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Zhong-Ming Qian

Publications and source records attributed to Zhong-Ming Qian.

18 recordsLinked to original sources
PubMed2006

Identification of transcriptionally regulated genes in response to cellular iron availability in rat hippocampus.

The present study was attempted to identify transcriptionally regulated genes of the normal neurocytes responsive to iron availability. Postnatal rat hippocampus cells were primarily cultured either under the iron-loaded or depleted conditions. These cultured cells were applied for the generation of subtracted complementary DNA libraries by the suppression subtraction hybridization (SSH) and for the subsequent identification of differentially expressed transcripts by reverse Northern blot. The differentially expressed genes were chosen to perform sequencing, and then some of them were performed by Northern blot analysis for observation of their expression in the hippocampus of rats with the different iron status. The results indicated that five unique transcripts were strong candidates for differential expression in cellular iron repletion, one of them is a novel sequence (GenBank No. AF 433878), while 26 unique transcripts were strong candidates for differential expression in cellular iron deprivation, one of them is a novel sequence (GenBank No. AY 912101). The revealed known genes responsive to iron availability were previously unknown to respond to iron availability, or have not been determined in the brain, have not even been currently determined in their physiological and biological functions. Interestingly, the proteins encoded by most of the known genes are either directly pointed to or indirectly associated with the molecules that play important, even key roles in cellular signal transduction and the cell cycle. These findings lead to the important suggestion that the cellular responses to iron availability involve extensive transcriptional regulation and cellular signal transduction. Therefore, iron may serve as a signal, which directly and/or indirectly regulates or modulates cell functions.

Animals↗
PubMed2006

Heat shock protein 27 downregulates the transferrin receptor 1-mediated iron uptake.

It has been reported that over-expression of human heat shock protein 27 (hsp27) in murine cells decreased the intracellular iron level [Arrigo, A. P., Virot, S., Chaufour, S., Firdaus, W., Kretz-Remy, C., & Diaz-Latoud, C. (2005). Hsp27 consolidates intracellular redox homeostasis by upholding glutathione in its reduced form and by decreasing iron intracellular levels. Antioxidants & Redox Signalling, 7, 412-422]. However, the mechanism involved is unknown. In this study, the regulation of transferrin receptor 1 (TfR1)-mediated iron uptake by human hsp27 was investigated in CCL39 cells by overexpression of human hsp27 and its dominant-negative mutant (hsp27-3G). The results showed that overexpression of hsp27 diminished intracellular labile iron pool, increased the binding activity of iron regulatory protein (IRP) to iron responsive element (IRE) and the cell surface-expressed TfR1s. However, the increased surface-expressed TfR1s resulted in decrease rather than increase of iron uptake. Further study revealed that overexpression of hsp27 decelerated transferrin endocytosis and recycling, while overexpressed hsp27-3G had a reversal effect. Moreover, flowcytometric analysis showed an enhanced actin polymerization in the cells overexpressing hsp27. In particular, fluorescence imaging of cytoskeleton displayed highly stabilized microfilaments and preferential localization of hsp27 in cortical area of the actin cytoskeleton. In contrast, disruption of actin cytoskeleton by cytochalasin B resulted in acceleration of the endocytosis and recycling of Tf, as well as increase of iron uptake. Meanwhile, the possible involvement of ferroportin 1 in down-regulation of intracellular iron level by overexpression of hsp27 was checked. However, the outcome was negative. Our findings indicate that hsp27 down-regulates TfR1-mediated iron uptake via stabilization of the cortical actin cytoskeleton rather than the classical IRP/IRE mode. The study may also imply that hsp27 protects cells from oxidative stress by reducing cellular iron uptake.

Actins↗
PubMed2006

[Experimental study of effect of tanshinone on artery restenosis in rat carotid injury model].

