A protein, ferritin, protects kidneys against a damaging after-effect of injury, heart failure or hardened arteries by controlling levels of iron, according to a study published Sept. 9, 2013 by UAB researchers in the Journal of Clinical Investigation.
The research team genetically engineered mice that clarified the role of ferritin in iron metabolism, setting the stage for research into future treatments that prevent acute kidney damage caused by iron.
Iron is the most common chemical element on Earth and a core player in the biochemical processes of animals that evolved in its presence. The human body uses iron because its atomic structure can readily accept or donate negatively charged atomic components called electrons, shifting back and forth as needed. Cells, and in particular the powerhouses within cells called mitochondria, pass around electrons and harness charge to drive life processes and make cellular energy with the help of iron.
Unfortunately, that same, useful atomic flexibility means that any iron free in the body will react with almost anything it encounters, disrupting charge balances and creating highly reactive free radicals that tear apart DNA and cause cells to self-destruct, mechanisms by which trauma and many diseases kill tissue.
Thus, iron is almost always bound to transporter and chaperone proteins. When the body suffers a crushing injury, however, iron-containing heme proteins like myoglobin spill out of crushed tissue into the bloodstream, get caught in the blood-filtering nephrons in the kidney and die, releasing their iron. When less oxygen reaches kidney tubules thanks to a failing heart, the lack disables heme proteins in the kidney cells, causing them to spill the iron they contain as well.The current study results confirm a protein called ferritin is among the most important of proteins charged with mopping up free iron. Beyond showing its ability to prevent iron-related cellular damage, UAB researchers and lead co-authors Abolfazl Zarjou, M.D., Ph.D., and Subhashini Bolisetty, Ph.D., say their study is the first to reveal the role of the kidney in the regulation of iron metabolism, a function until now linked to the liver and the intestines.
Read more about the study and its results.