Dan Wu - Academia.edu (original) (raw)
Papers by Dan Wu
Physical Review Letters, 2006
We report a state-of-the-art photoemission (ARPES) study of high quality single crystals of the N... more We report a state-of-the-art photoemission (ARPES) study of high quality single crystals of the NaxCoO2 series focusing on the fine details of the low-energy states. The Fermi velocity is found to be small (< 0.5 eV.Å) and only weakly anisotropic over the Fermi surface at all dopings setting the size of the pair wavefunction to be on the order of 10-20 nanometers. In the low doping regime the exchange inter-layer splitting vanishes and two dimensional collective instabilities such as 120 • -type fluctuations become kinematically allowed. Our results suggest that the unusually small Fermi velocity and the unique symmetry of kinematic instabilities distinguish cobaltates from other unconventional oxide superconductors such as the cuprates or the ruthenates.
Journal of Applied Physics, 1999
Raman spectroscopy and x-ray diffraction study of PbTiO thin films prepared by solgel technique.... more Raman spectroscopy and x-ray diffraction study of PbTiO thin films prepared by solgel technique. [Journal of Applied Physics 85, 2146 (1999)]. Ai-Dong Li, Di Wu, Chuan-Zhen Ge, Peng Lü, Wen-Hui Ma, Ming-Sheng Zhang, Cun-Yi Xu, Jian Zuo, Nai-Ben Ming. Abstract. ...
Glycobiology, 2012
Glycosphingolipids (GSLs) are information-bearing biomolecules that play critical roles in embryo... more Glycosphingolipids (GSLs) are information-bearing biomolecules that play critical roles in embryonic development, signal transduction and carcinogenesis. Previous studies indicate that certain GSLs are associated with differentiation in acute myeloid leukemia (AML) cells. In this study, we collected bone marrow samples from healthy donors and AML patients and analyzed the GSL expression profiles comprehensively using electrospray ionization linear ion-trap mass spectrometry. The results showed that AML patients had higher expression of the GSL lactotriaosylceramide (Lc3), GM3 and neolactotetraosylceramide (nLc4) in their bone marrow than did the healthy donors (P < 0.05), especially the M1 subtype of AML. To further explore the molecular mechanisms of Lc3, we examined the expression of the Lc3 synthase β1,3-N-acet-ylglucosaminyltransferase5 (β3Gn-T5) and found that the bone marrow samples of AML patients had 16-fold higher expression of β3Gn-T5 than those of healthy donors (P < 0.05). Our results suggest that AML-associated GSLs Lc3, GM3 and nLc4 are possibly involved in initiation and differentiation of AML.
Circulation, 2012
Endothelial senescence represents one of the major characteristics of vascular aging and promotes... more Endothelial senescence represents one of the major characteristics of vascular aging and promotes the development of atherosclerosis. Sirtuin-1 (SIRT1) is an NAD-dependent deacetylase possessing antiaging activities. During the occurrence of endothelial senescence, both the expression and activity of SIRT1 are downregulated. The present study was designed to investigate the molecular mechanisms contributing to the loss-of-SIRT1 function in senescent endothelial cells. After repetitive passages, primary cultures of porcine aortic endothelial cells exhibited a severe senescence phenotype. Western blotting revealed that phosphorylation of SIRT1 at serine 47 (S47) was significantly enhanced in senescent endothelial cells. S47 phosphorylation was stimulated by agents promoting senescence and attenuated by drugs with antisenescence properties. Mutation of S47 to nonphosphorable alanine (S47A) enhanced whereas replacing S47 with phospho-mimicking aspartic acid (S47D) abolished the antisenescent, growth-promoting, and LKB1-downregulating actions of SIRT1. Phosphorylation at S47 was critically involved in the nuclear retention of SIRT1 but abolished its association with the telomeric repeat-binding factor 2-interacting protein 1. Cyclin-dependent kinase 5 (CDK5) was identified as an SIRT1 kinase modulating S47 phosphorylation. Knockdown or inhibition of CDK5 reduced the number of senescent endothelial cells, promoted nuclear exportation of SIRT1, and attenuated the expression of inflammatory genes in porcine aortic endothelial cells. The truncated regulatory subunit of CDK5, P25, accumulated in senescent porcine aortic endothelial cells and atherosclerotic aortas. Long-term treatment with roscovitine, a CDK5 inhibitor, blocked the development of cellular senescence and atherosclerosis in aortas of hypercholesterolemic apolipoprotein E-deficient mice. CDK5-mediated hyperphosphorylation of SIRT1 facilitates the development of endothelial senescence and atherosclerosis.
