cAMP mediates transepithelial K+ and Na+ transport in a strial marginal cell line

Tu, Tzong-Yang; Chiu, Jen-Hwey; Shu, Ching‐Fong; Lien, Chiang-Feng

doi:10.1016/s0378-5955(98)00192-0

Cited by 9 publications

(7 citation statements)

References 32 publications

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“…The cells express I sK , a potassium channel believed to play a role in the generation of the endocochlear potential, and amiloride-sensitive Naϩ channels. Experiments using this cell line have shown that cAMP is the second messenger mediating transepithelial K ϩ and Na ϩ transport (Tu et al, 1999).…”

Section: Stria Vascularis Mcpv-8mentioning

confidence: 96%

Cell lines in inner ear research

Rivolta

Holley

2002

J. Neurobiol.

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Section: Stria Vascularis Mcpv-8mentioning

confidence: 96%

Cell lines in inner ear research

Rivolta

Holley

2002

J. Neurobiol.

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“…There is also high activity of the Na/K pump at basal cell processes [6][7][8] . At the plasma membrane on the luminal side, there are amiloride-sensitive epithelial Na-channel (ENaC), K-channel, cAMP-mediated trans epithelial K/Na transporters [4,5,9] . These reports indicate that ion channels and ion pumps of the plasma membrane have important roles in endolymph homeostasis.…”

Section: Introductionmentioning

confidence: 99%

Endocytosis of MPO in Marginal Cells Is Regulated by PKC, Protein Phosphatase, ERK and PI3-K Signaling Cascades, but Not by PKA and MEK Signaling Cascades

Kakigi

Okada

Takeda

et al. 2010

ORL

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Endocytosis of marginal cells plays a key role in maintaining the homeostasis of endocytosis and function of the organ of Corti. How the signaling cascade is involved in the regulation of endocytosis is an important issue at present. To investigate the regulation of endocytosis in marginal cells of the stria vascularis by the signaling network, we perfused MPO, an endocytosis tracer, with PMA, OA, staurosporin, PAO, PD98059, SB20580 or wortmannin into the cochlear duct. After 30 min endolymphatic perfusion, the tissues were fixed and the distribution of MPO was examined by electron microscopy. We explored the functions of PKC, RTK, PI3-K, PTP, and PP1/2A in MPO endocytosis and defined the MPO endocytic route. MPO endocytosis was strongly dependent on PKC, ERK, PTP, PP1/2A and PI3-K signaling networks, but not on PKA and MEK signaling networks. The MPO endocytic pathways are clathrin-, GPI-AP-, and caveolae-independent.

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“…K is secreted in endolymph by the marginal cells of the stria vascularis through an apical IsK/KvLQT1 K channel coupled with basolateral Na ϩ -K ϩ -ATPase and Na-K-Cl cotransport (39). It is transported out of endolymph by hair cell apical transduction channels and probably by outer sulcus cells' apical nonselective cationic channels (23), and is then probably recycled toward the stria vascularis through spiral ligament fibroblasts (34,37).…”

mentioning

confidence: 99%

Location and function of the epithelial Na channel in the cochlea

Couloigner

Fay

Djelidi

et al. 2001

American Journal of Physiology-Renal Physiology

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In the cochlea, endolymph is a K-rich and Na-poor fluid. The purpose of the present study was to check the presence and to assess the role of epithelial Na channel (ENaC) in this organ. alpha-, beta-, and gamma-ENaC subunit mRNA, and proteins were detected in rat cochlea by RT-PCR and Western blot. alpha-ENaC subunit mRNA was localized by in situ hybridization in both epithelial (stria vascularis, spiral prominence, spiral limbus) and nonepithelial structures (spiral ligament, spiral ganglion). The alpha-ENaC-positive tissues were also positive for beta-subunit mRNA (except spiral ganglion) or for gamma-subunit mRNA (spiral limbus, spiral ligament, and spiral ganglion), but the signals of beta- and gamma-subunits were weaker than those observed for alpha-subunit. In vivo, the endocochlear potential was recorded in guinea pigs under normoxic and hypoxic conditions after endolymphatic perfusion of ENaC inhibitors (amiloride, benzamil) dissolved either in K-rich or Na-rich solutions. ENaC inhibitors altered the endocochlear potential when Na-rich but not when K-rich solutions were perfused. In conclusion, ENaC subunits are expressed in epithelial and nonepithelial cochlear structures. One of its functions is probably to maintain the low concentration of Na in endolymph.

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cAMP mediates transepithelial K+ and Na+ transport in a strial marginal cell line

Cited by 9 publications

References 32 publications

Cell lines in inner ear research

Cell lines in inner ear research

Endocytosis of MPO in Marginal Cells Is Regulated by PKC, Protein Phosphatase, ERK and PI3-K Signaling Cascades, but Not by PKA and MEK Signaling Cascades

Location and function of the epithelial Na channel in the cochlea

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