scholarly journals Oxidative Stress Induces Telomere Dysfunction and Shortening in Human Oocytes of Advanced Age Donors

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1866
Author(s):  
Paweł Kordowitzki

Research from the past decades provided strong evidence that in humans the pool of oocytes starts to decline already before the birth of a female individual, and from menarche to menopause the oocyte is exposed to different environmental stimuli. Since more and more women of the 21st century in developed countries wish to postpone the first pregnancy to their thirties, higher rates of miscarriage and chromosomal non-disjunction might occur. In oocytes of advanced maternal age, meaning above 35 years of age, characteristics such as chromosomal instabilities/abnormalities, spindle defects, decreased mitochondrial function and telomere shortening become more prevalent than in younger counterparts. Telomere attrition belongs to the so-called “hallmarks of aging” which are also relevant for the female germ-line cells. In oocytes, telomeres shorten with advancing maternal age due to the effects of reactive oxygen species and not upon replicative senescence, similar to how it is common in dividing cells.

2018 ◽  
Vol 19 (9) ◽  
pp. 2841 ◽  
Author(s):  
Marketa Koncicka ◽  
Anna Tetkova ◽  
Denisa Jansova ◽  
Edgar Del Llano ◽  
Lenka Gahurova ◽  
...  

The rate of chromosome segregation errors that emerge during meiosis I in the mammalian female germ line are known to increase with maternal age; however, little is known about the underlying molecular mechanism. The objective of this study was to analyze meiotic progression of mouse oocytes in relation to maternal age. Using the mouse as a model system, we analyzed the timing of nuclear envelope breakdown and the morphology of the nuclear lamina of oocytes obtained from young (2 months old) and aged females (12 months old). Oocytes obtained from older females display a significantly faster progression through meiosis I compared to the ones obtained from younger females. Furthermore, in oocytes from aged females, lamin A/C structures exhibit rapid phosphorylation and dissociation. Additionally, we also found an increased abundance of MPF components and increased translation of factors controlling translational activity in the oocytes of aged females. In conclusion, the elevated MPF activity observed in aged female oocytes affects precocious meiotic processes that can multifactorially contribute to chromosomal errors in meiosis I.


Blood ◽  
1999 ◽  
Vol 93 (9) ◽  
pp. 2824-2830 ◽  
Author(s):  
Steven L. Zeichner ◽  
Paul Palumbo ◽  
YanRu Feng ◽  
Xiaodong Xiao ◽  
Dennis Gee ◽  
...  

Telomere shortening may reflect the total number of divisions experienced by a somatic cell and is associated with replicative senescence. We found that the average rate of telomere shortening in peripheral blood mononuclear cells (PBMCs) obtained longitudinally from nine different infants during the first 3 years of life (270 bp per year) is more than fourfold higher than in adults and does not correlate with telomerase activity. These results show that the rate of telomere loss changes during ontogeny, suggesting the existence of periods of accelerated cell division. Because human immunodeficiency virus (HIV) preferentially infects actively dividing cells, our observation suggesting accelerated cell division in children may provide an explanation for some of the distinctive pathogenic features of the HIV disease in infants, including higher viral loads and more rapid progression to acquired immunodeficiency syndrome (AIDS).


Blood ◽  
1999 ◽  
Vol 93 (9) ◽  
pp. 2824-2830 ◽  
Author(s):  
Steven L. Zeichner ◽  
Paul Palumbo ◽  
YanRu Feng ◽  
Xiaodong Xiao ◽  
Dennis Gee ◽  
...  

Abstract Telomere shortening may reflect the total number of divisions experienced by a somatic cell and is associated with replicative senescence. We found that the average rate of telomere shortening in peripheral blood mononuclear cells (PBMCs) obtained longitudinally from nine different infants during the first 3 years of life (270 bp per year) is more than fourfold higher than in adults and does not correlate with telomerase activity. These results show that the rate of telomere loss changes during ontogeny, suggesting the existence of periods of accelerated cell division. Because human immunodeficiency virus (HIV) preferentially infects actively dividing cells, our observation suggesting accelerated cell division in children may provide an explanation for some of the distinctive pathogenic features of the HIV disease in infants, including higher viral loads and more rapid progression to acquired immunodeficiency syndrome (AIDS).


2020 ◽  
pp. 49-57
Author(s):  
S. V. Orlova ◽  
E. A. Nikitina ◽  
L. I. Karushina ◽  
Yu. A. Pigaryova ◽  
O. E. Pronina

Vitamin A (retinol) is one of the key elements for regulating the immune response and controls the division and differentiation of epithelial cells of the mucous membranes of the bronchopulmonary system, gastrointestinal tract, urinary tract, eyes, etc. Its significance in the context of the COVID‑19 pandemic is difficult to overestimate. However, a number of studies conducted in the past have associated the additional intake of vitamin A with an increased risk of developing cancer, as a result of which vitamin A was practically excluded from therapeutic practice in developed countries. Our review highlights the role of vitamin A in maintaining human health and the latest data on its effect on the development mechanisms of somatic pathology.


Shore & Beach ◽  
2020 ◽  
pp. 65-73
Author(s):  
Gen Liu ◽  
Feng Cai ◽  
Hongshuai Qi ◽  
Jianhui Liu ◽  
Gang Lei ◽  
...  

Beach nourishment has been widely used for beach protection around the world. However, there is limited information about beach nourishment in China. This study offers an overview of beach nourishment practices, status and technological advances in China, based on the literature, reports, and personal communications. The results demonstrate that beach nourishment has been recognized as an effective and environmentally friendly measure to combat coastal erosion and has been increasingly adopted in China, especially in the past decade. The unique characteristics of coastal China resulted in a difference in beach nourishment between China and Western developed countries in terms of the types, objectives, and shapes of beach nourishment. For the types of nourishments in China, there were approximately the same number of restored beaches and newly constructed beaches. For fill sediment, homogeneous fill and heterogeneous fill comprised 51.1% and 48.9% of projects, respectively. The objective of beach nourishment was mainly to promote coastal tourism, and the shape of nourished beaches was dominated by headland bays. This study also indicated that China has achieved a number of technological advances in beach nourishment, including methods of beach nourishment on severely eroded coasts and muddy coasts, an optimized design of drain pipes involved in urban beaches, and ecological design considerations. From the past decade of practices, four aspects were proposed as considerations for future nourishment: sand sources, technique advances, ecological effects, and management of beach nourishments.


Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1227-1244 ◽  
Author(s):  
Steffi Kuhfittig ◽  
János Szabad ◽  
Gunnar Schotta ◽  
Jan Hoffmann ◽  
Endre Máthé ◽  
...  

Abstract The vast majority of the >100 modifier genes of position-effect variegation (PEV) in Drosophila have been identified genetically as haplo-insufficient loci. Here, we describe pitkinDominant (ptnD), a gain-of-function enhancer mutation of PEV. Its exceptionally strong enhancer effect is evident as elevated spreading of heterochromatin-induced gene silencing along euchromatic regions in variegating rearrangements. The ptnD mutation causes ectopic binding of the SU(VAR)3-9 heterochromatin protein at many euchromatic sites and, unlike other modifiers of PEV, it also affects stable position effects. Specifically, it induces silencing of white+ transgenes inserted at a wide variety of euchromatic sites. ptnD is associated with dominant female sterility. +/+ embryos produced by ptnD/+ females mated with wild-type males die at the end of embryogenesis, whereas the ptnD/+ sibling embryos arrest development at cleavage cycle 1-3, due to a combined effect of maternally provided mutant product and an early zygotic lethal effect of ptnD. This is the earliest zygotic effect of a mutation so far reported in Drosophila. Germ-line mosaics show that ptn+ function is required for normal development in the female germ line. These results, together with effects on PEV and white+ transgenes, are consistent with the hypothesis that the ptn gene plays an important role in chromatin regulation during development of the female germ line and in early embryogenesis.


2018 ◽  
Vol 7 (4.5) ◽  
pp. 65
Author(s):  
T. P.Deepa ◽  
Dr Pradeepa.P

Airport security system is mandatory in all developing and developed countries. The major threat to any country’s economy, health and development is targeted and transported via airports which are evident from the past historical examples. The developments in Science and Technology have improved the methods of surveillance but failed to address few key health issues including privacy. The main objective of this paper is to develop a smart IOT based surveillance systems that is implemented in airport in smart screening without causing any unpleasant disturbances to the passengers. This paper makes use of the recently developed smart sensors, Tiva processor from Texas instruments connected via IOT and cloud and a remote station to effectively secure the airport area and overcoming all the real time challenges. 


1990 ◽  
Vol 39 (3) ◽  
pp. 279-293 ◽  
Author(s):  
A.W. Eriksson

AbstractA study was conducted on twinning in relatives of consecutive triplet sets in the Åland Islands in the years 1740-1939. The incidence of twinning in sibships of triplets was extremely high, 80/1000 (56/1000 before and 143/1000 after the triplet maternity). In Finland as a whole, 1905-1954, the twinning rate was among mothers of triplets 38/1000, ie, about 2.6 times the rate in general population, and was higher after (48/1000) than before the triplet maternity (34/1000). In the sibships of fathers of triplets there was a low rate of twinning (below 10/1000) both of same-sexed (SS) and of opposite-sexed (OS) triplets. Among sibships of mothers of OS triplets the twinning rate was 18/1000 and among mothers' sibships of SS triplets 26/1000. The series of triplet families from both Åland and Finland as a whole indicate a considerably higher frequency of twinning on the maternal than on the paternal side. The sibships of OS triplets in Finland have higher twinning rates than sibships of SS triplets (50/1000 vs 27/1000). In sibships of triplets, not only the DZ but also the MZ twinning rates were approximately twice as high as those in the general population. The triplet rates in Finland were increasing strongly with maternal age and were in the last century among mothers of 30-39 years of age considerably higher than among mothers from this century. This, in combination with higher mean parity, may explain the high rates of multiple maternities in sibships of triplets in the past. The rate of triplet maternities seems to be more sensitive to sociodemographic changes than the rate of twin maternities. Mothers of triplets in Finland had a high frequency (more than 40%) of prenuptially conceived firstborn children. This, and a short protogenesic interval indicate that triplet-prone mothers are more fecundable, ie, they conceive with greater ease and/or may have a better physical condition than other women for completing a gestation with multiple embryos.


2006 ◽  
Vol 8 (1) ◽  
pp. 8-8
Author(s):  
Magdalena Skipper
Keyword(s):  

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