[The effect of a neuroprotective dose of isatin or deprenyl to mice on the profile of brain isatin-binding proteins]

The neuroprotective effect of isatin in the rotenone-induced model of parkinonism in rats: the study of delayed effects

Parkinsonism in rats induced by the pesticide rotenone is one of the most adequate models of Parkinson's disease (PD). Isatin (indole-2,3-dione) is an endogenous regulator found in mammals and humans and exhibiting a wide range of biological activities mediated by numerous isatin-binding proteins, including those associated with neurodegenerative pathology. A course of rotenone administration to rats caused behavioral impairments and changes in the profile and relative content of isatin-binding proteins in the brain. In this study, we have investigated the delayed neuroprotective effect of isatin (5 days after completion of the course of rotenone administration) on behavioral reactions and the relative content of isatin-binding proteins in the brain of rats with rotenone-induced experimental parkinsonism. Although during this period the rats retained locomotor dysfunction, the proteomic analysis data (profile of isatin-binding proteins in the brain and changes in their relative content) differed from the results obtained immediately after completion of the course of rotenone administration. Moreover, all isatin-binding proteins with altered relative content changed during this period are associated to varying degrees with neurodegeneration (many with Parkinson's and Alzheimer's diseases).

Tryptophan Metabolites as Mediators of Microbiota-Gut-Brain Communication: Focus on Isatin

Isatin (indole-2,3-dione) is an endogenous regulator, exhibiting various behavioral, biological, and pharmacological activities. Synthesis of isatin includes several crucial stages: cleavage of the tryptophan side chain and subsequent oxidation of the indole nucleus. Although these stages require concerted action of bacterial and host enzymes, there are two pathways of isatin formation: the host and bacterial pathways. Isatin acts as a neuroprotector in different experimental models of neurodegeneration. Its effects are realized via up- and downregulation of isatin-responsive genes and via interaction with numerous isatin-binding proteins identified in the brain. The effect of isatin on protein-protein interactions in the brain may be important for realization of weak inhibition of multiple receptor targets.

A Neuroprotective Dose of Isatin Causes Multilevel Changes Involving the Brain Proteome: Prospects for Further Research

Isatin (indole-2,3-dione) is an endogenous regulator, exhibiting a wide range of biological and pharmacological activities. At doses of 100 mg/kg and above, isatin is neuroprotective in different experimental models of neurodegeneration. Good evidence exists that its effects are realized via interaction with numerous isatin-binding proteins identified in the brain and peripheral tissues studied. In this study, we investigated the effect of a single dose administration of isatin to mice (100 mg/kg, 24 h) on differentially expressed proteins and a profile of the isatin-binding proteins in brain hemispheres. Isatin administration to mice caused downregulation of 31 proteins. However, these changes cannot be attributed to altered expression of corresponding genes. Although at this time point isatin influenced the expression of more than 850 genes in brain hemispheres (including 433 upregulated and 418 downregulated genes), none of them could account for the changes in the differentially expressed proteins. Comparative proteomic analysis of brain isatin-binding proteins of control and isatin-treated mice revealed representative groups of proteins sensitive to isatin administration. Control-specific proteins (n = 55) represent specific targets that interact directly with isatin. Appearance of brain isatin-binding proteins specific to isatin-treated mice (n = 94) may be attributed to the formation of new clusters of protein–protein interactions and/or novel binding sites induced by a high concentration of this regulator (ligand-induced binding sites). Thus, isatin administration produces multiple effects in the brain, which include changes in gene expression and also profiles of isatin-binding proteins and their interactomes. Further studies are needed for deeper insight into the mechanisms of the multilevel changes in the brain proteome induced by isatin. In the context of the neuroprotective action, these changes may be aimed at interruption of pathological links that begin to form after initiation of pathological processes.