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UV irradiation/cold shock-mediated apoptosis is switched to bubbling cell death at low temperatures.

Chen SJ, Lin PW, Lin HP, Huang SS, Lai FJ, Sheu HM, Hsu LJ, Chang NS - Oncotarget (2015)

Bottom Line: Arginine analog Nω-LAME inhibited NO synthase NOS2 and significantly suppressed the bubbling death.Bubbling death was significantly retarded in Wwox knockout MEF cells, as well as in cells overexpressing TRAF2 and dominant-negative p53.Presumably, proapoptotic WWOX and p53 block the protective TRAF2 to execute the bubbling death.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan, ROC.

ABSTRACT
When COS7 fibroblasts and other cells were exposed to UVC irradiation and cold shock at 4°C for 5 min, rapid upregulation and nuclear accumulation of NOS2, p53, WWOX, and TRAF2 occurred in 10-30 min. By time-lapse microscopy, an enlarging gas bubble containing nitric oxide (NO) was formed in the nucleus in each cell that finally popped out to cause "bubbling death". Bubbling occurred effectively at 4 and 22°C, whereas DNA fragmentation was markedly blocked at 4°C. When temperature was increased to 37°C, bubbling was retarded and DNA fragmentation occurred in 1 hr, suggesting that bubbling death is switched to apoptosis with increasing temperatures. Bubbling occurred prior to nuclear uptake of propidium iodide and DAPI stains. Arginine analog Nω-LAME inhibited NO synthase NOS2 and significantly suppressed the bubbling death. Unlike apoptosis, there were no caspase activation and flip-over of membrane phosphatidylserine (PS) during bubbling death. Bubbling death was significantly retarded in Wwox knockout MEF cells, as well as in cells overexpressing TRAF2 and dominant-negative p53. Together, UV/cold shock induces bubbling death at 4°C and the event is switched to apoptosis at 37°C. Presumably, proapoptotic WWOX and p53 block the protective TRAF2 to execute the bubbling death.

No MeSH data available.


Related in: MedlinePlus

Bubbling from a gas jet streamCOS7 cells were subjected to UV/cold shock and imaging by time-lapse microscopy at room temperature. (A) A representative COS7 cell exhibits a short gas tunnel or stalk (~1 μm in length; red arrow) connecting the cell and the bubble. (B) Release of nucleoli from a burst nucleus into the gas bubble is shown (red arrows). (C) Bubbling occurred prior to pickup of propidium iodide by the condensed nuclei. (D) A schematic model shows that the gas drives through the nucleus as a jet stream (yellow arrows) that punches out a single hole for generating a single bubble. The wall of the bubble is composed of the inner nuclear and outer cytoplasmic membranes.
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Figure 2: Bubbling from a gas jet streamCOS7 cells were subjected to UV/cold shock and imaging by time-lapse microscopy at room temperature. (A) A representative COS7 cell exhibits a short gas tunnel or stalk (~1 μm in length; red arrow) connecting the cell and the bubble. (B) Release of nucleoli from a burst nucleus into the gas bubble is shown (red arrows). (C) Bubbling occurred prior to pickup of propidium iodide by the condensed nuclei. (D) A schematic model shows that the gas drives through the nucleus as a jet stream (yellow arrows) that punches out a single hole for generating a single bubble. The wall of the bubble is composed of the inner nuclear and outer cytoplasmic membranes.

Mentions: It appears that under stimulation with UV/cold shock, the nuclear gas pushed forward as a jet stream in a single direction, so as to form a short stalk (~1–2 μm in length) to connect the bubble and the cell (see arrow; Figure 2A). Nucleoli were then released into the bubbles (see arrows; Figure 2B; Supplementary Video 3). Post bubbling for 30 min to 1 hr, cells were essentially dead as they failed to exclude trypan blue stain (> 95% cells) and their nuclei became positive for the propidium iodide stain (Figure 2C). A schematic graph shows a putative gas jet stream is formed and pops out to form a bubble. The wall of the bubble is probably enclosed by the outer plasma membrane and the inner nuclear membrane (Figure 2D).


