Abstract
Purpose::
To compare the metabolic profile in murine corneal epithelial progenitor cells (TKE2 clone) following calcium-induced differentiation.
Methods::
Murine corneal epithelial progenitor cells (TKE2) were cultured and passaged in serum-free low calcium medium (defined KSFM, Invitrogen). TKE2 cells were induced to differentiate by adding 0.9 mM Ca2+ in the medium. Differentiation was confirmed by the expression of involucrin by RT-PCR. Metabolomic profiles of TKE2 and calcium-treated TKE2 cells were differentially displayed (metabolomic analysis) by coupling capillary electrophoresis with electrospray ionization time-of-flight mass spectrometry (CE-TOFMS).
Results::
The addition of calcium induced differentiation of TKE2 cells shown by the upregulation of involucrin. A total of 36 anions, 56 cations and 31nucleotides were measured by CE-TOFMS. The majority of metabolites analyzed increased following the addition of calcium in the medium. Metabolites increasing by more than two fold included pyruvate, lactate, fumarate, arginosuccinate, fructose 1,6-diphosphate, adenosine, guanosine, AMP, GMP and NADH.
Conclusions::
Calcium-induced differentiation of TKE2 cells involved the increase of major metabolites of the oxydative phosphorylation and glycolysis pathway. A general shift was observed from nucleic acid synthesis to energy metabolism.
Keywords: cornea: epithelium • cornea: basic science • differentiation