Objective To investigate the role of H1 and H2 receptors in the locus ceruleus （LC） in carotid sinus baroreceptor reflex （CSR） resetting induced by intracerebroventricular （i.c.v.） injection of histamine （HA）....Objective To investigate the role of H1 and H2 receptors in the locus ceruleus （LC） in carotid sinus baroreceptor reflex （CSR） resetting induced by intracerebroventricular （i.c.v.） injection of histamine （HA）. Methods The left and right carotid sinus regions were isolated from the systemic circulation in 18 male Sprague-Dawley rats anesthetized with pentobarbital sodium. The intracarotid sinus pressure （ISP） was altered in a stepwise manner in vivo. ISP-mean arterial pressure （MAP） relationship curve and its characteristic parameters were constructed by fitting to the logistic function with five parameters. The changes in CSR performance induced by i.c.v. HA and the effects of pretreatment with H1 or H2 receptors selective antagonist, chlorpheniramine （CHL） or cimetidine （CIM） into the LC, on the responses of CSR to HA were examined. Results I.c.v. HA （100 ng in 5 μl） significantly shifted the ISP-MAP relationship curve upwards （P 〈 0.05） and obviously decreased the value of the reflex parameters such as MAP range and maximum gain （P 〈 0.05）, but increased the threshold pressure, saturation pressure and ISP at maximum gain （P 〈 0.05）. The pretreatment with CHL （0.5 μg in 1 μl） or CIM （1.5 μg in 1 μl） into the LC could obviously attenuate the changes mentioned above in CSR performance induced by HA, but the alleviative effect of CIM was less remarkable than that of CHL （P 〈 0.05）. Respective microinjection of CHL or CIM alone into the LC with the corresponding dose and volume did not change CSR performance significantly （P 〉 0.05）. Conclusion Intracerebroventricular administration of HA results in a rapid resetting of CSR and a decrease in reflex sensitivity, and the responses of CSR to HA may be mediated, at least in part, by H1 and H2 receptors activities in the LC, especially by H1 receptors. Moreover, the effects of the central HA on CSR might be related to a histaminergic descending pathway from the hypothalamus to LC.展开更多
Wheat high-molecular-weight glutenin subunits(HMW-GS) determine dough elasticity and play an essential role in processing quality. HMW-GS are encoded by Glu-1 genes and controlled primarily at transcriptional level, i...Wheat high-molecular-weight glutenin subunits(HMW-GS) determine dough elasticity and play an essential role in processing quality. HMW-GS are encoded by Glu-1 genes and controlled primarily at transcriptional level, implemented through the interactions between cis-acting elements and trans-acting factors. However, transcriptional mechanism of Glu-1 genes remains elusive. Here we made a comprehensive analysis of cis-regulatory elements within 1-kb upstream of the Glu-1 start codon(-1000 to-1) and identified 30 conserved motifs. Based on motif distribution pattern, three conserved cis-regulatory modules(CCRMs), CCRM1(-300 to-101), CCRM2(-650 to-400), and CCRM3(-950 to-750), were defined, and their functions were characterized in wheat stable transgenic lines transformed with progressive 5′ deletion promoter::GUS fusion constructs. GUS staining, qP CR and enzyme activity assays indicated that CCRM2 and CCRM3 could enhance the expression level of Glu-1, whereas the 300-bp promoter(-300 to-1), spanning CCRM1 and core region(-100 to-1), was enough to ensure accurate Glu-1 initiation at 7 days after flowering(DAF) and shape its spatiotemporal expression pattern during seed development. Further transgenic assays demonstrated that CCRM1-2(-300 to-209) containing Complete HMW Enhancer(-246 to-209) was important for expression level but had no effect on expression specificity in the endosperm. In contrast, CCRM1-1(-208 to-101) was critical for both expression specificity and level of Glu-1. Our findings not only provide new insights to uncover Glu-1 transcription regulatory machinery but also lay foundations for modifying Glu-1 expression.展开更多