UV irradiation/cold shock-mediated apoptosis is switched to bubbling cell death at low temperatures.

Chen SJ, Lin PW, Lin HP, Huang SS, Lai FJ, Sheu HM, Hsu LJ, Chang NS - Oncotarget (2015)

Bubbling from a gas jet streamCOS7 cells were subjected to UV/cold shock and imaging by time-lapse microscopy at room temperature. (A) A representative COS7 cell exhibits a short gas tunnel or stalk (~1 μm in length; red arrow) connecting the cell and the bubble. (B) Release of nucleoli from a burst nucleus into the gas bubble is shown (red arrows). (C) Bubbling occurred prior to pickup of propidium iodide by the condensed nuclei. (D) A schematic model shows that the gas drives through the nucleus as a jet stream (yellow arrows) that punches out a single hole for generating a single bubble. The wall of the bubble is composed of the inner nuclear and outer cytoplasmic membranes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4480731&req=5

Figure 2: Bubbling from a gas jet streamCOS7 cells were subjected to UV/cold shock and imaging by time-lapse microscopy at room temperature. (A) A representative COS7 cell exhibits a short gas tunnel or stalk (~1 μm in length; red arrow) connecting the cell and the bubble. (B) Release of nucleoli from a burst nucleus into the gas bubble is shown (red arrows). (C) Bubbling occurred prior to pickup of propidium iodide by the condensed nuclei. (D) A schematic model shows that the gas drives through the nucleus as a jet stream (yellow arrows) that punches out a single hole for generating a single bubble. The wall of the bubble is composed of the inner nuclear and outer cytoplasmic membranes.
Mentions: It appears that under stimulation with UV/cold shock, the nuclear gas pushed forward as a jet stream in a single direction, so as to form a short stalk (~1–2 μm in length) to connect the bubble and the cell (see arrow; Figure 2A). Nucleoli were then released into the bubbles (see arrows; Figure 2B; Supplementary Video 3). Post bubbling for 30 min to 1 hr, cells were essentially dead as they failed to exclude trypan blue stain (> 95% cells) and their nuclei became positive for the propidium iodide stain (Figure 2C). A schematic graph shows a putative gas jet stream is formed and pops out to form a bubble. The wall of the bubble is probably enclosed by the outer plasma membrane and the inner nuclear membrane (Figure 2D).

Bottom Line: Arginine analog Nω-LAME inhibited NO synthase NOS2 and significantly suppressed the bubbling death.Bubbling death was significantly retarded in Wwox knockout MEF cells, as well as in cells overexpressing TRAF2 and dominant-negative p53.Presumably, proapoptotic WWOX and p53 block the protective TRAF2 to execute the bubbling death.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan, ROC.

ABSTRACT
When COS7 fibroblasts and other cells were exposed to UVC irradiation and cold shock at 4°C for 5 min, rapid upregulation and nuclear accumulation of NOS2, p53, WWOX, and TRAF2 occurred in 10-30 min. By time-lapse microscopy, an enlarging gas bubble containing nitric oxide (NO) was formed in the nucleus in each cell that finally popped out to cause "bubbling death". Bubbling occurred effectively at 4 and 22°C, whereas DNA fragmentation was markedly blocked at 4°C. When temperature was increased to 37°C, bubbling was retarded and DNA fragmentation occurred in 1 hr, suggesting that bubbling death is switched to apoptosis with increasing temperatures. Bubbling occurred prior to nuclear uptake of propidium iodide and DAPI stains. Arginine analog Nω-LAME inhibited NO synthase NOS2 and significantly suppressed the bubbling death. Unlike apoptosis, there were no caspase activation and flip-over of membrane phosphatidylserine (PS) during bubbling death. Bubbling death was significantly retarded in Wwox knockout MEF cells, as well as in cells overexpressing TRAF2 and dominant-negative p53. Together, UV/cold shock induces bubbling death at 4°C and the event is switched to apoptosis at 37°C. Presumably, proapoptotic WWOX and p53 block the protective TRAF2 to execute the bubbling death.

No MeSH data available.


Related in: MedlinePlus