Lipopolysaccharide Model Group Research Articles

Intervention effects of low-molecular-weight chondroitin sulfate from the nasal cartilage of yellow cattle on lipopolysaccharide-induced behavioral disorders: regulation of the microbiome-gut-brain axis

Chondroitin sulfate (CS) is a sulfated linear polysaccharide with different functional activities, including antioxidant, anti-inflammatory, lipid-lowering, and immune regulation. As natural sulfated polysaccharides have high molecular weight, high apparent viscosity, low water solubility, complex structure, and high negative charge, they have difficulty binding to receptors within cells across tissue barriers, resulting in low bioavailability and unclear structure–activity relationships. In this study, an H2O2-Vc oxidative degradation system was employed to perform environmentally friendly and controllable degradation of CS extracted from the nasal cartilage of Shaanxi Yellow cattle. Two low-molecular-weight chondroitin sulfates (LMWCSs), CS-1 (14.8 kDa) and CS-2 (50.9 kDa), that exhibit strong in vitro free radical scavenging ability were obtained, and their structures were characterized. Mice intraperitoneally administered lipopolysaccharide (LPS) were used to explore the cognitive intervention effects of LMWCS. Supplementing CS-1 and CS-2 significantly downregulated the levels of the serum inflammatory factors, TNF-α and IL-1β, promoted the expression of GSH in the brain, and inhibited the production of the lipid peroxidation product, malondialdehyde (MDA), ultimately inhibiting LPS-induced cognitive impairment in mice. Surprisingly, compared to the LPS model group, the abundances of Streptococcus, Eisenbergiella, Vampirovibrio, Coprococcus, Enterococcus and Lachnoanaerobaculum were significantly increased in the intestines of mice in the CS-1 and CS-2 group, whereas those of Parabacteroides and Mycoplasma were significantly decreased. Altogether, this study provides a theoretical basis for the comprehensive utilization of agricultural and animal resources and the application of brain nutrition, anti-inflammatory, and LMWCS health products.

TRIM27-Induced Protective Autophagy: A Novel Therapeutic Approach for Pneumonia.

Pneumonia is a prevalent respiratory ailment involving complex physiological and pathological mechanisms. The tripartite motif containing 27 (TRIM27) plays a crucial role in regulating inflammation mechanisms. Therefore, the purpose of this study is to further explore the therapeutic potential of TRIM27 in pneumonia, based on its regulatory mechanisms in inflammation and autophagy. This study established a mouse pneumonia animal model through lipopolysaccharide (LPS) administration, designating it as the LPS model group. Subsequently, adenovirus-mediated TRIM27 overexpression was implemented in the animals of the LPS model group, creating the TRIM27 treatment group. After a 7-day treatment period, lung tissues from the mice were collected. Various techniques, including immunohistochemistry, quantitative reverse transcription PCR (RT-qPCR), western blot, enzyme-linked immunosorbent assay (ELISA), and electron microscopy were utilized to analyze the impact of TRIM27 overexpression on inflammatory factors, oxidative stress, autophagy, and inflammatory processes in pulmonary tissues. Finally, an in vitro LPS cell model was established, and the effects of TRIM27 overexpression and autophagy inhibition on inflammatory cytokines and autophagosomes in LPS-induced inflammatory cells were examined through RT-qPCR and immunofluorescence techniques. The research findings demonstrate a significant reduction in the elevated levels of interleukin-6 (IL-6), IL-1β, and Tumor necrosis factor-alpha (TNF-α) induced by LPS with TRIM27 overexpression (p < 0.01). Conversely, the autophagy inhibitor 3-Methyladenine (3-MA) diminished the effects induced by TRIM27 overexpression. Moreover, TRIM27 overexpression enhanced the expression of Microtubule-associated protein 1A/1B light chain 3 (LC3) II/I and Beclin-1 proteins in mice subjected to LPS stimulation (p < 0.01), while reducing the expression of the p62 protein (p < 0.01). The addition of 3-MA, however, decreased Beclin-1 expression and inhibited autophagy (p < 0.01). Additionally, TRIM27 overexpression decreased the expression of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), cleaved caspase-1, IL-1β, and Gasdermin D N-terminal fragment (GSDMD-N) proteins in LPS-stimulated mice (p < 0.05). TRIM27 overexpression also decreased the levels of malondialdehyde (MDA), Activating Transcription Factor 6 (ATF6), and C/EBP-homologous protein (CHOP), while increasing the levels of superoxide dismutase (SOD) and glutathione (GSH) in mice exposed to LPS (p < 0.01). The induction of TRIM27 overexpression emerges as a potential and effective pneumonia treatment. The underlying mechanism may involve inducing protective autophagy, thereby reducing oxidative stress and cell pyroptosis.

The Protective Effect of Broccoli Seed Extract against Lipopolysaccharide-Induced Acute Liver Injury via Gut Microbiota Modulation and Sulforaphane Production in Mice.

Broccoli seed extract (BSE) is rich in glucoraphanin (GRP), which may be transformed by intestinal microbes into sulforaphane (SFN), a compound with strong anti-inflammatory and antioxidant activities. Liver injury usually presents with inflammation and oxidative damage. Thus, dietary BSE supplementation may be an effective approach for alleviating liver injury. In this study, a mouse lipopolysaccharide (LPS)-induced acute liver injury model was used to evaluate the preventive effect of BSE and explore the relevant mechanisms. Compared with the LPS model group, the mice in the BSE group showed significantly lower activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) and higher levels of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity. Meanwhile, BSE significantly reduced the levels of pro-inflammatory cytokines (including IL-6 and TNF-α) in the liver and increased the level of anti-inflammatory factor (IL-10), indicating that BSE had a good preventive effect on acute liver injury. Additionally, after BSE intervention, the diversity of intestinal microbiota in the mice was higher than that in the LPS model group. The relative abundance of Akkermansia and Lactobacillus increased, while the relative abundance of Xylanophilum decreased. A correlation analysis revealed that the activities of SOD, GSH-Px, CAT and levels of IL-10 were positively correlated with the relative abundance of Lactobacillus. Furthermore, sulforaphane (SFN) and (Sulforaphane-N-Acetyl-Cysteine) SFN-NAC were detected in the urine of the mice after BSE intervention. Both q-PCR and an immunohistochemical analysis showed that BSE significantly regulated the expression level of the NF-κB (IκB-α, NF-κB) and Nrf2 (Nrf2, p-Nrf2 and HO-1) signaling pathways in the liver. In conclusion, BSE was shown to reduce LPS-induced acute liver injury through the conversion of glucoraphanin into sulforaphane and the regulation of the gut microbiota composition. These results suggest that BSE could be a promising ingredient in functional foods.

