ObjectiveTo observe the expression of Toll-like receptor 4 (TLR4) and inflammatory cytokines, leucocytic density and permeability in retina of diabetic rat. MethodsA total of 106 Brown Norway rats were randomly divided into experimental group and control group with 53 rats in each group. Diabetic model was established in experimental group by intraperitoneal injection of streptozotocin, and control rats received intraperitoneal injection of an equal volume of citric acid-sodium citrate buffer. Four weeks later, the retinas were collected for further analysis. TLR4 RNA and protein expression were measured by quantitative polymerase chain reaction and Western blot. Inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), monocyte chemo-attractant protein-1 (MCP-1), were measured by enzyme-linked immunosorbent assay in rat retina homogenate. Leukocyte density in the retina was measured by acridine orange fundus angiography. The retinal permeability was evaluated by Evans blue (EB) staining. ResultsTLR4 expression was significantly increased in diabetic rats of experimental group compared with non-diabetic rats of control group (F=1.606, 0.789; P < 0.05). Inflammatory cytokines (TNF-α, IL-1β and MCP-1) were significantly increased in retina of diabetic rats of experimental group versus non-diabetic rat of control group (F=24.622, 5.758, 4.829; P < 0.05). The retinal leukocyte density was (6.2±0.5)×10-5, (2.2±0.3)×10-5 cells/pixel2 in experimental and control group respectively, the difference was statistically significant (F=2.025, P < 0.05). The amount of retinal EB leakage was (23.41±4.47), (13.22±3.59) ng/mg in experimental and control group respectively, the difference was statistically significant (F=21.08, P < 0.05). ConclusionTLR4 and inflammatory cytokines expression, leucocytic density and permeability increased significantly in retina of diabetic rat.
ObjectiveTo investigate the expression of caspase-3 and Toll-like receptor 4 (TLR4) in the incised rat skin healing process and its relationship with the wound time and to provide an experimental evidence for the prediction of injury time. MethodsAfter the rat incised wound model was established, hematoxylin-eosin dyeing technology and immunohistochemical staining technique were used to observe the expression of caspase-3 and TLR4. Then Image Pro Plus Image analysis software and SPSS statistical analysis software were used to deal with the experimental results. ResultsCaspase-3- and TLR4-positive cells were detected in epidermis, hair follicle and sebaceous gland cells in the control skin. The expression of caspase-3 and TLR4 of the ante mortem groups were significantly different compared with the control group except the 0 h group (P<0.05). Caspase-3- and TLR4-positive cells were detected in neutrophils around the hair follicle half an hour later. Caspase-3- and TLR4-positive cell rate increased with the infiltration of inflammatory cells. Caspase-3- and TLR4-positive cell rate reached the maximum on the 3 rd day, and then it began to decrease, and they were mainly expressed in fibroblasts and mononuclear macrophages. Caspase-3- and TLR4-positive cells were mainly expressed in fibroblasts on the 10th day. There was no significant differences between the postmortem injury groups and the normal control groups (P>0.05). ConclusionCaspase-3- and TLR4-positive cell rate is time dependent and stable in 25℃ temperature environment which makes it possible to determine the time of injury.
Objective To observe the effects of nitric oxide ( NO) inhalation on lung inflammation of acute lung injury ( ALI) in rats. Methods Twenty-four SD rats were randomly divided into four groups, ie. a normal control group, an ALI group, a 20 ppm NO inhalation group, and a 100 ppm NO inhalation group. ALI model was established by LPS instillation intratracheally and the control group was instilled with normal saline. Then they were ventilated with normal air or NO at different levels, and sacrificed 6 hours later. Pathological changes were evaluated by HE staining. The expression of TLR4 in lung tissues was detected by immunohistochemistry. IL-6 level in lung homogenate was measured by ELISA. Results In the ALI group, the inflammation in bronchus and bronchioles was more apparently, and the expressions of TLR4and IL-6 were elevated significantly compared with the control group. 20 ppm NO inhalation significantly decreased the expression of TLR4 and IL-6, and alleviated the inflammation of ALI. However, 100 ppm NO inhalation did not change TLR4 expression and lung inflammation significantly, and increased IL-6 level.Conclusions Inhalation low level of NO( 20 ppm) can alleviate lung inflammation possibly by reducing theexpression of TLR4 and IL-6.
