Protective effects of SIP

Numerous studies have demonstrated the protective effect of exogenously apphed SIP. In many cases, the protective effects of SIP have been associated with the activation of signaling pathways mediated via EDG receptors (Figure 3). For example, S IP-dependent inhibition of serum-withdrawal-induced apoptosis of HTC4 hepatoma cells was mediated by transfected EDG3 or EDG5. S IP-induced protection involved EDG receptor-dependent activation of p42/p44 MAPK, inhibition of caspase-3... 

Lysophospholipids are usually bound to lipoproteins in vivo. Serum LPA binds to albumin, gelsolin, and other proteins (Moolenaar et al., 2004). SIP binds mainly to HDL and albumin (Levkau et al., 2004 Nofer et al., 2004 Okajima, 2002 Sato et al., 2007 Theilmeier et al., 2006). Such lipoproteins stabilize LPs in the hydrophilic environment and possibly protect them from rapid degradation. The stabilization effect of the lipoprotein is currently being studied (Moumtzi et al., 2007). 

Down-regulation of SIP biosynthesis provides another therapeutic modality for the treatment of cancers. On the other hand, exogenous SIP treatment exerts a protective role against cell death in normal (non-cancerous) human cells (Tilly and Kolesnick, 2002). Additionally, SIP has suppressive effects against chemotherapy-induced apoptosis in the ovary (Tilly and Kolesnick, 2002), and also blocked male germ cell apoptosis in the human testis (Suomalainen et al.,... 

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