Decoupling endothelial cell microparticles and coronary artery disease with new high-resolution flow technique

New high-resolution streaming technology deconstruction
Relationship between endothelial cell microparticles and coronary artery disease

Keywords: circulating microparticles (circulating microparticle, cMP), coronary artery disease (Coronary Artery Disease, CAD), particle detection cycle

What is circulating particles?

Circulating microparticles ( cMPs ) are small vesicles that detach from the cell membrane after cell activation , injury, or apoptosis . 1μm, the film surface exposed phosphatidylserine (posphatidylserine, PS) and a negatively charged cell membrane surface antigen specific sources - cMP diameter of about 0.1μm. These features distinguish the circulating microparticles apoptotic bodies (apoptotic body) and exosomes (exosome -), apoptotic bodies is apoptosis budding formed in a diameter greater than 1 m; and exosomes derived from multiple intracellular foam bodies (multivesicular bodies), other than the release of the secreted form, diameter of 30nm - 100nm.

According to the source of the microparticles, the microparticles can be divided into platelet microparticles ( PMPs ), erythrocyte microparticles ( Ery-MPs ), endothelial cell microparticles ( EMPs ), and granulocyte microparticles ( GMPs ). particles and lymphocytes (lymphocyte-derived microparticles, LMPs) and the like. Research confirms that in healthy people, the proportion of PMPs share of the largest in the circulating blood, followed Ery-MPs. In the past, microparticles were thought to be purely inactive cell debris , but more and more studies have shown that cMP plays an important role in physiological and pathological conditions, especially in anticoagulation , pro-inflammatory , endothelial injury , vasoconstriction , induction of blood vessel growth, and immune regulation plays an important role in diabetes, cardiovascular disease, AIDS, chronic inflammatory diseases and cancer are found in elevated levels of circulating particles, for its awareness are continuing to explore, more and more research .

Study of circulating microparticles in coronary artery disease

Coronary Artery Disease (Coronary Artery Disease, CAD) is the main type of heart disease, is the leading cause of heart attacks, it is due to the accumulation of plaque on the inner lining of arteries, resulting in smaller arteries, reducing blood flow . The development of CAD is very slow, and most patients may have no obvious symptoms for decades , until one day suddenly a heart attack . Therefore , the early diagnosis of CAD can greatly reduce the risk of heart attack in patients. Traditional diagnostic methods include electrocardiogram , blood pressure , angiography, etc. , but these methods can only work in the late stage . The study found that vascular endothelial cell dysfunction is an important factor in the development of CAD , and endothelial cell microparticles ( EMPs ) are a new biomarker for judging endothelial cell function . In fact , many studies

Detecting method of circulating particles

At present, cMP detection methods mainly include laser confocal microscopy, scanning and transmission electron microscopy , atomic force microscopy , flow cytometry and ELISA . Due to high throughput and simple operation , ELISA and flow cytometry are relatively common methods. The ELISA method is susceptible to interference by other soluble antigens, and it is impossible to know the size and quantity of the particles . Flow cytometry provides more efficient and fast particle analysis capabilities . A variety of flow cytometric markers are available for particle detection . They are primarily used to detect the activation state of microparticles and their cellular origin . However, the conventional flow cytometer detection limit of 0.5 m is usually, due to the background noise can not be distinguished with a diameter less than 0.3μm-0.5μm particle is difficult to detect.

The advantages of a new high-resolution flow cytometer for detecting circulating particles

British Apogee companies A50 high resolution limits conventional flow cytometer break detection flow cytometry to optimize an optical module and an excellent ability to detect the scattered light having the highest sensitivity of the detector such that A50 small particles (100 nm or) and the best light Scattering resolution ( 10 nm ). Fig. 2 shows the comparison between Apogee and traditional flow cytometry. It can be seen that FC500 and LSRII can barely distinguish between 0.5μm and 0.6μm beads, and beads below 0.5μm are completely indistinguishable, while Apogee can be easily The 0.2 μm microbeads and the 0.4 μm microbeads were divided into two groups. Due to the limitation of detection ability , FC500 and LSRII can only detect some 0.2μm and 0.4μm microbeads. For 0.2μm microspheres, the loss rates of LSRII and FC500 are 79% and 96% respectively ; for 0.4μm micro Beads, the loss rate also reached 12% and 56% respectively [2] . Conversely , with the high sensitivity and resolution highlighted by the Apogee A50 , particle samples with a diameter difference of 10 nm or more can be clearly grouped, counted , and analyzed . In addition , up to 9 channels of fluorescence detectors, flexible use of cMP specific

Grain flow cytometer, better than the traditional flow cytometry on a detection cycle microparticles.

Fig. 2. Size resolvability of different flow cytometers using polystyrene microspheres. Graphs show forward scatter relative intensity for 0.2 - 0.8μm polystyrene microspheres for three flow cytometers.

Application Prospect of Apogee A50

[1] Hu SS, Zhang HG, Zhang QJ, Xiu RJ (2014) Small-Size Circulating Endothelial Microparticles in Coronary Artery Disease. PLoS ONE 9(8): e104528.
[2] Chandler WL, Yeung W, Tait JF. A new microparticle size calibration standard for use in measuring smaller microparticles using a new flow cytometer. J Thromb Haemost 2011; 9: 1216–24.