Indoxyl sulfate impairs angiogenesis via chronic aryl hydrocarbon receptor activation

Chronic kidney disease (CKD) is associated with a substantial increased risk of cardiovascular disease. There is growing evidence that uremic metabolites, which accumulate in the blood with CKD, have detrimental impacts on endothelial cell health and function. However, the molecular mechanisms by which uremic metabolites negatively impact endothelial cell biology are not fully understood. In this study, activation of the aryl hydrocarbon receptor (AHR) via indoxyl sulfate, a known uremic metabolite, was found to impair endothelial cell tube formation and proliferation, but not migratory function. Moreover, aortic ring cultures treated with indoxyl sulfate also exhibited decreased sprouting and high AHR activation. Next, genetic knockdown of the AHR using shRNA was found to rescue endothelial cell tube formation, proliferation, and aortic ring sprouting. Similarly, pharmacological AHR antagonism using resveratrol and CH223191 were also found to rescue angiogenesis in cell and aortic ring cultures. Finally, a constitutively active AHR (CAAHR) vector was generated and used to confirm AHR-specific effects. Expression of the CAAHR recapitulated the impaired tube formation and proliferation in cultured endothelial cells and decreased sprouting in aortic ring cultures. Taken together, these data define the impact of AHR activation on angiogenesis and highlight the potential for therapeutic AHR antagonists which may improve angiogenesis in the context of CKD and cardiovascular disease.

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The Uremic Toxin Indoxyl Sulfate Impairs Angiogenesis Through Aryl Hydrocarbon Receptor Activation

The FASEB Journal ◽

10.1096/fasebj.2020.34.s1.03505 ◽

2020 ◽

Vol 34 (S1) ◽

pp. 1-1

Author(s):

Zachary R. Salyers ◽

Trace Thome ◽

Madeline Coleman ◽

Terence Ryan

Keyword(s):

Aryl Hydrocarbon Receptor ◽

Receptor Activation ◽

Indoxyl Sulfate ◽

Uremic Toxin ◽

Aryl Hydrocarbon

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Aryl Hydrocarbon Receptor Activation and Tissue Factor Induction by Fluid Shear Stress and Indoxyl Sulfate in Endothelial Cells

International Journal of Molecular Sciences ◽

10.3390/ijms21072392 ◽

2020 ◽

Vol 21 (7) ◽

pp. 2392 ◽

Cited By ~ 3

Author(s):

Guillaume Lano ◽

Manon Laforêt ◽

Clarissa Von Kotze ◽

Justine Perrin ◽

Tawfik Addi ◽

...

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Aryl Hydrocarbon Receptor ◽

Tissue Factor ◽

Target Genes ◽

Fluid Shear Stress ◽

Receptor Activation ◽

Indoxyl Sulfate ◽

Uremic Toxin ◽

Aryl Hydrocarbon

Endogenous agonists of the transcription factor aryl hydrocarbon receptor (AHR) such as the indolic uremic toxin, indoxyl sulfate (IS), accumulate in patients with chronic kidney disease. AHR activation by indolic toxins has prothrombotic effects on the endothelium, especially via tissue factor (TF) induction. In contrast, physiological AHR activation by laminar shear stress (SS) is atheroprotective. We studied the activation of AHR and the regulation of TF by IS in cultured human umbilical vein endothelial cells subjected to laminar fluid SS (5 dynes/cm2). SS and IS markedly increased the expression of AHR target genes PTGS2 (encoding for COX2), AHRR, CYP1A1, and CYP1B1, as well as F3 (encoding for TF), in an AHR-dependent way. IS amplified SS-induced TF mRNA and protein expression and upregulation of AHR target genes. Interestingly, tyrosine kinase inhibition by genistein decreased SS- but not IS-induced TF expression. Finally, the increase in TF expression induced by laminar SS was not associated with increased TF activity. In contrast, IS increased TF activity, even under antithrombotic SS conditions. In conclusion, IS and SS induce AHR activation and AHR-dependent TF upregulation by different mechanisms. Impairment of the antithrombotic properties of shear stressed endothelium by toxic AHR agonists could favor cardiovascular diseases in CKD.

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Resveratrol Rescue Indoxyl Sulfate-Induced Deterioration of Osteoblastogenesis via the Aryl Hydrocarbon Receptor /MAPK Pathway

International Journal of Molecular Sciences ◽

10.3390/ijms21207483 ◽

2020 ◽

Vol 21 (20) ◽

pp. 7483 ◽

Cited By ~ 1

Author(s):

Wen-Chih Liu ◽

Jia-Fwu Shyu ◽

Yuh-Feng Lin ◽

Hui-Wen Chiu ◽

Paik Seong Lim ◽

...

