Influence of blood donors' coagulation status in apheresis platelet aggregation in vitro / 中国输血杂志

【Objective】 To investigate whether the blood donors' coagulation status may lead to apheresis platelet aggregation in vitro. 【Methods】 Thirty blood donors with aggregation in apheresis platelets collected by AMICUS blood cell separator no less than 3 times previously and occurred when the last time of apheresis donation were observed in aggregated group (referred to as the experimental group); Thirty donors without aggregation in apheresis platelets collected by AMICUS blood cell separator no less than 3 times were observed in the control group simultaneously. The basic platelet parameters in the two groups, including Plt, MPV, PDW, Pet, P-LCR were detected by automatic blood cell analyzer (BC-3000Plus), and thromboelastogram indexes including reaction time(R), kinetics time(K), kinetics of clot development(α), maximum amplitude (MA) and coagulation index(CI) were tested by Thrombosis elastography (TEG) before collection. With SPSS24.0 software, t test was used to compare the differences between the two groups. 【Results】 The CI value in experimental group was significantly different from that of the control group (0.48± 1.00 vs -0.99 ±1.96, P0.05 ) . 【Conclusion】 The coagulation status of blood donors may be an independent risk factor for the in vitro aggregation of apheresis platelets.

miR-542-5p down-regulates IEC-6 cell proliferation induced by sphingosine-1-phosphate / 中国病理生理杂志

AIM: To observe the effects of miR-542-5p on the proliferation of rat small intestine crypt epithe-lial IEC-6 cells induced by sphingosine-1-phosphate (S1P).METHODS: Two IEC-6 cell lines (SphK1-IEC-C1 and SphK1-IEC-C2) were established, which expressed sphingosine kinase-1 (SphK1) stably.Radioactive tracer was used to detect SphK1 activity and S1P secretion.The cell proliferation was observed by cell counting and described by drawing growth curve, and the cell cycle analysis was carried out by flow cytometry.The level of miR-542-5p was evaluated by RT-qPCR.RESULTS: Compared with control vector cells without SphK1 cDNA, both SphK1-IEC-C1 and SphK1-IEC-C2 cell lines showed that Sphk1 was elevated, both intracellular and extracellular S1P increased dramatically, the rate of cell growth was faster, the percentage of the cells in S phase increased, and miR-542-5p expression decreased.S1P (0.5~10 μmol/L) led to the decrease in miR-542-5p expression.On the contrary, SphK1 silencing resulted in the increase in miR-542-5p expression in the IEC-6 cells.The miR-542-5p was elevated in SphK1-IEC-C1 cells and SphK1-IEC-C2 cells, which caused the decrease in the percentage of the cells in S phase.The cell growth rate in the above-mentioned 2 cell lines decreased compared with negative control group.CONCLUSION: In IEC-6 cells, S1P promotes proliferation by inhibiting miR-542-5p expression, which induces the cell cycle transferring from G1 phase to S phase.

SPIO-labeled rat bone marrow mesenchymal stem cells: alterations of biological activity and labeling efficiency assay in vitro / 生物医学工程学杂志

This study aimed to characterize and magnetic resonance imaging (MRI) track the mesenchymal stem cells labeled with polylysine-coated superparamagnetic iron oxide (PLL-SPIO). Rat bone marrow derived mesenchymal stem cells (rMSCs) were labeled with 25, 50 and 100 microg/mL PLL-SPIO for 24 hours. The labeling efficiency was assessed by iron content, Prussian blue staining, electron microscopy and in vitro MR imaging. The labeled cells were also analyzed for cytotoxicity and differentiation potential. Electron microscopic observations and Prussian blue staining revealed that 75% -100% of cells were labeled with iron particles. PLL-SPIO did not show any cytotoxicity up to 100 microg/mL concentration. Both 25 microg/mL and 50 microg/mL PLL-SPIO labeled stem cells did not exhibit any significant alterations in the adipo/osteo/chondrogenic differentiation potential compared to unlabeled control cells. The lower concentration of 25 microg/mL iron labeled cells emitted an obvious dark signal in T1W, T2WI and T2 * WI MR image. The novel PLL-SPIO enables to label and track rMSCs for in vitro MRI without cellular alteration. Therefore PLL-SPIO may potentially become a better MR contrast agent especially in tracking the transplanted stem cells and other cells without compromising cell functional quality.

