Investigation of plasma amyloid beta 1 - 42 levels and its correlation with some cardiovascular risk factors in people over forty years old

Nội dung text: Investigation of plasma amyloid beta 1 - 42 levels and its correlation with some cardiovascular risk factors in people over forty years old

1. Journal of military pharmaco-medicine N o7-2016 INVESTIGATION OF PLASMA AMYLOID BETA 1-42 LEVELS AND ITS CORRELATION WITH SOME CARDIOVASCULAR RISK FACTORS IN PEOPLE OVER FORTY YEARS OLD Nguyen Minh Hai*; Nguyen Minh Nui*; Ho Anh Son** SUMMARY Objectives: Amyloid beta 1-42 (A β 1-42) is related to several disorders including nervous, cardiovascular and metabolic disorder. We investigated plasma A β 1-42 level and examined its correlation with some cardiovascular risk factors. Subjects and methods: Level of A β 1-42 was measured in plasma of 40 people over forty years old without type 2 diabetes mellitus and hypertension by ELISA method. Results and conclusions: Average plasma A β 1-42 level was 98.88 ± 92.45 pg/mL, median was 65.49 pg/mL with wide range from 45.83 to 494.32 pg/mL. There was no significant correlation between plasma A β 1-42 level and cardiovascular risk factors such as age, plasma lipids. * Key words: Metabolic disorder; Amyloid beta. INTRODUCTION disease, diabetes, cardiovascular diseases [2]. Although many studies about A β 1-42 Amyloid is a specific peptide family have been performed, its role and physical including aggregating beta chains. Small, function is still unknown. So far in Vietnam, focal, clinically silent amyloid deposits in there has been no investigation about the the brain, heart, seminal vesicles, and joints exact physical function of A β 1-42. is a universal accompaniment of aging. Therefore, we carry out this study to: These results in amyloidosis, structural disorders, reduction and loss in function of - Examine the level of A β 1-42 plasma various organs in the body. The underlying in the people over 40 years old. molecular abnormalities may be either - Investigate whether there is any acquired or hereditary and about 20 different relationship between plasma A β 1-42 level proteins can form clinically or pathologically and cardiovascular risk factors. significant amyloid fibrils in vivo. Brain amyloid deposit is a major pathological SUBJECTS AND METHODS feature of Alzheimer disease. Islet amyloid 1. Subjects. deposits trigger type 2 diabetes mellitus. * Selection criteria: Amyloid also deposits in joints, peripheral arteries, kidneys. A β 1-42 is one of amyloid Study was carried out on 40 people molecular, which is considered to relate over forty years old without type 2 diabetes with different diseases such as Alzheimer’s mellitus and hypertension. * 103 Hospital ** Military Medical University Corresponding author: Nguyen Minh Nui (minhnuinguyen@gmail.com) 35
2. Journal of military pharmaco-medicine N o7-2016 2. Methods. proportional to the concentration of A β - Cross-sectional study without control 1-42. The concentration of A β 1-42 in the group. samples is calculated by comparing the optical density of the samples to the - All people were clinically and paraclinically standard curve. examined by measuring weight, height, blood pressure, level of glucose, creatinine, * Statistical analysis : to initially explore acid uric, lipid in their blood. Level of the relationship between variable sets, Aβ 1-42 plasma was measured by ELISA scattergram blots using Microsoft Excell method in Physiopathology Department, (2010), where a relationship was found. Vietnam Millitary Medical University. Stata verson 12.0 was used to verify the statistical significances of the association. - Methods of A β 1-42 measurement [9]: Simple linear regression was initially used. + 5 mL of whole bood was taken into Pearson chi-square was used to determine tubes with anticoagulant (citrate) in the the association between concentration morning. Afterward, the sample was of A β 1-42 plasma and baseline participant centrifugated for 20 min at 2,000 rpm. characteristics. Collect the supernatant carefully as plasma sample. If precipitate was seen during RESULTS reservation, the sample should be centrifugated 1. Characteristics of the subjects. again. 