Adenosine stimulates eNOS phosphorylation by a p42/44 MAPK‐dependent mechanism in microvascular endothelial cells

Introduction: Interferon (IFN) alpha (IFNα) and lambda3 (IFNL3) constitute the first line of immunity against SARS-CoV-2 infection by increasing interferon-stimulated genes (ISGs). IFNs influence the expression of angiotensin-converting enzyme 2 (ACE2), the receptor for S-protein (S1P) of SARS-CoV-2. Here we hypothesized that in human microvascular endothelial cells (EC) IFNL3 and IFNα influence ACE2 and immune/inflammatory responses mediated by S1P. Methods: EC were stimulated with S1P of SARS-CoV-2 (1 μg/10^6 cells), IFNα (100 ng/mL) or IFNL3 (100 IU/mL). Because ACE2, metalloproteinase domain 17 (ADAM17) and type II transmembrane serine protease (TMPRSS2) are important for SARS-CoV-2 infection, cells were treated with inhibitors of ADAM17 (marimastat, 3.8nM and TAPI-1, 100nM), ACE2 (MLN4760, 440pM), and TMPRSS2 (camostat, 50μM). Expression of ISGs (ISG15, IFIT1, and MX1) was investigated by real-time PCR (5h) and protein expression by immunoblotting (24h). Results: EC stimulated with S1P increased expression of ISGs: ISG15 (2 fold), IFIT1 (6 fold), MX1 (6 fold) (n=12, p<0.05). EC exhibited higher responses to IFNα (ISG15: 16 fold, IFIT1: 21 fold, MX1: 31 fold) than to IFNL3 (ISG15: 1.7 fold, IFIT1: 1.9 fold, MX1: 1.7 fold) (p<0.05). S1P increased gene expression of IL-6 (1.3 fold), TNFα (6.2 fold) and IL-1β (3.3 fold), effects that were maximized 100% by IFNα. Only marimastat inhibited S1P effects. IL-6 was increased by IFNα (1230 pg/mL) and IFNL3 (1124 pg/mL) vs control (591pg/mL). IFNα increased expression of ACE2 (75 kDa) (63%), ADAM17 (36%), and TMPRSS2 (65%). This was associated with increased phosphorylation of Stat1 (134%), Stat2 (102%), ERK1/2 (42%). Nitric oxide production and eNOS phosphorylation (Ser1177) were reduced by IFNα and (40%) and IFNL3 (40%). Conclusions: In human microvascular endothelial cells, S1P, IFNα and IFNL3 induced an immune response characterized by increased expression of interferon-stimulated genes and IL-6 production, processes that involve ADAM17. Inflammation induced by S1P was amplified by IFNα. Our novel findings demonstrate that S1P induces an endothelial immune/inflammatory response that may be important in endotheliitis associated with COVID-19.

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Resveratrol Reduces Matrix Metalloproteinase-2 Activity Induced by Oxygen-Glucose Deprivation and Reoxygenation in Human Cerebral Microvascular Endothelial Cells

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000119 ◽

2012 ◽

Vol 82 (4) ◽

pp. 267-274 ◽

Cited By ~ 5

Author(s):

Zahide Cavdar ◽

Mehtap Y. Egrilmez ◽

Zekiye S. Altun ◽

Nur Arslan ◽

Nilgun Yener ◽

...

Keyword(s):

Endothelial Cells ◽

Neuroprotective Effect ◽

Ischemia Reperfusion ◽

Neurovascular Unit ◽

Glucose Deprivation ◽

Matrix Metalloproteinase 2 ◽

Microvascular Endothelial Cells ◽

Oxygen Glucose Deprivation ◽

Microvascular Endothelial

The main pathophysiology in cerebral ischemia is the structural alteration in the neurovascular unit, coinciding with neurovascular matrix degradation. Among the human matrix metalloproteinases (MMPs), MMP-2 and -9, known as gelatinases, are the key enzymes for degrading type IV collagen, which is the major component of the basal membrane that surrounds the cerebral blood vessel. In the present study, we investigated the effects of resveratrol on cytotoxicity, reactive oxygen species (ROS), and gelatinases (MMP-2 and -9) in human cerebral microvascular endothelial cells exposed to 6 hours of oxygen-glucose deprivation and a subsequent 24 hours of reoxygenation with glucose (OGD/R), to mimic ischemia/reperfusion in vivo. Lactate dehydrogenase increased significantly, in comparison to that in the normoxia group. ROS was markedly increased in the OGD/R group, compared to normoxia. Correspondingly, ROS was significantly reduced with 50 μM of resveratrol. The proMMP-2 activity in the OGD/R group showed a statistically significant increase from the control cells. Resveratrol preconditioning decreased significantly the proMMP-2 in the cells exposed to OGD/R in comparison to that in the OGD/R group. Our results indicate that resveratrol regulates MMP-2 activity induced by OGD/R via its antioxidant effect, implying a possible mechanism related to the neuroprotective effect of resveratrol.

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