Unique Mitochondrial Ion Channels: Roles in Synaptic Transmission and Programmed Cell Death

Author(s):  
Elizabeth A. Jonas
2019 ◽  
Author(s):  
Maija Sierla ◽  
David L. Prole ◽  
Nuno Saraiva ◽  
Guia Carrara ◽  
Natalia Dinischiotu ◽  
...  

ABSTRACTProgrammed cell death regulates developmental and stress responses in eukaryotes. Golgi anti-apoptotic proteins (GAAPs) are evolutionarily conserved cell death regulators. Human and viral GAAPs inhibit apoptosis and modulate intracellular Ca2+fluxes, and viral GAAPs form cation-selective channels. Although most mammalian cell death regulators are not conserved at the sequence level in plants, the GAAP gene family shows expansion, with five paralogues (AtGAAP1-5) in the Arabidopsis genome. We pursued molecular and physiological characterization of AtGAAPs making use of the advanced knowledge of their human and viral counterparts. Structural modeling of AtGAAPs predicted the presence of a channel-like pore, and electrophysiological recordings from purified AtGAAP3 reconstituted into lipid bilayers confirmed that plant GAAPs can function as ion channels. AtGAAP1 and AtGAAP4 localized exclusively to the Golgi within the plant cell, while AtGAAP2, AtGAAP3 and AtGAAP5 also showed tonoplastic localization. Gene expression analysis revealed differential spatial expression and abundance of transcript forAtGAAPparalogues in Arabidopsis tissues. We demonstrate that AtGAAP1-5 inhibit Bax-induced cell death in yeast. However, overexpression of AtGAAP1 induces cell death inNicotiana benthamianaleaves and lesion mimic phenotype in Arabidopsis. We propose that AtGAAPs function as Golgi-localized ion channels that regulate cell death by affecting ionic homeostasis within the cell.HighlightArabidopsis Golgi anti-apoptotic proteins (GAAPs) share functional conservation with their human and viral counterparts in cell death regulation and ion channel activityAbbreviationsAtGAAP,Arabidopsis thalianaGAAP; BI-1, Bax inhibitor-1; CFP, cyan fluorescent protein; CMLV, camelpox virus; ER, Endoplasmic reticulum; GAAP, Golgi anti-apoptotic protein; GFP, green fluorescent protein; hGAAP, human GAAP; LFG, Lifeguard; LMM, lesion mimic mutant; PCD, programmed cell death; TMBIM, transmembrane Bax inhibitor-1 motif-containing; TMDs, transmembrane domains; vGAAP, viral GAAP; YFP, yellow fluorescent protein


2011 ◽  
Vol 301 (6) ◽  
pp. C1281-C1289 ◽  
Author(s):  
V'yacheslav Lehen'kyi ◽  
George Shapovalov ◽  
Roman Skryma ◽  
Natalia Prevarskaya

Ion channels contribute to virtually all basic cellular processes, including such crucial ones for maintaining tissue homeostasis as proliferation, differentiation, and apoptosis. The involvement of ion channels in regulation of programmed cell death, or apoptosis, has been known for at least three decades based on observation that classical blockers of ion channels can influence cell death rates, prolonging or shortening cell survival. Identification of the central role of these channels in regulation of cell cycle and apoptosis as well as the recent discovery that the expression of ion channels is not limited solely to the plasma membrane, but may also include membranes of internal compartments, has led researchers to appreciate the pivotal role of ion channels plays in development of cancer. This review focuses on the aspects of programmed cell death influenced by various ion channels and how dysfunctions and misregulations of these channels may affect the development and progression of different cancers.


2019 ◽  
Author(s):  
P. Seyed Mir ◽  
A.-S. Berghoff ◽  
M. Preusser ◽  
G. Ricken ◽  
J. Riedl ◽  
...  

2020 ◽  
Vol 31 (1) ◽  
pp. 3-10
Author(s):  
V. S. Nedzvetsky ◽  
V. Ya. Gasso ◽  
A. M. Hahut ◽  
I. A. Hasso

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.


Author(s):  
Luciano Carotenuto ◽  
Vincenza Pace ◽  
Dina Bellizzi ◽  
Giovanna De Benedictis

Author(s):  
L. M. Sosedova ◽  
V. S. Rukavishnikov ◽  
E. A. Titov

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.


Sign in / Sign up

Export Citation Format

Share Document