Crystal structures of human and mouse ketohexokinase provide a structural basis for species- and isoform-selective inhibitor design.

A molecular understanding of the proteins involved in fructose metabolism is essential for controlling the current spread of fructose-related obesity, diabetes and related adverse metabolic states in Western populations. Fructose catabolism starts with the phosphorylation of D-fructose to fructose 1-phosphate by ketohexokinase (KHK). KHK exists in two alternatively spliced isoforms: the hepatic and intestinal isoform KHK-C and the peripheral isoform KHK-A.

Discovery of BI-2545: A Novel Autotaxin Inhibitor That Significantly Reduces LPA Levels in Vivo.

In an effort to find new therapeutic interventions addressing the unmet medical need of patients with idiopathic pulmonary fibrosis, we initiated a program to identify new autotaxin (ATX) inhibitors. Starting from a recently published compound (PF-8380), we identified several highly potent ATX inhibitors with improved pharmacokinetic and safety profiles. Further optimization efforts resulted in the identification of a single-digit nanomolar lead compound (BI-2545) that shows substantial lowering of LPA in vivo and is therefore considered a valuable tool for further studies.

Ultrafast and Predictive Mass Spectrometry-Based Autotaxin Assays for Label-Free Potency Screening.

Autotaxin (ATX) is a promising drug target for the treatment of several diseases, such as cancer and fibrosis. ATX hydrolyzes lysophosphatidyl choline (LPC) into bioactive lysophosphatidic acid (LPA). The potency of ATX inhibitors can be readily determined by using fluorescence-based LPC derivatives.

Selective CB2 receptor agonists. Part 3: the optimization of a piperidine-based series that demonstrated efficacy in an in vivo neuropathic pain model.

A novel class of potent cannabinoid receptor 2 (CB2) agonists based on a (S)-piperidine scaffold was identified using ligand-based pharmacophore models. Optimization of solubility and metabolic stability led to the identification of several potent CB2 agonists (e.g.

Selective CB2 receptor agonists. Part 2: Structure-activity relationship studies and optimization of proline-based compounds.

Through a ligand-based pharmacophore model (S)-proline based compounds were identified as potent cannabinoid receptor 2 (CB2) agonists with high selectivity over the cannabinoid receptor 1 (CB1). Structure-activity relationship investigations for this compound class lead to oxo-proline compounds 21 and 22 which combine an impressive CB1 selectivity profile with good pharmacokinetic properties. In a streptozotocin induced diabetic neuropathy model, 22 demonstrated a dose-dependent reversal of mechanical hyperalgesia.

Inhibition of CDK5 is protective in necrotic and apoptotic paradigms of neuronal cell death and prevents mitochondrial dysfunction.

Previous studies suggested that pro-apoptotic stimuli may trigger a fatal reactivation of cell cycle elements in postmitotic neurons. Supporting this hypothesis, small molecule inhibitors of cyclin-dependent kinases (CDKs), which are known primarily as cell cycle regulators, are neuroprotective. However, available CDK inhibitors cannot discriminate between the different members of the CDK family and inhibit also CDK5, which is not involved in cell cycle control.

Elevated vulnerability to oxidative stress-induced cell death and activation of caspase-3 by the Swedish amyloid precursor protein mutation.

The Swedish double mutation (KM670/671NL) of amyloid precursor protein (APPsw) is associated with early-onset familial Alzheimer's disease (FAD) and results in from three- to sixfold increased beta-amyloid production. The goal of the present study was to elucidate the effects of APPsw on mechanisms of apoptotic cell death. Therefore, PC12 cells were stably transfected with human APPsw.

A pathogenic presenilin-1 deletion causes abberrant Abeta 42 production in the absence of congophilic amyloid plaques.

Familial Alzheimer's disease (FAD) is frequently associated with mutations in the presenilin-1 (PS1) gene. Almost all PS1-associated FAD mutations reported so far are exchanges of single conserved amino acids and cause the increased production of the highly amyloidogenic 42-residue amyloid beta-peptide Abeta42. Here we report the identification and pathological function of an unusual FAD-associated PS1 deletion (PS1 DeltaI83/DeltaM84).

