Substituted 2-(R)-methyl piperazines as muscarinic M(2) selective ligands

A novel series of 2-(R)-methyl-substituted piperazines (e.g., 2) is described. They are potent M(2) selective ligands that have >100-fold selectivity versus the M(1) receptor. In the rat microdialysis assay, compound 14 showed significantly enchanced levels of acetylcholine after oral administration.     

The effects of phenolic components of tea on the production of pro- and anti-inflammatory cytokines by human leukocytes in vitro

Epidemiological evidence suggests protective effects of dietary flavonoids against cardiovascular disease. Tea provides a major source of dietary flavonoids in many countries and its polyphenolic components have well-recognised antioxidant properties. However, scavenging of free radicals may not be the sole mechanism by which tea-derived polyphenols exert their protective effects. This study investigates the effects of four major tea-derived catechins and a black tea extract on the production of pro- and anti-inflammatory cytokines by human leukocytes in vitro. Epicatechin gallate, epigallocatechin and epigallocatechin gallate decreased the production of interleukin 1beta and enhanced the production of interleukin 10, but had no effect on the production of interleukin 6 or tumour necrosis factor-alpha. Although these effects suggest anti-inflammatory properties of the tea-derived catechins, they were observed at concentrations which were unlikely to be achievable in plasma in vivo and are therefore unlikely to contribute to the protective effects of tea-derived flavonoids in inflammatory diseases.     

Actin is oxidized during myocardial ischemia

Exposure of isolated rat hearts to 30 min global ischemia followed by 60 min reperfusion resulted in a significant 80% increase (p <.05) in actin content of carbonyl groups, which was associated with significant depression (p <.05) of postischemic contractile function. This result supports the hypothesis that one mechanism of postischemic contractile dysfunction may be oxidation of contractile proteins.     

Low seasonal temperatures promote life cycle synchronization

In this paper we discuss how seasonal temperature variation and life-stage specific developmental thresholds that cause quiescence can synchronize the seasonal development of exothermic organisms. Using a simple aging model it is shown that minimal seasonal temperature variation and periods of quiescence during extreme temperature conditions are sufficient to establish stable, univoltine ovipositional cycles. Quiescence induced by life-stage specific developmental thresholds, in fact, promotes synchronous oviposition and emergence. The mountain pine beetle, an important insect living in extreme temperature conditions and showing no evidence of diapause, invites direct application of this model. Simulations using mountain pine beetle parameters are used to determine temperature regimes for which stable ovipositional cycles exist.     

Epithelial Adhesion Mediated by Pilin SpaC Is Required for Lactobacillus rhamnosus GG-Induced Cellular Responses

Lactobacillus rhamnosus GG is a widely used probiotic, and the strain''s salutary effects on the intestine have been extensively documented. We previously reported that strain GG can modulate inflammatory signaling, as well as epithelial migration and proliferation, by activating NADPH oxidase 1-catalyzed generation of reactive oxygen species (ROS). However, how strain GG induces these responses is unknown. Here, we report that strain GG''s probiotic benefits are dependent on the bacterial-epithelial interaction mediated by the SpaC pilin subunit. By comparing strain GG to an isogenic mutant that lacks SpaC (strain GGΩspaC), we establish that SpaC is necessary for strain GG to adhere to gut mucosa, that SpaC contributes to strain GG-induced epithelial generation of ROS, and that SpaC plays a role in strain GG''s capacity to stimulate extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling in enterocytes. In addition, we show that SpaC is required for strain GG-mediated stimulation of cell proliferation and protection against radiologically inflicted intestinal injury. The identification of a critical surface protein required for strain GG to mediate its probiotic influence advances our understanding of the molecular basis for the symbiotic relationship between some commensal bacteria of the gut lumen and enterocytes. Further insights into this relationship are critical for the development of novel approaches to treat intestinal diseases.     

Homology across inheritance systems

Recent work on inheritance systems can be divided into inclusive conceptions, according to which genetic and non-genetic inheritance are both involved in the development and transmission of nearly all animal behavioral traits, and more demanding conceptions of what it takes for non-genetic resources involved in development to qualify as a distinct inheritance system. It might be thought that, if a more stringent conception is adopted, homologies could not subsist across two distinct inheritance systems. Indeed, it is commonly assumed that homology relations cannot survive a shift between genetic and cultural inheritance systems, and substantial reliance has been placed on that assumption in debates over the phylogenetic origins of hominin behavioral traits, such as male-initiated intergroup aggression. However, in the homology literature it is widely accepted that a trait can be homologous—that is, inherited continuously in two different lineages from a single common ancestor—despite divergence in the mechanisms involved in the trait’s development in the two lineages. In this paper, we argue that even on an extremely stringent understanding of what it takes for developmental resources to form a separate inheritance system, homologies can nonetheless subsist across shifts between distinct inheritance systems. We argue that this result is a merit of this way of characterizing what it is to be an inheritance system, that it has implications for adjudicating between alternative accounts of homology, and that it offers an important cautionary lesson about how (not) to reason with the homology concept, particularly in the context of cultural species.     

