Phospholipid-mediated signaling

Fig. 11.3 Mechanisms contributing to altered phospholipid-mediated signal transduction in congestive heart failure...

Fig. 11.4 Diabetes-induced generation of free radicals leading to altered membrane composition and sarcolemmal phospholipid-mediated signaling systems. RAS, renin angiotensin system SNS, sympathetic nervous system SL, sarcolemma...

Myocardial Ischemia-Reperfusion and Alterations in Phospholipid-Mediated Signal Transduction... 

It should be noted that agonists of PLD simulate the effects of IP, whereas the inhibition of PLD blocks the beneficial effects of IP (Ozer et al., 2005 Hashizume et al., 1997). In summary, the two extremes of stress imposed on the heart under I-R change the redox potential of the cardiomyocyte and affect redox-sensitive molecules involved in phospholipid-mediated signal transduction mechanisms. The early activation of specific PLC and PLD isozymes may represent initiation of redox signaling and cell survival pathways, whereas inactivation of specific PLC and PLD isozymes may contribute to impaired cardiac contractile function (Fig. 11.6). 

Special tasks. Some lipids have adopted special roles in the body. Steroids, eicosanoids, and some metabolites of phospholipids have signaling functions. They serve as hormones, mediators, and second messengers (see p.370). Other lipids form anchors to attach proteins to membranes (see p.214). The lipids also produce cofactors for enzymatic reactions—e.g., vitamin K (see p.52) and ubiquinone (see p.l04). The carotenoid retinal, a light-sensitive lipid, is of central importance in the process of vision (see p.358). 

Ryu, S.B., 2004, Phospholipid-derived signaling mediated by phospholipase A in plants. Trends Plant Sci. 9 229-235. 

In this context interest is focused on PKC, which plays a key role in mediating signals generated by hormones, growth factors and neurotransmitters (Nishizuka, 1988). Several isoforms of PKC have been described which show distinct sensitivity to Ca2+ and phospholipid-degradation products (Nishizuka, 1988). Their specific function, however, is not defined. It has been demonstrated previously that phorbol esters are potent activators of PKC and induce inhibition of the catalytic domain of the insulin receptor probably via serine phosphorylation of the insulin receptor )8-subunit (Muller et al., 1991). 

Erridge, C., Webb, D. J., and Spickett, C. M. 2007. Toll-like receptor 4 signalling is neither sufficient nor required for oxidised phospholipid mediated induction of interleukin-8 expression. 193, 77-85. 

F. 3a and b. Fluid mosaic structure of the cell membrane, a Overall representation 1 — talayer of hpid molecules 2 — membrane proteins, including receptors, membrane transport proteins, proteins mediating signal transfer etc. 3 — polysaccharide layer — glycocalyx b molecular structure of the lipid bilayer a — cholesterol b — lateral chains of fatty acids c — glycCTol residue d — phosphate moiety of the phospholipid molecule e — positively charged (amino) part of the pho holipid molecule (From Refs. 

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