Search

Dysregulated hepatic lipogenesis represents a promising druggable target for treating nonalcoholic steatohepatitis (NASH). This work aims to evaluate the therapeutic efficacy of caffeine in a NASH mouse model displaying increased hepatic lipogenesis driven by constitutive hepatic overexpression of the active v-akt murine thymoma viral oncogene homolog (AKT). Caffeine was administered in the AKT mice to study the efficacy

A homogenous polysaccharide from Codonopsis pilosula (CPP) was isolated and identified to be an inulin-type fructan, coded as CPP1-2-1. The polysaccharide exhibited anti-inflammatory effect against lipopolysaccharide (LPS) induced RAW264.7 cells in vitro and dextran sodium sulfate (DSS)-induced colitis mice in vivo. Moreover, the expression of cytokines was further detected by qPCR, and the results showed that the polysaccharides can reduce the expression of inflammatory factors such as TLR4, NF-κB, TNF-α and IL-6 in the cells, indicating the anti-inflammatory activities may be achieved by inhibiting the activation of TLR4/NF-κB pathway.

Mounting evidence indicates that hepatic de novo lipogenesis is a common abnormality in non-alcoholic fatty liver disease (NAFLD) patients. We investigated whether a selective COX-2 inhibitor, celecoxib, alleviates hepatic steatosis by targeting an Akt-driven lipogenic pathway. We estimated the efficacy of celecoxib in a novel Akt-driven NAFLD mouse model established via hydrodynamic transfection of activated forms of AKT and in fructose-fed NAFLD mice that exhibited increased insulin-independent hepatic lipogenesis. AKT-transfected and insulin-stimulated human hepatoma cells were used for the in vitro experiments. Haematoxylin and eosin staining, immunohistochemistry and immunoblotting were performed for mechanistic studies. The results revealed that celecoxib ameliorated hepatic steatosis in the AKT-triggered NAFLD mice. Mechanistically, celecoxib effectively suppressed AKT/mTORC1 signalling and its downstream lipogenic cascade in the Akt-driven NAFLD mice and in vitro. Furthermore, celecoxib had limited efficacy in alleviating hepatic lipid accumulation and showed no influence on lipogenic proteins associated with hepatic lipogenesis in fructose-administered mice. This study suggests that celecoxib may be favourable for the treatment of NAFLD, especially in the subset with Akt-triggered hepatic lipogenesis.

Our previous study proved that celastrol was a potential candidate for hepatocellular carcinoma (HCC) therapy. However, poor water solubility and toxic side effects may restrict its clinical application. To overcome these shortcomings and optimize its antitumor efficacy, we developed galactosylated liposomes using galactose-modified 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol) to deliver celastrol (C-GPL). C-GPL improved the water solubility of celastrol and exhibited high encapsulation efficiency, good stability in serum, and slow drug release profile. In vitro studies showed that C-GPL increased the cellular uptake of celastrol through receptor-mediated endocytosis, thereby enhancing celastrol cytotoxicity and cancer cell apoptosis. Particularly, in vivo antitumor activity of C-GPL was assessed in rapid HCC mouse models established via hydrodynamic transfection of the activated forms of AKT and c-Met. Compared to free celastrol, C-GPL significantly prevented liver weight gain, decreased liver damage biomarkers (glutamic-oxalacetic transaminase and alanine aminotransferase) and HCC marker (alpha-fetoprotein), and led to tumor disappearance on the liver surface. The improved therapeutic effect of C-GPL may be attributed to suppression of AKT activation, induction of apoptosis, and retardation of cell proliferation. Importantly, C-GPL exerted low toxicity to normal tissues without causing severe weight loss in mice. Taken together, C-GPL may become a promising drug delivery system for HCC treatment.

Hepatocellular carcinoma (HCC) is a lethal malignancy with few effective options for therapeutic treatment in its advanced stages. Metformin, a first-line oral agent used in the treatment of type 2 diabetes, exhibits efficacy in metabolic reprogramming fueling changes in cell growth and proliferation for multiple cancer types, including HCC. However, the molecular mechanism by which metformin delays hepatocarcinogenesis in individuals with hepatic steatosis remains rare. Here, we investigate the preventive efficacy of metformin in a rapid AKT/c-Met-triggered HCC mouse model featuring excessive levels of steatosis. Hematoxylin and eosin staining, Oil Red O staining and immunoblotting were applied for mechanistic investigations. Pharmacological and biochemical strategies were employed to illuminate molecular evidence for HCC cell lines. The results show that metformin obstructs the malignant transformation of hepatocytes in AKT/c-Met mice. Mechanistically, metformin reduces the expression of phospho-ERK (Thr202/Tyr204) and two forms of proto-oncogenes, Cyclin D1 and c-Myc, in AKT/c-Met mice. Moreover, metformin ameliorates FASN-mediated aberrant lipogenesis and HK2/PKM2-driven ATP generation in vivo. Furthermore, metformin represses the expression of FASN and HK-2 by targeting c-Myc in an AMPK-dependent manner in vitro. In addition, metformin is effective at inhibiting PKM2 expression in the presence of an AMPK inhibitor compound C, suggesting that its functioning in PKM2 is AMPK-independent. Our study experimentally validates a novel molecular mechanism by which metformin alleviates enhanced lipogenesis and high energy metabolism during hepatocarcinogenesis, indicating that metformin may serve as an agent for the prevention of HCC in patients with nonalcoholic fatty liver diseases.

