Aims: Gelatin-binding protein of 28 kDa (GBP28) is a collagen-like plasma protein having a binding capacity with collagens. We investigated GBP28 role on myocardial remodelling as well as the diagnostic significance of GBP28 immunostaining in myocardial infarction.
Methods and results: Myocardial tissues obtained from 47 autopsied hearts with infarction were immunostained with antibodies against GBP28, fibronectin, type III and IV collagens, and prolyl 4-hydroxylase. GBP28 was distributed in interstitium of infarcted lesions at an early stage. GBP28 was linearly found both along the border with vital myocardium and at the periphery of surviving cardiomyocyte around the lesion at granulative stage. However, it was not observed in the scar. GBP28 distribution patterns were similar to those of fibronectin in infarcted lesions and those of type IV collagen at the periphery of cardiomyocyte. Type III collagen was not recognized in the early-stage lesion but increased along with scar maturation. Prolyl 4-hydroxylase was found in surviving cardiomyocytes around the lesion during all stages and in interstitial cells appeared in granulation tissue.
Conclusion: GBP28 plays a role as a scaffold of newly formed collagen in myocardial remodelling after ischaemic injury, and GBP28 immunostaining may assist in a diagnosis of healing stage.