Functional role of bone morphogenetic protein-4 in isolated canine parietal cells

2007 ◽  
Vol 293 (3) ◽  
pp. G607-G614 ◽  
Author(s):  
Hildegard Nitsche ◽  
Saravanan Ramamoorthy ◽  
Mahdi Sareban ◽  
Nonthalee Pausawasdi ◽  
Andrea Todisco
Keyword(s):  
Gene Expression ◽  
Parietal Cell ◽  
Caspase 3 ◽  
Parietal Cells ◽  
Morphological Transformation ◽  
Western Blots ◽  
Mapk Activation ◽  
Morphogenetic Protein ◽  
Atpase Gene

Bone morphogenetic protein (BMP)-4 is an important regulator of cellular growth and differentiation. Expression of BMP-4 has been documented in the gastric mucosa. We reported that incubation of canine parietal cells with EGF for 72 h induced both parietal cell morphological transformation and inhibition of H+/K+-ATPase gene expression through MAPK-dependent mechanisms. We explored the role of BMP-4 in parietal cell maturation and differentiation. Moreover, we investigated if BMP-4 modulates the actions of EGF in parietal cells. H+/K+-ATPase gene expression was examined by Northern blots and quantitative RT-PCR. Acid production was assessed by measuring the uptake of [14C]aminopyrine. Parietal cell apoptosis was quantitated by Western blots with anti-cleaved caspase 3 antibodies and by counting the numbers of fragmented, propidium iodide-stained nuclei. MAPK activation and Smad1 phosphorylation were measured by Western blots with anti-phospho-MAPK and anti-phospho-Smad1 antibodies. Parietal cell morphology was examined by immunohistochemical staining of cells with anti-H+/K+-ATPase α-subunit antibodies. BMP-4 stimulated Smad1 phosphorylation and induced H+/K+-ATPase gene expression. BMP-4 attenuated EGF-mediated inhibition of H+/K+-ATPase gene expression and blocked EGF induction of both parietal cell morphological transformation and MAPK activation. Incubation of cells with BMP-4 enhanced histamine-stimulated [14C]aminopyrine uptake. BMP-4 had no effect on parietal cell apoptosis, whereas TGF-β stimulated caspase-3 activation and nuclear fragmentation. In conclusion, BMP-4 promotes the induction and maintenance of a differentiated parietal cell phenotype. These findings may provide new clues for a better understanding of the mechanisms that regulate gastric epithelial cell growth and differentiation.

scholarly journals Gene expression profiling of gastrin target genes in parietal cells

2006 ◽  
Vol 24 (2) ◽  
pp. 124-132 ◽  
Author(s):  
Renu N. Jain ◽  
Cynthia S. Brunkan ◽  
Catherine S. Chew ◽  
Linda C. Samuelson
Keyword(s):  
Gene Expression ◽  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Gastric Acid ◽  
Parietal Cell ◽  
Target Genes ◽  
Adaptor Protein ◽  
Parietal Cells ◽  
Cell Gene Expression ◽  
Cell Gene

Previous studies demonstrated that mice with a null mutation in the gene encoding the hormone gastrin have impaired gastric acid secretion. Hence, the aim of this study was to evaluate changes in the acid-secreting parietal cell in gastrin-deficient (GAS-KO) mice. Analysis of several transcripts encoding parietal cell proteins involved in gastric acid secretion showed reduced abundance in the GAS-KO stomach, including H+,K+-ATPase α- and β-subunits, KCNQ1 potassium channel, aquaporin-4 water channel, and creatine kinase B, which were reversed by gastrin infusion for 1 wk. Although mRNA and protein levels of LIM and SH3 domain-containing protein-1 (LASP-1) were not greatly changed in the mutant, there was a marked reduction in phosphorylation, consistent with its proposed role as a cAMP signal adaptor protein associated with acid secretion. A more comprehensive analysis of parietal cell gene expression in GAS-KO mice was performed using the Affymetrix U74AV2 chip with RNA from parietal cells purified by flow cytometry to >90%. Comparison of gene expression in GAS-KO and wild-type mice identified 47 transcripts that differed by greater than or equal to twofold, suggesting that gastrin affects parietal cell gene expression in a specific manner. The differentially expressed genes included several genes in signaling pathways, with a substantial number (20%) known to be target genes for Wnt and Myc.

scholarly journals Reduced Pepsin A Processing of Sonic Hedgehog in Parietal Cells Precedes Gastric Atrophy and Transformation

2007 ◽  
Vol 282 (46) ◽  
pp. 33265-33274 ◽  
Author(s):  
Yana Zavros ◽  
Meghna Waghray ◽  
Arthur Tessier ◽  
Longchuan Bai ◽  
Andrea Todisco ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sonic Hedgehog ◽  
Parietal Cell ◽  
Human Stomach ◽  
Gastric Atrophy ◽  
Parietal Cells ◽  
Tissue Extracts ◽  
Neoplastic Lesion ◽  
Acid Secreting ◽  
Normal Stomach

