MicroRNA expression profiling in HCV-infected human hepatoma cells identifies potential anti-viral targets induced by interferon-α.

OBJECTIVE: Increasing evidence suggests that miRNAs have a profound impact on host defense to Hepatitis C virus (HCV) infection and clinical outcome of standard HCV therapy. In this study, we investigated modulation of miRNA expression in Huh7.5 hepatoma cells by HCV infection and in vitro interferon-αtreatment. METHODS: MiRNA expression profiling was determined using Human miRNA TaqMan® Arrays followed by rigorous pairwise statistical analysis. MiRNA inhibitors assessed the functional effects of miRNAs on HCV replication. Computational analysis predicted anti-correlated mRNA targets and their involvement in host cellular pathways. Quantitative RTPCR confirmed the expression of predicted miRNA-mRNA correlated pairs in HCV-infected Huh7.5 cells with and without interferon-α. RESULTS: Seven miRNAs (miR-30b, miR-30c, miR-130a, miR-192, miR-301, miR-324-5p, and miR-565) were down-regulated in HCV-infected Huh7.5 cells (p<0.05) and subsequently up-regulated following interferon-α treatment (p<0.01). The miR-30(a-d) cluster and miR-130a/301 and their putative mRNA targets were predicted to be associated with cellular pathways that involve Hepatitis C virus entry, propagation and host response to viral infection. CONCLUSIONS: HCV differentially modulates miRNAs to facilitate entry and early establishment of infection in vitro. Interferon-α appears to neutralize the effect of HCV replication on miRNA regulation thus providing a potential mechanism of action in eradicating HCV from hepatocytes.

Elevated miR-155 promotes inflammation in cystic fibrosis by driving hyperexpression of interleukin-8.

Cystic Fibrosis (CF) is characterized by a massive proinflammatory phenotype in the lung arising from profound expression of inflammatory genes, including interleukin-8 (IL-8). We have previously reported that IL-8 mRNA is stabilized in CF lung epithelial cells, resulting in concomitant hyperexpression of IL-8 protein. However, the mechanistic link between mutations in CFTR and acquisition of the proinflammatory phenotype in the CF airway has remained elusive. We hypothesized that specific microRNAs (miRNAs) might mediate this linkage. To identify the potential link, we screened an miRNA library for differential expression in ΔF508-CFTR and wild type CFTR lung epithelial cell lines. Of 22 differentially and significantly expressed miRNAs, we found that expression of miR-155 was more than 5-fold elevated in CF IB3-1 lung epithelial cells in culture, compared with control IB3-1/S9 cells. Clinically, miR-155 was also highly expressed in CF lung epithelial cells and circulating CF neutrophils biopsied from CF patients. We report here that high levels of miR-155 specifically reduced levels of SHIP1, thereby promoting PI3K/Akt activation. However, overexpressing SHIP1 or inhibition of PI3K in CF cells suppressed IL-8 expression. Finally, we found that phospho-Akt levels were elevated in CF lung epithelial cells and were specifically lowered by either antagomir-155 or elevated expression of SHIP1. We therefore suggest that elevated miR-155 contributes to the proinflammatory expression of IL-8 in CF lung epithelial cells by lowering SHIP1 expression and thereby activating the PI3K/Akt signaling pathway. These data suggest that miR-155 may play an important role in the activation of IL-8-dependent inflammation in CF.

Novel 2-aminopyrimidine carbamates as potent and orally active inhibitors of Lck: synthesis, SAR, and in vivo antiinflammatory activity.

The lymphocyte-specific kinase (Lck) is a cytoplasmic tyrosine kinase of the Src family expressed in T cells and NK cells. Genetic evidence in both mice and humans demonstrates that Lck kinase activity is critical for signaling mediated by the T cell receptor (TCR), which leads to normal T cell development and activation. A small molecule inhibitor of Lck is expected to be useful in the treatment of T cell-mediated autoimmune and inflammatory disorders and/or organ transplant rejection. In this paper, we describe the synthesis, structure-activity relationships, and pharmacological characterization of 2-aminopyrimidine carbamates, a new class of compounds with potent and selective inhibition of Lck. The most promising compound of this series, 2,6-dimethylphenyl 2-((3,5-bis(methyloxy)-4-((3-(4-methyl-1-piperazinyl)propyl)oxy)phenyl)amino)-4-pyrimidinyl(2,4-bis(methyloxy)phenyl)carbamate (43) exhibits good activity when evaluated in in vitro assays and in an in vivo model of T cell activation.

