Overexpression of p53 due to excess protein O-GlcNAcylation is associated with coronary microvascular disease in type 2 diabetes.

Abstract

AIMS:

We previously reported that increased protein O-GlcNAcylation in diabetic mice led to vascular rarefaction in the heart. In this study, we aimed to investigate whether and how coronary endothelial cell (EC) apoptosis is enhanced by protein O-GlcNAcylation and thus induces coronary microvascular disease (CMD) and subsequent cardiac dysfunction in diabetes. We hypothesize that excessive protein O-GlcNAcylation increases p53 that leads to CMD and reduced cardiac contractility.

METHODS AND RESULTS:

We conducted in vivo functional experiments in control mice, TALLYHO/Jng (TH) mice, a polygenic type 2 diabetic (T2D) model, and EC-specific O-GlcNAcase (OGA, an enzyme that catalyzes the removal of O-GlcNAc from proteins)-overexpressing TH mice, as well as in vitro experiments in isolated ECs from these mice. TH mice exhibited a significant increase in coronary EC apoptosis and reduction of coronary flow velocity reserve (CFVR), an assessment of coronary microvascular function, in comparison to wild-type mice. The decreased CFVR, due at least partially to EC apoptosis, was associated with decreased cardiac contractility in TH mice. Western blot experiments showed that p53 protein level was significantly higher in coronary ECs from TH mice and T2D patients than in control ECs. High glucose treatment also increased p53 protein level in control ECs. Furthermore, overexpression of OGA decreased protein O-GlcNAcylation and down-regulated p53 in coronary ECs, and conferred a protective effect on cardiac function in TH mice. Inhibition of p53 with pifithrin-α attenuated coronary EC apoptosis and restored CFVR and cardiac contractility in TH mice.

CONCLUSIONS:

The data from this study indicate that inhibition of p53 or down-regulation of p53 by OGA overexpression attenuates coronary EC apoptosis and improves CFVR and cardiac function in diabetes. Lowering coronary endothelial p53 levels via OGA overexpression could be a potential therapeutic approach for CMD in diabetes.

• Authors: Rui Si, Qian Zhang, Atsumi Tsuji-Hosokawa, Makiko Watanabe, Conor Willson, Ning Lai, Jian Wang, Anzhi Dai, Brian T Scott, Wolfgang H Dillmann, Jason X-J Yuan, Ayako Makino
• Journal: Cardiovascular research (Cardiovasc Res) Vol. 116 Issue 6 Pg. 1186-1198 (05 01 2020) ISSN: 1755-3245 [Electronic] England
• PMID: 31504245 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: [email protected].

Chemical References

• Blood Glucose
• TP53 protein, human
• Trp53 protein, mouse
• Tumor Suppressor Protein p53
• Hyaluronoglucosaminidase

Topics

• Animals
• Apoptosis
• Blood Glucose (metabolism)
• Cells, Cultured
• Coronary Artery Disease (etiology, metabolism, pathology, physiopathology)
• Coronary Circulation
• Coronary Vessels (metabolism, pathology, physiopathology)
• Diabetes Mellitus, Type 2 (blood, complications)
• Disease Models, Animal
• Endothelial Cells (metabolism, pathology)
• Humans
• Hyaluronoglucosaminidase (genetics, metabolism)
• Male
• Mice, Inbred C57BL
• Mice, Transgenic
• Microcirculation
• Protein Processing, Post-Translational
• Signal Transduction
• Tumor Suppressor Protein p53 (genetics, metabolism)
• Up-Regulation