Specific Features of Intracellular Signal Transduction in the Regulation of Functions of Neural Stem Cells and Committed Neuronal Progenitors

The Role of cAMP-Dependent Intracellular Signaling Pathways in the Regulation of the Functions of Neural Stem Cells and Neuroglial Cells in Amyloid-β-Induced Neurodegeneration

Under conditions of neurodegeneration modeled in vitro by the β-amyloid peptide-(25-35) fragment (Aβ25-35), we studied the role of individual links of cAMP-dependent intracellular signaling pathways in determining the proliferation and differentiation status of neural stem cells (NSCs) and colony-stimulating activity of supernatants from neuroglial cells. The important role of intracellular cAMP and PKA in the inhibition of the progression of the NSC cell cycle and stimulation of the process of their specialization induced by Aβ25-35 was found. The selective ability of PKA to block the production of factors constituting colony-stimulating activity by neuroglial cells under conditions of their cultivation in vitro with a neurotoxic agent was revealed. Our results suggests that inhibitors of adenylate cyclase and PKA can increase the degree of implementation of the growth potential of NSCs and conjugation of the processes of their proliferation and differentiation in Alzheimer's disease. At the same time, selective PKA blockers can also induce the production of NSC-stimulating factors by neuroglial cells.

Psychopharmacological Effects of Stimulation of the Functions of Neural Stem Cells by STAT3 Inhibitor under Conditions of Modeled Ethanol-Induced Encephalopathy

The psychopharmacological effects of a stimulator of functions of progenitor cells of the nervous tissue STAT3 inhibitor (STAT3 Inhibitor XIV, LLL12) were studied under conditions of modeled alcoholic encephalopathy in C57BL/6 mice. The pharmacological agent corrected the parameters of exploratory behavior (characterizing predominantly cognitive activity) in the experimental animals at the late terms of observation. At the same time, the reproducibility of the conditioned passive avoidance response developed at the beginning of the course STAT3 inhibitor administration decreased. These effects developed against the background of a significant increase in the content of neural stem cells and their proliferative activity in the paraventricular zone of the brain.

The Role of MARK ERK1/2 and p38 in Regulation of Functions of Neural Stem Cells and Neuroglia under Conditions of β-Amyloid-Induced Neurodegeneration

The role of ERK1/2 and p38 in the realization of the growth potential of neural stem cells and secretion of neurotrophic growth factors by glial cells was studied using in vitro model of β-amyloid-induced neurodegeneration. It was shown that amyloid-β fragment 25-35 significantly inhibits the cell cycle progression of neural stem cells against the background of stimulation of their differentiation and reduced production of growth factors by neuroglia. The inhibitory role of ERK1/2 and p38 in relation to the proliferative activity of neural stem cells and the secretory activity of glial elements was revealed. ERK1/2 and p38 inhibitors increased proliferation of progenitor cells of the nervous tissue and reduced the intensity of their specialization, as well as stimulated production of growth factors by neuroglial cells under conditions of simulated β-amyloid-induced neurodegeneration.

Role of JNK in the Regulation of Xenobiotic Metabolizing Function of Hepatocytes

We studied the role of JNK in the regulation of the metabolism of xenobiotic venlafaxine by liver cells under in vitro conditions. The inhibitory role of this protein kinase in the biotransformation of this psychotropic agent by hepatocytes was demonstrated. JNK inhibitor added to the liver homogenate containing antidepressant enhanced and accelerated the formation of the only pharmacologically active venlafaxine metabolite O-desmethylvenlafaxine in the cell suspension. The results show the promise of studying modifiers of activity of intracellular signaling molecules (in particular, mitogen-activated protein kinases) to develop a fundamentally new approach to control the transformation of xenobiotics and to create a new class of pharmaceutical, target regulators of drugs metabolism.

Role of MAPK ERK1/2 and p38 in the Regulation of Secretory Functions of Different Populations of Neuroglia in Ethanol-Induced Neurodegeneration

We studied the participation of ERK1/2 and p38 in secretion of neurotrophic growth factors by various types of neuroglia under conditions of in vitro and in vivo modeled ethanol-induced neurodegeneration. The inhibitory role of these protein kinases in the production of neurotrophins by intact astrocytes and the absence of their participation in the regulation of functions of oligodendrocytes and microglial cells were shown. Under conditions of ethanol neurotoxicity, the role of ERK1/2 and p38 in the production of growth factors by glial elements was significantly changed. Neurodegeneration modeled in vitro led to inversion of the role of both protein kinases in the secretion of neurotrophins by astroglia and inhibition of the cytokine-synthesizing function of oligodendrocytes and microglial cells by ERK1/2 and p38. In mice receiving ethanol per os for a long time (as well as in cells in vitro exposed to ethanol), mitogen-activated kinases stimulated the function of astrocytes and inhibited the production of growth factors by microglial cells. At the same time, chronic alcoholization was accompanied by the appearance of the stimulating role of ERK1/2 and p38 in the implementation of the secretory function by oligodendrocytes.