Plasminogen

Plasminogen plays a crucial role in bone repair.

"we investigated bone repair and ectopic bone formation using plasminogen deficient (Plg-/- ) mice. Bone repair of the femur is delayed in Plg-/- mice, unlike that in the wild-type (Plg+/+ ) mice. The deposition of cartilage matrix and osteoblast formation were both decreased in Plg-/- mice. Vessel formation, macrophage accumulation, and the levels of vascular endothelial growth factor (VEGF) and transforming growth factor-β (TGF-β) were decreased at the site of bone damage in Plg-/- mice. Conversely, heterotopic ossification was not significantly different between Plg+/+ and Plg-/- mice. Moreover, angiogenesis, macrophage accumulation, and the levels of VEGF and TGF-β were comparable between Plg+/+ and Plg-/- mice in heterotopic ossification.  Plasminogen contributes to angiogenesis related to macrophage accumulation, TGF-β, and VEGF, thereby leading to the enhancement of bone repair. "

"In plasminogen-deficient mice, we showed that bone metabolism is regulated by plasminogen/plasmin through the expression of osteoprotegerin, a decoy receptor for receptor activator of NF-κB (RANK) ligand, in osteoblastic cells, and the increase in the number of
osteoclasts."

"The levels of type II and X collagens in the damaged femur of Plg−/− mice were decreased as compared with Plg+/+ mice"

"chondrogenesis is impaired by plasminogen deficiency during bone repair."<-Does plasminogen help chondrogenesis in conditions other than bone repair?

"The phosphorylation of Smad2/3 in the damaged femur of Plg−/− mice was decreased as compared with Plg+/+ mice"

"angiogenesis is suppressed by plasminogen deficiency, presumably through a reduction of TGF-β, rather than by decreased levels of BMP-2 and HIF-1α."

"local treatment of VEGF reversed delayed bone repair by plasminogen deficiency"

"plasminogen deficiency does not affect BMP-2-induced heterotopic ossification"

"plasminogen deficiency decreases angiogenesis as well as the accumulation of macrophages at the damaged site during bone repair"