1.Salidroside biosynthesis pathway: the initial reaction and glycosylation of tyrosol.
Lanqing MA ; Chunmei LIU ; Hansong YU ; Jixing ZHANG ; Dongyao GAO ; Yanfang LI ; Younian WANG
Chinese Journal of Biotechnology 2012;28(3):282-294
Salidroside, the 8-O-beta-D-glucoside of tyrosol, is a novel adaptogenic drug extracted from the medicinal plant Rhodiola sachalinensis A. Bor. Due to the scarcity of R. sachalinensis and its low yield of salidroside, there is great interest in enhancing the production of salidroside by biotechnological process. Glucosylation of tyrosol is thought to be the final step in salidroside biosynthesis. In our related works, three UGT clones were isolated from the roots and the cultured cells. Our intention was to combine the catalytic specificity of these UGTs in vitro in order to change the level of salidroside in vivo by over-expression of the above UGTs. However, as the aglycone substrate of salidroside, the biosynthetic pathway of tyrosol and its regulation are less well understood. The results of related studies revealed that there are two different possibilities for the tyrosol biosynthetic pathway. One possibility is that tyrosol is produced from a p-coumaric acid precursor, which is derived mainly from phenylalanine. The second possibility is that the precursor of tyrosol might be tyramine, which is synthesized from tyrosine. Our previous work demonstrated that over-expression of the endogenous phenylalanine ammonia-lyase gene (PALrs1) and accumulation of p-coumaric acid did not facilitate tyrosol biosynthesis. In contrast, the data presented in our recent work provide in vitro and in vivo evidence that the tyrosine decarboxylase (RsTyrDC) is most likely to have an important function in the initial reaction of the salidroside biosynthesis pathway in R. Sachalinensis.
Genetic Engineering
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Glucosides
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biosynthesis
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Glycosylation
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Phenols
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Phenylethyl Alcohol
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analogs & derivatives
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chemistry
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metabolism
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Rhodiola
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metabolism
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Tyrosine
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metabolism
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Tyrosine Decarboxylase
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metabolism
4.Evaluation of triple anti-platelet therapy by modified thrombelastography in patients with acute coronary syndrome.
Yi-hong REN ; Ting-shu YANG ; Yu WANG ; Lu-yue GAI ; Hong-bin LIU ; Lian CHEN ; Hong-ye WANG ; Chun-ya WANG ; Xiu-li XU ; Jing JIN ; You-hong XIN ; Rong-bin LI ; Hai-yan LI ; Lin LIN ; Chun-xue LIU
Chinese Medical Journal 2008;121(9):850-852
Acute Coronary Syndrome
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drug therapy
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Angioplasty, Balloon, Coronary
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Aspirin
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administration & dosage
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Humans
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Platelet Aggregation Inhibitors
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administration & dosage
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Thrombelastography
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Ticlopidine
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administration & dosage
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analogs & derivatives
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Tyrosine
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administration & dosage
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analogs & derivatives
5.Minor fibrillar collagens, variable regions alternative splicing, intrinsic disorder, and tyrosine sulfation.
Ming FANG ; Reed JACOB ; Owen MCDOUGAL ; Julia Thom OXFORD
Protein & Cell 2012;3(6):419-433
Minor fibrillar collagen types V and XI, are those less abundant than the fibrillar collagen types I, II and III. The alpha chains share a high degree of similarity with respect to protein sequence in all domains except the variable region. Genomic variation and, in some cases, extensive alternative splicing contribute to the unique sequence characteristics of the variable region. While unique expression patterns in tissues exist, the functions and biological relevance of the variable regions have not been elucidated. In this review, we summarize the existing knowledge about expression patterns and biological functions of the collagen types V and XI alpha chains. Analysis of biochemical similarities among the peptides encoded by each exon of the variable region suggests the potential for a shared function. The alternative splicing, conservation of biochemical characteristics in light of low sequence conservation, and evidence for intrinsic disorder, suggest modulation of binding events between the surface of collagen fibrils and surrounding extracellular molecules as a shared function.
Alternative Splicing
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genetics
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Animals
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Fibrillar Collagens
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chemistry
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genetics
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metabolism
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Humans
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Sulfates
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chemistry
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metabolism
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Surface Properties
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Tyrosine
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analogs & derivatives
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chemistry
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metabolism
6.Rescue Treatment with Intra-arterial Tirofiban Infusion and Emergent Carotid Stenting.
