miR-92b-5p attenuates renal injury and inflammatory response in diabetic nephropathy rats by targeting HMGB1

AIM To investigate the effect of microRNA-92b-5p （miR-92b-5p） on renal injury and inflammatory response in diabetic nephropathy （DN） rats and its mechanism. METHODS The rats were divided into control group， DN group， lentiviral negative control （LV-NC） group， LV-miR-92b group， LV-high mobility group protein B1 （LV-HMGB1） group and miR-92b+HMGB1 group， with 15 rats in each group. After fasting for 12 h， the model rats were intraperitoneally injected with streptozotocin at dose of 60 mg/kg， and the control rats were intraperitoneally injected with an equal volume of citrate buffer. Three days later， the rats in each treatment group were intravenously injected with 100 μL LV-NC， LV-miR-92b and LV-HMGB1 （1×10¹¹ U/L） twice a week for 8 consecutive weeks. Urinary protein， blood glucose， blood urea nitrogen and serum creatinine were detected by an automatic biochemical analyzer. The expression of miR-92b-5p and HMGB1 mRNA was detected by RT-qPCR. The targeting relationship between miR-92b-5p and HMGB1 was verified by dual-luciferase reporter assay. HMGB1 expression in kidney tissue was detected by Western blot. The kidney damage was observed by HE staining. The apoptosis was detected by flow cytometry. The levels of interleukin-6 （IL-6）， IL-1β and tumor necrosis factor-α （TNF-α） in renal tissues were detected by ELISA. RESULTS In DN model rats， miR-92b-5p was down-regulated， while HMGB1 was highly expressed. There was a binding site between miR-92b-5p and HMGB1 3'-untranslated region. High expression of miR-92b-5p inhibited the luciferase activity of the wild-type HMGB1 plasmid （P<0.01）， but had no effect on the luciferase activity of the mutant HMGB1 plasmid. Compared with DN group， urinary protein， blood glucose， serum creatinine and blood urea nitrogen in LV-miR-92b group were significantly reduced （P<0.01）. The degree of hyperplasia， swelling and inflammatory cell infiltration of glomerular mesangium and basement membrane tubules， the apoptosis rate of renal tissues， and the content of IL-6， IL-1β and TNF-α in renal tissues were significantly decreased （P<0.01）. Co-transfection of LV-HMGB1 significantly reversed the effect of miR-92b-5p on DN rats. CONCLUSION miR-92b-5p reduces renal injury and inflammatory response in DN rats by targeting HMGB1 and down-regulating its expression.     

Study on COX activity and its mRNA expression,and PGE2 release from cerebral microvascular endothelial cells stimulated by IL-1β

AIM: To study the cyclooxygenase(COX) activity and its mRNA expression, and PGE₂ release from rats cerebral microvascular endothelial cells (rCEMC) stimulated by IL-1β(30 μg/L) at different times. METHODS: rCMEC were cultured, and identified by immunohistochemistry for von Willebrand factor (Ⅷ factor, a marker for all endothelial cells) in cytoplasm of the cells. After rCEMC grew to confluency, they were stimulated with IL-1β for 0.5, 1, 2, 4, 8, 12 and 24 h, respectively. Activity of COX-1 and COX-2 in rCEMC and production of PGE₂ in the conditioned media were detected by ELISA. COX-1 and COX-2 mRNA expressions were measured by real-time quantity PCR. The amplification product was tested by melting curve and identified by electrophoretic gel. RESULTS: ① Positive immunostaining for Ⅷ factor was present diffusely in the cytoplasm in more than 90% rCMEC. ② Compared to the cells without IL-1β stimulation, the production of PGE₂ increased significantly (P<0.05) at 4 h after rCEMC were incubated with IL-1β and reached the top level at 12 h (P<0.01), then declined thereafter at 24 h (P<0.05). ③ There was no significant difference on COX-1 activity between IL-1β group and non-IL-1β group. COX-2 activity increased significantly compared with those in non-IL-1β (P<0.05) at 8 h after rCEMC were incubated with IL-1β and reached the top level at 12 h (P<0.01), then declined thereafter at 24 h (P<0.05). ④ There was no significant difference on COX-1 mRNA expression between IL-1β group and non-IL-1β group. COX-2 mRNA was induced and became detectable at 1 h, and reached the top level at 4 h, then declined thereafter at 8 h and became undetectable by 12 h and 24 h after incubation with IL-1β. The melting curve showed there was no nonspecific amplification and electrophoretic gel showed the lengths of amplification products accorded with the predicted lengths. CONCLUSION: While rCEMC are stimulated by IL-1β, the excretion of PGE₂ increases and reaches the top level at 12 h, which is related with its induction on COX-2 mRNA expression and COX-2 activity.     

