The Concentration Of Visinin-like Protein-1 In The Blood In Patients Of Mild Cognitive Impairment And Alzheimer Disease

Background: Alzheimer disease(AD) is a nervous system degenerative disease, is the main type of dementia.In China the prevalence rate of AD is up to 3-7% in the people over 65 years old, it has become one of the major diseases that threatening the elderly’s health.AD has an insidious onset, and its difficultly for early diagnosis, but has irreversible nervous system damage in the later period,and now many of the medications is ineffective. Therefore, the early diagnosis and intervention of AD has great significance in slowing the cognitive decline, improving the patient’s daily living,and reducing the burden of the families and society.And also, its an important way of controlling this disease.Scholars in and out abroad have done a lot of research on the markers of AD focusing on early diagnosis of it. In the pathogenesis of AD, there are abnormal Calcium Homeostasis and calcium signaling.The calcium ion(Ca2+) is an important second messenger inside and outside the central nervous system.It participated the pathology and the physiological processes in the nerve cells,like synapse transmission, gene expression, the cell apoptosis and so on.In neuron the Ca2+density is regulated by the nervous system calcium sensing proteins(NCS),And the Visinin-like Protein-1(VILIP-1) induce the Ca2+ density of the neuron in signal passing and protein expressing,and thus increases the vulnerability of neuron,enhancing the cell toxicity, all that lead to the death of the neuron,and it expresses highly in thecerebral cortex and the seahorse area of the brain.The correlation between VILIP-1 and AD has been multiply reported the literature. Researches have indicated that the density of VILIP-1 has obviously increased in the cerebrospinal fluid of AD patients. VILIP-1can respond the neuron damage, and it may be a new latent fluid biology of AD.As the cerebrospinal fluid gathering is invasive, the patient has a weak obedience, and the degree of adaptability is unsatisfactory,but on the other hand, blood is easier in the collection, can respond brain metabolism,so,it has become the hot pints in the biomarkers of AD at present.But where the density of VILIP-1 in the blood of AD patients or the mild cognitive impairment patients due to AD has any changes,or where it can be a new biomarker for the early diagnosis of AD,or for the detection of the progress of the disease and the curative effect, all need for further research.Objective: To explore the VILIP-1 levels in the blood in the AD and MCI due to AD patients, and also to explore its feasibility as a biomarker for the early diagnosis of AD and for the detection of progression of AD.Methods: There are 58 participants been included in this study :20 cases for AD group(including 8 cases of male and 12 cases of female);19 cases for MCI due to AD group(including 9 cases of male and 10 cases of female);19 cases for normal control group(including 9 cases of male and 10 cases of female).The diagnosis of AD is according with the National Institute on Aging(National Institute of Aging, the NIA) and Alzheimer’s disease Association(Alzheimer ’s Association, AA) which published a new diagnostic criteria(NIA- AA standard) in the journal of Alzheimer & Dementia on April 19, 2011.And the diagnosis of MCI due to AD in accord with the NIA- AA standard of the core clinical diagnosis standard of the MCI due to AD. All samples were collected about 5 ml blood in the morning, being centrifuged and saved for later use.The concentration of VILIP-1 is tested by the ELISA method,and detected its OD value by the ELIASA, then using CurveExpert1.4 software to draw standard curve, and use the fitting formula to calculate the corresponding densities. Statistical data was analyzed by SPSS19.0,and measurement data was representation by mean ±standard deviation( x± s), and different between groups was representation by Pearson and Spearmancorrelation analysis, with a P < 0.05 was considered to be significant,and a P < 0.01 was considered to be significant differences.Results: The average age of AD group is about 77.35 years old, and is about 77.11 years old for MCI due to AD group, and 73.95 years old for normal control group.There were no statistically significant difference between the three groups in age and sex.The MMSE scores in the AD group(15±3scores)and MCI due to AD group(23±2scores)were lower than the normal control group(27±2scores),all with a P<0.01, and AD group was lower than MCI due to AD group,also with a P<0.01.The VILIP-1 level was increased in AD group(9.0 ± 2.9 pg/ml) compared with normal control group(3.3±1.7 pg/ml)and MCI due to AD group( 6.5±3.1 pg/ml),and all had significant difference(p < 0.01); MCI due to AD group also had an increasing level of VILIP-1 in the blood compared with normal control group and also had significant difference(p < 0.01); and the blood VILIP-1 level was negatively correlated with MMSE score(r = 0.463, p < 0.01), but positively correlated with age(r = 0.417, p =0.01).Conclusions: With the progression of AD, the cognitive impairment of the AD patient is decreasing. VILIP-1 increased in the blood of the patients of AD and MCI due to AD,and the blood VILIP-1 concentration was negatively correlated with MMSE score but positively correlated with age.It means that the blood VILIP-1 could be a new and potential biomarker for the early diagnosis of AD,and it may be clinical useful for the early diagnosis and effective detection of AD to some extent.