Objective: To investigate the effects of exogenous hydrogen sulfide (H₂S) on pulmonary vascular reactivity induced by endotoxic shock (ES) in rabbits. Methods: In this experiment, the model of endotoxic shock (ES) was induced by injection of lipopolysaccharides (LPS) to New Zealand big eared white rabbit through jugular vein (8 mg/0.8 ml/kg), the intervention was performed by H₂S donor(sodium hydrosulfide, NaHS) which was injected intraperitoneally (28 μmol/kg) 15 min in advance. New Zealand rabbits were randomly divided into 4 groups(n=8):control group, LPS group, LPS+NaHS group and NaHS group. The changes of mean arterial pressure (MAP) and mean pulmonary arterial pressure (MPAP) were detected. The tension of pulmonary artery ring (PARs) was detected byin vitro vascular ring technique. The ultrastructure of pulmonary artery wall and pulmonary artery endothelial cells were observed by light microscope and scanning electron microscope. Results: ①MAP was decreased while MPAP was increased in rabbits after LPS injection, and ES animal model was established successfully. Compared with LPS group, mPAP of rabbit in LPS+NaHS group was decreased significantly (all P＜0.05). ②Compared with normal control group, pulmonary artery of rabbits in LPS group had an increased contractile response to phenylephrine (PE) and a decreased relaxation response to acetylcholine (ACh) (both P＜0.01); Compared with LPS group, pulmonary artery of rabbits in LPS+NaHS group had a decreased contractile response to PE and an increased relaxation response to ACh (both P＜0.05). ③Under light microscope, the structure of vascular endothelial cells was continuous in the normal control group, the elastic fibers were intact in the subcutaneous layer, and the smooth muscle layer was arranged neatly. LPS can shed some of the pulmonary artery endothelial cells, break the subcutaneous elastic fibers, and disorder the smooth muscle layer structure. Compared with LPS group, the injury of pulmonary artery wall in LPS+NaHS group was ameliorated. The morphology of pulmonary artery wall was normal in NaHS group. It is showed that some endothelial cells of pulmonary artery were missing in LPS group by Scanning electron microscopy. The morphology of pulmonary artery endothelial cells in LPS+NaHS group was similar to that in the control group: slightly widened intercellular space was observed, and no cell exfoliation was observed. Conclusion: These results suggest that exogenous H₂S can protect pulmonary artery endothelial cells and regulate the reactivity changes of pulmonary artery during ES, which may be one of the mechanisms reducing PAH in ES rabbits.
Animals ; Endothelial Cells ; Hydrogen Sulfide/pharmacology* ; Hypertension, Pulmonary ; Lipopolysaccharides/adverse effects* ; Pulmonary Artery ; Rabbits ; Shock, Septic

OBJECTIVETo establish a practical and reproducible animal model of human acute-on-chronic liver failure for further study of the pathophysiological mechanism of acute-on-chronic liver failure and for drug screening and evaluation in its treatment.

METHODSImmunological hepatic fibrosis was induced by human serum albumin in Wistar rats. In rats with early-stage cirrhosis (fibrosis stage IV), D-galactosamine and lipopolysaccharide were administered. Mortality and survival time were recorded in 20 rats. Ten rats were sacrificed at 4, 8, and 12 hours. Liver function tests and plasma cytokine levels were measured after D-galactosamine/lipopolysaccharide administration and liver pathology was studied. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay.

RESULTSMost of the rats treated with human albumin developed cirrhosis and fibrosis, and 90% of them died from acute liver failure after administration of D-galactosamine/lipopolysaccharide, with a mean survival time of (16.1+/-3.7) hours. Liver histopathology showed massive or submassive necrosis of the regenerated nodules, while fibrosis septa were intact. Liver function tests were compatible with massive necrosis of hepatocytes. Plasma level of TNFalpha increased significantly, parallel with the degree of the hepatocytes apoptosis. Plasma IL-10 levels increased similarly as seen in patients with acute-on-chronic liver failure.

CONCLUSIONWe established an animal model of acute-on-chronic liver failure by treating rats with human serum albumin and later with D-galactosamine and lipopolysaccharide. TNFalpha-mediated liver cell apoptoses plays a very important role in the pathogenesis of acute liver failure.

