Kouroku Y, Fujita E, Jimbo A, Mukasa T, Tsuru T, Momoi M Y, Momoi T
Division of Development and Differentiation, National Institute of Neuroscience, NCNP, Kodaira, Tokyo, 187-8502, Japan.
Biochem Biophys Res Commun. 2000 Apr 21;270(3):972-7. doi: 10.1006/bbrc.2000.2463.
The relation between activation of caspase-8 and polyglutamine aggregates has been focused. We prepared an antiserum (anti-m8D387) that recognizes the active form but not the proform of mouse caspase-8. We used immunostaining with anti-m8D387 antiserum to compare the localizations of activated mcaspase-8 in L929 (clone 1422) cells induced by TNF and polyglutamine aggregates. Anti-m8D387 was positive throughout cytoplasm of the TUNEL-positive cells induced by TNF treatment, whereas the anti-m8D387 reactivity was not positive throughout cytoplasm of the cells expressing polyglutamine but was restricted to polyglutamine aggregates. In contrast with TNF-treated cells, cells expressing anti-m8D387-positive cytoplasmic polyglutamine aggregates did not undergo TUNEL-positive apoptosis. Thus activated caspase-8 associated with polyglutamine aggregates alone was not sufficient to induce TUNEL-positive apoptosis of L929 (clone 1422) cells. The distribution of activated caspase-8 associated with polyglutamine aggregates may be essential for the polyglutamine-mediated cell death or downstream of caspase-8 may be different in the TNF-treated cells and cells expressing polyglutamine.
半胱天冬酶 -8 的激活与多聚谷氨酰胺聚集体之间的关系已受到关注。我们制备了一种抗血清（抗 -m8D387），它能识别小鼠半胱天冬酶 -8 的活性形式而非前体形式。我们使用抗 -m8D387 抗血清进行免疫染色，以比较肿瘤坏死因子（TNF）和多聚谷氨酰胺聚集体诱导的 L929（克隆 1422）细胞中活化的小鼠半胱天冬酶 -8 的定位。抗 -m8D387 在 TNF 处理诱导的 TUNEL 阳性细胞的整个细胞质中呈阳性，而在表达多聚谷氨酰胺的细胞的整个细胞质中，抗 -m8D387 的反应性并不呈阳性，而是局限于多聚谷氨酰胺聚集体。与 TNF 处理的细胞相反，表达抗 -m8D387 阳性细胞质多聚谷氨酰胺聚集体的细胞未发生 TUNEL 阳性凋亡。因此，单独与多聚谷氨酰胺聚集体相关的活化半胱天冬酶 -8 不足以诱导 L929（克隆 1422）细胞发生 TUNEL 阳性凋亡。与多聚谷氨酰胺聚集体相关的活化半胱天冬酶 -8 的分布可能对多聚谷氨酰胺介导的细胞死亡至关重要，或者在 TNF 处理的细胞和表达多聚谷氨酰胺的细胞中，半胱天冬酶 -8 的下游可能有所不同。
