What is BCL-2?

updated 11/2014

BCL-2 stands for B-cell lymphoma/leukemia-2, one of a large family of proteins that regulate cell death and growth. This protein is a death-preventer. Not all cell death is bad. That’s how the brain reshapes itself to meet current needs. But having more BCL-2 seems to be able to prevent cell death from things that stress brain cells, such as:

  • too little blood flow;
  • too little potassium;
  • too much of a very activating transmitter called “glutamate”; and
  • several other cell “toxins”.

How does BCL-2 protect cells?
The death-promoting factors, from the family of growth-regulating molecules are appropriately named, like something out of a Batman comic: “Bax” and “Bad”. They open holes in a structure inside cells called the “mitochondrion”. When these holes are opened in mitochondria, things like calcium and several destructive proteins leak out into the rest of the cell. BCL-2 keeps these holes from opening, by holding back the Bax activity. It also seems to be able to help damaged cells regenerate their connections to other cells.

If you’ve come this far maybe you have enough biochemistry to follow a 2014 review of the bcl-2 family. This very technical article takes you into the mitochondria. No wonder, we clinicians think: people with severe bipolar depression just look like there’s something wrong with their mitochondria…