Macroautophagy is a multistep, vacuolar, degradation pathway terminating in the lysosomal compartment, and it is of fundamental importance in tissue homeostasis. In this review, we consider macroautophagy in the light...Macroautophagy is a multistep, vacuolar, degradation pathway terminating in the lysosomal compartment, and it is of fundamental importance in tissue homeostasis. In this review, we consider macroautophagy in the light of recent advances in our understanding of the formation of autophagosomes, which are double-membrane-bound vacuoles that sequester cytoplasmic cargos and deliver them to lysosomes. In most cases, this final step is preceded by a maturation step during which autophagosomes interact with the endocytic pathway. The discovery of AuTophaGyrelated genes has greatly increased our knowledge about the mechanism responsible for antophagosome formation, and there has also been progress in the understanding of molecular aspects of autophagosome maturation. Finally, the regulation of autophagy is now better understood because of the discovery that the activity of Atg complexes is targeted by protein kinases, and owing to the importance of nuclear regulation via transcription factors in regulating the expression of autophagy genes.展开更多
Background： Acute coronary syndrome （ACS） is closely related to unstable plaques and secondary thrombosis. The inflammatory cells in plaques and their inflammatory products may be the cause for plaque instability a...Background： Acute coronary syndrome （ACS） is closely related to unstable plaques and secondary thrombosis. The inflammatory cells in plaques and their inflammatory products may be the cause for plaque instability and ruptures. The study aimed to disclose the changes of inflammatory factors including serum intracellular adhesion molecule-1（ICAM-1 ）, chitinase-3-like protein I （YKL-40）, and lipoprotein-associated phospholipase A2 （Lp-PLA2） in patients with ACS and its clinical significance. Methods： A total of 120 patients with coronary heart disease （CHD） were categorized into 2 groups： 69 with ACS and 51 with stable angina pectoris （SAP）： 20 patients with chest pain and normal angiography served as a control group. The 120 patients with CHD were categorized into single-vessel disease group, double-vessel disease group, and three-vessel disease group based on the number of coronary artery stenosis. The severity of coronary artery stenosis was quantified based on coronary angiography using Gensini score. They were further divided into mild CHD group with its Gensini score 〈26 （n = 36）, moderate CHD group with its Gensini score being 26-54 （n = 48） and severe CHD group with its Gensini score 〉54 （n = 36）. Serum levels of ICAM-1, YKL-40, and Lp-PLA2 of different groups were determined by enzyme-linked immunosorbent assay. Correlation between ICAM-1, YKL-40, Lp-PLA2, and Gensini score was analyzed. Results： The levels of serum inflammatory factors ICAM-1, YKL-40, and Lp-PLA2 were significantly higher in the ACS group than those in control group and SAP group （all P 〈 0.05）： and compared with control group, no significant difference was observed in terms of the serum ICAM-1, YKL-40, and Lp-PLA2 levels in the SAP group （P 〉 0.05）.The levels of serum ICAM-1, YKL-40, and Lp-PLA2 were not significantly different among control group, single-vessel disease group, double-vessel disease group, and three-vessel disease group （all P 〉 0.05）. The levels of seru展开更多
Objective： To investigate the relationship between inflammatory factors and two Chinese medicine（CM） syndrome types of qi stagnation and blood stasis（QSBS） and qi deficiency and blood stasis（QDBS） in patients w...Objective： To investigate the relationship between inflammatory factors and two Chinese medicine（CM） syndrome types of qi stagnation and blood stasis（QSBS） and qi deficiency and blood stasis（QDBS） in patients with acute coronary syndrome（ACS）. Methods： Sixty subjects with ACS, whose pathogenesis changes belongs to qi disturbance blood stasis syndrome, were divided into 2 groups： 30 in the QSBS group and 30 in the QDBS group. The comparative analysis on them was carried out through comparing general information, coronary angiography and inflammatory factors including intracellular adhesion molecule-1（ICAM-1）, chitinase-3-like protein 1（YKL-40） and lipoprotein-associated phospholipase A2（Lp-PLA2）. Results： Compared with the QSBS group, Lp-PLA2 and YKL-40 levels in the QDBS group showed no-significant difference（P〉0.05）; ICAM-1 was significantly higher in the QDBS group than in the QSBS group in the pathological processes of qi disturbance and blood stasis syndrome of ACS（P〈0.05）. Conclusion： Inflammatory factor ICAM-1 may be an objective basis for syndrome typing of QSBS and QDBS, which provides a research direction for standardization research of CM syndrome types.展开更多
Object: The authors studied the influence of CO2 pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation. Method: They set up a simulation o...Object: The authors studied the influence of CO2 pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation. Method: They set up a simulation of pneumoperitoneum under different CO2 pressure, and then measured the variation of intracellular pH (pHi) at different time and the activity of protein kinase C (PKC) and protein phosphatase 2a (PP2a) at the end of the pneumoperitoneum. After 1 week, the concentration of cancer cells in the culture medium was calculated. Result: When the pressure of CO2 pneumoperitoneum was 0, 10, 20, 30 mmHg respectively, the average pHi was 7.273, 7.075, 6.783, 6.693 at the end of the pneumoperitoneum; PKC activity was 159.4, 168.5,178.0, 181.6 nmol/(g.min) and PP2a was 4158.3, 4066.9, 3984.0, 3878.5 nmol/(g.min) respectively. After 1 week, the cancer cells concentration was 2.15×105, 2.03×105, 2.20×105, 2.18×105 L-1. Conclusion: CO2 pneumoperitoneum could promote acidosis in cancer cells, inducing the activation of protein kinase C and deactivation of protein phosphatase 2a, but it could not accelerate the mitosis rate of the cancer cells.展开更多
In this study, we established a Wistar rat model of right middle cerebral artery occlusion and observed pathological imaging changes （T2-weighted imaging [T2WI], T2FLAIR, and diffusion-weighted imaging [DWI]） follow...In this study, we established a Wistar rat model of right middle cerebral artery occlusion and observed pathological imaging changes （T2-weighted imaging [T2WI], T2FLAIR, and diffusion-weighted imaging [DWI]） following cerebral infarction. The pathological changes were divided into three phases： early cerebral infarction, middle cerebral infarction, and late cerebral infarction. In the early cerebral infarction phase （less than 2 hours post-infarction）, there was evidence of intracellular edema, which improved after reperfusion. This improvement was defined as the ischemic penumbra. In this phase, a high DWI signal and a low apparent diffusion coefficient were observed in the right basal ganglia region. By contrast, there were no abnormal T2WI and T2FLAIR signals. For the middle cerebral infarction phase （2-4 hours post-infarction）, a mixed edema was observed. After reperfusion, there was a mild improvement in cell edema, while the angioedema became more serious. A high DWI signal and a low apparent diffusion coefficient signal were observed, and some rats showed high T2WI and T2FLAIR signals. For the late cerebral infarction phase （4-6 hours post-infarction）, significant angioedema was visible in the infarction site. After reperfusion, there was a significant increase in angioedema, while there was evidence of hemorrhage and necrosis. A mixed signal was observed on DWI, while a high apparent diffusion coefficient signal, a high T2WI signal, and a high T2FLAIR signal were also observed. All 86 cerebral infarction patients were subjected to T2WI, T2FLAIR, and DWI. MRI results of clinic data similar to the early infarction phase of animal experiments were found in 51 patients, for which 10 patients （10/51） had an onset time greater than 6 hours. A total of 35 patients had MRI results similar to the middle and late infarction phase of animal experiments, of which eight patients （8/35） had an onset time less than 6 hours. These data suggest that defining the ＂therapeutic time window＂ as 展开更多
