The regulation of foreign gene expression in Insect-Baculovirus Expression System is very complex. In this report, the effect of 5′-UTR in the expression of hGH gene in cultured Sf9 cells was examined. A 18 bp length...The regulation of foreign gene expression in Insect-Baculovirus Expression System is very complex. In this report, the effect of 5′-UTR in the expression of hGH gene in cultured Sf9 cells was examined. A 18 bp length in the end of 5′-UTR of hGH (human Growth Hormone, hGH) cDNA including a stem-loop structure was deleted by PCR. The truncated hGH cDNA, Δ1hGH was cloned in pFastBac1, named pFast-Bac-Δ1hGH. After transforming into E.coli. DH10Bac, which have a shuttle vetor-Bacmid, the Δ1hGH was integrated into Bacmid by site-specific transposition, and an expression vector, rBacmid-Δ1hGH DNA was acquired. By transfecting the cultured Sf9 cells with the recombinant expression vector DNA, pure recombinant virus, rAcV-Bac-Δ1hGH was obtained, and hGH gene was expressed. Immuno-blot and Chemiluminescent assay revealed that the expressed hGH had normal immunological activity, the ammount of hGH expression level in Sf9 cell supernatant infected with rAcV-Bac-Δ1hGH containing the truncated 5′UTR was four to five times higher than that infected with rAcV-Bac-hGH.展开更多
DNA expression constructs containing hGH gene directed by bovine αsl-casein gene regulatory sequences were injected into mouse heart or mammary glands in vivo. hGH expression was readily detected by radioimmunoassay ...DNA expression constructs containing hGH gene directed by bovine αsl-casein gene regulatory sequences were injected into mouse heart or mammary glands in vivo. hGH expression was readily detected by radioimmunoassay in milk of the nursing mice throughout lactation. Our results demonstrated the value of this simple and rapid approach in screening gene constructs and identifying transcription regulation sequences in vivo prior to the generation of transgenic animals. For the First time we report the successful expression in mammary gland via intracardial injection.展开更多
To observe the effect of growth hormone on serum leptin levels, serum leptin concentrations were measured by enzyme immunoassay in 12 prebutal children with growth hormone deficiency 1, 3 and 6 months before and afte...To observe the effect of growth hormone on serum leptin levels, serum leptin concentrations were measured by enzyme immunoassay in 12 prebutal children with growth hormone deficiency 1, 3 and 6 months before and after the treatment with recombinant human growth hormone (r hGH). For comparison, 34 normal prepubertal children were also investigated. Relationship between leptin levels and body mass index (BMI) was observed at the same time. Our results showed that serum leptin level in normal prepubertal children was 1.22±0.34 ng/ml; the pretreatment serun leptin levels in GHD children was 3.08±2.41 ng/ml, which was significantly different from those 1, 3 and 6 months after GH treatment (i.e. 1.64±1.37 ng/ml,1.57±1.40 ng/ml and 1.35±0.89 ng/ml respectively) (all P <0.001). Our results suggested that r hGH has a suppressive effect on leptin expression.展开更多
文摘The regulation of foreign gene expression in Insect-Baculovirus Expression System is very complex. In this report, the effect of 5′-UTR in the expression of hGH gene in cultured Sf9 cells was examined. A 18 bp length in the end of 5′-UTR of hGH (human Growth Hormone, hGH) cDNA including a stem-loop structure was deleted by PCR. The truncated hGH cDNA, Δ1hGH was cloned in pFastBac1, named pFast-Bac-Δ1hGH. After transforming into E.coli. DH10Bac, which have a shuttle vetor-Bacmid, the Δ1hGH was integrated into Bacmid by site-specific transposition, and an expression vector, rBacmid-Δ1hGH DNA was acquired. By transfecting the cultured Sf9 cells with the recombinant expression vector DNA, pure recombinant virus, rAcV-Bac-Δ1hGH was obtained, and hGH gene was expressed. Immuno-blot and Chemiluminescent assay revealed that the expressed hGH had normal immunological activity, the ammount of hGH expression level in Sf9 cell supernatant infected with rAcV-Bac-Δ1hGH containing the truncated 5′UTR was four to five times higher than that infected with rAcV-Bac-hGH.
文摘DNA expression constructs containing hGH gene directed by bovine αsl-casein gene regulatory sequences were injected into mouse heart or mammary glands in vivo. hGH expression was readily detected by radioimmunoassay in milk of the nursing mice throughout lactation. Our results demonstrated the value of this simple and rapid approach in screening gene constructs and identifying transcription regulation sequences in vivo prior to the generation of transgenic animals. For the First time we report the successful expression in mammary gland via intracardial injection.
文摘To observe the effect of growth hormone on serum leptin levels, serum leptin concentrations were measured by enzyme immunoassay in 12 prebutal children with growth hormone deficiency 1, 3 and 6 months before and after the treatment with recombinant human growth hormone (r hGH). For comparison, 34 normal prepubertal children were also investigated. Relationship between leptin levels and body mass index (BMI) was observed at the same time. Our results showed that serum leptin level in normal prepubertal children was 1.22±0.34 ng/ml; the pretreatment serun leptin levels in GHD children was 3.08±2.41 ng/ml, which was significantly different from those 1, 3 and 6 months after GH treatment (i.e. 1.64±1.37 ng/ml,1.57±1.40 ng/ml and 1.35±0.89 ng/ml respectively) (all P <0.001). Our results suggested that r hGH has a suppressive effect on leptin expression.
