High glucose accelerates the life cycle of the in vivo exposed mesothelium.

Background: Mouse mesothelium exposed in vivo for 30 days to high glucose solutions develop morphological changes that characterize a population of cells near the end of their life span.

Methods: The present study was designed to explore, in mesothelial cell imprints, whether these changes could derive from an early acceleration of the cell population life cycle in mice exposed for periods of up to 30 days to a 4.25% glucose fluid (236 mmol/L/L) prepared in Hank's balanced salt solution (HBSS). Three critical points of the cell's life cycle were evaluated: the G1 checkpoint [proliferating cell nuclear antigen (PCNA) expression], DNA synthesis ((3)H-thymidine incorporation), and the prevalence of mitosis.

Results: Cell populations exposed to a high glucose concentration showed an initial acceleration of their life cycle, as sustained by a peak of mitosis at two hours, an early increase of DNA incorporation sustained during the first 24 hours, as well as a top level of PCNA expression after three to four hours. These significantly higher values, compared with the control animals treated with HBSS, collapsed after 24 hours and were nil after 30 days of exposure.

Conclusions: Exposure to a high glucose concentration induced an early and short-lived acceleration of the mesothelial cell cycle, and with a longer exposure this was followed by a depletion of the growth capabilities of the exposed monolayer.