Production of a new transgenic mouse (Jtmt) that specifically overexpresses the antioxidant metallothionein in endothelial cells

Abstract

Diabetes mellitus increases the risk for cardiovascular disease due, in part, to hyperglycemia‐induced oxidative stress. To investigate the potential for antioxidant protection of the vasculature, a transgenic mouse (Jtmt) that overexpresses the antioxidant metallothionein (MT) specifically in endothelial cells (EC) was produced. A 16kb transgene consisting of the murine Tie2 promoter and enhancer ligated to the human MTII gene was microinjected into FVB mouse embryos. Five Jtmt(1–5) founder mice were identified by PCR using human MTII primers. Two of these founder mice, Jtmt1 and Jtmt4, have generated numerous transgenic progeny. Further characterization of the Jtmt1 line showed that at 60 days of age heart, kidney and body weights as well as blood glucose, HbA1c, and urine albumin excretion levels were normal. Importantly, MT overexpression in EC in the micro‐ and macrovasculature of kidney, heart, and tail tissues was confirmed by immunohistochemical studies. Ongoing studies are assessing the amount of MT overexpression in renal, hepatic and myocardial tissues by competitive ELISA and Western blot analyses as well as the effect of MT overexpression on EC cytological features by TEM. Future studies include crossing Jtmt1 and OVE26 transgenic diabetic mice in an effort to determine the potential benefits of endothelial‐specific antioxidant protection of the diabetic vasculature.Grant Funding Source: North Dakota Lions Foundation