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We studied the effect of NF-κB blockade on the state of various pools of progenitor cells of the nervous tissue and the psychoneurological status of experimental animals with modeled Alzheimer's disease. Administration of scopolamine hydrobromide to C57BL/6 mice for 4 weeks was accompanied by the development of "persistent" disturbances in the orientation and exploratory behavior and mnestic function. An ameliorating effect of the NF-κB inhibitor on these cognitive disorders typical of senile dementia was revealed. At the same time, we observed an increase in the content of neural stem cells and committed neuronal precursors in the subventricular zone of the brain., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

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., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

We performed a comparative in vitro study of the involvement of NF-κB, PI3K, cAMP, ERK1/2, p38, JAKs, STAT3, JNK, and p53-dependent intracellular signaling in the functioning of neural stem cells (NSC) under the influence of basic fibroblast growth factor (FGF) and FGF receptor agonist, diterpene alkaloid songorine. The significant differences in FGFR-mediated intracellular signaling in NSC were revealed for these ligands. In both cases, stimulation of progenitor cell proliferation occurs with the participation of NF-κB, PI3K, ERK1/2, JAKs, and STAT3, while JNK and p53, on the contrary, inhibit cell cycle progression. However, under the influence of songorin, cAMP- and p38-mediated cascades are additionally involved in the transmission of the NSC division-activating signal. In addition, unlike FGF, the alkaloid stimulates progenitor cell differentiation by activating ERK1/2, p38, JNK, p53, and STAT3., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

We studied the involvement of cAMP and PKA in the regulation of the secretion of neurotrophic growth factors by macro-and microglial cells in the model of ethanol-induced neurodegeneration in vitro and in vivo. The stimulating role of cAMP in the secretion of neurotrophins by intact astrocytes and oligodendrocytes was shown, while PKA does not participate in this process. On the contrary, the inhibitory role of cAMP (implemented via PKA activation) in the production of neurogenesis stimulators by microglial cells under conditions of optimal vital activity was found. Under the influence of ethanol, the role of cAMP and PKA in the production of growth factors by macroglial cells was considerably changed. The involvement of PKA in the cAMP-dependent signaling pathways and inversion of the role of this signaling pathway in the implementation of the neurotrophic secretory function of astrocytes and oligodendrocytes, respectively, directly exposed to ethanol in vitro were noted. Long-term exposure of the nervous tissue to ethanol in vivo led to the loss of the stimulating role of cAMP/PKA signaling on neurotrophin secretion by macroglial cells without affecting its inhibitory role in the regulation of this function in microglial cells., (© 2023. Springer Science+Business Media, LLC, part of Springer Nature.)

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., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature.)

The effects of JAK and STAT3 inhibitors on the production of neurotrophic growth factors by different types of neuroglial cells were studied under conditions of in vitro and in vivo models of ethanol-induced neurodegeneration. It was shown that these signaling molecules do not participate in the secretion of neurotrophins by intact astrocytes and oligodendrocytes. The inhibitory role of JAK in the regulation of this function of microglial cells was revealed. We also revealed significant changes in the role of JAK and the presence of STAT3 specifics within the framework of JAK/STAT signaling in the production of growth factors by various glial elements under the influence of ethanol. Neurodegeneration modeled in vitro led to the appearance of a "negative" effect of STAT3 on the production of neurogenesis stimulants by all types of glial cells. Moreover, the role of STAT3 in oligodendrocytes and microglial cells generally corresponded to that of JAK/STAT signaling. In astrocytes, only selective blockade of STAT3 (but not JAK) led to stimulation of their function. In mice subjected to prolonged peroral alcoholization, the neuroglial responses to the pharmacological regulation of JAK/STAT signaling were different. An inversion of the role of JAK and STAT3 in the production of neurotrophins by oligodendrocytes was noted. In addition, JAK inhibitor did not stimulate secretory function of microglial cells under conditions of prolonged exposure to ethanol in vivo., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature.)

