Objective To observe the effects of exogenous pulmonary surfactant (PS) on ventilation-induced lung injury (VILI) in rats, and to investigate its possible mechanisms. Methods A total of 40 Wistar rats were divided into 4 groups with randomized blocks method: control group, high tidal volume (HV) group, VILI group, and PS group, with 10 rats in each group. The control group was subjected to identical surgical procedure but was never ventilated. After 30 min of mechanical ventilation (MV) with Vt 45 ml/kg, the rats in HV group were killed immediately; rats in the VILI group were continually ventilated for up to 150 min with Vt 16 ml/kg; in the PS group, 100 mg/kg of PS administered intratracheally and with the same settings as VILI group. Mean artery pressure (MAP), blood gas analysis, lung wet to dry weight ratios (W/D), thorax-lung compliance, and cell counts in bronchoalveolar lavage fluid (BALF) were determined. Nuclear factor-κB(NF-κB) activity in lungs was measured by enzyme-linked immunosorbent assay (ELISA), interleukin-8(IL-8) in serum and BALF was determined by radioimmunoassay (RIA). Pathological examination of the lung was performed. Results Injurious ventilation significantly decreased MAP and PaO2/FiO2, but increased NF-κB activity and W/D. MAP and PaO2/FiO2 improved, but NF-κB activity, IL-8 in serum and BALF, and cell counts in BALF reduced significantly in PS group compared with those in VILI group. Histological studies showed reduced pulmonary edema and atelectasis in the PS group. Conclusion PS administered intratracheally can suppress the increased activity of NF-κB induced by VILI, exogenous PS can be used to treat VILI.
【 Abstract 】 Objective Overexpressions of epidermal growth factor (EGF) and EGF receptor have been associated with progression and invasive phenotype of pancreatic cancer. However, the underlying molecular mechanism by which EGF worked in pancreatic cancer cells has not been completely understood. In this study, effect of EGF on the invasion and metastasis of pancreatic cancer cells and its regulatory mechanism were investigated. Methods The effects of EGF on the proliferation, adhesion and invasion of pancreatic cancer cells were detected by WST-1 proliferation assay, adhesion assay and invasive assay, respectively. The activity and expression of MMP-2 and MMP-9 were examined by zymography, Western blot and RT-PCR, respectively. The activity of NF- κ B was examined by EMSA. Results EGF could significantly promote the invasiveness of pancreatic cancer cells but did not affect cell proliferation or adhesion. The expressions of NF- κ B and MMP-9 were significantly increased by EGF, but EGF did not affect the activity and expression of MMP-2. Furthermore, EGF stimulated the NF- κ B binding activity. Pretreatment with NF- κ B inhibitors, pyrrolidine dithiocarbamate (PDTC), could significantly inhibit the activity of NF- κ B induced by EGF. Meanwhile, the EGF-induced expression and activity of MMP-9, as well as cell invasiveness were also inhibited by NF- κ B inhibitor. Conclusion EGF could increase the expression and promote the invasiveness of MMP-9 via the activation of NF- κ B in pancreatic cancer cells, which implies that NF- κ B inhibitant, such as PDTC, may diminish the invasiveness of pancreatic cancer cells.
Objective To investigate influence of genders on the activity of nuclear factor-kappa B (NF-κB) in lungs of endotoxemic rats. Methods Twenty female and 20 male Wistar rats were randomly divided into four groups as follow: female control group (n=10), male control group (n=10), male endotoxemic group (n=10), and female endotoxemic group (n=10). The endotoxemic rats model was made by injecting lipopolysaccharide (5 mg/kg) into the abdominal cavity. Tissue samples were collected from the lungs in different groups and electrophoresis mobility shift assay was used to measure the activity of NF-κB. The levels of serum TNF-α and estrogen were measured at the same time. Results There was no significant difference between the activities of NF-κB in male and female control groups (1.33±0.24 vs 1.47±0.40）, and there was also no significant difference between other items in these groups as well (Pgt;0.05). Yet, the activity of NF-κB (female: 12.10±2.89; male: 19.53±2.12) and the level of TNF-α 〔female: (4.10±0.72) ng/ml; male: (6.37±1.29) ng/ml〕 were significantly increased after injection of lipopolysaccharide (Plt;0.01), and the indices in female group were significantly lower than those in male group (Plt;0.01). Correlation analysis showed that there was a positive relation between the activity of NF-κB in lungs and the level of TNF-α (female: r=0.921 1, P=0.013; male: r=0.907 2, P=0.017), and there was a negative correlation between the activity of NF-κB and the level of estrogen (female: r=-0.887 5, P=0.017; male: r=0.872 3, P=0.022) in both male endotoxemic group and female endotoxemic group (Plt;0.05). Conclusion Gender may be one of the factors that influence the activity of NF-κB in the lungs of endotoxemic rats. While on the other hand, endogenous estrogen may protect the lungs of endotoxemic rats from injury by inhibiting the activity of NF-κB.