40 people included 24 males (60%) and + The Microelisa stripplate provided in 16 females (40%). Mean age was 54.38 ± the ELISA kit has been pre-coated with an 11.23 years. antibody specific to A β 1-42. Standards or 2. Plasma A β 1-42 levels. samples were added to the appropriate Microelisa stripplate wells and combined Table 1 : Plasma A β 1-42 level. to the specific antibody. Then a Horseradish Level of A β 1-42 plasma (pg/ml) Peroxidase (HRP) - conjugated antibody Variable specific for A β 1-42 was added to each Median Mean ± SD Microelisa stripplate well and incubated. (Min - max) 64.46 Free components were washed away before Male (n = 24) 83.77 ± 58.17 (45.83 - 313.64) adding the Chromogen solution A and 66.67 Chromogen solution B to each well. Blue Female (n = 16) 121.55 ± 126.97 (47.59 - 494.32) only appreared in those wells that contain 65.49 Aβ 1-42 and Horseradish peroxidase Summarization 98.88 ± 92.45 (45.83 - 494.32) conjugated A β 1-42 antibody and then it turned yellow after addition of the stop Both mean and medium plasma A β 1-42 solution. The optical density is measured in male were not significantly lower than spectrophotometrically at a wavelength those in female (p > 0.05). Levels of A β 1-42 of 450 nm. The optical density value is fluctuated from 45.83 pg/mL to 494.32 pg/mL. 36
3. Journal of military pharmaco-medicine N o7-2016 3. Association between plasma A β 1-42 levels with age, blood glucose and acid uric levels. * Association between plasma A β 1-42 levels and age: 1-42 (pg/mL) β A Figure 1: Correlation between plasma Aβ 1-42 levels and age. No significant correlation between plasma Aβ 1-42 levels and age of participants was found (p > 0.05). * Association of plasma A β 1-42 level with blood glucose and acid uric levels: A = 5.6765 * Glucose + 71.579 A = -0.311 * Uric + 209.48 r = 0.043, p= 0.79 r = 0.251, p = 0.11 600 600 500 500 400 400 300 300 200 200 1-42 (pg/mL) 1-42 (pg/mL) β β A A 100 100 0 0 0 200 400 600 2 4 6 8 Glucose (mmol/L) Acid uric ( µmol/L) A B Figure 2: Correlation between plasma A β 1-42 levels and glucose (A), acid uric (B) levels. Plasma Aβ 1-42 levels did not correlate with either glucose or acid uric levels (p > 0.05). 37
4. Journal of military pharmaco-medicine N o7-2016 4. Association between plasma A β 1-42 levels with total cholesterol, HDL-C, LDL-C, and triglyceride levels. A = -20.324 * Cholesterol + 208.69 A = -7.332 * Triglyceride +114.19 r = -0.022, p = 0.61 r = -0.138, p = 0.43 600 600 500 500 400 400 300 300 1-42 (pg/mL) 200 1-42 (pg/mL) 200 β β A 100 A 100 0 0 0 2 4 6 8 0 5 10 Cholesterol (mmol/L) Triglyceride (mmol/L) A B A= 111.17 * HDL - 40.721 r = 0.327, p = 0.08 A = -37.177 * LDL + 222.65 r =-0.34, p = 0.44 600 600 500 500 400 400 300 300 200 200 1-42 (pg/mL) 1-42 (pg/mL) β β A 100 A 100 0 0 0 2 4 6 0 0.5 1 1.5 2 LDL-C (mmol/L) HDL-C (mmol/L) C D Figure 1: Correlation between plasma A β 1-42 levels, cholesterol (A), triglyceride (B), HDL-C (C) and LDL-C (D). No significant correlation of plasma A β 1-42 plasma levels with cholesterol, triglyceride, HDL-C and LDL-C was observed. DISCUSSION can be solute in cerebrospinal fluid and blood or deposits in brain, pancreas. Aβ 1-42 is supposed to relate to a variety We investigated whether there were any of disorders such as Alzheimer’s disease, associations between plasma A β 1-42 type 2 diabetes mellitus. In the body, A β 1-42 levels and cardiovascular risk factors. 38
5. Journal of military pharmaco-medicine N o7-2016 In our study, the mean (±SD) and median Metti and his colleagues (2012) used plasma A β 1-42 were 98.88 ± 92.45 (pg/mL) Innogenetics INNO-BIA assays to measure and 65.49 (pg/mL). The concentration of plasma A β 1-42 level in 988 community- Aβ 1-42 plasma fluctuated in a large range dwelling elders who suffer from diabetes, between 45.83 (pg/mL) and approximately stroke, myocardial infarction and hypertension. 