Calcium and alpha-adrenergic regulation of Na-Cl(K) cotransport in rabbit tracheal epithelial cells

1990 ◽  
Vol 259 (2) ◽  
pp. L66-L72
Author(s):  
C. M. Liedtke

The marked sensitivity of Cl and fluid secretion in mammalian airways to basolateral application of loop diuretics has led to postulates that electrically neutral Na-Cl entry plays a critical role during secretion. Electrically neutral Na-Cl(K) cotransport was investigated by determining the initial rate of 22Na and 36Cl efflux in epithelial cells isolated from rabbit trachea and preequilibrated with radioactive tracer at 25 degrees C. Tracer transport was initiated by 10-fold dilution of an aliquot of cells in radioisotope-free medium. The initial rate of radiolabeled ion transport was calculated from the linear portion of efflux curves. Base-line Na and Cl transport rates were not affected by furosemide or bumetanide. l-Epinephrine stimulated Na and Cl transport rates 1.8-fold each in Ca2(+)-replete and 2.6- and 2.3-fold, respectively, in Ca2(+)-deficient transport medium. Loop diuretics and yohimbine, an alpha 2-adrenergic antagonist, blocked the effects of l-epinephrine, and, clonidine, an alpha 2-adrenergic agonist, stimulated yohimbine- and furosemide-sensitive Cl transport. The beta-adrenergic agonist l-isoproterenol alone did not affect tracer transport and, in combination with clonidine, did not affect the response to clonidine. Elevation of intracellular Ca2+ with ionomycin stimulated tracer transport, and buffering of intracellular Ca2+ with 1,2-bis(aminophenoxy)ethane- N,N,N',N'-tetraacetic acid blocked the stimulatory effects of alpha-adrenergic agents. These results indicate an alpha 2-adrenergic stimulation of loop diuretic-sensitive Na and Cl transport that requires elevated intracellular Ca2+ as the second messenger. The transport mechanism is probably a Na-Cl or Na-K-2Cl cotransport located in the basolateral membrane.

1989 ◽  
Vol 257 (2) ◽  
pp. L125-L129 ◽  
Author(s):  
C. M. Liedtke

The demonstration of abnormal beta-adrenergic and cAMP-modulated apical Cl- channels in cystic fibrosis (CF) airway epithelial cells suggests that other transporters, which are required for Cl- secretion, may also be abnormally regulated. A basolateral cotransporter was investigated by determining the initial rate of 36Cl efflux from cells isolated from CF nasal polyps or trachea and non-CF trachea. Cells were preequilibrated with radioactive tracer at 25 degrees C, and tracer transport was initiated by 10-fold dilution of an aliquot of cells in radioisotope-free medium. The initial rate of Cl transport was calculated from the linear portion of the efflux curves. In CF and non-CF cells, base-line Cl- transport was not blocked by furosemide but was stimulated twofold by l-epinephrine in Ca2+-deficient and Ca2+-replete transport medium. In both types of cells, furosemide blocked 70 and 77%, respectively, of the stimulated Cl- transport. Prazosin, an alpha 1-adrenergic antagonist, blocked the effects of l-epinephrine and methoxamine, an alpha 1-adrenergic agonist, stimulated prazosin- and furosemide-sensitive Cl transport. Ionomycin mimicked the effects of l-epinephrine. l-Isoproterenol, a beta-adrenergic agonist, did not affect Cl transport. The results of this study indicate an alpha 1-adrenergic stimulation of furosemide-sensitive Cl transport in human airway epithelium that functions normally in CF airway epithelial cells. The transport mechanism is probably a Na-Cl or Na-K-2Cl cotransport located in the basolateral membrane and requires elevated intracellular Ca2+ for activation.


