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The long lifespan and how turnover of human islet beta cells estimated by mathematical modelling of lipofuscin accumulation.

Journal Contribution - Journal Article

AIMS/HYPOTHESIS: Defects in pancreatic beta cell turnover are implicated in the
pathogenesis of type 2 diabetes by genetic markers for diabetes. Decreased beta
cell neogenesis could contribute to diabetes. The longevity and turnover of human
beta cells is unknown; in rodents estimated. Intracellular lipofuscin body (LB) accumulation is a hallmark of
ageing in neurons. To estimate the lifespan of human beta cells, we measured beta
cell LB accumulation in individuals aged 1-81 years. METHODS: LB content was
determined by electron microscopical morphometry in sections of beta cells from
human (non-diabetic, n = 45; type 2 diabetic, n = 10) and non-human primates (n =
10; 5-30 years) and from 15 mice aged 10-99 weeks. Total cellular LB content was
estimated by three-dimensional (3D) mathematical modelling. RESULTS: LB area
proportion was significantly correlated with age in human and non-human primates.
The proportion of human LB-positive beta cells was significantly related to age,
with no apparent differences in type 2 diabetes or obesity. LB content was low in
human insulinomas (n = 5) and alpha cells and in mouse beta cells (LB content in
mouse the LB-positive human beta cells (representing aged cells) increased from >or=90%
(or=97% (>20 years) and remained constant thereafter.
CONCLUSIONS/INTERPRETATION: Human beta cells, unlike those of young rodents, are
long-lived. LB proportions in type 2 diabetes and obesity suggest that little
adaptive change occurs in the adult human beta cell population, which is largely
established by age 20 years.
Journal: Diabetologia
ISSN: 0012-186X
Volume: 53
Pages: 321-330
Number of pages: 10
Publication year:2010
Keywords:Lipofuscin, Age distribution, Cse of Death
  • Scopus Id: 77949289481