Urolithin A (Uro-A), a metabolite of ellagitannins in mammals’ intestinal tract, displays broad biological properties in preclinical models, including anti-oxidant, anti-inflammatory, and anti-tumor effects. However, the clinical application of Uro-A is restricted because of its low aqueous solubility and short elimination half-life. Our purpose was to develop a delivery system to improve the bioavailability and anti-tumor efficacy of Uro-A. To achieve this goal, urolithin A–loaded PEGylated liposomes (Uro-A-PEG-LPs) were prepared for the first time and its physicochemical properties and anti-tumor efficacy in vitro were evaluated. The morphology of Uro-A-PEG-LPs displayed a uniform sphere under transmission electron microscope. The particle size, polydispersity index, zeta potential, and encapsulation efficiency of Uro-A-PEG-LPs were 122.8 ± 7.4 nm, 0.25 ± 0.16, − 25.5 ± 2.3 mV, and 94.6 ± 1.6%, respectively. Moreover, Uro-A-PEG-LPs possessed higher stability and could be stably stored at 4°C for a long time. In vitro release characteristics indicated that Uro-A-PEG-LPs possessed superior sustained release properties. The results of confocal laser scanning microscopy experiment showed that the coumarin 6–loaded PEGylated liposomes (C6-PEG-LPs) have superior cellular uptake than that of conventional liposomes. In addition, in vitro tests demonstrated that Uro-A-PEG-LPs elevated cytotoxicity and pro-apoptotic effect in human hepatoma cells comparing with free Uro-A. Furthermore, the results of pharmacokinetic experiments showed that the t1/2, AUC0-t, and MRT0-t of Uro-A-PEG-LPs increased to 4.58-fold, 2.33-fold, and 2.43-fold than those of free Uro-A solution, respectively. Collectively, these manifested that PEGylated liposomes might be a potential delivery system for Uro-A to prolonging in vivo circulation time, promoting cellular uptake, and enhancing its anti-tumor efficacy.

Previous studies in humans have indicated that de novo lipogenesis contributes considerably to redundant lipid storage and steatosis in the liver of patients with nonalcoholic fatty liver disease (NAFLD), and then more severe complications occur. Recently, ellagic acid (EA) has drawn attention mainly due to its biological functionalities and a series of molecular targets. However, the molecular mechanism by which EA attenuates hepatic steatosis in individuals with undesirable hepatic genetic alterations remains rarely studied. Here, we evaluate the therapeutic efficacy of EA in a hepatic steatosis mouse model featuring elevated expression of sterol regulatory element-binding protein-1 (SREBP-1) and its downstream modulators of lipogenesis by hydrodynamic injection of v-akt murine thymoma viral oncogene homolog (AKT). Hematoxylin and eosin staining, oil red O staining, immunohistochemistry, immunoblotting, and quantitative polymerase chain reaction (qPCR) were performed for mechanistic investigations. Human hepatoma cell lines were used for mechanical validation in vitro. The results suggest that EA lightens the accumulation of lipids in hepatocytes of AKT-injected mice and an oleic acid-induced in vitro hepatic steatosis model. Mechanistically, EA administration decreases the expression of phospho-AKT (Thr308) and suppresses two effectors lying downstream of the AKT/mTORC1 pathway, ribosomal protein S6 (RPS6) and SREBP-1, in the AKT-injected mice. The consequence of the EA-mediated decrease of SREBP-1 is found to be a transcriptional and translational inhibition of fatty acid synthase (FASN), accompanied by the downregulation of acetyl-CoA carboxylase (ACC). Consistent with in vivo findings, EA efficiently represses the SREBP-1/FASN axis in vitro. Collectively, our study provides a novel mechanism whereby EA alleviates AKT-triggered hepatic de novo lipogenesis, indicating that EA might serve as a potential agent in the therapy of hepatic steatosis in patients with NAFLD and/or steatosis-associated complications, especially in that characterized by activation of AKT/mTORC1 signaling in the liver.

