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1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

The modulatory effect of physical activity on APE1-mediated telomere length and stability. A narrative review

100%
Betlej G., Kwiatkowska A., Bator E.
Central European Journal of Sport Sciences and Medicine
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2019
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tom 28
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nr 4
2

Structural polymorphism of telomeres studied by photon correlation spectroscopy

100%
Wlodarczyk A., Gapinski J., Patkowski A., Dobek A.
Acta Biochimica Polonica
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1999
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tom 46
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nr 3
Photon Correlation Spectroscopy (PCS) was used to study the dynamics and structure of Tetrahymena telomeric sequence d(5'-TGGGGT-3')4. Two different modes were observed, corresponding to the following structures: intermolecular (tetramolecular) G-quadruplex and intramolecular (monomeric) G-quartet. Experimental values of translational diffusion coefficients DT were obtained for each structural form. The value of DT for the monomer equals to 1.4 × 106(cm2/s), while for the tetramolecular structure, to 0.8 × 106(cm2/s). The relative weight concentrations of these two forms were analyzed versus the concentration of NaCl varied from 10 mM to 500 mM. The values of experimentally determined diffusion coefficients were compared with those calculated assuming the "bead model" and with the atomic coordinates from the NMR and X-ray crystallographic data. For both structures the experimental and calculated values of DT were in reasonable agreement. In the entire NaCl concentration range studied, the contribution of the relative weight concentration of the monomeric telomere form changed from 85% for 10 mM NaCl to 60% for 500 mM NaCl.
3

The telomere-specific non-LTR retrotransposons SART 1 and TRAS1 are suppressed by PIWI subfamily proteins in the silkworm, Bombyx mori

84%
Tatsuke T., Sakashita K., Masaki Y., Lee J. M., Kawaguchi Y., Kusakabe T.
Cellular and Molecular Biology Letters
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2010
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tom 15
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nr 1
118-133
The telomere structures in Bombyx mori are thought to be maintained mainly by the transposition of the specialized telomeric retroelements SART and TRAS. The silkworm genome has telomeric TTAGG repeats and telomerase, but this telomerase displays little or no activity. Here, we report that the transcription of the telomeric retroelements SART1 and TRAS1 is suppressed by the silkworm Piwi subfamily proteins BmAgo3 and Siwi. The silkworm Piwi subfamily was found to be expressed predominantly in the gonads and early embryo, as in other model organisms, but in BmN4 cultured cells, these proteins formed granules that were separate from the nuage, which is a different behaviour pattern. The expression of TRAS1 was increased in BmN4 cells when BmAgo3 or Siwi were silenced by RNAi. Our results suggest that B. mori Piwi proteins are involved in regulating the transposition of telomeric retroelements, and that the functional piRNA pathway is conserved in BmN4 cultured cells.
4

Age dynamics of telomere length of Baikal gastropods is sex-specific and multidirectional

84%
Maximova N., Koroleva A., Sitnikova T., Khanaev I., Bukin Y., Kirilchik S.
Folia Biologica
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2017
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tom 65
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nr 4
5

In vitro culture of primary human myoblasts by using the dextran microcarriers Cytodex3

84%
Rozwadowska N., Malcher A., Baumann E., Kolanowski T. J., Rucinski M., Mietkiewski T., Fiedorowicz K., Kurpisz M.
Folia Histochemica et Cytobiologica
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2016
|
tom 54
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nr 2
6
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Telomeropathies: rare disease syndromes

84%
Panczyszyn A., Boniewska-Bernacka E.
Medical Science Pulse
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2018
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tom 12
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nr 2
Telomeres are located at the end of the chromosomes. They protect chromosomes from fusion and degradation. Every cell division causes a shortening of the telomeres. A special enzymatic complex called telomerase is responsible for maintaining telomere length in intensively dividing cells, such as epithelial cells and bone marrow cells. The enzymatic complex includes the TERT subunit, which has reverse transcriptase activity, and the TERC subunit, which acts as a template. Other important components of telomerase are the proteins that are responsible for structural stability. Telomerase remains active only in the dividing cells of the body. The rate of telomere shortening depends on many factors including age, sex, and comorbidities. Faster shortening of telomeres is caused by gene defects, which have an impact on telomerase action. Collectively, these are called telomeropathies. Common causes of telomeropathies are mutations in the TERT and TERC telomerase genes. Types of telemeropathies include dyskeratosis congenita, idiopathic pulmonary fibrosis, and aplastic anaemia, among others. Clinical manifestations and prognoses depend on the type and quantity of mutated genes. Diagnosis of telomeropathies is often problematic because they present with the same symptoms as other diseases. So far, no effective therapeutic methods have been developed for telomeropathies. A therapeutic method for patients with bone marrow failure may be the transplantation of hematopoietic stem cells. For patients with idiopathic pulmonary fibrosis, treatments include immunosuppressive therapy, lung transplantation, or palliative care. In the future, gene therapy may be an effective treatment strategy for telomeropathies. Lifestyle changes may also have a positive impact on the person. Physical activity combined with a healthy diet rich in antioxidants and unsaturated fatty acids can decrease the oxidative stress levels in cells and lead to a slower shortening of the telomeres.
7
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Reduced fertility and meiotic abnormalities in late generations of telomerase-deficient Arabidopsis thaliana