Effect of Isodon ternifolius-medicated serum on hepatic stellate cells based on TLR4/NF-κB/NLRP3 signaling pathway

The present study aimed to investigate the inhibitory effect and mechanism of Isodon terricolous-medicated serum on lipopolysaccharide(LPS)-induced hepatic stellate cell(HSC) activation. LPS-induced HSCs were divided into a blank control group, an LPS model group, a colchicine-medicated serum group, an LPS + blank serum group, an I. terricolous-medicated serum group, a Toll-like receptor 4(TLR4) blocker group, and a TLR4 blocker + I. terricolous-medicated serum group. HSC proliferation was detected by methyl thiazolyl tetrazolium(MTT) assay. Enzyme-linked immunosorbent assay(ELISA) was used to measure type Ⅰ collagen(COL Ⅰ), COL Ⅲ, transforming growth factor-β1(TGF-β1), intercellular adhesion molecule-1(ICAM-1), α-smooth muscle actin(α-SMA), vascular cell adhesion molecule-1(VCAM-1), cysteinyl aspartate-specific proteinase-1(caspase-1), and monocyte chemotactic protein-1(MCP-1). Real-time PCR(RT-PCR) was used to detect mRNA expression of TLR4, IκBα, and NOD-like receptor thermal protein domain associated protein 3(NLRP3), nuclear factor-κB(NF-κB) p65, gasdermin D(GSDMD), and apoptosis-associated speck-like protein containing a CARD(ASC) in HSCs. Western blot(WB) was used to detect the protein levels of TLR4, p-IκBα, NF-κB p65, NLRP3, ASC, and GSDMD in HSCs. The results showed that I. terricolous-medicated serum could inhibit the proliferation activity of HSCs and inhibit the secretion of COL Ⅰ, COL Ⅲ, α-SMA, TGF-β1, caspase-1, MCP-1, VCAM-1, and ICAM-1 in HSCs. Compared with the LPS model group, the I. terricolous-medicated serum group, the colchicine-medicated serum group, and the TLR4 blocker group showed down-regulated expression of p-IκBα, NLRP3, NF-κB p65, GSDMD, and ASC, and up-regulated expression of IκBα. Compared with the TLR4 blocker group, the TLR4 blocker + I. terricolous-medicated serum group showed decreased expression of TLR4, p-IκBα, NLRP3, NF-κB p65, GSDMD, and ASC, and increased expression of IκBα. In conclusion, I. terricolous-medicated serum down-regulates HSC activation by inhibiting the TLR4/NF-κB/NLRP3 signaling pathway.

Betaine Inhibits NLRP3 Inflammasome Hyperactivation and Regulates Microglial M1/M2 Phenotypic Differentiation, Thereby Attenuating Lipopolysaccharide-Induced Depression-Like Behavior.

Depression is one of the most important mental illnesses and is closely related to inflammation. Betaine is a natural product with an anti-inflammatory and antioxidant activities. However, the mechanism by which betaine ameliorates depression-like behaviors induced by lipopolysaccharide (LPS) is poorly understood. The purpose of this study was to investigate the neuroprotective effect of betaine on LPS-induced depression-like behavior in mice and its mechanism of action. ICR mice were randomly divided into four groups: the control group, the LPS model group (0.83 mg/kg), the positive drug group (MIDO, 50 mg/kg), and the betaine group (5% and 1% in drinking water). The betaine group was administered for 21 days, and on the 22nd day, except for the blank group, LPS (0.83 mg/kg) was intraperitoneally injected to establish a lipopolysaccharide-induced mice depression-like model. Twenty-four hours after LPS injection, the tail suspension test (TST), open field test (OFT), and sucrose preference test (SPT) were performed to evaluate the effect of betaine on LPS-induced depressive behavior in mice. After the behavioral study, the mouse brain, hippocampus, and serum were taken for detection. The expressions of cytokines and inflammatory mediators were detected by ELISA, HE staining, immunofluorescence, immunohistochemistry, and western blotting. Western blotting was used to detect the protein expression levels of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), caspase-1, and ASC, the protein expression levels of the microglial polarization markers COX-2, inducible nitric oxide synthase (iNOS), and CD206. The results showed that betaine significantly ameliorated the depression-like behavior in LPS-induced mice, significantly attenuated the production of proinflammatory cytokines and increased the release of an anti-inflammatory cytokines. Betaine decreased the expression of the NLRP3 inflammasome, decreased the expression of M1 polarization markers, tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), COX-2, and iNOS and promoted the expression of M2 polarization marker CD206. Our study suggests that betaine may promote the transition of microglia from the M1 to the M2 phenotype by inhibiting NLRP3 inflammasome activation, thereby attenuating lipopolysaccharide-induced depression-like behavior.

Abietane-Type Diterpenoids From Nepeta bracteata Benth. and Their Anti-Inflammatory Activity.

Terpenes possess a wide range of structural features and pharmaceutical activities and are promising for drug candidates. With the aim to find bioactive terpene molecules, eight new compounds were isolated from the medicinal plant Nepeta bracteata Benth., including seven new abietane-type diterpenoids (1–7), along with a new ursane-type triterpenoid (8). The structures of compounds 1–8 were elucidated through the detailed spectroscopic analyses of their 1D and 2D NMR and MS data, and the absolute configurations of compounds 1–7 were determined by comparing their experimental and calculated ECD spectra. Compound 1 was a novel degraded carbon diterpene with the disappearing of methyl signal at C-19, while compound 7 possessed a new norabietane-type diterpenoid carbon skeleton with the presence of five-membered lactone arising from ring rearrangement. The anti-inflammatory of all obtained isolates were evaluated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the results of anti-inflammatory activity screening showed that compared with the LPS model group, all compounds were significantly down-regulation the TNF-α inflammatory factor at the specific concentration, except for compound 6.

