PMID- 34916192 OWN - NLM STAT- MEDLINE DCOM- 20211220 LR - 20231108 IS - 1673-4254 (Print) IS - 2663-0842 (Electronic) IS - 1673-4254 (Linking) VI - 41 IP - 11 DP - 2021 Nov 20 TI - [Extranuclear p53 suppresses autophagy through AMPK/mTOR signaling to promote heat stress-induced vascular endothelial cell damage]. PG - 1664-1671 LID - 10.12122/j.issn.1673-4254.2021.11.10 [doi] AB - OBJECTIVE: To explore the role of extranuclear p53-mediated autophagy suppression by regulating AMPK/mTOR signaling pathway in heat stress (HS)-induced injury of mouse aortic endothelial cells (MAECs). METHODS: Primary cultures of MAECs were pretreated with compound C (an AMPK inhibitor), rapamycin (a mTOR inhibitor) or pifithrin-alpha (PFT, a selective p53 inhibitor) for 1 h before exposure to HS (43 ℃) for 2 h. The changes in cell viability at different time points after HS were examined using CCK-8 assay, and the protein expressions of P53, LC3-II, Beclin-1, p62 and the AMPK/mTOR signaling proteins were detected using Western blotting. In the animal experiment, C57 mice were pretreated with compound C, rapamycin or PFT and exposed to a high temperature at 40 ℃ to induce HS. The pathological changes in the aorta of the mice were observed with HE staining, and cell apoptosis was detected using TUNEL staining. RESULTS: In cultured MAECs, the cell viability was significantly reduced (P < 0.05) and the mitochondrial fraction of p53 increased while its cytoplasmic fraction decreased progressively over time following HS. HS significantly lowered the expressions of LC3-II and Beclin-1, increased p62 level, suppressed AMPK phosphorylation, and increased mTOR phosphorylation and the expressions of its downstream proteins at 6 h after the exposure (P < 0.05). Pretreatment with compound C significantly inhibited LC3-II and Beclin- 1 expression, enhanced p62 expression, and aggravated HS-induced cell injury and apoptosis in MAECs; rapamycin treatment produced the opposite effects (P < 0.05). PFT treatment significantly enhanced the viability of MAECs and alleviated HSinduced injury and apoptosis; PFT also significantly promoted activation of AMPK phosphorylation, inhibited mTOR phosphorylation and its downstream proteins (P < 0.05), enhanced the expressions of LC3-II and Beclin 1, and inhibited p62 expression in the MAECs (P < 0.05). In C57 mice, HS resulted in swelling, shedding and apoptosis of aortic vascular endothelial cells. Pretreatment with compound C obviously aggravated HS-induced vascular injury and endothelial cell apoptosis, while pretreatment with either rapamycin or PFT significantly alleviated these injuries. CONCLUSION: Autophagy inhibition mediated by extranuclear p53 via inhibiting AMPK activity and activating mTOR signaling participates in HS-induced injury of MAECs. FAU - Li, L AU - Li L AD - Treatment Center for Traumatic Injuries, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China. AD - Academy of Orthopedics of Guangdong Province//Orthopedic Hospital of Guangdong Province//Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, Guangzhou 510630, China. FAU - Zou, Z AU - Zou Z AD - Treatment Center for Traumatic Injuries, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China. AD - Academy of Orthopedics of Guangdong Province//Orthopedic Hospital of Guangdong Province//Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, Guangzhou 510630, China. FAU - Li, Q AU - Li Q AD - Treatment Center for Traumatic Injuries, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China. AD - Academy of Orthopedics of Guangdong Province//Orthopedic Hospital of Guangdong Province//Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, Guangzhou 510630, China. FAU - Zhang, K AU - Zhang K AD - Treatment Center for Traumatic Injuries, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China. AD - Academy of Orthopedics of Guangdong Province//Orthopedic Hospital of Guangdong Province//Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, Guangzhou 510630, China. FAU - Su, L AU - Su L AD - Department of Critical Medicine, General Hospital of Southern Theater Command of PLA, Guangzhou 510010, China. FAU - Gu, Z AU - Gu Z AD - Treatment Center for Traumatic Injuries, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China. AD - Academy of Orthopedics of Guangdong Province//Orthopedic Hospital of Guangdong Province//Guangdong Provincial Key Laboratory of Bone and Joint Degenerative Diseases, Guangzhou 510630, China. LA - chi PT - Journal Article PL - China TA - Nan Fang Yi Ke Da Xue Xue Bao JT - Nan fang yi ke da xue xue bao = Journal of Southern Medical University JID - 101266132 RN - 0 (Tumor Suppressor Protein p53) RN - EC 2.7.11.1 (TOR Serine-Threonine Kinases) RN - EC 2.7.11.31 (AMP-Activated Protein Kinases) SB - IM MH - *AMP-Activated Protein Kinases MH - Animals MH - Autophagy MH - *Endothelial Cells MH - Heat-Shock Response MH - Mice MH - Signal Transduction MH - TOR Serine-Threonine Kinases MH - Tumor Suppressor Protein p53 PMC - PMC8685697 OTO - NOTNLM OT - AMPK OT - autophagy OT - extranuclear p53 OT - heat stress OT - mTOR OT - vascular endothelial cells EDAT- 2021/12/18 06:00 MHDA- 2021/12/21 06:00 PMCR- 2021/11/20 CRDT- 2021/12/17 06:10 PHST- 2021/12/17 06:10 [entrez] PHST- 2021/12/18 06:00 [pubmed] PHST- 2021/12/21 06:00 [medline] PHST- 2021/11/20 00:00 [pmc-release] AID - nfykdxxb-41-11-1664 [pii] AID - 10.12122/j.issn.1673-4254.2021.11.10 [doi] PST - ppublish SO - Nan Fang Yi Ke Da Xue Xue Bao. 2021 Nov 20;41(11):1664-1671. doi: 10.12122/j.issn.1673-4254.2021.11.10.