Animals ; Disease Models, Animal ; Female ; Galactosamine ; adverse effects ; Humans ; Lipopolysaccharides ; adverse effects ; Liver Failure, Acute ; chemically induced ; Rats ; Rats, Wistar ; Serum Albumin ; adverse effects

OBJECTIVETo observe the effect of mastoparan-1 (MP-1) on lipopolysaccharide (LPS)-induced acute hepatic injury in mice and probe into its possible mechanism.

METHODSOne hundred and four BALB/c mice were randomly divided into healthy control group (n = 8, without treatment, HC), LPS group (n = 48, with injection of LPS 5 mg/kg via tail vein), and MP-1 group (n = 48, with injection of LPS 5 mg/kg and MP-1 3 mg/kg via tail vein). Mice in LPS group and MP-1 group were sacrificed at 2nd, 6th, 12th, 24th, 48th and 72nd post injection hour (PIH), 8 mice at each time point in each group. Blood samples were collected for determination of plasma levels of LPS by kinetic turbidimetric limulus test, TNF-alpha and IL-6 by ELISA, serum levels of ALT and AST by automatic biochemistry analyzer respectively. Hepatic tissue samples were collected for determination of TLR4, TNF-alpha and IL-6 mRNA by real-time fluorescent quantitation reverse transcription polymerase chain reaction, along with the observation of pathological changes in hepatic tissue at each time point. Above-mentioned examinations were also performed in HC group.

RESULTSCompared with those of HC group, plasma levels of LPS and TNF-alpha in LPS group significantly increased at 2nd PIH (18,320.50 +/- 2782.50 EU/mL and 988 +/- 130 ng/L, respectively), then decreased gradually to 1.80 +/- 0.80 EU/mL and 150 +/- 44 ng/L at 72nd PIH, which was close to those of HC group. The values of IL-6, ALT and AST peaked at 12th PIH, which declined to the levels close to those of HC group at 72nd PIH. Meanwhile, the expressions of TLR4, TNF-alpha and IL-6 mRNA in liver were remarkably up-regulated after injection, and the pathological changes in hepatic tissue pronounced significantly at 12th, 24th and 48th PIH. Compared with those of LPS group, the levels of LPS, cytokines, ALT and AST decreased in MP-1 group in different degrees after injection (P < 0.05 or P < 0.01), genes expression (P < 0.05 or P < 0.01) and pathological changes was respectively suppressed and alleviated in hepatic tissue.

CONCLUSIONSMP-1 can alleviate LPS-induced acute hepatic injury in mice, which may be associated with its neutralization of LPS and attenuation of synthesis and release of inflammatory mediators.

Animals ; Chemical and Drug Induced Liver Injury ; pathology ; Endotoxins ; adverse effects ; Inflammation ; Lipopolysaccharides ; adverse effects ; Liver ; drug effects ; pathology ; Mice ; Mice, Inbred BALB C ; Peptides ; pharmacology ; Wasp Venoms ; pharmacology

OBJECTIVETo compare the effects of different approaches to establishing rat models of acute liver failure (ALF).

METHODSSixty-eight Sprague-Dawley rats were randomly divided into 3 groups for establishing ALF models using 3 different approaches, namely conventional hepatectomy for resecting 90% liver tissue as described by Higgins and Anderson, modified bloodless hepatectomy for resecting 90% liver tissue, and intraperitoneal injections of 700 mg/kg D-galactosamine (D-gal) and 5 µg/kg lipopolysaccharide (LPS). The mortality of the rats due to postoperative bleeding and survival rate at 7 days after the surgery were recorded. The levels of alanine aminotransferase (ALT), total bilimbin (Tbil), albumin (ALB), NH3, glucose (Glu) and prothrombin time (PT) were monitored, and histopathologies of the liver were examined at 24 and 72 h after the surgery.

RESULTSThe mortality rate due to postoperative bleeding was higher in conventional hepatectomy group than in the modified surgical group (15% vs 0). The survival rate at 7 days was 25%, 0%, 15% in conventional surgical group, modified surgical group and drug injection group, respectively. In the latter two groups, significant changes of ALT, Tbil, ALB, NH3, Glu, and PT were recorded at 24 and 72 h after the modeling (P<0.05), and these changes were the most obvious at 24 h in modified surgical group and at 72 h in the drug injection group; ALB in both groups declined to the lowest at 7 days and then increased gradually. Liver cell degeneration and necrosis were found in modified surgical group and drug injection group at 24 h and 72 h after the modeling.

