This study investigates the aerodynamic performance of the NACA 633-421 airfoil and the effectiveness and feasibility of intermittent disturbance flow control methods on laminar separation bubbles(LSBs).It is found th...This study investigates the aerodynamic performance of the NACA 633-421 airfoil and the effectiveness and feasibility of intermittent disturbance flow control methods on laminar separation bubbles(LSBs).It is found that the average velocity and influence range of the synthetic jet actuator increase with the increasing of driving frequency and driving amplitude.LSB occurs at Re=1.0×10^(5),and ruptures atα=6°.But with intermittent disturbance control,the stall angle of attack(AoA)increases while significantly reducing drag.Research shows that although certain disturbance cannot fully recover from LSB stall,decreasing driving amplitude partially restores wing aerodynamic performance,more effectively than increasing driving amplitude.展开更多
To understand the regulatory mechanisms of gonadotropin secretion in Rana rugulosa ,this study investigated the effects of dopamine (DA),estradiol (E 2) and testosterone (T) on the in vitro release of luteiniz...To understand the regulatory mechanisms of gonadotropin secretion in Rana rugulosa ,this study investigated the effects of dopamine (DA),estradiol (E 2) and testosterone (T) on the in vitro release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the pituitary fragments of female Rana rugulosa using a static incubation system and radio immunoassay (RIA). The results indicated that DA at the concentration from 0 1?μmol/L to 10?μmol/L inhibited the release of LH and FSH from the pituitary fragments of sexually pre mature or hibernating individuals,and the inhibitory effects enhanced with increasing concentrations of DA. E 2 at 1?μmol/L and 10?μmol/L significantly stimulated the release of LH of sexually pre mature individuals,but inhibited their FSH release at 0 1?μmol/L to 10?μmol/L;T had no obvious effects on their FSH release,but significantly inhibited their LH release at 10?μmol/L. Neither E 2 nor T,at the concentration from 0 1?μmol/L to 100?μmol/L,had obvious effects on the release of LH and FSH of hibernating individuals. The data suggest that DA and sexual steroids may have direct regulatory actions on LH and FSH release at the pituitary level in Rana rugulosa ,and the action of sexual steroids may relate to the gonadal development stages (seasons).展开更多
The aim was to compare the effects of hormone treatments on the ovari- an follicular development and in vitro embryo development between 5-week and 13- week old lambs. FSH and pregnant mare serum gonadotropin (PMSG)...The aim was to compare the effects of hormone treatments on the ovari- an follicular development and in vitro embryo development between 5-week and 13- week old lambs. FSH and pregnant mare serum gonadotropin (PMSG) treatment were used to compare the number of 2-8 mm follicles in the ovary and the in vitro embryo development. The results showed that: the 5-week old lambs had larger fol- licular numbers and collected oocytes numbers (58.6±1.9, 47.4±4.2) than the 13- week old lambs (14.4±4.1, 11.6±1.7), and the difference was significant (P〈0.05). However, there was no significant difference in the cleavage rate (60.0±1.9%, 61.6± 5.2%) and blastocyst rate (27.4±2.1%, 28.2±3.7%) of the fertilized oocytes between the 5-week and 13-week old lambs.展开更多
For understanding the function of tonoplast protein in plant cell signal pathway, we have identified an integral protein kinase activity from the highly purified tonoplast isolated from maize ( Zea mays L.) root by...For understanding the function of tonoplast protein in plant cell signal pathway, we have identified an integral protein kinase activity from the highly purified tonoplast isolated from maize ( Zea mays L.) root by a new nonradioactive method in which a color labeled peptide was used as substrate. The protein kinase was Ca 2+ _dependent and CaM and phosphatidylserine_independent, like the calmodulin_like domain protein kinase (CDPK) in many plants. The optimal pH value and Ca 2+ concentration were 6.5 and 10 μmol/L, respectively. According to the optimal pH value and the effect of detergent, it could be inferred that the active site of this protein kinase is oriented toward the cytoplasm. Zn 2+ had no obvious effect on its activity, indicating that this protein kinase has no zinc_finger domain that exists in some mammalian protein kinases. At the same time, when tonoplast proteins were prephosphorylated in the presence of Ca 2+ and ATP, both the ATP_hydrolysis and the proton_transport activity of vacuolar H +_ATPase were stimulated. This stimulation could be reversed by an alkaline_phosphatase. These results indicate that a Ca 2+ _dependent protein kinase was located in the tonoplast, and a Ca 2+ _dependent phosphorylation, probably caused by this kinase, activated the vacuolar H +_ATPase activity. These results are helpful for further research on the function of CDPK in the course of signal transduction in plants.展开更多