Heme oxygenase-1 reduces inflammatory response by inhibiting thioredoxin interacting protein/NOD-like receptor protein 3 inflammasome activation in RAW264.7 cells

To investigate the inhibitory effect and mechanism of heme oxygenase-1 (HO-1) on the inflammatory response of macrophages. Mouse macrophage strain RAW264.7 was cultured in vitro, and the cells in the logarithmic growth phase were used for the experiment. The RAW264.7 cells were divided into four groups. In blank control group, the cells were continuously incubated and received no treatment (cultured at 37 centigrade, 95% air, 5% CO2). In lipopolysaccharide (LPS) model group, 1 mg/L LPS was added to the medium to prepare LPS challenge model. In HO-1 inducer group, the cells were incubated with 30 μmol/L HO-1 inducer hemin for 1 hour, and then 1 mg/L LPS was added for incubation. In HO-1 inhibition group, the cells were incubated with 5 μmol/L HO-1 specific antagonist Zinc protoporphyrin IX (ZnPPIX) for 0.5 hour, and then 1 mg/L LPS was added for incubation. After 48 hours of incubation with LPS, the supernatant of each group was taken, and the protein expressions of HO-1, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), thioredoxin interacting protein (TXNIP), NOD-like receptor protein 3 (NLRP3) and mitochondrial autophagy marker microtubule-associated protein 1 light chain 3B (LC-3B) were detected by Western blotting. The expression of reactive oxygen species (ROS) was detected by immunofluorescence staining. Compared with the blank control group, the cells in the LPS model group had a certain stress response, and autophagy occurred in mitochondria, but the expression of some inflammatory factors was restricted, which was related to the impairment of cell function. The protein expressions of HO-1, IL-1β, LC-3B, ROS were significantly increased, the protein expressions of TNF-α, TXNIP, and NLRP3 were decreased significantly, indicating that the cells were seriously injured after LPS challenge, and the model was successfully established. Compared with the LPS model group, HO-1 protein expression in the HO-1 inducer group was significantly increased (HO-1/GAPDH: 0.31±0.03 vs. 0.22±0.03, P < 0.05), the protein expressions of TNF-α, IL-1β, TXNIP, NLRP3, LC-3B and ROS were significantly inhibited [TNF-α protein (TNF-α/GAPDH): 0.08±0.01 vs. 0.45±0.05, IL-1β protein (IL-1β/GAPDH): 0.50±0.01 vs. 0.82±0.03, TXNIP protein (TXNIP/GAPDH): 0.21±0.02 vs. 0.28±0.02, NLRP3 protein (NLRP3/GAPDH): 0.11±0.01 vs. 0.17±0.02, LC-3B protein (LC-3B/GAPDH): 0.67±0.04 vs. 0.92±0.12, ROS (fluorescence intensity): 80.9±12.5 vs. 94.1±19.5, all P < 0.05], indicating that HO-1 could inhibit inflammatory response and oxidative stress, and reduce mitochondrial autophagy. Antagonizing HO-1 could increase inflammatory response, oxidative stress and mitochondrial autophagy, the inhibitory degree of TNF-α and IL-1β expression was significantly reduced as compared with the HO-1 inducer group [TNF-α protein (TNF-α/GAPDH): 0.26±0.02 vs. 0.08±0.01, IL-1β protein (IL-1β/GAPDH): 0.76±0.01 vs. 0.50±0.01, both P < 0.05], the protein expressions of TXNIP, NLRP3, LC-3B and ROS were significantly increased as compared with the LPS model group [TXNIP protein (TXNIP/GAPDH): 0.43±0.02 vs. 0.28±0.02, NLRP3 protein (NLRP3/GAPDH): 0.24±0.02 vs. 0.17±0.02, LC-3B protein (LC-3B/GAPDH): 1.12±0.07 vs. 0.92±0.12, ROS (fluorescence intensity): 112.0±17.0 vs. 94.1±19.5, all P < 0.05]. HO-1 can reduce the inflammatory response by inhibiting the activation of TXNIP/NLRP3 inflammasome and reducing the release of inflammatory mediators.

Secretory leukocyte peptidase inhibitor inhibits the inflammatory response and apoptosis of lipopolysaccharide-induced human proximal renal tubular cells

To screen out the potential key genes of sepsis-associated acute kidney injury (AKI), and provide theoretical and experimental evidence for the treatment of sepsis-associated AKI. (1) Bioinformatics analysis: two gene expression datasets (GSE30718 and GSE53773) were downloaded for bioinformatics analysis from the Gene Expression Omnibus (GEO). These two datasets recorded mRNA microarray data from kidney biopsies before and after kidney transplantation, and a subset of patients developed AKI after kidney transplantation. Differential analysis was conducted, and the genes with the same differential expression and a higher area under the receiver operator characteristic curve (AUC) in both databases were used as the target gene for subsequent cell experiments. (2) Cell validation experiment: human proximal renal tubular cells HK2 were cultured in vitro, and lipopolysaccharide (LPS) was used for establishing LPS-HK2 cell model (LPS 10 mg/L for 6 hours, LPS model group), and the blank control group was set. Then, small interfering RNA (siRNA) technology was used to knock down the target gene obtained by bioinformatics analysis in LPS-HK2 cells (gene knockdown group), and a gene negative control group was set. The real-time fluorescent quantitative reverse transcription-polymerase chain reaction (RT-qPCR) technique was used to detect the expression of the target gene in HK2 cells. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors in the cell supernatants. Western blotting was used to detect the expressions of key apoptosis proteins. (1) Results of bioinformatics analysis: 325 genes in the two datasets showed the same expression trend, of which 144 were significantly down-regulated and 181 were significantly up-regulated, while the expression difference of secretory leukocyte protease inhibitor (SLPI) in the two datasets was both statistically significant. Further receiver operator characteristic curve (ROC curve) analysis confirmed that the SLPI expression in GSE30718 and GSE53773 datasets had a high diagnostic efficiency for AKI, with AUC of 0.83 and 0.92, respectively. Therefore, SLPI was selected as the target gene for subsequent cell validation experiment. (2) Cell validation experiment: the RT-qPCR analysis showed that the expression of SLPI in LPS-HK2 cells of the LPS model group was significantly higher than that of the blank control group (2-ΔΔCT: 1.80±0.14 vs. 1.00±0.11, P < 0.01), and the change trend was the same with the results of bioinformatics analysis. Furthermore, knockdown SLPI gene analysis showed that the levels of inflammatory factors in LPS-HK2 cells supernatants in the gene knockdown group were significantly higher than those in the negative control group [Interleukin-6 (IL-6, ng/L): 509.58±27.08 vs. 253.87±75.83, IL-1β (ng/L): 490.99±49.52 vs. 239.67±26.97, tumor necrosis factor-α (TNF-α, ng/L): 755.22±48.66 vs. 502.06±10.92, all P < 0.01]. The above results indicated that SLPI could inhibit the inflammatory response of HK2 cells induced by LPS. The expressions of key apoptosis proteins Bax and caspase-3 in LPS-HK2 cells in the gene knockdown group were significantly higher than those in the negative control group [Bax protein (Bax/GAPDH): 1.38±0.12 vs. 1.00±0.10, caspase-3 protein (caspase-3/GAPDH): 1.44±0.15 vs. 1.00±0.11, both P < 0.05], and Bcl-2 expression was significantly decreased (Bcl-2/GAPDH: 0.83±0.08 vs. 1.00±0.05, P < 0.05), the above results indicated that SLPI could inhibit the apoptosis of cells in the inflammatory response. SLPI can inhibit the inflammatory response and apoptosis of HK2 cells induced by LPS, which may be involved in the protective mechanism of renal tubular cells in the response to sepsis, and is a potential target for the treatment of sepsis-associated AKI.

