The sequence of gene expression in cultured human saphenous vein after injury

The objective of this study was a description of changes in gene expression that occur in response to mechanical injury of cultured human saphenous vein.

Restriction fragment differential display (Display Systems Biotech, Vista, Calif) was used for the comparison of the gene expression profile in seven sets of vein, with the first set representing gene expression at the time of harvest of the vein and the other six sets representing different lengths of time in culture with or without crush injury. All seven sets were from a single, freshly harvested vein. Each set contained eight separate vein segments. The first set (Set 1) was taken from the freshly harvested vein, and the RNA was immediately extracted. This set reflects the in vivo gene expression profile at the time of harvest. Three sets of vein segments (Sets 2, 4, and 6) were cultured for 24, 48, or 72 hours after harvest (culture only). Three sets of vein segments (Sets 3, 5, and 7) were harvested, crush-injured, and then cultured for 24, 48, or 72 hours (crush injury + culture). The gene expression profiles of these six cultured sets of vein segments were compared with the gene expression profile of the set of vein segments that were obtained at harvest.

The crush injury of the vein segments resulted in the up-regulated expression of 21 identified (including inducible nitric oxide synthase) and nine unknown genes and in the down-regulated expression of eight identified and seven unknown genes within the first 72 hours after harvest. The vein segments that were cultured without crush injury had the up-regulated expression of nine identified and seven unknown genes and the down-regulated expression of five identified (including platelet-derived growth factor-B and transforming growth factor-beta2) and seven unknown genes within the first 72 hours after harvest. The pattern of gene regulation after transmural crush injury revealed eight genes whose products support cell migration and seven genes whose products oppose cell proliferation.

The comparison of gene expression between those vein segments designated culture only and those vein segments designated crush injury and culture shows that some cells of the vein segments express phenotypic changes that are consistent with cell migration. Further studies of gene expression changes in vitro may elucidate the endogenous response of vascular tissue to injury.