Scientist Studies Cell Suicide in Kidneys

A researcher at the Medical College of Georgia in Augusta has found that two proteins appear to conspire to kill kidney cells when oxygen supplies are low.

Dr. Zheng Dong, a cell biologist, said understanding how this happens may open the door to better treatment of renal failure.

Dehydration, low blood pressure, septic shock, trauma or removing a kidney for transplantation can temporarily halt or reduce blood and oxygen supplies, leading to cell suicide, especially in the critical tubular cells, Dong said.

Two proteins, Bid and Bax, are activated in the low-oxygen environment. Both can kill and appear to be more dangerous when both are activated.

When oxygen supplies are low, Bid appears to be cut into fragments that move toward the mitochondria, Dong said. The fragments may interact with Bax, which then moves toward the mitochondria and forms a complex structure, creating a hole that allows critical proteins to escape.

This process as we have shown probably is mediated by Bax, and now we have found that Bid can be a critical trigger of Bax, Dr. Dong says.

Dong has received a $1 million grant from the National Institute of Diabetes & Digestive & Kidney Diseases for further study of the process.