Kir2 1. Moreover, drop of pHi reduced the M 1 induced inhibition of Kir3 1/3 4 currents, and enhanced the desensitization of M 2 induced Kir3 1/3 4 activation. CONCLUSION The basal currents and M receptor induced currents of Kir3 1/3 4 can be regulated by intracellular pH. These changes may play some important roles in pathophysiological conditions like cardiac ischemia.

Aim To study the modulation of KCNQ2/3 potassium cha nn els by extracellular pH.Methods In vitro transcription was used to synthesize cRNA of KCNQ2/3 potassium channels.The cRNA was injected into Xenopus oocytes to express the KCNQ2/3 channel.The modulation of KCNQ2/3 potass ium channels by extracellular pH was studied by two electrodes voltage clamp tec hniques.Results KCNQ2/3 currents were inhibited and current-vo ltage relationship of activation were shifted to the right with decreased extrac ellular pH. pH modulation of KCNQ2/3 currents was voltage dependent,with a more pronounced effect at more negative potentials above the activation threshold (-60 mV). Extracelluar pH also decreased activation and deactivation kinetics of KCNQ2/3 currents.Conclusion KCNQ2/3 channels, known to contr ibute to neuronal excitability, were modulated by extracelluar pH. The profound effects of the extracelluar pH exerted on KCNQ2/3 channel may play an important role during physiology neuronal activity and pathological events such a s epileptic seizures, cerebral ischemia and shock etc.

Aim To visualize the dynamics of PtdIns(4,5)P 2 hyd ro lysis and resynthesis, and modulate it by pharmacological agents wortmannin, LiC l, U73122 and neomycin. Methods We used a fusion construct of g reen fluorescent protein(GFP) with the PH domain of phospholipase C ?1(PL C ?1PH)(PLC ?1PH-GFP) known to bind PtdIns(4,5)P 2 specifically , and laser-scanning confocal microscopy to trace PtdIns(4,5)P 2 translocatio n. Results Stimulation of endogenous P 2Y receptors by ATP in CHO cells induced a reversible PLC ?1PH-GFP translocation, indicating Pt dIns(4,5)P 2 hydrolysis through the receptor-mediated phospholipase C (PLC) ac tivation. Wortmannin and LiCl did not affect the translocation of PLC ?1PH -GFP from plasma membrane to cytosol but blocked the recovery after the translo cation. The transient translocation from plasma membrane was blocked by the PLC inhibitor U73122 but was not affected by another PLC inhibitor neomycin. However , in the absence of PLC ?1PH-GFP expression, neomycin inlibited the recep tor-induced PLC hydrolysis of PtdIns(4,5)P 2.Conclusion PLC ?1PH-GFP can be used as a valuable fluorescence probe to visualize the dyn amic change of PtdIns(4,5)P 2 in living cells. Wortmannin, LiCl, U73122 and neo mycin have distinct modulation effects on PtdIns(4,5)P 2 metabolism. PLC ?1 PH,when bound to PtdIns(4,5)P 2,prevents neomycin from inhibiting PLC hydro lyzing PtdIns(4,5)P 2.

To investigate the effects of the effective component group of Xiaoxuming Decoction (XXM), a compound traditional Chinese herbal medicine, on cerebral mitochondria in rats with chronic cerebral ischemia.

To study the effects of the active components of Xiaoxuming Decoction (XXM), a compound traditional Chinese herbal medicine, on chronic cerebral ischemia in rats.

Aim To study the regulatory effects of PMA,a PKC activator,on Kir 2.3 channel function expressed in Xenopus oocytes and COS-7 cells,and PIP2 involvement in these regulations.Methods Kir 2.3 channel was expressed in Xenopus oocytes and COS-7 cell by RNA microinjection and DNA transfection using calcium phosphate precipitate,respectively.Two-electrode-voltage-clamp and whole-cell patch clamp were used to record the Kir 2.3 current in Xenopus oocytes and COS-7 cell.The PIP2 hydrolysis was detected by confocal microscopy.Results PMA significantly inhibited Kir 2.3 current in Xenopus oocytes.But PMA had no effect on the Kir 2.3 current expressed in COS-7 cell,in which activation of M1 receptor,however,induced a significant inhibition of Kir 2.3 current.It was reported recently that PMA could trigger the PIP2 hydrolysis in membrane of oocytes.Thus PKC inhibition of Kir 2.3 current seen in oocytes could be the result of PIP2 hydrolysis.Following the same line,the inability of PKC inhibition of Kir 2.3 current seen in COS-7 cells would suggest PKC could not induce PIP2 hydrolysis in these cells. This hypothesis was tested by monitoring the PIP2 level in COS-7 cell membrane by confocal microscopy.Dynamic changes in membrane PIP2 level were imaged using GFP fluorescence signal that had been tagged to the PLC?1PH domain known to be able to bind PIP2 specifically. There was no significant change of PIP2 level on COS-7 cell membrane after longtime treatment of PMA,whereas again,the activation of M1 receptor by ACh induced a significant change in the PIP2 level.These results were in perfect agreement with the electrophysiological results.Conclusions PMA,through activation of PKC,inhibited Kir 2.3 current expressed in Xenopus oocytes but not in COS-7 cells.Similarly PMA induced significant reduction in membrane PIP2 level in Xenopus oocytes but not in COS-7 cells. PIP2 hydrolysis plays an important role in PKC-induced inhibition of the Kir channel currents.

