AIM： To evaluate the effects of betaine on the ethanolinduced secretion of IGF-I and IGFBP-1 using radioimrnunoassay and Western blotting, respectively, in primary cultured rat hepatocytes. METHODS： Hepatocytes isol...AIM： To evaluate the effects of betaine on the ethanolinduced secretion of IGF-I and IGFBP-1 using radioimrnunoassay and Western blotting, respectively, in primary cultured rat hepatocytes. METHODS： Hepatocytes isolated from male SpragueDawley rats were incubated with various concentrations of ethanol and PD98059 procedures. The hepatocytes were also treated with different doses of betaine （10^-5, 10^-4, and 10^-3 mol/L）. We measured IGF-I and IGFBP-1 using radioimmunoassay and Western blotting, respectively. RESULTS： The ethanol-induced inhibition of IGF-I secretion was attenuated by betaine in a concentration-dependent manner in primary cultured rat hepatocytes. At 10^-3 mol/L, betaine significantly increased IGF-I secretion but decreased IGFBP-1 secretion. In addition, p42/44 rnitogen-activated protein kinase （MAPK） activity was accelerated significantly from 10 min to 5 h after treatment with 10^-3 mol/L betaine. Furthermore, the changes in IGF-1 and IGFBP-1 secretion resulting from the increased betaine-induced p42/44 MAPK activity in primary cultured rat hepatocytes was blocked by treatment with the MAPK inhibitor PD98059. Betaine treatment blocked the ethanol-induced inhibition of IGF-I secretion and p42/44 MAPK activity, and the ethanol-induced increase in IGFBP-1 secretion.CONCLUSION： Betaine modulates the secretion of IGF-I and IGFBP-1 via the activation of p42144 MAPK in primary cultured rat hepatocytes. Betaine also alters the MAPK activations induced by ethanol.展开更多
In this paper, the function of the iel gene from baculovirus Spodoptera exigua multiple nucleopolyhedrovirus （SeMNPV）, belonging to group II nucleopolyhedrovirus, was studied in mammalian cells We amplified the SeMN...In this paper, the function of the iel gene from baculovirus Spodoptera exigua multiple nucleopolyhedrovirus （SeMNPV）, belonging to group II nucleopolyhedrovirus, was studied in mammalian cells We amplified the SeMNPV iel gene and expressed it by fusing to the C terminal of enhanced GFP protein in HEK 293 cells. Confocal microscopy revealed that the IE1-GFP fusion protein was localized in the nucleus of the mammalian cells. The promoter sequences of AcMNPV gp64, SeMNPV F protein and Drosophila hsp70 were also analyzed, to further study the function of SeMNPV IE1. The results showed that, in the absence of the hr sequence, IE1 improved the expression of the F promoter but didn＇t influence the gp64 promoter significantly, but IE1 moderately stimulated the hsp70 promoter.展开更多
Pulsed electric field is an innovative method for non-thermal food processing. The effects of pulsed electric field on cell disintegration and mass transfer in sugar beet were studied. Sugar beet slices were treated b...Pulsed electric field is an innovative method for non-thermal food processing. The effects of pulsed electric field on cell disintegration and mass transfer in sugar beet were studied. Sugar beet slices were treated by various Field strengths （0.5-6 kV cm^-1）, capacity of capacitors （0.5, 8 and 32 μF） and pulse numbers （1-100 pulses）. The cell disintegration index and energy input for each treated sample was evaluated. The results showed that the cell membrane of PEF （Pulsed Electric Field） treated samples using 2 kV cm^-1, 8 μF after 20 pulses, and 3 kV cm1, 8 μF after 10 pulses were rapidly disintegrated in less than 1 min. Most important parameters during cell permeabilization were the total energy input followed by field strength. Energy efficiency index was defined as cell disintegration index per energy input unit. The maximum efficiency index was achieved using 2 kV cm^-1, 8 μF after 5 pulses. Comparison between PEF pretreatment and thermal method showed that large amount of sugar may be extracted after PEF pretreatment using field strength of 2 Kv cm^-1, 8μF in less than 10 min at ambient temperature. In.addition, the consumed energy for thermal treatment was approximately 20 to 50 times more than PEF pretreatment. Optimizing the field conditions in PEF treatment is an important factor to achieve high amount of sugar extraction from sugar beet.展开更多
