3-Hydroxy-4-oxo-4H-pyrido[1,2-a]pyrimidine-2-carboxylates—A new class of HIV-1 integrase inhibitors

A new class of inhibitors of HIV-1 integrase has been optimized to provide selective and highly efficient strand transfer inhibition.     

N-(4-Fluorobenzyl)-3-hydroxy-9,9-dimethyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrazino[1,2-a]pyrimidine-2-carboxamides a novel class of potent HIV-1 integrase inhibitors

A novel class of tetrahydro-pyrazinopyrimidine-2-carboxamides have been identified as HIV-1 integrase inhibitors. Optimization of the initial lead culminated in the discovery of a series of compounds with high potency on the enzyme and an antiviral cell-based activity equivalent to that showed by Raltegravir, the first in class HIV-1 integrase inhibitor.     

Interaction of the amyloid imaging tracer FDDNP with hallmark Alzheimer's disease pathologies

The distinctive cortical uptake of the tracer ¹⁸F-FDDNP (2-(1-{6-[(2-fluoroethyl(methyl)amino]-2-naphthyl}ethylidene)malononitrile) in Alzheimer's disease (AD) is believed to be because of its binding to both neurofibrillary tangles (NFTs) and highly fibrillar senile plaques. We therefore investigated the binding of a tracer concentration of ³H-FDDNP to brain sections containing AD hallmark pathologies. Semi-adjacent sections were labelled with ³H-PIB (Pittsburgh compound-B, 2-[4'-(methylamino)phenyl]-6-hydroxybenzothiazole) and ¹⁴C-SB13 (4- N -methylamino-4'-hydroxystilbene) for comparison. Neocortical sections containing widespread senile plaques and cerebrovascular amyloid angiopathy, produced a sparse and weak labelling following incubation with ³H-FDDNP. Furthermore, in sections containing NFTs, there was no overt labelling of the pathology by ³H-FDDNP. In contrast, sections labelled with ³H-PIB displayed extensive labelling of diffuse plaques, classical plaques, cerebrovascular amyloid angiopathy and NFTs. ¹⁴C-SB13 produced a broadly similar binding pattern to PIB. Radioligand binding assays employing in vitro generated amyloid-β peptide fibrils demonstrated a ∼10-fold reduced affinity for ³H-FDDNP (85.0 ± 2.0 nM) compared with ³H-PIB (8.5 ± 1.3 nM). These data provide an alternative mechanistic explanation for the observed low cortical uptake of ¹⁸F-FDDNP in AD; in that the ligand is only weakly retained by the hallmark neuropathology because of its low affinity for amyloid structures.     

Lesion Load May Predict Long-Term Cognitive Dysfunction in Multiple Sclerosis Patients

Background

Magnetic Resonance Imaging (MRI) techniques provided evidences into the understanding of cognitive impairment (CIm) in Multiple Sclerosis (MS).

Objectives

To investigate the role of white matter (WM) and gray matter (GM) in predicting long-term CIm in a cohort of MS patients.

Methods

303 out of 597 patients participating in a previous multicenter clinical-MRI study were enrolled (49.4% were lost at follow-up). The following MRI parameters, expressed as fraction (f) of intracranial volume, were evaluated: cerebrospinal fluid (CSF-f), WM-f, GM-f and abnormal WM (AWM-f), a measure of lesion load. Nine years later, cognitive status was assessed in 241 patients using the Symbol Digit Modalities Test (SDMT), the Semantically Related Word List Test (SRWL), the Modified Card Sorting Test (MCST), and the Paced Auditory Serial Addition Test (PASAT). In particular, being SRWL a memory test, both immediate recall and delayed recall were evaluated. MCST scoring was calculated based on the number of categories, number of perseverative and non-perseverative errors.

Results

AWM-f was predictive of an impaired performance 9 years ahead in SDMT (OR 1.49, CI 1.12–1.97 p = 0.006), PASAT (OR 1.43, CI 1.14–1.80 p = 0.002), SRWL-immediate recall (OR 1.72 CI 1.35–2.20 p<0.001), SRWL-delayed recall (OR 1.61 CI 1.28–2.03 p<0.001), MCST-category (OR 1.52, CI 1.2–1.9 p<0.001), MCST-perseverative error(OR 1.51 CI 1.2–1.9 p = 0.001), MCST-non perseverative error (OR 1.26 CI 1.02–1.55 p = 0.032).

Conclusion

In our large MS cohort, focal WM damage appeared to be the most relevant predictor of the long-term cognitive outcome.     

