Publications (26)79.33 Total impact
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Article: GLB-13 is associated with oxidative stress resistance in caenorhabditis elegans.
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ABSTRACT: Globins constitute a superfamily of heme-binding proteins that is widely present in many species. There are 33 putative globins in the genome of Caenorhabditis elegans, where glb-13 is a homolog of neuroglobin (Ngb) based on sequence analysis and specific expression in neurons. Here we examined whether glb-13 as well as Ngb is also associated with resistance to reactive oxygen species (ROS) induced by paraquat. Our results showed that the mRNA level of glb-13 was significantly upregulated after paraquat exposure. Expression of a green fluorescent protein (GFP) reporter gene directed by the glb-13 promoter was increased by paraquat exposure. The mutant C. elegans strain glb-13(tm2825) was sensitive to paraquat-induced oxidative stress. Overexpression of human Ngb (hNgb) in C. elegans neuronal cells can rescue the paraquat sensitive phenotype of the mutant strain. glb-13 mutation or hNgb overexpression did not affect the expression of antioxidant enzymes such as superoxide dismutase (SOD). To examine the ROS-scavenging capabilities of hNgb and glb-13, we further examined the level of ROS in glb-13 mutant and hNgb transgenic (hNgb-Tg) worms. There was no statistical difference in ROS levels in the untreated controls; however in paraquat-treated worms, the ROS level was statistically repressed in the hNgb-Tg relative to enhanced green fluorescent protein (EGFP)-Tg worms or wildtype animals. Additionally, the ROS level of glb-13 mutant was statistically higher than the wildtype animals. Furthermore, hNgb overexpression diminished the ROS level of glb-13 mutant. In conclusion, hNgb can rescue the ROS sensitive phenotype of the glb-13 mutant strain. The protein GLB-13 seems to have an hNgb-like function, suggesting the importance of the globin protein family in maintaining the homeostasis of ROS signals. Our data provided evidence for the first time that glb-13 is associated with the resistance against oxidative stress-induced toxicity. © 2013 IUBMB Life, 2013.International Union of Biochemistry and Molecular Biology Life 03/2013; · 3.51 Impact Factor -
Article: Dynamic Expression Pattern of Neuro-oncological Ventral Antigen 1 (Nova1) in the Rat Brain after Focal Cerebral Ischemia/Reperfusion Insults.
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ABSTRACT: The present study aimed to evaluate the expression of neuro-oncological ventral antigen 1 (Nova1) in cerebral ischemia/reperfusion (I/R) insults by immunohistochemistry. The focal cerebral I/R model was induced by right middle cerebral artery occlusion (MCAO) for 120 min followed by 1 day, 7 days, and 14 days of reperfusion in Sprague-Dawley (SD) rats. The results showed that Nova1 was expressed in nearly the whole brain, although with higher density in hippocampus, hypothalamus, cingulate cortex, and medial habenular nucleus. The immunoreactivity of Nova1 neurons was increased dramatically, especially on both sides of the hippocampal CA(1) region, after 1 day of reperfusion. A strong response occurred at the ipsilateral CA(1) region between 1 day and 7 days of reperfusion. Likewise, strong compensatory responses of Nova1 expression were observed on the contralateral side of the striate cortex, dentate gyrus, and hypothalamus. Interestingly, more Nova1 neurons were observed to translocate to the dendrites and growth cones of the axons in the hypothalamus on the ischemic side after 7 days of reperfusion. In conclusion, our data suggest that Nova1 might mediate neuronal responsiveness, and its expression might positively correlate with neural repair after I/R insults in the rat brain.Journal of Histochemistry and Cytochemistry 10/2012; · 2.72 Impact Factor -
Article: In vitro kinetic evaluation of the free radical scavenging ability of propofol.
