Dataset Information

Na+/K+-ATPase ?1 identified as an abundant protein in the blood-labyrinth barrier that plays an essential role in the barrier integrity.

ABSTRACT:

Background

The endothelial-blood/tissue barrier is critical for maintaining tissue homeostasis. The ear harbors a unique endothelial-blood/tissue barrier which we term "blood-labyrinth-barrier". This barrier is critical for maintaining inner ear homeostasis. Disruption of the blood-labyrinth-barrier is closely associated with a number of hearing disorders. Many proteins of the blood-brain-barrier and blood-retinal-barrier have been identified, leading to significant advances in understanding their tissue specific functions. In contrast, capillaries in the ear are small in volume and anatomically complex. This presents a challenge for protein analysis studies, which has resulted in limited knowledge of the molecular and functional components of the blood-labyrinth-barrier. In this study, we developed a novel method for isolation of the stria vascularis capillary from CBA/CaJ mouse cochlea and provided the first database of protein components in the blood-labyrinth barrier as well as evidence that the interaction of Na(+)/K(+)-ATPase ?1 (ATP1A1) with protein kinase C eta (PKC?) and occludin is one of the mechanisms of loud sound-induced vascular permeability increase.

Methodology/principal findings

Using a mass-spectrometry, shotgun-proteomics approach combined with a novel "sandwich-dissociation" method, more than 600 proteins from isolated stria vascularis capillaries were identified from adult CBA/CaJ mouse cochlea. The ion transporter ATP1A1 was the most abundant protein in the blood-labyrinth barrier. Pharmacological inhibition of ATP1A1 activity resulted in hyperphosphorylation of tight junction proteins such as occludin which increased the blood-labyrinth-barrier permeability. PKC? directly interacted with ATP1A1 and was an essential mediator of ATP1A1-initiated occludin phosphorylation. Moreover, this identified signaling pathway was involved in the breakdown of the blood-labyrinth-barrier resulting from loud sound trauma.

Conclusions/significance

The results presented here provide a novel method for capillary isolation from the inner ear and the first database on protein components in the blood-labyrinth-barrier. Additionally, we found that ATP1A1 interaction with PKC? and occludin was involved in the integrity of the blood-labyrinth-barrier.

SUBMITTER: Yang Y

PROVIDER: S-EPMC3031570 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature

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Publications

Na+/K+-ATPase α1 identified as an abundant protein in the blood-labyrinth barrier that plays an essential role in the barrier integrity.

Yang Yue Y Dai Min M Wilson Teresa M TM Omelchenko Irina I Klimek John E JE Wilmarth Phillip A PA David Larry L LL Nuttall Alfred L AL Gillespie Peter G PG Shi Xiaorui X

PloS one 20110131 1

<h4>Background</h4>The endothelial-blood/tissue barrier is critical for maintaining tissue homeostasis. The ear harbors a unique endothelial-blood/tissue barrier which we term "blood-labyrinth-barrier". This barrier is critical for maintaining inner ear homeostasis. Disruption of the blood-labyrinth-barrier is closely associated with a number of hearing disorders. Many proteins of the blood-brain-barrier and blood-retinal-barrier have been identified, leading to significant advances in understan ...[more]

PMID: 21304972

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