Human GW182 Paralogs Are the Central Organizers for RNA-Mediated Control of Transcription.

In the cytoplasm, small RNAs can control mammalian translation by regulating the stability of mRNA. In the nucleus, small RNAs can also control transcription and splicing. The mechanisms for RNA-mediated nuclear regulation are not understood and remain controversial, hindering the effective application of nuclear RNAi and investigation of its natural regulatory roles.

Non-coding RNAs as drug targets.

Most of the human genome encodes RNAs that do not code for proteins. These non-coding RNAs (ncRNAs) may affect normal gene expression and disease progression, making them a new class of targets for drug discovery. Because their mechanisms of action are often novel, developing drugs to target ncRNAs will involve equally novel challenges.

HP1BP3, a Chromatin Retention Factor for Co-transcriptional MicroRNA Processing.

Recent studies suggest that the microprocessor (Drosha-DGCR8) complex can be recruited to chromatin to catalyze co-transcriptional processing of primary microRNAs (pri-miRNAs) in mammalian cells. However, the molecular mechanism of co-transcriptional miRNA processing is poorly understood. Here we find that HP1BP3, a histone H1-like chromatin protein, specifically associates with the microprocessor and promotes global miRNA biogenesis in human cells.

Argonaute 2-dependent Regulation of Gene Expression by Single-stranded miRNA Mimics.

MicroRNAs (miRNAs) are small noncoding transcripts that regulate gene expression. Aberrant expression of miRNAs can affect development of cancer and other diseases. Synthetic miRNA mimics can modulate gene expression and offer an approach to therapy.

Effect of 2'-O-methyl/thiophosphonoacetate-modified antisense oligonucleotides on huntingtin expression in patient-derived cells.

Optimizing oligonucleotides as therapeutics will require exploring how chemistry can be used to enhance their effects inside cells. To achieve this goal it will be necessary to fully explore chemical space around the native DNA/RNA framework to define the potential of diverse chemical modifications. In this report we examine the potential of thiophosphonoacetate (thioPACE)-modified 2'-O-methyl oligoribonucleotides as inhibitors of human huntingtin (HTT) expression.

Activating frataxin expression by repeat-targeted nucleic acids.

Friedreich's ataxia is an incurable genetic disorder caused by a mutant expansion of the trinucleotide GAA within an intronic FXN RNA. This expansion leads to reduced expression of frataxin (FXN) protein and evidence suggests that transcriptional repression is caused by an R-loop that forms between the expanded repeat RNA and complementary genomic DNA. Synthetic agents that increase levels of FXN protein might alleviate the disease.

Reduced Expression of Argonaute 1, Argonaute 2, and TRBP Changes Levels and Intracellular Distribution of RNAi Factors.

Until recently, Argonaute 2 (AGO2) and other RNA factors were believed to be restricted to the cytoplasm of mammalian somatic cells. It is now becoming appreciated that RNAi factors can also be found in cell nuclei, but much remains to be learned about their transport, molecular recognition, and function. We find that siRNA-mediated reduction of AGO1 or AGO2 increases the proportion of AGO1 or AGO2 in cell nuclei.

Promoter RNA links transcriptional regulation of inflammatory pathway genes.

Although many long non-coding RNAs (lncRNAs) have been discovered, their function and their association with RNAi factors in the nucleus have remained obscure. Here, we identify RNA transcripts that overlap the cyclooxygenase-2 (COX-2) promoter and contain two adjacent binding sites for an endogenous miRNA, miR-589. We find that miR-589 binds the promoter RNA and activates COX-2 transcription.

Transcriptional silencing by single-stranded RNAs targeting a noncoding RNA that overlaps a gene promoter.

RNAi using single-strand RNA would provide new options for therapeutic development and for investigating critical questions of mechanism. Using chemically modified single-strands, we test the hypothesis that single-stranded RNAs can engage the RNAi pathway and silence gene transcription. We find that a chemically modified single-stranded silencing RNA (ss-siRNA) designed to be complementary to a long noncoding RNA (lncRNA) requires argonaute protein, functions through the RNAi pathway, and inhibits gene transcription.

Enhanced binding of trigonal DNA-carbohydrate conjugates to lectin.