Effect of dexmedetomidine on astrocytes in rats with focal cerebral ischemia-reperfusion

AIM: To investigate the effects of dexmedetomidine on astrocytes in rats with focal cerebral ischemia-reperfusion. METHODS: Sixty female SD rats, weighing 230~250 g, were randomly divided into sham operation group, ischemia-reperfusion group, dexmedetomidine preconditioning group 1 and dexmedetomidine preconditioning group 2. The model of middle cerebral artery occlusion (MCAO) was established by thread embolism of middle cerebral artery. In sham operation group, the carotid arteries were exposed without performing MCAO. In ischemia-reperfusion group, NS was injected intraperitoneally 30 min before focal cerebral ischemia-reperfusion. The rats in dexmedetomidine preconditioning group 1 and dexmedetomidine preconditioning group 2 received intraperitoneal injection of dexmedetomidine at doses of 20 μg/kg and 40 μg/kg, respectively. The neurological scores were studied, and the pathological changes were observed under microscope with HE staining. The expression of glial fibrillary acidic protein (GFAP) and tumor necrosis factor α (TNF-α) in astrocytes was detected by the methods of immunohistochemistry and immunoblotting 24 h after cerebral ischemia-reperfusion. RESULTS: No neurological change was observed in sham operation group. The neurological deficiency scores in ischemia-reperfusion group were markedly higher than those in dexmedetomidine preconditioning group 1 and group 2 (P<0.05). Compared with sham operation group, the expression of GFAP and TNF-α in astrocytes and the level of GFAP increased significantly 24 h after focal cerebral ischemia-reperfusion. Pretreatment with dexmedetomidine significantly attenuated the expression of GFAP and reduced the infarct size and inflammation. CONCLUSION: Dexmedetomidine has a neuroprotective effect on focal cerebral ischemia-reperfusion injury by inhibiting the astrocytes.     

IL-33-modified BMSCs attenuate acute kidney injury induced by sepsis in rats through MyD88