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ABSTRACT: Propofol is a widely used, short-acting, and intravenously administered hypnotic agent with notable antioxidant and free radical scavenging activities. However, there are relatively few kinetic studies on the free radical scavenging ability of propofol. The goal of this study is to evaluate the kinetics of propofol scavenging 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical (ABTS(·+)). The stock solution of ABTS(·+) was prepared by incubating 7 mM ABTS with 2.8 mM potassium persulfate in deionized water, and then diluted with 5 mM phosphate-buffered saline (pH 7.2) to get a working solution (36 μM ABTS(·+) and 18 μM ABTS). The reaction was monitored by measuring specific absorbance changes of ABTS and ABTS(·+) after adding 4 μM propofol (final concentration) to the working solution. The propofol-ABTS(·+) reaction products were analyzed by high-performance liquid chromatography and liquid chromatography mass spectrometry/mass spectrometry. Wave scanning and kinetic evaluation demonstrated that the ABTS(·+) scavenging process of propofol is relatively fast. The ABTS(·+) consumption rate by propofol is greater than the rate of ABTS formation. The degradation products of reaction between propofol and ABTS(·+) were mainly ABTS-propofol, a part of the ABTS molecule, and a combination of propofol with a part of the ABTS molecule. Propofol scavenges ABTS(·+) with a fast and stable kinetic feature in vitro, which is useful and important for understanding propofol's antioxidant properties. The kinetic process of the free radical scavenging activity of propofol may also play a role in dynamic protection in the body.Anesthesiology 04/2012; 116(6):1258-66. · 5.36 Impact Factor -
Article: Calpain 2 regulates Akt-FoxO-p27(Kip1) protein signaling pathway in mammary carcinoma.
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ABSTRACT: We investigated the role of the ubiquitously expressed calpain 2 isoform in breast tumor cell growth, migration, signaling, and tumorigenesis. RNAi-mediated knockdown of the capn2 transcript was used to manipulate expression of the catalytic subunit of calpain 2 in the AC2M2 mouse mammary carcinoma cell line. Stable knockdown of capn2 correlated with reduced in vitro proliferation rates, soft agar colony formation efficiency, and migration rates, indicating roles for calpain 2 in mitogenesis, survival, and motogenesis. Biochemical analysis showed increased levels of protein phosphatase 2A and reduced levels of activated Akt in calpain 2-deficient cells, and this correlated with increased levels of the FoxO3a target gene product p27(Kip1), a key regulator of cell proliferation. Calpain 2 deficiency in the AC2M2 cells correlated with enhanced nuclear localization of FoxO3a, consistent with it being in a derepressed state capable of regulating transcriptional targets. Orthotopically engrafted calpain 2 knockdown AC2M2 cells generated tumors with reduced growth rates and enhanced in vivo expression of p27(Kip1). In summary, calpain 2 deficiency correlated with reduced Akt activity, increased protein phosphatase 2A levels, derepression of FoxO3a, and enhanced expression of the p27(Kip1) tumor suppressor. These observations argue that calpain 2 promotes tumor cell growth both in vitro and in vivo through the PI3K-Akt-FoxO-p27(Kip1) signaling cascade. Inhibition of calpain 2 might therefore provide therapeutic benefits in the treatment of cancer.Journal of Biological Chemistry 03/2012; 287(19):15458-65. · 4.77 Impact Factor -
Article: Pregnancy outcome after intracytoplasmic sperm injection with strontium oocyte activation in a globozoospermic patient.
Asian Journal of Andrology 03/2012; 14(2):341-3. · 1.52 Impact Factor -
Article: Glyceraldehyde-3-phosphate dehydrogenase: a universal internal control for Western blots in prokaryotic and eukaryotic cells.
