Mice
The inbred strains, B6 (#000664), Lepob (#000632), A/J (#000646) and gene-targeted plasminogen (Plg) activator inhibitor deficient mice (PAI-1-/-) (#002507) [15] mice in a B6 background were obtained from Jackson Laboratory (Bar Harbor, Maine) at 6 wks-of-age. The Plg-/- mice were generated as previously described [16] and maintained in the B6 background, generated by crossing mice from the original mixed (B6:129) background for eight generations with B6 mice. The Plg-/- mice do not reproduce well and Plg heterozygous pairs were used for breeding. Genotypes (Plg+/+, Plg+/-, Plg-/-) of the offspring were determined by a PCR assay at 3–4 weeks-of-age from an ear punch [17]. Breeding pairs of the CSS mice were transferred from Dr. Nadeau's laboratory. All mice were housed and bred in the Biological Resource Unit at the Cleveland Clinic Foundation (CCF). Mice were housed in sterilized isolator cages, maintained on a 14 hr light/10 hr dark cycle, and were provided sterilized food and water ad libitum. Mice were fed a standard autoclavable laboratory diet consisting of: 23% protein, 4.5% fat, 6% fiber, (Purina, St. Louis, MO), and tested between 7 and 9 wks-of-age. All animal experiments were performed in accordance with a protocol approved by the Institutional Animal Care and Research Advisory Committee at CCF.