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Biomedical subjects

Feng Ye

Publications and source records attributed to Feng Ye.

48 records · Page 3Linked to original sources
PubMed2004

[Effects of vascular endothelial growth factor on differentiation and function of dendritic cells generated from CD34+ hematopoietic progenitor cells in vitro].

OBJECTIVE: To investigate the effects of vascular endothelial growth factor (VEGF) on differentiation and function of dendritic cells derived from CD34+ hematopoietic progenitor cells. METHODS: After isolation from umbilical cord blood with a high-gradient magnetic cell sorting system (MACS), the CD34+ cells were cultured with a cocktail cytokines for differentiating into dendritic cells (DC). The cells were stimulated by VEGF (25 ng/ml) either at the beginning or at day 9 of culture. Kinetics analysis of cell proliferation was performed during the process of cell culture, and the expression of DC differentiation antigens including CD1alpha, CD83, CD80, CD54 and HLA-DR was examined by flow cytometry. DC function was evaluated by the ability to induce proliferation of allogeneic T cells in mixed lymphocyte reaction (MLR) assay, and the production of IL-12 by ELISA. RESULTS: VEGF added at day 1 of culture induced an increase of total cell numbers by (1.51 +/- 0.23)-folds (P = 0.001). VEGF added at the initial but not the late stage of culture could dramatically down-regulate the expression of CD1a [(33.00 +/- 2.12)% vs (81.20 +/- 6.93)%], CD83 [(42.23 +/- 1.15)% vs (87.98 +/- 7.97)%], CD80 (42.93 +/- 1.32)% vs (94.53 +/- 0.87)%], and HLA-DR [(37.93 +/- 5.30)% vs (74.15 +/- 3.74)%], while obviously up-regulate the expression of CD14. Moreover, the inhibitory effect of VEGF on DC function was confirmed by a reduced ability to induce proliferation of allogeneic T cells and production of IL-12 (P < 0.01). CONCLUSIONS: VEGF could induce the expansion of hematopoietic progenitor cells and inhibit at the early stage their differentiation into mature DC.

Antigens, CD↗
PubMed2003

An increase in the synthesis and release of calcitonin gene-related peptide in two-kidney, one-clip hypertensive rats.

Previous investigations have indicated that capsaicin-sensitive sensory nerves play an important role in modulation of the peripheral resistance of the circulation system. In the present study, we examined the role of capsaicin-sensitive sensory nerves in two-kidney, one-clip (2K1C) renovascular hypertension rats. Systolic blood pressure (BP) was monitored by the tail-cuff method throughout the experiment. Concentrations of calcitonin gene-related peptide (CGRP) in the plasma, the level of CGRP mRNA in dorsal root ganglia (DRG) and the density of CGRP immunoreactive (CGRP-ir) fibers in mesenteric artery were measured. Blood pressure was significantly elevated at day 10 postoperation (BP was 143+/-10 and 114+/-7 mm Hg for 2K1C and Sham groups, respectively, p<0.05). Treatment with capsaicin, which selectively depletes neurotransmitters in sensory nerves, enhanced hypertensive responses to clipping (BP was 168+/-7 and 143+/-10 mm Hg at day 10 postoperation for Cap1+2K1C and 2K1C groups, respectively, p<0.05), and BP in the rats treated with a second injection of capsaicin was greater than that in the rats treated with a single injection of capsaicin (At day 30 postoperation, BP was 199+/-7 and 166+/-9 mm Hg for Cap2+2K1C and 2K1C groups, respectively, p<0.01; mean arterial pressure was 185.2+/-6.6 and 150.5+/-4.1 mm Hg for Cap2+2K1C and 2K1C groups, respectively, p<0.01). The expression of alpha-CGRP mRNA in DRG (122.87+/-3.67 arbitrary units, p<0.05), the level of CGRP in the plasma (75.40+/-4.99 pg/ml, p<0.01) and the density of CGRP-ir fibers in mesenteric artery (525.67+/-31.42 intersections, p<0.05) were significantly increased in 2K1C rats. Treatment with capsaicin, a single injection or a second injection, prevented the increased in the expression of CGRP mRNA in DRG. However, the decreased level of CGRP was only observed in the rats treated with a second capsaicin. These results suggest that in 2K1C hypertensive rats, the activity of capsaicin-sensitive sensory nerves is increased, which is playing a compensatory depressor role to partially counteract the increase in blood pressure, and that the cardiovascular actions of CGRP is mediated by the alpha-CGRP isoform.