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ABSTRACT: In the current study, we examined the expression level of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein in a number of organisms and the stability of GAPDH under various conditions. Our results revealed that GAPDH is present in multiple Escherichia coli strains, the yeast strain GS115, Caenorhabditis elegans, rat PC12 cells, and both mouse and rat brain. Furthermore, GAPDH was stably expressed under different concentrations of inducer and at different times of induction in E. coli (BL21) cells and yeast GS115 cells. Stable expression of GAPDH protein was also observed in C.elegans and PC12 cells that were treated with different concentrations of paraquat or sodium sulfite, respectively. In addition, we were able to detect and identify the endogenous gapA protein in E.coli via immunoprecipitation and MALDI-TOF-MS analysis. Endogenous gapA protein and exogenously expressed (subcloned) GAPDH proteins were detected in E. coli BL21 but not for gapC. With the exception of gapC in E. coli, the various isoforms of GAPDH possessed enzymatic activity. Finally, sequence analysis revealed that the GAPDH proteins were 76% identical, with the exception of E. coli gapC. Taken together, our results indicate that GAPDH could be universally used as an internal control for the Western blot analysis of prokaryotic and eukaryotic samples.Analytical Biochemistry 01/2012; 423(1):15-22. · 3.00 Impact Factor -
Article: Lyophilization is suitable for storage and shipment of fresh tissue samples without altering RNA and protein levels stored at room temperature.
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ABSTRACT: Lyophilization has been widely used for preservation, such as in food industry, pharmacy, biotechnology and tissues engineering, etc. However, there is no report on whether it could affect stability of RNA and protein levels in biological tissue samples. Herein we show that lyophilization can be used for storage of biological tissue samples without loss of bioactivities even stored at room temperature for 7-14 days. To address this issue, C57BL mouse tissues were prepared and dried by lyophilization and a baking method, respectively, followed by examination of morphological structure and total proteins by SDS-PAGE as well as gelatin zymography. Subsequently, the stability of RNAs and proteins, which were lyophilized and stored at room temperature (23°C) for 14 days was further examined by RT-PCR, SDS-PAGE and western blot. Results demonstrated that lyophilization did not alter total protein activities of various tissues, including enzyme activities, immunoreactivities and phosphorylation, and did not affect several RNAs in lyophilized tissues. Taken together, lyophilization may represent a valuable approach for preservation and long-distance shipment of biological samples, particularly for the international exchange of biological samples without altering their bioactivities.Amino Acids 01/2012; 43(3):1383-8. · 3.25 Impact Factor -
Article: Bidirectional Crosstalk between Stress-Induced Gastric Ulcer and Depression under Chronic Stress.
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ABSTRACT: Stress contributes to a variety of diseases and disorders such as depression and peptic ulcer. The present study aimed to investigate the correlation between stress ulcer and depression in pathogenesis and treatment by using chronic stress depression (CSD), chronic psychological stress ulcer (CPSU) and water immersion restrain stress models in rats. Our data showed that the ulcer index of the animals after CSD exposure was significantly higher than that of controls. Depression-like behaviors were observed in rat after CPSU exposure. Fluoxetine hydrochloride significantly reduced the ulcer index of rats exposed to CPSU stress, while ranitidine inhibited depression-like behavior of the animals in CSD group. The ulcer index of rats administered with mifepristone after CPSU stress was markedly reduced compared to CPSU group, although there was no significant difference in the depression-like behavior between mifepristone-treated CSD group and naive controls. We also found that the rats exposed to CPSU or CSD stress displayed a lower level of corticosterone than naive controls, however, the acute stress (AS) group showed an opposite result. Additionally, in order to study the relevance of H(2) receptors and depression, we treated the CSD group with cimetidine and famotidine respectively. The data showed that cimetidine inhibited depression-like behavior in CSD rats, and famotidine had no impact on depression. Overall our data suggested that the hypothalamic-pituitary-adrenal (HPA) axis dysfunction may be the key role in triggering depression and stress ulcer. Acid-suppressing drugs and antidepressants could be used for treatment of depression and stress ulcer respectively. The occurrence of depression might be inhibited by blocking the central H(2) receptors.PLoS ONE 01/2012; 7(12):e51148. · 4.09 Impact Factor -
Article: [Experimental study on the induced differentiation of human amnion mesenchymal cells into osteoblasts].
