Olfactory ensheathing cell (OEC) transplantation has emerged as a very promising therapy for spinal cord repair. In this study, we tested the ability of genetically modified OECs to secrete high levels of glial cell l...Olfactory ensheathing cell (OEC) transplantation has emerged as a very promising therapy for spinal cord repair. In this study, we tested the ability of genetically modified OECs to secrete high levels of glial cell line-derived neu-rotrophic factor (GDNF) to promote spinal cord repair. The GDNF gene was transduced into OECs using展开更多
AIM: Recent reports have shown the capacity of mesenchymal stem cells (MSCs) to differentiate into hepatocytes in vitro and in vivo. MSCs administration could repair injured liver, lung, or heart through reducing infl...AIM: Recent reports have shown the capacity of mesenchymal stem cells (MSCs) to differentiate into hepatocytes in vitro and in vivo. MSCs administration could repair injured liver, lung, or heart through reducing inflammation, collagen deposition, and remodeling. These results provide a clue to treatment of liver fibrosis. The aim of this study was to investigate the effect of infusion of bone marrow (BM)-derived MSCs on the experimental liver fibrosis in rats. METHODS: MSCs isolated from BM in male Fischer 344 rats were infused to female Wistar rats induced with carbon tetrachloride (CCI4) or dimethylnitrosamine (DMN). There were two random groups on the 42nd d of CCI4: CCl4/MSCs, to infuse a dose of MSCs alone; CCI4/saline, to infuse the same volume of saline as control. There were another three random groups after exposure to DMN: DMN10/MSCs, to infuse the same dose of MSCs on d 10; DMN10/saline, to infuse the same volume of saline on d 10; DMN20/MSCs, to infuse the same dose of MSCs on d 20. The morphological and behavioral changes of rats were monitored everyday. After 4-6 wk of MSCs administration, all rats were killed and fibrosis index were assessed by histopathology and radioimmunoassay. Smooth muscle alpha-actin (alpha-SMA) of liver were tested by immunohistochemistry and quantified by IBAS 2.5 software. Male rats sex determination region on the Y chromosome (sry) gene were explored by PCR. RESULTS: Compared to controls, infusion of MSCs reduced the mortality rates of incidence in CCl4-induced model (10% vs 20%) and in DMN-induced model (20-40% vs 90%).The amount of collagen deposition and alpha-SMA staining was about 40-50% lower in liver of rats with MSCs than that of rats without MSCs. The similar results were observed in fibrosis index. And the effect of the inhibition of fibrogenesis was greater in DMN10/MSCs than in DMN20/MSCs. The sry gene was positive in the liver of rats with MSCs treatment by PCR. CONCLUSION: MSCs treatment can protect against experimental liver fibrosis in CCMnduced or DMN-induced rats and the mechanisms of the anti-fibrosis by MSCs will be studied further.展开更多
AIM: To study the change of intracellular calcium-magnesium ATPase (Ca^2+-Mg^2+-ATPase) activity in pancreas, liver and kidney tissues of rats with acute pancreatitis (AP), and to investigate the effects of Qingyitang...AIM: To study the change of intracellular calcium-magnesium ATPase (Ca^2+-Mg^2+-ATPase) activity in pancreas, liver and kidney tissues of rats with acute pancreatitis (AP), and to investigate the effects of Qingyitang (QYT) (Decoction for clearing the pancreas) and tetrandrine (Tet) and vitamin E(VitE) on the activity of Ca^2+-Mg^2+-ATPase. METHODS: One hundred and five Sprague-Dawley rats were randomly divided into: normal control group, AP group,treatment group with QYT (1 ml/100 g) or Tet (0.4 ml/100 g) or VitE (100 mg/kg). AP model was prepared by a retrograde injection of sodium taurocholate into the pancreatic duct. Tissues of pancreas, liver and kidney of the animals were taken at 1 h, 5 h, 10 h respectively afer AP induction, and the activity of Ca^2+-Mg^2+-ATPase was studied using enzymehistochemistry staining. Meanwhile, the expression of Ca^2^+-Mg^2+-ATPase of the tissues was studied by RT-PCR. RESULTS: The results showed that the positive rate of Ca^2+-Mg^2+-ATPase in AP group (8.3%, 25%, 29.2%) was lower than that in normal control group (100%) in all tissues(P<0.01), the positive rate of Ca^2+-Mg^2+-ATPase in treatment group with QYT (58.3%, 83.3%, 83.3%), Tet (50.0%,70.8%, 75.0%) and VitE (54.2%, 75.0%, 79.2%) was higher than that in AP group (8.3%, 25.0%, 29.2%) in all tissues(P<0.01). RT-PCR results demonstrated that in treatment groups Ca^2+-Mg^2+-ATPase gene expression in pancreas tissue was higher than that in AP group at the observing time points, and the expression at 5 h was higher than that at 1 h. The expression of Ca^2+-Mg^2+-ATPase in liver tissue was positive, but without significant difference between different groups. CONCLUSION: The activity and expression of intracellular Ca^2+-Mg^2+-ATPase decreased in rats with AP, suggesting that Ca^2+-Mg^2+-ATPase may contribute to the occurrence and development of cellular calcium overload in AP. QYT, Tet and VitE can increase the activity and expression of Ca^2+-Mg^2+-ATPase and may relieve intracellular calcium overload to protect the tissue and cells from injuries.展开更多
AIM: Available experimental evidence from both clinical andanimal models shows that both Chinese medicines tetrandine(Tet) and Qing Yi Tong (QYT) have positive treatment effectson acute pancreatitis (AP). This investi...AIM: Available experimental evidence from both clinical andanimal models shows that both Chinese medicines tetrandine(Tet) and Qing Yi Tong (QYT) have positive treatment effectson acute pancreatitis (AP). This investigation was conductedto explore the treatment mechanisms of Tet and QYT on APat the molecular level and thereby explain their therapeuticaffects. It included an invest igation of the effects of thesedrugs on gene expression of both intercellular adhesionmolecule 1 (ICAM-1) and superoxide dismutase (Mn-SODand Cu, Zn-SOD) in a rat model with ARMETHODS: AP in the test rats was induced by subjectingthem to laparotomy followed by a retrograde injection of 4 %sodium taurocholate into the bilio-pancreatic duct. The testrats with AP were divided into three groups. One was treatedwith Tet, one with QYT, and one with normal saline solution.The sham-operated control group (SO) rats were only subjectedto laparotomy. They were given no further treatment. For theTet group, Tet was injected intraperitoneally, and for the QYTgroup, QYT was given with a nose-gastric catheter. Theseprocedures were done at both 10 min and 5 h after APinduction. The levels of ICAM-1 mRNA expression and ofSOD (Mn-SOD and Cu, Zn-SOD) mRNA expression in thepancreas and liver tissues were measured by RT-PCR at 1,5, and 10 h after AP induction.RESULTS: When compared with the SO group during theobservation time, rats with AP showed a higher expressionof ICAM and a lower expression of Mn-SOD in both pancreasand liver tissues, and a lower expression of Cu, Zn-SOD inthe pancreas. Tet treatment attenuated changes in theexpression of both ICAM-1, and SOD (Mn-SOD and Cu, Zn-SOD) to a significant degree. A similar effect on theexpression of SOD (Mn-SOD and Cu, Zn-SOD) was also foundin the QYT group, but no obvious suppressive effect onICAM-1 expression was observed.CONCLUSION: The results of this study suggest that oneof the main mechanisms of Tet and QYT in treating AP is toenhance anti-oxidation of the body. The results also suggestthat the anti-inflammatory effect of Tet is involved in thereduction of ICAM-1 expression. This explains why Tet andQYT are beneficial in treating AP.展开更多
AIM: To investigate the expression of NDRG2 and mutation of the entire coding region of NDRG2 in human liver and pancreatic cancers, and to further discuss the possible causes of NDRG2 distinct expression patterns.MET...AIM: To investigate the expression of NDRG2 and mutation of the entire coding region of NDRG2 in human liver and pancreatic cancers, and to further discuss the possible causes of NDRG2 distinct expression patterns.METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to analyze the expression of NDRG2 mRNA in 37 fresh cancer specimens (including 8 cases of pancreatic cancer and 29 cases of liver cancer) and adjacent normal tissues collected from clinical operation. In addition,mutation analysis of the whole coding region of NDRG2 in these cancers was examined by polymerase chain reactionsingle strand conformational polymorphism (PCR-SSCP).RESULTS: Compared with adjacent normal tissues, the expression levels of NDRG2 mRNA in corresponding cancer tissues reduced significantly (pancreatic cancer: 0.680±0.112 vs 2.089±0.214, P<0.01) (liver cancer: 0.894±0.098 vs 1.345±0.177, P<0.05). Using PCR-SSCP, the mutation of the whole coding region of NDRG2 was not found in those cancer tissues where the expression of NDRG2 mRNA reduced markedly.CONCLUSION: NDRG2 gene might express differently between normal tissues and cancer tissues, and might play an important role in the development of pancreatic cancer and liver cancer. Low expression of NDRG2 might be unrelated to the mutation of coding region of NDRG2.展开更多
