scholarly journals Functional Dioecy inEchinocereus: Ontogenetic Patterns, Programmed Cell Death, and Evolutionary Significance

2018 ◽  
Vol 179 (4) ◽  
pp. 257-274 ◽  
Author(s):  
Rocío Hernández-Cruz ◽  
Fátima Barrón-Pacheco ◽  
Daniel Sánchez ◽  
Salvador Arias ◽  
Sonia Vázquez-Santana
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Evolutionary Significance ◽  
Functional Dioecy

scholarly journals Pollen and anther development malfunction in distylous flowers of Palicourea padifolia (Rubiaceae)

2020 ◽  
Vol 98 (4) ◽  
pp. 554-569
Author(s):  
Juan Francisco Ornelas ◽  
Judith Márquez-Guzmán ◽  
Mónica Pérez Pacheco
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Pollen Development ◽  
Developmental Stages ◽  
Initial Step ◽  
Anther Development ◽  
Sexual Selection Theory ◽  
Allocation Patterns ◽  
Functional Dioecy ◽  
Study Species

Background: Heterostyly is a genetic polymorphism in which flowers differ between individual plants of a species in heights at which stamens and style are reciprocally positioned. In these species, sexual selection theory predicts that different allocation patterns affect the functioning of polymorphism, enabling the evolutionary transition between heterostyly and dioecy. Questions: Because heterostyly can transit into dioecy, does anther/pollen development differ between floral morphs (LS and SS) of P. padifolia? Is pollen/anther development malfunction associated with one morph more than the other? Study species: Palicourea padifolia (Rubiaceae), a distylous plant. Methods: Tiny floral buds to flowers at anthesis were collected, processed for microphotography, and examined to describe pollen developmental pathways in LS and SS flowers. In addition, we used the TUNEL test to detect programmed cell death. Results: Stages of normal pollen development are fully described and illustrated in LS and SS flowers. Abnormalities due to tapetal degeneration were observed at various developmental stages; at later stages, SS flowers showed more abnormalities than LS flowers. The TUNEL test showed that degeneration was by programmed cell death. Conclusions: Along with previous results of asymmetrical fecundity and pollen transfer of morphs in P. padifolia, our study of pollen development indicates that the SS morph was more prone to lose the male function, though male sterility is far from being complete, which it might be an initial step towards functional dioecy.

Programmed Cell Death Ligand 1 and Venous Thromboembolism in Patients with Primary Brain Tumors

2019 ◽  
Author(s):  
P. Seyed Mir ◽  
A.-S. Berghoff ◽  
M. Preusser ◽  
G. Ricken ◽  
J. Riedl ◽  
...  
Keyword(s):  
Cell Death ◽  
Venous Thromboembolism ◽  
Programmed Cell Death ◽  
Brain Tumors ◽  
Primary Brain Tumors

Glial cytotoxicity of low doses of cadmium as a model of heavy metal pollution influence on vertebrates

2020 ◽  
Vol 31 (1) ◽  
pp. 3-10
Author(s):  
V. S. Nedzvetsky ◽  
V. Ya. Gasso ◽  
A. M. Hahut ◽  
I. A. Hasso
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Oxidative Damage ◽  
Cadmium Chloride ◽  
Glioma Cells ◽  
Low Doses ◽  
Genotoxic Effects ◽  
Cadmium Ions

Cadmium is a common transition metal that entails an extremely wide range of toxic effects in humans and animals. The cytotoxicity of cadmium ions and its compounds is due to various genotoxic effects, including both DNA damage and chromosomal aberrations. Some bone diseases, kidney and digestive system diseases are determined as pathologies that are closely associated with cadmium intoxication. In addition, cadmium is included in the list of carcinogens because of its ability to initiate the development of tumors of several forms of cancer under conditions of chronic or acute intoxication. Despite many studies of the effects of cadmium in animal models and cohorts of patients, in which cadmium effects has occurred, its molecular mechanisms of action are not fully understood. The genotoxic effects of cadmium and the induction of programmed cell death have attracted the attention of researchers in the last decade. In recent years, the results obtained for in vivo and in vitro experimental models have shown extremely high cytotoxicity of sublethal concentrations of cadmium and its compounds in various tissues. One of the most studied causes of cadmium cytotoxicity is the development of oxidative stress and associated oxidative damage to macromolecules of lipids, proteins and nucleic acids. Brain cells are most sensitive to oxidative damage and can be a critical target of cadmium cytotoxicity. Thus, oxidative damage caused by cadmium can initiate genotoxicity, programmed cell death and inhibit their viability in the human and animal brains. To test our hypothesis, cadmium cytotoxicity was assessed in vivo in U251 glioma cells through viability determinants and markers of oxidative stress and apoptosis. The result of the cell viability analysis showed the dose-dependent action of cadmium chloride in glioma cells, as well as the generation of oxidative stress (p <0.05). Calculated for 48 hours of exposure, the LD50 was 3.1 μg×ml-1. The rates of apoptotic death of glioma cells also progressively increased depending on the dose of cadmium ions. A high correlation between cadmium concentration and apoptotic response (p <0.01) was found for cells exposed to 3–4 μg×ml-1 cadmium chloride. Moreover, a significant correlation was found between oxidative stress (lipid peroxidation) and induction of apoptosis. The results indicate a strong relationship between the generation of oxidative damage by macromolecules and the initiation of programmed cell death in glial cells under conditions of low doses of cadmium chloride. The presented results show that cadmium ions can induce oxidative damage in brain cells and inhibit their viability through the induction of programmed death. Such effects of cadmium intoxication can be considered as a model of the impact of heavy metal pollution on vertebrates.

Dynamical analysis of the programmed cell death pathway

2007 ◽  
Author(s):  
Luciano Carotenuto ◽  
Vincenza Pace ◽  
Dina Bellizzi ◽  
Giovanna De Benedictis
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Dynamical Analysis ◽  
Cell Death Pathway

Biological response of the organism to the introduction of metal nanocomposites

2020 ◽  
pp. 761-762
Author(s):  
L. M. Sosedova ◽  
V. S. Rukavishnikov ◽  
E. A. Titov
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Biological Response ◽  
Brain Cell ◽  
Metal Nanocomposites ◽  
The Brain

The results of a study on rats toxicity of nanoparticles of metals bismuth, gadolinium and silver encapsulated in a natural biopolymer matrix arabinogalactan are presented. When intake of nanocomposite of silver revealed the readiness of the brain cell to apoptosis. The effect of bismuth and gadolinium nanocomposites did not cause an increase in the process of programmed cell death.

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