Transglutaminase (TGase), a calcium-dependent enzyme, is involved in the regulation of cell growth and differentiation. Studies from several laborato¬ries have indicated that TGase may play an important role in macrophage function. Activation of macrophages in-vivo is associated with marked increases in TGase activity. Indeed, many reports have suggested that in¬flammatory macrophages have higher levels of TGase activity than resident, non-activated macrophages. We have undertaken a combined immuno¬chemical and enzymological approach both to evaluate the TGase levels in alveolar macrophages from normal subjects and from asthmatic patients, and to investigate the mechanism that may account for the elevation that we have found in macrophages from patients with asthma. We have shown that the elevated enzyme activity in macrophages from asthmatic subjects, if com¬pared with normal individuals (35±7 vs 9±1 TGase activity; pmols/min/mg), is due to a marked accumulation of TGase into the cells, and that this reduc¬tion can be stimulated by exposure, in vitro, of alveolar macrophages to activating factors.
TRANSGLUTAMINASE IN ALVEOLAR MACROPHAGES FROM NORMAL AND ASTHMATIC SUBJECTS
MAZZARELLA, Gennaro;MEZZOGIORNO, Antonio;
1995
Abstract
Transglutaminase (TGase), a calcium-dependent enzyme, is involved in the regulation of cell growth and differentiation. Studies from several laborato¬ries have indicated that TGase may play an important role in macrophage function. Activation of macrophages in-vivo is associated with marked increases in TGase activity. Indeed, many reports have suggested that in¬flammatory macrophages have higher levels of TGase activity than resident, non-activated macrophages. We have undertaken a combined immuno¬chemical and enzymological approach both to evaluate the TGase levels in alveolar macrophages from normal subjects and from asthmatic patients, and to investigate the mechanism that may account for the elevation that we have found in macrophages from patients with asthma. We have shown that the elevated enzyme activity in macrophages from asthmatic subjects, if com¬pared with normal individuals (35±7 vs 9±1 TGase activity; pmols/min/mg), is due to a marked accumulation of TGase into the cells, and that this reduc¬tion can be stimulated by exposure, in vitro, of alveolar macrophages to activating factors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