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., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

Under conditions of steady-state hemopoiesis, nuclear factor NF-κB, in contrast to MAP kinase p38, plays an important role in the maintenance of the initial level of secretory activity of monocytes. The increase in the production of G-CSF under stress conditions (10-h immobilization) is mainly regulated by the alternative p38MARK signaling pathway via activation of p38 synthesis. It was shown that under conditions of cytostatic-induced myelosuppression, the production of protein kinase p38 in cells decreases, and it, like NF-κB, is not the main one in the production of hemopoietin by mononuclear phagocytes., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

We studied the participation of JNK and p53 in the realization of the growth potential of different types of progenitors of the subventricular zone of mouse brain and secretion of neurotrophins by glial cells. The stimulating role of these signaling molecules in mitotic activity and specialization of multipotent neural stem cells was shown. It was found that JNK and p53 do not participate in the regulation of committed neuronal progenitor cells (clonogenic PSA-NCAM + cells). A dependence of neurotrophic growth factors in individual populations of neuroglia on activity of these protein kinase and transcription factor was revealed. The role of JNK and p53 in astrocytes consists in stimulation of their secretion, and in microglial cells, on the contrary, in its inhibition. The secretory neurotrophic function of oligodendrogliocytes is not associated with JNK and p53 activity., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

We studied the role of NF-κB-, cAMP/PKA-, JAKs/STAT3-, ERK1/2-, p38-, JNK- and p53- mediated signaling pathways in the realization of the growth potential of neural stem cells and committed neuronal progenitors under in vitro conditions. The method of pharmacological blockade with selective inhibitors of individual signaling molecules revealed some principal differences in their role in the determination of the proliferation and differentiation status of progenitor cells of different classes. Analysis of the peculiarities of intracellular signaling in cells and comparison of the role of its individual elements attest to the prospects of developing new drugs with neuroregenerative activity based on STAT3 inhibitors or JNK activators. These modulations of activity of signaling molecules can stimulate the realization of the growth potential of committed neuronal progenitors and neutral stem cells, respectively. The blockade of STAT3 and an increase in the content of phosphorylated forms of JNK had no "negative" effects on the functioning of multipotent neural stem cells and committed neuronal progenitors, respectively.

The role of NF-κВ in the realization of the growth potential of neural progenitor cells from the subventricular area of cerebral hemispheres and secretion of neurotrophins by glial elements was studied under conditions of in vitro and in vivo modeled ethanol-induced neurodegeneration. It was found that this transcription factor does not participate in the regulation of mitotic activity of neural stem cells and neuronal-committed progenitors under optimal conditions and under the influence of ethanol in vitro. At the same time, NF-κВ suppresses differentiation/maturation of neural progenitor cells. Long-term peroral administration of ethanol to mice was accompanied by the inhibitory influence of NF-κВ on proliferation of progenitor cells. Blockade of NF-κВ in neural stem cells and committed neuronal precursors in animals with neurodegeneration induced cell cycle progression in these elements. The involvement of NF-κВ in the secretory function of astrocytes and oligodendrogliocytes was established. Inactivation of the nuclear transcription factor reduced the production of neurotrophins, in particular, in the case of ethanol exposure. At the same time, no changes in the function of microglia were noted.

We studied the peculiarities of the participation of ERK1/2 and р38 in regulation of various types of progenitor cells of the nervous tissue under conditions of ethanol-induced neurodegeneration modeled in vitro and in vivo. The stimulating role of these signaling molecules in the realization of the growth potential of intact multipotent neural stem cells and committed neuronal precursors (clonogenic PSA-NCAM+ cells) was demonstrated. In vitro exposure to neurotoxic doses of ethanol led to the loss of the specified role of ERK1/2 and p38 in the cell cycle regulation. Inversion of the role of both studied MAP-kinases in determining the proliferation status of neural stem cells after long-term administration of ethanol to experimental animals was revealed. In committed neuronal precursors, this inversion (inhibition of mitotic activity instead of activation) was revealed only for ERK1/2. In mice exposed to chronic alcoholization, ERK1/2 no longer participated in the process of specialization of both types of regeneration-competent cells of the nerve tissue. The revealed fundamental difference between the functions of ERK1/2 and p38 in the cell cycle regulation in neural stem cells and committed neuronal precursors under optimal conditions and during ethanol-induced neurodegeneration does not allow drawing definite conclusions about the prospect of using modifiers of their activity for the therapy for alcohol-related CNS pathologies.

