Inhibition of the Schizophrenia-Associated MicroRNA miR-137 Disrupts Nrg1α Neurodevelopmental Signal Transduction

Genomic studies have repeatedly associated variants in the gene encoding the microRNA miR-137 with increased schizophrenia risk. Bioinformatic predictions suggest that miR-137 regulates schizophrenia-associated signaling pathways critical to neural development, but these predictions remain largely unvalidated. In the present study, we demonstrate that miR-137 regulates neuronal levels of p55γ, PTEN, Akt2, GSK3β, mTOR, and rictor. All are key proteins within the PI3K-Akt-mTOR pathway and act downstream of neuregulin (Nrg)/ErbB and BDNF signaling. Inhibition of miR-137 ablates Nrg1α-induced increases in dendritic protein synthesis, phosphorylated S6, AMPA receptor subunits, and outgrowth. Inhibition of miR-137 also blocks mTORC1-dependent responses to BDNF, including increased mRNA translation and dendritic outgrowth, while leaving mTORC1-independent S6 phosphorylation intact. We conclude that miR-137 regulates neuronal responses to Nrg1α and BDNF through convergent mechanisms, which might contribute to schizophrenia risk by altering neural development.

Symptomatic gastrointestinal amyloidosis in an HIV-infected patient

We report a rare case of symptomatic GI amyloidosis in an HIV-infected patient who ultimately developed uncontrollable upper GI bleeding. Gastric and jejunal biopsies revealed amyloidosis. Although the patient's history suggested the possibility of secondary amyloidosis, immunohistochemical staining together with serum electrophoresis and immunofixation revealed the presence of lambda light chains indicating primary amyloidosis.

Achieving compliance with the radium standards for drinking water in a midwestern community: a case study

The problem of elevated levels of radium in the drinking-water supply of DeKalb, Illinois, a Midwestern community about 65 miles west of Chicago with approximately 35,000 residents, has been a contentious issue for over a decade. The central players in the controversy include a group of concerned citizens, city officials, the Illinois Pollution Control Board, the Illinois Environmental Protection Agency, and the U.S. Environmental Protection Agency (U.S. EPA). Achieving a satisfactory resolution to the problem has been a long, drawn-out process that illustrates how ill-timed proposals, changing risk assessments, different perceptions of risk, and the high costs of compliance can influence the direction of risk management decisions. The purpose of this study is to analyze how these factors sustained the debate and prevented an expeditious solution to the problem. The study uses document analysis as its primary research tool. The questions raised by the controversy, along with their implications for environmental policy, are discussed, as are some of the more important lessons learned from the case. Because of many uncertainties, there were no clear winners in the controversy, although, in the context of the most recent U.S. EPA risk assessments, the community is now poised for better protection from the potential dangers of radium in drinking water than it might have been had citizen action been absent.