AIM: To investigate the therapeutic effects of recombinant human growth hormone (rhGH) on rat septic shock with intraabdominal infection by E. coli and its possible mechanism. METHODS: 76 SD rats were divided into 3 g...AIM: To investigate the therapeutic effects of recombinant human growth hormone (rhGH) on rat septic shock with intraabdominal infection by E. coli and its possible mechanism. METHODS: 76 SD rats were divided into 3 groups randomly:control group (group C, n=16) without any special treatnent,of E. coli(1×1010 cfu@ L-1,15 ml@kg-1, ip), treated group (group by rhGH injection (2.25 U@kg-1@d-1, im). Group S and group T were further divided into 1d and 3d subgroups, respectively (n=15 each). Mean arterial pressure (MAP), levels of plasma TNFα and endotoxin and leukocyte count were determined on 1st day and 3rd day after E. coli injection. Another 39 SD rats were divided into groups C, S and T (n=13 each) just for observing survival rate within 1 week.RESULTS: (1) On 1st and 3rd day, MAP in group S decreased markedly, and MAP on 1st day lowered more than that of 3rd day (P＜0.01), while MAP in group T just decreased slightly. The survival rate within 1 week was much higher in group T (84.6 %) than in group S (46.2 %) (P＜0.01). (2)On 1st day, plasma TNFα and endotoxin elevated significantly in group S and group T (P＜0.05), and endotoxin in group S had more increase (P＜0.01). On 3rd day, TNFα in group S returned to the level of group C (P＞0.05),while TNFα in group T went down below the level of group C(P＜0.01). On 3rd day, endotoxin in group S declined, but was still higher than that of group C (P＜0.01), endotoxin in group T returned to the level of group C (P＞0.05). (3) On 1st day, neutrophil ratio in total leukocyte count in both group S and group T increased significantly (P＜0.05 vs group C).CONCLUSION: rhGH showed beneficial effects on rat septic shock. The possible mechanisms may involve the attenuation of bacteria/endotoxin translocation and decreased systemic endotoxin level; inhibition of the production and release of TNFα; improved circulatory function; improved systemic host defenses and maintenance of intestinal mucosa barrier.展开更多
AIM: To observe how acupuncture stimulation influences the visceral nociception in rat and to clarify the interactions between acupuncture or somatic input and visceral nociceptive inputs in the spinal dorsal horn. Th...AIM: To observe how acupuncture stimulation influences the visceral nociception in rat and to clarify the interactions between acupuncture or somatic input and visceral nociceptive inputs in the spinal dorsal horn. These will provide scientific base for illustrating the mechanism of acupuncture on visceral pain.METHODS: Experiments were performed on SpragueDawley rats and the visceral nociceptive stimulus was generated by colorectal distention (CRD). Unit discharges from individual single neuron were recorded extracellularly with glass-microelectrode in L1-3 spinal dorsal horn.Acupuncture stimulation was applied at contralateral heterotopic acupoint and ipsilateral homotopic acupoint,both of which were innervated by the same segments that innervate also the colorectal-gut.RESULTS: The visceral nociception could be inhibited at the spinal level by the heterotopic somatic mechanical stimulation and acupuncture. The maximal inhibition was induced by acupuncture or the somatic noxious stimulation at spinal dorsal horn level with inhibiting rate of 68.61%and 60.79%, respectively (P＜0.01 and ＜0.001). In reversible spinalized rats (cervical-thoracic cold block)both spontaneous activity and responses to CRD increased significantly in 16/20 units examined, indicating the existence of tonic descending inhibition. The inhibition of acupuncture on the noxious CRD disappeared totally in the reversible spinalized rats (P＜0.001).CONCLUSION: The inputs of noxious CRD and acupuncture may interact at the spinal level. The nociceptive visceral inputs could be inhibited by acupuncture applied to hetero-topic acupoint. The effect indicates that the spinal dorsal horn plays a significant role in mediating the inhibition of acupuncture and somatic stimulation on the neuronal response to the noxious visceral stimulation and the inhibition is modulated by upper cervical cord and/or supra-spinal center.展开更多
AIM: To evaluate effects of nitric oxide (NO) and peroxynitrite anion (ONOO-) on lung injury following intestinal ischemia-reperfusion (IR) in rats.
METHODS: A rat model of intestinal ischemia was made by clamping sup...AIM: To evaluate effects of nitric oxide (NO) and peroxynitrite anion (ONOO-) on lung injury following intestinal ischemia-reperfusion (IR) in rats.
METHODS: A rat model of intestinal ischemia was made by clamping superior mesenteric artery and lung injury was resulted from reperfusion. The animals were randomly divided into 3 groups: sham operation (Sham), 2 h ischemia followed by 2 h reperfusion (IR) and IR pretreated with aminoguanidine (AG) - an inhibitor of inducible NO synthase (iNOS) 15 minutes before reperfusion (IR+AG). The lung malondialdehyde (MDA) and nitrate/nitrite (NO2/NO3)contents and morphological changes were examined.Western blot was used to detect the iNOS protein expression.Immunohistochemical staining was used to determine the change of nitrotyrosine (NT)- a specific 'footprint' of ONOO-.
RESULTS: The morphology revealed evidence for lung edema, hemorrhage and polymorphonuclear sequestration after intestinal IR. Compared with sham group, lung contents of MDA and NO2-/NO3- in IR group were significantly increased (12.00±2.18 vs23.44±1.25 and 76.39±6.08 vs140.40±4.34,P＜0.01) and the positive signals of iNOS and NT were also increased in the lung. Compared with IR group, the contents of MDA and NO2/NO3 in IR+AG group were significantly decreased (23.44±1.25 vs14.66±1.66 and 140.40±4.34 vs 80.00±8.56, P＜0.01) and NT staining was also decreased.
CONCLUSION: Intestinal IR increases NO and ONOO production in the lung, which may be involved in intestinal IR-mediated lung injury.展开更多
AIM: To eluddate whether CCK receptors exist in lung tissues and their precise cellular localization in the lung.METHODS: CCK-AR and CCK-BR mRNA expression and cellular distribution in the rat lung were detected by hi...AIM: To eluddate whether CCK receptors exist in lung tissues and their precise cellular localization in the lung.METHODS: CCK-AR and CCK-BR mRNA expression and cellular distribution in the rat lung were detected by highly sensitive method of/n $I^J reverse transcription-polymerase chain reaction (RT-PCR) and conventional in situ hybridization.RESULTS: CCK-AR and CCK-BR gene positive signals were observed in bronchial epithelial cells, alveolar epithelial cells,pulmonary macrophages and vascular endothelial cells of the rats' lung by in sitv RT-PCR. The hybridization signals of CCK-AR were relatively faint. By in sitv hybridization,however, only the signals of CCK-BR but not CCK-AR were detected in the lung, and the positive staining was only found in vascular endothelial cells and macrophages.CONCLUSION: CCK-AR and CCK-BR gene were present in pulmonary vascular endothelial cells, macrophages, bronchial epithelial cells and alveolar epithelial cells, which play an important role in mediating the regulatory actions of CCK-8 on these cells.展开更多
AIM: To study the effect of cholecystokinin-octapeptide (CCK-8) on lipopolysaccharide (LPS) -induced pulmonary artery smooth muscle cell (PASMCs) injury and the role of heine oxygenase-1 (HO-1), and to explore the reg...AIM: To study the effect of cholecystokinin-octapeptide (CCK-8) on lipopolysaccharide (LPS) -induced pulmonary artery smooth muscle cell (PASMCs) injury and the role of heine oxygenase-1 (HO-1), and to explore the regulation mechanism of c-Jun N-terminal kinase (JNK) and activator protein-1 (AP-1) signal transduction pathway in inducing HO-1 expression further. METHODS: Cultured PASMCs were randomly divided into 4 or 6 groups: normal culture group, LPS (10 mg/L), CCK-8 (10^-6 mol/L) plus LPS (10 mg/L) group, CCK-8 (10^-6 mol/L) group, zinc protoporphyrin 9 (ZnPPIX) (10^-6 mol/L) plus LPS (10 mg/L) group, CCK-8 (10^-6 mol/L) plus ZnPPIX and LPS (10 mg/L) group. Seven hours after LPS administration, ulterstructrual changes and content of malondialdehyde (MDA) of PASMCs in each group were investigated by electron microscopy and biochemical assay respectively. HO-1 mRNA and protein of PASMCs in the former4 groups were examined by reverse transcriptase polymerase chain reaction (RT-PCR) and immunocytochemistry staining. Changes of c-fos expression and activation of JNK of PASMCs in the former 4 groups were detected with immunocytochemistry staining and Western blot 30 min after LPS administration. RESULTS: The injuries of PASMCs and the increases of MDA content induced by LPS were alleviated and significantly reduced by CCK-8 (P<0.05). The specific HO-1 inhibitor-ZnPPIX could worsen LPS-induced injuries and weaken the protective effect of CCK-8. The expressions of c-fos, p-JNK protein and HO-1 mRNA and protein were all slightly increased in LPS group, and significantly enhanced by CCK-8 further (P<0.05). CONCLUSION: HO-1 may be a key factor in CCK-8 attenuated injuries of PASMCs induced by LPS, and HO-1 expression may be related to the activation of JNK and activator protein (AP-1).展开更多