AIM To investigate the effect of interleukin-33 (IL-33)-modified bone marrow mesenchymal stem cells (BMSCs) on sepsis-induced acute kidney injury (AKI) in rats and the expression of myeloid differentiation factor 88(MyD88). METHODS A septic rat model was established by cecal ligation and puncture. The SD rats (n=80) were randomly divided into control group, model group, negative transfection group (transplanting untransfected BMSCs) and IL-33 transfection group (transplanting BMSCs transfected with IL-33), with 20 in each group. Survival rates of the rats within 72 h in the 4 groups were compared. Serum creatinine (SCr) and blood urea nitrogen (BUN) levels were measured before, and 24, 48 and 72 h after transplantation. The kidney pathological damage was observed by HE staining, and the apoptosis of renal cells was detected by TUNEL method 72 h after transplantation. Western blot was used to detect the protein expression levels of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), Toll-like receptor 4 (TLR4) and MyD88. RESULTS The survival rate of the rats in model group was significantly lower than that in control group (P<0.05). The survival rate of the rats in IL-33 transfection group was higher than that in model group and negative transfection group (P<0.05). The levels of SCr and BUN in model group were higher than those in control group (P<0.05). The levels of SCr and BUN in IL-33 transfection group were significantly reduced after transplantation, and were lower than those in model group and negative transfection group (P<0.05). The renal tissue pathological injury score in model group was significantly higher than that in control group (P<0.05). Compared with model group and negative transfection group, the renal tissue pathological injury score in IL-33 transfection group was significantly reduced (P<0.05). The proportion of apoptotic cells in the kidney tissues in model group were higher than that in control group (P<0.05). Compared with model group and negative transfection group, the proportion of apoptotic cells in the kidney tissues in IL-33 transfection group was significantly reduced (P<0.05). The protein expression levels of IL-1β, IL-6, TNF-α, TLR4 and MyD88 in model group were significantly higher than those in control group (P<0.05). Compared with model group and negative transfection group, the protein expression levels of IL-1β, IL-6, TNF-α, TLR4 and MyD88 in IL-33 transfection group were significantly decreased (P<0.05). CONCLUSION IL-33 gene-modified BMSCs significantly improve the renal function of AKI rats with sepsis. The mechanism may be related to IL-33 regulating TLR4/MyD88 signaling pathway and inhibiting renal inflammatory response.     

Effects of neutrophil extracellular traps on acute lung injury in neonatal rats

AIMTo investigate the role of neutrophil extracellular traps (NETs) in neonatal rats with acute lung injury (ALI). METHODSThirty 7-day-old SD rats were randomly divided into normal saline control group, ALI group and ALI+deoxyribonuclease (Dnase) group (each n=10). The rats in ALI group were intraperitoneally injected with lipopolysaccharides (LPS) at 20 mg/kg, and the rats in ALI+Dnase group were intraperitoneally injected with Dnase at 5 mg/kg after LPS injection. After 6 h, the rats were anesthetized with chloral hydrate, bronchial alveolar lavage fluid (BALF) was collected, and the content of cell-free DNA (cf-DNA) in BALF was detected by fluorescence microarray. The right lung tissues were fixed in 4% paraformaldehyde, and the morphological structure of the lung tissues were observed by HE staining. The content of interleukin-6 (IL-6) and tumor necrosis factor-α （TNF-α） in the left lung homogenate was measured by ELISA. Immunofluorescence and Western blot were used to detect the production of citrullinated histone H3 (CitH3) and myeloperoxidase (MPO) in the rat lung tissues. RESULTSCompared with control group, the levels of cf-DNA, CitH3, MPO, IL-6 and TNF-α in lung tissues of neonatal rats in ALI group and ALI+Dnase group were all increased (P<0.05), and severe inflammatory infiltration in the lung tissues was observed. Compared with ALI group, the levels of cf-DNA, CitH3, MPO, IL-6 and TNF-α in ALI+Dnase group were decreased (P<0.05), and the inflammatory infiltration was attenuated. CONCLUSION In neonatal rats with ALI, the level of NETs is an important indicator of lung tissue injury, and NETs may be a new target for the treatment of neonatal ALI.     

Effect of aminoguanidine on TNF-α,IL-1β and neuronal apoptosis after focal cerebral ischemic injury in rats