Sonic hedgehog (Shh) is not only essential to the development of the gastrointestinal tract, but is also necessary to maintain the characteristic acid-secreting phenotype of the adult stomach. Gastrin is the only hormone capable of stimulating gastric acid and is thus required to maintain functional parietal cells. We have shown previously that gastrin-null mice display gastric atrophy and metaplasia prior to progression to distal, intestinal-type gastric cancer. Because reduced levels of Shh peptide correlate with gastric atrophy, we examined whether gastrin regulates Shh expression in parietal cells. We show here that gastrin stimulates Shh gene expression and acid-dependent processing of the 45-kDa Shh precursor to the 19-kDa secreted peptide in primary parietal cell cultures. This cleavage was blocked by the proton pump inhibitor omeprazole and mediated by the acid-activated protease pepsin A. Pepsin A was also the protease responsible for processing Shh in tissue extracts from human stomach. By contrast, extracts prepared from neoplastic gastric mucosa had reduced levels of pepsin A and did not process Shh. Therefore processing of Shh in the normal stomach is hormonally regulated, acid-dependent, and mediated by the aspartic protease pepsin A. Moreover parietal cell atrophy, a known pre-neoplastic lesion, correlates with loss of Shh processing.

scholarly journals An Improved Method for the Study of Apoptosis-Related Genes Using the Tet-On System

2011 ◽  
Vol 16 (3) ◽  
pp. 332-337 ◽  
Author(s):  
Marc W. Halterman
Keyword(s):  
Gene Expression ◽  
Caspase 3 ◽  
Functional Characterization ◽  
Continuous Exposure ◽  
Genetic Screens ◽  
Pulse Dose ◽  
Target Effect ◽  
Regulated Gene Expression

Inducible gene expression systems are particularly useful for the functional characterization of genes with putative toxic properties. In the course of studying the role of hypoxia-regulated gene expression on cell survival using the tetracycline-inducible (tet-on) system, the author noted that exposure to the inducing ligand doxycycline (dox) inhibited caspase-3 cleavage in control samples. To limit this confounding off-target effect, he devised an in vitro pulse dose, delayed-injury protocol testing both dox and a novel tetracycline analog 9-t-butyl doxycycline (9-TB). Although 9-TB induced higher transgene levels compared to matched concentrations of dox, continuous exposure to both drugs inhibited caspase-3 cleavage in hypoxic samples. Conversely, a 6-h pulse dose of 9-TB followed by a 40-h washout period prior to hypoxic challenge activated robust transgene expression and lessened the inhibitory effects on caspase-3 processing. It is anticipated that these protocol modifications will improve the performance of tet-regulated genetic screens, particularly in situations where cell death is used as a primary end point.

An inhibitor of Ca2+/calmodulin-dependent protein kinase II, KN-62, inhibits cholinergic-stimulated parietal cell secretion

1992 ◽  
Vol 262 (1) ◽  
pp. G118-G122 ◽  
Author(s):  
Y. Tsunoda ◽  
M. Funasaka ◽  
I. M. Modlin ◽  
H. Hidaka ◽  
L. M. Fox ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Parietal Cell ◽  
Parietal Cells ◽  
Cell Secretion ◽  
Dependent Protein Kinase ◽  
Protein Kinase Ii ◽  
Dependent Protein ◽  
High Concentrations ◽  
Total Membrane

Cholinergic stimulation of parietal cell secretion is mediated by an increase in intracellular calcium. KN-62, a selective inhibitor of Ca2+/calmodulin-dependent protein kinase II (CaMK II), has recently been synthesized (Tokomitsu et al. J. Biol. Chem. 265: 4315-4320, 1990). To define the role of CaMK II in parietal cell secretion, we determined the effects of KN-62 on secretagogue-stimulated acid secretion in isolated rabbit parietal cells. Pretreatment of parietal cells with KN-62 resulted in the inhibition of carbachol-stimulated [14C]aminopyrine uptake over a concentration range of 3 to 60 microM (IC50 of 20 microM). KN-62 (60 microM) reduced carbachol-stimulated aminopyrine uptake to unstimulated levels. KN-62 did not alter carbachol-stimulated increases in cytoplasmic free Ca2+ concentration. High concentrations of KN-62 (60 microM) elicited a small decrease in aminopyrine uptake stimulated by forskolin, but did not significantly inhibit histamine stimulation. A potent CaMK II activity was identified in total membrane from parietal cells. These results suggest that CaMK II may mediate cholinergic-stimulated parietal cell secretion.

