Bioremediation is the process of using plants and microorganisms (or aspects of their biochemistry) to restore a damaged or polluted environment. Medical bioremediation applies this same philosophy to the aging body - many aspects of aging can be thought of as having roots in damage and pollution at the level of our cells and cellular machinery. For example, as we grow older, the garbage removal and recycling functions in our cells are increasingly hampered by a buildup of metabolic byproducts and other materials that cannot be broken down and removed by human biochemistry. As this state of affairs becomes progressively worse with time, other forms of biochemical damage - normally kept in check by recycling of damaged cellular components - start to spiral out of control. Developing bioremediation techniques to remove this unwanted chemical gunk is one of the lines of research funded by the SENS Foundation:

The most promising approach is to enable cells to break the junk down so that they don't fill up after all. This can be accomplished by equipping the lysosome with new enzymes that can degrade the relevant material. The natural place to seek such enzymes is in soil bacteria and fungi, as these aggregates, despite not being degraded in mammals, do not accumulate in soil in which animal carcasses are decaying, nor in graveyards where humans are decaying. This suggests that the micro-organisms present in soil have enzymes capable of breaking these aggregates down, and work now being carried on at Arizona State University, has already confirmed this analysis.

Removing this gunk should restore cellular garbage collection and recycling to youthful levels, which in turn will address a number of secondary causes of age-related degeneration. Such a result would in effect be a reversal of one contributing factor to aging, a therapy beneficial to everyone who is old and suffering - just the sort of thing we want to see more of. With that in mind, I note that the December 2009 issue of Rejuvenation Research is available online, and contains an update on the SENS Foundation bioremediation research under the title "Medical Bioremediation: A Concept Moving Toward Reality":

A major driver of aging is catabolic insufficiency, the inability of our bodies to break down certain substances that accumulate slowly throughout the life span. Even though substance buildup is harmless while we are young, by old age the accumulations can reach a toxic threshold and cause disease. This includes some of the most prevalent diseases in old age - atherosclerosis and macular degeneration. Atherosclerosis is associated with the buildup of cholesterol and its oxidized derivatives (particularly 7-ketocholesterol) in the artery wall. Age-related macular degeneration is associated with carotenoid lipofuscin, primarily the pyridinium bisretinoid A2E.

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We report on an enzyme discovery project to survey the availability of microorganisms and enzymes with these abilities. We found that such microorganisms and enzymes exist. We identified numerous bacteria having the ability to transform cholesterol and 7-ketocholesterol. Most of these species initiate the breakdown by same reaction mechanism as cholesterol oxidase, and we have used this enzyme directly to reduce the toxicity of 7-ketocholesterol, the major toxic oxysterol, to cultured human cells. We also discovered that soil fungi, plants, and some bacteria possess peroxidase and carotenoid cleavage oxygenase enzymes that effectively destroy with varied degrees of efficiency and selectivity the carotenoid lipofuscin found in macular degeneration.

Look closely enough and all life science work starts to resemble the production process in a chemical factory. The next steps in this development cycle will involve establishing methods to introduce new enzymes into the body and determine which of those discovered are safe for use - which of course will require more fundraising. Because we humans can tolerate several decades of buildup in unwanted biochemicals like 7-ketocholesterol and A2E without undue harm, it seems plausible that a treatment similar to a course of drugs or chemotherapy will result at the end of the day. It will be a procedure that a person undergoes once every 20 years or so, in which the body is temporarily suffused with enzymes that clear out unwanted chemical gunk, thereby restoring the cellular recycling machinery of the lysosomes to pristine condition.

Schloendorn, J., Webb, T., Kemmish, K., Hamalainen, M., Jackemeyer, D., Jiang, L., Mathieu, J., Rebo, J., Sankman, J., Sherman, L., Tontson, L., Qureshi, A., Alvarez, P., & Rittmann, B. (2009). Medical Bioremediation: A Concept Moving Toward Reality Rejuvenation Research, 12 (6), 411-419 DOI: 10.1089/rej.2009.0917

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