Biochemistry and Pharmacology - Research Publications

Permanent URI for this collection

http://hdl.handle.net/11343/214

Filters

2013 1
Reset filters

Settings
Statistics
Citations
Type: Journal Article × Author: Bogoyevitch, Marie × Author: YEAP, YVONNE × Subject: c-Jun N-terminal kinase (JNK) ×

Search Results

Now showing 1 - 1 of 1
  • Item
    No Preview Available
    Cardioprotective 3′,4′-dihydroxyflavonol attenuation of JNK and p38MAPK signalling involves CaMKII inhibition
    Lim, NR ; Thomas, CJ ; Silva, LS ; Yeap, YY ; Yap, S ; Bell, JR ; Delbridge, LMD ; Bogoyevitch, MA ; Woodman, OL ; Williams, SJ ; May, CN ; Ng, DCH (PORTLAND PRESS LTD, 2013-12-01)
    DiOHF (3',4'-dihydroxyflavonol) is cardioprotective against I/R (ischaemia/reperfusion) injury. The biological activities of flavonols are associated with kinase modulation to alter cell signalling. We thus investigated the effects of DiOHF on the activation of MAPKs (mitogen-activated protein kinases) that regulate the cardiac stress response. In an ovine model of I/R, JNK (c-Jun N-terminal kinase), p38(MAPK), ERK (extracellular-signal-regulated kinase) and Akt were activated, and NP202, a pro-drug of DiOHF, reduced infarct size and inhibited JNK and p38(MAPK) activation, whereas ERK and Akt phosphorylation were unaltered. Similarly, in cultured myoblasts, DiOHF pre-treatment preserved viability and inhibited activation of JNK and p38(MAPK), but not ERK in response to acute oxidative and chemotoxic stress. Furthermore, DiOHF prevented stress-activation of the direct upstream regulators MKK4/7 (MAPK kinase 4/7) and MKK3/6 respectively. We utilized small-molecule affinity purification and identified CaMKII (Ca(2+)/calmodulin-dependent protein kinase II) as a kinase targeted by DiOHF and demonstrated potent CaMKII inhibition by DiOHF in vitro. Moreover, the specific inhibition of CaMKII with KN-93, but not KN-92, prevented oxidative stress-induced activation of JNK and p38(MAPK). The present study indicates DiOHF inhibition of CaMKII and attenuation of MKK3/6→p38(MAPK) and MKK4/7→JNK signalling as a requirement for the protective effects of DiOHF against stress stimuli and myocardial I/R injury.