Objective To study the effect of microRNA-204 (miR-204) on the biological characteristics of breast cancer cells.Methods Real-time PCR was used to detect the expression of miR-204 in human breast cancer cell MDA-MB-231 after transfection of miR-204 mimics and inhibitor for 48 h.Flow cytometry was used to analyse the effect of miR-204 on the proliferation and apoptosis of MDA-MB-231 cells.The effect of miR-204 on the migration of MDA-MB-231 cells was detected by Transwell migration assay.Results Real-time PCR analysis showed that miR-204 mimics and inhibitors had significant effect compared with normal control group(P<0.01).Flow cytometry analysis showed that compared with normal control group,the number of G1 phase cells of miR-204 mimics group was significantly decreased(P<0.01),while the number of G2/M cells of miR-204 mimics group was significantly increased(P<0.01).In contrast,the number of G1 phase cells of miR-204 inhibitor group was significantly increased(P<0.01),while the number of G2/M cells of miR-204 inhibitor group was significantly decreased(P<0.01).miR-204 mimics group significantly promoted apoptosis,while the inhibitor group significantly inhibited apoptosis(P<0.01).Transwell migration analysis showed that the number of cells of miR-204 mimics group were significantly reduced,while the number of cells was significantly increased in the inhibitor group(P<0.01).Conclusion We find miR-204,which can promote cell apoptosis and inhibit cell proliferation and migration,is a negative factor in the breast cancer cell line MDA-MB-231.

OBJECTIVEOn basis of preliminary studies, to prepare the effective components group of Xiaoxuming decoction for anti-ischemic by combining chemical analysis with pharmacological activity screening.

METHODFree radical scavenging was assayed by DPPH method; the cell viability injured by hydrogen peroxide, L-glutamate, and hypoxia was determined by MTT assay; TBA method was used to determine mitochondrial lipid peroxidation.

RESULTComprehensive analysis of multi-target results, the comprehensive activities of 40% ethanol elution and the middle layer were the highest.

CONCLUSION40% ethanol elution and the middle layer were proportionally mixed as the effective components group of Xiaoxuming decoction.

Animals ; Brain ; blood supply ; drug effects ; metabolism ; Cell Survival ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Free Radical Scavengers ; pharmacology ; therapeutic use ; Glutamic Acid ; adverse effects ; Hydrogen Peroxide ; adverse effects ; Ischemia ; drug therapy ; metabolism ; Male ; Mitochondria ; drug effects ; metabolism ; PC12 Cells ; Rats ; Rats, Wistar

Objective To investigate the effects of homocysteine(Hcy) on myocardial injury and its possible mechanisms.Methods The selected H9C2 cardiomyocytes were intervened with various concentrations of Hcy and 4-phenyl butyric acid(4-PBA).The H9C2 cells were divided into the control group,H400 group and H400P2 group.The control group used the common medium,the H400 group was added with 400 μmol/L Hcy,the H400P2 group was added with 2 mmol/L 4-PBBA on the basis of H400 group.The cell livability was detected by using cell counting kit-8 (CCK-8).Apoptosis was evaluated by using the terminal deoxynucleotidyl transferase mediated nick-end labelling(TUNEL) staining.The ERO1α expression was determined by using immunocytochemistry,and the protein expression difference was determined by using Western blot.Results The injury of Hey on H9C2 cardiomyocytes showed a concentration-dependent manner(F=2 039.958,P＜0.01).Compared with the control group,the apoptosis percentages and expression levels of PERK,p-PERK,CHOP and ERO1α in the H400 group were increased(P＜0.01);while which in the H400P2 group were decreased,the difference was statistically significant(P＜0.05).Conclusion Hcy mediates myocardial apoptosis through endoplasmic reticulum stress mechanism.

OBJECTIVETo investigate the chemical constituents from the rhizomes of Zingiber officinale.

METHODIsolation and purification of the chemical constituents were carried out on the column chromatography of silica gel and Sephadex LH-20. The structures were elucidated on basis of physicochemical properties and spectral data.

RESULTTen compounds were isolated and identified as beta-sitosterol palmitate (1), isovanillin (2), glycol monopalmitate (3), hexacosanoic acid 2,3-dihydroxypropyl ester (4), maleimide-5-oxime (5), p-hydroxybenzaldehyde (6), adenine (7), 6-gingerol (8), 6-shogaol (9), and 1-(omega-ferulyloxyceratyl) glycerols (10a-10f).

CONCLUSIONCompounds 1-7 and 10a-10e are obtained from Z. officinale for the first time, and compound 10f is a new compound.

Ginger ; chemistry ; Rhizome ; chemistry