Our scientists discovered that the human FSTL1 protein stimulates heart regeneration.


The Discovery: FSTL1’s regenerative activity was detected using an unbiased screen for cardiac proliferation-inducing factors.  The regenerative activity is a property of a hypoglycosylated variant of human FSTL1 (hgFSTL1) that is protected by a WW composition of matter patent application. In vivo activity was first demonstrated in the mouse model of myocardial infarction after delivery to the heart via a sustained release collagen patch. This formulation safely promoted:

  • new cardiac muscle growth,  

  • new myocardial blood vessel formation, 

  • significant scar reduction.

This structural cardiac regeneration resulted in dramatic and stable improvement in both heart function and animal survival.


Confirmation: hgFSTL1 was shown to be equally effective in treating myocardial infarction in the adult pig. The pig has similar cardiac physiology and anatomy to humans making confirmation in this model an important step before testing in humans.