Lipopolysaccharide induces acute lung injury and alveolar haemorrhage in association with the cytokine storm, coagulopathy and AT1R/JAK/STAT augmentation in a rat modelthat mimics moderate and severe Covid-19 pathology.

Progress in the study of Covid-19 disease in rodents has been hampered by the lack of angiotensin-converting enzyme 2 (ACE2; virus entry route to the target cell) affinities for the virus spike proteins across species. Therefore, we sought to determine whether a modified protocol of lipopolysaccharide (LPS)-induced acute respiratory distress syndrome in rats can mimic both cell signalling pathways as well as severe disease phenotypes of Covid-19 disease. Rats were injected via intratracheal (IT) instillation with either 15mg/kg of LPS (model group) or saline (control group) before being killed after 3days. A severe acute respiratory syndrome (SARS)-like effect was observed in the model group as demonstrated by the development of a "cytokine storm" (>2.7 fold increase in blood levels of IL-6, IL-17A, GM-CSF, and TNF-α), high blood ferritin, demonstrable coagulopathy, including elevated D-dimer (approximately 10-fold increase), PAI-1, PT, and APTT (p<0.0001). In addition, LPS increased the expression of lung angiotensin II type I receptor (AT1R)-JAK-STAT axis (>4 fold increase). Chest imaging revealed bilateral small patchy opacities of the lungs. Severe lung injury was noted by the presence of both, alveolar collapse and haemorrhage, desquamation of epithelial cells in the airway lumen, infiltration of inflammatory cells (CD45+ leukocytes), widespread thickening of the interalveolar septa, and ultrastructural alterations similar to Covid-19. Thus, these findings demonstrate that IT injection of 15mg/kg LPS into rats, induced an AT1R/JAK/STAT-mediated cytokine storm with resultant pneumonia and coagulopathy that was commensurate with moderate and severe Covid-19 disease noted in humans.

Mechanisms of sodium butyrate inhibition of microglia inflammatory activation in hippocampus via Toll-like receptor 4/nuclear factor-κB p65 pathway

To investigate the effects of sodium butyrate (NaB) on long-term anxiety like behavior and inflammatory activation of microglia in the hippocampus of sepsis-associated encephalopathy (SAE) mice. (1) Animal experiment: fifty C57BL/6 mice aged 6-8 weeks were randomly divided into Sham group (only the cecum was found by laparotomy without perforation or ligation), and SAE model group caused by cecal ligation and puncture (CLP; SAE model group, the cecum was found by laparotomy and perforated after ligation. The open field test indicated that the ability of independent exploration decreased and showed anxiety like behavior, which proved that the SAE model was successfully replicated) and NaB pretreatment group was established (NaB was administered at a dose of 500 mg×kg-1×d-1 for 3 days before modeling, and the same dose once a day for 3 days after modeling). Open field test was used to detect the anxiety like behavior of mice at 7 days. The protein expressions and content changes of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in hippocampus of mice at 1 day and 3 days after operation were detected by Western blotting and enzyme linked immunosorbent assay (ELISA). Immunofluorescence staining was used to observe microglia labeled protein ionized calcium bindingadaptor molecule-1 (Iba-1) and TNF-α protein co localization. (2) Cell experiment: mouse microglia cell line BV-2 microglia were divided into blank control group, lipopolysaccharide (LPS) group (cells were treated with 1 mg/L LPS), and NaB treatment group (cells were treated with 1 mg/L LPS+5 mmol/L NaB). The protein expressions of IL-1β, TNF-α, Toll-like receptor 4 (TLR4), phosphorylated nuclear factor-κB p65 (p-NF-κB p65), nuclear factor-κB p65 (NF-κB p65) and NF-κB inhibitor protein-α (IκB-α) were detected by Western blotting. The expressions of Iba-1 and TNF-α in each group were observed by immunofluorescence. (1) Animal experiment: compared with the Sham group, the distance and duration of movement in the central area, the total distance moved of mice decreased 7 days after the establishment of SAE model group were decreased [distance of movement in the central area (mm): 13.45±3.97 vs. 161.44±27.00, duration of movement in the central area (s): 1.82±0.58 vs. 13.45±2.17, the total distance moved (mm): 835.01±669.67 vs. 2 254.51±213.45, all P < 0.05]. In the hippocampus tissues of mice, a large number of nerve nuclei were pyknotic and deeply stained, and the arrangement of nerve cells was disordered. The cell bodies of microglia in mouse hippocampus increased significantly. The number of positive cells of Iba-1/TNF-α (Iba-1+/TNF-α+) increased significantly. The contents and protein expression of proinflammatory factors TNF-α, IL-1β in hippocampal homogenate supernatant 3 days after operation in SAE model group were significantly higher than those in Sham group [TNF-α (ng/L): 119.17±18.40 vs. 90.18±21.17, IL-1β (ng/L): 407.89±70.64 vs. 313.69±34.63; TNF-α/GAPDH: 1.42±0.50 vs. 0.80±0.08, IL-1β/GAPDH: 1.27±0.22 vs. 0.85±0.25, all P < 0.05]. After intragastric administration of NaB, the distance and duration of movement in the central area of mice were significantly higher than those in SAE model group [distance of movement in the central area (mm): 47.39±15.63 vs. 13.45±3.97, duration of movement in the central area (s): 6.12±1.87 vs. 1.82±0.58, all P < 0.05]. There was no significant change in the total distance moved (mm: 1 550.59±1 004.10 vs. 835.01±669.67, P > 0.05). The pyknosis and deep staining of nerve nuclei in mice were significantly less than those in SAE model group. The number of Iba-1+/TNF-α+ positive cells decreased significantly. The contents and protein expression levels of proinflammatory factors TNF-α, IL-1β in hippocampal homogenate supernatant 3 days after operation were significantly lower than those in SAE model group [TNF-α (ng/L): 64.95±9.10 vs. 119.17±18.40, IL-1β (ng/L): 311.94±69.92 vs. 407.89±70.64; TNF-α/GAPDH: 1.02±0.36 vs. 1.42±0.50, IL-1β/GAPDH: 0.86±0.20 vs. 1.27±0.22, all P < 0.05]. (2) Cell experiment: after LPS intervention, the fluorescence intensity of TNF-α in BV-2 cells was significantly enhanced, the protein expression levels of TNF-α, IL-1β, TLR4 and p-NF-κB p65 protein increased (TNF-α/GAPDH: 0.39±0.06 vs. 0.20±0.02, IL-1β/GAPDH: 0.27±0.03 vs. 0.19±0.01, TLR4/GAPDH: 0.55±0.12 vs. 0.33±0.09, p-NF-κB p65/NF-κB p65: 0.55±0.05 vs. 0.29±0.04, all P < 0.05), the expression level of IκB-α was lower than that in the control group(IκB-α/GAPDH: 0.54±0.06 vs. 0.81±0.03, P < 0.05). After NaB treatment, the fluorescence intensity of TNF-α in BV-2 cells was decreased. The protein expression levels of TNF-α, IL-1β, TLR4 and p-NF-κB p65 protein were significantly lower than that of LPS model group (TNF-α/GAPDH: 0.26±0.02 vs. 0.39±0.06, IL-1β/GAPDH: 0.11±0.04 vs. 0.27±0.03, TLR4/GAPDH: 0.28±0.14 vs. 0.55±0.12, p-NF-κB p65/NF-κB p65: 0.29±0.01 vs. 0.55±0.05, all P < 0.05), the protein expression level of IκB-α was significantly higher than that in the LPS group (IκB-α/GAPDH: 0.75±0.01 vs. 0.54±0.06, P < 0.05). NaB could antagonism the TLR4 activation induced by LPS, thus inhibiting p-NF-κB p65 nuclear transcription and IκB-α degradation. It can reduce microglia activation and secretion of inflammatory factors, and finally improve the inflammation in the hippocampus of septic mice and long-term anxiety like behavior.

