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
8.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
10.Safety and efficacy of early administration of tirofiban in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: a meta-analysis.
Yangchun LIU ; Qiang SU ; Lang LI
Chinese Medical Journal 2014;127(6):1126-1132
BACKGROUNDTirofiban has been widely used as an adjunctive pharmacologic agent for revascularization in patients undergoing percutaneous coronary intervention, and the outcomes appear attractive. However, the potential benefits from early administration of tirofiban in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) remain unclear.
METHODSWe conducted a search in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials up to September 2012 without language restriction. A total of eight randomized trials (n = 1 577 patients) comparing early (emergency department or ambulance) versus late (catheterization laboratory) administration of tirofiban in STEMI patients undergoing PPCI were included in this meta-analysis. Risk ratio (RR) was computed from individual studies and pooled with random- or fixed-effect models.
RESULTSThere were no differences in post-procedural Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 and Corrected TIMI Frame Count (RR = 1.02, 95% confidence interval (CI): 0.99-1.05, P = 0.18; weighted mean difference (WMD) = -0.93, 95% CI: -5.37-3.52, P = 0.68, respectively) between the two groups. Similarly, there were no significant differences in the incidence of 30-day mortality (RR = 1.69, 95% CI: 0.69-4.13, P = 0.25) and re-myocardial infarction (RR = 0.71, 95% CI: 0.21-2.35, P = 0.57) between early and late administration of tirofiban. As to the safety end points, no significant difference was observed in hospital minor bleeding (RR = 1.08, 95% CI: 0.54-2.14, P = 0.83) and hospital and 30-day major bleeding between the two groups (RR = 0.98, 95% CI: 0.46-2.10, P = 0.96; RR = 1.32, 95% CI: 0.59-2.97, P = 0.49, respectively).
CONCLUSIONSEarly administration of tirofiban in patients undergoing PPCI for STEMI was safe, but no beneficial effects on post-procedural angiographic or clinical outcomes could be identified as compared with late administration. Besides the negative finding, more high-quality randomized clinical trials are still needed to explore the efficacy of adequate, earlier administration of tirofiban in patients undergoing PPCI.
Fibrinolytic Agents ; adverse effects ; therapeutic use ; Humans ; Myocardial Infarction ; drug therapy ; surgery ; Percutaneous Coronary Intervention ; methods ; Thrombolytic Therapy ; Tyrosine ; analogs & derivatives