An increasing incidence of diagnosed type 2 diabetes was observed for each sex in most age groups in Taiwan, but was most marked in the youngest age group. A parallel increase in obesity was observed with the increasing incidence of diabetes.

Podoplanin (PDPN) enhances tumor metastases by eliciting tumor cell-induced platelet aggregation (TCIPA) through activation of platelet C-type lectin-like receptor 2 (CLEC-2). A novel and non-cytotoxic 5-nitrobenzoate compound 2CP was synthesized that specifically inhibited the PDPN/CLEC-2 interaction and TCIPA with no effect on platelet aggregation stimulated by other platelet agonists. 2CP possessed anti-cancer metastatic activity in vivo and augmented the therapeutic efficacy of cisplatin in the experimental animal model without causing a bleeding risk. Analysis of the molecular action of 2CP further revealed that Akt1/PDK1 and PKCμ were two alternative CLEC-2 signaling pathways mediating PDPN-induced platelet activation. 2CP directly bound to CLEC-2 and, by competing with the same binding pocket of PDPN in CLEC-2, inhibited PDPN-mediated platelet activation. This study provides evidence that 2CP is the first defined platelet antagonist with CLEC-2 binding activity. The augmentation in the therapeutic efficacy of cisplatin by 2CP suggests that a combination of a chemotherapeutic agent and a drug with anti-TCIPA activity such as 2CP may prove clinically effective.

The non-coding microRNA (miRNA) is involved in the regulation of hepatitis C virus (HCV) infection and offers an alternative target for developing anti-HCV agent. In this study, we aim to identify novel cellular miRNAs that directly target the HCV genome with anti-HCV therapeutic potential. Bioinformatic analyses were performed to unveil liver-abundant miRNAs with predicted target sequences on HCV genome. Various cell-based systems confirmed that let-7b plays a negative role in HCV expression. In particular, let-7b suppressed HCV replicon activity and down-regulated HCV accumulation leading to reduced infectivity of HCVcc. Mutational analysis identified let-7b binding sites at the coding sequences of NS5B and 5'-UTR of HCV genome that were conserved among various HCV genotypes. We further demonstrated that the underlying mechanism for let-7b-mediated suppression of HCV RNA accumulation was not dependent on inhibition of HCV translation. Let-7b and IFNα-2a also elicited a synergistic inhibitory effect on HCV infection. Together, let-7b represents a novel cellular miRNA that targets the HCV genome and elicits anti-HCV activity. This study thereby sheds new insight into understanding the role of host miRNAs in HCV pathogenesis and to developing a potential anti-HCV therapeutic strategy.

Hepatitis C virus (HCV) is a positive-stranded RNA virus classified in the Hepacivirus genus in the family Flaviviridae. The 9.6-kb viral RNA genome encodes a precursor polyprotein that is processed to generate at least 10 viral proteins, including structural proteins (core, E1, E2, and p7) and nonstructural proteins (NS2, NS3, NS4A, NS4B, NS5A, and NS5B) (1). The NS5B RNA polymerase, together with other nonstructural viral proteins (NS3, NS4A, NS4B, and NS5A) and host factors, constitutes the active replication complexes (RC) for viral RNA replication. These proteins are directly or indirectly associated with the endoplasmic reticulum (ER)-derived structure called the "membranous web," where replication occurs (2, 3). However, the exact host factors and detailed interactions within the RC remain to be determined.HCV infection usually causes chronic hepatitis and frequently leads to cirrhosis and hepatocellular carcinoma (HCC). Besides, HCV-induced end-stage liver disease is an important indication for liver transplantation in most of the Western countries (4, 5). At present, no effective vaccine to prevent HCV infection is available. The current treatment strategies for HCV infection are valid only for individuals with a particular single nucleotide polymorphism (SNP) in the interleukin-28B gene or for infections caused by certain viral genotypes (6). Accordingly, the prevalence of hepatic steatosis in HCV-infected patients is much higher than that in the general population or in hepatitis B virus (HBV)-infected patients (7). Hepatic steatosis has also been reported to be associated with an increased rate of HCC in chronic hepatitis C patients (8).Lipid metabolic pathways are essential for the entry, secretion, and replication of HCV. For example, apolipoprotein E (apoE) is essential for the production of HCVcc (HCV produced in cell culture) and for viral entry (9, 10). Downregulation of apoA-I decreases levels of HCV replication and viral particle production in cell culture (11). HCV coopts the secretory pathway of very low density lipoprotein (VLDL) for its own secretion (12, 13). Moreover, HCV replication is regulated through induction of lipogenic gene expression in HCV replicon cells (14) or geranylgeranylation of host proteins required for HCV RNA replication (15,16). Fatty acid synthesis is also required for HCV RNA replication (14). Inhibition of fatty acid synthase (FASN) by cerulenin (17) or C75 (18) reduces the replication of subgenomic HCV replicons as well as JFH-1-based HCVcc virion production. Although the underlying mechanisms are not yet completely understood, these studies imply that FASN is essential for HCV replication.In this study, HCV NS5B was used as the bait to screen for NS5B-interacting proteins that are present in Huh7 hepatoma cell lysates. After mass spectrophotometric analysis, FASN was found to interact with NS5B, and this interaction was further confirmed in vitro and in vivo. Our data indicate that FASN interacts with NS5B to enhance NS5B RNA-dependent RNA polymerase (RdRp) act...

Hepatitis C virus (HCV) NS5B protein is the viral RNA-dependent RNA polymerase capable of directing RNA synthesis. In this study, an electrophoretic mobility shift assay demonstrated the interaction between a partially purified recombinant NS5B protein and a 3′ viral genomic RNA with or without the conserved 98-nucleotide tail. The NS5B-RNA complexes were specifically competed away by the unlabeled homologous RNA but not by the viral 5′ noncoding region and very poorly by the 3′ conserved 98-nucleotide tail. A 3′ coding region with conserved stem-loop structures rather than the 3′ noncoding region of the HCV genome is critical for the specific binding of NS5B. Nevertheless, no direct interaction between the 3′ coding region and the HCV NS5A protein was detected. Furthermore, two independent RNA-binding domains (RBDs) of NS5B were identified, RBD1, from amino acid residues 83 to 194, and RBD2, from residues 196 to 298. Interestingly, the conserved motifs of RNA-dependent RNA polymerase for putative RNA binding (220-DxxxxD-225) and template/primer position (282-S/TGxxxTxxxNS/T-292) are present in the RBD2. Nevertheless, the RNA-binding activity of RBD2 was abolished when it was linked to the carboxy-terminal half of the NS5B. These results provide some clues to understanding the initiation of HCV replication.

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