Advanced glycation end products (AGEs) could be implicated in insulin resistance. However, the molecular mechanisms underlying this are not fully understood. Since pigment epithelium-derived factor (PEDF) blocks the AGE-signaling pathways, we examined here whether and how PEDF improves insulin resistance in AGE-exposed hepatoma cells, Hep3B cells. Proteins were extracted from Hep3B cells, immunoprecipitated with or without insulin receptor substrate-1 (IRS-1) antibodies, and subjected to Western blot analysis. Glycogen synthesis was measured using [ (14)C]-d-glucose. AGE induced Rac-1 activation and increased phosphorylation of IRS-1 at serine-307 residues, JNK, c-JUN, and IkappaB kinase in association with decreased IkappaB levels in Hep3B cells. PEDF or overexpression of dominant negative Rac-1 blocked these effects of AGE on Hep3B cells. Further, AGEs decreased tyrosine phosphorylation of IRS-1, and subsequently reduced the association of p85 subunit of phosphatidylinositol 3-kinase with IRS-1 and glycogen synthesis in insulin-exposed Hep3B cells, all of which were inhibited by PEDF. Our present study suggests that PEDF could improve the AGE-elicited insulin resistance in Hep3B cells by inhibiting JNK- and IkappaB kinase-dependent serine phosphorylation of IRS-1 via suppression of Rac-1 activation. PEDF may play a protective role against hepatic insulin resistance in diabetes.

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Protein kinase (PK)-responsive nanoparticles (NPs) comprising a hydrophobically modified peptide substrate for PKs and a fluorescein-labeled polyanion (pA-F) were reported for monitoring PK activity via fluorescence intensity measurements. In this system, the formation of NPs by mixing lipopeptides and pA-Fs results in fluorescence quenching, while the quenched fluorescence recovered following dissociation of the NPs owing to the phosphorylation reaction of PKs. Eleven lipopeptides with different hydrophobic moieties (hydrocarbon and lithocholic acid) and four pA-Fs having main chains with differing flexibilities and fluorescein contents were synthesized and used to fabricate a series of twenty-four PK-responsive NP probes. The responses of the PK-responsive NP probes to PKs were evaluated to screen the most suitable NP probes. The assay system was then used to determine the IC(50) values for five inhibitors, the results of which were very similar to those previously reported. Thus, PK-responsive NPs are useful tools for high-throughput screening (HTS) of PK inhibitors.

AIMTo analyzed the correlation between smoking status and surgical outcomes in patients with non-B non-C hepatocellular carcinoma (NBNC-HCC), and we investigated the patients’ clinicopathological characteristics according to smoking status.METHODSWe retrospectively analyzed the consecutive cases of 83 NBNC-HCC patients who underwent curative surgical treatment for the primary lesion at Saga University Hospital between 1984 and December 2012. We collected information about possibly carcinogenic factors such as alcohol abuse, diabetes mellitus, obesity and smoking habit from medical records. Smoking habits were subcategorized as never, ex- and current smoker at the time of surgery. The diagnosis of non-alcoholic steatohepatitis (NASH) was based on both clinical information and pathological confirmation.RESULTSAlcohol abuse, diabetes mellitus, obesity and NASH had no significant effect on the surgical outcomes. Current smoking status was strongly correlated with both overall survival (P = 0.0058) and disease-specific survival (P = 0.0105) by multivariate analyses. Subset analyses revealed that the current smokers were significantly younger at the time of surgery (P = 0.0002) and more likely to abuse alcohol (P = 0.0188) and to have multiple tumors (P = 0.023).CONCLUSIONCurrent smoking habit at the time of surgical treatment is a risk factor for poor long-term survival in NBNC-HCC patients. Current smokers tend to have multiple HCCs at a younger age than other patients.

AIMTo investigate the prevalence, clinicopathological characteristics and surgical outcomes of occult hepatitis B virus (HBV) infection (OBI) in patients with non-B, non-C (NBNC) hepatocellular carcinoma (HCC).METHODSThis study retrospectively examined the cases of 78 NBNC patients with curative resection for HCC for whom DNA could be extracted from formalin-fixed paraffin-embedded tissue. OBI was determined by the HBV-DNA amplification of at least two different sets of primers by TaqMan real-time polymerase chain reaction. Possibly carcinogenetic factors such as alcohol abuse, diabetes mellitus, obesity and non-alcoholic steatohepatitis (NASH) were examined. Surgical outcomes were evaluated according to disease-free survival (DFS), overall survival (OS) and disease-specific survival (DSS).RESULTSOBI was found in 27/78 patients (34.6%) with NBNC HCC. The OBI patients were significantly younger than the non-OBI cases at the time of surgery (average age 63.0 vs 68.1, P = 0.0334) and the OBI cases overlapped with other etiologies significantly more frequently compared to the non-OBI cases (P = 0.0057). OBI had no impact on the DFS, OS or DSS. Only tumor-related factors affected these surgical outcomes.CONCLUSIONOur findings indicate that OBI had no impact on surgical outcomes. The surgical outcomes of NBNC HCC depend on early tumor detection; this reconfirms the importance of a periodic medical examination for individuals who have NBNC HCC risk factors.