RÉSUMÉ
Objective @#To examine the role of LMO4 in the regulation of endothelial cell differentiation and angio- genesis in murine embryonic stem cells (mESC) ．@*Methods @#Mouse Lmo4 cDNA was obtained from MEL cells by using the reverse transcription-polymerase chain reaction (RT-PCR) and subcloned into the expression vector pFG to generate the pFLG ，in which contained Flk-1 promoter to drive Lmo4 expresses in only FLK-1 + cells．The mESC were transfected with pFG or pFLG plasmids and subsequently screened with geneticin ( G418) to produce cell clones． These cell clones were named mESC /pFG and mESC /pFLG ，respectively． The mESC /pFG and mESC /pFLG were cultured in the differentiation medium for either 4 days or 10 days to generate embryoid bodies (EB) ．The 10-day embryoid bodies ( 10 d-EBs) carrying the pFG and pFLG vectors were subsequently stimulated to generate the blast-colony forming cells (BL-CFC) ，which indicated the presence of hemangioblasts．The endo- thelial cell sprouting analysis was performed by using 10 d-EBs．The expression of the interest genes was detected by using qualitative RT-PCR or Western blot analysis. @*Results @#The pFLG expression vector was successfully con- structed through PCR identification．The mESC /pFG and mESC /pFLG cells were obtained after transfected with the pFG or pFLG vectors and selected by G418．The cells spontaneously differentiate to generate EBs，in which some green fluoresce cells were present．Western blot analysis showed that a significant increase in LMO4 expression in both 4 d-EB and 10 d-EB when compared to mESC．BL-CFC analysis showed that the 4 d-EB/ pFLG had a higher cloning efficiency ( 7. 70% ± 1. 27% ) ，comparing with that of the 4 d-EB/ pFG ( 1. 15% ± 0. 48% ) ( P = 0. 021) ．Quantitative RT-PCR results showed that the expression of Flk-1，C-kit，Tie-2 and Ve-cad genes in 10 d- EBs /pFLG increased more than 2-fold compared to 10 d-EBs /pFG．The endothelial cell sprouting analysis result showed a significant increase in the number and length of new blood vessels in 10 d-EB/ pFLG compared to 10 d- EB/ pFG (P＜0. 05) ．@*Conclusion @#Overexpression of LMO4 promotes hemangioblast differentiation from mESC， and benefits for endothelial cell differentiation and angiogenesis.
RÉSUMÉ
Objective @#To investigate lim domain protein 4 (LMO4) functions and mechanisms in regulating proliferation of skin squamous cells (A431) , the shRNAs targeted to human LMO4 were coated by calcium phosphate nanoparticles (NP) and transfected into A431 cells to inhibit LMO4 expression. @*Methods @#Reverse transcription and quantitative polymerase chain reaction ( RT⁃qPCR) , immunohistochemistry analysis and Western blot were used to detect expression of the interest genes. The expression vectors with shRNA targeted to human LMO4 (NP/sh⁃L) were coated by the calcium phosphate nanoparticles , and transfected into A431 . The MTT assay was conducted to determine cell proliferation after transfected for 24 , 36 and 48 h. Cells were stained with propidium iodide and examined cell cycles by using flow cytometry. @*Results @# LMO4 expressed at higher levels both in the skin squacalcium phosphate nanoparticles and DNA was 10 ∶ 1 . There was no significant difference of transfection efficiency between the NP/sh⁃L and lipofection approaches. The MTT assay showed that silencing LMO4 inhibited proliferadown did not alter expression of CDK4 and cyclin D1 .@*Conclusion@#The calcium phosphate nanoparticles could bind and transfer the foreign DNA into the targeted cells with high efficiency. Silencing LMO4 decreased expression of cyclin E and CDK2 resulted in inhibition of cell proliferation.
RÉSUMÉ
The term "population medicine" refers to a branch of clinical medicine that focuses on both individual health care and group health enhancement, even for the benefit of humanity as a whole. It encompasses a wide range of comprehensive health care practices, including "health promotion, prevention, diagnosis, control, treatment, and rehabilitation" and is closely related to the theoretical and technological advancements in medical physics. The primary challenge that medical physics currently faces is how to best utilize its technological advancements to serve the need of the development of "population medicine".