Suppression of the production of granulocytic CSF under the effect of 5-fluorouracyl is related to disorders in the NF-κB-, cAMP-dependent signaling pathways and MAPK cascade. These secondary messengers are involved in the regulation of functional activity of nonadherent myelokaryocytes starting from day 10 of the experiment (initial period of the hemopoietic granulocytic stem regeneration after antimetabolite challenge). Granulocytic CSF does not play essential role in the formation of colony-stimulating activity of cells of the adherent and nonadherent fractions of the bone marrow. Only cAMP-dependent pathway is involved in the regulation of the realization of the granulocytic precursor growth potential in response to the challenge.

The hemostimulating effects of c-Jun N-terminal kinase (JNK) inhibitor were examined on the mouse model of myelosuppression provoked by 5-fluorouracil. Blockade of JNK during postcytostatic period accelerated recovery of granulomonocytopoiesis and erythropoiesis. It also increased the content of neutrophilic granulocytes and erythroid cells in the hematopoietic tissue and elevated the counts of neutrophils and reticulocytes in the peripheral blood. The development of these phenomena resulted from elevated content and up-regulated functional activity of bone marrow hematopoietic progenitors associated with the direct action of JNK inhibitor on these progenitors and enhanced secretion of hemopoietins by stromal elements of the hematopoiesis-inducing microenvironment.

Peculiar roles of JAKs and STAT3 in realization of growth potential of various types of progenitor cells in neural tissue were examined during ethanol-induced neurodegeneration modeled both in vitro and in vivo. During in vitro action of C 2 H 5 OH, these signal molecules exerted the opposite effects on mitotic activity of multipotent neural stem cells and committed neural progenitors (the clonogenic PSA-NCAM + cells). The JAKs and STAT3 inhibitors down-regulated the rate of neural stem cell division (proliferative activity) but up-regulated such activity of the committed neural progenitors. A long-term in vivo exposure of mice to ethanol inversed the roles of JAKs and STAT3 in determination of proliferative status of neural stem cells and eliminated involvement of JAKs in functional control over the committed progenitors of neurons. The data attest to much promise of STAT3 inhibitors in treatment of ethanol-induced CNS diseases as the remedies that stimulate realization of growth potential in multipotent neural stem cells and committed neural progenitors.

We studied the involvement of cAMP/PKA signaling in the realization of the growth potential of neural progenitors and secretion of neurotrophic growth factors by glial elements under conditions of ethanol-induced neurodegeneration in vitro and in vivo. The stimulating role of cAMP and PKA in cell cycle progression of the neural progenitor cells and in production of neurotrophins by the cells in nervous tissue under the optimal conditions to vital activity was demonstrated. Ethanol inverted the role of cAMP/PKA signaling pathways in determination of the proliferation-differentiation status of neural stem cells. Selective blockade of adenylate cyclase or PKA in neural stem cells increased the rate of their division against the background of relative decrease in differentiation rate. In addition, cAMP/PKA signaling does not longer participate in neurotrophin production by glial cells in neurodegeneration. These findings suggest that inhibitors of activity/expression of adenylate cyclase and PKA can be considered as possible drugs with regenerative activity for the treatment of nervous system pathologies provoked by alcohol.

The role of NF-κB, cAMP/PKA, JAKs/STAT3, ERK1/2, p38, JNK, and p53 signaling pathways in the realization of growth potential of mesenchymal, neural, erythroid, and granulomonocytic progenitor cells were examined in vitro. Using selective blockers of signaling molecules, we revealed some principal distinctions of their involvement in determination of proliferation-differentiation status of the progenitor cells of different functional classes. The most salient peculiarities were observed in the roles of cAMP/PKA, JNK, and JAKs/STAT3 signaling pathways in the control of functions of various types of the regeneration-competent elements. The specific features of intracellular signaling revealed in histogenetically and functionally different progenitor cells attest to visibility of differentiated pharmacological stimulation of regeneration in individual tissues and prospectiveness in the development of targeted remedies for regenerative medicine based on modifiers of activity of the intracellular signaling molecules.

