New approach towards carotane sesquiterpenes: a short synthesis of (-)-daucene

An enantioselective synthesis of sesqui-terpene hydrocarbon (-)-daucene 1 from R-(+)-limonene involving acid catalysed enone- olefln cyclisation (5 ° 6) as the key step is described

Polyethylene Glycol Camouflaged Earthworm Hemoglobin.

Nearly 21 million components of blood and whole blood and transfused annually in the United States, while on average only 13.6 million units of blood are donated. As the demand for Red Blood Cells (RBCs) continues to increase due to the aging population, this deficit will be more significant. Despite decades of research to develop hemoglobin (Hb) based oxygen (O2) carriers (HBOCs) as RBC substitutes, there are no products approved for clinical use. Lumbricus terrestris erythrocruorin (LtEc) is the large acellular O2 carrying protein complex found in the earthworm Lumbricus terrestris. LtEc is an extremely stable protein complex, resistant to autoxidation, and capable of transporting O2 to tissue when transfused into mammals. These characteristics render LtEc a promising candidate for the development of the next generation HBOCs. LtEc has a short half-life in circulation, limiting its application as a bridge over days, until blood became available. Conjugation with polyethylene glycol (PEG-LtEc) can extend LtEc circulation time. This study explores PEG-LtEc pharmacokinetics and pharmacodynamics. To study PEG-LtEc pharmacokinetics, hamsters instrumented with the dorsal window chamber were subjected to a 40% exchange transfusion with 10 g/dL PEG-LtEc or LtEc and followed for 48 hours. To study the vascular response of PEG-LtEc, hamsters instrumented with the dorsal window chamber received multiple infusions of 10 g/dL PEG-LtEc or LtEc solution to increase plasma LtEc concentration to 0.5, then 1.0, and 1.5 g/dL, while monitoring the animals' systemic and microcirculatory parameters. Results confirm that PEGylation of LtEc increases its circulation time, extending the half-life to 70 hours, 4 times longer than that of unPEGylated LtEc. However, PEGylation increased the rate of LtEc oxidation in vivo. Vascular analysis verified that PEG-LtEc showed the absence of microvascular vasoconstriction or systemic hypertension. The molecular size of PEG-LtEc did not change the colloid osmotic pressure or blood volume expansion capacity compared to LtEc, due to LtEc's already large molecular size. Taken together, these results further encourage the development of PEG-LtEc as an O2 carrying therapeutic

Synthesis of some novel heteropolyquinanes

Synthesis of structurally novel aza-and oxa-polyquinanes from the abundantly available cis,syn,cis-triquinane dione 1 via transannular nucleo-phillc additions is reported

S-nitrosocaptopril nanoparticles as nitric oxide-liberating and transnitrosylating anti-infective technology

Nitric oxide (NO) is an essential agent of the innate immune system which exhibits multi-mechanistic antimicrobial activity. Previously, increased antimicrobial activity against E. coli with nitric oxide releasing nanoparticles (NO-np) was demonstrated when combined with glutathione, versus NO-np alone, due to formation of S-nitrosoglutathione (GSNO), a potent transnitrosylating agent. To capitalize on this finding, the thiol-containing ACE-inhibitor, captopril, was incorporated into the NO-np system to form SNO-CAP-nps, nanoparticles that can both release NO as well as form S-nitrosocaptopril. SNO-CAP-nps demonstrated sustained release of NO and GSNO production in the presence of GSH over time. Both E. coli and MRSA were highly susceptible to SNO-CAP-np in a dose-dependent fashion, with E. coli being highly sensitive, while demonstrating no toxicity when exposed to zebrafish embryos. Given the significance of E. coli in urosepsis, as well as the ability of nanotechnology to overcome biofilm formation, SNO-CAP-np may prove useful against catheter-associated urinary tract infection.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/nanomedicine-nanotechnology-biology-and-medicineKeywords: Antibacterial, Nitric oxide, Nanotechnology, Nitrosothiols, E. col

Mice with Mutation in Dynein Heavy Chain 1 Do Not Share the Same Tau Expression Pattern with Mice with SOD1-Related Motor Neuron Disease

Due to controversy about the involvement of Dync1h1 mutation in pathogenesis of motor neuron disease, we investigated expression of tau protein in transgenic hybrid mice with Dync1h1 (so-called Cra1/+), SOD1G93A (SOD1/+), double (Cra1/SOD1) mutations and wild-type controls. Total tau-mRNA and isoforms 0, 1 and 2 N expression was studied in frontal cortex, hippocampus, spinal cord and cerebellum of presymptomatic and symptomatic animals (age 70, 140 and 365 days). The most significant differences were found in brain cortex and cerebellum, but not in hippocampus and spinal cord. There were less changes in Cra1/SOD1 double heterozygotes compared to mice harboring single mutations. The differences in total tau expression and in profile of its isoforms between Cra1/+ and SOD1/+ transgenics indicate a distinct pathogenic entity of these two conditions