Numerical Simulation of Carotid Bifurcation Flow Field in Atherosclerosis Model / 航天医学与医学工程

Objective To simulate local hemodynamic factors at particular arterial positions.Method A combination of high-lipid diet and immuoreactive injury was used to establish a hyperlipemia and atherosclerosis model in rabbit.Serrial sections were analysed by OLYSIA software.Data of caliber at different positions of carotid bifurcation,areas and circumference and thickness of the atherosclerotic plaque at carotid bifurcation were obtained and to establish a geometric model of rabbit carotid artery bifurcation with Gambit software.Wall shear stress distribution of the carotid sinus were analysed by numerical simulation.Result 1) A geometric model of rabbit carotid artery bifurcation was obtained.2) The wall shear stress of the carotid sinus of the atherosclerosis(AS) model group was found to be lower than that of the control group at shear rate 128.5 S~(-1).The lowest wall shear stress of the control was 4.028 times that of the AS model.Conclusion Low wall shear stress is a risk hemodynamic factor in the development of atherosclerotic plaque.

Delayed preconditioning reduced apoptosis of myocardial cells in rats / 基础医学与临床

Objective Investigate the relation between decrease of apoptosis caused by delayed preconditioning and expression of SMAC and XIAP.Methods Sprage-Dawleyt rats were divided into four groups: control,sham,I/R and IPC/SWOP.The rats in I/R group underwent ischemia for 1 hour by classic artery ligation and reperfusion for 1 hour.The rats in IPC/SWOP group underwent tree cycles of 5-minute ischemia and 5-minute reperfusion 24 hours prior to the index occlusion.Cell apoptosis was measured by flow cytometry,the activity of caspase-3 was also measured.The expression of SMAC and XIAP in cytosol of myocardial cell was measured by Western blot.Results Cell apoptosis rate,activity of caspase-3 and expression of SMAC significantly increased in I/R as compared with control(P

Dynamic alteration of blood lipid and hemodynamics parameters and vascular intima in the process of atherosclerosis / 生物医学工程学杂志

To establish and observe rabbit hyperlipemia and atherosclerosis model, we combined the method of high-lipid diet and immuoreactive injure. We divided 45 New Zealand rabbit into control group and high-lipid group. According to the time (4, 8, 12 weeks) of established model, the control group and high-lipid group were divided into 3 groups respectively. The blood-lipid, the hemodynamics parameter and vascular intima were determined and observed. The results showed: (1) After feeding 4, 8, 12 weeks, TC and LDL-C of the high-lipid group in the serum increased obviously. After feeding 8 week, TG of the high-lipid group began to increase obviously. HDL-C of the high-lipid group was higher than control group, but with a descendent trend. (2) Blood viscosity of the high-lipid group increased obviously under the 0.512 S(-1) and 5.96 S(-1) at 12 week. Blood flow increased obviously at 8 and 12 week. SBP increased evidently at 8 and 12 week. Alteration of the plasma viscosity and vascular diameter were not obvious. (3) By observing with optical microscope the intima of the control group is smooth. The intima of the high-lipid group has a light incrassation at 4 week. The intima of the high-lipid group has a obvious incrassation at 8 and 12 week. By observing with through transmission electron microscopy (TEM), the lipid vacuole is under the endothelium cell. (4) By adopting the immunohistochemistry, the foam cell that derived from smooth muscle cell were determined. We concluded that the blood lipid can have a prefigurative role in atherosclerosis; blood flow and blood pressure and blood viscosity increase at low shear rate in the course of the atherosclerosis; vascular intima is incrassate and the composition of the AS plaque is variational continually.

Effect of ERK1/2 on low shear stress-induced expression of IL-8 mRNA in human endothelial cells / 生物医学工程学杂志

Fluid shear stress plays an important role in many physiological and pathophysiological processes of the cardiovascular system. It modulates vascular function and structure via stimulating mechanosensitive endothelial cell signal events. Previous studies have identified that the exposure of vascular endothelial cells to fluid mechanical forces can modulate the expressions of many genes, including IL-8 gene. In order to gain an insight into the role of extracellular signal regulated kinase (ERK1/2) signal pathway in the expression of IL-8 mRNA in human umbilical vein endothelial cells (HUVECs) under the stimulation by low shear stress (4.20 dyne/cm2), we employed Western blot to measure phosphorylation of ERK1/2 and used quantitative reversal transcription-polymerase chain reaction (qRT-PCR) to assay the expression of IL-8 mRNA. The results showed: (1) Shear stress could activate ERK1/2 with a rapid, biphasic time course (maximum by 10 min and basal by 2 h); the treatment of HUVECs with Genistein (a highly specific inhibitor of tyrosine protein kinase, TPK) or PD98059 (the inhibitor of mitogen-activated protein/extracellular signal regulated kinase kinase, MEK) culd prevent shear-dependent activation of ERK1/2; (2) When treated with Genistein or PD98059, significant inhibition of IL-8 mRNA expression induced by low shear stress was observed in HUVECs. This in vitro study demonstrates that ERK1/2 plays an important role in IL-8 mRNA expression induced by low shear stress.

