Pyroptosis and polarization of macrophages in septic acute lung injury induced by lipopolysaccharide in mice.

BACKGROUND: Pyroptosis and polarization are significant contributors to the onset and development of many diseases. At present, the relationship between pyroptosis and polarization in acute lung injury (ALI) caused by sepsis remains unclear. METHODS: The ALI model for sepsis was created in mice and categorized into the blank control, lipopolysaccharide (LPS) group, LPS + low-dose Belnacasan group, LPS + high-dose Belnacasan group, LPS + low-dose Wedelolactone group, LPS + high-dose Wedelolactone group, and positive control group. The wet-dry specific gravity was evaluated to compare pulmonary edema. Hematoxylin-eosin, Masson, and terminal deoxynucleotidyl transferase dUTP nick end labeling staining techniques were conducted to observe and contrast the pathological changes in lung tissue. ELISA was utilized to identify M1 and M2 macrophages and correlated inflammatory factors. Immunohistochemical staining and flow cytometry were employed to identify markers of M1 and M2 macrophages in lung tissue. Propidium iodide staining, together with flow cytometry, was utilized to observe the degree and positive rate of pyroptosis of alveolar macrophages. Western blot analysis was conducted to detect the expression levels of Caspase 1, Caspase 11, GSDMD, and IL-18 in the lung tissues of each group. The real-time quantitative polymerase chain reaction method was used to ascertain relative expression levels of NLRP3, Caspase 1, Caspase 11, GSDMD, IL-18, iNOS, and Arg-1 in lung tissues of all groups. RESULTS: In mice with sepsis-induced ALI, both classical and nonclassical pathways of pyroptosis are observed. Inhibiting pyroptosis has been found to ameliorate lung injury, pulmonary edema, and inflammation induced by LPS. Notably, the expression of NLRP3, Caspase 1, Caspase 11, GSDMD, IL-1ß, IL-18, TGF-ß, CD86, CD206, iNOS, and Arg-1 were all altered in this process. Additionally, alveolar macrophages were polarized along with pyroptosis in mice with ALI caused by sepsis. CONCLUSION: Pyroptosis of alveolar macrophages in the context of ALI in mice infected with sepsis has been linked to the polarization of alveolar macrophages toward type M1.

Simultaneous reduction in cadmium and arsenic accumulation in rice (Oryza sativa L.) by iron/iron-manganese modified sepiolite.

It is challenging to reduce the cadmium (Cd) and arsenic (As) contents of brown rice simultaneously due to their converse chemical behaviors in the paddy soil. Clay minerals, such as sepiolite (SEP), have significant advantages in remediating Cd-contaminated soil. Moreover, iron or manganese oxide loaded SEP can improve the As adsorption efficiency. Herein, ferric nitrate modified sepiolite (NIMS) and iron­manganese modified sepiolite (FMS) were prepared to study their effects on Cd and As accumulation in rice using pot experiments. The results showed that NIMS and FMS had a larger specific surface area than SEP. The application of SEP only decreased Cd content (by 45%), while NIMS and FMS treatments reduced both Cd (by 57% and 87%) and As (by 30% and 25%) contents in brown rice compared with the control. The X-ray photoelectron spectroscopy (XPS) analysis results indicated that MnO2 and MnOOH⁎ in FMS enhanced the adsorption and co-precipitation of Cd as well as the oxidation of As(III) to As(V). The NIMS, as well as the FMS application, increased soil pH, decreased the exchangeable Cd and non-specifically and specifically adsorbed As fractions in soil, and reduced the level of Cd in the pore water. Moreover, NIMS and FMS addition limited the transfer of As from the soil to the roots by enhancing its sequestration in the iron plaque. On the other hand, FMS treatment significantly promoted the uptake of Mn by rice (P < 0.05). The results suggested that both NIMS and FMS were promising materials for simultaneous reduction of Cd and As accumulation in rice. Notably, FMS had better performance in reducing the Cd content in rice than that of NIMS.