L-Serine plays a critical role as a building block for cell growth, and thus it is difficult to achieve the direct fermentation of L-serine from glucose. In this study, Corynebacterium glutamicum ATCC 13032 was engine...L-Serine plays a critical role as a building block for cell growth, and thus it is difficult to achieve the direct fermentation of L-serine from glucose. In this study, Corynebacterium glutamicum ATCC 13032 was engineered de novo by blocking and at- tenuating the conversion of L-serine to pyruvate and glycine, releasing the feedback inhibition by L-serine to 3-phosphoglycerate dehydrogenase （PGDH）, in combination with the co-expression of 3-phosphoglycerate kinase （PGK） and feedback-resistant PGDH （PGDHr）. The resulting strain, SER-8, exhibited a lower specific growth rate and significant differ- ences in L-serine levels from Phase I to Phase V as determined for fed-batch fermentation. The intracellular L-serine pool reached （14.22_＋1.41） ~trnol gcoM-1, which was higher than glycine pool, contrary to fermentation with the wild-type strain. Furthermore, metabolic flux analysis demonstrated that the over-expression of PGK directed the flux of the pentose phosphate pathway （PPP） towards the glycolysis pathway （EMP）, and the expression of PGDHr improved the L-serine biosynthesis pathway. In addition, the flux from L-serine to glycine dropped by 24%, indicating that the deletion of the activator GlyR re- sulted in down-regulation of serine hydroxymethyltransferase （SHMT） expression. Taken together, our findings imply that L-serine pool management is fundamental for sustaining the viability of C. glutamicum, and improvement of C1 units genera- tion by introducing the glycine cleavage system （GCV） to degrade the excessive glycine is a promising target for L-serine pro- duction in C. glutamicum.展开更多
Since it was first postulated by Wigglesworth in 1934, juvenile hormone (JH) is considered a status quo hormone in insects because it prevents metamorphosis that is initiated by the molting hormone 20-hydroxyecdysone ...Since it was first postulated by Wigglesworth in 1934, juvenile hormone (JH) is considered a status quo hormone in insects because it prevents metamorphosis that is initiated by the molting hormone 20-hydroxyecdysone (20E). During the last decade, significant advances have been made regarding JH signaling. First, the bHLH-PAS transcription factor Met/Gce was identified as the JH intracellular receptor. In the presence of JH, with the assistance of Hsp83, and through physical association with a bHLH?PAS transcriptional co-activator, Met/Gce enters the nucleus and binds to E-box-like motifs in promoter regions of JH primary?response genes for inducing gene expression. Second, the zinc finger transcription factor Kr-hl was identified as the anti-metamorphic factor which transduces JH signaling. Via Kr-hl binding sites, Kr-hl represses expression of 20E primary?response genes (i.e. Bi\ E93 and E5) to prevent 20E-induced metamorphosis. Third, through the intracellular signaling, JH promotes differ ent aspects of female reproduction. Nevertheless, this action varies greatly from species to species. Last, a hypothetical JH membrane receptor has been predicted to be either a GPCR or a tyrosine kinase receptor. In future, it will be a great challenge to understand how the JH intracellular receptor Met/Gce and the yet unidentified JH membrane receptor coordinate to regulate metamorphosis and reproduction in insects.展开更多
Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in t...Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in the cellular membrane, storing as dormant forms. Upon exposure to environmental and developmental cues, these transcription factors are released from the membrane and translocated to the nucleus, where they regulate associated target genes. As this process skips both transcriptional and translational regulations, it guarantees prompt response to external and internal signals. Membrane- bound transcription factors （MTFs） undergo several unique steps that are not involved in the action of canonical nuclear transcription factors： proteolytic processing and intracellular movement. Recently, alternative splicing has also emerged as a mechanism to liberate MTFs from the cellular membranes, establishing an additional activation scheme independent of proteolytic processing. Multiple layers of MTF regulation add complexity to transcriptional regulatory scheme and ensure elaborate action of MTFs. In this review, we provide an overview of recent findings on MTFs in plants and highlight the molecular mechanisms underlying MTF liberation from cellular membranes with an emphasis on intracellular movement.展开更多
Objective:To study the effects of 18β-glycyrrhetinic acid (GA) on proliferation inhibition, apop totic induction, and the relationship between GA-induced apoptosis and intracellular Ca2+ concentration in human breast...Objective:To study the effects of 18β-glycyrrhetinic acid (GA) on proliferation inhibition, apop totic induction, and the relationship between GA-induced apoptosis and intracellular Ca2+ concentration in human breast carcinoma (MCF-7) cells. Methods: After MCF-7 cells were treated with GA at the concentrations from 50 μmol/L to 250 μmol/L for 24 h, cell viability of proliferation was assessed by MTT assay. After the cells were treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L GA for 24 h, the rates of cell apoptosis were examined by terminal deoxynucleotide transferase mediated dUTP nick-end-labeling method and flow cytometry with Annexin V/propidium iodide fluorescent stain. After the cells treated with 150 μmol/L GA for 24 h, intracellular Ca2+ concentration was measured by Fure-2 fluorescein load method. Results: After the cells were treated with GA at the concentrations from 100 μmol/L to 250 μmol/L, the rates of proliferative inhibition were increased significantly (P<0.05 and P<0.01) in a dose dependent fashion. IC50 of the proliferation inhibition was 234.33 μmol/L. Treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L, the rates of cell apoptosis were increased significantly (P<0.01). Intracellular Ca2+ concentration after treatment with GA was higher evidently than that of control (P<0.05). Conclusion: 18β-glycyrrhetinic acid has the effects of the proliferation inhibition and the apoptotic induction on MCF-7 cells. The rise of intracellular Ca2+ level may be depended on apoptosis induced by GA in MCF-7 cells.展开更多
Liver cell transplantation presents clinical benefit in patients with inborn errors of metabolism as an alternative,or at least as a bridge,to orthotopic liver transplantation.The success of such a therapeutic approac...Liver cell transplantation presents clinical benefit in patients with inborn errors of metabolism as an alternative,or at least as a bridge,to orthotopic liver transplantation.The success of such a therapeutic approach remains limited by the quality of the transplanted cells.Cryopreservation remains the best option for long-term storage of hepatocytes,providing a permanent and sufficient cell supply.However, isolated adult hepatocytes are poorly resistant to such a process,with a significant alteration both at the morphological and functional levels.Hence,the aim of the current review is to discuss the state of the art regarding widely-used hepatocyte cryopreservation protocols,as well as the assays performed to analyse the post-thawing cell quality both in vitro and in vivo. The majority of studies agree upon the poor quality and efficiency of cryopreserved/thawed hepatocytes as compared to freshly isolated hepatocytes.Intracellular ice formation or exposure to hyperosmotic solutionsremains the main phenomenon of cryopreservation process,and its effects on cell quality and cell death induction will be discussed.The increased knowledge and understanding of the cryopreservation process will lead to research strategies to improve the viability and the quality of the cell suspensions after thawing.Such strategies,such as vitrification,will be discussed with respect to their potential to significantly improve the quality of cell suspensions dedicated to liver cell-based therapies.展开更多