AIM: To evaluate the effect of aminoguanidine (AG) on inflammatory factors and neuronal apoptosis after focal cerebral ischemic injury in rats and the possible mechanism of protective effect of AG against cerebral ischemic injury.METHODS: Thirty male SD rats (weighing 250 g-280 g) were randomly divided into three groups: (1) sham operated group (SH group,n=10),(2) ischemic groups (IS group,n=10),(3) AG group (n=10).In AG group,AG at dose of 100 mg·kg-1 was given intraperitoneally twice a day for 3 consecutive days.In IS group,normal saline was given instead of AG.Focal cerebral ischemia was produced by middle cerebral artery occlusion (MCAO) for 12 h.A nylon thread with rounded tip was inserted into left internal carotid artery cranially until resistance was felt.The distance from bifurcation of common carotid artery to the tip of the thread was about 18-19 mm.Focal cerebral ischemia was confirmed by left Horners syndrome and right side hemiplegia.In SH group,the carotid artery was exposed but no thread was inserted.The expression of tumor necrosis factor-α(TNF-α) was determined by immunochemistry and the content of interleulin-1β(IL-1β) was measured by radioimmunoassay.The expressions of Bcl-2 and Bax protein were detected by flow cytometry.RESULTS: The expression of TNF-α and the content of IL-1β were markedly increased after MCAO.Significantly increased DNA fragmentation,the indication of apoptosis,was detected after MCAO.The expression of TNF-α and the content of IL-1β were significantly lower in AG group than those in IS group.The percentage of apoptosis cells and expression of Bax protein were markedly lower in AG group than those in IS group but still significantly higher than those in SH group.The expression of Bcl-2 protein was markedly higher in AG group than that in IS group.No significant difference in the expression of Bcl-2 protein between IS and SH group was observed.CONCLUSION: AG inhibits the increase in the expression of TNF-α and the content of IL-1β,and protects neurons from apoptosis induced by focal cerebral ischemia through increasing the Bcl-2 protein expression and inhibiting the Bax protein expression.     

Influence of losartan potassium on renal expression of TGF-β1, CD68 and MCP-1 in type 2 diabetic nephropathy rats

AIM: To observe the effects of losartan potassium on renal expression of transforming growth factor beta 1(TGF-β₁), CD68 and monocyte chemoattractant protein-1 (MCP-1) in type 2 diabetic nephropathy rats for exploring the protective mechanism of losartan potassium on type 2 diabetic rat kidney. METHODS: Thirty Sprague-Dawley rats were randomized into 3 groups: normal control group, model group and treatment group. The morphology of kidney tissues, the renal function, and the change of 24 h urinary protein quantitative index were measured after 15 weeks of treatment, while TGF-β₁, CD68 and MCP-1 expression in kidney cortex was observed by immunohistochemistry. RESULTS: Compared with the normal control rats, the body weight of the rats was lower in other groups, but the levels of blood glucose, triglyceride and cholesterol were higher.The expression of CD68, MCP-1 and TGF-β₁, 24 h urinary protein quantitative index and serum creatinine were higher in model group than those in normal control rats. However, compared with model group, serum creatinine, 24 h urinary protein quantitative index and the expression of CD68, MCP-1 and TGF-β₁ were decreased in treatment group. CONCLUSION: Losartan potassium protects the kidney of diabetic nephropathy rats through inhibiting the expression of TGF-β₁ and MCP-1 in the kidney and restraining macrophage infiltration.     

Phosphodiesterase 4 inhibitor rolipram prevents depression- and anxiety-like behaviors in rats exposed to chronic restraint stress