scholarly journals The Effect of Eight Weeks of Training on Positive and Negative Slopes with Royal Jelly Consumption on MGMT and ATPase Gene Expression Levels in the Hippocampus Tissue of Trimethyltin-Induced Alzheimer’s Rats

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Zahra Giti ◽  
Abdolali Banaeifar ◽  
Sajad Arshadi ◽  
Mohammad Ali Azarbayjani
Keyword(s):  
Gene Expression ◽  
Royal Jelly ◽  
Interactive Effect ◽  
Negative Slope ◽  
Common Disease ◽  
Positive Slope ◽  
Expression Levels ◽  
Atpase Gene ◽  
Gene Expression Levels

Background: Alzheimer’s disease (AD) is a common disease in the elderly that is associated with impaired metabolism and biology of the hippocampus. Although the role of exercise and natural antioxidants in improving the disease has been reported, the role of muscle contraction-related physical activity along with royal jelly (RJ) consumption is not yet well understood. Objectives: This study aimed to investigate the effect of eight weeks of training on positive slope (ETPS) and negative slope (ETNS) with royal jelly (RJ) consumption on O-6-methylguanine DNA methyltransferase (MGMT) and ATPase gene expression levels in the hippocampus tissue of trimethyltin (TMT)-induced AD rats. Methods: In this experimental trial, 36 male Sprague-Dawley AD rats (induced with 8 mg/kg TMT) were divided into (1) control + normal saline/royal jelly solvent) (Sh); (2) ETPS; (3) ETNS; (4) ETPS + RJ; (5) ETNS + RJ, and (6) RJ groups. Six rats were placed in the healthy control (HC) group. Then the training groups trained on ( + 15 and -15) slopes for eight weeks, five sessions per week, and each session lasted 60 minutes at a speed of 16 m/min. The royal jelly (RJ) groups received 100 mg/kg royal jelly per day by intraperitoneal injection. Results: ETNS, ETPS, ETPS + RJ, and ETNS + RJ increased MGMT gene expression (P ≥ 0.05). ETPS and ETPS + RJ also increased ATPase gene expression (P ≥ 0.05). However, RJ had no significant effect on increasing MGMT and ATPase gene expression in the hippocampus tissue of AD rats (P ≥ 0.05). Conclusions: It seems that the improvement of DNA damage markers and energy levels depends on the type of contraction. Although training on positive and negative slopes with royal jelly consumption has an interactive effect on DNA repair markers, training on a positive slope and royal jelly consumption has an interactive effect on ATPase gene expression.

Activation of Fgf-4 and HoxD gene expression by BMP-2 expressing cells in the developing chick limb

Development ◽  
1996 ◽  
Vol 122 (6) ◽  
pp. 1821-1828 ◽  
Author(s):  
D.M. Duprez ◽  
K. Kostakopoulou ◽  
P.H. Francis-West ◽  
C. Tickle ◽  
P.M. Brickell
Keyword(s):  
Gene Expression ◽  
Anterior Part ◽  
Ectopic Expression ◽  
Mirror Image ◽  
Limb Bud ◽  
Bone Morphogenetic Protein 2 ◽  
Morphogenetic Protein ◽  
Wing Bud ◽  
Hoxd Gene

Bone morphogenetic protein-2 (BMP-2) has been implicated in the polarizing region signalling pathway, which specifies pattern across the antero-posterior of the developing vertebrate limb. Retinoic acid and Sonic Hedgehog (SHH) can act as polarizing signals; when applied anteriorly in the limb bud, they induce mirror-image digit duplications and ectopic Bmp-2 expression in anterior mesenchyme. In addition, the two signals can activate Fgf-4 expression in anterior ridge and HoxD expression in anterior mesenchyme. We tested the role of BMP-2 in this signalling cascade by ectopically expressing human BMP-2 (hBMP-2) at the anterior margin of the early wing bud using a replication defective retroviral vector, and found that ectopic expression of Fgf-4 was induced in the anterior part of the apical ectodermal ridge, followed later by ectopic expression of Hoxd-11 and Hoxd-13 in anterior mesenchyme. This suggests that BMP-2 is involved in regulating Fgf-4 and HoxD gene expression in the normal limb bud. Ectopically expressed hBMP-2 also induced duplication of digit 2 and bifurcation of digit 3, but could not produce the mirror-image digit duplications obtained with SHH-expressing cells. These results suggest that BMP-2 may be involved primarily in maintenance of the ridge, and in the link between patterning and outgrowth of the limb bud.

Role of enhanced Na+ entry in the control of Na,K-ATPase gene expression by serum

1994 ◽  
Vol 137 (1) ◽  
Author(s):  
A. Kirtane ◽  
N. Ismail-Beigi ◽  
F. Ismail-Beigi
Keyword(s):  
Gene Expression ◽  
Atpase Gene
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