Reduced acute vascular injury and atherosclerosis in hyperlipidemic mice transgenic for lysozyme

Am J Pathol. 2006 Jul;169(1):303-13. doi: 10.2353/ajpath.2006.050885.

Abstract

Hyperlipidemia promotes oxidant stress, inflammation, and atherogenesis in apolipoprotein E-deficient (ApoE((-/-))) mice. Mice transgenic for lysozyme (LZ-Tg) are resistant to acute and chronic oxidative stress and have decreased circulating levels of pro-oxidant advanced glycation end-products (AGEs). Herein we report that TIB-186 macrophages transduced with adenovirus-expressing human LZ (AdV-LZ) containing the AGE-binding domain facilitated AGE uptake and degradation and that AdV-LZ-transduced macrophages and peritoneal macrophages from LZ-Tg mice suppressed the AGE-triggered tumor necrosis factor-alpha response. We assessed atherosclerosis in LZ-Tg mice crossed with ApoE((-/-)) mice (LZ/ApoE((-/-))) and found increased serum LZ levels and decreased AGE and 8-isoprostanes levels, although hyperlipidemia remained similar to ApoE((-/-)) controls. Atherosclerotic plaques and neointimal lesions at the aortic root and descending aorta were markedly decreased (by 40% and 80%, respectively) in LZ/ApoE((-/-)) versus ApoE((-/-)) mice, as were inflammatory infiltrates. The arterial lesions following femoral artery injury in LZ/ApoE((-/-)) mice were suppressed (intimal to media ratio decreased by 50%), as were AGE deposits and vascular smooth muscle cell activation, compared to ApoE((-/-)) mice. Despite hyperlipidemia, development of atheroma and occlusive, inflammatory arterial neointimal lesions in response to injury was suppressed in LZ/ApoE((-/-)) mice. This effect may be due to the antioxidant properties of LZ, which is possibly linked to the AGE-binding domain region of the molecule.

MeSH terms

  • Adenoviridae / genetics
  • Animals
  • Aorta / pathology
  • Apolipoproteins E / deficiency
  • Apolipoproteins E / genetics
  • Atherosclerosis / enzymology
  • Atherosclerosis / etiology
  • Atherosclerosis / metabolism
  • Atherosclerosis / pathology*
  • Blotting, Western
  • Cells, Cultured
  • Femoral Artery / injuries
  • Femoral Artery / pathology
  • Genetic Vectors
  • Glycation End Products, Advanced / metabolism*
  • Humans
  • Hyperlipidemias / complications*
  • Immunohistochemistry
  • Macrophages / metabolism
  • Mice
  • Mice, Transgenic
  • Muramidase / genetics*
  • Muramidase / metabolism*
  • Muscle, Smooth, Vascular / metabolism
  • RNA, Messenger / analysis
  • Recombinant Proteins
  • Transduction, Genetic
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Apolipoproteins E
  • Glycation End Products, Advanced
  • RNA, Messenger
  • Recombinant Proteins
  • Tumor Necrosis Factor-alpha
  • Muramidase