Creation of doubled haploid lines of maize <i>Zea mays</i> L. by resynthesis from a tetraploid population

The search for new, effective methods for broadening the genetic polymorphism of the original breeding material remains one of important problems of hybrid maize breeding. Globally, breeding of commercial maize varieties and hybrids is carried out using diploid genotypes, whereas tetraploid sources of initial material and wild relatives of maize are poorly involved in the breeding process. The direct heteroploid crosses between diploid and tetraploid genotypes lead to the formation of weakly fertile or completely sterile triploid hybrids, which are cytologically unstable in subsequent generations. Tetraploid maize (2n=40), as well as some wild relatives with tetraploid genome, such as Zea perennis Hitchk. (2n=40) and Tripsacum dactiloides (L.) L. (2n=72), are attractive to breeders as sources for improving economically valuable traits. The attractiveness of resynthesized diploid lines is explained by the fact that unequal crossing over between homologous chromosomes forming polyvalent associations of chromosomes, more chromosomal rearrangements occur in tetraploids than in diploid genotypes, the chromosomes of which form bivalents. Synthetic tetraploid populations of maize and its tetraploid wild relatives have great potential of variability for improving diploid maize. The authors proposed a direct method for the resynthesis of doubled haploid lines using haploid induction and an indirect method for obtaining diploid lines by heteroploid crossing and subsequent segregation of a triploid hybrid in the progeny. The method of resynthesizing the tetraploid maize genome to diploid serves as an ideal model for studying the processes of crossing over in meiosis between multivalent associations of homologous chromosomes; it is promising for obtaining diploid lines with an increased frequency of recombination between the homologous chromosomes of different genomes, combined into a common one, and can serve as a source for obtaining aneuploid series

ROS-Induced DNA Damage Associates with Abundance of Mitochondrial DNA in White Blood Cells of the Untreated Schizophrenic Patients

Objective. The aim of this study was (1) to examine the leukocyte mtDNA copy number (CN) in unmedicated (SZ (m−)) and medicated (SZ (m+)) male patients with paranoid schizophrenia (SZ) in comparison with the healthy male controls (HC) and (2) to compare the leukocyte mtDNA CN with the content of an oxidation marker 8-oxodG in lymphocytes of the SZ (m−) patients. Methods. We evaluated leukocyte mtDNA CN of 110 subjects with SZ in comparison with 60 male HC by the method qPCR (ratio mtDNA/nDNA (gene B2M) was detected). SZ patients were divided into two subgroups. The patients of the subgroups SZ (m+) (N=55) were treated with standard antipsychotic medications in the hospital. The patients of the subgroup SZ (m−) (N=55) were not treated before venous blood was sampled. To evaluate oxidative DNA damage, we quantified the levels of 8-oxodG in lymphocytes (flow cytometry) of SZ (m−) patients (N=55) and HC (N=30). Results. The leukocyte mtDNA CN showed no significant difference in SZ (m+) patients and HC. The mtDNA CN in the unmedicated subgroup SZ (m−) was significantly higher than that in the SZ (m+) subgroup or in HC group. The level of 8-oxodG in the subgroup SZ (m−) was significantly higher than that in HC group. Conclusion. The leukocytes of the unmedicated SZ male patients with acute psychosis contain more mtDNA than the leukocytes of the male SZ patients treated with antipsychotic medications or the healthy controls. MtDNA content positively correlates with the level of 8-oxodG in the unmedicated SZ patients

Low-Dose Ionizing Radiation Affects Mesenchymal Stem Cells via Extracellular Oxidized Cell-Free DNA: A Possible Mediator of Bystander Effect and Adaptive Response

We have hypothesized that the adaptive response to low doses of ionizing radiation (IR) is mediated by oxidized cell-free DNA (cfDNA) fragments. Here, we summarize our experimental evidence for this model. Studies involving measurements of ROS, expression of the NOX (superoxide radical production), induction of apoptosis and DNA double-strand breaks, antiapoptotic gene expression and cell cycle inhibition confirm this hypothesis. We have demonstrated that treatment of mesenchymal stem cells (MSCs) with low doses of IR (10 cGy) leads to cell death of part of cell population and release of oxidized cfDNA. cfDNA has the ability to penetrate into the cytoplasm of other cells. Oxidized cfDNA, like low doses of IR, induces oxidative stress, ROS production, ROS-induced oxidative modifications of nuclear DNA, DNA breaks, arrest of the cell cycle, activation of DNA reparation and antioxidant response, and inhibition of apoptosis. The MSCs pretreated with low dose of irradiation or oxidized cfDNA were equally effective in induction of adaptive response to challenge further dose of radiation. Our studies suggest that oxidized cfDNA is a signaling molecule in the stress signaling that mediates radiation-induced bystander effects and that it is an important component of the development of radioadaptive responses to low doses of IR