AIM: To observe the gastric mucosal injury caused by hemorrhagic shock and reperfusion and to compare the effect between Salvia miltiorrhizae extract F (SEF) and cimetidine (CI) on it. METHODS: A model of hemorrhage/r...AIM: To observe the gastric mucosal injury caused by hemorrhagic shock and reperfusion and to compare the effect between Salvia miltiorrhizae extract F (SEF) and cimetidine (CI) on it. METHODS: A model of hemorrhage/reperfusion injury was produced by Itoh method. Wistar rats were randomly divided into three groups: 0.9% sodium chloride treatment group (NS group), SEF treatment group (SEF group), and CI treatment group (CI group). Saline, SEF and CI were injected respectively. The index of gastric mucosal lesions (IGML) was expressed as the percentage of lesion area in the gastric mucosa. The degree of gastric mucosal lesions was categorized into grades 0, 1, 2, 3. Atom absorption method was used to measure the intracellular calcium content. Radioimmunoassay was used to measure the concentrations of prostaglandins. RESULTS: IGML (%) and grade 3 (%) were 23.18±6.82, 58.44±9.07 in NS group, 4.42±1.39, 20.32±6.95 in SEF group and 3.74±1.56, 23.12±5.09 in CI group, and the above parameters in SEF group and CI group decreased significantly (IGML: SEF vs NS, t=6.712, P=0.000<0.01; CI vs NS, t=6.943, P=0.000<0.01; grade 3: SEF vs HS, t=8.386, P=0.000; CI vs HS, t=8.411, P= 0.000), but the grade 0 and grade 1 damage in SEF group (22.05±5.96, 34.12±8.12) and CI group (18.54±4.82, 30.15±7.12) were markedly higher than those in NS group (3.01±1.01, 8.35±1.95; grade 0: SEF vs HS, t=8.434, P=0.000<0.01; CI vs NS, t=7.950, P=0.000<0.01; grade 1: SEF vs NS, t =8.422, P=0.000<0.01; CI vs NS, t=8.448, P=0.000<0.01). The intracellular calcium content (μg/mg) in SEF group (0.104±0.015) and CI group (0.102±0.010) was markedly lower than that in NS group (0.131±0.019, SEF vs NS, t=2.463, P=0.038<0.05; CI vs HS, t=3.056, P=0.017<0.05). The levels (pg/mg) of PGE_2, 6-keto-PGF_(1α) and 6-keto-PGF_(1α)/TXB_2 were 540±183, 714±124,17.38±5.93 in NS group and 581±168, 737±102, 19.04±8.03 in CI group, 760±192,1 248±158, 33.42±9.24 in SEF group, and the above parameters in SEF group markedly raised (PGE_2: SEF vs NS, t=2.282, P=0.046<0.05; SEF vs CI, t=2.265, P=0.047<0.05; 6-keto-PGF_(1α): SEF vs NS, t=6.583, P=0.000<0.000; SEF vs CI, t=6.708, P=0.000<0.01; 6-keto-PGF_(1α)/TXB_2: SEF vs NS, t=3.963, P=0.003<0.001; SEF vs Cl, t=3.243, P=0.009<0.01), whereas TXB_2 level in SEF group (45.37±7.54) was obviously lower than that in NS group (58.28±6.74, t=3.086, P=0.014<0.05) and CI group (54.32±6.89, t=2.265, P=0.047<0.05). No significant difference was shown between NS group and CI group (PGE_2: t=0.414, P=0.688>0.05; 6-keto-PGF_(1α): t=0.310, P=0.763>0.05; TXB_2: t=1.099, P=0.298>0.05; 6-keto-PGF_(1α)/TXB_2: t=0.372, P=0.718>0.05). CONCLUSION: Both SEF and CI could inhibit reperfusioninduced injury in gastric mucosa, but with different mechanisms. SEF could not only enhance the protective effect of gastric mucosa, but also abate the injury factors, while CI can only abate the injury factors.展开更多
AIM: To understand the response of human REV3gene to gastric cancer inducing carcinogen N-methyl-N'-nitro-Nnitrosoguanidine (MNNG) and its role in human mutagenesis.METHODS: The response of the human REV3 gene to ...AIM: To understand the response of human REV3gene to gastric cancer inducing carcinogen N-methyl-N'-nitro-Nnitrosoguanidine (MNNG) and its role in human mutagenesis.METHODS: The response of the human REV3 gene to MNNG was measured in human 293 cells and FL cells by RT-PCR. By using antisense technology, mutation analysis at HPRTlocus (on which lesion-targeted mutation usually occurs) was conducted in human transgenic cell line FLREV3- by 8-azaguanine screening, and mutation occurred on undamaged DNA template was detected by using a shuttle plasmid pZ189 as the probe in human transgenic cell lines 293-REV3- and FL-REV3-. The blockage effect of REV3 was measured by combination of reverse transcriptionpolymerase chain reaction to detect the expression of antisense REV3 RNA and Western blotting to detect the REV3protein level.RESULTS: The human REV3 gene was significantly activated by MNNG treatment, as indicated by the upregulation of REV3 gene expression at the transcriptional level in MNNG-treated human cells, with significant increase of REV3 expression level by 0.38 fold, 0.33 fold and 0.27fold respectively at 6 h, 12 h and 24 h in MNNG-treated 293 cells (P＜0.05); and to 0.77 fold and 0.65 fold at 12 h and 24 h respectively in MNNG-treated FL cells (P＜0.05).In transgenic cell line (in which REV3 was blocked by antisense REV3 RNA), high level of antisense REV3 RNA was detected, with a decreased level of REV3 protein.MNNG treatment significantly increased the mutation frequencies on undamaged DNA template (untargeted mutation), and also at HPRT locus (lesion-targeted mutation). However, when REV3 gene was blocked by antisense REV3 RNA, the MNNG-induced mutation frequency on undamaged DNA templates was significantly decreased by 3.8 fold (P＜0.05) and 5.8 fold (P＜0.01)respectively both in MNNG-pretreated transgenic 293 cells and FL cells in which REV3was blocked by antisense RNA,and almost recovered to their spontaneous mutation levels.The spontaneous HPRT mutation was disappeared in REV3disrupted cells, and induced mutation frequency at HPRT locus significantly decreased from 8.66×10-6 in FL cells to 0.14×10-6 in transgenic cells as well (P＜0.01).CONCLUSION: The expression of the human REV3 can be upregulated at the transcriptional level in response to MNNG. The human REV3 gene plays a role not only in lesion-targeted DNA mutagenesis, but also in mutagenesis on undamaged DNA templates that is called untargeted mutation.展开更多
Objective To deduce all potential ligands undiscovered experimentally by searching all the proteins containing same C-termini, which can bind a certain PDZ domain. Methods We developed a JAVA program for searching sho...Objective To deduce all potential ligands undiscovered experimentally by searching all the proteins containing same C-termini, which can bind a certain PDZ domain. Methods We developed a JAVA program for searching short exact sequence matches at C-terminus. According to the known C-termini, which PDZ domains recognized experimentally, Swissprot database has been searched by this program for all potential ligands. Results Some PDZ domains may have more potential ligand proteins, which are undiscovered yet experimentally. These bioinformatic results also provide clues for studying functions of hypothetical proteins and PDZ domains’ protein interactions in many different organisms. Conclusion The results may provide useful clues for discovering potential functions of hypothetical proteins and new functions of known proteins.展开更多
Objective To investigate effect of inhibiting melatonin biosynthesis on activities of protein kinase A (PKA), glycogen synthase kinase-3 (GSK-3) and tau phosphorylation at PS214 and M4 epitopes using haloperidol, a sp...Objective To investigate effect of inhibiting melatonin biosynthesis on activities of protein kinase A (PKA), glycogen synthase kinase-3 (GSK-3) and tau phosphorylation at PS214 and M4 epitopes using haloperidol, a specific inhibitor of 5-hydroxyindole-O-methyltransferase. Methods Brain ventricular and intraperitoneal injections were used for haloperidol administration, Western blots for tau phosphorylation, 32P-labeling for PKA and GSK-3 activity, and high performance liquid chromatograph for detection of serum melatonin levels. Results Haloperidol injection through the lateral ventricle and intraperitoneal reinforcement significantly stimulated PKA activity with a concurrent hyperphosphorylation of tau at M4 (Thr231/Ser235) and PS214 (Ser214) sites. Prior treatment of the rats using melatonin supplement for one week and reinforcement during the haloperidol administration arrested PKA activity and attenuated tau hyperphosphorylation. GSK-3 activity showed no obvious change after haloperidol injection, however, melatonin supplements and reinforcements during haloperidol infusion inactivated basal activity of GSK-3. Conclusion Decreased melatonin may be involved in Alzheimer-like tau hyperphosphorylation, and overactivation of PKA may play a crucial role in this process.展开更多