Interleukin-8 protein and gene expression in atherosclerotic lesions of hyperlipemia rabbits / 生物医学工程学杂志

Interleukin-8 is CXC chemokine that is initially discovered using chemotaxis and the activation of neutrophils and induces the migration and proliferation of smooth muscle cells. Interleukin-8 is a potent angiogenic factor that may play a role in atherosclerosis. To establish the temporal correlation between IL-8 expression and plaque development, we examined the expression during atherosclerosis of hyperlipemia rabbits using immunohistochemistry, ELISA, in situ hybridization. By location of immunohistochemistry, the expression of IL-8 protein increased obviously in intima of hyperlipemia rabbits at 8 and 12 week. Quantitative analysis of the expression of IL-8 Immunohistochemistry indicated that positive area of AS model was 4.48 times and 8.76 times that of control group at 8 and 12 week. The valuation of IOD of AS model was 4.16 times and 4.36 times that of control group at 8 and 12 week. By specific ELISA, the ratio of the IL-8 protein to total protein of AS model was 1.84 times and 2.06 times that of control group at 8 and 12 week. By location of in situ hybridization, positive location was strong in intima of hyperlipemia rabbits at 8 week. We observed the dynamic alteration of interleukin-8 protein and gene expression in atherosclerotic lesions of hyperlipemia rabbits with establishing model. Interleukin-8 protein and gene expression was up-regulation in the development of fatty streaks in hyperlipemia rabbit.

Time-dependent increase of interleukin-8 production in endothelial cells exposed to fluid shear stress / 生物医学工程学杂志

Fluid shear stress plays an important role in many physiological and pathological processes of the cardiovascular system. Being constantly exposed to mechanical shear stress, vascular endothelial cells can sense the changes of blood flow forces and regulate vascular structure and function. Previous studies demonstrated that IL-8 mRNA expression in endothelial cells was modulated by fluid shear stress. To identify the effect of fluid shear stress on IL-8 protein production of human umbilical vein endothelial cells (HUVECs), we employed quantitative sandwich enzyme-linked immunosorbent assay (ELISA) to measure the IL-8 protein. It was found that the HUVECs not treated with fluid shear stress secreted very little IL-8 in culture media. However, after 1 hour of exposure to shear stress, the secretion of IL-8 increased; at 5 hours of exposure, the seceretion reached the summit; at 8 hours of exposure, the secretion of IL-8 decreased and then remained at a constant level till the end (12 hours) of the experiment. The increase of IL-8 secretion induced by shear stress was time-dependent. The biphasic response of IL-8 protein production was found in experiments in which the shear stress applied was 2.09 dyne/cm2, 4.61 dyne/cm2, and 6.19 dyne/cm2. The IL-8 protein production in response to shear stress was very similar to the IL-8 gene expression in response to shear stress, and had the obvious delay. The induction of IL-8 protein production by fluid shear stress is probably due to the gene expression. This in vitro study demonstrates that the production of IL-8 can be regulated by fluid shear stress. Fluid shear stress induces a biphasic response of human HUVECs' production of IL-8 protein. These observations suggest that the process of the fluid shear stress induced HUVECs' production of IL-8 may play an important role in the genesis and development of both inflammation and atherosclerosis.

Force-dependent effects of interleukin-8 production in endothelial cells exposed to fluid shear stress / 生物医学工程学杂志

Fluid shear stress plays a key role in many physiological activities and pathological processes of the cardiovascular diseases. In vivo, endothelial cells (ECs) are constantly exposed to hemodynamic force which can modulate structure and function of ECs. Previous studies have demonstrated that IL-8 protein production in endothelial cells was modulated by fluid shear stress, and IL-8 protein production induced by fluid shear stress was time-dependent. In order to identify the role of intensity of fluid shear stress on IL-8 protein production of human umbilical vein endothelial cells (HUVECs), we had HUVECs exposed to shear stress 2.09, 4.61, 6.19, 8.51, 10.50, 12.59, 14.41, 17.22, 18.32 dyne/cm2 respectively and employed quantitative sandwich enzyme-linked immunosorbent assay (ELISA) to measure the IL-8 protein. Here we show that HUVECs untreated with fluid shear stress secreted very little IL-8 in culture media. The IL-8 protein production induced by shear stress was force intensity-dependent. After HUVECs being subjected to low fluid shear stress (2.09 dyne/cm2) for 5 h or 6 h, IL-8 protein production increased and was nearly 6 times or 7 times over that of HUVECs subjected to high fluid shear stress (18.32 dyne/cm2). The linear regression equations between IL-8 protein production (y) and shear stress (dyne/cm2, x) are y=760.12-36.06x, gamma=-0.978 (for 5 h); y=781.87-36.66x, gamma=-0.980 (for 6 h). This in vitro study demonstrates that the production of IL-8 can be regulated by fluid shear stress, and the production of IL-8 induced by shear stress is not only time-dependent but also force intensity-dependent. These observations suggest that the low fluid shear stress induces much more IL-8 secretion, which may play an important role in the pathogenesis and development of both inflammation and atherosclerosis.