The Role of Smad3 in the Realization of the Growth Potential of Different Types of Neural Progenitor Cells and the Secretory Function of Neuroglia.

The features of the participation of Smad3 in the functioning of neural stem cells (NSC), neuronal committed precursors (NCP), and neuroglial elements were studied in vitro. It was found that this intracellular signaling molecule enhances the clonogenic and proliferative activities of NCP and inhibits specialization of neuronal precursors. At the same time, Smad3 does not participate in the realization of the growth potential of NSC. With regard to the secretory function (production of neurotrophic growth factors) of neuroglial cells, the stimulating role of Smad3-mediated signaling was shown. These results indicate the promise of studying the possibility of using Smad3 as a fundamentally new target for neuroregenerative agents.

Functional State of Various Types of Regenerative-Competent Neural Tissue Cells in ß-Amyloid-Induced Neurodegeneration.

We analyzed the content and functional activity of various types of regenerative-competent cells of the subventricular zone of the cerebral hemispheres in experimental mice under conditions of in vitro modeling of ß-amyloid-induced neurodegeneration. Fundamentally different (opposite) effects of ß-amyloid on functional activity of multipotent neural stem cells (NSC) and neuronal committed progenitors (NCP) were revealed. ß-Amyloid suppressed proliferation of NSC and stimulated their differentiation. At the same time, an increase in the mitotic activity of NCP was observed with a decrease in the intensity of their specialization. These changes in the functioning of progenitor cells developed against the background of a significant drop in the production of neurotrophic growth factors by neuroglia. These phenomena indicate marked discoordination of the activity of regenerative-competent cells of various types.

The Role of JAKs and STAT3 in Regulation of Regenerative-Competent Cells of the Nervous Tissue in ß-Amyloid-Induced Neurodegeneration.

We studied the role of JAKs and STAT3 in the growth potential of neural stem cells and the humoral neurotrophic function of neuroglia in modeling ß-amyloid-induced neurodegeneration in vitro. It was found that these signaling molecules do not participate in the neural stem cell functioning, and JAKs plays an inhibitory role (realized, however, without STAT3) in the secretion of neurotrophins by glial cells under conditions of their optimal vital activity. The effect of ß-amyloid on progenitor cells is accompanied by the appearance of a "negative" effect of STAT3 signaling pathway on their proliferative activity. At the same time, JAKs and STAT3 during neurodegeneration stimulate specialization/differentiation of neural stem cells and production of growth factors by neuroglial cells. These results indicate the possibility of stimulating proliferation of neural stem cells coupled with their differentiation by using selective STAT3 inhibitors.

The Role of MARK ERK1/2 and p38 in Regulation of Functions of Neural Stem Cells and Neuroglia under Conditions of ß-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 ß-amyloid-induced neurodegeneration. It was shown that amyloid-ß 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 ß-amyloid-induced neurodegeneration.

Erythropoiesis-Stimulating Properties of Anthocyanin-Containing Complex from Sorbus aucuparia L. in Cytostatic Anemic Syndrome in Mice with Lewis Lung Carcinoma.

The results of studying the effect of the anthocyanin-containing complex from Sorbus aucuparia L. on the main indicators of erythropoiesis in the blood and bone marrow of mice with Lewis lung carcinoma against the background of doxorubicin administration were presented. It was shown that administration of the anthocyanin-containing complex from S. aucuparia L. to animals with the tumor prevented the development of anemic syndrome by promoting regeneration of the erythropoiesis after its depletion caused by single administration of a cytostatic agent.

Mechanisms underlying modulation of the pharmacological properties of pegylated erythropoietin by pegylated hyaluronate-endo-ß-N-acetylhexosaminidase.

Pegylated hyaluronate-endo-ß-N-acetylhexosaminidase was shown to potentiate significantly the hemostimulatory effect of pegylated erythropoietin. It was found that enhanced production of hemopoietin by adherent and non-adherent cells of the hemopoiesis-inducing microenvironment and elevated serum content of endogenous erythropoietin along with increased susceptibility of erythroid precursors to pegylated erythropoietin underlay this phenomenon.

Potentiation of hemostimulating effects of erythropoietin with pegylated hyaluronate-endo-ß-N-acetylhexosaminidase.

Pegylated hyaluronate-endo-ß-N-acetylhexosaminidase considerably potentiates the hemostimulating effects of erythropoietin due to intensification of proliferation and differentiation of erythroid precursors against the background of enhanced secretion of hemopoietins by nonadherent hemopoiesis-inducing environment cells and elevation of serum erythropoietin concentration. The use of the enzyme allows 10-fold reduction of the maximum effective erythropoietin dose.