Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths among cancer patients. Genes correlated with the progression and prognosis of HCC are critically needed to be identified. In the present study, 3 Gene Expression Omnibus (GEO) datasets (GSE46408, GSE65372 and GSE84402) were used to analyze the differentially expressed genes (DEGs) between HCC and non-tumor liver tissues. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to clarify the functional roles of DEGs. A protein-protein interaction network was established to screen the hub genes associated with HCC. The prognostic values of hub genes in HCC patients were analyzed using The Cancer Genome Atlas (TCGA) database. The expression levels of hub genes were validated based on ONCOMINE, TCGA and Human Protein Atlas (HPA) databases. Notably, 56 upregulated and 33 downregulated DEGs were markedly enriched under various GO terms and four KEGG terms. Among these DEGs, 10 hub genes with high connectivity degree were identified, including cyclin B1, cyclin A2, cyclin B2, condensin complex subunit 3, PDZ binding kinase, nucleolar and spindle-associated protein 1, aurora kinase A, ZW10 interacting kinetochore protein, protein regulator of cytokinesis 1 and kinesin family member 4A. The upregulated expression levels of these hub genes in HCC tissues were further confirmed by ONCOMINE, TCGA, and HPA databases. Additionally, the increased mRNA expression of each hub gene was related to the unfavorable disease-free survival and overall survival of HCC patients. The present study identified ten genes associated with HCC, which may help to provide candidate targets for the diagnosis and treatment of HCC.

A recent study found an increased level of 3DG during oral glucose load in healthy individuals, which redirects our attention to the effect of high plasma 3DG level in the pathophysiology of type 2 diabetes mellitus. We found previously that abnormally elevated plasma 3DG was significantly associated with the impaired glucose regulation in non-diabetic seniors. The current study aimed to investigate the acute effects of exogenous 3DG on plasma 3DG levels, glucose tolerance and insulin levels. A significant increase in the plasma level of 3DG was observed in rats administrated 50 mg/kg 3DG i. v. even 2 h after. With the acute elevation of circulating 3DG, intravenous glucose tolerance of normal rats was impaired, whereas plasma insulin levels were higher. The 3DG-mediated impairment in glucose tolerance was associated with the attenuated insulin-stimulated glucose uptake in the adipose and liver tissues and the decreased glucose-stimulated insulin secretion in the pancreas tissue. In rats treated with 50 mg/kg 3DG i. v., a reduced phosphorylation of p85-PI3K was observed in both the liver and pancreas tissues. The increase in plasma levels of 3DG and the deleterious effects of 3DG were attenuated by aminoguanidine pretreatment. Our results indicated a close association of 3DG with diabetes through participating in inducing acute glucose intolerance involvement of PI3K signaling in healthy individuals. By such a mechanism, a 3DG-targeted intervention to attenuation of the acute elevation of circulating 3DG is promising new therapeutic and prevention strategies for diabetes and its complications.

Our previous research suggests that 3-deoxyglucosone (3DG), formed in the caramelization course and Maillard reactions in food, is an independent factor for the development of prediabetes. Since the relationship between type 2 diabetes (T2D) and intestinal microbiota is moving from correlation to causality, we investigated the alterations in the composition and function of the intestinal microbiota in 3DG-induced prediabetic rats. Rats were given 50 mg/kg 3DG by intragastric administration for two weeks. Microbial profiling in faeces samples was determined through the 16S rRNA gene sequence. The glucagon-like peptide 2 (GLP-2) and lipopolysaccharide (LPS) levels in plasma and intestinal tissues were measured by ELISA and Limulus test, respectively. 3DG treatment did not significantly change the richness and evenness but affected the composition of intestinal microbiota. At the phylum level, 3DG treatment increased the abundance of nondominant bacteria Proteobacteria but did not cause the change of the dominant bacteria. Meanwhile, the abundance of the Prevotellaceae family and Parasutterela genus and the Alcaligencaeae family and Burkholderiales order and its attachment to the Betaproteobacteria class were overrepresented in the 3DG group. The bacteria of Candidatus Soleaferrea genus, Gelria genus, and Thermoanaerobacteraceae family and its attachment to Thermoanaerobacterales order were apparently more abundant in the control group. In addition, 45 KEGG pathways were altered after two-week intragastric administration of 3DG. Among these KEGG pathways, 13 KEGG pathways were involved in host metabolic function related to amino acid metabolism, carbohydrate metabolism, metabolism of cofactors and vitamins, and metabolism of terpenoids and polyketides. Moreover, the increased LPS levels and the decreased GLP-2 concentration in plasma and intestinal tissues were observed in 3DG-treated rats, together with the impaired fasting glucose and oral glucose tolerance. The alterations in composition and function of the intestinal microbiota were observed in 3DG-treated rats, which provides a possible mechanism linking exogenous 3DG intake to the development of prediabetes.

