• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.86-89
• /
• 2002

Blue light activates proton pump, and creates electrical gradient across the plasma membrane and drives $K^{+}$ uptake in stomatal guard cells. In this presentation, we provide evidence for regulatory mechanisms of the pump and the identification of blue light receptor. The pump is shown to be the plasma membrane H$^{+}$- ATPase and is activated through phosphorylation of the C-terminus. Phosphorylation occurred and 14-3-3 protein bound to the phosphorylation site. The binding of 14-3-3 protein was required for the H$^{+}$-ATPase activation. We also found that phot1 phot2 double mutant does not respond to blue light but other mutants respond to blue light by stomatal opening. However, all these mutants are capable of stomatal opening in the presence of fusicoccin, an activator of the H$^{+}$-ATPase. These results suggest that both photl and phot2 act as blue light receptors in guard cells.d cells.

• Journal of Gastric Cancer
• /
• v.5 no.3 s.19
• /
• pp.191-199
• /
• 2005

Background: Though infections of Helicobacter pylori (H. pylori) are closely associated with activation of host angiogenesis, the underlying mechanisms, as well as the strategy for its prevention, have not been identified. Here, we investigated a causal role of H. pylori infection in angiogenesis of gastric mucosa and a potent inhibitory effect of a gastric proton pump inhibitor (PPI) on the gastropathy. Materials and Methods: A comparative analysis of CD 34 expression in tissues obtained from 20 H. pylori-associated gastritis and 18 H. pylori-negative gastritis patients was performed. Expression of $HIF-1{\alpha}$ and VEGF were tested by using RT-PCR. To evaluate the direct effect of H. pylori infection on differentiation of endothelial HUVEC cells, we carried out an in vitro angiogenesis assay. Results: H. pyfori-associated gastritis tissues showed significantly higher density of $CD34^+$ blood vessels than did H. pylori-negative gastritis tissues, and the levels were well correlated with expressions of $HIF-1{\alpha}$. Conditioned media from H. pylori-infected gastric mucosal cells stimulated a tubular formation of HUVEC cells. We also found a significant inhibitory effect of PPI, an agent frequently used for H. pylori eradication, on H. pylori-induced angiogenesis. This drug effectively inhibited the phosphorylation of MAP kinase ERK1/2, which is a principal signal for H. pylori-induced angiogenesis. Conclusion: The fact that PPls can down-regulate H. pylori-induced angiogenesis suggest that anti-angiogenic treatment using PPI may be a preventive approach for H. pylori-associated carcinogenesis.

• Journal of Microbiology
• /
• v.39 no.1
• /
• pp.62-66
• /
• 2001

Unlike eukaryotic efflux pumps energized by ATPase bacterial efflux pumps are energized by the proton motive force. That is the reason why CCCP, an inhibitor of proton motive forcer is widely used to study the bacterial efflux pump. In many cases, efflux systems have been observed only in quinolone-resistant bacteria. Most of the quinolone-susceptible strains have been found to maintain little efflux pump. However some susceptible bacteria skewed the increased intracellular quinolone concentration only at a low concentration (0.01 or 0.1 mM) but net at a high concentration (1 mM) of CCCP. If bacterial cells were killed at high concentrations of CCCP and lost the integrity of their membranes, the intracellular quinolone would leak out from cells with no efflux system. The efflux pump system in the quinolone-susceptible strains could net be detected at the same concentration used for resistant bacteria. To test this hypothesist the intracellular quinolone concentration in the quinolone-susceptible and -resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was assayed at various concentrations of CCCP. Since the effect of CCCP is very rapid, the survival of bacteria was observed by assaying the DNA synthesis in 5 min. In the case of E. coli, but not P. aeruginosa or S. aureus, the quinolone susceptible strain was more susceptible to CCCP than the quinolone resistant ones, especially when the incubation with CCCP was extended. Decrease of the intracellular quinolone concentration resulted in a false result-no or weak efflux system in the quinolone susceptible strains. Results suggested that the concentration of CCCP should be optimized in order to detect the efflux system in the quinolone susceptible strains of E. coli.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.106-109
• /
• 2002

