Knockdown of PHLDA1 alleviates sepsis-induced acute lung injury by downregulating NLRP3 inflammasome activation.

OBJECTIVE: To investigate the regulatory mechanism of pleckstrin homology-like domain, family A, member 1 (PHLDA1) in sepsis-induced acute lung injury (ALI). METHOD: Mice model of sepsis were established by cecal ligation and puncture (CLP). The expression of PHLDA1 was reduced by injecting short hairpin RNA (shRNA)-PHLDA1 into the tail vein. The levels of PHLDA1, pro-inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), IL-1ß, IL-18, super-oxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH), molecular mechanism related to pyroptosis, such as caspase 1, adaptor apoptosis-associated speck-like protein containing a CARD (ASC), and gasdermin D (GSDMD)-N, and nucleotide oligomerization domain (NOD)-like receptor family pyrin domain-containing 3 (NLRP3) were tested by Western blot analysis, quantitative real-time polymerase chain reaction, and enzyme-linked-immunosorbent serologic assay. Pathological changes in lung tissues were examined by hematoxylin and eosin staining. Wet-dry weight ratio of lung tissues was observed. RESULTS: The expression of PHLDA1 was up-regulated in lung tissues from CLP-induced septic mice. Knockdown of PHLDA1 could reduce lung injury and wet-dry weight ratio in mice with sepsis-induced ALI. Moreover, silencing of PHLDA1 decreased the expressions of IL-1ß, TNF-α, IL-18, IL-6, and MDA but increased SOD and GSH expressions in CLP-induced septic mice. The expressions of NLRP3, GSDMD-N, ASC, and caspase 1 were decreased by PHLDA1 silencing. CONCLUSION: Knockdown of PHLDA1 inhibited lung inflammation and pyroptosis in mice with sepsis-induced ALI by down-regulating NLRP3.

Knockdown of PHLDA1 alleviates sepsis-induced acute lung injury by downregulating NLRP3 inflammasome activation

Objective: To investigate the regulatory mechanism of pleckstrin homology-like domain, family A, member 1 (PHLDA1) in sepsis-induced acute lung injury (ALI). Method: Mice model of sepsis were established by cecal ligation and puncture (CLP). The expression of PHLDA1 was reduced by injecting short hairpin RNA (shRNA)–PHLDA1 into the tail vein. The levels of PHLDA1, pro-inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), IL-1β, IL-18, super-oxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH), molecular mechanism related to pyroptosis, such as caspase 1, adaptor apoptosis-associated speck-like protein containing a CARD (ASC), and gasdermin D (GSDMD)-N, and nucleotide oligomerization domain (NOD)-like receptor family pyrin domain-containing 3 (NLRP3) were tested by Western blot analysis, quantitative real-time polymerase chain reaction, and enzyme-linked-immunosorbent serologic assay. Pathological changes in lung tissues were examined by hematoxylin and eosin staining. Wet–dry weight ratio of lung tissues was observed. Results: The expression of PHLDA1 was up-regulated in lung tissues from CLP-induced septic mice. Knockdown of PHLDA1 could reduce lung injury and wet–dry weight ratio in mice with sepsis-induced ALI. Moreover, silencing of PHLDA1 decreased the expressions of IL-1β, TNF-α, IL-18, IL-6, and MDA but increased SOD and GSH expressions in CLP-induced septic mice. The expressions of NLRP3, GSDMD-N, ASC, and caspase 1 were decreased by PHLDA1 silencing. Conclusion: Knockdown of PHLDA1 inhibited lung inflammation and pyroptosis in mice with sepsis-induced ALI by down-regulating NLRP3 (AU)

Induced transformation of antimony trioxide by Mn(II) oxidation and their co-transformed mechanism.

