Background Melatonin, an indoleamine produced by the pineal gland, plays a pivotal role in maintaining circadian rhythm homeostasis. Recently, the strong antioxidant and anti-inflammatory properties of melatonin have attracted attention of researchers. We evaluated the therapeutic efficacy of melatonin in experimental autoimmune uveitis (EAU), which is a representative animal model of human autoimmune uveitis. Methods EAU was induced in mice via immunization with the peptide interphotoreceptor retinoid binding protein 1–20 (IRBP1–20). Melatonin was then administered via intraperitoneal injection to induce protection against EAU. With EAU induction for 14 days, clinical and histopathological scores were graded to evaluate the disease progression. T lymphocytes accumulation and the expression of inflammatory cytokines in the retinas were assessed via flow cytometry and RT-PCR, respectively. T helper 1 (Th1), T helper 17 (Th17), and regulatory T (Treg) cells were detected via flow cytometry for both in vivo and in vitro experiments. Reactive-oxygen species (ROS) from CD4 + T cells was tested via flow cytometry. The expression of thioredoxin-interacting protein (TXNIP) and hypoxia-inducible factor 1 alpha (HIF-1α) proteins were quantified via western blot. Results Melatonin treatment resulted in notable attenuation of ocular inflammation in EAU mice, evidenced by decreasing optic disc edema, few signs of retinal vasculitis, and minimal retinal and choroidal infiltrates. Mechanistic studies revealed that melatonin restricted the proliferation of peripheral Th1 and Th17 cells by suppressing their transcription factors and potentiated Treg cells. In vitro studies corroborated that melatonin restrained the polarization of retina-specific T cells towards Th17 and Th1 cells in addition to enhancing the proportion of Treg cells. Pretreatment of retina-specific T cells with melatonin failed to induce EAU in naïve recipients. Furthermore, the ROS/ TXNIP/ HIF-1α pathway was shown to mediate the therapeutic effect of melatonin in EAU. Conclusions Melatonin regulates autoimmune T cells by restraining effector T cells and facilitating Treg generation, indicating that melatonin could be a hopeful treatment alternative for autoimmune uveitis.

A sequence of Til-,Al,N films has been prepared by rf reactive magnetron sputtering. The optical and electric properties versus aluminum content x have been studied. Values suitable for magneto-optic protective layers have been achieved in Til-,Al,N thin films with aluminum content x > 0.75. X-ray diffraction results show that Til-,Al,N thin films in this study are a bcc structure u p to x = 0.75, further increase in the aluminum content gives a wurtzite structure. All of the results show that the optical and electric properties of Til-,Al,N films might be related to the crystal structure.

ImportanceMild thyroid-associated ophthalmopathy (TAO) negatively impacts quality of life, yet no clinical guidelines for its treatment are available. Existing evidence supports the use of doxycycline in treating mild TAO.ObjectiveTo evaluate the short-term (12 weeks) efficacy of doxycycline in treating mild TAO.Design, Setting, and ParticipantsIn this placebo-controlled multicenter randomized double-masked trial, 148 patients were assessed for eligibility. After exclusions (patients who were pregnant or lactating, had an allergy to tetracyclines, or had uncontrolled systematic diseases), 100 patients with mild TAO (orbital soft tissue affected mildly) at 5 centers in China were enrolled from July 2013 to December 2019 and monitored for 12 weeks.InterventionsParticipants were randomly assigned 1:1 to receive doxycycline (50 mg) or placebo once daily for 12 weeks.Main Outcomes and MeasuresThe primary outcome was the rate of improvement at 12 weeks compared with baseline assessed by a composite indicator of eyelid aperture (reduction ≥2 mm), proptosis (reduction ≥2 mm), ocular motility (increase ≥8°), and Graves ophthalmopathy-specific quality-of-life (GO-QOL) scale score (increase ≥6 points). Adverse events were recorded.ResultsA total of 50 participants were assigned to doxycycline and 50 to placebo. The mean (SD) age was 36.7 (9.1) years; 75 participants (75.0%) were female and 100 (100.0%) were Asian. Medication compliance was checked during participant interviews and by counting excess tablets. At week 12, the improvement rate was 38.0% (19 of 50) in the doxycycline group and 16.0% (8 of 50) in the placebo group (difference, 22.0%; 95% CI, 5.0-39.0; P = .01) in the intention-to-treat population. The per-protocol sensitivity analysis showed similar results (39.6% [19 of 48] vs 16.0% [8 of 50]; difference, 23.6%; 95% CI, 6.4-40.8; P = .009). No adverse events other than 1 case of mild gastric acid regurgitation was recorded in either group.Conclusions and RelevanceThe results of this study indicate that oral doxycycline, 50 mg daily, resulted in greater improvement of TAO-related symptoms at 12 weeks compared with placebo in patients with mild TAO. These findings support the consideration of doxycycline for mild TAO but should be tempered by recognizing the relatively short follow-up and the size of the cohort.Trial RegistrationClinicalTrials.gov Identifier: NCT02203682

