Macrophage-specific overexpression of human matrix metalloproteinase-12 in transgenic rabbits.
Increased matrix metalloproteinase-12 (MMP-12) has been implicated in atherosclerosis and many other inflammatory processes. To define MMP-12 functions in vivo, we generated transgenic rabbits that expressed human (h) MMP-12 gene under the control of a macrophage-specific promoter, the human scavenger receptor promoter. Two transgenic founder rabbits were found to have hMMP-12 transgene integration by Southern blot analysis. hMMP-12 mRNA was expressed in peritoneal and alveolar macrophages, and in tissues enriched in macrophages in transgenic rabbits. High levels of hMMP-12 protein were detected in the conditioned media of cultured peritoneal and alveolar macrophages from transgenic rabbits. Zymography showed that hMMP-12 secreted from macrophages possessed enzymatic activity toward beta-casein. To evaluate the expression of hMMP-12 in inflammatory sites, we used carrageenan-induced granulomas as an in vivo model for tissue macrophages and foam cells. Granuloma size in transgenic rabbits was significantly increased compared to that in control rabbits, and histological examination revealed that granulomas of transgenic rabbits were enriched in macrophages associated with increased hMMP-12 expression. We believe that this transgenic rabbit model with increased expression of hMMP-12 may become a useful model for further mechanistic studies of MMP-12 in inflammatory diseases and cancer invasion; it is also an ideal model for testing the in vivo action of MMP-12 inhibitors.
Fan
Jianglin
J
Laboratory of Cardiovascular Disease, Department of Pathology, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba 305-8575, Japan. j-lfan@md.tsukuba.ac.jp
Wang
Xiaofei
X
Wu
Lihua
L
Matsumoto
Shin-Ich
SI
Liang
Jingyan
J
Koike
Tomonari
T
Ichikawa
Tomonaga
T
Sun
Huijun
H
Shikama
Hisataka
H
Sasaguri
Yasuyuki
Y
Watanabe
Teruo
T
D000818:Animals; D030801:Animals, Genetically Modified; D015139:Blotting, Southern; D002364:Caseins; D017931:DNA Primers; D015870:Gene Expression; D006099:Granuloma / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000378:metabolism*; D053508:Matrix Metalloproteinase 12; D008666:Metalloendopeptidases / Q000378:metabolism*; D023421:Models, Animal; D011401:Promoter Regions, Genetic / Q000235:genetics; D011817:Rabbits / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000235:genetics; D051116:Receptors, Scavenger; D014170:Transformation, Genetic; D019076:Transgenes / Q000235:genetics
D002364:Caseins; D017931:DNA Primers; D011971:Receptors, Immunologic; D051116:Receptors, Scavenger; D008666:Metalloendopeptidases; C507122:MMP12 protein, human; D053508:Matrix Metalloproteinase 12