scholarly journals Constitutive Activation of rac 1 Results in Mitochondrial Oxidative Stress and Induces Premature Endothelial Cell Senescence

Author(s):  
Shailesh S. Deshpande ◽  
Bing Qi ◽  
Young Chul Park ◽  
Kaikobad Irani
Hypertension ◽  
2009 ◽  
Vol 53 (2) ◽  
pp. 417-422 ◽  
Author(s):  
Hisko Oeseburg ◽  
Dilek Iusuf ◽  
Pim van der Harst ◽  
Wiek H. van Gilst ◽  
Robert H. Henning ◽  
...  

2013 ◽  
Vol 16 (2) ◽  
pp. 261-267 ◽  
Author(s):  
Xiao-hua Shen ◽  
Sheng-jie Xu ◽  
Chong-yin Jin ◽  
Fang Ding ◽  
Yu-cheng Zhou ◽  
...  

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1292
Author(s):  
Ellen E. Salmon ◽  
Jason J. Breithaupt ◽  
George A. Truskey

Clinical studies have established a connection between oxidative stress, aging, and atherogenesis. These factors contribute to senescence and inflammation in the endothelium and significant reductions in endothelium-dependent vasoreactivity in aged patients. Tissue-engineered blood vessels (TEBVs) recapitulate the structure and function of arteries and arterioles in vitro. We developed a TEBV model for vascular senescence and examined the relative influence of endothelial cell and smooth muscle cell senescence on vasoreactivity. Senescence was induced in 2D endothelial cell cultures and TEBVs by exposure to 100 µM H2O2 for one week to model chronic oxidative stress. H2O2 treatment significantly increased senescence in endothelial cells and mural cells, human neonatal dermal fibroblasts (hNDFs), as measured by increased p21 levels and reduced NOS3 expression. Although H2O2 treatment induced senescence in both the endothelial cells (ECs) and hNDFs, the functional effects on the vasculature were endothelium specific. Expression of the leukocyte adhesion molecule vascular cell adhesion molecule 1 (VCAM-1) was increased in the ECs, and endothelium-dependent vasodilation decreased. Vasoconstriction and endothelium-independent vasodilation were preserved despite mural cell senescence. The results suggest that the functional effects of vascular cell senescence are dominated by the endothelium.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Rong Liu ◽  
Hua Liu ◽  
Yonju Ha ◽  
Ronald G. Tilton ◽  
Wenbo Zhang

Accumulating evidence has shown that diabetes accelerates aging and endothelial cell senescence is involved in the pathogenesis of diabetic vascular complications, including diabetic retinopathy. Oxidative stress is recognized as a key factor in the induction of endothelial senescence and diabetic retinopathy. However, specific mechanisms involved in oxidative stress-induced endothelial senescence have not been elucidated. We hypothesized that Sirt6, which is a nuclear, chromatin-bound protein critically involved in many pathophysiologic processes such as aging and inflammation, may have a role in oxidative stress-induced vascular cell senescence. Measurement of Sirt6 expression in human endothelial cells revealed that H2O2treatment significantly reduced Sirt6 protein. The loss of Sirt6 was associated with an induction of a senescence phenotype in endothelial cells, including decreased cell growth, proliferation and angiogenic ability, and increased expression of senescence-associatedβ-galactosidase activity. Additionally, H2O2treatment reduced eNOS expression, enhanced p21 expression, and dephosphorylated (activated) retinoblastoma (Rb) protein. All of these alternations were attenuated by overexpression of Sirt6, while partial knockdown of Sirt6 expression by siRNA mimicked the effect of H2O2. In conclusion, these results suggest that Sirt6 is a critical regulator of endothelial senescence and oxidative stress-induced downregulation of Sirt6 is likely involved in the pathogenesis of diabetic retinopathy.


Biomolecules ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 85 ◽  
Author(s):  
Hao Zhou ◽  
Sam Toan

Mitochondria are key regulators of cell fate through controlling ATP generation and releasing pro-apoptotic factors. Cardiac ischemia/reperfusion (I/R) injury to the coronary microcirculation has manifestations ranging in severity from reversible edema to interstitial hemorrhage. A number of mechanisms have been proposed to explain the cardiac microvascular I/R injury including edema, impaired vasomotion, coronary microembolization, and capillary destruction. In contrast to their role in cell types with higher energy demands, mitochondria in endothelial cells primarily function in signaling cellular responses to environmental cues. It is clear that abnormal mitochondrial signatures, including mitochondrial oxidative stress, mitochondrial fission, mitochondrial fusion, and mitophagy, play a substantial role in endothelial cell function. While the pathogenic role of each of these mitochondrial alterations in the endothelial cells I/R injury remains complex, profiling of mitochondrial oxidative stress and mitochondrial dynamics in endothelial cell dysfunction may offer promising potential targets in the search for novel diagnostics and therapeutics in cardiac microvascular I/R injury. The objective of this review is to discuss the role of mitochondrial oxidative stress on cardiac microvascular endothelial cells dysfunction. Mitochondrial dynamics, including mitochondrial fission and fusion, are critically discussed to understand their roles in endothelial cell survival. Finally, mitophagy, as a degradative mechanism for damaged mitochondria, is summarized to figure out its contribution to the progression of microvascular I/R injury.


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