RESUMO
With the increasing severity of global aging, aging-related issues have become the hotspot in the field of health. In recent years, animal aging models have been widely developed and applied, which is of great significance in the study of aging mechanism. Animals with short life span, such as Caenorhabditis Elegans and Drosophila Melanogaster, have natural advantages in the study of aging. Various rat and mouse aging models have been used in aging studies. In recent years, new animal aging models have been developed, such as the African turquoise killifish. The authors reviewed main animal models used in the study of aging, and analyzed the establishment methods, evaluation indexes, advantages and disadvantages of each model in order to provide reference for related research.
RESUMO
OBJECTIVE@#To investigate the effect of estradiol (E2)/estrogen receptor 1 (ESR1) on the proliferation of human chondrocytes and explore the molecular mechanism.@*METHODS@#The Ad-Easy adenovirus packaging system was used to construct and package the ESR1-overexpressing adenovirus Ad-ESR1. Western blotting and qPCR were used to detect the expression of ESR1 protein and mRNA in human chondrocyte C28I2 cells. In the cells treated with different adenoviruses, the effects of E2 were tested on the expressions of proteins related with cell autophagy and apoptosis and the phosphorylation of ERK signaling pathway using Western blotting. Immunofluorescence assay was used to observe the intracellular autophagic flow, flow cytometry was performed to analyze the cell apoptosis rate and the cell cycle changes, and qPCR was used to detect the expressions of PCNA, cyclin B1 and cyclin D1 mRNAs. The inhibitory effect of the specific inhibitor of ERK on the expressions of autophagy- and apoptosis-related genes at both the protein and mRNA levels were detected using Western blotting and qPCR.@*RESULTS@#Transfection with the recombinant adenovirus overexpressing ESR1 and E2 treatment of C28I2 cells significantly enhanced the expressions of autophagy-related proteins LC3, ATG7, promoted the colocalization of LC3 and LAMP1 in the cytoplasm, increased the expressions of the proliferation-related marker genes PCNA, cyclin B1 and cyclin D1, and supressed the expressions of cleaved caspase-3, caspase-12 and pERK. RNA interference of ESR1 obviously lowered the expression levels of autophagy-related proteins in C28I2 cells, causing also suppression of the autophagic flow, increments of the expressions of apoptosis-related proteins and pERK, and down-regulated the expressions of the proliferation marker genes. Blocking ERK activation with the ERK inhibitor obviously inhibited the effects of E2/ESR1 on autophagy, proliferationrelated gene expressions and cell apoptosis.@*CONCLUSIONS@#The targeted binding of E2 with ESR1 promotes the proliferation of human chondrocytes possibly by inhibiting the activation of ERK signaling pathway to promote cell autophagy and induce cell apoptosis.