Lysosomes are the incinerators of your cells, breaking down junk and old, damaged components, such as mitochondria, so that the raw materials can be reused - a process called autophagy. Some portion of aging is caused by the buildup of materials that the lysosomes cannot degrade, a situation that looks something like lysosomal storage diseases (LSDs) wherein lysosomes are flawed to start with. LSDs "are debilitating genetic conditions that frequently manifest as neurodegenerative disorders. They severely affect eye, motor and cognitive functions and, in most cases, abbreviate the lifespan. Cell death is well documented in parts of the brain and in other cells of LSD patients and animal models ... We suggest that the lysosomal deficiencies in LSDs inhibit autophagic maturation, leading to a condition of autophagic stress. The resulting accumulation of dysfunctional mitochondria [increases] the vulnerability of the cells to pro-apoptotic signals." Which is another way of saying that the worn parts pile up until the cell self-destructs in the process called apoptosis. Some of the possible approaches to dealing with LSDs - such as the bioremediation research funded by Methuselah Foundation donors - are likely to prove useful in reversing this contribution to age-related degeneration.