Objective: To investigate the effect of asiaticoside for fibrosis in lung tissues of rats exposed to silica and to explore its possible mechanism. Methods: 144 SD male rats were randomly divided into control group, model group, positive drug control group, asiaticoside high-dose group, medium-dose group and low-dose group, each group included 24 rats. Rats in the control group were perfused with 1.0 ml of normal saline, and the other groups were given 1.0 ml 50 mg/ml SiO(2) suspension. Gavage of herbal was given from the next day after model establishment, once a day. Rats in the positive drug control group were administration with 30 mg/kg tetrandrine and rats in the low-dose group, medium-dose group and high-dose group were given 20 mg/kg, 40 mg/kg and 60 mg/kg asiaticoside for fibrosis respectively. Rats in the control group and the model group were given 0.9% normal saline. The rats were sacrificed in on the 14th, 28th and 56th day after intragastric administration and collect the lung tissues to detect the content of hydroxyproline, TGF-β(1) and IL-18, observe the pathological changes of the lung tissues by HE and Masson staining and determine the expressions of Col-I, a-SMA, TGF-β in lung tissues by Western Blot. Results: On the 14th day, 28th day and 56th day after model establishment, the lung tissues of rats in the model group showed obvious inflammatory response and accumulation of collagen fibers, and the degree of inflammation and fibrosis increased with time. The intervention of asiaticoside could effectively inhibit the pathological changes of lung tissues. The contents of hydroxyproline, IL-18 and TGF-β1 in lung tissues of model group were higher than those in the control group (P<0.05) , while the level of hydroxyproline, IL-18 and TGF-β1 in asiaticoside groups were significantly decreased, and the difference was statistically signicant (P<0.05) . Compared with the control group, the expression levels of Col-I, TGF-β1and α-SMA in lung tissue of model group were increased (P<0.05) , while the expression level of Col-I, TGF-β1 and α-SMA were decreased after the intervention of asiaticoside, and the difference was statistically signicant (P<0.05) . Conclusion: Asiaticoside can inhibit the increase of Col-I, TGF-β1 and α-SMA content in the SiO(2)-induced lung tissues of rats, reduce the release of TGF-β1 and IL-18 inflammatory factors in lung tissue, and then inhibit the synthesis and deposition of extracellular matrix in rat lung tissue, and improve silicosis fibrosis.
Animals ; Dust ; Lung ; Male ; Pulmonary Fibrosis/metabolism* ; Rats ; Silicon Dioxide/adverse effects* ; Silicosis/metabolism* ; Transforming Growth Factor beta1/metabolism*

OBJECTIVE: To construct mesoporous nano-bioactive glass (MNBG) microspheres load-release minocycline as an antibacterial drug delivery system. METHODS: Sol-gel method was used to synthesze MNBG microspheres as drug carrier. The MNBG consisted of SiO2, CaO, and P2O5. According to the content of silicon, MNBG microspheres were divided into four groups (60S, 70S, 80S and 90S). Scanning electron microscopy (SEM) was used to observe the surface characteristic and particle size of MNBG; Nitrogen adsorption-desorption experiment was performed to calculate the MNBG's specific surface area and the pore sizes; The Fourier transform infrared spectrum (FT-IR) and the thermogravimetric analysis were conducted to calculate the loading efficiencies of minocycline hydrochloride; UV spectrophotometric was used to determine the cumulative release of minocycline from drug-loaded particles in PBS solution within 21 d. Agar diffusion test (ADT) was performed to evaluate the antibacterial properties on Enterococcus faecalis. The inhibition zone was observed and the diameter was measured. RESULTS: The MNBG microspheres had good dispersion, large surface area, and even particle size. The pore sizes ranged from 4.77 nm to 7.33 nm. The loading experiment results showed that the minocycline hydrochloride loading efficiency of MNBG was related to the pore size of the microspheres. Among 60S, 70S, 80S and 90S, 60S MNBG had the highest loading efficiency of 16.33% due to its high calcium content and large pore sizes. A slow minocycline release rate from MNBG particles in PBS solution until d 21 was observed. It was showed that a burst release of 28% of the total drug for the first 24 h. A cumulative release of 35% was found, and the final concentration of minocycline maintained at about 47 mg/L. ADT showed that mino-MNBG had inhibitory effect on the growth of Enterococcus faecalis. 1 g/L minocycline, 1 g/L mino-MNBG, and 0.1 g/L minocycline presented inhibition zone, however, PBS and 1 g/L MNBG didn't. The diameter of the inhibition zone of minocycline groups was significant larger than that of mino-MNBG group (P<0.05), which was also significant larger than those of PBS and MNBG groups (P<0.05). It showed that mino-MNBG drug delivery system had antibacterial properties on Enterococcus faecalis. CONCLUSION The 60S MNBG that can effectively load and release minocycline may be an ideal drug carrier.
Adsorption ; Anti-Bacterial Agents/administration & dosage* ; Drug Carriers ; Drug Delivery Systems ; Glass ; Microscopy, Electron, Scanning ; Microspheres ; Minocycline/adverse effects* ; Nitrogen ; Particle Size ; Porosity ; Silicon Dioxide ; Spectroscopy, Fourier Transform Infrared

OBJECTIVETo study the effect of nano-SiO2 on spatial learning and memory.