Novel trigonal DNA-carbohydrate conjugates were prepared and evaluated to explore efficient carbohydrate-lectin interactions. Carbohydrate-modified oligonucleotides were enzymatically prepared, then hybridized to form 3-way junction DNAs. The thermal stabilities of the junctions were assessed by UV melting analysis and formation of constructs was confirmed by gel electrophoresis.

Allele-selective inhibition of trinucleotide repeat genes.

Expanded trinucleotide repeats cause Huntington's disease (HD) and many other neurodegenerative disorders. There are no cures for these devastating illnesses and treatments are urgently needed. Each trinucleotide repeat disorder is the result of the mutation of just one gene, and agents that block expression of the mutant gene offer a promising option for treatment.

Activation of LDL receptor expression by small RNAs complementary to a noncoding transcript that overlaps the LDLR promoter.

Low-density lipoprotein receptor (LDLR) is a cell-surface receptor that plays a central role in regulating cholesterol levels. Increased levels of LDLR would lead to reduced cholesterol levels and contribute to strategies designed to treat hypercholesterolemia. We have previously shown that duplex RNAs complementary to transcription start sites can associate with noncoding transcripts and activate gene expression.

Allele-selective inhibition of mutant huntingtin by peptide nucleic acid-peptide conjugates, locked nucleic acid, and small interfering RNA.

The ability to inhibit expression of a mutant allele while retaining expression of a wild-type protein might provide a useful approach to treating Huntington's Disease (HD) and other inherited pathologies. The mutant form of huntingtin (HTT), the protein responsible for HD, is encoded by an mRNA containing an expanded CAG repeat. We demonstrate that peptide nucleic acid conjugates and locked nucleic acids complementary to the CAG repeat selectively block expression of mutant HTT.

Allele-specific silencing of mutant huntingtin and ataxin-3 genes by targeting expanded CAG repeats in mRNAs.

Expanded trinucleotide repeats cause many neurological diseases. These include Machado-Joseph disease (MJD) and Huntington's disease (HD), which are caused by expanded CAG repeats within an allele of the ataxin-3 (ATXN3) and huntingtin (HTT) genes, respectively. Silencing expression of these genes is a promising therapeutic strategy, but indiscriminate inhibition of both the mutant and wild-type alleles may lead to toxicity, and allele-specific approaches have required polymorphisms that differ among individuals.

[Ten cases of acute superior mesenteric artery occlusion].

This report deals with the perioperative management of ten patients with acute superior mesenteric artery occlusion. All ten patients survived after the surgery. Anesthesia in six patients were maintained with isoflurane, and in four patients with propofol, fentanyl and ketamine (PFK).

Construction of saccharide-modified DNAs by DNA polymerase.

Novel deoxyribonucleotide triphosphates bearing maltose or lactose groups were synthesized as substrates for DNA polymerase. The incorporation efficiencies of these modified substrates were investigated in both primer extension reactions and PCR. The stability and conformation of saccharide-modified dsDNAs were assessed by UV absorbance melting experiments and CD analysis.

Ectopic varices in a right diaphragm that ruptured into the pleural cavity.

The term ectopic varices is used to describe dilated portosystemic collateral veins in unusual locations other than the gastroesophageal region. We recently experienced a rare case of ectopic varices that developed in the right diaphragm and ruptured into the pleural cavity. A 68-year-old female with hepatocellular carcinoma complicated with liver cirrhosis was admitted due to an acute onset of dyspnea and right bloody pleural effusion.

Enricher for fraction of high-pressure liquid chromatography.

A device is developed for concentrating a dilute solution without losing the components with boiling points slightly higher than the solvent. The device consists of an evaporator, receptor, and approximately 100 capillaries. A dilute solution is introduced into the evaporator and heated at a lower temperature than the boiling point of the solvent with the addition of a helium gas flow.

Severe manifestation of acute hepatitis A recently found in Gunma, Japan.

Background: The incidence of acute hepatitis A infection in Japan peaked 10 years ago and has been decreasing since then. However, an increase in severe cases of the disease has been documented recently. We experienced an outbreak in 1998-1999, and compared the clinical features of the disease in 1998-1999 (recent outbreak) and in 1987-1988 (past outbreak) in our prefecture (Gunma).