Mice carrying mutant amyloid precursor protein and presenilin-1 genes （APP/PS1 double trans- genic mice） have frequently been used in studies of Alzheimer＇s disease; however, such studies have focused mainly on hip...Mice carrying mutant amyloid precursor protein and presenilin-1 genes （APP/PS1 double trans- genic mice） have frequently been used in studies of Alzheimer＇s disease; however, such studies have focused mainly on hippocampal and cortical changes. The severity of Alzheimer＇s disease is known to correlate with the amount of amyloid-13 protein deposition and the number of dead neurons in the locus coeruleus. In the present study, we assigned APP/PS1 double transgenic mice to two groups according to age： young mice （5-6 months old） and aged mice （16-17 months old）. Age-matched wild-type mice were used as controls. Immunohistochemistry for tyrosine hydroxylase （a marker of catecholaminergic neurons in the locus coeruleus） revealed that APP/PS1 mice had 23% fewer cells in the locus coeruleus compared with aged wild-type mice. APP/PS1 mice also had increased numbers of cell bodies of neurons positive for tyrosine hydroxylase, but fewer tyrosine hydroxylase-positive fibers, which were also short, thick and broken. Quantitative analysis using unbiased stereology showed a significant age-related increase in the mean volume of tyrosine hy- droxylase-positive neurons in aged APP/PS1 mice compared with young APP/PS1 mice. Moreover, the mean volume of tyrosine hydroxylase-positive neurons was positively correlated with the total volume of the locus coeruleus. These findings indicate that noradrenergic neurons and fibers in the locus coeruleus are predisposed to degenerative alterations in APP/PS1 double transgenic mice.展开更多
Eighty two F1 seeds selected randomly from 33 hybrid ears of 23 crosses between 8 parental varieties were examined by 10% SDS PAGE for HMW glutenin expression and accumulation. The following results were obtained. 1. ...Eighty two F1 seeds selected randomly from 33 hybrid ears of 23 crosses between 8 parental varieties were examined by 10% SDS PAGE for HMW glutenin expression and accumulation. The following results were obtained. 1. All tested 8 alleles co dominated in the F1 seeds of 22 crosses. 2. In the 6 F1 seeds of the cross Pan 555 / Zheng 891, a novel subunit appeared in stead of the expected subunit 9 (contributed by Pan 555) and subunit 10 (contributed by Zheng 891), indicating that an interaction of unknown nature between the maternal and paternal genome had affected the expression of some HMW glutenin genes in the endospermic cells of the hybrid seed. 3. The subunits specified by the maternal genes accumulated twice as much as those specified by the paternal genes.展开更多
文摘Objective To investigate the role of H1 and H2 receptors in the locus ceruleus （LC） in carotid sinus baroreceptor reflex （CSR） resetting induced by intracerebroventricular （i.c.v.） injection of histamine （HA）. Methods The left and right carotid sinus regions were isolated from the systemic circulation in 18 male Sprague-Dawley rats anesthetized with pentobarbital sodium. The intracarotid sinus pressure （ISP） was altered in a stepwise manner in vivo. ISP-mean arterial pressure （MAP） relationship curve and its characteristic parameters were constructed by fitting to the logistic function with five parameters. The changes in CSR performance induced by i.c.v. HA and the effects of pretreatment with H1 or H2 receptors selective antagonist, chlorpheniramine （CHL） or cimetidine （CIM） into the LC, on the responses of CSR to HA were examined. Results I.c.v. HA （100 ng in 5 μl） significantly shifted the ISP-MAP relationship curve upwards （P 〈 0.05） and obviously decreased the value of the reflex parameters such as MAP range and maximum gain （P 〈 0.05）, but increased the threshold pressure, saturation pressure and ISP at maximum gain （P 〈 0.05）. The pretreatment with CHL （0.5 μg in 1 μl） or CIM （1.5 μg in 1 μl） into the LC could obviously attenuate the changes mentioned above in CSR performance induced by HA, but the alleviative effect of CIM was less remarkable than that of CHL （P 〈 0.05）. Respective microinjection of CHL or CIM alone into the LC with the corresponding dose and volume did not change CSR performance significantly （P 〉 0.05）. Conclusion Intracerebroventricular administration of HA results in a rapid resetting of CSR and a decrease in reflex sensitivity, and the responses of CSR to HA may be mediated, at least in part, by H1 and H2 receptors activities in the LC, especially by H1 receptors. Moreover, the effects of the central HA on CSR might be related to a histaminergic descending pathway from the hypothalamus to LC.
基金This work was supported by the National Natural Science Foundation of China (No. 30170502) and Chunhui Plan of Ministry of Education (No. 2004251008).