Chrysomycin A Attenuates Neuroinflammation by Down-Regulating NLRP3/Cleaved Caspase-1 Signaling Pathway in LPS-Stimulated Mice and BV2 Cells.

Chrysomycin A (Chr-A), an antibiotic chrysomycin, was discovered in 1955 and is used to treat cancer and tuberculosis. In the present study, the anti-neuroinflammatory effects and possible mechanism of Chr-A in BALB/c mice and in BV2 microglia cells stimulated by lipopolysaccharide (LPS) were investigated. Firstly, the cortex tissues of mice were analyzed by RNA-seq transcriptome to identify differentially expressed genes (DEGs) regulated by Chr-A in LPS-stimulated mice. Inflammatory cytokines and inflammatory proteins were detected by enzyme-linked immunosorbent assay and Western blot. In RNAseq detection, 639 differential up-regulated genes between the control group and LPS model group and 113 differential down-regulated genes between the LPS model group and Chr-A treatment group were found, and 70 overlapping genes were identified as key genes for Chr-A against neuroinflammation. Subsequent GO biological process enrichment analysis showed that the anti-neuroinflammatory effect of Chr-A might be related to the response to cytokine, cellular response to cytokine stimulus, and regulation of immune system process. The significant signaling pathways of KEGG enrichment analysis were mainly involved in TNF signaling pathway, cytokine–cytokine receptor interaction, NF-κB signaling pathway, IL-17 signaling pathway and NOD-like receptor signaling pathway. Our results of in vivo or in vitro experiments showed that the levels of pro-inflammatory factors including NO, IL-6, IL-1β, IL-17, TNF-α, MCP-1, CXCL12, GM-CSF and COX2 in the LPS-stimulated group were higher than those in the control group, while Chr-A reversed those conditions. Furthermore, the Western blot analysis showed that its anti-neuroinflammation appeared to be related to the down-regulation of NLRP3/cleaved caspase-1 signaling pathway. The current findings provide new insights into the activity and molecular mechanisms of Chr-A for the treatment of neuroinflammation.

Isoniazid promotes the anti-inflammatory response in zebrafish associated with regulation of the PPARγ/NF-κB/AP-1 pathway

ObjectiveZebrafish inflammation models were used to evaluate the anti-inflammatory activity of isoniazid (INH) and preliminarily investigate the underlying mechanism. MethodsLocal, acute, and systemic zebrafish inflammation models were established by tail cutting, copper sulfate (CuSO4), and lipopolysaccharide (LPS) endotoxin treatments, respectively, to evaluate the anti-inflammatory activity of INH. Zebrafish in the inflammatory state were exposed to different concentrations of INH (1, 2, and 4 mM) for 72 h to observe changes in the migration and accumulation of inflammatory cells and measure the reactive oxygen species (ROS) content in zebrafish after INH treatment. The transcription levels of inflammation-related genes in zebrafish from all groups were measured using real-time polymerase chain reaction (RT-PCR). ResultsCompared to those observed in the control inflammation model group, the numbers of migrated and accumulated inflammatory cells in zebrafish in the INH-treated group significantly decreased. INH significantly decreased the ROS content induced by LPS. Compared to that observed in the LPS model group, INH at 1 and 2 mM significantly increased the expression of PPARγ and inhibited the expression of NF-κB, iκbαa, and AP-1 as well as the inflammatory factors TNF-ɑ, TGF-β, IL-1b, and COX-2. ConclusionIn this study, different zebrafish inflammation models were used to confirm that INH has anti-inflammatory activity. The associated mechanism may occur through the inhibition of ROS release, activation of PPARγ expression, inhibition of the transcriptional regulatory activity of NF-κB and AP-1, and reduction of INH inflammatory factor expression to relieve inflammation. The results of this study provide references for the clinical application of INH.

Protective effect of sodium 4-phenylbutyrate on rats with acute respiratory distress syndrome related right ventricular dysfunction by alleviating endoplasmic reticulum stress