Bioorganic & Medicinal Chemistry Letters, 2011
a b s t r a c t a-FABP is indespensible in inflammation and may serve as a new potential drug tar... more a b s t r a c t a-FABP is indespensible in inflammation and may serve as a new potential drug target for inflammation related diseases. We have successfully designed and synthesized a series of aromatic substituted pyrazoles as new human a-FABP inhibitors. The compounds strongly bound to the hydrophobic binding pocket of a-FABP, while showed significantly lower binding affinities to the closely related homologue protein h-FABP. The most potent and selective compound 5g bound to a-FABP with an apparent K i value below 1.0 nM, while did not inhibit h-FABP at 50 lM and thus represents one of the most potent and selective a-FABP inhibitors to date. The strong binding capacity of these inhibitors was further validated by their effective blockade of inflammatory responses as determined by the production of pro-inflammatory cytokines upon LPS stimulation. Compound 5g may serve as a lead compound for developing new effective therapeutic agent for prevention and treatment of atherosclerosis, type 2 diabetes and other inflammatory and metabolic related diseases.
Tetrahedron Letters, 2008
A series of 2,3-dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones have been synthesized in g... more A series of 2,3-dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones have been synthesized in good to excellent yields and high selectivity by one-pot reaction using isatoic anhydride, ammonium acetate (or amines), and aldehydes in ethanol or in DMSO under mild conditions, ...
AJP: Regulatory, Integrative and Comparative Physiology, 2008
Sex differences may play a significant role in determining the risk of hypertension. Bulbospinal ... more Sex differences may play a significant role in determining the risk of hypertension. Bulbospinal neurons in the rostral ventrolateral medulla (RVLM) are involved in the tonic regulation of arterial pressure and participate in the central mechanisms of hypertension. Angiotensin II (ANG II) acting on angiotensin type 1 (AT1) receptors in RVLM neurons is implicated in the development of hypertension by activating NADPH oxidase and producing reactive oxygen species (ROS). Therefore, we analyzed RVLM bulbospinal neurons to determine whether there are sex differences in: 1) immunolabeling for AT1 receptors and the key NADPH oxidase subunit p47 using dual-label immunoelectron microscopy, and 2) the effects of ANG II on ROS production and Ca2+ currents using, respectively, hydroethidine fluoromicrography and patch-clamping. In tyrosine hydroxylase-positive RVLM neurons, female rats displayed significantly more AT1 receptor immunoreactivity and less p47 immunoreactivity than male rats ( P &l...
Physical Review Letters, 2006
We report a state-of-the-art photoemission (ARPES) study of high quality single crystals of the N... more We report a state-of-the-art photoemission (ARPES) study of high quality single crystals of the NaxCoO2 series focusing on the fine details of the low-energy states. The Fermi velocity is found to be small (< 0.5 eV.Å) and only weakly anisotropic over the Fermi surface at all dopings setting the size of the pair wavefunction to be on the order of 10-20 nanometers. In the low doping regime the exchange inter-layer splitting vanishes and two dimensional collective instabilities such as 120 • -type fluctuations become kinematically allowed. Our results suggest that the unusually small Fermi velocity and the unique symmetry of kinematic instabilities distinguish cobaltates from other unconventional oxide superconductors such as the cuprates or the ruthenates.
Journal of Applied Physics, 1999
Raman spectroscopy and x-ray diffraction study of PbTiO thin films prepared by solgel technique.... more Raman spectroscopy and x-ray diffraction study of PbTiO thin films prepared by solgel technique. [Journal of Applied Physics 85, 2146 (1999)]. Ai-Dong Li, Di Wu, Chuan-Zhen Ge, Peng Lü, Wen-Hui Ma, Ming-Sheng Zhang, Cun-Yi Xu, Jian Zuo, Nai-Ben Ming. Abstract. ...
Glycobiology, 2012
Glycosphingolipids (GSLs) are information-bearing biomolecules that play critical roles in embryo... more Glycosphingolipids (GSLs) are information-bearing biomolecules that play critical roles in embryonic development, signal transduction and carcinogenesis. Previous studies indicate that certain GSLs are associated with differentiation in acute myeloid leukemia (AML) cells. In this study, we collected bone marrow samples from healthy donors and AML patients and analyzed the GSL expression profiles comprehensively using electrospray ionization linear ion-trap mass spectrometry. The results showed that AML patients had higher expression of the GSL lactotriaosylceramide (Lc3), GM3 and neolactotetraosylceramide (nLc4) in their bone marrow than did the healthy donors (P < 0.05), especially the M1 subtype of AML. To further explore the molecular mechanisms of Lc3, we examined the expression of the Lc3 synthase β1,3-N-acet-ylglucosaminyltransferase5 (β3Gn-T5) and found that the bone marrow samples of AML patients had 16-fold higher expression of β3Gn-T5 than those of healthy donors (P < 0.05). Our results suggest that AML-associated GSLs Lc3, GM3 and nLc4 are possibly involved in initiation and differentiation of AML.
