Atractylenolide III Attenuates Apoptosis in H9c2 Cells by Inhibiting Endoplasmic Reticulum Stress through the GRP78/PERK/CHOP Signaling Pathway

Abstract

The objective of this study was to determine the effect of atractylenolide III (ATL-III) on endoplasmic reticulum stress (ERS) injury, H9c2 cardiomyocyte apoptosis induced by tunicamycin (TM), and the GRP78/PERK/CHOP signaling pathway. Molecular docking was applied to predict the binding affinity of ATL-III to the key proteins GRP78, PERK, IREα, and ATF6 in ERS. Then, in vitro experiments were used to verify the molecular docking results. ERS injury model of H9c2 cells was established by TM. Cell viability was detected by MTT assay, and apoptosis was detected by Hoechst/PI double staining and flow cytometry. Protein expression levels of GRP78, PERK, eIF2α, ATF4, CHOP, Bax, Bcl-2, and Caspase-3 were detected by Western blot. And mRNA levels of GRP78, CHOP, PERK, eIF2α, and ATF4 were detected by RT-qPCR. Moreover, the mechanism was further studied by using GRP78 inhibitor (4-phenylbutyric acid, 4-PBA), and PERK inhibitor (GSK2656157). The results showed that ATL-III had a good binding affinity with GRP78, and the best binding affinity was with PERK. ATL-III increased the viability of H9c2 cells, decreased the apoptosis rate, downregulated Bax and Caspase-3, and increased Bcl-2 compared with the model group. Moreover, ATL-III downregulated the protein and mRNA levels of GRP78, CHOP, PERK, eIF2α, and ATF4, consistent with the inhibition of 4-PBA. ATL-III also decreased the expression levels of PERK, eIF2α, ATF4, CHOP, Bax, and Caspase-3, while increasing the expression of Bcl-2, which is consistent with GSK2656157. Taken together, ATL-III could inhibit TM-induced ERS injury and H9c2 cardiomyocyte apoptosis by regulating the GRP78/PERK/CHOP signaling pathway and has myocardial protection.

Sulfated Laminarin Polysaccharides Reduce the Adhesion of Nano-COM Crystals to Renal Epithelial Cells by Inhibiting Oxidative and Endoplasmic Reticulum Stress

“…To delve deeper into the potential mechanism of ER stress-induced apoptosis in HK-2 cells, alterations in Caspase 12, a prominent marker of ER stress, were examined through an immunofluorescence assay [ 37 ]. The findings notably unveiled that exposure to nano-COM elicited a substantial rise in Caspase 12 expression.…”

Chemical Constitution, Pharmacological Effects and the Underlying Mechanism of Atractylenolides: A Review

“…ATL III was discovered to reduce apoptosis and ROS, MDA, and LDH levels in H 2 O 2 -induced endoplasmic reticulum stress-injured cardiomyocytes H9c2, increase SOD activity and protect cardiomyocytes by regulating the ROS/GRP78/Caspase-12 signaling pathway, which could be a potential drug for the treatment of chronic heart failure according to Zuo et al [ 84 ]. In addition, by inhibiting GRP 78/PERK/CHOP signaling pathway, ATL III can also inhibit the endoplasmic reticulum stress injury induced by chlamycin and the apoptosis of H9c2 cardiomyocytes, thus protecting myocardium [ 85 ]. In patients with advanced chronic renal disease, muscle atrophy owing to oxidative stress is a typical consequence.…”