METHODSTwenty-four male rats were randomly divided into 3 groups: control group (C group), low dose group (L group) and high dose group (H group). The rats were intragastrically administrated with nanometer particles at 25 and 100 mg/kg body weight every day for 4 weeks. After exposure, the ability of learning and memory of rats was tested by Morris water maze, and electrophysiological brain stereotactic method was used to test long-tear potentiation (LTP) in dentate gyrus (DG) of the rats.

RESULTSThe increase rate of body weight in H group was reduced significantly compared with C group ( P < 0.05). In the space exploration experiment of Morris water maze test, the escape latency of H group was longer than that of C group (P < 0.05). The rats of H group spent less time in finding the target quadrant (P < 0.05) . The rate of LP induction of H group was significantly lower than that of C group (P < 0.05). After high fre quency stimulation (HFS), The changes of amplitude of population spike (PS) of L group and H group were lower than those of C group significantly (P < 0.05, P < 0.01).

CONCLUSIONNano-SiO₂may result in impairment of spatial learning and memory ability by reducing the rate of LTP induction and the increase of PS in hippocampus.

Animals ; Dentate Gyrus ; drug effects ; Long-Term Potentiation ; drug effects ; Male ; Maze Learning ; drug effects ; Memory ; drug effects ; Nanoparticles ; adverse effects ; Rats ; Silicon Dioxide ; adverse effects ; Spatial Learning ; drug effects

Dust ; Humans ; Maximum Allowable Concentration ; Occupational Exposure ; adverse effects ; Research Report ; Silicon Dioxide ; toxicity

OBJECTIVETo study the effect of silicon dioxide nanoparticles on the expression and promoter region CpG islands methylation of (Poly [ADP-ribose] polymerase 1, PARP-1) gene in human HaCaT Cell.

METHODSHaCaT Cells were treated with nm-SiO₂at 0, 2.5, 5 and 10 µg/mL and micro-SiO₂at 10 µg/ml for 24 h and DAC treatment was given at 10 µg/ml group for 48 h. Real-time PCR and western blot assay was used to detect the expression of PARP-1 mRNA and protein. BSP (Bisulfite Pyrosequence, BSP) assay was used to detect the promoter region CpG islands methylation status of PARP-1 gene.

RESULTSAfter exposure to nano-SiO₂particles, compared to CTRL group, the mRNA and protein expression of PARP-1 in micro-SiO₂and 2.5 µg/ml group unchanged, but he mRNA and protein expression of PARP-1 in 5, 10 µg/ml as well as DAC group was down-regulated and there are statistical significance between CTRL group and 5, 10 µg/ml as well as DAC group and the PARP-1 promoter region CpG islands showed methylation.

CONCLUSIONnano-SiO₂can down-regulate PARP-1 expression in HaCaT Cell and this is associated with the change in the methylation of PARP-1 gene promoter region CpG islands induced by nano-SiO₂particles.

Cell Line, Tumor ; CpG Islands ; DNA Methylation ; Humans ; Nanoparticles ; adverse effects ; Poly (ADP-Ribose) Polymerase-1 ; Poly(ADP-ribose) Polymerases ; metabolism ; Promoter Regions, Genetic ; RNA, Messenger ; metabolism ; Silicon Dioxide ; adverse effects

Silica nanoparticles (SNPs) are widely used in many scientific and industrial fields despite the lack of proper evaluation of their potential toxicity. This study examined the effects of acute exposure to SNPs, either alone or in conjunction with ovalbumin (OVA), by studying the respiratory systems in exposed mouse models. Three types of SNPs were used: spherical SNPs (S-SNPs), mesoporous SNPs (M-SNPs), and PEGylated SNPs (P-SNPs). In the acute SNP exposure model performed, 6-week-old BALB/c female mice were intranasally inoculated with SNPs for 3 consecutive days. In the OVA/SNPs asthma model, the mice were sensitized two times via the peritoneal route with OVA. Additionally, the mice endured OVA with or without SNP challenges intranasally. Acute SNP exposure induced significant airway inflammation and airway hyper-responsiveness, particularly in the S-SNP group. In OVA/SNPs asthma models, OVA with SNP-treated group showed significant airway inflammation, more than those treated with only OVA and without SNPs. In these models, the P-SNP group induced lower levels of inflammation on airways than both the S-SNP or M-SNP groups. Interleukin (IL)-5, IL-13, IL-1beta and interferon-gamma levels correlated with airway inflammation in the tested models, without statistical significance. In the mouse models studied, increased airway inflammation was associated with acute SNPs exposure, whether exposed solely to SNPs or SNPs in conjunction with OVA. P-SNPs appear to be relatively safer for clinical use than S-SNPs and M-SNPs, as determined by lower observed toxicity and airway system inflammation.
Animals ; Asthma/*chemically induced/pathology ; Female ; Inflammation/*chemically induced/pathology ; Interferon-gamma/analysis ; Interleukins/analysis ; Lung/drug effects/*pathology ; Mice, Inbred BALB C ; Nanoparticles/*adverse effects/chemistry ; Ovalbumin/adverse effects ; Polyethylene Glycols/adverse effects/chemistry ; Silicon Dioxide/*adverse effects/chemistry ; Surface Properties

OBJECTIVETo Investigate the biological effects of miR-144 in rats' pulmanory injury induced by nanosized SiO₂preliminarily.