【Abstract】 Objective To study the role of house dust mite ( HDM) induced airway epithelium TLR4 expression and T lymphocyte activation in asthmatic inflammation. Methods Thirty BALB/ c mice were randomly divided into an ovalbumin ( OVA) group, a HDMgroup, and a control group. The mice in the OVA group were sensitized with OVA and Al( OH) 3 , and repeatedly exposed to aerosolized OVA. The mice in the HDMgroup and the control group were sensitized and challenged with HDMand saline, respectively.Histopathology changes of pulmonary tissue and airway were observed under light microscope. Levels of IL-4, IL-5, IL-13, IL-17, and IFN-γin BALF were measured by ELISA. Total and differential cell counts in bronchoalveolar lavage fluid ( BALF) were also measured. The mRNA and protein expressions of TLR4 weredetected by quantitative real-time PCR and Western blot, respectively. Th1, Th2, and cells in the peripheral blood were detected by flow cytometry. Results Light microscope revealed eosinophil specific inflammatory cells infiltration around the peribronchovascular region,mucus gland hyperplasia, and airway mucous plug inthe OVA group. The HDM group showed more severe alveolar and intersititial congestion and neutrophils infiltration. The control group showed intact alveolus with few mucous plug and inflammatory cells.Compared with the OVA group, significant increases in the number of total cells and neutrophils, as well as significantly higher expression of IL-4, IL-5, IL-13, and IL-17 were detected in the HDMgroup ( P lt;0. 05) ,while IFN-γexpression had no significant change ( P gt;0. 05) . The expression of TLR4 mRNA and protein significantly increased in the HDMgroup( P lt; 0. 05) , and did not change significantly in the other two groups ( P gt;0. 05) . The percentages of Th2 and Th17 cells in peripheral blood in the HDMgroup were significantly higher than the OVA group ( P lt;0. 05) . Conclusion HDM may induce inflammatory cells infiltration andactivation of Th2 and Th17 lymphocyte cells via up-regulation of TLR4 expression in airway epithelium,which might play an important role in asthmatic inflammation.
【Abstract】Objective To explore Toll-like receptor 4 (TLR4) expression and distribution in rat pancreas.Methods Reverse transcriptase-polymerase chain reaction (RTPCR) and immunohistochemistry (IHC) were applied to detect expression of TLR4-mRNA and TLR4 protein respectively. Results RT-PCR of RNA isolated from rat pancreatic tissue yielded the predicted amplicon for the TLR4. IHC/immunofluorescence revealed TLR4 protein mainly distributed in the epithelium of the pancreatic duct, vascular endothelium of the exocrine section, endocrine islet also had some signs of distribution. No TLR4 protein signal could be detected in the acinar cells. Conclusion TLR4 could be detected in rat pancreas. Its distribution is consistent with its roles in immune surveillance, mainly in tissues exposed to the external environment such as pancreatic duct as well as in immunologically important settings such as pancreatic vascular endothelium. Islet also has some signs of distribution. No TLR4 expression in acinar cells, suggesting TLR4 immunological involvement in the pathophysiology of pancreas.
ObjectiveTo investigate the protective effect and mechanism of curcumin on lipopolysaccharide (LPS)-induced acute lung injury.MethodsTotally 24 SD rats were randomly divided into a control group, a LPS group and a LPS+curcumin group (n=8 in each group). The degree of lung injury (oxygen partial pressure, wet/dry ratio, pathological scores) and inflammatory levels [tumor necrosis factor (TNF)-α, interleukin (IL)-6, monocyte chemotactic protein (MCP)-1, Toll-like receptor 4 (TLR4), mobility group box 1 protein (HMGB1) expression] of the lung were detected in different groups.ResultsOxygen partial pressure was significantly lower in the LPS group than that in the control group (P<0.05), while wet/dry ratio, pathological scores and expression levels of TNF-α, IL-6, MCP-1, TLR4 and HMGB1 were significantly higher in the LPS group than those in the control group (P<0.05). Compared with the LPS group, curcumin significantly reduced wet/dry ratio, pathological scores and expression levels of TNF-α, IL-6, MCP-1, TLR4 and HMGB1 in the LPS+curcumin group (P<0.05), while it significantly improved oxygen partial pressure (P<0.05).ConclusionCurcumin might protect LPS-induced acute lung injury through inhibition of TLR4-HMGB1-inflammation pathway.
