The Impact of NAD Bioavailability on DNA Double-Strand Break Repair Capacity in Human Dermal Fibroblasts after Ionizing Radiation.

Nicotinamide adenine dinucleotide (NAD) serves as a substrate for protein deacetylases sirtuins and poly(ADP-ribose) polymerases, which are involved in the regulation of DNA double-strand break (DSB) repair molecular machinery by various mechanisms. However, the impact of NAD bioavailability on DSB repair remains poorly characterized. Herein, using immunocytochemical analysis of γH2AX, a marker for DSB, we investigated the effect of the pharmacological modulation of NAD levels on DSB repair capacity in human dermal fibroblasts exposed to moderate doses of ionizing radiation (IR).

Purine nucleoside phosphorylase controls nicotinamide riboside metabolism in mammalian cells.

Nicotinamide riboside (NR) is an effective precursor of nicotinamide adenine dinucleotide (NAD) in human and animal cells. NR supplementation can increase the level of NAD in various tissues and thereby improve physiological functions that are weakened or lost in experimental models of aging or various human pathologies. However, there are also reports questioning the efficacy of NR supplementation.

Equilibrative Nucleoside Transporters Mediate the Import of Nicotinamide Riboside and Nicotinic Acid Riboside into Human Cells.

Nicotinamide riboside (NR), a new form of vitamin B3, is an effective precursor of nicotinamide adenine dinucleotide (NAD) in human and animal cells. The introduction of NR into the body effectively increases the level of intracellular NAD and thereby restores physiological functions that are weakened or lost in experimental models of aging and various pathologies. Despite the active use of NR in applied biomedicine, the mechanism of its transport into mammalian cells is currently not understood.

Degradation of Extracellular NAD Intermediates in Cultures of Human HEK293 Cells.

Nicotinamide adenine dinucleotide (NAD) is an essential redox carrier, whereas its degradation is a key element of important signaling pathways. Human cells replenish their NAD contents through NAD biosynthesis from extracellular precursors. These precursors encompass bases nicotinamide (Nam) and nicotinic acid and their corresponding nucleosides nicotinamide riboside (NR) and nicotinic acid riboside (NAR), now collectively referred to as vitamin B3.

Relative Human Telomere Length Quantification by Real-Time PCR.

Telomere measurement by quantitative PCR amplification is a well-known simple method to detect telomere length that involves large numbers of samples. The method has been developed by Cawthon in 2002 (Cawthon, Nucleic Acids Res 30:47e-47, 2002) and remains the most frequently used technique either in original or modified version. Telomere length is estimated by comparing the amount of telomere repeat amplification product (T) to a single copy gene (S) product.

[PRODUCT OF THE BMI1--A KEY COMPONENT OF POLYCOMB--POSITIVELY REGULATES ADIPOCYTE DIFFERENTIATION OF MOUSE MESENCHYMAL STEM CELLS].

Bmil is a key component of Polycomb (PcG), which in mammals controls the basic functions of mammalian somatic stem cells (SSC) such as self-renewal and differentiation. Bmi1 supports SSC via transcriptional suppression of genes associated with cell cycle and differentiation. The most studied target genes of Bmi1 are the genes of Ink4 locus, CdkI p16(Ink4a) and p1(Arf), suppression of which due to activating mutations of the BMI1 results in formation of cancer stem cells (CSC) and carcinomas in various tissues.

DNA double-strand break repair is impaired in presenescent Syrian hamster fibroblasts.

Background: Studies of DNA damage response are critical for the comprehensive understanding of age-related changes in cells, tissues and organisms. Syrian hamster cells halt proliferation and become presenescent after several passages in standard conditions of cultivation due to what is known as "culture stress". Using proliferating young and non-dividing presenescent cells in primary cultures of Syrian hamster fibroblasts, we defined their response to the action of radiomimetic drug bleomycin (BL) that induces DNA double-strand breaks (DSBs).

DNA damage modulates interactions between microRNAs and the 26S proteasome.

26S proteasomes are known as major non-lysosomal cellular machines for coordinated and specific destruction of ubiquitinylated proteins. The proteolytic activities of proteasomes are controlled by various post-translational modifications in response to environmental cues, including DNA damage. Besides proteolysis, proteasomes also associate with RNA hydrolysis and splicing.

