TY  - JOUR
A1  - Soehnlein, Oliver
A1  - Drechsler, Maik
A1  - Döring, Yvonne
A1  - Lievens, Dirk
A1  - Hartwig, Helene
A1  - Kemmerich, Klaus
A1  - Ortega-Gómez, Almudena
A1  - Mandl, Manuela
A1  - Vijayan, Santosh
A1  - Projahn, Delia
A1  - Garlichs, Christoph D.
A1  - Koenen, Rory R.
A1  - Hristov, Mihail
A1  - Lutgens, Esther
A1  - Zernecke, Alma
A1  - Weber, Christian
T1  - Distinct functions of chemokine receptor axes in the atherogenic mobilization and recruitment of classical monocytes
JF  - EMBO Molecular Medicine
N2  - We used a novel approach of cytostatically induced leucocyte depletion and subsequent reconstitution with leucocytes deprived of classical \((inflammatory/Gr1^{hi})\) or non-classical \((resident/Gr1^{lo})\) monocytes to dissect their differential role in atheroprogression under high-fat diet (HFD). Apolipoprotein E-deficient \((Apoe^{-/-})\) mice lacking classical but not non-classical monocytes displayed reduced lesion size and macrophage and apoptotic cell content. Conversely, HFD induced a selective expansion of classical monocytes in blood and bone marrow. Increased CXCL1 levels accompanied by higher expression of its receptor CXCR2 on classical monocytes and inhibition of monocytosis by CXCL1-neutralization indicated a preferential role for the CXCL1/CXCR2 axis in mobilizing classical monocytes during hypercholesterolemia. Studies correlating circulating and lesional classical monocytes in gene-deficient \(Apoe^{-/-}\) mice, adoptive transfer of gene-deficient cells and pharmacological modulation during intravital microscopy of the carotid artery revealed a crucial function of CCR1 and CCR5 but not CCR2 or \(CX_3CR1\) in classical monocyte recruitment to atherosclerotic vessels. Collectively, these data establish the impact of classical monocytes on atheroprogression, identify a sequential role of CXCL1 in their mobilization and CCR1/CCR5 in their recruitment.
KW  - hypercholeterolemia
KW  - CCR2
KW  - atherosclerosis
KW  - chemokine
KW  - accumulation
KW  - subsets
KW  - inflammatory sites
KW  - fractalkine
KW  - marcophages
KW  - mobilization
KW  - monocyte
KW  - recruitment
KW  - bone-marrow
KW  - atheriosclerotic lesions
KW  - hyperlipedemic mice
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122204
SN  - 1757-4676
VL  - 5
ER  - 
TY  - JOUR
A1  - Tilstam, Pathricia V.
A1  - Gijbels, Marion J.
A1  - Habbeddine, Mohamed
A1  - Cudejko, Celine
A1  - Asare, Yaw
A1  - Theelen, Wendy
A1  - Zhou, Baixue
A1  - Döring, Yvonne
A1  - Drechsler, Maik
A1  - Pawig, Lukas
A1  - Simsekyilmaz, Sakine
A1  - Koenen, Rory R.
A1  - de Winther, Menno P. J.
A1  - Lawrence, Toby
A1  - Bernhagen, Jürgen
A1  - Zernecke, Alma
A1  - Weber, Christian
A1  - Noels, Heidi
T1  - Bone Marrow-Specific Knock-In of a Non-Activatable Ikkα Kinase Mutant Influences Haematopoiesis but Not Atherosclerosis in Apoe-Deficient Mice
JF  - PLOS ONE
N2  - Background: The Ikkα kinase, a subunit of the NF-kappa B-activating IKK complex, has emerged as an important regulator of inflammatory gene expression. However, the role of Ikkα-mediated phosphorylation in haematopoiesis and atherogenesis remains unexplored. In this study, we investigated the effect of a bone marrow (BM)-specific activation-resistant Ikk alpha mutant knock-in on haematopoiesis and atherosclerosis in mice. 
Methods and Results: Apolipoprotein E (Apoe)-deficient mice were transplanted with BM carrying an activation-resistant Ikkα gene (Ikkα(AA/AA) Apoe(-/-)) or with Ikkα(+/+) Apoe(-/-) BM as control and were fed a high-cholesterol diet for 8 or 13 weeks. Interestingly, haematopoietic profiling by flow cytometry revealed a significant decrease in B-cells, regulatory T-cells and effector memory T-cells in Ikkα(AA/AA) Apoe(-/-) BM-chimeras, whereas the naive T-cell population was increased. Surprisingly, no differences were observed in the size, stage or cellular composition of atherosclerotic lesions in the aorta and aortic root of Ikkα(AA/AA) Apoe(-/-) vs Ikkα(+/+) Apoe(-/-) BM-transplanted mice, as shown by histological and immunofluorescent stainings. Necrotic core sizes, apoptosis, and intracellular lipid deposits in aortic root lesions were unaltered. In vitro, BM-derived macrophages from Ikkα(AA/AA) Apoe(-/-) vs Ikkα(+/+) Apoe(-/-) mice did not show significant differences in the uptake of oxidized low-density lipoproteins (oxLDL), and, with the exception of Il-12, the secretion of inflammatory proteins in conditions of Tnf-α or oxLDL stimulation was not significantly altered. Furthermore, serum levels of inflammatory proteins as measured with a cytokine bead array were comparable. 
Conclusion: Our data reveal an important and previously unrecognized role of haematopoietic Ikkα kinase activation in the homeostasis of B-cells and regulatory T-cells. However, transplantation of Ikkα AA mutant BM did not affect atherosclerosis in Apoe(-/-) mice. This suggests that the diverse functions of Ikkα in haematopoietic cells may counterbalance each other or may not be strong enough to influence atherogenesis, and reveals that targeting haematopoietic Ikkα kinase activity alone does not represent a therapeutic approach.
KW  - NF-KAPPA-B
KW  - regulatory T cells
KW  - indoleamine 2,3-dioxygenase
KW  - dendritic cells
KW  - gene expression
KW  - increases atherosclersosis
KW  - receptor
KW  - inhibition
KW  - pathway
KW  - beta
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117450
VL  - 9
IS  - 2
ER  -