AIM: To identify the new alternative splicing variants of human CYP2D6 in human extratumoral liver tissue with RT-PCR and sequencing. METHODS: Full length of human CYP2D6 cDNAs was amplificated by reverse transcriptio...AIM: To identify the new alternative splicing variants of human CYP2D6 in human extratumoral liver tissue with RT-PCR and sequencing. METHODS: Full length of human CYP2D6 cDNAs was amplificated by reverse transcription-polymerase chain reaction (RT-PCR) from a human extratumoral liver tissue and cloned into pGEM-T vector. The cDNA was sequenced. Exons from 1 to 4 of human CYP2D6 cDNAs were also amplificated by RT-PCR from extratumoral liver tissues of 17 human hepatocellular carcinomas. Some RT-PCR products were sequenced. Exons 1 to 4 of CYP2D6 gene were amplified by PCR from extratumoral liver tissue DNA. Two PCR products from extratumoral liver tissues expressing skipped mRNA were partially sequenced. RESULTS: One of the CYP2D6 cDNAs had 470 nucleotides from 79 to 548 (3' portion of exons 1 to 5' portion of exon 4), and was skipped. Exons 1 to 4 of CYP2D6 cDNA were assayed with RT-PCR in 17 extratumoral liver tissues. Both wild type and skipped mRNAs were expressed in 4 samples, only wild type mRNA was expressed in 5 samples, and only skipped mRNA was expressed in 8 samples. Two more variants were identified by sequencing the RT-PCR products of exons 1 to 4 of CYP2D6 cDNA. The second variant skipped 411 nucleotides from 175 to 585. This variant was identified in 4 different liver tissues by sequencing the RT-PCR products. We sequenced partially 2 of the PCR products amplified of CYP2D6 exon 1 to exon 4 from extratumoral liver tissue genomic DNA that only expressed skipped mRNA by RT-PCR. No point mutations around exon 1, intron 1, and exon 4, and no deletion in CYP2D6 gene were detected. The third variant was the skipped exon 3, and 153 bp was lost. CONCLUSION: Three new alternative splicing variants of CYP2D6 mRNA have been identified. They may not be caused by gene mutation and may lose CYP2D6 activity and act as a down-regulator of CYP2D6.展开更多
Objective To investigate the sensitivity of the human sperm motility assay for detecting endotoxin in culture mediumMaterials &. Methods Motile sperm were separated and exposed to different concentrations of endot...Objective To investigate the sensitivity of the human sperm motility assay for detecting endotoxin in culture mediumMaterials &. Methods Motile sperm were separated and exposed to different concentrations of endotoxin (0.5 ng/mL, 1ng/mL, 10ng/mL, 1000ng/mL, 10 000ng/ mL, and 50 000ng/mL), and sperm motility was determined after incubation. Effects of endotoxin on sperm motility in media without albumin were also examined. In addition, at the same concentrations of endotoxin (0. 5ng/mL, 1 ng/mL, and 10 ng/ mL ) , the sensitivity of the human sperm motility assay was compared to those of 1-cell and 2-cell mouse embryo bioassays.Results At levels of 0. 5ng/mL-1000ng/mL endotoxin in media with 2mg/mL albumin, sperm did not show significant change in motility during 24 h of incubation when compared with the control (P>0. 05). However, the sperm motility was significantly inhibited at endotoxin dosages of 10 000 and 50 000 ng/mL. In the absence of albumin supplementation, at endotoxin levels of 50 000ng/mL, and 1 000ng/mL, there was a marked decrease in sperm motility compared with the control after 2 h or 8 h of incubation, respectively (P<0. 01). In media containing 0. 5 ng/mL and 1 ng/ mL endotoxin, 1-cell and 2-cell mouse embryos had significantly reduced developmental rates in all developmental stages, and at the level of 10ng/mL, the development of the embryos was arrested. Conclusion The human sperm motility assay could detect high levels of endotoxin in culture medium but its sensitivity to endotoxin would be inferior to that of the 1-cell or 2-cell mouse embryo bioassay. In the absence of albumin supplementation, the sensitivity of the sperm motility assay could be improved.展开更多
Abnormal deposition of amyloid-p(Ap) peptides and formation of neuritic plaques are recognized as pathological processes in Alzheimer's disease (AD) brain. By using amyloid precursor protein (APP) transfected cell...Abnormal deposition of amyloid-p(Ap) peptides and formation of neuritic plaques are recognized as pathological processes in Alzheimer's disease (AD) brain. By using amyloid precursor protein (APP) transfected cells, this study aims to investigate the effect of overproduction of Aβ on cell differentiation and cell viability. It was shown that after serum withdrawal, untransfected cell (N2a/Wt) and vector transfected cells (N2a/vector) extended long and branched cell processes, whereas no neurites was induced in wild type APP (N2a/APP695) and Swedish mutant APP (N2a/ APPswe) transfected N2a cells. After differentiation by serum withdrawal, the localization of APP/AP and neurofilament was extended to neurites, whereas those of APP-transfected cells were stillrestricted within the cell body. Levels of both APP and Aβ were significantly higher in N2a/APP695 and N2a/APPswe than in N2a/Wt, as determined by Western blot and Sandwich ELISA, respectively. To further investigate the effect of A0 on the inhibition of cell differentiation, we added exogenously the similar level or about 10-times of the AP level produced by N2a/APP695 and N2a/APPswe to the culture medium and co-cultured with N2a/Wt for 12 h, and we found that the inhibition of serum withdrawal-induced differentiation observed in N2a/APP695 and N2a/APPswe could not be reproduced by exogenous administration of AP into N2a/Wt. We also observed that neither endogenous production nor exogenous addition of Aβ1-40 or Aβ1-42, even to hundreds fold of the physiological concentration, affected obviously the cell viability. These results suggest that the overproduction of AP could not arrest cell differentiation induced by serum deprivation and that, at least to a certain degree and in a limited time period, is not toxic to cell viability.展开更多
Information about the mechanisms that generate mutationsin eukaryotes is likely to be useful for understanding humanhealth concerns, such as genotoxicity and cancer.Eukaryotic mutagenesis is largely the outcome of att...Information about the mechanisms that generate mutationsin eukaryotes is likely to be useful for understanding humanhealth concerns, such as genotoxicity and cancer.Eukaryotic mutagenesis is largely the outcome of attacksby' endogenous and environmental agents. Except for DNArepair, cell cycle checkpoints and DNA damage avoidance,cells have also evolved DNA damage tolerance mechanism,by which lesion-targeted mutation might occur in thegenome during replication by specific DNA polymerases tobypass the lesions (translesion DNA synthesis, TLS), ormutation on undamaged DNA templates (untargetedmutation) might be induced. DNA polymerase ζ (poiζ),which was found firstly in budding yeast Saccharomycescerevisiae and consists of catalytic subunit scRev3 and stimulating subunit scRev7, has Received more attention in recent years. Poi ζ is a member of DNA polymerase δsubfamily, which belongs to DNA polymerase B family, and exists in almost all eukaryotes. Human homolog of the scRev3gene is located in chromosome region 6q21, and the mouse equivalent maps to chromosome 10, distal to the c-myb gene and close to the Macs gene. Alternative splicing, upstream out-of frame ATG can be found in yeast scRev3, mouse and human homologs. Furthermore, the sequence from 253-323 immediate upstream of the AUG initiator codon has the potential to form a stem-loop hairpin secondary structure in REV3 mRNA, suggesting that human REV3 protein may be expressed at low levels in human cells under normal growth conditions. The functional domain analysis showed that yeast Rev3-980 tyrosine in conserved region II is at the polymerase active site. Human REV3 amino acid residues 1 776-2 195 provide a REV7binding domain, and REV7 amino acid residues 1-211provide a bind domain for REV1, REV3 and REV7 itself.More interestingly, REV7 interacts with hMAD2 and therefore might function in the cell cycle control by affecting the activation of APC (anaphase promoting complex).Currently it has been known that poi ζ is involved in most spontaneous mutation, lesion-targeted mutation via TLS,chemical carcinogen induced untargeted mutation and somatic hypermutation of antibody genes in mammalian.In TLS pathway, polζ acts as a "mismatch extender" with combination of other DNA polymerases, such as pol t. Unlike in yeast, it was found that pol ζ also functioned in mouse embryonic development more recently. It was hypothesized that the roles of pol ζ in TLS and cell cycle control might contribute to mouse embryonic lethality.展开更多