Animals↗
PubMed2003

Involvement of calcitonin gene-related peptide in the depressor effects of losartan and perindopril in rats.

Previous investigations have indicated that calcitonin gene-related peptide (CGRP) plays an important role in the regulation of cardiovascular function, and that the development of hypertension may be related to the reduction of sensory vasodilator nerve actions. In the present study, we examined the effect of perindopril, an angiotensin-converting enzyme inhibitor, and losartan, an angiotensin II receptor antagonist, on the plasma level and synthesis of CGRP in 2 kidneys, 1-clip hypertensive rats (2K1C, Goldblatt). In the hypertension group, systolic blood pressure and mean artery pressure were raised, and the level of CGRP in plasma was slightly raised compared with control groups. Chronic treatment with losartan or perindopril significantly increased the plasma concentration of CGRP and the expression of CGRP mRNA in dorsal root ganglia in the 2K1C, Goldblatt hypertensive rats. These results suggest that the 2K1C, Goldblatt hypertensive model has a compensatory increase of sensory nerve actions, and that the depressor effects of perindopril or losartan may be related to stimulation of the synthesis and release of CGRP in the 2K1C, Goldblatt hypertensive rats.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2003

Protective effects of calcitonin gene-related peptide-mediated evodiamine on guinea-pig cardiac anaphylaxis.

Previous investigations have indicated that the pharmacological effects of evodiamine, a major alkaloidal component of the dried, unripe fruit of Evodia rutaecarpa Bentham (Rutaceae), are associated with stimulation of calcitonin gene-related peptide (CGRP) release and CGRP prevents cardiac anaphylactic injury. In the present study, the protective effects of evodiamine on cardiac anaphylaxis were examined. Presensitized guinea-pig hearts challenged with specific antigen (bovine serum albumin) caused a marked decrease in coronary flow, left ventricular pressure and its derivatives (+/-dp/dt(max)), an increase in heart rate, and prolongation of P-R interval. Evodiamine (0.3 microM or 1 microM) markedly increased the content of CGRP in the coronary effluent concomitantly with a significant improvement of cardiac function and alleviation of the extension of P-R interval. Evodiamine at the concentration of 1 microM also inhibited the sinus tachycardia. The protective effect of evodiamine on cardiac anaphylaxis was abolished by CGRP(8-37), the selective CGRP receptor antagonist. These results suggest that evodiamine possesses a protective effect of cardiac anaphylactic injury and that the effect of evodiamine is related to stimulation of CGRP release.

Anaphylaxis↗
PubMed2003

Protective effects of xanthones against myocardial ischemia-reperfusion injury in rats.

AIM: To investigate the protective effect of xanthones against myocardial ischemia-reperfusion injury in rats. METHODS: Ischemia-reperfusion injury was induced by 20 min of global ischemia and 40 min of reperfusion in isolated rat hearts or 60-min coronary artery occlusion and 180-min reperfusion in vivo, respectively. Heart rate, coronary flow, left ventricular pressure (LVP), and its first derivative (+/- dp/dtmax) were recorded, and the activity of creatine kinase in coronary effluent and malondialdehyde contents in myocardial tissues were measured in vitro. The activity of serum creatine kinase and myocardium infarct size were measured in vivo. RESULTS: Xanthones (90 or 300 microg/L) caused a significant improvement of cardiac function (LVP and +/- dp/dtmax) and a decrease in the release of creatine kinase in coronary effluent as well as the level of malondialdehyde in myocardial tissues. Xanthones (0.5 or 1.0 mg/kg) also markedly decreased infarct size and the release of creatine kinase in vivo. CONCLUSION: Xanthones protect the myocardium against the damages induced by ischemia-reperfusion in rats, and the effect of xanthones may be related to the inhibition of lipid peroxidation.

