The autophagy process degrades and recycles malformed proteins or worn-out organelles using lysosomal machinery. In the past, autophagy has been shown to act only as an adaptive response to extreme physiologic conditions, such as nutrient deprivation. Then, in 2006, two teams of Japanese researchers published papers on autophagy in Nature - both Hot Papers this month - showing that autophagy is important not only in stressed cells, but also is essential to the health and development of normal cells.
Both teams of researchers, based at the Tokyo Metropolitan Institute of Medical Science, knocked out mouse genes that code for enzymes central to autophagy in neurons. They studied the effects of short-circuiting autophagy in otherwise healthy mice and found similar results: Healthy mice deprived of autophagy in neurons suffer progressive neurodegeneration, marked by the accumulation of abnormal, or misfolded, proteins inside nerve cells.
"These were two of the most exciting papers ...