Antioxidants and vision health: facts and fiction

A number of nutritional supplements containing antioxidants are advertised for better vision health. Do they benefit the average consumer? The literature was examined for the effectiveness of antioxidants for human eye health, and for the intricacies in collection of such evidence. The following diseases were considered: cataract, glaucoma, age-related macular degeneration (AMD), retinopathy, retinitis pigmentosa, eye infections, and uveitis. The literature indicates that antioxidant supplements plus lutein have a reasonable probability of retarding AMD. For glaucoma, such supplements were ineffectual in some studies but useful in others. In some studies, antioxidant rich fruits and vegetables were also useful for protection against glaucoma. For diabetic retinopathy, antioxidant supplements may have a small benefit, if any, but only as an adjunct to glycemic control. In very high-risk premature retinopathy and retinitis pigmentosa, antioxidant supplements may be beneficial but those with excess Vitamin E should be avoided. For cataract, there is no evidence for an advantage of such nutritional supplements. However, lubricant drops containing N-acetylcarnosine may be helpful in initial stages of the disease. For eye infections and other causes of uveitis, antioxidants have not been found useful. We recommend that a diet high in antioxidant rich foods should be developed as a habit from an early age. However, when initial signs of vision health deterioration are observed, the appropriate nutritional supplement products may be recommended but only to augment the primary medical treatments.     

TRP14 Inhibits Osteoclast Differentiation via Its Catalytic Activity

We previously reported the inhibitory role of thioredoxin-related protein of 14 kDa (TRP14), a novel disulfide reductase, in nuclear factor-κB (NF-κB) activation, but its biological function has remained to be explored. Here, we evaluated the role of TRP14 in the differentiation and function of osteoclasts (OCs), for which NF-κB and cellular redox regulation have been known to be crucial, using RAW 264.7 macrophage cells expressing wild-type TRP14 or a catalytically inactive mutant, as well as its small interfering RNA. TRP14 depletion enhanced OC differentiation, actin ring formation, and bone resorption, as well as the accumulation of reactive oxygen species (ROS). TRP14 depletion promoted the activation of NF-κB, c-Jun NH₂-terminal kinase, and p38, the expression of c-Fos, and the consequent induction of nuclear factor of activated T cell, cytoplasmic 1 (NFATc1), a key determinant of osteoclastogenesis. However, pretreatment with N-acetylcysteine or diphenylene iodonium significantly reduced the OC differentiation, as well as the ROS accumulation and NF-κB activation, that were enhanced by TRP14 depletion. Furthermore, receptor activator of NF-κB ligand (RANKL)-induced ROS accumulation, NF-κB activation, and OC differentiation were inhibited by the ectopic expression of wild-type TRP14 but not by its catalytically inactive mutant. These results suggest that TRP14 regulates OC differentiation and bone resorption through its catalytic activity and that enhancing TRP14 may present a new strategy for preventing bone resorption diseases.     

Positioning of aminopeptidase inhibitors in next generation cancer therapy

Aminopeptidases represent a class of (zinc) metalloenzymes that catalyze the cleavage of amino acids nearby the N-terminus of polypeptides, resulting in hydrolysis of peptide bonds. Aminopeptidases operate downstream of the ubiquitin–proteasome pathway and are implicated in the final step of intracellular protein degradation either by trimming proteasome-generated peptides for antigen presentation or full hydrolysis into free amino acids for recycling in renewed protein synthesis. This review focuses on the function and subcellular location of five key aminopeptidases (aminopeptidase N, leucine aminopeptidase, puromycin-sensitive aminopeptidase, leukotriene A₄ hydrolase and endoplasmic reticulum aminopeptidase 1/2) and their association with different diseases, in particular cancer and their current position as target for therapeutic intervention by aminopeptidase inhibitors. Historically, bestatin was the first prototypical aminopeptidase inhibitor that entered the clinic 35 years ago and is still used for the treatment of lung cancer. More recently, new generation aminopeptidase inhibitors became available, including the aminopeptidase inhibitor prodrug tosedostat, which is currently tested in phase II clinical trials for acute myeloid leukemia. Beyond bestatin and tosedostat, medicinal chemistry has emerged with additional series of potential aminopeptidases inhibitors which are still in an early phase of (pre)clinical investigations. The expanded knowledge of the unique mechanism of action of aminopeptidases has revived interest in aminopeptidase inhibitors for drug combination regimens in anti-cancer treatment. In this context, this review will discuss relevant features and mechanisms of action of aminopeptidases and will also elaborate on factors contributing to aminopeptidase inhibitor efficacy and/or loss of efficacy due to drug resistance-related phenomena. Together, a growing body of data point to aminopeptidase inhibitors as attractive tools for combination chemotherapy, hence their implementation may be a step forward in a new era of personalized treatment of cancer patients.