Wnt5a is expressed in murine and human atherosclerotic lesions.
Atherosclerosis is an inflammatory disease involving the accumulation of macrophages in the intima. Wnt5a is a noncanonical member of the Wnt family of secreted glycoproteins. Recently, human macrophages have been shown to express Wnt5a upon stimulation with bacterial pathogens in vitro and in granulomatous lesions in the lung of Mycobacterium tuberculosis-infected patients. Wnt5a expression has also been liked to Toll-like receptor-4 (TLR-4), an innate immune receptor implicated in atherosclerosis. These observations, along with the fact that Wnt5a is involved in cell migration and proliferation, led us to postulate that Wnt5a plays a role in atherosclerosis. To investigate this hypothesis, we characterized Wnt5a expression in murine and human atherosclerotic lesions. Tissue sections derived from the aortic sinus to the aortic arch of apolipoprotein E-deficient mice and sections derived from the carotid arteries of patients undergoing endarterectomy were subjected to immunohistochemical analysis. All samples were found to be positive for Wnt5a with predominant staining in the areas of macrophage accumulation within the intima. In parallel, we probed for the presence of TLR-4 and found coincident TLR-4 and Wnt5a expression. For both the Wnt5a and TLR-4 staining, consecutive tissue sections treated with an isotype- and species-matched Ig served as a negative control and exhibited little, if any, reactivity. Quantitative RT-PCR revealed that Wnt5a mRNA expression in RAW264.7 murine macrophages can be induced by stimulation with LPS, a known ligand for TLR-4. Combined, these findings demonstrate for the first time Wnt5a expression in human and murine atherosclerotic lesions and suggest that cross talk between TLR-4 and Wnt5a is operative in atherosclerosis.
Christman
Mark A
MA
Department of Chemical and Biomolecular Engineering, Ohio University, Columbus, Ohio, USA.
Goetz
Douglas J
DJ
Dickerson
Eric
E
McCall
Kelly D
KD
Lewis
Christopher J
CJ
Benencia
Fabian
F
Silver
Mitchell J
MJ
Kohn
Leonard D
LD
Malgor
Ramiro
R
D000818:Animals; D001018:Aortic Diseases / Q000378:metabolism* / Q000473:pathology; D001057:Apolipoproteins E / Q000235:genetics / Q000378:metabolism; D050197:Atherosclerosis / Q000378:metabolism* / Q000473:pathology; D002340:Carotid Artery Diseases / Q000378:metabolism* / Q000473:pathology; D002460:Cell Line; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D012333:RNA, Messenger / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000032:analysis; D051153:Wnt Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D000071818:Wnt-5a Protein
D001057:Apolipoproteins E; D008070:Lipopolysaccharides; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; C495345:TLR4 protein, human; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C438615:Wnt5a protein, mouse