Ribosomal DNA as DAMPs Signal for MCF7 Cancer Cells

Introduction: The cell free ribosomal DNA (cf-rDNA) is accrued in the total pool of cell free DNA (cfDNA) in some non-cancer diseases and demonstrates DAMPs characteristics. The major research questions: (1) How does cell free rDNA content change in breast cancer; (2) What type of response in the MCF7 breast cancer cells is caused by cf-rDNA; and (3) What type of DNA sensors (TLR9 or AIM2) is stimulated in MCF7 in response to the action of cf-rDNA?Materials and Methods: CfDNA and gDNA were isolated from the blood plasma and the cells derived from 38 breast cancer patients and 20 healthy female controls. The rDNA content in DNA was determined using non-radioactive quantitative hybridization. In order to explore the rDNA influence on MCF7 breast cancer cells, the model constructs (GC-DNAs) were applied: pBR322-rDNA plasmid (rDNA inset 5836 bp long) and pBR322 vector. ROS generation, DNA damage, cell cycle, expression of TLR9, AIM2, NF-kB, STAT3, and RNA for 44 genes affecting the cancer cell viability were evaluated. The methods used: RT-qPCR, fluorescent microscopy, immunoassay, flow cytometry, and siRNA technology.Results: The ratio R = cf-rDNA/g-rDNA for the cases was higher than for the controls (median 3.4 vs. 0.8, p &lt; 10−8). In MCF7, GC-DNAs induce a ROS burst, DNA damage response, and augmentation of NF-kB and STAT3 activity. The number of the apoptotic cells decreases, while the number of cells with an instable genome (G2/M– arrest, micronuclei) increase. Expression of anti-apoptotic genes (BCL2, BCL2A1, BCL2L1, BIRC3, MDM2) is elevated, while expression of pro-apoptotic genes (BAX, BID, BAD, PMAIP1, BBC3) is lowered. The cells response for pBR322-rDNA is much more intense and develops much faster, than response for pBR322, and is realized through activation of TLR9- MyD88 - NF-kB- signaling. This difference in response speed is owing to the heightened oxidability of pBR322-rDNA and better ability to penetrate the cell. Induction of TLR9 expression in MCF7 is followed by blocking AIM2 expression.Conclusion: (1) Ribosomal DNA accumulates in cfDNA of breast cancer patients; (2) Cell free rDNA induce DNA damage response and stimulates cells survival, including cells with an instable genome; (3) Cell free rDNA triggers TLR9- MyD88- NF-kB- signaling, with significantly repressing the expression of AIM2

Синдром VEXAS: на рубеже смены представлений об известных заболеваниях

This article presents the first case of VEXAS syndrome identified in the Russian Federation as well as characteristics of currently known clinical manifestations and treatment approaches. The clinical observation described is an impressive example of how the identification of a new pathogenic mutation can change the understanding of the classification, diagnosis and treatment of previously known immunoinflammatory diseases. Thus, in refractory forms of relapsing polychondritis, neutrophilic dermatosis, atypical forms of vasculitis, inflammatory joint diseases or undifferentiated systemic inflammatory syndrome, especially when associated with macrocytic anemia and myelodysplastic syndrome, VEXAS syndrome should be suspected and genetic testing should be performed to exclude the autoinflammatory nature of the existing condition.В статье приведен первый случай синдрома VEXAS, выявленный в Российской Федерации, а также характеристика известных на настоящий момент клинических проявлений и подходов к его терапии. Описанное клиническое наблюдение является ярким примером того, как выявление новой патогенной мутации может изменить представление о классификации, диагностике и терапии ранее известных иммуновоспалительных заболеваний. Так, при рефрактерных формах рецидивирующего полихондрита, нейтрофильного дерматоза, нетипичных формах васкулита, воспалительных заболеваний суставов или недифференцированном системном воспалительном синдроме, особенно при ассоциации с макроцитарной анемией и миелодиспластическим синдромом, необходима настороженность в отношении синдрома VEXAS и проведение генетического исследования для исключения аутовоспалительной природы имеющегося состояния