84%
Puizina J., Samanic I.
Acta Biologica Cracoviensia. Series Botanica
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2013
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tom 55
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nr 1
Here we report the consequences of telomere erosion in Arabidopsis thaliana, studied by examining seed and pollen production and the course of male meiosis through the last five generations (G5–G9) of telomerase-deficient Arabidopsis mutants. We used a previously described mutant line in which telomerase activity was abolished by T-DNA insertion into the TERT gene encoding telomerase reverse transcriptase. Reduced fertility accompanied by morphological abnormalities occurred in G6, which produced on average 35 seeds per silique (vs. 43 in wild type) and worsened in G7 (30 seeds) and G8 (14 seeds), as did the morphological abnormalities. The last generation of tert mutants (G9) did not form reproductive organs. Analysis of meiosis indicated that the main cause of reduced fertility in the late generation tert mutants of Arabidopsis was the numerous chromosomal end-to-end fusions which led to massive genome rearrangements in meiocytes. Fusion of meiotic chromosomes began in G5 and increased in each of the next generations. Unpaired chromosomes (univalents) were observed in G7 and G8. The study highlights some differences in the meiotic consequences of telomere shortening between plant and animal systems.
8

FISH and GISH analysis of Brassica genomes

84%
Hasterok R., Ksiazczyk T., Wolny E., Maluszynska J.
Acta Biologica Cracoviensia. Series Botanica
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2005
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tom 47
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nr 1
Fluorescence and genomic in situ hybridization (FISH and GISH) methods were used for discrimination of Brassica genomes. The three diploid and three allotetraploid species of Brassica, known as the "U-triangle," represent an attractive model for molecular and cytologieal analysis of genome changes during phylogeny in the genus Brassica. The use of genomic DNA probes enabled unambiguous discrimination of the ancestral genomes in B. juncea and B. carinata, and was only partially successful in B. napus. GISH signals in all genomes were localized predominantly in pericentromeric regions of chromosomes. Simultaneous application of genomic and ribosomal DNA probes in multicolor GISH and FISH allowed identification of a significant number of chromosomes in the B. juncea complement. The study also revealed that species of Brassica possess Arabidopsis-type telomeric repeats which in all genomes occupied exclusively terminal, that is, telomeric, locations of chromosomes.
9

Molecular cytogenetic analysis of genome structure in Chenopodium album complex

84%
Kolano B., Siwinska D., Maluszynska J.
Seria Biologiczna. Uniwersytet im. Adama Mickiewicza w Poznaniu
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2005
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tom 72
10

Fragments of LINE-1 retrotransposons flanked by inverted telomeric repeats are present in the bovine genome. Homology with human LINE-1 elements

84%
Plucienniczak G., Plucienniczak A.
Acta Biochimica Polonica
|
1999
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tom 46
|
nr 4
In the bovine genome we found two intrachromosomal DNA fragments flanked by inverted telomeric repeats (GenBank Accession Nos. AF136741 and AF136742). The internal parts of the fragments are homologous exclusively to the human sequences and to the consensus sequence of the L1MC4 subfamily of LINE-1 retrotransposons which are widespread among mammalian genomes. We found that distribution of homologous human sequences within our fragments is not random, reflecting a complicated pattern of insertion mechanisms of and maintenance of retrotransposons in mammalian genomes. One of the possible explanations of the origin of LINE-1 truncated elements flanked by inverted telomeric repeats in the bovine genome is that extrachromosomal DNA fragments may be modified by telomerase and subsequently, transferred into chromosomal DNA.
11

