[Fibrinogen](https://ul.orna.me/KOge/librarybiomarker?id=20) is a protein that is essential for wound healing and blood clotting in the body. However, a study published in the journal Scientific Reports shows that it is also a natural inhibitor (suppressor) of an enzyme called MMP2, which is important for normal organ repair. Levels of fibrinogen that are too high can prevent MMP2 from doing its job, which can lead to arthritis and heart disorders — including heart attacks. ## Evidence base The scientists' hypothesis was confirmed by experiments on mice. Whenever infection or injury occurred, the level of fibrinogen in the blood increased dozens of times. At such a level, MMP2 practically stopped working and heart and joints suffered. Superficial wounds healed better, but internal organs suffered. There is speculation that abnormal fibrinogen activity may be an unwanted side effect of common medications such as cholesterol-lowering drugs and antibiotics from certain groups. The researchers emphasize that future developments should balance MMP2 and fibrinogen levels so that net MMP2 activity in the body remains at normal levels. "We don't want to inhibit them more than necessary, and we don't want their levels to be higher than necessary," Fernandez-Patron says. Knowing how these enzymes are regulated is key to improving the diagnosis, prognosis, and treatment of patients with abnormal levels of MMP2 and fibrinogen. __Sources__: Hassan Sarker et al, Identification of fibrinogen as a natural inhibitor of MMP-2, Scientific Reports (2019). DOI: 10.1038/s41598-019-40983-y