Ethanol-induced neurodegeneration was modeled in vitro to study the roles of ERK1/2 and p38 in realization of the growth potential of neural progenitor cells and secretion of neurotrophic growth factors by glial elements. Addition of the neurotoxic dose of C 2 H 5 OH (65 mM) to the culture medium abolished the effects of specific ERK1/2 and p38 inhibitors on the formation of colonies (neurospheres) and proliferative activity of neural CFU in cultured cells derived from paraventricular region of the mouse brain. The study established that these protein kinases are not implicated in ethanol-induced stimulation of the formation of neural CFU, differentiation of neural progenitors, and synthesis of humoral functional regulators of neural CFU by glial cells.

The role of signaling molecules in synthesis of humoral regulators of granulocytopoiesis by the hematopoietic microenvironmental cells during stress was analyzed using specific inhibitors. The major role in stimulation of the synthesis of granulocytic CSF during stressful stimulation is played by PI3K/Akt signaling cascade. Nuclear transcription factor NF-κB plays an auxiliary role in the regulation of functional activity of the bone marrow mononuclears. However, this factor affects the synthesis of granulocytic CSF by CD4 + cells of the bone marrow in response to stressful stimulation. Different degree and specific character of involvement of the signaling proteins in the regulation of the production of humoral factors determining colony-stimulating activity are explained by changes in functional state of monocyte-derived macrophages in different periods of stress response.

The in vitro and in vivo models of ethanol-induced neurodegeneration were used to evaluate the content and functional activity of various types of regeneration-competent cells in subventricular zone of the cerebral hemispheres in C57Bl/6JY mice. In nervous tissue culture, ethanol (65 mM) produced no effect on formation of neurospheres. When administered per os in a daily dose of 3 g/kg for 8 weeks, ethanol produced no effect on the number of neural CFU in situ. In both cases, ethanol reduced proliferative activity of neural CFU. Long-term administration of ethanol in vivo suppressed differentiation of neural stem cells and decreased the number of committed precursors (neural cluster-forming units) in the subventricular zone of cerebral hemispheres. In vitro application of ethanol stimulated secretion of humoral growth factors by the cluster-forming neural glial cells. In contrast, in vivo administration of ethanol suppressed this secretion.

We studied myelotoxicity of modern schemes of chemotherapy for breast cancer (docetaxel/doxorubicin and cyclophosphamide/doxorubicin/5-fluorouracil) towards granulocytopoiesis, the mechanisms determining the differences of hematological effects of these schemes, and the efficiency of correction of the observed changes with granulocyte CSF (filgrastim). Granulocytopoiesis stimulation with filgrastim during the treatment with docetaxel/doxorubicin combination was more pronounced than during cyclophosphamide/doxorubicin/5-fluorouracil therapy. The observed differences were found at all levels of granulocyte lineage organization (central and peripheral), which is related to different effects of the cytostatic substances used in the proposed protocols on the structures controlling hemopoiesis.

JAK/STAT signaling pathway was examined comparatively during realization of growth potential of mesenchymal progenitor cells stimulated with diterpene alkaloid songorine or fibroblast growth factor. The stimulating role of JAKs and STAT3 on the mitotic activity and differentiation of progenitor cells cultured with songorine was revealed. Under these conditions, the study demonstrated suppression of fibroblast colony formation against the background of reduced number of actively proliferating CFU-fibroblasts and a drop of differentiation index of progenitor cells induced by pan-JAKs and STAT3 inhibitors. The observed changes were in almost complete agreement with the character of functional reactions of the progenitor elements in response to blockade of JAKs and STAT3 with fibroblast growth factor. In addition, blockade of JAKs with this factor enhanced the differentiation rate of the progenitor cells.

JAK/STAT signaling pathway was examined during functional stimulation of mesenchymal progenitor cells with fibroblast growth factor. The differences were observed in the realizations of the proliferation-differentiation potential of CFU-fibroblasts under blockade of JAKs or during selective inactivation of STAT3. The study revealed stimulating influences of JAKs and STAT3 on mitotic activity of progenitor cells and individual roles of these proteins in the control of their maturation. Blockade of JAKs diminished the level of fibroblast colony formation and the score of actively proliferating CFU-fibroblasts at the background increase of the differentiation rate of progenitor cells. In contrast, STAT3 inhibitor resulted in a coordinated decrease of all examined parameters.