Aneuploidy and Confined Chromosomal Mosaicism in the Developing Human Brain

BACKGROUND: Understanding the mechanisms underlying generation of neuronal variability and complexity remains the central challenge for neuroscience. Structural variation in the neuronal genome is likely to be one important mechanism for neuronal diversity and brain diseases. Large-scale genomic variations due to loss or gain of whole chromosomes (aneuploidy) have been described in cells of the normal and diseased human brain, which are generated from neural stem cells during intrauterine period of life. However, the incidence of aneuploidy in the developing human brain and its impact on the brain development and function are obscure. METHODOLOGY/PRINCIPAL FINDINGS: To address genomic variation during development we surveyed aneuploidy/polyploidy in the human fetal tissues by advanced molecular-cytogenetic techniques at the single-cell level. Here we show that the human developing brain has mosaic nature, being composed of euploid and aneuploid neural cells. Studying over 600,000 neural cells, we have determined the average aneuploidy frequency as 1.25-1.45% per chromosome, with the overall percentage of aneuploidy tending to approach 30-35%. Furthermore, we found that mosaic aneuploidy can be exclusively confined to the brain. CONCLUSIONS/SIGNIFICANCE: Our data indicates aneuploidization to be an additional pathological mechanism for neuronal genome diversification. These findings highlight the involvement of aneuploidy in the human brain development and suggest an unexpected link between developmental chromosomal instability, intercellural/intertissular genome diversity and human brain diseases

Клинические рекомендации по оказанию медицинской помощи пациентам с болезнью Помпе

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Vitamin D Status Among Children With Juvenile Idiopathic Arthritis: A Multicenter Prospective, Non-randomized, Comparative Study

BackgroundJuvenile idiopathic arthritis (JIA) is a chronic autoimmune disease characterized by destructive and inflammatory damage to the joints. The aim in this study was to compare vitamin D levels between children and adolescents, 1–18 years of age, with juvenile idiopathic arthritis (JIA) and a health control group of peers. We considered effects of endogenous, exogenous, and genetic factors on measured differences in vitamin D levels among children with JIA.MethodsOur findings are based on a study sample of 150 patients with various variants of JIA and 277 healthy children. The blood level of vitamin D was assessed by calcidiol level. The following factors were included in our analysis: age and sex; level of insolation in three regions of country (center, south, north); assessment of dietary intake of vitamin D; effect of prophylactic doses of cholecalciferol; a relationship between the TaqI, FokI, and BsmI polymorphisms of the VDR gene and serum 25(OH)D concentration.ResultsWe identified a high frequency of low vitamin D among children with JIA, prevalence of 66%, with the medial level of vitamin D being within the range of “insufficient” vitamin D. We also show that the dietary intake of vitamin D by children with JIA is well below expected norms, and that prophylactic doses of vitamin D supplementation (cholecalciferol) at a dose of 500–1,000 IU/day and 1,500–2,000 IU/day do not meet the vitamin D needs of children with JIA. Of importance, we show that vitamin D levels among children with JIA are not affected by clinical therapies to manage the disease nor by the present of VDR genetic variants.ConclusionProphylactic administration of cholecalciferol and season of year play a determining role in the development of vitamin D deficiency and insufficiency

Эффективность CFTR-модуляторов в клинической практике (6-месячное наблюдение)