Behcet's Disease (BD) is a multisystem vasculitis characterized by disease alternated with recurrent episodes and remissions, involving genital, oral, ocular uvea, cutaneous, and articular manifestations. The nuclear factor (NF)-κB signaling pathway paly an important role in the BD progression. It encompasses diverse gene, protein, and cellular regulatory mechanisms operating across various levels, alongside microbiological and experimental studies involving animals and cells. At the protein research findings, activation of the NF-κB pathway in BD patients is marked by elevated plasma levels of soluble CD40 ligand, which stimulates neutrophils to release reactive oxygen species and extracellular traps, thereby promoting inflammation. At the cellular research findings, macrophages in BD patients polarize towards classically activated macrophages phenotype through the NF-κB pathway, exacerbating the inflammatory response. The activation of NF-κB is associated with increased expression of anti-apoptotic proteins in T cells, leading to prolonged inflammation. Microbiological investigations reveal that the decreased gut microbiota diversity in BD patients compromises intestinal barrier integrity. NF-κB pathway involvement in regulating neutrophil and type 1 helper T cell (Th) 1/Th17 cell function worsens inflammation. Genetically, BD patients exhibit polymorphisms in immune regulatory genes, which contribute to inflammation through the NF-κB pathway. Mutations in NF-κB-associated genes elevate the risk of BD, while mutations in the endogenous inhibitor A20 lead to abnormal NF-κB activity, sustaining inflammation. Animal experiments and in vitro experiments corroborate the efficacy of NF-κB inhibitors in attenuating inflammation. Targeting upstream inflammatory factors within the NF-κB pathway yields positive outcomes in BD patients. In summary, the NF-κB signaling pathway plays a pivotal role in the development of BD. Developing NF-κB inhibitors may open new avenues for treating BD. Further research is necessary to comprehensively elucidate the precise mechanisms by which NF-κB operates in the pathogenesis of BD, as well as its potential clinical applications in therapy.
Abstract: Objective To study the preventive effect of n-3 polyunsaturated fatty acids on allograft arteriosclerosis. Methods Arterial homeotransplant model were created with 480 rats which were divided into four groups. Control group, no n-3 lyunsaturated fatty acids were taken. Group A, n-3 polyunsaturated fatty acids were taken for two weeks before operation with the dose of EPA 600mg/kg. Group B, 300 mg/kg and group C 150 mg/kg were taken respectively. The recipient’s transplanted vessel was excised after 1,7,14,21and 28 days respectively. The tissue pathological variations, ultrastructure variations and expression variations of intercellular adhesion molecule-1(ICAM-1), vascular cell adhesion molecule-1（VCAM-1）, nuclear factorkappa B（NF-κB） had been observed. Results The pathological changes occurred 7 days after operation in control group and were most prominent on the 28th day, blood vessels were obstructed and the expressions of ICAM-1, VCAM1,NF-κB were markedly intensified than those of group A, B, C (Plt;0.05). The pathological variations of transplanted vessel in group A, B, C occurred later than those in control group. The nonobstruction rates in group A, B, C were better than that in control group. The expressions of ICAM-1， VCAM-1， NF-κB in control group were ber than those in group A， B， C (Plt;0.05). The expressions of ICAM-1， VCAM-1， NF-κB after 1 day or 7 days demonstrated no statistically significant change in group A， B， C （Pgt;0.05）. The preventive effect for allograft vessel atheromatosis in group A and group B was ber than that in group C after 14, 21 and 28d (Plt;0.05). There were no significant difference between group A and group B (Pgt; 0.05). Conclusion The n-3 polyunsaturated fatty acids can prevent the allograft vessel atheromatosis, the most effective dose of n-3 polyunsaturated fatty acids is 300 mg/kg.