Most of the conventional chemotherapeutic agents used for cancer chemotherapy suffer from multidrug resistance of tumor cells and poor antitumor efficacy.Based on physiological differences between the normal tissue an...Most of the conventional chemotherapeutic agents used for cancer chemotherapy suffer from multidrug resistance of tumor cells and poor antitumor efficacy.Based on physiological differences between the normal tissue and the tumor tissue,one effective approach to improve the efficacy of cancer chemotherapy is to develop pH-sensitive polymeric micellar delivery systems.The copolymers with reversible protonationedeprotonation core units or acid-liable bonds between the therapeutic agents and the micelle-forming copolymers can be used to form pH-sensitive polymeric micelles for extracellular and intracellular drug smart release.These systems can be triggered to release drug in response to the slightly acidic extracellular fluids of tumor tissue after accumulation in tumor tissues via the enhanced permeability and retention effect,or they can be triggered to release drug in endosomes or lysosomes by pH-controlled micelle hydrolysis or dissociation after uptake by cells via the endocytic pathway.The pH-sensitive micelles have been proved the specific tumor cell targeting,enhanced cellular internalization,rapid drug release,and multidrug resistance reversal.The multifunctional polymeric micelles combining extracellular pH-sensitivity with receptor-mediated active targeting strategies are of great interest for enhanced tumor targeting.The micelles with receptor-mediated and intracellular pH targeting functions are internalized via receptor-mediated endocytosis followed by endosomal-pH triggered drug release inside the cells,which reverses multidrug resistance.The pH sensitivity strategy of the polymeric micelles facilitates the specific drug delivery with reduced systemic side effects and improved chemotherapeutical efficacy,and is a novel promising platform for tumor-targeting drug delivery.展开更多
Background Methylprednisolone (MP), a synthetic glucocorticosteroid, has been broadly studied in experiments on endotoxin-induced shock and septic shock. This study was designed to ascertain whether glycine and MP ca...Background Methylprednisolone (MP), a synthetic glucocorticosteroid, has been broadly studied in experiments on endotoxin-induced shock and septic shock. This study was designed to ascertain whether glycine and MP can protect against organ injury and death caused by hemorrhagic shock, and to elucidate the underlying mechanisms of these protective effects in rats.Method To establish a shock model, Wistar rats were bled to maintain mean arterial pressure at 30-50 mmHg for 1 hour and subsequently resuscitated with the shed blood and normal saline. Just prior to resuscitation, the rats were randomly assigned to four groups: sham group (operation performed without inducing shock), shock group, shock+glycine group (glycine injected at the beginning of resuscitation) and shock+MP group (MP injected at the beginning of resuscitation).Results ① Seventy-two hours after resuscitation, the survival rate of rats from the shock group had decreased to 20%, while the survival rates of rats from the shock+glycine and shock+MP groups were 77.8% and 80%, respectively. The difference was significant (P<0.05). ② Eighteen hours after resuscitation, pathological alterations in the organs of the rats were apparent. In rats from the shock group, edema, interstitial leukocyte infiltration, and cellular degeneration occurred in the liver, lungs, kidneys, and heart. Glycine and MP reduced these pathological changes significantly. ③ Eighteen hours after resuscitation, the levels of creatine phosphokinase, transaminases, and creatine were elevated significantly in rats from the shock group, indicating injury to the heart, liver, and kidneys, while these levels were elevated only slightly in the shock+glycine and shock+MP groups. The differences were significant (P<0.01). ④ There were significant increases in intracellular calcium and production of tumor necrosis factor (TNF-α) by isolated Kupffer cells stimulated by endotoxin after hemorrhagic shock. These changes were completely prevented by glycine and MP (P<0.01). Conclusion G展开更多
Background The contractility of hepatic stellate cells (HSCs) may play an important role in the pathogenesis of cirrhosis with portal hypertension. The aim of this study was to research the effects of octreotide,an an...Background The contractility of hepatic stellate cells (HSCs) may play an important role in the pathogenesis of cirrhosis with portal hypertension. The aim of this study was to research the effects of octreotide,an analogue of somatostatin,on intracellular Ca 2+ and on the expression of L-type voltage-operated calcium channels (L-VOCCs) in activated HSCs,and to try to survey the use of octreotide in treatment and prevention of cirrhosis with portal hypertension complications. Methods HSC-T_6,an activated HSCs line,was plated on small glass coverslips in 35-mm culture dishes at a density of 1×10 5/ml,and incubated in DMEM media for 24 hours. After the cells were loaded with Fluo-3/AM,intracellular Ca 2+ was measured by Laser Scanning Confocal Microscopy (LSCM). The dynamic changes in activated HSCs of intracellular Ca 2+ ,stimulated by octreotide,endothelin-1,and KCl, respectively,were also determined by LSCM. Each experiment was repeated six times. L-VOCC expression in HSCs was estimated by immunocytochemistry. Results After octreotide stimulation,a signifcant decrease in the intracellular Ca 2+ of activated HSCs was observed. However,octreotide did not inhibit the increases in intracellular Ca 2+ after stimulation by KCl and endothelin-1. Moreover,octreotide did not significantly affect L-VOCC expression. These results suggest that neither L-VOCC nor endothelin-1 receptors in activated HSCs are inhibited by octreotide. Conclusions Octreotide may decrease portal hypertension and intrahepatic vascular tension by inhibiting activated HSCs contractility through decreases in intracellular Ca 2+ . The somatostatin receptors in activated HSCs may be inhibited by octreotide.展开更多
Background： Appropriate expression and regulation of the transcriptome, which mainly comprise ofmRNAs and lncRNAs, are important for all biological and cellular processes including the physiological activities of bon...Background： Appropriate expression and regulation of the transcriptome, which mainly comprise ofmRNAs and lncRNAs, are important for all biological and cellular processes including the physiological activities of bone microvascular endothelial cells （BMECs）. Through an intricate intraeellular signaling systems, the transcriptome regulates the pharmacological response of the cells. Although studies have elucidated the impact of glucocorticoids （GCs） cell-specific gene expression signatures, it remains necessary to comprehensively characterize the impact of lncRNAs to transcriptional changes. Methods： BMECs were divided into two groups. One was treated with GCs and the other left untreated as a paired control. Differential expression was analyzed with GeneSpring software V12.0 （Agilent, Santa Clara, CA, USA） and hierarchical clustering was conducted using Cluster 3,0 software. The Gene Ontology （GO） analysis was performed with Molecular Annotation System provided by CapitalBio Corporation. Results： Our results highlight the involvement of genes implicated in development, differentiation and apoptosis following GC stimulation. Elucidation of differential gene expression emphasizes the importance of regulatory gene networks induced by GCs. We identified 73 up-regulated and 166 down-regulated long noncoding RNAs, the expression of 107 of which significantly correlated with 172 mRNAs induced by hydrocortisone. Conclusions： Transcriptome analysis of BMECs from human samples was performed to identify specific gene networks induced by GCs. Our results identified complex RNA crosstalk underlying the pathogenesis of steroid-induced necrosis of femoral head.展开更多
