Adsorption and bacterial performance of Nd2O3 modified Ag nanoparticles with enhanced degradation of methylene blue

Our study focused on the optical behavior, methylene blue (MB) dye degradation potential, antibacterial performance, and silver and trioxide mineral interaction with different bacterial species. We found that the addition of silver nanoparticles (Ag NPs) to neodymium oxide (Nd2O3) resulted in a significant response, with an enlargement of the inhibition zone for bacterial species such as Staphylococcus aureus and Escherichia coli. Specifically, the inhibition zone for S. aureus increased from 9.3 ± 0.5 mm for pure Nd2O3 to 16.7 ± 0.4 mm for the Ag/Nd2O3 nano-composite, while for E. coli, it increased from 8.8 ± 0.4 mm for Nd2O3 to 15.9 ± 0.3 mm for Ag/Nd2O3. Furthermore, the optical behavior of the composites showed a clear band-gap narrowing with the addition of Ag NPs, resulting in enhanced electronic localization. The direct and indirect transitions reduced from 6.7 to 6.1 eV and from 5.2 to 2.9 eV, respectively. Overall, these results suggest that the Ag/Nd2O3 nano-composite has potential applications in sensor industries and water treatment, thanks to its enhanced optical behavior, antibacterial performance, and efficient MB degradation capabilities. In terms of MB degradation, the Ag/Nd2O3 mixed system exhibited more efficient degradation compared to pure Nd2O3. After 150 min, the MB concentration in the mixed system decreased to almost half of its starting point, while pure Nd2O3 only reached 33%.

[The role of Keap1/Nrf2/HO-1 signal pathway in liver injury induced by rare earth neodymium oxide in mice]

Objective: To investigate the role of Keap1/Nrf2/HO-1 signaling pathway in liver injury induced by neodymium oxide (Nd(2)O(3)) in mice. Methods: In March 2021, forty-eight SPF grade healthy male C57BL/6J mice were randomly divided into control group (0.9% NaCl), low dose group (62.5 mg/ml Nd(2)O(3)), medium dose group (125.0 mg/ml Nd(2)O(3)), and high dose group (250.0 mg/ml Nd(2)O(3)), each group consisted of 12 animals. The infected groups were treated with Nd(2)O(3) suspension by non-exposed tracheal drip and were killed 35 days after dust exposure. The liver weight of each group was weighed and the organ coefficient was calculated. The content of Nd(3+) in liver tissue was detected by inductively coupled plasma mass spectrometry (ICP-MS). HE staining and immunofluorescence was used to observe the changes of inflammation and nuclear entry. The mRNA expression levels of Keap1, Nrf2 and HO-1 in mice liver tissue were detected by qRT-PCR. Western blotting was used to detect the protein expression levels of Keap1 and HO-1. The contents of catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) were detected by colorimetric method. The contents of interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by ELISA. The data was expressed in Mean±SD. Two-independent sample t-test was used for inter-group comparison, and one-way analysis of variance was used for multi-group comparison. Results: Compared with the control group, the liver organ coefficient of mice in medium and high dose groups were increased, and the Nd(3+) accumulation in liver of mice in all dose groups were significantly increased (P<0.05). Pathology showed that the structure of liver lobules in the high dose group was slightly disordered, the liver cells showed balloon-like lesions, the arrangement of liver cell cords was disordered, and the inflammatory exudation was obvious. Compared with the control group, the levels of IL-1β and IL-6 in liver tissue of mice in all dose groups were increased, and the levels of TNF-α in liver tissue of mice in high dose group were increased (P<0.05). Compared with the control group, the mRNA and protein expression levels of Keap1 in high dose group were significantly decreased, while the mRNA expression level of Nrf2, the mRNA and protein expression levels of HO-1 were significantly increased (P<0.05), and Nrf2 was successfully activated into the nucleus. Compared with the control group, the activities of CAT, GSH-Px and T-SOD in high dose group were significantly decreased (P<0.05) . Conclusion: A large amount of Nd(2)O(3) accumulates in the liver of male mice, which may lead to oxidative stress and inflammatory response through activation of Keap1/Nrf2/HO-1 signal pathway. It is suggested that Keap1/Nrf2/HO-1 signal pathway may be one of the mechanisms of Nd(2)O(3) expose-induced liver injury in mice.

