scholarly journals Ano1 as a regulator of proliferation

2011 ◽  
Vol 301 (6) ◽  
pp. G1044-G1051 ◽  
Author(s):  
Jennifer E. Stanich ◽  
Simon J. Gibbons ◽  
Seth T. Eisenman ◽  
Michael R. Bardsley ◽  
Jason R. Rock ◽  
...  

Ano1 is a recently discovered Ca2+-activated Cl− channel expressed on interstitial cells of Cajal (ICC) that has been implicated in slow-wave activity in the gut. However, Ano1 is expressed on all classes of ICC, even those that do not contribute to generation of the slow wave, suggesting that Ano1 may have an alternate function in these cells. Ano1 is also highly expressed in gastrointestinal stromal tumors. Mice lacking Ano1 had fewer proliferating ICC in whole mount preparations and in culture, raising the possibility that Ano1 is involved in proliferation. Cl− channel blockers decreased proliferation in cells expressing Ano1, including primary cultures of ICC and in the pancreatic cancer-derived cell line, CFPAC-1. Cl− channel blockers had a reduced effect on Ano1(−/−) cultures, confirming that the blockers are acting on Ano1. Ki67 immunoreactivity, 5-ethynyl-2′-deoxyuridine incorporation, and cell-cycle analysis of cells grown in low-Cl− media showed fewer proliferating cells than in cultures grown in regular medium. We confirmed that mice lacking Ano1 had less phosphorylated retinoblastoma protein compared with controls. These data led us to conclude that Ano1 regulates proliferation at the G1/S transition of the cell cycle and may play a role in tumorigenesis.

2017 ◽  
Vol 149 (7) ◽  
pp. 703-725 ◽  
Author(s):  
Bernard T. Drumm ◽  
Grant W. Hennig ◽  
Matthew J. Battersby ◽  
Erin K. Cunningham ◽  
Tae Sik Sung ◽  
...  

Interstitial cells of Cajal (ICC) in the myenteric plexus region (ICC-MY) of the small intestine are pacemakers that generate rhythmic depolarizations known as slow waves. Slow waves depend on activation of Ca2+-activated Cl− channels (ANO1) in ICC, propagate actively within networks of ICC-MY, and conduct to smooth muscle cells where they generate action potentials and phasic contractions. Thus, mechanisms of Ca2+ regulation in ICC are fundamental to the motor patterns of the bowel. Here, we characterize the nature of Ca2+ transients in ICC-MY within intact muscles, using mice expressing a genetically encoded Ca2+ sensor, GCaMP3, in ICC. Ca2+ transients in ICC-MY display a complex firing pattern caused by localized Ca2+ release events arising from multiple sites in cell somata and processes. Ca2+ transients are clustered within the time course of slow waves but fire asynchronously during these clusters. The durations of Ca2+ transient clusters (CTCs) correspond to slow wave durations (plateau phase). Simultaneous imaging and intracellular electrical recordings revealed that the upstroke depolarization of slow waves precedes clusters of Ca2+ transients. Summation of CTCs results in relatively uniform Ca2+ responses from one slow wave to another. These Ca2+ transients are caused by Ca2+ release from intracellular stores and depend on ryanodine receptors as well as amplification from IP3 receptors. Reduced extracellular Ca2+ concentrations and T-type Ca2+ channel blockers decreased the number of firing sites and firing probability of Ca2+ transients. In summary, the fundamental electrical events of small intestinal muscles generated by ICC-MY depend on asynchronous firing of Ca2+ transients from multiple intracellular release sites. These events are organized into clusters by Ca2+ influx through T-type Ca2+ channels to sustain activation of ANO1 channels and generate the plateau phase of slow waves.


2007 ◽  
Vol 131 (9) ◽  
pp. 1393-1396
Author(s):  
Janet Graham ◽  
Maria Debiec-Rychter ◽  
Christopher L. Corless ◽  
Robin Reid ◽  
Rosemarie Davidson ◽  
...  

Abstract Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gut and are distinguished by expression of CD117 (c-Kit). Oncogenic mutations in the KIT or PDGFRA gene are detected in approximately 85% of sporadic GISTs. In recent years, examples of familial GIST have been reported in which germline mutations of KIT or PDGFRA result in multiple GISTs, skin disorders, and other abnormalities. The most common germline mutations are in KIT exon 11, mutations in exons 8 and 17 have also been described, and there are 2 families with germline PDGFRA mutations. We present a case in which a germline KIT exon 13 mutation (K642E) was discovered in a patient with multiple GISTs of rectum, small intestine, and esophagus, as well as diffuse hyperplasia of the interstitial cells of Cajal. To our knowledge, this is only the second germline example of this particular mutation. The patient's esophageal tumors were stabilized with imatinib.


Oncotarget ◽  
2017 ◽  
Vol 8 (25) ◽  
pp. 41026-41043 ◽  
Author(s):  
Pierre Vandenberghe ◽  
Perrine Hagué ◽  
Steven C. Hockman ◽  
Vincent C. Manganiello ◽  
Pieter Demetter ◽  
...  