Primary canalicular bile undergoes a process of fluidization and alkalinization along the biliary tract that is influenced by several factors including hormones, innervation/neuropeptides, and biliary constituents. Th...Primary canalicular bile undergoes a process of fluidization and alkalinization along the biliary tract that is influenced by several factors including hormones, innervation/neuropeptides, and biliary constituents. The excretion of bicarbonate at both the canaliculi and the bile ducts is an important contributor to the generation of the so-called bile-salt independent flow. Bicarbonate is secreted from hepatocytes and cholangiocytes through parallel mechanisms which involve chloride efflux through activation of Cl- channels, and further bicarbonate secretion via AE2/SLC4A2-mediated Cl-/HCO3- exchange. Glucagon and secretin are two relevant hormones which seem to act very similarly in their target cells （hepatocytes for the former and cholangiocytes for the latter）. These hormones interact with their specific G protein-coupled receptors, causing increases in intracellular levels of cAMP and activation of cAMP-dependent Cl- and HCO3- secretory mechanisms. Both hepatocytes and cholangiocytes appear to have cAMP-responsive intracellular vesicles in which AE2/SLC4A2 colocalizes with cell specific Cl- channels （CFTR in cholangiocytes and not yet determined in hepatocytes） and aquaporins （AQP8 in hepatocytes and AQP1 in cholangiocytes）, cAMP-induced coordinated trafficking of these vesicles to either canalicular or cholangiocyte lumenal membranes and further exocytosis results in increased osmotic forces and passive movement of water with net bicarbonate-rich hydrocholeresis.展开更多
ErbB2, a member of the receptor tyrosine kinase family, is frequently over-expressed in breast cancer. Proteolysis ofthe extracellular domain of ErbB2 results in constitutive activation of ErbB2 kinase. Recent study r...ErbB2, a member of the receptor tyrosine kinase family, is frequently over-expressed in breast cancer. Proteolysis ofthe extracellular domain of ErbB2 results in constitutive activation of ErbB2 kinase. Recent study reported that ErbB2is found in the nucleus. Here, we showed that ErbB2 is imported into the nucleus through a nuclear localization signal(NLS)-mediated mechanism. The NLS sequence KRRQQKIRKYTMRR (aa655-668) contains three clusters of basicamino acids and it is sufficient to target GFP into the nucleus. However, mutation in any basic amino acid cluster of thisNLS sequence significantly affects its nuclear localization. Furthermore, it was found that this NLS is essential for thenuclear localization of ErbB2 since the intracellular domain of Erb2 lacking NLS completely abrogates its nucleartranslocation. Taken together, our study identified a novel nuclear localization signal and reveals a novel mechanismunderlying ErbB2 nuclear trafficking and localization.展开更多
BACKGROUND:Edaravone(3-methyl-1-penyl-2-pyrazolin-5-one) is a potent free-radical scavenger and has the antioxidant ability to inhibit lipid peroxidation.The study aimed to examine the effect of edaravone on protectin...BACKGROUND:Edaravone(3-methyl-1-penyl-2-pyrazolin-5-one) is a potent free-radical scavenger and has the antioxidant ability to inhibit lipid peroxidation.The study aimed to examine the effect of edaravone on protecting the acute injury of human type II alveolar epithelial cells(A549cells) induced by paraquat(PQ) and the change of production of reactive oxygen species(ROS),malondialdehyde(MDA),superoxide dismutase(SOD).METHODS:A549 cells were cultured and divided into PQ group(group P),edaravone-treated group(group E) and normal control group(group C).The cells in group P were exposed to paraquat(600 umol/L),and the cells in group E were treated with edaravone(100 umol/L) additionally,and no drug intervention was given to the cells in group C.Real-time monitoring by LSCM was used to detect the cell response and the intracellular dynamic change of ROS level in A549 cells after administration of PQ and edaravone.And the levels of SOD and MDA were detected respectively by biochemistry colorimetry.Data were expressed as mean ± standard error of the mean.Statistical analysis was carried out with the soft SPSS 16.0.RESULTS:The concentration of intracellular ROS significantly increased when PQ was given to A549 cells.But after administration of edaravone,the concentration of intracellular ROS was decreased.Compared to the PQ group,the levels of SOD in the edaravone group were significantly increased while the levels of MDA were markedly decreased.CONCLUSIONS:Paraquat can increase the oxidative stress,and induce the lipid peroxidation of A549 cells.Edaravone has the effect to scavenge reactive oxygen species,and to protect against the PQ-induced lung toxicity.展开更多
AIM:To investigate the effect of chloride intracellular channel 1(CLIC1) on the cell proliferation,apoptosis,migration and invasion of gastric cancer cells.METHODS:CLIC1 expression was evaluated in human gastric cance...AIM:To investigate the effect of chloride intracellular channel 1(CLIC1) on the cell proliferation,apoptosis,migration and invasion of gastric cancer cells.METHODS:CLIC1 expression was evaluated in human gastric cancer cell lines SGC-7901 and MGC-803 by real time polymerase chain reaction(RT-PCR).Four segments of small interference RNA(siRNA) targeting CLIC1 mRNA and a no-sense control segment were designed by bioinformatics technology.CLIC1 siRNA was selected using Lipofectamine 2000 and transfected transiently into human gastric cancer SGC-7901 and MGC-803 cells.The transfected efficiency was observed under fluorescence microscope.After transfection,mRNA expression of CLIC1 was detected with RT-PCR and Western blotting was used to detect the protein expression.Proliferation was examined by methyl thiazolyl tetrazolium and apoptosis was detected with flow cytometry.Polycarbonate membrane transwell chamber and Matrigel were used for the detection of the changes of invasion and migration of the two cell lines.RESULTS:In gastric cancer cell lines SGC-7901 and MGC-803,CLIC1 was obviously expressed and CLIC1 siRNA could effectively suppress the expression of CLIC1 protein and mRNA.Proliferation of cells transfected with CLIC1 siRNA3 was enhanced notably,and the highest proliferation rate was 23.3%(P = 0.002) in SGC-7901 and 35.55%(P = 0.001) in MGC-803 cells at 48 h.The G2/M phase proportion increased,while G0/G1 and S phase proportions decreased.The apoptotic rate of the CLIC1 siRNA3 group obviously decreased in both SGC-7901 cells(62.24%,P = 0.000) and MGC-803 cells(52.67%,P = 0.004).Down-regulation of CLIC1 led to the inhibition of invasion and migration by 54.31%(P = 0.000) and 33.62%(P = 0.001) in SGC-7901 and 40.74%(P = 0.000) and 29.26%(P = 0.002) in MGC-803.However,there was no significant difference between the mock group cells and the negative control group cells.展开更多
文摘Macroautophagy is a multistep, vacuolar, degradation pathway terminating in the lysosomal compartment, and it is of fundamental importance in tissue homeostasis. In this review, we consider macroautophagy in the light of recent advances in our understanding of the formation of autophagosomes, which are double-membrane-bound vacuoles that sequester cytoplasmic cargos and deliver them to lysosomes. In most cases, this final step is preceded by a maturation step during which autophagosomes interact with the endocytic pathway. The discovery of AuTophaGyrelated genes has greatly increased our knowledge about the mechanism responsible for antophagosome formation, and there has also been progress in the understanding of molecular aspects of autophagosome maturation. Finally, the regulation of autophagy is now better understood because of the discovery that the activity of Atg complexes is targeted by protein kinases, and owing to the importance of nuclear regulation via transcription factors in regulating the expression of autophagy genes.