LncRNA H19 via miR-29a-3p is involved in lung inflammation and pulmonary fibrosis induced by neodymium oxide

The occupational and environmental health safety of rare earths has attracted considerable attention. In China, the rare earth neodymium oxide (Nd₂O₃) is extensively refined and utilized. However, the mechanisms of Nd₂O₃-induced lung injury are elusive. In the present study, we found that exposure of mice to Nd₂O₃ caused an inflammatory reaction and fibrosis in lung tissues, which was in relation to the Nd₂O₃-induced higher levels of the lncRNA H19 (H19), tumor necrosis factor receptor 1 (TNFRSF1A), p-p65, and p-IKKβ and lower levels of miR-29a-3p. Further, in mouse monocyte macrophage leukemia cells (RAW264.7), Nd₂O₃ induced an inflammatory reaction, increases of H19 and TNFRSF1A levels, decreases of miR-29a-3p levels, and activation of the nuclear factor (NF)-κB signaling pathway. Further, we established that miR-29a-3p regulates TNFRSF1A expression. Up-regulation of miR-29a-3p and down-regulation of H19 blocked the Nd₂O₃-induced secretion of TNF-α, MIP-1α, and IL-6; the increases of TNFRSF1A levels; and activation of the NF-κB signaling pathway in RAW264.7 cells. Further, in Nd₂O₃-treated RAW26.4 cells, H19 inhibited the expression of miR-29a-3p, which targets TNFRSF1A, and activated the NF-κB signaling pathway to enhance the expression of TNF-α, MIP-1α, and IL-6. Moreover, for mice, up-regulation of miR-29a-3p reversed lung tissue inflammation, pulmonary fibrosis, and activation of the NF-κB signaling pathway induced by Nd₂O₃. In sum, the present investigation shows that H19 via miR-29a-3p is involved in lung inflammation and pulmonary fibrosis induced by Nd₂O₃, which is a mechanism for the Nd₂O₃-induced lung inflammatory response and pulmonary fibrosis. This information is useful for development of a biomarker of Nd₂O₃-induced lung injury.

LncRNA loc105377478 promotes NPs-Nd2O3-induced inflammation in human bronchial epithelial cells through the ADIPOR1/NF-κB axis

With the wide application of neodymium oxide nanoparticles (NPs-Nd₂O₃) in various fields, their health hazards have aroused public concern in recent years. However, data regarding the cytotoxicity of NPs-Nd₂O₃ is limited. In this study, we investigated the function and mechanism of long-chain non-coding RNAs (lncRNAs) in NPs-Nd₂O₃-induced airway inflammation. Treatment with NPs-Nd₂O₃ induced an inflammatory response in human bronchial epithelial cells (16HBE) by upregulating the expression of interleukin-6 (IL-6) and interleukin-8 (IL-8). The levels of LDH and intracellular ROS in the cells treated by various doses of NPs-Nd₂O₃ also increased significantly. After treatment with 10 μg/ml NPs-Nd₂O₃, RNA microarray and real-time quantitative polymerase chain reaction (qRT-PCR) showed a significant upregulation of lncRNA loc105377478. Functional experiments suggested lncRNA loc105377478 enhanced the expression of IL-6, IL-8 and ROS in NPs-Nd₂O₃-treated 16HBE cells, and it was further demonstrated that lncRNA loc105377478 promoted the activation of NF-κB by negatively regulating ADIPOR1 expression. Moreover, the expression of IL-6 and IL-8 in NPs-Nd₂O₃-treated 16HBE cells was regulated by lncRNA loc105377478, which was mediated by the NF-κB signaling pathway. In conclusion, lncRNA loc105377478 promotes NF-κB activation by negatively regulating ADIPOR1 expression, thereby upregulating the expression of IL-6 and IL-8 in 16HBE cells treated with NPs-Nd₂O₃.

circ_0000638 inhibits neodymium oxide-induced bronchial epithelial cell inflammation through the miR-498-5p/NF-κB axis

Inhalation of neodymium oxide, a type of rare earth metal, can induce various respiratory diseases, such as lung tissue inflammation, but the associated mechanisms underlying this induction are still unclear. In this study, we explored the role and mechanisms of circular RNA in neodymium oxide-induced airway inflammation. Our study showed that treating human bronchial epithelial (16HBE) cells with neodymium oxide caused an inflammatory response by upregulating the expression of interleukin-8 (IL-8) and interleukin-1 beta (IL-1β). Quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed significant downregulation of circRNA_0000638 in neodymium oxide-treated 16HBE cells. Data from functional analyses further showed that circ_0000638 inhibited inflammation induced by neodymium oxide in 16HBE cells. circ_0000638 targeted miR-498-5p and further increased the expression of NKRF (NF-κB repressing factor), which inhibited the activation of NF-κB (nuclear factor κB). Moreover, circ_0000638 reduced the expression of IL-8 and IL-1β by inhibiting NF-κB activation in neodymium oxide-treated 16HBE cells. These results suggest that circ_0000638 can inhibit NF-κB activation by competitively binding to miR-498-5p, further downregulating the expression of IL-8 and IL-1β in neodymium oxide-treated 16HBE cells.