KCNQ1OT1 Knock Down Alleviates Hyperosmlity Induced Dry Eye Disease via Inhibiting NLRP3 Inflammsome Activation and IL-1β Release

Background. Long noncoding RNAs (lncRNAs) have been indicated that participate in inflammatory diaeases and age related diseases by regulating physiological and pathological processes directly or indirectly. Evidences have indicated lncRNAs might be involving in dry eye disease which can cause pathological changes of cornea and conjunctiva in ocular surface though inflammatory response. KCNQ1OT1 is a novel lncRNA, whose function remains totally unclear.Methods. qRT-PCR was performed to detect the expression of KCNQ1OT1, miR-214 and inflammasome-related genes NLRP3, caspase1 and IL-1β. Western blotting was carried out to detect inflammasome-related markers. The dry eye disease (DED) model was set up by scopolamine hydrobromide though subcutaneous injection. Bioinformatics was used to predict and validate the interaction between KCNQ1OT1 and miR-214 as well caspase1 and miR-214.Results. KCNQ1OT1 was significantly up-regulated during the process of DED while miR-214 was contrarily down-regulated. Knockdown of KCNQ1OT1 promoted cornea epithelial cells migration and down-regulated inflammasome-related genes. It was also confirmed that KCNQ1OT1 directly interacted with miR-214. Meanwhile, miR-214 could bind to 3'UTR of caspase1 and therefore inhibited its expression. Furthermore, co-transfection of miR-214 inhibitor could rescue the down-regulation of cell migration induced by KCNQ1OT1 knockdown.

Electroacupuncture Alleviates Inflammation of Dry Eye Diseases by Regulating the α7nAChR/NF-κB Signaling Pathway

Purpose. We tried to investigate whether electroacupuncture (EA) can reduce inflammation of dry eye disease (DED) by regulating α7nAChR and inhibiting the NF-κB signaling pathway. Methods. Healthy New Zealand white rabbits were treated with scopolamine hydrobromide (Scop) for 21 consecutive days to establish the DED animal model. After 21 days, EA, fluorometholone (Flu), and α7nAChR antagonist (α-BGT) treatments were performed, and the Scop injection was continued until day 35. During treatment, the fluorescence staining of the corneal epithelium and the level of tear flow were observed. The influence of EA on the LG pathology and inflammatory factors ACh, α7nAChR, and NF-κB was detected using the LG histopathology, transmission electron microscopy (TEM), cytokine protein chip technology, enzyme-linked immunosorbent assay (ELISA), and Western blot. Results. The EA stimulation can reduce the corneal epithelial damage and repair epithelial cell ultrastructure, promote the tear secretion, relieve the LG atrophy and decrease lipid droplet accumulation in LG acinar cell, and reduce the levels of inflammatory cytokines (i.e., IL-1, MIP-1b, TNF-α, and IL-8) in the LG. The protective effect of EA on the inflammation and the ocular surface is similar to the corticosteroid Flu. EA and Flu can upregulate the expression of the α7nAChR and downregulate the expression of NF-κB. The α7nAChR antagonist α-BGT can reverse the protective effect of EA on the LG and the inhibitory effect on the NF-κB pathway and the expression of inflammatory factors but cannot affect the expression of Flu on the NF-κB pathway and inflammatory factors. Conclusion. These results prove that EA can alleviate DEDs by stimulating the acupoints around the eyes. These beneficial effects are related to the upregulation of α7nAChR and the downregulation of NF-κB in the LG. The protective effect of LG is mediated through the anti-inflammatory pathway mediated by α7nAChR. EA can reduce the NF-κB P65 nuclear transcription and reduce inflammatory factors by regulating α7nAChR. This expression indicates that the α7nAChR/NF-κB signaling pathway may serve as a potential therapeutic target for EA to treat DEDs.

CLINICAL AND HISTOPATHOLOGICAL FEATURES OF SCOPOLAMINE HYDROBROMIDE INDUCED DRY EYE SYNDROME IN SPRAGUE-DAWLEY RATS

Dry eye syndrome (DES), is one of the most common and irritating ocular diseases in humans and animals due to deficits in quantities or/and quality of tear film. In this study, a rat model of experimental DES has been developed using the cholinergic inhibitor, scopolamine hydrobromide (SCOP), at the dose of 25[Formula: see text]mg/rat/day via subcutaneous injection, for a consecutive 21 days without low humidity environment. Clinical ophthalmic evaluations were performed by tear volume assessment using endodontic paper point, slit-lamp biomicroscope, and fluorescein staining at day 0, 7, 14, and 21 post-inductions. The results of ophthalmic examination showed that rats with SCOP treatment reduced about 40% of tear secretion. Half of the SCOP-treated rats exhibited diffuse corneal fluorescein staining involving 80% of the corneal surface, minimal keratoconjunctivitis, roughened corneal surface and thin corneal epithelium under histopathological examination. About 30% of the rats showed variable infiltration of lymphocytes in between the tubular acinar glands. This animal model with significant reduction of tear production and diffuse corneal fluorescein staining in rats could be used for the preclinical assessment of therapeutic interventions.