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Regulation of the expression and processing of caspase-12.

Kalai M, Lamkanfi M, Denecker G, Boogmans M, Lippens S, Meeus A, Declercq W, Vandenabeele P - J. Cell Biol. (2003)

Bottom Line: The effect is increased further when IFN-gamma is combined with TNF, lipopolysaccharide (LPS), or dsRNA.Transient overexpression of full-length caspase-12 leads to proteolytic processing of the enzyme and apoptosis.Similar processing occurs in TNF-, LPS-, Fas ligand-, and thapsigargin (Tg)-induced apoptosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biomedical Research, Unit of Molecular Signalling and Cell Death, Ghent University, Ledeganckstraat 35, B-9000 Ghent, Belgium.

ABSTRACT
Phylogenetic analysis clusters caspase-12 with the inflammatory caspases 1 and 11. We analyzed the expression of caspase-12 in mouse embryos, adult organs, and different cell types and tested the effect of interferons (IFNs) and other proinflammatory stimuli. Constitutive expression of the caspase-12 protein was restricted to certain cell types, such as epithelial cells, primary fibroblasts, and L929 fibrosarcoma cells. In fibroblasts and B16/B16 melanoma cells, caspase-12 expression is stimulated by IFN-gamma but not by IFN-alpha or -beta. The effect is increased further when IFN-gamma is combined with TNF, lipopolysaccharide (LPS), or dsRNA. These stimuli also induce caspase-1 and -11 but inhibit the expression of caspase-3 and -9. In contrast to caspase-1 and -11, no caspase-12 protein was detected in macrophages in any of these treatments. Transient overexpression of full-length caspase-12 leads to proteolytic processing of the enzyme and apoptosis. Similar processing occurs in TNF-, LPS-, Fas ligand-, and thapsigargin (Tg)-induced apoptosis. However, B16/B16 melanoma cells die when treated with the ER stress-inducing agent Tg whether they express caspase-12 or not.

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Effect of IFN-γ and TNF on the expression of the mRNAs of the mouse inflammatory caspase subfamily in L929r2 fibrosarcoma and B16/B16 melanoma cells. Cells were treated or not with IFN-γ (1,000 U/ml) or TNF (5,000 U/ml) alone or in combination. The next day, mRNA was extracted and analyzed by Northern blotting using specific probes. The size of the hybridizing bands is indicated in kb. UV imaging of ethidium bromide intercalated in the 18S and 28S rRNAs was used to monitor loading of the gels (bottom).
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fig4: Effect of IFN-γ and TNF on the expression of the mRNAs of the mouse inflammatory caspase subfamily in L929r2 fibrosarcoma and B16/B16 melanoma cells. Cells were treated or not with IFN-γ (1,000 U/ml) or TNF (5,000 U/ml) alone or in combination. The next day, mRNA was extracted and analyzed by Northern blotting using specific probes. The size of the hybridizing bands is indicated in kb. UV imaging of ethidium bromide intercalated in the 18S and 28S rRNAs was used to monitor loading of the gels (bottom).

Mentions: Several reports have demonstrated that the expression of caspase-1 and -11 can be induced by proinflammatory stimuli such as IFN-γ, TNF, or LPS (Lin et al., 2000; Schauvliege et al., 2002). The L929r2 murine fibrosarcoma and B16/B16 murine melanoma cells respond to TNF only when cotreated with IFN-γ (Mareel et al., 1988; Vanhaesebroeck et al., 1991). Therefore, we compared the effect of IFN-γ with and without TNF on the expression levels of caspase-1, -11, and -12 in these two cell lines. Northern blot analysis demonstrated that the expression of caspase-12 mRNA is further enhanced in L929r2 and induced in Bl6/B16 cells by IFN-γ (Fig. 4). Synergism between TNF and IFN-γ was observed with caspase-12 mRNA in B16/B16 cells and with caspase-11 mRNA in both L929r2 and B16/B16 cells. Such an effect was not observed for caspase-1 and -12 in L929r2 cells. Treatment of L929r2 cells for 24 h with IFN-γ and TNF leads to cell death, about half of the cells are propidium iodide positive at 24 h, whereas B16/B16 cells still survive at that time point. This may explain the apparent difference observed in the response of these cell lines. An increase in caspase-1 mRNA was observed only in L929r2 treated with IFN-γ, whereas no caspase-1 mRNA expression was observed in B16/B16 cells in any of the treatments.


Regulation of the expression and processing of caspase-12.

