Heat shock protein 70 inhibits hydrogen peroxide-induced nucleolar fragmentation via suppressing cleavage and down-regulation of nucleolin

• DOI: 10.1007/s12192-011-0292-4
• Publication Date: 2011-09-29T07:29:59Z
• Authors: Kangkai Wang; Gonghua Deng; Guangwen Chen; Meidong Liu; Yuxin Yi; Tubao Yang; Daniel R. McMillan; Xiangzhong Xiao
• Keywords: Nucleolin; HSF1; Fragmentation

It has been reported that nucleolar fragmentation is a part of the overall apoptotic morphology, however, it currently obscure whether and how can be induced by hydrogen peroxide (H(2)O(2)) heat shock protein 70 (Hsp70) prevent fragmentation. To dissect these two questions, C(2)C(12) myogenic cells immortalized mouse embryonic fibroblasts (MEFs) with transcriptional factor 1 (HSF1) null mutation were treated response (HS) (42.5 ± 0.5°C for h recovery at 37°C 24 h) then insulted 0.5 mmol/L H(2)O(2). Morphological changes nucleoli observed under contrast microscope or electronic microscope. was found (1) stimulation H(2)O(2)-induced mediating cleavage down-regulation protein, nucleolin in myocytes MEFs; (2) HS suppressed inducing expression Hsp70 an HSF1-dependent manner as indicated assays transfection antisense oligonucleotides (AS-ONs) recombinant plasmids full-length cDNA; (3) protection against related to its accumulation nucleolus mediated nuclear localization sequence inhibition nucleolin. These results suggested inhibit through translocation into impairment