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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/cold shock induces NOS2 and TRAF2 expression(A) COS7 cell were exposed to UV irradiation (480 mJoule/cm2) and subsequent incubation at 4°C for 5 and 10 min. Cold shock alone weakly induced the expression of both endogenous NOS2 and TRAF2. Pre-exposure of cells to UV and then cold shock enhanced the generation of both proteins. UV alone rapidly induced the expression of TRAF2. (B) Down-regulation of antiapoptotic TRAF2 and NF-κB/p65 occurred when Wwox wild type MEF cells were exposed to UV (480 mJoule/cm2) and subsequent cold shock for 30 min to 3 hr. However, TRAF2 was upregulated in UV/cold shock-treated Wwox knockout MEF cells. (C) By immunohistochemistry, the expression of WWOX/WOX1 and TRAF2 in normal human skin and frostbitten skin is shown. Scale bars: 20 μm. (D) A schematic graph for the TRAF2 domains is shown. Ring = Ring-type zinc finger domain; CC = Coiled coil domain; MATH = MATH/TRAF domain. COS7 cells were transiently overexpressed with ECFP, truncated ECFP-TRAF2(113–312), and 2 identical full-length ECFP-TRAF2, respectively. UV (480 mJoule/cm2)/cold shock (4°C for 5 min)-induced bubbling death in cells expressing the indicated protein was counted (~100 cells counted; n = 3).
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Figure 7: UV/cold shock induces NOS2 and TRAF2 expression(A) COS7 cell were exposed to UV irradiation (480 mJoule/cm2) and subsequent incubation at 4°C for 5 and 10 min. Cold shock alone weakly induced the expression of both endogenous NOS2 and TRAF2. Pre-exposure of cells to UV and then cold shock enhanced the generation of both proteins. UV alone rapidly induced the expression of TRAF2. (B) Down-regulation of antiapoptotic TRAF2 and NF-κB/p65 occurred when Wwox wild type MEF cells were exposed to UV (480 mJoule/cm2) and subsequent cold shock for 30 min to 3 hr. However, TRAF2 was upregulated in UV/cold shock-treated Wwox knockout MEF cells. (C) By immunohistochemistry, the expression of WWOX/WOX1 and TRAF2 in normal human skin and frostbitten skin is shown. Scale bars: 20 μm. (D) A schematic graph for the TRAF2 domains is shown. Ring = Ring-type zinc finger domain; CC = Coiled coil domain; MATH = MATH/TRAF domain. COS7 cells were transiently overexpressed with ECFP, truncated ECFP-TRAF2(113–312), and 2 identical full-length ECFP-TRAF2, respectively. UV (480 mJoule/cm2)/cold shock (4°C for 5 min)-induced bubbling death in cells expressing the indicated protein was counted (~100 cells counted; n = 3).

Mentions: UVB activates TNF receptor-associated factor-2 (TRAF2), p53 and WWOX/WOX1 in the skin [12–14, 20, 28]. In COS7 cells, UV irradiation rapidly induced the expression of endogenous TRAF2 in the cytoplasm, and that subsequent cold shock caused upregulation and colocalization of TRAF2 and NOS2 in the nucleus in 10 min, as determined by immunofluorescence microscopy (Figure 7A). The nuclear accumulation of TRAF2 and NOS2 was greater than 95% (~100 cells counted; n = 3).


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/cold shock induces NOS2 and TRAF2 expression(A) COS7 cell were exposed to UV irradiation (480 mJoule/cm2) and subsequent incubation at 4°C for 5 and 10 min. Cold shock alone weakly induced the expression of both endogenous NOS2 and TRAF2. Pre-exposure of cells to UV and then cold shock enhanced the generation of both proteins. UV alone rapidly induced the expression of TRAF2. (B) Down-regulation of antiapoptotic TRAF2 and NF-κB/p65 occurred when Wwox wild type MEF cells were exposed to UV (480 mJoule/cm2) and subsequent cold shock for 30 min to 3 hr. However, TRAF2 was upregulated in UV/cold shock-treated Wwox knockout MEF cells. (C) By immunohistochemistry, the expression of WWOX/WOX1 and TRAF2 in normal human skin and frostbitten skin is shown. Scale bars: 20 μm. (D) A schematic graph for the TRAF2 domains is shown. Ring = Ring-type zinc finger domain; CC = Coiled coil domain; MATH = MATH/TRAF domain. COS7 cells were transiently overexpressed with ECFP, truncated ECFP-TRAF2(113–312), and 2 identical full-length ECFP-TRAF2, respectively. UV (480 mJoule/cm2)/cold shock (4°C for 5 min)-induced bubbling death in cells expressing the indicated protein was counted (~100 cells counted; n = 3).
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Related In: Results  -  Collection

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Figure 7: UV/cold shock induces NOS2 and TRAF2 expression(A) COS7 cell were exposed to UV irradiation (480 mJoule/cm2) and subsequent incubation at 4°C for 5 and 10 min. Cold shock alone weakly induced the expression of both endogenous NOS2 and TRAF2. Pre-exposure of cells to UV and then cold shock enhanced the generation of both proteins. UV alone rapidly induced the expression of TRAF2. (B) Down-regulation of antiapoptotic TRAF2 and NF-κB/p65 occurred when Wwox wild type MEF cells were exposed to UV (480 mJoule/cm2) and subsequent cold shock for 30 min to 3 hr. However, TRAF2 was upregulated in UV/cold shock-treated Wwox knockout MEF cells. (C) By immunohistochemistry, the expression of WWOX/WOX1 and TRAF2 in normal human skin and frostbitten skin is shown. Scale bars: 20 μm. (D) A schematic graph for the TRAF2 domains is shown. Ring = Ring-type zinc finger domain; CC = Coiled coil domain; MATH = MATH/TRAF domain. COS7 cells were transiently overexpressed with ECFP, truncated ECFP-TRAF2(113–312), and 2 identical full-length ECFP-TRAF2, respectively. UV (480 mJoule/cm2)/cold shock (4°C for 5 min)-induced bubbling death in cells expressing the indicated protein was counted (~100 cells counted; n = 3).
Mentions: UVB activates TNF receptor-associated factor-2 (TRAF2), p53 and WWOX/WOX1 in the skin [12–14, 20, 28]. In COS7 cells, UV irradiation rapidly induced the expression of endogenous TRAF2 in the cytoplasm, and that subsequent cold shock caused upregulation and colocalization of TRAF2 and NOS2 in the nucleus in 10 min, as determined by immunofluorescence microscopy (Figure 7A). The nuclear accumulation of TRAF2 and NOS2 was greater than 95% (~100 cells counted; n = 3).

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