文摘Background： Acute coronary syndrome （ACS） is closely related to unstable plaques and secondary thrombosis. The inflammatory cells in plaques and their inflammatory products may be the cause for plaque instability and ruptures. The study aimed to disclose the changes of inflammatory factors including serum intracellular adhesion molecule-1（ICAM-1 ）, chitinase-3-like protein I （YKL-40）, and lipoprotein-associated phospholipase A2 （Lp-PLA2） in patients with ACS and its clinical significance. Methods： A total of 120 patients with coronary heart disease （CHD） were categorized into 2 groups： 69 with ACS and 51 with stable angina pectoris （SAP）： 20 patients with chest pain and normal angiography served as a control group. The 120 patients with CHD were categorized into single-vessel disease group, double-vessel disease group, and three-vessel disease group based on the number of coronary artery stenosis. The severity of coronary artery stenosis was quantified based on coronary angiography using Gensini score. They were further divided into mild CHD group with its Gensini score 〈26 （n = 36）, moderate CHD group with its Gensini score being 26-54 （n = 48） and severe CHD group with its Gensini score 〉54 （n = 36）. Serum levels of ICAM-1, YKL-40, and Lp-PLA2 of different groups were determined by enzyme-linked immunosorbent assay. Correlation between ICAM-1, YKL-40, Lp-PLA2, and Gensini score was analyzed. Results： The levels of serum inflammatory factors ICAM-1, YKL-40, and Lp-PLA2 were significantly higher in the ACS group than those in control group and SAP group （all P 〈 0.05）： and compared with control group, no significant difference was observed in terms of the serum ICAM-1, YKL-40, and Lp-PLA2 levels in the SAP group （P 〉 0.05）.The levels of serum ICAM-1, YKL-40, and Lp-PLA2 were not significantly different among control group, single-vessel disease group, double-vessel disease group, and three-vessel disease group （all P 〉 0.05）. The levels of seru
基金Supported by National Basic Research Program of China(973 program,No.2015CB554404)
文摘Objective： To investigate the relationship between inflammatory factors and two Chinese medicine（CM） syndrome types of qi stagnation and blood stasis（QSBS） and qi deficiency and blood stasis（QDBS） in patients with acute coronary syndrome（ACS）. Methods： Sixty subjects with ACS, whose pathogenesis changes belongs to qi disturbance blood stasis syndrome, were divided into 2 groups： 30 in the QSBS group and 30 in the QDBS group. The comparative analysis on them was carried out through comparing general information, coronary angiography and inflammatory factors including intracellular adhesion molecule-1（ICAM-1）, chitinase-3-like protein 1（YKL-40） and lipoprotein-associated phospholipase A2（Lp-PLA2）. Results： Compared with the QSBS group, Lp-PLA2 and YKL-40 levels in the QDBS group showed no-significant difference（P〉0.05）; ICAM-1 was significantly higher in the QDBS group than in the QSBS group in the pathological processes of qi disturbance and blood stasis syndrome of ACS（P〈0.05）. Conclusion： Inflammatory factor ICAM-1 may be an objective basis for syndrome typing of QSBS and QDBS, which provides a research direction for standardization research of CM syndrome types.
基金Project supported by Research and Development Funds of Second Affiliated Hospital, School of Medicine, Zhejiang University, China
文摘Object: The authors studied the influence of CO2 pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation. Method: They set up a simulation of pneumoperitoneum under different CO2 pressure, and then measured the variation of intracellular pH (pHi) at different time and the activity of protein kinase C (PKC) and protein phosphatase 2a (PP2a) at the end of the pneumoperitoneum. After 1 week, the concentration of cancer cells in the culture medium was calculated. Result: When the pressure of CO2 pneumoperitoneum was 0, 10, 20, 30 mmHg respectively, the average pHi was 7.273, 7.075, 6.783, 6.693 at the end of the pneumoperitoneum; PKC activity was 159.4, 168.5,178.0, 181.6 nmol/(g.min) and PP2a was 4158.3, 4066.9, 3984.0, 3878.5 nmol/(g.min) respectively. After 1 week, the cancer cells concentration was 2.15×105, 2.03×105, 2.20×105, 2.18×105 L-1. Conclusion: CO2 pneumoperitoneum could promote acidosis in cancer cells, inducing the activation of protein kinase C and deactivation of protein phosphatase 2a, but it could not accelerate the mitosis rate of the cancer cells.
