Targeting the P2X7 receptor in microglial cells to prevent brain inflammation

Microglial cells are the key innate immune cells in the brain and they are crucial in maintaining brain parenchyma homeostasis.Under physiological conditions,microglial cells assume a ramified morphology with a small cell body and an extensive network of fine processes,which secrete neurotrophic factors and patrol the surroundings in search for pathogens and eliminate cellular debris via phagocytosis.Microglial cells express a repertoire of pattern recognition receptors(PRRs)that enable them to detect diverse danger-associated molecular patterns(DAMPs)released from damaged cells or cells under stress,or pathogen-associated molecular patterns generated by pathogens during infection.

STUDY ON INFLAMMATORY CELLS IN BALF OF SMOKE-INDUCED CHRONIC BRONCHITIS RAT MODEL

Objective To establish a smoke-induced chronic bronchitis rat model and evaluate the patho-logical change semi-quantitatively, and study the characteristics of the inflammatory cells in the bronchoalveolar lav-age fluid (BALF) in various stages. Methods Chronic bronchitis sequential rat model was established by passively inhaling smoke mixture. Experiments were performed in 30 young male Sprague-Dawley rats, which comprised 5 groups in random, i.e.,4 chronic bronchitis model groups and 1 control group. After stained with hematoxylin and eosin, the specimens were studied by semi-quantitative method to evaluate the morphologic changes in various stages. Meanwhile, the inflammatory cells of the BALF and the activity of myeloperoxidase (MPO) of lung tissue were analysed. Results During the process of the chronic bronchitis, the pathologic score was increasing as time went on, and the typical morphologic changes of chronic bronchitis emerged in the group 7 weeks. The total number of inflammatory cells in BALF was increasing as time went on, correlated with the pathologic scores (P <0.01). And the percentage of lymphocyte increased as well as positively correlated with pathologic scores (P < 0. 05) , whereas that of macrophage decreased and negatively correlated with pathologic scores (P <0. 05). The MPO lever of lung tissue was correlated with the pathologic scores (P < 0. 01). But the percentage of the neutrophil in the BALF was just in a high level during the first week, then it maintained relatively lower. Conclusion Smoke-induced chronic bronchitis is a slowly progressive inflammation process. The model we established is convenient and simple for the longitudinal study on the inflammatory process of chronic bronchitis and the therapy in the early stage. The semi-quantitative evaluation for the pathological change is with much more value. During the inflammatory sequential process of early stage of chronic bronchitis, the cellular characteristics are similar to that of the common chronic inflammation.

Bone Marrow Mesenchymal Stem Cells Ameliorate Lung Injury through Anti-inflammatory and Antibacterial Effect in COPD Mice

The anti-inflammatory and antibacterial mechanisms of bone marrow mesenchymal stem cells（MSCs） ameliorating lung injury in chronic obstructive pulmonary disease（COPD） mice induced by cigarette smoke and Haemophilus Parainfluenza（HPi） were studied. The experiment was divided into four groups in vivo： control group, COPD group, COPD＋HPi group, and COPD＋HPi＋MSCs group. The indexes of emphysematous changes, inflammatory reaction and lung injury score, and antibacterial effects were evaluated in all groups. As compared with control group, emphysematous changes were significantly aggravated in COPD group, COPD＋HPi group and COPD＋HPi＋MSCs group（P〈0.01）, the expression of necrosis factor-kappa B（NF-κB） signal pathway and proinflammatory cytokines in bronchoalveolar lavage fluid（BALF） were increased（P〈0.01）, and the phagocytic activity of alveolar macrophages was downregulated（P〈0.01）. As compared with COPD group, lung injury score, inflammatory cells and proinflammatory cytokines were significantly increased in the BALF of COPD＋HPi group and COPD＋HPi＋MSCs group（P〈0.01）. As compared with COPD＋HPi group, the expression of tumor necrosis factor-α stimulated protein/gene 6（TSG-6） was increased, the NF-κB signal pathway was depressed, proinflammatory cytokine was significantly reduced, the anti-inflammatory cytokine IL-10 was increased, and lung injury score was significantly reduced in COPD＋HPi＋MSCs group. Meanwhile, the phagocytic activity of alveolar macrophages was significantly enhanced and bacterial counts in the lung were decreased. The results indicated cigarette smoke caused emphysematous changes in mice and the phagocytic activity of alveolar macrophages was decreased. The lung injury of acute exacerbation of COPD mice induced by cigarette smoke and HPi was alleviated through MSCs transplantation, which may be attributed to the fact that MSCs could promote macrophages into anti-inflammatory phenotype through secreting TSG-6, inhibit NF-кB signaling pathway, and reduce inflammatory response through reducing proinflammatory cytokines and promoting the expression of the anti-inflammatory cytokine. Simultaneously, MSCs could enhance phagocytic activity of macrophages and bacterial clearance. Meanwhile, we detected anti-inflammatory and antibacterial activity of macrophages regulated by MSCs in vitro. As compared with RAW264.7＋HPi＋CSE group, the expression of NF-кB p65, IL-1β, IL-6 and TNF-α was significantly reduced, and the phagocytic activity of macrophages was significantly increased in RAW264.7＋HPi＋CSE＋MSCs group（P〈0.01）. The result indicated the macrophages co-cultured with MSCs may inhibit NF-кB signaling pathway and promote phagocytosis by paracrine mechanism.