1991 ◽  
Vol 69 (8) ◽  
pp. 1133-1142 ◽  
Author(s):  
Jan D. Huizinga

Recent investigation of the ultrastracture and electrophysiology of gastrointestinal smooth muscle layers has revealed a fascinating heterogeneity in cell type, cell structure, intercellular communication, and generated electrical activities. Networks of interstitial cells of Cajal (ICC) have been identified in many muscle layers and evidence is accumulating for a role of these networks in gut pacemaking activity. Synchronized motility in the organs of the gut result from interaction between ICC, neural-tissue, and smooth muscle cells. Regulation of cell to cell communication between the different cell types will be an important area for further research. Progress has been made in the elucidation of the ionic basis of the slow wave type action potentials and the spike-like action potentials. The mechanism underlying smooth muscle autorhythmicity seems different from that encountered in cardiac tissue, and evidence exists for metabolic regulation of the frequency of slow wave type action potentials.Key words: pacemaker activity, slow wave, autorhythmicity, interstitial cells of Cajal.


2009 ◽  
Vol 136 (5) ◽  
pp. A-51
Author(s):  
Michael R. Bardsley ◽  
Laura Popko ◽  
David L. Young ◽  
Gianrico Farrugia ◽  
Brian P. Rubin ◽  
...  

Medicina ◽  
2011 ◽  
Vol 47 (11) ◽  
pp. 86
Author(s):  
Povilas Ignatavičius ◽  
Tomas Petraitis ◽  
Žilvinas Saladžinskas ◽  
Lilija Butkevičienė ◽  
Kristina Žvinienė

Gastrointestinal stromal tumors are rare tumors, originating from the interstitial cells of Cajal. They are the most common mesenchymal tumors of the gastrointestinal tract. Metastatic tumor is treated with imatinib mesylate. A case of large metastases of a gastrointestinal stromal tumor to the omentum, diagnosis and treatment principles are presented in this case report.


1994 ◽  
Vol 266 (3) ◽  
pp. G485-G496 ◽  
Author(s):  
L. W. Liu ◽  
L. Thuneberg ◽  
J. D. Huizinga

Incubation with 50 microM methylene blue (MB) and subsequent intense illumination resulted in abolition of the slow-wave activity in the submuscular interstitial cells of Cajal-circular muscle (ICC-CM) preparations of canine colon. This was often accompanied by a decrease in resting membrane potential. Repolarization of cells back to -70 mV did not restore the slow-wave activity, indicating that MB plus light directly interrupted the generation mechanism of slow waves. After MB incubation, a 2-min illumination consistently changed the mitochondrial conformation in ICCs from very condensed to orthodox, without inducing any obvious changes in smooth muscle cells. After 4- to 10-min illumination, ICCs became progressively more damaged with swollen and ruptured mitochondria, loss of cytoplasmic contrast and detail, loss of caveolae, and rupture of the plasma membrane. No damage was seen in smooth muscle cells or nerves. Gap junctional ultrastructure was preserved. Intense illumination without preincubation with MB left the slow waves and the ultrastructure of ICC-CM preparations unaffected. In CM preparations, without the submuscular ICC-smooth-muscle network, MB plus light induced no changes in electrical activity. We conclude that the correlation between selective damage to the submuscular ICCs (relative to smooth muscle) and selective loss of the slow-wave activity (relative to other electrical activity of the CM) strongly indicates that the ICCs play an essential role in the generation of slow waves.


2019 ◽  
Vol 92 (1) ◽  
pp. 1-5
Author(s):  
Ashish Gupta

Mesenchymal tumors of the gallbladder are rarely encountered in clinical practice. The Gastrointestinal Stromal tumors(GIST) of the gallbladder are rarely encountered. These tumors most commonly arise from the interstitial cells of cajal(ICC), the pacemakers of the intestinal system. There can be benign as well as malignant form of GIST .The literature on GIST arising from the gallbladder wall is limited to few case reports only.on extensive search of the indexed literature only 9 cases of gallbladder GIST were retrieved. Based on the available literature these tumors are commonly found in females. They usually present with hypochondrial pain with or without other features of cholangitis. These tumors are usually malignant and warrant a radical surgical excision.The data on postoperative adjuvant therapy and survival is limited. The authors are presenting a review of the available literature on this rare pathology.


2008 ◽  
Vol 294 (4) ◽  
pp. G989-G995 ◽  
Author(s):  
Alberto Corrias ◽  
Martin L. Buist

Interstitial cells of Cajal (ICC) are responsible for the spontaneous and omnipresent electrical activity in the stomach. A quantitative description of the intracellular processes whose coordinated activity is believed to generate electrical slow waves has been developed and is presented here. In line with recent experimental evidence, the model describes how the interplay between the mitochondria and the endoplasmic reticulum in cycling intracellular Ca2+ provides the primary regulatory signal for the initiation of the slow wave. The major ion channels that have been identified as influencing slow wave activity have been modeled according to data obtained from isolated ICC. The model has been validated by comparing the simulated profile of the slow waves with experimental recordings and shows good correspondence in terms of frequency, amplitude, and shape in both control and pharmacologically altered conditions.


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