ABSTRACT
AIM:To observe the toxic effects of zinc oxide nanoparticles(ZnO NPs)on cornea by constructing intoxicated model in vivo and in vitro.METHODS:Human corneal epithelial cells(HCEpiC)were cultured in vitro and exposed to different concentrations(0.5, 5, 12.5, 25, 50, 100, 250 μg/mL)of ZnO NPs for 24h. The cell culture medium without nano-solution was used as the blank control group. The viability of the cells was assessed by MTT assay. Three different concentrations(25, 50 and 100 μg/mL)of ZnONPs dispersions were exposed to the conjunctival sac of anesthetized mice three times a day for 7d consecutively. The phosphate buffered saline(PBS)eye group was the PBS control group. Corneal morphology was observed on 1, 3, 5 and 7d, and the eyes were removed on 8d for various laboratory examinations, including corneal pathological changes and expression levels of inflammatory factors(TNF-α, IL-6).RESULTS:After treatment of HCEpiC cells with different concentrations of ZnO NPs for 24h, the MTT results showed that Zno NPs cause damage to cells at 0.5 μg/mL, and the cell survival rate was about 80%(P<0.05). Half of the cells were killed at a dose of 5 μg/mL, the damaging effect on cells in the concentration range of 5～250 μg/mL was concentration-dependent(P<0.0001). After 7d of conjunctival capsule spotting in mice, dot-like staining of fluorescein was seen in the 25 μg/mL ZnO NPs and 50 μg/mL ZnO NPs groups. Localized circular fluorescein stained areas were seen in the corneas of the 100 μg/mL ZnO NPs group. HE staining showed that the corneal epithelial layer, stromal layer thickness and stromal layer immune cell number did not change significantly in the 25 μg/mL and 50 μg/mL ZnO NPs groups(all P>0.05), while the corneal epithelial layer thinned, the corneal stromal layer thickened and the stromal layer immune cells increased significantly in the 100 μg/mL ZnO NPs group(all P<0.05). Immunohistochemical staining showed that the number of corneal stromal immune cells producing TNF-α and IL-6 and the mean integral optical density(IOD)values of TNF-α and IL-6 were significantly higher in the 100 μg/mL ZnO NPs group than in the PBS control group(P<0.05), and the degree of inflammation response was concentration-dependent. Compared with the PBS control group, no significant increase in immune cell count and IOD values in the 25 μg/mL ZnO NPs and 50 μg/mL ZnO NPs groups(P>0.05).CONCLUSION:The toxic damaging effect of ZnO NPs on the cornea was confirmed from both in vitro and in vivo, which provided a theoretical basis for the ocular safety evaluation of ZnO NPs.
ABSTRACT
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.
Subject(s)
Mice , Male , Animals , NF-E2-Related Factor 2/metabolism , Tumor Necrosis Factor-alpha/metabolism , Kelch-Like ECH-Associated Protein 1/metabolism , Interleukin-6/metabolism , Mice, Inbred C57BL , Oxidative Stress , Liver/metabolism , Metals, Rare Earth , Signal Transduction , Superoxide Dismutase/metabolism , RNA, Messenger/metabolismABSTRACT
Objective: To explore the effect of modified Si Junzitang (MSJZT) drug serum on the expression of apoptosis-related molecules of gastric cancer cell SGC-7901 and further its anti-tumor mechanism.Method: A total of 40 SD rats were randomly divided into four groups:low-dose,middle-dose,high-dose MSJZT (0.213,0.426,0.853 g·kg-1) groups and normal group (n=10).The treatment groups were administrated through gastric perfusion,and the normal group was given the equivalent volume of normal saline for 10 days.1.5 h after the last treatment,chloral hydrate peritoneal anesthesia was performed,blood was collected from heart,and different doses of serum were separated to prepare drug-containing serum of low-dose,middle-dose,high-dose MSJZT groups,in order to incubate SGC-7901 gastric cancer cell.Early and late apoptosis rates were detected with flow cytometry.Afterwards,the tumor suppressor gene p53,c-nucleoprotein gene (c-Myc),cysteine-aspartic acid protease-3(Caspase-3),B-cell lymphoma-2(Bcl-2) mRNA expressions were confirmed by fluorescence quantitative polymerase chain reaction (Real-time PCR).The protein expressions of p53,c-Myc,Caspase-3,Bcl-2 were detected by immunofluorescence.Result: Compared with the normal group,the high-dose MSJZT group could obviously increase the apoptosis rate to 22.58%(PPPPPPConclusion: MSJZT drug serum could exert an anti-tumor effect by inhibiting the expression of the anti-apoptotic protein Bcl-2,and promoting the expressions of pro-apoptotic-related molecules p53,c-Myc,Caspase-3.