Aim: To investigate the effect of experimental varicocele on mitochondrial calcium and cytochrome C of the epididymal cells in adolescent rats. Methods: Forty male adult Wistar rats were divided into two groups random...Aim: To investigate the effect of experimental varicocele on mitochondrial calcium and cytochrome C of the epididymal cells in adolescent rats. Methods: Forty male adult Wistar rats were divided into two groups randomly: the varicocele group (VG) and the sham operated group (SOG). Varicocele was produced by partial ligation of the left renal vein. Bilateral epididymides were removed after ten weeks. The mitochondrial calcium and cytochrome C levels of the epididymal cells were determined. Results: The mi-tochondrial calcium was decreased (P<0.01) while the cytochrome C increased (P<0.05) markedly in the experimental group compared with the controls. Conclusion: Varicocele-induced calcium dyshomeostasis and mitochondrial damage of the epididymal cells may play an important role in causing subfertility.展开更多
文摘Olfactory ensheathing cell (OEC) transplantation has emerged as a very promising therapy for spinal cord repair. In this study, we tested the ability of genetically modified OECs to secrete high levels of glial cell line-derived neu-rotrophic factor (GDNF) to promote spinal cord repair. The GDNF gene was transduced into OECs using
基金Supported by the Major State Basic Research Development Program of China (973 Program),No. 2001CB509904 the Key Scientific and Technological Projects of Guangdong Province, No. 2003A3020103+1 种基金the Key Scientific and Technological Projects of Guangzhou City, No. 2002U13E0011the National Natural Science Foundation of China, No. 30100188
文摘AIM: Recent reports have shown the capacity of mesenchymal stem cells (MSCs) to differentiate into hepatocytes in vitro and in vivo. MSCs administration could repair injured liver, lung, or heart through reducing inflammation, collagen deposition, and remodeling. These results provide a clue to treatment of liver fibrosis. The aim of this study was to investigate the effect of infusion of bone marrow (BM)-derived MSCs on the experimental liver fibrosis in rats. METHODS: MSCs isolated from BM in male Fischer 344 rats were infused to female Wistar rats induced with carbon tetrachloride (CCI4) or dimethylnitrosamine (DMN). There were two random groups on the 42nd d of CCI4: CCl4/MSCs, to infuse a dose of MSCs alone; CCI4/saline, to infuse the same volume of saline as control. There were another three random groups after exposure to DMN: DMN10/MSCs, to infuse the same dose of MSCs on d 10; DMN10/saline, to infuse the same volume of saline on d 10; DMN20/MSCs, to infuse the same dose of MSCs on d 20. The morphological and behavioral changes of rats were monitored everyday. After 4-6 wk of MSCs administration, all rats were killed and fibrosis index were assessed by histopathology and radioimmunoassay. Smooth muscle alpha-actin (alpha-SMA) of liver were tested by immunohistochemistry and quantified by IBAS 2.5 software. Male rats sex determination region on the Y chromosome (sry) gene were explored by PCR. RESULTS: Compared to controls, infusion of MSCs reduced the mortality rates of incidence in CCl4-induced model (10% vs 20%) and in DMN-induced model (20-40% vs 90%).The amount of collagen deposition and alpha-SMA staining was about 40-50% lower in liver of rats with MSCs than that of rats without MSCs. The similar results were observed in fibrosis index. And the effect of the inhibition of fibrogenesis was greater in DMN10/MSCs than in DMN20/MSCs. The sry gene was positive in the liver of rats with MSCs treatment by PCR. CONCLUSION: MSCs treatment can protect against experimental liver fibrosis in CCMnduced or DMN-induced rats and the mechanisms of the anti-fibrosis by MSCs will be studied further.
基金Supported by National Natural Science Foundation of China,No.30060031
文摘AIM: To study the change of intracellular calcium-magnesium ATPase (Ca^2+-Mg^2+-ATPase) activity in pancreas, liver and kidney tissues of rats with acute pancreatitis (AP), and to investigate the effects of Qingyitang (QYT) (Decoction for clearing the pancreas) and tetrandrine (Tet) and vitamin E(VitE) on the activity of Ca^2+-Mg^2+-ATPase. METHODS: One hundred and five Sprague-Dawley rats were randomly divided into: normal control group, AP group,treatment group with QYT (1 ml/100 g) or Tet (0.4 ml/100 g) or VitE (100 mg/kg). AP model was prepared by a retrograde injection of sodium taurocholate into the pancreatic duct. Tissues of pancreas, liver and kidney of the animals were taken at 1 h, 5 h, 10 h respectively afer AP induction, and the activity of Ca^2+-Mg^2+-ATPase was studied using enzymehistochemistry staining. Meanwhile, the expression of Ca^2^+-Mg^2+-ATPase of the tissues was studied by RT-PCR. RESULTS: The results showed that the positive rate of Ca^2+-Mg^2+-ATPase in AP group (8.3%, 25%, 29.2%) was lower than that in normal control group (100%) in all tissues(P<0.01), the positive rate of Ca^2+-Mg^2+-ATPase in treatment group with QYT (58.3%, 83.3%, 83.3%), Tet (50.0%,70.8%, 75.0%) and VitE (54.2%, 75.0%, 79.2%) was higher than that in AP group (8.3%, 25.0%, 29.2%) in all tissues(P<0.01). RT-PCR results demonstrated that in treatment groups Ca^2+-Mg^2+-ATPase gene expression in pancreas tissue was higher than that in AP group at the observing time points, and the expression at 5 h was higher than that at 1 h. The expression of Ca^2+-Mg^2+-ATPase in liver tissue was positive, but without significant difference between different groups. CONCLUSION: The activity and expression of intracellular Ca^2+-Mg^2+-ATPase decreased in rats with AP, suggesting that Ca^2+-Mg^2+-ATPase may contribute to the occurrence and development of cellular calcium overload in AP. QYT, Tet and VitE can increase the activity and expression of Ca^2+-Mg^2+-ATPase and may relieve intracellular calcium overload to protect the tissue and cells from injuries.
基金the National Natural Scientific Foundation of China, No.30060031
文摘AIM: Available experimental evidence from both clinical andanimal models shows that both Chinese medicines tetrandine(Tet) and Qing Yi Tong (QYT) have positive treatment effectson acute pancreatitis (AP). This investigation was conductedto explore the treatment mechanisms of Tet and QYT on APat the molecular level and thereby explain their therapeuticaffects. It included an invest igation of the effects of thesedrugs on gene expression of both intercellular adhesionmolecule 1 (ICAM-1) and superoxide dismutase (Mn-SODand Cu, Zn-SOD) in a rat model with ARMETHODS: AP in the test rats was induced by subjectingthem to laparotomy followed by a retrograde injection of 4 %sodium taurocholate into the bilio-pancreatic duct. The testrats with AP were divided into three groups. One was treatedwith Tet, one with QYT, and one with normal saline solution.The sham-operated control group (SO) rats were only subjectedto laparotomy. They were given no further treatment. For theTet group, Tet was injected intraperitoneally, and for the QYTgroup, QYT was given with a nose-gastric catheter. Theseprocedures were done at both 10 min and 5 h after APinduction. The levels of ICAM-1 mRNA expression and ofSOD (Mn-SOD and Cu, Zn-SOD) mRNA expression in thepancreas and liver tissues were measured by RT-PCR at 1,5, and 10 h after AP induction.RESULTS: When compared with the SO group during theobservation time, rats with AP showed a higher expressionof ICAM and a lower expression of Mn-SOD in both pancreasand liver tissues, and a lower expression of Cu, Zn-SOD inthe pancreas. Tet treatment attenuated changes in theexpression of both ICAM-1, and SOD (Mn-SOD and Cu, Zn-SOD) to a significant degree. A similar effect on theexpression of SOD (Mn-SOD and Cu, Zn-SOD) was also foundin the QYT group, but no obvious suppressive effect onICAM-1 expression was observed.CONCLUSION: The results of this study suggest that oneof the main mechanisms of Tet and QYT in treating AP is toenhance anti-oxidation of the body. The results also suggestthat the anti-inflammatory effect of Tet is involved in thereduction of ICAM-1 expression. This explains why Tet andQYT are beneficial in treating AP.
