MYB transcription factors compose one of the largest transcription factor families in Arabidopsis, which play important roles in vari- ous developmental processes as well as defense responses against environmental str...MYB transcription factors compose one of the largest transcription factor families in Arabidopsis, which play important roles in vari- ous developmental processes as well as defense responses against environmental stresses. In this study, we report the characterization of AtMYB17 gene, a putative R2R3 type MYB gene family member in Arabidopsis. AtMYB17 was found exclusively localized in nuclear, with an activation domain at its C-terminus. AtMYBI7 was highly expressed in inflorescences and siliques, especially at early flower developmental stages. The level of AtMYB17 transcripts was also found to increase after imbibition during seed germination and gradually concentrate to the shoot apex. Bioinformatics analysis identified several binding sites of LEAFY （LFY） and AGL15 in the promoter re- gion of AtMYB17. Promoter-GUS fusion analysis showed that the LFY binding sites were important in fine-tuning regulation of the spatio-temporal expression ofAtMYB17 in transgenic plants. Moreover, AtMYB17 was up-regulated in 35S：：AGL15 plants. Taken together, our data suggest that LFY may be involved in the regulation of AtMYB17, possibly together with AGL 15, and thereafter in early inflores- cence development and seed germination.展开更多
The liver is unique in regenerative potential, which could recover the lost mass and function after injury from ischemia and resection. The underlying molecular mechanisms of liver regeneration have been extensively s...The liver is unique in regenerative potential, which could recover the lost mass and function after injury from ischemia and resection. The underlying molecular mechanisms of liver regeneration have been extensively studied in the past using the partial hepatectomy(PH) model in rodents, where 2/3 PH is carried out by removing two lobes. The whole process of liver regeneration is complicated, orchestrated event involving a network of connected interactions, which still remain fully elusive. Bile acids(BAs) are ligands of farnesoid X receptor(FXR), a nuclear receptor of ligand-activated transcription factor. FXR has been shown to be highly involved in liver regeneration. BAs and FXR not only interact with each other but also regulate various downstream targets independently during liver regeneration. Moreover, recent findings suggest that tissue-specific FXR also contributes to liver regeneration significantly. These novel findings suggest that FXR has much broader role than regulating BA, cholesterol, lipid and glucose metabolism. Therefore, these researches highlight FXR as an important pharmaceutical target for potentialuse of FXR ligands to regulate liver regeneration in clinic. This review focuses on the roles of BAs and FXR in liver regeneration and the current underlying molecular mechanisms which contribute to liver regeneration.展开更多
BackgroundGrowth differentiation factor （GDF）-15, a divergent member of the transforming growth factor beta super-family does appear to be up-regulated in response to experimental pressure overload and progression o...BackgroundGrowth differentiation factor （GDF）-15, a divergent member of the transforming growth factor beta super-family does appear to be up-regulated in response to experimental pressure overload and progression of heart failure （HF）. HF frequently develops after myocardial infarction （MI）, contributing to worse outcome. The aim of this study is to assess the correlation between GDF-15 levels and markers related to collagen turnover in different stages of HF.MethodsThe study consists of a cohort of 179 patients, including stable angina pectoris patients （AP group,n= 50）, old MI patients without HF （OMI group,n = 56）, old MI patients with HF （OMI-HF group,n= 38） and normal Control group （n = 35）. Both indicators reflecting the synthesis and degradation rates of collagen including precollagen I N-terminal peptide （PINP）, type I collagen carboxy-terminal peptide （ICTP）, precollagen III N-terminal peptide （PIIINP） and GDF-15 were measured using an enzyme-linked inmunosorbent assay.ResultsThe plasma GDF-15 level was higher in OMI-HF group （1373.4 ± 275.4 ng/L） than OMI group （1036.1 ± 248.6 ng/L）, AP group （784.6 ± 222.4 ng/L） and Control group （483.8 ± 186.4 ng/L） （P〈 0.001）. The indi-cators of collagen turnover （ICTP, PINP, PIIINP） all increased in the OMI-HF group compared with Control group （3.03 ± 1.02μg/Lvs. 2.08 ± 0.95μg/L, 22.2 ± 6.6μg/Lvs. 16.7 ± 5.1μg/L and 13.2 ± 7.9μg/Lvs. 6.4 ± 2.1μg/L, respectively;P〈 0.01）. GDF-15 positively cor-related with ICTP and PIIINP （r = 0.302,P〈 0.001 andr= 0.206,P= 0.006, respectively）. GDF-15 positively correlated to the echocardio-graphic diastolic indicators E/Em and left atrial pressure （r= 0.349 and r= 0.358, respectively;P〈 0.01）, and inversely correlated to the systolic indicators left ventricular ejection fraction and the average of peak systolic myocardial velocities （Sm） （r=-0.623 and r=-0.365, respectively;P〈 0.01）.ConclusionPlasma GDF-15 is associated wit展开更多
基金supported by the State Key Basic Research and Development Plan (No. 2006CB100105)the 111 Project of Peking University in China.