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ABSTRACT: To investigate the feasibility of inducing differentiation of the human amniotic mesenchymal cells (hAMCs) into osteoblasts in vitro, so as to provide the seed cells for bone tissue engineering. The hAMCs were isolated from abandoned human amnion and cultured in osteogenic media to induce the osteogenic differentiation in vitro. After hAMCs were induced by osteogenic media for 15 days, morphological observation, immunocytochemistry and western blot were used to study the cellular morphology and expression of alkaline phosphatase (ALP), type I collagen, osteopontin and osteocalcin. The primary cultured hAMCs had long spindle shape or irregular shape, which were distributed evenly. The cells were usually suheultured in 5 or 7 days. After subculture, the cells became larger. After cultured by osteogenic media for 15 days, the hAMCs were detected to express ALP, osteocalcin and osteopontin, and secrete type I collagen. The hAMCs are isolated, cultured and amplified easily in vitro. The induced differentiated cells by osteogenic media have typical osteoblast morphological and functional characteristics, which can be used as seed cells for bone tissue engineering.Zhonghua zheng xing wai ke za zhi = Zhonghua zhengxing waike zazhi = Chinese journal of plastic surgery 09/2011; 27(5):362-7. -
Article: Different expression patterns of Ngb and EPOR in the cerebral cortex and hippocampus revealed distinctive therapeutic effects of intranasal delivery of Neuro-EPO for ischemic insults to the gerbil brain.
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ABSTRACT: The purpose of this study was to evaluate the neuroprotective effects of intranasally delivered recombinant human neuronal erythropoietin (Neuro-EPO) on brain injury induced by unilateral permanent ischemia in the Mongolian gerbil. Expression of EPO receptor (EPOR) and neuroglobin (Ngb) over 5 weeks after intranasal treatment with Neuro-EPO was determined using immunohistochemistry. Mortality of Neuro-EPO-treated gerbils decreased after surgery, and the sensory and motor function was significantly improved. Histopathological mapping showed that Neuro-EPO significantly reduced delayed neuronal death in the brain. Expression of Ngb was upregulated in the cerebral cortex at most time points (expect for 10 min and 48 hr) and in the hippocampus at 10 min and from 48 hr to 5 weeks, whereas EPOR was almost downregulated or unchanged in the brain (expect for 48 hr). The 10 min and 48 hr seemed to be two time points for the brain to switch the expression of both Ngb and EPOR to early and late recovery phase, respectively. In addition, there were two phases, 10 min to 1 hr and 24 hr to 72 hr, respectively, closing to the "golden hour" of about 60 min and the "silver day" of 1 to 3 days, for the brain to recover from stroke onset with intranasal Neuro-EPO treatment. Therefore, the results suggest that the intranasal administration of Neuro-EPO is effective in the treatment of acute brain ischemia. The different expression patterns of Ngb and EPOR is probably due to ischemic tolerance in the cerebral cortex and ischemic sensitivity in the hippocampus.Journal of Histochemistry and Cytochemistry 02/2011; 59(2):214-27. · 2.72 Impact Factor -
Article: Performance Research of Modulation for Optical Wireless Communication System.
JNW. 01/2011; 6:1099-1105. -
Article: Working memory task decreases the survival of newly born neurons in hippocampus.
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ABSTRACT: Throughout life new neurons are generated in dentate gyrus of hippocampus. Previous studies have found that spatial tasks can rescue newly born neurons from death. However, it is still unknown whether new neurons are similarly affected by all types of hippocampal-dependent tasks. Here we investigated the possible effects of working memory task (WMT) on immature neurons. Mice were trained in reference memory task and WMT respectively. The reference memory task used the classical hidden platform (HP) water maze task, while WMT used a delayed matching-to-place (DMTP) water maze task. Bromodeoxyuridine (BrdU) was administrated during the early or late phase of training, or 1week prior to training, in order to label dividing proliferating cells. After water maze training, the number of BrdU-labeled cells in dentate gyrus of hippocampus was compared. In addition, hippocampal brain-derived neurotrophic factor (BDNF) and Notch 1 receptor were characterized using Western blot. Serum corticosterone levels were also measured using enzyme immunoassay. Results showed that HP task and DMTP task did not change the number of BrdU-labeled cells produced during the early or late phase of training. As expected, the HP task increased the number of BrdU-labeled cells produced 1 week prior to training. However, DMTP task decreased the number of BrdU-labeled cells produced 1 week prior to training. Both tasks lead to a significant increase in serum corticosterone levels and did not change the expression of BDNF and Notch 1 receptor in hippocampus. Taken together, these results demonstrate that WMT has different effects on survival of immature neurons, and therefore suggests immature neurons may have more than one role depending on the demands of the tasks.Neurobiology of Learning and Memory 11/2010; 95(3):239-47. · 3.42 Impact Factor -
Article: Chronic corticosterone administration from adolescence through early adulthood attenuates depression-like behaviors in mice.
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ABSTRACT: There is evidence that depression may have a different neural basis at different ages. Although chronic stress and elevated glucocorticoid levels have been demonstrated to lead to the emergence of mood disorders, it remains unclear how moderate elevation of glucocorticoid levels in young animals influences depression-like behaviors and brain functions. To address this issue, the present study examines how chronic corticosterone (CORT) administration during adolescence and early adulthood influences depression-like behaviors, hypothalamic-pituitary-adrenal (HPA) axis response and hippocampal cell proliferation. Male mice were chronically administrated with CORT drinking water (20mg/L) during adolescence. After two months of treatment, serum CORT levels were measured using enzyme immunoassay. Hippocampal glucocorticoid and mineralocorticoid receptors were characterized using Western blot. Tail suspension and forced swim tests were used to assess depression-related behaviors in mice. Immunohistochemistry was performed to measure bromodeoxyuridine (BrdU) incorporation in order to assess cell proliferation in the hippocampus. Our results suggest that chronic CORT administration induced a mild but not significant elevation in basal CORT levels and attenuated the physiological responses to stress. Chronic CORT administration also reduced expression of the hippocampal mineralocorticoid receptor and decreased immobility time in both the tail suspension test and the forced swim test. Moreover, chronic CORT administration increased the BrdU immunoreactivities in the hippocampus. Taken together, these findings suggest that chronic mild elevation by CORT administration during the adolescence and early adulthood attenuates depression-like behaviors.Journal of affective disorders 11/2010; 131(1-3):128-35. · 3.76 Impact Factor -
Article: Sodium sulfite is a potential hypoxia inducer that mimics hypoxic stress in Caenorhabditis elegans.
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ABSTRACT: Physical and chemical hypoxia have been widely used in the study of hypoxic injury; however, both of these hypoxia models have their own limitations. Physical hypoxia is usually difficult to control and maintain. Chemical hypoxia, which is usually induced by chemical hypoxia-mimicking agents, such as CoCl(2), may result in heavy metal toxicity or impose security threats. To develop a more suitable hypoxia model, we focused on sodium sulfite (Na(2)SO(3)) and evaluated its ability to remove dissolved oxygen in aqueous solutions. Our results showed that sodium sulfite successfully induced hypoxic conditions. The degree of hypoxia and the guarantee period of the sodium sulfite solution could be easily controlled by the concentration of soluble sodium sulfite. In addition, we used sodium sulfite to create a hypoxia model in Caenorhabditis elegans. Similar to physical hypoxia, the sodium sulfite solutions induced hypoxia-related death in the worms and led to morphologic cell defects and C. elegans hypoxia inducible factor 1 stabilization. Taken together, our data show that sodium sulfite is a potential hypoxia inducer that mimics hypoxic stress in C. elegans.European Journal of Biochemistry 10/2010; 16(2):267-74. · 3.42 Impact Factor -
Article: The activity of recombinant human neuroglobin as an antioxidant and free radical scavenger.
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ABSTRACT: Free radicals are by-products of metabolism and exist in a homeostasis between generation and scavenging in vivo. Excessive free radicals cause various diseases, including nervous system diseases. Neuroglobin (Ngb), a nervous system-specific oxygen-binding protein, has been suggested to be a potential free radical scavenger in the nervous system in vivo; however, its underlying mechanism remains unclear. In this study, we investigated the antioxidant potential and free radical scavenging properties of recombinant human Ngb (rhNgb) in vitro. Interestingly, we found that the rhNgb protein itself has a direct and distinct antioxidant capacity and can efficiently scavenge a variety of free radicals, including the [2,2'-azino-di-(3-ethyl-benzthiazoline-6-sulfonic acid)] (ABTS) cation, superoxide anion, hydrogen peroxide, and hydroxyl radical. The capacity of rhNgb to scavenge the superoxide anion and hydrogen peroxide was even comparable to that of vitamin C. In addition, rhNgb had Fe(2+) chelating activity but hemoglobin did not. In conclusion, our results indicated that the rhNgb protein itself has antioxidant and free radical scavenging activities, providing fundamental evidence for the neuroprotective function of Ngb. These data provide key information for the origin of the neuroprotective and physiological role of Ngb and will promote the treatment of reactive oxygen species (ROS)-related diseases using this novel oxygen-binding globin.Proteins Structure Function and Bioinformatics 09/2010; 79(1):115-25. · 3.39 Impact Factor -
Article: Histochemical mapping of hnRNP A2/B1 in rat brain after ischemia-reperfusion insults.
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ABSTRACT: Cerebral ischemia-reperfusion (I/R) insults result in neuronal cell death, brain tissue loss, and severe neurological deficits. However, the underlying mechanism is still not fully understood. Heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 belongs to a family of RNA-binding proteins that plays a central role in pre-mRNA processing. Recent studies have revealed that hnRNP A2/B1 may be involved in the progress of I/R; therefore, the present study aimed to examine expression patterns of hnRNP A2/B1 to better understand posttranscriptional regulations in cerebral I/R insults. Focal cerebral I/R models were induced by right middle cerebral artery occlusion (MCAO) for 120 min followed by 3, 6, 12, 24, 48, and 72 hr of reperfusion in male Sprague-Dawley rats. We employed immunohistochemistry to examine expression of hnRNP A2/B1 in rat cerebral cortex (including cingulate cortex, striate cortex, temporal cortex, and piriform cortex) and hippocampus after I/R insults. Results showed that expression of hnRNP A2/B1 was significantly downregulated in cerebral cortex and hippocampus from 3 to 24 hr of reperfusion after MCAO for 120 min, but significantly upregulated at 48 hr of reperfusion. Unexpectedly, translocation of hnRNP A2/B1 from nucleus to cytoplasm and even to neurites was observed in cerebral cortex at 3 hr of reperfusion, reaching a peak at 24 hr of reperfusion, but not in hippocampus, indicating different posttranscriptional regulation patterns in different brain regions. Interestingly, translocation of hnRNP A2/B1 was only observed in cerebral cortex with MCAO but not in the opposite side, suggesting an I/R-specific expression pattern in the brain. Our data suggest that hnRNP A2/B1 participates in posttranscriptional regulation of neurons in cerebral cortex and hippocampus that suffered I/R insults, although posttranscriptional regulation is more extensive in neuronal cells of cerebral cortex than in hippocampus.Journal of Histochemistry and Cytochemistry 08/2010; 58(8):695-705. · 2.72 Impact Factor -
Article: A novel method for promoting heterologous protein expression in Escherichia coli by fusion with the HIV-1 TAT core domain.
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ABSTRACT: The human immunodeficiency virus type 1 (HIV-1) transactivator of transcription (TAT) protein, a member of the protein transduction domain (PTD) superfamily, can deliver heterologous proteins across most biomembranes without losing bioactivity. However, there is no report on whether the TAT core domain containing the sequence 'YGRKKRRQRRR' has other functions. As the TAT core domain is most basic (pI=12.8) and has biomembrane crossing ability, we hypothesized it might probably influence the protein expression level due to subcellular redistribution of target proteins in the cells. To address this issue, we constructed the prokaryotic expression vector pET28b-TAT-EGFP (using the vector pET28b-EGFP for control) containing the core domain coding region, and transformed the vector into E. coli BL21 (DE3) cells for expression of the enhanced green fluorescent protein (EGFP) with the inducer isopropyl-beta-D-thiogalactopyranoside (IPTG). Equal amount of the total proteins were fractionated using 15% SDS-PAGE and identified by western blot, and the plasmid copy number was assayed by Southern blot. In order to further study the subcellular localization of heterologous proteins in E. coli cells, the cytoplasmic and periplasmic components were extracted by chloroform and osmotic shock techniques. Interestingly, our data showed that the TAT core domain was not only able to promote the heterologous protein expression in E. coli, but also improve the yields and the solubility of heterologous proteins, while the plasmid copy number of TAT-containing clones and TAT-free clones was not affected by the TAT core domain. In addition, the TAT-tagged protein was mainly localized in the cytoplasm and also accumulated in the periplasmic space along with the time for protein expression, while in contrast, the TAT-free protein was mainly expressed in the periplasm and only a few in cytoplasm. A further examination on the distribution of the expressed proteins in cytoplasm and periplasm suggested that the TAT core domain might promote protein expression in the cytoplasm initially and then partially deliver them across the cytomembrane to the periplasmic space in a concentration-dependent manner. Taken together, our current data have provided a novel method for improving heterologous protein expression in prokaryotic cells by fusion with the TAT core domain, which will promote expression efficiency of bioactive proteins for protein engineering.Amino Acids 03/2010; 39(3):811-20. · 3.25 Impact Factor -
Article: A proteomic view of Caenorhabditis elegans caused by short-term hypoxic stress.
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ABSTRACT: The nematode Caenorhabditis elegans is both sensitive and tolerant to hypoxic stress, particularly when the evolutionarily conserved hypoxia response pathway HIF-1/EGL-9/VHL is involved. Hypoxia-induced changes in the expression of a number of genes have been analyzed using whole genome microarrays in C. elegans, but the changes at the protein level in response to hypoxic stress still remain unclear. Here, we utilized a quantitative proteomic approach to evaluate changes in the expression patterns of proteins during the early response to hypoxia in C. elegans. Two-dimensional difference gel electrophoresis (2D-DIGE) was used to compare the proteomic maps of wild type C. elegans strain N2 under a 4-h hypoxia treatment (0.2% oxygen) and under normoxia (control). A subsequent analysis by MALDI-TOF-TOF-MS revealed nineteen protein spots that were differentially expressed. Nine of the protein spots were significantly upregulated, and ten were downregulated upon hypoxic stress. Three of the upregulated proteins were involved in cytoskeletal function (LEV-11, MLC-1, ACT-4), while another three upregulated (ATP-2, ATP-5, VHA-8) were ATP synthases functionally related to energy metabolism. Four ribosomal proteins (RPL-7, RPL-8, RPL-21, RPS-8) were downregulated, indicating a decrease in the level of protein translation upon hypoxic stress. The overexpression of tropomyosin (LEV-11) was further validated by Western blot. In addition, the mutant strain of lev-11(x12) also showed a hypoxia-sensitive phenotype in subsequent analyses, confirming the proteomic findings. Taken together, our data suggest that altered protein expression, structural protein remodeling, and the reduction of translation might play important roles in the early response to oxygen deprivation in C. elegans, and this information will help broaden our knowledge on the mechanism of hypoxia response.Proteome Science 01/2010; 8:49. · 2.33 Impact Factor -
Article: Antidepressive behaviors induced byenriched environment might be modulated by glucocorticoid levels.
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ABSTRACT: Exposure to enriched environment (EE) can influence expression of depression symptoms, however, the underlying mechanism has not been established, although neurogenesis was probably involved. It has been reported that EE stimulates glucocorticoids release. However, the role of corticosterone (CORT) in effects of EE is still unknown. To address these issues, we examined depression-like behaviors of the animals exposed to EE with low dose CORT supplement following bilateral adrenalectomy (ADX+CORT). Two months after housing, tail suspension test and forced swim test were used to assess depression-related behavior of mice. Serum CORT levels were measured by radio-immunoassay. Signals of DNA synthesis marker bromodeoxyuridine and immature neuronal marker doublecortin were measured by immunohistochemistry. Results showed that EE significantly decreased immobility time of the mice in both the tail suspension test and forced swim test, showing distinctive antidepressive behaviors. Exposure to EE also increased serum CORT level, and prevention of this increase with ADX+CORT eliminated the decrease of immobility time of the animals. Both the mice exposed to EE and those receiving ADX+CORT treatment showed enhanced newly born cells and immature granule neurons in the hippocampus. Taken together, our data suggest that glucocorticoids elevation is required for antidepressive behaviors of EE.European neuropsychopharmacology: the journal of the European College of Neuropsychopharmacology 09/2009; 19(12):868-75. · 3.68 Impact Factor -
Article: Transcription and splicing regulation in human umbilical vein endothelial cells under hypoxic stress conditions by exon array.
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ABSTRACT: The balance between endothelial cell survival and apoptosis during stress is an important cellular process for vessel integrity and vascular homeostasis, and it is also pivotal in angiogenesis during the development of many vascular diseases. However, the underlying molecular mechanisms remain largely unknown. Although both transcription and alternative splicing are important in regulating gene expression in endothelial cells under stress, the regulatory mechanisms underlying this state and their interactions have not yet been studied on a genome-wide basis. Human umbilical vein endothelial cells (HUVECs) were treated with cobalt chloride (CoCl2) both to mimic hypoxia and to induce cell apoptosis and alternative splicing responses. Cell apoptosis rate analysis indicated that HUVECs exposed to 300 microM CoCl2 for 24 hrs were initially counterbalancing apoptosis with cell survival. We therefore used the Affymetrix exon array system to determine genome-wide transcript- and exon-level differential expression. Other than 1583 differentially expressed transcripts, 342 alternatively spliced exons were detected and classified by different splicing types. Sixteen alternatively spliced exons were validated by RT-PCR. Furthermore, direct evidence for the ongoing balance between HUVEC survival and apoptosis was provided by Gene Ontology (GO) and protein function, as well as protein domain and pathway enrichment analyses of the differentially expressed transcripts. Importantly, a novel molecular module, in which the heat shock protein (HSP) families play a significant role, was found to be activated under mimicked hypoxia conditions. In addition, 46% of the transcripts containing stress-modulated exons were differentially expressed, indicating the possibility of combinatorial regulation of transcription and splicing. The exon array system effectively profiles gene expression and splicing on the genome-wide scale. Based on this approach, our data suggest that transcription and splicing not only regulate gene expression, but also carry out combinational regulation of the balance between survival and apoptosis of HUVECs under mimicked hypoxia conditions. Since cell survival following the apoptotic challenge is pivotal in angiogenesis during the development of many vascular diseases, our results may advance the knowledge of multilevel gene regulation in endothelial cells under physiological and pathological conditions.BMC Genomics 04/2009; 10:126. · 4.07 Impact Factor
Top co-authors
Top Journals
Institutions
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2013
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Xuanwu hospital
Beijing, Beijing Shi, China
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2007–2012
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State Key Laboratory of Medical Genetics of China
Changsha, Hunan, China
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2010
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Nanjing Agricultural University
Nanjing, Jiangsu Sheng, China
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2007–2008
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China Institute for Radiation Protection
Beijing, Beijing Shi, China
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