Objective:To investigate the influence of miR-7 knock down on the development of CD 4+SP cells in the thymus in mice,and preliminary explore its possible mechanism.Methods:The changes of volume ,weight and total cell counts of thymus in miR-7 knock down (miR-7KD) mice were observed compared with Wild-type(WT)mice;the pathological changes of thymus were observed by HE staining.FACS analysis was performed on the proportion ,as well as the expression level of CD44 and CD62L,of thymus CD4+single positive (SP) cells.Meanwhile,the proliferation percentage of CD4+SP cells was measured by Ki-67 staining.The apoptosis percentage of CD4+SP cells was analyzed by FACS.The changes on the transduction of ERK 1/2 pathways were determined by Western blot.Results:Compared with WT mice ,the size,weight and total cell number of thymus were marked reduced in miR-7KD mice( P<0.05 );moreover ,pathological change also was presented.The proportion and total cell number of thymus CD 4+SP cells were marked decreased ( P<0.05 ).Furthermore ,the expression level of CD 44 and proliferation percentage ,as well as apoptosis percentage ,of CD4+SP cells were obviously increased (P<0.05),however,the expression level of CD62L of CD4+SP cells were decreased (P<0.05). Finally,the level of total ERK1/2 and phosphor-ERK1/2 was decreased obviously ( P<0.05 ).Conclusion: miR-7 knock down can affect the development of CD 4+SP cells in the thymus , which might be closely related to the cell activation state and altered the transduction of ERK1/2 pathways.

Objective To screen the secretory factor-related, mechanoresponsive microRNAs (miRNA) of osteocytes. Methods Cyclic mechanical tensile strain (ε=2.5,f=0.5 Hz) was applied to osteocytes and osteoblasts cultured in vitro respectively, and the differentially expressed miRNAs only in the osteocytes were screened out by using miRNA chip. Through bioinformatics technology, in these differentially expressed miRNAs, the target genes of secretory factors including insulin-like growth factor-1(IGF-1), nitric oxide synthesase (NOS), fibroblast growth factor 23 (FGF23) and sclerostin (SOST) were further screened out. Then the selected miRNAs were compared with the biochip detected, differentially expressed miRNAs in femur bone of the mice which were trained on treadmill, and four of these miRNAs were randomly selected for quantitative PCR verification. Results For the 77 differentially expressed miRNAs only in the mechanically strained osteocytes in vitro, 22 miRNAs whose target genes were the 4 secreted factors (IGF-1, NOS, FGF23 and SOST), were screened out. Moreover, a total of 11 miRNAs in the 22 miRNAs were differentially expressed in femur bone of the treadmill trained mice with the same trend as those in osteocytes in vitro, and the randomly selected miR-361-3p, miR-3082-5p, miR-6348 and miR-706 were confirmed to be differentially expressed with the same trend in femur bone and osteocytes. Conclusions These mechanoresponsive miRNAs differentially expressed only in osteocytes, such as miR-361-3p, miR-3082-5p, miR-6348 and miR-706, probably influence osteoblastic differentiation or bone metabolism through regulating the secretory factors.

Humans ; Consensus ; Pancreatic Neoplasms/therapy* ; Neuroendocrine Tumors/therapy*