AIM: To discuss the impact of phosphodiesterase 4 (PDE4) inhibitor rolipram on chronic restraint stress-induced depression- and anxiety-like behaviors in rats. METHODS: (1)Forty SD rats were randomly divided into 4 weight-matched groups: unstressed animals injected with vehicle of lithium chloride (LiCl) and rolipram, restraint-stressed animals injected daily with vehicle prior to stress, restraint stress plus 100 mg/kg LiCl group and restraint stress plus 1 mg/kg rolipram group. The open field test was conducted 24 h before the first stress and drug administration,and then the rats received drugs daily 1 h prior to restraint stress (6 h/d) for 25 d. Daily body weight recording, forced swimming test, elevated plus-maze and open field test were conducted to determine the changes of depression- and anxiety-like behaviors. The expression of phosphorylated cAMP response element-binding protein (p-CREB), brain-derived Reurotrophic factor (BDNF), p-Ser21-glycogen synthase kinase (GSK) 3α, p-Ser9-GSK3β, p-Tyr279-GSK3α, p-Tyr216-GSK3β, total GSK3α and total GSK3β was measured by Western blotting. (2)Thirty SD rats were randomly divided into 6 groups and the cannula was surgically placed above the CA1 region in the hippocampus. Seven days after the surgery, the restraint stress was conducted for 21 d after microinjection of protein kinase A (PKA) antagonist H89 and intraperitoneal injection of LiCl and rolipram everyday. The expression of PDE4D, PKA, p-CREB and p-Ser9-GSK3β was measured by Western blotting. RESULTS: (1)No difference of the locomotor activity among all groups before stress was observed. After repeated stress, the body weight,and the crossing, rearing and grooming in open field test were lower than those in control group, and LiCl and rolipram reversed these effects significantly. In addition, in comparison with control group, the immobility in forced swimming test was increased, the climbing in forced swimmming test and the open-arm exploration in elevated plus-maze were decreased and the expression of p-CREB, BDNF, p-Ser21-GSK3α and p-Ser9-GSK3β was down-regulated. Stress induced depression- and anxiety-like behaviors, and rolipram reversed these changes. The LiCl showed similar effects as rolipram except for the expression of p-CREB and BDNF. No significant difference of the expression of p-Tyr279-GSK3α, p-Tyr216-GSK3β, total GSK3α and total GSK3β among all groups was found. (2)The expression of PDE4D was increased, the expression of PKA, p-CREB and p-Ser9-GSK3β was decreased in the hippocampus induce by restraint stress. However, the effect of rolipram on the expression of PKA, p-CREB and p-Ser9-GSK3β was blocked by PKA inhibitor H89. CONCLUSION: Rolipram significantly reduces the depression- and anxiety-like behaviors, possibly through CREB/BDNF signaling and inhibitory serine-phosphorylation of GSK3-mediated signaling. Importantly, the CREB/BDNF signaling also plays a key role in the down-regulation of serine-phosphorylation of GSK3.     

Effects of microglia-derived IL-1β on differentiation of OPCs in corpus callosum of septic neonatal rats

AIM: To explore whether IL-1β inhibits the oligodendrocyte precursor cell (OPCs) differentiation and affects axonal myelination. METHODS: One-day-old SD rats were randomly divided into control group and LPS group (48 rats in each group). The rats in LPS group were intraperitoneally injected with 1 mg/kg LPS. The rats in control group were injected with an equal volume of PBS. The rats in each group were further divided into 3 h, 24 h, 3 d, 7 d, 14 d and 28 d subgroups after injection. The expression of IL-1β and IL-1R₁ in the rat corpus callosum at 3 h, 24 h, 3 d, 7 d was determined by double immunofluorescence and Western blotting. The myelin basic protein(MBP) expression in the rat corpus callosum at 14 d, 28 d after injection was also measured. In vitro, primary OPCs culture was performed and divided into control group, 30 μg/L IL-1β group, 30 μg/L IL-1β+IL-1Ra group and 30 μg/L IL-1Ra group. The expression of MBP in the OPCs induced differentiation for 3 d was observed by double immunofluorescence and Western blotting. RESULTS: The expression of IL-1β and IL-1R₁ in the rat corpus callosum at 3 h, 24 h, 3 d, 7 d after LPS injection was obviously increased and the expression of MBP in the rat corpus callosum at 14 d, 28 d in LPS group was obviously decreased compared with control group in vivo. The level of MBP was significantly decreased after IL-1β treatment for 3 d in vitro. However, IL-1Ra (IL-1R inhibitor) reversed the down-regulation of MBP expression. IL-1β inhibited the expression of p-ERK, ERK over-expression reversed the down-regulation of MBP expression compared with IL-1β group. CONCLUSION: IL-1β inhibits the differentiation of OPCs, which may be involved in ERK pathways, thus leading to axonal hypomyelination in the corpus callosum of septic neonatal rats.     