Pathogenetic therapy for the treatment of cystic fibrosis (CF) has been developed that modulates the CFTR protein and restores its activity as a chloride channel. This treatment is represented by CFTR modulators for various genotypes covering 85 - 90% of patients with CF.The aim was to analyze the efficacy of two targeted drugs in patients aged 6 - 18 years with CF in clinical practice during a 6-month follow-up.Methods. The study was conducted based on the analysis of the database “CF Patient Registry of the Russian Federation” for 2021 - 2022. The study included 178 patients receiving lumacaftor/ivacaftor and 158 patients receiving elexacaftor/tezacaftor/ivacaftor. Respiratory function indicators (FEV1, FVC), sweat test, and anthropometric data were analyzed.Results. In the group of children treated with lumacaftor/ivacaftor, Me (Q1 - Q3) body weight (kg) increased at 6-month follow-up from 40.0 (28.9 - 48.0) to 44.9 (29.3 - 50.8), p &lt; 0.001, and the height (cm) increased from 156.0 (140.0 - 161.0) to 158.0 (143.0 - 162.0),p &lt; 0.001. Me (Q1 - Q3) FEV1 improved from 63.5 (42.3 - 84.8) to 72.0 (56.9 - 82.4) %,p &lt; 0.045. Sweat test (mmol/l) decreased Me (Q1 - Q3) from 115 (101.0 - 123.0) to 86.5 (79.0 - 103.0), p &lt; 0.001. During therapy with elexacaftor/tezacaftor/ ivacaftor, Me (Q1 - Q3) body weight (kg) increased at 6-month follow-up from 44.4 (36.8 - 50.0) to 49.3 (44.1 - 51.9),p &lt; 0.001, and Me (Q1 -Q3) height (cm) increased from 160.5 (152.3 - 165.1) to 163.0 (155.5 - 166.9),p &lt; 0.001. Me (Q1 - Q3) FVC and FEV1 improved: FVC from 78.5 (60.9 - 91.0) to 90.5 (76.8 - 106.8) %,p &lt; 0.001, FEV1 from 73.5 (60.5 - 82.1) to 95.0 (65.3 - 107.0) %,p &lt; 0.001. Sweat test (mmol/l) decreased from 119 (108 - 126) to 75.5 (65.3 - 88);р &lt; 0.001.Conclusion. Health status indicators of of children with CF aged 6 - 18 years were analyzed for 6 months of targeted therapy (lumacaftor/ivacaftor and elexacaftor/tezacaftor/ivacaftor). Positive changes were observed in weight, height, respiratory function, and sweat test.В настоящее время для лечения муковисцидоза (МВ) разработана патогенетическая терапия, направленная на модуляцию белка CFTR и восстановление его активности в качестве хлорного канала. Она представлена таргетными препаратами (CFTR-модуляторами) для пациентов с различными генотипами и охватывает 85—90 % больных МВ.Целью исследования явился анализ эффективности применения 2 таргетных препаратов у пациентов с МВ 6—18 лет в условиях клинической практики в течение 6 мес. наблюдения.Материалы и методы. Исследование проведено на основе анализа базы данных Регистра больных МВ Российской Федерации (2021-2022). В 2021 г. разработан блок «Таргетная терапия» для оценки эффективности и безопасности терапии. В исследовании принимали участие пациенты с МВ в возрасте 6-18 лет, получавшие лумакафтор / ивакафтор (n = 178) и элексакафтор / тезакафтор / ивакафтор (n = 158). Анализировались показатели функции внешнего дыхания (форсированная жизненная емкость легких (ФЖЕЛ), объем форсированного выдоха за 1-ю секунду (ОФВ1)), проводимость электролитов потовой жидкости, антропометрические данные.Результаты. В группе детей, получавших лумакафтор / ивакафтор, через 6 мес. наблюдения отмечено увеличение медианы (Ме) (Q1-Q3) массы тела с 40,0 (28,9-48,0) до 44,9 (29,3-50,8) кг (р &lt; 0,001) и роста - с 156,0 (140,0-161,0) до 158,0 (143,0-162,0) см (р &lt; 0,001). Ме (Q1-Q3) ОФВ1 достоверно улучшилась - с 63,5 (42,3-84,8) до 72,0 (56,9-82,4) %долж (р &lt; 0,045). Проводимость пота достоверно снизилась (Ме (Q1-Q3) - со 115 (101,0-123,0) до 86,5 (79,0-103,0) (р &lt; 0,001) ммоль / л. На фоне терапии комбинацией элексакафтор / тезакафтор / ивакафтор через 6 мес. отмечено увеличение Ме (Q1-Q3) массы тела - с 44,4 (36,8-50,0) до 49,3 (44,1-51,9) кг (р &lt; 0,001), роста - с 160,5 (152,3-165,1) до 163,0 (155,5-166,9) см (р &lt; 0,001). Ме (Q1-Q3) показателей ФЖЕЛ и ОФВ1 улучшились: ФЖЕЛ - с 78,5 (60,9-91,0) до 90,5 (76,8-106,8) %долж (р &lt; 0,001), ОФВ1 - с 73,5 (60,5-82,1) до 95,0 (65,3-107,0) %долж (р &lt; 0,001). Достоверно снизились показатели потового теста - с 119 (108-126) до 75,5 (65,3-88) ммоль / л (р &lt; 0,001).Заключение. Проведен анализ показателей, характеризующих состояние здоровья детей 6-18 лет с МВ за 6 мес. применения таргетной терапии (лумакафтор / ивакафтор и элексакафтор / тезака-фтор / ивакафтор). Отмечена положительная динамика массы тела, роста, показателей функции внешнего дыхания и потового теста