paullone and Alzheimer-Disease

Neurodegenerative diseases are among the most challenging diseases with poorly known mechanism of cause and paucity of complete cure. Out of all the neurodegenerative diseases, Alzheimer's disease is the most devastating and loosening of thinking and judging ability disease that occurs in the old age people. Many hypotheses came forth in order to explain its causes. In this review, we have enlightened Glycogen Synthase Kinase-3 which has been considered as a concrete cause for Alzheimer's disease. Plaques and Tangles (abnormal structures) are the basic suspects in damaging and killing of nerve cells wherein Glycogen Synthase Kinase-3 has a key role in the formation of these fatal accumulations. Various Glycogen Synthase Kinase-3 inhibitors have been reported to reduce the amount of amyloid-beta as well as the tau hyperphosphorylation in both neuronal and nonneuronal cells. Additionally, Glycogen Synthase Kinase-3 inhibitors have been reported to enhance the adult hippocampal neurogenesis in vivo as well as in vitro. Keeping the chemotype of the reported Glycogen Synthase Kinase-3 inhibitors in consideration, they may be grouped into natural inhibitors, inorganic metal ions, organo-synthetic, and peptide like inhibitors. On the basis of their mode of binding to the constituent enzyme, they may also be grouped as ATP, nonATP, and allosteric binding sites competitive inhibitors. ATP competitive inhibitors were known earlier inhibitors but they lack efficient selectivity. This led to find the new ways for the enzyme inhibition.

Topics: Alzheimer Disease; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Diabetes Mellitus; Glycogen Synthase Kinase 3; Hippocampus; Humans; Hypoglycemic Agents; Inflammation; Molecular Targeted Therapy; Neoplasms; Protein Kinase Inhibitors

Paullones constitute a new family of benzazepinones with promising antitumoral properties. They were recently described as potent, ATP-competitive, inhibitors of the cell cycle regulating cyclin-dependent kinases (CDKs). We here report that paullones also act as very potent inhibitors of glycogen synthase kinase-3beta (GSK-3beta) (IC50: 4-80 nM) and the neuronal CDK5/p25 (IC50: 20-200 nM). These two enzymes are responsible for most of the hyperphosphorylation of the microtubule-binding protein tau, a feature observed in the brains of patients with Alzheimer's disease and other neurodegenerative 'taupathies'. Alsterpaullone, the most active paullone, was demonstrated to act by competing with ATP for binding to GSK-3beta. Alsterpaullone inhibits the phosphorylation of tau in vivo at sites which are typically phosphorylated by GSK-3beta in Alzheimer's disease. Alsterpaullone also inhibits the CDK5/p25-dependent phosphorylation of DARPP-32 in mouse striatum slices in vitro. This dual specificity of paullones may turn these compounds into very useful tools for the study and possibly treatment of neurodegenerative and proliferative disorders.

Topics: Adenosine Triphosphate; Alzheimer Disease; Animals; Apoptosis; Benzazepines; Binding, Competitive; Calcium-Calmodulin-Dependent Protein Kinases; Cells, Cultured; Corpus Striatum; Cyclin-Dependent Kinase 5; Cyclin-Dependent Kinases; Dopamine and cAMP-Regulated Phosphoprotein 32; Enzyme Activation; Enzyme Inhibitors; Genetic Vectors; Glycogen Synthase Kinase 3; Glycogen Synthase Kinases; Growth Inhibitors; Mice; Nerve Tissue Proteins; Nucleopolyhedroviruses; Phosphoproteins; Phosphorylation; Protein Processing, Post-Translational; Recombinant Fusion Proteins; Spodoptera; tau Proteins; Transfection