Protective effects of physcion against cerebral injury induced by ischemia-reperfusion in rats

AIM: To explore the effect of physcion (P) on the level of IL-1β and expression of ICAM-1 and caspase-3 during cerebral ischemia-reperfusion injury. METHODS: The 91 healthy adult SD rats were selected, and were randomly divided into normal group, sham-operated group, cerebral ischemia-reperfusion group (model), low-dose physcion (PLD) and high-dose physcion (PHD) treatment group. The level of IL-1β was detected by radioimmunoassay. The expression of ICAM-1 and caspase-3 was detected by immunohistochemistry. The changes of tissue pathology were also investigated. RESULTS: The level of IL-1β reached the peak at 6 h after ischemia-reperfusion (IR). The protein expression of ICAM-1 and caspase-3 reached the peak at 24 h after IR. The level of IL-1β and the protein expression of ICAM-1 and caspase-3 in PHD group decreased obviously compared with those in model group (P<0.05 or P<0.01), infiltration and adhesiveness of neutrophils were less serious at the same time. CONCLUSION: Physcion decreases the level of IL-1β and the protein expression of ICAM-1 and caspase-3 to protect brain tissue from cerebral ischemia-reperfusion injury.     

Effects of diosmin on changes of TNF-α, IL-1β, IL-6, IL-8 and IL-10 in serum and kidney tissues of rats with kidney ischemia and reperfusion

AIM: To observe the effects of diosmin on the production of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), IL-6, IL-8 and IL-10 in serum and kidney tissues of rats with kidney ischemia and reperfusion (I/R). METHODS: Sprague-Dawley rats (180 in total) were randomly divided into 3 groups including sham operation group (sham),I/R group and diosmin+I/R group (diosmin+I/R). At the end of the experiment, the blood and kidney tissues were obtained and TNF-α, IL-1β, IL-6, IL-8 and IL-10 were detected by ELISA. RESULTS: The levels of TNF-α, IL-1β, IL-6, IL-8 and IL-10 in serum and kidney tissues in I/R group and diosmin+I/R group were significantly higher than those in sham group (P<0.01 or P<0.05). Following the development of the pathologic process, the level of TNF-α, IL-1β, IL-6 and IL-8 was significantly increased in I/R group and diosmin+I/R groups, but the level of IL-10 was significantly decreased in I/R group and significantly increased in diosmin+I/R group. The levels of TNF-α, IL-1β, IL-6 and IL-8 in I/R group was significantly higher than those in diosmin+I/R group (except TNF-α at 1 h in diosmin+I/R group). The level of IL-10 in diosmin+I/R group was significantly higher than that in I/R group (P<0.01 or P<0.05). CONCLUSION: Diosmin not only decreases the production of TNF-α, IL-1β, IL-6 and IL-8, but also promotes the production of anti-inflammatory cytokine IL-10, suggesting that the protective effect of diosmin on kidney I/R injury was associated with anti-inflammatory mechanism.     

Effects of peritoneal cooling on inflammation after cardiopulmonary resuscitation in rabbits