Autoimmune uveitis (AU) is a sight-threatening ocular inflammatory disorder, characterized by massive retinal vascular leakage and inflamed lesions with infiltration of the uveitogenic T cells in the retina and disorders of the T cell–related immune response in the system. Stimulation of TCRs can trigger calcium release and influx via Ca2+ channels and then transmit signals from the surface to the nucleus, which are important for energy metabolism, proliferation, activation, and differentiation. Inhibition of Ca2+ influx by pharmacological modulation of Ca2+ channels may suppress T cell function, representing a novel anti-inflammatory strategy in the treatment of AU. This study investigated the effects of the l-type voltage-gated calcium channel blocker nimodipine in experimental AU (EAU). Nimodipine was found to not only decrease the clinical and histopathological inflammation score of EAU (C57BL/6J mice) but also dwindle the infiltration of uveitogenic CD4+ T cells into the retina. Moreover, nimodipine decreased the effector T cells and increased the regulatory T cells in the immune system. In vitro, nimodipine reduced the effector T cell differentiation of the IRBP1–20–specific CD4+ T cells of EAU mice and LPS-stimulated PBMCs of uveitis patients. Meanwhile, nimodipine suppressed the energy metabolism, proliferation, activation, and Th1 cell differentiation of T cells. Further studies on RNA sequencing and molecular mechanisms have established that nimodipine alleviates EAU by regulating T cells response through the p38–MAPK pathway signaling. Taken together, our data reveal a novel therapeutic potential of the l-type Ca2+ channels antagonist nimodipine in AU by regulating the balance of T cell subsets.

PurposeInflammation triggers the activation of CD4+T cells and the breakdown of blood–retinal barrier, thus contributing to the pathology of experimental autoimmune uveitis (EAU). We explored the anti-inflammatory effect of hydroxychloroquine (HCQ) on EAU and the potential mechanisms active in T cells and retinal vascular endothelial cells (RVECs).MethodsC57BL/6J mice were immunized with interphotoreceptor retinoid binding protein 1-20 (IRBP1–20) to induce EAU and then treated with the vehicle or HCQ (100 mg/kg/day). On day 7, 14, 21, 30 and 60 after immunization, clinical scores were evaluated. On day 14, histopathological scores were assessed, and retinas, spleens, and lymph nodes were collected for quantitative polymerase chain reaction or flow cytometry analysis. RVEC dysfunction was induced by tumor necrosis factor α (TNF-α) stimulation. The expression of cytokines, chemokines, adhesion molecules, and lectin-like oxidized LDL receptor-1 (LOX-1)/nuclear factor κB (NF-κB) was measured in RVECs with or without HCQ.ResultsHCQ treatment protected mice from uveitis, evidenced by reduced expression of inflammatory factors, chemokines, and adhesion molecules in the retina. In systemic immune response, HCQ inhibited the activation of naïve CD4+T cells and frequencies of T effector cells, and promoted T regulatory cells. HCQ decreased IRBP1-20–specific T cell responses and proliferation of CD4+T cells in vitro. Further studies established that TNF-α induced RVECs to express inflammatory cytokines, chemokines, and adhesion molecules, whereas HCQ alleviated the alterations via the LOX-1/NF-κB pathways.ConclusionsHCQ alleviates EAU by regulating the Teff/Treg balance and ameliorating RVECs dysfunction via the LOX-1/NF-κB axis. HCQ may be a promising therapeutic candidate for uveitis.