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Aim To investigate the effect of DNA methyltransferase 3A (DNMT3A) on the proliferation and migration of cardiac fibroblasts (CFs) in C57 mice under high glucose environment. Methods The hearts of C57 mice were taken from 1 to 3 days. After cutting and digesting, CFs were extracted by differential adherance centrifugattion and observed under microscope. After cell attachment, the cells were cultured under low glucose (5.5 mmol • L
ABSTRACT
ObjectiveTo explore a new model for lens-induced myopia （LIM） in mice and describe the changes of diopter and ocular biological parameters. MethodsTwenty-seven 21-day-old C57BL/6 mice were divided into three groups （ratio， 5：1：3）： LIM group， plano lens （PL） group and normal control （N） group. The right eyes were intervened while the left eyes were left as control. The refraction was detected with retinoscopy after the pupils were dilated with compound topicamide and ocular axial length was measured by optical coherence tomography （OCT） in vivo at baseline and 1， 2， 3， and 4 weeks after the intervention. Paired t test was performed between left and right eyes within each group. Welch's ANOVA was used for comparison among the three groups. When the difference was statistically significant， the Dunnett's T3 was used to correct P value for pairwise comparison. ResultsAfter 2 weeks of defocus induction， the refraction of the intervened eye in LIM group shifted to myopia about （-2.55±1.54） D（t=6.430， P＜0.000 1）， and the ocular axial length （AL） increased about （0.051±0.024） mm（t=7.837， P＜0.000 1）. The difference of interocular change in refraction in LIM group compared with PL group and N group was -2.30 D （P=0.014） and -2.55 D （P＜0.000 1）， respectively. The difference of interocular change in AL in LIM group was 0.048 mm （P<0.000 1） and 0.047 mm （P<0.000 1） compared with that in PL group and N group， respectively. With the extension of intervention time， the degree of myopia drift increased. ConclusionIn this study， a clasp-based and detachable LIM model was described and validated. After 2 weeks of intervention， the refraction shifted significantly toward myopia and the AL increased significantly. The LIM model is simple to construct and can provide a reference for the model construction of animal experiments in myopia research.
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Objective The mechanisms of methylation acting on myocardial fibrosis are not yet clear at present. The aim of this study was to investigate the role of DNA methyltransferase 3A (DNMT3A) in regulating the expressions of collagens during the activation of cardiac fibroblasts.Methods Cardiac fibroblasts were obtained from 50 neonatal mice and divided into three groups: blank control, DNMT3A overexpression plasmid (mDNMT3A-pEGFP-C3) and small interference DNMT3A siRNA. The contents of collagens in the cell supernatant were detected by ELISA. The mRNA and protein expressions of type I collagen (Col Ⅰ), type Ⅲ collagen (Col Ⅲ) and DNMT3A in the cardiac fibroblasts were determined by real-time quantitative PCR and Western blot respectively and the proliferative activity of the cardiac fibroblasts measured by CCK8 assay.Results The contents of Col I and Col Ⅲ in the cell supernatant were significantly increased in the DNMT3A overexpression plasmid group but decreased in the DNMT3A siRNA group as compared with those in the blank control (P<0.05). The expressions of Col Ⅰ, Col Ⅲ and DNMT3A were remarkably higher in the DNMT3A overexpression plasmid group but lower in the DNMT3A siRNA group than in the blank control (P<0.05). The cell activity was markedly higher in the DNMT3A overexpression plasmid group than in the empty vector plasmid and control groups (2.087±0.317 vs 1.063±0.223 and 1.082±0.207, P<0.05) but lower in the DNMT3A siRNA group (0.463±0.087) than in the latter two (P<0.05).Conclusion DNMT3A can increase the proliferation and activation of cardiac fibroblasts, upregulate the expressions of collagens and thus promote myocardial fibrosis.