文摘MYB transcription factors compose one of the largest transcription factor families in Arabidopsis, which play important roles in vari- ous developmental processes as well as defense responses against environmental stresses. In this study, we report the characterization of AtMYB17 gene, a putative R2R3 type MYB gene family member in Arabidopsis. AtMYB17 was found exclusively localized in nuclear, with an activation domain at its C-terminus. AtMYBI7 was highly expressed in inflorescences and siliques, especially at early flower developmental stages. The level of AtMYB17 transcripts was also found to increase after imbibition during seed germination and gradually concentrate to the shoot apex. Bioinformatics analysis identified several binding sites of LEAFY （LFY） and AGL15 in the promoter re- gion of AtMYB17. Promoter-GUS fusion analysis showed that the LFY binding sites were important in fine-tuning regulation of the spatio-temporal expression ofAtMYB17 in transgenic plants. Moreover, AtMYB17 was up-regulated in 35S：：AGL15 plants. Taken together, our data suggest that LFY may be involved in the regulation of AtMYB17, possibly together with AGL 15, and thereafter in early inflores- cence development and seed germination.
基金supported by the National Institutes of Health Fund (Nos.DK081343,DK090036 and GM104037 to Grace L.Guo)the National Natural Science Foundation of China (No.81302059)+2 种基金the Natural Science Foundation of Heilongjiang Province of China (No.LC2013C35)the Foundation of Educational Committee of Heilongjiang Province of China (No.12541300)supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry and Science Foundation for The Excellent Youth Scholars of the Fourth Hospital of Harbin Medical University in China
文摘The liver is unique in regenerative potential, which could recover the lost mass and function after injury from ischemia and resection. The underlying molecular mechanisms of liver regeneration have been extensively studied in the past using the partial hepatectomy(PH) model in rodents, where 2/3 PH is carried out by removing two lobes. The whole process of liver regeneration is complicated, orchestrated event involving a network of connected interactions, which still remain fully elusive. Bile acids(BAs) are ligands of farnesoid X receptor(FXR), a nuclear receptor of ligand-activated transcription factor. FXR has been shown to be highly involved in liver regeneration. BAs and FXR not only interact with each other but also regulate various downstream targets independently during liver regeneration. Moreover, recent findings suggest that tissue-specific FXR also contributes to liver regeneration significantly. These novel findings suggest that FXR has much broader role than regulating BA, cholesterol, lipid and glucose metabolism. Therefore, these researches highlight FXR as an important pharmaceutical target for potentialuse of FXR ligands to regulate liver regeneration in clinic. This review focuses on the roles of BAs and FXR in liver regeneration and the current underlying molecular mechanisms which contribute to liver regeneration.
基金All authors have no conflict of interest regarding this paper. This work was supported by Grant National Natural Science Foundation of China （81400262） ＆ Backbone Fund of Peking University Third Hospital.
文摘BackgroundGrowth differentiation factor （GDF）-15, a divergent member of the transforming growth factor beta super-family does appear to be up-regulated in response to experimental pressure overload and progression of heart failure （HF）. HF frequently develops after myocardial infarction （MI）, contributing to worse outcome. The aim of this study is to assess the correlation between GDF-15 levels and markers related to collagen turnover in different stages of HF.MethodsThe study consists of a cohort of 179 patients, including stable angina pectoris patients （AP group,n= 50）, old MI patients without HF （OMI group,n = 56）, old MI patients with HF （OMI-HF group,n= 38） and normal Control group （n = 35）. Both indicators reflecting the synthesis and degradation rates of collagen including precollagen I N-terminal peptide （PINP）, type I collagen carboxy-terminal peptide （ICTP）, precollagen III N-terminal peptide （PIIINP） and GDF-15 were measured using an enzyme-linked inmunosorbent assay.ResultsThe plasma GDF-15 level was higher in OMI-HF group （1373.4 ± 275.4 ng/L） than OMI group （1036.1 ± 248.6 ng/L）, AP group （784.6 ± 222.4 ng/L） and Control group （483.8 ± 186.4 ng/L） （P〈 0.001）. The indi-cators of collagen turnover （ICTP, PINP, PIIINP） all increased in the OMI-HF group compared with Control group （3.03 ± 1.02μg/Lvs. 2.08 ± 0.95μg/L, 22.2 ± 6.6μg/Lvs. 16.7 ± 5.1μg/L and 13.2 ± 7.9μg/Lvs. 6.4 ± 2.1μg/L, respectively;P〈 0.01）. GDF-15 positively cor-related with ICTP and PIIINP （r = 0.302,P〈 0.001 andr= 0.206,P= 0.006, respectively）. GDF-15 positively correlated to the echocardio-graphic diastolic indicators E/Em and left atrial pressure （r= 0.349 and r= 0.358, respectively;P〈 0.01）, and inversely correlated to the systolic indicators left ventricular ejection fraction and the average of peak systolic myocardial velocities （Sm） （r=-0.623 and r=-0.365, respectively;P〈 0.01）.ConclusionPlasma GDF-15 is associated wit