ObjectiveTo explore the relationship between single nucleotide polymorphisms (SNPs) of the Toll-like receptor 4 (TLR4) gene and the risk of pulmonary tuberculosis (PTB) more comprehensively and objectively through meta-analysis.MethodsWe searched all available articles published before June 13th, 2019 in main Chinese and English databases systematically and comprehensively, including PubMed, Embase, China National Knowledge Infrastructure, Wanfang and CQVIP databases. The literature was screened according to the inclusion and exclusion criteria set in advance. In addition, the basic characteristics and data of the included literature were recorded according to a pre-made data collection form. Statistical analyses were performed using the Stata 15.0 software.ResultsA total of 17 eligible original articles were included in the study eventually. Furthermore, allele and genotype data of the 4 most widely studied SNPs (rs4986790, rs4986791, rs10759932, and rs11536889) in the TLR4 gene were extracted. And their allelic model, dominant model, recessive model, homozygous model, and heterozygous model were separately analyzed by meta-analysis. The results showed that the C allele of rs10759932 increased the risk of PTB [odd ratio (OR)=1.144, 95% confidence interval (CI) (1.043, 1.254), P=0.004]. Compared with the TT genotype, the CC+CT genotype and the CT genotype alone of rs10759932 also increased the risk of PTB [OR=1.218, 95%CI (1.084, 1.369), P=0.001; OR=1.227, 95%CI (1.085, 1.387), P=0.001]. Nevertheless, there was no statistical correlation between the other three SNPs (rs4986790, rs4986791 and rs11536889) and the susceptibility to PTB (P>0.05).ConclusionThe allele model, dominant model (CC+CT vs. TT), and heterozygous model (CT vs. TT) of rs10759932 located on the TLR4 gene are closely related to the risk of PTB.
Objective To verify tissue factor (TF)-bearing microparticle (TF-MP) could be released from Kupffer cells (KCs) stimulated by lipopolysaccharide (LPS) and TF controlled by Toll-like receptor 4 (TLR4) could induce acute pancreatitis. Methods After the acute pancreatitis model completed, the wild type C57/BL6 mouse (WT group) and the TLR4-/- mouse (TLR4-/- group) received intraperitioneal injections of 10 mg/kg LPS. The degree of pathological lesion and the TF expression were detected in the pancreas tissue. The TF and TLR4 protein and mRNA expressions in the KCs were detected at 6, 12, and 24 h after the last injection of LPS. The survival rates were campared in these estabilshed acute pancreatitis model mice. The TF and TLR4 protein and mRNA expressions in the KCs stimulated with LPS (300 μg/L) were also detected at 0, 15, 30, 60, and 120 min. The TF and TF-MP levels were detected in the supernatants of the KCs at these time point. Results The injury of the pancreas in the TLR4-/- group was slighter than that in the WT group. The TF proteins in the liver and pancreas tissues of the TLR4-/- group were significantly lower than those of the WT group (P<0.05). The survival rate of the TLR4-/- group was significantly higher than that of the WT group under the situation of the acute pancreatitis (P<0.05). The TLR4 and TF protien and mRNA expressions of the KCs were significantly decreased in the TLR4-/- group as compared with the WT group at 30, 60, and 120 min (P<0.05). The levels of TF and TF-MP in the supernatant of the TLR4-/- group were significantly lower than those of the WT group at 30, 60, and 120 min (P<0.05). Conclusion Acute pancretitis can be induced by TF and TF-MP expressions in KCs which could be regulated by TLR4 pathway.