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Objective:To explore the establishment of radiation-induced heart damage (RIDH) SD rat models caused by irradiation of 15Gy/3f and the changes in early detection indicators, and evaluate the effect of irradiation combined with recombinant human endostatin (Endostar).Methods:75 adult male SD rats were randomly divided into the blank control group (C group), Endostar group (E group), 25Gy irradiation group (MHD 25 group), 15Gy irradiation group (MHD 15 group) and 15Gy irradiation combined with Endostar group (MHD 15+ E group), respectively. Blood sample was taken to measure the CK, CK-MB, LDH and CRP at 24h, 48h and 15d after corresponding interventions. After cardiac echocardiography at 1, 3 and 6 months, 5 rats in each group were randomly sacrificed and myocardial tissues were collected for HE and Masson staining. Two-way ANOVA was employed for statistical analysis. Results:Compared with group C, myocardial fibrosis were observed in the MHD 15 group at 6 months ( P<0.05), which occurred later than that in the MHD 25 group. Ejection fraction (EF) and fractional shortening (FS) were significantly decreased after 3 months in each irradiation group (all P<0.05), whereas the degree of decrease was similar among all groups (all P>0.05). The expression levels of myocardial enzymes and inflammatory cytokines did not significantly differ among different groups (all P>0.05). Conclusions:In the early stage, exposure to 15Gy/3f irradiation can cause cardiac function damage in SD rat hearts, such as the reduction of EF and FS, and even lead to myocardial fibrosis in the late stage, which is delayed and less severe than high-dose irradiation. Irradiation combined with Endostar has no significant effect on radiation myocardial injury in rats.
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Objective@#To evaluate the expression of histone H4 acetylation(Ac-H4) during the cleft palates formation induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin(TCDD) in C57BL/6J mice.@*Methods@#Forty-eight pregnant C57BL/6J mice were completely randomly divided into two groups: ① TCDD group, mice were treated with 20ug/kg of TCDD on gestation day (GD) 10.5 by gastric perfusion; ② control group, mice were treated with an equivalent of corn oil. The head samples were collected and sliced in coronal plane on GD13.5, GD14.5 and GD15.5 respectively. Histone H4 acetylation in the palates were evaluated by immunohistochemical staining and Western Blot in the two groups.@*Results@#Histone H4 acetylation was mainly expressed in the palatal epithelial cells and slightly expressed in mesenchymal cells. The expression level of histone H4 acetylation was 0.6002±0.2530, 0.9180±0.0941 and 0.8966±0.0908 respectively in control group on GD13.5, GD14.5 and GD15.5; while 1.0229±0.2779, 1.6095±0.2651 and 1.2758±0.1251 in TCDD group. There were statistically significant differences between the control group and TCDD group (P<0.05).@*Conclusions@#The histone H4 acetylation was involved in the cleft palate formation induced by TCDD in C57BL/6J mice.
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Objective@#To explore the common differentially expressed proteins in 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin(TCDD) and retinoic acid-induced cleft palate of fetal mice by isobaric tags for relative and absolute quantitation(iTRAQ) combined with mass spectrometry.@*Methods@#Thirty-six pregnant C57BL/6J mice were randomly divided into 3 groups, 12 cases in each group. C57BL/6J pregnant mice were given a gavage of TCDD 28 μg/kg or retinoic acid 80 mg/kg on gestational day 10.5(GD10.5) as experimental groups, while the control group received equivalent corn oil. Anatomical and histological changes of palates in fetal mice were observed on GD17.5. Total proteins were extracted from palates of fetal mice in each group on GD17.5. Differentially expressed proteins were identified in experimental groups as well as in control group by iTRAQ combined with two-dimensional liquid chromatography/tandem mass spectrometry. Western Blot was used for validation of the differentially expressed proteins of Annexin A1 and 14-3-3 sigma. All statistical analyses were measured with SPSS software(version 17.0). Chi-square test was used to compare the incidence of cleft palate. One-way ANOVA was carried out for comparison of the relative expression levels of three groups, homogeneity of variance was analyzed by Levene test, and Turkey HSD test was used for comparison between two groups. P values were judged as significant difference if they were less than 0.05.@*Results@#①Model of cleft palate in fetal mice were successfully established with incidence of cleft palate of 97.1%(68/70)in TCDD group and 98.6%(70/71) in retinoic acid group, respectively(χ2=0.00, P>0.05), without significant difference between two groups. However, they were similar on the phenotype. ② A total of 2 996 proteins were identified. Compared with control group, 75 and 90 differentially expressed proteins were screened out from TCDD group and retinoic acid group respectively. There were 18 differentially expressed proteins in common both in two experimental groups. ③Western Blot assay indicated that the expression of Annexin A1 protein was 0.52±0.11 in control group, while in TCDD group was 0.99±0.34 and in retinoic acid group was 0.98±0.31, with significant difference between any of two experimental groups and control group(P<0.05). The expression of 14-3-3 sigma protein in control group was 0.55±0.15, while in TCDD group was 0.86±0.17 and in retinoic acid group was 0.93±0.13, with significant difference between any of two experimental groups and control group(P<0.05). These results were consistent with the results of iTRAQ experiment.@*Conclusions@#Using iTRAQ technology can quickly and effectively filtrate the common differentially expressed proteins in fetal mice with cleft palate induced by TCDD and retinoic acid. These proteins may have closely related relationship with the occurrence of cleft palate induced by TCDD or retinoic acid.
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BACKGROUND:Compared with traditional hydrogels, intel igent hydrogels can appear to exhibit different responses to different stimuli such as temperature, pH value, light, and magnetic field, produce two-stage structure and alter chemical structure to generate the ordered supramolecular structure by self-assembling, and ultimately cause the formation of the gel with three-dimensional structure. OBJECTIVE:To review the research status of intel igent hydrogels and its application in tissue engineering. METHODS:A computer-based search of CNKI and PubMed databases was performed to retrieve articles addressing intel igent hydrogels in tissue engineering published before 2014. The keywords were“hydrogel, tissue engineering”in Chinese and English. RESULTS AND CONCLUSION:Intel igent hydrogels are classified into temperature sensitivity, pH sensitivity, photosensitivity, magnetic susceptibility and temperature/pH dual responsive hydrogels. The change of the external environment can be automatical y detected and responded. Intel igent hydrogels exhibit a series of outstanding performances in drug delivery systems, drug delivery, repair and improvement of defected tissues, which are not possessed by traditional materials. In particular, the intel igent hydrogels show considerable superiorities in tissue engineering, including low immunogenicity that reducing inflammation and rejection, biodegradability, realizing the three-dimensional scale simulation of cel microenvironment that is conducive to cel adhesion, growth, migration and differentiation.