The serum reproductive hormone levels were examined with radioimmunoassay in women of child-bearing age before and after treatment with the prescriptions containing Lei Gong Teng ([symbol: see text] Radix Tripterygii ...The serum reproductive hormone levels were examined with radioimmunoassay in women of child-bearing age before and after treatment with the prescriptions containing Lei Gong Teng ([symbol: see text] Radix Tripterygii Wilfordii). The results showed that Lei Gong Teng could induce amenorrhea, but it was reversible.展开更多
Follistatin(FST) is a monomeric glycoprotein highly enriched in cysteines and belongs to TGF-β superfamily. FST can suppress the secretion of follicle-stimulating hormone and plays a vital role in the reproduction of...Follistatin(FST) is a monomeric glycoprotein highly enriched in cysteines and belongs to TGF-β superfamily. FST can suppress the secretion of follicle-stimulating hormone and plays a vital role in the reproduction of vertebrates. We used rapid amplification of cDNA ends technology to clone the FST gene of half-smooth tongue sole,Cynoglossus semilaevis. We characterized its phylogenetic context and expression patterns to elucidate its function in the breeding season. The full-length sequence of FST is 1 455 bp and encodes a protein of 321 amino acids. We investigated the expression pattern of FST in C. semilaevis at different stages of reproduction using reverse transcription-polymerase chain reaction(RTPCR). FST m RNA was expressed in all 13 tissues analyzed,and was expressed at high levels in gonad and at slightly lower levels in gill and brain. During the reproductive cycle of C. semilaevis,the transcript level of FST was the highest in the perinucleolus stage,decreased in the primary yolk stage,slightly increased in the tertiary yolk stage,and then reduced to a minimal level in the atretic follicles stage of the ovary. We concluded that FST suppressed follicle-stimulating hormone,which stimulated oocyte development. However,no significant variation was observed across all stages of testis development,although the expression level in the spermatogenesis stage was relatively low,which may result from the regulation of FST by aromatase.展开更多
Objective To investigate the association between two polymorphisms of follicle stimulating hormone receptor (FSHR) gene and polycystic ovary syndrome (PCOS) susceptibility. Methods Case-control studies on relatio...Objective To investigate the association between two polymorphisms of follicle stimulating hormone receptor (FSHR) gene and polycystic ovary syndrome (PCOS) susceptibility. Methods Case-control studies on relationship of Thr307Ala and Asn680Ser polymorphisms in FSHR gene and PCOS susceptibility were searched from PubMed, ISI web of knowledge, EBSCO, and China National Knowledge Infrastructure (CNKI) databases up to March 21, 2013. The pooled odds ratio (OR) and 95% confidence interval (CO were calculated using fixed- or random-effect model based on heterogeneity test in 5 genotype models analyses. Results A total of 11 studies were included in the Meta-analysis. The random-effect analysis showed Asn680Ser was significantly associated with the reduced susceptibility to PCOS with dominant model (Asn/Asn+Asn/Ser vs. Ser/Ser, OR=0.83, 95% CI: 0.69-1.00), recessive model (Asn/Asn vs. Asn/Ser+ Ser/Ser, OR=0.84, 95% CI: 0.72-0.98), homozygote comparison (Ash/Ash vs. Ser/Ser, 0R=0.79, 95% CI: 0.63-0.98), and the allele contrast (Asn vs. Ser, OR=0.87, 95% CI: 0.79-0.97) respectively(P=0.02, I2=56.0%), being protective factors for PCOS. However, no significant associations were found between Thr307Ala and PCOS. Conclusion There might be a significant association between Asn680Ser polymorphism and PCOS.展开更多