To investigate the role of endoplasmic reticulum stress (ERS) in rats with acute respiratory distress syndrome (ARDS) related right ventricular dysfunction and the protective effect of sodium 4-phenylbutyrate (4-PBA) on right ventricle. Sixty male Spragne-Dawley (SD) rats were randomly divided into control group (CON group), lipopolysaccharide (LPS) model group, 4-PBA prevention group and 4-PBA treatment group, with 15 rats in each group. ARDS rat model was established by intratracheal instillation of LPS 10 mg/kg after tracheotomy; CON group was given the same amount of saline. 4-PBA prevention group and 4-PBA treatment group were given 4-PBA 500 mg/kg intragastric administration 2 hours before and after LPS respectively. Echocardiography was performed 12 hours after treatment to evaluate the right ventricular function. Then, the rats were sacrificed by bloodletting, and the serum and right ventricular tissue were harvested. The histopathological changes of myocardial were observed by hematoxylin-eosin (HE) staining, the levels of tumor necrosis factor-α (TNF-α), interleukins (IL-1β and IL-6) in serum and myocardial were detected by enzyme linked immunosorbent assay (ELISA), and Western Blot was used to detect the expression of the marker proteins of ERS in myocardial, including glucose regulatory protein 78 (GRP78), C/EBP cyclic adenosine phosphate reaction primitive binding transcription factor homologous protein (CHOP), caspase-12 and caspase-3. Compared with the CON group, the echocardiography showed pulmonary artery maximum pressure gradient (PAmaxPG), pulmonary artery acceleration time (PAAT), tricuspid annular plane systolic excursion (TAPSE) in LPS model group were significantly decreased, and right ventricular end-diastolic excursion (RVDd) was significantly increased, and the levels of TNF-α, IL-1β and IL-6 in serum and myocardial, as well as the expressions of GRP78, CHOP, caspase-12 and caspase-3 in myocardial were significantly increased. Compared with LPS model group, TAPSE of 4-PBA preventive and treatment groups were significantly increased (mm: 3.08±0.65, 2.96±0.61 vs. 2.48±0.45), RVDd were significantly decreased (mm: 3.67±0.58, 3.60±0.61 vs. 4.18±0.71), the levels of TNF-α, IL-1β and IL-6 in serum and myocardial were significantly decreased [TNF-α (ng/L): 187.98±18.98, 176.08±17.98 vs. 332.00±19.90 in serum, 135.06±19.00, 132.78±17.00 vs. 155.00±20.00 in myocardial; IL-1β(ng/L): 12.07±2.98, 11.05±2.41 vs. 24.06±4.01 in serum, 19.89±2.80, 21.06±2.80 vs. 26.00±2.60 in myocardial; IL-6 (ng/L): 42.98±7.90, 34.05±6.09 vs. 89.80±10.07 in serum, 129.45±25.00, 127.08±26.06 vs. 145.77±23.00 in myocardial]; the expressions of GRP78, CHOP, caspase-12 and caspase-3 in myocardial were significantly decreased (GRP78/GAPDH: 0.090±0.070, 0.103±0.060 vs. 0.167±0.090, CHOP/GAPDH: 0.109±0.090, 0.090±0.080 vs. 0.186±0.090, caspase-12/GAPDH: 0.769±0.230, 0.799±0.210 vs. 1.040±0.350, caspase-3/GAPDH: 0.391±0.060, 0.401±0.054 vs. 0.603±0.340), with statistically significant differences (all P < 0.05). There were no significant differences in each indexes between 4-PBA prevention group and 4-PBA treatment group (all P > 0.05). ERS is involved in ARDS-related right ventricular dysfunction. 4-PBA can protect the right ventricular function of ARDS rats by inhibiting ERS and alleviating inflammation, and the preventive and therapeutic effects of 4-PBA are similar.

Dexmedetomidine attenuates lipopolysaccharide induced acute lung injury in rats by inhibition of caveolin-1 downstream signaling

ObjectiveToll-like receptor 4(TLR-4)/nuclear factor-kappa B(NF-κB) pathway plays an important role in inducing acute lung injury (ALI). Studies have proved Dexmedetomidine (Dex) inhibits inflammatory response to mitigate lipopolysaccharide (LPS)‐induced ALI and protect against multiorgan injury in various scenarios via restraining TLR-4/NF-κB signaling pathway. Many of the known downstream molecules have been orientated with a protein caveolin-1(Cav-1), which is supposed to take part in regulating TLR4-mediated inflammatory responses. However, its mechanisms have not been confirmed. The aim of this study is to evaluate the protective effects and potential mechanisms of Dex against LPS-induced ALI in male rats. MethodsMale rats received tail-vein injection of LPS to form ALI model. Rats were administrated with intraperitoneal injection Dex0.5 h before ALI. At 6 h after LPS injection, bronchoalveolar lavage fluid (BALF) and lung tissue were harvested. We stained the lung tissue sections with hematoxylin eosin (HE) staining to observe the histopathological damage and measure the ALI pathology score. We also measured the wet-to-dry(W/D) weight ratio of lung tissue. Lung myeloperoxidase (MPO) and inflammatory cytokines in the BALF were detected by Enzyme‐linked immunosorbent assay(ELISA). Protein levels of Cav-1, TLR-4 and NF-κB in lung tissue were tested by immunohistochemistry method. The mRNA expression of Cav-1, TLR4 and the NF-κB in lung tissue were measured to determine the related mechanisms by quantitative real-time polymerase chain reaction(RT-PCR). ResultsIt was indicated that Dex pretreatment markedly mitigated pathomorphologic changes and pathological lung injury scores. Besides, Dex pretreatment obviously decreased the W/D weight ratio of lung tissue, attenuated MPO activity significantly, along with LPS-stimulated augment of lung inflammatory cells infiltration in BALF. Moreover, compared with LPS model group, Dex pretreatment apparently increased the protein levels of Cav-1 downregulated by sepsis and decreased the protein levels of TLR-4 and NF-κB in lung tissue. Furthermore, Dex pretreatment apparently upregulated the expression of Cav-1 mRNA, restrained TLR4 and NF-κB mRNA. ConclusionDex pretreatment protects against LPS‐induced ALI via inhibiting the activation of the TLR-4/NF-kB signaling pathway by upregulating the expression of Cav-1 downregulated by sepsis.

Jian-Pi-Yi-Fei granule suppresses airway inflammation in mice induced by cigarette smoke condensate and lipopolysaccharide.

INTRODUCTION:As a chronic, progressive, and lethal pulmonary disease, chronic obstructive pulmonary disease (COPD) is lacking effective treatment. Chronic inflammatory processes, including inflammatory cytokines, play an important role with in its pathogenesis. Jianpiyifei (JPYF) granule is a traditional Chinese herbal formula historically used to strengthen the spleen and tonify the lung. JPYF is used clinically to treat stable COPD. However, whether the purported anti-inflammatory effect of JPYF in COPD involves regulation of key inflammatory cytokines is not clear.MATERIALS AND METHODS:The mice model of pulmonary inflammation was induced by lipopolysaccharide (LPS) and cigarette smoke condensate (CSC). The influence of JPYF on airway inflammation in vivo was investigated. Mice were divided into three groups: control, model, and treatment groups. In the CSC + LPS model group and JPYF treatment group, intratracheal injection of CSC and LPS was used to induce airway inflammation for 5 days. JPYF group animals were also orally administered 5.5 g/kg JPYF granule for 12 days.RESULTS:The number of neutrophils and total cells in bronchoalveolar lavage fluid of the JPYF group were markedly lower than in the model group. The levels of interleukin (IL)-1 β and IL-6 were lower; tumor necrosis factor-alpha was downregulated, and IL-10 was higher in the JPYF group than the model group. In the JPYF group, histone deacetylase 2 (HDAC2) activity and protein expression were restored.CONCLUSION:The anti-inflammatory activity of JPYF involves the suppression of pro-inflammatory cytokines, enhanced IL-10 secretion, and the restoration of HDAC2 activity.

