Calreticulin Ameliorates Hypoxia/Reoxygenation-Induced Human Microvascular Endothelial Cell Injury By Inhibiting Autophagy.

Abstract

BACKGROUND:

Autophagy has been found to be involved in myocardial ischemia/reperfusion injury. However, the underlying mechanism and significance of autophagy in reperfusion injury remain unclear. Herein, we evaluated the effects of exogenous calreticulin (CRT) on autophagy in hypoxia/reoxygenation (H/R)-treated human microvascular endothelial cells (MECs).

METHODS:

Human MECs were pretreated with CRT (25 pg/mL) for 30 min, followed by exposure in an incubator filled with a gas mixture of 90% N2, 5% O2, and 5% CO2 for 8-h hypoxia. The cells were then placed back in the normoxic CO2 incubator for 16-h reoxygenation. Cell injury was assessed by the cell counting kit-8 assay. Autophagosomes were detected by transmission electron microscopy and immunofluorescence staining. Western blot analysis was performed to detect phosphorylated mammalian target of rapamycin (p-mTOR), Beclin 1, and microtubule-associated protein 1 light chain 3 (LC3).

RESULTS:

H/R induced marked autophagy through the mTOR pathway. CRT suppressed rapamycin- and H/R-induced autophagosome formation, the LC3-II/LC3-I ratio, and Beclin 1 expression in human MECs by upregulating mTOR phosphorylation, consequently attenuating H/R-induced human MEC injury.

CONCLUSIONS:

Exogenous CRT attenuated H/R-induced human MEC injury by inhibiting autophagy.

• Authors: You Wang, Tian-Qi Tao, Dan-Dan Song, Xiu-Hua Liu
• Journal: Shock (Augusta, Ga.) (Shock) Vol. 49 Issue 1 Pg. 108-116 (Jan 2018) ISSN: 1540-0514 [Electronic] United States
• PMID: 28520695 (Publication Type: Journal Article)

Chemical References

• Calreticulin
• Sirolimus

Topics

• Autophagy (drug effects)
• Blotting, Western
• Calreticulin (pharmacology)
• Cell Hypoxia (drug effects)
• Cell Line
• Cell Survival (drug effects)
• Endothelial Cells (drug effects, metabolism)
• Humans
• Microscopy, Electron, Transmission
• Sirolimus (pharmacology)