Vacuolar H+-ATPase in ocular ciliary epithelium.

Proc Natl Acad Sci U S A

Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.

Published: June 1997

The mechanisms controlling the production of aqueous humor and the regulation of intraocular pressure are poorly understood. Here, we provide evidence that a vacuolar H+-ATPase (V-ATPase) in the ocular ciliary epithelium is a key component of this process. In intracellular pH (pHi) measurements of isolated ciliary epithelium performed with 2',7-biscarboxyethyl-5(6)-carboxyfluorescein (BCECF), the selective V-ATPase inhibitor bafilomycin A1 slowed the recovery of pHi in response to acute intracellular acidification, demonstrating the presence of V-ATPase in the plasma membrane. In isolated rabbit ciliary body preparations examined under voltage-clamped conditions, bafilomycin A1 produced a concentration-dependent decrease in short-circuit current, and topical application of bafilomycin A1 reduced intraocular pressure in rabbits, indicating an essential role of the V-ATPase in ciliary epithelial ion transport. Immunocytochemistry utilizing antibodies specific for the B1 isoform of the V-ATPase 56-kDa subunit revealed localization of V-ATPase in both the plasma membrane and cytoplasm of the native ciliary epithelium in both rabbit and rat eye. The regional and subcellular distribution of V-ATPase in specific regions of the ciliary process was altered profoundly by isoproterenol and phorbol esters, suggesting that change in the intracellular distribution of the enzyme is a mechanism by which drugs, hormones, and neurotransmitters modify aqueous humor production.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC21230PMC
http://dx.doi.org/10.1073/pnas.94.13.6752DOI Listing

Publication Analysis

Top Keywords

ciliary epithelium
16
vacuolar h+-atpase
8
ocular ciliary
8
aqueous humor
8
intraocular pressure
8
v-atpase plasma
8
plasma membrane
8
ciliary
7
v-atpase
7
h+-atpase ocular
4

Similar Publications

Primary ciliary dyskinesia (PCD, OMIM 244400) is a rare genetic disorder that affects motile cilia and is characterised by impaired mucociliary clearance of the airway epithelium, which results in chronic upper and lower airway infections. While short-read next-generation sequencing technology has been used for the genetic testing of PCD, its effectiveness is limited in identifying variants in the gene because of the nearly identical pseudogene As we confirmed that the gene was not expressed in airway cells, we obtained nasal mucosa biopsy specimens for total RNA sequencing (RNA-seq) with library enrichment using exome oligos. Among the 34 nasal samples from patients suspected of having PCD, three aberrant splicing patterns in were identified in two samples.

View Article and Find Full Text PDF

Introduction: The ability of SARS-CoV-2 to evade antiviral immune signaling in the airway contributes to the severity of COVID-19 disease. Additionally, COVID-19 is influenced by age and has more severe presentations in older individuals. This raises questions about innate immune signaling as a function of lung development and age.

View Article and Find Full Text PDF

Polycystic ovarian syndrome (PCOS) is a heterogeneous condition characterized by hyperandrogenism (HA), polycystic ovaries, and dysfunctional ovulation, and it is associated with metabolic problems such as insulin resistance (IR) and obesity. After having investigated the morphological and antioxidant/antiglycative alterations on mouse ovaries and uteri, we here focus on PCOS oviducts, a tract of the reproductive system essential for the nourishment and transport of gametes and embryos. The modulating effects of L-carnitine (LC) and acetyl-L-carnitine (ALC) were also assessed.

View Article and Find Full Text PDF

Organ-on-a-chip (OOC) devices mimic human organs, which can be used for many different applications, including drug development, environmental toxicology, disease models, and physiological assessment. Image data acquisition and analysis from these chips are crucial for advancing research in the field. In this study, we propose a label-free morphology imaging platform compatible with the small airway-on-a-chip system.

View Article and Find Full Text PDF

Adeno-associated virus (AAV)-based vectors are the most frequently used platform for retinal gene therapy. Initially explored for the treatment of loss-of-function mutations underpinning many inherited retinal diseases, AAV-based ocular gene therapies are increasingly used to transduce endogenous cells to produce therapeutic proteins, thus producing site-specific biofactories. Relatively invasive ocular routes of administration (ROA) mean prominent procedure-related in-life, and histopathological findings may be observed with some regularity.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!