1999 ◽  
Vol 276 (1) ◽  
pp. L1-L8 ◽  
Author(s):  
Edward Abraham ◽  
Debra J. Kaneko ◽  
Robert Shenkar

Endotoxemia produces elevations in catecholamine levels in the pulmonary and systemic circulation as well as rapid increases in neutrophil number and proinflammatory cytokine expression in the lungs. In the present experiments, we examined the effects of endogenous and exogenous adrenergic stimulation on endotoxin-induced lung neutrophil accumulation and activation. Levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and macrophage inflammatory protein (MIP)-2 mRNAs were increased in lung neutrophils from endotoxemic mice compared with those present in lung neutrophils from control mice or in peripheral blood neutrophils from endotoxemic or control mice. Treatment with the β-adrenergic antagonist propranolol before endotoxin administration did not affect trafficking of neutrophils to the lungs or the expression of IL-1β, TNF-α, or MIP-2 by lung neutrophils. Administration of the α-adrenergic antagonist phentolamine before endotoxemia did not alter lung neutrophil accumulation as measured by myeloperoxidase (MPO) levels but did result in significant increases in IL-1β, TNF-α, and MIP-2 mRNA expression by lung neutrophils compared with endotoxemia alone. Administration of the α1-adrenergic agonist phenylephrine before endotoxin did not affect trafficking of neutrophils to the lungs but was associated with significantly increased expression of TNF-α and MIP-2 mRNAs by lung neutrophils compared with that found after endotoxin alone. In contrast, treatment with the α2-adrenergic agonist UK-14304 prevented endotoxin-induced increases in lung MPO and lung neutrophil cytokine mRNA levels. The suppressive effects of UK-14304 on endotoxin-induced increases in lung MPO were not affected by administration of the nitric oxide synthase inhibitor N-nitro-l-arginine methyl ester. These data demonstrate that the initial accumulation and activation of neutrophils in the lungs after endotoxemia can be significantly diminished by α2-adrenergic stimulation. Therapy with α2-adrenergic agents may have a role in modulating inflammatory pulmonary processes associated with sepsis-induced acute lung injury.


Author(s):  
Georgia Colleluori ◽  
Jessica Perugini ◽  
Giorgio Barbatelli ◽  
Saverio Cinti

AbstractThe mammary gland (MG) is an exocrine gland present in female mammals responsible for the production and secretion of milk during the process of lactation. It is mainly composed by epithelial cells and adipocytes. Among the features that make the MG unique there are 1) its highly plastic properties displayed during pregnancy, lactation and involution (all steps belonging to the lactation cycle) and 2) its requirement to grow in close association with adipocytes which are absolutely necessary to ensure MG’s proper development at puberty and remodeling during the lactation cycle. Although MG adipocytes play such a critical role for the gland development, most of the studies have focused on its epithelial component only, leaving the role of the neighboring adipocytes largely unexplored. In this review we aim to describe evidences regarding MG’s adipocytes role and properties in physiologic conditions (gland development and lactation cycle), obesity and breast cancer, emphasizing the existing gaps in the literature which deserve further investigation.


2020 ◽  
Vol 10 (1) ◽  
pp. 56-61
Author(s):  
Vishal Somnay ◽  
Thomas Duong ◽  
Ray-Young Tsao ◽  
Joseph A. Prahlow

Forensic DNA testing can play a critical role in homicide investigations. Selecting the appropriate evidence on which to perform DNA testing requires foresight and reasoning based on experience and science. Although successful DNA testing can occur using many substrates, including blood, hair, and sweat/epithelial cells, positive results can also result from testing various unorthodox samples. The authors report on a triple-murder investigation where DNA testing of dog feces at the crime scene matched DNA testing of feces found on the shoe of a suspect resulting in successful prosecution of the case.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jing Xie ◽  
Long Fan ◽  
Liya Xiong ◽  
Peiyu Chen ◽  
Hongli Wang ◽  
...  

Abstract Background Helicobacter pylori (H. pylori) is a common pathogen in development of peptic ulcers with pyroptosis. Rabeprazole, a critical component of standard triple therapy, has been widely used as the first-line regimen for H. pylori infectious treatment. The aim of this study to explore the function of Rabeprazole on cell pyroptosis in vitro. Methods The clinical sample from patients diagnosed with or without H. pylori-infection were collected to analyze by Immunohistochemistry (IHC). Real-time quantitative PCR (qPCR), western blot (WB) and enzyme linked immunosorbent assay (Elisa) were performed to analyze the effect of Rabeprazole on cell pyroptosis, including LDH, IL-1β and IL-18. Results In this study, we showed that Rabeprazole regulated a phenomenon of cell pyroptosis as confirmed by lactate dehydrogenase (LDH) assay. Further results showed that Rabeprazole inhibited cell pyroptosis in gastric epithelial cells by alleviating GSDMD-executed pyroptosis, leading to decrease IL-1β and IL-18 mature and secretion, which is attributed to NLRP3 inflammasome activation inhibition. Further analysis showed that ASC, NLRP3 and Caspase-1, was significantly repressed in response to Rabeprazole stimulation, resulting in decreasing cleaved-caspase-1 expression. Most important, NLRP3 and GSDMD is significantly increased in gastric tissue of patients with H. pylori infection. Conclusion These findings revealed a critical role of Rabeprazole in cell pyroptosis in patients with H. pylori infection, suggesting that targeting cell pyroptosis is an alternative strategy in improving H. pylori treatment.


