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BACKGROUND:The temporal and spatial expression of fibroblast growth factor receptors 1 and 2 remains a controversial issue during kidney development,so the relationship between them and kidney development remains unclear. OBJECTIVE:To observe the dynamic expression of fibroblast growth factor receptors 1 and 2 during kidney development of mice,and to investigate the relationship between them and kidney development. METHODS:The kidneys of fetal mice[embryotic days(E)12,14,16,and 18]and neonatal mice[neonatal days(N)1,3,7,14,24,and 40]were selected to examine the temporal and spatial expression of fibroblast growth factor receptors 1 and 2 by immunohistochemistry method in kidney tissues,and quantitative analysis was performed using western blot assay. RESULTS AND CONCLUSION:(1)Immunohistochemistry showed that fibroblast growth factor receptor 1 was mainly localized in metanephric tissue surrounding the tip of the ureteral bud at E12.Subsequently,fibroblast growth factor receptor 1 was expressed in immature renal corpuscles at various stages,some distal convoluted tubules and capillary loops.The positive site was mainly concentrated in the generative region.Fibroblast growth factor receptor 2 was initially expressed in both ureteral buds and metanephric tissue.Fibroblast growth factor receptor 2 was localized in immature renal corpuscles,distal tubules,collecting ducts and thin segments of medullary loops with kidney development.However,the expression of renal corpuscles was weak.(2)Stereology and western blot assay showed that the expression of fibroblast growth factor receptor 1 was high before birth and gradually decreased after birth,while the expression was very low after N7 day.The expression level of fibroblast growth factor receptor 2 increased gradually with the kidney development and tended to be stable after N7 day.(3)The results exhibit that fibroblast growth factor receptors 1 and 2 are expressed spatially and temporally during kidney development.It is speculated that fibroblast growth factor receptors 1 and 2 may influence nephron development and maturation,and fibroblast growth factor receptor 2 is critical during the formation of ureteral buds and morphology.
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Objective:To explore the role of activated CD4 + T cells in cardiac remodeling after myocardial infarction (MI). Methods:① Experiment in vitro: naive CD4 + T cells were isolated in mouse spleen, and then stimulated with plate-bound anti-CD3 and anti-CD28 for 48 hours. Exosomes isolated from the supernatant of activated CD4 + T cells were incubated with cardiac fibroblasts (CFs) for 48 hours, and then the ability of CFs proliferation, migration and differentiation were detected by cell counting kit-8 (CCK-8) assay, Transwell assay, and immunofluorescence assay. ② Experiment in vivo: 40 male C57 mice were divided into 4 groups according to random number table method, including control group (Ctrl group), sham operation group (Sham group), MI group, and exosome treatment group (MI+Exo group), with 10 in each group. The mice model of MI was established by ligating the left anterior descending coronary artery. In MI+Exo group, 40 μg/d exosomes were injected intravenously into the tail after modeling. Cardiac function and cardiac fibrosis post-MI were assessed by echocardiography and quantitative polymerase chain reaction (qPCR) at 4th week. Results:① In vitro: exosomes derived from activated CD4 + T cells significantly promote CFs proliferation, migration and differentiation [proliferation ability ( A value): 0.31±0.01 vs. 0.21±0.01, migration capability (cells/MP): 79.20±3.34 vs. 48.80±2.13, differentiation ability (α-smooth muscle actin, α-SMA; fluorescence intensity): 1.56±0.03 vs. 1.00±0.02, all P < 0.05]. ② In vivo: echocardiographic analysis showed that exosomes derived from activated CD4 + T cells aggravated the deterioration of cardiac dysfunction post-MI than MI group, as indicated by left ventricular ejection fraction (LVEF) and fractional shortening (FS) decreased significantly [LVEF: 0.185±0.008 vs. 0.257±0.022, FS: (9.72±1.72)% vs. (14.08±1.08)%, both P < 0.05], left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) increased significantly [LVEDD (mm): 5.43±0.29 vs. 4.62±0.35, LVESD (mm): 4.94±0.12 vs. 3.69±0.29, both P < 0.05]. Additionally, qPCR showed that exosomes derived from activated CD4 + T cells remarkably promoted myocardial fibrosis post-MI than MI group, as indicated by the mRNA expression of α-SMA, collagens (Col1a1, Col3a1) in MI+Exo group was significantly higher than that in MI group [α-SMA (2 -ΔΔCT): 4.72±0.89 vs. 3.58±0.78, Col1a1 (2 -ΔΔCT): 6.59±0.56 vs. 4.23±0.42, Col3a1 (2 -ΔΔCT): 13.40±1.03 vs.4.96±0.36, all P < 0.05]. Conclusion:Activated CD4 + T cells promote cardiac remodeling following MI through transferring exosomes to CFs.
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Objective The purpose of this study is to select suitable ages of rats for the CPR ( cardiopulmonary resuscitation) animal model.The neurological function score and subgroups analysis are evaluated in 2 month old and 4 month old animal groups.Methods Based on the evaluation of physiological indexes including ECG, blood pressure and neurological function defect score ( NDS) and subgroup analysis, the stability of CPR rats model was compared between 2 month old and 4 month old animal groups.Results The results showed that, the model rate of the ventricular fibrillation was induced by electrical stimulation , the 4 month old group was 87.5%, significantly higher than the 2 month old group, however, there was no significant difference between the two groups in the mortality rate;For the changes of blood pressure during the process of CA( cardiac arrest) induced by electrical stimulation, the 4 month old group was significantly lower than the 2 month old group (P <0.01); for the NDS at each time point after CPR, there was no significant difference between the two groups; however, the NDS subgroup analysis at different time points showed that there were different degrees of differences between the two age groups ( P <0.05) .Comparing with the 2 month old group, the 4 month old group had a stable process during the animal model preparation, had an obvious cerebral blood hypoperfusion phenomenon and aggravation of brain injury after CPR.Conclusion The 4 month old rats are more suitable for preparation of CPR animal mode , the model rate is high, the brain injury aggravate.It is more suitable evaluation for basic research and treatment of CPR.
