scholarly journals Responses of Marine Diatom Skeletonema marinoi to Nutrient Deficiency: Programmed Cell Death

2019 ◽  
Vol 86 (3) ◽  
Author(s):  
Hualong Wang ◽  
Feng Chen ◽  
Tiezhu Mi ◽  
Qian Liu ◽  
Zhigang Yu ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Enzymatic Activity ◽  
Marine Environment ◽  
Caspase 3 ◽  
Marine Diatom ◽  
Content Type ◽  
Nutrient Limitations ◽  
Insight Into ◽  
Skeletonema Marinoi

ABSTRACT Diatoms are important phytoplankton and contribute greatly to the primary productivity of marine ecosystems. Despite the ecological significance of diatoms and the importance of programmed cell death (PCD) in the fluctuation of diatom populations, little is known about the molecular mechanisms of PCD triggered by different nutrient stresses. Here we describe the physiological, morphological, biochemical, and molecular changes in response to low levels of nutrients in the ubiquitous diatom Skeletonema marinoi. The levels of gene expression involved in oxidation resistance and PCD strongly increased upon nitrogen (N) or phosphorus (P) starvation. The enzymatic activity of caspase 3-like protein also increased. Differences in mRNA levels and protein activities were observed between the low-N and low-P treatments, suggesting that PCD could have a differential response to different nutrient stresses. When cultures were replete with N or P, the growth inhibition stopped. Meanwhile, the enzymatic activity of caspase 3-like protein and the number of cells with damaged membranes decreased. These results suggest that PCD is an important cell fate decision mechanism in the marine diatom S. marinoi. Our results provide important insight into how diatoms adjust phenotypic and genotypic features of their cell-regulated death programs when stressed by nutrient limitations. Overall, this study could allow us to better understand the molecular mechanism behind the formation and termination of diatom blooms in the marine environment. IMPORTANCE Our study showed how the ubiquitous diatom S. marinoi responded to different nutrient limitations with PCD in terms of physiological, morphological, biochemical, and molecular characteristics. Some PCD-related genes (PDCD4, GOX, and HSP90) induced by N deficiency were relatively upregulated compared to those induced by P deficiency. In contrast, the expression of the TSG101 gene in S. marinoi showed a clear and constant increase during P limitation compared to N limitation. These findings suggest that PCD is a complex mechanism involving several different proteins. The systematic mRNA level investigations provide new insight into understanding the oxidative stress- and cell death-related functional genes of diatoms involved in the response to nutrient fluctuations (N or P stress) in the marine environment.

scholarly journals Inhibition of cathepsin B by caspase-3 inhibitors blocks programmed cell death in Arabidopsis

2016 ◽  
Vol 23 (9) ◽  
pp. 1493-1501 ◽  
Author(s):  
Y Ge ◽  
Y-M Cai ◽  
L Bonneau ◽  
V Rotari ◽  
A Danon ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Enzymatic Activity ◽  
Cathepsin B ◽  
Caspase 3 ◽  
Animal Cells ◽  
Biotic And Abiotic Stresses ◽  
Triple Mutant ◽  
Mutant Lines

Abstract Programmed cell death (PCD) is used by plants for development and survival to biotic and abiotic stresses. The role of caspases in PCD is well established in animal cells. Over the past 15 years, the importance of caspase-3-like enzymatic activity for plant PCD completion has been widely documented despite the absence of caspase orthologues. In particular, caspase-3 inhibitors blocked nearly all plant PCD tested. Here, we affinity-purified a plant caspase-3-like activity using a biotin-labelled caspase-3 inhibitor and identified Arabidopsis thaliana cathepsin B3 (AtCathB3) by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Consistent with this, recombinant AtCathB3 was found to have caspase-3-like activity and to be inhibited by caspase-3 inhibitors. AtCathepsin B triple-mutant lines showed reduced caspase-3-like enzymatic activity and reduced labelling with activity-based caspase-3 probes. Importantly, AtCathepsin B triple mutants showed a strong reduction in the PCD induced by ultraviolet (UV), oxidative stress (H2O2, methyl viologen) or endoplasmic reticulum stress. Our observations contribute to explain why caspase-3 inhibitors inhibit plant PCD and provide new tools to further plant PCD research. The fact that cathepsin B does regulate PCD in both animal and plant cells suggests that this protease may be part of an ancestral PCD pathway pre-existing the plant/animal divergence that needs further characterisation.