ObjectiveTo investigate the effect of Metformin (MET) on the anxiety behavior of mice with Pentylenetetrazol (PTZ)-induced epilepsy and the mechanisms. MethodsSixty male 8-week-old C57BL/6 mice were randomly divided into normal control group (Normal), Temporal lobe epilepsy (TLE) model control group (TLE-con), TLE + MET treatment group (TLE-MET), and normal mice + MET intervention group (MET-con) (n=15/group). In the TLE-con group and the TLE-MET group, mice were injected intraperitoneally with PTZ every other day to establish the TLE model, while mice in the Normal group and the MET group were given the same dose of normal saline. During PTZ administration, mice in the TLE-MET treatment group and the MET-con group were intraperitoneally injected with MET at 200 mg/(kg·d) every other day, for 14 times in a total of 28 days. The mice in the Normal group and the TLE-con group were intraperitoneally injected with the same amount of normal saline. Open field test (OFT) and elevated cross maze (EPM) were used to evaluate the anxiety behavior of mice in each group, and the Western blotting analysis was performed to detect expression of Toll like receptor 4 (TLR4), Nuclear factor-kappa B (NF-κB) p65 in brain tissues. ResultsCompared with the Normal group, the TLE-con group showed decreased times in the open arm in the EPM test (P<0.01) and in the center of open field in the OFT test (P<0.01), while MET intervention could increase the times of epileptic mice in the central area and the open arm (P<0.05). Compared with the Normal group, the expression of TLR4 and NF-κB in the cerebral cortex in the TLE-con group was increased significantly (P<0.05), while MET intervention could partially decrease the expression of TLR4 and NF-κB in the cerebral cortex of epileptic mice (P<0.05). ConclusionMET may improve the anxiety behavior of epileptic mice by reducing the inflammatory TLR4–NF-κB pathway.
ObjectiveTo investigate the role and mechanism of P-selectin glycoprotein ligand-1 (PSGL-1) in hydrochloric acid-induced acute lung injury (ALI) in mice.MethodsWild-type mice (WT) and PSGL-1 knockout mice (PSGL-1 -/-) were randomly subjected to normal saline (NS) or hydrochloric acid (HCl) challenged group. The mice were intratracheally instilled with NS or HCl (1 μl/g weight) into the left lung with a catheter. After 2 hours, respiratory function index enhanced pause (Penh), PaO2 and PaO2 were analyzed. The wet to dry weight ratio (W/D) of the left lung and total protein concentration in bronchoalveolar lavage fluid (BALF) were measured. The number of leukocytes in BALF was counted too. Targeted lung tissue was processed for further HE or immunohistochemistry staining. Meanwhile, the expressions of interleukin-6 (IL-6), IL-1β, nuclear factor-κB (NF-κB), IκBa and p-IκBa in lung tissue were measured.ResultsThe Penh (4.77±1.22 vs. 5.80±0.84) and PaCO2 [(63.7±3.9) mm Hg vs. (74.4±7.4) mm Hg] in the PSGL-1 knockout mice were significantly lower than those in the WT mice after HCl stimulation (P<0.05), while the PaO2 was higher than that in the WT mice [(81.0±7.1) mm Hg vs. (62.0±8.9) mm Hg, P<0.05)]. The lung W/D ratio (4.86±0.15 vs. 5.22±0.20), protein concentration [(3.71±0.64) μg/μl vs. (4.74±0.98) μg/μl] and total leukocyte count [(13.00±2.18) ×107/L vs. (49.42±3.35) ×107/L] in BALF were significantly lower in the PSGL-1 knockout mice challenged with HCl than those in the WT mice (P<0.05). Besides, the protein expressions of IL-6, IL-1β, p65 and p-IκBa in the PSGL-1 knockout mice were lower than those in the WT mice after HCl instillation, while the IκBa expression was higher than that in the WT mice (P<0.05). More numbers of neutrophils and macrophages were found in the lung of the WT mice than the PSGL-1 knockout mice challenged with HCl. However, the differences of above values between the WT mice and the PSGL-1 knockout mice instilled with NS were not found, all of which were significantly lower than the correspongding HCl group except for IκBa (P<0.05).ConclusionPSGL-1 may play important roles in the development of HCl-induced ALI via the NF-κB signaling pathway and inflammation.