基金Supported by the National Natural Science Foundation of China,No.30370315,No.30171044 and Medical and pharmaceutical Research Fund of PLA,No.01MA185
文摘AIM: To investigate the expression of NDRG2 and mutation of the entire coding region of NDRG2 in human liver and pancreatic cancers, and to further discuss the possible causes of NDRG2 distinct expression patterns.METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to analyze the expression of NDRG2 mRNA in 37 fresh cancer specimens (including 8 cases of pancreatic cancer and 29 cases of liver cancer) and adjacent normal tissues collected from clinical operation. In addition,mutation analysis of the whole coding region of NDRG2 in these cancers was examined by polymerase chain reactionsingle strand conformational polymorphism (PCR-SSCP).RESULTS: Compared with adjacent normal tissues, the expression levels of NDRG2 mRNA in corresponding cancer tissues reduced significantly (pancreatic cancer: 0.680±0.112 vs 2.089±0.214, P<0.01) (liver cancer: 0.894±0.098 vs 1.345±0.177, P<0.05). Using PCR-SSCP, the mutation of the whole coding region of NDRG2 was not found in those cancer tissues where the expression of NDRG2 mRNA reduced markedly.CONCLUSION: NDRG2 gene might express differently between normal tissues and cancer tissues, and might play an important role in the development of pancreatic cancer and liver cancer. Low expression of NDRG2 might be unrelated to the mutation of coding region of NDRG2.
文摘AIM: To investigate the therapeutic effects of recombinant human growth hormone (rhGH) on rat septic shock with intraabdominal infection by E. coli and its possible mechanism. METHODS: 76 SD rats were divided into 3 groups randomly:control group (group C, n=16) without any special treatnent,of E. coli(1×1010 cfu@ L-1,15 ml@kg-1, ip), treated group (group by rhGH injection (2.25 U@kg-1@d-1, im). Group S and group T were further divided into 1d and 3d subgroups, respectively (n=15 each). Mean arterial pressure (MAP), levels of plasma TNFα and endotoxin and leukocyte count were determined on 1st day and 3rd day after E. coli injection. Another 39 SD rats were divided into groups C, S and T (n=13 each) just for observing survival rate within 1 week.RESULTS: (1) On 1st and 3rd day, MAP in group S decreased markedly, and MAP on 1st day lowered more than that of 3rd day (P＜0.01), while MAP in group T just decreased slightly. The survival rate within 1 week was much higher in group T (84.6 %) than in group S (46.2 %) (P＜0.01). (2)On 1st day, plasma TNFα and endotoxin elevated significantly in group S and group T (P＜0.05), and endotoxin in group S had more increase (P＜0.01). On 3rd day, TNFα in group S returned to the level of group C (P＞0.05),while TNFα in group T went down below the level of group C(P＜0.01). On 3rd day, endotoxin in group S declined, but was still higher than that of group C (P＜0.01), endotoxin in group T returned to the level of group C (P＞0.05). (3) On 1st day, neutrophil ratio in total leukocyte count in both group S and group T increased significantly (P＜0.05 vs group C).CONCLUSION: rhGH showed beneficial effects on rat septic shock. The possible mechanisms may involve the attenuation of bacteria/endotoxin translocation and decreased systemic endotoxin level; inhibition of the production and release of TNFα; improved circulatory function; improved systemic host defenses and maintenance of intestinal mucosa barrier.
文摘AIM: To observe how acupuncture stimulation influences the visceral nociception in rat and to clarify the interactions between acupuncture or somatic input and visceral nociceptive inputs in the spinal dorsal horn. These will provide scientific base for illustrating the mechanism of acupuncture on visceral pain.METHODS: Experiments were performed on SpragueDawley rats and the visceral nociceptive stimulus was generated by colorectal distention (CRD). Unit discharges from individual single neuron were recorded extracellularly with glass-microelectrode in L1-3 spinal dorsal horn.Acupuncture stimulation was applied at contralateral heterotopic acupoint and ipsilateral homotopic acupoint,both of which were innervated by the same segments that innervate also the colorectal-gut.RESULTS: The visceral nociception could be inhibited at the spinal level by the heterotopic somatic mechanical stimulation and acupuncture. The maximal inhibition was induced by acupuncture or the somatic noxious stimulation at spinal dorsal horn level with inhibiting rate of 68.61%and 60.79%, respectively (P＜0.01 and ＜0.001). In reversible spinalized rats (cervical-thoracic cold block)both spontaneous activity and responses to CRD increased significantly in 16/20 units examined, indicating the existence of tonic descending inhibition. The inhibition of acupuncture on the noxious CRD disappeared totally in the reversible spinalized rats (P＜0.001).CONCLUSION: The inputs of noxious CRD and acupuncture may interact at the spinal level. The nociceptive visceral inputs could be inhibited by acupuncture applied to hetero-topic acupoint. The effect indicates that the spinal dorsal horn plays a significant role in mediating the inhibition of acupuncture and somatic stimulation on the neuronal response to the noxious visceral stimulation and the inhibition is modulated by upper cervical cord and/or supra-spinal center.
文摘AIM: To evaluate effects of nitric oxide (NO) and peroxynitrite anion (ONOO-) on lung injury following intestinal ischemia-reperfusion (IR) in rats.
METHODS: A rat model of intestinal ischemia was made by clamping superior mesenteric artery and lung injury was resulted from reperfusion. The animals were randomly divided into 3 groups: sham operation (Sham), 2 h ischemia followed by 2 h reperfusion (IR) and IR pretreated with aminoguanidine (AG) - an inhibitor of inducible NO synthase (iNOS) 15 minutes before reperfusion (IR+AG). The lung malondialdehyde (MDA) and nitrate/nitrite (NO2/NO3)contents and morphological changes were examined.Western blot was used to detect the iNOS protein expression.Immunohistochemical staining was used to determine the change of nitrotyrosine (NT)- a specific 'footprint' of ONOO-.
RESULTS: The morphology revealed evidence for lung edema, hemorrhage and polymorphonuclear sequestration after intestinal IR. Compared with sham group, lung contents of MDA and NO2-/NO3- in IR group were significantly increased (12.00±2.18 vs23.44±1.25 and 76.39±6.08 vs140.40±4.34,P＜0.01) and the positive signals of iNOS and NT were also increased in the lung. Compared with IR group, the contents of MDA and NO2/NO3 in IR+AG group were significantly decreased (23.44±1.25 vs14.66±1.66 and 140.40±4.34 vs 80.00±8.56, P＜0.01) and NT staining was also decreased.
CONCLUSION: Intestinal IR increases NO and ONOO production in the lung, which may be involved in intestinal IR-mediated lung injury.
基金National Natural Science Foundation of China,No.39570304
文摘AIM: To eluddate whether CCK receptors exist in lung tissues and their precise cellular localization in the lung.METHODS: CCK-AR and CCK-BR mRNA expression and cellular distribution in the rat lung were detected by highly sensitive method of/n $I^J reverse transcription-polymerase chain reaction (RT-PCR) and conventional in situ hybridization.RESULTS: CCK-AR and CCK-BR gene positive signals were observed in bronchial epithelial cells, alveolar epithelial cells,pulmonary macrophages and vascular endothelial cells of the rats' lung by in sitv RT-PCR. The hybridization signals of CCK-AR were relatively faint. By in sitv hybridization,however, only the signals of CCK-BR but not CCK-AR were detected in the lung, and the positive staining was only found in vascular endothelial cells and macrophages.CONCLUSION: CCK-AR and CCK-BR gene were present in pulmonary vascular endothelial cells, macrophages, bronchial epithelial cells and alveolar epithelial cells, which play an important role in mediating the regulatory actions of CCK-8 on these cells.
文摘AIM: To study the effect of cholecystokinin-octapeptide (CCK-8) on lipopolysaccharide (LPS) -induced pulmonary artery smooth muscle cell (PASMCs) injury and the role of heine oxygenase-1 (HO-1), and to explore the regulation mechanism of c-Jun N-terminal kinase (JNK) and activator protein-1 (AP-1) signal transduction pathway in inducing HO-1 expression further. METHODS: Cultured PASMCs were randomly divided into 4 or 6 groups: normal culture group, LPS (10 mg/L), CCK-8 (10^-6 mol/L) plus LPS (10 mg/L) group, CCK-8 (10^-6 mol/L) group, zinc protoporphyrin 9 (ZnPPIX) (10^-6 mol/L) plus LPS (10 mg/L) group, CCK-8 (10^-6 mol/L) plus ZnPPIX and LPS (10 mg/L) group. Seven hours after LPS administration, ulterstructrual changes and content of malondialdehyde (MDA) of PASMCs in each group were investigated by electron microscopy and biochemical assay respectively. HO-1 mRNA and protein of PASMCs in the former4 groups were examined by reverse transcriptase polymerase chain reaction (RT-PCR) and immunocytochemistry staining. Changes of c-fos expression and activation of JNK of PASMCs in the former 4 groups were detected with immunocytochemistry staining and Western blot 30 min after LPS administration. RESULTS: The injuries of PASMCs and the increases of MDA content induced by LPS were alleviated and significantly reduced by CCK-8 (P<0.05). The specific HO-1 inhibitor-ZnPPIX could worsen LPS-induced injuries and weaken the protective effect of CCK-8. The expressions of c-fos, p-JNK protein and HO-1 mRNA and protein were all slightly increased in LPS group, and significantly enhanced by CCK-8 further (P<0.05). CONCLUSION: HO-1 may be a key factor in CCK-8 attenuated injuries of PASMCs induced by LPS, and HO-1 expression may be related to the activation of JNK and activator protein (AP-1).