[Changes in the heart of neonatal rats after cryptosporidial gastroenteritis of different degrees of severity].

Disturbances at the childhood age increase risk of the appearance of cardiovascular diseases decades later. The nature of this interconnection called ontogenetic programming is not completely understood. Valuable sources of knowledge about mechanisms of ontogenetic programming are data of interspecies study of biology of the body life cycles and of heart physiological capabilities.

[Threshold rat neonatal cardiomyocyte response to gradual cryptosporidial infection severity increase].

Infectious gastroenteritis is one of the common causes of tachyarrythmia, malabsorbtion and growth retardation in children. Our recent studies have indicated that neonatal.cryptosporidial gastroenteritis is associated with long-term cardiomyocyte abnormalities.

[Rat cardiomyocyte remodeling after neonatal cryptosporidiosis. II. Elongation, excessive polyploidization and HIF-1alpha overexpression].

Retrospective epidemyological studies evidence that infant diseases leave survivors with an increased susceptibility to cardiovascular diseases in later life. At the same time, the mechanisms of this link remain poorly understood. Based on medical statistics reporting that infectious gastroenteritis is the most common cause of maladies in babies, infants and children, we analysed the effects of moderate cryptosporidial gastroenteritis on the heart and ventricular cardiomyocyte remodelling in rats of the first month of life.

Dynamics of γH2AX formation and elimination in mammalian cells after X-irradiation.

Phosphorylation of the replacement histone H2AX occurs in megabase chromatin domains around DNA double-strand breaks (DSBs), and this modification called γH2AX can be used as an effective marker for DSB repair and DNA damage response. In this study, we examined a bystander effect (BE) in locally irradiated embryonic human fibroblasts. Using fluorescence microscopy, we found that BE could be observed 1 h after X-ray irradiation (IR) and was completely eliminated 24 h after IR.

[Cardiomyocyte myosin heavy chain composition change after cryptosporidial gastroenteritis].

Cardiovascular diseases are the most common case of human death in developed countries. Thus, the discovering of their new risk factors is of primary importance. Based on epidemiology studies, vertebrate life-history traits comparison and cross-species cardiomyocyte transcriptome analysis, we suggest that one of these factors could be infectious gastroenteritis.

[Phosphorylation of histone H2AX in human lymphocytes as a possible marker of effective cellular response to ionizing radiation].

DNA double-strand breaks (DSBs) which occurs in cells after ionizing radiation (IR) or chemical agents are the most dangerous lesions in eukariotic cells, which leads to cell death or chromosome abberations and cancer. One of the earliest response of cells to DSBs formation is phosphorylation by 139 serine of core variant histone H2AX in megabase chromatin domains around DSB (gamma-H2AX), which amplify signal and makes it possible to identify even one DSB in genome. Effective formation of gamma-H2AX is very important for maintenance of genome stability.

[NADP increases the level of histone H2AX phosphorylation in mouse heart cells after ionizing radiation].

Phosphorylation of replaceable histone H2AX occurs in megabase chromatin domains around DNA double-strand breaks (DSBs), and this modification called gamma-H2AX can be used as an effective marker for DSBs repair and DNA damage response. Using Western blotting and immunohistochemistry techniques we have studied here the influence of exogenous nicotinamide adenine dinucleotide phosphate (NADP) which could potentially increase the intracellular level of NAD+ and on the level of gamma-H2AX formation in mouse heart cells after ionizing radiation (IR). We have found that injection of NAD+ in different doses immediately after IR causes an increased level of gamma-H2AX in mouse heart cells 20 min after IR at the dose of 3 Gy compared to control mice after IR exposure.

Transcription factor GABP/NRF-2 controlling biogenesis of mitochondria regulates basal expression of peroxiredoxin V but the mitochondrial function of peroxiredoxin V is dispensable in the dog.

Peroxiredoxins (PRDXs) represent a conserved family of six antioxidant proteins which are widely expressed in different organisms. Human PRDX5 is detected in the cytosol and nucleus and can also target peroxisomes and mitochondria. However, it remains unknown if mitochondrial localization of PRDX5 is essential for its functions.

Peroxiredoxin V contributes to antioxidant defense of lung epithelial cells.