文摘AIM： To evaluate the effects of betaine on the ethanolinduced secretion of IGF-I and IGFBP-1 using radioimrnunoassay and Western blotting, respectively, in primary cultured rat hepatocytes. METHODS： Hepatocytes isolated from male SpragueDawley rats were incubated with various concentrations of ethanol and PD98059 procedures. The hepatocytes were also treated with different doses of betaine （10^-5, 10^-4, and 10^-3 mol/L）. We measured IGF-I and IGFBP-1 using radioimmunoassay and Western blotting, respectively. RESULTS： The ethanol-induced inhibition of IGF-I secretion was attenuated by betaine in a concentration-dependent manner in primary cultured rat hepatocytes. At 10^-3 mol/L, betaine significantly increased IGF-I secretion but decreased IGFBP-1 secretion. In addition, p42/44 rnitogen-activated protein kinase （MAPK） activity was accelerated significantly from 10 min to 5 h after treatment with 10^-3 mol/L betaine. Furthermore, the changes in IGF-1 and IGFBP-1 secretion resulting from the increased betaine-induced p42/44 MAPK activity in primary cultured rat hepatocytes was blocked by treatment with the MAPK inhibitor PD98059. Betaine treatment blocked the ethanol-induced inhibition of IGF-I secretion and p42/44 MAPK activity, and the ethanol-induced increase in IGFBP-1 secretion.CONCLUSION： Betaine modulates the secretion of IGF-I and IGFBP-1 via the activation of p42144 MAPK in primary cultured rat hepatocytes. Betaine also alters the MAPK activations induced by ethanol.
基金The knowledge innovation program of the Chinese Academy of Sciences (KSCX2-YW-Z-0938)
文摘In this paper, the function of the iel gene from baculovirus Spodoptera exigua multiple nucleopolyhedrovirus （SeMNPV）, belonging to group II nucleopolyhedrovirus, was studied in mammalian cells We amplified the SeMNPV iel gene and expressed it by fusing to the C terminal of enhanced GFP protein in HEK 293 cells. Confocal microscopy revealed that the IE1-GFP fusion protein was localized in the nucleus of the mammalian cells. The promoter sequences of AcMNPV gp64, SeMNPV F protein and Drosophila hsp70 were also analyzed, to further study the function of SeMNPV IE1. The results showed that, in the absence of the hr sequence, IE1 improved the expression of the F promoter but didn＇t influence the gp64 promoter significantly, but IE1 moderately stimulated the hsp70 promoter.
文摘Pulsed electric field is an innovative method for non-thermal food processing. The effects of pulsed electric field on cell disintegration and mass transfer in sugar beet were studied. Sugar beet slices were treated by various Field strengths （0.5-6 kV cm^-1）, capacity of capacitors （0.5, 8 and 32 μF） and pulse numbers （1-100 pulses）. The cell disintegration index and energy input for each treated sample was evaluated. The results showed that the cell membrane of PEF （Pulsed Electric Field） treated samples using 2 kV cm^-1, 8 μF after 20 pulses, and 3 kV cm1, 8 μF after 10 pulses were rapidly disintegrated in less than 1 min. Most important parameters during cell permeabilization were the total energy input followed by field strength. Energy efficiency index was defined as cell disintegration index per energy input unit. The maximum efficiency index was achieved using 2 kV cm^-1, 8 μF after 5 pulses. Comparison between PEF pretreatment and thermal method showed that large amount of sugar may be extracted after PEF pretreatment using field strength of 2 Kv cm^-1, 8μF in less than 10 min at ambient temperature. In.addition, the consumed energy for thermal treatment was approximately 20 to 50 times more than PEF pretreatment. Optimizing the field conditions in PEF treatment is an important factor to achieve high amount of sugar extraction from sugar beet.