基金Supported by the National Natural Science Foundation of China, No. 3870890
文摘AIM: To observe the gastric mucosal injury caused by hemorrhagic shock and reperfusion and to compare the effect between Salvia miltiorrhizae extract F (SEF) and cimetidine (CI) on it. METHODS: A model of hemorrhage/reperfusion injury was produced by Itoh method. Wistar rats were randomly divided into three groups: 0.9% sodium chloride treatment group (NS group), SEF treatment group (SEF group), and CI treatment group (CI group). Saline, SEF and CI were injected respectively. The index of gastric mucosal lesions (IGML) was expressed as the percentage of lesion area in the gastric mucosa. The degree of gastric mucosal lesions was categorized into grades 0, 1, 2, 3. Atom absorption method was used to measure the intracellular calcium content. Radioimmunoassay was used to measure the concentrations of prostaglandins. RESULTS: IGML (%) and grade 3 (%) were 23.18±6.82, 58.44±9.07 in NS group, 4.42±1.39, 20.32±6.95 in SEF group and 3.74±1.56, 23.12±5.09 in CI group, and the above parameters in SEF group and CI group decreased significantly (IGML: SEF vs NS, t=6.712, P=0.000<0.01; CI vs NS, t=6.943, P=0.000<0.01; grade 3: SEF vs HS, t=8.386, P=0.000; CI vs HS, t=8.411, P= 0.000), but the grade 0 and grade 1 damage in SEF group (22.05±5.96, 34.12±8.12) and CI group (18.54±4.82, 30.15±7.12) were markedly higher than those in NS group (3.01±1.01, 8.35±1.95; grade 0: SEF vs HS, t=8.434, P=0.000<0.01; CI vs NS, t=7.950, P=0.000<0.01; grade 1: SEF vs NS, t =8.422, P=0.000<0.01; CI vs NS, t=8.448, P=0.000<0.01). The intracellular calcium content (μg/mg) in SEF group (0.104±0.015) and CI group (0.102±0.010) was markedly lower than that in NS group (0.131±0.019, SEF vs NS, t=2.463, P=0.038<0.05; CI vs HS, t=3.056, P=0.017<0.05). The levels (pg/mg) of PGE_2, 6-keto-PGF_(1α) and 6-keto-PGF_(1α)/TXB_2 were 540±183, 714±124,17.38±5.93 in NS group and 581±168, 737±102, 19.04±8.03 in CI group, 760±192,1 248±158, 33.42±9.24 in SEF group, and the above parameters in SEF group markedly raised (PGE_2: SEF vs NS, t=2.282, P=0.046<0.05; SEF vs CI, t=2.265, P=0.047<0.05; 6-keto-PGF_(1α): SEF vs NS, t=6.583, P=0.000<0.000; SEF vs CI, t=6.708, P=0.000<0.01; 6-keto-PGF_(1α)/TXB_2: SEF vs NS, t=3.963, P=0.003<0.001; SEF vs Cl, t=3.243, P=0.009<0.01), whereas TXB_2 level in SEF group (45.37±7.54) was obviously lower than that in NS group (58.28±6.74, t=3.086, P=0.014<0.05) and CI group (54.32±6.89, t=2.265, P=0.047<0.05). No significant difference was shown between NS group and CI group (PGE_2: t=0.414, P=0.688>0.05; 6-keto-PGF_(1α): t=0.310, P=0.763>0.05; TXB_2: t=1.099, P=0.298>0.05; 6-keto-PGF_(1α)/TXB_2: t=0.372, P=0.718>0.05). CONCLUSION: Both SEF and CI could inhibit reperfusioninduced injury in gastric mucosa, but with different mechanisms. SEF could not only enhance the protective effect of gastric mucosa, but also abate the injury factors, while CI can only abate the injury factors.
基金the National Natural Science Foundation of China for Key Program,No.39830210a grant from the National Natural Science Foundation of China,No.39960067a grant from National Key Basic Research and Development Program,No.2002CB512904
文摘AIM: To understand the response of human REV3gene to gastric cancer inducing carcinogen N-methyl-N'-nitro-Nnitrosoguanidine (MNNG) and its role in human mutagenesis.METHODS: The response of the human REV3 gene to MNNG was measured in human 293 cells and FL cells by RT-PCR. By using antisense technology, mutation analysis at HPRTlocus (on which lesion-targeted mutation usually occurs) was conducted in human transgenic cell line FLREV3- by 8-azaguanine screening, and mutation occurred on undamaged DNA template was detected by using a shuttle plasmid pZ189 as the probe in human transgenic cell lines 293-REV3- and FL-REV3-. The blockage effect of REV3 was measured by combination of reverse transcriptionpolymerase chain reaction to detect the expression of antisense REV3 RNA and Western blotting to detect the REV3protein level.RESULTS: The human REV3 gene was significantly activated by MNNG treatment, as indicated by the upregulation of REV3 gene expression at the transcriptional level in MNNG-treated human cells, with significant increase of REV3 expression level by 0.38 fold, 0.33 fold and 0.27fold respectively at 6 h, 12 h and 24 h in MNNG-treated 293 cells (P＜0.05); and to 0.77 fold and 0.65 fold at 12 h and 24 h respectively in MNNG-treated FL cells (P＜0.05).In transgenic cell line (in which REV3 was blocked by antisense REV3 RNA), high level of antisense REV3 RNA was detected, with a decreased level of REV3 protein.MNNG treatment significantly increased the mutation frequencies on undamaged DNA template (untargeted mutation), and also at HPRT locus (lesion-targeted mutation). However, when REV3 gene was blocked by antisense REV3 RNA, the MNNG-induced mutation frequency on undamaged DNA templates was significantly decreased by 3.8 fold (P＜0.05) and 5.8 fold (P＜0.01)respectively both in MNNG-pretreated transgenic 293 cells and FL cells in which REV3was blocked by antisense RNA,and almost recovered to their spontaneous mutation levels.The spontaneous HPRT mutation was disappeared in REV3disrupted cells, and induced mutation frequency at HPRT locus significantly decreased from 8.66×10-6 in FL cells to 0.14×10-6 in transgenic cells as well (P＜0.01).CONCLUSION: The expression of the human REV3 can be upregulated at the transcriptional level in response to MNNG. The human REV3 gene plays a role not only in lesion-targeted DNA mutagenesis, but also in mutagenesis on undamaged DNA templates that is called untargeted mutation.
基金Supported by the National Natural Sciences Foundation of China(General Program: 3037030 30270657 and Key Program: 30230150) Early Phase Study Supported by the Key Basic Research Project (2002-CCA04100) the National High Technology Research and Devel
文摘Objective To deduce all potential ligands undiscovered experimentally by searching all the proteins containing same C-termini, which can bind a certain PDZ domain. Methods We developed a JAVA program for searching short exact sequence matches at C-terminus. According to the known C-termini, which PDZ domains recognized experimentally, Swissprot database has been searched by this program for all potential ligands. Results Some PDZ domains may have more potential ligand proteins, which are undiscovered yet experimentally. These bioinformatic results also provide clues for studying functions of hypothetical proteins and PDZ domains’ protein interactions in many different organisms. Conclusion The results may provide useful clues for discovering potential functions of hypothetical proteins and new functions of known proteins.
基金Supported by grands from theNaturalScience Foundation of China(39925012 and 30170221 ),and the Scienceand Technology Committee of China (G1999054007).
文摘Objective To investigate effect of inhibiting melatonin biosynthesis on activities of protein kinase A (PKA), glycogen synthase kinase-3 (GSK-3) and tau phosphorylation at PS214 and M4 epitopes using haloperidol, a specific inhibitor of 5-hydroxyindole-O-methyltransferase. Methods Brain ventricular and intraperitoneal injections were used for haloperidol administration, Western blots for tau phosphorylation, 32P-labeling for PKA and GSK-3 activity, and high performance liquid chromatograph for detection of serum melatonin levels. Results Haloperidol injection through the lateral ventricle and intraperitoneal reinforcement significantly stimulated PKA activity with a concurrent hyperphosphorylation of tau at M4 (Thr231/Ser235) and PS214 (Ser214) sites. Prior treatment of the rats using melatonin supplement for one week and reinforcement during the haloperidol administration arrested PKA activity and attenuated tau hyperphosphorylation. GSK-3 activity showed no obvious change after haloperidol injection, however, melatonin supplements and reinforcements during haloperidol infusion inactivated basal activity of GSK-3. Conclusion Decreased melatonin may be involved in Alzheimer-like tau hyperphosphorylation, and overactivation of PKA may play a crucial role in this process.