Circulation, 2012
Endothelial senescence represents one of the major characteristics of vascular aging and promotes... more Endothelial senescence represents one of the major characteristics of vascular aging and promotes the development of atherosclerosis. Sirtuin-1 (SIRT1) is an NAD-dependent deacetylase possessing antiaging activities. During the occurrence of endothelial senescence, both the expression and activity of SIRT1 are downregulated. The present study was designed to investigate the molecular mechanisms contributing to the loss-of-SIRT1 function in senescent endothelial cells. After repetitive passages, primary cultures of porcine aortic endothelial cells exhibited a severe senescence phenotype. Western blotting revealed that phosphorylation of SIRT1 at serine 47 (S47) was significantly enhanced in senescent endothelial cells. S47 phosphorylation was stimulated by agents promoting senescence and attenuated by drugs with antisenescence properties. Mutation of S47 to nonphosphorable alanine (S47A) enhanced whereas replacing S47 with phospho-mimicking aspartic acid (S47D) abolished the antisenescent, growth-promoting, and LKB1-downregulating actions of SIRT1. Phosphorylation at S47 was critically involved in the nuclear retention of SIRT1 but abolished its association with the telomeric repeat-binding factor 2-interacting protein 1. Cyclin-dependent kinase 5 (CDK5) was identified as an SIRT1 kinase modulating S47 phosphorylation. Knockdown or inhibition of CDK5 reduced the number of senescent endothelial cells, promoted nuclear exportation of SIRT1, and attenuated the expression of inflammatory genes in porcine aortic endothelial cells. The truncated regulatory subunit of CDK5, P25, accumulated in senescent porcine aortic endothelial cells and atherosclerotic aortas. Long-term treatment with roscovitine, a CDK5 inhibitor, blocked the development of cellular senescence and atherosclerosis in aortas of hypercholesterolemic apolipoprotein E-deficient mice. CDK5-mediated hyperphosphorylation of SIRT1 facilitates the development of endothelial senescence and atherosclerosis.
Bioorganic & Medicinal Chemistry Letters, 2011
a b s t r a c t a-FABP is indespensible in inflammation and may serve as a new potential drug tar... more a b s t r a c t a-FABP is indespensible in inflammation and may serve as a new potential drug target for inflammation related diseases. We have successfully designed and synthesized a series of aromatic substituted pyrazoles as new human a-FABP inhibitors. The compounds strongly bound to the hydrophobic binding pocket of a-FABP, while showed significantly lower binding affinities to the closely related homologue protein h-FABP. The most potent and selective compound 5g bound to a-FABP with an apparent K i value below 1.0 nM, while did not inhibit h-FABP at 50 lM and thus represents one of the most potent and selective a-FABP inhibitors to date. The strong binding capacity of these inhibitors was further validated by their effective blockade of inflammatory responses as determined by the production of pro-inflammatory cytokines upon LPS stimulation. Compound 5g may serve as a lead compound for developing new effective therapeutic agent for prevention and treatment of atherosclerosis, type 2 diabetes and other inflammatory and metabolic related diseases.
Tetrahedron Letters, 2008
A series of 2,3-dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones have been synthesized in g... more A series of 2,3-dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones have been synthesized in good to excellent yields and high selectivity by one-pot reaction using isatoic anhydride, ammonium acetate (or amines), and aldehydes in ethanol or in DMSO under mild conditions, ...
AJP: Regulatory, Integrative and Comparative Physiology, 2008
Sex differences may play a significant role in determining the risk of hypertension. Bulbospinal ... more Sex differences may play a significant role in determining the risk of hypertension. Bulbospinal neurons in the rostral ventrolateral medulla (RVLM) are involved in the tonic regulation of arterial pressure and participate in the central mechanisms of hypertension. Angiotensin II (ANG II) acting on angiotensin type 1 (AT1) receptors in RVLM neurons is implicated in the development of hypertension by activating NADPH oxidase and producing reactive oxygen species (ROS). Therefore, we analyzed RVLM bulbospinal neurons to determine whether there are sex differences in: 1) immunolabeling for AT1 receptors and the key NADPH oxidase subunit p47 using dual-label immunoelectron microscopy, and 2) the effects of ANG II on ROS production and Ca2+ currents using, respectively, hydroethidine fluoromicrography and patch-clamping. In tyrosine hydroxylase-positive RVLM neurons, female rats displayed significantly more AT1 receptor immunoreactivity and less p47 immunoreactivity than male rats ( P &l...