Replicatively senescent human fibroblasts reveal a distinct intracellular metabolic profile with alterations in NAD+ and nicotinamide metabolism

Developers

Emma L. James, James A. E. Lane, Edward D. Karoly, E. Kenneth Parkinson, etc.

Description of the technology

Cellular senescence occurs by proliferative exhaustion or following multiple cellular stresses but had not previously been subject to detailed metabolomic analysis.

This technology has formed in process of metabolomics method application to replicative senescence of fibroblasts. Comparisons of fibroblasts’ proliferative exhaustion with proliferating and transiently growth arrested controls was carried out using a combination of different mass spectroscopy techniques. Proliferative exhaustion cells was accompanied with many specific alterations in both the NAD+ de novo and salvage pathways including accumulations of nicotinamide mononucleotide and nicotinamide riboside in the amidated salvage pathway despite no increase in nicotinamide phosphoribosyl transferase or in the nicotinamide riboside transport protein, CD73. Extracellular nicotinate was depleted and metabolites of the deamidated salvage pathway were reduced but intracellular NAD+ and nicotinamide were nevertheless maintained. However, sirtuin 1 was downregulated and so the accumulation of nicotinamide mononucleotide and nicotinamide riboside was best explained by reduced flux through the amidated arm of the NAD+ salvage pathway due to reduced sirtuin activity. Proliferative exhaustion cells also showed evidence of increased redox homeostasis and upregulated pathways used to generate energy and cellular membranes; these included nucleotide catabolism, membrane lipid breakdown and increased creatine metabolism.

Thus, proliferative exhaustion cells upregulate several different pathways to sustain their survival, which may serve as pharmacological targets for the elimination of senescent cells in age-related disease.

Practical application

This technology can be applied for evaluation of proliferative exhaustion. The results of this use are valuable information, which serves a basis for development of pharmacological intervention in age-related diseases. Herewith the passways of maintenance of cell survival will be serve as pharmacological targets

Laboratories

• Centre for Clinical & Diagnostic Oral Sciences, Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London (UK)
• Metabolon, Durham (USA)

Links

Publications

• James, E.L. et al. «Replicatively senescent human fibroblasts reveal a distinct intracellular metabolic profile with alterations in NAD+ and nicotinamide metabolism." 6 Scientific Reports, (2016): 38489.
• James, E. L. et al. «Senescent human fibroblasts show increased glycolysis and redox homeostasis with extracellular metabolomes that overlap with those of irreparable DNA damage, aging, and disease." 14 J Proteome Res, (2015): 1854–71.