It has been shown that lysosomes are involved in B cell apoptosis but lysosomal glycohydrolases have never been investigated during this event. In this study we determined the enzymatic activities of some lysosomal glycohydrolases in human tonsil B lymphocytes (TBL) undergoing in vitro spontaneous apoptosis. Fluorimetric methods were used to evaluate the activities of beta-hexosaminidases, alpha-mannosidase, beta-mannosidase, alpha-galactosidase, beta-glucuronidase and alpha-fucosidase. Results show that in TBL during spontaneous apoptosis, there is a significant increase in the activity of beta-hexosaminidases, alpha-mannosidase, beta-mannosidase and beta-galactosidase. Also beta-glucuronidase and alpha-fucosidase activities increase but not in a significant manner. Further studies on beta-hexosaminidases revealed that also mRNA expression of the alpha- and beta-subunits, which constitute these enzymes, increases during spontaneous TBL apoptosis. When TBL are protected from apoptosis by the thiol molecule N-acetyl-L-cysteine (NAC), there is no longer any increase in glycohydrolase activities and mRNA expression of beta-hexosaminidase alpha- and beta-subunits. This study demonstrates for the first time that the activities and expression of some lysosomal glycohydrolases are enhanced in TBL during spontaneous apoptosis and that these increases are prevented when TBL apoptosis is inhibited.

Enhancement of lysosomal glycohydrolase activity in human primary B lymphocytes during spontaneous apoptosis

ROSATI, Emanuela;MENCARELLI, Simona;MAGINI, Alessandro;SABATINI, Rita;TASSI, Carmelo;ORLACCHIO, Aldo;COACCIOLI, Stefano;FRENGUELLI, Antonio;MARCONI, Pierfrancesco;EMILIANI, Carla
2007

Abstract

It has been shown that lysosomes are involved in B cell apoptosis but lysosomal glycohydrolases have never been investigated during this event. In this study we determined the enzymatic activities of some lysosomal glycohydrolases in human tonsil B lymphocytes (TBL) undergoing in vitro spontaneous apoptosis. Fluorimetric methods were used to evaluate the activities of beta-hexosaminidases, alpha-mannosidase, beta-mannosidase, alpha-galactosidase, beta-glucuronidase and alpha-fucosidase. Results show that in TBL during spontaneous apoptosis, there is a significant increase in the activity of beta-hexosaminidases, alpha-mannosidase, beta-mannosidase and beta-galactosidase. Also beta-glucuronidase and alpha-fucosidase activities increase but not in a significant manner. Further studies on beta-hexosaminidases revealed that also mRNA expression of the alpha- and beta-subunits, which constitute these enzymes, increases during spontaneous TBL apoptosis. When TBL are protected from apoptosis by the thiol molecule N-acetyl-L-cysteine (NAC), there is no longer any increase in glycohydrolase activities and mRNA expression of beta-hexosaminidase alpha- and beta-subunits. This study demonstrates for the first time that the activities and expression of some lysosomal glycohydrolases are enhanced in TBL during spontaneous apoptosis and that these increases are prevented when TBL apoptosis is inhibited.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11391/152642
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 19
  • ???jsp.display-item.citation.isi??? 19
social impact