Urolithins are bioactive ellagic acid-derived metabolites produced by human colonic microflora. Although previous studies have demonstrated the cytotoxicity of urolithins, the effect of urolithins on miRNAs is still unclear. In this study, the suppressing effects of methylated urolithin A (mUA) on cell viability in human prostate cancer DU145 cells was investigated. mUA induced caspase-dependent cell apoptosis, mitochondrial depolarization and down-regulation of Bcl-2/Bax ratio. The results showed that upon exposure to mUA, miR-21 expression was decreased and the expression of PTEN and Pdcd4 protein was elevated. mUA could further suppress Akt phosphorylation and increase protein expression of FOXO3a, and the effects of mUA on Akt phosphorylation and protein expression of FOXO3a were blocked by PTEN silence. Moreover, mUA suppressed the Wnt/β-catenin-mediated transcriptional activation of MMP-7 and c-Myc, and this function of mUA on MMP-7 and c-Myc was attenuated by over-expression of miR-21. In conclusion, our data suggest that mUA can suppress cell viability in DU145 cells through modulating miR-21 and its downstream series-wound targets, including PTEN, Akt and Wnt/β-catenin signaling.

Orlistat (Xenical™), a US Food and Drug Administration (FDA)-approved anti-obesity drug, shows efficacy against multiple tumor types, including hepatocellular carcinoma (HCC), due to its ability to inhibit fatty acid synthase (FASN) activity. However, whether orlistat affects hepatocellular malignant transformation during hepatocarcinogenesis in vivo is unknown. This study assessed the antisteatotic and antitumorigenic efficacy of orlistat in a rapid HCC FVB/N mouse model established via hydrodynamic transfection of activated forms of AKT and c-Met proto-oncogenes. Human hepatoma cell lines were used for mechanical validation in vitro. Hematoxylin and eosin staining, immunohistochemistry, and immunoblotting were applied for the mechanistic investigation. The results revealed that when orlistat was administered in the early stage of AKT/c-Met-triggered hepatocarcinogenesis, it resulted in the elimination of hepatic tumor burden. Mechanistically, orlistat efficiently elevated PTEN expression and suppressed AKT/SREBP1/FASN signaling both in vivo and in vitro, impairing AKT/c-Met-driven de novo lipogenesis and aberrant proliferation. Altogether, this study demonstrates the antilipogenic and antiproliferative efficacy of orlistat in hepatocarcinogenesis, suggesting that orlistat may be beneficial for the treatment of HCC, especially in NAFLD-related HCCs featuring activated AKT/mTOR cascade and increased lipogenesis in livers.

Hepatocellular carcinoma (HCC) is one of the most common fatal malignancies worldwide. Inhibition of the lipogenic enzymes involved in hepatic de novo lipogenesis can both effectively restrain proliferation of HCC cells in vitro and reduce the risk of hepatocarcinogenesis in vivo. Although a natural coumarin derivative osthole shows efficacy in suppressing cell proliferation and inducing apoptosis in cultured hepatoma cells and HCC xenograft tumors, the molecular mechanism by which osthole delays hepatocellular malignant transformation during lipogenesis-driven hepatocarcinogenesis remains unknown. Here, we evaluate the efficacy of osthole in a rapid HCC mouse model featuring excessive levels of hepatic steatosis established via hydrodynamic transfection of activated forms of AKT and c-Met proto-oncogenes. Moreover, human hepatoma cell lines were employed for in vitro assessment. Hematoxylin and eosin staining, immunoblotting and immunohistochemistry were applied for mechanistic investigations. The results revealed that if osthole was administered in the early stage of AKT/c-Met-driven HCC, it led to disease stabilization. Moreover, osthole alleviated hepatic steatosis in the AKT/c-Met mice. Further evidence at the molecular level suggested that osthole reduced the expression of phosphor-extracellular signal-regulated kinase 1/2 (ERK1/2), proliferating cell nuclear antigen (PCNA) and Ki67 in livers of the AKT/c-Met mice. Mechanically, osthole efficiently repressed the phospho-AKT (Thr308) / ribosomal protein S6 (RPS6) / fatty acid synthase (FASN) signaling both in mice and in vitro. Altogether, this study suggests that osthole exerts its antilipogenic and antiproliferative efficacy by suppressing the AKT/FASN axis and ERK phosphorylation, which contributes to its capacity to delay hepatocarcinogenesis.

miRNAs and their validated miRNA targets appear as novel effectors in biological activities of plant polyphenols; however, limited information is available on miR-34a mediated cytotoxicity of pomegranate rind polyphenols in cancer cell lines. For this purpose, cell viability assay, Realtime quantitative PCR for mRNA quantification, western blot for essential protein expression, p53 silencing by shRNA and miR-34a knockdown were performed in the present study. EJ cell treatment with 100 µg (GAE)/mL PRE for 48 h evoked poor cell viability and caspase-dependent pro-apoptosis appearance. PRE also elevated p53 protein and triggered miR-34a expression. The c-Myc and CD44 were confirmed as direct targets of miR-34a in EJ cell apoptosis induced by PRE. Our results provide sufficient evidence that polyphenols in PRE can be potential molecular clusters to suppress bladder cancer cell EJ proliferation via p53/miR-34a axis.