Caseinphosphopeptide-induced calcium uptake in human intestinal cell lines HT-29 and Caco2 is correlated to cellular differentiation.
Caseinphosphopeptides (CPPs) are considered as mineral carriers because of their ability to bind and solubilize calcium ions, with the possible role, yet to be definitely assessed, of improving calcium absorption at the intestinal level. Previous works demonstrated that CPPs improve calcium uptake, with increasing intracellular calcium concentration, by human differentiated tumor HT-29 cells, and that this effect correlates with the supramolecular structure of CPPs in the presence of calcium ions. The aim of the present study was to establish whether the CPP effect on calcium uptake is specific for HT-29 cells and depends on the differentiated state of the cells. To this purpose, HT-29 and Caco2 cells, two models of intestinal cells, were differentiated following appropriate protocols, including treatment with 1,25-(OH)2 vitamin D3. The CPP-dependent intracellular calcium rises were monitored at the single-cell level through fura2-fluorescence assays, and cell differentiation was assessed by biochemical and morphological methods. Results clearly showed that the ability to take up extracellular calcium ions under CPP stimulation is exhibited by both HT-29 and Caco2 cells, but only upon cell differentiation. This evidence adds novel support to the notion that CPPs favour calcium absorption, thus possibly acting as cellular bio-modulators and carrying a nutraceutical potential.
Department of Medical Chemistry, Biochemistry and Biotechnology, LITA Segrate, University of Milan, 20090 Milan, Italy.
Stefania
S
Cosentino
Claudia
C
Gravaghi
Elena
E
Donetti
Bianca M
BM
Donida
Giovanni
G
Lombardi
Marzia
M
Bedoni
Amelia
A
Fiorilli
Guido
G
Tettamanti
Anita
A
Ferraretto
D000469:Alkaline Phosphatase / Q000378:metabolism; D018938:Caco-2 Cells; D002117:Calcitriol / Q000494:pharmacology; D002118:Calcium / Q000493:pharmacokinetics* / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects; D002364:Caseins / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D049109:Cell Proliferation / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology*; D019587:Dietary Supplements; D019073:HT29 Cells; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D007700:Kinetics; D008871:Microvilli / Q000201:enzymology; D010446:Peptide Fragments / Q000494:pharmacology*; D010748:Phosphopeptides / Q000494:pharmacology*; D013394:Sucrase-Isomaltase Complex / Q000378:metabolism
D002364:Caseins; D002614:Chelating Agents; D010446:Peptide Fragments; D010748:Phosphopeptides; D000469:Alkaline Phosphatase; D013394:Sucrase-Isomaltase Complex; D002117:Calcitriol; D002118:Calcium