Parkinson’s disease (PD) is characterized by a long prodromal period, during which patients often have sleep disturbances. The histaminergic system and circadian rhythms play an important role in the regulation of the sleep–wake cycle. Changes in the functioning of these systems may be involved in the pathogenesis of early stages of PD and may be age-dependent. Here, we have analyzed changes in the expression of genes associated with the regulation of the sleep–wake cycle (Hnmt, Hrh1, Hrh3, Per1, Per2, and Chrm3) in the substantia nigra (SN) and striatum of normal male mice of different ages, as well as in young and adult male mice with an MPTP-induced model of the early symptomatic stage (ESS) of PD. Age-dependent expression analysis in normal mouse brain tissue revealed changes in Hrh3, Per1, Per2, and Chrm3 genes in adult mice relative to young mice. When gene expression was examined in mice with the MPTP-induced model of the ESS of PD, changes in the expression of all studied genes were found only in the SN of adult mice with the ESS model of PD. These data suggest that age is a significant factor influencing changes in the expression of genes associated with sleep–wake cycle regulation in the development of PD.

Parkinson’s disease (PD) is one of the most common progressive neurodegenerative diseases. An important feature of the disease is its long latent period, which necessitates search for prognostic biomarkers. One method of identifying biomarkers of PD is to study changes in gene expression in peripheral blood of the patients in early stages of the disease and have not been treated. In this study, we analyzed relative mRNA levels of the genes GRIPAP1, DLG4, KIF1B, NGFRAP1, and NRF1, which are associated with neurotransmitter transport, apoptosis, and mitochondrial dysfunction, in the peripheral blood of PD patients using reverse transcription and real-time PCR with TaqMan probes. The results of this study suggest that the GRIPAP1 and DLG4 genes could be considered as potential biomarkers for the early clinical stages of Parkinson’s disease. The data obtained may indicate that NGFRAP1 is involved in pathogenesis of both PD and other neurodegenerative diseases. Furthermore, in the early clinical stages of the disease we studied, the KIF1B and NRF1 genes were found not to be involved in PD pathogenesis at the expression level.

Parkinson’s disease (PD) is one of the most common human neurodegenerative diseases. Belated diagnoses of PD and late treatment are caused by its elongated prodromal phase. Thus, searching for new candidate genes participating in the development of the pathological process in the early stages of the disease in patients who have not yet received therapy is relevant. Changes in mRNA and protein levels have been described both in the peripheral blood and in the brain of patients with PD. Thus, analysis of changes in the mRNA expression in peripheral blood is of great importance in studying the early stages of PD. This work aimed to analyze the changes in MEF2C, SLC22A4, P2RY12, and LRRN3 gene expression in the peripheral blood of patients in the early stages of PD. We found a statistically relevant and PD-specific change in the expression of the LRRN3 gene, indicating a disruption in the processes of neuronal regeneration and the functioning of synapses. The data obtained during the study indicate that this gene can be considered a potential biomarker of the early stages of PD.

Background/Objectives: MicroRNAs are key post-transcriptional regulators involved in various diseases. Despite its status as the gold standard, real-time RT-PCR faces challenges arising from high sequence homology among closely related microRNAs and the substantial biomaterial required to enrich small RNA fractions. This study aimed to develop an optimized protocol for simultaneous analysis of microRNA and mRNA expression from a single total RNA sample using mouse (Mus musculus) brain tissue, avoiding dependence on pre-designed commercial assay panels. Methods: We optimized a real-time RT-PCR workflow enabling simultaneous analysis of mature microRNAs and mRNAs from a single total RNA sample. Modifications include a redesigned universal reverse primer, LNA-modified TaqMan probes, and omission of the 65 °C denaturation step during reverse transcription. The method was validated for five microRNAs in mouse brain tissue. Results: The assay showed high specificity, discriminating closely related miR-125a-5p and miR-125b-5p with a ΔCt difference of 6.7 ± 1.2 cycles. Co-analysis with Oligo(dT)₁₈ and Random hexamer primers did not interfere with microRNA detection. Conclusions: The developed approach enables reliable detection of closely related microRNAs and parallel analysis of different RNA types, which is particularly important for studying regulatory networks when working with limited amounts of biomaterial. This protocol provides a complementary, accessible option for targeted studies in resource-limited settings or for non-cataloged miRNA targets.

It was shown earlier that induced pluripotent stem cells (iPSCs) differentiate into a heterogeneous cell population enriched in dopaminergic neurons on a m

Introduction. It was previously shown that induced pluripotent stem cells (iPSCs) differentiate into a heterogeneous cell population enriched in dopaminergic neurons on a microgel matrix based on recombinant spidroin rS1/9. To further study the functional activity of the resulting neuronal culture, it was used to administer it to mice with a toxic model of Parkinson’s disease (PD) in order to assess the possibility of modulating motor behavior impaired by the introduction of MPTP(1-methyl-4-phenyl-1.2,3.6-tetrahydropyridine). Material and methods. Mice with a toxic model of early symptomatic PD were used for stereotaxic transplantation of neuronal cells. Motor behavior was assessed using the open field test. Results. It has been shown that in vitro cultivation of neuronal cells on a microgel-free medium has a pronounced effect on the motor activity of mice 2 weeks after their introduction into the mouse brain and 3 weeks after toxic damage to neurons of the substantia nigra. The effect of short-term 3-day cultivation turned out to be negative — the motor activity of mice decreased. With longer cultivation, on the contrary, it increases — which is manifested primarily in an increase in the duration of the active period and the distance traveled. This is especially clearly manifested when comparing the motor activity of mice that were injected with neuronal cells cultured on a microgel-free medium for 2 weeks or 3 days. These effects are modulated by cell cultivation on a microgel — and this effect is different for neuronal cultures with different periods of in vitro cultivation. Conclusion. Neuronal cell cultures derived from iPSCs and differentiated in vitro can increase motor activity when stereotaxically introduced into the brain of mice with a toxic model of PD. This effect depends on the duration of cell culture in vitro and on the matrices used in the cultivation process.