Swelling-Activated Potassium Channel in Porcine Pigmented Ciliary Epithelial Cells

Takahira, Masayuki; Sakurai, Minoru; Sakurada, N.; Sugiyama, Kazuhisa

doi:10.1167/iovs.11-7173

Cited by 3 publications

(4 citation statements)

References 20 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since it was observed that ARPE-19 cells show a neuronal-like morphology following treatment with Cur 0.1 mM, we investigated both control and treated ARPE-19 cells for the presence of voltage-gated channels, which are usually expressed in electrically excitable cells, using the patch clamp technique in the whole cell configuration. In both cases, most cells presented a resting potential, ranging from −5 to −15 mV, higher if compared with what was found in previous studies [ 32 ]. Cells were clamped at −50 mV, and all cells with a holding current of less than −500 Pa were not included in the analysis.…”

Section: Resultscontrasting

confidence: 48%

“…Both protocols only elicited outward currents that were only slightly affected by TEA or 4-AP, which were used to evaluate the possibility that the current could be due to potassium voltage-gated channels. Since 4-AP and TEA insensitive channels have already been described in pigmented ciliary epithelial cells [ 32 ], the activation of voltage-dependent potassium channels cannot be excluded. Recently, the presence in ARPE-19 cells of both cationic and anionic depolarizing voltage-induced currents was described, and current values at +70 mV were found compatible with those observed in our experiments [ 46 ].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

New Insights into Dose-Dependent Effects of Curcumin on ARPE-19 Cells

Carozza

Tisi

Capozzo

et al. 2022

IJMS

View full text Add to dashboard Cite

Opposing dose-dependent effects of curcumin (Cur) have been documented in Retinal Pigment Epithelium (RPE); therefore, to shed the light on the mechanisms of action is crucial for ophthalmic applications. On this basis we explored new insights about the dose-dependent mechanisms triggered by Cur in human retinal pigment epithelial cells (ARPE-19). Three concentrations (0.01 mM; 0.05 mM; 0.1 mM) of Cur were tested, followed by morphological, molecular, and functional analysis of the cells. Cur 0.01 mM promotes a significant increase in cell proliferation, not affecting cell cycle progression and apoptosis; by contrast, Cur 0.05 mM and 0.1 mM block cellular proliferation and trigger S-phase cell cycle arrest without inducing apoptosis. The observation of neuronal-like morphological changes in Cur 0.05 mM and 0.1 mM were not associated with neuronal differentiation, as observed by the quantification of Neurofilament-200 and by the analysis of voltage-dependent currents by patch clamp. Evaluation of autophagic markers LC3BII and p62 revealed significant modulations, suggesting an important activation of autophagy in ARPE-19 cells treated with Cur 0.05 mM and Cur 0.1 mM; conversely, Cur 0.01 mM did not affect autophagy. Altogether, our findings show new dose-dependent mechanisms of action of Cur that suggest a wide therapeutic application in ocular diseases with different pathogenesis (i.e., proliferative vitreoretinopathy or Age-Related Macular Degeneration).

show abstract

Section: Resultscontrasting

confidence: 48%

Section: Discussionmentioning

confidence: 99%

New Insights into Dose-Dependent Effects of Curcumin on ARPE-19 Cells

Carozza

Tisi

Capozzo

et al. 2022

IJMS

View full text Add to dashboard Cite

show abstract

“…Moreover, recently the evidences have been provided that BEST1 may be a crucial component of VRAC function in human RPE cells and in mouse sperm (335). (188,276,484). In Xenopus oocytes, expression system coupling of K v 7.1 to cell volume changes was shown to occur through interactions between the cytoskeleton and the NH 2 terminus of the channel protein (188), whereas in rat hepatocytes cytoskeletal rearrangement translated to channel activation through involvement of protein kinase C (PKC) (277).…”

Section: Ion Channels Important For Cell Volume Regulationmentioning

confidence: 99%

Ion Channels in Cancer: Are Cancer Hallmarks Oncochannelopathies?