Antimony (Sb) is a toxic and carcinogenic element that often enters soil in the form of antimony trioxide (Sb2O3) and coexists with manganese (Mn) in weakly alkaline conditions. Mn oxides such as birnessite have been found to promote the oxidative dissolution of Sb2O3, but few researches concerned the co-transformations of Sb2O3 and Mn(II) in environment. This study investigated the mutual effect of abiotic oxidation of Mn(II) and the coupled oxidative dissolution of Sb2O3. The influencing factors, such as Mn(II) concentrations, pH and oxygen were also discussed. Furthermore, their co-transformed mechanism was also explored based on the analysis of Mn(II) oxidation products with or without Sb2O3 using XRD, SEM and XPS. The results showed that the oxidative dissolution of Sb2O3 was enhanced under higher pH and higher Mn(II) loadings. With a lower Mn(II) concentration such as 0.01 mmol/L Mn(II) at pH 9.0, the improved dissolution of Sb2O3 was attributed to the generation of dissolved intermediate Mn(III) species with strong oxidation capacity. However, under higher Mn(II) concentrations, both amorphous Mn(III) oxides and intermediate Mn(III) species were responsible for promoting the oxidative dissolution of Sb2O3. Most released Sb (∼72%) was immobilized by Mn oxides and Sb(V) was dominant in the adsorbed and dissolved total Sb. Meanwhile, the presence of Sb2O3 not only inhibited the removal of Mn(II) by reducing Mn(III) to Mn(II) but also affected the final products of Mn oxides. For example, amorphous Mn oxides were formed instead of crystalline Mn(III) oxides, such as MnOOH. Furthermore, rhodochrosite (MnCO3) was formed with the high Mn(II)/Sb2O3 ratio, but without being observed in the low Mn(II)/Sb2O3 ratio. The results of study could help provide more understanding about the fate of Sb in the environment and the redox transformation of Mn.

The influence of water level fluctuations on the migration and enrichment of phosphorus in an agricultural groundwater system, Jianghan Plain.

The enrichment of phosphorus (P) in groundwater (GW) has been regarded as one of the most important sources of water eutrophication, but its sources and mechanisms have remained unclear. This study focused on hydraulic change show that drove the migration of P in an agricultural groundwater system, Jianghan Plain, Central China. Based on four rounds of field investigation over different seasons and across two consecutive years. Seasonable water table fluctuations (WLFs) reached 1.6 m and 3.8 m in GW and surface water (SW), respectively. Moreover, the concentrations of P in GW were obviously higher than those in SW where 54.1% of all GW samples presented higher content of P than the World Health Organization (WHO) limit of 0.4 mg/L with the highest one arriving to 1.97 mg/L. Although the trends and amplitudes varied at different points and depths, the spatial and temporal distribution of P corresponded with the local WLFs that were responsible for the enrichment of GW P. On the one hand, WLFs changed hydraulic conditions to enhance the migration of soluble P in the unsaturated zone into the aquifer. On the other hand, WLFs resulted in changes to the redox conditions or to the GW hydrochemical compositions, which promoted the dissolution of Fe or Mn containing P. These caused the release and enrichment of P in GW. Therefore, this study helps understand the geochemical cycling of P and improves GW management in the local GW system, Jianghan Plain.

Phenol driven changes onto MnO2 surface for efficient removal of methyl parathion: The role of adsorption.

Manganese oxides (MnO2), important environmental oxides, have drawn significant attention in areas such as detoxification of micro-hazardous organic contaminants with electron-donating functional groups such as -OH. However, studies on whether these oxidized processes might further impact the fate of some esters like organophosphorus pesticide (OPPs) remain poorly understood. Herein, we propose a new mechanism involved in the enhanced removal of methyl parathion in mixtures of MnO2 and phenol. Specifically, the removal of methyl parathion (up to 73.7%) was significantly higher for a binary system than for MnO2 alone (approximately 9.3%) and was primarily due to adsorption rather than degradation. The extent of methyl parathion adsorption was dependent significantly on pH, reactant loading and metal ion co-solutes (such as Ca2+, Mg2+, Fe3+ and Mn2+). Both spectroscopic (FT-IR, SEM-EDX and XPS) and chromatographic (LC/HRMS) analyses showed that the remarkable increase in the number of organics (e.g., polymers) onto the MnO2 surface dominated methyl parathion adsorption via hydrogen bonding, n-π and π-π interactions, van der Waals forces and pore-diffusion. The results from this study provided evidence for the role of manganese oxides in adsorption of methyl parathion in soil-aquatic environments involving phenolic compounds.