For eliminating the negative effects of lock-in region and optical elements in cavity,the non-planar structure is strongly needed in laser gyro. In this paper,the theoretical formula of rotatory effect in non-planar c...For eliminating the negative effects of lock-in region and optical elements in cavity,the non-planar structure is strongly needed in laser gyro. In this paper,the theoretical formula of rotatory effect in non-planar cavity is presented deducing from basic light propagating law. Based on the 8-like plane cavity,a novel non-planar structure is designed and numerically calculated. The results show that for obtaining the required rotatory angle,it just needs to adjust the structural parameters of the original 8-like plane cavity. The four-frequency-differential laser gyro which adopts the non-planar 8-like structure has the same advantages as those with the planar 8-like structure,such as the gain region locates at one leg,the position of Faraday rotator has better spatial symmetry and the coating films of the output mirror is easily designed.展开更多
Eight-seven cases of male infertility due to spermatopathy were treated with Sheng Jing Zhong Zi Tang (SJZZT [symbol: see text]) for 1-3 courses. The total effective rate was 95.40% (83/87). 56.32% (49/87) of their sp...Eight-seven cases of male infertility due to spermatopathy were treated with Sheng Jing Zhong Zi Tang (SJZZT [symbol: see text]) for 1-3 courses. The total effective rate was 95.40% (83/87). 56.32% (49/87) of their spouses got pregnant and the semen quality was markedly improved (P展开更多
A self-developed laser image measurement system was established to study the behavior of bubble for- mation at a single orifice in non-Newtonian polyacrylamide(PAAm)solutions.Images of bubbles were captured by a CCD c...A self-developed laser image measurement system was established to study the behavior of bubble for- mation at a single orifice in non-Newtonian polyacrylamide(PAAm)solutions.Images of bubbles were captured by a CCD camera and volumes of bubbles were digitally analyzed online.The effects of rheological property of PAAm solution,orifice,reservoir,and gas flowrate on bubble formation were studied experimentally.It is found that the volume of bubble increases with the concentration of PAAm solution,the diameter of the orifice,and the gas flowrate,respectively,whereas little effect of reservoir is observed in experiments.展开更多
Baekgound Recent studies have suggested a potential role for liraglutide in the prevention and stabilization ofatherosclerotic vascular disease. However, the molecular mechanisms underlying the effect of liraglutide o...Baekgound Recent studies have suggested a potential role for liraglutide in the prevention and stabilization ofatherosclerotic vascular disease. However, the molecular mechanisms underlying the effect of liraglutide on atherosclerosis have not been well elucidated. The pur- pose of this study was to examine whether liraglutide protects against oxidative stress and fatty degeneration via modulation of AMP-activated protein kinase (AMPK)/sterol regulatory element binding transcription factor 1 (SREBP1) signaling pathway in foam ceils. Methods Mouse macrophages Raw264.7 cells were exposed to oxidized low density lipoprotein (oxLDL) to induce the formation of foam cells. The cells were incubated with oxLDL (50 μg/mL), liraglutide (0.1, 0.5, 1 and 2 nmol/L) or exendin-3 (9-39) (1, 10 and 100 nmol/L) alone, or in combination. Oil Red O staining was used to detect intracellular lipid droplets. The levels of TG and cholesterol were measured using the commercial kits. Oxidative stress was determined by measuring intracellular reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase 1 (SOD). Western blot analysis was used to examine the expression of AMPKal, SREBP1, phosphory- lated AMPKal, phosphorylated SREBP1, glucagon-like peptide-1 (GLP-1) and GLP-1 receptor (GLP-1R). Results Oil Red O staining showed that the cytoplasmic lipid droplet accumulation was visibly decreased in foam cells by treatment with liraglutide. The TG and cholesterol content in the liraglutide-treated foam cells was significantly decreased. In addition, foam ceils manifested an impaired oxidative stress following liraglutide treatment, as evidenced by increased SOD, and decreased ROS and MDA. However, these effects of liraglutide on foam cells were attenuated by the use of GLP-IR antagonist exendin-3 (9-39). Furthermore, we found that the expression level of AMPKa 1 and phosphorylated AMPKct 1 was significantly increased while the expression level of SREBP 1 and phosphorylated SREBP 1 was significantly decreased in foam cells following treatment with liraglutide. Conclusions This study for the first time demonstrated that the effect of liraglutide on reducing oxidative stress and fatty degeneration in oxLDL-induced Raw264.7 cells is accompanied by the alteration of AMPK/SREBP1 pathway. This study provided a potential molecular mechanism for the effect of liraglutide on reducing oxidative stress and fatty degeneration.展开更多
