Background This study transferred a recombinant gene encoding human insulin like growth factor-1 （hIGF-1） into modified primary skeletal myoblasts with a retroviral vector （pLgXSN） and determined whether the hIGF-...Background This study transferred a recombinant gene encoding human insulin like growth factor-1 （hIGF-1） into modified primary skeletal myoblasts with a retroviral vector （pLgXSN） and determined whether the hIGF-1 promoted growth of skeletal muscle in rat.Methods hlGF-lcDNA was amplified in vitro from normal human liver cells by using RT-PCR and cloned into plasmid vector pLgXSN. The recombinant vector pLghIGF-1SN and control vector pLgGFPSN were transfected into packaging cell PT67 and G418 was used to select positive colony. Myoblasts were infected with a high titre viral supernatant and transduction efficiency was evaluated as GFP expression. The expression of hIGF-1 mRNA in myoblasts was investigated by immunocytochernistry and RT-PCR. MTT assays detected the growth of myoblasts in vitro. Myoblasts transduced with pLghlGF-1SN were injected into hind limb muscles of 10-12 week male SD rats. Formed tissues were harvested 4 weeks later. Myocyte diameter, mean weight of hind limb and body were measured to evaluate the skeletal muscle growth. Results Recombinant retroviral plasmid vector pLghlGF-1SN was constructed successfully. The titre of the packaged recombinant retrovirus was 1 × 106 cfu/ml. The transfection rate of PT67 cells reached 100% after G418 screening, hIGF-1 expression was positive in myoblast-IGF-1. The proliferation rate of myoblast-IGF-1 in vitro was higher than GFP-myoblast or myoblast （P〈 0.05）. The mean weights of hind limb and body of rats injected myoblast-IGF-1 were higher than those of the rats injected with myoblast-GFP or myoblast （P〈 0.05）. Myocyte diameter had a significant increase in IGF-1 group compared to GFP group and myobiast group （P〈 0.05）. Conclusions The transfection of the human IGF- 1 gene mediated by a retroviral vector can promote the growth of skeletal muscle in rats. Genetically modified primary skeletal myoblasts provide a possibly effective approach to treat some skeletal muscle diseases.展开更多
This study was aimed to determine whether flaxseed lignans could affect the growth of skeletal muscle in male animals and its possible mechanisms. The impact of flaxseed lignans on the skeletal muscle in male rats was...This study was aimed to determine whether flaxseed lignans could affect the growth of skeletal muscle in male animals and its possible mechanisms. The impact of flaxseed lignans on the skeletal muscle in male rats was determined in vivo. Flaxseed lignans （50 ppm） and daidzein （5 ppm） were added into the basal diets, respectively. The concentrations of serum lignans and daidzein were measured by high performance liquid chromatography （HPLC）, and the serum growth hormone and testosterone （T） levels were analyzed by radioimmunoassay （RIA）, and the expression of estrogen receptor β （ER β） in the soleus muscle and hypothalamus were determined by reverse-transcription polymerase chain reaction （RT-PCR）. Flaxseed lignans and daidzein could significantly improve the feed efficiency and facilitate the weight gain of the femoral muscle in male rats. The ratio of RNA to DNA in the muscles and serum T levels was remarkably increased, whereas, the urea nitrogen concentrations were significantly decreased by flaxseed lignan and/or its metabolites and daidzein. Meanwhile, the expression of ER β in soleus muscle and hypothalamus were both upgraded by the two phytoestrogens. Flaxseed lignan promoted the growth of male rats, and it might be by regulating serum T levels by binding to ER β in the hypothalamus. In turn, it depressed the catabolism of protein and promoted the hypertrophy of skeletal muscle ceils.展开更多
基金This work was supported by a grant from the National Natural Science Foundation of China (No.30470457).
文摘Background This study transferred a recombinant gene encoding human insulin like growth factor-1 （hIGF-1） into modified primary skeletal myoblasts with a retroviral vector （pLgXSN） and determined whether the hIGF-1 promoted growth of skeletal muscle in rat.Methods hlGF-lcDNA was amplified in vitro from normal human liver cells by using RT-PCR and cloned into plasmid vector pLgXSN. The recombinant vector pLghIGF-1SN and control vector pLgGFPSN were transfected into packaging cell PT67 and G418 was used to select positive colony. Myoblasts were infected with a high titre viral supernatant and transduction efficiency was evaluated as GFP expression. The expression of hIGF-1 mRNA in myoblasts was investigated by immunocytochernistry and RT-PCR. MTT assays detected the growth of myoblasts in vitro. Myoblasts transduced with pLghlGF-1SN were injected into hind limb muscles of 10-12 week male SD rats. Formed tissues were harvested 4 weeks later. Myocyte diameter, mean weight of hind limb and body were measured to evaluate the skeletal muscle growth. Results Recombinant retroviral plasmid vector pLghlGF-1SN was constructed successfully. The titre of the packaged recombinant retrovirus was 1 × 106 cfu/ml. The transfection rate of PT67 cells reached 100% after G418 screening, hIGF-1 expression was positive in myoblast-IGF-1. The proliferation rate of myoblast-IGF-1 in vitro was higher than GFP-myoblast or myoblast （P〈 0.05）. The mean weights of hind limb and body of rats injected myoblast-IGF-1 were higher than those of the rats injected with myoblast-GFP or myoblast （P〈 0.05）. Myocyte diameter had a significant increase in IGF-1 group compared to GFP group and myobiast group （P〈 0.05）. Conclusions The transfection of the human IGF- 1 gene mediated by a retroviral vector can promote the growth of skeletal muscle in rats. Genetically modified primary skeletal myoblasts provide a possibly effective approach to treat some skeletal muscle diseases.
基金supported by the National Natural Science Foundation of China (39970534)
文摘This study was aimed to determine whether flaxseed lignans could affect the growth of skeletal muscle in male animals and its possible mechanisms. The impact of flaxseed lignans on the skeletal muscle in male rats was determined in vivo. Flaxseed lignans （50 ppm） and daidzein （5 ppm） were added into the basal diets, respectively. The concentrations of serum lignans and daidzein were measured by high performance liquid chromatography （HPLC）, and the serum growth hormone and testosterone （T） levels were analyzed by radioimmunoassay （RIA）, and the expression of estrogen receptor β （ER β） in the soleus muscle and hypothalamus were determined by reverse-transcription polymerase chain reaction （RT-PCR）. Flaxseed lignans and daidzein could significantly improve the feed efficiency and facilitate the weight gain of the femoral muscle in male rats. The ratio of RNA to DNA in the muscles and serum T levels was remarkably increased, whereas, the urea nitrogen concentrations were significantly decreased by flaxseed lignan and/or its metabolites and daidzein. Meanwhile, the expression of ER β in soleus muscle and hypothalamus were both upgraded by the two phytoestrogens. Flaxseed lignan promoted the growth of male rats, and it might be by regulating serum T levels by binding to ER β in the hypothalamus. In turn, it depressed the catabolism of protein and promoted the hypertrophy of skeletal muscle ceils.