Kalai M, Lamkanfi M, Denecker G, Boogmans M, Lippens S, Meeus A, Declercq W, Vandenabeele P - J. Cell Biol. (2003)

Effect of IFN-γ and TNF on the expression of the mRNAs of the mouse inflammatory caspase subfamily in L929r2 fibrosarcoma and B16/B16 melanoma cells. Cells were treated or not with IFN-γ (1,000 U/ml) or TNF (5,000 U/ml) alone or in combination. The next day, mRNA was extracted and analyzed by Northern blotting using specific probes. The size of the hybridizing bands is indicated in kb. UV imaging of ethidium bromide intercalated in the 18S and 28S rRNAs was used to monitor loading of the gels (bottom).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2172698&req=5

fig4: Effect of IFN-γ and TNF on the expression of the mRNAs of the mouse inflammatory caspase subfamily in L929r2 fibrosarcoma and B16/B16 melanoma cells. Cells were treated or not with IFN-γ (1,000 U/ml) or TNF (5,000 U/ml) alone or in combination. The next day, mRNA was extracted and analyzed by Northern blotting using specific probes. The size of the hybridizing bands is indicated in kb. UV imaging of ethidium bromide intercalated in the 18S and 28S rRNAs was used to monitor loading of the gels (bottom).
Mentions: Several reports have demonstrated that the expression of caspase-1 and -11 can be induced by proinflammatory stimuli such as IFN-γ, TNF, or LPS (Lin et al., 2000; Schauvliege et al., 2002). The L929r2 murine fibrosarcoma and B16/B16 murine melanoma cells respond to TNF only when cotreated with IFN-γ (Mareel et al., 1988; Vanhaesebroeck et al., 1991). Therefore, we compared the effect of IFN-γ with and without TNF on the expression levels of caspase-1, -11, and -12 in these two cell lines. Northern blot analysis demonstrated that the expression of caspase-12 mRNA is further enhanced in L929r2 and induced in Bl6/B16 cells by IFN-γ (Fig. 4). Synergism between TNF and IFN-γ was observed with caspase-12 mRNA in B16/B16 cells and with caspase-11 mRNA in both L929r2 and B16/B16 cells. Such an effect was not observed for caspase-1 and -12 in L929r2 cells. Treatment of L929r2 cells for 24 h with IFN-γ and TNF leads to cell death, about half of the cells are propidium iodide positive at 24 h, whereas B16/B16 cells still survive at that time point. This may explain the apparent difference observed in the response of these cell lines. An increase in caspase-1 mRNA was observed only in L929r2 treated with IFN-γ, whereas no caspase-1 mRNA expression was observed in B16/B16 cells in any of the treatments.

Bottom Line: The effect is increased further when IFN-gamma is combined with TNF, lipopolysaccharide (LPS), or dsRNA.Transient overexpression of full-length caspase-12 leads to proteolytic processing of the enzyme and apoptosis.Similar processing occurs in TNF-, LPS-, Fas ligand-, and thapsigargin (Tg)-induced apoptosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biomedical Research, Unit of Molecular Signalling and Cell Death, Ghent University, Ledeganckstraat 35, B-9000 Ghent, Belgium.

ABSTRACT
Phylogenetic analysis clusters caspase-12 with the inflammatory caspases 1 and 11. We analyzed the expression of caspase-12 in mouse embryos, adult organs, and different cell types and tested the effect of interferons (IFNs) and other proinflammatory stimuli. Constitutive expression of the caspase-12 protein was restricted to certain cell types, such as epithelial cells, primary fibroblasts, and L929 fibrosarcoma cells. In fibroblasts and B16/B16 melanoma cells, caspase-12 expression is stimulated by IFN-gamma but not by IFN-alpha or -beta. The effect is increased further when IFN-gamma is combined with TNF, lipopolysaccharide (LPS), or dsRNA. These stimuli also induce caspase-1 and -11 but inhibit the expression of caspase-3 and -9. In contrast to caspase-1 and -11, no caspase-12 protein was detected in macrophages in any of these treatments. Transient overexpression of full-length caspase-12 leads to proteolytic processing of the enzyme and apoptosis. Similar processing occurs in TNF-, LPS-, Fas ligand-, and thapsigargin (Tg)-induced apoptosis. However, B16/B16 melanoma cells die when treated with the ER stress-inducing agent Tg whether they express caspase-12 or not.

Show MeSH
Related in: MedlinePlus