The effect of adipose-derived stem cells on the lung colonization, TNF-α and IL-4 in rats with LPS-induced acute lung injury

Objective To explore the effect of 5-ethynyl-2'-deoxyuridine (EdU) -labeled adipose-derived stem cells (ADSCs) on lung colonization, TNF-α and IL-4 in rats induced by lipopolysaccharide (LPS) with acute lung injury. Methods Thirty male Sprague-Dawley (SD) rats were randomly divided into the normal control group (n=10), LPS model group (n=10), and LPS+ADSCs intervention group (n=10). The ALI model rats were intraperitoneally injected with 8 mg/kg LPS, rats in the normal control group were intraperitoneally injected with 4 mL/kg physiological saline, and rats in the LPS+ADSCs group were intravenously injected with 300 μL ADSCs by tail vein after 30 minutes for the ALI model establishment, and rats in the normal control group and LPS group were intravenously injected with 300 μL physiological saline by tail vein. The time of death in rats was observed, lung tissue and blood from left ventricular were collected, and the serum tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-4) were detected by Enzyme-linked immunosorbent assay (ELISA). Lung wet/dry weight (W/D) ratio was detected by thoracotomy, the pathological changes of lung tissue were observed under optical microscope, and the colonization of ADSCs in the lungs were observed under immunofluorescence microscopy. LSD-t method was used to compare between every two groups. Results There was no significant difference in mortality between the LPS group and LPS + ADSCs group (50% vs. 70%, P> 0.05); EdU-labeled ADSCs were extensively colonized in the lungs by tail vein injection after 24 h; Compared with the normal control group, the lung injury of the LPS group was heavier, the ratio of lung W/D and TNF-α were significantly increased (all P< 0.01), and IL-4 level was significantly decreased (P< 0.01). Compared with the LPS model group, the degree of lung injury in the LPS + ADSCs group was significantly reduced, lung W/D ratio (5.57±0.27 vs. 5.98±0.28) and TNF-α level of blood [(41.51±4.14)ng/L vs. (45.52±3.74)ng/L] were significantly reduced (all P< 0.05), whereas the IL-4 levels were significantly increased [(7.01±1.11)pg/mL vs. (3.27±0.54)pg/mL, P< 0.05]. Conclusions EdU-labeled ADSCs could be colonized in the lungs of LPS-induced ALI rats, reduce the inflammatory response from TNF-α and improve the anti-inflammatory response from IL-4. Key words: Acute lung injury; Adipose-derived stem cell; Lipopolysaccharide; EdU; Tracer

Mechanism of MCP-1 in Acute Lung Injury and Advanced Therapy by Drug-Loaded Dextrin Nanoparticle

Objective. To observe the expression of monocyte chemotactic protein 1 (MCP-1) in acute lung injury (ALI) rat model, to characterize its effect on the development and progression of ALI, and to identify the potential new drug delivery approach during in vivo experiment. Method. The effects of different doses of lipopolysaccharide (LPS) on human pulmonary artery endothelial cells (HPAEC) were tested. For the animal experiments, thirty Sprague-Dawley (SD) rats were divided into physiological saline control group (NC group), the LPS model group (L group), the antagonist RS102895 combined with LPS group (R + L group), and the antagonist RS102895-loaded polyaldehyde dextran nanoparticles combined with LPS group (DNPR + L group). The blood gas analysis and dry/wet weight ratio were detected 24 hours after interventions. The levels of inflammatory factors, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), were tested by ELISA. The expression of monocyte chemoattractant protein-1 (MCP-1) in lung tissues was examined through Western blot, and the change of MCP-1 mRNA expression level was detected by performing RT-PCR. Result. LPS was responsible for inducing ALI in rats, and the degree of cell damage was dose-dependent. Blood gas analysis of L group showed that PaO2 and PaO2/FiO2 levels were significantly lower than those of the NC group (P&lt;0.05), while the dry/wet weight ratio of lung tissues in L group increased (P&lt;0.05). Inflammatory factors including TNF-α and IL-1β and the expression of MCP-1 in both protein and mRNA levels were higher in L group than in the NC group (P&lt;0.05). The inhibition of the interaction between MCP-1 and chemokines receptor 2 (CCR2) by antagonist RS102895 can significantly alleviate the ALI in rats, which is accompanied by a significant decrease of inflammatory factors and MCP-1 expression (P&lt;0.05). Compared with R + L group, treatment with DNPR and LPS combination significantly improved the condition of rats and decreased the level of TNF-α, IL-1β, and MCP-1 expression (P&lt;0.05). Conclusion. In ALI, RS102895 can inhibit the MCP-1/CCR2 interaction, therefore, retarding the progress of ALI. Because of the high transfection efficiency of inhibitor RS102895packgaed by polyaldehyde dextran nanoparticles, this phenomenon particularly reached a significant level. The results imply new insights for the treatment of ALI.

Rutin protects against lipopolysaccharide-induced mastitis by inhibiting the activation of the NF-κB signaling pathway and attenuating endoplasmic reticulum stress

Rutin, found widely in traditional Chinese medicine materials, is used to treat eye swelling and pain, hypertension, and hyperlipidemia. In the present study, a mouse mastitis model induced by lipopolysaccharide (LPS) was established to explore rutin's inhibitory mechanism on mastitis via nuclear factor kappa B (NF-κB) inflammatory signaling and the relationship between NF-κB signaling and endoplasmic reticulum (ER) stress. Mice were divided into six groups: Control group, LPS model group, LPS + rutin (25, 50, and 100mg/kg) and LPS + dexamethasone (DEX) group. DEX, rutin, and PBS (control and LPS groups) were administered 1h before and 12h after perfusion of LPS. After LPS stimulation for 24h, to evaluate rutin's therapeutic effect on mastitis, the mammary tissues of each group were collected to detect histopathological injury, tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 mRNA and protein levels; and glucose-regulated protein, 78kDa (GRP78) protein levels. The protein and mRNA levels of TNF-α, IL-1β, and IL-6 in the LPS + rutin group were significantly lower than those in the LPS model group. Similarly, p50/p105, phosphorylated (p)-p65/p65 and p-inhibitor of nuclear factor kappa b kinase subunit beta (p-IKKβ)/IKKβ ratios in the LPS + rutin group (50mg/kg) and LPS + rutin group (100mg/kg) decreased significantly. GRP78 protein expression was significantly higher in LPS + rutin group (100mg/kg). The structure of mammary tissue became gradually more intact and vacuolization of acini decreased as the rutin concentration increased. The nuclear quantity of p65 in the LPS + rutin group decreased significantly in a rutin dose-dependent manner. Rutin had an anti-inflammatory effect in the LPS-induced mouse mastitis model, manifested by inhibition of NF-κB pathway activation and attenuation of ER stress.