The effect of epidermal growth factor(EGF) on follicular development and steroidogenesis was investigated using an in vitro perfused immature rat ovary model. Type 3a and type 3b follicles were counted in the section...The effect of epidermal growth factor(EGF) on follicular development and steroidogenesis was investigated using an in vitro perfused immature rat ovary model. Type 3a and type 3b follicles were counted in the sections of perfused ovaries. To determine action of EGF on amortize activity, effect of testosterone(10-5 M) plus EGF(10 ng/ml) and that of testosterone(10-5 M) alone were compared. EGF(10 ng/ml) significantly increased the number of both types of follicles. At time-course experiment, EGF(10 ng/ml) did not enhance the number of both types of follicles after 10 hr perfusion, but significantly augmented it after perfusion of 20 hrs. EGF(10 ng/m) also stimulated progesterone production. There was no significant difference in estradiol level when ovaries were treated with EGF alone. The addition of testosterone significantly increased estradiol production. EGF inhibited testosterone-derived ovary estradiol production. These results suggest that EGF induces development of the primordial and primary follicles and plays an important role in controlling development by regulating function of granulosa cells.展开更多
The development of ovarian follicular cells is controlled by multiple circulating and local hormones and factors, including follicle-stimulating hormone (FSH) and epidermal growth factor (EGF). In this study, the ...The development of ovarian follicular cells is controlled by multiple circulating and local hormones and factors, including follicle-stimulating hormone (FSH) and epidermal growth factor (EGF). In this study, the stagespecific effect of EGF on FSH-induced proliferation of granulosa cells was evaluated in the ovarian follicles of egg-laying chickens. Results showed that EGF and its receptor (EGFR) mRNAs displayed a high expression in granulosa cells from the prehierarchical follicles, including the large white follicle (LWF) and small yellow follicle (SYF), and thereafter the expression decreased markedly to the stage of the largest preovulatory follicle. SYF represents a turning point of EGF/EGFR mRNA expression during follicle selection. Subsequently the granulosa cells from SYF were cultured to reveal the mediation of EGF in FSH action. Cell proliferation was remarkably increased by treatment with either EGF or FSH (0.1-100 ng/ml). This result was confirmed by elevated proliferating cell nuclear antigen (PCNA) expression and decreased cell apoptosis. Furthermore, EGF-induced cell proliferation was accompanied by increased mRNA expressions of EGFR, FSH receptor, and the cell cycle-regulating genes (cyclins D1 and El, cyclin-dependent kinases 2 and 6) as well as decreased expression of luteinizing hormone receptor mRNA. However, the EGF or FSH-elicited effect was reversed by simultaneous treatment with an EGFR inhibitor AG1478. In conclusion, EGF and EGFR expressions manifested stage-specific changes during follicular development and EGF mediated FSH-induced cell proliferation and retarded cell differentiation in the prehierarchical follicles. These expressions thus stimulated follicular growth before selection in the egg-laying chicken.展开更多
文摘This study investigates the aerodynamic performance of the NACA 633-421 airfoil and the effectiveness and feasibility of intermittent disturbance flow control methods on laminar separation bubbles(LSBs).It is found that the average velocity and influence range of the synthetic jet actuator increase with the increasing of driving frequency and driving amplitude.LSB occurs at Re=1.0×10^(5),and ruptures atα=6°.But with intermittent disturbance control,the stall angle of attack(AoA)increases while significantly reducing drag.Research shows that although certain disturbance cannot fully recover from LSB stall,decreasing driving amplitude partially restores wing aerodynamic performance,more effectively than increasing driving amplitude.
