Statistical kinetic approach for modeling lifespan

Lifespan regulation through gene expression involves complex biochemical processes. Unfortunately, current mathematical models for treating lifespan data afford little insight into the mechanisms that control longevity. In this work, we demonstrate the use of a novel kinetic model to successfully fit the lifespan curves of the nematode, Caenorhabditis elegans. Our findings show that population aging may be treated analogously to a dispersive chemical process [P.J. Skrdla, R.T. Robertson., J. Phys. Chem. B 109 10611 (2005)]. Much like the Gompertz model, only two fit parameters, α and β, are needed to adequately describe the entire data set for each nematode population. These parameters relate a ‘global first-order time constant’ and a ‘global second-order rate constant’, with units of (time) and (time)− 2, respectively. In C. elegans, the increased longevity resulting from DAF-16 (a transcription factor) activity in the intestinal tissue correlates with a larger α value and a smaller β value; the opposite is true for animals with shorter lifespans. A basic physical interpretation of the two parameters is provided.