基金Supported by the National Key Basic Research and Development Program of China,No.2002CB512901National Natural Science Foundation of China,No.39770868 and Natural Science Foundation of Zhejiang Province,No.397490
文摘AIM: To identify the new alternative splicing variants of human CYP2D6 in human extratumoral liver tissue with RT-PCR and sequencing. METHODS: Full length of human CYP2D6 cDNAs was amplificated by reverse transcription-polymerase chain reaction (RT-PCR) from a human extratumoral liver tissue and cloned into pGEM-T vector. The cDNA was sequenced. Exons from 1 to 4 of human CYP2D6 cDNAs were also amplificated by RT-PCR from extratumoral liver tissues of 17 human hepatocellular carcinomas. Some RT-PCR products were sequenced. Exons 1 to 4 of CYP2D6 gene were amplified by PCR from extratumoral liver tissue DNA. Two PCR products from extratumoral liver tissues expressing skipped mRNA were partially sequenced. RESULTS: One of the CYP2D6 cDNAs had 470 nucleotides from 79 to 548 (3' portion of exons 1 to 5' portion of exon 4), and was skipped. Exons 1 to 4 of CYP2D6 cDNA were assayed with RT-PCR in 17 extratumoral liver tissues. Both wild type and skipped mRNAs were expressed in 4 samples, only wild type mRNA was expressed in 5 samples, and only skipped mRNA was expressed in 8 samples. Two more variants were identified by sequencing the RT-PCR products of exons 1 to 4 of CYP2D6 cDNA. The second variant skipped 411 nucleotides from 175 to 585. This variant was identified in 4 different liver tissues by sequencing the RT-PCR products. We sequenced partially 2 of the PCR products amplified of CYP2D6 exon 1 to exon 4 from extratumoral liver tissue genomic DNA that only expressed skipped mRNA by RT-PCR. No point mutations around exon 1, intron 1, and exon 4, and no deletion in CYP2D6 gene were detected. The third variant was the skipped exon 3, and 153 bp was lost. CONCLUSION: Three new alternative splicing variants of CYP2D6 mRNA have been identified. They may not be caused by gene mutation and may lose CYP2D6 activity and act as a down-regulator of CYP2D6.
基金This study was supported by the Science&Technology Commission of Guangdong Province,P.R.China
文摘Objective To investigate the sensitivity of the human sperm motility assay for detecting endotoxin in culture mediumMaterials &. Methods Motile sperm were separated and exposed to different concentrations of endotoxin (0.5 ng/mL, 1ng/mL, 10ng/mL, 1000ng/mL, 10 000ng/ mL, and 50 000ng/mL), and sperm motility was determined after incubation. Effects of endotoxin on sperm motility in media without albumin were also examined. In addition, at the same concentrations of endotoxin (0. 5ng/mL, 1 ng/mL, and 10 ng/ mL ) , the sensitivity of the human sperm motility assay was compared to those of 1-cell and 2-cell mouse embryo bioassays.Results At levels of 0. 5ng/mL-1000ng/mL endotoxin in media with 2mg/mL albumin, sperm did not show significant change in motility during 24 h of incubation when compared with the control (P>0. 05). However, the sperm motility was significantly inhibited at endotoxin dosages of 10 000 and 50 000 ng/mL. In the absence of albumin supplementation, at endotoxin levels of 50 000ng/mL, and 1 000ng/mL, there was a marked decrease in sperm motility compared with the control after 2 h or 8 h of incubation, respectively (P<0. 01). In media containing 0. 5 ng/mL and 1 ng/ mL endotoxin, 1-cell and 2-cell mouse embryos had significantly reduced developmental rates in all developmental stages, and at the level of 10ng/mL, the development of the embryos was arrested. Conclusion The human sperm motility assay could detect high levels of endotoxin in culture medium but its sensitivity to endotoxin would be inferior to that of the 1-cell or 2-cell mouse embryo bioassay. In the absence of albumin supplementation, the sensitivity of the sperm motility assay could be improved.
文摘Abnormal deposition of amyloid-p(Ap) peptides and formation of neuritic plaques are recognized as pathological processes in Alzheimer's disease (AD) brain. By using amyloid precursor protein (APP) transfected cells, this study aims to investigate the effect of overproduction of Aβ on cell differentiation and cell viability. It was shown that after serum withdrawal, untransfected cell (N2a/Wt) and vector transfected cells (N2a/vector) extended long and branched cell processes, whereas no neurites was induced in wild type APP (N2a/APP695) and Swedish mutant APP (N2a/ APPswe) transfected N2a cells. After differentiation by serum withdrawal, the localization of APP/AP and neurofilament was extended to neurites, whereas those of APP-transfected cells were stillrestricted within the cell body. Levels of both APP and Aβ were significantly higher in N2a/APP695 and N2a/APPswe than in N2a/Wt, as determined by Western blot and Sandwich ELISA, respectively. To further investigate the effect of A0 on the inhibition of cell differentiation, we added exogenously the similar level or about 10-times of the AP level produced by N2a/APP695 and N2a/APPswe to the culture medium and co-cultured with N2a/Wt for 12 h, and we found that the inhibition of serum withdrawal-induced differentiation observed in N2a/APP695 and N2a/APPswe could not be reproduced by exogenous administration of AP into N2a/Wt. We also observed that neither endogenous production nor exogenous addition of Aβ1-40 or Aβ1-42, even to hundreds fold of the physiological concentration, affected obviously the cell viability. These results suggest that the overproduction of AP could not arrest cell differentiation induced by serum deprivation and that, at least to a certain degree and in a limited time period, is not toxic to cell viability.
文摘Information about the mechanisms that generate mutationsin eukaryotes is likely to be useful for understanding humanhealth concerns, such as genotoxicity and cancer.Eukaryotic mutagenesis is largely the outcome of attacksby' endogenous and environmental agents. Except for DNArepair, cell cycle checkpoints and DNA damage avoidance,cells have also evolved DNA damage tolerance mechanism,by which lesion-targeted mutation might occur in thegenome during replication by specific DNA polymerases tobypass the lesions (translesion DNA synthesis, TLS), ormutation on undamaged DNA templates (untargetedmutation) might be induced. DNA polymerase ζ (poiζ),which was found firstly in budding yeast Saccharomycescerevisiae and consists of catalytic subunit scRev3 and stimulating subunit scRev7, has Received more attention in recent years. Poi ζ is a member of DNA polymerase δsubfamily, which belongs to DNA polymerase B family, and exists in almost all eukaryotes. Human homolog of the scRev3gene is located in chromosome region 6q21, and the mouse equivalent maps to chromosome 10, distal to the c-myb gene and close to the Macs gene. Alternative splicing, upstream out-of frame ATG can be found in yeast scRev3, mouse and human homologs. Furthermore, the sequence from 253-323 immediate upstream of the AUG initiator codon has the potential to form a stem-loop hairpin secondary structure in REV3 mRNA, suggesting that human REV3 protein may be expressed at low levels in human cells under normal growth conditions. The functional domain analysis showed that yeast Rev3-980 tyrosine in conserved region II is at the polymerase active site. Human REV3 amino acid residues 1 776-2 195 provide a REV7binding domain, and REV7 amino acid residues 1-211provide a bind domain for REV1, REV3 and REV7 itself.More interestingly, REV7 interacts with hMAD2 and therefore might function in the cell cycle control by affecting the activation of APC (anaphase promoting complex).Currently it has been known that poi ζ is involved in most spontaneous mutation, lesion-targeted mutation via TLS,chemical carcinogen induced untargeted mutation and somatic hypermutation of antibody genes in mammalian.In TLS pathway, polζ acts as a "mismatch extender" with combination of other DNA polymerases, such as pol t. Unlike in yeast, it was found that pol ζ also functioned in mouse embryonic development more recently. It was hypothesized that the roles of pol ζ in TLS and cell cycle control might contribute to mouse embryonic lethality.
文摘Aim: To investigate the effect of experimental varicocele on mitochondrial calcium and cytochrome C of the epididymal cells in adolescent rats. Methods: Forty male adult Wistar rats were divided into two groups randomly: the varicocele group (VG) and the sham operated group (SOG). Varicocele was produced by partial ligation of the left renal vein. Bilateral epididymides were removed after ten weeks. The mitochondrial calcium and cytochrome C levels of the epididymal cells were determined. Results: The mi-tochondrial calcium was decreased (P<0.01) while the cytochrome C increased (P<0.05) markedly in the experimental group compared with the controls. Conclusion: Varicocele-induced calcium dyshomeostasis and mitochondrial damage of the epididymal cells may play an important role in causing subfertility.
基金This work was supported by the National Nature Science F oundation of China (No. 3 983 0 2 1 0 ) and the Natural Science F oundation of Zhe-jiang Province (No, 3 97454and No. 3 992 50