[Influences and mechanisms of somatostatin on inflammation in endotoxin-induced acute lung injury mice].

OBJECTIVE: To investigate the effects of somatostatin on inflammation in endotoxin-induced acute lung injury mice and its underlying mechanisms. METHODS: 72 ICR male mice of specific pathogen free (SPF) were randomly divided into four groups: control group, SST control group, model group and SST intervention group, each group included 18 mice. The ALI model was reproduced by intraperitoneal injection of 40 mL/kg endotoxin, and the mice in control group was given intraperitoneal injection of equivalent normal saline. The mice in SST intervention group was given the subcutaneous injection of SST (20 µg, 20 mL/kg) at 0.5, 2, 6 and 12 hours after model reproduction. Six mice were sacrificed at 3, 8 and 16 hours after the first injection of LPS or NS. The lung wet/dry ratio (W/D) was calculated with oven drying method. Pathological changes in lung tissues were observed by light microscope. Serum SST, tumor necrosis factor-α (TNF-α), interleukins (IL-6, IL-10) levels were determined by enzyme linked immunosorbent assay (ELISA). The mRNA and protein expressions of Toll like receptor 4 (TLR4) and nuclear factor-ΚBp65 (NF-ΚBp65) were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western Blot. RESULTS: There were no significant differences in above indexes between control group and SST control group. Compared with control group, lung W/D ratio, serum SST, TNF-α, IL-6, IL-10, and the mRNA and protein expressions of TLR4 and NF-ΚBp65 in model group were significantly increased. The W/D ratio, IL-6, IL-10, and the mRNA and protein expressions of TLR4 all peaked at 16 hours (W/D ratio: 6.32±0.18 vs. 4.14±0.14, IL-6: 673.78±56.13 ng/L vs. 50.17±7.06 ng/L, IL-10: 481.13±40.78 ng/L vs. 61.71±10.05 ng/L, TLR4 mRNA: 0.740±0.099 vs. 0.180±0.028, TLR4 protein: 0.935±0.067 vs. 0.222±0.019, all P<0.05), and SST, TNF-α, the mRNA and protein expressions of NF-ΚBp65 peaked at 8 hours (SST: 254.97±38.75 ng/L vs. 95.87±13.95 ng/L, TNF-α: 139.69±19.06 ng/L vs. 21.90±4.52 ng/L, NF-ΚBp65 mRNA: 0.753±0.065 vs. 0.190±0.026, NF-ΚBp65 protein: 1.214±0.079 vs. 0.303±0.067, all P<0.05). Compared with model group, the lung injury in SST intervention group was significantly improved, and the indexes were significantly decreased except for serum SST which was gradually increased (16-hour W/D ratio: 5.21±0.14 vs. 6.32±0.18, 8-hour TNF-α: 80.48±8.52 ng/L vs. 139.69±19.06 ng/L, 16-hour IL-6: 394.99±37.17 ng/L vs. 673.78±56.13 ng/L, 16-h IL-10: 326.95±36.41 ng/L vs. 481.13±40.78 ng/L, 16-hour TLR4 mRNA: 0.240±0.028 vs. 0.740±0.099, 16-hour TLR4 protein: 0.618±0.066 vs. 0.935±0.067, 8-hour NF-ΚBp65 mRNA: 0.240±0.045 vs. 0.753±0.065, 8-hour NF-ΚBp65 protein: 0.784±0.041 vs. 1.214±0.079, all P<0.05). CONCLUSIONS: SST has significant protective effects on endotoxin-induced ALI via direct suppression of the TLR4-NF-ΚB cytokine pathway, thus alleviate lung tissue inflammation.

[Effects of NF-E2-related factor-2 promoter polymorphism on lipopolysaccharide-induced inflammatory responses in macrophages].

