Naringin 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.
This study examined the relationship between glucose uptake and AMP-activated protein kinase (AMPK) phosphorylation by naringenin and naringin in high glucose-treated HepG2 cells.
Glucose 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.
The 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.
The increased phosphorylation of AMPK at Thr172 by naringenin and naringin might enhance glucose uptake regardless of insulin stimulation in high glucose treated HepG2 cells.
Flavonoids are natural polyphenols found widely in citrus fruit and peel that possess anti-adipogenic effects. On the other hand, the detailed mechanisms for the anti-adipogenic effects of flavonoids ...are unclear.
The present study observed the anti-adipogenic effects of five major citrus flavonoids, including hesperidin (HES), narirutin (NAR), nobiletin (NOB), sinensetin (SIN), and tangeretin (TAN), on AMP-activated protein kinase (AMPK) activation in palmitate (PA)-treated HepG2 cells.
The intracellular lipid accumulation and triglyceride (TG) contents were quantified by Oil-red O staining and TG assay, respectively. The glucose uptake was assessed using 2-N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino-2-deoxy-d-glucose (2-NBDG) assay. The levels of AMPK, acetyl-CoA carboxylase (ACC), and glycogen synthase kinase 3 beta (GSK3β) phosphorylation, and levels of sterol regulatory element-binding protein 2 (SREBP-2) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) expression were analyzed by Western blot analysis. The potential interaction between the flavonoids and the γ-subunit of AMPK was investigated by molecular docking analysis.
The flavonoid treatment reduced both intracellular lipid accumulation and TG content in PA-treated HepG2 cells significantly. In addition, the flavonoids showed increased 2-NBDG uptake in an insulin-independent manner in PA-treated HepG2 cells. The flavonoids increased the AMPK, ACC, and GSK3β phosphorylation levels and decreased the SREBP-2 and HMGCR expression levels in PA-treated HepG2 cells. Molecular docking analysis showed that the flavonoids bind to the CBS domains in the regulatory γ-subunit of AMPK with high binding affinities and could serve as potential AMPK activators.
The overall results suggest that the anti-adipogenic effect of flavonoids on PA-treated HepG2 cells results from the activation of AMPK by flavonoids.
BACKGROUNDNaringenin and its glycoside naringin are well known citrus flavonoids with several therapeutic benefits. Although the anti-adipogenic effects of naringenin and naringin have been reported ...previously, the detailed mechanism underlying their anti-adipogenesis effects is poorly understood. OBJECTIVESThis study examined the anti-adipogenic effects of naringenin and naringin by determining differential gene expression patterns in these flavonoids-treated 3T3-L1 adipocytes. METHODSLipid accumulation and triglyceride (TG) content were determined by Oil red O staining and TG assay. Glucose uptake was measured using a 2-N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino-2-deoxy-d-glucose fluorescent d-glucose analog. The phosphorylation levels of AMP-activated protein kinase (AMPK) and acetyl Co-A carboxylase (ACC) were observed via Western blot analysis. Differential gene expressions in 3T3-L1 adipocytes were evaluated via RNA sequencing analysis. RESULTSNaringenin and naringin inhibited both lipid accumulation and TG content, increased phosphorylation levels of both AMPK and ACC and decreased the expression level of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) in 3T3-L1 adipocytes. RNA sequencing analysis revealed that 32 up-regulated (> 2-fold) and 17 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Scd1, Mogat1, Dgat, Lipin1, Cpt1a, and Lepr, were normalized to the control level in naringenin-treated adipocytes. In addition, 25 up-regulated (> 2-fold) and 25 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Fabp5, Scd1, Srebf1, Hmgcs1, Cpt1c, Lepr, and Lrp1, were normalized to the control level by naringin. CONCLUSIONSThe results indicate that naringenin and naringin have anti-adipogenic potentials that are achieved by normalizing the expression levels of lipid metabolism-related genes that were perturbed in differentiated 3T3-L1 cells.
Cudrania tricuspidata is a perennial plant, and Sargassum fusiforme is a brown seaweed with numerous potential benefits, including anticancer, anti-inflammatory, and antioxidant activities. However, ...the efficacies of C. tricuspidata and S. fusiforme on hair growth have not yet been elucidated. Therefore, the present study examined the effects of C. tricuspidata and S. fusiforme extracts on hair growth in C57BL/6 mice.
ImageJ demonstrated that drinking and skin application of C. tricuspidata and/or S. fusiforme extracts significantly increased the hair growth rate in the dorsal skin of C57BL/6 mice compared to the control group. Histological analysis confirmed that drinking and skin application of C. tricuspidata and/or S. fusiforme extracts for 21 days significantly increased the length of hair follicles on the dorsal skin of treated C57BL/6 mice compared to that in the control mice. RNA sequencing analysis revealed that hair growth cycle-related factors (anagen factors) such as Catenin Beta 1 (Ctnnb1) and platelet-derived growth factor (Pdgf) were upregulated (> twofold) only by C. tricuspidate extracts, whereas vascular endothelial growth factor (Vegf) and Wnts were upregulated by both C. tricuspidata or S. fusiforme applications in treated mice (compared to the control mice). In addition, oncostatin M (Osm, a catagen-telogen factor) was downregulated (< 0.5 fold) by C. tricuspidata when administered via both skin and drinking mode in treated mice compared to that in control mice.