The activity of human telomerase in the cells of acute leukaemias

84%
Kocki J., Kolano J., Cioch M., Dmoszynska A., Wojcierowski J.
Folia Morphologica
|
2004
|
tom 63
|
nr 1
Telomeres are the end fragments of chromosomes formed by a number of non-coding double-stranded TTAGGG repeats in vertebrates. During cell division the number of repeats decreases, leading to cell senescence or apoptosis. In immortal cells, including cancer cells, the telomere length is stable and maintained by, among other factors, telomerase. The aim of the study is to compare telomerase activity in normal lymphocytes and in leukaemic cells. Samples of acute leukaemia cells, HL 60 cell line and the lymphocytes of healthy volunteers were examined. Telomerase analysis was performed using TeloTAGGG Telomerase PCR ELISAplus (Roche). The relative telomerase activities (RTA) in leukaemic and normal cells were analysed. A high level of RTA was observed in leukaemic cells.
12

Nuclear extrachromosomal DNA of higher plants

84%
Buchowicz J.
Acta Biochimica Polonica
|
1997
|
tom 44
|
nr 1
Recent reports indicate that mini chromosomes and other small genetic enti­ties may occur in the nuclei of uninfected higher plants. They become especially abundant under some special growth conditions and, sometimes, resemble extrachromosomal genes of ciliated protozoa. An example of such a gene-sized DNA species was isolated from resting wheat embryos. Hie presence of telo- meric sequences at its termini and the ability to replicate autonomously in wheat nuclei made it possible to distinguish this nuclear mini chromosome from chromosomal DNA fragmentation products. The biological significance of plant mini chromosomes remains to be elucidated.
13
Content available remote

Telomere shortening and ageing of the immune system

67%
Kaszubowska L.
Journal of Physiology and Pharmacology. Supplement
|
2008
|
tom 59
|
nr 9
169-186
14

Application of primed in situ DNA synthesis [PRINS] with telomere human commercial kit in molecular cytogenetics of Equus caballus and Sus scrofa scrofa

67%
Wnuk M., Bugno M., Slota E.
Folia Histochemica et Cytobiologica
|
2008
|
tom 46
|
nr 1
85-88
15
Content available remote

Sensitivity of natural killer cells to activation in the process of ageing is related to the oxidative and inflammatory status of the elderly

67%
Kaszubowska L., Kaczor J. J., Hak L., Dettlaff-Pokora A., Szarynska M., Kmiec Z.
Journal of Physiology and Pharmacology
|
2011
|
tom 62
|
nr 1
The role of the innate immunity during human ageing is not well understood. The aim of the study was to estimate reactivity of NK (natural killer) cells in the very old (mean age 91 years) and old subjects (mean age78 years) compared to young individuals (mean age 26 years) in respect to the indices of the oxidative stress (telomere length of NK cells, serum content of –SH groups), serum total antioxidant status and serum concentrations of interleukin 6 and tumor necrosis factor- (TNF-). The activation state of NK cells, reflected by telomerase activity and intracellular interferon (IFN) content, was also measured. We found that length of telomeres in NK cells and serum concentration of -SH groups decreased both in the old and the oldest subjects as compared to young individuals. The oldest seniors, on the contrary to the old ones, revealed similar level of serum antioxidant status as the young subjects. The serum level of IL-6, not detectable in the young subjects, did not differ in the oldest and old seniors. TNF- serum concentrations progressively increased with age. After stimulation, NK cells of both old groups showed higher intracellular levels of IFN than young subjects. IL-2-activated NK cells of the oldest seniors showed the highest increase of telomerase activity as compared to the other age groups. Serum level of IL-6 correlated positively with activation markers of NK cells. Moreover, in seniors but not in young subjects, the number of active, IFN-expressing NK cells, correlated positively with the serum content of the –SH groups. These findings indicate that sensitivity of NK cells to activation is maintained during ageing and this phenomenon may be related to the oxidative and inflammatory status of the elderly.
16
Content available remote

Successful ageing of nonagenarians is related to the sensitivity of NK cells to activation

67%
Kaszubowska L., Dettlaff-Pokora A., Hak L., Szarynska M., Ryba M., Mysliwska J., Mysliwski A.
Journal of Physiology and Pharmacology. Supplement
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2008
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tom 59
|
nr 9
187-199
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