CONCLUSIONBoth the modified 90% bloodless hepatectomy and injections of D-gal and LPS can be used to establish ideal rat models of ALF to suit different ALF-related researches.

Animals ; Disease Models, Animal ; Galactosamine ; adverse effects ; Hepatectomy ; Injections, Intraperitoneal ; Lipopolysaccharides ; adverse effects ; Liver Failure, Acute ; chemically induced ; pathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo establish a chronic obstructive pulmonary disease (COPD) model by passive cigarette smoking and (or) intratracheal instillation of lipopolysaccharide (LPS) in spontaneously hypertensive (SH) rats.

METHODSFifteen male SH rats were randomly divided into control group, cigarette smoking exposure (CS) group and CS+LPS (cigarette smoking exposure plus intratracheal instillation of LPS) group. After 8 weeks' treatment, the COPD model was validated by inspecting the general condition and examining lung function and pulmonary pathological changes. The expressions of surfactant-associated protein A (SP-A), NF-κB, histone, p-Iκ-Kα/β, Iκ-Kα/β, and IκB-α were determined with Western blotting, and the expression of TNF-α and IL-6 mRNA were measured using qRT-PCR.

RESULTSThe rats in both CS and CS+LPS groups were marantic with intermittent cough and tachypnea. Lung function test showed increased RI and lowered peak expiratory flow in CS group, which were more prominent in CS+LPS group (P<0.05). HE staining demonstrated typical chronic bronchitic inflammation and emphysema in the lungs of the two model groups with significantly decreased mean alveolar number and significantly increased mean lining intermittent and destruction index. The emphysema level was more serious in CS+LPS group than in CS group. Western blotting showed markedly decreased expressions of SP-A and IκB-α in CS group and CS+LPS , especially the latter group. The protein levels of NF-κB, Iκ-K phosphorylation and mRNA expressions of TNF-α and IL-6 increased obviously in the two model groups.

CONCLUSIONCOPD model can be established by passive smoking and (or) intratracheal instillation of LPS in SH rats, and the model induced by combined exposures is optimal.

Animals ; Disease Models, Animal ; Lipopolysaccharides ; adverse effects ; Male ; Pulmonary Disease, Chronic Obstructive ; etiology ; Rats ; Rats, Inbred SHR ; Tobacco Smoke Pollution ; adverse effects

OBJECTIVETo study the role of endoplasmic reticulum stress (ERS) in acute liver failure (ALF) using a mouse model of D-Galactosamine/lipopolysaccharide (D-GalN/LPS)-induced ALF.

METHODSThe ALF model was established by administering intraperitoneal (i.p.) injections of D-Ga1N (700 mg/kg) and LPS (10 mug/kg) to six C57BL/6 mice. Three of the modeled mice were also administered 4-phenylbutyrate (4-PBA; 100 mg/kg i.p.) at 6 hours before the onset of ALF and served as the intervention group. Non-modeled mice served as controls. All mice were analyzed by western blotting and qRT-PCR to determine the expression levels of ERS-related proteins in liver tissue. Liver function was assessed by measuring levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum. Extent of injury to the liver tissue was assessed by hematoxylin-eosin staining and histological analysis. qRT-PCR was also used to detect differences in expression of inflammation-related genes, and western blotting was also used to detect differences in expression of the apoptosis related protein Caspase-3.The extent of apoptosis in liver tissue was assessed by TUNEL assay.

RESULTSThe ERS markers GRP78 and GRP94 showed increased expression at both the gene and protein levels which followed progression of ALF. The ERS effector proteins XBP-1, ATF-6 and IRE 1 a involved in the unfolded protein response were activated in the early stages of ALF, and the ERS-induced apoptosis regulators Caspase-12 and CHOP were activated in the late stage of ALF. Inhibition of ERS by 4-PBA intervention protected against injury to liver tissue and function, as evidenced by significantly lower levels of serum ALT and AST and a remarkably decreased extent of histological alterations. Furthermore, the inhibition of ERS suppressed expression of the proinflammatory cytokines TNFa, IL-6 and IL-1 β, and reduced the extent of hepatocyte apoptosis.

CONCLUSIONERS is activated in the mouse model of D-GalN/LPS-induced ALF. Inhibition of ERS may be protective against liver injury and the mechanism of action may involve reductions in inflammatory and apoptotic factors and/or signaling. Therefore, inhibiting ERS may represent a novel therapeutic approach for treating ALF.

