Objective To observe the influence of the expression of CD18 on the neutrophile and the leukocyte adhesion to retinal vascular endothelium by hypoxia-inducible factor-1 alpha (HIF-1alpha;) in early diabetic retinopathy rats. Methods Male Sprague-Dawley rats received intraperitoneal injection of streptozotocin to induce diabetes model. 18 diabetic rats were divided into 3 groups randomly after 2 months of diabetes induction, including diabetic group (group B), HIF-1alpha; anti-sense oligonucleotides (ASODN) injection group (group C) and HIF-1alpha; sense oligonucleotides (SODN) injection group (group D), the age and weigh matched health rats were chosen as control group (group A), with 6 rats in each group. Then group A and B rats received 5% glucose solution caudalis veins injection, group C and group D rats received HIF-1alpha; ASODN and HIF-1alpha; SODN caudalis veins injection, respectively(025 mg/kg).The level of CD18 on the neutrophil isolated from the peripheral blood was measured by flow cytometry. Retinal leukostasis was quantified with acridine orange leukocyte fluorography. Results The percentage of CD18 positive neutrophil cell was（44.93plusmn;3.60）% in group B，（18.66plusmn;1.52）% in group A，（31.66plusmn;4.72）% in group C，（51.00plusmn;5.66）% in group D. Compared with each other groups，the differences are statistically significant （F=42.46, Plt;0.001）. The number of positive staining cells of retinal leukocyte was （46.16plusmn;10.68）in group A，（133.83plusmn;20.43）in group B,（99.83plusmn;9.28）in group C，（121.33plusmn;10.23） in group C. Compared group B with group C，the number of positive staining cells raised about 2.89 times；compared group B with group C and D，the differences are statistically significant （P=0.12，95% confidence interval -3.69~28.69）. Conclusions In vivo, HIF-1alpha; can decreased the expression of CD18 on neutrophils from diabetic ratsprime; peripheral blood and the collection of retinal leukostasis in the diabetic animals. HIF-1alpha; may serve as a therapeutic target for the treatment and/or prevention of early diabetic retinopathy. （Chin J Ocul Fundus Dis，2008，24：268-271）
ObjectiveTo evaluate the value of serum procalcitonin (PCT) level after conventional intravenous antibiotic treatment to predict the risk of re-exacerbation, and vertify the feasiblity of an additional course of oral antibiotics after discharge to reduce the risk of re-exacerbation. MethodsThe patients who hospitalized in West China Hospital from October 2012 to October 2013 because of infectious acute exacerbation of chronic obstructive pulmonary disease (AECOPD) were recruited. The concentrations of PCT and C-reactive protein (CRP), the number of white blood cell (WBC) and neutrophil percentage at the end of intravenous antibiotic therapy were recorded. The information about additional course of antibiotics was collected according to the medical instruction and visit. The subjects were followed up for 1 year.The time to the first re-exacerbation and frequencies of exacerbations were recorded. The Cox regression model was used to estimate the hazard rations (HR). ResultsOne hundred and thirty-eight eligible patients were included totally. The HRs in PCT≥0.11μg/L and neutrophil percentage≥70% were 1.462 (P=0.035) and 1.673 (P=0.005) respectively, suggesting higher risk of re-exacerbation. There was no relationship of CRP (P=0.330) or WBC (P=0.432) with the risk of re-exacerbation. Generally an additional course of antibiotics had no effects on re-exacerbation (P=0.231) but this therapy could reduce the risk of re-exacerbation in high PCT level group (HR=2.29, P=0.004). ConclusionsSerum PCT concentrations and neutrophil percentage after conventional intravenous antibiotic treatment can predict the risk of re-exacerbations in the future. An additional course of antibiotics in the patients with high PCT level can reduce the risk of re-exacerbation.
ObjectiveBased on the rat in situ perfusion system, to explore the effect of up-regulating Chemokine (C-X-C motif) receptor 4 (CXCR4) expression on bone marrow neutrophils in modulating its ECC-related rapid release. MethodsTwelve SD rats were randomly divided into fucoidan perfusion group (F, n=6) and control group (C, n=6) after in situ perfusion system establishment. Rats in F group received perfusion of fucoidan solution (total volume 6 ml, 1 h) and C group received buffer only. Femurs from two groups were dissected after one-hour perfusion and bone marrow tissues were collected. The neutrophil CXCR4 expression in two groups were compared using flowcytometry. Eighteen SD rats were randomly divided into fucoidan perfusion group (F', n=6), fucoidan and AMD-3100 perfusion group (F+AMD3100, n=6) and control group (C', n=6) after in situ perfusion system establishment. Rats received desired interventions before stimulation from ECC plasma. After that, 40-min perfusions of buffer were added and total counts of neutrophil in perfusates were compared. ResultsThe percentages of CXCR4 (+) cell and CXCR4 expression fluorescence in F group were 4.71%±0.21% and 161.3±7.8 respectively while the values were 1.11%±0.11% and 58.4±6.5 respectively in C group. Values in F group were both significantly higher than those in C group (P<0.05). The total counts of neutrophil in perfusates from F' group, F+AMD3100 and C' group were 261 393.7±12 470.6, 872 635.2±10 430.6 and 818 675.2±10 708.8, respectively. Statistically differences were observed between each other (P<0.05). ConclusionBone marrow neutrophil CXCR4 expression of SD rat could be effectively up-regulated by perfusion of fucoidan within the in situ perfusion system. ECC-plasma-stimulated bone marrow neutrophil release in rat could be inhibited by fucoidan induced up-regulation of neutrophil CXCR4 expression, and this inhibition effect could be canceled by AMD-3100 intervention.