Objective To investigate the expression changes of nuclear factor kappa B (NF-κB) and matrix metalloproteinase-9 (MMP-9) in the cultured hepatocellular carcinoma cells 9204 (HCC9204) transfected with inhibitory kappa B alpha（IκB-α)vector. Methods After pcDNA3-IκB-α vector and pcDNA3 were transfected into HCC9204 by lipofectamine method, Western-blot and RT-PCR analysis were used to detect the expressions of NF-κB and MMP-9. Migration and invasion of tumor cells were assayed by fundus membrane invaded by them. Results When pcDNA3-IκB-α was transfected into HCC9204, the expression of NF-κB was decreased at the protein level, and the expression of MMP-9 mRNA and the invision and metastasis ability of transfected cells were obviously decreased. Conclusion When the activity of NF-κB is inhibited, the ability of invasion and metastasis in HCC9204 cells decrease, which could be related to the decreased the expression of MMP-9.
Objective To investigate the changes in osteoprotegerin (OPG) / receptor activator of nuclear factor-κB ligand (RANKL) ratio in sepsis-associated acute lung injury (SA-ALI) and the role of regulation of this ratio on the inflammatory response in SA-ALI. Methods Eighteen C57BL/6 male mice were randomly divided into sham operation group, cecal ligation and perforation (CLP) group and RANKL group, with 6 mice in each group. Before the experiment, the RANKL group was intraperitoneally injected with 5 μg (0.2 mL) of recombinant RANKL antibody, whereas both the sham operation group and the CLP group were intraperitoneally injected with a volume-matched normal saline. One hour later, the sham operation group underwent only abdominal exploration and repositioning, while the other groups underwent the CLP surgery to induce the SA-ALI model. After 24 h of modelling, all mice were sacrificed and samples were collected. Pathological evaluation of lung tissues was performed by haematoxylin-eosin staining; enzyme-linked immunosorbent assay was used to detect serum concentrations of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β; while the mRNA and protein expression of OPG and RANKL, along with their ratio values, were detected by real-time polymerase chain reaction for quantitative analysis and protein immunoblotting. Results The SA-ALI mouse model was successfully established. Compared with the sham operation group, mice in the CLP group showed disturbed alveolar structure, obvious alveolar and interstitial haemorrhage and inflammatory cell infiltration, elevated serum levels of IL-6, TNF-α and IL-1β (P<0.05), significantly increased mRNA and protein expression of OPG and elevated OPG/RANKL ratio in lung tissue (P<0.05), whereas RANKL mRNA and protein expression was significantly decreased (P<0.05). Compared with the CLP group, the pathological damage of lung tissue in the RANKL group was reduced, the infiltration of alveolar and interstitial inflammatory cells was significantly improved, and the alveolar structure and morphology were more regular, with lower serum levels of IL-6, TNF-α and IL-1β (P<0.05), significantly lower mRNA and protein expression of OPG and OPG/RANKL ratio in lung tissue (P<0.05), and significantly higher mRNA and protein expression of RANKL in lung tissue (P<0.05). Conclusion The alteration of OPG/RANKL ratio may be related to the pathophysiological process of SA-ALI, and the decrease in its level may reflect the attenuation of the inflammatory response in SA-ALI.
Objective To observe the effect of epidermal growth factor (EGF) on the proliferation, adhesion, invasiveness and the activation of nuclear factor-κB (NF-κB), matrix metalloproteinases (MMPs) expression and explore related mechanisms in pancreatic cancer cells. Methods Cell invasion assay, proliferation assay and adhesion assay were used to examine the proliferation, adhesion and invasiveness of pancreatic cancer cells, respectively. NF-κB activity was detected by electrophoretic mobility shift assay (EMSA), and MMPs protein and mRNA expressions were investigated by gelatin zymography, Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR). Results EGF increased the invasiveness of pancreatic cancer cell in a dose-dependent manner (P＜0.05), but did not affect cell proliferation or adhesion. The expressions of MMP-9 mRNA and protein significantly increased after induction by EGF and were highest when EGF concentration was 50 ng/ml, while there was no effect on the expressions of MMP-2 mRNA and protein. Furthermore, NF-κB activity increased with increased concentration of EGF in a concentration-dependent manner (P＜0.05). In addition, NF-κB activity and the expressions of MMP-9 mRNA and protein by pretreatment with both pyrrolidine dithiocarbamate (PDTC) and EGF decreased when compared that by pretreatment with EGF alone. The invasiveness of pancreatic cancer cell by pretreatment with both PDTC and EGF decreased when compared that by pretreatment with EGF alone and nothing (P＜0.05).Conclusion The findings indicate that the NF-κB-mediated MMP-9 induction is essential for EGF-induced invasiveness in pancreatic cancer cells, which can be inhibited by PDTC.