Tae Jin SONG ; Kee Oog LEE ; Dong Joon KIM ; Kyung Yul LEE
Yonsei Medical Journal 2008;49(5):857-859
Rapid arterial rethrombosis is associated with high-grade residual stenosis and usually occurs at the site of the initial occlusion, resulting in reocclusion of the recanalized artery. Platelets may play an active role in such rethrombosis after thrombolytic-induced clot lysis. Given that glycoprotein IIb/IIIa receptor blockers, like tirofiban, prevent thrombus formation by inhibiting the final common pathway of platelet aggregation, they may be helpful for treating rethrombosis after thrombolysis. A 64-year-old man presented with an acute ischemic stroke due to internal carotid artery (ICA) occlusion. The ICA was recanalized by intravenous thrombolysis but reoccluded shortly after recanalization. The reoccluded ICA was successfully recanalized using intra-arterial tirofiban. A carotid stent was subsequently inserted to relieve severe stenosis and to prevent recurrent stroke. Here, we report a case of rescue treatment of a successfully recanalized ICA by intra- arterial tirofiban. We suggest that rescue use of intra-arterial tirofiban may be effective and safe, especially in hemorrhage prone situations, due to the relatively lower dose of tirofiban compared with intravenous doses.
*Carotid Artery, Internal
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Carotid Stenosis/*drug therapy/radiography/surgery
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Emergency Treatment
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Humans
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Infusions, Intra-Arterial
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Male
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Middle Aged
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Stents
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Tyrosine/administration & dosage/*analogs & derivatives/therapeutic use
7.Effect of nitrotyrosine on renal expressions of NF-κB, MCP-1 and TGF-β1 in rats with diabetic nephropathy.
Zhao-Zhong XU ; Ming WANG ; Yan-Jing WANG ; Hong-Xin NIU ; Xiao-Yun LI ; Wei-Dong ZHOU ; Yan ZHU ; Hai-Bo LONG
Journal of Southern Medical University 2013;33(3):346-350
OBJECTIVETo observe the effect of nitrotyrosine on renal expressions of nuclear factor-κB (NF-κB), monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-β1 (TGF-β1) in rats with diabetic nephropathy (DN).
METHODSRat DN models established by a single intraperitoneal injection of streptozotocin (STZ) were randomly allocated into model group, nitrotyrosine group and ebselen group, with untreated rats as the normal control group. The rats were given the corresponding drugs for 8 weeks, and after the last administration, the 24-h urinary protein level was measured and the kidneys of the rats were harvested for detecting the protein and mRNA expressions of NF-κB, MCP-1 and TGF-β1 with immunohistochemistry and RT-PCR, respectively. The pathological changes of the kidneys were assessed microscopically.
RESULTSCompared with those in the model group, the 24-h urinary protein level and expressions of NF-κB, MCP-1 and TGF-β1 mRNA and protein in the renal tissues were significantly increased by nitrotyrosine treatment, which also caused worsened renal pathology, while treatment with ebselen significantly ameliorated these changes.
CONCLUSIONNitrotyrosine can up-regulate the mRNA and protein expressions of NF-κB, MCP-1 and TGF-β1 and aggravate the inflammatory reaction in the renal tissue of DN rats to promote the progression of DN.
Animals ; Chemokine CCL2 ; metabolism ; Diabetes Mellitus, Experimental ; Diabetic Nephropathies ; metabolism ; Male ; NF-kappa B ; metabolism ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; metabolism ; Tyrosine ; analogs & derivatives ; pharmacology
8.Establishment and application of double-antibody sandwich ELISA for determination of 3-nitrotyrosine.
Li YAN ; Yan-Wu XU ; Xiao-Liang WANG ; Ye WU ; Jue TIAN ; Guang-Zhao YANG ; Xiu-Rui MA ; Hui-Rong LIU
Chinese Journal of Applied Physiology 2009;25(4):569-572
AIMTo prepare the working standards of 3-nitrotyrosine (3-NT) and establish a two-antibody-sandwich ELISA for determining the concentration of peroxynitrite in the tissue.
METHODSNitrated bovine serum albumin was prepared by additions of an alkaline stock solution of peroxynitrite which was synthesized by a quenched-flow reactor. The monoclone anti-3-NT antibody from mouse was used as coating antibody and the polyclone anti-3-NT antibody from as labeling antibody to prepare the standard work curve by orthogonal design. The concentrations of 3-NT in cardiac tissue from rats subjected to myocardial ischemia and reperfusion (MI/R) were analyzed.
RESULTSA two-antibody-sandwich ELISA method for measuring 3-NT content in biological fluids and homogenates was successfully established. The detecting limit was 0.1 ng x ml(-1) and the linear range of standard work curve was 0.15 - 7.50 ng x ml(-1) (r2 = 0.995). The 3-NT concentration in cardiac tissue from rats subjected to MI/R (1022.42 +/- 97.35 ng x mg pro(-1)) was significantly higher than that in the sham group (246.58 +/- 56.52 ng x mg pro(-1), P < 0.01).
CONCLUSIONA two-antibody-sandwich ELISA was established for determining the 3-NT concentration in the tissue and conveniently, quickly, accurately quantitative analysis of the content of 3-NT. The assay provides a new method for quantitative analysis of the peroxyinitrite in the future.
Animals ; Antibodies, Monoclonal ; Enzyme-Linked Immunosorbent Assay ; methods ; Male ; Myocardial Reperfusion Injury ; Myocardium ; chemistry ; Peroxynitrous Acid ; analysis ; Rats ; Rats, Wistar ; Sensitivity and Specificity ; Tyrosine ; analogs & derivatives ; analysis