Animals ; Apoptosis ; Disease Models, Animal ; Endoplasmic Reticulum Stress ; Galactosamine ; adverse effects ; Lipopolysaccharides ; adverse effects ; Liver Failure, Acute ; chemically induced ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL

OBJECTIVETo apply an orthogonal design optimization strategy to a mouse model of acute liver failure induced by D-galactosamine (D-GalN) and lipopolysaccharide (LPS) exposure.

METHODSA four-level orthogonal array design (L16(45)) was constructed to test factors with potential impact on successful establishment of the model (D-GalN and LPS dosages, and dilution rate of the D-GalN/LPS mixture). The mortality rate of mice within 24 hours of D-GalN/LPS administration was determined by the Kaplan-Meier method. The model outcome was verified by changes in serum alanine transferase level, liver histology, and hepatocyte apoptosis.

RESULTSThe orthogonal array identified the optimal model technique as intraperitoneal injection of a combination of D-GalN and LPS at dosages of 350 mg/kg and 30 mug/kg, respectively, and using a dilution rate of 3. The dosages tested had no effect on survival. The typical signs of liver failure appeared at 6 hrs after administration of the D-GalN/LPS combination.

CONCLUSIONThe orthogonal design optimization strategy provided a procedure for establishing a mouse model of acute liver failure induced by D-GalN and LPS that showed appropriate disease outcome and survival, and which will serve to improve future experimental research of acute liver failure.

Animals ; Apoptosis ; Disease Models, Animal ; Galactosamine ; adverse effects ; Lipopolysaccharides ; adverse effects ; Liver Failure, Acute ; chemically induced ; Male ; Mice ; Mice, Inbred C57BL

Objective: To explore the new mechanism of liver fibrosis through D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced necroptosis as an entry point to inhibit lethal injury. Methods: The carbon tetrachloride (CCl4)-induced mouse model of liver fibrosis was established. At 6 weeks of fibrosis, the mice were challenged with a lethal dose of D-GalN/LPS, and the normal mice treated with the same treatment were used as the control. The experiment was divided into four groups: control group (Control), acute injury group (D-GalN/LPS), liver fibrosis group (Fib), and liver fibrosis + acute challenge group (Fib + D-GalN/LPS). Quantitative PCR and immunofluorescence were used to analyze the expression of necroptosis key signal molecules RIPK1, RIPK3, MLKL and/or P-MLKL in each group. Normal mice were treated with inhibitors targeting key signaling molecules of necroptosis, and then given an acute challenge. The inhibitory effect of D-GalN/LPS-induced-necroptosis on acute liver injury was evaluated according to the changes in transaminase levels and liver histology. Liver fibrosis spontaneous ablation model was established, and then acute challenge was given. Necroptosis key signal molecules expression was analyzed in liver tissue of mice in each group and compared by immunohistochemistry. The differences between groups were compared with t-test or analysis of variance. Results: Quantitative PCR and immunofluorescence assays result showed that D-GalN/LPS-induced significant upregulation of RIPK1, RIPK3, MLKL and/or P-MLKL. Necroptosis key signal molecules inhibition had significantly reduced D-GalN/LPS-induced liver injury, as manifested by markedly reduced serum ALT and AST levels with improvement in liver histology. Necroptosis signaling molecules expression was significantly inhibited in fibrotic livers even under acute challenge conditions. Additionally, liver fibrosis with gradual attenuation of fibrotic ablation had inhibited D-GalN/LPS-induced necroptosis. Conclusion: Liver fibrosis may protect mice from acute lethal challenge injury by inhibiting D-GalN/LPS-induced necroptosis.
Animals ; Chemical and Drug Induced Liver Injury/pathology* ; Galactosamine/adverse effects* ; Lipopolysaccharides/adverse effects* ; Liver/pathology* ; Liver Cirrhosis/pathology* ; Liver Failure, Acute/chemically induced* ; Mice ; Necroptosis