基金supported by the National Natural Science Foundation of China,No.30960399,and No.81160181
文摘In this study, we established a Wistar rat model of right middle cerebral artery occlusion and observed pathological imaging changes （T2-weighted imaging [T2WI], T2FLAIR, and diffusion-weighted imaging [DWI]） following cerebral infarction. The pathological changes were divided into three phases： early cerebral infarction, middle cerebral infarction, and late cerebral infarction. In the early cerebral infarction phase （less than 2 hours post-infarction）, there was evidence of intracellular edema, which improved after reperfusion. This improvement was defined as the ischemic penumbra. In this phase, a high DWI signal and a low apparent diffusion coefficient were observed in the right basal ganglia region. By contrast, there were no abnormal T2WI and T2FLAIR signals. For the middle cerebral infarction phase （2-4 hours post-infarction）, a mixed edema was observed. After reperfusion, there was a mild improvement in cell edema, while the angioedema became more serious. A high DWI signal and a low apparent diffusion coefficient signal were observed, and some rats showed high T2WI and T2FLAIR signals. For the late cerebral infarction phase （4-6 hours post-infarction）, significant angioedema was visible in the infarction site. After reperfusion, there was a significant increase in angioedema, while there was evidence of hemorrhage and necrosis. A mixed signal was observed on DWI, while a high apparent diffusion coefficient signal, a high T2WI signal, and a high T2FLAIR signal were also observed. All 86 cerebral infarction patients were subjected to T2WI, T2FLAIR, and DWI. MRI results of clinic data similar to the early infarction phase of animal experiments were found in 51 patients, for which 10 patients （10/51） had an onset time greater than 6 hours. A total of 35 patients had MRI results similar to the middle and late infarction phase of animal experiments, of which eight patients （8/35） had an onset time less than 6 hours. These data suggest that defining the ＂therapeutic time window＂ as
基金supported by grants from Ministry of Science and Technology of China (Grant Nos.2008ZX09401-05 and 2010ZX09401-403)the National Natural Science Foundation of China (Grant No. 31100074)Chinese Academy of Sciences (Grant No. XBXA-2011-009)
文摘L-Serine plays a critical role as a building block for cell growth, and thus it is difficult to achieve the direct fermentation of L-serine from glucose. In this study, Corynebacterium glutamicum ATCC 13032 was engineered de novo by blocking and at- tenuating the conversion of L-serine to pyruvate and glycine, releasing the feedback inhibition by L-serine to 3-phosphoglycerate dehydrogenase （PGDH）, in combination with the co-expression of 3-phosphoglycerate kinase （PGK） and feedback-resistant PGDH （PGDHr）. The resulting strain, SER-8, exhibited a lower specific growth rate and significant differ- ences in L-serine levels from Phase I to Phase V as determined for fed-batch fermentation. The intracellular L-serine pool reached （14.22_＋1.41） ~trnol gcoM-1, which was higher than glycine pool, contrary to fermentation with the wild-type strain. Furthermore, metabolic flux analysis demonstrated that the over-expression of PGK directed the flux of the pentose phosphate pathway （PPP） towards the glycolysis pathway （EMP）, and the expression of PGDHr improved the L-serine biosynthesis pathway. In addition, the flux from L-serine to glycine dropped by 24%, indicating that the deletion of the activator GlyR re- sulted in down-regulation of serine hydroxymethyltransferase （SHMT） expression. Taken together, our findings imply that L-serine pool management is fundamental for sustaining the viability of C. glutamicum, and improvement of C1 units genera- tion by introducing the glycine cleavage system （GCV） to degrade the excessive glycine is a promising target for L-serine pro- duction in C. glutamicum.
基金support by the National Science Foundation of China(Grants No.31620103917,31330072,and 31572325 to SL,31702053 to KL)the National Science Foundation of Guangdong Province(Grants No.2017A030310270)to KLthe Postdoctoral Foundation of China(Grant No.2017M610534 to KL and 2018M633068 to QJ).
文摘Since it was first postulated by Wigglesworth in 1934, juvenile hormone (JH) is considered a status quo hormone in insects because it prevents metamorphosis that is initiated by the molting hormone 20-hydroxyecdysone (20E). During the last decade, significant advances have been made regarding JH signaling. First, the bHLH-PAS transcription factor Met/Gce was identified as the JH intracellular receptor. In the presence of JH, with the assistance of Hsp83, and through physical association with a bHLH?PAS transcriptional co-activator, Met/Gce enters the nucleus and binds to E-box-like motifs in promoter regions of JH primary?response genes for inducing gene expression. Second, the zinc finger transcription factor Kr-hl was identified as the anti-metamorphic factor which transduces JH signaling. Via Kr-hl binding sites, Kr-hl represses expression of 20E primary?response genes (i.e. Bi\ E93 and E5) to prevent 20E-induced metamorphosis. Third, through the intracellular signaling, JH promotes differ ent aspects of female reproduction. Nevertheless, this action varies greatly from species to species. Last, a hypothetical JH membrane receptor has been predicted to be either a GPCR or a tyrosine kinase receptor. In future, it will be a great challenge to understand how the JH intracellular receptor Met/Gce and the yet unidentified JH membrane receptor coordinate to regulate metamorphosis and reproduction in insects.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2013R1A1A1004831)research funds of Chonbuk National University in 2012
文摘Transcription factors constitute numerous signal transduction networks and play a central role in gene expression regulation. Recent studies have shown that a limited portion of transcription factors are anchored in the cellular membrane, storing as dormant forms. Upon exposure to environmental and developmental cues, these transcription factors are released from the membrane and translocated to the nucleus, where they regulate associated target genes. As this process skips both transcriptional and translational regulations, it guarantees prompt response to external and internal signals. Membrane- bound transcription factors （MTFs） undergo several unique steps that are not involved in the action of canonical nuclear transcription factors： proteolytic processing and intracellular movement. Recently, alternative splicing has also emerged as a mechanism to liberate MTFs from the cellular membranes, establishing an additional activation scheme independent of proteolytic processing. Multiple layers of MTF regulation add complexity to transcriptional regulatory scheme and ensure elaborate action of MTFs. In this review, we provide an overview of recent findings on MTFs in plants and highlight the molecular mechanisms underlying MTF liberation from cellular membranes with an emphasis on intracellular movement.
文摘Objective:To study the effects of 18β-glycyrrhetinic acid (GA) on proliferation inhibition, apop totic induction, and the relationship between GA-induced apoptosis and intracellular Ca2+ concentration in human breast carcinoma (MCF-7) cells. Methods: After MCF-7 cells were treated with GA at the concentrations from 50 μmol/L to 250 μmol/L for 24 h, cell viability of proliferation was assessed by MTT assay. After the cells were treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L GA for 24 h, the rates of cell apoptosis were examined by terminal deoxynucleotide transferase mediated dUTP nick-end-labeling method and flow cytometry with Annexin V/propidium iodide fluorescent stain. After the cells treated with 150 μmol/L GA for 24 h, intracellular Ca2+ concentration was measured by Fure-2 fluorescein load method. Results: After the cells were treated with GA at the concentrations from 100 μmol/L to 250 μmol/L, the rates of proliferative inhibition were increased significantly (P<0.05 and P<0.01) in a dose dependent fashion. IC50 of the proliferation inhibition was 234.33 μmol/L. Treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L, the rates of cell apoptosis were increased significantly (P<0.01). Intracellular Ca2+ concentration after treatment with GA was higher evidently than that of control (P<0.05). Conclusion: 18β-glycyrrhetinic acid has the effects of the proliferation inhibition and the apoptotic induction on MCF-7 cells. The rise of intracellular Ca2+ level may be depended on apoptosis induced by GA in MCF-7 cells.