[Screening of Amendments for Simultaneous Cd and As Immobilization in Soil].

Simultaneously reducing the availability of Cd and As is difficult owing to converse chemical behaviors of Cd and As in soil. In this study, amendments that can simultaneously immobilize Cd and As in soil were determined by an pure soil culture experiment in which flooding and wetting were performed for 30 d each. The effects of sepiolite (Sep), modified sepiolite (IMS and Sep-FM), steel slag (SS), and iron modified biochar (Fe-Bio) on soil pH, Eh, Cd, and As concentrations in pore water, and Cd and As fractions in soil were investigated. It showed that Sep (1%, 2.5%), IMS (1%, 2.5%), Sep-FM (1%, 2.5%), and SS (1%, 5%) treatments increased soil pH value and decreased Eh value and Cd concentrations in soil solution. In addition, As concentrations in soil solution treated with high doses of IMS (2.5%) and SS (5%) were lower than that of CK treatment during the whole incubation period. However, Fe-bio treatment decreased soil pH and increased Eh value and only decreased Cd and As concentrations in soil solution under wet conditions. Compared with the control, the application of the above amendments promoted the transformation of Cd fraction from exchangeable to reducible, oxidizable, and residual. High application rates of IMS (2.5%), Sep-FM (2.5%), and SS (5%) also reduced available As fraction (non-specifically sorbed and specifically-sorbed As fraction), and increased amorphous and poorly-crystalline hydrated Fe and Al oxide-bound As. On the contrary, Fe-bio treatment increased the fractions of non-specifically sorbed, specifically sorbed and residual As in soil. In short, IMS, Sep-FM, and SS are potential materials for remediation of Cd and As contaminated soil. They can effectively immobilize soil Cd and As and promote their transformation to the fractions that plants are difficult to uptake.

Comparative efficacy of organic and inorganic silicon fertilizers on antioxidant response, Cd/Pb accumulation and health risk assessment in wheat (Triticum aestivum L.).

In wheat production areas of China, soil lead (Pb) pollution is generally accompanied by cadmium (Cd) pollution and it is of considerable significance in repairing the Cd and Pb co-contaminated soils for safe agronomic production. Organosilicon fertilizer (OSiF) is a new type of silicon (Si) fertilizer that can effectively alleviate heavy metal toxicity in plants, but the mechanisms on its heavy metal detoxification are poorly understood. A soil pot experiment was conducted to evaluate and compare the effects of two OSiFs (OSiFA and OSiFB) and an inorganic silicon fertilizer (InOSiF) on wheat heavy metal uptake and biochemical parameters in a Cd and Pb co-contaminated soil. The results demonstrated that OSiFA, OSiFB and InOSiF could alleviate the Cd and Pb toxicity of wheat, as indicated by increasing wheat grain yield by 65%, 45% and 22%, respectively. The Si fertilizers enhanced leaf gas exchange attributes and chlorophyll content, whereas diminished the oxidative damage, as indicated by a lower level of hydrogen peroxide (H2O2) and malondialdehyde (MDA) content, and lower activity of superoxide dismutase (SOD) and catalase (CAT) activity, as compared with control. Adding OSiFA, OSiFB and InOSiF increased Si uptake in roots and shoots, thus reducing Cd and Pb accumulation in the wheat shoot, bran and flour, especially, flour Cd contents by 17%, 10% and 31% respectively, flour Pb contents by 74%, 53% and 48% respectively. Also, Si fertilizers application decreased the health risk index (HRI) of both Cd and Pb. The grey correlation degrees of OSiFA, OSiFB and InOSiF are 0.72, 0.77 and 0.61, respectively, indicating that the effects of OSiFs on detoxifying Cd and Pb could be better than that of InOSiF in wheat. Thus, the use of OSiFs might be a feasible approach to reduce Cd and Pb entry into the human body through crops.