Developments of diagnostics for Mild Cognitive Impairment by patients serum and inhibition of the disease progress with vitamin D

聚集的淀粉样蛋白-β是阿尔茨海默病（AD）的病理特征，轻度认知障碍（MCI）是AD的早期阶段。迄今为止，还没有通过患者血清诊断MCI的方法。MCI患者血清25（OH）V-D_3浓度低于正常人，而1，25（OH）_2 V-D_3浓度与正常人无显著性差异。提示血清25（OH）V-D_3浓度对MCI的诊断有一定的参考价值。25（OH）V-D3在体外对聚集没有抑制作用，反而促进了聚集。PrPsc是引起羊瘙痒病的主要蛋白质，它来源于PrPc在正常脑内的构象转变。PrPc的低聚是PrPsc的前阶段。我们发现VD 3不能破坏寡聚化，而VD 2可以破坏寡聚化，这表明VD 2可用于瘙痒症的治疗。

Aggregated amyloid-beta is a pathological feature in Alzheimer's disease(AD) and mild cognitive impairment(MCI) is an early stage of AD. Up to date, there is no diagnostics of MCI by patients serum. We found that the concentration of 25(OH)V-D3 in serum with MCI is lower than that of normal volunteers, and there is no differences in the concentration of 1,25(OH)2V-D3 between them. We suggest that the serum concentration of 25(OH)V-D3 is useful for the diagnostics of MCI. Unexpectedly, 25(OH)V-D3 showed no inhibitory effects for the aggregation in vitro, and rather promoted the aggregation.PrPsc is the responsible protein to cause scrapie, which derived from the conformational transition of PrPc in normal brain. Oligomerization of PrPc is a pre-stage of PrPsc. We found that V-D3 could not break the oligomerization, however VD2 could break the oligzation, suggesting that VD2 is useful for scrapie therapy.