Glycine 384 is required for presenilin-1 function and is conserved in bacterial polytopic aspartyl proteases.

Endoproteolysis of beta-amyloid precursor protein (betaAPP) and Notch requires conserved aspartate residues in presenilins 1 and 2 (PS1 and PS2). Although PS1 and PS2 have therefore been proposed to be aspartyl proteases, no homology to other aspartyl proteases has been found. Here we identify homology between the presenilin active site and polytopic aspartyl proteases of bacterial origin, thus supporting the hypothesis that presenilins are novel aspartyl proteases.

A loss of function mutant of the presenilin homologue SEL-12 undergoes aberrant endoproteolysis in Caenorhabditis elegans and increases abeta 42 generation in human cells.

The familial Alzheimer's disease-associated presenilins (PSs) occur as a dimeric complex of proteolytically generated fragments, which functionally supports endoproteolysis of Notch and the beta-amyloid precursor protein (betaAPP). A homologous gene, sel-12, has been identified in Caenorhabditis elegans. We now demonstrate that wild-type (wt) SEL-12 undergoes endoproteolytic cleavage in C.

Separation of presenilin function in amyloid beta-peptide generation and endoproteolysis of Notch.

Most of the genetically inherited Alzheimer's disease cases are caused by mutations in the presenilin genes, PS1 and PS2. PS mutations result in the enhanced production of the highly amyloidogenic 42/43 amino acid variant of amyloid beta-peptide (Abeta). We have introduced arbitrary mutations at position 286 of PS1, where a naturally occurring PS1 mutation has been described (L286V).

Presenilin-1 differentially facilitates endoproteolysis of the beta-amyloid precursor protein and Notch.

Mutations in the presenilin-1 (PS1) gene are associated with Alzheimer's disease and cause increased secretion of the neurotoxic amyloid-beta peptide (Abeta). Critical intramembraneous aspartates at residues 257 and 385 are required for the function of PS1 protein. Here we investigate the biological function of a naturally occurring PS1 splice variant (PS1 Deltaexon 8), which lacks the critical aspartate 257.

Amyloidogenic function of the Alzheimer's disease-associated presenilin 1 in the absence of endoproteolysis.

Alzheimer's disease (AD) is characterized by the invariant accumulation of senile plaques predominantly composed of the pathologically relevant 42-amino acid amyloid beta-peptide (Abeta42). The presenilin (PS) proteins play a key role in Abeta generation. FAD-associated mutations in PS1 and PS2 enhance the production of Abeta42, and PS1 is required for physiological Abeta production, since a gene knockout of PS1 and dominant negative mutations of PS1 abolish Abeta generation.

Zebrafish (Danio rerio) presenilin promotes aberrant amyloid beta-peptide production and requires a critical aspartate residue for its function in amyloidogenesis.

Alzheimer's disease (AD) is characterized by the invariable accumulation of senile plaques composed of amyloid beta-peptide (Abeta). Mutations in three genes are known to cause familial Alzheimer's disease (FAD). The mutations occur in the genes encoding the beta-amyloid precursor protein (betaAPP) and presenilin (PS1) and PS2 and cause the increased secretion of the pathologically relevant 42 amino acid Abeta42.

A loss of function mutation of presenilin-2 interferes with amyloid beta-peptide production and notch signaling.

Presenilin-1 (PS1) facilitates gamma-secretase cleavage of the beta-amyloid precursor protein and the intramembraneous cleavage of Notch1. Although Alzheimer's disease-associated mutations in the homologous presenilin (PS2) gene elevate amyloid beta-peptide (Abeta42) production like PS1 mutations, here we demonstrate that a gene ablation of PS2 (unlike that of PS1) in mice does not result in a severe phenotype resembling that of Notch-ablated animals. To investigate the amyloidogenic function of PS2 more directly, we mutagenized a conserved aspartate at position 366 to alanine, because the corresponding residue of PS1 is known to be required for its amyloidogenic function.

The biological and pathological function of the presenilin-1 Deltaexon 9 mutation is independent of its defect to undergo proteolytic processing.

