Indolyl-naphthyl-maleimides as potent and selective inhibitors of protein kinase C-α/β.

The indolyl-naphthyl maleimide 7 is a potent inhibitor of the classical PKC isotypes α,β and shows excellent selectivity over the novel PKC isotypes δ,ε,η,θ and other kinases belonging to the AGC family. The SAR around 7 as well as the physico-chemical characteristics of selected derivatives and their activity in T and B cell activation and proliferation assays are discussed.

Discovery and profiling of a selective and efficacious Syk inhibitor.

We describe the discovery of selective and potent Syk inhibitor 11, which exhibited favorable PK profiles in rat and dog and was found to be active in a collagen-induced arthritis model in rats. Compound 11 was selected for further profiling, but, unfortunately, in GLP toxicological studies it showed liver findings in rat and dog. Nevertheless, 11 could become a valuable tool compound to investigate the rich biology of Syk in vitro and in vivo.

Novel ROCK inhibitors for the treatment of pulmonary arterial hypertension.

A novel class of selective inhibitors of ROCK1 and ROCK2 has been identified by structural based drug design. PK/PD experiments using a set of highly selective Rho kinase inhibitors suggest that systemic Rho kinase inhibition is linked to a reversible reduction in lymphocyte counts. These results led to the consideration of topical delivery of these molecules, and to the identification of a lead molecule 7 which shows promising PK and PD in a murine model of pulmonary hypertension after intra-tracheal dosing.

Syk inhibitors with high potency in presence of blood.

We describe two series of Syk inhibitors which potently abrogate Syk kinase function in enzymatic assays, cellular assays and in primary cells in the presence of blood. Introduction of a 7-aminoindole substituent led to derivatives with good kinase selectivity and little or no hERG channel inhibition (3b, 10c).

2,6-Naphthyridines as potent and selective inhibitors of the novel protein kinase C isozymes.

The present study describes a novel series of ATP-competitive PKC inhibitors based on the 2,6-naphthyridine template. Example compounds potently inhibit the novel Protein Kinase C (PKC) isotypes δ, ε, η, θ (in particular PKCε/η, and display a 10-100-fold selectivity over the classical PKC isotypes. The prototype compound 11 was found to inhibit PKCθ-dependent pathways in vitro and in vivo.

Identification of potent and selective amidobipyridyl inhibitors of protein kinase D.

The synthesis and biological evaluation of potent and selective PKD inhibitors are described herein. The compounds described in the present study selectively inhibit PKD among other putative HDAC kinases. The PKD inhibitors of the present study blunt phosphorylation and subsequent nuclear export of HDAC4/5 in response to diverse agonists.

Identification of orally available naphthyridine protein kinase D inhibitors.

A novel 2,6-naphthyridine was identified by high throughput screen (HTS) as a dual protein kinase C/D (PKC/PKD) inhibitor. PKD inhibition in the heart was proposed as a potential antihypertrophic mechanism with application as a heart failure therapy. As PKC was previously identified as the immediate upstream activator of PKD, PKD vs PKC selectivity was essential to understand the effect of PKD inhibition in models of cardiac hypertrophy and heart failure.

Diffusion- and perfusion-weighted MR imaging of transient focal cerebral ischaemia in mice.

Temporary focal ischaemia was induced in wild-type C57Black/6 mice by thread occlusion of the middle cerebral artery (MCA). Recirculation was started after 60 min and maintained for 24 h, after which the mouse brain was frozen in situ. Development of the cerebral infarct was monitored by diffusion-, perfusion- and T(2)-weighted magnetic resonance imaging (MRI) during ischaemia, during the early reperfusion period of 90 min, and at 24 h after reperfusion.

Regional and directional anisotropy of apparent diffusion coefficient in rat brain.

Quantitative diffusion maps were recorded in normal rat brain. In multi-slice sections covering the whole brain, strong variation of the apparent diffusion coefficient (ADC) was observed depending on slice position at constant gradient direction. Furthermore, a varying difference between apparent diffusion coefficients depending on gradient direction was found, reaching 32% in the cortex of the ventral-most horizontal sections while showing equal ADC on the dorsal cortex side.

1,4-Addition of a Terminal Phosphinidene Complex to [5]Metacyclophane.

Three novel aspects emerge for the reaction of [5]metacyclophane (1) with the (intermediate) phenylphosphinidene complex 2 to give the 7-phosphanorbornadiene 3. It is the first 1,4-addition of a phosphinidene complex to an unsaturated system, the first addition of a phosphinidene complex to a benzene ring, and the first [4+1] cycloaddition to an aromatic compound.

Nonsteroidal-induced benign strictures of the colon: a case report and review of the literature.

Colonic strictures are a rare complication reported to result from chronic use of sustained release formulations of indomethacin and diclofenac. Such strictures often present with associated mucosal ulceration and are thought to result from nonsteroidal antiinflammatory drug-induced alterations in enterocyte homeostasis. Strictures generally occur in the cecum, ascending, and proximal transverse colon with symptoms of occult blood loss, obstruction, changes in bowel habits, and rarely, perforation.

Inhibition of nonselective cation channels reduces focal ischemic injury of rat brain.

The effect of the novel inhibitor of receptor-activated and calcium store-operated nonselective cation channels, (RS)-(3,4-dihydro-6,7-dimethoxyisoquinoline-1-gamma 1)-2-phenyl-N, N-di-[2(2,3,4-trimethoxyphenyl) ethyl]acetamide (LOE 908 MS), on focal cerebral ischemia was studied in halothane-anesthetized rats submitted to permanent suture occlusion of the right middle cerebral artery (MCA). The treated group (n = 7) received subcutaneous injections of 30 mg/kg LOE 908 MS (in 1 ml saline) 10 min after vascular occlusion and again after 3 h. The untreated group (n = 11) was injected subcutaneously with 1 ml saline at the same times.

