Pinitol protects against ox-LDL-induced endothelial inflammation and monocytes attachment

We assessed endothelial function by flow-mediated dilatation (FMD), levels of the NO-precursor L-arginine, and markers of endothelial inflammation before, at the finish line, and one week after the Norseman Xtreme triathlon. The race is an Ironman distance triathlon with a total elevation of 5200 m. Nine male participants were included. They completed the race in 14.5 (13.4–15.3) h. FMD was significantly reduced to 3.1 (2.1–5.0)% dilatation compared to 8.7 (8.2–9.3)% dilatation before the race (p < 0.05) and was normalized one week after the race. L-arginine showed significantly reduced levels at the finish line (p < 0.05) but was normalized one week after the race. Markers of endothelial inflammation E-Selectin, VCAM-1, and ICAM-1 all showed a pattern with increased values at the finish line compared to before the race (all p < 0.05), with normalization one week after the race. In conclusion, we found acutely reduced FMD with reduced L-arginine levels and increased E-Selectin, VCAM-1, and ICAM-1 immediately after the Norseman Xtreme triathlon. Our findings indicate a transient reduced endothelial function, measured by the FMD-response, after prolonged strenuous exercise that could be explained by reduced NO-precursor L-arginine levels and increased endothelial inflammation.

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Endothelial activation and dysfunction in COVID-19: from basic mechanisms to potential therapeutic approaches

Signal Transduction and Targeted Therapy ◽

10.1038/s41392-020-00454-7 ◽

2020 ◽

Vol 5 (1) ◽

Author(s):

Yuefei Jin ◽

Wangquan Ji ◽

Haiyan Yang ◽

Shuaiyin Chen ◽

Weiguo Zhang ◽

...

Keyword(s):

Molecular Mechanisms ◽

Endothelial Activation ◽

World Health ◽

Therapeutic Approaches ◽

Inflammatory Reactions ◽

Angiotensin Converting Enzyme 2 ◽

Therapeutic Implications ◽

Endothelial Inflammation ◽

The World ◽

Health Organization

AbstractOn 12 March 2020, the outbreak of coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization. As of 4 August 2020, more than 18 million confirmed infections had been reported globally. Most patients have mild symptoms, but some patients develop respiratory failure which is the leading cause of death among COVID-19 patients. Endothelial cells with high levels of angiotensin-converting enzyme 2 expression are major participants and regulators of inflammatory reactions and coagulation. Accumulating evidence suggests that endothelial activation and dysfunction participate in COVID-19 pathogenesis by altering the integrity of vessel barrier, promoting pro-coagulative state, inducing endothelial inflammation, and even mediating leukocyte infiltration. This review describes the proposed cellular and molecular mechanisms of endothelial activation and dysfunction during COVID-19 emphasizing the principal mediators and therapeutic implications.

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Focal TLR4 activation mediates disturbed flow-induced endothelial inflammation

Cardiovascular Research ◽

10.1093/cvr/cvz046 ◽

2019 ◽

Vol 116 (1) ◽

pp. 226-236 ◽

Cited By ~ 12

Author(s):

Dan Qu ◽

Li Wang ◽

Mingyu Huo ◽

Wencong Song ◽

Chi-Wai Lau ◽

...

Keyword(s):

Vascular Inflammation ◽

Subsequent Development ◽

Tlr4 Expression ◽

Disturbed Flow ◽

Atherosclerotic Lesions ◽

Endothelial Inflammation ◽

En Face ◽

Induced Flow ◽

Tlr4 Activation

Abstract Aims Disturbed blood flow at arterial branches and curvatures modulates endothelial function and predisposes the region to endothelial inflammation and subsequent development of atherosclerotic lesions. Activation of the endothelial Toll-like receptors (TLRs), in particular TLR4, contributes to vascular inflammation. Therefore, we investigate whether TLR4 can sense disturbed flow (DF) to mediate the subsequent endothelial inflammation. Methods and results En face staining of endothelium revealed that TLR4 expression, activation, and its downstream inflammatory markers were elevated in mouse aortic arch compared with thoracic aorta, which were absent in Tlr4mut mice. Similar results were observed in the partial carotid ligation model where TLR4 signalling was activated in response to ligation-induced flow disturbance in mouse carotid arteries, and such effect was attenuated in Tlr4mut mice. DF in vitro increased TLR4 expression and activation in human endothelial cells (ECs) and promoted monocyte-EC adhesion, which were inhibited in TLR4-knockdown ECs. Among endogenous TLR4 ligands examined as candidate mediators of DF-induced TLR4 activation, fibronectin containing the extra domain A (FN-EDA) expressed by ECs was increased by DF and was revealed to directly interact with and activate TLR4. Conclusion Our findings demonstrate the indispensable role of TLR4 in DF-induced endothelial inflammation and pinpoint FN-EDA as the endogenous TLR4 activator in this scenario. This novel mechanism of vascular inflammation under DF condition may serve as a critical initiating step in atherogenesis.

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