2001 ◽  
Vol 152 (6) ◽  
pp. 1183-1196 ◽  
Author(s):  
Atsushi Suzuki ◽  
Tomoyuki Yamanaka ◽  
Tomonori Hirose ◽  
Naoyuki Manabe ◽  
Keiko Mizuno ◽  
...  

We have previously shown that during early Caenorhabditis elegans embryogenesis PKC-3, a C. elegans atypical PKC (aPKC), plays critical roles in the establishment of cell polarity required for subsequent asymmetric cleavage by interacting with PAR-3 [Tabuse, Y., Y. Izumi, F. Piano, K.J. Kemphues, J. Miwa, and S. Ohno. 1998. Development (Camb.). 125:3607–3614]. Together with the fact that aPKC and a mammalian PAR-3 homologue, aPKC-specific interacting protein (ASIP), colocalize at the tight junctions of polarized epithelial cells (Izumi, Y., H. Hirose, Y. Tamai, S.-I. Hirai, Y. Nagashima, T. Fujimoto, Y. Tabuse, K.J. Kemphues, and S. Ohno. 1998. J. Cell Biol. 143:95–106), this suggests a ubiquitous role for aPKC in establishing cell polarity in multicellular organisms. Here, we show that the overexpression of a dominant-negative mutant of aPKC (aPKCkn) in MDCK II cells causes mislocalization of ASIP/PAR-3. Immunocytochemical analyses, as well as measurements of paracellular diffusion of ions or nonionic solutes, demonstrate that the biogenesis of the tight junction structure itself is severely affected in aPKCkn-expressing cells. Furthermore, these cells show increased interdomain diffusion of fluorescent lipid and disruption of the polarized distribution of Na+,K+-ATPase, suggesting that epithelial cell surface polarity is severely impaired in these cells. On the other hand, we also found that aPKC associates not only with ASIP/PAR-3, but also with a mammalian homologue of C. elegans PAR-6 (mPAR-6), and thereby mediates the formation of an aPKC-ASIP/PAR-3–PAR-6 ternary complex that localizes to the apical junctional region of MDCK cells. These results indicate that aPKC is involved in the evolutionarily conserved PAR protein complex, and plays critical roles in the development of the junctional structures and apico-basal polarization of mammalian epithelial cells.


2004 ◽  
Vol 286 (3) ◽  
pp. G479-G490 ◽  
Author(s):  
Sujoy Bhattacharya ◽  
Ramesh M. Ray ◽  
Leonard R. Johnson

It has been documented that polyamines play a critical role in the regulation of apoptosis in intestinal epithelial cells. We have recently reported that protection from TNF-α/cycloheximide (CHX)-induced apoptosis in epithelial cells depleted of polyamines is mediated through the inactivation of a proapoptotic mediator, JNK. In this study, we addressed the involvement of the MAPK pathway in the regulation of apoptosis after polyamine depletion of IEC-6 cells. Polyamine depletion by α-difluromethylornithine (DFMO) resulted in the sustained activation of ERK in response to TNF-α/CHX treatment. Pretreatment of polyamine-depleted IEC-6 cells with a cell membrane-permeable MEK1/2 inhibitor, U-0126, significantly inhibited TNF-α/CHX-induced ERK phosphorylation and significantly increased DNA fragmentation, JNK activity, and caspase-3 activity in response to TNF-α/CHX. Moreover, the dose dependency of U-0126-mediated inhibition of TNF-α/ CHX-induced ERK phosphorylation correlated with the reversal of the antiapoptotic effect of DFMO. IEC-6 cells expressing constitutively active MEK1 had decreased TNF-α/CHX-induced JNK phosphorylation and were significantly protected from apoptosis. Conversely, a dominant-negative MEK1 resulted in high basal activation of JNK, cytochrome c release, and spontaneous apoptosis. Polyamine depletion of the dominant-negative MEK1 cells did not prevent JNK activation or cytochrome c release and failed to confer protection from both TNF-α/CHX and camptothecin-induced apoptosis. Finally, expression of a dominant-negative mutant of JNK significantly protected IEC-6 cells from TNF-α/CHX-induced apoptosis. These data indicate that polyamine depletion results in the activation of ERK, which inhibits JNK activation and protects cells from apoptosis.


