Effects of lens extirpation with anterior vitrectomy on vitreous three-dimensional mesh structure

AIM： To investigate the changes in vitreous gel structure after lens extirpation combined with anterior vitrectomy in rabbit eyes. METHODS： Twenty-eight chinchilla rabbits were divided into three groups. The control group （Group I） included 16 eyes from eight rabbits who did not receive any treatment. Group II included 20 eyes from 10 rabbits that underwent lens aspiration only. Group III included 20 eyes from 10 rabbits that underwent lens aspiration combined with posterior capsulotomy and anterior vitrectomy. Eyes were harvested on the 30th and 60th day postoperatively, respectively. Changes in vitreous gel stretch length due to gravity and the rate of vitreous liquefaction were observed. The collagen content in the vitreous body was examined using the L-hydroxyproiine test. Electronic microscopic images were obtained from each eyeball. RESULTS： On both the 30th and 60th day postoperatively, the vitreous gel length of group III was significantly shorter than group I and group II （P〈0.05）, while the rate of liquefaction of the vitreous body in group III was significantly higher than group I and group II （P〈0.05）. The collagen content in group Ul was also higher than that in group I and group II （P〈0.05）. CONCLUSION： Loss of vitreous gel mass is more likely to occur in the eyes of rabbits receiving anterior vitrectomy. Lensectomy combined with anterior vitrectomy may damage the stable three-dimensional mesh structure of collagen, which could aggravate vitreous gel liquefaction.

Influence of β-catenin Small Interfering RNA on Human Osteosarcoma Cells

This study examined the effect of small interfering RNA-mediated β-catenin knockdown on the survival,invasion and chemosensitivity of human osteosarcoma cells（U2-OS cells）.The siRNA against β-catenin was constructed and transfected into U2-OS cells.The expression of β-catenin was detected by qRT-PCR and Western blotting.Cell growth and apoptosis was detected in the presence or absence of doxorubicin by MTT and flow cytometry,respectively.Cell invasion ability was measured by transwell assay.The results showed that the transfection of β-catenin siRNA resulted in decreased expression of β-catenin,suppression of invasion and motility of U2-OS cells,reduced chemosensitivity to doxorubicin in vitro,and little change in cell growth and apoptosis.Additionally,down-regulated MT1-MMP expression was found after transfection.It was concluded that knockdown of β-catenin gene may decrease the invasive ability of human osteosarcoma cells through down-regulated MT1-MMP expression,and the chemosensitivity of osteosarcoma cells against doxorubicin.

Effect of p27Kip1 Inhibition on Proliferation of Bovine Corneal Endothelial Cells by RNA Interference

Three plasmids （pGenesil-P1, pGenesil-P2, pGenesil-P3） with different p27Kip1-shRNA sequences were designed and synthesized. Their effects on the proliferation of bovine corneal endothelial cells （bCEC） were investigated. Plasmid expressing irrelevant shRNA with a random combination was used as negative control （pGenesil-HK）. The recombination of four plamids was confirmed by restrictive enzyme digestion and sequence analysis. The expression of mRNA and protein of p27Kip1 was detected by RT-PCR and Western blotting after stable transfection. The expressions of p27Kip1 mRNA and p27Kip1 protein of pGenesil-P1 group, pGenesil-P2 group and pGenesil-P3 group were all lower than those in the pGenesil-HK group and the blank group （non-transfected group）, pGenesil-P3 had the strongest inhibitory effect and was selected for the next steps. The proliferation rates of the pGenesil-P3 group, the pGenesil-HK group and the blank group were assessed by MTT. The influence of shRNA-p27Kip1 on bCEC cell cycle was detected by flow cytometry （FCM）. Compared with the control groups, the proliferation rate of the pGenesil-P3 group was increased significantly, and the ratio of S-phase also increased. It is concluded that shRNA-p27Kip1 could down-regulate the expression of p27Kip1 effectively and increase the proliferation of bCEC. RNA interference （RNAi） may be an effective means to promote the proliferation of CEC.