scholarly journals EG-VEGF, BV8, and their receptor expression in human bronchi and their modification in cystic fibrosis: Impact of CFTR mutation (delF508)

2015 ◽  
Vol 309 (3) ◽  
pp. L314-L322 ◽  
Author(s):  
Sylvain Chauvet ◽  
Wael Traboulsi ◽  
Laura Thevenon ◽  
Amal Kouadri ◽  
Jean-Jacques Feige ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cells ◽  
Chloride Channel ◽  
Mrna Level ◽  
Cellular Level ◽  
Receptor Expression ◽  
Endocrine Gland ◽  
Channel Activity ◽  
Endothelial Growth Factor

Enhanced lung angiogenesis has been reported in cystic fibrosis (CF). Recently, two highly homologous ligands, endocrine gland vascular endothelial growth factor (EG-VEGF) and mammalian Bv8, have been described as new angiogenic factors. Both ligands bind and activate two closely related G protein-coupled receptors, the prokineticin receptor (PROKR) 1 and 2. Yet, the expression, regulation, and potential role of EG-VEGF, BV8, and their receptors in normal and CF lung are still unknown. The expression of the receptors and their ligands was examined using molecular, biochemical, and immunocytochemistry analyses in lungs obtained from CF patients vs. control and in normal and CF bronchial epithelial cells. Cystic fibrosis transmembrane conductance regulator (CFTR) activity was evaluated in relation to both ligands, and concentrations of EG-VEGF were measured by ELISA. At the mRNA level, EG-VEGF, BV8, and PROKR2 gene expression was, respectively, approximately five, four, and two times higher in CF lungs compared with the controls. At the cellular level, both the ligands and their receptors showed elevated expressions in the CF condition. Similar results were observed at the protein level. The EG-VEGF secretion was apical and was approximately two times higher in CF compared with the normal epithelial cells. This secretion was increased following the inhibition of CFTR chloride channel activity. More importantly, EG-VEGF and BV8 increased the intracellular concentration of Ca2+ and cAMP and stimulated CFTR-chloride channel activity. Altogether, these data suggest local roles for epithelial BV8 and EG-VEGF in the CF airway peribronchial vascular remodeling and highlighted the role of CFTR activity in both ligand biosynthesis and secretion.

Differential expression of ORCC and CFTR induced by low temperature in CF airway epithelial cells

1995 ◽  
Vol 268 (1) ◽  
pp. C243-C251 ◽  
Author(s):  
M. E. Egan ◽  
E. M. Schwiebert ◽  
W. B. Guggino
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cells ◽  
Incubation Temperature ◽  
Cell Types ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Channel Activity ◽  
Patch Clamp Recording ◽  
Cl Channel ◽  
Channel Expression

When nonepithelial cell types expressing the delta F508-cystic fibrosis transmembrane conductance regulator (CFTR) mutation are grown at reduced temperatures, the mutant protein can be properly processed. The effect of low temperatures on Cl- channel activity in airway epithelial cells that endogenously express the delta F508-CFTR mutation has not been investigated. Therefore, we examined the effect of incubation temperature on both CFTR and outwardly rectifying Cl- channel (ORCC) activity in normal, in cystic fibrosis (CF)-affected, and in wild-type CFTR-complemented CF airway epithelia with use of a combination of inside-out and whole cell patch-clamp recording, 36Cl- efflux assays, and immunocytochemistry. We report that incubation of CF-affected airway epithelial cells at 25-27 degrees C is associated with the appearance of a protein kinase A-stimulated CFTR-like Cl- conductance. In addition to the appearance of CFTR Cl- channel activity, there is, however, a decrease in the number of active ORCC when cells are grown at 25-27 degrees C, suggesting that the decrease in incubation temperature may be associated with multiple alterations in ion channel expression and/or regulation in airway epithelial cells.

MO092THE ROLE OF CALCIUM IN UROMODULIN EXPRESSION AND SECRETION FROM RENAL MEDULLARY EPITHELIAL CELLS OF HYPERTENSIVE AND NORMOTENSIVE RATS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Philipp Boder ◽  
Sheon Mary ◽  
Lesley Graham ◽  
Christian Delles
Keyword(s):  
Blood Pressure ◽  
Epithelial Cells ◽  
Mrna Level ◽  
Extracellular Calcium ◽  
Female Rats ◽  
Thick Ascending Limb ◽  
Molecular Signaling ◽  
Extracellular Secretion ◽  
Wistar Kyoto