Our results suggest that C. tricuspidata and/or S. fusiforme extracts show potential hair growth efficacy by upregulating anagen factor genes, including β-catenin, Pdgf, Vegf, and Wnts, and downregulating catagen-telogen factor genes, including Osm, in C57BL/6 mice. The findings suggest that C. tricuspidata and/or S. fusiforme extracts are potential drug candidates to treat alopecia.
Software protection and software piracy Jha, Amit Kumar; Rajan, Priyanka
The Journal of world intellectual property,
July 2022, Letnik:
25, Številka:
2
Journal Article
Recenzirano
This paper explores the dynamic long‐term relationship between software protection and software piracy rates across 108 countries over the period of 20 years (1994–2015), with the help of the ARDL ...model. The analysis employs a new way of utilising the membership duration of Trade related Intellectual Property Rights agreement and World Intellectual Property Organisation Copyright Treaty agreements of different countries in a panel framework, apart from constructing an index of copyright software protection by focusing on enforcement provisions. The paper overcomes various shortcomings of earlier literatures by thoughtful inclusion of independent variables and methodological techniques. Results show that both copyright software protection and income share a negative long‐term relationship with software piracy. Even the enforcement provisions are important in mitigating software piracy. In addition, the model finds a negative relationship between demand for intellectual property protection and software piracy rates.
Abstract
DNA-targeting drugs are widely used for anti-cancer treatment. Many of these drugs cause different types of DNA damage, i.e. alterations in the chemical structure of DNA molecule. However, ...molecules binding to DNA may also interfere with DNA packing into chromatin. Interestingly, some molecules do not cause any changes in DNA chemical structure but interfere with DNA binding to histones and nucleosome wrapping. This results in histone loss from chromatin and destabilization of nucleosomes, a phenomenon that we call chromatin damage. Although the cellular response to DNA damage is well-studied, the consequences of chromatin damage are not. Moreover, many drugs used to study DNA damage also cause chromatin damage, therefore there is no clarity on which effects are caused by DNA or chromatin damage. In this study, we aimed to clarify this issue. We treated normal and tumor cells with bleomycin, nuclease mimicking drug which cut predominantly nucleosome-free DNA and therefore causes DNA damage in the form of DNA breaks, and CBL0137, which causes chromatin damage without direct DNA damage. We describe similarities and differences between the consequences of DNA and chromatin damage. Both agents were more toxic for tumor than normal cells, but while DNA damage causes senescence in both normal and tumor cells, chromatin damage does not. Both agents activated p53, but chromatin damage leads to the accumulation of higher levels of unmodified p53, which transcriptional activity was similar to or lower than that of p53 activated by DNA damage. Most importantly, we found that while transcriptional changes caused by DNA damage are limited by p53-dependent activation of a small number of p53 targets, chromatin damage activated many folds more genes in p53 independent manner.
Graphical Abstract
Graphical Abstract
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•HES improved glucose uptake in an insulin-independent manner in PA-treated HepG2 cells.•HES exert an insulin-sensitizing effect by increasing insulin mediated phosphorylations of Akt ...and GSK3β in PA-treated HepG2 cells.•HES improved insulin sensitivity and glucose metabolism via normalizing the expression of genes related to insulin signaling and glucose metabolism in HFD-induced obese mice.•HES normalized the expression levels of proteins including hexokinase-II, enolase-1 and PI3 kinase p110δ, which are involved in insulin signaling and glucose metabolism in HFD-induced obese mice.
The present study examined the relationship between the anti-diabetic effect of hesperidin (HES) and the differential gene expression in HES treated high fat diet (HFD)-induced obese mice. Based on the glucose uptake assay, the treatment of HES restored the glucose uptake to control level in an insulin-independent manner in PA-treated HepG2 cells. Western blot analysis confirmed that the treatment of HES increased the insulin-stimulated phosphorylation of Akt and GSK3β in insulin-resistant PA-treated HepG2 cells. HFD-induced obese mice treated with HES significantly reduced serum insulin, blood glucose, and homeostatic model assessment for insulin resistance (HOMA-IR) values. In addition, both glucose tolerance and insulin tolerance were significantly improved to normal level by HES in HFD-induced obese mice. RNA sequencing analysis disclosed that the expression levels of up-regulated 12 genes and down-regulated 6 genes related to insulin signaling and glucose metabolism were restored to normal level by HES in the liver of HFD-induced obese mice. A protein–protein interaction (PPI) network was constructed via search tool for the retrieval of interacting genes/proteins (STRING) analysis, and Eno1, Pik3cd, Hk2, Trib3, Myc, Nos3, Ppargc1a, and Igf2 were located in the functional hubs of the PPI network of glucose metabolism. Furthermore, Western blot analysis confirmed that HES improved insulin sensitivity and glucose homeostasis by normalizing the expression levels of hexokinase-II, enolase-1, and PI3 kinase p110δ to normal level. The overall results suggest that HES possess a potential anti-diabetic effect by normalizing the expression levels of the insulin signaling and glucose metabolism related genes which were perturbed in the liver of HFD-induced obese mice.
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