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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

UV irradiation and cold shock did not cause flip-over of PS onto cell surface(A) B16F10 cells in culture were added aliquots of PI and Annexin V stains, exposed to UV irradiation (480 mJoule/cm2) and cold shock (4°C for 5 min), and subjected to time-lapse imaging at room temperature (2 min per frame). Little or no Annexin V-positive cells were observed. (B) Similarly, B16F10 cells were treated with betulinic acid (100 μM) and subjected to time-lapse imaging at room temperature (2 min per frame).
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Figure 4: UV irradiation and cold shock did not cause flip-over of PS onto cell surface(A) B16F10 cells in culture were added aliquots of PI and Annexin V stains, exposed to UV irradiation (480 mJoule/cm2) and cold shock (4°C for 5 min), and subjected to time-lapse imaging at room temperature (2 min per frame). Little or no Annexin V-positive cells were observed. (B) Similarly, B16F10 cells were treated with betulinic acid (100 μM) and subjected to time-lapse imaging at room temperature (2 min per frame).

Mentions: To further verify the aforementioned results, time-lapse microscopy was carried out using melanoma B16F10 cells. Aliquots of green fluorescent Annexin V and red fluorescent propidium iodide were added to the culture of B16F10 cells. The cells were subjected to UV/cold shock and time-lapse microscopy at room temperature. Again, damage to the nucleus that led to bubble formation occurred in less than one hour, as revealed by accumulation of the red fluorescent propidium iodide in the nucleus, whereas no green fluorescence showing the flip-over of PS to the cell surface was observed (Figure 4A). To induce mitochondrial apoptosis, B16F10 cells were treated with betulinic acid [20, 21]. Time-lapse microscopy showed the presence of green fluorescence prior to the cell death (Figure 4B).


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)

UV irradiation and cold shock did not cause flip-over of PS onto cell surface(A) B16F10 cells in culture were added aliquots of PI and Annexin V stains, exposed to UV irradiation (480 mJoule/cm2) and cold shock (4°C for 5 min), and subjected to time-lapse imaging at room temperature (2 min per frame). Little or no Annexin V-positive cells were observed. (B) Similarly, B16F10 cells were treated with betulinic acid (100 μM) and subjected to time-lapse imaging at room temperature (2 min per frame).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 4: UV irradiation and cold shock did not cause flip-over of PS onto cell surface(A) B16F10 cells in culture were added aliquots of PI and Annexin V stains, exposed to UV irradiation (480 mJoule/cm2) and cold shock (4°C for 5 min), and subjected to time-lapse imaging at room temperature (2 min per frame). Little or no Annexin V-positive cells were observed. (B) Similarly, B16F10 cells were treated with betulinic acid (100 μM) and subjected to time-lapse imaging at room temperature (2 min per frame).
Mentions: To further verify the aforementioned results, time-lapse microscopy was carried out using melanoma B16F10 cells. Aliquots of green fluorescent Annexin V and red fluorescent propidium iodide were added to the culture of B16F10 cells. The cells were subjected to UV/cold shock and time-lapse microscopy at room temperature. Again, damage to the nucleus that led to bubble formation occurred in less than one hour, as revealed by accumulation of the red fluorescent propidium iodide in the nucleus, whereas no green fluorescence showing the flip-over of PS to the cell surface was observed (Figure 4A). To induce mitochondrial apoptosis, B16F10 cells were treated with betulinic acid [20, 21]. Time-lapse microscopy showed the presence of green fluorescence prior to the cell death (Figure 4B).

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