Non-FK506-binding protein-12 neuroimmunophilin ligands increase neurite elongation and accelerate nerve regeneration.

Neurotrophic activity of neuroimmunophilin ligands (FK506 and its nonimmunosuppressant derivatives) has been assumed to be mediated by the FK506-binding protein-12 (FKBP-12). We recently showed that activity is retained in hippocampal neurons from FKBP-12 knockout mice, indicating that binding to FKBP-12 is not necessary. Here we show that three nonimmunosuppressant FK506 derivatives (V-13,450, V-13,629, and V-13,670) that do not bind FKBP-12 (>12.5 mM affinity) are equipotent to FKBP-12 ligands (FK506, V-10,367, and V-13,449) for increasing neurite elongation in SH-SY5Y cells. One non-FKBP-12 ligand (V-13,670) is also shown to accelerate functional recovery and nerve regeneration in the rat sciatic nerve crush model. Surprisingly, it exhibited an unusual dose-response effect upon oral administration, showing a novel bimodal dose-response for behavioral functional recovery and myelination, but not for axonal size, suggesting both Schwann cell and neuronal targets. Orally active non-FKBP-12 neuroimmunophilin ligands may be useful for the treatment of human neurological disorders without any potential side effects resulting from FKBP-12 binding.

Heparin-independent mitogenicity in an endothelial and smooth muscle cell chimeric growth factor (S130K-HBGAM).

BACKGROUND: Through site-directed mutagenesis we have created a favorable fibroblast growth factor-1 (FGF-1) mutant (S130K) and linked it to a heparin-binding growth-associated molecule (HBGAM) to form the chimera S130K-HBGAM creating a heparin-independent, endothelial cell (EC)-specific mitogen. METHODS: The proliferative responses of primary canine carotid artery smooth muscle cells (SMC) and jugular vein EC to FGF-1, S130K, or S130K-HBGAM, with and without heparin (5 U/mL), was quantitated by measuring tritiated thymidine uptake over 24 hours and expressing the results as percent of positive control (20% fetal bovine serum [FBS]) for group comparison. RESULTS: Unlike FGF-1, both S130K and S130K-HBGAM are heparin-independent mitogens for EC and SMC. S130K-HBGAM was equivalent to FGF-1 with heparin at 6 nmol/L. S130K-HBGAM did not demonstrate relative EC specificity in this assay. CONCLUSIONS: At higher concentrations, S130K-HBGAM is a potent, heparin-independent EC and SMC mitogen. Co-culture assays and in vivo delivery models may demonstrate EC specificity not identified in this single cell type proliferation assay.

Control region mutations and the 'common deletion' are frequent in the mitochondrial DNA of patients with esophageal squamous cell carcinoma.

BACKGROUND: North central China has some of the highest rates of esophageal squamous cell carcinoma in the world with cumulative mortality surpassing 20%. Mitochondrial DNA (mtDNA) accumulates more mutations than nuclear DNA and because of its high abundance has been proposed as a early detection device for subjects with cancer at various sites. We wished to examine the prevalence of mtDNA mutation and polymorphism in subjects from this high risk area of China. METHODS: We used DNA samples isolated from tumors, adjacent normal esophageal tissue, and blood from 21 esophageal squamous cell carcinoma cases and DNA isolated from blood from 23 healthy persons. We completely sequenced the control region (D-Loop) from each of these samples and used a PCR assay to assess the presence of the 4977 bp common deletion. RESULTS: Direct DNA sequencing revealed that 7/21 (33%, 95% CI = 17-55%) tumor samples had mutations in the control region, with clustering evident in the hyper-variable segment 1 (HSV1) and the homopolymeric stretch surrounding position 309. The number of mutations per subject ranged from 1 to 16 and there were a number of instances of heteroplasmy. We detected the 4977 bp 'common deletion' in 92% of the tumor and adjacent normal esophageal tissue samples examined, whereas no evidence of the common deletion was found in corresponding peripheral blood samples. CONCLUSIONS: Control region mutations were insufficiently common to warrant attempts to develop mtDNA mutation screening as a clinical test for ESCC. The common deletion was highly prevalent in the esophageal tissue of cancer cases but absent from peripheral blood. The potential utility of the common deletion in an early detection system will be pursued in further studies.