ResultsThe SFN treatment significantly attenuated the iNOS and COX-2 expression levels and inhibited NO, TNF-α, IL-1β, and IL-6 production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. RNA sequencing analysis showed that the expression levels of 28 genes related to inflammation were up-regulated (> 2-fold), and six genes were down-regulated (< 0.6-fold) in the control ob/ob mice compared to normal mice. In contrast, the gene expression levels were restored to the normal level by SFN. The protein-protein interaction (PPI) network showed that chemokine ligand (Cxcl14, Ccl1, Ccl3, Ccl4, Ccl17) and chemokine receptor (Ccr3, Cxcr1, Ccr10) were located in close proximity and formed a “functional cluster” in the middle of the network.ConclusionsThe overall results suggest that SFN has a potent anti-inflammatory effect by normalizing the expression levels of the genes related to inflammation that were perturbed in ob/ob mice.  相似文献   

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An 8-week feeding trial was conducted to evaluate the effects of sodium butyrate (SB) on growth, digestive enzymes, body composition and nutrient retention-related gene expression of juvenile yellow catfish (Pelteobagrus fulvidraco). Five isonitrogenous and isolipidic diets (420 g/kg protein and 90 g/kg lipid) were formulated to contain 0 (control), 250, 500, 1,000 or 2,000 mg/kg SB. Triplicate groups of 40 fish (BW = 1.26 ± 0.01 g) per tank (300-L cylindrical fiberglass tanks) for each diet were fed to apparent satiation twice daily. Stomach, hepatopancreas and intestine samples were obtained for digestive enzymes activities analyses. A real-time quantitative PCR analysis was performed to determine the relative expression of target of rapamycin (TOR) and lipoprotein lipase (LPL) in the hepatopancreas and intestine. Fish fed the diets supplemented with SB at 500 and 1,000 mg/kg showed significantly higher specific growth rate and significantly lower feed conversion ratio compared to the control (P < 0.05). Dietary SB inclusion did not alter activities of intestinal amylase, creatine kinase and sodium–potassium adenosine triphosphatase (Na+/K+-ATPase), but increased activities of hepatic trypsin, stomachic lipase, intestinal lipase, alkaline phosphatase and γ-glutamyl transpeptidase for fish fed 1,000 mg/kg SB compared to the control (P < 0.05). Intestine length index, intestine somatic index, fold height and muscular thickness of distal intestine were significantly higher in 1,000 mg/kg SB groups compared to the control (P < 0.05). Significantly higher levels of whole-body crude protein, ash, calcium, phosphorus, nutrition retention and relative mRNA of intestinal TOR were observed in 1,000 mg/kg SB group (P < 0.05). Whole-body lipid content and hepatopancreas LPL mRNA expression in 2,000 mg/kg SB group were significantly higher than the control (P < 0.05). Relative mRNA levels of intestinal LPL and hepatopancreas TOR were significantly higher in the 500 mg/kg SB group compared to those in other groups (P < 0.05). The increased growth performance, digestive enzymes and nutrient retention in fish fed the diets supplemented with SB at 500 and 1,000 mg/kg suggests that SB can be a desirable growth promoter as an antibiotic alternative in diets.  相似文献   

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Many studies suggest significant genetic variation in the resistance of cattle and humans to infection with Mycobacterium bovis, the causative agent of zoonotic tuberculosis. The inducible nitric oxide synthase (iNOS which is encoded by the NOS2 gene) plays a key role in the immunological control of a broad spectrum of infectious agents. This study aimed to investigate the influence of genetic variations in the promoter of the NOS2 gene on bovine tuberculosis (bTB) susceptibility. In this study, the NOS2 genes of 74 bTB-infected Holstein cows and 90 healthy controls were genotyped using PCR followed by nucleotide sequencing. Polymorphisms at rs207692718, rs109279434, rs209895548, rs385993919, rs433717754, rs383366213, rs466730386, rs715225976, rs525673647, rs720757654 and g.19958101T>G in the promoter region of the NOS2 gene were detected. The g.19958101T>G SNP produced two different conformation patterns (TT and TG) and the TG genotype was over-represented in the bTB group (20.27%) compared with the control group (2.22%). The TG genotype frequency of the g.19958101T>G variant was significantly higher in bTB cattle than in healthy controls (OR, 11.19; 95% CI, 2.47–50.73; P=0.0002). The G allele of the g.19958101T>G polymorphism was more frequent in bTB group when compared to control group (10.14% versus 1.11%). Furthermore, the G allele was a risk factor for bTB susceptibility (OR, 10.04; 95% CI, 2.26–44.65; P=0.0002). In conclusion, the g.19958101T>G polymorphism of the NOS2 gene may contribute to the susceptibility of Holstein cattle to bTB.  相似文献   

20.
Despite its medical use, little is known about the mechanisms underlying amikacin-induced embryotoxicity, including fin reduction, in zebrafish. In this study, we examined the expression of well-known autophagy markers mTOR (target of rapamycin), atg10 (autophagy-related gene), atg12 and LC3 (mammalian homolog of Atg8) in amikacin-treated zebrafish embryos. Our results indicated that the mRNA expression level of atg12 in the amikacin-treated group was significantly increased by 1.5-fold (p<0.05) compared with the corresponding mock control group, while the expression levels of atg10 and mTOR were significantly decreased by 0.74-fold (p<0.05) and 0.58-fold (p<0.05), respectively. Western blot analysis revealed that LC3 protein expression was induced by amikacin. Taken together, these data suggest that amikacin-induced fin reduction is mediated by fin cell autophagy.  相似文献   

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