The role of JAK/STAT3-mediated signaling pathway in the realization of the growth potential of mesenchymal precursor cells was examined in vitro. The stimulating role of JAKs and STAT3 towards proliferating activity of progenitor cells and their different role in the regulation of differentiation of the progenitor elements were demonstrated. Inhibitors of JAKs and STAT3 reduced the yield of fibroblast CFU and their mitotic activity. Blockade of JAKs accelerated and selective inactivation of STAT3 decelerated differentiation of progenitor cells.

The toxic effects of combined cisplatin/docetaxel therapy cycles on erythroid and granulocytic hematopoietic lineages as well as their intercycle recovery were examined in patients with stage III-IV non-small-cell lung carcinoma. Responsiveness of the blood system to this therapy remained at a high level. Combined therapy pronouncedly activated the key elements of the erythroid and granulocytic hematopoietic lineages leading to accumulation of immature and mature myelokaryocytes in the bone marrow, enlargement of the medullary pool of mature neutrophils, and increase in the count of medullary erythroid and granulocytic precursor cells under conditions of their accelerated maturation.

We studied the role of some JAK in the effect of diterpene alkaloid songorine on realization of the growth potential of mesenchymal precursor cells. The participation of JAK1, JAK2, and JAK3 in stimulation of proliferation of the precursor cells was demonstrated. Specific inhibitors of these JAK reduced the yield of fibroblast CFU and the rate of their division. Inhibition of JAK2 against the background of songorine treatment increased the rate of precursor differentiation.

The involvement of the studied signal cascades in the regulation of erythropoietin production by bone marrow nuclears under conditions of immobilization stress depends on the type of the hemopoiesis-inducing microenvironment cells and the period of blood system reaction to stress exposure. Secretory activity of monocytes is regulated mainly by PI3K improving cell resistance to disturbances. The functional role of signal cascades involved in the production of erythropoietin by T cells is determined by the stage of the common adaptation syndrome.

Psychopharmacological effects of JNK inhibitor were studied using a mouse model of posthypoxic encephalopathy. The preparation exhibited a pronounced cerebroprotective effect manifested in normalization of orientation and exploratory behavior and conditioned responses in posthypoxic mice. These effects were accompanied by marked elevation of neural stem cell content in the paraventricular region of the brain.

We studied the involvement of individual JAK kinases in the realization of the growth potential of mesenchymal precursors under the effect of fibroblast growth factor. The important role of JAK2 and JAK3 in determining the initial level of mitotic activity of progenitor cells and participation of JAK1 in this process under conditions of cytokine stimulation of progenitor cells were demonstrated. Specific inhibitors of these kinases reduced the yield of fibroblast CFU and the rate of their division. Moreover, blockade of JAK1, JAK2, and JAK3 under the effect of fibroblast growth factor was accompanied by an increase in the intensity of progenitor cell differentiation.

The leading role in the regulation of erythropoietic activity of adherent bone marrow cells under conditions of post-hemorrhagic anemia is played by classical MAP kinase pathway (ERK pathway). Erythropoietin is not the decisive factor in the formation of erythropoietic activity of adherent cells. PI3K, MAPK/ERK 1/2, and p38-signaling proteins are not the main regulators of local production of erythropoietin after 30% loss of circulating blood volume.

Involvement of individual JAK kinases in the realization of growth potential of mesenchymal progenitor cells was examined in vitro. Important role of JAK2 and JAK3 in determining the initial level of mitotic activity of progenitor cells was established. The yield of fibroblast CFUF was suppressed under the effect of specific inhibitors of JAK kinases. Blockade of JAK3 increased the rate of progenitor element differentiation. JAK1 had no effect on proliferation and differentiation status of progenitor cells.

Psychopharmacological effects of atisine-type diterpene alkaloid Z77 were studied under conditions of experimental posthypoxic encephalopathy. The preparation had a pronounced cerebroprotective effect consisting in normalization of orientation and exploratory behavior and conditioned activity in experimental animals. These changes were accompanied by significant increase in the number of neural stem cells in the paraventricular region of the brain and markedly enhanced production of neurotrophic growth factors by neural tissue microenvironment cells.