Potassium-induced cortical spreading depressions during focal cerebral ischemia in rats: contribution to lesion growth assessed by diffusion-weighted NMR and biochemical imaging.

In focal ischemia of rats, the volume of ischemic lesion correlates with the number of peri-infarct depolarizations. To test the hypothesis that depolarizations accelerate infarct growth, we combined focal ischemia with externally evoked spreading depression (SD) waves. Ischemic brain infarcts were produced in halothane-anaesthetized rats by intraluminal thread occlusion of the middle cerebral artery (MCA).

Reduction of excitotoxicity-induced brain damage by the competitive NMDA antagonist CGP 40116: a longitudinal study using diffusion-weighted imaging.

The cerebroprotective properties of the competitive N-methyl-D-aspartate (NMDA) antagonist CGP 40116 were evaluated in a rat model of excitotoxicity-induced brain damage using direct intrastriatal injection of quinolinic acid and subsequent (5 or 45 min later) i.p. administration of the drug.

Early-onset multifocal inflammation in the transforming growth factor beta 1-null mouse is lymphocyte mediated.

Transforming growth factor beta 1 (TGF beta 1)-null mice die fro complications due to an early-onset multifocal inflammatory disorder. We show here that cardiac cells are hyperproliferative and that intercellular adhesion molecule 1 (ICAM-1) is elevated. To determine which phenotypes are primarily caused by a deficiency in TGF beta 1 from those that are secondary to inflammation, we applied immunosuppressive therapy and genetic combination with the severe combined immunodeficiency (SCID) mutation to inhibit the inflammatory response.

High resolution quantitative relaxation and diffusion MRI of three different experimental brain tumors in rat.

The potential of quantitative parameter images of the relaxation times T1 and T2, the proton density rho and the apparent diffusion coefficient (ADC) to characterize three different experimental rat brain tumors (F98 glioma, RN6 Schwannoma, and E376 neuroblastoma) was studied. All parameter values, as determined in histologically confirmed regions of interest (ROI), were higher in edema than in tumor, which in turn were elevated with respect to normal brain. ROI values of ADC and T2 delivered statistically significant (P < 0.

Changes of relaxation times (T1, T2) and apparent diffusion coefficient after permanent middle cerebral artery occlusion in the rat: temporal evolution, regional extent, and comparison with histology.

The quantitative NMR parameters T1, T2, rho, and apparent diffusion coefficient (ADC) were determined during the 7 h after middle cerebral artery occlusion in rats. In the normal caudate-putamen (CP), 869 +/- 145 ms and 72 +/- 2 ms for T1 and for T2, respectively, were found; the corresponding values for cortex were 928 +/- 117 ms and 73 +/- 2 ms. The ADC showed significant dependence on gradient direction: diffusion along x resulted in 534 +/- 53 microns 2/s (CP) and 554 +/- 62 microns 2/s (cortex), and along y in 697 +/- 58 microns 2/s (CP) and 675 +/- 53 microns 2/s (cortex).

Simultaneous recording of EEG, DC potential and diffusion-weighted NMR imaging during potassium induced cortical spreading depression in rats.

Electrophysiological recording during in vivo NMR imaging for correlation of electrophysiological events with changes in NMR parameters has, until now, not been satisfactory. Here we present a method that uses specially prepared calomel electrodes for the continuous monitoring of both cortical steady potential and EEG during in vivo NMR imaging studies of experimental animal models. In order to demonstrate the reliability of this approach we elicited single episodes of cortical spreading depression in rats by intracortical potassium acetate injection, using an intracerebral micropipette.

Diffusion-weighted MR imaging of experimental brain tumors in rats.

Diffusion-weighted magnetic resonance imaging was used for the description of experimental brain tumors in rat. To validate this approach, diffusion-weighted images (DWI) were compared with native T1- and T2-weighted images, and with T1-weighted images following contrast enhancement with the tumor-specific contrast agent manganese (III) tetraphenylporphine sulfonate (MnTPPS). Three tumor types were studied: F98 glioma, RN6 Schwannoma, and E376 neuroblastoma.

Onset and progression of pathological lesions in transforming growth factor-beta 1-deficient mice.

Null-mutant (knockout) mice were obtained through disruption of the sixth exon of the endogenous transforming growth factor-beta 1 allele in murine embryonic stem cells via homologous recombination. Mice lacking transforming growth factor-beta 1 (mutants) were born grossly indistinguishable from wild-type littermates. With time, mutant mice exhibited a wasting phenotype that manifested itself in severe weight loss and dishevelled appearance (between 15 and 36 days of age).

Quantitative diffusion MR imaging of cerebral tumor and edema.

The detection of brain tumors using standard techniques of qualitative, relaxation-weighted magnetic resonance imaging (MRI) requires the application of contrast agents. We investigated whether or not it is possible to use diffusion-weighted MRI to localize tumors without contrast enhancement. Three different experimental rat brain tumors were studied: F98 glioma, RN6 Schwannoma and E376 neuroblastoma.

In vivo relaxometry of three brain tumors in the rat: effect of Mn-TPPS, a tumor-selective contrast agent.

T1 and T2 were determined simultaneously in vivo at 4.7 T in implanted rat brain tumors. Three different tumor cell lines were implanted in the right caudate nucleus: the F98 glioma, the E367 neuroblastoma, and the RN6 schwannoma.