Autofluorescence and ageing: changes in ribosome accuracy and lysosome [corrected] function

Autofluorescence increased with decreasing proliferative capacity of fibroblast cultures. It also increased rapidly when cultures were treated with the aminoglycosides, streptomycin, paromomycin and G418, as well as with ammonium chloride. All these compounds are known to accumulate in lysosomes. Paromomycin is known to reduce proliferative capacity and G418 was found to have a similar effect. As these aminoglycosides accumulate in the lysosomes, promote errors in protein synthesis and reduce proliferative capacity this has led us to suggest that such compounds may cause a loss of homeostasis between erroneous protein synthesis and lysosome function. The increase in autofluorescence may be a consequence of reduced lysosome function arising from lack of control of the intralysosomal pH.