文摘To understand the regulatory mechanisms of gonadotropin secretion in Rana rugulosa ,this study investigated the effects of dopamine (DA),estradiol (E 2) and testosterone (T) on the in vitro release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the pituitary fragments of female Rana rugulosa using a static incubation system and radio immunoassay (RIA). The results indicated that DA at the concentration from 0 1?μmol/L to 10?μmol/L inhibited the release of LH and FSH from the pituitary fragments of sexually pre mature or hibernating individuals,and the inhibitory effects enhanced with increasing concentrations of DA. E 2 at 1?μmol/L and 10?μmol/L significantly stimulated the release of LH of sexually pre mature individuals,but inhibited their FSH release at 0 1?μmol/L to 10?μmol/L;T had no obvious effects on their FSH release,but significantly inhibited their LH release at 10?μmol/L. Neither E 2 nor T,at the concentration from 0 1?μmol/L to 100?μmol/L,had obvious effects on the release of LH and FSH of hibernating individuals. The data suggest that DA and sexual steroids may have direct regulatory actions on LH and FSH release at the pituitary level in Rana rugulosa ,and the action of sexual steroids may relate to the gonadal development stages (seasons).
基金Supported by the Project of the Finance Department of Heilongjiang Province(2016-10)the Key Program for Agriculture of Qiqihar City(NYGG-201425)~~
文摘The aim was to compare the effects of hormone treatments on the ovari- an follicular development and in vitro embryo development between 5-week and 13- week old lambs. FSH and pregnant mare serum gonadotropin (PMSG) treatment were used to compare the number of 2-8 mm follicles in the ovary and the in vitro embryo development. The results showed that: the 5-week old lambs had larger fol- licular numbers and collected oocytes numbers (58.6±1.9, 47.4±4.2) than the 13- week old lambs (14.4±4.1, 11.6±1.7), and the difference was significant (P〈0.05). However, there was no significant difference in the cleavage rate (60.0±1.9%, 61.6± 5.2%) and blastocyst rate (27.4±2.1%, 28.2±3.7%) of the fertilized oocytes between the 5-week and 13-week old lambs.
文摘For understanding the function of tonoplast protein in plant cell signal pathway, we have identified an integral protein kinase activity from the highly purified tonoplast isolated from maize ( Zea mays L.) root by a new nonradioactive method in which a color labeled peptide was used as substrate. The protein kinase was Ca 2+ _dependent and CaM and phosphatidylserine_independent, like the calmodulin_like domain protein kinase (CDPK) in many plants. The optimal pH value and Ca 2+ concentration were 6.5 and 10 μmol/L, respectively. According to the optimal pH value and the effect of detergent, it could be inferred that the active site of this protein kinase is oriented toward the cytoplasm. Zn 2+ had no obvious effect on its activity, indicating that this protein kinase has no zinc_finger domain that exists in some mammalian protein kinases. At the same time, when tonoplast proteins were prephosphorylated in the presence of Ca 2+ and ATP, both the ATP_hydrolysis and the proton_transport activity of vacuolar H +_ATPase were stimulated. This stimulation could be reversed by an alkaline_phosphatase. These results indicate that a Ca 2+ _dependent protein kinase was located in the tonoplast, and a Ca 2+ _dependent phosphorylation, probably caused by this kinase, activated the vacuolar H +_ATPase activity. These results are helpful for further research on the function of CDPK in the course of signal transduction in plants.
文摘The serum reproductive hormone levels were examined with radioimmunoassay in women of child-bearing age before and after treatment with the prescriptions containing Lei Gong Teng ([symbol: see text] Radix Tripterygii Wilfordii). The results showed that Lei Gong Teng could induce amenorrhea, but it was reversible.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A403)
文摘Follistatin(FST) is a monomeric glycoprotein highly enriched in cysteines and belongs to TGF-β superfamily. FST can suppress the secretion of follicle-stimulating hormone and plays a vital role in the reproduction of vertebrates. We used rapid amplification of cDNA ends technology to clone the FST gene of half-smooth tongue sole,Cynoglossus semilaevis. We characterized its phylogenetic context and expression patterns to elucidate its function in the breeding season. The full-length sequence of FST is 1 455 bp and encodes a protein of 321 amino acids. We investigated the expression pattern of FST in C. semilaevis at different stages of reproduction using reverse transcription-polymerase chain reaction(RTPCR). FST m RNA was expressed in all 13 tissues analyzed,and was expressed at high levels in gonad and at slightly lower levels in gill and brain. During the reproductive cycle of C. semilaevis,the transcript level of FST was the highest in the perinucleolus stage,decreased in the primary yolk stage,slightly increased in the tertiary yolk stage,and then reduced to a minimal level in the atretic follicles stage of the ovary. We concluded that FST suppressed follicle-stimulating hormone,which stimulated oocyte development. However,no significant variation was observed across all stages of testis development,although the expression level in the spermatogenesis stage was relatively low,which may result from the regulation of FST by aromatase.