Effects of interleukin-18 on airway inflammation and the Th1/Th2 cytokine imbalance in guinea pig asthmatic model

In order to investigate the effects of interleukin-18 （IL-18） on airway inflammation and the Th1/Th2 cytokine balance in guinea pig asthmatic model as well as its possible mechanisms, the asthmatic model was established by intraperitoneal injection of ovalbumin （OVA） and aerosol challenges into guinea pigs, and 30 treated animals were randomly divided into three groups of 10 animals in each groups, in which group A served as the asthmatic model, group B as the controls and group C as the group treated with IL-18. The counting and categorization of the inflammatory cells in bronchoalveolar lavage fluid （BALF） were performed by using light microscopy, and the contents of cytokines （ IFN-γ, IL- 2, IL-4 and IL-5） were assayed by means of the ELISA kit. The experimental results showed that the numbers of eosinophils （ESO） in BALF of group A, B and C were （97.70 ± 58.03） × 10^6/L, （11.68 × 9.95） × 10^6/L and （28.62 ± 10.46） × 10^6/L, respectively, in which the number of eosinophils in group A was significantly higher than those of group B and C. Also, the number of neutrophils in BALF of group A was even higher than those in group B and C. In addition, the contents of IFN-7 and IL-2 in group A were lower than those in group B and C, but the contents of IL-4 as well as IL-5 were rather higher than those in group B and C. It is evident from the above observations that IL-18 can effectively inhibit the asthmatic inflammatory cells in BALF with an imbalance of the Thl/Th2 cytokines, thus offer- ing the experimental basis for the clinical application of IL-18 in the prevention and treatment of asthma.

Rho A/Rho kinase in spinal cord injury

A spinal cord injury refers to an injury to the spinal cord that is caused by a trauma instead of diseases. Spinal cord injury includes a primary mechanical injury and a much more complex secondary injury process involving inflammation, oxidation, excitotoxicity, and cell death. During the secondary injury, many signal pathways are activated and play important roles in mediating the pathogenesis of spinal cord injury. Among them, the Rho A/Rho kinase pathway plays a particular role in mediating spinal degeneration and regeneration. In this review, we will discuss the role and mechanism of Rho A/Rho kinase-mediated spinal cord pathogenesis, as well as the potential of targeting Rho A/Rho kinase as a strategy for promoting both neuroprotection and axonal regeneration.

Mesenchymal Stem Cell Attenuates Neutrophil-predominant Inflammation and Acute Lung Injury in an In Vivo Rat Model of Ventilator-induced Lung Injury

Background： Subsequent neutrophil （polymorphonuclear neutrophil [PMN]）-predominant inflammatory response is a predominant feature of ventilator-induced lung injury （VILI）, and mesenchymal stem cell （MSC） can improve mice survival model of endotoxin-induced acute lung injury, reduce lung impairs, and enhance the repair inflammatory in the VILI is still unknown. This study aimed to inflammatory in the mechanical VILI. of VILI. However, whether MSC could attenuate PMN-predominant test whether MSC intervention could attenuate the PMN-predominate Methods： Sprague-Dawley rats were ventilated for 2 hours with large tidal volume （20 mL/kg）. MSCs were given before or after ventilation. The inflammatory chemokines and gas exchange were observed and compared dynamically until 4 hours after ventilation, and pulmonary pathological change and activation of PMN were observed and compared 4 hours after ventilation. Results： Mechanical ventilation （MV） caused significant lung injury reflected by increasing in PMN pulmonary sequestration, inflammatory chemokines （tumor necrosis factor-alpha, interleukin-6 and macrophage inflammatory protein 2） in the bronchoalveolar lavage fluid, and injury score of the lung tissue. These changes were accompanied with excessive PMN activation which reflected by increases in PMN elastase activity, production of radical oxygen series. MSC intervention especially pretreatment attenuated subsequent lung injury, systemic inflammation response and PMN pulmonary sequestration and excessive PMN activation initiated by injurious ventilation. Conclusions： MV causes profound lung injury and PMN-predominate inflammatory responses. The protection effect of MSC in the VILI rat model is related to the suppression of the PMN activation.