Animals↗
PubMed2002

Effect of age on alpha-calcitonin gene-related peptide-mediated delayed cardioprotection induced by intestinal preconditioning in rats.

In the present study, we examined whether age-related reduction in cardioprotection of intestinal ischemic preconditioning is related to stimulation of the release and synthesis of calcitonin gene-related peptide (CGRP) in rats. Ischemia-reperfusion injury was induced by a 45-min coronary artery occlusion and 180-min reperfusion, and ischemic preconditioning was induced by six cycles of 4-min ischemia and 4-min reperfusion of the small intestine. The serum concentration of creatine kinase, infarct size, the expression of CGRP isoforms (alpha- and beta-CGRP) mRNA in lumbar dorsal root ganglia and CGRP concentration in plasma were measured. Pretreatment with intestinal ischemic preconditioning for 24 h significantly reduced infarct size and creatine kinase release concomitantly with a significant increase in the expression of alpha-CGRP mRNA, but not beta-CGRP mRNA, and plasma concentrations of CGRP at 6 months of age but not at 24 months of age. These results suggest that the delayed cardioprotective effect of intestinal ischemic preconditioning is decreased in senescent rats, and the age-related change is related to reduction of the synthesis and release of alpha-CGRP.

Age Factors↗
PubMed2002

Delayed cardioprotection induced by nitroglycerin is mediated by alpha-calcitonin gene-related peptide.

Previous investigations have demonstrated that early preconditioning induced by nitroglycerin is mediated by calcitonin gene-related peptide (CGRP). In the present study, we addressed the question of whether delayed preconditioning induced by nitroglycerin in the rat is related to stimulation of the release and synthesis of CGRP. Sprague-Dawley rats were pretreated with nitroglycerin 24 h before the experiment. The left main coronary artery was occluded for 60 min, followed by 3 h reperfusion. Infarct size, serum creatine kinase activity, serum levels of NO and CGRP and the expression of alpha- and beta-CGRP isoform mRNA in lumbar dorsal root ganglia were measured. Pretreatment with nitroglycerin (60 or 120 microg/kg i.v.) reduced both the infarct size and the release of creatine kinase during reperfusion and caused a significant increase in the expression of alpha-CGRP mRNA, but not beta-CGRP mRNA, concomitantly with an increase in concentrations of NO and CGRP. The increase in CGRP expression preceded the increase in CGRP release. The effects of nitroglycerin were abolished completely by pretreatment with methylene blue (30 mg/kg i.p.), an inhibitor of guanylate cyclase, or capsaicin (50 mg/kg s.c.), which selectively depletes transmitters in capsaicin-sensitive sensory nerves. The present results suggest that the delayed cardioprotection induced by nitroglycerin is mediated mainly by the alpha-CGRP isoform via the NO-cGMP pathway.

Animals↗
PubMed2002

The heme oxygenase-1 pathway is involved in calcitonin gene-related peptide-mediated delayed cardioprotection induced by monophosphoryl lipid A in rats.

In order to explore whether monophosphoryl lipid A (MLA)-induced delayed cadioprotection is mediated by calcitonin gene-related peptide (CGRP) and the regulatory effect of inducible heme oxygenase isorform (HO-1)/carbon monoxide (CO) on CGRP synthesis and release, the expression of CGRP and HO-1 in dorsal root ganglia (DRG) and CGRP concentration in plasma were determined in rats. Pretreatment with MLA (500 microg/kg, i.p.) significantly reduced infarct size and creatine kinase release after the 45-min coronary artery occlusion and 180-min reperfusion. MLA caused a significant increase in the expression of CGRP and HO-1 and plasma concentrations of CGRP. The cardioprotection as well as the synthesis and release of CGRP induced by MLA were completely abolished by pretreatment with zinc protoporphrin IX (ZnPP-9), an inhibitor of HO-1, or by capsaicin (50 mg/kg, s.c.), which selectively depletes transmitters in capsaicin-sensitive sensory nerves. Pretreatment with Znpp-9 had no effect on HO-1 expression, but capsaicin abrogated the expression of HO-1 induced by MLA in DRG. These results suggest that the delayed cardioprotection afforded by MLA is mediated by CGRP via activation of the HO-1 pathway.