OBJECTIVE: To observe the preventive and therapeutic effect of tanshinone (TA) on artery restenosis in the rat carotid injury model and explor the mechanism. METHOD: Male SD rats were randomly divided into model control group, and low dose, moderate dose and high dose TA groups. Each group had 10 rats. The rats in the high, moderate and low dose groups were respectively fed with TA 120, 40,13.3 mg x kg(-1) x d(-1) by gast rogavage; the rats in the model control group were fed with the same volume solvent. Two days later, the rat's right carotid artery was injuried by balloon dilatation to induce intimal thickening for establishing the restenosis model. After 2 weeks of treatment, the artery was harvested and stained by hematoxylin-elsin (HE) and immunohistochemistry of PCNA, NF-kappaB and iNOS. The morphological changes were checked under microscope. The area of the intimal and medial layer of the vessels, and their ratios were analyzed with image analysis software. The expression level of PCNA, NF-kappaB and iNOS were used as the positive index. RESULT: The intimal area and intima-to-media ratio of the injuried artery increased obviously, suggesting the model was successful. Compared with the model group, TA significantly decreased the intimal area and intima-to-media ratio (P < 0.05), and also decreased the positive index of PCNA and the positive ratio of NF-kappaB and iNOS (P < 0.05). CONCLUSION: TA can effectively inhibit intimal thickening and inflammation. This result suggestes that TA may play a positive role in the prevention of restenosis after PTCA.

Abietanes↗
PubMed2005

Increased divalent metal transporter 1 expression might be associated with the neurotoxicity of L-DOPA.

Based on the available data, we speculated that changes in brain iron metabolism induced by L-DOPA might be associated with the neurotoxicity of L-DOPA. To investigate this possibility, the effects of L-DOPA on the expression of iron influx proteins [transferrin receptor (TfR) and divalent metal transporter 1 (DMT1)], iron efflux protein (ferroportin 1), and iron uptake in C6 glioma cells were determined in this study using Northern blot and Western blot analysis and the calcein method. The findings showed that treatment of C6 cells with different concentrations of L-DOPA (0-100 microM) did not affect the expression of mRNA and protein of TfR and DMT1 with iron-responsive element (+IRE) and protein of ferroportin 1. However, a significant increase in the expression of DMT1(-IRE) mRNA and protein was found in cells treated, respectively, with 10 and 30 microM L-DOPA (mRNA) and 1, 5, 10 and 30 microM L-DOPA (protein). The increase in DMT(-IRE) protein induced by L-DOPA treatment was in parallel with the increase in DMT(-IRE) mRNA. The levels of DMT1(-IRE) mRNA and protein peaked in the cells treated with 10 microM L-DOPA and then decreased progressively with increasing concentrations of L-DOPA. Further study demonstrated that treatment of the cells with 10 microM L-DOPA induced a significant increase in ferrous uptake by C6 glioma cells. The findings suggested that the increased DMT1(-IRE) expression might be partly associated with the neurotoxicity of L-DOPA. Clinical relevance of the findings needs to be investigated further.

Animals↗
PubMed2005

Tanshinone inhibits intimal hyperplasia in the ligated carotid artery in mice.

Vascular smooth muscle cell (VSMC) proliferation is considered to play a central role in the development of intimal hyperplasia with pathological artery healing. Danshen, the Salvia miltiorrhiza Bge., has long been regarded as an effective traditional Chinese medicine for cardiovascular diseases. In this paper, the effects of tanshinone (TA), the lipid-soluble pharmacological constituents of danshen, on the intima hyperplasia and proliferating state of VSMC were described in a mouse carotid artery injured by complete cessation of blood flow. This study showed that oral administration of TA could significantly decrease the intimal thickening of injured vessels and proliferating cell nuclear antigen (PCNA)-positive VSMC in intimal area. These results suggested that the suppressive effects of TA on intimal hyperplasia might partly result from its inhibitory effect against VSMC proliferation.

Abietanes↗
PubMed2005

Iron loading inhibits ferroportin1 expression in PC12 cells.

Ferroportin1 (FP1 or MTP1/IREG1), the product of the SLC40A1 gene, is a main iron export protein in mammals. Its mRNA contains an iron response element (IRE) in its 5' untranslated region, but the way this gene is regulated by iron is still unclear. The existence of FP1 in the brain has been recently confirmed. To better understand the role of this important transmembrane iron exporter in brain iron homeostasis, we investigated the effects of iron and nitric oxide (NO) on FP1 expression and that of a FP1 antibody on iron release in nerve growth factor-treated rat PC12 cells. We found that FP1 expression was down-regulated by iron loading but stimulated by iron chelation and treatment with a NO donor, S-nitroso-N-acetylpenicillamine (SNAP). In addition, a significant decrease in iron release was found in cells treated with a FP1 antibody. Our findings imply that regulation of FP1 by iron in the cells is at the transcriptional level, rather than by an IRE/IRP-mediated pathway. Based on our results and published data, it is suggested that the transcriptional and translational (IRP/IRE pathway) mechanisms of FP1 expression might both operate in a tissue-specific manner and that FP1 might have a role in iron export from PC12 cells.