基金Supported by The Belgian National Fund for Medical Research, the Région Wallonne-DGTRE(Grant WALEO/HEPATERA) and "La Fondation St Luc-ARC Thérapie Cellulaire"Stéphenne Xis recipient of a Grant-FNRS for cell cryopreservation
文摘Liver cell transplantation presents clinical benefit in patients with inborn errors of metabolism as an alternative,or at least as a bridge,to orthotopic liver transplantation.The success of such a therapeutic approach remains limited by the quality of the transplanted cells.Cryopreservation remains the best option for long-term storage of hepatocytes,providing a permanent and sufficient cell supply.However, isolated adult hepatocytes are poorly resistant to such a process,with a significant alteration both at the morphological and functional levels.Hence,the aim of the current review is to discuss the state of the art regarding widely-used hepatocyte cryopreservation protocols,as well as the assays performed to analyse the post-thawing cell quality both in vitro and in vivo. The majority of studies agree upon the poor quality and efficiency of cryopreserved/thawed hepatocytes as compared to freshly isolated hepatocytes.Intracellular ice formation or exposure to hyperosmotic solutionsremains the main phenomenon of cryopreservation process,and its effects on cell quality and cell death induction will be discussed.The increased knowledge and understanding of the cryopreservation process will lead to research strategies to improve the viability and the quality of the cell suspensions after thawing.Such strategies,such as vitrification,will be discussed with respect to their potential to significantly improve the quality of cell suspensions dedicated to liver cell-based therapies.
基金This work was financially supported from the National Nature Science Foundation of China(NO.81360483)from the Nature Science Foundation of Ningxia(No.NZ12193).
文摘Most of the conventional chemotherapeutic agents used for cancer chemotherapy suffer from multidrug resistance of tumor cells and poor antitumor efficacy.Based on physiological differences between the normal tissue and the tumor tissue,one effective approach to improve the efficacy of cancer chemotherapy is to develop pH-sensitive polymeric micellar delivery systems.The copolymers with reversible protonationedeprotonation core units or acid-liable bonds between the therapeutic agents and the micelle-forming copolymers can be used to form pH-sensitive polymeric micelles for extracellular and intracellular drug smart release.These systems can be triggered to release drug in response to the slightly acidic extracellular fluids of tumor tissue after accumulation in tumor tissues via the enhanced permeability and retention effect,or they can be triggered to release drug in endosomes or lysosomes by pH-controlled micelle hydrolysis or dissociation after uptake by cells via the endocytic pathway.The pH-sensitive micelles have been proved the specific tumor cell targeting,enhanced cellular internalization,rapid drug release,and multidrug resistance reversal.The multifunctional polymeric micelles combining extracellular pH-sensitivity with receptor-mediated active targeting strategies are of great interest for enhanced tumor targeting.The micelles with receptor-mediated and intracellular pH targeting functions are internalized via receptor-mediated endocytosis followed by endosomal-pH triggered drug release inside the cells,which reverses multidrug resistance.The pH sensitivity strategy of the polymeric micelles facilitates the specific drug delivery with reduced systemic side effects and improved chemotherapeutical efficacy,and is a novel promising platform for tumor-targeting drug delivery.
文摘Background Methylprednisolone (MP), a synthetic glucocorticosteroid, has been broadly studied in experiments on endotoxin-induced shock and septic shock. This study was designed to ascertain whether glycine and MP can protect against organ injury and death caused by hemorrhagic shock, and to elucidate the underlying mechanisms of these protective effects in rats.Method To establish a shock model, Wistar rats were bled to maintain mean arterial pressure at 30-50 mmHg for 1 hour and subsequently resuscitated with the shed blood and normal saline. Just prior to resuscitation, the rats were randomly assigned to four groups: sham group (operation performed without inducing shock), shock group, shock+glycine group (glycine injected at the beginning of resuscitation) and shock+MP group (MP injected at the beginning of resuscitation).Results ① Seventy-two hours after resuscitation, the survival rate of rats from the shock group had decreased to 20%, while the survival rates of rats from the shock+glycine and shock+MP groups were 77.8% and 80%, respectively. The difference was significant (P<0.05). ② Eighteen hours after resuscitation, pathological alterations in the organs of the rats were apparent. In rats from the shock group, edema, interstitial leukocyte infiltration, and cellular degeneration occurred in the liver, lungs, kidneys, and heart. Glycine and MP reduced these pathological changes significantly. ③ Eighteen hours after resuscitation, the levels of creatine phosphokinase, transaminases, and creatine were elevated significantly in rats from the shock group, indicating injury to the heart, liver, and kidneys, while these levels were elevated only slightly in the shock+glycine and shock+MP groups. The differences were significant (P<0.01). ④ There were significant increases in intracellular calcium and production of tumor necrosis factor (TNF-α) by isolated Kupffer cells stimulated by endotoxin after hemorrhagic shock. These changes were completely prevented by glycine and MP (P<0.01). Conclusion G
基金Thisworkwassupportedbythegrant (No 95 4812 5 0 0 )fromtheBeijingSciences&TechnologicalCommittee
文摘Background The contractility of hepatic stellate cells (HSCs) may play an important role in the pathogenesis of cirrhosis with portal hypertension. The aim of this study was to research the effects of octreotide,an analogue of somatostatin,on intracellular Ca 2+ and on the expression of L-type voltage-operated calcium channels (L-VOCCs) in activated HSCs,and to try to survey the use of octreotide in treatment and prevention of cirrhosis with portal hypertension complications. Methods HSC-T_6,an activated HSCs line,was plated on small glass coverslips in 35-mm culture dishes at a density of 1×10 5/ml,and incubated in DMEM media for 24 hours. After the cells were loaded with Fluo-3/AM,intracellular Ca 2+ was measured by Laser Scanning Confocal Microscopy (LSCM). The dynamic changes in activated HSCs of intracellular Ca 2+ ,stimulated by octreotide,endothelin-1,and KCl, respectively,were also determined by LSCM. Each experiment was repeated six times. L-VOCC expression in HSCs was estimated by immunocytochemistry. Results After octreotide stimulation,a signifcant decrease in the intracellular Ca 2+ of activated HSCs was observed. However,octreotide did not inhibit the increases in intracellular Ca 2+ after stimulation by KCl and endothelin-1. Moreover,octreotide did not significantly affect L-VOCC expression. These results suggest that neither L-VOCC nor endothelin-1 receptors in activated HSCs are inhibited by octreotide. Conclusions Octreotide may decrease portal hypertension and intrahepatic vascular tension by inhibiting activated HSCs contractility through decreases in intracellular Ca 2+ . The somatostatin receptors in activated HSCs may be inhibited by octreotide.
基金Source of Support： This work was funded by a grant from National Natural Science Foundation of China （No. 81273972）. Conflict of Interest： None declared.
文摘Background： Appropriate expression and regulation of the transcriptome, which mainly comprise ofmRNAs and lncRNAs, are important for all biological and cellular processes including the physiological activities of bone microvascular endothelial cells （BMECs）. Through an intricate intraeellular signaling systems, the transcriptome regulates the pharmacological response of the cells. Although studies have elucidated the impact of glucocorticoids （GCs） cell-specific gene expression signatures, it remains necessary to comprehensively characterize the impact of lncRNAs to transcriptional changes. Methods： BMECs were divided into two groups. One was treated with GCs and the other left untreated as a paired control. Differential expression was analyzed with GeneSpring software V12.0 （Agilent, Santa Clara, CA, USA） and hierarchical clustering was conducted using Cluster 3,0 software. The Gene Ontology （GO） analysis was performed with Molecular Annotation System provided by CapitalBio Corporation. Results： Our results highlight the involvement of genes implicated in development, differentiation and apoptosis following GC stimulation. Elucidation of differential gene expression emphasizes the importance of regulatory gene networks induced by GCs. We identified 73 up-regulated and 166 down-regulated long noncoding RNAs, the expression of 107 of which significantly correlated with 172 mRNAs induced by hydrocortisone. Conclusions： Transcriptome analysis of BMECs from human samples was performed to identify specific gene networks induced by GCs. Our results identified complex RNA crosstalk underlying the pathogenesis of steroid-induced necrosis of femoral head.