Expression of platelet-endothelial cell adhesion molecule-1 in human umbilical vein endothelial cells by exposure to advanced glycosylation end products and inflammatory mediators

Objective To determine whether advanced glycosylation end products modified bovine serum albumin (AGEs-BSA) affects endothelial cell lateral junction protein, platelet-endothelial cell adhesion molecule-1 (PECAM-1) in the presence or absence of inflammatory mediators.Methods Cultured human umbilical vein endothelial cells (HUVECs) were exposed to AGEs-BSA for 6, 12, 24, and 36 hours, and exposed to AGEs-BSA glycosylated with different concentrations of glucose, tumor necrosis factord-α (TNF-α), interferon (IFN-γ), TNF-α + IFN-y and AGEs-BSA + TNF-α for 24 hours, respectively. Expression of PECAM-1 mRNA was measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) with β-actin as an internal standard, and sequencing of RT-PCR products was performed to confirm the specificity of amplification for PECAM-1 gene. The endothelial cell surface expression of PECAM-1 was determined by flow cytometry (FCM).Results There were no significant changes in the expression of PECAM-1 mRNA and protein when the cells were exposed to AGEs-BSA with different concentrations or periods ( P>0. 05). However, PECAM-1 expression was reduced in the cells treated with TNF-α, IFN-y, TNF-α + IFN-γ and AGEs-BSA + TNF-α. The level of PECAM-1 treated with AGEs-BSA + TNF-α was lower than that of TNF-α treated alone (P<0. 01).Conclusions AGEs-BSA had no effect on the expression of PECAM-1 mRNA and protein in cultured HUVEC. With the presence of inflammatory mediator TNF-α, AGEs-BSA decreased the level of PECAM-1, which might reduce the adhesion interaction between adjacent endothelial cells, enhance the permeability of endothelial cells, and might be implicated in the endothelial dysfunction and pathogenesis of atherosclerosis in patients with diabetes mellitus. The significance of this phenomenon in intracellular signal transduction remains to be determined.

Research on airway inflammation: present status in China's Mainland

Airway inflammation involving activated eosinophils, mast cells and T lymphocytes is an established feature of asthma and has been the key target to treatment. Airway structural changes that occur in patients with asthma in response to persistent inflammation are termed airway remodeling. These findings are documented in studies reaching back more than 20 years. However, among investigators concerning on asthma, airway inflammation and subsequent remodeling as a target of investigation was hardly a blip on the radar screen until a few years ago. Now the subject is of expanding concern to respiratory researchers of many stripes and persuasions, as judged by the rapid rise in the number of publications. Symposia, workshops, lectures, reviews, and grant proposal on this subject also are surging.This review will not attempt to provide a comprehensive description of all aspects of airway inflammation. Rather, it will focus on current data studied by Chinese researchers in the last few years, in which the depth and scope of the discussions were much more profound than before.

Splenectomy protects experimental rats from cerebral damage after stroke due to anti-inflammatory effects

Background A recent study demonstrated that the inflammatory response accompanying necrotic brain injury played an important role in stroke.Thus,inhibition of this response may help to stop the expansion of infarcts.It has been also shown that the spleen,a major peripheral immune organ,plays a role in stroke-induced immune responses.This study aimed to establish rat models of middle cerebral artery occlusion （MCAO） and to investigate the effect of splenectomy and possible mechanisms in that rat models.Methods Infarct size in a stroke model was measured with the Nissl body staining method,numbers of inflammatory cells in ischemic regions were detected by immunofluorescence staining,and inflammatory factors were assayed by enzyme-linked immunosorbent assay and real-time polymerase chain reaction （PCR） in brain homogenates and sera.The significance of differences was determined by one-way analysis of variance （ANOVA） followed by the least significant difference post hoc test.Results Infarct size in the brain of rats that underwent splenectomies 2 weeks before permanent MCAO （（34.93±3.23）%） was over 50% smaller than that of rats subjected to the stroke surgery alone （（74.33±2.36）%,P 〈0.001; （77.30±2.62）%,P 〈0.001）.Lower numbers of T cells,neutrophils,and macrophages in brain tissue and lower levels of pro-inflammatory cytokines,such as interleukin （IL）-1β and tumor necrosis factor （TNF）-α,were observed in rats that underwent splenectomies,compared with the two other groups,but splenectomized rats showed higher levels of the anti-inflammatory factor IL-10 in the brain.Conclusion The mechanism（s） by which splenectomy protects brain from damage induced by stroke may correlate with the decreased numbers of inflammatory cells and changes in inflammatory cytokines.