2010 ◽  
Vol 79 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Min Wu ◽  
Huang Huang ◽  
Weidong Zhang ◽  
Shibichakravarthy Kannan ◽  
Andrew Weaver ◽  
...  

ABSTRACTAlthough DNA repair proteins in bacteria are critical for pathogens' genome stability and for subverting the host defense, the role of host DNA repair proteins in response to bacterial infection is poorly defined. Here, we demonstrate, for the first time, that infection with the Gram-negative bacteriumPseudomonas aeruginosasignificantly altered the expression and enzymatic activity of 8-oxoguanine DNA glycosylase (OGG1) in lung epithelial cells. Downregulation of OGG1 by a small interfering RNA strategy resulted in severe DNA damage and cell death. In addition, acetylation of OGG1 is required for host responses to bacterial genotoxicity, as mutations of OGG1 acetylation sites increased Cockayne syndrome group B (CSB) protein expression. These results also indicate that CSB may be involved in DNA repair activity during infection. Furthermore, OGG1 knockout mice exhibited increased lung injury after infection withP. aeruginosa, as demonstrated by higher myeloperoxidase activity and lipid peroxidation. Together, our studies indicate thatP. aeruginosainfection induces significant DNA damage in host cells and that DNA repair proteins play a critical role in the host response toP. aeruginosainfection, serving as promising targets for the treatment of this condition and perhaps more broadly Gram-negative bacterial infections.


1981 ◽  
Vol 90 (1) ◽  
pp. 123-142
Author(s):  
M. M. P. RAMOS ◽  
J. C. ELLORY

1. The tissue was found to have a serosa negative potential, and short-circuit currents equivalent to the net Cl transport. 2. A significant part of the Cl uptake was Na dependent and a similar fraction of the Na uptake was Cl dependent. 3. Short-circuit current and uptake of both ions were inhibited by loop diuretics and analogues. 4. I80 and P.D. were abolished by ouabain. 5. The observations are consistent with the idea of a coupled NaCl entry into the cell, using the energy inherent in the Na gradient; Na being pumped out of the cells by the Na pump and followed electrically by Cl−. Net chloride transport and the serosa negative potential would be a consequence of the permselective properties of the junctions allowing Na but not Cl to recycle back to the mucosal solution.


2017 ◽  
Vol 42 (6) ◽  
pp. 2552-2558 ◽  
Author(s):  
Jingsong Liu ◽  
Ying Zhong ◽  
Guoyong Liu ◽  
Xiaobai Zhang ◽  
Bofei Xiao ◽  
...  

Background/Aims: Transforming growth factor β 1 (TGFβ1) plays a critical role in the epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells (TECs) during renal injury, a major cause of acute renal failure, renal fibrosis and obstructive nephropathy. However, the underlying molecular mechanisms remain ill-defined. Here, we addressed this question. Methods: Expression of TGFβ1, Snail, and phosphorylated Stat3 was examined by immunohistochemistry in the kidney after induction of unilateral ureteral obstruction (UUO) in mice. In vitro, primary TECs were purified by flow cytometry, and then challenged with TGFβ1 with/without presence of specific inhibitors for phosphorylation of SMAD3 or Stat3. Protein levels were determined by Western blotting. Results: We detected significant increases in Snail and phosphorylated Stat3, an activated form for Stat3, in the kidney after induction of UUO in mice. In vitro, TGFβ1-challenged primary TECs upregulated Snail, in a SMAD3/Stat3 dependent manner. Conclusion: Our study sheds light on the mechanism underlying the EMT of TECs after renal injury, and suggests Stat3 signaling as a promising innovative therapeutic target for prevention of renal fibrosis.


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