Archaeal rhodopsins possess retinal molecule as their chromophores, and their light-energy and light-signal conversions are triggered by all-trans to 13-cis isomerization of the retinal chromophore. Relaxation through structural changes of protein then leads to functional processes, proton pump in bacteriorhodopsin (bR) and transducer activation in phoborhodopsin (pR). It is known that sensory rhodopsins can pump protons in the absence of their transducers. Thus, there should be common and specific features in their protein structural changes for function. In this paper, our r ecent studies on pR from Natronobacterium pharaonis (ppR) by means of low-temperature Fourier-transform infrared (FTIR) spectroscopy are compared with those of bR. In particular, protein structural changes upon retinal photoisomerization are studied. Comparative investigation of ppR and bR revealed the similar structures of the polyene chain of the chromophore and water-containing hydrogen-bonding network, whereas the structural changes upon photoisomerization were more extended in ppR than in bR. Extended protein structural changes were clearly shown by the assignment of the C=O stretch of Asnl05. FTIR studies of a ppR mutant with the same retinal binding site as in bR revealed that the Schiff base region is important to determine their colors.

• Applied Microscopy
• /
• v.22 no.2
• /
• pp.84-96
• /
• 1992

This study was carried out to examine the $H^+$ transport mechanism by observing the properties of cellular membrane having an ${\alpha}$ type of carbonic anhydrase (CA)-containing cells in turtle urinary bladder. The urinary bladder consists of a heterogenous population of cells. As a result of fine observation with traditional thin-section electron microscopy. the bladder epithelium has three different cell types on mucosal surface. They are a basal cell, a granular cell and a third type of CA-rich cell. The CA-rich cells are divided into two distinct smaller groups within them and called them ${\alpha}$ type and ${\beta}$ type of CA cells. The ${\alpha}$ type of CA cells are responsible for the proton secretion using the proton pumps on the apical plasma membrane, while the ${\beta}$ type of CA cells secrete bicarbonate via an oppositely-directed proton pumps in their basolateral plasma membrane. After performing the freeze-fracture technique, it was shown that there were distributed a large number of intramembranous particles having a special structure on the apical membrane of ${\alpha}$ type of CA-rich cells in the process of their $H^+$ secretion. In turtle bladder ${\alpha}$ type of CA-rich cells, this particle was the only prominent structure in the apical membrane. These intramembrane rod-shaped particles probably represent the integral membrane components of the proton pump. This result may explain that carbonic anhydrase within epithelial cell of urinary bladder takes part in formation of $H^+$ and bicarbonate, that active transport of $H^+$ is done, and that the reabsorption of bicarbonate suggests transport mechanism containing $H^+$ secretion. However, it seems that more studies are required for considering their regular transport pathway.

• Applied Microscopy
• /
• v.19 no.2
• /
• pp.119-137
• /
• 1989

It has been shown in this and earlier investigation that the turtle bladder mucosa has three main cell types on their mucosal surface. They are the granular cells, ${\alpha}$ CA cells, and ${\beta}$ CA cells. The three major transport mechanisms that occurs in the turtle bladder are sodium reabsorption, proton secretion, and bicarbonate secretion. In the present work the trans-port mechanisms by bladder epithelial cells of freshwater turtle, Pseudemys scripta, are summarized as follows. 1. The granular cells play an important role in sodium transport, while the ${\alpha}$ and ${\beta}$ CA cells do not appear to play a determining role in sodium transport. 2. It appears that the active sodium transport in the granular cells occurs in two-step process, implying that first, sodium diffuses into the cells, followed by an energy-dependent efflux step, which is catalyzed by the ouabain-sensitive Na-K ATPase. 3. The ${\alpha}$ type of CA cells are responsible for the proton secretion using the proton pump on the apical plasma membrane, while the ${\beta}$ type of CA cells are believed to be responsible for bicarbonate secretion. 4. When looked at under freeze-fracture electron microscopy, the apical plasma membrane of ${\alpha}$ cells have a characteristic population of rod-shaped intramembranous particles which are believed to be components of the proton pumps. Conversely, ${\beta}$ type of CA cells show rod-shaped particles in their basolateral plasma membranes, which is consistent with the proton absorptive, bicarbonate secretory mechanism. 5. In the turtle bladder, the ${\alpha}$ and ${\beta}$ type of cells are believed to be both responsible for proton transport, but in opposite directions.

