Chalimoniuk Malgorzata, Langfort Józef, Lukacova Nadezda, Marsala Józef
Department of Cellular Signaling, Medical Research Centre, Polish Academy of Sciences, Pawińskiego St. 5, 02-106 Warsaw, Poland.
Biochem Biophys Res Commun. 2004 Nov 5;324(1):118-26. doi: 10.1016/j.bbrc.2004.09.028.
The aim of our study was to investigate the expression and the activity of soluble guanylyl cyclase (GC) and phosphodiesterase (PDE) activities that regulate cGMP level in the striatum, hippocampus, and brain cortex in an animal model of PD, induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We observed the increase of total activity and protein level of GC in striatum after MPTP injection. It was accompanied by an enhancement of both mRNA expression and protein level of GCbeta1 subunit. MPTP induces mRNA expression and elevates protein concentration of GCbeta1 in striatum up to 14 days after its injection, which in turn causes a marked enhancement of cGMP formation. Furthermore, the activation of GC occurs through change of maximal enzyme activity (V(max)). Simultaneously, no change in PDE activity has been detected in all investigated regions of the brain after MPTP. MPTP injection caused the elevation of GCbeta1 protein level in both the membrane and cytosol fractions being significantly higher in cytosol. Western blot analysis demonstrated about 45-67% decrease of tyrosine hydroxylase protein content in striatum. These data suggest that NO/cGMP signaling pathway may at least partially contribute to dopaminergic fiber degeneration in the striatum, the damage attributed to PD.
我们研究的目的是在由1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP）诱导的帕金森病动物模型中，研究可溶性鸟苷酸环化酶（GC）的表达和活性以及调节纹状体、海马体和大脑皮质中cGMP水平的磷酸二酯酶（PDE）活性。我们观察到MPTP注射后纹状体中GC的总活性和蛋白水平增加。这伴随着GCβ1亚基的mRNA表达和蛋白水平的增强。MPTP注射后长达14天可诱导纹状体中GCβ1的mRNA表达并提高其蛋白浓度，进而导致cGMP生成显著增强。此外，GC的激活是通过最大酶活性（V(max)）的改变发生的。同时，在MPTP处理后的所有脑研究区域均未检测到PDE活性的变化。MPTP注射导致膜和胞质部分中GCβ1蛋白水平升高，胞质部分升高更为显著。蛋白质印迹分析表明纹状体中酪氨酸羟化酶蛋白含量降低了约45 - 67%。这些数据表明，NO/cGMP信号通路可能至少部分导致了纹状体中多巴胺能纤维变性，这是帕金森病所致的损伤。