Adjuvants, Immunologic↗
PubMed2002

Protective effects of demethylbellidifolin on myocardial ischemia-reperfusion injury in rats.

The effect of demethylbellidifolin (DMB), a major compound of Swertia davidi Franch, on ischemia-reperfusion injury was studied in rats. Ischemia-reperfusion injury in vivo and in vitro was induced by 20 min of global ischemia followed 40 min of reperfusion and 60 min of coronary artery occlusion followed 180 min of reperfusion, respectively. DMB (100 or 300 microg/L) significantly improved the recovery of cardiac function during reperfusion in isolated rat hearts, as shown by enhancement of coronary flow, left ventricular pressure and its first derivatives (+/-dp/dt(max)). DMB decreased the release of creatine kinase in coronary effluent as well as the level of malondialdehyde in myocardial tissues. In vivo, DMB (0.5 or 1.0 mg/kg) markedly decreased infarct size and the release of creatine kinase. These results suggest that DMB protects the myocardium against damage due to ischemia-reperfusion in rats. The present study also suggests that the effect of DMB may be related to inhibition of lipid peroxidation.

Animals↗
PubMed2002

Involvement of heme oxygenase-1 in delayed cardioprotection induced by monophosphoryl lipid A in rats.

AIM: To explore whether the heme oxygenase-1 (HO-1) pathway is involved in the delayed cardioprotection induced by monophosphoryl lipid A (MLA). METHODS: Sprague-Dawley rats were pretreated with MLA 24 h before the experiment. Ischemia-reperfusion injury was induced by 60 min coronary artery occlusion followed by 3 h reperfusion. Infarct size, the serum creatine kinase (CK) activity, the serum content of nitric oxide (NO), and expression of HO-1 mRNA and protein in the heart were measured. RESULTS: Pretreatment with MLA (500 microg/kg, ip) markedly reduced infarct size and CK release and increased the serum content of NO (P < 0.01). The effects of MLA were completely abolished by pretreatment with L-nitroarginine methyl ester (L-NAME 10 mg/kg, ip), an inhibitor of NO synthase (P < 0.01), or Zinc protoporphyrin IX (45 micromol/kg, ip), an inhibitor of HO (P < 0.01). MLA caused a significant increase in the expression of HO-1 mRNA and protein, an effect which was not affected by L-NAME (P > 0.05). CONCLUSION: The results suggest that the HO-1/NO pathway is involved in the delayed cardioprotection induced by MLA.

Animals↗
PubMed2002

Genetic instability in cancer tissues analyzed by random amplified polymorphic DNA PCR.

OBJECTIVE: To detect DNA and chromosomes instabilities during the progression of tumors and screen new molecular markers coupled to putative or unknown oncogenes and/or tumor suppressor genes. METHODS: Five kinds of tumors, in a total of 128 specimens, were analyzed by random amplified polymorphic DNA (RAPD) PCR. Bands representing instabilities were recovered, purified, and cloned, labeled as probes for Southern and Northern blot analysis and DNA sequencing. RESULTS: Sample 5 and 3 of the gastric cancer tissues showed the highest genomic changes and the average detectability in five cancers was up to at least 40% (42.2% - 49.4%). There were significant differences in the ability of each primer to detect genomic instability, which ranged from 27% (primer 8) to 68% (primer 2). Band B is a single copy fragment, and was found to be an allelic loss in gastric and colon cancers. It is a novel sequence and was registered in GenBank with Accession Number AF151005. Further analysis revealed that it might be part of a cis-regulatory element of a new tumor suppressor gene, containing a promoter of cis-action "CACA" box, an enhancer of "GATA" family and a start codon. CONCLUSIONS: It was impossible or difficult to get great achievements for cancer treatments with the procedure of gene therapy only to one oncogene or one tumor suppressor gene because the extensive DNA variations occurred during the progression of tumor. RAPD assay connected with other techniques was a good tool for the detection of genomic instabilities and direct screening of some new molecular markers related to tumor suppressor genes or oncogenes.

Base Sequence↗