Keyword(s):

Aryl Hydrocarbon Receptor ◽

Mapk Pathway ◽

Mapk Signaling ◽

Indoxyl Sulfate ◽

Mitogen Activated Protein Kinase ◽

Uremic Toxin ◽

Aryl Hydrocarbon ◽

The Impact

Indoxyl sulfate (IS), a uremic toxin derived from dietary tryptophan metabolism by the gut microbiota, is an endogenous aryl hydrocarbon receptor (AhR) agonist and a key player in bone remodeling. Resveratrol (RSV), an AhR antagonist, plays a protective role in shielding against AhR ligands. Our study explored the impact of IS on osteoblast differentiation and examined the possible mechanism of IS in controlling the expression of osteoblastogenesis markers through an in-depth investigation of AhR signaling. In vivo, we found histological architectural disruption of the femoral bones in 5/6 nephrectomies of young adult IS exposed mice, including reduced Runx2 antigen expression. RSV improved the diaphysis architecture, Runx2 expression, and trabecular quality. In vitro data suggest that IS at 500 and 1000 μM disturbed osteoblastogenesis through suppression of the ERK and p38 mitogen-activated protein kinase (MAPK) pathways, which were found to be downstream of AhR. RSV proved to ameliorate the anti-osteoblastogenic effects of IS through the inhibition of AhR and downstream signaling. Taken together, we demonstrated that the IS/AhR/MAPK signaling pathway plays a crucial role in the inhibition of osteoblastogenesis, and RSV has a potential therapeutic role in reversing the IS-induced decline in osteoblast development and suppressing abnormal bone turnover in chronic kidney disease patients.

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Characterizing the Role of HMG-CoA Reductase in Aryl Hydrocarbon Receptor-Mediated Liver Injury in C57BL/6 Mice

Scientific Reports ◽

10.1038/s41598-019-52001-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Peter Dornbos ◽

Amanda Jurgelewicz ◽

Kelly A. Fader ◽

Kurt Williams ◽

Timothy R. Zacharewski ◽

...

Keyword(s):

Liver Injury ◽

Aryl Hydrocarbon Receptor ◽

Cholesterol Biosynthesis ◽

Competitive Inhibitor ◽

Cholesterol Homeostasis ◽

Hepatic Glycogen ◽

Alcoholic Fatty Liver ◽

Female Mice ◽

Aryl Hydrocarbon ◽

The Impact

Abstract The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor. The prototypical ligand of the AHR is an environmental contaminant called 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD exposure is associated with many adverse health outcomes in humans including non-alcoholic fatty liver disease (NAFLD). Previous studies suggest that AHR ligands alter cholesterol homeostasis in mice through repression of genes involved in cholesterol biosynthesis, such as Hmgcr, which encodes the rate-limiting enzyme of cholesterol biosynthesis called 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (HMGCR). In this study, we sought to characterize the impact of HMGCR repression in TCDD-induced liver injury. C57BL/6 mice were exposed to TCDD in the presence or absence of simvastatin, a competitive inhibitor of HMGCR. Simvastatin exposure decreased TCDD-induced hepatic lipid accumulation in both sexes, but was most prominent in females. Simvastatin and TCDD (S + T) co-treatment increased hepatic AHR-battery gene expression and liver injury in male, but not female, mice. In addition, the S + T co-treatment led to an increase in hepatic glycogen content that coincides with heavier liver in female mice. Results from this study suggest that statins, which are amongst the most prescribed pharmaceuticals, may protect from AHR-mediated steatosis, but alter glycogen metabolism and increase the risk of TCDD-elicited liver damage in a sex-specific manner.

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Impact of established cardiovascular disease on 10-year death after coronary revascularization for complex coronary artery disease

Clinical Research in Cardiology ◽

10.1007/s00392-021-01922-y ◽

2021 ◽

Author(s):

Rutao Wang ◽

Scot Garg ◽

Chao Gao ◽

Hideyuki Kawashima ◽

Masafumi Ono ◽

...

Keyword(s):

Cardiovascular Disease ◽

Coronary Artery Disease ◽

Coronary Artery ◽

Coronary Revascularization ◽

Long Term Outcomes ◽

Vital Status ◽

Increased Risk ◽

Artery Disease ◽

The Impact

Abstract Aims To investigate the impact of established cardiovascular disease (CVD) on 10-year all-cause death following coronary revascularization in patients with complex coronary artery disease (CAD). Methods The SYNTAXES study assessed vital status out to 10 years of patients with complex CAD enrolled in the SYNTAX trial. The relative efficacy of PCI versus CABG in terms of 10-year all-cause death was assessed according to co-existing CVD. Results Established CVD status was recorded in 1771 (98.3%) patients, of whom 827 (46.7%) had established CVD. Compared to those without CVD, patients with CVD had a significantly higher risk of 10-year all-cause death (31.4% vs. 21.7%; adjusted HR: 1.40; 95% CI 1.08–1.80, p = 0.010). In patients with CVD, PCI had a non-significant numerically higher risk of 10-year all-cause death compared with CABG (35.9% vs. 27.2%; adjusted HR: 1.14; 95% CI 0.83–1.58, p = 0.412). The relative treatment effects of PCI versus CABG on 10-year all-cause death in patients with complex CAD were similar irrespective of the presence of CVD (p-interaction = 0.986). Only those patients with CVD in ≥ 2 territories had a higher risk of 10-year all-cause death (adjusted HR: 2.99, 95% CI 2.11–4.23, p < 0.001) compared to those without CVD. Conclusions The presence of CVD involving more than one territory was associated with a significantly increased risk of 10-year all-cause death, which was non-significantly higher in complex CAD patients treated with PCI compared with CABG. Acceptable long-term outcomes were observed, suggesting that patients with established CVD should not be precluded from undergoing invasive angiography or revascularization. Trial registration SYNTAX: ClinicalTrials.gov reference: NCT00114972. SYNTAX Extended Survival: ClinicalTrials.gov reference: NCT03417050. Graphic abstract

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