文摘Objective To investigate the association between two polymorphisms of follicle stimulating hormone receptor (FSHR) gene and polycystic ovary syndrome (PCOS) susceptibility. Methods Case-control studies on relationship of Thr307Ala and Asn680Ser polymorphisms in FSHR gene and PCOS susceptibility were searched from PubMed, ISI web of knowledge, EBSCO, and China National Knowledge Infrastructure (CNKI) databases up to March 21, 2013. The pooled odds ratio (OR) and 95% confidence interval (CO were calculated using fixed- or random-effect model based on heterogeneity test in 5 genotype models analyses. Results A total of 11 studies were included in the Meta-analysis. The random-effect analysis showed Asn680Ser was significantly associated with the reduced susceptibility to PCOS with dominant model (Asn/Asn+Asn/Ser vs. Ser/Ser, OR=0.83, 95% CI: 0.69-1.00), recessive model (Asn/Asn vs. Asn/Ser+ Ser/Ser, OR=0.84, 95% CI: 0.72-0.98), homozygote comparison (Ash/Ash vs. Ser/Ser, 0R=0.79, 95% CI: 0.63-0.98), and the allele contrast (Asn vs. Ser, OR=0.87, 95% CI: 0.79-0.97) respectively(P=0.02, I2=56.0%), being protective factors for PCOS. However, no significant associations were found between Thr307Ala and PCOS. Conclusion There might be a significant association between Asn680Ser polymorphism and PCOS.
文摘For eliminating the negative effects of lock-in region and optical elements in cavity,the non-planar structure is strongly needed in laser gyro. In this paper,the theoretical formula of rotatory effect in non-planar cavity is presented deducing from basic light propagating law. Based on the 8-like plane cavity,a novel non-planar structure is designed and numerically calculated. The results show that for obtaining the required rotatory angle,it just needs to adjust the structural parameters of the original 8-like plane cavity. The four-frequency-differential laser gyro which adopts the non-planar 8-like structure has the same advantages as those with the planar 8-like structure,such as the gain region locates at one leg,the position of Faraday rotator has better spatial symmetry and the coating films of the output mirror is easily designed.
文摘Eight-seven cases of male infertility due to spermatopathy were treated with Sheng Jing Zhong Zi Tang (SJZZT [symbol: see text]) for 1-3 courses. The total effective rate was 95.40% (83/87). 56.32% (49/87) of their spouses got pregnant and the semen quality was markedly improved (P
基金Supported by the National Natural Science Foundation of China (No.20476073) and the Programs of Introducing Talents of Discipline to Universities (Grant No.B06006).
文摘A self-developed laser image measurement system was established to study the behavior of bubble for- mation at a single orifice in non-Newtonian polyacrylamide(PAAm)solutions.Images of bubbles were captured by a CCD camera and volumes of bubbles were digitally analyzed online.The effects of rheological property of PAAm solution,orifice,reservoir,and gas flowrate on bubble formation were studied experimentally.It is found that the volume of bubble increases with the concentration of PAAm solution,the diameter of the orifice,and the gas flowrate,respectively,whereas little effect of reservoir is observed in experiments.