Screening the anti-gout traditional herbs from TCM using an in vitro method

The aim of this work was to evaluate the ability of 33 herbal extracts in inhibiting the acute inflammation and xanthine oxidase （XOD） activity. The anti-inflammation effects of the herbal extracts were detected by an in vitro cell model, which was established by stimulating human umbilical vein endothelial cells （HUVEC） using sodium urate （MSU）. In this model, the intercellular adhesion molecule-1 （ICAM-1） and interleukin-1 beta （IL-1β） were expressed, and the anti-inflammation effects of herbal extracts were evaluated by detecting the content changes of ICAM-1 and IL-1β in cell lysates and cell culture supernates using an enzyme-linked immunosorbent assay （ELISA）. Moreover, an ultrahigh performance liquid chromatography and tandem mass spectrometry （UPLC-MS/MS） method was used for the detection of XOD activity and the screening of XOD inhibitors in this research. The amount of uric acid from each analyte was directly detected using the multiple reaction monitoring mode and the uric acid level could be reduced via the addition of an inhibitor. Results indicated that Salviae Miltiorrhizae Radix et Rhizome, Rhei Radix et Rhizoma, Polygoni Cuspidati Rhizoma et Radix, Selaginellae Herba, Paeoniae Radix Rubra, especially Ginkgo Folium seemed to be more effective in anti-inflammation and inhibiting XOD activity. The anti-inflammation and enzyme inhibitory activities of the herbal extracts may be correlated with their bioactive components. And the differences between the herbal extracts were correlated with the amount of flavonoid and anthraquinone components. In our study, we have investigated the potential anti-inflammation bioactivity of 33 herbal extracts in vitro, which could provide a reference for further in vivo research in the orevention and treatment of gout.

Human bronchial epithelial cell injuries induced by fine particulate matter from sandstorm and non-sandstorm periods：Association with particle constituents

Epidemiological studies have demonstrated the exacerbation of respiratory diseases following sandstorm-derived particulate matter（PM） exposure.The presence of anthropogenic and biological agents on the sandstorm PM and the escalation of PM 〈 2.5 μm（PM2.5）pollution in China have led to serious concerns regarding the health effects of PM2.5during Asian sandstorms.We investigated how changes in PM2.5composition,as the weather transitioned towards a sandstorm,affected human airway epithelial cells.Six PM2.5samples covering two sandstorm events and their respective background and transition periods were collected in Baotou,an industrial city near the Gobi Desert in China.PM samples from all three periods had mild cytotoxicity in human bronchial epithelial cell line BEAS-2B,which was positively correlated with the contents of polycyclic aromatic hydrocarbons and several metals.All PM samples potently increased the release of interleukin-6（IL-6） and interleukin-8（IL-8）.Endotoxin in all samples contributed significantly to the IL-6 response,with only a minor effect on IL-8.Cr was positively correlated with both IL-6 and IL-8 release,while Si was only associated with the increase of IL-6.Our study suggests that local agricultural and industrial surroundings in addition to the sandstorm play important roles in the respiratory effects of sandstorm-derived PM.

The regulation effect of AMPK in immune related diseases

AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that plays a key role in energetic metabolism regulation.Metabolic changes in immune cells, such as dendritic cell (DC), macrophages, neutrophils and lymphocytes that participate in the signal directed programs that promote or inhibit immune mediated diseases, including cancer, atherosclerosis and inflammatory diseases. Multiple pathogenic mechanisms are involved in the initiation and progression of disease, and many pathways have been uncovered. The mechanistic overlap in the metabolic changes and inflammation could indicate that some of the targets they have are in common, whereas AMPK could be useful in treatment of both disorders. The insight into identification of AMPK responsible for specific immune regulation, anti-inflammatory actions and understanding of the underlying molecular mechanism will promote the generation of novel AMPK activators, and provide novel therapy strategy.