Apoptosis after traumatic human spinal cord injury

1998 ◽  
Vol 89 (6) ◽  
pp. 911-920 ◽  
Author(s):  
Evelyne Emery ◽  
Philipp Aldana ◽  
Mary Bartlett Bunge ◽  
William Puckett ◽  
Anu Srinivasan ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Caspase 3 ◽  
Apoptotic Cells ◽  
Content Type ◽  
Human Spinal Cord ◽  
Cord Injury ◽  
Fine Print

Object. Apoptosis is a form of programmed cell death seen in a variety of developmental and disease states, including traumatic injuries. The main objective of this study was to determine whether apoptosis is observed after human spinal cord injury (SCI). The spatial and temporal expression of apoptotic cells as well as the nature of the cells involved in programmed cell death were also investigated. Methods. The authors examined the spinal cords of 15 patients who died between 3 hours and 2 months after a traumatic SCI. Apoptotic cells were found at the edges of the lesion epicenter and in the adjacent white matter, particularly in the ascending tracts, by using histological (cresyl violet, hematoxylin and eosin) and nuclear staining (Hoechst 33342). The presence of apoptotic cells was supported by staining with the terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick-end labeling technique and confirmed by immunostaining for the processed form of caspase-3 (CPP-32), a member of the interleukin-1β-converting enzyme/Caenorhabditis elegans D 3 (ICE/CED-3) family of proteases that plays an essential role in programmed cell death. Apoptosis in this series of human SCIs was a prominent pathological finding in 14 of the 15 spinal cords examined when compared with five uninjured control spinal cords. To determine the type of cells undergoing apoptosis, the authors immunostained specimens with a variety of antibodies, including glial fibrillary acidic protein, 2′,3′-cyclic nucleotide 3′-phosphohydrolase (CNPase), and CD45/68. Oligodendrocytes stained with CNPase and a number of apoptotic nuclei colocalized with positive staining for this antibody. Conclusions. These results support the hypothesis that apoptosis occurs in human SCIs and is accompanied by the activation of caspase-3 of the cysteine protease family. This mechanism of cell death contributes to the secondary injury processes seen after human SCI and may have important clinical implications for the further development of protease inhibitors to prevent programmed cell death.

scholarly journals Cell Death and Metabolic Stress in Gymnodinium catenatum Induced by Allelopathy

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 506
Author(s):  
Leyberth José Fernández-Herrera ◽  
Christine Johanna Band-Schmidt ◽  
Tania Zenteno-Savín ◽  
Ignacio Leyva-Valencia ◽  
Claudia Judith Hernández-Guerrero ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Protein Content ◽  
Caspase 3 ◽  
Cellular Stress ◽  
Allelopathic Effect ◽  
Sod Activity ◽  
Free Media ◽  
O2 Production ◽  
Gymnodinium Catenatum

Allelopathy between phytoplankton species can promote cellular stress and programmed cell death (PCD). The raphidophyte Chattonella marina var. marina, and the dinoflagellates Margalefidinium polykrikoides and Gymnodinium impudicum have allelopathic effects on Gymnodinium catenatum; however, the physiological mechanisms are unknown. We evaluated whether the allelopathic effect promotes cellular stress and activates PCD in G. catenatum. Cultures of G. catenatum were exposed to cell-free media of C. marina var. marina, M. polykrikoides and G. impudicum. The mortality, superoxide radical (O2●−) production, thiobarbituric acid reactive substances (TBARS) levels, superoxide dismutase (SOD) activity, protein content, and caspase-3 activity were quantified. Mortality (between 57 and 79%) was registered in G. catenatum after exposure to cell-free media of the three species. The maximal O2●− production occurred with C. marina var. marina cell-free media. The highest TBARS levels and SOD activity in G. catenatum were recorded with cell-free media from G. impudicum. The highest protein content was recorded with cell-free media from M. polykrikoides. All cell-free media caused an increase in the activity of caspase-3. These results indicate that the allelopathic effect in G. catenatum promotes cell stress and caspase-3 activation, as a signal for the induction of programmed cell death.

Region of caspase-3 activation and programmed cell death in the early development of the mouse forebrain

2003 ◽  
Vol 145 (2) ◽  
pp. 241-248 ◽  
Author(s):  
Koko Urase ◽  
Yoriko Kouroku ◽  
Eriko Fujita ◽  
Takashi Momoi
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Early Development ◽  
Caspase 3
Sign in / Sign up

Export Citation Format

Share Document