In support to the present findings, proteasome inhibitors have been demonstrated to have anti-inflammatory activities by blocking the activation of NF-kappaB and by reducing the production of inflammatory mediators and cytokines [ 47, 48].
Cyclosporine's cellular mechanism of action involves binding cyclophilin; this complex then inhibits the phosphatase activity of calcineurin, thereby blocking the activation of transcription factor NF-AT (nuclear factor of activated T cells).
Previous study from Hou et al. [ 48] has demonstrated that one of the flavonoid compounds (C3G aglycone-cyanidin) effectively inhibits iNOS and COX-2 expression in LPS-activated murine macrophages via blocking the activation of NF- κβ.
HSP27 is also an inhibitor of apoptosis by sequestering cytochrome c when released from the mitochondria, preventing the mitochondrial release of second mitochondria-derived activator of caspases (SMAC), blocking the activation of the proliferative PI3K-AKT pathway that enables cells to divert energy consumption toward relieving the ER stress, and stimulating prosurvival NF-κB signaling [ 430].
CHS-111 was subsequently found to reduce levels of active GTP-bound RhoA by blocking the activation of the RhoA-specific GEF Vav.
VA RNAI acts against cellular antiviral defense by blocking the activation of the protein kinase PKR, which when activated turns off protein synthesis in infected cells [ 56].
Recently, it has been observed (Murakami et al, 2007) that PEITC suppresses receptor activator of NF- κB ligand-induced osteoclastogenesis by blocking the activation of ERK1/2 and p38 MAPK in RAW264.7 macrophages.
The anti-inflammatory effects are achieved by blocking the activation of NF-κB, secreting anti-inflammatory cytokines, and inhibiting the release of pro-inflammatory cytokines, such as TNF-α and IL-6 (Tilg and Moschen, 2006).
Several mechanisms blocking the activation of apoptotic pathways, including caspase 9 activation blocking, have been postulated in GBM cells, which could explain the low level of this protein in GBM [36,37].
The X-linked inhibitor of apoptosis protein (XIAP) is overexpressed in several malignant cells where it prevents apoptosis by binding to, and blocking, the activation of caspase-3, -7, and -9.
Thus, our experiment strongly suggests that the administration of valsartan can ameliorate the ER stress through blocking the activation of CHOP/Puma signaling pathway, which provides a new insight into the potential molecular mechanism of cardiomyocyte apoptosis.