We studied the mechanisms of erythropoiesis stimulation and effectiveness of Poetam, a preparation containing release-active anti-erythropoietin antibodies as a supplement treatment for experimental iron deficiency anemia during gestation. The results confirmed potency of combined therapy to stimulate erythropoiesis, which was more efficacious in comparison with monotherapy as assessed by the count of erythrokaryocytes and erythroid progenitors in the hematopoietic tissue as well as by the content of erythrocytes and hemoglobin in the peripheral blood. Activation of erythropoiesis is related to the modulatory effect of Poetam on proliferative activity and differentiation of erythroid precursors, which in most aspects results from stimulatory action of Poetam on secretion of the hematopoietically active factors by adherent elements of the hematopoietic microenvironment.

We studied the dynamics of erythropoiesis in CBA mice during gestation against the background of treatment with iron-binding drug. The mechanisms of suppression of the bone marrow erythroid stem were evaluated. Administration of deferoxamine in a dose of 1 g/kg induced hypoplasia of the erythroid hemopoietic lineage. Suppression of bone marrow erythropoiesis manifested in a decrease of hemoglobin concentration and counts of reticulocytes, erythrocytes, and erythrokaryocytes. These changes were accompanied by a decrease in functional activity of erythropoietic precursors and secretion of erythropoietically active humoral factors by bone marrow myelokaryocytes. These data indicate that deferoxamine can be used for modeling of iron defi ciency anemia in pregnancy.

PI3- and MAP-kinase signaling pathways duplicate and interchange each other in production of agents that determine total erythropoietic activity under conditions of balanced erythropoiesis. The alternative p38-dependent MAP-kinase pathway is the major regulator of erythropoietic activity of adherent bone marrow cells. Blockade of PI3K and p38 signaling pathways stimulated production of erythropoietin by cells that do not produce it constitutively.

The role of JNK-mediated signal pathway and participation of p53 transcription factor in stimulation of realization of the growth potential of the mesenchymal precursor cells by alkaloid songorine were examined in vitro. Specific inhibitors of JNK and p53 enhanced stimulation of fibroblast colony/cluster formation and proliferative activity of mesenchymal precursor cells. Under these conditions, more pronounced effects were observed with early precursors of fibroblast CFU and in both cases were accompanied by a decrease in differentiation index of progenitor elements.

A decrease in the total number of sperm cells and reduction of spermatogonium population were observed upon cytostatic damage of spermatogenous tissue caused by single paclitaxel administration. It was established that the paclitaxel-induced damage to the testicular tissue is underlain by reduction of its regenerative potential consisting in depletion of regional precursor pool. Changes in functional activity of progenitor cells were caused not only by direct action of paclitaxel, but also by suppression of the secretory function of the tissue microenvironment.

The role of cAMP- and IKK-2-dependent pathways in stimulation of the growth capacity of mesenchymal progenitor cells with alkaloid songorine was studied in vitro. Inhibitors of adenylate cyclase and IKK-2 were shown to abolish the increase in proliferative activity of progenitor cells. Moreover, blockade of the inhibitory kinase complex was accompanied by a decrease in the intensity of progenitor cell differentiation.

The role of JNK-mediated signal pathway and participation of p53 transcription factor in stimulation of mesenchymal precursor cell function by the fibroblast growth factor was studied. The levels of fibroblast colony- and cluster formation and proliferative activity of mesenchymal precursors increased in response to JNK and p53 specific inhibitors. JNK and p53 blockers did not change the rate of fibroblast growth factor-induced progenitor element differentiation.

Specific JNK and p53 inhibitors stimulated the formation of fibroblast colonies (CFU-F) and clusters (ClFU-F) and increased proliferative activity of mesenchymal progenitor cells. No effects of inhibitors of JNK and p53 on differentiation of progenitor elements were revealed.

We studied the role of intracellular signaling molecules PI3K, МАРK ERK1/2, and р38 in stimulation of realization of the growth potential of mesenchymal progenitor cells by alkaloid songorine in vitro. Inhibitors of PI3K, ERK1/2 and р38 canceled the increase in proliferative activity of progenitor cells, the blockers of ERK1/2 and р38 reduced the intensity of progenitor cell differentiation.

