Focal cerebral ischemia (ischemic stroke) is the most common cause of disability and the fourth leading cause of death in the United State. Despite of the efforts on developing the pharmacological and surgical treatments of the disease, tissue plasminogen activator (tPA) is the only effective therapy at present. A better understanding of the pathological process and the discovery of new targets and therapies will significantly advance the field. There have been little studies on lncRNAs in cerebral ischemia. Through an lncRNA array analysis in a rat model of focal cerebral ischemia/reperfusion (IR), we have identified CAMK2D-associated transcript 1 (C2dat1) and 2 (C2dat2) (C2dat1-2) as two novel IR-induced lncRNAs that specifically regulated the expression of CaMKII? in rat and mouse models of focal cerebral IR. In our pilot study, C2dat1-2 mRNAs were upregulated in a time-dependent manner in mouse cortical penumbra after focal ischemic brain injury, which was accompanied by increased expression of CaMKII? at transcript and protein levels. The expression patterns of C2dat1-2 and CAMK2D were confirmed in mouse Neuro-2a cells in response to in vitro ischemia (oxygen-glucose deprivation/re-oxygenation, OGD/R). Knockdown of C2dat1 resulted in a significant blockade of CaMKII? expression, and potentiated OGD/R-induced cell death. Mechanistically, reduced CaMKII? expression upon silencing C2dat1 inhibited OGD/R-induced activation of the NF-?B signaling pathway. Further analysis showed that the downregulation of IKK? and further inhibition of I?B? degradation accounted for the inhibition of the NF-?B signaling activity by depleting C2dat1-2. Thus, C2dat1 appears to promote neuronal survival through regulating the NF-?B signaling pathway. Therefore, lncRNAs may be potential targets for therapeutic intervention of ischemia brain injury. Based on these preliminary findings, we hypothesize that C2dat1-2 are novel IR-induced lncRNAs that regulate the expression of CaMKII? to promote neuronal survival through the activation of the NF-?B signaling pathway. The primary goal of this application is to determine the function and signaling mechanisms of C2dat1-2, as well as the associated CaMKII? in IR- induced neuronal injury. The long-term goal is to gain more insights into the molecular bases of IR-associated biological processes and to identify novel therapeutic targets that confer neuroprotection during IR.
Two specific aims are proposed:
Specific Aim 1. Define the role of C2dat1-2 as novel ischemia-induced lncRNAs that promote neuronal survival by modulating CaMKII? expression in mouse primary neuronal cultures.
Specific Aim 2. Determine if knockdown of C2dat1-2 potentiate IR-induced cell death in mouse model of focal cerebral ischemia and if the effects are mediated through down-regulation of CaMKII?.
Focal cerebral ischemia (stroke) is the most common cause of disability and the fourth leading cause of death in the United State, yet few effective therapie are available. There is an urgent need to gain a better understanding of the pathological process and to identify new targets and therapies to treat this detrimental disease. We have identified two novel ischemia/reperfusion (IR)-induced lncRNAs that regulate the expression of CaMKII? in cellular and animal models of focal cerebral ischemia. Our proposed studies will test the hypothesis that C2dat1 and C2dat2 are novel IR-induced lncRNAs that regulate the expression of CaMKII? to promote neuronal survival through the activation of the NF-?B signaling pathway. The completion of the study will define the function and signaling mechanisms of C2dat1-2 and their target CaMKII? in IR-induced neuronal injury. The neural protective role of C2dat1-2/CaMKII? may be exploited for therapeutic intervention of stroke.
| Roy, Adhiraj; Ye, Jing; Deng, Fan et al. (2017) Protein kinase D signaling in cancer: A friend or foe? Biochim Biophys Acta Rev Cancer 1868:283-294 |
| Xu, Q; Deng, F; Qin, Y et al. (2016) Long non-coding RNA regulation of epithelial-mesenchymal transition in cancer metastasis. Cell Death Dis 7:e2254 |
| Xu, Q; Deng, F; Xing, Z et al. (2016) Long non-coding RNA C2dat1 regulates CaMKII? expression to promote neuronal survival through the NF-?B signaling pathway following cerebral ischemia. Cell Death Dis 7:e2173 |