Animals↗
PubMed2005

Age-dependent and iron-independent expression of two mRNA isoforms of divalent metal transporter 1 in rat brain.

The DMT1(Nramp2/DCT1) is a newly discovered proton-coupled metal-ion transport protein. The cellular localization and functional characterization of DMT1 suggest that it might play a role in physiological iron transport in the brain. In the study, we evaluated effects of dietary iron and age on iron content and DMT1 expression in four brain regions: cortex, hippocampus, striatum, substantia nigra. Total iron content in all regions was significantly lower in the low-iron diet rats and higher in the high-iron diet rats than that in the control animals, showing that dietary iron treatment for 6-weeks can alter brain iron levels. Contrary to our expectation, there was no significant alternation in DMT1(+IRE) and (-IRE) mRNA expression and protein content in all brain regions examined in spite of the existence of the altered iron levels in these regions after 6-weeks' diet treatment although TfR mRNA expression and protein level were affected significantly, as was expected. The data demonstrates that expression of DMT1(+IRE) and (-IRE) was not regulated by iron in these regions of adult rats. The lack of response of DMT1 to iron status in the brain suggests that the IRE of brain DMT1 mRNA might be not really iron-responsive and that DMT1-mediated iron transport might be not the rate-limiting step in brain iron uptake in adult rats. Our findings also showed that development can significantly affect brain iron and DMT1(+IRE) and (-IRE) expression but the effect varies in different brain regions, indicating a regionally specific regulation in the brain.

Age Factors↗
PubMed2005

[Phylogenetic analysis of the surface glycoprotein genes of an aquatic bird origin influenza virus isolate A/Duck/Yangzhou/233/2002 (H6N2)].

Several H6 subtype avian A influenza viruses were isolated from aquatic birds in some live bird markets when we surveyed the ecology of the influenza in East China for more than two years and identified by specific RT-PCR. In this paper, the hemagglutinin (HA) and neuraminidase (NA) gene of one representative virus named A/Duck/Yangzhou/233/ 2002 (H6N2) (Dk/YZ/233/02) had been sequenced. Phylogenetic analysis of the H6 gene sequences available in the Influenza Sequence Database showed that the Dk/YZ/233/02 viruse cluster together with Dk/HK/3461/99 (H6N1) and Ck/Taiwan/na3/98 (H6N1). Phylogenetic analysis of the N2 NA genes of Dk/YZ/233/02 revealed that the NA gene of Dk/YZ/233/02 had genetically close relationships with that of H9N2 viruses isolated from duck in Japan and from chickens in South Korea, which were distinct from those of Ck/Beijing/94 (H9N2). The sequence of cleavage site between HA1 and HA2 of Dk/YZ/233/02 is P-Q-I-E-T-R-D, which was the typical characterization of the LPAIV.

Animals↗
PubMed2005

[The new progress of the study about volatile oil of the angelica].

To summarize the new progress of the study about volatile oil of the angelica, including the distillable methods, the analysis of the chemical components, the pharmacological effects and the clinical applications. We tracked and searched the correlative references and study reports about volatile oil of the angelica in CNKI data base(1994-2004) and Medline data base (1997-2004). We summarized and compared the different distillable methods of volatile oil of the angelica, meanwhile we summarized many study reports about the analysis of the chemical components of volatile oil of the angelica and it's pharmacological effects, including the toxicity of the volatile oil and it's effects on the uterus smooth muscle, cardiovascular system, respiratory system, central nerve system and immune system. Finally we summarized the clinical application of the volatile oil of the angelica. There are three distillable methods of volatile oil of the angelica . The harvest efficiency of volatile oil is different with different distillable methods. The chemical components are very complicated and the new chemical components are separated and identified. The volatile oil has bidirectional effects on the uterus smooth muscle. It can inhibit the contraction of the uterus smooth muscle induced by different mechanisms. Meanwhile it can depress the blood pressure and ameliorate the cardiac ischemia. The volatile oil can resist the arrhythmia and asthma, restrain the central system, improve the immune function. Nowadays the volatile oil of the angelica is applied to therapy the dysmenorrhea and disorder of the catamenia. The chemical components of the volatile oil of the angelica are very complicated, moreover the pharmacological effects of the volatile oil are comprehensive. People make the new progress of the study about volatile oil of the angelica.

