Oxidative Damage of Proteins Precedes Loss of Cholinergic Phenotype in the Septal Neurons of Olfactory Bulbectomized Mice

BACKGROUND

The development of cholinergic deficit is considered an early sign of a number of pathological conditions, including Alzheimer's disease. Cholinergic dysfunction underlies cognitive decline associated with both normal aging and Alzheimer's disease.

OBJECTIVE

Here, we studied a possible mechanism of functional impairment of cholinergic neurons using an olfactory bulbectomy model.

METHODS

Male mice were subjected to olfactory bulbectomy or sham surgery. Three weeks after that they were trained in Morris water maze and then euthanized one month after surgery. The cholinergic indices as well as the indices of oxidative stress were studied using immunohistochemistry, western blot and ELISA. Gene expression was studied using RT-qPCR.

RESULTS

The experimental treatment was followed by impaired learning of a standard spatial task in a water maze. This was associated with a decrease in the number of cells containing choline acetyltransferase (ChAT), in relation to total number of neurons in the medial septum and lower ChAT enzymatic activity in the hippocampus. However, the levels of mRNAs of ChAT, vesicular ACh transporter and acetylcholine esterase remained unchanged in bulbectomized mice compared to sham-operated animals. These alterations were preceded by the accumulation of protein-bound carbonyls, indicating oxidative damage of proteins, whereas oxidative damage of nucleic acids was not detected.

CONCLUSION

We assume that in olfactory bulbectomy model, oxidative damage of proteins may cause cholinergic dysfunction rather than irreversible neuronal damage. These data indicate that cholinergic neurons of the basal forebrain are very sensitive to oxidative stress, which may be responsible for the appearance of early cognitive decline in Alzheimer's disease.

[The prospects of using the technology of genome editing for correction of neurodegenerative diseases.]

We reviewed the results of modern studies using gene therapy methods for correction of neurodegenerative diseases. We analyzed approaches based on the technologies of gene editing and their prospective use in medicine. We discussed some limitations associated with the features of pathogenesis of neurodegenerative diseases for application of the genome editing tools directing to for the treatment of these pathologies.

Prophylaxis of encephalopathies and risk factors of atherogenesis development in the postresuscitation period in rats by means of succinic acid

The effect of oral administration of succinic acid was studied in 66 rats exposed to 10 min cardiac arrest with further resuscitation. A total of 30 mg/kg of the drug were administered daily for 5 days starting with day 3 up to day 7 after resuscitation. The experiments have revealed that treatment with succinic acid caused normalization of the orienting behavior in an 'open field' test, decrease of the intensity of response to electric shock, normalization of free radical formation in the brain and serum and reduced cerebral morphological changes. The succinic acid prevented the increase of cholesterol, triglyceride and low density lipoproteins in the blood. The data suggested that after additional trials the succinic acid could be used to prevent development of postresuscitation encephalopathies (3 months after reanimation).