Figure 5

Schematic diagram depicting the mechanism underlying worsened recovery of cardiac function in aging hearts following global I/R. Myocardial I/R causes the release of HSP27, and extracellular HSP27 is one of the factors that activate myocardial TLR4. Aging exaggerates myocardial inflammatory responses to I/R through enhancing HSP27 release and elevating myocardial TLR4 levels, resulting in attenuated recovery of contractile function.