The two homologous presenilins are key factors for the generation of amyloid beta-peptide (Abeta), since Alzheimer's disease (AD)-associated mutations enhance the production of the pathologically relevant 42-amino acid Abeta (Abeta42), and a gene knockout of presenilin-1 (PS1) significantly inhibits total Abeta production. Presenilins undergo proteolytic processing within the domain encoded by exon 9, a process that may be closely related to their biological and pathological activity. An AD-associated mutation within the PS1 gene deletes exon 9 (PS1Deltaexon9) due to a splicing error and results in the accumulation of the uncleaved full-length protein.

Expression of Alzheimer's disease-associated presenilin-1 is controlled by proteolytic degradation and complex formation.

Numerous mutations causing early onset Alzheimer's disease have been identified in the presenilin (PS) genes, particularly the PS1 gene. Like the mutations identified within the beta-amyloid precursor protein gene, PS mutations cause the increased generation of a highly neurotoxic variant of amyloid beta-peptide. PS proteins are proteolytically processed to an N-terminal approximately 30-kDa (NTF) and a C-terminal approximately 20-kDa fragment (CTF20) that form a heterodimeric complex.

Dependence of cerebrospinal fluid Tau protein levels on apolipoprotein E4 allele frequency in patients with Alzheimer's disease.

Consistent pathological hallmarks of Alzheimer's disease (AD) are the formation of brain amyloid and neurofibrillary tangles (NFTs). Levels of the major protein component of NFTs, the microtubule associated protein Tau, were shown to be increased in cerebrospinal fluid (CSF) of AD patients as compared to age-matched controls. The presence of apolipoprotein E-epsilon 4 allele (APOE4) is a risk factor for sporadic and familial late-onset AD.

Characterisation of two intronic nuclear-matrix-attachment regions in the human DNA topoisomerase I gene.

We identify two high-affinity matrix-attachment regions (MAR elements) located in two introns of the human DNA topoisomerase I gene (TOP1). These intronic MAR elements, designated MI and MII, are specifically bound by the nuclear matrix and partition with scaffolds in vitro. One of these MAR elements, MII, is part of a genomic region which is hypersensitive for endogenous nucleases.

Characterization of SAF-A, a novel nuclear DNA binding protein from HeLa cells with high affinity for nuclear matrix/scaffold attachment DNA elements.

We identified four proteins in nuclear extracts from HeLa cells which specifically bind to a scaffold attachment region (SAR) element from the human genome. Of these four proteins, SAF-A (scaffold attachment factor A), shows the highest affinity for several homologous and heterologous SAR elements from vertebrate cells. SAF-A is an abundant nuclear protein and a constituent of the nuclear matrix and scaffold.

Expression of the topoisomerase I gene in serum stimulated human fibroblasts.

We have determined the levels of mRNA coding for human type I DNA topoisomerase (EC 5.99.1.

Expression of the type I DNA topoisomerase gene in adenovirus-5 infected human cells.

The amount of topoisomerase I specific mRNA increases three- to fivefold during the early phase of infection of HeLa cells with adenovirus-5. The observed increase in specific mRNA is mainly due to an increased rate of transcription of the gene. In human 293 cells, which constitutively express the viral E1A and E1B genes, we determined an elevated level of topoisomerase I mRNA, comparable to the amount of mRNA present in HeLa cells early after infection with adenovirus.

Psychomotor disturbances in psychiatric patients as a possible basis for new attempts at differential diagnosis and therapy. III. Cross validation study on depressed patients: the psychotic motor syndrome as a possible state marker for endogenous depression.

This study investigates the presence and course of motor symptoms in endogenous (n = 42) and non-endogenous (n = 15) depressed patients (both medicated and unmedicated) in comparison to 15 healthy control persons. As in our previous studies on schizophrenic and depressed patients, we used a motor test battery, which consisted of the Motorische Leistungsserie, a modified version of the Lincoln Oseretzky Motor Development Scale and the motor subtest of the Luria Nebraska Neuropsychological Battery. Previous findings had suggested the existence of a psychotic motor syndrome (PMS) in endogenous depressed patients (and schizophrenics), involving disturbances of the lips and tongue, fine and gross movements of the dominant right hand and the complex motor coordination of the extremities.