文摘Baekgound Recent studies have suggested a potential role for liraglutide in the prevention and stabilization ofatherosclerotic vascular disease. However, the molecular mechanisms underlying the effect of liraglutide on atherosclerosis have not been well elucidated. The pur- pose of this study was to examine whether liraglutide protects against oxidative stress and fatty degeneration via modulation of AMP-activated protein kinase (AMPK)/sterol regulatory element binding transcription factor 1 (SREBP1) signaling pathway in foam ceils. Methods Mouse macrophages Raw264.7 cells were exposed to oxidized low density lipoprotein (oxLDL) to induce the formation of foam cells. The cells were incubated with oxLDL (50 μg/mL), liraglutide (0.1, 0.5, 1 and 2 nmol/L) or exendin-3 (9-39) (1, 10 and 100 nmol/L) alone, or in combination. Oil Red O staining was used to detect intracellular lipid droplets. The levels of TG and cholesterol were measured using the commercial kits. Oxidative stress was determined by measuring intracellular reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase 1 (SOD). Western blot analysis was used to examine the expression of AMPKal, SREBP1, phosphory- lated AMPKal, phosphorylated SREBP1, glucagon-like peptide-1 (GLP-1) and GLP-1 receptor (GLP-1R). Results Oil Red O staining showed that the cytoplasmic lipid droplet accumulation was visibly decreased in foam cells by treatment with liraglutide. The TG and cholesterol content in the liraglutide-treated foam cells was significantly decreased. In addition, foam ceils manifested an impaired oxidative stress following liraglutide treatment, as evidenced by increased SOD, and decreased ROS and MDA. However, these effects of liraglutide on foam cells were attenuated by the use of GLP-IR antagonist exendin-3 (9-39). Furthermore, we found that the expression level of AMPKa 1 and phosphorylated AMPKct 1 was significantly increased while the expression level of SREBP 1 and phosphorylated SREBP 1 was significantly decreased in foam cells following treatment with liraglutide. Conclusions This study for the first time demonstrated that the effect of liraglutide on reducing oxidative stress and fatty degeneration in oxLDL-induced Raw264.7 cells is accompanied by the alteration of AMPK/SREBP1 pathway. This study provided a potential molecular mechanism for the effect of liraglutide on reducing oxidative stress and fatty degeneration.
文摘The effect of epidermal growth factor(EGF) on follicular development and steroidogenesis was investigated using an in vitro perfused immature rat ovary model. Type 3a and type 3b follicles were counted in the sections of perfused ovaries. To determine action of EGF on amortize activity, effect of testosterone(10-5 M) plus EGF(10 ng/ml) and that of testosterone(10-5 M) alone were compared. EGF(10 ng/ml) significantly increased the number of both types of follicles. At time-course experiment, EGF(10 ng/ml) did not enhance the number of both types of follicles after 10 hr perfusion, but significantly augmented it after perfusion of 20 hrs. EGF(10 ng/m) also stimulated progesterone production. There was no significant difference in estradiol level when ovaries were treated with EGF alone. The addition of testosterone significantly increased estradiol production. EGF inhibited testosterone-derived ovary estradiol production. These results suggest that EGF induces development of the primordial and primary follicles and plays an important role in controlling development by regulating function of granulosa cells.
基金supported by the National Natural Science Foundation of China (No. 30871843)the Zhejiang Provincial Natural Science Foundation (No. Z3110115)the Fundamental Research Funds for the Central Universities,China
文摘The development of ovarian follicular cells is controlled by multiple circulating and local hormones and factors, including follicle-stimulating hormone (FSH) and epidermal growth factor (EGF). In this study, the stagespecific effect of EGF on FSH-induced proliferation of granulosa cells was evaluated in the ovarian follicles of egg-laying chickens. Results showed that EGF and its receptor (EGFR) mRNAs displayed a high expression in granulosa cells from the prehierarchical follicles, including the large white follicle (LWF) and small yellow follicle (SYF), and thereafter the expression decreased markedly to the stage of the largest preovulatory follicle. SYF represents a turning point of EGF/EGFR mRNA expression during follicle selection. Subsequently the granulosa cells from SYF were cultured to reveal the mediation of EGF in FSH action. Cell proliferation was remarkably increased by treatment with either EGF or FSH (0.1-100 ng/ml). This result was confirmed by elevated proliferating cell nuclear antigen (PCNA) expression and decreased cell apoptosis. Furthermore, EGF-induced cell proliferation was accompanied by increased mRNA expressions of EGFR, FSH receptor, and the cell cycle-regulating genes (cyclins D1 and El, cyclin-dependent kinases 2 and 6) as well as decreased expression of luteinizing hormone receptor mRNA. However, the EGF or FSH-elicited effect was reversed by simultaneous treatment with an EGFR inhibitor AG1478. In conclusion, EGF and EGFR expressions manifested stage-specific changes during follicular development and EGF mediated FSH-induced cell proliferation and retarded cell differentiation in the prehierarchical follicles. These expressions thus stimulated follicular growth before selection in the egg-laying chicken.