BACKGROUND: Signal regulatory protein alpha1 (Sirpα1) is a negative regulatory factor, and inhibits receptor tyro- sine kinase-dependent cell proliferating signal. This study was undertaken to observe the effect of s...BACKGROUND: Signal regulatory protein alpha1 (Sirpα1) is a negative regulatory factor, and inhibits receptor tyro- sine kinase-dependent cell proliferating signal. This study was undertaken to observe the effect of signal regulatory proteinα1 ( Sirpα1) on gankyrin, cyclin D1, CDK4 and Fas expression in Sk-hep1 mouse hepatoma carcinoma cell line. METHODS: BOSC 23 packed cells were respectively trans- fected by means of recombinated retrovirus including pLX- SN, pLXSN-Sirpα1 and pLXSN-Sirpα1Δ4Y2 with lipofec- tin, and various plasmid virus media (viral titer 2.1 × 106 CFU/ml) were collected and infected respectively in 80% confluent Sk-hepl cells. Transfected Sk-hep1 cells were se- lectively screened with G418 (1200 μg/ml), and Sk-hep1 cell lines transfected with various plasmids were obtained. The protein expressions of gankyrin, cyclin D1, CDK4 and Fas in various Sk-hep1 lines were determined by Western blotting. Various Sk-hep1 lines were recovered to culture with 10% fetal bovine serum at 12 hours and 24 hours after starving culture with free serum for 72 hours, and cells were collected to determine the percentage of S phase cells of proliferating cycle by flow cytometry. RESULTS: Sirpα1 transfection remarkably downregulated gankyrin and cyclin D1 expression. Sirpα1Δ4Y2 downregu- lation of gankyrin expression was greater than that of Sirpα1(P <0.05), but no significant effect of Sirpα1 and Sirpα1Δ4Y2 on CDK4 and Fas protein expression was ob- served in transfected Sk-hep1 lines (P >0.05). The per- centage of S phase cells significantly decreased in Sk-hep1 cells transfected with Sirpα1 and Sirpα1Δ4Y2 plasmids (vs pLXSN Sk-hep1, P <0.05). The percentage of S phase cells in various Sk-hep1 cells increased when recovering to culture with 10% fetal bovine serum at 12 hours, but the percentage of S phase cells in Sk-hep1 cells transfected with Sirpα1 was the lowest ( vs pLXSN and Sirpα1Δ4Y2 Sk- hepl, P<0.05). The percentage of S phase cells in trans- fected pLSXN Sk-hep1 cells was the largest (vs Sirpα1 and Sirpα1Δ4Y2 Sk-hepl, P <0. 05). There was no significant difference between the transfected Sirpα1 Sk-hepl cells and Sirpα1Δ4Y2 Sk-hep1 cells (P>0.05). CONCLUSIONS: Sirpα1 decreases gankyrin and cyclin D1 expression, and inhibits proliferation of liver carcinoma cells. It may be one of the forms for an Sirpα1 negative regulation of carcinogenesis and development of hepatocel- lular carcinoma.展开更多
Formation control is a cooperative control concept in which multiple autonomous underwater mobile robots are deployed for a group motion and/or control mission. This paper presents a brief review on various cooperativ...Formation control is a cooperative control concept in which multiple autonomous underwater mobile robots are deployed for a group motion and/or control mission. This paper presents a brief review on various cooperative search and formation control strategies for multiple autonomous underwater vehicles （AUV） based on literature reported till date. Various cooperative and formation control schemes for collecting huge amount of data based on formation regulation control and formation tracking control are discussed. To address the challenge of detecting AUV failure in the fleet, communication issues, collision and obstacle avoidance are also taken into attention. Stability analysis of the feasible formation is also presented. This paper may be intended to serve as a convenient reference for the further research on formation control of multiple underwater mobile robots.展开更多
基金This work was supported by a grant from the NationalNatural Science Foundation of China (No. 30000159).
文摘BACKGROUND: Signal regulatory protein alpha1 (Sirpα1) is a negative regulatory factor, and inhibits receptor tyro- sine kinase-dependent cell proliferating signal. This study was undertaken to observe the effect of signal regulatory proteinα1 ( Sirpα1) on gankyrin, cyclin D1, CDK4 and Fas expression in Sk-hep1 mouse hepatoma carcinoma cell line. METHODS: BOSC 23 packed cells were respectively trans- fected by means of recombinated retrovirus including pLX- SN, pLXSN-Sirpα1 and pLXSN-Sirpα1Δ4Y2 with lipofec- tin, and various plasmid virus media (viral titer 2.1 × 106 CFU/ml) were collected and infected respectively in 80% confluent Sk-hepl cells. Transfected Sk-hep1 cells were se- lectively screened with G418 (1200 μg/ml), and Sk-hep1 cell lines transfected with various plasmids were obtained. The protein expressions of gankyrin, cyclin D1, CDK4 and Fas in various Sk-hep1 lines were determined by Western blotting. Various Sk-hep1 lines were recovered to culture with 10% fetal bovine serum at 12 hours and 24 hours after starving culture with free serum for 72 hours, and cells were collected to determine the percentage of S phase cells of proliferating cycle by flow cytometry. RESULTS: Sirpα1 transfection remarkably downregulated gankyrin and cyclin D1 expression. Sirpα1Δ4Y2 downregu- lation of gankyrin expression was greater than that of Sirpα1(P <0.05), but no significant effect of Sirpα1 and Sirpα1Δ4Y2 on CDK4 and Fas protein expression was ob- served in transfected Sk-hep1 lines (P >0.05). The per- centage of S phase cells significantly decreased in Sk-hep1 cells transfected with Sirpα1 and Sirpα1Δ4Y2 plasmids (vs pLXSN Sk-hep1, P <0.05). The percentage of S phase cells in various Sk-hep1 cells increased when recovering to culture with 10% fetal bovine serum at 12 hours, but the percentage of S phase cells in Sk-hep1 cells transfected with Sirpα1 was the lowest ( vs pLXSN and Sirpα1Δ4Y2 Sk- hepl, P<0.05). The percentage of S phase cells in trans- fected pLSXN Sk-hep1 cells was the largest (vs Sirpα1 and Sirpα1Δ4Y2 Sk-hepl, P <0. 05). There was no significant difference between the transfected Sirpα1 Sk-hepl cells and Sirpα1Δ4Y2 Sk-hep1 cells (P>0.05). CONCLUSIONS: Sirpα1 decreases gankyrin and cyclin D1 expression, and inhibits proliferation of liver carcinoma cells. It may be one of the forms for an Sirpα1 negative regulation of carcinogenesis and development of hepatocel- lular carcinoma.
文摘Formation control is a cooperative control concept in which multiple autonomous underwater mobile robots are deployed for a group motion and/or control mission. This paper presents a brief review on various cooperative search and formation control strategies for multiple autonomous underwater vehicles （AUV） based on literature reported till date. Various cooperative and formation control schemes for collecting huge amount of data based on formation regulation control and formation tracking control are discussed. To address the challenge of detecting AUV failure in the fleet, communication issues, collision and obstacle avoidance are also taken into attention. Stability analysis of the feasible formation is also presented. This paper may be intended to serve as a convenient reference for the further research on formation control of multiple underwater mobile robots.
