Do AMPK phosphorylation and ATP level control vascular calcification?
The strengthening and hardening of soft tissues by calcification is a very interesting phenomenon. The same process takes place in the strengthening of bones, but is usually undesirable in the case of soft tissues. Actually, it is not calcium as such at all, but calcium phosphate ( hydroxyapatite, HA, Ca10(PO4)6(OH)2 ), which strengthens soft tissues. It is the very same material that is missing from the bones in osteoporosis, while it builds up and damages the soft tissues. The driving force of calcification is therefore not calcium at all, but phosphorus, or inorganic phosphate (Pi). And to make it not so simple, it depends on its form. Inorganic phosphate (Pi) accelerates calcification, inorganic pyrophosphate (PPi) protects against calcification. The difference or ratio between the levels of these two forms of inorganic phosphorus is stabilized and balanced by a group of enzymes called alkaline phosphatases (ALP/TNAP). These break down the pyrophosphate into two phosphate molecules