• Clinical and Experimental Pediatrics
• /
• v.62 no.10
• /
• pp.400-404
• /
• 2019

Background: An increase in the numbers of patients with gastrointestinal symptoms has recently been observed. Purpose: To investigate the effects of proton pump inhibitor (PPI) therapy on intestinal inflammation in children and adolescents as confirmed by clinical manifestations and objectively assessed by fecal calprotectin (FC) level measurement. Methods: Consecutive children (aged 3-18 years) who presented with gastrointestinal symptoms and were treated with or without PPI for at least 1 month were enrolled. Patients were divided into PPI and non-PPI groups. The PPI group was further subdivided by treatment duration and type of PPI used. Stool samples were collected for FC evaluation at baseline and after treatment and clinical data and FC levels were compared between the groups. Results: Fifty-one patients (15 boys, 36 girls) were enrolled in the study. The PPI group included 37 patients, while the non-PPI group included 14 patients. Clinical symptoms were not significantly different. FC levels and laboratory results, including C-reactive protein levels, white blood cell count, and absolute neutrophil count, were not statistically different before versus after PPI treatment. After treatment, FC levels decreased to 8.1 mg/kg (-575.4 to 340.3 mg/kg) in the PPI group and increased to 5.6 mg/kg (-460.0 to 186.9 mg/kg) in the non-PPI group compared to those before treatment (P=0.841). The number of patients with increased FC levels was not significantly different between the 2 groups (48.6% vs. 64.3%, P=0.363), similar to that observed in patients with an FC level > 50 mg/kg (24.3% and 7.1%, P=0.250). PPI therapy type and duration did not affect the FC levels (P=0.811 and P=0.502, respectively). Conclusion: Although we aimed to confirm the evidence of intestinal inflammation due to PPI use in children and adolescents through clinical symptoms and FC measurement, no significant changes were observed.

• Journal of Food Hygiene and Safety
• /
• v.31 no.4
• /
• pp.286-293
• /
• 2016

This study is an experiment for gastric protective effects of ursolic acid. In order to identify the effects of ursolic acid on gastrointestinal disorder, acute and chronic gastritis were also observed using HCl ethanol and indomethacin-induced gastric lesion models, respectively. As for gastric acid, it was also identified through proton pump ($H^+/K^+-ATPase$) inhibiting activity. In regards to protective factor for gastric damage, prostaglandin $E_2$ ($PGE_2$) was quantitatively analyzed. Antibacterial activity experiment was done on Helicobacter pylori (H.pylori), which is known to be the causing factor of chronic gastritis, gastric ulcer and gastric cancer. By making use of AGS cell, it was confirmed that ursolic acid was involved in apoptosis of gastric cancer cell through 4',6-diamidino-2-phenylindol (DAPI) staining and flow cytometry analysis. As a result, ursolic acid reduced gastric lesions caused by HCl ethanol and indomethacin. Ursolic acid inhibited acid secretion by inhibiting proton pump ($H^+/K^+-ATPase$), which is the gastric acid secreting enzyme involved at the final phase of gastric acid secretion. And ursolic acid was identified with gastric mucosa protection effects by increasing the concentration of $PGE_2$, a protective factor of gastric mucosa preservation. The antibacterial activity on H. pylori, which is aggressive factor in gastrointestinal disorder, ursolic acid showed inhibitory effects on H. pylori colonization. In the DAPI nuclear staining, unlike the control group, shape of the nucleus has deformed, and has been observed either shrinked cell or chromatin condensation phenomenon. In the Flow cytometry assay, confirmed the growth rate of apoptosis in a concentration-dependent manner.