ObjectiveTo determine whether there is an imbalance of KLF2/RelA in peripheral blood neutrophils in patients with bronchial asthma, and explore the relationship between KLF2/RelA imbalance and neutrophil apoptosis.MethodsFrom April 2011 to April 2012, a total of 39 patients with acute attack of asthma in Hunan People's Hospital and Third People's Hospital of Changsha were enrolled, with 13 cases in mild asthma group, 17 cases in moderate asthma group, and 9 cases in severe asthma group. Fifteen healthy subjects were recruited as control group. Peripheral blood were collected from all subjects followed by separation of neutrophils. The apoptosis of neutrophils were measured by flow cytometry. The expression of KLF2 and RelA were detected by Western blot. The relationship between the ratio of KLF2/RelA and neutrophil apoptosis rate was analyzed by Pearson correlation test.ResultsNeutrophil apoptosis rates in the mild, moderate and severe asthma groups [(4.45±0.76)%, (2.10±0.25)%, (1.81±0.67)%, repectively] were lower than that in the healthy control group [(5.36±0.57)%, all P<0.01]. The apoptosis rates of neutrophils in the moderate and severe asthma groups were lower than that in the mild asthma group (bothP<0.01), but there was no significant difference between the moderate asthma group and the severe asthma group (P>0.05). The ratios of neutrophil KLF2/RelA in the mild, moderate and severe asthma groups were lower than that in the normal control group (0.667±0.351, 0.384±0.203, 0.536±0.293vs. 4.038±2.011, all P<0.01). There was no significant difference between the groups of mild, moderate and severe asthma (P>0.05). The neutrophil apoptosis rate was positively correlated with the percentage of neutrophil KLF2/RelA (r=0.592 0, P<0.000 1).ConclusionThere is an imbalance of KLF2/RelA in peripheral blood neutrophils in patients with bronchial asthma, and the imbalance of KLF2/RelA may be the mechanism of apoptosis of peripheral blood neutrophils.
The body of patient undergoing cardiopulmonary resuscitation after cardiac arrest experiences a process of ischemia, hypoxia, and reperfusion injury. This state of intense stress response is accompanied with hemodynamic instability, systemic hypoperfusion, and subsequent multiple organ dysfunction, and is life-threatening. Pulmonary vascular endothelial injury after cardiopulmonary resuscitation is a pathological manifestation of lung injury in multiple organ injury. Possible mechanisms include inflammatory response, neutrophil infiltration, microcirculatory disorder, tissue oxygen uptake and utilization disorder, etc. Neutrophils can directly damage or indirectly damage lung vascular endothelial cells through activation and migration activities. They also activate the body to produce large amounts of oxygen free radicals and release a series of damaging cytokines that further impaire the lung tissue.
Cell migration is defined as the directional movement of cells toward a specific chemical concentration gradient, which plays a crucial role in embryo development, wound healing and tumor metastasis. However, current research methods showed low flux and are only suitable for single-factor assessment, and it was difficult to comprehensively consider the effects of other parameters such as different concentration gradients on cell migration behavior. In this paper, a four-channel microfluidic chip was designed. Its characteristics were as follows: it relied on laminar flow and diffusion mechanisms to establish and maintain a concentration gradient; it was suitable for observation of cell migration in different concentration gradient environment under a single microscope field; four cell isolation zones (20 μm width) were integrated into the microfluidic device to calibrate the initial cell position, which ensured the accuracy of the experimental results. In particular, we used COMSOL Multiphysics software to simulate the structure of the chip, which demonstrated the necessity of designing S-shaped microchannel and horizontal pressure balance channel to maintain concentration gradient. Finally, neutrophils were incubated with advanced glycation end products (AGEs, 0, 0.2, 0.5, 1.0 μmol·L−1), which were closely related to diabetes mellitus and its complications. The migration behavior of incubated neutrophils was studied in the 100 nmol·L−1 of chemokine (N-formylmethionyl-leucyl-phenyl-alanine) concentration gradient. The results prove the reliability and practicability of the microfluidic chip.
Circadian rhythm is a physiological regulation mechanism evolved by the body to adapt to the 24-hour fluctuations in the internal and external environment. It plays an important role in many physiological and pathological processes including the immune system. Neutrophils are the most important immune cells in the human circulation, and their numbers and phenotypes also show obvious circadian fluctuations. A growing number of studies have shown that the cellular and molecular mechanisms of neutrophil circadian rhythms are disease-related. Combining the latest research on neutrophil circadian rhythm, this article briefly introduces the recruitment of neutrophils in the bone marrow, the aging of neutrophils and their infiltration into various tissues of the body, and discusses the interventions. It also discusses the therapeutic prospects based on neutrophil circadian rhythm-related mechanisms from the perspectives of intervening neutrophil aging-related chemokines and chronotherapy.