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Objective@#To investigate the effects of cerebral cavernous malformation 3 (CCM3) gene knockout on the lead exposure-induced blood-brain barrier malfunction in mice brain, and the relationship between CCM3 knockout and the Alzheimer's disease (AD).@*Methods@#Wide type (WT) mice and CCM3+/- mice were divided into 4 groups, control group and lead exposed group in WT as well as CCM3+/- mice. Lead exposed groups were treated with 0.05% lead acetate in drinking water for 12 weeks, while control group drink deionized water freely. Blood lead and brain lead levels in each group were detected by graphite furnace atomic absorption spectrometry. The brain tissue of each group was made into paraffin sections, whose morphology were observed by HE staining. The expression of Aβ1-42 in brain tissue was detected by immunohistochemistry and the brain capillaries were labeled by VRGFR2. The protein expression of Claudin-5, ZO-1, and p-Tau was detected by Western blot. The brain tissue RNA was extracted and the relative expression of LRP-1 mRNA was detected by qRT-PCR.@*Results@#The levels of blood lead WT (216.07±84.16) and CCM3+/- (189.64±101.86) μg/L in lead exposed group were higher than those in control group WT (19.52±11.46) and CCM3+/- (11.79±8.20) μg/L, the difference was statistically significant (t=4.18, P=0.006; t=3.79, P=0.016). The levels of brain lead WT (1.78±0.69) and CCM3+/- (1.74±0.66) μg/L were higher than those in control group WT (1.06±0.87) and CCM3+/- (0.97±0.64) μg/L, the difference was statistically significant (t=3.67, P=0.018; t=3.88, P=0.015). The HE staining showed no obvious lesions in the brain of each group of mice. The results of immunohistochemistry showed that there was no Aβ1-42 deposition in the brain of mice in each group. The numbers of microvessels in the brain of CCM3+/- mice in the lead exposed group were decreased. Compared with the relative expression levels of Claudin-5 (WT: 1.30±0.03, CCM3+/-: 1.07±0.08) in control group mice brain, the relative expression of Claudin-5 (WT: 0.96±0.04, CCM3+/-: 0.59±0.01) was decreased with statistical significance (F=199.27, P<0.001). The relative expression level of LRP-1 gene mRNA in brain of lead exposed group (WT: 0.32±0.10, CCM3+/-: 0.06±0.01) was higher than that of unexposed group (WT:1.00±0.06, CCM3+/-:2.12±0.18), the difference was statistically significant (F=288.29, P<0.001). The relative expression level of LRP-1 gene mRNA in brain of CCM3+/- mice exposed to lead was lower than that of WT mice ((0.06±0.01)vs(0.32±0.10), t=26.90, P<0.001).@*Conclusion@#The mice did not show significant AD-like lesions under low-does lead exposure, but resulted in early damage of brain blood-brain barrier and early changes of AD-like lesions in mice, with CCM3+/- mice being sensitive to lead exposure stronger than that of WT mice, suggesting that deletion of CCM3 gene may be one of the potential risk factors for accelerating the development of AD in mice exposed to lead.
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Objective@#To establish the immortalized mouse brain microvascular pericytes model and to apply to the cerebrovascular toxicants screening study.@*Methods@#Brain pericytes were isolated from 3 weeks of mice by tissue digestion. Immortalized pericyte cell line was constructed by infecting with LT retrovirus. Monoclone was selected to purify the immortalized pericyte cell line. The pericyte characteristics and purity were explored by immunocytochemistry. Cell proliferation was measured by using the Pomega MTS cell Proliferation Colorimetric Assay Kit. Pericytes were treated with 0, 160, 320, 640, 1 280, 2 560 μmol/L lead acetate, 0, 5, 10, 20, 40, 80 μmol/L cadmium chloride and 0, 5, 10, 20, 40, 80 μmol/L sodium arsenite in 24 hours. Cell toxicity of each group was determined by MTS assay, median lethal dose (LD50) was calculated in linear regression.@*Results@#Mouse brain pericytes were successfully isolated by tissue separation and enzyme digestion method. After immortalized by LT retroviruses, monoclone was selected and expanded to establish pericyte cell line. The brain pericytes exhibited typical long spindle morphology and positive staining for α-SMA and Vimentin. The proliferation of brain pericytes cell lines was very slowly, and the doubling time was about 48 hours. The proliferation of immortalized brain pericytes cell lines was very quickly, and the doubling time was about 24 hours. After lead acetate, cadmium chloride and sodium arsenite treatment for 24 hours respectively, gradual declines in cell viability were observed. The LD50 of lead acetate was 2 025.0 μmol/L, the LD50 of cadmium chloride was 36.6 μmol/L, and the LD50 of sodium arsenite was 33.2 μmol/L.@*Conclusion@#The immortalized mouse brain microvascular pericyte model is established successfully by infecting with LT retrovirus, and can be applied to screen cerebrovascular toxicants. The toxicity of these toxicants to immortalized mouse brain microvascular pericyte is in sequence: sodium arsenite,cadmium chloride, lead acetate.
