Metallothionein downregulation in very old age: a phenomenon associated with cellular senescence?
It is known that metallothionein (MT) mRNA expression first increases with age, but then decreases again in the very elderly. Here we report that MT protein levels also decrease in very old age, and that this is independent of dietary zinc intake. Age-related changes of MT, as well as alterations of zinc homeostasis (intracellular labile zinc and NO-induced zinc release), occur both in human PBMCs ex vivo and also in CD4+ T cell clones progressing through their finite life span in vitro. These results suggest that phenomena observed in very old people can be at least partially attributed to diminished cell proliferation.
Malavolta
Marco
M
Immunology Center, Section of Nutrition, Immunity and Ageing, Res. Department INRCA, Ancona, Italy. m.malavolta@inrca.it
Cipriano
Catia
C
Costarelli
Laura
L
Giacconi
Robertina
R
Tesei
Silvia
S
Muti
Elisa
E
Piacenza
Francesco
F
Pierpaoli
Sara
S
Larbi
Annis
A
Pawelec
Graham
G
Dedoussis
George
G
Herbein
George
G
Monti
Daniela
D
Jajte
Jolanta
J
Rink
Lothar
L
Mocchegiani
Eugenio
E
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D016922:Cellular Senescence; D002999:Clone Cells; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008297:Male; D008668:Metallothionein / Q000378:metabolism*; D008875:Middle Aged
D008668:Metallothionein