4-Butyrolactone↗
PubMed2004

Baroreceptor reflex in heart failure.

Congestive heart failure is a syndrome that is usually initiated by a reduction in pump function of the heart, i.e. a decrease in cardiac output. Initially, a reduction in cardiac output leads to unloading of baroreceptor reflex that, in turn, increases heart rate through vago-sympathetic mechanisms and total peripheral resistance via an increase in sympathetic outflow to vascular beds. In this review we are thinking on how baroreceptor reflex plays a role in the abnormal control of the circulation in heart failure. This review and our recent studies suggest that: (1) baroreceptor reflex is blunted in heart failure; (2) central angiotensin II and reactive oxygen species play an important role in blunted baroreceptor reflex; (3) cardiac sympathetic afferent stimulation and chemoreceptor reflex inhibit baroreceptor reflex; and (4) exercise training normalizes abnormal reflexes in the heart failure state.

Angiotensin II↗
PubMed2003

[Increased DMT1 expression and iron content in MPTP-treated C57BL/6 mice].

Iron plays a key role in Parkinson s disease (PD). To illustrate the mechanism underlying the increase of iron in substantia nigra (SN) in PD, changes of the expression of divalent metal transporter 1 (DMT1) and iron content were examined in SN in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treated mice using immunohistochemistry and histochemistry respectively. Following MPTP treatment for 3 d, elevated iron staining was found in SN. A further increase in iron content was observed after 7 d. In these lesioned animals, tyrosine hydroxylase-immunoreactive DA neurons exhibited a decrease in number and morphological changes as well. There were two isoforms of DMT1 expressed in SN of mice. After MPTP treatment, the expression of DMT1 without IRE form increased in either group, whereas DMT1 with IRE form increased only after 7 d of MPTP treatment. These observations suggest that DMT1 is possibly involved in the process of iron accumulation in SN of MPTP-treated mice, which might be responsible for the subsequent death of DA neurons.

Animals↗
PubMed2003

Intracellular Ca(2+) regulates the cellular iron uptake in K562 cells.

Fluorescence quenching was used to study the kinetics of the transferrin receptor (TfR)-mediated iron uptake in the calcein-loaded K562 cells. It was found that elevation of intracellular free Ca(2+) ([Ca(2+)](i)) by thapsigargin (TG) speeds up the initial rate of iron uptake and increases the overall capacity of the cells in taking up iron. Depletion of intracellular Ca(2+) or complete chelation of extracellular Ca(2+) results in complete inhibition of the iron uptake in cells. To gain insight into molecular mechanism, IANBD-labeled transferrin (Tf) and microscopic fluorescence imaging were used to observe the endocytosis and recycling of the Tf-TfR complex in single live cells. The study showed that the preincubation of cells with TG or phorbol myristate acetate (PMA), the direct activator of protein kinase C (PKC), accelerated the endocytosis and recycling of the complex in a dose-dependent manner. W-7, the calmodulin antagonist, and GF109203X, a selected cell-permeant inhibitor of PKC, can reverse the acceleration. Analysis of actin polymerization in controlled, [Ca(2+)](i)-elevated and W-7-treated cells revealed that the actin polymerization is enhanced as [Ca(2+)](i) is raised, but reduced by W-7. The results suggest that the regulation of actin polymerization by intracellular Ca(2+) may play a central role in Ca(2+)-dependent iron uptake.

Actins↗
PubMed2003

[Developmental expression and regulation of divalent metal transporter 1 in rat heart].