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OBJECTIVE: To investigate the effects of knockout cerebral cavernous malformation(CCM) virulence gene CCM3 on the migration induced by lead acetate in immortalized human umbilical vein endothelial cells(HUVECs) and to explore the possible mechanism of endoplasmic reticulum stress(ERS). METHODS: CCM3 wildtype(CCM3-WT) and CCM3 knockout(CCM3-KO) HUVECs were used as experimental cells. a) CCM3-WT and CCM3-KO HUVECs were treated with lead acetate at 0,10,50 and 200 μmol/L for 24 hours. The migration of these cells was observed by woundhealing assay. b) CCM3-WT and CCM3-KO HUVECs were treated with lead acetate at 0,10,50 and 200 μmol/L for 24 hours,and at 50 μmol/L for 0,6,12,24 and 48 hours,and the mRNA expression of genes of unfolded protein response pathway were detected by quantitative real-time polymerase chain reaction; the protein expression of glucose-regulated protein 78(GRP78) was detected by Western blotting. c) CCM3-WT and CCM3-KO HUVECs were divided into lead exposure group and tauroursodeoxycholic acid(TUDCA) group. The former was treated with 50 μmol/L lead acetate for 24 hours,and the latter was pre-treated with ERS inhibitor TUDCA,followed by 50 μmol/L lead acetate. The migration of these cells was observed by wound-healing assay. RESULTS: a) The migration of CCM3-WT and CCM3-KO cells decreased and showed a dose-effect relationship with the increase of lead acetate concentration(P < 0. 05). b) The mRNA relative expression of the GRP78,protein kinase-like endoplasmic reticulum kinase(PERK),transcription activator 4(ATF4) and CCAAT enhancer binding homologous protein(CHOP) in CCM3-KO cells treated with 10,50 and 200 μmol/L lead acetate were higher than that in CCM3-WT cells at the same doses,except for the GRP78 in CCM3-KO cells treated with10 μmol/L lead acetate(P < 0. 05). The mRNA expression of PERK and CHOP in CCM3-KO cells increased in a timeeffect relationship with the increase of lead-exposure time(P < 0. 05). The mRNA relative expression of the four genes in CCM3-KO cells were higher than those in CCM3-WT cells at 48 hours(P < 0. 05). When cells were treated with 50μmol/L lead acetate,the protein expression of GRP78 in CCM3-KO cells was higher than that in CCM3-WT cells(P <0. 05),and the protein expression of GRP78 in CCM3-KO cells increased in a time-effect relationship with the increase of lead-exposure time(P < 0. 05). c) The cell migration of TUDCA group was lower than that of lead-exposure group(P <0. 05). CONCLUSION: Lead acetate may activate ERS by activating the PERK-ATF4-CHOP signaling pathway,thereby reducing the migration of HUVECs. CCM3 gene has a protective effect on cell migration.