BackgroundOur recent findings support the idea that 3-deoxyglucosone (3DG), a dietary composition, has been suggested as an independent factor for the development of prediabetes. Secretion of glucagon-like peptide-1 (GLP-1) has been suggested to be impaired in T2DM and in conditions associated with hyperglycemia. Since low oral bioavailability of 3DG has been indicated in a single administration study, in the present study we examined if 3DG is capable of accumulating in intestinal tissue of rats after 2-week administration of 3DG, and the 3DG treatment affects GLP-1 secretion and glucose tolerance.MethodsRats were administered by gastric gavage for 2 weeks. We measured 3DG contents of intestinal tissues (by HPLC), plasma levels of total GLP-1 (by ELISA), insulin and glucagon (both by radioimmunoassay) and blood glucose concentrations. The expressions of the sweet receptor subunits (TAS1R2, TAS1R3) and its downstream molecule TRPM5 in duodenum and colon tissues of rats were quantified by WB. We examined GLP-1 secretion in enteroendocrine STC-1 cells exposured to 3DG.Results3DG treatment for 2 weeks increased 3DG content of intestinal tissues, fasting blood glucose concentration, and reduced plasma concentrations of GLP-1 and insulin at fasting and 15 and 180 min after the glucose load and oral glucose tolerance in conjunction with increased plasma glucagon concentrations. The expressions of TAS1R2, TAS1R3 and TRPM5 were shown to be reduced whereas 3DG treatment did not affect plasma dipeptidyl peptidase-4 activity, indicating an impaired GLP-1 secretion in 3DG-treated rats. This idea was further supported by the fact that exposure to 3DG directly decrease GLP-1 secretion in STC-1.ConclusionIt is the first demonstration that 3DG was capable of accumulating in intestinal tissue and thereby decreased secretion of GLP-1 and insulin in a similar manner. 3DG-treated rats developed impaired glucose regulation (IGR) with obviously pancreatic islet cell dysfunction. It is further concluded that a decrease in the biological function of GLP-1 resulting from the decreased GLP-1 secretion is the most likely mechanism for the impaired insulin secretion, which ultimately promoted the development of IGR. These results will also contribute to a better understanding of the significance for restoring physiological GLP-1 secretion.Electronic supplementary materialThe online version of this article (doi:10.1186/s13098-016-0194-9) contains supplementary material, which is available to authorized users.

3-Deoxyglucosone (3DG), a highly reactive dicarbonyl intermediate generated during glycation, has been confirmed to be markedly elevated in the plasma of patients with diabetes. Our previous study found that there is an association between increasing accumulation of plasma 3DG and impaired glucose regulation in non-diabetic seniors (females, >50 years old; males, >55 years old). It was also found that 3DG led to impaired plasma glucose homeostasis in healthy mice, however, the mechanisms underlying the deleterious effect of 3DG in diabetes remain to be fully elucidated. The present study aimed to investigate the ability of 3DG to cause hepatic insulin resistance in a cell model by assessing glucose uptake and glycogen content. In addition, the molecular signaling events, including the phosphoinositide 3‑kinase (PI3K)/AKT/glucose transporter 2 (GLUT2) and PI3K/AKT/glycogen synthase kinase‑3 (GSK‑3) pathways, which affect hepatic insulin resistance, were further investigated using Western blot analysis. The results showed that 3DG (10‑300 ng/ml) had no significant effect on HepG2 cell viability, however, the viability of the HepG2 cells decreased with exposure to concentrations of 500 and 1,000 ng/ml. Treatment with non‑cytotoxic 3DG concentrations resulted in decreased uptake of glucose and glycogen content with insulin stimulation, but not under basal conditions. The insulin‑induced expression of GLUT2 and p‑GSK‑3 were eliminated by 3DG (80 and 300 ng/ml), in addition to inhibiting the phosphorylation of downstream effectors of the insulin signaling pathway, including insulin receptor substrate 1, PI3K and AKT. In conclusion, the findings of the present study indicated that the addition of exogenous 3DG directly contributed to the induction of insulin resistance by impairing insulin signaling in the HepG2 cells, which suggested that 3DG may be involved in worsening of the diabetic condition.