OBJECTIVE: To explore the effects of NF-E2-related factor-2 (NRF2)-617C/A promoter polymorphism on NRF2 expression as well as lipopolysaccharide-induced inflammatory responses in macrophages. METHODS: NRF2-617C/A promoter fragments were synthesized by chemical method and cloned into a pUC57 vector. The dul-luciferase reporter assay was employed to determine the activity of promoters. Then recombinant adenoviral vectors were constructed and transfected into macrophages. The expression of Nrf2 was examined by Western blotting and reverse transcription (RT)-PCR. The expressions of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) in macrophages after the stimulation of LPS were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: The activity of NRF2-617C promoter-luciferase reporter (FLuc/RLuc activity ratio) was significantly higher than that of NRF2-617A group (0.584 ± 0.016 vs 0.258 ± 0.018, P < 0.05).The NRF2 protein and mRNA levels in -617C group were much higher than those of 617A group (1.123 ± 0.080 vs 0.951 ± 0.057,1.889 ± 0.031 vs 1.647 ± 0.323, both P < 0.05). After the stimulation of LPS, the NRF2 protein expression in macrophages significantly increased (0.584 ± 0.016 vs 0.258 ± 0.018, P < 0.05). Compared with -617A group, there was a significantly higher expression of NRF2 in -617C group (0.671 ± 0.033 vs 0.751 ± 0.014, P < 0.05). Additionally, the productions of IL-6 and IL-10 in -617C group were markedly lower than those in -617A group as well as IL-6/IL-10 (both P < 0.05). However, no significant difference existed in the levels of TNF-α between -617C and -617A groups (P > 0.05). CONCLUSIONS: The -617C/A promoter polymorphism of NRF2 may influence the NRF2 expression. And it appears to be associated with the LPS-induced inflammatory responses in macrophages.

[Effect of thalidomide in a mouse model of paraquat-induced acute lung injury and the underlying mechanisms].

OBJECTIVE: To investigate the intervention effect of thalidomide on paraquat-induced acute lung injury in mice and its mechanism. METHODS: Male ICR mice were randomly allocated to negative control group (n = 30), thalidomide control group (n = 30), paraquat poisoning group (n = 30), 50 mg/kg thalidomide treatment group (n = 30), 100 mg/kg thalidomide treatment group (n = 30), and 150 mg/kg thalidomide treatment group (n = 30). The negative control group was intraperitoneally injected with the same volume of saline; the thalidomide control group was intraperitoneally injected with thalidomide (150 mg/kg); the paraquat poisoning group was intraperitoneally injected with diluted paraquat solution (22 mg/kg); each thalidomide treatment group was intraperitoneally injected with the same volume of paraquat solution (22 mg/kg) and was injected with thalidomide (50, 100, or 150 mg/kg) 1 h later. All mice were anesthetized and sacrificed at 1, 3, or 7 d after paraquat poisoning, and their lung tissue was collected. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 in lung tissue were measured by double-antibody sandwich ELISA; the mRNA expression of nuclear factor-kappa B (NF-κB) was measured by RT-PCR; the protein expression of nuclear NF-kgr;B p65 was measured by Western blot. The pathological changes of lung tissue were observed under light microscope; the wet/dry ratio of the lung was calculated. RESULTS: Compared with the negative control group, the paraquat poisoning group had significantly increased levels of TNF-α, IL-1ß, IL-6, NF-κB mRNA, and nuclear NF-κB p65 and wet/dry ratio of the lung (P < 0.05). Compared with the paraquat poisoning group, the thalidomide treatment groups had significantly decreased levels of TNF-α, IL-1ß, IL-6, NF-κB mRNA, and nuclear NF-κB p65 and wet/dry ratios of the lung (P < 0.05), and the 150 mg/kg thalidomide treatment group showed the most significant decrease in the levels of TNF-α, IL-1ß, IL-6, NF-κB mRNA, and nuclear NF-κB p65. The observation of pathological changes showed that the paraquat poisoning group had the most marked lung tissue damage at 3 d after poisoning, and the lung tissue damage was lessened in the thalidomide treatment groups. CONCLUSION: Thalidomide can reduce paraquat-induced acute lung injury and lung edema. The mechanism may include inhibition of NF-κB activation and expression and downregulation of TNF-α, IL-1ß, and IL-6.