Highlights
- •The degree of vascular IKKα expression and kinase activation differs between aortic root and aortic arch.
- •Ablation of IKKα kinase activation differentially affects atherosclerosis in aortic root vs. aortic arch.
- •This is associated with a vascular site-dependent impact on lesional smooth muscle cell accumulation and protein profiles.
Abstract
Background and aims
IKKα is an important regulator of gene expression. As IKKα kinase inactivity in bone
marrow-derived cells does not affect atherosclerosis, we here investigate the impact
of a whole body-IKKα kinase inactivity on atherosclerosis.
Methods
Apolipoprotein E (Apoe)-deficient mice homozygous for an activation-resistant Ikkα-mutant (IkkαAA/AAApoe−/−) and Ikkα+/+Apoe−/− controls received a Western-type diet. Atherosclerotic lesion size and cellular content
were analyzed using histology and immunofluorescence. Vascular protein expression
and IKKα kinase activity were quantified by Luminex multiplex immuno-assay and ELISA.
Results
A vascular site-specific IKKα expression and kinase activation profile was revealed,
with higher total IKKα protein levels in aortic root but increased IKKα phosphorylation,
representing activated IKKα, in the aortic arch. This was associated with a vascular
site-specific effect of IkkαAA/AA knock-in on atherosclerosis: in the aortic root, IkkαAA/AA knock-in decreased lesion size by 22.0 ± 7.7% (p < 0.01), reduced absolute lesional smooth muscle cell numbers and lowered pro-atherogenic
MMP2. In contrast, IkkαAA/AA knock-in increased lesion size in the aortic arch by 43.7 ± 20.1% (p < 0.001), increased the abundance of lesional smooth muscle cells in brachiocephalic
artery as main arch side branch and elevated MMP2. A similar profile was observed
for MMP3. No effects were observed on necrotic core or collagen deposition in atherosclerotic
lesions, nor on absolute lesional macrophage numbers.
Conclusions
A non-activatable IKKα kinase differentially affects atherosclerosis in aortic root
vs. aortic arch/brachiocephalic artery, associated with a differential vascular IKKα
expression and kinase activation profile as well as with a vascular site-dependent
impact on lesional smooth muscle cell accumulation and protein expression profiles.
Graphical abstract
Graphical Abstract
Keywords
Abbreviations:
BC (brachiocephalic artery), CCL (CC chemokine ligand), IκB (inhibitor of kappa B), IKK (IκB kinase), MAC2 (macrophage galactose-specific lectin-2 (Galectin-3)), MMP (matrix metalloproteinase), SMA (smooth muscle actin), SMC (smooth muscle cell), TIMP (tissue inhibitor of metalloproteinases)To read this article in full you will need to make a payment
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References
- Epidemiology of atherosclerosis and the potential to reduce the global burden of atherothrombotic disease.Circ. Res. 2016; 118: 535-546
- Atherosclerosis: current pathogenesis and therapeutic options.Nat. Med. 2011; 17: 1410-1422
- Crosstalk in NF-kappaB signaling pathways.Nat. Immunol. 2011; 12: 695-708
- The nuclear factor NF-kappaB pathway in inflammation.Cold Spring Harb. Perspect. Biol. 2009; 1: a001651
- The nuclear factor--kappa B pathway in atherosclerosis: a potential therapeutic target for atherothrombotic vascular disease.Thromb. Res. 2011; 128: 117-123
- The NF-kappaB family of transcription factors and its regulation.Cold Spring Harb. Perspect. Biol. 2009; 1: a000034
- Compensatory IKKalpha activation of classical NF-kappaB signaling during IKKbeta inhibition identified by an RNA interference sensitization screen.Proc. Natl. Acad. Sci. U. S. A. 2008; 105: 20798-20803
- IKKalpha limits macrophage NF-kappaB activation and contributes to the resolution of inflammation.Nature. 2005; 434: 1138-1143
- The kinase IKKalpha inhibits activation of the transcription factor NF-kappaB by phosphorylating the regulatory molecule TAX1BP1.Nat. Immunol. 2011; 12: 834-843
- Proinflammatory stimuli induce IKKalpha-mediated phosphorylation of PIAS1 to restrict inflammation and immunity.Cell. 2007; 129: 903-914
- The IkappaB kinase complex in NF-kappaB regulation and beyond.EMBO Rep. 2013; 15: 46-61
- The noncanonical NF-kappaB pathway.Immunol. Rev. 2012; 246: 125-140
- Histone H3 phosphorylation by IKK-alpha is critical for cytokine-induced gene expression.Nature. 2003; 423: 655-659
- A nucleosomal function for IkappaB kinase-alpha in NF-kappaB-dependent gene expression.Nature. 2003; 423: 659-663
- IKKalpha provides an essential link between RANK signaling and cyclin D1 expression during mammary gland development.Cell. 2001; 107: 763-775
- Bone marrow-specific knock-in of a non-activatable Ikkalpha kinase mutant influences haematopoiesis but not atherosclerosis in Apoe-deficient mice.PLoS One. 2014; 9e87452
- MicroRNA-126-5p promotes endothelial proliferation and limits atherosclerosis by suppressing Dlk1.Nat. Med. 2014; 20: 368-376
- Upregulation of VCAM-1 and ICAM-1 at atherosclerosis-prone sites on the endothelium in the ApoE-deficient mouse.Arterioscler. Thromb. Vasc. Biol. 1998; 18: 842-851