Abstract Background and Aims Uromodulin (UMOD) is the most abundantly secreted protein found within the urine, primarily produced by medullary thick ascending limb (mTAL) epithelial cells of the kidneys. There is accruing genetic evidence implicating UMOD in blood pressure regulation and consequently hypertension. The molecular signaling induced by calcium in the kidney and its influence on blood pressure are not well understood. The aim of this study was to investigate the potential role of extracellular calcium and the calcium-sensing receptor (CaSR) in mTAL on UMOD production and secretion in TAL cells with the hope of defining novel clinical targets for the treatment of hypertension. Method Kidneys were harvested from normotensive Wistar-Kyoto (WKY) and stroke-prone spontaneously hypertensive (SHRSP) female rats. To determine the effect of extracellular calcium on UMOD secretion, mTAL tubules were incubated in media with and without 1mM calcium, nifedipine (10µM), NPS2143 (1 or 5 µM) and spermine (2mM). Extracellular and intracellular UMOD protein levels were detected by Western blot. Gene expression of Umod was determined by qRT-PCR. Results Calcium increased mTAL tubule UMOD secretion in WKY and SHRSP. Nifedipine slightly decreased UMOD secretion in WKY without calcium. In both strains, NPS2143 increased calcium-induced UMOD secretion, with an enhanced effect in SHRSP. Stimulation of CaSR with spermine decreased UMOD secretion in WKY. Analysis of intracellular UMOD levels in these conditions demonstrated increased accumulation when extracellular secretion was low, and vice versa. Incubation of primary mTAL cells with calcium confirmed increased localisation of UMOD at the membrane compared to the cytosol, without any major differences in cell morphology. The Umod mRNA level changes were not statistically significant among conditions. Conclusion Trafficking of UMOD in the mTAL is influenced by the type of CaSR ligand and the biased nature of G-protein coupled CaSR signalling. Unravelling the signalling events post-calcium will be necessary for identification of key regulators of UMOD secretion and provide new sites for therapeutic intervention in hypertension.

scholarly journals What is the role of melatonin within the anterior pituitary?

2001 ◽  
Vol 170 (3) ◽  
pp. 493-501 ◽  
Author(s):  
DG Hazlerigg
Keyword(s):  
Anterior Pituitary ◽  
Cellular Level ◽  
Prolactin Secretion ◽  
Receptor Expression ◽  
Melatonin Receptors ◽  
Seasonal Effects ◽  
Pars Tuberalis ◽  
Melatonin Receptor ◽  
Functional Studies

The pineal hormone, melatonin, is uniquely defined by its role as hormonal time, but the processes whereby cells extract temporal information from the melatonin signal are not understood. Melatonin receptors are expressed in the pars tuberalis (PT) and, during fetal and perinatal life, in the pars distalis (PD). Functional studies suggest that the PT mediates the seasonal effects of melatonin on prolactin secretion, whilst the PD may be involved in photoperiodic programming of the developing gonadotrophic axis. To understand these effects at the cellular level we need to know the phenotype of melatonin-responsive cells. This review summarises current understanding in this area, and highlights present shortcomings. A case is presented for exploring the hypothesis that there is a functional association between melatonin receptor expression and cell differentiation in the anterior pituitary.

scholarly journals Role of Exchange Protein Activated by cAMP 1 in Regulating Rates of Microtubule Formation in Cystic Fibrosis Epithelial Cells

2015 ◽  
Vol 53 (6) ◽  
pp. 853-862 ◽  
Author(s):  
Sharon M. Rymut ◽  
Tracy Ivy ◽  
Deborah A. Corey ◽  
Calvin U. Cotton ◽  
James D. Burgess ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cells ◽  
Microtubule Formation ◽  
Exchange Protein

The cystic fibrosis mutation (ΔF508) does not influence the chloride channel activity of CFTR

1993 ◽  
Vol 3 (4) ◽  
pp. 311-316 ◽  
Author(s):  
Canhui Li ◽  
Mohabir Ramjeesingh ◽  
Evangelica Reyes ◽  
Tim Jensen ◽  
Xiubao Chang ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Chloride Channel ◽  
Channel Activity ◽  
Cystic Fibrosis Mutation

scholarly journals Ablation of Internalization Signals in the Carboxyl-terminal Tail of the Cystic Fibrosis Transmembrane Conductance Regulator Enhances Cell Surface Expression

2002 ◽  
Vol 277 (51) ◽  
pp. 49952-49957 ◽  
Author(s):  
Krisztina Peter ◽  
Karoly Varga ◽  
Zsuzsa Bebok ◽  
Carmel M. McNicholas-Bevensee ◽  
Lisa Schwiebert ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Chloride Channel ◽  
Surface Expression ◽  
Transmembrane Conductance Regulator ◽  
Channel Activity ◽  
Transmembrane Conductance ◽  
Coated Pits ◽  
Double Mutation ◽  
Carboxyl Terminal ◽  
Cystic Fibrosis Transmembrane

The cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel that undergoes endocytosis through clathrin-coated pits. Previously, we demonstrated that Y1424A is important for CFTR endocytosis (Prince, L. S., Peter, K., Hatton, S. R., Zaliauskiene, L., Cotlin, L. F., Clancy, J. P., Marchase, R. B., and Collawn, J. F. (1999)J. Biol. Chem.274, 3602–3609). Here we show that a second substitution in the carboxyl-terminal tail of CFTR, I1427A, on Y1424A background more than doubles CFTR surface expression as monitored by surface biotinylation. Internalization assays indicate that enhanced surface expression of Y1424A,I1427A CFTR is caused by a 76% inhibition of endocytosis. Patch clamp recording of chloride channel activity revealed that there was a corresponding increase in chloride channel activity of Y1424A,I1427A CFTR, consistent with the elevated surface expression, and no change in CFTR channel properties. Y14124A showed an intermediate phenotype compared with the double mutation, both in terms of surface expression and chloride channel activity. Metabolic pulse-chase experiments demonstrated that the two mutations did not affect maturation efficiency or protein half-life. Taken together, our data show that there is an internalization signal in the COOH terminus of CFTR that consists of Tyr1424-X-X-Ile1427where both the tyrosine and the isoleucine are essential residues. This signal regulates CFTR surface expression but not CFTR biogenesis, degradation, or chloride channel function.

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