500 (pg/mL). It was interesting to note that Mean age of these patients was 74.0 ± participants who had the highest plasma 3 years. The mean (±SD) and median of plasma A β 1-42 levels were 33.9 ± 9.7 and Aβ 1-42 level had normal levels of lipid, 32.83 (pg/mL) [7]. The mean and plasma glucose, acid uric in the blood with total Aβ 1-42 levels in our study were both similar cholesterol = 5.17 (mmol/L), HDL-C = 1.8 to Mehta and Metti’s findings. Thus, the mmol/L, LDL-C = 3 (mmol/L), LDL-C = 3 differences in plasma A β 1-42 levels in (mmol/L), triglyceride = 0.54 (mmol/L), acid these studies were affected significantly uric = 327 (µmol/L). by age. In the study by Kelvin et al, mean (±SD) High plasma cholesterol, triglyceride and medium of plasma A β 1-42 levels in and LDL levels, as well as low plasma a group of 18 healthy adults were 29.1 ± HDL levels have long been known to be 18.1 (pg/mL) and 27 (pg/mL). These results associated with cardiovascular risk factors were lower than our findings and the and have been identified as significant concentration of plasma A β 1-42 levels risk factors for Alzheimer’s disease. HDL fluctuated in narrower range between 2.5 has been shown to carry A β 1-42 in plasma (pg/mL) and 62 (pg/mL). However, mean and cerebrospinal fluid [1]. Plasma HDL age of the participants in Kelvin’s research has been reported to be lower in patients was 36, which was lower than the figure with Alzheimer’s disease and is highly in our study [4]. correlated with lower cognitive scores from these patients [1, 3]. Many studies In 2000, Mehta and his colleagues indicated that HDL which interact with conducted a study on the patients older Aβ 1-42 in plasma, can regulate A β 1-42 than forty with Alzheimer’s disease and aggregation, degradation and toxicity control subjects. Levels of A β 1-42 plasma [5, 8]. Our study did not show significant were measured by a sandwich enzyme- associations between levels of total linked immunosorbent assay. Both the cholesterol, triglyceride, LDL-C or HDL-C medium of plasma A β 1-42 levels in group and A β 1-42 levels. This results were of Alzheimer’s disease and control group similar to those of Kelvin et al in 2005 [4]. were higher than the results of our study However, our study was performed in with 73 (pg/mL) (minimum = 25 pg/mL, healthy individuals. Whether there is any maximum = 880 pg/mL) and 81 (pg/mL) correlation between A β 1-42 levels and (minimum = 25 pg/mL, maximum = 905 cardiovascular risk factors in diabetic patients pg/mL), respectively. The plasma A β 1-42 as well as in healthy people, which need levels also fluctuated in a large range [6]. to be investigated in the future. 39
6. Journal of military pharmaco-medicine N o7-2016 CONCLUSION positively with increased body fat in healthy individuals. Journal of Alzheimer’s Disease. The mean and medium of plasma A β 1-42 2005, 8, pp.269-282. levels in people over forty years old were 5. Kuo YM, Emmerling MR, Bisgaier CL et al. 98.88 ± 92.45 (pg/mL) and 65.49 (pg/mL) Elevated low-density lipoprotein in Alzheimer's and plasma A β 1-42 levels fluctuated in a disease correlates with brain abeta 1-42 levels. large range between 45.83 (pg/mL) and Biochem Biophys Res Commun. 1998, 252 (3), 494.32 (pg/mL). No correlations between pp.711-715. Aβ 1-42 levels and several cardiovascular 6. Mehta PD, Pirttila T, Mehta SP et al. risk factors such age, plasma glucose, Plasma and cerebrospinal fluid levels of acid uric and lipids levels were observed. amyloid beta proteins 1-40 and 1-42 in Alzheimer disease. Arch Neurol. 2000, 57 (1), pp. 5-100. REFERENCES 7. Metti AL, Cauley JA, Newman AB et al. 1. Cole G. M, Beech W, Frautschy S. A et al. Plasma beta amyloid level and depression in Lipoprotein effects on Abeta accumulation and older adults. J Gerontol A Biol Sci Med Sci. degradation by microglia in vitro. J Neurosci Res. 2013, 68 (1), pp.74-79. 1999, 57 (4), pp. 504-520. 8. Olesen OF, Dago L. High density 2. David A. Warrell, Timothy M. Cox, Firth. lipoprotein inhibits assembly of amyloid beta- JD. Oxford Textbook of Medicine. 4th Edition ed.: peptides into fibrils. Biochem Biophys Res Oxford University Press. 2003, pp.163-167. Commun. 2000, 270 (1), pp.62-66. 3. Farhangrazi ZS, Ying H, Bu G et al . High 9. Schmidt S, Matthew J, Nixon R, Mathews density lipoprotein decreases beta-amyloid P. Aβ measurement by enzyme-linked toxicity in cortical cell culture. Neuroreport. immunosorbent assay in Sigurdsson, E.M., 1997, 8 (5), pp.1127-1130. Calero, M. & Gasset, M. (eds.) Amyloid 4. Kelvin Balakrishnana, Giuseppe Verdilea, Proteins Methods in Molecular Biology: Pankaj D. Mehtad et al. Plasma A β42 correlates Humana Press. 2012, pp.507-527. 40