AIM:To explore the effects of different cooling methods on systemic inflammation after cardiopulmonary resuscitation(CPR) in New Zealand rabbits. METHODS:Ventricular fibrillation in 48 adult New Zealand rabbits was induced by alternating current and was resuscitated after cardiac arrest for 5 min. The rabbits were randomly divided into 4 groups according to the way of cooling methods:normothermia group(NT), peritoneal cooling group(PC), surface cooling group(SC) and local cooling group(LC). The plasma concentrations of tumor necrosis factor α(TNF-α) and interleukin-6(IL-6) were measured in each group at different time points after return of spontaneous circulation(ROSC). The liver tissues were removed 12 h after ROSC, and the levels of NF-κB p65 and NF-κB p50 were tested by Western blotting. The survival time was recorded and compared 96 h after ROSC. RESULTS:The plasma concentration of TNF-α in PC group was lower than that in NT group 4 h, 8 h and 12 h after ROSC, and was also lower than that in SC group and LC group 12 h after ROSC. The level of IL-6 in PC group was lower than that in NT group 2 h, 4 h, 8 h and 12 h after ROSC, while there was no difference between the other 2 groups. The levels of p65 and p50 in PC group were lower than those in other groups(P<0.05), while there was no difference between the other 3 groups. The cumulative survival rate after ROSC in PC group was higher than that in NT group, SC group and LC group. CONCLUSION:The novel peritoneal cooling rapidly induces and maintains mild hypothermia, and decreases the peritoneal temperature quickly, thus inhibiting liver NF-κB activation, reducing the releases of TNF-α and IL-6, subsequently relieving systemic inflammation after ROSC and prolonging rabbit survival.     

Alteration of AQP2 expression in kidney tissues of emphysema model rats

AIM: To observe the expressions of aquaporin 2 (AQP2) in kidney tissues and the contents of endotoxin (ET), interleukin-1 β (IL-1β), tumor necrosis factor-α (TNF-α) in serum in emphysema model rats, and to investigate the relationship between lungs and kidney in humoral metabolism. METHODS: The rats of emphysema were treated by injecting lipopolysaccharide into the trachea with cigarette smoking. Immunohistochemistry and Western blotting analysis were used to observe the expression of AQP2 in kidney tissues. RT-PCR was applied to detect the expression of AQP2 mRNA in kidney tissues. Blood sample and lung tissue were taken and the levels of ET, IL-1β and TNF-α were measured by radioimmunoassay. RESULTS: AQP2 expression in the kidney tissue in model group was greater than that in control group, and the expression of AQP2 mRNA showed the same results (P<0.01). ET, IL-1β and TNF-α levels in serum and lung tissue in model group were markedly higher than those in control group (P<0.01). CONCLUSION: In the emphysema model rats, AQP2 expression is up-regulated in the kidney tissue. The mechanism of emphysema may be related to increasing the levels of ET, IL-1β and TNF-α in the serum and lung tissue obviously.     

Polysaccharides of Dicliptera chinensis (L.) Nees. alleviates liver injury of GalN/LPS-induced fulminant hepatitis in rats

AIM: To investigate the liver protective effects of polysaccharides of Dicliptera chinensis (L.) Nees. on fulminant hepatitis caused by D-galactosamine (D-GalN)/lipopolysaccharide (LPS) in rats. METHODS: Male Wistar rats were divided into 4 groups (12 rats in each group), including normal control group, GalN/LPS-treated group, and two Dicliptera chinensis (L.) Nees. polysaccharides-treated groups (150 mg/kg, 300 mg/kg, ig, respectively). The Dicliptera chinensis (L.) Nees. polysaccharides and controlled normal saline (NS) were administered once 1 d for 6 d. One hour after the latest administration, all animals except for the animals in control group were administered with D-GalN (500 mg/kg, ip), then treated with LPS 1 h later. The mortality was observed at 6 h and 12 h after modeling. The serum samples were collected at 6 h and 12 h in the survival rats by retro-orbital sampling. All samples were measured for ALT, AST, TNF-α and IL-1β. The samples collected at 12 h were also detected for NO. At 12 h, all survival rats were sacrificed and liver section was prepared for histological evaluation. RESULTS: Pretreatment with polysaccharides of Dicliptera chinensis (L.) Nees. significantly improved the histopathological changes and attenuated GalN/LPS-induced severe hepatotoxicity as evidenced by decrease in the levels of ALT and AST. The polysaccharides of Dicliptera chinensis (L.) Nees. inhibited the elevated levels of TNF-α, IL-1β and NO. CONCLUSION: Using Dicliptera chinensis (L.) Nees. polysaccharides as anti-inflammatory reagent provides a definite protective way against fulminant hepatitis caused by GalN/LPS in rat.     

