Perturbed ER homeostasis by IGF-IIR[alpha] promotes cardiac damage under stresses

The heart is a very dynamic pumping organ working perpetually to maintain a constant blood supply to the whole body to transport oxygen and nutrients. Unfortunately, it is also subjected to various stresses based on physiological or pathological conditions, particularly more vulnerable to damages ca...

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Published in:Molecular and cellular biochemistry 2022-01, Vol.477 (1), p.143
Main Authors: Pandey, Sudhir, Kuo, Chia-Hua, Chen, William Shao-Tsu, Yeh, Yu-Lan, Kuo, Wei-Wen, Chen, Ray-Jade, Day, Cecilia Hsuan
Format: Article
Language:English
Subjects:
Ethylenediaminetetraacetic acid
Genetic engineering
Medical colleges
Proteins
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Summary:The heart is a very dynamic pumping organ working perpetually to maintain a constant blood supply to the whole body to transport oxygen and nutrients. Unfortunately, it is also subjected to various stresses based on physiological or pathological conditions, particularly more vulnerable to damages caused by oxidative stress. In this study, we investigate the molecular mechanism and contribution of IGF-IIR[alpha] in endoplasmic reticulum stress induction in the heart under doxorubicin-induced cardiotoxicity. Using in vitro H9c2 cells, in vivo transgenic rat cardiac tissues, siRNAs against CHOP, chemical ER chaperone PBA, and western blot experiments, we found that IGF-IIR[alpha] overexpression enhanced ER stress markers ATF4, ATF6, IRE1[alpha], and PERK which were further aggravated by DOX treatment. This was accompanied by a significant perturbation in stress-associated MAPKs such as p38 and JNK. Interestingly, PARKIN, a stress responsive cellular protective mediator was significantly downregulated by IGF-IIR[alpha] concomitant with decreased expression of ER chaperone GRP78. Furthermore, ER stress-associated pro-apoptotic factor CHOP was increased considerably in a dose-dependent manner followed by elevated c-caspase-12 and c-caspase-3 activities. Conversely, treatment of H9c2 cells with chemical ER chaperone PBA or siRNA against CHOP abolished the IGF-IIR[alpha]-induced ER stress responses. Altogether, these findings suggested that IGF-IIR[alpha] contributes to ER stress induction and inhibits cellular stress coping proteins while increasing pro-apoptotic factors feeding into a cardio myocyte damage program that eventually paves the way to heart failure.
ISSN:0300-8177
DOI:10.1007/s11010-021-04261-8