Neurotrophins stimulate the regeneration of neural tissue after lesions. It is also known that the sources of neurogenesis and cerebral function recovery are predominantly located in subcortical brain structures. The effects of ischemia on the expression of genes that encode neurotrophins (Bdnf, Ngf, Nt-3) and their receptors (TrkB, TrkA, TrkC, p75) in brain structures outside the lesion site were studied 3, 24, and 72 h after irreversible unilateral occlusion of the middle cerebral artery in rats. Changes in the mRNA expression of these genes were assessed by relative quantification using real-time RT-PCR. Sham surgery was found to stimulate the expression of genes that encode neurotrophins (Bdnf, Ngf) and their receptor (p75). It has been shown that ischemia influenced the expression of neurotrophins (Bdnf, Ngf, Nt-3) and their receptors (TrkB, TrkA, TrkC, p75) in brain structures outside the lesion focus, including the contralateral hemisphere. The downregulation of Bdnf and TrkB transcripts and Ngf and TrkA upregulation in the contralateral cortex on the first day of ischemia obviously reflected stress response. On day 3, Nt-3 transcription increased in all investigated structures outside the lesion focus. In the contralateral hemisphere, relative levels of TrkA and TrkC mRNA expression increased, while p75 expression decreased. Presumably, the observed changes in gene transcription serve to facilitate neuroplasticity and neural tissue regeneration.
Методом ПЦР в реальном времени в подкорковых структурах мозга крыс, содержащих очаг ишемического повреждения, показано активирующее влияние ишемии на экспрессию циклических РНК (циклоРНК) генов Ece1, Mvp, Egfem1 и Cdyl, а также репрессирующее влияние на экспрессию циклоРНК гена Rgs9. Биоинформатический анализ выявил возможные цис-регуляторные взаимодействия между микроРНК, а также циклоРНК и мРНК исследуемых генов, что указывает на функциональную роль данных циклоРНК в ответе клеток мозга на ишемию.
Using real-time PCR, the activating effect of ischemia on the expression of circular RNAs (circRNAs) of Ece1, Mvp, Egfem1 and Cdyl genes, as well as the repressing effect on the expression of circRNA of the Rgs9 gene, is shown in the subcortical structures of the rat brain containing the focus of ischemic damage. Bioinformatics analysis revealed possible cis-regulatory interactions between miRNAs, as well as circRNAs and mRNAs of the studied genes. The result indicates the functional role of these circRNAs in the response of brain cells to ischemia.
В условиях модели экспериментальной ишемии мозга крыс, вызванной обратимой окклюзией правой средней мозговой артерии, с использованием методов RNA-Seq и ПЦР в реальном времени были выявлены гены, значительно меняющие свою активность в мозге крыс. Для 38 наиболее активных генов были определены гены-ортологи у человека. С использованием баз данных проекта 1000 геномов (популяция CEU) был изучен полиморфизм каждого из генов и отобраны локусы, которые демонстрировали максимальное число ассоциаций с другими полиморфизмами (tagSNPs). На первом этапе был исследован полиморфизм генов DRD2, CCL23, SOCS3, HSPB1 и CHRM4, в каждом из которых были идентифицированы от одного до трех tagSNPs. С использованием метода ПЦР в режиме реального времени (TaqMan) аллельные варианты отобранных локусов были генотипированы в выборке больных ишемическим инсультом (100 чел.) и контрольной группе (100 чел.). Частоты встречаемости генотипов исследованных полиморфизмов в контрольной группе, в большинстве случаев, оказались близкими таковым в группе больных с ишемическим инсультом. Наиболее существенные различия в распределении генотипов между выборками (p = 0,088) были продемонстрированы для локуса rs8069976 из региона локализации гена SOCS3. Для уточнения направленности выявленных различий планируется их проверка на выборках больных и контроля больших размеров.
In a model of experimental rat brain ischemia caused by the right transient middle cerebral artery occlusion using RNA-Seq and real-time PCR, genes that significantly change their activity in the rat brain were revealed. For 38 most active rat genes their human orthologous genes were identified. Using the genotype data from the 1000 genome project (CEU population), we explored the polymorphism of each of the genes and identified the loci showed the maximum number of associations with other polymorphisms (tagSNPs). At the first stage, the polymorphisms in DRD2, CCL23, SOCS3, HSPB1 and CHRM genes were studied. From one to three tagSNPs were selected for further analysis in each gene. Using TaqMan real-time PCR assays, allelic variants of the selected loci were genotyped in 100 patients with ischemic stroke and in 100 controls. In the most cases the frequencies of genotypes of the SNPs in the control group were similar to those in the group of patients with ischemic stroke. The most substantial differences in the distribution of genotypes between the groups (p = 0.088) were demonstrated for the SNP rs8069976 from the region of SOCS3 gene. To clarify the direction of the differences revealed, their testing in the patient and control samples of larger sizes is planned.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.