Prevarskaya

Skryma

Shuba³

2018

Physiological Reviews

332

292

View full text Add to dashboard Cite

Genomic instability is a primary cause and fundamental feature of human cancer. However, all cancer cell genotypes generally translate into several common pathophysiological features, often referred to as cancer hallmarks. Although nowadays the catalog of cancer hallmarks is quite broad, the most common and obvious of them are 1) uncontrolled proliferation, 2) resistance to programmed cell death (apoptosis), 3) tissue invasion and metastasis, and 4) sustained angiogenesis. Among the genes affected by cancer, those encoding ion channels are present. Membrane proteins responsible for signaling within cell and among cells, for coupling of extracellular events with intracellular responses, and for maintaining intracellular ionic homeostasis ion channels contribute to various extents to pathophysiological features of each cancer hallmark. Moreover, tight association of these hallmarks with ion channel dysfunction gives a good reason to classify them as special type of channelopathies, namely oncochannelopathies. Although the relation of cancer hallmarks to ion channel dysfunction differs from classical definition of channelopathies, as disease states causally linked with inherited mutations of ion channel genes that alter channel's biophysical properties, in a broader context of the disease state, to which pathogenesis ion channels essentially contribute, such classification seems absolutely appropriate. In this review the authors provide arguments to substantiate such point of view.

show abstract

“…Other findings of the presence of the Na + /K + ATPase on the basolateral membrane of the PE and Na + /K + /2Cl − cotransporter on the basolateral membrane of the NPE suggest a potential reabsorptive role of the ciliary epithelium (see [41,53]). In addition, while aquaporin proteins have been identified as a means of facilitated diffusion of water across the NPE (see [33,49]), the effects of previously identified swelling activated K + channels and osmosensors such as transient receptor potential vanilloid isoform 4 is unclear (see [46,51]). More recent findings of ENaC channels in the ciliary epithelial membrane and hemichannels, as well as inwardly rectifying K + channels located on the basolateral membrane of the NPE (see [35,47,52]), demonstrate that there are more discoveries to be made to fully understand the interplay between ion transporters and channels in the ciliary epithelium.…”

Section: Study Speciesmentioning

confidence: 99%

A Theoretical Approach for the Electrochemical Characterization of Ciliary Epithelium

Sacco

Guidoboni

Jerome

et al. 2020

Life

View full text Add to dashboard Cite

The ciliary epithelium (CE) is the primary site of aqueous humor (AH) production, which results from the combined action of ultrafiltration and ionic secretion. Modulation of ionic secretion is a fundamental target for drug therapy in glaucoma, and therefore it is important to identify the main factors contributing to it. As several ion transporters have been hypothesized as relevant players in CE physiology, we propose a theoretical approach to complement experimental methods in characterizing their role in the electrochemical and fluid-dynamical conditions of CE. As a first step, we compare two model configurations that differ by (i) types of transporters included for ion exchange across the epithelial membrane, and by (i) presence or absence of the intracellular production of carbonic acid mediated by the carbonic anhydrase enzyme. The proposed model configurations do not include neurohumoral mechanisms such as P2Y receptor-dependent, cAMP, or calcium-dependent pathways, which occur in the ciliary epithelium bilayer and influence the activity of ion transporters, pumps, and channels present in the cell membrane. Results suggest that one of the two configurations predicts sodium and potassium intracellular concentrations and transmembrane potential much more accurately than the other. Because of its quantitative prediction power, the proposed theoretical approach may help relate phenomena at the cellular scale, that cannot be accessed clinically, with phenomena occurring at the scale of the whole eye, for which clinical assessment is feasible.

show abstract

Swelling-Activated Potassium Channel in Porcine Pigmented Ciliary Epithelial Cells

Abstract: Porcine PCE cells express a swelling-activated K(+) channel, which may be a member of the KCNQ/Kv7 channel family. This K(+) channel is active near resting potentials and could contribute to the regulation of cell volume and water transport via the ciliary epithelia.

Cited by 3 publications

References 20 publications

New Insights into Dose-Dependent Effects of Curcumin on ARPE-19 Cells

New Insights into Dose-Dependent Effects of Curcumin on ARPE-19 Cells

Ion Channels in Cancer: Are Cancer Hallmarks Oncochannelopathies?

A Theoretical Approach for the Electrochemical Characterization of Ciliary Epithelium

Contact Info

Product

Resources

About