This study investigated the mechanism of baicalin on lipopolysaccharide(LPS)/interferon γ(IFN-γ)-induced inflammatory microglia based on the triggering receptor expressed on myeloid cells 2(TREM2)/Toll-like receptor 4(TLR4)/nuclear factor kappaB(NF-κB) pathway. Specifically, LPS and IFN-γ were used to induce inflammation in mouse microglia BV2 cells. Then the normal group, model group, low-dose(5 μmol·L~(-1)) baicalin group, medium-dose(10 μmol·L~(-1)) baicalin group, high-dose(20 μmol·L~(-1)) baicalin group, and minocycline(10 μmol·L~(-1)) group were designed. Cell viability was detected by CCK-8 assay and cell morphology was observed under bright field. The expression of interleukin-1β(IL-1β), interleukin-4(IL-4), inducible nitric oxide synthase(iNOS), interleukin-6(IL-6), interleukin-10(IL-10), and arginase-1(Arg-1) mRNA was detected by real-time quantitative PCR, the protein expression of tumor necrosis factor-α(TNF-α), IL-1β, TREM2, TLR4, inhibitor kappaB-alpha(IκBα), p-IκBα, NF-κB p65 and p-NF-κB p65 by Western blot, and transfer of NF-κB p65 from cytoplasm to nucleus by cellular immunofluorescence. Compared with the normal group, most of the BV2 cells in the model group tended to demonstrate the pro-inflammatory M1 amoeba morphology, and the model group showed significant increase in the mRNA levels of IL-1β, IL-6, and iNOS, decrease in the mRNA levels of IL-4, IL-10, and Arg-1(P<0.01), rise of the protein expression of TNF-α, IL-1β, TLR4, p-IκBα, and p-NF-κB p65(P<0.01), reduction in TREM2 protein expression, and increase in the expression of NF-κB p65 in nucleus. Compared with the model group, baicalin groups and minocycline group showed the recovery of BV2 cell morphology, significant decrease in the mRNA levels of IL-1β, IL-6 and iNOS, increase in the mRNA levels of IL-4, IL-10, and Arg-1(P<0.01), reduction in the protein expression of TNF-α, IL-1β, TLR4, p-IκBα, and p-NF-κB p65(P<0.05), rise of TREM2 protein expression, and decrease in the expression of NF-κB p65 in nucleus. In summary, these results suggest that baicalin can regulate the imbalance between TREM2 and TLR4 of microglia and inhibit the activation of downstream NF-κB, thus promoting the polarization of microglia from pro-inflammatory phenotype to anti-inflammatory phenotype.
Animals ; Flavonoids ; Inflammation/genetics* ; Interferon-gamma ; Lipopolysaccharides/adverse effects* ; Mice ; NF-kappa B/metabolism* ; Toll-Like Receptor 4/metabolism*

OBJECTIVE: To investigate the effect of open wedge tibial high osteotomy on patella position, anterior knee pain and joint function. METHODS: From June 2016 to June 2021, 109 patients (111 knees) with medial knee osteoarthropathy treated by open wedge tibial high osteotomy were included according to the inclusion and exclusion criteria, including 41 males and 68 females;the age ranged from 38 to 78 years old with an average of(57.98±7.07) years;the course of disease ranged from 1 to 36 months with an average of (8.58±6.91) months. The femoral tibial angle(FTA), medial proximal tibial angle(MPTA), weight bearing line(WBL) percentage, Caton Deschamps index (CD index), lateral patella tilt angle (LPTA) and lateral patella shift (LPS) were observed and compared before and after operation. Lysholm score was used to evaluate the knee function, visual analogue scale(VAS) was used to evaluate the degree of anterior knee pain, and Kellgren Lawrence(K-L) grading system was used to evaluate the progress of patellofemoral osteoarthritis. RESULTS: All patients were followed up for 6 to 38 months with an average of (12.41±2.40) months. The preoperative FTA, MPTA, WBL percentage, CD index, and LPTA were significantly different from those at the last follow-up(P<0.05). There was no significant difference between before and after LPS operation(P=0.78). Lysholm score increased from (58.79±7.90) scores to (76.05±7.36) scores (P<0.05). The VAS of anterior knee pain decreased from (3.28±1.95) scores to(1.07±1.75) scores(P<0.05). Knee patellofemoral osteoarthritis showed progressive changes, but there was no significant difference in K-L grading before and after operation (P>0.05). CONCLUSION After open wedge tibial high osteotomy, the position of patella is lowered and the patella is tilted outward, but the knee function and anterior knee pain are significantly improved. Adverse changes in patella position caused by open wedge tibial high osteotomy may not affect clinical outcomes.
Male ; Female ; Humans ; Child, Preschool ; Child ; Patella/surgery* ; Lipopolysaccharides ; Retrospective Studies ; Osteotomy/adverse effects* ; Osteoarthritis, Knee/surgery* ; Pain/etiology*