Stable Mutated tau441 Transfected SH-SY5Y Cells as Screening Tool for Alzheimer’s Disease Drug Candidates

The role of hyperphosphorylation of the microtubule-associated protein tau in the pathological processes of several neurodegenerative diseases is becoming better understood. Consequently, development of new compounds capable of preventing tau hyperphosphorylation is an increasingly hot topic. For this reason, dependable in vitro and in vivo models that reflect tau hyperphosphorylation in human diseases are needed. In this study, we generated and validated an in vitro model appropriate to test potential curative and preventive compound effects on tau phosphorylation. For this purpose, a stably transfected SH-SY5Y cell line was constructed over-expressing mutant human tau441 (SH-SY5Y-TMHT441). Analyses of expression levels and tau phosphorylation status in untreated cells confirmed relevance to human diseases. Subsequently, the effect of different established kinase inhibitors on tau phosphorylation (e.g., residues Thr231, Thr181, and Ser396) was examined. It was shown with several methods including immunosorbent assays and mass spectrometry that the phosphorylation pattern of tau in SH-SY5Y-TMHT441 cells can be reliably modulated by these compounds, specifically targeting JNK, GSK-3, CDK1/5, and CK1. These four protein kinases are known to be involved in in vivo tau phosphorylation and are therefore authentic indicators for the suitability of this new cell culture model for tauopathies

Protein Aggregation and Protein Instability Govern Familial Amyotrophic Lateral Sclerosis Patient Survival

The nature of the “toxic gain of function” that results from amyotrophic lateral sclerosis (ALS)-, Parkinson-, and Alzheimer-related mutations is a matter of debate. As a result no adequate model of any neurodegenerative disease etiology exists. We demonstrate that two synergistic properties, namely, increased protein aggregation propensity (increased likelihood that an unfolded protein will aggregate) and decreased protein stability (increased likelihood that a protein will unfold), are central to ALS etiology. Taken together these properties account for 69% of the variability in mutant Cu/Zn-superoxide-dismutase-linked familial ALS patient survival times. Aggregation is a concentration-dependent process, and spinal cord motor neurons have higher concentrations of Cu/Zn-superoxide dismutase than the surrounding cells. Protein aggregation therefore is expected to contribute to the selective vulnerability of motor neurons in familial ALS

Towards a correlation of specific posttranslational modifications of tau protein with characteristics of amyloid deposition

Tau is a microtubule-associated protein mainly responsible for stabilizing the neuronal microtubule network in the brain. Under normal conditions, tau is a highly soluble protein adopting an ‘unfolded’ monomeric conformation. However, it undergoes conformational changes resulting in a less soluble form with weakened stabilizing properties. Altered tau forms pathogenic inclusions characteristically seen in Alzheimer’s disease and related tauopathies. Tau aggregates have been observed to be deposited surrounding prion protein amyloid plaques in mouse brains infected with the 87V murine adapted scrapie (87V-VM). Although tau hyperphosphorylation is widely considered as the major trigger of tau malfunction, tau is subject to a variety of other post-translational modifications, the site-specific impact of which on tau physiology and pathology remains unclear. Therefore, we used mass spectrometry to map post-translationally modified sites on tau purified from normal and 87V-VM mouse brains. We identified five types of site-dependent modifications in normal soluble tau, seven types in soluble tau extracted form 87V-VM brains and six types in insoluble aggregated tau. In preliminary, we showed that we can use LC-MS with a multiple reaction monitoring approach to determine relative levels of specific post-translational modifications of tau after only crude extractions. Once optimized, this workflow could be used to correlate the abundance of a wide variety of different modifications with specific properties of tau, such as solubility or morphologies of deposits

Tau filament self-assembly and structure: tau as a therapeutic target

Tau plays an important pathological role in a group of neurodegenerative diseases called tauopathies, including Alzheimer's disease, Pick's disease, chronic traumatic encephalopathy and corticobasal degeneration. In each disease, tau self-assembles abnormally to form filaments that deposit in the brain. Tau is a natively unfolded protein that can adopt distinct structures in different pathological disorders. Cryo-electron microscopy has recently provided a series of structures for the core of the filaments purified from brain tissue from patients with different tauopathies and revealed that they share a common core region, while differing in their specific conformation. This structurally resolvable part of the core is contained within a proteolytically stable core region from the repeat domain initially isolated from AD tau filaments. Tau has recently become an important target for therapy. Recent work has suggested that the prevention of tau self-assembly may be effective in slowing the progression of Alzheimer's disease and other tauopathies. Here we review the work that explores the importance of tau filament structures and tau self-assembly mechanisms, as well as examining model systems that permit the exploration of the mode of action of potential inhibitors