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Basal neuro‐immune interactions between resident dentritic cells and corneal sensory nerves
Author(s) -
RinconFrutos Laura,
Luna Carolina,
Acosta M.Carmen,
Belmonte Carlos,
Hamrah Pedram,
SeyedRazavi Yashar,
Gallar Juana
Publication year - 2019
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2019.5439
Subject(s) - sensory system , chemistry , sensory nerve , basal (medicine) , endocrinology , medicine , anatomy , anesthesia , ophthalmology , biology , neuroscience , insulin
Purpose To determine the influence of dendritic cells (DCs) in modulating corneal sensory nerve activity at basal conditions using a DC‐depletion mice model. Methods C57BL/6 CD11c‐DTR mice (5‐6 month old) of both sexes were used. The effect of short‐term (2 days) and long‐term (8 days) DC depletion on corneal sensory nerve activity was studied in eyes following bilateral temporal and nasal subconjunctival injections of diphtheria toxin (DT) in anesthetized animals. Nerve terminal impulse (NTI) activity of corneal cold thermoreceptor endings was recorded in excised eyes continuously superfused with saline solution at 34ºC. Background and stimulus‐evoked (cooling and heating ramps) activity was studied. Naïve (no DT injections) CD11c‐DTR mice served as controls. Results Short‐term DC depletion produced a significant decrease in heating threshold (37.65±0.66 ºC, n=10; p=0.003, ANOVA) compared with naïve (41.57±1.77 ºC, n=4) and long‐term DC depletion conditions (42.27±0.97 ºC, n=8). However, long‐term DC depletion seemed to desensitize cold responses of sensory nerve endings, with higher cooling threshold and temperature to reach the peak frequency during the cooling ramp (30.65±0.48 ºC, n=17 vs. naïve, 32.31±0.29 ºC, n=20 and short‐term DC depletion, 32.2±0.44 ºC, n=17; p=0.005, ANOVA). Besides, in long‐term DC depleted eyes, NTI shape was altered: duration of NTIs was significantly increased (1.9± 0.06 ms, n=16; p=0.009, ANOVA) compared with naïve (1.5± 0.1 ms, n=18) and short‐term DC depleted eyes (1.7± 0.1 ms, n=11), having both longer depolarization and repolarization times. Conclusions The differences observed in both NTI firing and spike shape of cold nerve endings, suggest that depletion of resident DC alters corneal sensory nerve activity, therefore supporting the idea of a neuro‐immune interaction at basal conditions. (Support: SAF2017‐83674‐C2‐2‐R and ‐1‐R, AEI, Spain, and ERDF, EU; ACIF/2017/169 Fellowship from Generalitat Valenciana‐FSE to LR‐F)