Murray K D, Hayes V Y, Gall C M, Isackson P J
Department of Biochemistry and Molecular Biology, Mayo Clinic Jacksonville, FL 32224, USA.
Eur J Neurosci. 1998 Jan;10(1):377-87. doi: 10.1046/j.1460-9568.1998.00019.x.
We have examined the potential involvement of calcium/calmodulin-dependent protein kinases in the regulation of brain-derived neurotrophic factor mRNA in vivo following kainic acid (kainate)-induced seizure activity by in situ hybridization. KN-62, a specific inhibitor of calcium/calmodulin-dependent protein kinase type II and IV, blocked the characteristic induction of brain-derived neurotrophic factor mRNA seen following seizure activity. This blockade was specific to calcium/calmodulin-dependent protein kinase type II and IV as inhibitors of both protein kinase C and cAMP-dependent protein kinase had no effect. Inhibition of brain-derived neurotrophic factor mRNA increases varied between brain regions; an almost complete inhibition was seen throughout cortical regions, whereas only partial inhibitory effects were noted within hippocampus. A similar inhibition of increased c-fos mRNA was observed throughout cortical, hippocampal and diencephalic regions. The two predominant brain-derived neurotrophic factor transcripts induced by kainate, containing exons I or III, were differentially affected by KN-62. The cortical induction of exon I was blocked by KN-62, whereas exon III was not, providing additional evidence for the differential regulation of individual brain-derived neurotrophic factor transcripts and demonstrating that inhibition of brain-derived neurotrophic factor induction was not due to general blockade of seizure activity throughout the neocortex. These data implicate calcium/calmodulin-dependent protein kinase type II or IV in the regulation of brain-derived neurotrophic factor mRNA in vivo and suggest regionally specific mechanisms occur throughout the brain.
我们通过原位杂交技术，研究了钙/钙调蛋白依赖性蛋白激酶在海藻酸诱导癫痫发作活动后，对体内脑源性神经营养因子mRNA表达调控中的潜在作用。KN-62是钙/钙调蛋白依赖性蛋白激酶II型和IV型的特异性抑制剂，它能阻断癫痫发作活动后出现的脑源性神经营养因子mRNA的特征性诱导表达。这种阻断作用具有钙/钙调蛋白依赖性蛋白激酶II型和IV型的特异性，因为蛋白激酶C和环磷酸腺苷依赖性蛋白激酶的抑制剂均无此作用。脑源性神经营养因子mRNA表达增加的抑制作用在不同脑区有所差异；在整个皮质区域观察到几乎完全的抑制，而在海马体内仅观察到部分抑制作用。在整个皮质、海马和间脑区域均观察到对c-fos mRNA增加的类似抑制作用。海藻酸诱导产生的两种主要的脑源性神经营养因子转录本，包含外显子I或III，受KN-62的影响不同。外显子I在皮质中的诱导表达被KN-62阻断，而外显子III则未被阻断，这为单个脑源性神经营养因子转录本的差异调控提供了额外证据，并表明脑源性神经营养因子诱导表达的抑制并非由于整个新皮质癫痫活动的普遍阻断。这些数据表明钙/钙调蛋白依赖性蛋白激酶II型或IV型参与了体内脑源性神经营养因子mRNA的调控，并提示在全脑存在区域特异性机制。