Inhibitors of hepatitis C virus NS3/4A: α-Ketoamide based macrocyclic inhibitors

A novel series of hepatitis C virus (HCV) NS3/4A protease inhibitors bearing a P2-P4 macrocycle and a P1-P1′ α-ketoamide serine trap is reported. The NS3 protease, which is essential for viral replication, is considered one of the most attractive targets for developing novel anti-HCV therapies. The optimization of both the macrocycle and the warhead portions led to the discovery of compounds 8b and 8g with a good activity both in the enzyme as well as in the cell based (replicon) assays with favorable PK profile in a preclinical species.     

Aryl azoles with neuroprotective activity--parallel synthesis and attempts at target identification

A parallel synthesis of aryl azoles with neuroprotective activity is described. All compounds obtained were evaluated in an in vitro assay using a NMDA toxicity paradigm showing a neuroprotective activity between 15% and 40%. The potential biological target of the active compounds was investigated by extensive literature searches based around similar scaffolds with reported neuroprotective activity. The most interesting molecules active in the NMDA toxicity assay (3a and 2g) showed moderate but significant activity in the inhibition of the Site 2 Sodium Channel binding assay at 10 microM. To confirm our hypothesis compounds 3a, c, f and 2g were tested in the Veratridine assay which is one of the excitotoxicity assays of relevance to NaV channels. The compounds tested showed an activity between 40% and 70%. The identification of neuroprotective small molecules and the identification of NaV channels as the potential site of action were the most important goals of this work.     

Localization of ank1.5 in the sarcoplasmic reticulum precedes that of SERCA and RyR: relationship with the organization of obscurin in developing sarcomeres

Ank1.5 is a muscle-specific isoform of ankyrin1 localized on the sarcoplasmic reticulum (SR) membrane that has been shown to interact with obscurin, a sarcomeric protein. We report here studies on the localization of obscurin and ank1.5 in embryonic and postnatal rodent skeletal muscles. Using two antibodies against epitopes in the N- and C-terminus of obscurin, two distinct patterns of localization were observed. Before birth, the antibodies against the N- and the C-terminus of obscurin stained the Z-disk and M-band, respectively. At the same time, ank1.5 was detected at the Z-disk, rising the possibility that obscurin molecules at M-band may not be able to interact with ank1.5. Localization of ank1.5 at Z-disks in E14 muscle fibers revealed that ank1.5 is among the earliest SR proteins to assemble, since its organization preceded that of other SR proteins, like SERCA and RyR. After birth, the antibody against the N-terminus of obscurin stained the M-band while that against the C-terminus stained both M-bands and the Z-disks. Starting from postnatal day 1, ank1.5 was found at the level of both M-bands and Z-disks. Altogether, from these results we infer that exposure of some obscurin epitopes changes during skeletal muscle development, resulting in distinct, antibody-specific, localization pattern. Why this occurs is not clear, yet these data indicate that the organization of obscurin at different locations in the sarcomere changes during muscle development and that this might affect the interaction with ank1.5.     

A Radial Glia Gene Marker,Fatty Acid Binding Protein 7 (FABP7), Is Involved in Proliferation and Invasion of Glioblastoma Cells

Glioblastoma multiforme (GBM) is among the most deadly cancers. A number of studies suggest that a fraction of tumor cells with stem cell features (Glioma Stem-like Cells, GSC) might be responsible for GBM recurrence and aggressiveness. GSC similarly to normal neural stem cells, can form neurospheres (NS) in vitro, and seem to mirror the genetic features of the original tumor better than glioma cells growing adherently in the presence of serum. Using cDNA microarray analysis we identified a number of relevant genes for glioma biology that are differentially expressed in adherent cells and neurospheres derived from the same tumor. Fatty acid-binding protein 7 (FABP7) was identified as one of the most highly expressed genes in NS compared to their adherent counterpart. We found that down-regulation of FABP7 expression in NS by small interfering RNAs significantly reduced cell proliferation and migration. We also evaluated the potential involvement of FABP7 in response to radiotherapy, as this treatment may cause increased tumor infiltration. Migration of irradiated NS was associated to increased expression of FABP7. In agreement with this, in vivo reduced tumorigenicity of GBM cells with down-regulated expression of FABP7 was associated to decreased expression of the migration marker doublecortin. Notably, we observed that PPAR antagonists affect FABP7 expression and decrease the migration capability of NS after irradiation. As a whole, the data emphasize the role of FABP7 expression in GBM migration and provide translational hints on the timing of treatment with anti-FABP7 agents like PPAR antagonists during GBM evolution.     

Genetic Footprints of Iberian Cattle in America 500 Years after the Arrival of Columbus

Background

American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, and may have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources.

Methodology/Principal Findings

We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu.

Conclusions/Significance

Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental conditions.