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<p><b>OBJECTIVE</b>To investigate the effect of CCM3 gene defection on lead induced cell genotoxicity in mouse embryonic fibroblasts.</p><p><b>METHODS</b>C57 female mice were mated with CCM3 gene heterozygous male mice. E13.5 embryos were taken to isolate primary mouse embryonic fibroblasts. After genotyping, wild type and heterozygous cells were treated with different doses of lead acetate. Cell viability, genotoxicity and protein expression were detected by MTS assay, CB micronucleus method and Western blot, respectively.</p><p><b>RESULTS</b>Mouse embryonic fibroblasts with lead acetate treatment for 24 h, wild-type cells 100.00 µmol/L lead acetate-treated group (69.16±1.36) and the control group (100.00±2.33) compared to cells decreased by 30%, CCM3 heterozygous type cell 100.00 µmol/L lead acetate-treated group (87.16±5.50) and the control group (100.00±2.06) compared to cells decreased by 13%, the difference was statistically significant (F values were 98.59, 82.63, P<0.001). Lead acetate treatment after 48 h, wild-type cells 100.00 µmol/L lead acetate-treated group (51.99±5.62) and the control group (100.00±3.11) compared to cells decreased by 50%, heterozygous type cells 100.00 µmol/L lead acetate treatment group (66.33±4.06) and the control group (100.00±5.72) compared to cells decreased by 35%, the differences were statistically significant (F values were 82.63, 36.86, P < 0.001). The results of CBMN test showed that with increased dose, micronucleus cell rate of two genotypes showed an increasing trend, in the wild-type cells, the micronucleus cell rate (/1 000) for the control group, 29.6±2.2, 6.25 µmol/L dose group 47.3±6.6, 25 µmol/L dose group 55.5±9.1, 100.00 µmol/L dose group 66.8±3.5; heterozygous cells micronucleus cell rate (/1 000) for the control group, 35.3±5.6, 6.25 µmol/L dose of 50.0±8.3, 25.00 µmol/L dose group 57.0±8.5, 100.00 µmol/L dose group 58.8±2.1. Micronucleus cell rates (/1 000) were significant differences, in 100.00 µmol/L dose groups of two genotypes. Western blot results showed that wild-type cells CCM3 expression 100.00 µmol/L lead acetate-treated group (0.70±0.03) was 1.32 times higher than the control group (0.53±0.07), heterozygous cells CCM3 expression 100.00 µmol/L lead acetate-treated group (0.48±0.02) was 1.77 times higher than control group that of 0.27±0.04, there was statistically significant difference (F values were 14.77, 25.74, P < 0.001); wild-type cells γ-H2AX expression 100.00 µmol/L lead acetate-treated group (0.69±0.03) was 1.06 times higher than the control group (0.65±0.07), heterozygous cells γ-H2AX expression 100.00 µmol/L lead acetate-treated group (0.99±0.04) was 1.55 times higher than the control group CCM3 expression levels (0.64±0.06), there was statistically significant difference (wild-type cells: F = 7.08, P = 0.012, heterozygous type cell: F = 13.49, P = 0.002).</p><p><b>CONCLUSION</b>CCM3 gene may play a role in lead-induced genetic toxicity of mouse embryonic fibroblasts, CCM3 gene-lead interactions effects on mouse embryonic fibroblasts cell toxicity.</p>
Subject(s)
Animals , Female , Male , Mice , Apoptosis Regulatory Proteins , DNA Damage , Embryo, Mammalian , Fibroblasts , Genotype , Membrane Proteins , Mice, Inbred Strains , Micronuclei, Chromosome-Defective , Organometallic Compounds , Proto-Oncogene ProteinsABSTRACT
Deer antlers are the unique mammalian organs that can be periodically regenerated,i.e.,they hold interest for researchers on stem cells and regenerative medicine,and have the potential to become an excellent biomedical research model.Deer antler regeneration may use stem cells.Antler growth appears to involve specific stimulation of the necessary stem cells present in the locality,and involves similar mechanisms to those used in limb development,unlike the regenerative process in the newt.Development regulation of antler and growth mechanism of antler stem cells have significance in limb regenerated medicine and stem cell research.Many scientists have carried out thorough research on the deer antlers development,thus,have drawn many concepts.This article reviews the field of deer antlers development such as antler regeneration and stem cells,and introduces research technique of antler development and relevant theories.