Dataset Information

Polymodal Sensory Transduction in Mouse Corneal Epithelial Cells.

ABSTRACT: Purpose:Contact lenses, osmotic stressors, and chemical burns may trigger severe discomfort and vision loss by damaging the cornea, but the signaling mechanisms used by corneal epithelial cells (CECs) to sense extrinsic stressors are not well understood. We therefore investigated the mechanisms of swelling, temperature, strain, and chemical transduction in mouse CECs. Methods:Intracellular calcium imaging in conjunction with electrophysiology, pharmacology, transcript analysis, immunohistochemistry, and bioluminescence assays of adenosine triphosphate (ATP) release were used to track mechanotransduction in dissociated CECs and epithelial sheets isolated from the mouse cornea. Results:The transient receptor potential vanilloid (TRPV) transcriptome in the mouse corneal epithelium is dominated by Trpv4, followed by Trpv2, Trpv3, and low levels of Trpv1 mRNAs. TRPV4 protein was localized to basal and intermediate epithelial strata, keratocytes, and the endothelium in contrast to the cognate TRPV1, which was confined to intraepithelial afferents and a sparse subset of CECs. The TRPV4 agonist GSK1016790A induced cation influx and calcium elevations, which were abolished by the selective blocker HC067047. Hypotonic solutions, membrane strain, and moderate heat elevated [Ca2+]CEC with swelling- and temperature-, but not strain-evoked signals, sensitive to HC067047. GSK1016790A and swelling evoked calcium-dependent ATP release, which was suppressed by HC067027 and the hemichannel blocker probenecid. Conclusions:These results demonstrate that cation influx via TRPV4 transduces osmotic and thermal but not strain inputs to CECs and promotes hemichannel-dependent ATP release. The TRPV4-hemichannel-ATP signaling axis might modulate corneal pain induced by excessive mechanical, osmotic, and chemical stimulation.

SUBMITTER: Lapajne L

PROVIDER: S-EPMC7401707 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Polymodal Sensory Transduction in Mouse Corneal Epithelial Cells.

Lapajne Luka L Lakk Monika M Yarishkin Oleg O Gubeljak Lara L Hawlina Marko M Križaj David D

Investigative ophthalmology & visual science 20200401 4

<h4>Purpose</h4>Contact lenses, osmotic stressors, and chemical burns may trigger severe discomfort and vision loss by damaging the cornea, but the signaling mechanisms used by corneal epithelial cells (CECs) to sense extrinsic stressors are not well understood. We therefore investigated the mechanisms of swelling, temperature, strain, and chemical transduction in mouse CECs.<h4>Methods</h4>Intracellular calcium imaging in conjunction with electrophysiology, pharmacology, transcript analysis, im ...[more]

PMID: 32271891

Similar Datasets

Project description:BackgroundAvoidance of noxious stimuli is essential for the survival of an animal in its natural habitat. Some avoidance responses require polymodal sensory neurons, which sense a range of diverse stimuli, whereas other stimuli require a unimodal sensory neuron, which senses a single stimulus. Polymodality might have evolved to help animals quickly detect and respond to diverse noxious stimuli. Nematodes inhabit diverse habitats and most nematode nervous systems are composed of a small number of neurons, despite a wide assortment in nematode sizes. Given this observation, we speculated that cellular contribution to stereotyped avoidance behaviors would also be conserved between nematode species. The ASH neuron mediates avoidance of three classes of noxious stimuli in Caenorhabditis elegans. Two species of parasitic nematodes also utilize the ASH neuron to avoid certain stimuli. We wanted to extend our knowledge of avoidance behaviors by comparing multiple stimuli in a set of free-living nematode species.ResultsWe used comparative behavioral analysis and laser microsurgery to examine three avoidance behaviors in six diverse species of free-living nematodes. We found that all species tested exhibit avoidance of chemo-, mechano- and osmosensory stimuli. In C. elegans, the bilaterally symmetric polymodal ASH neurons detect all three classes of repellant. We identified the putative ASH neurons in different nematode species by their anatomical positions and showed that in all six species ablation of the ASH neurons resulted in an inability to avoid noxious stimuli. However, in the nematode Pristionchus pacificus, the ADL neuron in addition to the ASH neuron contributed to osmosensation. In the species Caenorhabditis sp. 3, only the ASH neuron was required to mediate nose touch avoidance instead of three neurons in C. elegans. These data suggest that different species can increase or decrease the contribution of additional, non-ASH sensory neurons mediating osmosensation and mechanosensation.ConclusionThe overall conservation of ASH mediated polymodal nociception suggests that it is an ancestral evolutionarily stable feature of sensation. However, the finding that contribution from non-ASH sensory neurons mediates polymodal nociception in some nematode species suggests that even in conserved sensory behaviors, the cellular response network is dynamic over evolutionary time, perhaps shaped by adaptation of each species to its environment.

Project description:Altered dosage of the transcription factor PAX6 causes multiple human eye pathophysiologies. PAX6?/? heterozygotes suffer from aniridia and aniridia-related keratopathy (ARK), a corneal deterioration that probably involves a limbal epithelial stem cell (LESC) deficiency. Heterozygous Pax6(+/Sey-Neu) (Pax6?/?) mice recapitulate the human disease and are a good model of ARK. Corneal pathologies also occur in other mouse Pax6 mutants and in PAX77(Tg/-) transgenics, which over-express Pax6 and model human PAX6 duplication.We used electron microscopy to investigate ocular defects in Pax6?/? heterozygotes (low Pax6 levels) and PAX77(Tg/-) transgenics (high Pax6 levels). As well as the well-documented epithelial defects, aberrant Pax6 dosage had profound effects on the corneal stroma and endothelium in both genotypes, including cellular vacuolation, similar to that reported for human macular corneal dystrophy. We used mosaic expression of an X-linked LacZ transgene in X-inactivation mosaic female (XLacZ(Tg/-)) mice to investigate corneal epithelial maintenance by LESC clones in Pax6?/? and PAX77(Tg/-) mosaic mice. PAX77(Tg/-) mosaics, over-expressing Pax6, produced normal corneal epithelial radial striped patterns (despite other corneal defects), suggesting that centripetal cell movement was unaffected. Moderately disrupted patterns in Pax6?/? mosaics were corrected by introducing the PAX77 transgene (in Pax6?/?, PAX77(Tg/-) mosaics). Pax6(Leca4/+), XLacZ(Tg/-) mosaic mice (heterozygous for the Pax6(Leca4) missense mutation) showed more severely disrupted mosaic patterns. Corrected corneal epithelial stripe numbers (an indirect estimate of active LESC clone numbers) declined with age (between 15 and 30 weeks) in wild-type XLacZ(Tg/-) mosaics. In contrast, corrected stripe numbers were already low at 15 weeks in Pax6?/? and PAX77(Tg/-) mosaic corneas, suggesting Pax6 under- and over-expression both affect LESC clones.Pax6?/? and PAX77(Tg/-) genotypes have only relatively minor effects on LESC clone numbers but cause more severe corneal endothelial and stromal defects. This should prompt further investigations of the pathophysiology underlying human aniridia and ARK.

Dataset Information

Polymodal Sensory Transduction in Mouse Corneal Epithelial Cells.

Publications

Polymodal Sensory Transduction in Mouse Corneal Epithelial Cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets