scholarly journals Age-Dependent Regulation of Notch Family Members in the Neuronal Stem Cell Niches of the Short-Lived Killifish Nothobranchius furzeri

2021 ◽  
Vol 9 ◽  
Author(s):  
Sara Bagnoli ◽  
Eva Terzibasi Tozzini
Keyword(s):  
Notch Pathway ◽  
Model Organism ◽  
Active Regions ◽  
Proliferative Potential ◽  
Neuronal Stem Cell ◽  
Nothobranchius Furzeri ◽  
Age Dependent ◽  
Embryonic Origin ◽  
Stem Cell Niches

Background: The annual killifish Nothobranchius furzeri is a new experimental model organism in biology, since it represents the vertebrate species with the shortest captive life span and also shows the fastest maturation and senescence recorded in the laboratory. Here, we use this model to investigate the age-dependent decay of neurogenesis in the telencephalon (brain region sharing the same embryonic origin with the mammalian adult niches), focusing on the expression of the Notch pathway genes.Results: We observed that the major ligands/receptors of the pathway showed a negative correlation with age, indicating age-dependent downregulation of the Notch pathway. Moreover, expression of notch1a was clearly limited to active neurogenic niches and declined during aging, without changing its regional patterning. Expression of notch3 is not visibly influenced by aging.Conclusion: Both expression pattern and regulation differ between notch1a and notch3, with the former being limited to mitotically active regions and reduced by aging and the latter being present in all cells with a neurogenic potential, regardless of the level of their actual mitotic activity, and so is less influenced by age. This finally suggests a possible differential role of the two receptors in the regulation of the niche proliferative potential throughout the entire fish life.

scholarly journals A miRNA catalogue and ncRNA annotation of the short-living fish Nothobranchius furzeri

2017 ◽  
Author(s):  
Mario Baumgart ◽  
Emanuel Barth ◽  
Aurora Savino ◽  
Marco Groth ◽  
Philipp Koch ◽  
...  
Keyword(s):  
Gasterosteus Aculeatus ◽  
Model Organism ◽  
Takifugu Rubripes ◽  
Aging Research ◽  
Control Of Gene Expression ◽  
Non Coding Rna ◽  
Nothobranchius Furzeri ◽  
In Captivity ◽  
Supplementary Material

ABSTRACTBackground: The short-lived fish Nothobranchius furzeri is the shortest-lived vertebrate that can be cultured in captivity and was recently established as a model organism for aging research. Small non-coding RNAs, especially miRNAs, are implicated in age-dependent control of gene expression.Results: Here, we present a comprehensive catalogue of miRNAs and several other non-coding RNA classes (ncRNAs) for Nothobranchius furzeri. Analyzing multiple small RNA-Seq libraries, we show most of these identified miRNAs are expressed in at least one of seven Nothobranchius species. Additionally, duplication and clustering of N. furzeri miRNAs was analyzed and compared to the four fish species Danio rerio, Oryzias latipes, Gasterosteus aculeatus and Takifugu rubripes. A peculiar characteristic of N. furzeri as compared to other teleosts was a duplication of the miR-29 cluster.Conclusion: The completeness of the catalogue we provide is comparable to that of zebrafish. This catalogue represents a basis to investigate the role of miRNAs in aging and development in this species.Availability: All supplementary material can be found online at http://www.rna.uni-jena.de/en/supplements/nothobranchius-furzeri-mirnome/.

Influence of Magnetic Fields on Solar Hydrodynamics: Experimental Results

1977 ◽  
Vol 36 ◽  
pp. 143-180 ◽  
Author(s):  
J.O. Stenflo
Keyword(s):  
Solar Activity ◽  
Energy Balance ◽  
Magnetic Fields ◽  
Solar Atmosphere ◽  
General Problem ◽  
Solar Rotation ◽  
Active Regions ◽  
Physical Conditions ◽  
Dynamic Phenomena

It is well-known that solar activity is basically caused by the Interaction of magnetic fields with convection and solar rotation, resulting in a great variety of dynamic phenomena, like flares, surges, sunspots, prominences, etc. Many conferences have been devoted to solar activity, including the role of magnetic fields. Similar attention has not been paid to the role of magnetic fields for the overall dynamics and energy balance of the solar atmosphere, related to the general problem of chromospheric and coronal heating. To penetrate this problem we have to focus our attention more on the physical conditions in the ‘quiet’ regions than on the conspicuous phenomena in active regions.

scholarly journals Understanding the unimodal distributions of cancer occurrence rates: it takes two factors for a cancer to occur

2020 ◽  
Author(s):  
Shuang Qiu ◽  
Zheng An ◽  
Renbo Tan ◽  
Ping-an He ◽  
Jingjing Jing ◽  
...  
Keyword(s):  
Occurrence Rate ◽  
Cancer Drug ◽  
Proliferative Potential ◽  
Cancer Type ◽  
Cancer Occurrence ◽  
Important Relationship ◽  
Age Regression ◽  
Age Dependent ◽  
Two Factors ◽  
Realistic Possibility

Abstract Data from the SEER reports reveal that the occurrence rate of a cancer type generally follows a unimodal distribution over age, peaking at an age that is cancer-type specific and ranges from 30+ through 70+. Previous studies attribute such bell-shaped distributions to the reduced proliferative potential in senior years but fail to explain why some cancers have their occurrence peak at 30+ or 40+. We present a computational model to offer a new explanation to such distributions. The model uses two factors to explain the observed age-dependent cancer occurrence rates: cancer risk of an organ and the availability level of the growth signals in circulation needed by a cancer type, with the former increasing and the latter decreasing with age. Regression analyses were conducted of known occurrence rates against such factors for triple negative breast cancer, testicular cancer and cervical cancer; and all achieved highly tight fitting results, which were also consistent with clinical, gene-expression and cancer-drug data. These reveal a fundamentally important relationship: while cancer is driven by endogenous stressors, it requires sufficient levels of exogenous growth signals to happen, hence suggesting the realistic possibility for treating cancer via cleaning out the growth signals in circulation needed by a cancer.

Role of Notch pathway in effect of mono‐2‐ethylhexyl phthalate on the proliferation and cell cycle of SH‐SY5Y cell

2021 ◽  
Author(s):  
Bo Zhang ◽  
Xu Li ◽  
Xueting Zhang ◽  
Jiaming Ye ◽  
Weisen Zhao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Notch Pathway ◽  
Ethylhexyl Phthalate

scholarly journals Chloroplast Hsp70 Isoform Is Required for Age-Dependent Tissue Preference of Bamboo mosaic virus in Mature Nicotiana benthamiana Leaves

2017 ◽  
Vol 30 (8) ◽  
pp. 631-645 ◽  
Author(s):  
Ying Wen Huang ◽  
Chung Chi Hu ◽  
Ching Hsiu Tsai ◽  
Na Sheng Lin ◽  
Yau Heiu Hsu
Keyword(s):  
Mosaic Virus ◽  
Nicotiana Benthamiana ◽  
Transit Peptide ◽  
Plant Viruses ◽  
Age Dependent ◽  
Efficient Replication ◽  
Underlying Mechanisms ◽  
Lines Of Evidence ◽  
Suitable Environment

Plant viruses may exhibit age-dependent tissue preference in their hosts but the underlying mechanisms are not well understood. In this study, we provide several lines of evidence to reveal the determining role of a protein of the Nicotiana benthamiana chloroplast Hsp70 (NbcpHsp70) family, NbcpHsp70-2, involved in the preference of Bamboo mosaic virus (BaMV) to infect older tissues. NbcpHsp70 family proteins were identified in complexes pulled down with BaMV replicase as the bait. Among the isoforms of NbcpHsp70, only the specific silencing of NbcpHsp70-2 resulted in the significant decrease of BaMV RNA in N. benthamiana protopalsts, indicating that NbcpHsp70-2 is involved in the efficient replication of BaMV RNA. We further identified the age-dependent import regulation signal contained in the transit peptide of NbcpHsp70-2. Deletion, overexpression, and substitution experiments revealed that the signal in the transit peptide of NbcpHsp70-2 is crucial for both the import of NbcpHsp70-2 into older chloroplasts and the preference of BaMV for infecting older leaves of N. benthamiana. Together, these data demonstrated that BaMV may exploit a cellular age-dependent transportation mechanism to target a suitable environment for viral replication.

Notch restricts lymphatic vessel sprouting induced by vascular endothelial growth factor

Blood ◽  
2011 ◽  
Vol 118 (4) ◽  
pp. 1154-1162 ◽  
Author(s):  
Wei Zheng ◽  
Tuomas Tammela ◽  
Masahiro Yamamoto ◽  
Andrey Anisimov ◽  
Tanja Holopainen ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Target Genes ◽  
Notch Pathway ◽  
Lymphatic Vessels ◽  
Soluble Form ◽  
Fibrin Gel ◽  
3 Dimensional ◽  
Endothelial Growth Factor

Abstract Notch signaling plays a central role in cell-fate determination, and its role in lateral inhibition in angiogenic sprouting is well established. However, the role of Notch signaling in lymphangiogenesis, the growth of lymphatic vessels, is poorly understood. Here we demonstrate Notch pathway activity in lymphatic endothelial cells (LECs), as well as induction of delta-like ligand 4 (Dll4) and Notch target genes on stimulation with VEGF or VEGF-C. Suppression of Notch signaling by a soluble form of Dll4 (Dll4-Fc) synergized with VEGF in inducing LEC sprouting in 3-dimensional (3D) fibrin gel assays. Expression of Dll4-Fc in adult mouse ears promoted lymphangiogenesis, which was augmented by coexpressing VEGF. Lymphangiogenesis triggered by Notch inhibition was suppressed by a monoclonal VEGFR-2 Ab as well as soluble VEGF and VEGF-C/VEGF-D ligand traps. LECs transduced with Dll4 preferentially adopted the tip cell position over nontransduced cells in 3D sprouting assays, suggesting an analogous role for Dll4/Notch in lymphatic and blood vessel sprouting. These results indicate that the Notch pathway controls lymphatic endothelial quiescence, and explain why LECs are poorly responsive to VEGF compared with VEGF-C. Understanding the role of the Notch pathway in lymphangiogenesis provides further insight for the therapeutic manipulation of the lymphatic vessels.

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