The aim of this study was to determine the functional significance of peroxiredoxin V (PRXV) in defense against oxidative stress and changes of its expression in human lung inflammation. We used in vitro cell cultures and retrospective analyses of human sputum samples to perform the study. We found that stable clones of lung epithelial cell lines A549 and U1810 with reduced expression of PRXV were prone to oxidative damage.

Mitochondrial targeting of human peroxiredoxin V protein and regulation of PRDX5 gene expression by nuclear transcription factors controlling biogenesis of mitochondria.

Peroxiredoxin V (PRDX5) is a member of the family of mammalian proteins that neutralize reactive oxygen species. The PRDX5 gene is constitutively expressed at a high level in many human tissues, but functional elements of its promoter responsible for a high basal activity in the absence of oxidative stress have still not been identified. Among predicted binding sites for transcription factors in the human PRDX5 promoter are binding sites for nuclear respiratory factor 1 (NFR-1) and nuclear respiratory factor 2 (also called GABPA), which regulate the biogenesis of mitochondria.

EGF-induced apoptosis in A431 cells is dependent on STAT1, but not on STAT3.

EGF in high concentrations has a growth-inhibitory effect on human epidermoid carcinoma cells A431. The transcription factor STAT1 is the most probable candidate for mediating this effect. In the present study, we demonstrated a strong reduction of the expression level of STAT1 in EGF-resistant sub-clones of A431 cells.

[Toxicity assessment of the vegetable emulsifier- the aqueous extract from the common soapwort roots].

Within the limits of experimental observation the assessment of acute and subacute safety of an aqueous extract from Acanthophyllum roots with a solids content of 7%, used as an emulsifier has been manufactured by production of emulsion products. Acute toxicity (LD50) AEAR, probed on mice-male; has allowed to refer to an emulsifier to a class of nontoxic substance. The assessmentof subacute toxicity of an extract (injection in a food allowance within 30 days in a recommended dose--5 ml on 100 g of a standard food allowance) was spent on laboratory rats.

Migrating leukocytes are the source of peroxiredoxin V during inflammation in the airways.

Background: We characterized changes in expression of the antioxidant protein Peroxiredoxin V (PRXV) during airway inflammation.

Methods: Studies in anesthetized rats and mice; PRXV expression determined by Western blot analyses and immunohistochemistry; PRXV m-RNA expression determined by Taq-Man RT-PCR.

Results: Bacterial lung inflammation did not change expression of PRXV in murine epithelia but produced massive influx of leukocytes highly expressing PRXV.

Constitutive expression of the human peroxiredoxin V gene contributes to protection of the genome from oxidative DNA lesions and to suppression of transcription of noncoding DNA.

Peroxiredoxins belong to a family of antioxidant proteins that neutralize reactive oxygen species. One member of this family, peroxiredoxin I (PRDX1), suppresses DNA oxidation. Peroxiredoxin V (PRDX5) has been cloned as a transcriptional corepressor, as a peroxisomal/mitochondrial antioxidant protein, and as an inhibitor of p53-dependent apoptosis.

Peroxiredoxin V is essential for protection against apoptosis in human lung carcinoma cells.

Sensitivity of tumor cells to treatment with anticancer drugs depends on expression and function of antiapoptotic and antioxidant proteins. The goal of our study was to determine the functional role of the novel antioxidant protein Peroxiredoxin V (PrxV), in protection of human lung carcinoma cell lines against apoptosis. Analysis of expression of PrxV in multiple lung carcinoma cell lines revealed a positive correlation between the expression of PrxV and radioresistance in vitro.

Cigarette smoke extract inhibits expression of peroxiredoxin V and increases airway epithelial permeability.

Inhaled cigarette smoke induces oxidative stress in the epithelium of airways. Peroxiredoxin V (PRXV) is a potent antioxidant protein, highly expressed in cells of the airway epithelium. The goal of our study was to determine whether cigarette smoke extract (CSE) influenced expression of this protein in airway epithelia in vivo and in vitro.

BM-derived cells restore expression of peroxiredoxin V in the airways following acute naphthalene injury in mice.

Background: Naphthalene-induced respiratory tract toxicity in mice is characterized by specific and rapid loss of the Clara cell population, which is restored only after several days. The sources of restoration of this cell population remain unclear. We investigated whether BM-derived cells participated in the process of epithelial restoration following naphthalene toxicity compared with bacterial infection.