Protective effect of gabexate mesilate on blood-brain barrier in rats with cerebral ischemia-reperfusion

AIM To investigate the protective effects of gabexate mesilate （GM） on blood-brain barrier （BBB） permeability in rat model with cerebral ischemia-reperfusion （I/R）. METHODS Adult male SD rats （n=180） were randomly divided into sham group, I/R group, nimodipine （NMP; 2 mg·kg^-1·d^-1） group and GM （5, 10 and 20 mg·kg^-1·d^-1） groups （n=30 in each group）. The rat model of cerebral I/R was established by blocking the middle cerebral artery with thread plug for 2 h. Ten min before modeling, the drugs were given intraperitoneally. The nerve function was detected by Longa scoring method. The permeability of BBB was measured by Evans blue permeation method, and the brain water content was measured by dry-wet weight method. The activity of superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px）, and the content of malondialdehyde （MDA） in brain tissue were determined by biochemical analysis. The content of tumor necrosis factor-α （TNF-α）, interleukin-1β （IL-1β） and IL-6 was measured by ELISA. The mRNA expression of matrix metalloproteinase-2 （MMP-2）, MMP-9 and nuclear factor-κB （NF-κB） was detected by RT-PCR. The protein levels of MMP-2, MMP-9 and NF-κB were determined by Western blot. RESULTS Compared with I/R group, the Longa score, permeability of Evans blue and brain water content of the rats in GM （10 and 20 mg·kg^-1·d^-1） and NMP （2 mg·kg^-1·d^-1） groups were decreased. The activity of SOD and GSH-Px was increased, while the content of MDA was decreased. The content of TNF-α, IL-1β and IL-6 was decreased, and the mRNA and protein expression levels of MMP-2, MMP-9 and NF-κB were significantly down-regulated. Compared with NMP （2 mg·kg^-1·d^-1） group, the Longa score and permeability of Evans blue were decreased in GM （20 mg·kg^-1·d^-1） group, the activity of SOD was increased, and the content of MDA and TNF-α was decreased. The mRNA and protein expression levels of MMP-2, MMP-9 and NF-κB were down-regulated. All of the differences were significant （P<0.05 or P<0.01）. CONCLUSION GM has protective effect on BBB in the rats with cerebral I/R. Its mechanism may be related to inhibition of oxidative stress and inflammation, and down-regulation of MMP-2, MMP-9 and NF-κB expression.     

Porcine surfactant in treatment of LPS-induced early-stage acute lung injury in rats

AIM: To evaluate the therapeutic efficacy of intratracheal instillation of porcine pulmonary surfactant (PPS) in rats with lipopolysaccharides (LPS)-induced early-stage ALI in this study.METHODS: SD rats weighing 200 g-300 g were randomly divided into 4 groups: LPS (1.5 mg·kg-1)+saline,LPS+PPS 100 mg·kg^-1,LPS+PPS 150 mg·kg^-1,LPS+PPS 200 mg·kg^-1.The PaO₂ and PaCO₂,as well as survival rate of rats were examined for 6 h after the start of PPS-instillation.Then,rats were killed and lungs were immediately removed for lung index (LI) and histological analysis.The bronchoalveolar lavage fluid (BALF) was collected for measurement of total protein (TP) contents,TNF-α level and white blood cell(WBC) numbers.RESULTS: Significantly increased PaO₂,reduced mortality rate,decreased total protein and TNF-α contents in BAL,as well as lung index and meliorated histological appearance were observed in three PPS-treated groups compared with group given saline after LPS (P<0.05).The therapeutic effect in PPS150 and PPS200 groups was better than that in PPS100 group.CONCLUSION: Intratracheal PPS instillation provides protective effect on acute lung injury in rats induced by LPS.