Mechanisms of heme oxygenase-1 induction by cobalt protoporphyrin and cobalt chloride

Heme oxygenase-1 (HO-1) is claimed to have a protective effect in many diseases including cardiovascular disorders, renal failure or transplantation. Therefore, its induction can be considered as a therapeutic strategy. HO-1 expression is regulated mainly at the transcriptional level and many transcription factors and regulatory elements present in HO-1 gene were discovered. Among different HO-1 inducers, metals (like cobalt) and metalloporphyrins (e.g. cobalt protoporphyrin), which are used both in vitro and in vivo, act via discrete pathways. Here we describe the possible mechanisms involved in HO-1 regulation by those cobaltous compounds.