Effectiveness of the DNA Double-Strand Breaks Repair System in Lymphocytes of Patients with Cognitive Impairments and Healthy Volunteers

Autor: I K Malashenkova, S A Krynskiy, E. Yu. Moskaleva, Gavrilova Si, Yu. P. Semochkina, D P Ogurtsov, N A Hailov, E. V. Ponomareva
Rok vydání: 2021
Předmět:
Zdroj: Biochemistry (Moscow), Supplement Series B: Biomedical Chemistry. 15:139-146
ISSN: 1990-7516
1990-7508
DOI: 10.1134/s1990750821020098
Popis: The individual differences in the efficiency of DNA DSB repair were estimated by the level of residual γH2AX foci after γ-irradiation at a dose of 2 Gy, in lymphocytes of patients with amnestic mild cognitive impairment (AMCI) and Alzheimer's disease (AD) and of healthy volunteers. Lymphocytes were isolated from the peripheral blood of the examined patients and were frozen in a medium for freezing cells. Before the study, the lymphocytes were thawed, suspended in RPMI 1640 culture medium supplemented with 10% inactivated fetal bovine serum, and half of the cells were γ-irradiated at 4°C from a 60Co source on a GUT-200M facility at a dose of 2 Gy (a dose rate of 0.75 Gy/min). Control and irradiated lymphocytes were cultured for 24 h, collected, fixed, and stored until the study of the number of spontaneous and residual foci of γH2AX using fluorescent microscopy after staining with fluorescent labeled antibodies. In lymphocytes of patients with AMCI and AD a higher number of residual γH2AX foci in lymphocytes and the higher number of lymphocytes with foci were found compared with healthy volunteers. This indicates a decrease in the ability to repair DNA DSB in these patients. Indicators of cellular immunity and the concentration of TNF-α in the blood serum in the group of examined patients were normal. In the group of patients with the cognitive impairments (AMCI+AD), a correlation was found between the number of residual foci of γH2AX and the number of CD3+CD4+ lymphocytes and the concentration of proinflammatory cytokine TNF-α in the blood serum. This suggests the development of stronger neuroinflammation in patients with reduced ability to repair DNA DSB in this pathology.Izucheny individual'nye razlichiia v éffektivnosti reparatsii dvunitevykh razryvov (DR) DNK, otsenivaemykh po urovniu ostatochnykh fokusov γH2AX cherez 24 ch posle γ-oblucheniia v doze 2 Gr v limfotsitakh zdorovykh dobrovol'tsev i patsientov s miagkim kognitivnym snizheniem amnesticheskogo tipa (MKSA) i bolezn'iu Al'tsgeĭmera (BA). Limfotsity vydeliali iz perifericheskoĭ krovi obsleduemykh lits i zamorazhivali v srede dlia zamorazhivaniia kletok. Pered provedeniem issledovaniia limfotsity razmorazhivali, suspendirovali v kul'tural'noĭ srede RPMI 1640 s dobavleniem 10% inaktivirovannoĭ fetal'noĭ syvorotki krupnogo rogatogo skota i polovinu kletok obluchali pri 4°S pri deĭstvii γ-izlucheniia ot istochnika 60So na ustanovke “GUT-200M” v doze 2 Gr pri moshchnosti dozy 0,75 Gr/min. Kontrol'nye i obluchennye limfotsity kul'tivirovali v techenie 24 ch, sobirali, fiksirovali i khranili do provedeniia analiza chisla spontannykh i ostatochnykh fokusov γH2AX s pomoshch'iu fluorestsentnoĭ mikroskopii posle okrashivaniia fluorestsentno-mechenymi antitelami. Pri MKSA i BA obnaruzheno bolee vysokoe chislo ostatochnykh fokusov gistona γN2AKh i kolichestvo limfotsitov, soderzhashchikh fokusy, po sravneniiu so zdorovymi dobrovol'tsami. Éto svidetel'stvuet o snizhenii sposobnosti k reparatsii DR DNK u étikh patsientov. Pokazateli kletochnogo immuniteta i kontsentratsiia provospalitel'nogo tsitokina faktora nekroza opukholi-α (TNF-α) v gruppe obsledovannykh patsientov sootvetstvovali norme. V gruppe patsientov s kognitivnym snizheniem (MKSA+BA) obnaruzhena korreliatsiia chisla ostatochnykh fokusov γN2AKh s kolichestvom SD3+CD4+-limfotsitov i kontsentratsieĭ TNF-α v syvorotke krovi, chto svidetel'stvuet o razvitii bolee sil'nogo neĭrovospaleniia u patsientov so snizhennoĭ sposobnost'iu k reparatsii DR DNK pri étoĭ patologii.
Databáze: OpenAIRE
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