基金the "UTE for CIMA project" as well as by a grant from the "Institute de Salud CarlosⅢ" (PI051098). J. M. B. has a grant from the Spanish Ministry of Science and Technology
文摘Primary canalicular bile undergoes a process of fluidization and alkalinization along the biliary tract that is influenced by several factors including hormones, innervation/neuropeptides, and biliary constituents. The excretion of bicarbonate at both the canaliculi and the bile ducts is an important contributor to the generation of the so-called bile-salt independent flow. Bicarbonate is secreted from hepatocytes and cholangiocytes through parallel mechanisms which involve chloride efflux through activation of Cl- channels, and further bicarbonate secretion via AE2/SLC4A2-mediated Cl-/HCO3- exchange. Glucagon and secretin are two relevant hormones which seem to act very similarly in their target cells （hepatocytes for the former and cholangiocytes for the latter）. These hormones interact with their specific G protein-coupled receptors, causing increases in intracellular levels of cAMP and activation of cAMP-dependent Cl- and HCO3- secretory mechanisms. Both hepatocytes and cholangiocytes appear to have cAMP-responsive intracellular vesicles in which AE2/SLC4A2 colocalizes with cell specific Cl- channels （CFTR in cholangiocytes and not yet determined in hepatocytes） and aquaporins （AQP8 in hepatocytes and AQP1 in cholangiocytes）, cAMP-induced coordinated trafficking of these vesicles to either canalicular or cholangiocyte lumenal membranes and further exocytosis results in increased osmotic forces and passive movement of water with net bicarbonate-rich hydrocholeresis.
基金This work was supported by Hi-Tech Research and Development Program of China(2004AA215260).
文摘ErbB2, a member of the receptor tyrosine kinase family, is frequently over-expressed in breast cancer. Proteolysis ofthe extracellular domain of ErbB2 results in constitutive activation of ErbB2 kinase. Recent study reported that ErbB2is found in the nucleus. Here, we showed that ErbB2 is imported into the nucleus through a nuclear localization signal(NLS)-mediated mechanism. The NLS sequence KRRQQKIRKYTMRR (aa655-668) contains three clusters of basicamino acids and it is sufficient to target GFP into the nucleus. However, mutation in any basic amino acid cluster of thisNLS sequence significantly affects its nuclear localization. Furthermore, it was found that this NLS is essential for thenuclear localization of ErbB2 since the intracellular domain of Erb2 lacking NLS completely abrogates its nucleartranslocation. Taken together, our study identified a novel nuclear localization signal and reveals a novel mechanismunderlying ErbB2 nuclear trafficking and localization.
基金supported by a grant form the Natural Science Foundation of China(Grant No.C030105)
文摘BACKGROUND:Edaravone(3-methyl-1-penyl-2-pyrazolin-5-one) is a potent free-radical scavenger and has the antioxidant ability to inhibit lipid peroxidation.The study aimed to examine the effect of edaravone on protecting the acute injury of human type II alveolar epithelial cells(A549cells) induced by paraquat(PQ) and the change of production of reactive oxygen species(ROS),malondialdehyde(MDA),superoxide dismutase(SOD).METHODS:A549 cells were cultured and divided into PQ group(group P),edaravone-treated group(group E) and normal control group(group C).The cells in group P were exposed to paraquat(600 umol/L),and the cells in group E were treated with edaravone(100 umol/L) additionally,and no drug intervention was given to the cells in group C.Real-time monitoring by LSCM was used to detect the cell response and the intracellular dynamic change of ROS level in A549 cells after administration of PQ and edaravone.And the levels of SOD and MDA were detected respectively by biochemistry colorimetry.Data were expressed as mean ± standard error of the mean.Statistical analysis was carried out with the soft SPSS 16.0.RESULTS:The concentration of intracellular ROS significantly increased when PQ was given to A549 cells.But after administration of edaravone,the concentration of intracellular ROS was decreased.Compared to the PQ group,the levels of SOD in the edaravone group were significantly increased while the levels of MDA were markedly decreased.CONCLUSIONS:Paraquat can increase the oxidative stress,and induce the lipid peroxidation of A549 cells.Edaravone has the effect to scavenge reactive oxygen species,and to protect against the PQ-induced lung toxicity.
基金Supported by The National Natural Science Foundation of China,No.30560151the Key Research Project of Guangxi Municipal Health Bureau,No.200824+1 种基金the Research Project of Guangxi Educational Department,No.201012MS062 and No. 2011105981002M204the Natural Science Foundation of Guangxi,No.0832113
文摘AIM:To investigate the effect of chloride intracellular channel 1(CLIC1) on the cell proliferation,apoptosis,migration and invasion of gastric cancer cells.METHODS:CLIC1 expression was evaluated in human gastric cancer cell lines SGC-7901 and MGC-803 by real time polymerase chain reaction(RT-PCR).Four segments of small interference RNA(siRNA) targeting CLIC1 mRNA and a no-sense control segment were designed by bioinformatics technology.CLIC1 siRNA was selected using Lipofectamine 2000 and transfected transiently into human gastric cancer SGC-7901 and MGC-803 cells.The transfected efficiency was observed under fluorescence microscope.After transfection,mRNA expression of CLIC1 was detected with RT-PCR and Western blotting was used to detect the protein expression.Proliferation was examined by methyl thiazolyl tetrazolium and apoptosis was detected with flow cytometry.Polycarbonate membrane transwell chamber and Matrigel were used for the detection of the changes of invasion and migration of the two cell lines.RESULTS:In gastric cancer cell lines SGC-7901 and MGC-803,CLIC1 was obviously expressed and CLIC1 siRNA could effectively suppress the expression of CLIC1 protein and mRNA.Proliferation of cells transfected with CLIC1 siRNA3 was enhanced notably,and the highest proliferation rate was 23.3%(P = 0.002) in SGC-7901 and 35.55%(P = 0.001) in MGC-803 cells at 48 h.The G2/M phase proportion increased,while G0/G1 and S phase proportions decreased.The apoptotic rate of the CLIC1 siRNA3 group obviously decreased in both SGC-7901 cells(62.24%,P = 0.000) and MGC-803 cells(52.67%,P = 0.004).Down-regulation of CLIC1 led to the inhibition of invasion and migration by 54.31%(P = 0.000) and 33.62%(P = 0.001) in SGC-7901 and 40.74%(P = 0.000) and 29.26%(P = 0.002) in MGC-803.However,there was no significant difference between the mock group cells and the negative control group cells.
