Targeting Adenylate Cyclase: A Novel Concept for Stimulation of Neurogenesis and Pharmacotherapy of Alzheimer's Disease.

BACKGROUND: The low effectiveness of existing pharmacotherapy strategies for Alzheimer's disease (AD) makes it necessary to develop a new concept for the treatment of this type of dementia. This search is promising to be carried out within the framework of the paradigm of targeting intracellular signaling pathways in Regenerative-Competent Cells (RCCs). OBJECTIVE: The purpose of the research is to study the impact of adenylate cyclase (AC) inhibitor on disorders of the psychoemotional status in aged male C57BL/6 mice, as well as on the dynamics of the content and functioning of RCCs nervous tissue. METHODS: We examined the effect of the AC inhibitor (2',5'-Dideoxyadenosine) on conditioned reflex activity, behavioral and emotional profile in a mouse AD model (16-month-old (aged) male C57BL/6 mice), as well as the functioning of neural stem cells (NSCs), neuronal-committed progenitors (NCPs), and neuroglial cells in the subventricular zone of the cerebral hemispheres (SVZ). RESULTS: In aged C57BL/6 mice, we found impairments in exploratory behavior, emotional reactivity, and memory, which are the characteristics of senile dementia. Therapy based on AC inhibition led to an increase in the number of NSCs and NPCs in the SVZ due to an increase in their proliferative activity. These changes were more pronounced in NCPs. At the same time, a decrease in the specialization intensity was recorded in NSCs. These phenomena developed against the background of increased secretion of neurotrophic growth factors by oligodendrocytes and microglial cells. The neuroregenerative effects of 2',5'-dideoxyadenosine correlated with the correction of age-related disorders of the psychoemotional status in aged mice. CONCLUSION: The results provide the basis for the development of targeted drugs based on AC inhibitors to stimulate neurogenesis as an approach for the effective treatment of AD.

Targeting cAMP-pathway in Regeneration-competent Cells of Nervous Tissue: Potential to Create a Novel Drug for Treatment of Ethanol-induced Neurodegeneration.

BACKGROUND: Existing neuroprotective drugs are not effective enough to treat alcoholic encephalopathy. This makes the development of novel pharmacological approaches to treating patients with ethanol-induced neurodegeneration(EIN) relevant. Therefore, the search for new targets among intracellular signaling molecules of regeneration-competent cells of nervous tissue is promising. OBJECTIVE: This study aims to explore the involvement of cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) in the realization of the functions of nervous tissue progenitors and glial cells in EIN. METHODS: Experiments were conducted on mice of C57B1/6. EIN was modeled in vitro and in vivo. The effects of the adenylate cyclase (AC) and PKA inhibitors on the colony-forming capacity of neural stem cells (NSC) and neuronal-committed progenitors (NCP), their proliferative activity, and intensity of specialization were investigated. The secretion of neurotrophins by astrocytes, oligodendrocytes, and microglial cells was also evaluated. Individual fractions of cells were obtained using the immunomagnetic separation method. RESULTS: The cAMP/PKA signaling is shown to stimulate the proliferation of the NSC and inhibit the mitotic activity of the NCP under the conditions of their optimal vital activity. cAMP reduces the specialization intensity of both types of progenitors. EIN leads to the inversion of the role of the cAMP/PKA-pathway in the regulation of NSC functions. cAMP-pathway has varying influences on the secretion of neurotrophic growth factors by glial cells depending on their living conditions. AC blockage stimulates the realization of the NSC and NCP growth potential and production of neurotrophins by astrocytes and microglial cells in EIN. CONCLUSION: These findings show the potential for the use of AC inhibitors as novel effective drugs for the therapy of alcoholic encephalopathy.

Intracellular signaling molecules of nerve tissue progenitors as pharmacological targets for treatment of ethanol-induced neurodegeneration.

OBJECTIVES: The development of approaches to the treatment of neurodegenerative diseases caused by alcohol abuse by targeted pharmacological regulation of intracellular signaling transduction of progenitor cells of nerve tissue is promising. We studied peculiarities of participation of NF-кB-, сАМР/РКА-, JAKs/STAT3-, ERK1/2-, p38-pathways in the regulation of neural stem cells (NSC) and neuronal-committed progenitors (NCP) in the simulation of ethanol-induced neurodegeneration in vitro and in vivo. METHODS: In vitro, the role of signaling molecules (NF-кB, сАМР, РКА, JAKs, STAT3, ERK1/2, p38) in realizing the growth potential of neural stem cells (NSC) and neuronal-committed progenitors (NCP) in ethanol-induced neurodegeneration modeled in vitro and in vivo was studied. To do this, the method of the pharmacological blockade with the use of selective inhibitors of individual signaling molecules was used. RESULTS: Several of fundamental differences in the role of certain intracellular signaling molecules (SM) in proliferation and specialization of NSC and NCP have been revealed. It has been shown that the effect of ethanol on progenitors is accompanied by the formation of a qualitatively new pattern of signaling pathways. Data have been obtained on the possibility of stimulation of nerve tissue regeneration in ethanol-induced neurodegeneration by NF-кB and STAT3 inhibitors. It has been found that the blockage of these SM stimulates NSC and NCP in conditions of ethanol intoxication and does not have a «negative¼ effect on the realization of the growth potential of intact progenitors (which will appear de novo during therapy). CONCLUSIONS: The results may serve as a basis for the development of fundamentally new drugs to the treatment of alcoholic encephalopathy and other diseases of the central nervous system associated with alcohol abuse.