- Cytokines and atherosclerosis: a comprehensive review of studies in mice.Cardiovasc. Res. 2008; 79: 360-376
- Cytokines in atherosclerosis: key players in all stages of disease and promising therapeutic targets.Cytokine Growth Factor Rev. 2015; 26: 673-685
- Increased levels of CCR7 ligands in carotid atherosclerosis: different effects in macrophages and smooth muscle cells.Cardiovasc. Res. 2013; 102: 148-156
- CCL19 and CCL21 modulate the inflammatory milieu in atherosclerotic lesions.Drug Des. Dev. Ther. 2014; 8: 2359-2371
- Major reduction of atherosclerosis in fractalkine (CX3CL1)-deficient mice is at the brachiocephalic artery, not the aortic root.Proc. Natl. Acad. Sci. U. S. A. 2004; 101: 17795-17800
- Site-specific effects of PECAM-1 on atherosclerosis in LDL receptor-deficient mice.Arterioscler. Thromb. Vasc. Biol. 2008; 28: 1996-2002
- Site-specific antiatherogenic effect of probucol in apolipoprotein E-deficient mice.Arterioscler. Thromb. Vasc. Biol. 2000; 20: E26-E33
- Site-specific antiatherogenic effect of the antioxidant ebselen in the diabetic apolipoprotein E-deficient mouse.Arterioscler. Thromb. Vasc. Biol. 2009; 29: 823-830
- The NF-kappa B signal transduction pathway in aortic endothelial cells is primed for activation in regions predisposed to atherosclerotic lesion formation.Proc. Natl. Acad. Sci. U. S. A. 2000; 97: 9052-9057
- I kappa B kinase alpha (IKKalpha) activity is required for functional maturation of dendritic cells and acquired immunity to infection.EMBO J. 2013; 32: 816-828
- Activation by IKKalpha of a second, evolutionary conserved, NF-kappa B signaling pathway.Science. 2001; 293: 1495-1499
- Matrix metalloproteinases in atherosclerosis: role of nitric oxide, hydrogen sulfide, homocysteine, and polymorphisms.Vasc. Health Risk Manag. 2015; 11: 173-183
- MMP-2 and MMP-9 are prominent matrix metalloproteinases during atherosclerosis development in the Ldlr(-/-)Apob(100/100) mouse.Int. J. Mol. Med. 2011; 28: 247-253
- Metalloproteinase expression in monocytes and macrophages and its relationship to atherosclerotic plaque instability.Arterioscler. Thromb. Vasc. Biol. 2008; 28: 2108-2114
- Matrix metalloproteinases: influence on smooth muscle cells and atherosclerotic plaque stability.Expert Rev. Cardiovasc Ther. 2007; 5: 265-282
- Plaque rupture is a determinant of vascular events in carotid artery atherosclerotic disease: involvement of matrix metalloproteinases 2 and 9.J. Clin. Neurol. 2011; 7: 69-76
- Effect of MMP-2 deficiency on atherosclerotic lesion formation in apoE-deficient mice.Arterioscler. Thromb. Vasc. Biol. 2006; 26: 1120-1125
- Persistence of atherosclerotic plaque but reduced aneurysm formation in mice with stromelysin-1 (MMP-3) gene inactivation.Arterioscler. Thromb. Vasc. Biol. 2001; 21: 1440-1445
- Divergent effects of matrix metalloproteinases 3, 7, 9, and 12 on atherosclerotic plaque stability in mouse brachiocephalic arteries.Proc. Natl. Acad. Sci. U. S. A. 2005; 102: 15575-15580
- Serum matrix metalloproteinase-3 concentration is influenced by MMP-3 -1612 5A/6A promoter genotype and associated with myocardial infarction.J. Intern. Med. 2005; 258: 411-419
- Correlations of MMP-1, MMP-3, and MMP-12 with the degree of atherosclerosis, plaque stability and cardiovascular and cerebrovascular events.Exp. Ther. Med. 2018; 15: 1994-1998
- TIMP-2 (tissue inhibitor of metalloproteinase-2) regulates MMP-2 (matrix metalloproteinase-2) activity in the extracellular environment after pro-MMP-2 activation by MT1 (membrane type 1)-MMP.Biochem. J. 2003; 374: 739-745
- Suppression of atherosclerotic plaque progression and instability by tissue inhibitor of metalloproteinase-2: involvement of macrophage migration and apoptosis.Circulation. 2006; 113: 2435-2444
- Differential effects of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 on atherosclerosis and monocyte/macrophage invasion.Cardiovasc. Res. 2016; 109: 318-330
- IKKalpha, a critical regulator of epidermal differentiation and a suppressor of skin cancer.EMBO J. 2008; 27: 2639-2647
- IKKalpha/CHUK regulates extracellular matrix remodeling independent of its kinase activity to facilitate articular chondrocyte differentiation.PLoS One. 2013; 8e73024
- IKKbeta regulates essential functions of the vascular endothelium through kinase-dependent and -independent pathways.Nat. Commun. 2011; 2: 318
- Deletion of IkappaB-kinase beta in smooth muscle cells induces vascular calcification through beta-catenin-runt-related transcription factor 2 signaling.J. Am. Heart Assoc. 2018; 7
- Macrophage IKKalpha deficiency suppresses Akt phosphorylation, reduces cell survival, and decreases early atherosclerosis.Arterioscler. Thromb. Vasc. Biol. 2016; 36: 598-607
Article info
Publication history
Published online: November 02, 2019
Accepted:
October 31,
2019
Received in revised form:
October 25,
2019
Received:
December 17,
2018
Identification
Copyright
© 2019 Elsevier B.V. All rights reserved.
