3.4.2. Mast Cells
Mast cell activation plays an important role in various immediate
allergic diseases. ROS functions in FcεRI-mediated degranulation of mast
cells,85,86 and many ROS are generated during the
FcεRI-mediated activation of mast cells. Thus, blocking the production
of intracellular ROS can prevent the release of FcεRI-mediated allergic
mediators from rat mast cells.87 Son et al.stimulated mast cells from WT and Trx1-Tg mice with Ag, DNP-bovine serum
albumin; compared with that of WT mice, levels of histamine secreted by
mast cells from Trx1-Tg mice were significantly reduced, and the level
of intracellular ROS suggested that Trx1 may inhibit mast cell
degranulation by blocking ROS production.51 As the
underlying mechanism, ROS mainly activates phospholipase Cγ (PLCγ),
protein kinase C (PKC) and Ca2+ influx to cause medium
release,86,88 whereas Trx1 effectively inhibits PLCγ,
PKC and Ca2+ influx in the signal transmission of
ROS-activated FcεRI-dependent mast cells (Figure 1c).
βII-tryptase is one of the most abundant proteins stored and released in
mast cells; it participates in various acute and chronic allergic
processes and is commonly found in patients with asthma and
AR.89,90 The redox activity of the allosteric
disulphide bond (Cys220-Cys248disulphide bond) in βII-tryptase plays an essential role in exerting
enzyme activity, and Trx1 is a related βII-tryptase reducing agentin vivo ; it can selectively reduce the disulphide bonds and
potently reduce the catalytic activity of βII-tryptase in the reduced
state91 (Figure 1c).