We studied the psychopharmacological effects of atisine-type diterpene alkaloid Z77 in a rat model of brain ischemia in the morning and at night. The type of developing locomotor disorders in animals was shown to depend on circadian rhythms. Administration of Z77 substantially corrected manifestations of psychoneurological symptoms. The parameters of orientation and exploratory behavior and conditioned reflex activity were normalized. The key role of receptors of neural stem cells to fibroblast growth factor in the realization of their growth potential under the influence of the alkaloid was demonstrated. Under in vitro conditions, antibodies to fibroblast growth factor receptor abolished the increase in the number of neural CFU caused by Z77 in the culture of intact cells from the paraventricular region of the brain.

We studied the role of NF-κB/IKK-mediated signaling in the stimulation of growth potential of mesenchymal progenitor cells by alkaloid songorine in vitro. Specific NF-κB inhibitor oridonin abolished activation of proliferation and differentiation of progenitor cells. Aurothiomalate, a selective blocker of IKK-2, also suppressed mitotic activity of fibroblast precursors, but had no effect on the rate of the differentiation.

The involvement of PI3K, ERK and p38-dependent signaling system in the regulation of functional activity of erythroid precursors after blood loss (30% of circulating volume) was studied. We demonstrated the important role of PI3K and p38 in the suppression of differentiation of erythroid precursors the contribution of p38 to stimulation of mitotic activity of erythroid CFU, which maintains the growth potential of the precursors at the optimal physiological level. The classical MAPK/ERK-kinase pathway does not determine the proliferative and differentiation status of erythroid CFU.

We studied the psychopharmacological effects of atisine-type diterpene alkaloid Z77 in a rat model of cerebral ischemia. Pronounced cerebroprotective effect was found consisting in normalization of the orienting and exploratory activity and conditioned behavior associated with significant correction of morphological changes in the brain. The direct stimulatory effect of Z77 on neural stem cells was shown in vitro.

We studied the role of signaling pathways in the regulation of erythropoiesis against the background of myelosuppression caused by administration of 5-fluorouracil. The important role of cyclic AMP in the maturation of erythroid progenitors after cytostatic treatment was demonstrated. The secretory activity of myelokaryocytes during the period of erythroid hemopoiesis recovery is mainly regulated via the p38 MAPK signaling pathway; non-erythropoietin factors are involved in the formation of erythropoietic activity of adherent cells of the microenvironment.

Protein kinase p38 was shown to contribute to the increase in production of granulocyte CSF by microenvironmental cells under conditions of restraint stress. Stimulation of colony-forming activity was not accompanied by the increase in maturation of clonogenic structures in the bone marrow granulocytic stem. This process was realized with the involvement of NF-κB-dependent signaling and p38 MAPK signaling pathway. Our study showed that the p38 MAPK signaling pathway plays an important role in the regulation of granulocytopoiesis, but not of erythropoiesis.

We studied PI3K, MAPK/EPK1/2 and p38-dependent signaling cascade under stimulation of the functions of mesenchymal progenitor cells by fibroblast growth factor. The important role of PI3K and EPK1/2 in the realization of their growth potential has been revealed. Experiments have demonstrated a blocking effect of PI3K inhibitor on proliferation and differentiation of progenitor cells and EPK1/2 inhibitor on mitotic activity of the progenitor cells. The p38-mediated MAPK pathway did not play a role in determining the proliferative and differentiation status of fibroblast CFU.

We studied the in vitro role of NF-κB-dependent signaling in the growth capacity of mesenchymal progenitor cells upon stimulation by basic fibroblast growth factor. Proliferative activity of progenitor cells was suppressed by specifi c inhibitors of this transcription factor (NF-κB), oridonin and aurothiomalate. These inhibitors had no effect on differentiation of fibroblast CFU.

We studied the role of cAMP- and IKK-2-dependent pathways under conditions of functional stimulation of mesenchymal progenitor cells by basic fibroblast growth factor. An adenylate cyclase inhibitor 2',5'-dideoxyadenosine had no effect on functional activity of early (primitive) mesenchymal precursors. This agent produced a stimulatory effect on proliferation of stromal precursor cells. Mitotic activity of mesenchymal progenitor cells was shown to decrease after treatment with a specific blocker of the IKK-2 kinase-inhibitor complex.