OBJECTIVE: To investigate the expression of divalent metal transporter 1 (DMT1) mRNA in male Sprague-Dawley rat heart of different ages and the expression of DMT1 regulated by dietary iron. METHODS: Reverse transcriptase (RT)-PCR and Western blot were used in this study. RESULTS: (1)Two isoforms of DMT1 mRNA [with and without iron-responsive element (IRE)] were both detected in rat heart, which were correlated with heart iron content. During development, both of two isoforms of DMT1 mRNA expression were the lowest at the age of PND 7, and increased at PND 21, 63 to 196. (2) After fed with a high iron diet or low iron diet for 6 weeks, the rats developed iron overload or iron deficiency respectively. No significant differences in DMT1 mRNA expression were detected among iron overload, iron deficiency and control rats. By using Western blot analysis, a 21% and 40% reduction in DMT1 protein non IRE form and IRE form respectively were found in iron overload rat (P<0.01, compared with control). Increases (26% approximate, equals 28%) in the levels of two isoforms of DMT1 protein were also observed in iron deficient rat (P<0.01, compared with control). CONCLUSION: The level of DMT1 mRNA expression in heart is age dependent;the two isoforms of DMT1 protein may be both regulated by iron on the posttranscriptional mechanism.

Age Factors↗
PubMed2002

Complexation of ytterbium to human transferrin and its uptake by K562 cells.

There is an increasing interest in the use of lanthanides in medicine. However, the mechanism of their accumulation in cells is not well understood. Lanthanide cations are similar to ferric ions with regard to transferrin binding, suggesting transferrin-receptor mediated transport is possible; however, this has not yet been confirmed. In order to clarify this mechanism, we investigated the binding of Yb3+ to apotransferrin by UV-Vis spectroscopy and stopped-flow spectrophotometry, and found that Yb3+ binds to apotransferrin at the specific iron sites in the presence of bicarbonate. The apparent binding constants of these sites showed that the affinity of Yb3+ is lower than that of Fe3+and binding of Yb3+ in the N-lobe is kinetically favored while the C-lobe is thermodynamically favored. The first Yb3+ bound to the C-lobe quantitatively with a Yb/apotransferrin molar ratio of < 1, whereas the binding to the other site is weaker and approaches completeness by a higher molar ratio only. As demonstrated by 1H NMR spectra, Yb3+ binding disturbed the conformation of apotransferrin in a manner similar to Fe3+. Flow cytometric studies on the uptake of fluorescein isothiocyanate labeled Yb3+-bound transferrin species by K562 cells showed that they bind to the cell receptors. Laser scanning confocal microscopic studies with fluorescein isothiocyanate labeled Yb3+-bound transferrin and propidium iodide labeled DNA and RNA in cells indicated that the Yb3+ entered the cells. The Yb3+-transferrin complex inhibited the uptake of the fluorescein labeled ferric-saturated transferrin (Fe2-transferrin) complex into K562 cells. The results demonstrate that the complex of Yb3+-transferrin complex was recognized by the transferrin receptor and that the transferrin-receptor-mediated mechanism is a possible pathway for Yb3+ accumulation in cells.

Binding, Competitive↗
PubMed2002

Distribution of constitutive nitric oxide synthase in the jejunum of adult rat.

AIM: To study the distribution of the constitutive nitric oxide synthase (NOS) in the jejunum of adult rat. METHODS: The distribution of endothelial NOS (eNOS) was detected by immunohistochemistry. Immunofluorescence histochemical dual staining technique were used for studying the distribution of neuronal NOS (nNOS) and eNOS. The dual stained slides were observed under a confocal laser scanning microscope. RESULTS: Positive neuronal NOS (nNOS) and endothelial NOS (eNOS) cells were found to be distributed in lamina propria of villi, and the epithelial cell was not stained. eNOS was mainly located in submucosal vascular endothelia, while nNOS was mainly situated in myenteric plexus. Some cells in the villi had both nNOS and eNOS. More than 80% of the cells were positive for both nNOS and eNOS, the rest cells were positive either for nNOS or for eNOS. CONCLUSION: The two constitutive nitric oxide synthases are distributed differently in the jejunum of rat. nNOS distributed in myenteric plexus is a neurotransmitter in the non-adrenergic non-cholinergic (NANC) inhibitory nerves. eNOS distributed in endothelial and smooth muscle cells of blood vessels plays vasodilator role. eNOS and nNOS are coexpressed in some cells of lamina propria of villi. NO generated by those NOS is very important in the physiological and pathological process of small intestine.

Animals↗