METHOD150 healthy SD rats were divided into five groups randomly: the control group, the nanosized SiO₂groups of 6.25, 12.5, 25.0 mg/ml, and the microsized SiO₂group of 25.0 mg/ml, 30 rats each group. Six rats were sacrificed for their pathological change on the 7th, 15th, 30th, 60th and 90th day after exposure. The expression levels of mature miR-144 in lung tissue of the rats after instilled intracheally nanosized SiO₂at 90d was detected by Quantitative Reverse Transcription PCR. Target prediction for miR-144 was conducted by databases of Target-scan, microRNA.org and miRDB. Function-significant enrichment analysis and signal pathway analysis for predicted target genes were respectively conducted by the Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes, then target genes related to pulmonary fibrosis were screened out.

RESULTSThe expression of miR-144 was up-regulated in lung tissue of rats exposed to nanosized SiO₂. The result was consistent with the results of high-throughput sequencing Hiseq 2000. The target genes of miR-144 related to fibrosis or signal pathway involved in fibrosis were screened out.They are SMAD4, SMAD5, ADAMTS3, ADAMTS15 and ADAMTS19.

CONCLUSIONMiR-144 probably participate in the regulation of fibrosis, which may play an important role in pulmonary injury induced by nanosized SiO₂.

Animals ; Lung ; pathology ; Lung Injury ; chemically induced ; metabolism ; pathology ; MicroRNAs ; metabolism ; Nanoparticles ; adverse effects ; Pulmonary Fibrosis ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Silicon Dioxide ; toxicity

OBJECTIVE: To establish 2-dimensional gel electrophoresis (2-DE) image for the early lung injury rats induced by silica dioxide and to identify differentially expressed protein biomarkers during the early stage of silicosis.
 METHODS: The animal models of silicosis were established and morphology changes were observed by HE staining, and then the key protein biomarkers in silicosis were identified by 2-DE and matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry (MALDI-TOF-MS) and verified by Western blot.
 RESULTS: The well qualified 2-DE gel images for experimental and control lung tissues were successfully established, and 40 different protein spots was observed when comparing the gel images between the experimental and control groups. Twenty of them were analyzed by MALDI-TOF-MS. A total of 13 altered proteins were identified, including alpha B-crystallin, mast cell protease 6, annexin 1, etc. The expression of alpha B-crystallin in lung was further verified by Western blot.
 CONCLUSION The protein expression of alpha B-crystallin was increased significantly, suggesting that it might play an important role in the progress of silicosis.
Animals ; Biomarkers ; metabolism ; Blotting, Western ; Disease Models, Animal ; Electrophoresis, Gel, Two-Dimensional ; Lung ; metabolism ; pathology ; Proteomics ; Rats ; Silicon Dioxide ; adverse effects ; Silicosis ; diagnosis ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; alpha-Crystallin B Chain ; metabolism

Dust ; Humans ; Inflammation ; metabolism ; Intercellular Signaling Peptides and Proteins ; metabolism ; Silicon Dioxide ; adverse effects ; Silicosis ; metabolism

OBJECTIVETo investigate the bioeffects of extremely low frequency (ELF) magnetic field (MF) (50 Hz, 400 μT) and magnetic nanoparticles (MNPs) via cytotoxicity and apoptosis assays on PC12 cells.

METHODSMNPs modified by SiO₂ (MNP-SiO₂) were characterized by transmission electron microscopy (TEM), dynamic light scattering and hysteresis loop measurement. PC12 cells were administrated with MNP-SiO2 with or without MF exposure for 48 h. Cytotoxicity and apoptosis were evaluated with MTT assay and annexin V-FITC/PI staining, respectively. The morphology and uptake of MNP-SiO₂ were determined by TEM. MF simulation was performed by Ansoft Maxwell based on the finite element method.

RESULTSMNP-SiO₂ were identified as ~20 nm (diameter) ferromagnetic particles. MNP-SiO₂ reduced cell viability in a dose-dependent manner. MF also reduced cell viability with increasing concentrations of MNP-SiO₂. MNP-SiO₂ alone did not cause apoptosis in PC12 cells; instead, the proportion of apoptotic cells increased significantly under MF exposure and increasing doses of MNP-SiO₂. MNP-SiO₂ could be ingested and then cause a slight change in cell morphology.

CONCLUSIONCombined exposure of MF and MNP-SiO₂ resulted in remarkable cytotoxicity and increased apoptosis in PC12 cells. The results suggested that MF exposure could strengthen the MF of MNPs, which may enhance the bioeffects of ELF MF.

Animals ; Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Magnetic Fields ; adverse effects ; Magnetite Nanoparticles ; toxicity ; Microscopy, Electron, Transmission ; PC12 Cells ; Rats ; Silicon Dioxide