Effect of pyrrolidine dithiocarbamate on oxidative stress and mitochondrial function of lung tissue in mice with acute lung injury

To investigate the effects of pyrrolidine dithiocarbamate (PDTC) on oxidative stress and mitochondrial function of lung tissue in mice with acute lung injury (ALI) induced by lipopolysaccharide (LPS). Forty female Balb/c mice were randomly divided into normal saline (NS) control group, LPS model group, PDTC group, and PDTC+LPS group, with 10 mice in each group. The model of mice with ALI was reproduced by intraperitoneal injection of 15 mg/kg LPS. PDTC was administered intraperitoneally with 50 mg/kg PDTC 1 hour before LPS treatment in the PDTC+LPS group. The mice in NS control group was given intraperitoneal injection of 0.1 mL NS only, and those in PDTC group was given intraperitoneal injection of 50 mg/kg PDTC only. The mice were sacrificed at 24 hours after model reproduction, and the lung tissues were harvested. The total antioxidant capacity (T-AOC) of lung tissue was measured by spectrophotometric kits. The content of malondialdehyde (MDA) was determined by thiobarbituric acid reactive substances assay. The protein expressions of superoxide dismutases (SOD1, SOD2) and catalase (CAT) in lung tissue were determined by Western Blot. Mitochondria from mouse lungs were isolated, and adenosine triphosphate (ATP) synthesis was measured with a luciferase/luciferin-based approach. The mitochondrial membrane potential (ΔΨm) was estimated by using Rhodamine. The mRNA expressions of mitochondrial uncoupling proteins (UCPs) were determined by reverse transcription-polymerase chain reaction (RT-PCR). LPS stimulation could significantly increase oxidative stress in lung tissue of mice and lead to mitochondrial dysfunction. The results showed that the protein expressions of T-AOC and SOD1 were decreased, the level of MDA was increased, the ATP synthesis was decreased in the mitochondrial, the ΔΨm was decreased, and the mRNA expression of UCP2 was decreased. However, there was no significant change in the expressions of SOD2, CAT in lung tissue and UCP1, UCP3 in the mitochondria. Pretreatment with PDTC could obviously alleviate the increase in LPS-induced oxidative stress in lung tissue and mitigate mitochondrial dysfunction. Compared with the LPS model group, T-AOC in lung tissue of PDTC+LPS group was significantly increased (U/g: 0.35±0.08 vs. 0.31±0.07), the level of MDA was significantly decreased (μmol/mg: 13.29±1.13 vs. 17.54±1.72), the protein expression of SOD1 was significantly upregulated (SOD1 protein: 1.13±0.11 vs. 0.71±0.09), ATP synthesis was significantly increased in the mitochondrial (μmol/mg: 49.23±5.42 vs. 36.92±2.21), ΔΨm was significantly increased (mV: 226.03±11.69 vs. 194.86±7.79), and the mRNA expression of UCP2 was significantly increased (2-ΔΔCt: 0.88±0.06 vs. 0.73±0.04). The differences were statistically significant (all P < 0.05). In lung tissue of normal mice, PDTC treatment also had the effect of anti-oxidizing, reducing oxidative stress and promoting ATP synthesis in the mitochondrial. Compared with the NS control group, the level of T-AOC (U/g: 0.49±0.09 vs. 0.43±0.06) and the protein expressions of SOD2 and CAT (SOD2 protein: 1.33±0.08 vs. 1.00±0.11, CAT protein: 1.39±0.08 vs. 1.00±0.11), and ATP synthesis in the mitochondrial of PDTC group was significantly increased (μmol/mg: 61.53±4.92 vs. 53.33±3.20), MDA was significantly decreased (μmol/mg: 10.27±1.25 vs. 12.27±1.36), with statistical differences, but had no effect on the protein expression of SOD1 in lung tissue and ΔΨm and UCPs mRNA expressions in mitochondrion. LPS can induce ALI in mice, increased oxidative stress in lung tissue, and induce mitochondrial dysfunction by inhibiting ATP synthesis. PDTC pretreatment has anti-oxidative effect on LPS-induced ALI, and can mitigate mitochondrial dysfunction.

Effects of acute respiratory distress syndrome induced by endotoxin on the right ventricular function in rats

To explore the effect of acute respiratory distress syndrome (ARDS) induced by endotoxin on the right ventricular function in rats. Sixty male Sprague-Dawley (SD) rats were randomly divided into normal saline (NS) control group and lipopolysaccharide (LPS) model group with 30 rats in each group. The rat model of ARDS was reproduced by intratracheal instillation of LPS 10 mg/kg after tracheotomy, and the rats in NS control group was intratracheally given the same volume of NS instead of LPS. The survival of rats in each group was observed. Right ventricular function was evaluated by echocardiography at 6 hours and 12 hours after instillation of LPS or NS respectively. Then the rats were sacrificed by bloodletting, and the right heart and lung tissue were harvested. The lung wet/dry weight (W/D) ratio was assessed. The pathological changes in cardiopulmonary tissue in rats were observed with hematoxylin and eosin (HE) strain, and the pathological score of lung injury was calculated. There was no animal death in NS control group. In LPS model group, there were 3 rats dead at 6 hours, and 4 dead at 12 hours. The pathological manifestations of lung injury were found at 6 hours after instillation of LPS, and the marked pathological changes of ARDS, such as atelectasis and hyaline membranes were observed at 12 hours. There was no obvious abnormality in the lung tissue of the NS control group. Compared with the NS control group, the 12-hour lung W/D ratio and the lung injury pathological score in the LPS model group were significantly increased (lung W/D ratio: 7.69±1.02 vs. 4.14±0.48, lung injury pathological score: 8.26±2.12 vs. 1.32±0.94, both P < 0.01). Echocardiography showed that the right heart function of rats was significantly abnormal with the prolongation of LPS induction time, which showed that pulmonary arterial diameter (PAD) and right ventricular diastolic diameter (RVDd) were increased, maximum blood flow velocity of pulmonary artery (PAVmax), maximum pulmonary artery pressure gradient (PAmaxPG), pulmonary artery acceleration time (PAAT) and tricuspid annular plane systolic excursion (TAPSE) were decreased, with significant differences at 12 hours as compared with those of NS normal group [PAD (mm): 2.84±0.31 vs. 2.11±0.37, RVDd (mm): 4.18±0.71 vs. 3.17±0.40, PAVmax (mm/s): 704.00±145.13 vs. 809.59±120.48, PAmaxPG (mmHg, 1 mmHg = 0.133 kPa): 2.07±0.88 vs. 2.73±0.76, PAAT (ms): 23.80±4.87 vs. 30.01±3.02, TAPSE (mm): 2.48±0.45 vs. 3.56±0.40, all P < 0.01]. Pathological examination showed that the cardiac tissue in the LPS model group showed disorder of myocardial cells and scattered inflammatory cells at 6 hours, and cardiomyocyte degeneration, structural destruction and inflammatory cells were found at 12 hours. ARDS induced by instillation of LPS at 12 hours causes right ventricular dysfunction in rats.