Actin is abundant in the nucleus and has been implicated in transcription; however, the nature of this involvement has not been established. Here we demonstrate that beta-actin is critically involved in transcription because antibodies directed against beta-actin, but not muscle actin, inhibited transcription in vivo and in vitro. Chromatin immunoprecipitation assays demonstrated the recruitment of actin to the promoter region of the interferon-gamma-inducible MHC2TA gene as well as the interferon-alpha-inducible G1P3 gene. Further investigation revealed that actin and RNA polymerase II co-localize in vivo and also co-purify. We employed an in vitro system with purified nuclear components to demonstrate that antibodies to beta-actin block the initiation of transcription. This assay also demonstrates that beta-actin stimulates transcription by RNA polymerase II. Finally, DNA-binding experiments established the presence of beta-actin in pre-initiation complexes and also showed that the depletion of actin prevented the formation of pre-initiation complexes. Together, these data suggest a fundamental role for actin in the initiation of transcription by RNA polymerase II.

A nuclear isoform of myosin I beta that contains a unique 16-amino acid amino-terminal extension has been identified. An affinity-purified antibody to the 16-amino acid peptide demonstrated nuclear staining. Confocal and electron microscopy revealed that nuclear myosin I beta colocalized with RNA polymerase II in an alpha-amanitin- and actinomycin D-sensitive manner. The antibody coimmunoprecipitated RNA polymerase II and blocked in vitro RNA synthesis. This isoform of myosin I beta appears to be in a complex with RNA polymerase II and may affect transcription.

Postoperative itching is an important problem in the postoperative care unit. Pruritus after surgery may be drug induced (including intrathecal opioids) or secondary to a preexisting systemic disease. Mechanisms of itching are complex and not completely understood. The purpose of this review is to highlight new discoveries in pathways and mechanisms of pruritus and to summarize up-to-date knowledge about treatment of itching after surgery. More basic and clinical studies are needed to address the effects of drugs on specific receptors and improve the treatment of postoperative pruritus.

The nuclear isoform of myosin, Nuclear Myosin I (NMI) is involved in transcription by RNA polymerase I. Previous experiments showing that antibodies to NMI inhibit transcription by RNA polymerase II using HeLa cell nuclear extract (NE) suggested that NMI might be a general transcription factor for RNA polymerases. In this study we used a minimal in vitro transcription system to investigate the involvement of NMI in transcription by RNA polymerase II in detail. We demonstrate that NMI co-purifies with RNA polymerase II and that NMI is necessary for basal transcription by RNA polymerase II because antibodies to NMI inhibit transcription while adding NMI stimulates transcription. Further investigation revealed that NMI is specifically involved in transcription initiation. Finally, by employing an abortive transcription initiation assay, we demonstrate that NMI is crucial for the formation of the first phosphodiester bond during transcription initiation.

Beneficial effects of angiotensin converting enzyme inhibitors (ACEI) and angiotensin type 1 receptor (AT1) blockers in patients with cardiovascular and renal diseases have been clearly demonstrated in numerous large outcomes studies. In patients with heart failure (HF), ACEI have been shown to reduce overall mortality, mortality from cardiovascular causes, to increase life expectancy, as well as to preserve the renal function (CONSENSUS, SAVE, TRACE, AIRE, AIREX, CATS trials). In addition, in the PROGRESS study ACEI substantially decreased the risk of stroke and transient ischemic attacks in patients with cerebrovascular disorders. The HOPE and EUROPA studies confirmed that long term therapy with ACEI provides significant survival benefit in patients with broad range of atherosclerotic cardiovascular diseases. After these large and well designed clinical studies, ACEI have become standard therapy for routine secondary prevention in all patients with cardiovascular diseases, unless contraindicated. AT1 receptor blockers have been recently added to the cardiovascular therapeutic armamentarium. They are believed to provide additional protection by inhibition of locally synthesized angiotensin II on the level of AT1 receptor. The ELITE II, ValHeFT and CHARM studies have shown that AT1 receptor blockers are equally effective as ACEI in reduction of mortality and morbidity in patients with HF. Importantly, they may be used together with ACEI, or as alternative treatment in ACEI intolerant patients. Renal protection is another important effect of both ACEI and AT1 blockers that has been confirmed in several large clinical trials. The North American Microalbuminemia Study group and EUCLID group demonstrated significant reduction in progression of diabetic nephropathy in patients with insulin dependent diabetes mellitus (IDDM) treated with ACEI. AT1 receptor blockers are mainly studied in the non-insulin dependent diabetes mellitus (NIDDM) nephropathy. Four recent clinical trials (IRMA-2, DETAIL, RENAAL and IDNT) examined the effect of AT1 receptor blockers in patients with NIDDM nephropathy. These studies confirmed the beneficial effect of AT1 receptor blockers in patients with NIDDM nephropathy that was extended beyond the blood pressure reduction. Ongoing studies (ONTARGET, TRANSCEND and PROTECTION) should provide us with additional insights about cardiovascular, renal and other end-organ protective effects of these therapeutics.