Secretion of glucagon-like peptide-1 has been suggested to be impaired in T2DM and in conditions associated with hyperglycemia. 3-Deoxyglucosone, a dietary composition, has been suggested as an independent factor for the development of prediabetes. A-pathophysiological very high condition of 3DG concentrations administered i. v. induced acute glucose intolerance in rats. In this study, to examine the acute effects of single intragastric administration of 3DG at dose of potentially single-meal intake on plasma glucose, insulin, glucagon, total GLP-1 and total GIP levels in response to a glucose load, OGTT was performed immediately in normal Kunming mice or Sprague-Dawleys rats after 3DG administration. GLP-1 secretion, intracellular cAMP levels and 2-NBDG uptake were examined in STC-1 cells exposured to 3DG. In rats, 20 mg/kg 3DG i.g. (3DG-20 i.g.) impaired glucose tolerance (<0.05) with increased AUC (1 070±105.2 vs. 918.0±91.20, <0.05). The mice treated with 3DG-20 i.g. exhibited a similar effect, independent of the effect of plasma 3DG concentration. 3DG-20 i.g. treatment reduced plasma insulin concentrations with decreased AUC (3 552±300.2 vs. 4 715±420.5, <0.05) in rats whereas plasma glucagon levels were not significantly different. These changes occurred in conjunction with decreased plasma GLP-1 and GIP levels (<0.05). Furthermore, non-cytotoxic 3DG concentrations directly reduced GLP-1 secretion in STC-1, at least in part, by decreasing intracellular cAMP level and glucose uptake. We demonstrated for the first time that single intragastric administration of 3DG resulted in acute reduction of incretin effect and glucose intolerance, which was associated with a decrease in the biological function of GLP-1 by decreasing GLP-1 secretion.

The tumor immunological microenvironment in hepatocellular carcinoma (HCC) is the T-helper (Th) 2 dominant inhibition state. Improving the immunosuppressive tumor microenvironment represents an important strategy for HCC treatment. TSLP-OX40L pathway is a target to improve Th2 immunosuppression. Yupingfeng granule (YPF) is clinically used to effectively improve the immune status of HCC. In this study, YPF increased the percentage of mature dendritic cells (DCs) and decreased levels of TSLP, TSLPR, and OX40L in tumor and adjacent tissues of the orthotopic-HCC mice model. This occurs together with the decreased levels of Th2 cytokines and increased levels of Th1 cytokines and Th1/Th2 ratio. In vitro experiment showed that YPF not only increased the percentage of mature DCs and stimulated IL-12 secretion in DCs but also reduced the positive rate of OX40L expression, decreased the proportion of CD4+ IL-13+ T cells, increased levels of Th1 cytokines, and decreased levels of Th2 cytokines from TSLP-treated DCs. In summary, these findings demonstrated that YPF promoted the maturation of DCs, decreased OX40L in TSLP-induced DCs, and improved the immunosuppressive state of Th2 in HCC microenvironment. Our results suggest that the mechanism underlying the improving effect of YPF on the immunosuppression is related to the DC-mediated TSLP-OX40L pathway.

3DG attenuates high glucose-stimulated GLP-1 secretion by reducing STR subunit expression and downstream signaling components.