基金funded by the National Key Research and Development Program of China (2016YFD0100500)the National Natural Science Foundation of China (31571663, 31371623)Genetically Modified Organisms Breeding Major Project (2016ZX08009003-004)
文摘Wheat high-molecular-weight glutenin subunits(HMW-GS) determine dough elasticity and play an essential role in processing quality. HMW-GS are encoded by Glu-1 genes and controlled primarily at transcriptional level, implemented through the interactions between cis-acting elements and trans-acting factors. However, transcriptional mechanism of Glu-1 genes remains elusive. Here we made a comprehensive analysis of cis-regulatory elements within 1-kb upstream of the Glu-1 start codon(-1000 to-1) and identified 30 conserved motifs. Based on motif distribution pattern, three conserved cis-regulatory modules(CCRMs), CCRM1(-300 to-101), CCRM2(-650 to-400), and CCRM3(-950 to-750), were defined, and their functions were characterized in wheat stable transgenic lines transformed with progressive 5′ deletion promoter::GUS fusion constructs. GUS staining, qP CR and enzyme activity assays indicated that CCRM2 and CCRM3 could enhance the expression level of Glu-1, whereas the 300-bp promoter(-300 to-1), spanning CCRM1 and core region(-100 to-1), was enough to ensure accurate Glu-1 initiation at 7 days after flowering(DAF) and shape its spatiotemporal expression pattern during seed development. Further transgenic assays demonstrated that CCRM1-2(-300 to-209) containing Complete HMW Enhancer(-246 to-209) was important for expression level but had no effect on expression specificity in the endosperm. In contrast, CCRM1-1(-208 to-101) was critical for both expression specificity and level of Glu-1. Our findings not only provide new insights to uncover Glu-1 transcription regulatory machinery but also lay foundations for modifying Glu-1 expression.
基金supported by the National Natural Science Foundation of China, No. 81100663the Scientific Research Funds of the Health Department of Hunan Province, No.120303+1 种基金Hunan Provincal Natural Science Foundation of China, No. 13JJ3058a grant from the Scientific Research Program of Hunan Provincial Higher Education Institutes, No. 11C0829
文摘Mice carrying mutant amyloid precursor protein and presenilin-1 genes （APP/PS1 double trans- genic mice） have frequently been used in studies of Alzheimer＇s disease; however, such studies have focused mainly on hippocampal and cortical changes. The severity of Alzheimer＇s disease is known to correlate with the amount of amyloid-13 protein deposition and the number of dead neurons in the locus coeruleus. In the present study, we assigned APP/PS1 double transgenic mice to two groups according to age： young mice （5-6 months old） and aged mice （16-17 months old）. Age-matched wild-type mice were used as controls. Immunohistochemistry for tyrosine hydroxylase （a marker of catecholaminergic neurons in the locus coeruleus） revealed that APP/PS1 mice had 23% fewer cells in the locus coeruleus compared with aged wild-type mice. APP/PS1 mice also had increased numbers of cell bodies of neurons positive for tyrosine hydroxylase, but fewer tyrosine hydroxylase-positive fibers, which were also short, thick and broken. Quantitative analysis using unbiased stereology showed a significant age-related increase in the mean volume of tyrosine hy- droxylase-positive neurons in aged APP/PS1 mice compared with young APP/PS1 mice. Moreover, the mean volume of tyrosine hydroxylase-positive neurons was positively correlated with the total volume of the locus coeruleus. These findings indicate that noradrenergic neurons and fibers in the locus coeruleus are predisposed to degenerative alterations in APP/PS1 double transgenic mice.
文摘Eighty two F1 seeds selected randomly from 33 hybrid ears of 23 crosses between 8 parental varieties were examined by 10% SDS PAGE for HMW glutenin expression and accumulation. The following results were obtained. 1. All tested 8 alleles co dominated in the F1 seeds of 22 crosses. 2. In the 6 F1 seeds of the cross Pan 555 / Zheng 891, a novel subunit appeared in stead of the expected subunit 9 (contributed by Pan 555) and subunit 10 (contributed by Zheng 891), indicating that an interaction of unknown nature between the maternal and paternal genome had affected the expression of some HMW glutenin genes in the endospermic cells of the hybrid seed. 3. The subunits specified by the maternal genes accumulated twice as much as those specified by the paternal genes.