• Journal of Gastric Cancer
• /
• v.17 no.2
• /
• pp.120-131
• /
• 2017

Purpose: Tumor bleeding is a major complication in inoperable gastric cancer. The study aim was to investigate the effects of proton pump inhibitor (PPI) treatment for the prevention of gastric tumor bleeding. Materials and Methods: This study was a prospective double-blind, randomized, placebo-controlled trial. Patients with inoperable gastric cancer were randomly assigned to receive oral lansoprazole (30 mg) or placebo daily. The primary endpoint was the occurrence of tumor bleeding, and the secondary endpoints were transfusion requirement and overall survival (OS). Results: This study initially planned to enroll 394 patients, but prematurely ended due to low recruitment rate. Overall, 127 patients were included in the analyses: 64 in the lansoprazole group and 63 in the placebo group. During the median follow-up of 6.4 months, tumor bleeding rates were 7.8% and 9.5%, in the lansoprazole and placebo groups, respectively, with the cumulative bleeding incidence not statistically different between the groups (P=0.515, Gray's test). However, during the initial 4 months, 4 placebo-treated patients developed tumor bleeding, whereas there were no bleeding events in the lansoprazole-treated patients (P=0.041, Gray's test). There was no difference in the proportion of patients who required transfusion between the groups. The OS between the lansoprazole (11.7 months) and the placebo (11.0 months) groups was not statistically different (P=0.610). Study drug-related serious adverse event or bleeding-related death did not occur. Conclusions: Treating patients with inoperable gastric cancer with lansoprazole did not significantly reduce the incidence of tumor bleeding. However, further studies are needed to evaluate whether lansoprazole can prevent tumor bleeding during earlier phases of chemotherapy (ClinicalTrial.gov, identifier No. NCT02150447).

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.6
• /
• pp.1549-1554
• /
• 2007

To verify the effects of JAUN-1, which is a water-extracted herbal mixture, on gastroenteric disorders induced by 0.1 percent of iodoacetamide (IA) in rats. We divided four groups, $Na{\"{\i}}ve$ + Distilled Water (DW), 0.1% IA + DW, 0.1% IA + Proton pump inhibitor (Lansoprazole, 5 mg/kg) and 0.1% IA + Herbal mixture (JAUN-1, 50mg/kg) and performed following experimental methods to confirm its advantageous effects against ulcerogenic stomach in rats induced by 0.1% IA; cell cytotoxicity, analysis of lesions score, Hematoxylin & Eosin (H&E) stain, RT-PCR for ${\beta}-actin$, COX-1 and COX-2 and evaluation of intestinal prokinetic activity. No cytotoxicity was elucidated at the concentration of 1, 5, 10, 50, 100, $500\;{\mu}g/ml$ and 1mg/ml JAUN-1 through MTT Assay using by human stomach epithelial AGS cells, respectively. In addition, the JAUN-1 treated group and the lansoprazole treated group significantly decreased in lesions score compared to the DW treated group in the gastritis induced rat model, and results of immunohistochemistry by H&E staining showed that histological recovery in Proton Pump Inhibitor (PPI) and JAUN-1 treated groups rather than the DW administrated group. Another outcome was that ${\beta}-actin$ relative COX-2 expression level was significantly promoted in the DW treated group while ${\beta}-actin$ relative COX-1 expression level was no meaningful change in this rat model. Finally, intestinal prokinetic activity was recovered from low level of prokinetic activity due to 0.1% IA induced gastritis to the similar level of Normal group. These results suggested that JAUN-1 may have beneficial effects against 0.1% IA-induced gastritis rat model through decreasing lesions score, histological recovery, ${\beta}-actin$ relative COX-1, 2 expression level and prokinetic activity.